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Publication numberUS2382745 A
Publication typeGrant
Publication date14 Aug 1945
Filing date31 Oct 1942
Priority date31 Oct 1942
Publication numberUS 2382745 A, US 2382745A, US-A-2382745, US2382745 A, US2382745A
InventorsPowers Marvin A
Original AssigneeDouglas Aircraft Co Inc
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Bending machine
US 2382745 A
Abstract  available in
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Claims  available in
Description  (OCR text may contain errors)

Aug. 14, 1945. A. POWERS BENDING MACHINE Filed 001;. 31, 1942 4 Sheets-Shee t l- IN V EN TOR. M/LQV/A A. POM 25 Arrow 5y 1945 M. A. POWERS BENDING MACHINE 4 Sheets-Sheet 2 Filed Oct. 31

INVENTOR; MAQW/VAPOWEQS 7 BY ATTOE/YEY Aug 14, 1945.

4 Sheets-Sheet 3 A TTQQ/VE/ Aug. 14, 1945. M, POWERS 2,3825745 BENDING- MACHINE Filed Oct. 31, 1942 4 Sheets-Sheet 4 llIIillL-U I N V EN TOR.

MA EV/ly A. POWEQS Retained Aug. 34, 1945 STATES PATENT OFFICE i BENDING MACHINE Marvin A. Powers, Oklahoma City, Okla, assignor to Douglas Aircraft Company, Inc, Santa Monica, (Jalii.

Application October 31, 1942, Serial No. 464,116

29 Claims.

by visual observation of a scale. The angle be-' tween the planes of successive bends is obtained by manually rotating the tube preparatory to making a later bend of a series of bends until the first formed bend of the series makes the desired It is still another object of the invention to provide a tube bender which will automatically space one .or more bends along a tube according to a predetermined and automatically measured pattern without any measuring act by the operator.

It is also an object of the invention to provide a tube bender which will, without any measuring act by the operator, form in a tube a succession 01' two or more bends of predetermined and automatically *measured angular relation to each other.

angle with the plane of the bender as measured .not accurate. When the job requirement is a plurality of tubes of identical bend pattern, the distance and arcuate spacing between correspondsponding'bends are subject to variation preventing accurate standardization of bend pattern for the tubes of the lot. Secondly, the operation of the machine is slow, as a necessary result of the requirement that visual observations be made by the operator to fix each one of the measurements affecting each bend. In the third place, a relatively skilled operator is required for its operation.

This invention is designed to obviate these disadvantages. It also is designed to provide improved means for holding the tube for rotational and lengthwise movement and for feeding it step by step to the bending device.

It is an object of the invention to provide a tube bending machine constructed to hold the tube in true alignment with respect to the direction of approach of the radius block.

It is another object of the invention to provide a tube bending machine having a means for holding the trailing end of the tube as it is fed to the bending device without deformation of the tube and in a manner to permit the making of a bend closely proximate the trailing end of the tube, thereby eliminating or minimizing waste of stock beyond the last bend.

Another object of the invention is to provide a tube bender which will, without any measuring act of the operator, produce a plurality of tube lengths automatically measured and standardized as to the spacing between bends, the angles of the planes and the arcuate lengths of corresponding bends.

' ing adjacent bends and the degree of arcs of corre- Another object of the invention is the provision of a tube bender which will fprm in a tube a succession of two or more bends of predetermined and automatically measured arcuate lengths without any measuring act by the operator.

The invention also has as its object the provision of a tube bender which will cooperatively and sequentially correlate for each successive bend the several automatic means for determining the spacin plane angles and arcuate lengths of a series of bends.

It is also an object of the invention to provide a tube bender in which the indexing devices are automatically reset for repeating a bend pattern on a straight piece of tubing by the normal operative acts performed in completing the bending processes upon a preceding piece of tubing and initiating the bending processes upon arnew piece of tubing.

It is also an object of the invention to provide a tube bender which will hold the tubing in position for feeding to the bending block by a countar-balanced device facilitating advancing of the tube between the'bending operations and removing it from the machine.

Further objects and advantages of this invention will be brought out in the following description taken in connection with the accompanying drawings and appended claims. which are for illustrative purposes only:

Figure 1 is a perspective view of the tube bending machine embodying the invention.

Figure 2 is a vertical sectional view of the carriage and bedplate of the machine, taken as indicated by a line 22 on Figure 1.

Figure 3 is a schematic view in perspective showing the manner in which a carriage is moved at the beginning of the process of bending apiece of tube.

Figure 4 is a partial schematic view of the carriage showing the manner in which the plane of a bend is determined.

Figure 5 is a partial schematic view of the bending head showing how the degree of the arc of a bend is determined.

Figure 6 is a fragmentary schematic view of the escapement mechanism by which the means of spacing the bends and the means for determining the angular position of the planes of the bends In th drawings,

' the Web l1.

are correlated, and of parts associated with the escapement mechanism.

Figure '7 is a vertical sectional view showing the plane angle indexing drum and associated parts.

Figure 8 is a central longitudinal sectional view of the chuck for holding the tube and of the parts associated therewith.

