US3846860A - Movable access ramp for vehicles - Google Patents

Abstract

A foldable ramp for loading and unloading a roll on-roll off type cargo ship and consisting of three pivotally interconnected sections the innermost one of which is pivoted with its inboard end to the ship for being lowerable and extendable onto a wharf by ramp handling cables and winches provided on the ship. The two outboard sections of the ramp are connected by ropes and sheaves to king-posts provided on the ship for automatically extending said sections while lowering the innermost ramp section through gravity.

Description

United States Patent 11 1 Kum rma 51 Nov. 12, 1974 154] LE ACCESS RAMP FOR VEHICLES 2,641,785 6/1953 P1115 14/71 [75] Inventor: Henri Kummerman, Geneva,

sw'lzcrllmd 3,468,280 9/1969 Williams 14 71 x 73 M 3,580,404 5/1971 Moser.............. 14/71 x l I Wgncg fgg g g gggg S A 3,687,308 8/1972 Apelstrand 14/71 x 3,747,354 7/1973 Macomber 61/48 I22] Filed: June 21, 1973 121] App]. No.: 372,051

[30] Foreign Application Priority Data June 28, 1972 France 72.23373 May 29, 1973 France 73.19511 [52] US. Cl. 14/71, 61/48, 214/15 R [51] Int. Cl. 865g 11/00 [58] Field of Search 14/71, 1, 7,17, 37; 214/15 R; 61/48 [56] References Cited UNITED STATES PATENTS 2,556,175 (7/1951 Frost 14/1 2,617.131 ll/l952 Harris ,.14/71 Primary Examiner-Nile C.-Byers, Jr. Attorney, Agent, or Firm-Kenyon & Kenyon Reilly Carr & Chapin [57] ABSTRACT A foldable ramp for loading and unloading a roll onroll off type cargo ship and consisting of three pivotally interconnected sections the innermost one of which is pivoted with its inboard end to the ship for being lowerable and extendable onto a wharf by ramp handling cables and winches provided on the ship. The two outboard sections of the ramp are connected by ropes and sheaves to king-posts provided on the ship for automatically extending said sections while lowering the innermost ramp section through gravity.

30 Claims, 20 Drawing Figures PATENTEDNUV 12 I974 SHEET [12 HF 11 PATENTEDNUV 12 IBM sum on or 11 PATENTED Nov 12 I974 SHEET 05 0F 11 PMENTEHMJV 1 2 I974 sum 06 or 11 PATENTED NOV 12 I974 SHEET PATENTED NEW 12 I974 sum as or 11 PATENTEDunv 12 I974 sum 09 0F 11 PATENTEBHUHQIQM 3346860 SHEET 10 0F 11 MOVABLE ACCESS RAMP FOR VEHICLES The present invention relates generally and is essentially directed to a movable device forming an access ramp or like gangway, horse or bridge means adapted to provide a communication, passage, conveyance, transhipment or like means between on the one hand any vehicle in particular of land or marine character such as for instance a ship, boat or like floating vessel and on the other hand an outside loading or unloading area or platform such as a quay, pier, wharf, bank, shore or beach or yet another vehicle as well as the various applications and uses resulting from implementing same and the systems, arrangements, assemblies, appliances, equipments and installations provided with such devices.

There are already known in particular in naval or marine applications, transport or cargo ships of the roll on-roll off type for conveying for instance wheeled vehicles and in particular automotive or motor vehicles or various goods and products. In the case of automotive vehicles, the shipping and unshipping thereof are effected by their own self-contained or independent propulsion or drive means by rolling individually or separately and directly on a movable access ramp interconnecting the ship (and more specifically the loading deck or flooring thereof) and the quay or the like. In the case of general cargo, such a ramp is also used directly by automotive handling carriages, trucks or like carts or wheeled cargo-handling gears running on said ramp in a shuttle-like manner enabling them to have direct access to the ship and to come back to the quay for loading or shipping and unloading or unshipping goods and like cargoes. For this purpose, the ship is provided either aft or astern, or afore at the bow, or yet sidewise, with at least one large ramp of the kind pivotally connected with its inboard end to the ship for swinging vertically so as to be liftable or raisable upwards to a substantially inoperative upstanding position in a stowed or lashed condition on the ship during its sea trip and lowerable in operative working position to bear onto the quay with its opposite, i.e. outboard end. As the ship is generally moored or secured along the quay berth in parallel relation thereto, said ramp, when it is located astern i.e. at the rear end of the ship, is generally positioned slantwise in its lowered working condition with respect to the longitudinal central vertical plane of the ship so that the longitudinal direction of the ramp is at an angle of about 45 with respect to the longitudinal-direction of the ship. Such a ramp thus enables various kinds of wheeled vehicles to be taken aboard the ship for instance from quays which are not fitted up or suited for such a use.

To enable the ship to use various kinds of quays while retaining an acceptable slope with respect to the horizontal direction for the passage of wheeled vehicles, said ramp is required to be long enough and for this ground it is necessary that the ramp may be folded vertically back against the planking or structure of the ship so as not to offer a too strong hold to the wind when the ship is at sea or'an excessive height likely to affect the stability of the ship.

For example, from the U.S. Pat. No. 3,687,308 is already known such a ramp consisting of three successive sections pivotally interconnected to each other, respectively, in the longitudinal direction, the innermost end or inboard section being pivoted to the ship in particular at the level of any opening thereof for example at a cargo port provided at one of its ends or laterally in the side of the ship whereas the outer end or outboard section serves as a bearing or supporting flap member onto the quay and is pivotally connected with an intermediate point thereof to the corresponding outer end portion of the intermediate section. In this known arrangement, the intermediate and outermost sections may be folded back together by being laid downwards against the bottom portion of the innermost or inboard section alongside thereof in a substantially upward raised or vertical position and both opposite side frame members or like girders or spars of the inboard section are extended outwards through a pair of booms or armlike beams extending beyond the vehicle runway carried therebetween and on either side of and along the intermediate section so as to bear in the lowered and extended working condition onto a pair of sidewise outwards projecting supports provided on the intermediate section on either side thereof, through the medium of a pair of longitudinal lower levers pivotally connected to the side frame members so that said levers may be swung in a vertical plane to an adjustable relative angular position by pressure fluid operated ram-type actuators or like power means. This arrangement enables to adjust the angle between the outboard and intermediate sections in the lowered and extended working state. The innermost or inboard section is secured with an intermediate point of one or each side frame member thereof and adjacent to its pivotal connection with the intermediate section to at least one handling cable or rope or to a pair of handling cables or ropes each one of which is wound up on an associated operating winch located on the ship whereby the ramp may be raised through a powered action or lowered through gravity. The innermost section is partially suspended from each handling rope because the latter is kept taut with a determined constant tension corresponding for instance to the total weight of the loading ramp and each rope may be automatically wound up or paid out according to the variation in the load. At least one winch and possibly both powered winches for extending the intermediate section are mounted on one or both of the side frame members, respectively, of the innermost section and the rope of each winch is successively reeved onto a first guide sheave or pulley carried by the free end of said extension boom and onto a second guide pulley or sheave carried by the intermediate section to be made fast at a stationary point of said boom. The outermost section, forming a supporting pad or flap member to enable the ramp to bear onto the quay, is pivotally connected substantially at its centre of gravity to said intermediate section so as to be always at poise, i.e. in a state of indifferent equilibrium or like balanced condition about its substantially horizontal pivot axis.

