US3017917A - Tube bending machine - Google Patents

Description

Jan. 23, 1962 c. T. STREIT TUBE BENDING MACHINE.

5 Sheets-Sheet 1 Filed Dec. 10. 1959 y aw INVENTOR. Clarence 7:56:22 BY Jan. 23, 1962 c. T. STRElT TUBE BENDING MACHINE 5 Sheets-Sheet 2 Filed Dec. 10, 1959 INVENTOR. Clarence 7156a? 'Jan. 23, 1962 c. 'r. STRElT TUBE BENDING MACHINE 5 Sheets-Sheet 3 Filed Dec. 10, 1959 mm .mm a

NW m fi mm, B WI P 1M 7. W.

Jan. 23, 1962"- c. T. STREIT TUBE BENDING MACHINE 5 Sheets-Sheet 4 Filed Dec. 10, 1959 INVENTOR. Clarence TJZrezLZ Jan. 23,1962 c. T. STREIT TUBE BENDING MACHINE 5 Sheets-Sheet 5 Filed Dec. 10, 1959 INVENTOR. Claim 65% 3,017,917 TUBE BENDHNG MAC Clarence 'l. Streit, Aurora, llll., assignor to Pines Engineering (10., line, Aurora, lit, a corporation of Illinois Filed Dec. 10, 1959, Ser. No. 858,699 7 Claims. (Cl. 153-45) The present invention relates to improvements in tube bending machines and is particularly concerned with the structure and assembly of a machine adapted for righthand and left-hand bending and including positive drive means for the pressure die holder.

More particularly the tube bending machine herein disclosed includes a base structure upon which is mounted a top assembly including a hydraulically operated piston assembly for operating the bending form and pressure die holder which are integrally connected so as to operate in unison. The top assembly is pivotally mounted on the base structure so as to be capable of being swung through an arc of 180, thus adopting the machine for right-hand and left-hand bending. Toolin changeovers for righthand and left-hand bending are maintained at a minimum by providing the top assembly with dual sets of bending forms and clamp and pressure die holders, one set being available for use for right-hand bending and the other set for left-hand bending. An angle of bend selector is contained in the top assembly and may be indexed manually'or hydraulically.

The machine herein disclosed has the advantage of being capable of performing right-hand and left-hand bends with minimum changeover time and labor and is eX- tremely accurate in its bending operations owing primarily to the positive controlled drive of its pressure die holder. Furthermore, the base structure serves as a large capacity reservoir for hydraulic fluid, thus affording long production runs at full speed.

It is therefore an object of the invention to provide a novel ruggedly constructed tube bending machine.

Another object is to provide a bending machine of the character herein disclosed with a novelly mounted top assembly which may be easily and quickly swung into positions for right-hand and left-hand bending operations.

Another object is to provide a novelly constructed bending form and pressure die holder assembly adapted to be positively driven in unison and hydraulically.

Another object is to provide novel hydraulic drive means for the bending form and pressure die holder assembly.

With the foregoing and other objects in view which will appear as the description proceeds, the invention consists of certain novel features of construction, arrangement and combination of parts hereinafter fully described, iliustrated in the accompanying drawings, and

particularly pointed out in the appended claims, it being understood that various changes in the form, proportion, size and minor details of the structure may be made without departing from the spirit or sacrificing any of the advantages of the invention.

For the purpose of facilitating and understanding of" spection of which, when considered in connection with the following description, the invention, its mode of construction, assembly and operation, and many of its advantages should be readily understood and appreciated.

Referring to the drawings in which the same char-' 3,dl7,l7 Patented Jan. 23, 1962 FIG. 2 is a top plan view thereof.

FIG. 3 is an elevational view of the front end thereof, showing the base structure broken away.

FIG. 4 is an enlarged horizontal sectional view of the top assembly, showing parts in elevation.

FIG. 5 is a vertical longitudinal sectional view taken substantially on line 5-5 of FIG. 4, showing parts in elevation.

FIG. 6 is a vertical sectional view taken substantially on line 66 of FIG. 2.

FIG. 7 is a transverse sectional view of the top assembly, taken on line 7-7 of FIG. 4.

FIG. 8 is a transverse sectional view of the top assembly, taken substantially on line S8 of FIG. 4.

FIG. 9 is a transverse sectional view of the top assembly, taken on line 9-9 of FIG. 2.

