WO2000043635A1

WO2000043635A1 - Hydrodemolition apparatus for degrading a target

Info

Publication number: WO2000043635A1
Application number: PCT/US2000/001055
Authority: WO
Inventors: Charles N. Redstreake; James W. Redstreake
Original assignee: Vacuum Sales, Inc.
Priority date: 1999-01-20
Filing date: 2000-01-18
Publication date: 2000-07-27
Also published as: AU2508100A

Abstract

A hydrodemolition apparatus and method for using water to demolish a target. The apparatus includes a housing (20) with at least one nozzle and at least one suction port. The housing is positioned over a target which may be a railroad tie (12) embedded in concrete (14). Water is supplied under pressure to the nozzle using a pump (38); the water is impinged onto the target with sufficient force to disintegrate the target; the water and debris are suctioned from the housing with a suction pump (36); and a filter is used to remove solid material from the water so that it may be recycled. A separate power source (50) supplies hydraulic or pneumatic power to a motor (19) which controls rotation of the nozzle within the housing.

Description

TITLE

HYDRODEMOLITION APPARATUS FOR DEGRADING A TARGET

BACKGROUND OF THE INVENTION The present invention relates to apparatus for degrading a target, and more particularly, to an apparatus for degrading railroad tie butts which are seated into a bed of concrete using of streams of high-pressure water and simultaneous suction removal of debris and water waste.

Railroad tracks have traditionally been constructed of a pair of rails held in spaced relationship to one another by railroad ties set upon a bed of aggregate. In more recent times, railroad tracks, particularly those used in tunnels or passenger rail stations, have used shortened versions of typical railroad ties called tie butts, which have been set onto a bed of concrete rather than aggregate. The tie butts are typically countersunk into the concrete, essentially forming concrete vaults for the tie butts.

While construction of railroad tracks using tie butts and a concrete bed offer significant advantages in terms of durability and economy, the maintenance of such systems has proved problematic. Because the tie butts eventually deteriorate or become rotted, they must be replaced periodically. Whereas in traditional aggregate- bed railroad track systems worn or rotted railroad ties could merely be lifted from the aggregate bed in preparation for the installation of new ties, railroad tie butts countersunk into concrete are not able to be removed intact. Rather, tie butts countersunk into concrete have been, to this point, removed through the use of large hydraulic jackhainmers carried by heavy machinery, such as a front end loader. The jackhammer is used to demolish the tie butt so that it can be manually removed in pieces. A fifteen man crew is needed to carry out this conventional procedure of demolishing ties and removing the debris. Moreover, the fifteen man crew and the heavy machinery can accomplish removal of only about six tie butts per hour.

The drawbacks of the jackhammer method of removal are apparent. In addition to being very labor intensive and slow, the procedure creates high levels of noise and sends large amounts of flying debris and dust into the air. Tie butts countersunk into concrete are generally found in railroad tunnels and railroad passenger stations. This procedure creates significant risk for the fifteen man crew performing the procedure, in addition to creating unsafe conditions for other railroad personnel and passengers, because railroad tunnels and passenger stations are often poorly ventilated. Furthermore, the equipment used to carry out this procedure is incapable of exact precision and, consequently, the concrete vaults in which the tie butts sit are often damaged by the tie butt removal process. The damaged concrete vaults must then be repaired before new tie butts can be installed.

The present invention is designed to overcome these problems by using streams of high-pressure water to demolish the tie butts. More specifically, the present invention uses streams of water at a pressure sufficient to demolish the tie butts without causing undue harm to the concrete vault, while simultaneously using suction to remove water and wood debris from the vault. The present invention is capable of accomplishing removal of approximately one tie per minute, a ten-fold increase over the removal speed possible with the old fifteen-man-crew process.

SUMMARY OF THE INVENTION

Briefly stated, the present invention is a hydrodemolition apparatus for using water to demolish a target. The hydrodemolition apparatus includes a housing having a wall defining an interior cavity and a nozzle in the interior cavity. The nozzle is for communication with a source of water and for directing the water toward the target. The hydrodemolition apparatus also includes a suction pump in fluid communication with the interior cavity for creating a partial vacuum within the interior cavity for removing at least a portion of the water from the interior of the housing.

In another aspect, the present invention is directed to a method of degrading a target includes the steps of positioning an enclosure over the target, directing a quantity of water into the enclosure and impinging that water onto the target with sufficient force to degrade the target. At least a portion of the water and a portion of the degraded target is suctioned from the enclosure. BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing summary, as well as the following detailed description of the presently preferred embodiments of the invention, will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, there is shown in the drawings, an embodiments which are presently preferred. It should be understood, however, that the present invention is not limited to the particular arrangements and instrumentalities shown. In the drawings:

Fig. 1 is a perspective view, partially broken away, showing the hydrodemolition apparatus in accordance with a first preferred embodiment of the present invention;

Fig. 2 is a front elevational view, partially broken away, of a hydrodemolition cart of a second preferred embodiment of the present invention;

Fig. 3 is a perspective view showing the housing of the second preferred embodiment of the present invention; and