This known appliance exhibits various inconveniences since on the one hand it requires a relatively complex special mechanism to achieve a temporary engagement or like bearing connection between each boom end in extension of one side frame member of the innermost section with a corresponding sidewise projecting supporting pad of the intermediate section and on the other hand it requires the provision of at least state of indifferent equilibrium, i.e. likely to take any relative angular position about its swivel axis, there may be a possibility that this section, when being lowered onto the quay, is not in the proper relative position, i.e. substantially in parallel relation to the quay surface so that there may be a wrong bearing in particular in view of some buttressing or abutting effect so that a manual action has to be taken to overcome or obviate such a difficulty.

One main object of the invention is therefore to remove the aforementioned drawbacks inherent in the prior known state of the art by providing a device of a simpler hence more economical construction performing a more effective and reliable operation. For this purpose the invention is starting from the known kind of movable device forming a foldable access ramp for interconnecting a vehicle and an outside platform, which is swingable in parallel relation to a vertical plane so that it may be raised upwards to an inoperative position in a stowed or lashed condition on said vehicle and lowered downwards to an operativeworking position for resting partially on said platform, said ramp comprising at least two successive sections pivotally interconnected endwise in the longitudinal direction thereof, the first one of which forms the innermost or inboard section which is pivotally connected to said vehicle and secured with at least one point to at least one handling cable always kept taut and wound up onto at least one winch located on said vehicle whereas the other or second section may be folded back downwards against and along the first one and is fastened to at least one handling cable for extending said other section to a position which is at least approximatively in aligned registering relation to said innermost section in the lowered working condition of the ramp. To solve the technical problem set, the invention therefore proposes a device of the aforesaid kind which is characterized in that each handling cable for extending said other section is connected to means for tensioning and for automatically taking up any possible slack of said cable through the action of potential energy, which means are located on said vehicle and include self-acting means for automatically and unidirectionally stopping the cable and holding it against motion, said means being adapted to provide a stationary fastening point for causing through locking of the effective useful length of said cable, a tractive reaction force to arise for extending said other section during the downward motion of said innermost section which is always suspended from each aforesaid handling cable.

Such an arrangement offers the advantage to enable the second ramp section to be extended without the use of any powered winch for this purpose but by exclusively making use of the potential energy stored in the innermost ramp section in its raised position whereby said innermost section tends byitself to rock or tilt naturally downwards through gravity under the action of its own weight while causing at the same time the adjacent ramp section to be extended accordingly. At the beginning or during the initial period of downward motion of the innermost section from its substantially vertically or upright raised and stowed position, the component of the total ramp weight which is likely to act upon each handling cable for extending said adjacent portion is inadequate for exerting any significant rotary effect thereon, so that according to another characterizing feature of the invention, said automatic means for 4 stopping and unidirectionally holding against motion each handling cable for extending said adjacent section are arranged so as to be operative only from some determined angle of slope for instance of about 20 of the innermost section with respect to the vertical direction during the starting period of downward motion thereof.

According to a further characterizing feature of the invention, as said innermost ramp section is suspended from the end of each aforementioned handling cable, there are provided selectively adjustable load transfer means for varying at will the bearing reaction of the ramp onto said platform in the extended working configuration of the ramp thereby transferring at least one selectively variable part of the weight and instant load of said second ramp section either onto said innermost ramp section or onto an independent auxiliary supporting system mounted on said vehicle. Such an arrangement offers the advantage to possibly achieve an automatic control of the bearing pressure force of the ramp onto said platform in accordance with the true load carried by said second ramp section.

According to still another characterizing feature of the invention, the means for tensioning and automati cally taking up the slack of each cable controlling the extension of said second ramp section consist of a movable counterweight and for this purpose each handling cable for controlling the extension of said second ramp section is reeved on at least one preferably elevated or overhead loose guide pulley 0r idle sheave mounted on said vehicle to terminate into said counterweight whereas said automatic means for stopping and unidirectionally holding against motion consist of a stationary stop means provided on said vehicle for limiting the upward motion or stroke of said counterweight.

According to a further characterizing feature of the invention, each aforesaid counterweight has a selectively adjustable weight to provide one aforesaid load transfer means.

According to an alternative embodiment, each aforesaid handling cable for controlling the extension of said second ramp section is connected to a stationary fastening point provided on said vehicle through the medium of an adjusting member having a selectively variable length, such as a turn buckle or like tension shackle, rope tightener or stretcher forming an aforesaid tensioning and load transfer means.

According to a modification, each aforesaid handling cable for controlling the extension of said second ramp section is connected to a pressure fluid-operated lineardisplacement actuator for example of the ram type having a selectively adjustable force to form an aforesaid tensioning and load transfer means.

Accordingto still another alternative embodiment, said automatic tensioning and slack taking-up means consist of at least one resiliently deformable spring-like member and for this purpose each aforesaid handling cable for controlling the extension of said second ramp section is connected to a stationary fastening point provided on said vehicle through the medium of this spring, whereas said automatic means for stopping and unidirectionally holding against motion consist of a stationary stop means for limiting the strain or deformation of said spring under maximum stress.

According to a further alternative embodiment, said automatic tensioning and slack taking-up means consist of a possibly self-acting winding-up appliance to which each aforesaid handling cable for controlling the extension of said second ramp section is connected whereas said automatic means for stopping and unidirectionally holding against motion consist either of the stationary fastening point of the end of said cable on said appliance or of a locking or braking member of said appliance for braking said cable at the end of its useful paying-out motion.

According to still a further modification of the invention, each aforesaid handling cable for controlling the extension of said second ramp section is connected to a power winch as known per se and the winding-up device consists of said winch which is preferably provided with means for keeping the cable tension constant and is located on said vehicle to form an aforesaid load transfer means.

Finally according to still another alternative embodiment, said load transfer means consist of at least one counterweight or like counterbalancing or weighting body and preferably of a body with an adjustable weight fitted on one lever arm fast with said second ramp section so as to bias or urge same upwards i.e. towards its extended position.

When the ramp comprises, as known per se, a third or outermost section forming a supporting pad for bearing engagement with said outside platform and which is pivotally connected preferably with an intermediate point thereof to the corresponding outer end of said second section forming an intermediate section, there are provided self-acting or operated means for raising said outermost section. For this purpose and according to one embodiment of the invention, each handling cable for controlling the extension of said intermediate section is reeved as known per se on at least one, associated main loose guide pulley or sheave carried by said intermediate section and this cable is secured with its aforesaid outer end at a point located outwards beyond the pivotal connection of said outermost section with said intermediate section. Such an arrangement offers the advantage to enable said outermost section to be automatically raised so as to assume a proper flat-laid position when engaging the quay thereby preventing any possibility of buttressing or abutting against some projection of the quay.