Figure 9 is a perspective view of the means for indexing the angles of the bends of a piece of tub-- generally designated by the numeral I3, the latter assembly being mounted on a bedp ate M which constitutes an extension of the bedplate Ill.

The principal frame element of the tube holder assembly I2 is a longitudinal member 15, of the cross-sectional shape of an inverted T, having a vertical plate l8 and a horizontal web H, the web IT being transversely slidable upon the upper face of the bedplate l0 and the vertical plate l8 serving as a rail for a carriage 32 upon which one end of the piece of tube to be bent is mounted. The frame member l5 has a transverse sliding engagement at its ends with cross rails ii on the bedplate l0.

t the head of the member I5 is secured an end plate [9 and at the tail end thereof is secured an upright support 26. A shaft 20 is rotatably mounted in the end plate I!) and upright support 26 and is supported intermediate its ends by an arm 2! which extends laterally outwardly from The shaft 20 carries at each end a gear wheel 22 which engages teeth 24 upon the cross rails 16. The shaft 20 is manually rotated by a reversible rachet and operating handle 23 thereforfor the purpose of transversely shifting the tube holder assembly I2 to properly align the tubing with the tub bender assembly l3. The tube to be bent is telescopically carried by a mandrel rod 25 at the head end of which is a mandrel 21. The tail end of the mandrel rod 25 is mounted on the upright support 26. seated under compression between a nut 26 threaded upon the mandrel rod 25 and the upright support 26. A hand wheel 28 is threaded on the mandrel rod 25 beyond the upright support 26 and when rotated upon. the mandrel rod serves A coil spring 29 isto longitudinally adjust the position of the mandrel 21. A foot pedal 36 's connected by means of linkage to the tail end of the mandrel rod 25. The linkage rod 3| is shown connected to the foot pedal. The remainder (not shown) of this linkage extends from the rod 3! along and under bed plate Ill in a. manner known to th art, its final element bearing rearwardly upon a collar (not shown) fixed to the rod 25 just to the rear of the support 26 and hidden from view thereby in Figure 1. Depression of the footpedal 36 serves to pull the rod 25 rearwardly against the action of spring 29 and thereby withdraw the mandrel v2'! a small distance for the purpose of releasing the mandrel from the tubing at the completion of carries a lateral rail 34, the two sides of which are engaged by rollers 36 which are mounted on vertical axes on a bracket 35 extending outwardly from the carriage 32.

Two arms 39 which are hinged at their lower ends to the bracket 35 and a bracket 31 secured to the sides respectively of the carriage 32, extend upwardly and forwardly in arcuate fashion and support at their upper ends a circular plate 40. This plate is also supported upon the carriage 32 at its lower edge by a compression spring 42 suitably seated under compression between a bracket 49 on the plate 40 and the carriage 32.

The plate 40 is centrally apertured and has 'welded to it a cylindrical bearing 4! extending rearward from the aperture of the plate. Within a bearing sleeve 43 which lines the bearing 4! is rotatably mounted a hollow shaft 44 which has a threaded end extending beyond the bearing 4i toward the tail end of the machine and a cylindrical extension 69 which extends toward the head end of the machine beyond the plate 46. A drum 45 having a hub 46 is threadedly secured to the inner end of the hollow shaft 44 and is of a length to extend from the plate 46 toward the tail of the machine to a point substantially beyond the end of the hollow shaft 44. r

The forward end portion 69 of the hollow shaft .44 is split and provided with clamping ears 41 and a clamping bolt 48 by which it is secured in fixed position to a sleeve 5 lwhich is rotatably mounted upon a sleeve 59, this sleeve in turn slidably and rotatably engaging the mandrel rod 25. A housing 52 is welded to the forward end of the sleeve 5! and is welded at its forward wall to a sleeve 53 which slidably engages the mandrel rod 25 and extends toward the tube bending assembly l3. The outer'end of the sleeve 53 has a conical mandrel 54 which constitutes a stationary jaw of a chuck for holding the tailward end of a piece of tubing. The movable jaw of the chuck is a semi-cylindrical member 55 which is pivotally connected at 51 to a lever 56. The inner, tube engaging surface of the jaw 55 and the surface of the mandrel cone 54 are smooth surfaced, effective engagement of the two jaws with the tubing being accomplished by the clamping action of the lever 56. The lever 56 is medianly fulcrumed at 66, close to the pivot 51, to ears 6! on sleeve 53, and is pivotally connected at its rear end at 66 to a lifter rod59 which is vertically slidably mounted in the housing 52 and is held in its upper position by a compression spring 6! seated between the lower end of the lifter rod 59 and the bottom wall of the housing 52. The spring Si by reason of the mechanical advantage of the lever connections applies a powerful gripping action to a tubing inserted between the movable jaw 55 and the stationary conical mandrel 54.

