US2749962A - Helix former - Google Patents

Description

June 12, 1956 H. L. KITSELMAN 2,749,962

HELIX FORMER Filed Nov. 21, 1951 2 Sheets-Sheet l 3a a; 3 9 a 32 45 JNVE TOR.

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June 12, 1956 H. KITSELMAN HELIX FORMER 2 Sheets-Sheet 2 Filed Nov. 21 1951 .M mm M M: e a V M r K r m R JZM'RY Z,

United States Patent HELIX FORMER Harry L. Kitselman, Muncie, Ind, assignor to Kitselman Brothers, Muncie, Ind., a corporation of Indiana Application November 21, 1951, Serial No. 257,467

15 Claims. (Cl. 153-64) This invention relates to a machine for forming wire continuously into a helix. The invention is especially suited for the formation of a helix of relatively long pitch, by which I mean a helix whose pitch is considerably greater, and usually several times greater, than its diameter. The machine operates to bend at a constant curvature a wire which is fed into it and to rotate the plane of bending about the axis of the Wire.

It is an object of the invention to produce a machine of the type described which can be simply and economically constructed and which is readily adjustable to vary the pitch, the diameter, and the hand of the helix produced.

In carrying out the invention in its preferred form I employ a rotating bending unit having a series of three or more wire-engaging elements, desirably rollers, adjacent ones of which are offset transversely of the axis of unit rotation to produce a bend in the wire. Wire-feeding means forces the wire into and through the bending unit, which rotates at a speed co-ordinated with the speed of wire-feed to produce the desired helix. The wireengaging elements of the bending unit are mounted for independent adjustment transversely of the axis of unit rotation so as to vary the degree of bending they effect. In addition, the wire-engaging elements are mounted for adjustment axially of the unit to vary the pitch of the helix produced. Conveniently, the wire-feeding means is arranged to feed Wire at a constant rate and a variablespeed means is employed to rotate the bending unit. If the driving means for the bending unit is made reversible, helixes of either hand can be produced.

The accompanying drawing illustrates the invention: Fig. 1 is a plan view of the helix-forming machine; Fig. 2 is a fragmental front elevation of the machine shown in Fig. 1; Fig. 3 is a fragmental view similar to Fig. 2 but on an enlarged scale illustrating details of the bending unit; Fig. 4 is a rear elevation of the machine; Fig. 5 is a transverse section on the line 5-5 of Fig. 3; and Fig. 6 is a fragmental view similar to Fig. 5, but showing a modified construction.

The machine shown in the drawing comprises a base 10 from which there are supported a wire-feeding unit 11, a wire-bending unit 12, a variable-speed transmission unit 13 and a driving means such as an electric motor 14 (Fig. 4) for driving the wire-feeding unit 1.1 and transmission 13. As shown, the motor 14 is mounted near the bottom of the base and is connected through a belt drive 15 to the feed unit 11 and transmission device 13.

The wire-feed unit shown is conventional in type and includes two pairs of wire-gripping rolls. Each such pair of rolls comprises a lower 'roll mounted on a fixed axis and an upper roll 21 rotatably supported from a vertically movable slide 22. A leaf spring 23 urges the slides 22 downwardly with a force which can be varied by the adjusting nuts 24. The feed rolls are provided With coplanar grooves which receive the stockwire 2'5,

Patented June 12, 1956 and the lower rolls are driven through gearing (not shown) from a pulley 27 over which the belt 15 passes. Between and beyond the feed rolls 20, 21, the stock wire 25 is supported by suitable guides 28.

Supported from the base 10 beyond the wire-feeding unit 11 in the direction of wire feed is a housing 30 within which there is mounted a hollow shaft 31 rotatable about an axis aligned with the stock wire 25 and operatively connected as through worm gearing (not shown) with the driven element of the transmission device 13. Desirably, the shaft 31 is provided with a bushing or liner 32 which rather closely receives and supports the stock wire 25 after it leaves the feeding unit 11.

The transmission device 13, which is driven from the belt 15 as above noted, is desirably of the type which provides an infinitely or steplessly variable ratio between its driving and driven elements. Reversibility of the shaft 31 necessary to the alternative production of righthand or left-hand helixes, may be provided by the transmission device 13; but if the transmission device itself is not capable of driving the shaft 31 alternatively in either direction, a supplementary reversing gear may be employed for the purpose.

The wire-bending unit 12 comprises a pair of spaced, co-axial heads 35 and 36, the former connected to the shaft 31 and the latter rotatably supported from the base 10 through an appropriate bearing 37. Conveniently, the shaft 31 is provided with a flange 38 to which the head 35 is removably secured as by means of screws 3?.