According to an alternative embodiment, an operated means for controlling the raising of said outermost element may consist of at least one preferably lineardisplacement, pressure fluid operated for instance ramp-like actuator mounted between the intermediate and outermost ramp sections and remote-controlled either automatically or by an operator from a remotecontrol station or desk.

Moreover, in the device according to the invention, the ramp, in its lowered and extended working condition, remains at least partially suspended from its handling cables or ropes reeved on the associated kingposts, respectively, of the ship and made fast adjacent to the outer end of the inboard ramp section (i.e. that section which is pivoted to the ship) so a to relieve the quay from the load sustained by decreasing the bearing pressure of the free end of the ramp thereon by transferring or carrying over at least one part of the total ramp weight and of its possible instant load to the ship. The bearing pressure exerted onto the quay by the outermost ramp section may also or in addition be decreased by applying a suitable adequate tension to the handling cables or ropes for controlling the extension of said intermediate section, so that their reeved portions between pulley or tackle blocks, interconnecting the innermost ramp section and the adjacent outer or intermediate ramp section pivotally connected thereto thereby exerts a relative lifting force on the combination of said intermediate ramp section and outermost ramp section for thereby transferring at least one part of the weight of such an assembly and of the instant load possibly carried thereby to said innermost ramp section while unidirectionally blocking the pivotal direction between both innermost and intermediate ramp sections in the relative swinging direction for holding same together (and this at least to some extent).

Such a load transfer to said handling cables required at least in part owing to the fact that the ramp forms a beam consisting of several pivotally interconnected sections results in applying corresponding tractive forces to the tops of said king-posts which are extending upwards to a relatively large height above the level of the horizontal centre line passing through the centre of gravity of the ship so that such tractive forces are applied to the ship with a rather significant lever arm generating a corresponding tilting moment tending to cause the ship to list or to be tilted to the side where the ramp is located thereby heeling over.

To remove or obviate such a drawback to a large extent, i.e. to prevent the ship from listing or heeling over during the use of the ramp, it is known in particular from the US. Pat. No. 3,687,308 to provide on at least one side frame member of the innermost ramp section pivotally connected to the ship, a pressure-operated extensible and retractable actuator with a substantially linear displacement in translatory motion, in particular of the ram-type formingg a cylinder and piston assembly the line of action of which is spaced from the geometrical pivot axis of the pivotal connection between both inner and outer or intermediate adjacent ramp sections, said actuator being adapted to removably bear against an abutment member rigidly secured to the corresponding side of said adjacent outer section in the extended and lowered working configuration of said ramp for locking said pivotal connection in the direction of rotation of increasing extension in a selectively variable relative angular position through the adjustable active extension length of said actuator whereas selectively variable connecting means between said side frame member and said corresponding side, respectively, of both ramp sections involved enable to lock said pivotal connection in the direction of rotation of ramp folding in the same relative angular position. In this known prior art arrangement, said actuator bears upon the adjacent outer ramp section through the medium of an arm pivotally connected to said inner ramp section and slidably engageable with the adjacent outer ramp section and said selectively variable connecting means consist of handling cables or ropes for controlling the extension of said outer ramp section and one reeved portion of which interconnects both pivotally interconnected ramp sections, these cables being operated by at least one winch mounted on the inner ramp section and adapted to exert a selectively adjustable fixed tension on said cables controlling the extension of said outer ramp section. Such a combined system enables to achieve a buttressing effect locking or holding against motion the pivotal connection between both aforesaid ramp sections in both opposite directions of rotation thereby preventing any variation in the relative angular position of both ramp sections involved (with attendant upward or downward motion of the absolute position of the pivotal connection in space), so that the ramp behaves bodily as a bridge-like stiff or rigid continuous beam which is suported on the quay and by the pivotal connections with the ship at a location very close to the centre line of gravity of the ship thereby reducing by a corresponding amount the length of the lever arm generating the aforementioned tilting or tipping moment hence the possible resulting list of the ship.

The aforesaid known construction exhibits several inconveniences. On the one hand, the pushing buttressing actuator and pivoted arm assembly engaging a sidewise projecting abutment directly intergral with the runway forming the intermediate or outer ramp section which isdevoid of side frame members, is of a rather complicated construction. On the other hand the use of a cable or rope system in combination with the buttressing actuator exhibits the disadvantage of separating the buttressing functions in both opposite directions of rotations, respectively, of the pivotal connection, thereby also complicating the construction to a significant extent. Moreover, the locking effect achieved by the cables controlling the relative extension of the intermediate or outer section by means of their associated individual winch does not allow to achieve an absolutely positive locking effect, i.e. resulting in an adequate stiffness of the ramp in the relative lifting direction of the pivotal connection, thereby decreasing the effectivenes of the desired locking action by a corresponding amount. Said known system is accordingly rather expensive, of a rather difficult handling in view of the difficult mutual adaptation of both separate locking functions in opposite directions, respectively, and of a rather unreliable effectiveness and operation.

There are in addition known ramps consisting of three pivotally interconnected sections the innermost section of which is pivoted to the ship while being suspended from a pair of cables or ropes made fast with one end to the ship and with the opposite end to the opposite longitudinal edges, respectively, of said innermost ramp section adjacent to theouter end thereof.

On either longitudinal side of the innermost section is pivoted the bottom or back end of the cylinder of a linear-displacement type pressure fluid operated actuator extending substantially in parallel relation to the relative vertical longitudinal plane of said side frame member and the piston rod of which s pivotally connected with its end to the adjacent inner end of the adjacent intermediate ramp section.

In Applicants co-pending U.S. Pat. Application Ser. No. 380,469 filed on July 18, 1973 and not yet publicly disclosed is proposed a foldable ramp which may be raised and lowered and consists of three pivotally interconnected sections the innermost section of which is pivoted to the ship and suspended from handling cables or ropes kept taut or stretched with an adjustable constant tension (and wound up on respective winches provided on the ship) adjacent to its outer ends of its opposite side frame members forming a kind of guardrailing. The central or intermediate ramp section also comprises side frame members forming a kind of guard-railing on its opposite sides and a lineardisplacement buttressing actuator is mounted on either longitudinal side of the ramp on the adjacent ends of the side frame members of the inner and central ramp sections, respectively, above the pivotal connection therebetween and in the relative longitudinal vertical plane of the side frame members in the lowered working position of the ramp, thereby interconnecting these ends so as to exert a buttressing effect onto the ramp. The cylinder of each actuator is mounted on the innermost ramp section so that each actuator exerts through its piston rod a thrust or pushing force onto the adjacent intermediate ramp section, whereby the pivotal connection between both of these ramp sections may be lifted upwards or raised in space so as to form an upward projecting angle therebetween.

One object of the invention is also to remove said drawbacks by providing a double buttressing arrangement of a simpler hence less expensive construction and combining into one single and same assembly the functions of locking the pivotal connection between both ramp sections in either of the opposite directions of relative rotation thereof, respectively. For this purpose the device according to the invention is characterized in that on the one hand said actuator is pivotally connected with its casing or body portion onto the side frame member of said innermost ramp section and extends substantially in parallel relation to the relative longitudinal vertical plane of said side frame member and higher than the geometrical pivot axis between both innermost and central ramp sections in the working position of the ramp whereas said central ramp section also comprises a pair of side frame members on its opposite longitudinal sides, respectively and on the other hand the movable thrust or pushing head of said actuator is freely engageable directly with at least one substantially concave thrust or buffer or like pad means forming said abutment member and secured onto the adjacent end of a corresponding side frame member of said outer ramp section, operated or boosted locking means being provided on said corresponding side frame member of said outer ramp section to rigidly connect said actuator head with said thrust or buffer member, these means forming said selectively variable connecting means.

