US3444716A - Device for bending,coiling,or straightening tubing - Google Patents

Description

- Mai 20, 1969 J'. R. MARTIN DEVICE FOR BENDING, COILING, OR STRAIGHTENING TUBING Filed June 13. 1966 FIGA .i-I iI-F incl-.2: .l...

INVENTOR. JOHN R. MARTIN ATTORNE S United States Patent 3,444,716 DEVICE FOR BENDING, COILING, 0R STRAIGHTENTNG TUBING John R. Martin, Allen Park, Mich., assignor to Calumet & Hecla, Inc., Allen Park, Mich., a corporation of Michigan Filed June 13, 1966, Ser. No. 557,002 Int. Cl. B21f 3/02 US. Cl. 72-135 9 Claims ABSTRACT OF THE DISCLOSURE The device comprises a rigid grooved roll associated with a second roll at least the periphery of which is formed of yieldable resilient material. Preferably, the yieldable resilient material is a ring received in a peripheral channel formed in a rigid circular support body. The rolls are adjustable towards and away from each other to vary the amount of curvature imparted to or removed from tubing.

It is an object of the present invention to provide a device for bending, coiling or straightening tubing in which the efiectiveness is readily adjustable.

More specifically it is an object of the present invention to provide a tube bending device comprising a relatively small peripherally grooved steel roller associated with a pressure roller having at least its peripheral portion formed of a readily distortable resilient material such for example as urethane.

It is a further object of the present invention to provide a device as described in the preceding paragraph in conjunction with means for varying the spacing between the rollers so as to vary the pressure applied by the roller comprising yieldable material and thereby to vary the radius of curvature imparted to the tubing.

It is a feature of the present invention to provide tube bending equipment comprising a rigid relatively small peripherally grooved metal roller and a relatively larger pressure roller having yieldable resilient material disposed around its periphery and rigid means at the sides of the yieldable resilient material confining the material against lateral displacement.

It is a further feature of the present invention to provide a device as described in the preceding paragraph in which the roller provided with the yieldable resilient material includes a peripheral groove or channel shaped to provide lateral support to the yieldable resilient material thereby preventing lateral displacement thereof and provided further with a centrally grooved bottom wall aflording an annular space into which the yieldable resilient material is displaced under pressure.

Other objects and features of the invention will become apparent as the description proceeds, especially when taken in conjunction with the accompanying drawings, illustrating a preferred embodiment of the invention, wherein:

FIGURE 1 is a diagrammatic elevational view showing the relationship between rollers and tubing.

FIGURE 2 is a side view of the structure shown in FIGURE 1.

FIGURE 3 is a sectional view illustrating adjustable means for mounting one of the rollers.

FIGURE 4 is an enlarged fragmentary sectional view through the roller provided with yieldable resilient material.

FIGURE 5 is a fragmentary elevation of an alternative pressure adjusting structure.

FIGURE 6 is a diagrammatic showing of a plurality of sets of rollers used concurrently.

The device disclosed in the figures may be employed in bending, coiling or straightening tubing by passing the 3,444,716 Patented May 20, 1969 tubing between a pair of opposed rollers. One roller 10 is formed of metal, such for example as steel, and is provided with a peripheral groove 12 of semi-circular cross section and conforming to the diameter of the tubing to be operated upon.

Associated with the relatively small metal roller 10 is a pressure roller 14 having the peripheral portion 15 formed of yieldable resilient material. This material is a rubber-like material of medium hardness having for example a hardness in the neighborhood of 70 on a Shore durometer. A suitable material for this purpose is urethane. The outer surface of the yieldable resilient material may if desired be provided with a shallow annular groove 16, or this groove may be omitted and the outer surface of the yieldable material may be a truly cylindrical surface.

In operation one or both of the rollers is driven and the end of a tube T to be bent is advanced on a horizontal supporting table 17 to introduce the end of the tubing into the bight between the rollers. The table 17 may have a flat upper surface or it may be provided with a groove conforming to the diameter of the tubing, the groove being of a depth not exceeding the radius of the tubing.