Fig. 4 is a greatly simplified elevational view of a movable vehicle and hydrodemolition cart in accordance with the second preferred embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION As used in the claims, the word "a" is defined to mean "at least one." Referring to the drawings, wherein like numerals indicate like elements throughout, there is shown in Fig. 1 a first preferred embodiment of a hydrodemolition apparatus, generally designated 8, which uses water to demolish a target 12. The hydrodemolition apparatus includes a hydrodemolition cart 10, a suction pump and storage tank apparatus 32, a high-pressure water pump 38, and a high-pressure air compressor 50. An operator 11 grips the handle 21 of the hydrodemolition cart 10 and pushes or guides the hydrodemolition cart 10 over the target 12. In the embodiment shown in Fig. 1, the target 12 is preferably a wooden railroad tie butt countersunk into a concrete railway bed 14. It is contemplated that the present invention is not limited to demolishing targets 12 in the form of railroad tie butts, but could be used on any target 12, such as concrete structures (not shown).

The preferred hydrodemolition cart 10 is a cleaning unit that employs high-pressure water dispensed by at least one high-pressure water nozzle (not shown in Fig. 1, but such a nozzle is shown in Fig. 2, discussed below) rotated about a vertical axis of the cart. Such a cleaning unit is disclosed in United States Patent Nos. 4,219,155 and 4,443,271 (the "Goerss patents"), which patents are hereby incorporated herein in their entirety by reference. Commercial embodiments of the cart disclosed in the Goerss patents are available from NLB Corporation, located in Wixom, Michigan, and are sold under the trademark "Spin-Jet"(R) Cleaners. The high-pressure nozzle(s) are preferably pencil point nozzles or cavitating jet nozzles of the type disclosed in U.S. Patent Nos. 5,086,974 and 5,217,163, which patents are hereby incorporated herein in their entirety by reference.

In the first preferred embodiment, the hydrodemolition cart 10 embodies a modification to the cleaner unit of the previously-mentioned incorporated Goerss patents, the modification including the addition of suction capability via a pair of suction ports 16 and 18 on the hydrodemolition cart 10. More particularly, the hydrodemolition cart 10 includes a housing 20 having a wall 27 which defines an interior cavity 21 within which degradation of the railroad tie butts 12 occurs. The nozzle is in the interior cavity 21 and is in fluid communication with a source of water (i.e., the high-pressure water pump 38) for directing the water toward the target 12.

The housing 20, as discussed in the Goerss patents, is preferably generally in the form of a parallelepiped and includes a top surface 22 and an open bottom. Those of ordinary skill in the art will recognize that the housing 20 may be of any shape, such as cylindrical, that provides an enclosure within which demolition may occur. In the first preferred embodiment, the suction ports 16 and 18 are welded to the top surface 22 of housing 20 and are in fluid communication with the interior cavity 21 of the housing 20, such that an uninterrupted flow path is created from the interior cavity 21 of the housing 20 through suction ports 16 and 18. It will also be understood by those of ordinary skill in the art that while there are two suction ports shown, there need only be one suction port, or there could be several, and that the suction ports 16 and 18 may be connected to any part of the wall 27 that would enable the ports to provide an uninterrupted flow path to the interior cavity 21. It will also be understood by those skilled in the art that the suction ports 16 and 18 can be attached using methods other than welding, such as mechanical forms of attachment in the nature of, for example, bolts, screws, rivets, or adhesives.

Further description of the first preferred embodiment of the hydrodemolition cart 10 is herein provided. Still with reference to Fig. 1, the hydrodemolition cart 10 is preferably supported on or slightly above the concrete bed 14 by four wheels 13 which hold the hydrodemolition cart a predetermined spaced distance above the concrete bed 14. Other methods of supporting the hydrodemolition cart 10 may be used, for example, fewer or more than four wheels, skids, rollers, a movable vehicle 200 as shown in Fig. 4, or other methods of facilitating support and/or movement of the hydrodemolition cart 10. The wheels 13 are supported on the housing 20 by bifurcated supports 15 which are each attached on an inboard end to the housing 20 and on an outboard end to the axles 17 which pass through the rotational center of the wheels 13. Any gap created between the concrete bed 14 and the housing 20 by supporting the hydrodemolition cart 10 above the concrete bed 14 is substantially filled by skirts 25, which enhance the ability to suctionably remove wood debris and process water from beneath the hydrodemolition cart 10 and minimize the ejection of such debris and waste from the interior cavity 21.

Connected to the outlet portions of the suction ports 16 and 18 are two suction hoses 24, 26. The suction hoses 24, 26 are connected on their ends opposite from those attached to suction ports 16, 18 to a manifold 28. The manifold 28 is preferably a Y-type hose fitting or equivalent manifold-type fitting. It is understood by those of ordinary skill in the art from this disclosure that if only a single suction port 16 is employed, there would be no need for the manifold 28. Connected to the opposite side of the manifold 28 is a main suction hose 30, which is connected at its remote end to a suction pump and storage tank apparatus 32. The assembly of the suction ports 16, 18, the suction hoses 24, 26, the manifold 28, and the main suction hose 30 creates a continuous flow path from the interior cavity 21 of the housing 20 to the suction pump and storage tank apparatus 32 such that there is fluid coinmunication among all of these components.