In addition to the aforesaid advantages aimed at by the objects of the present invention, such an arrangement is also advantageous in view of its rather more reduced size as compared with the known system. Moreover thebuttressing actuator serves itself as a bracing or like tie-member invariably connecting together both interconnected ramp sections in the locking position of the actuator thereby positively and effectively preventing any relative folding or rotary motion about the pivotal connection between both ramp sections involved.

According to another characterizing feature of the invention, the movable thrust head of said actuator comprises at least one sidewise projecting portion such as for instance a transverse projecting stud-pin adapted to bearingly engage said buffer member or pad or like abutment means which is preferably a substantially square-shaped bracket and said locking means comprise at least one movable retaining member actuated in particular by an associated power-operated actuator and mounted on said adjacent outer ramp section, said retaining member being adapted to engage said studpin or like trunnion member to keep it in abutting engagement with said thrust or buffer pad.

According to still another characterizing feature of the invention, each aforesaid retaining member is constantly biased or urged automatically towards its operative locking position either by a resilient spring-like biasing or return means or by gravity so that its associated power-operated actuator serves for unlocking purposes only.

This retaining member thus provides a temporary rigid working assembly secured against any separation, disengagement or like disconnection and against any slipping or sliding motion through mutual displacement, preferably by a shape-conditioned stop means or fit or the like thereby achieving a closed assembly.

Owing to its technical unobvious effects and advantageous results obtained the device according to the present invention brings about a substantial progress or advance or significant improvement over previously known devices of the same kind.

The invention will be better understood and further objects, characterizing features, details and advantages thereof will appear as the following explanatory description proceeds with reference to the diagrammatic accompanying drawings given by way of non limiting examples only illustrating various presently preferred specific forms of embodiment of the invention and wherein:

FIG. 1 shows a perspective view of the ramp of the invention according to a first embodiment thereof, with a second ramp section provided with cantilever booms or outriggers or like projecting arms, the ramp being mounted astern i.e. at the rear portion of a ship moored longitudinally along a quay berth and shown in its lowered extended working configuration wherein its longitudinal direction makes an acute angle with the general backwards pointing longitudinal direction of the ship;

FIG. 2 is a fragmentary top view of the arrangement shown in FIG. 1;

FIG. 3 is a fragmentary side view on a larger scale showing the ramp in a raised and folded stowing position, in an intermediate handling position in a partially lowered and extended state and in two lowered and extended working positions, respectively, in both cases where the access area of the ship is located higher or lower than the quay surface, respectively;

FIG. 4 is a partial side view of the upper right-hand portion of FIG. 3 showing the use of a counterweight for each handling cable controlling the extension of said second ramp section;

FIG. 5 is a view similar to FIG. 4, showing an alternative embodiment illustrating the use of a hydraulic actuator for each handling cable controlling the relative extension of said second ramp section;

FIG. 6 is a view similar to FIGS. 4 or-5, showing another modification illustrating the use of a spring for each handling cable controlling said relative extension of the second ramp section;

FIG. 7 is a view similar to FIGS. 4 to 6, showing still a further alternative embodiment illustrating the use of a constant-tension winch for each handling cable controlling the relative extension of said second ramp secvention wherein said cantilever booms or projecting outriggers are carried by the innermost ramp section instead of being carried by the intermediate ramp section;

FIG. 10 is a fragmentary side view of the preceding device shown in its raised and folded stowing position;

FIG. 11 is a view similar to the preceding one but corresponding to the configuration shown in FIG. 9 when assuming the level of the access area of the ship to be approximately the same as or slightly higher than that of the quay;

FIG. 12 is a fragmentary side view on a larger scale in the encircled detail XII of FIG. 3;

FIG. 13 is a view similar to FIG. 11 but wherein the access area of the ship is assumed to be located higher than the quay surface;

FIG. 14 is an enlarged fragmentary side view of the encircled detail XIV in FIG. 13;

FIG. 15 is a view similar to FIG. 11 or 13 but wherein the level of the access area of the ship is assumed to be located below the quay surface level;

FIG. 16 is an enlarged fragmentary side view of the encircled detail XVI in FIG. 15;

FIG. 17 is a fragmentary side view on a larger scale, similar to FIGS. 10, ll, 13 and 15 and showing the ramp in different successive end and intermediate positions, respectively, to show the various steps of its operation in both cases where the access area of the ship is located lower and higher, respectively, than the quay surface;

FIG. 18 is a fragmentary outside lateral view, with parts broken away, of the ramp portion located adjacent to the pivotal connection between the innermost and central or intermediate ramp sections in a relative configuration partially folded with an upward projecting angle, said portion being provided with a device according to the invention, placed in its retracted inoperative position, i.e. without producing any buttressing effect;

FIG. 19 is a fragmentary side view on a larger scale of a still more reduced ramp portion about its pivotal connection in a relative lowered and extended working position with the innermost and intermediate ramp sections substantially aligned in mutually registering relationship in extension of each other, said buttressing appliance being in its operative extended position; and

FIG. 20 is a fragmentary top view of the adjacent end portions of both corresponding side frame members of both ramp sections involved, respectively, shown in the preceding Figure.

According to the exemplary form of embodiment shown in FIGS. 1 to 8, a ship, generally denoted by the reference numeral 1 and the stem or rear end portion of which only is shown, is moored adjacent a quay 2 for instance alongside thereof, so that the longitudinal direction 3 of the ship is substantially parallel or coextensive with the direction of the quay edge. The rear portion of the ship is fitted with a movable access ramp 4 consisting of three successive innermost or foremost, central or intermediate and rearmost or outermost sections 40, 4b and 4c, respectively, pivotally connected to each other in the longitudinal direction in substantially aligned mutually registering relationship in the lowered extended working position by pivot hinges or the like 5, 5', respectively. The outermost section 40 is desirably in the shape of a bearing pad or like engaging plate serving to support the ramp onto the quay 2, so that this section automatically conforms to the quay surface irrespective of the relative slope of the intermediate section 4b. In order to facilitate the passage of vehicles on the ramp, the outermost section 40 is as known per se wider on at least one side and at least towards its free end than the adjacent intermediate section 4b. The innermost or inboard section 4a is made desirably wider at least towards one side as known per se at its forward or inner end through which it is pivoted at 6 to the ship 1.