The rear end of the lever 56 may be depressed manually by pressure upon a grip 68, allowing a catch lug 65 on a collar-63 secured to the sleeve the action of a spring 84 seated under compression between the forward wall of the housing 52 and the collar 88. The sleeve 58 projects. slightly beyond the tailward end of the sleeve i and the inner end plane of the drum 85. The sleeve 5! and housing 52 secured thereto are clamped to the shaft 44 as above described, which is in turn fixedly related to the drum 85, and while rotatable with respect to the plate 88 is longitudinally fixed with respect thereto by the annular flange I81 on the shaft 88 which bears against one end of the bearing sleeve 83 secured to the plate 88 and by the drum hub 46 bearing against the other end of the bearing sleeve 88.

When a tube is loosely inserted between the separated chuck jaws 58 and 55 and the carriage is pushed tailward the projecting end of sleeve 58 contacts a stop in projecting headward from a movable stop carriage 76 which may be selectively clamped at any desired position on the frame member I5. The sleeve 58 moves forward relative to sleeve 5i and the housing 52, compressing the spring 84 and releasing the lifter rod as from the catch 65. The spring 8| causes the jaws 54 and 55 to firmly clamp the end of the tube ready for the bending operation. The tailward end of the carriage 82 strikes the stop carriage I8 immediately after the release of the lifter rod 59 setting the carriage in proper initial position for making the first bend in the tube.

A series of adjustably positioned stops 92 on a stop rail 83 secured to the side of the upright plate I8 of the frame member I5, determine the position of the several bends along the tube. A pawl 85, Figure 6, vertically slidable in the bracket block '48 and yieldably held downward with respect to the block by a compression spring 8| has a forward and upwardy beveled face 88 at its lower end to ride over matingly beveled upper end faces on the stops 82. carriage are pulled forward from the above mentioned initial position until the pawl rides over and passes the first of the stops 82. The operator then back-tracks the tube and carriage until the rear vertical face of the pawl strikes the front vertical face of the stop 82, in which position the machine is ready for making the second bend upon the tube. In a similar manner the carriage and tube are successively set for making the remaining bends. A scale 85 on the face of the stop rail 83 affords the measuring means for spacing the stops 92.

The angular spacings of the planes of the bends in a tube are determined by a plurality of slip rings II rotatively slidable upon the drum 85. Each of these rings is made in two semicircular halves, joined at one side of the rings by ears TI and I8 and a securing bolt, and at the other side by a quick clamping assembly comprising an arcuate extension 13 welded to one ring half and bifurcated at its free end, a lug I8 on the other ring half disposed between the forks of the extension I3, and a lever 15 pivoted to the forks of the extension I3 and having an eccentrical cam face I9 which engages the lug I4 to draw the ring ends together when the lever is pushed inwardly.

The connection between the ears TI and 18 is employed to take up wear as it develops; the

slip ring is rotated, moves across the path of longitudinal translative movement or a stop lug 88 on a slide block 88. The slide block 88 is reciprocati'vely and horizontally movable in a guideway 8| formed in the upper face of the bracket 48. A tension spring 82 (Figure 12) secured at its ends to the tailward end of the bracket 48 and the headward end of the block 38 yieldably pulls the block tailward of the carriage assembly and of the drum 45 and slip rings II thereon.

The pawl 85 which is vertically slidably movable in the bracket 48 and the slide block 88 which is horizontally slidably movable in the same bracket 49 have an esoapement movement relationship provided by the two vertically and horizontally displaced horizontal pins 88 and 81 at the upper The tube and quick clamping connection at the other side of v the slip rings is employed to set the ring for. each new bending layout.

The ear TI on each slip ring is provided with an outwardly extending lug I2 which, when the end of the centrall facing side of the pawl 85, by the outwardly extending horizontal escapement lugs 84 along the outer edge of the slide block 88, and by the tension spring 82. For each upward movement of the pawl as it rides over a stop 82 the upper pin 88 upwardly clears one of the stops 84 permitting tailward movement of the slide block 88 until the next stop 84 contacts the lower pin 81. Upon downward movement of the pawl 85 under action'of the spring 8|, the lower pin 81 dowwardly clears the stop 84 held against it and the slide block 88 moves tailward until this stop 84 contacts the upper pin 88. The

distance on centers between two lugs 84 is equal to the distance on centers of the slip rings II. Consequently one escapement movement of the slide block 88 moves the stop 83 from a point in the plane of rotation of one of the slip ring lugs 12 to a point in the plane of rotation of the next slip ring lug toward the tail end of the machine.

A limit stop 84onthe stop rail 88 (Figure 1) raises the pawl higher than do the stops 82 causing both pins 86 and 81 to clear upwardly the escapement lugs 84 permitting the tension spring 82 to retract the slide block 88 the full limit of its tailward travel on the bracket 48. A leaf spring I82 on a face of the bracket 48 forces a trigger latch 81 into a notch 88 on the side of the pawl 85 securing the pawl in its uppermost position allowing it to clear the stops 84 and 82 when the operator gives a retrograde movement to the carriage after completion of all the bends in a tube.

