US2743757A - Bending apparatus - Google Patents

Description

M 1%. H. L. TERWHLLIGER BENDING APPARATUS 3 Sheets-Sheat 1.

Filed Dec. 15, 1954 INVENTOR.

TMI L W% H. a... TERWBLMGIEH BENDING APPARATUS 3 Sheets$heet 5 Filed Dec. 1.5, 1954 INVENTOR.

Unite dtates Patent BEN DING APPARATUS Henry L. Terwilliger, Detroit, Mich, assignor to Calumet and Hecla, Ina, Calumet, Micln, a corporation of Michigan Application December 13, 1954, Serial No. 474,840

14 Claims. (Cl. 153-46) The present invention relates in general to a bending apparatus for bending rod, bar or tubing in opposite directions, and finds a particular field of utility in the bending of tubing to be used in the refrigeration field where serpentine and W-shaped coils requiring alternate clockwise and counterclockwise bends are employed.

The invention is embodied in apparatus of the class having two rollers disposed at opposite sides of and with their axes perpendicular to the length of incoming stock to be bent, and positioned directly opposite each other. These rollers may be controlled such that during the bending operation they may both rotate about their own axis, or alternatively, either or both of the rollers may be prevented from rotating about its own axis. In either case, the roller positioned at the side of the tube toward which the tube is to be bent has its axis held in a fixed position and thus acts as a bending die. The remaining roller at the opposite side of the stock is then swung or revolved about the axis of the roller acting as the bending die, thus making a bend in one direction on the stock and returned to its rest or idle position. Upon suficient advancement of the stock such that the tube may be bent in the opposite direction, the roller which was the forming die now becomes the bending roller, and is swung or revolved about the axis of the other roller which is now held in its rest position, thus effecting a bend in the opposite direction.

During the bending operation, the tube may be clamped and positioned such as to prevent movement longitudinally of the incoming tube stock, thus causing the apparatus to act as a compression bender. Alternatively, the stock may be allowed to advance axially while the rollers are prevented from rotating on their own axes, thus caus ing the apparatus to perform a combined bending and drawing operation. It is also within the contemplation of the present invention to carry out the bending operation with the use of a retractable mandrel as is well understood in the art.

it is accordingly an object of the present invention to provide bending apparatus fully adjustable so as to perform bends in opposite directions and of different desired radii.

it is a further object of the present invention to pro vide bending apparatus of the character described in which the radius of curvature of bends of one hand may differ from the radius of curvature of bends of the opposite hand.

it is a feature of the present invention to provide bending apparatus comprising a pair of rollers having laterally spaced parallel axes and means selectively operable to swing or revolve either of said rollers in an arcuate path about the axis of the other roller.

More specifically, it is a feature of the present invention to provide a pair of rotary carriers having laterally spaced parallel axes, a roller on each of said carriers, said rollers being disposed to occupy the same plane, each of said rollers being located when both of said carrlers are in rest position, eccentric to the axis of its own carrier but with its axis coincident to the axis of the other carrier.

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

Figure 1 is a front elevation of bending apparatus with parts broken away.

Figure 2 is a fragmentary side elevational view of the bending apparatus shown in Figure 1.

Figure 3 is a sectional view on the line 3--3, Figure 2.

Figure 4 is a fragmentary sectional view taken on the line 4-4, Figure 2.

Figure 5 is a fragmentary sectional view taken on the line 5-5, Figure 3.

The bending apparatus comprises a frame including a lower stationary base It) and an upper stationary base 12, the latter being held suspended above the lower base 10 by means of a column 14- and being rigidly positioned by means of a vertically and forwardly extending rib portion 16 reinforced by triangular plates 17. In the illustrated embodiment of the invention the top surface of the lower base 10 and the lower surface of the upper base 12 are parallel and lie in horizontal planes. The column 14 is provided with an aperture 17a through which in coming stock to be bent is extended. Preferably, the incoming stock is located substantially midway between the upper and lower bases. Mounted on the top of the lower base 10 is a sub'base or slide in which is adjustable transversely of the lower base ill by means of ways indicated at 2t). Suitable means are provided for adjusting the slide 18 and as herein illustrated, comprises a feed nut 22 associated with an adjusting screw 24 mounted in the lower base ill for rotation and held therein against axial movement. The screw 24 is provided with a hand wheel 26. If desired, suitable means such for example as T bolts (not shown), may be provided to lock the slide 18 in any desired position of adjustment.