At least the innermost section 4a is provided on either side thereof with two side frame members 7. The innermost section 4a is secured preferably at its outer ,end or adjacent to its pivotal connection with the intermediate section 4b to at least one handling cable or rope wound up on an associated power-operated handling winch located on the ship. There are preferably provided at least two handling cables 8, 8 made fast at 9, 9', respectively, onto the side frame members 7 of the ramp section 4a and winding up on two corresponding handling winches 10, 10', respectively, desirably located at an overhead or elevated level, for instance on the upper deck 11 of the ship. Each handling cable 8, 8, extending from its associated power-operated winch l0, 10' passes at first on at least one preferably elevated auxiliary guide pulley or sheave mounted for instance on a deck erection or like superstructure such as a suitable king-post or mast 13, 13 (at the bottom portions of which the winches 10, 10 are located) and then on at least one main guide-pulley 9, 9' mounted on the side frame members 7 of the ramp section 411. In order to reduce the tractive force to be exerted on the handling cables 8, 8, it is advantageous that each handling cable 8, 8 forms a suitable reeved portion or the like interconnecting the ramp section 4a with the corresponding king-post l3, 13 while thus passing successively on several auxiliary guide-pulleys l2, 12 mounted in a same pulley or tackle block carried by the corresponding king- post 13, 13 and then on several main guide-pulleys-9, 9' also fitted together in a same tackle block secured to the corresponding side frame member 7, 7'. Each cable 8, 8 thus exhibits multiple runs extending between the ship and the ramp. To balance the tensions in the various runs of the cables 8, 8, one single cable only is used which, extending from the winch 10 and after having passed on the pulley-blocks l2 and 9 is reeved at 8" successively onto the guidepulleys 9a, 9a located beneath the ramp section 40 at the outlet of pulley-block 9 and the inlet of pulleyblock 9', respectively, for passing then on the latter and afterwards on the tackle-block 12 to be finally taken up by the other winch 10.

As known per se, the intermediate section 4b is foldable downwards against the innermost section 4a along the latter and secured at at least one point and preferably at two points 19, 19 located for example sidewise of each side on the opposite longitudinal edges, respectively, to at least one and preferably two handling cables l5, l5 controlling the relative extension of said intermediate section and passing each one on at least one loose guide sheave and for instance two loose guide- sheaves 16, 16 which are preferably at an elevated position and carried for instance by a king-post or the like l3, 13, respectively, to be made fast through the medium of a turn-buckle, rope stretcher or stiffener or like cable tensioning or tightening device 17, 17 to a stationary point 18, 18 fast for instance with the associated king-post 13, 13'.

As known per se the intermediate section 4b extends beyond its pivotal connection 5 with the innermost section 40 with at least one longitudinal projecting armlike boom or integral outrigger carrying towards its free end at least one auxiliary guide-sheave for each handling cable 15, 15 controlling the extension of said intermediate section. For this purpose there are desirably provided two such cantilever arm-like booms or projecting outriggers 23, 23 consisting of outwards offset extensions of the corresponding longitudinal edges of the intermediate section 4b beyond the pivotal connection 5 forming the outer end of the vehicle runway sup ported by the side frame members 7 of the innermost section 4a, these booms being preferably arranged so as to be located higher than the innermost section 4a in the extended position of the ramp and to embrace the latter. Each projecting boom 23, 23' carries at least one auxiliary guide-pulley 19, 19' for the handling cable 15,15 controlling the extension of said intermediate section, which thus is reeved successively over this pulley 19, 19' and then on a main loose associated guide-pulley 14, 14' carried by the innermost secton 4a respectively at the corresponding auxiliary sheave 19, 19' to be made fast at a stationary point 14a, 14b on the associated side frame member of the innermost section 4a. There are desirably provided, on each boom 23, 23', several auxiliary loose guide-pulleys l9, 19' mounted in a same tackle-block and, on the innermost section 40 on either side thereof, several loose main guide- pulleys 14, 14 also mounted in a same tackleblock so as to form a force-reducing reeving between each boom 23, 23 and the innermost section.

At least one (hydraulic or pneumatic) pressure fluid operated actuator, preferably of the lineardisplacement type consisting of a cylinder and piston assembly mounted between the intermediate ramp section 412 and the innermost ramp section 40 and pivotally connected with its cylinder bottom or back end to the end of the section 4b and with its piston rod to the end portion forming the heel part of the section 40 located under the section 4b (see FIG. 3). This actuator is desirably provided and remote-controlled for raising the innermost section 4c so that the latter rests entirely throughout its seating surface in a flat-laid condition onto the quay 2, so as to properly connect the runway surface of the intermediate section 4b to the quay surface and to distribute the load uniformly on the latter to avoid any buttressing, punching or like effect. FIG. 2 shows that it is advantageous to provide two such actuators 26 preferably arranged in symmetrical relation to the longitudinal vertical center plane of the ramp towards the side edges, respectively, of the innermost ramp section 4c. Independent segmented flap elements 27 pivoted to the transverse end edge of the section 40 in juxtaposed relationship across the latter serve to engage the quay 2 to facilitate through their tapering wedge-shaped cross-sectional contour the access to the section 40. Also, a set of similar flap elements 28 are likewise pivoted to the inner transverse end edge of the ramp section 4a'to facilitate the access to the tweendeck 29 of the ship while spanning the cargo port 30 in the side thereof.

The tractive reaction force at the fastening point of each handling cable 15, 15' controlling the extension of the intermediate section, on its associated derrick or 13 king-post 13, 13' may be produced in various ways. Thus in FIGS. 1 and 3, this reaction force is merely produced by the stationary fastening point l8, 18 of each cable at the top of the associated king or derrick post. In the alternative embodiment according to FIG. 4, each cable 15, 15', after having been reeved over a first guide-pulley 16 located at the free end of the jib portion of the associated king-post or derrick mast 13, 13' passes on a second guide-pulley 16a located at the opposite end of this jib portion to extend downwards again along the king-post and to terminate into a movable counterweight or the like 31 mounted for instance on rollers 32 for riding on or within a corresponding forced-guide track 33 sloping downwards from top to bottom and away from the ramp in the downward direction. This guide-track 33 is provided at its upper end with a stationary stop means 34 for limiting the upward stroke of the associated counterweight 31. The position of the counterweight obviously varies with the relative position of the ramp during operation thereof, the engagement of the counterweight 31 with the stop means 34 automatically causing the relative raising and extension of the intermediate ramp section 4b.

In the alternative embodiment according to FIG. 5, each cable 15, 15', after passing over the associated guide-pulley 16a is reeved on a guide-pulley 35 carried by the piston rod of a linear-displacement pressure fluid operated, for example, hydraulic actuator 36 mounted on the associated king-post 13, 13', the thus returning run of each cable 15, 15' being made fast at a stationary point 37 of the corresponding derrick mast or king-post. Each actuator 36 thus allows to vary at will and preferably at the same time or synchronously the tension in the associated cable 15, 15' in particular through selective adjustment of the control fluid pressure fed into the cylinder of actuator 36.

In the alternative embodiment shown in FIG. 6, the pressure fluid operated actuator 36 has been replaced by a spring-operated actuator or the like 38 secured to the corresponding king-post 13, 13' and comprising for instance a cylinder containing at least one for instance helical compression spring with one end of which cooperates a sliding piston coaxially integral with a rod carrying at its free outer end the pulley 35. The helical spring could possibly be replaced by a compressible preferably gaseous fluid such s nitrogen.

