US3555868A - Pipe bender - Google Patents

Abstract

A PIPE BENDER UTILIZING A CURVED BENDING SHOE OPERATED BY A HYDRAULIC RAM WHICH CAUSES PIVOTAL MOVEMENT OF THE BENDING SHOE WHILE A PIPE IS HELD IN THE SHOE BY A FOLLOW BAR ENGAGING A BACKUP ROLLER, INCLUDING A READILY REMOVABLE MEANS FOR QUICKLY MOUNTING THE BACKUP ROLLER IN DIFFERENT POSITIONS IN THE FORM OF A SHAFT PROVIDING A BEARING SURFACE FOR ROTATABLY SUPPORTING THE ROLLER TOGETHER WITH ECCENTRIC SHAFT END PORTIONS WHICH PREVENT

SHAFT ROTATION DURING BENDING AND MEANS ON THE END PORTIONS TO LOCATE THE SHAFT AXIALLY.

Description

J n. 19,1911 v K. L. HAGEMEYQ 3,555,868

' PIPE BENDER Filed July 18, 1968 4 i Q 5 Z A L-.

United States Patent 3,555,868 PIPE BENDER Kenneth L. Hagemeyer, Rockford, Ill., assignor to Greenlee Bros. & Co., a corporation of Delaware Filed July 18, 1968, Ser. No. 745,730 Int. Cl. B21d 7/02 US. Cl. 72154 9 Claims ABSTRACT OF THE DISCLOSURE A pipe bender utilizing a curved bending shoe operated by a hydraulic ram which causes pivotal movement of the bending shoe while a pipe is held in the shoe by a follow bar engaging a backup roller, including a readily removable means for quickly mounting the backup roller in different positions in the form of a shaft providing a bearing surface for rotatably supporting the roller together with eccentric shaft end portions which prevent shaft rotation during bending and means on the end portions to locate the shaft axially.

BACKGROUND OF THE INVENTION In the past, it has been conventional in pipe benders, particulaly those of the character mentioned, to provide a pair of spaced frame plates or straps between which a bending shoe works, often under power provided by a hydraulic ram to act against a length of pipe which is opposed by means on the frame arranged in a manner suitable to complement the particular action of the bending shoe, whether it be reciprocable or pivotal or otherwise. In most cases, the backup means opposing the bending shoe includes a backup roller. In order to provide for versatility, provision is often made for using a number of different bending shoes to accommodate pipes of different diameters to produce bends of different degrees. Generally, when the bending shoe is changed, the backup means is also changed. To facilitate the latter, it is desirable to provide means permitting quick insertion and removal of the backup roller while still retaining the roller in place in the frame during bending. Further, in those benders utilizing pivoted bending shoes where the opposition is provided by a follow bar engaging a backup roller, it is desirable to provide relative rotation between parts having relatively large interengaged bearing areas in order to distribute the rather large loads encountered in a manner to reduce wear and provide long life. Prior art devices known to me have not provided all the desirable objects referred to above.

SUMMARY OF THE INVENTION In accordance with the present invention, means is provided for mounting a backup roller in a pipe bender for quick insertion and removal. In the preferred form illustrated, the mounting means is in the form of a cylindrical shaft providing a bearing surface for rotatably supporting a backup roller with opposite end portions on the shaft within the circumference of the shaft but of reduced diameter and eccentric relative to the axis of the shaft. The reduced eccentric opposite end portions are positionable in apertures in the spaced frame plates of the bender corresponding in size to the diameter of the shaft so that insertion and removal are easy and so that on operation of the bender, when the shaft is rotated 180, the eccentric end portions resist further rotation, holding the shaft stationary while the roller is forced to rotate on the shaft. In this manner, the wear due to rotation is spread over the relatively large interengaged bearing surfaces of the shaft and the roller, while the relatively smaller areas of interengagement bet-ween the shaft end 3,555,868 Patented Jan. 19, 1971 portions and the relatively thin frame plates remain stationary for the most part.