When the carriage at the end of this retrograde movement contacts the stop carriage I8 8. pin I25 at the rear end of the slide block 88 at the same moment strikes a depending stop arm I88 which moves the slide block forward in the bracket 49 until its front end strikes the plate 48. At this juncture the rear end of a groove I88 in a side face of the slide block 88 (Figure 12) depresses a pin I8I projecting into the groove from a side wall of the guideway 8i. Depression of this pin moves a pusher arm I88, integrally formed with the pin, to move a bell crank 88, pivotally mounted on the bracket 48, this bell crank lever in turn withdrawing the trigger latch 81 against the action of the leaf spring I82 from the notch 86 allowing the spring 8I to push the pawl to its lowermost position. In this position of the pawl, escapement pins 88 and 81 hold the slide block 88 against the action of the tension spring 82 and the lower end of the pawl is at a dial. A pointer I06 is fastened to the annular.

flange I01 of the hollow shaft 44, the hub of the pointer being centrally apertured to fit around the forward end of the bearing sleeve 46.

A scaled arm I04 (Figure 1) projects forwardly from the stop carriage 16 with its forward end,

bearing the zero reading of the scale, vertically aligned with the rear vertical face of the pawl 66 when the carriage 32 is in its initial position. The function of this scale will be presented later in describing the operation of the machine.

The tube bender assembly I3 is mounted at the head end of the machine. It consists essentially of a bending arm I having a handle I36 and secured to a vertical shaft I40 mounted in a bearing I49 carried by the bed plate extension I4, of a radius block I42 also secured to the shaft I40 and formed with the usual tube-receiving groove I43 and curvilinearly contoured at its ends and rectilinearly contoured at I44 between its ends, of a clamping block I45 for the radius block I42 equipped with a quick acting clamp I46, and of a stationary aligning arm I50 carrying at its inner end a sliding follower block I41 and equipped with a quick acting clamp I5I.

Enclosed within a protective shield I56, is the indexing mechanism by which the tube bending device I3 is set to make a succession of bends of predetermined arcuate lengths. A drum I52 is fixed to the shaft I40 and carries at its upper end a dial I53 bearing the indicia I54 of an angle degree scale with the 0 degree mark centered in a pointer window I55 when the bender arm I is in its initial position parallel to the aligning arm I50. A second window I48 may be provided for additional inspection of the dial I53.

The drum I52 carries a plurality of split slip rings- I51, each provided with clamping ears I58 at the ring gap for securing the ring in any desired angular position on the drum and with a lug I59. A bracket I65 having a vertical guideway slot I69 is secured in a depending position to the underside of the bed plate extension I4 adjacent the drum I52; A vertical rack bar I66 having teeth I61, a neck portion I64 disposed in the slot I69, and an inner retaining flange I10, slides on the bracket I65. The rack bar I66 has, at its upper end an inwardly projecting stop lug- I66, which projects into the path of revolution of one or another of the lugsI59 on the slip rings I51, depending upon the level of the stop lug I68 as determined by the position of the rack bar I66 in the guideway slot I69;

The lower end of the shaft I40 carries a block I to which is horizontally pivoted a radial arm I1I having radial movement about the pivot upwardly from a horizontal position which is determined by the recess I18 and pin I19. To the outer end of the radial arm IN is vertically pivoted at I13 a pawl I12 resiliently held inwardly to a shoulder stopped position, normal to the arm "I, by a compression spring I14. The outer end of the pawl, as the radius block I42 is returned to its initial position after making a bend, contacts the teeth I61 of the rack bar I66, a downwardly and outwardly beveled face I80 on the pawl engaging the nether face of one of the teeth to lift the rack bar a small vertical increment which is somewhat larger than is due to the action of the beveled face I by reason of the small upward swing of the arm I upon its engagement with a cam lug I11 (Figure 10) on the side of the bracket I66.

The teeth I61 have an escapement engagement with a latch I8I which is held yieldably against the teeth by a tension spring I82 and is moved outwardly upon each elevation of the rack bar by the pawl I12 by reason of the engagement of the beveled underface I86 of the pawl I8! (Figure ll) with the beveled upper face I84 of one of the teeth I61 and thereafter springs inwardly to latch againstthe under face I86 of the tooth I61. For each increment of upward movement of the rack bar I66, the stop I68 is moved upwardly the pitch distance of the teeth I61 which is equal to the width of one of the slip rings I61. moving the stop I68 from the path of revolution of one slip ring to the path of revolution of the slip ring next thereabove.

A vertically adjustable cam lug I66 on the rack bar I66 has a beveled face I81 which, when the lug I86 is at the level of the pawl I12, engages a beveled inner side face I66 (Figure 11) on the outer end of the pawl to swing the pawl outwardly against the action of the spring I14. As it is thus outwardly deflected the pawl moves to a position in which it vertically clears the teeth I61 and at the same time pushes the latch I8I to a position in which it also vertically clears the teethi61. A vertical pin I89 mounted on a horizontal plate I62 forming a part of the bracket I66, engages a recess I80 in the outer side face of the pawl I12 when the pawl is thus outwardly deflected and holds the pawl in its deflected position, allowing the rack bar to drop by gravity to its lowermost position with the connecting neck I64 at the upper end of the rack bar resting on the plate I62 at the bottom of the slot I68, the teeth I61 and cam lug I86 dropping through an aperture I6I in the plate I62.