In the embodiment of FIG. 7, each cable 15, 15', after passing on the guide- pulley 16, 16, is wound up on a power-operated winch 39 preferably applying a constant tension to the cable and mounted on the associated king- post 13, 13, said winch being driven for example hydraulically or electrically.

The actuators 36 in the embodiment of FIG. or the winches 39 in the embodiment of FIG. 7 allow to selectively vary the tension in the cables 15, in the extended and lowered working configuration of the ramp 4, thereby tending to lift the intermediate ramp section 4b upwards to thus release selectively the bearing pressure exerted on the quay 2 by the outermost ramp section 4c. Another means enabling to produce the same relief effect consists according to the embodiment of FIG. 8 to provide on each projecting boom 23, 23' of the intermediate ramp section 4b a counterweight or the like 40 having for instance a selectively variable weight and desirably located endwise of the associated projecting boom 23, 23'. Each counterweight 40 thus applies a tilting moment to the section 4b about its pivot axis 5 in the upward direction or direction of raising of said section. Instead of a counterweight it is also possible to correspondingly weight the structure of the booms 23, 23' by increasing their mass.

Automatic control means are desirably provided to keep the innermost section 4a away or spaced from the quay in the lowered working configuration of the ramp in order that it never directly engages the quay and each operating winch 10, 10' is phase-locked in followup relationship to these control means which consist for instance of at least one sensor or like detector 21 (see FIGS. 2, 3 and 8) secured for example to the intermediate section 4b in particular below same and towards its inner end and adapted to bear upon the surface of the quay 2, preferably adjacent to the edge of the quay to'detect any variation in relative position in height or in the level difference between the ship I and the quay as caused in particular by an upward motion of the ship. Such a sensor 21 may consist for example of an electric limit switch with normally open contacts adapted to'control the simultaneous or synchronized operation of the respective motors or prime movers of the handling winches 10, 10' by acting for instance either upon an electromagnetic valve in the case of pressure-fluid operated motors such as hydraulic or pneumatic motors or upon an electric switch relay in the case of electric motors.

The system is desirably fitted with automatic control means for adjusting the relative angular position of the innermost and intermediate ramp sections 4a and 4b,

a respectively, to keep same substantially aligned or inclinedwith an optimum slope in the lowered extended working configuration of the ramp, each aforesaid handling winch 10, 10' being then phase-locked in followup relationship to such control means. These control means consist for example of at least one sensor or like detector 22 mounted on one of the two adjacent ramp sections 4a, 4b, preferably in the vicinity of its pivotal connection 5 with the other section and adapted to engage said other section so as to measure the angle formed therebetween in particular during the raising motion of the ship. In the example shown, this detector 22 is mounted on the protruding boom 23 of the intermediate ramp section 4b between the latter and the side frame member 7 of the innermost ramp section 4a. This detector 22 may as well as the sensor 21 consist advantageously of an electric limit switch or of a position pick-up or detecting means with an equivalent action.

In the embodiment of FIGS. 1 through 8, each aforesaid protruding boom 23, 23' is in extension of the corresponding side edge of the intermediate section 4b. It is apparent however that generally each projecting boom may be in extension of any one of the two innermost and intermediate ramp sections 4a, 4b, respectively, while extending beyond the common pivotal connection between the adjacent ends thereof towards the other section which then carries at least one main guide-pulley or tackle-block for the handling cable 15, 15' controlling the extension of the intermediale section whereas the free end of the corresponding boom then carries at least one auxiliary guide-pulley or tackle-block for this cable.

FIGS. 9 through 17 show another embodiment of the invention wherein the relative arrangement of said booms and sheaves or pulley-blocks has been reversed with respect to that of the first embodiment shown in FIGS. 1 to 8. In this alternative embodiment, it is the innermost ramp section 40 which extends beyond its pivotal connection 5 with the intermediate section 4b with at least one integral projecting longitudinal armlike boom or outrigger and preferably with two such booms 7a, 7b substantially co-extensive in parallel relationship with the general longitudinal direction of the ramp in extension of the side frame members 7, on either side of the intermediate section 4b while being desirably transversely offset outwards so as to be spaced sidewise from the intermediate section 4b and preferably somewhat elevated or higher with respect thereto. Each projecting boom 7a, 7b then carries the or each main guide-pulley or tackle-block 19, 19' for the han dling cable 15, controlling the relative extension of the intermediate section, whereas the intermediate section 4b carries at an intermediate point thereof at least one auxiliary guide-pulley or tackle-block 14, 14' for each handling cable 15, 15' controlling the extension of said intermediate .section and leading from each main guide-pulley or tackle-block 19, 19'. Each handling cable 8, 8' for the ramp is then made fast for instance with a tackle-block at a point 9, 9' of the innermost section 4a towards the pivotal connection 5 or outer end of same. On each king-post or derrick mast 13, 13', the free downward extending run of each cable 15, 15 terminates in a counterweight or the like 31, 31'. Each king- post 13, 13 comprises a stationary stop means 34, 34' limiting the upward vertical stroke of the associated counterweight 31, 31.

Each handling cable 15, 15' controlling the relative extension of the intermediate ramp section is desirably made fast with the end of its run leading from the corre sponding reeving portion 14, 14' thereof and after havin g passed over an additional guide-pulley 25, 25 (FIGS. 10, 11, l3, 15) to the outermost section 4c at a point 20, located outwards beyond the pivotal connection 5' of this outermost section with the intermediate section 4b. The cables 15, 15 also serve to automatically raise or lift the outermost section 4c so that the latter rests entirely throughout its seating surface on the quay 2 thereby properly connecting the runway surface of the intermediate section 4b to the quay surface and distributing the load uniformly on the latter to avoid any punching or like buttressing effect. This arrangement is also applicable to the embodiment of FIGS. 1 through 8 instead of the actuators 26 and it is advantageous that each guide-pulley 25, for each handling cable 15, 15' controlling the relative extension of the intermediate section be located preferably substantially at the pivotal connection 5 between the innermost section 4a and the intermediate section 4bfor instance in coaxial relationship therewith to return or guide backwards the associated cable 15, 15' leading from the guide-pulley or tackle- block 14, 14 to the fastening point 20, 20' provided on the outermost section 40.

Pushing or thrust means such as one or several lineardisplacement type pressure-fluid operated for instance hydraulic or pneumatic actuators with a cylinder and piston assembly 24 mounted on the ship 1 are adapted to bear freely in abutting relationship against the innermost ramp section 4a in the fully raised position thereof (FIG. 3) to initiate its downward tilting or swinging motion through gravity and possibly to brake or slow down same at the end of its raising motion at which it is engageable with stationary stop or rest means 41 forming wooden or rubber buffers or like pads provided on the ship. Alternatively these thrust actuators 24 could themselves form such stop or abutment means. Each actuator 24 instead of being mounted on the ship 1 could as well be mounted on the innermost ramp section 4a so as to be freely engageable with a stationary portion of the ships structure at the start of the downward tilting or swinging motion of the ramp or at the end of the raising motion thereof.

The innermost section 4a is desirably enlarged or widened at 4 towards its inner end and preferably at least towards the obtuse angle defined between its own longitudinal direction and the longitudinal direction of the ship in the case of a ramp arranged towards one end for example aft of the ship with a view to facilitate access therto.