Extending between and secured to the heads 35 and 36 on opposite sides of their common axis of rotation are two parallel rods 40 which slidably support crossmembers 41 providing space mountings for wire-engaging elements desirably in the form of grooved rollers 42. Each of such rollers is supported for rotation about its own axis in a yoke 43 which is in turn supported from the cross member 41 for rotation about an axis coplanar with and perpendicular to the axis of rotation of the wire-bending unit. In addition to being rotatable about the axis last mentioned, each yoke 43 is mounted for adjustment transversely of the axis of unit rotation.

In the preferred arrangement for supporting the yokes from the cross-members 41, each yoke has a shank 4d rotatably received in a sleeve 45 which is slidable radially of the bending unit in the associated cross-member 41. A clamp screw 46 extends through the end of the sleeve 45 and into the shank 44 so that the yoke 43 may be clamped in any desired position of adjustment about the shank-axis. On diametrically opposite sides of the sleeve 45 are two holes which are parallel to the axis of the sleeve and each of which is located half in the sleeve and half in the cross-member 41. In one of such holes, the half located in the cross member 41 is provided with screw threads, as indicated at 47, while in the other hole the half located in the sleeve 45 is screw-threaded as shown at 48. The former hole receives a set screw 49 which cooperates with the screw threads 47 and seats against a shoulder 50 at the inner end of the hole-half in the sleeve 45; while the other hole receives a set screw 51 cooperating with the screw threads 48 and similarly seating against a shoulder 52. It will be obvious that the screws 49 and 51 can be rotated tomove the sleeve 45 toward or away from the axis of rotation of the wire-bending unit and that engagemcnt of the screws with the shoulders 5d and 52 will lock the sleeve 45 in any desired position of adjustment.

In manufacture of the sleeve-adjusting means just described, which is not new with me, the sleeve 45 is secured in the cross member 41, and two holes are drilled on diametrically opposite 'sides of the "sleeve axis with their 3. axes approximately coinciding with the outer surface of the sleeve. One of these holes is conveniently deeper than the other and has a diameter equal to the tap-drill diameter of the threads on the screws 49 and 51; while the other, or shallower, hole has a diameter equal to or slightly greater than the outer diameter of the screws 4-9 and 51. With the sleeve still held in the position it occupied when the holes were drilled, the deeper hole is tapped to provide the threads 47 and 43. After the tapping operation, the sleeve 45 is turned through 180 about its axis into the position shown, and the screws 49 and 51 are inserted.

For the purpose of locating the cross-members 41 in the desired positions of axial adjustment along the rods 41, any convenient form of clamping means may be employed. In the arrangement illustrated each of the crossmembers 41 is provided with a pair of holes 55 located in a plane normal to the rods 40 and offset from but intersecting the holes which slidably receive the rods 40. In each of tl e holes 55, there is a slidablc plug 56 having one end struclt off to conform approximately to the curvature of the surface of the rod 40. A clamp screw 5'7 serves to draw the plug 56 longitudinally of the hole 55 and to force it into firm gripping engagement with the associated rod 40.

in setting up the machine illustrated to produce a helix of any given proportions, the cross-members 41 are distributes. along the rods 40 at intervals equal to one-half the pitch of the helix which is to be formed, adjacent cross members facing in opposite directions transversely of the axis of rotation of the bending unit. The sleeves 45 are then adjusted axially of themselves and radially of the unit to produce the desired degree of bending of the wire. To facilitate threading of the wire through the bending unit, advancing of the sleeves 45 to their final position may be deferred until after the wire has been passed completely through the bending unit. With the clamp screws 47 loosened to permit free rotation of the yokes 43 in the sleeves 45, the bending unit is ready for its initial operation. Before beginning such initial operation, the transmission device 13 is adjusted to coordinate properly the rotational speed of the bending unit both with the rate of wire-feed and with the pitch of the which is to be produced. The machine is then p in operation, the rollers 2t}-21 feeding the stock wire axially through the shaft 31 and the bending unit 12. rotating to rotate relatively to the stock-wire the plane in which the wire is bent by the opposing pressures which the rollers 42 exert upon it. The grip of the feed rolls on the wire prevents the stock wire from rotating; t a result, the wire emerges from the bending unit ii in the form of a helix 60. Since the clamp screws 47 are loosened. and the yokes 43 free to swing about the axes of the sleeves 45, the rollers 42 will assume inclined pt... l ons conforming to the pitch angle of the helix being produced. After a short period of initial operation, the machine may be stopped and the helix checked to determi "2 whether or not any adjustment of the rolls 42 either transversely or axially of the bending unit is necessary to produce a helix of the required conformation. If any such adjustments are indicated, they are made and the lTlI hiue is again placed in operation. After it has been date iined that the rolls 42 are properly adjusted both ally and axially the clamp screws 47 may be tightened.