In like manner, an upper sub-base or slide 23 is carried at the underside of the upper base 12 and is adjusted horizontally and in parallelism with the adjustment of the lower slide 18 in suitable ways indicated at 3t). Again, adjusting means including the feed nut 32 and feed screw 34 is provided for effecting separate adjustment of the slide 28. The slide 28 may if desired be provided with separate looking or clamping means of con ventional type and not illustrated herein.

Mounted on the lower slide lie is an upwardly projecting portion 36. Rotatably mounted on the projecting portion 36 is a carrier or carrier plate 355 which in the illus trated embodiment of the invention is in the form of a relatively large flat gear mounted at its center for rotation in the portion 36 by a shaft th. In like manner, an upper carrier 42 also in the form of a relatively large flat gear, is rotatably suspended by a shaft M from a downwardly extending projection 46 on the upper slide 28. As will be evident by a comparison of the figures, and particular- 1y Figures 1 and 3, the upper carrier 4L2 substantially overlaps the lower carrier 33 and the axes of the two carriers are thus laterally spaced but are parallel to each other.

The lower carrier Ell is provided with a. bending roller Stl. The roller St) is carried by a shaft 52 extending upwardly from a slide 54 mounted for adjustment longitudinally of ways 5'6 formed in or provided on the upper surface of the carrier it will be observed that the ways 55 extend radially with respect to the axis of the carrier so that adjustment of the slide 54 and the roller 50 is in effect radial of the carrier 33.

In like manner, a second roller 53 is provided which extends downwardly from the upper carrier '42. The

rollers 50 and 58 in the illustrated embodiment of the invention occupy the same horizontal plane and have their peripheral portions concavely formed to correspond to the cross-sectional shape of the stock which is to be bent. In the case of cylindrical tubing the cross-sectional shape of the concave portions of the peripheries of the rollers is thus arcuate. t

From the foregoing it will be observed that in the res-t or idle position of the carriers and rollers best indicated in Figure 3, the axes of the carriers 33 and 42 and the axes of the rollers t and 58 all occupy the same vertical plane which is perpendicular to the direction of advance of the stock toward the rolling station. Furthermore, it will be observed that the roller is located eccentrically with respect to its carrier 38 at such a position that its axis is coincident with the axis of rotation of the carrier 42. In like manner, the roller 58, while eccentric to the axis of its carrier 42, has its axis coincident with the axis of rotation of the carrier 38.

Independently operable means are provided for effecting rotation of the carriers 38 and 42. The lower carrier 33 is adapted to be rotated by an elongated rack 69 carried by or connected to a piston rod 62 of a piston longitudinally 'reciprocable in a cylinder 64. The cylinder 64 is mounted on a plate 66 which is adjustable transversely on a bed 68 carried by the lower base 10. Any suitable means for effecting adjustment of the plate 66 may be provided, but as illustrated herein the means for effecting this adjustment comprises elongated slots 79 and clamping screws '72. justed to a new position, the plate 66 will be adjusted to acorrespond-ing position to properly locate the actuating rack 6i with reference to the toothed periphery of the carrier 53. Sui-table guide means indicated at 74- are provided for guiding the rack during its reciprocation and for insuring its proper meshing engagement during actuation with the toothed portion of the carrier 33.

The upper carrier 42 is provided with similar actuating means including a rack 76 actuated by the piston and cylinder device indicated generally at 73 which iscarried by a transversely adjustable plate 30.

One operation of the bending apparatus contemplates clamping of the elongated stock during the bending operation so that compressive bending of the stock results. For this purpose there is provided a tube clamp best illustrated in Figure 4, comprising a lower clamping element '82 and an upper clamping element 84, these elements having cooperating cylindrical recesses which together define a generally circular opening '36 through which tubular stock such as tubing may extend. The lower clamping element 82 is rigidly mounted on an upward extension 88 of the lower base 10. The upper clamping element 84 is connected by a connecting rod 90 to a piston 92 vertically movable in a cylinder 94 suspendedfrom the underside of the upper base 12. Thus, when fluid pressure is admitted to the interior of the cylinder 94, the upper clamping element 84 is moved downwardly and the recesses in the clamping elements are designed so as to permit firm gripping of the stock during the bending operation. In this operation the bend ing rollers are freely rotatable on their axes and the bending operation is accompanied by compression of the stock at the inner side of the bend.