Further, bearing in mind that the bender is normally horizontally disposed with one frame plate above the other, the mounting assembly includes a radial pin projecting from one reduced shaft end portion beyond the circumference of the shaft and beyond the circumference of the apertures in all angular positions of the shaft in order to prevent the assembly from passing completely through the frame, thereby to locate the mounting assembly axially.

Additionally, during operation of the bender, it is desirable to prevent the mounting assembly from climbing in a manner to be dislodged from the lower frame plate, and for such purpose, the opposite reduced end portion is provided with an enlarged terminus concentric with the shaft, to latch beneath the lower frame plate when the shaft is turned from the angular position it assumes during insertion.

BRIEF DESCRIPTION OF THE DRAWINGS Further objects and advantages will become apparent from the following detailed description taken in connection with the accompanying drawings, in which:

FIG. 1 is a plan view of a pipe bender embodying the present invention with the backup roller and mounting assembly shown in the position assumed during insertion and with the remaining parts disposed as to begin a bending operation;

FIG. 2 is a right side elevational view of the bender illustrated in FIG. 1 with the parts similarly disposed;

FIG. 3 is an enlarged fragmentary sectional View taken through the backup roller and mounting assembly at about the line 33 of FIG. 1; and

FIG. 4 is a similar view with the mounting shaft rotated 180 from the position shown in FIG. 3.

DESCRIPTION OF THE PREFERRED EMBODIMENT In a preferred embodiment as illustrated in the drawings, a pipe bender includes a pair of generally similar spaced parallel frame plates or straps 10 and 11 which are elongate in shape. Adjacent one end, which may be referred to as the inner end, the plates 10 and 11 are widened and bifurcated to provide parallel projections as at 10a and 10b which engage a housing or holder 12 having a rectangular outer periphery. In order to secure the straps ends to the housing member 12, pins as at 13 and 14 pass through apertures in the housing member and the strap ends and are retained in position by means such as that illustrated at 15 in the nature of a cotter pin radially disposed in opposite ends of the mounting pins 13 and 14. The member 12 is centrally apertured to support a hydraulic cylinder as at 17 suitably secured in position in the member 12 and housing a reciprocable ram as at 18. If desired, the ram 18 may be spring urged in a well known manner to a retracted position and driven outwardly in a direction to effect the bending operation upon admission of hydraulic fluid to the opposite end of the cylinder 17 as through a fitting 20.

The outer end of the ram is formed to receive a yoke, as at 25, suitably retained in place as by a pin 26 and shaped with spaced projections 27 having aligned apertures to receive a pin 28 removably positionable for holding a bending shoe such as that illustrated at 30 pivotally mounted relative to the ram and adapted for ready removal to permit substitution of a bending shoe of different size and/or degree of curvature.

As best seen in FIG. 2, the outer face of the bending shoe 30 is arcuately recessed as shown at 31 to fit a pipe cross section of predetermined diameter. As best seen in FIG. 1, the recessed face 31 of the bending shoe is curved in a manner to effect some predetermined bend in a pipe of the predetermined diameter. As illustrated, the shoe 30 will produce a bend of approximately 45.

In order to effect a bend, a length of pipe, such as that illustrated at P, is positioned in the bending shoe as shown, and held there while the bending shoe is forced to pivot about the attachment to the ram at 28. For such purpose, the ram is driven outwardly, and the bending shoe 30 has a U-shaped strap 35 pivotally connected to the bending shoe by a pin 36 located off the axis of the ram. The strap 35 embraces the pipe P and has a working face recessed arcuately, as shown at 37, to fit a predetermined pipe diameter, complementary to the bending shoe. A straight follow bar 38 adjacent the strap 35 also has a working face arcuately recessed like the face 37 to engage the pipe. The back surface of the follow bar 38 engages a backup roller 40 fitted between the outboard ends of the frame plates and 11 and held in position by a mounting assembly 42.