A lashing or locking appliance 42 is desirably provided on the ship for locking or holding the ramp 4 against motion in the stowed noperative position, i.e. when it is folded back and swung up (see FIGS. 3 to 7). Each locking or lashing device 42 is adapted to preferably engage the intermediate ramp section 4b folded downwards against the innermost section 4a which has come in abutment with the buffers 41 after having been run or extended through the latter, Each locking device 42 may be operated either manually or automatically for instance may hydraulic actuators and consist in particular of a latch, lockbolt or like hook member adapted to engage a bolt-clasp or equivalent catch or keeper means integral with the intermediate section 4b while preferably exerting a tractive force urging said ramp to bear against its abutment pads or buffers 41. Instead of being placed on the ship 1, each locking device 42 could also be provided on the ramp 4 to be engageable with a complementary or mating stationary catch element integral with the ships structure.

Automatic control means, not shown, are advantageously provided to selectively vary the bearing reaction of the ramp 4 on the platform or quay 2, each aforesaid load transfer means, such as in particular the hydraulic actuators 36 or the winches 39 applying a constant tension to the associated cables, being then phase-locked in follow-up relationship to said control means. These control means consist for instance for a sensor or like detector forming a pressure pick-up device mounted on the ramp towards its outer end for bearing upon the quay 2 in the working position so as to measure the bearing reaction of said quay.

As shown in particular in FIGS. 10 to 16, each sensor element 21 is here secured to the innermost section 4a in particular underneath the latter and towards its outer end whereas the detector 22 is mounted on the intermediate ramp section 4b between the latter and the projecting boom 7a of the innermost ramp section 4a.

The operation of the ramp 4 is then the following with reference at first to FIG. 3 showing the first embodiment when assuming the ramp initially in the position C wherein it is folded back and entirely raised to an upstanding position. In thisposition, the ramp is held against motion in abutment against the buffers 41 by the locking arrangement 42, the ramp sections 4b and 40 being folded back against the section 4a. To lower the ramp into the extended working position, the locking device 42 is at first unlocked in order to disengage or release the ramp 4 and the winches 10, 10 which are desirably provided with means for automati-

Claims (30)

1. A movable device forming a foldable access ramp to interconnect a vehicle with an outside platform, said ramp being adapted to swing in parallel relation to a vertical plane so as to be raised into inoperative stowed position on said vehicle and lowered into operative working position to rest at least partially on said platform, said ramp comprising at least two successive ramp sections pivotally interconnected endwise in the longitudinal direction and the first one of which forming an innermost section is pivotally connected to said vehicle and attached with at least one point of said ramp section to at least one constantly tensioned handling cable winding up on at least one winch located on said vehicle whereas the other or second ramp section may be folded back and downwards against and along said innermost ramp section and is attached to at least one handling cable controlling its outward extension for raising said other ramp section into the extended position in at least approximatively aligned registering relationship with said innermost ramp section in the lowered working position, wherein the improvement consists in that each handling cable for controlling the outward extension of said second ramp section is connected to means for automatically tensioning and taking up the slack of said cable through the action of potential energy, said means being provided on said vehicle and comprising self-acting means for stopping said cable and holding it unidirectionally against motion, said latter means being adapted to form a stationary fastening means for generating, through blocking of the effective useful length of said cable, a tractive reaction force tending to raise said second ramp section into its outward extended position during the lowering motion through gravity of said innermost ramp section which is constantly suspended from each one of its own handling cables.

2. A device according to claim 1, comprising selectively adjustable load transfer means for varying at will the bearing reaction force of said ramp onto said platform in the working extended position of the ramp to thereby transfer at least one selectively variable part of the weight and instant load of said second ramp section to either of said innermost ramp sections and of independent auxiliary supporting means provided on said vehicle.

3. A device according to claim 1, wherein said self-acting means for automatically stopping said handling cables and unidirectionally Holding same against motion are arranged so as to be operative only from a given angle of slope of said innermost ramp section with respect to the vertical direction during the starting period of lowering motion thereof.

4. A device according to claim 1, wherein each handling cable for controlling the relative outward extension of said second ramp section is reeved over at least one elevated loose guide pulley mounted on said vehicle and terminates in a movable counterweight forming said automatic tensioning and slack taking-up means whereas said automatic means for stopping said handling cables and unidirectionally holding same against motion consist of a stationary stop means limiting the upward motion of said counterweight provided on said vehicle.

5. A device according to claim 2, wherein each handling cable controlling the relative outward extension of said second ramp section is reeved on at least one elevated loose guide pulley mounted on said vehicle and terminates into a movable counterweight forming said tensioning and slack taking-up means whereas said automatic means for stopping said handling cables and unidirectionally holding same against motion consist of a stationary stop means limiting the upward motion of said counterweight and provided on said vehicle, the weight of each counterweight being selectively adjustable so that said counterweight forms said load transfer means.

6. A device according to claim 2, wherein each handling cable controlling the relative outward extension of said second ramp section is connected to a stationary fastening point provided on said vehicle through the medium of an adjusting member having a selectively variable length and forming one aforesaid tensioning and load transfer means.

7. A device according to claim 2, wherein each handling cable controlling the relative outward extension of said second ramp section is connected to a linear-displacement type pressure fluid operated actuator generating a selectively adjustable force and forming one aforesaid tensioning and load transfer means.

8. A device according to claim 1, wherein each handling cable controlling the relative outward extension of said second ramp section is connected to a stationary fastening point provided on said vehicle through the medium of at least one resiliently deformable spring-like member constituting said automatic tensioning and slack taking-up means whereas said automatic means for stopping said handling cables and unidirectionally holding same against motion consist of a stationary stop means limiting the strain of said spring-like member under maximum stress.

9. A device according to claim 1, wherein each cable controlling the relative outward extension of said second ramp section is connected to a self-acting winding-up appliance forming said self-acting tensioning and slack taking-up means whereas said automatic means for stopping said handling cable and unidirectionally holding samd against motion consist of a stationary fastening means for the end of said cable on said appliance.

10. A device according to claim 1, wherein each handling cable controlling the device outward extension of said second ramp section is connected to an automatic winding-up appliance forming said self-acting tensioning and slack taking-up means whereas said automatic means for stopping said cable and unidirectionally holding same against motion consist of braking means for braking said appliance at the end of the useful paying out motion.

11. A device according to claim 2, wherein each handling cable controlling the relative outward extension of said second ramp section is connected to a power-operated winch providing for constant cable tensioning and which is located on said vehicle to form one aforesaid load transfer means.

12. A device according to claim 2, wherein said load transfer means consist of at least one counterweight having a selectively adjustable weight and located on a lever arm integral with said second ramp section so as to urge the Latter towards its rasied outward extended position.

13. A device according to claim 1, comprising a third or outermost ramp section forming a supporting pad to bear on said outside platform and pivotally connected with an intermediate point thereof to the corresponding outer end of said second ramp section forming now an intermediate ramp section, said device comprising operated means for raising said outermost ramp section.