Referring to the accompanying drawings, the tube bending machine disclosed in an exemplary form comprises essentially a base structure 11 and a top assembly generally indicated at 12. The base structure preferably is fabricated from heavy steel plate to form a rigid load supporting assembly, the lower portion of which comprises a reservoir for hydraulic fluid used in the operation of hydraulic operating means to be described presently. Mounted on one end of the base structure and in flow communication with the fluid reservoir is a pump, generally indicated at 13 (FIG. 1) having an operating connection through a shaft 14 with a suitable power source such as electric motor 15.

The top assembly 12 is in the form of a horizontally elongated steelplate casing 16 that is arranged in a horizontal plane above the base structure and which extends beyond each end thereof. The top assembly is hingedly mounted on the base structure, as by means of a heavy duty hinge assembly 17 comprised of a strip 18, secured to the top wall of the base structure as by bolts or rivets 19, and having upstanding journals 2.1, to each of which is pivotally secured, as by pivot pins 22, one of a pair of bearing lugs 23 integrally connected to one side wall 16a of casing 16.

The hinge mounting for the top assembly affords means whereby said assembly may be swung from the position illustrated in full lines in FIGS. 2 and 3 into a position shown in broken lines in said figures. The purpose of such hinge mounting will become more apparent as the description proceeds but may be broadly stated as affording a primary structure adapting the machine to be used for forming either right-hand or lefthand bends in tubing being serviced on the machine without costly delays for re-tooling. The top assembly 12 houses and mounts the bending forms, the stationary clamp die holders, the swinging pressure die holders and the drive mechanism therefor, as Well as an angle of bend selector all to be described in detail hereinafter.

The bending forms 24'are mounted at one end of the top assembly. This is best illustrated in FIGS. 2 and 6, wherein said bending forms are shown mounted at opposite ends of a spindle assembly journalled in a nose housing 25 fixedly secured to one end of the steel plate casing 16. More specifically, the nose housing comprises a hollow casting suitably flanged at its open end, as at 26, for securement to said casing and provided with vertically aligned anti-friction bearings 27 in its top and bottom walls to provide journals for hub portions 28 projecting one on each side of a sprocket 29. Each of the hub portions 28 have end extensions 31 of reduced" diameter each mounting a non-circular mounting member 32 having studs 3334 (FIG. 2) extending outwardly thereof to receive the bending forms 24. Set screws 35 (only one shown in FIG. 6) secure the mounting members to the respective hub portions 28 for rotation therewith. In the present disclosure the axial studs 33 are connected by an axial tie rod 36.

A forked arm 37 is fitted over hubs 28 in embracing relationship to sprocket 29 and is secured thereto for rotation with the sprocket by one or more threaded pins 38. The arm 37 projects outwardly radially through a slot 39 in the side wall of nose housing 25 and is secured firmly, as by bolts or rivets 41 to one end of a vertically disposed swing plate 42 having upper and lower guide flanges 43 on its horizontally disposed longitudinal edges. As best shown in FIG. 6, the guide flanges 4-3 are comprised of heavy strips that are welded or otherwise secured integrally to said plate and they extend inwardly beyond the inner edge thereof and are in tight endwise abutment with the related side face of the respective mounting members 32. The structure, insofar as it is described, affords a firm mounting for swing plate 42 and assures that it will at all times rotate about the axis of sprocket 29 and bending forms 24 when the latter are rotated in a manner to be described presently. This assembly is adapted to mount one or two pressure die holders to be described presently.

A similarly constructed but rigidly mounted plate 45 including upper and lower guide flanges 46 is mounted directly on the nose housing longitudinally inwardly of the axis of bending forms 24 and extends perpendicular to the longitudinal axis of the top assembly as best shown in FIG. 2. This plate assembly is adapted to mount one or two stationary clamp die holders. The pressure die holders and the stationary clamp die holders are alike in their construction and operation and the following description of one will be fully applicable to the other and like numerals are used to identify corresponding parts.

Referring specifically to the disclosure of the pair of pressure die holders best illustrated in FIG. 6, it will be observed that one is shown mounted on the upper guide flange 43 and the other is mounted on the lower guide flange 43. Each holder comprises an assembly including a toggle casting 47 slidable on flange 43 but adapt-ed to be fixedly secured in a position of longitudinal adjustment therealong as by means of a lick screw 48. A backup plate 49 is arranged on flange 43 between the rear edge of said toggle casting and an adjustment screw 51 carried by a vertically extending end plate 52 secured to the free or rear end of swing plate 42. Upon loosening screw 48 and adjusting screw 51, the toggle casting 47 can be moved into any required position of adjustment along flange 43.