In operation, when fluid under pressure is admitted to the cylinder 17 behind the ram 18, the ram is forced outwardly and the bending shoe is forced to pivot at 28. Such movement of the bending shoe acts through the strap 35 to pull the pipe along with the bending shoe while the pipe engages the follow bar in turn opposed by the backup roller.

According to the present invention, the mounting assembly '42 includes a main or central shaft portion 44 of cylindrical configuration providing an outer bearing surface engaging the surface of a bore in the roller 40 to support the roller. Opposite ends of the shaft 44 are reduced in diameter and eccentric to the axis of the main portion 44 as at 46 and 48. The central shaft portion 44 is equal in length to the length of the roller 40 so that the reduced end portions 48 are located at apertures 50 and 51 in the frame plates 10 and 11 when the assembly is in proper position. In order to locate the assembly axially and prevent passage through the framework, the reduced end portion 46 has a radial pin 52 which is long enough to project outwardly beyond the shaft portion 44 and the aperture 50 in all angular positions of the assembly. Thus, with the bender laid horizontally on a floor or the like, with the frame plate 11 on the bottom and the frame plate 10 at the top, the roller 40 may be located between the plates 10 and 11 with the bore in the roller aligned with the apertures 50 and 51 of similar size. With such relationship established, the assembly 42 may be simply dropped into place by inserting the lower end of the shaft in the aperture 50. The shaft portion 44 slides through the aperture 50 and into the bore in the roller, as shown in FIG. 3. Since the shaft is of the same size as the roller bore and as the apertures 50 and 51, it is prevented from dropping too far by contact of the pin 52 with the plate 10'.

During operation, when the ram 18 is extended, the bending shoe pivots, moving the strap 35, the pipe P and the follow bar 38 toward the right, as viewed in FIG. 1. Movement of the follow bar 38 past the roller 40 causes rotation of the roller. Initial angular movement of the roller also causes angular movement of the assembly 42 since it is free to rotate at least a limited amount. After angular movement of about 180, the shaft end portions 46 and 48 bottom or seal in a position where it is easier for the roller 40 to rotate on the shaft 44 than it is for the shaft end portions 46 and 48 to rotate in the apertures 50 and 51, as shown in FIG. 4. At that point, the shaft remains stationary while the roller turns on the shaft. In this way, the relatively large loads are distributed over the relatively large bearing area of the interengaged surfaces of the shaft and roller rather than being borne by rotation of the shaft ends in the relatively thin plates 50 and 51. In order to prevent the shaft from climbing out of the frame during operation,

and to hold the frame plate ends together, the reduced shaft end portion 48 includes an enlarged terminus 54 concentric with shaft 44 and of a similar size. When the parts are initially assembled, the terminus 54 passes entirely through the plate 10, the roller 40, and the plate 11, as shown in FIG. 3. When the shaft rotates the terminus 54 in effect latches the shaft against movement upwardly.

A bender of the type described usually includes a plurality of different bending shoes which may be attached to the ram. With the different bending shoes, there are also different straps as at 35, and different follow bars as at 38. With the various different shoes and associated equipment, the backup roller 40 may be mounted in different positions at varying distances from the end of the ram 1 8. For such purpose, there are a plurality of pairs of aligned apertures similar to those shown at 50 and 5.1. Four additional pairs of such apertures are shown at 5'5, 56, 57 and 58 at varying distances along the frame plates. The mounting assembly 42 is readily disassembled from and mountable in each of the sets of aligned apertures. To remove the mounting assembly, the ram 18 is retracted to take the pressure oh? the backup roller whereupon a knurled terminus 59 on the shaft end portion 46 may be grasped to rotate the shaft 180 from the position of FIG. 4 back to the position of FIG. 3. During assembly, a suitable shoe, strap and follow bar are put together with the ram retracted to space the parts from the backup roller 40 whatever position the latter is to be moutned in.