14. A device according to claim 13, wherein each handling cable controlling the extension of said intermediate ramp section is reeved over at least one associated loose main guide pulley carried by said intermediate ramp section and said cable is secured with its outer end to said outermost ramp section at a point located outwards beyond the pivotal connection of the latter with said intermediate ramp section to form said operated raising means.

15. A device according to claim 13, wherein at least one ram-like pressure fluid operated actuator is provided between said intermedate and outermost ramp sections to form said operated raising means.

16. A device according to claim 1, wherein one of said first and second ramp sections extends beyond its pivotal connection with the other ramp section with at least one longitudinal projecting integral boom carrying towards its free end at least one auxiliary guide pulley for each handling cable controlling the relative outward extension of said second ramp section and each cable for operating said first ramp section is reeved over several elevated auxiliary guide pulleys mounted in a same pulley block provided on said vehicle and on a plurality of main guide pulleys mounted in a same pulley block carried by said innermost or first ramp section, so as to form a reeving whereas each handling cable is reeved over several guide pulleys mounted on two pulley blocks, respectively, carried by each projecting boom, respectively, and by said other ramp section so as to form a reeving.

17. A device according to claim 16, wherein said second ramp section extends beyond its pivotal connection with said innermost or first ramp section with at least one integral projecting longitudinal boom carrying towards its free end each aforesaid main guide pulley whereas said innermost ramp section carries at least one auxiliary guide pulley for each handling cable controlling the relative outward extension of said second ramp section and leading from each main guide pulley.

18. A device according to claim 1, comprising automatic control means for keeping said innermost ramp section spaced from said platform in its lowered working position, each handling winch being phase-locked in follow-up relationship to said control means which consist of at least one sensor member secured to one of said first and second ramp sections adjacent to their pivotal connection and adapted to bear upon said platform for detecting any variation in the difference between the levels of said vehicle and said platform.

19. A device according to claim 1, comprising automatic control means for adjusting the relative angular positions of said first and second ramp sections to keep same in substantially aligned registering relationship or at an optimum slope, each handling winch being phase-locked in follow-up relationship to said control means which consist of at least one sensor member mounted on one of said ramp sections in the vicinity of its pivotal connection with the other ramp section, said sensor member being adapted to engage said other ramp section so as to measure the angle formed therebetween in particular during any upward motion of said vehicle.

20. A device according to claim 7, comprising automatic control means for adjusting the bearing reaction of said ramp onto said platfrom, each aforesaid load transfer means being phase-locked in follow-up relationship to said control means which consist of at least one pressured-detecting sensor member mounted on said ramp towards its outer end for bearing upon said platform in the working posItion of said ramp and for measuring said bearing reaction.

21. A device according to claim 1, comprising push ram means mounted on said vehicle and adapted to freely engage said innermost ramp section in its raised position to initiate its downward swinging motion through gravity and to brake or slow down its upward swinging motion at the end thereof, abutment and rest means being provided on said vehicle and engageable by said ramp in its raised and stowed position.

22. A device according to claim 1, wherein said innermost ramp section is provided with a pair of side frame members at least one of which carries a buttressing ram the line of action of which is spaced from the geometrical axis of pivotal connection between said adjacent innermost and second ramp sections, said buttressing ram being adapted to bear removably against an abutment means intergral with the corresponding side of said adjacent ramp section in the lowered and extended working position of said ramp for blocking said pivotal connection in the direction of rotation of increasing extension of the ramp, in a relative angular position which is selectively variable through the adjustable operative length of stroke of said ram, whereas selectively variable connecting means are provided between said side frame member and said corresponding side, respectively, of both ramp sections for blocking said pivotal connection in the direction of rotation of folding back said ramp, in the same relative angular position, and wherein on the one hand said ram is of the double-acting kind and pivotally connected with its body onto said side frame member of said innermost ramp section while extending in substantially parallel relation to the longtiudinal relative vertical plane of said side frame member, said ram being located higher than the geometrical axis of said pivotal connection between both ramp sections in their working position and said adjacent second ramp section also comprising a pair of side frame members on its opposite sides, respectively, whereas on the other hand said ram is provided with a movable push head adapted to freely and directly engage at least one substantially concave abutment pad forming said abutment means and secured to the adjacent end of said corresponding side frame member of said second ramp section; operated locking means being provided on said corresponding side frame member of said adjacent second ramp section to rigidly connect said movable push head with said abutment pad thereby to form said selectively variable connecting means.

23. A device according to claim 22, wherein said movable push head of said ram comprises at least one sidewise projecting portion adapted to engage said abutment pad; said abutment pad being substantially square shaped and said locking means comprising at least one movable retaining member actuated by an associated actuator and mounted on said adjacent second ramp section, said retaining member being adapted to bear against said sidewise projecting portion to keep same in engagement with said abutment pad.

24. A device according to claim 23, wherein each retaining member is automatically urged constantly towards its operative locking position by a resilient biasing means or through gravity so that its associated actuator is only used for unlocking purposes.

25. A device according to claim 22, wherein said retaining member consists of at least one arm adapted to swing in a plane substantially at right angles to said sidewise projecting portion and to be lowered into engagement with said sidewise projecting portion on that surface portion thereof which is opposite from said abutment pad to hold said sidewise projecting portion against motion, said swinging arm being on the other hand adapted to be swung upwards and away from said sidewise projecting portion to release same, said arm being engageable with said sidewise projecting portion through the tip of its free end portion, said tip having a mating shape which is complementary of that of thE lateral surface of said sidewise projecting portion.

26. A device according to claim 25, wherein said movable push head of said ram comprises a pair of transversely opposite and coaxially aligned thrust pins forming said sidewise projecting portions and adapted to co-operate with a pair of corresponding associated transversely spaced abutment pads whereas said retaining member is a fork-shaped part of the legs of which form locking arms spaced from each other according to the spacing between said abutment pads, said fork-shaped part being rotatably mounted on a transverse shaft fitted on said adjacent second ramp section, said fork-shaped part being connected through a radial crank arm to an auxiliary linear-displacement type pressure fluid operated actuator mounted on said adjacent second ramp section for rotating said fork-shaped part.

27. A device according to claim 22, comprising automatic safety means for avoiding any wrong operation and rendering the device fail-safe, said means being mounted on said adjacent second ramp section and adapted to check and to report the relative position of said locking means at the ends of the locking and unlocking strokes, respectively.

28. A device according to claim 22, comprising self-acting means for controlling the relative position of said movable push head of said ram, at the end of its stroke, against each abutment pad, said means consisting of at least one proximity detector which is phase-locked in follow-up relationship to means operating said locking means.

29. A device according to claim 22, comprising means for detecting the maximum motion of outward extension of both aforesaid successive ramp sections into their substantially aligned registering position and accordingly the end of maximum retraction stroke of said ram, said ram comprising inner mechanical stop means and said detecting means being adapted to discontinue the energizing of said ram.

30. A device according to claim 25, comprising by means for forced guiding of the movable push head of said ram, said means consisting of each sidewise projecting portion which is of elongated shape so as to project sidewise beyond said associated abutment pad and engage a guide slot carried by an associated supporting structure integral with the side frame member of said innermost ramp section.

Images