In FIGURE 4 the detailed construction of the pressure roller 14 is illustrated. The roller comprises a circular support body 18 having a generally cylindrical peripheral surface 20 provided intermediate its edges with an annular relief groove 22. At one edge of the body 18 is pro vided a flange 24. The yieldable resilient ring 26 is provided as illustrated in FIGURE 4 and is retained in position by a support plate 28, the peripheral edge of which has the same diameter as the [flange 2'4 and is adapted to extend to the outer surface of the yieldable ring 26. The plate 28 is attached to the body 18 by suitable means such for example as screws (not shown).

Referring now to FIGURE 3, there is illustrated mechanism for supporting the rollers in operative relation, for driving one of the rollers and for providing adjustment of one roller radially of the other so as to vary the pressure developed by distortion of the yieldable ring and thereby to predetermine the radius of curvature imparted to the tubing. In this figure a support 30 is provided having a pair of upstanding flanges 32 and 34 separated to provide a roller receiving space 36 therebetween. The relatively small peripherally grooved metal roller 10 is supported on a drive shaft 38 to one end of which is fixed a drive gear 40 in mesh with a pinion 42 driven by suitable means such for example as a motor (not shown). The relatively large roller 14 is supported on a shaft 44 the ends of which are vertically adjustable in elongated slots 46 formed in the flanges 32 and 34. Adjustment screws 48 are provided extending through threaded openings into the slots 46 and the inner ends of the screws are illustrated as engaging the opposite ends of the shaft 44.

In use the roller 10 is driven in rotation through the gearing 42, 40 and the frictional engagement between the rollers causes the pressure roller 14 to rotate with the same surface speed as the small steel roller. The axial spacing between the rollers 10 and 14 is adjusted by suitable adjustment of the screws 48 and accordingly the deflection of the yieldable resilient material of the ring 26 is similarly varied. The distortion of the yieldable resilient material applies bending pressure to the portion of the tubing extending to the left of a line joining the centers of the rollers as seen in FIGURE 1 and this pressure is effective to bend the tubing. It is found that the tubing is bent to a substantially uniform radius and this radius is directly controllable by varying the pressure applied through the adjusting screws 48.

Referring now to FIGURE 5, there is illustrated a modification of the device for adjustably supporting a shaft 50 mounting one of the rollers for adjustment radially with respect to the other. In this embodiment the ends of the shaft are journaled in blocks 52 slidable vertically in slots 54- provided in support structure such as the flanges 32 and 34 seen in FIGURE 3. The blocks 52 are biased upwardly by resilient means such as coil compression Springs 56 the lower ends of which as illustrated may be received in pockets 58. Adjusting screws 60 extend through threaded openings 62 in the support structure and engage the upper ends of the blocks 52.

In use the blocks 52 are urged upwardly against the lower ends of the adjusting screws 66 not only by the action of the compression springs 56 but also by the yieldable force exerted by the resilient ring 26 as previously described.

As the tube passes between the rollers, the flexible ring 26 deflects in the area of contact with the tube, thus increasing the length of surface in contact with the tube. This increased length of contact by one roller and not the other causes the tube to be bent to a definite predetermined degree with respect to the solid roller. The amount of pressure of the yieldable ring bearing against the tube determines the amount of deflection of the yieldable material and thus the amount of bend or curvature imparted to the tube at the point of roller contact. The tube being drawn between the rotating rollers results in this bend being placed progressively longitudinally of the tube.

The device can be applied to form coils or any portion thereof, flat or pancake coils, odd shaped coils, or U-bends. It can also be used to straighten previously coiled or bent metal or to straighten any tube that requires straightening.

In order to form a tube into various designs, or in order to straighten a tube, it may be necessary to have more than one set of rollers. For example, two pairs of rollers positioned in different planes in relation to each other will produce helical tubing.

This arrangement is diagrammatically illustrated in FIGURE 6 where one set of rollers 70 bends the tubing T into a continuous curve which is then led to a second set of rollers 72 occupying a plane different from the plane containing rollers 70 with the result that the tubing after emerging from the rollers 72 is given a helical configuration.