The suction pump and storage tank apparatus 32 preferably comprises a truck 33 or other mobile apparatus such as a railroad car (not shown) having a water storage tank 34, a debris collection tank 35, and a suction pump 36, all in fluid communication with one another, providing multiple functions in a single, combined mobile apparatus. The suction pump 36 is also in fluid communication with the interior cavity 21, preferably via the suction ports 16, 18, creating a partial vacuum within the interior cavity 21 for removing at least a portion of the water from the interior cavity 21 of the housing 20.

In operation, the suction pump and storage tank apparatus 32 is positioned nearby the site where tie butts 12 are to be removed. Once the main suction hose 30 is connected to the suction pump and storage tank apparatus 32, an operator 11 starts the suction pump 36. The suction pump 36 retrieves at least a portion of the wood debris and water waste from the interior cavity 21 such that the hydrodemolition process can be performed by a single operator 11 and does not require significant clean-up after the hydrodemolition process. The wood debris and water waste retrieved from the interior cavity 21 are then sent to the debris collection tank 35. The debris collection tank 35 is in fluid communication with the water storage tank 34, and both are in fluid communication with the suction pump 36. The wood debris and water preferably are separated such that at least a portion of the water, and preferably substantially all of the water, is passed on to the storage tank 34 for reuse in the hydrodemolition process. Further, at least a portion and preferably substantially all of the target debris is retained in the debris collection tank 35. Separation of water from wood debris can be achieved by any of a number of methods well known to those of ordinary skill in the art such as by filtration, settling, and/or centrifuging (all not shown). If reuse of water is not desired, when the storage tank 34 is filled, the suction pump and storage tank apparatus 32 is taken to a location where the operator 11 offloads the waste, thereby preparing the storage tank 34 for refilling. A commercial embodiment of a combined mobile suction pump and storage tank apparatus 32 is a Power Vac manufactured by Pres-Vac located in Burlington, Ontario, Canada, and sold in the United States by Vacuum Sales Inc., located in Lindenwold, NJ.

Those of ordinary skill in the art will recognize from this disclosure that the storage tank 34, debris collection tank 35, and suction pump 36 need not be provided by a single combined unit, but may be provided by two or more separate units and need not be capable of self-propelled mobile operation. If the storage tank 34, debris collection tank 35, and suction pump 36 are not parts of a single combined unit, the main suction hose 30 can either be connected directly to the debris collection tank 35, the storage tank 34 (if reuse of water is not desired), or could be connected directly to the suction pump 36 wherein water is then passed to the water storage tank 34 or debris collection tank 35. In the former, debris and water passing through the main suction hose 30 would pass directly into the debris collection tank 35 or storage tank 34, and in the latter, debris and water passing through the main suction hose 30 would pass through the suction pump 36 prior to entering the storage tank 34 or debris collection tank 35.

Referring still to Fig. 1, there is also shown a high-pressure water pump assembly 38 including a pump 40 in fluid communication with the nozzle 174 (see Fig. 2). The pump 40 has a suitable intake 42 for receiving water to be used in the hydrodemolition process and a motor 44 for driving the pump 40. The pump 40 preferably receives supply water from the water storage tank 34, but alternatively could be supplied from a municipal water supply or other source capable of supplying a quantity of water sufficient for the hydrodemolition process. Water is supplied from the water storage tank 34 to the pump intake 42 via conduit 37 and from the pump 40 to the hydrodemolition cart 10 via a high-pressure water delivery conduit 46. One end of the high-pressure water delivery conduit 46 is attached to the outlet 48 of the pump and the other end of the high-pressure conduit 46 is attached to the hydrodemolition cart 10.

The high-pressure water pump assembly 38 must be capable of delivering water at a volume and pressure sufficient to demolish the target 12, but yet not destroy concrete that may be surrounding the target 12. One benefit from the present apparatus when the target 12 is a railroad tie butt embedded in concrete is that the concrete surrounding the tie butt 12 will not be destroyed, but weak portions of the concrete will in most instances be removed with the tie butt 12, thereby revealing substandard concrete portions and providing an opportunity to repair any substandard concrete surrounding the tie butt 12. The high-pressure water pump assembly 38 is preferably of the type sold by NLB Corporation as model number 20253E, which is capable of providing water at pressures up to 20,000 pounds per square inch at a flow rate of 22J gallons per minute. Preferably water is supplied to the nozzle at 10,000 pounds per square inch at a flow rate of 15-18 gallons per minute. It will be understood by those skilled in the art reading this disclosure that other types of high- pressure pumps may be used without departing from the spirit of the invention, so long as those pumps are capable of delivering an adequate supply of water at pressures sufficient to achieve the objectives of the invention and that less or more pressure and/or flow rate could be used without departing from the spirit and scope of the invention.

A high-pressure air compressor 50 is connected via an air conduit 52 to a handle 21 wherein it is delivered to a hand-operated valve (not shown) for operating air motor 19 and high-pressure dump valve assembly 23. The structure and operation relating to the hand-operated valve, air motor 19, and high-pressure dump valve assembly are fully described in the above-referenced and incorporated Goerss patents. High-pressure air compressor 50 delivers compressed air to hydrodemolition cart 10 at between 60 and 90 pounds per square inch. It is contemplated that a hydraulic-drive motor (not shown) could be employed in place of the air motor 19 without departing from the spirit and scope of the invention. In such event, the fluid driving the hydraulic-drive motor would be either high-pressure water from the pump 40 or hydraulic fluid from a separate pump (not shown).