A toggle link 53 is pivotally connected, at 54, to toggle casting 47 and is connected by a chain link 55 to a slide casting 56 also guided on flange 43. The slide casting on the pressure die holder assembly is adapted to have removably mounted thereon, pressure die 57 which has its face opposed to bending form 24 provided with a semicircular recess 58 that is complemental to the perimeter recess 59 in said bending form. In the instance of the stationary clamp die holder assembly, the slide casting 56 receives and mounts a clamp die 57a which is structurally similar to the pressure die 57.

The function and operation of the pressure die holder and stationary clamp die holder and the dies mounted therein will be explained in detail presently but it should be noted at this time that the provision of a pair of dies one on each edge of the respective holder assemblies affords means whereby the top assembly 12 may be positioned on the base assembly for immediate operation to effect right-hand or left-hand bending. In the drawings, the top assembly is shown in full lines in the position assumed for making left-hand bends. In order to make right-hand bends, the top assembly is swung 180 about its pivotal mounting 17 from said full line position into a position fully overlying base structure 11, substantially as shown in broken lines in FIGS. 2 and 3. Such repositioning of the top assembly reverses the positions of the stationary clamp die holders and the swinging pressure die holders and makes the bending form and dies previously disposed on the bottom side of the nose assembly available for use on the upper side thereof.

In use, while in either of its positions, a tube or rod 61 to be bent, is laid over the upper face of the top assembly with its rearmost end held by a conventional holder assembly (not shown) and its forward end extended beyond and clamped firmly between the stationary clamp die 57a and the bending form 24. Power is applied, in a manner to be described presently, for rotating the bending form and the swinging pressure die holder in unison to effect the desired bending of forward end portion of the tube.

As earlier indicated herein, hydraulic fluid supplied by operation of pump 13, provides the motivating power for rotating the spindle assembly. This means, best shown in FIGS. 4 and 5, includes a cylinder 62 mounted in a horizontal plane on a platform 63 secured to the inside face of the bottom wall 16b of the steel plate casing 16. A piston 64 is operable within said cylinder which has hydraulic lines 65-66 one in flow communication with each end thereof and connected to pump 13. A suitable three-way valve (not shown) is provided in said lines which is under control of the operator for admitting fluid to either end of said cylinder so as to drive the piston in either direction therein. A piston rod 67, connected to said piston, extend through a packing gland 68 on the rear end of said cylinder and carries a cross-head 69 having a connecting lug 71 integral therewith. A length of sprocket chain 72 or other flexible medium, is connected at one of its ends to said connecting lug 71 as by a pin 73. This chain is trained around an idler sprocket 74 journalled in bearing plates 75 (FIG. 9) secured firmly to and within the steel plate casing 16, and its other end is connected, as at 76, to one end of a tie bar 77 extending longitudinally within said casing.

Tie bar 77 is of such length as to terminate short of nose housing 25 and its forward end is connected, as at 78, to one end of a second length of sprocket chain 79 that is trained around spindle sprocket 29 and has its other end connected by a pin 81 to a cross-head 82. Rods 33 rigidly connect cross-head 82 to the piston rod cross-head 69, said rods extending through apertures therein and being secured thereto firmly, as by means of lock nuts 84 and 85 respectively.

The rods 83 are guided for longitudinal reciprocation in an upstanding wall 86 secured at its lower margin to the forward end of platform 63 as by screws 87. In operation, any longitudinal movement imparted to piston 64 by selective operation of the hydraulic control valve is transmitted to the sprocket chain and bar assembly for rotating spindle sprocket 29 and rotating the bending form and pressure die holder assembly.

In order to control the angle of bend obtained by operation of the bending form and pressure die, and particularly the angle of each bend when successive bends are made in a length of tubing, the machine is provided with an angle of bend selector 88, best shown in FIGS. 4, 5 and 7. This selector comprises a turret or indexing cylinder 89 journalled for free rotation on one of the rods 83. Preferably, it includes a bearing sleeve 91 fitted over said rod and journalled also in the upstanding wall 86. If desired, said sleeve may have on its rearwardly extending end, a ratchet 92 adapted, for use in automatic indexing of the turret. In such instance hydraulic means, not shown, may be associated with the ratchet 92 for incremental rotation thereof. Specifically, turret 89 has a plurality of circumferentially spaced stop rods 93 mounted securely therein and each projecting forwardly therefrom. Rods 93 are of lengths each representing the amount of rotation of the pressure die holder and bending form assembly required to obtain the desired amount of bending in the tube during each bending operation.