The upward extension 88 is provided with a forward extension 96 which carries a stock supporting device 98 adapted to guide and engage, and support stock right up to the point where it enters the bight of the rollers. This device puts a restraining pressure on the portion of the stock just before it enters the rollers and prevents its being bent or sprung out of position during the bending operation.

Referring now to Figure 5, there is diagrammatically illustrated means mounting the rollers for adjustment radially of their respective carriers. In thisfigure the roller 50 is shown as carried by the shaft52 which extends upwardly from the slide 54 received in suitable Thus, when slide 18 is adways in the carrier 38. A lock nut 100 is provided and is associated with a washer 102 which extends across the open top of the ways 56 so that when the nut 100 is tightened down, the slide 54 is locked against movement in the ways. The roller 50 may be freely rotatable on its shaft 52 but may for certain operations be locked against rotation thereon by tightening down the nut 104.

From the foregoing description it is believed the operation of the apparatus is clearly evident. Elongated stock, such for example as tubing, is advanced longitudinally of the machine through the opening defined by the clamping elements 82 and 84 and through the guiding surface of the device 98-into the space between the rollers 50 and 58. Suflicient stock isextended through the space between the rollers to bring the portion to be bent into this space. Thereafter, the stock may be bent either clockwise or counterclockwise by rotating the selected one of the carriers 38 and 42. It will be appreciated that during the bending operation, one of the rollers remains fixed and locked in its idle or rest position and operates as the die while the other roller is swung or revolved in an are about the stationary roller to bend the stock. The roller which wasswung in the arc is then returned to its rest or idle position and the stock is further advanced to bring the next zone to be bent into position. At this time the other carrier is actuated in working and return strokes and will bend the tubing in the opposite direction.

As previously indicated, the bending operation may be either compressive bending or bending accompanied by drawing, depending upon whether the tube is clamped by the clamping elements 82 and 84,. or is left free and the rollers 50 and 58 are locked against rotation.

In the embodiment of the invention illustrated it will of course be apparent that a curvature equal to the effective radius of the two rollers 50 and 58 will be imparted to the stock. However, this radius may be quickly changed by employing different rollers which of course requires adjustment of the carriers to bring the peripheral portions of the rollers into adjacency and this of course also requires adjustment of the cylinders 64 and 78.

The present invention also permits bending to different radii in opposite directions. Thus for example, the two rollers 50 and 58 need not be of the same radius so long as they are in proper juxtaposition and each is located with its axis coincident with the axis of rotation of the carrier member for the other roller.

It will be apparent that tubing or other elongated stock may be rapidly and accurately bent to irregular configurations, such for example as W formation, serpentine formation, and the like. The operation involves simply feeding predetermined lengths of stock through the rollers, followed by actuation of the cylinders 64 and 78 in the required sequence. In any case, each cylinder will have fluid admitted thereto to effect a working and return rotation of the associated carrier to move the roller carried thereby from its rest position in a bending stroke in an arc concentric with the axis ofthe other roller and return.

The drawings and the foregoing specification constitute a description of the improved bending apparatus 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. Bending apparatus comprising a pair of roller carriers, means mounting said roller carriers for rotation from a rest position about spaced parallel-axes, a roller on each of said carriers, said rollers having their axes parallel to each other and to the axes of rotation of said carriers, each of said rollers being located eccentrically of its own carrier but with its axis coincident with the axis of rotation of the other-carrier when said carriers are in rest position.

2. Bending apparatus comprising a pair of rolle1wcarriers, means mounting said roller carriers for rotation from a rest position about spaced parallel axes, a roller on each of said carriers, said rollc rs having their axes parallel to each other and to the axes of rotation of said carriers, each of said rollers being located eccentrically of its own carrier but with its axis coincident with the axis of rotation of the other carrier when said carriers are in rest position, and separately operable means for rotating each of said carriers from rest position and return to form opposite bends in elongated stock.