The operation of the first preferred embodiment is hereinafter described. In normal operation the suction pump and storage tank apparatus 32 would be transported to the work site, as would the high-pressure air compressor 50 and the high-pressure water pump assembly 38. Upon making the above-described connections between each of the high-pressure air compressor 50, high-pressure water pump assembly 38, and suction pump and storage tank apparatus 32 and the hydrodemolition cart 10, and starting the air compressor 50 and suction pump 36, the hydrodemolition cart 10 is positioned by the operator 11 over a railroad tie butt 12. The enclosure or housing 20 is positioned over the target 12 such that the nozzle is directed toward the target 12.

As described in more fully described in the Goerss patents incorporated herein, to initiate the hydrodemolition process, the operator 11 actuates the hand- operated air valve (not shown) which directs a quantity of water into the enclosure or housing 20, thus impinging water onto the target 12 with sufficient force to degrade the target 12. Specifically, actuation of the hand-operated valve provides motive force to the air motor 19 and the high-pressure dump valve assembly 23. Operation of the air motor 19 causes the rotating seal assembly (not shown) and nozzle(s) (not shown) to rotate at a controlled speed about a vertical axis of the hydrodemolition cart 10. Actuation of the high-pressure dump valve assembly 23 causes high-pressure water from the pump 40 to be directed to the rotating seal assembly and nozzle(s). As high- pressure water exits the nozzle(s), the hydrodemolition cart 10 is slowly reciprocated back and forth over railroad tie butt 12. The water demolishes the target 12 while leaving the concrete bed 14 substantially unharmed.

Simultaneously with the process of impinging water onto the target 12, at least a portion of the wood debris and water waste from the hydrodemolition process is suctionably removed from within the interior cavity 21, i.e., from within the enclosure or housing 20, by a suction force created by the suction pump 36. The wood debris and waste water are carried via the suction ports 16, 18, suction hoses 24, 26, manifold 28, and main suction hose 30 and deposited into the debris collection tank 35 where at least a portion of the target 12 and a portion of the water taken from the interior cavity 21, i.e., from within the enclosure or wall 27, are separated from one another. Portions of the target 12 are preferably stored separately from the water, the water being passed along to the storage tank 34 where it is reused or recycled by being supplied to the pump 40 via conduit 37 for reimpingement onto the target 12. If reuse of the water is not desired, when the storage tank 34 is filled to capacity, the suction pump and storage tank apparatus 32 is taken to a suitable site to discard the waste water and/or target debris, whereupon the suction pump and storage tank apparatus 32 is returned to the work site for subsequent fillings of the storage tank 34.

Referring now to Figs. 2-4, there is shown a hydrodemolition cart 10 in accordance with a second embodiment of the hydrodemolition apparatus of the present invention. The second preferred embodiment of the hydrodemolition apparatus has the same features as the first embodiment, with the exception of the particular features relating to the hydrodemolition cart 10. Accordingly, descriptions of the overlapping features of the first and second preferred embodiments of the hydrodemolition apparatus are not repeated herein. Instead, identical elements have been given identical element numerals and only the differences between the hydrodemolition carts 10 of the first and second embodiments are described below with prime numerals being used for the new features of like elements.

As best shown in Figs. 2 and 3, the housing 20' of the second preferred embodiment is a parallelapiped having an open bottom 121 and walls 27' defining an interior cavity 21 '. The housing 20' has a first suction port 16' extending through a wall 27' of the housing 20' and in fluid communication with the interior cavity 21 '. A standpipe 122 is connected at one end, preferably by welding, to the wall 27' and has a flange 124 at its opposite end. Alternatively, the suction standpipe 122 could be attached to the housing 20' by use of a flange (not shown) on the standpipe 122 which would be fastened to the wall 27'. The flange 124 is connected to the main suction hose 30. It is contemplated that the main suction hose 30 could be connected directly to the housing 20', thus omitting the suction standpipe 122 altogether. A vacuum relief valve 125 is connected to the suction standpipe 122 and is in fluid communication with the interior cavity 21 ' such that the partial vacuum within the interior cavity 21 ' can be modulated or released. A perforated shield 127 is attached to the vacuum relief valve 125 to prevent foreign objects from entering the vacuum relief valve 125 and for safety of the operator. Still referring to Fig. 2, there is shown a vertical movement mechanism 112 as described herein. Attached to the lower portions of the wall 27' on opposing ends of the housing 20' are first, second, third, and fourth lower frame members 126, 128, 130, 132. The lower frame members 126, 128, 130, 132 are preferably made from rigid metal structural members such as square stock, channel stock, or angle stock. Each lower frame member 126, 128, 130, 132 has at its outboard end a hole 134 therethrough. As best shown in Fig. 3, first and second rods 136, 138 pass between the first and second lower frame members 126, 128 and between the third and fourth lower frame members 130, 132, respectively. Extending upwardly from the first and second rods and substantially perpendicularly to the lower frame members 126, 128, 130, 132 are first and second linear actuators 140, 142. The first and second linear actuators 140, 142 are substantially parallel to one another and preferably are hand-operated screw jacks. Those of ordinary skill in the art will recognize that alternate types of linear actuators could be employed without departing from the spirit and scope of the invention. Such alternate linear actuators include hydraulic actuators or scissor jacks. The first and second linear actuators 140, 142 and lower frame members 126, 128, 130, 132 are connected via first and second rods 136, 138 to provide a pivotable interconnection between the former and the latter, the purpose of which will become evident from further discussion below. As only a small range of motion is required in the pivotable attachment of the first and second linear actuators 140, 142 to the lower frame members 126, 128, 130, 132, alternative structures for attaching the former to the latter may be used, such as rubber mounts or spring loaded mounts (not shown).