A tape 200 having marked thereon ordinals beginning with I and to the number of the teeth on the rack bar, is secured at one end to the rack bar I66, passes over a pulley 204 and is secured at the other end to a light tension spring 208 which is in turn secured to the bracket I66. The ordinals on the tape as it moves over the pulley 204 are spaced and disposed to indicate through a window (not shown) in the extension plate I4 the ordinal of the bend about to be formed in a tube.

In describing the operation of the machine, the word leading will be used to mean toward the head end of the machine or to designate that end of the tube to be bent which is adjacent the first formed bend and the word ti-ailing" to mean toward the tail end of the machine or to designate the end of the tube adjacent the last formed bend.

A radius block I42 of the desired degree of ourvature for a job is installed on the bending arm' I M. The bending arm I is placed parallel to the aligning arm I50. Clamps I46 and I6I are released. The ratchet handle 22 is operated to move the frame member I6 transversely of the bed plate I0 to bring the mandrel rod 26 and anvil 21 in alignment with the axis of the straight section I44 of the groove of the radius block. The mandrel rod 26 is adjusted longitudinally by the hand wheel 28' to bring the mandrel 21 with its leading end Just at the trailing end of the straight groove section I. The stop carriage 18 is clamped to the stop rail 68 and frame member I6 with the zero mark on scale I04 registering with the mark on the scale 85 designating the distance between the trailing end of the tube and the leading end of the first bend. Alternatively, the mark on scale I04 designating the distance between the leading end of the tube and the leading end of the first bend may be set in registry with the mark on scale 85 designating the length of the tube.

The stops 02 are then set along the stop bar with the leading vertical face of each stop spaced toward the head end of the machine from the zero mark on scale I04 in the case of the first stop or from the leading vertical face of the next preceding stop in the case of the other stops. The distance from the 'zero mark on scale I04 to the front face of the first stop represents the spacing between the leading ends of the first and second bends, the remaining bends being similarly set. The limit stop 94 is placed a short distance in the lead of the stop for the last bend to be formed. Thus if a tube pattern has five bends, the stop 94 is placed in the lead of the fourth stop.

Then with the drum $5 turned on its bearing ti to bring the pointer I06 at the zero mark at the top of the dial I05, the first or leading slip ring ii on the drum is set with its lug 12 in contact with one side or the other of the stop 83 on the slide block 80. The plane of the first bend then becomes the reference or zero angle plane.

The pawl 85 is manually operated to permit the escapement mechanism to move the stop 88 to the vertical plane of the second or next rearward slip ring on the drum 55. The drum is then rotated either clockwise or anti-clockwise to move the lug 12 of the leading slip ring away from the stop 83, depending upon which side of the stop is contacted by the lug, until the pointer registers the required angle (less than 180 degrees) between the reference or zero angle and the plane of the second bend. The second slip ring is then turned in the same direction to bring the advancing face of its lug 12 against the stop 83. The slip ring is then clamped to the drum.

The remaining slip rings are similarly set, one slip ring for each bend in the tube.

The slip rings I51 on the bender drum I40 are set to determine the degree of each bend, the lowermost ring corresponding to the first bend and each ring being set on the drum with the advancing face of its lug I59 contacting the stop lug I68 when the dial I54 indicates the required angle through the front pointer window I55. The movable, escapement-trip lug I85 is then set between the tooth I51. corresponding to the last bend of the tube and the tooth next below it, the uppermost tooth corresponding to the first bend of the tube. The rack bar I65 is disposed in its lowermost position.

The machine is now set for bending one tube or a plurality of tubes according to aprescribed pattern. A tube 205 is inserted between the clamping block I45 and radius block I42 and passed over the mandrel .21 and mandrel rod 25 with its trailing end between the loosely related clutch jaws 54 and 55. The carriage 32 with the pawl 85 in its uppermost position is then pushed backward against the stop carriage 15, setting the slide block 80 in its initial position with its escapement mechanism in operative condition, and clamping the clutch jaws 54 and 55 on the trailing end of the tube. The tube clutch and drum are then rotated until the lug 12 on the first slip ring H is against the same side of the slide block lug 83 as that used in setting the the clamping block I45, the counterbalancing I compression spring 42 (Figure 7) on the carriage facilitating this lifting of the tube. The bending arm is returned to-its initial position causing the pawl I12 to elevate the stop I58 in readiness for engagement with the lug I59 of the second slip ring I51 on the bender index drum I52. The tube is lowered to position between radius block I42 and clamping block I45 and pulled forward until pawl 85 on carriage 32 rides over the first 'stop 82. If the mandrel 21 has become wedged in the tube during the preceding bending operation, preventing this forward pull of the tube, it is released by depression of the foot pedal 30. The tube is then pushed backward until the pawl strikes the front face of first stop 92. The escapement pins and 81 and escapementlugs 84 permit the slide block stop to move to position for engagement with the lug 12 on the second ring H. The tube, clutch and drum are rotated until this slip ring lug- 12 engages stop 83. The bender clampsare set and, the bender arm I is pulled to make the second bend. Upon completion of the last bend and release of the bender clamps, the carriage is pulled forward by the tube until the limit stop 94 trips and releases the escapement slide block and secures the pawl 85 in its uppermost position. The operator then pushes down on the grip 58 on the lever 55 releasing the'clutch jaws from the tube, removes the tube from the machine and returns the bender arm I 4| to its initial position. The pawl I12 thereupon hits the lug I86 and trips the rack bar escapement; the rack bar drops to its initial position ready for bending the next tube. The pin I89 holds the pawl I12 inoperative until the bending arm moves-outward in making the first bend on the next tube. The machine is now ready for a repetition of the operative cycle described above on a new straight tube.