3. Bending apparatus comprising a pair of roller carriers, means mounting said roller carriers for rotation from a rest position about spaced parallel axes, a roller on each of said carriers, said rollers having their axes parallel to each other and to the axes of rotation of said carriers, each of said rollers being located eccentrically of its own carrier but with its axis coincident with the axis of rotation of the other carrier when said carriers are in rest position, means for advancing elongated stock into the bight of said rollers along a path perpendicular to the line joining the axes of said rollers when in rest position, and separately operable means for rotating each of said carriers from a rest position and return to form opposite bends in elongated stock.

4. Bending apparatus comprising a pair of rotary carriers having spaced parallel axes of rotation, means for adjusting the spacing between said axes, a bending roller on each of said carriershaving an axis of rotation spaced from but parallel to the axis of rotation of its own carrier and coincident with the axis of rotation of said other carrier in a rest position in which all of said axes are coplanar, whereby rotation of either carrier from rest position will swing the roller carried thereby about the axis of the other roller to bend stock between said rollers in opposite directions.

5. Bending apparatus comprising a pair of rotary carriers having spaced parallel axes of rotation, means for adjusting the spacing between said axes, a bending roller adjustably mounted on each of said carriers having an axis of rotation spaced from but parallel to the axis of rotation of its own carrier and coincident with the axis of rotation of said other carrier in a rest position in which all of said axes are coplanar, whereby rotation of either carrier from rest position will swing the roller carried thereby about the axis of the other roller to bend stock between said rollers in opposite direction.

6. Bending apparatus comprising a pair of rotary carriers having spaced parallel axes of rotation, means for adjusting the spacing between said axes, a bending roller radially adjustable on each of said carriers having an axis of rotation spaced from but parallel to the axis of rotation of its own carrier and coincident with the axis of rotation of said other carrier in a rest position in which all of said axes are coplanar, whereby rotation of either carrier from rest position will swing the roller carried thereby about the axis of the other roller to bend stock between said rollers in opposite directions.

7. Bending apparatus comprising a pair of rotary carriers having spaced parallel axes of rotation, means for adjusting the spacing between said axes, a bending roller on each of said carriers having an axis of rotation spaced from but parallel to the axis of rotation of its own carrier and coincident with the axis of rotation of said other carrier in a rest position in which all of said axes are coplanar, and selectively operable power means for rotating said carriers from and back to a rest position in which all of said axes are coplanar.

8. Apparatus as defined in claim 7 in which said carriers are in the form of flat gears, and said power means includes racks meshed therewith.

9. Apparatus as defined in claim 7 which comprises selectively operable means for locking said rollers to said carriers to prevent rotation of said rollers thereon.

10. Bending apparatus comprising means for guiding SlZOCli along a straight path, fixed bases at opposite sides of said path, a slide on each of said bases, a rotatable carrier on each of said slides, means mounting said carriers on said slides for rotation with respect thereto about parallel axes occupying a plane perpendicular to said path, means mounting said slides on said bases for independent rectilinear adjustment in said plane and perpendicular to the axes of said carriers, and a circular bending element on each of said carriers having its axis parallel to but spaced from the axis of the carrier on which it is mounted by a radial distance equal to the spacing between the axes of said carriers, whereby in rest position the axis of the bending element on each of said carriers is coincident with the axis of the other of said carriers.

11. Apparatus as defined in claim 10 which comprises means for adjusting each of said elements on its carrier radially of the axis of its carrier.

12. Apparatus as defined in claim 10 which comprises selectively operable power means for rotating either of said carriers while maintaining the other of said carriers fixed against rotation.

13. Bending apparatus comprising a pair of carriers, means mounting said carriers for rotation from a rest position about spaced parallel axes, a peripherally grooved circular bending element on each of said carriers, said elements having their axes parallel to each other and the axes of rotation of said carriers, each of said elements being located eccentrically of its own carrier by an amount equal to the spacing between the axes of said carriers and with its axis coincident with the axis of rotation of the other carrier when said carriers are in rest position.

14. Bending apparatus as defined in claim 13 which comprises means for efiecting independent adjustment of said carriers in the plane containing their axes and in directions in such plane perpendicular to their axes, and means for eifecting independent adjustment of said ele-- ments radially of their respective carriers.

References Cited in the file of this patent UNITED STATES PATENTS 468,301 Cooper Feb. 2, 1892 519,812 Griswold May 15, 1894 2,453,868 Shaw Nov. 16, 1948 2,454,290 Payne Nov. 23, 1948 2,565,940 Armstrong Aug. 28, 1951

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