The first and second linear actuators 140, 142 are pivotably attached to a first lateral member 148 and a second lateral member (not shown) at the respective outboard ends of the first and second lateral members 148. (For purposes of brevity in the drawings, the second lateral member is not shown, but in Fig. 2 is located directly behind the first lateral member 148 and is preferably a mirror image of the first lateral member 148). The first and second linear actuators 140, 142 are connected to the first and second lateral members 148 by first and second pivot connections 144 and 146. The first and second lateral members 148 are preferably rigid metal structural members such as angle or channel stock.

A nozzle drive and supply assembly 152, which receives high pressure water from the pump 40 and directs it at the target or tie butt 12, is movably mounted on the first and second lateral members 148 for lateral movement in the longitudinal direction of the first and second lateral members 148. The nozzle drive and supply assembly 152 is movably mounted on the first and second lateral members 148 by conventional means well known to those of ordinary skill in the art. Preferably the first and second lateral members 148 are channel stock, with the open faces opposing one another. The nozzle drive and supply assembly 152 is mounted on the first and second lateral members 148 via pins or wheels (neither shown) fixedly or rotatably mounted on the nozzle drive and supply assembly 152 and positioned within the open channel of the first and second lateral members 148 such that the nozzle drive and supply assembly 152 is readily laterally movable, as will be discussed below. Ultimately, then, the vertical movement mechanism 112 is operatively connected to the nozzles 174 of the nozzle drive and supply assembly 152 and is configured to move the nozzles 174 substantially vertically with respect to the target 12, i.e., substantially toward and away from surface 12a of the target 12, by extending or retracting the first and second linear actuators 140, 142.

Those of ordinary skill in the art will now recognize that by providing pivoting joints at the first rod 136, second rod 138, and first and second pivot connections 144, 146, the linear actuators 140, 142 may be longitudinally actuated independently so as to provide the capability to vary the angle of impingement of the water on the target 12 by varying the angle of the nozzle drive and supply assembly 152 with respect to an axis A perpendicular to the impingement surface 12a of the target 12. It is contemplated that the pivoting joints at the first and second rods 136, 138 and the first and second pivot connections 144, 146, need not be pivotable as the ability to vary the angle of impingement could be accomplished by integrating a variable angle mounting mechanism (not shown) into the apparatus used to mount the nozzle drive and supply assembly 152 to the lateral members 148. Alternatively, it is also contemplated that variable-angle-impingement capability could be eliminated from the cart 10 without departing from the spirit and scope of the present invention, thereby obviating the need for any pivoting at the joints.

The nozzle drive and supply assembly 152 is moved laterally by a lateral movement mechanism 114 consisting of the first and second lateral members 148 and a linear actuator 149 fixedly attached to either of the first or second lateral member 148 and to the nozzle drive and supply assembly 152. In other words, the linear actuator is operatively attached to the nozzles 174 and to a lateral member 148 to provide for lateral travel of the nozzle drive and supply assembly 152 with respect to the longitudinal axes of the lateral members 148. The liner actuator 149 is preferably a two-way hydraulic actuator which receives hydraulic pressure from a pair of hydraulic lines 151, 153. Hydraulic fluid is supplied to the hydraulic lines 151, 153 by any of a number of mechanisms which are well known to those of ordinary skill in the art, such mechanisms including a hand-operated hydraulic pump or a motorized hydraulic pump (not shown). By applying hydraulic pressure to one or the other of the hydraulic lines 151, 153, the nozzle drive and supply assembly 152 is moved laterally in the longitudinal direction of the lateral members 148. It is contemplated that alternate forms of linear actuators may be used such as cable operated actuators, direct motor drive applied via rack and pinion, and a one-way hydraulic cylinder combined with a return spring (not shown).

The nozzle drive and supply assembly 152 components include a swivel connector 154, a first rotatable tube 164, a reduction gearbox 166, a drive motor 167, a second rotatable tube 168, nozzle conduits 172, and nozzles 174. The purpose of the nozzle drive and supply assembly 152 is to provide fluid communication between the pump 40, and more particularly, the high-pressure water delivery conduit 46, and the nozzles 174, while permitting rotation of the nozzles 174 about an axis A which is substantially perpendicular to the impingement surface 12a of the target 12.