In the foregoing description reference has been made to the use of a roller having a ring of yieldable resilient material at its periphery which is of larger diameter than the rigid roller associated therewith. This is ordinarily the desirable arrangement but in some cases the two rollers may have equal or substantially equal diameters and even in some cases, the rigid roller may be of larger diameter than the roller provided with the yieldable peripheral portion.

In FIGURE 1 of the drawing a rigid support 17 has been illustrated and described for supporting a straight section of the tube T as it advances into the bight of the rollers. Where the rollers are used for straightening tubing it is desirable in some cases to provide, in addition to the support 17, a generally flat or grooved tube support similar to the support 17 at the other side of the rollers.

The advantages of the tube bending device disclosed herein reside in its simplicity of design, requiring less tooling, and being more versatile in application. More specifically, the use of the pressure roller with the yieldable resilient peripheral ring shows less tendency to flatten tubing during bending, reduces marking of the tube, and provides a much greater pulling force on the tube due to the area engaged by the yieldable ring and the resultant high friction.

The drawings and the foregoing specification constitute a description of the improved device for bending, coiling or straightening tubing in such full, clear, concise and exact terms as to enable any person skilled in the art to practice the invention, the scope of Which is indicated by the appended claims.

What I claim as my invention is:

1. A tube coiling device for coiling a length of tube without any interior tube supporting means, said device having a roller set comprising a rigid roller formed in its entirety of rigid material and having a peripheral groove of substantially semi-circular cross-section having a radius substantially equal to the radius of tubing for which the device is designed, a pressure roller substantially larger in diameter than said rigid roller comprising a rigid support body having at its periphery a ring of yieldable resilient material, means for supporting said rollers at fixed positions with their peripheral portions in pressure contact, means for driving one of the rollers in continuous rotation, and means for varying the spacing between the axes of said rollers to vary the bending pressure applied to tubing advanced between said rollers to vary the radius of bend imparted thereto.

2. A device as defined in claim 1 which comprises a straight support surface at the inlet side of said rollers extending generally perpendicularly to the plane containing the axes of both of said rollers.

3. A device as defined in claim 1 in which said ring is rubber-like material of medium hardness.

4. A device as defined in claim 3 in which said materail has a hardness in the neighborhood of on a Shore durometer.

5. A device as defined in claim 3 in which said material is urethane.

6. A device as defined in claim 5 in which said material has a hardness in the neighborhood of 70 on a Shore durometer.

7. A device as defined in claim 1 comprising in addition a second roller set substantially similar to the first set positioned to receive bent tubing from said first set, the second roller set having its rollers occupying a plane disposed at an angle to the plane occupied by said first roller set.

8. A tube bending device having a roller set comprising a rigid roller formed in its entirety of rigid material and having a peripheral groove of substantially semicircular crosssection having a radius substantially equal to the radius of tubing for which the device is designed, a pressure roller comprising a rigid circular support body having at its periphery a ring of yieldable resilient material, means for supporting said rollers with their peripheral portions in pressure contact, means for driving one of the rollers in rotation, and means for varying the spacing between the axes of said rollers to vary the bending pressure applied to tubing advanced between said rollers to vary the radius of bend imparted thereto, the peripherally grooved rigid roller having a diameter substantially less than the diameter of the pressure roller, said circular support body having an annular channel at its periphery in which said resilient ring is located, the sides of said channel extending to the outer surface of said ring to confine the ring against lateral deflection.

9. A device as defined in claim 8 in which said channel has a bottom surface grooved midway between its edges to provide an annular space inwardly of the central por tion of said yieldable ring.

References Cited UNITED STATES PATENTS 3,371,513 3/1968 Achler et al. 72166 1,908,373 5/1933 Loepsinger 72166 X 2,310,091 2/1943 Kepler 72l72 X 2,335,028 11/1943 Rose et al 72-173 X 2,467,671 4/1949 Hurlburt et al. 72-175 2,769,477 11/ 1956 Neer 72--l66 3,195,338 7/1965 Bram 72l45 X 3,205,689 9/1965 Joseph 72-146 3,229,489 1/1966 Huet 72166 X 3,279,234 10/1966 Ames 72-465 X MILTON S. MEHR, Primary Examiner.

US. Cl. X.R.

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