The rods 93 are positioned, selectively or automatically, by rotation of the turret for in-line abutment by a stop boss 94 carried on the rearwardly disposed face of cross-head 82. Otherwise stated, the turret may be positioned to locate any one of its stop rods 93 in axial alignment with stop boss 94. When the machine is operated to form a bend in the tube, it will continue the bending operation until stop boss 94 strikes the end of the aligned rod 93. This holds the piston against further movement under its hydraulically applied power whereupon the operator will release the clamping and pressure dies 57a and 57 respectively, and then reverse the hydraulic flow valve to return the bending form and pressure die holder to their initial or at rest positions. The tube being formed is then advanced into the next bend position, the clamp and pressure dies reset and the turret indexed, manually or automatically, to locate the required rod 93 in position for abutment by stop boss 94 during the next bending operation. Accurate indexing of the turret is assured by providing the indexing cylinder 89 with a recess 95 for cooperative engagement by an indexing ball 96 carried by wall 86. This ball preferably is urged into such engagement by a spring 97 carried in the ball containing recess 98. Variation in the effective tension of said spring may be obtained by adjustment of a set screw 99. This sequence is repeated for each bend to be made in the tube and should the machine be positioned at any time to make right-hand bends, the top assembly 12 may be swung over easily and quickly about its hinge mounting 17 to adapt it for making any required left-hand bend without materially slowing down bending operations; it being necessary only to reposition the tube on the then top side of the top assembly and engage it in the uppermost bending form and die assembly.

It is believed that the invention, its mode of construction and assembly, and many of its advantages should be readily understood from the foregoing without further description; and it should also be manifest that, while preferred embodiments of the invention has been shown and described for illustrative purposes, the structural details are nevertheless capable of wide variation within the purview of the invention as defined in the appended claims.

What I claim and desire to secure by Letters Patent of the United States is:

1. In a tube bending machine including a base structure and a top assembly, said assembly comprising an elongated casing having a pair of bending forms, clamp die holders and pressure die holders operably associated therewith, and hinge means connecting the top assembly to the base structure adapting the former to be swung into positions permitting use of one or the other of said pair of bending forms, clamp die holders and pressure die holders.

2. The tube bending machine of claim 1, in which the hinge means is of a character that permits the top assembly to be swung 180 on an axis parallel to its longitudinal axis.

3. The tube bending machine of claim 1, in which the hinge means comprises a hinge element mounted on the top surface of the base structure and complemental hinge elements carried on one longitudinal side wall of said elongated casing.

4. In atube bending machine including a base structure having a hydraulic fluid reservoir therein, a top assembly mounted on said base structure, a hydraulic piston-cylinder assembly mounted in said top assembly, a bending form spindle assembly including a sprocket mounted on one end of said top assembly, an idler sprocket mounted adjacent to the other end of said top assembly, an endless chain assembly trained over said sprockets and connected to the piston for rotating the sprockets and spindle assembly when the piston is operated, means to deliver fluid from the reservoir to said piston-cylinder for operating the piston, a pair of bending forms mounted on each end of the spindle assembly, a stationary arm secured firmly to the top assembly, a pair of clamp dies carried by the stationary arm one for cooperative association with each bending form, a swinging arm connected firmly to the spindle assembly and movable therewith, a pair of pressure dies carried by the swinging arm one for cooperative association with each bending form, and means mounting the top assembly on the base structure to permit it to be swung through an arc of so as to enable use of either one of the bending forms and the clamp and pressure dies associated therewith.

5. In a tube bending machine, a housing including top and bottom walls and a substantially circular side wall connecting said top and bottom walls, a spindle journalled in the top and bottom walls and extending outwardly therefrom, a bending form secured to one end of said spindle, a sprocket on said spindle and within said housing, said housing side wall having a circumferential opening therein, and a pressure die holder secured firmly to said sprocket and extending outwardly radially through said opening.

6. The tube bending machine of claim 5, in which the pressure die holder has a pressure die thereon for cooperation with the bending form during a tube bending operation.

7. The tube bending machine of claim 5, in which a bending form is secured to each end of said spindle and the pressure die holder has pressure dies mounted thereon one for cooperation with each bending form.

References Cited in the tile of this patent UNITED STATES PATENTS 404,012 Nickerson May 28, 1889 1,545,164 Norton July 7, 1925 2,022,912 Heineman Dec. 3, 1935 2,143,443 Kelso Jan. 10, 1939 2,488,896 Bertolini et al. Nov. 22, 1949 2,614,605 Senna Oct. 21, 1952 2,655,193 Payne Oct. 13, 1953 2,672,224 Horwitz Mar. 16, 1954 2,810,422 Bower Oct. 22, 1957 2,871,909 Bower Feb- 3, 1959 FOREIGN PATENTS 155,378 Australia Feb. 23, 1954

Images