The swivel connector 154 consists of a stationary portion 156 and a rotating portion 158. The stationary portion 156 is connected to the high-pressure water delivery conduit 46 and receives high pressure water therefrom. The rotating portion 158 is rotatably connected to the stationary portion 156 and provides a mechanism by which water from a non-rotating source (the high-pressure water delivery conduit 46) passes to a rotating component (the rotating portion 158). The stationary portion 156 is prevented from rotating by a rod 162 which is attached to any stationary component of the hydrodemolition cart 10, and preferably slidably attached to one of the first and second lateral members 148. A pin 160 is fixedly connected to the stationary member 156 and to the rod 162, thereby preventing the stationary portion 156 from rotating. It will be obvious to one of ordinary skill in the art that the stationary portion 156 can be prevented from rotating by any type of bracket assembly which attaches to a nonrotating component of the hydraulic cart 10 and either to the stationary portion 156 or to the high-pressure water delivery conduit 46.

A first tube 164 is connected at one end to the rotating portion 158 and at its other end to the reduction gearbox 166 and passes high-pressure water from the swivel connector 154 to the reduction gearbox 166. The reduction gearbox 166 receives high-pressure water from the first rotatable tube 164 and passes it internally through a tube (not shown) to a second rotatable tube 168 which is in fluid communication with the first rotating tube 164. It is contemplated that a single tube (not shown) passing from the rotating portion 158 through the reduction gearbox 166 may be used as an alternative to the first and second rotatable tubes 164, 168.

The reduction gearbox 166 imparts rotational motion to the first and second rotatable tubes 164, 168, thereby rotating the nozzles 174 about the longitudinal axis of the nozzle drive and supply apparatus 152. The reduction gearbox 166 is driven by a drive motor 167 attached to the reduction gearbox 166 (the reduction gearbox 166 and drive motor 167 are collectively referred to as the rotary drive apparatus). The drive motor 167 is preferably air driven, receiving its air supply from the air conduit 52, but alternatively, could be hydraulically driven receiving drive fluid from either the pump 40 or from another source.

As stated above, the second tube 168 is connected to the reduction gearbox 166 at one end and to a distributor head 170 at its other end. The second rotatable tube 168 is preferably elongated so as to provide a means of passing high- pressure water into the interior cavity 21 ' of the housing 20' through the narrowest opening feasible, as will be discussed more fully below. The distributor head 170 acts to distribute high-pressure water from the second rotatable tube 168 to the first and second nozzle conduits 172, 173. The first and second nozzle conduits 172, 173 are connected at one end to the distributor head 170 and at the opposite end to the nozzles 174. It is contemplated that in alternative embodiments any number of nozzles 174 (and hence nozzle conduits 172, 173) may be used to achieve the desired result of degrading a target 12 without departing from the spirit and scope of the present invention. A commercial embodiment of the nozzle drive and supply assembly 152 is available from Waterjet Engineering located in Durango, Colorado as model numbers G-GBA-A12-K and SA 103 KP8 45°.

Given the difficulty of determining the lateral and vertical placement of the nozzles 174 within the housing 20', the hydrodemolition apparatus is provided with vertical scales 176 and a lateral scale 178 to assist in positioning the nozzles 174 with respect to the target 12. The vertical scales 176, which are a part of the vertical movement mechanism, are preferably connected to the housing 20' and are gauged to indicate the height of the nozzles 174 from the bottom of the housing 20'. While it is preferred that there be two vertical scales 176, one positioned toward each outboard end of the lateral members 148, it will be recognized that there need be only a single vertical scale 176 and the vertical scale(s) 176 need not be mounted on the housing 20', but may be mounted to the first and/or second linear actuators 140, 142 or to any other portion of the hydrodemolition apparatus that allows measurement of the distance from the bottom of the housing 20' to the nozzles 174. A lateral scale 178 which is part of the lateral movement mechanism 114 is preferably located on the first or second lateral member 148 such that when the nozzle drive and supply assembly 152 is moved laterally, its position with respect to the center of the housing 20' and with respect to the target 12 can be determined. Again, it will be recognized that the lateral scale 178 need only be attached to a stationary point on the hydrodemolition apparatus such that the lateral position of the nozzle drive and supply assembly 152 may be perceived. Referring now to Fig. 3, there is shown the housing 20' of the second preferred embodiment wherein the wall 27' has an elongate channel 180 therethrough for permitting lateral movement of the nozzles 174 with respect to the target 12. A movable baffle 182 is slidably positioned to substantially cover the elongate channel 180 to prevent the water and debris generated by the hydrodemolition process from escaping the housing 20'. The movable baffle 182 is preferably a section of spring steel which is coiled at each end to provide reserve material 183 so that a hole 184 in the movable baffle 182 is movable laterally with the nozzle drive and supply assembly 152. The movable baffle 182 is guided over the channel by guides 186, which are simply elongate sheets of metal attached to the wall 27, providing slots (not shown) through which the movable baffle 182 slides.

To provide for feeding the reserve material 183 when needed to accommodate lateral movement of the nozzle drive and supply assembly 152, the coiled ends of the movable baffle 182 are rotatably fixed to the wall 27' at opposite ends of the housing 20'. It will now be recognized that the second rotatable tube 168 of the nozzle drive and supply assembly 152 passes through the hole 184 to carry high pressure water into the interior cavity 21 '. Accordingly, as discussed above, it is preferred that the second rotatable tube 168 be elongated such that vertical movement of the nozzle drive and supply assembly 152 may be accomplished. It is contemplated that alternative types of baffles may be used without departing from the spirit and scope of the invention. Such alternate baffles include single or multiple plates (not shown).