The ordinals on the tape 200 enable the operator to check the bend number with the movement of the bending arm.

While the invention has been described herein as embodied in a machine for bending tubes, it is. applicable as to some of its features to a machine for bending solid bars, rods and other elongated objects of circular or other cross sectional configuration so characterized structurally that they may be bent by a machine constructed in accordance with this invention. 5

The word tube as used hereinincludes pipes and other hollow elongated objects of circular or other cross sectional configuration so characterized structurally that they may be bent by a ma- :ihine constructed in accordance with this inven- I claim:

1. In a tube bending machine, the combination of: a frame first member; a carriage second member translatively movable on said frame member; means for supporting a tube parallel to the direction of said translative movement, and extending toward they head end of the machine, including a fastening third member on the carriage member rotatable about the tube axis for holding the tailward end of the tube longitudinally immovable on the carriage member; a bending device on the head end of the framemember comprising stationary and swinging elements and disposed along the position of the supported tube; a plurality of first stop means rectilinearly adjustably secured on one .of the swinging element of said bending device on said frame.

2. In a tube bending machine, the combination of: a frame member; a carriage member translatively movable on said frame member; means on the carriage member for longitudinally immovably thereof supporting a tube parallel to the direction of said translative movement andextending toward the head end of the machine; a bending device on the head end of the frame member disposed along the position of the supported ,tube; and a plurality of stop means for mechanically translatively positioning the carriage on the frame, each said stop means being rectilinearly adjustably secured on one of said members and constructed to abuttingly engage the other member upon movement of said carriage away from the bending device and to automatically permit movement of the carriage toward the bending device.

3. In a tube bending machine, the combination of: a frame; a carriage member translatively movable on said frame; means for supportiny a tube parallel to the direction of said translative movement and extending toward the head end of the machine, including a fastening member on the carriage member rotatable about the tube axis for holding the tailward end of the tube longitudinally immovable on the carriage member; a bending device on the head end of the frame disposed along the position of the supported tube; and a plurality of stop means rotatively adjustably secured on one of said members to abutting engage the other member for mechanically angularly positioning said fastening member on said carriage.

4. In a tube bending machine, the combination of: a frame; means for supporting a tube in longitudinal slidable relation with said frame; a bending device on the head end of the frame comprising stationary and swinging elements and disposed along the position of the supported tube; and a plurality of stop means rotatively adjustably secured on one of said elements to abuttingly engage the other element for mechanically limiting arcuate movement about its axis of the swinging element of said bending device on said frame,

5. In a tube bending machine, the combination of a frame first member; a carriage second member translatively movable on said frame member; means for supporting a tube parallel to the direction of said translative movement and extending toward the head end of the maaseans chine, including a fastening third member on the carriage rotatable about the tube axis for holding the tailward end of the tube longitudinally immovable on the carriage member; a bending device on the head end of the frame member disposed along the position of the supported tube; a plurality of first stop means rectilinearly adiustably secured on one of said first and second members to abuttingly engage the other thereof for mechanically translatively positioning the carriage member on the frame member; and a plurality of second stop means rotatively adiustably secured on one of said second and third members to abuttingly engage the other member thereof for mechanically angularly positioning said fastening member on said carriage member.

6. The combination defined in claim 5, and in addition thereto; means automatically placing each of said second stop means in operative position upon disposition of a corresponding one of said first stop means in operative position.

7. The combination defined in claim 4, and in addition thereto; means automatically placing said stop means successively in operative position in correlated response to successive operations respectively of said bending device.

8. The combination defined in claim 1 in which said carriage member may be moved toward said bending device as said bending device is successively operated to form bends in the tube beginning at the free end of the pipe and in addition thereto; means automatically placing said second stop means successively in operative position in correspondence with successive positions of said carriage member in its movement toward said bendingdevice as determined by said first stop means; and means automatically placing said third step means successively in operative position in correlated response to successive operations respectively of said bending device.

9. In a tube bending machine, the combination of: a frame member; a carriage member translatively movable on said frame member; means on the carriage member for longitudinally immovably thereof supporting a tube parallel to the direction of said translative movement, and extending toward the head end of the machine; a bending device on the head end of the frame member disposed along the position of the supported tube; a plurality of adjustable stop means on one of said members to abuttingly engage the other member operative only on tailward movement of said carriage member for succesively mechanically positioning the carriage member at stations progressively nearer the head end of the machine; means adjustably positioned on said frame member toward the head end of the carriage member travel for rendering said stop means inoperative; and means adiustabiy positioned on said frame member toward the tail end of the carriage member travel for rendering said stop means operative.