I claim:

1. In a pipe bender, a frame, a bending shoe movably mounted on the frame and having a working face formed to engage and bend a length of pipe on movement of the shoe, meansv on the frame to engage the pipe in 0pp0sition to the bending shoe including a backup roller, means for mounting the roller for quick insertion and removal including a shaft having a bearing surface rotatably supporting the roller and eccentric opposite end portions positionable in the frame to hold the shaft stationary while the roller turns on the shaft, said frame being constructed to permit free rotation of the shaft to a position where the axis of the shaft is displaced from the axis of the eccentric portions away from the bending shoe, and means for working the bending shoe.

2. In a pipe bender, a frame, a bending shoe pivoted on the frame having a working face formed to receive a length of pipe, a follow bar complementary to the bending shoe for holding the pipe, a strap on the bending shoe for holding the pipe on the shoe, a backup roller disposed behind the follow bar, means for mounting the roller comprising a cylindrical shaft providing a bearing surface rotatably receiving the roller, and eccentric opposite end portions of the shaft positionable in recesses in the frame so that on angular movement of the shaft the eccentric end portions seat in the recesses to retain the shaft stationary while the roller turns on the shaft, said frame being constructed to permit free rotation of the shaft to a position where the axis of the shaft is displaced from the axis of the eccentric portions away from the bending shoe, and means for pivoting the bending shoe.

3-. A combination as defined in claim 2 including a radial projection on one shaft end portion to engage the frame and locate the shaft longitudinally.

4. In a pipe bender,

a frame,

a reciprocable ram on the frame,

a bending shoe pivoted on the ram having a working face curved lengthwise and recessed transversely to receive a length of pipe,

a follow bar recessed transversely complementary to the bending shoe for holding the pipe,

a strap on the bending shoe for holding the pipe on the shoe,

a backu roller disposed behind the follow bar in opposition to the ram, and

a mounting for the roller comprising a cylindrical shaft providing a bearing surface positionable in the roller, and reduced eccentric opposite end portions on the shaft positionable in apertures in the frame corresponding in size to the shaft to support the shaft, so that on angular movement of the shaft the eccentric end portions seat to retain the shaft stationary while the roller rotates on the shaft.

5. A combination as defined in claim 4 including a radial projection on one shaft end portion projecting outwardly beyond the shaft and the recesses in all positions of the shaft to locate the shaft axially.

6. A combination as defined in claim 4 including a radial projection on one shaft end portion having a terminus within the circumference of the shaft bearing surface to pass through the roller and the recesses in one angular position and to extend beyond the adjacent recess when angularly rotated to seat.

7. A pipe bender comprising,

a frame including a pair of spaced parallel plates,

a reciprocable ram on the frame between the plates,

a removable bending shoe pivoted on the ram having a working face curved lengthwise and recessed transversely to receive a length of pipe,

a follow bar recessed transversely complementary to the bending shoe for holding the pipe,

a removable strap on the bending shoe off the axis of the ram for holding the pipe on the shoe,

a backup roller disposed behind the follow bar in opposition to the ram, and

means for removably mounting the roller comprising means providing a plurality of pairs of aligned apertures in the spaced frame plates,

a cylindrical shaft corresponding in size to the apertures providing a bearing surface positionable in the roller,

reduced eccentric opposite end portions on the shaft positionable in the apertures in the frame plates so that on angular movement of the shaft the eccentric end portions seat to retain the shaft stationary while the roller rotates on the shaft, and

means to locate the shaft axially.

8. A pipe bender as defined in claim 7 wherein the means to locate the shaft axially includes a transverse pin in one shaft end portion projecting outwardly beyonfd the shaft and the apertures in all positions of the sha t.

9. A pipe bender as defined in claim 8 wherein the means to locate the shaft axially includes an enlarged terminus on the other shaft end portion concentric with the shaft to pass through the roller and apertures in one angular position and to latch behind one frame plate when angularly rotated to seat.

References Cited UNITED STATES PATENTS 2,375,310 5/1945 Mandl 72-1S4 FOREIGN PATENTS 1,210,700 10/1959 France 72-219 RIOHARD J HERBST, Primary Examiner US. Cl. X.R, 72-219

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