Referring now to Fig. 4, there is shown the hydrodemolition apparatus of the second preferred embodiment connected to a movable vehicle 200 for transport and positioning of the cart 10. The hydrodemolition apparatus is shown in greatly simplified form, but reflects that the movable vehicle 200 preferably attaches to the housing 20', either directly or via structural members attached to the housing 20'. The movable vehicle 200 includes a base 201 and rolling members 202 attached to the base 201. The rolling members 202 preferably are ordinary pneumatic tires, but alternatively could be rail wheels (not shown). The movable vehicle 200 includes a telescoping boom 204 which is capable of extending along the longitudinal axis of the boom 204 and which is capable of being directed upwardly, pivoting about the pivot axis 206, as a result of extension of a hydraulic cylinder 208. Those of ordinary skill in the art will recognize that the movable vehicle 200 can be fitted to carry any of the components described above, beyond just the cart 10. It is also contemplated that the movable vehicle 200 could be in the form of the suction pump and storage apparatus 32 as shown in Fig. 1, thus combining the boom 204 of the movable vehicle 200 with the multi-component-carrying capability of the suction pump and storage apparatus 32.

As can be perceived from the above discussion, the method of using the hydrodemolition apparatus of the second preferred embodiment to degrade a target 12 includes the steps of positioning the cart 10, and specifically an enclosure, i.e., the housing 20', over the target 12. It is contemplated that the cart 10 be carried to the work site and placed over the target 12 by a movable vehicle 200, but the cart 10 is also configured to be manually rolled using wheels 13.

Prior to maneuvering the cart 10 over the target 12, the nozzle drive and supply assembly would need to be elevated to a point whereby the nozzles 174 would not impact on the target 12. Accordingly, the vertical movement mechanism 112 would be actuated such that the nozzle drive and supply assembly 152 is at or near its uppermost position, or at least at a point whereby it would not physically impact on the target 12. Such actuation would be accomplished by extending the first and second linear actuators 140, 142, which would elevate the lateral members 148, thereby elevating the nozzle drive and supply assembly 152. Preferably the operator would know how far the target 12 extends above or below the ground level, and using the vertical scales 176, could preset the vertical position of the nozzle drive and supply assembly 152 prior to positioning the cart 10 over the target 12. It is preferred that the nozzles 174 be positioned approximately one-half inch from the impingement surface 12a of the target 12.

It is also preferred that the lateral position of the target 12 within the housing 20' be known and that the position of the target 12 with respect to the lateral scale 178 be known. In this way, by actuating the lateral movement mechanism 114 through the known position of the target 12 as indicated by the lateral scale 178, the nozzle drive and supply assembly 152 could be passed over the entire target 12 without the need to lift the cart 10 to observe the position of the nozzle drive and supply assembly 152 with respect to the target 12.

The connection of the suction apparatus and water supply apparatus to be used with the second preferred embodiment is as described above with respect to the first preferred embodiment, and therefore for purposes of brevity will not be repeated here.

Once the cart 10 is positioned over the target 12, and the suction pump 36 has been started, a quantity of water is directed into the enclosure and impinged onto the target 12 with sufficient force to degrade the target 12. As water is being impinged on the target 12, the lateral movement mechanism 114 is actuated by applying hydraulic pressure to one of the hydraulic lines 151, 153 such that the nozzle drive and supply assembly 152 is moved laterally, preferably substantially along a longitudinal axis of the target 12. The water is impinged on the target 12 for a period of time sufficient to cause the target 12 to become at least partially degraded such that removal of the target 12 is readily accomplished. In the case where the target 12 is a railroad tie butt, it is contemplated that the nozzle drive and supply assembly 152 will have to be passed laterally over the target 12 more than one time. For example, a standard tie butt is made from creosote-soaked oak and measures approximately eight inches wide by seven inches deep by twenty-four inches long. In such a case the hydrodemolition apparatus will degrade approximately two to three inches of depth of the tie butt in a single pass, depending of course on the relative strength of the wood. Accordingly, in this scenario, at least three passes would be required to degrade the tie butt sufficiently to facilitate removal.

As described above with respect to the first preferred embodiment, at least a portion of the water and a portion of the degraded target is suctioned from the enclosure or housing 20'. Preferably the portions of water and degraded target retrieved are separated from one another and the portions of degraded target are stored. If the water is to be reused or recycled in the hydrodemolition process, the portion of water retrieved is stored preferably separately from the portions of degraded target retrieved such that the water can be recycled by being reimpinged on the target 12, thereby greatly decreasing water consumption and waste.

Once the target 12 is sufficiently degraded to be removed without undue difficulty (in the case of a tie butt the degree of degradation desired is such as to make the tie butt resemble a piece of rotted wood) the water supply and suction pump 36 are preferably shut down and any residual vacuum within the housing 20' is relieved by opening the vacuum relief valve 125. The cart 10 is then positioned over the next target 12 and the process begins anew.

It will be appreciated by those skilled in the art that the present invention may be used in other applications where a target is to be degraded, and particularly where a target is in a fixed setting, such as decorative or structural wood set into concrete or metal.