10. In a tube bending machine, the combination of: a frame; a carriage translatively movable on said frame; releasable fastening means on the carriage for laterally gripping a tube at one extreme end of the tube, the tube being positioned parallel to the direction of travel of the carriage, comprising a stub mandrel means insertable within the tube bore at said tube end, and a longitudinally short clamping member which is mounted on the carriage to be movable radially of the tube for applying unilateral pressure to force the tube wall at said tube end against the mandrel means; a means spaced from said fastening means for supporting the tube in said position; and a bending device on the head end of the frame disposed along the position of the supported tube.

ll. In a tube bending machine, the combination of: a frame; a carriage translatively movable. on said frame; means for supporting a tube parallel to the direction of said translative movement and extending toward the head end of the machine, including a fastening means on the carriage rotatable about the tube axis for holding the tailward end of the tube; a bending device on the head end of the frame disposed along the position of the supported tube; a plurality of adjustable first stops on the frame for translatively positioning the carriage on the frame; a pawl on the carriage for riding engagement with said first stops upon headward movement of the carriage and engageably abutting said first stops on tailward movement of the carriage; a plurality of adjustable second stops rotatable with said fastening means and axially spaced along said carriage; an axially movable rotatively immovable member on said carriage for engageably abutting said second stops; an escapement means operatively connecting said pawl with said member for progressively moving said member by successive steps into positions for 'seriatim engagement with said second stops in response to seriatim riding engagement respectively of said pawl with said first stops.

12. The combination defined in claim 11 in,

which said pawl is movable to a position in which it is non-engageable with said stops, and operatively disconnected from said escapement means; and in addition thereto means securable to said carriage longitudinally thereof and selectively with respect to said first stops for moving said pawl to said non-engageable position; a stop on said frame toward the tail end thereof for returning said escapement means to its initial position and immediately thereafter returning said pawl to its stop engageable and escapement operative position.

13. The combination defined in claim 11 in which said pawl is movable to a position in which it is non-engageable with said stops, and operatively disconnected from said escapement means and in which said fastening means is release able; and in addition thereto means securable to said carriage longitudinally thereof and selectively with respect to said first stops for moving said pawl to said non-engageable position; a-stop on said frame toward the'tail end thereof for returning said escapement means to its initial position and immediately thereafter returning said pawl to its stop engageable and escapement operative position and for functionally positioning said fastening means.

14. In a tube bending machine, the combination of: a frame; a carriage translatively movable on said frame; a stationary mandrel rod secured at its tail end to the frame and provided at its head end with a mandrel; abending device on the frame disposed in operative relation to said mandrel; a bearing sleeve fixed on said carriage and encircling said rod; a drum rotatably carried by said bearing; a chuck for holding the tailward end of a tube in concentric position on said rod, said chuck being rotatable with said drum; a plurality of slip rings axially aligned on said drum and angularly adjustable to fixed position thereon; a radially projecting stop on each ring; a stop engaging member on the carriage; means responsive to successive headward corresponding successive engagement with said stops.

15. In a tube bending machine,'the combination of a frame; a carriage translatively movable on said frame; a stationary mandrel rod secured at its tail end to the frame and provided at its head end with a mandrel; a bending device on the frame disposed in operative relation to said mandrel; a bearing sleeve fixed on said carriage and encircling said rod; a chuck assembly rotatable on said bearing sleeve including cooperating jaws for holding the tailward end of a tube mounted on said rod, at least one of said jaws being movable for clamping and releasing the tube and being yieldably held in clamping position; a spring positioned detent means connected to hold said movable jaw in tube releasing position; and a stop on the frame at the tailward side of said carriage for disconnecting said detent means from said movable jaw against the action of said positioning spring upon tailward movement of said carriage.

16. The combination defined in claim 15, in which said detent means is axially movable with respect to said clutch assembly and includes a member slidable on said carriage extending tailward for engagement with said stop, in which said yieldable holding means of said movabl jaw includes a lever movable in an axial plane of said rod and operatively connected at its resistance point to said movable jaw and includes a detent notched, radially outwardly spring-urged mov-' able member operatively connected to the power point of said lever and held by said detent means and in which said spring for positioning said detent means is mounted between said chuck assembly and said detent means and opposes movement of said slidable member.

17. The combination defined in claim 3, and in addition thereto; an angle meter for measuring the angular relationship of said fastening member and carriage member for use in selectively setting said adjustable stop means angularly of said carriage member.

18. The combination defined in claim 4 and in addition thereto an angle meter for measuring the angular relationship of said swinging eelment and frame for use in selectively setting said adjustable stop means angularly of said frame about the axis of said bending device.