It will also be appreciated by those skilled in the art that changes could be made to the embodiment described above without departing from the broad inventive concept thereof. It is understood, therefore, that this invention is not limited to the particular embodiment disclosed, but is intended to cover all modifications which are within the spirit and scope of the invention.

Claims

What is claimed is:

1. A hydrodemolition apparatus for using water to demolish a target, the hydrodemolition apparatus comprising: a housing having a wall defining an interior cavity; a nozzle in the interior cavity, the nozzle for communication with a source of water and for directing the water toward the target; and a suction pump in fluid communication with the interior cavity for creating a partial vacuum within the interior cavity for removing at least a portion of the water from the interior cavity of the housing.

2. The hydrodemolition apparatus of claim 1 , further comprising: a water storage tank; a debris collection tank in fluid communication with the water storage tank, the water storage tank and debris collection tank being in fluid communication with the suction pump wherein at least some portions of the target retrieved from the interior cavity are retained in the debris collection tank and at least some of the water is returned to the storage tank.

3. The hydrodemolition apparatus of claim 2, further comprising a water pump in fluid communication with the nozzle.

4. The hydrodemolition apparatus of claim 1, further comprising a suction port extending through the wall and being in fluid communication with the interior cavity, the suction pump being in fluid communication with the suction port.

5. The hydrodemolition apparatus of claim 1, further comprising a vacuum relief valve in fluid communication with the interior cavity.

6. The hydrodemolition apparatus of claim 1, further comprising a movable vehicle for transporting the hydrodemolition apparatus.

7. The hydrodemolition apparatus of claim 1, further comprising a rotatable swivel coupling in fluid communication with the nozzle for connection to the source of water, the nozzle being rotatable about an axis substantially perpendicular to an impingement surface of the target.

8. The hydrodemolition apparatus of claim 7, further comprising: a rotatable tube in fluid commumcation with the nozzle and the rotatable swivel coupling; and a rotary drive apparatus in operative commumcation with the rotatable tube.

9. The hydrodemolition apparatus of claim 8, wherein the rotary drive apparatus includes a reduction gearbox and a drive motor in operative communication with the reduction gearbox.

10. The hydrodemolition apparatus of claim 9, wherein the drive motor is an air motor.

11. The hydrodemolition apparatus of claim 1 , further comprising a lateral movement mechanism operatively attached to the nozzle and configured to move the nozzle substantially laterally with respect to the target.

12. The hydrodemolition apparatus of claim 11 , wherein the lateral movement mechanism further includes a lateral member to which the nozzle is operatively attached, and a linear actuator attached operatively attached to the lateral member.

13. The hydrodemolition apparatus of claim 12, wherein the lateral movement mechanism further includes a scale for indicating a lateral position of the nozzle.

14. The hydrodemolition apparatus of claim 1 , wherein the wall of the housmg has an elongate channel therethrough for permitting lateral movement of the nozzle with respect to the target.

15. The hydrodemolition apparatus of claim 14, further comprising a movable baffle positioned on the channel.

16. The hydrodemolition apparatus of claim 1, further comprising a vertical movement mechanism operatively attached to the nozzle and configured to move the nozzle substantially vertically with respect to the target.

17. The hydrodemolition apparatus of claim 16, wherein the vertical movement mechanism includes a scale for indicating a vertical position of the nozzle.

18. The hydrodemolition apparatus of claim 16, further comprising a lateral movement mechanism operatively attached to the nozzle and configured to move the nozzle substantially laterally with respect to the target.

19. The hydrodemolition apparatus of claim 18, wherein the vertical movement mechanism comprises: a lower lateral frame member attached to the wall, the lower lateral frame member having a first outboard end and a second, opposing outboard end; a first linear actuator pivotably attached to the first outboard end of the lower lateral frame member and extending substantially perpendicularly therefrom; a second linear actuator pivotably attached to the second outboard end of the lower lateral frame member and extending substantially peφendicularly therefrom and substantially parallel to the second linear actuator; a lateral member having a first and a second outboard end, the lateral member being pivotably attached at its first outboard end to the first linear actuator and at its second outboard end being pivotably attached to the second linear actuator such that the first and second outboard ends of the lateral member are independently vertically movable with actuation of the respective linear actuator; and the lateral movement mechanism including a third linear actuator operatively attached to the nozzle and fixedly attached to the lateral member for lateral movement of the nozzle within the internal cavity.

20. A method of degrading a target, the method comprising the steps of: positioning an enclosure over the target; directing a quantity of water into the enclosure; impinging the water onto the target with sufficient force to degrade the target; and suctioning at least a portion of the water and a portion of the degraded target from the enclosure.

21. The method of claim 20, further comprising the steps of: recycling the portion of the water suctioned from the enclosure for being reimpinged onto the target.

22. The method of claim 21, wherein the recycling step includes the steps of: separating the portion of the target suctioned from the enclosure and the portion of water suctioned from the enclosure from one another; storing the portion of the target suctioned from the enclosure separately from the portion of water suctioned from the enclosure; and reimpinging the portion of water suctioned from the enclosure onto the target.

23. The method of claim 20, further comprising the steps of: separating the portion of the target suctioned from the enclosure and the portion of water suctioned from the enclosure from one another; storing the portion of the target suctioned from the enclosure; and discarding the portion of the water suctioned from the enclosure.