19. In a tube bending machine, the combination of: a frame; a carriage translatively movable on said frame; means for supporting a tube parallel to the direction of said translative movement and extending toward the head end of the machine, including chuck means on the carriage for holding the tailward end of the tube; and a countor-balancing means between said chuck means and said frame for facilitating lifting the chuck ing the chuck means and the other portion engaging the frame; and a counterbalancing spring interposed between said portions for facilitating swinging upwardly the chuck carrying portion of the carriage and with it the tube and rod supported thereby and elastically flexing downwardly the rod between the carriage and its tail end.

21. In a tube bending machine the combination of; a frame; means for supporting a tube in longitudinally slidable relation with said frame; a radius block assembly disposed on said frame; means for holding the tube against the radius block during the bending operation; a plurality of angularly adjustable stops carried by said radius block assembly angularly disposable about the axis of rotation of said radius block assembly and longitudinally fixedly spaced therealong; a member mounted on said frame to be longitudinally movable from an initial position against a yieldable force and rotatively immovable with respect to said axis for engagement, one at a time,

pawl at the end of the return movement of said radius block assembly and swinging it against with said stops; means actuated successively by said radius block assembly during successive bending operations respectively for moving said member longitudinally of said axis from an initial position in one direction to new positions in a series of steps and for holding said member in said new positions. against said yieldable force, each step being from the plane of movement of one stop to the plane of movement of the next adjacent stop.

22. In a tube bending machine the combination of a frame; means for supporting a tube in longitudinally slidable relation with said frame; a radius block assembly disposed on said frame; means for holding the tube against the radius block during the bending operation; a plurality of angularly adjustable stops carried by said radius block assembly angularly disposable about the axis of rotation of said radius block assembly and longitudinally spaced therealong; a guide member mounted on said frame parallel to said axis; a rack bar slidable on and longitudinally of said guide member and carrying a lug projecting into the path of movement of said stops for engagement one at a time with said stops in accordance with the position of said guide member; and escapement means including the teeth on said rack bar and operated by the return movements of said radius block assembly for moving said rack bar step by step from an initial position for successive engagements of said lug with said stops; and adjustable means for automatically disconnecting said escapement means and returning said rack bar to its initial position after any desired number of bending operations.

23. The combination defined in claim 22 in which said escapement means comprises in addition to said teeth; an arm secured to said radius block assembly; a pawl pivoted to said arm to swing in a plane normal to said rack bar and spring-held in a position to engage the trailing faces of said teeth as said radius block assembly is returned to its initial position, said pawl being beveled at its. outer end to lift said rack bar upon engagement with each of said teeth; a spring projected latch on said guide member, camshaped for automatic successive retraction by said advancing teeth and making automatic engagement with the trailing face of one of said teeth after each cam retraction; a cam'lug adjustably securable between any selected adjacent two of said teeth for engaging the outer end of said the action of the pawl spring to an inoperative position out of the travel path of said teeth; and a catch on said guide member for engaging said pawl to hold it in said inoperative position, said pawl having a cam shaped surface for engaging said catch when said radius block assembly is in its initial position and disengaging said catch upon operative movement of said radius block assembly.

24. The combination defined in claim 21, and in addition thereto; a counter means operated by said member for visibly indicating the ordinals of the bending operations performed on a tube.

25. The combination defined in claim 4 and in addition thereto; means automatically placing said stop means successively in operative position in correlated response to successive operations respectively of said bending device; and a counter means operated by said bending device for visibly indicating the ordinals of the bending operations performed on a tube.

26. The combination defined in claim 1 in which said carriage member may be moved toward said bending device as said bending device is successively operated to form bends in the pipe beginning at the free end of the pipe and in addition thereto; means automatically placing said second stop means successively in operative position in correspondence with successive positions of said carriage member in its movement toward said bending device as determined by said first stop means; and means automatically placing said third stop means successively in operative position in correlated response to successive operations respectively of said bending device; and counter means operated by said bending device for visibly indicating the ordinals of the bending operations performed on a tube.

27. The combination defined in claim 10 in which the clamping member has a smooth surfaced tube contacting face, and in addition thereto: a lever medially fulcrumed on the carriage relatively close to the work end of the-lever for moving the clamping member into and out of contact with the tube; and a spring operatively connected to the power end of the lever.

28. In a tube bending machine, the combination of: a frame, a carriage translatively movable on said frame; means for supporting a tube parallel to the direction of said translative movement and extending toward the head end of the machine. including a releasable fastening means on the carriage for holding one end of the tube; a stop adjustable on the frame between the carriage and tail end of the machine; movable means on the carriage for abuttingly engaging said stop and to be automatically moved by said engagement to mechanically position said fastening means in fastening position upon tailward movement of said carriage; and a bending device on the head end of the frame disposed along the position of the supported tube.

29. The combination defined in claim 21 and in addition thereto; selectively adjustable means on said member for engaging and rendering inoperative said moving and holding means for returning said member by the action of said yieldable force to its initial position after any desired number of bending operations.

MARVIN A. POWERS.

Referenced by
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Classifications
U.S. Classification72/15.2, 72/421, 72/133, 72/156
International ClassificationB21D7/12, B21D7/00
Cooperative ClassificationB21D7/12
European ClassificationB21D7/12