l? the rotational speed of the shaft 31 is exactly coordi with the helix-pitch and rate of stock-wire feed, tb'v finished helix 6t) will emerge from the machine withrotating about its axis. However, if the rotational ced of the shaft 31 is not exactly co-ordinated with the l'.ElCil and rate of stock-wire feed, the completed helix will rotate in one direction or the other depending upon whether the rotational speed of the shaft 31 is greater or less than it should be. I

it may or may not be advisable to employ all the rolls 42 in effecting the necessary transverse bending of the wire. If the helix-diameter is great relatively to the diameter of the stock wire it may be desirable to distribute the bending by increasing progressively from one end of the head to the other the extent to which the rollers 42 project beyond the axis of bending-unit rotation. On the other hand, if the helix diameter is relatively small, the necessary bending may be efiected by only three or four successive rollers 42. in the latter event, it is desirable to employ as the bending rollers those located near the forward or left-hand end (Figs. 1 and 3) of the bending unit, the remaining rollers near the opposite end of the bending unit being adjusted merely to hold the wire in position without exerting any effective bending effort.

in adjusting the respective positions of the rollers 42, it is necessary to take into account the spring-back of the wire after it is relieved of the forces exerted on it by the rollers. Generally speaking, the spring-back which the finished helix undergoes when relieved of roller-pressure decreases helix-diameter to a slight extent and also slightly increases the pitch of the helix.

l n the particular arrangement illustrated in the drawings, the cross-members are distributed along substantially the entire length of the rod 49. If the helix had a shorter pitch than that illustrated, the cross-members would be closer together and would occupy less than the full length of the rods 40. in such a situation, it is desirable to group the cross-members near the discharge end of the bending unit, maintaining the proper interval between them, and to provide for the shaft 31 a liner 32 which will project rearwardly from the shaft and support the stock wire to a point adjacent the first of the wirebending rollers 42.

Obviously, the hand of the helix produced will depend upon the direction in which the bending unit rotates. By providing a reversible drive for the shaft 31 and by utilizing the rotatability of the yokes 43 about the axes of their shanks 44, helixes of. either hand can be produced.

in the modified form of wire-engaging element shown in Fig. 6, each grooved roller 42 is replaced by a pair of rollers 42 mounted on a support 43 with their axes per endicular to each other and their peripheral portions closely adjacent to define a wire-receiving space functionally equivalent to the groove in the roller 42. The rollers 42 may be the outer races of ball-bearings.

it will be understood that the structure illustrated and described above is a preferred form and that changes in the construction and arrangement may be made without departing from the scope and spirit of the invention claimed.

l claim as my invention:

t. In a. machine for forming wire or the like into a helix. 2; wire-bending unit, means supporting said unit for rotation about an axis, means for feeding wire longitudinally of itself to said unit along a line coincident with such axis, said unit including a series of wireengaging members spaced from each other axially of the unit, adjacent ones of said members being offset oppositely from each other transversely of the axis of unit rotation to cause progressive bending of the wire fed through the unit, said wire-engaging members being provided with wire-receiving grooves and being mounted in said supporting means for angular adjustment about axes radial adjustment parallel to the axis of bending-unit rotation.

5. The invention set forth in claim 4 with the addition that said wire-engaging members are rollers.

6. The invention set forth in claim 1 with the addition of means supporting said wire-engaging members for adjustment both transversely of and parallel to the axis of bending-unit rotation.

7. The invention set forth in claim 6 with the addition that said wire-engaging members are rollers.

8. In a machine for forming wire or the like into a helix, a wire-bending unit, means supporting said unit for rotation about an axis, means for feeding Wire longitudinally of itself to said unit along a line coincident with such axis, said unit including a series of wire-engaging members spaced from each other axially of the unit, adjacent ones of said members being offset oppositely from each other transversely of the axis of unit rotation to cause progressive bending of the wire fed through the unit, and means for driving said Wire feeding means and said wire-bending unit, said driving means including adjustable mechanism to vary the relation between the rate of wire feeding produced by said wire-feeding means and the rate of rotation imparted to said Wire-bending unit.

9. The invention set forth in claim 8 with the addition of means supporting said wire-engaging members for adjustment transversely of the axis of bending-unit rotation.

10. The invention set forth in claim 8 with the addition of means supporting said Wire-engaging members for adjustment parallel to the axis of bending-unit rotation.

'11. The invention set forth in claim 8 with the addition of means supporting said wire-engaging members for adjustment both transversely of and parallel to the axis of bending-unit rotation.

12. In a machine for forming wire or the like into a helix, a rotatable shaft, a wire-bending unit located at one end of said shaft and operatively connected thereto for rotation therewith, said shaft having an axial opening through which wire may be fed to the bending unit, wire-feeding means located at the other end of the shaft for feeding wire through said opening to and through the bending unit, said bending unit including a series of wireengaging members spaced from each other axially of the bending unit, adjacent ones of said members being offset oppositely from each other transversely of the axis of unit rotation to cause progressive bending of wire fed through the unit, means operatively connected to said shaft for rotating it and the unit in timed relation to the rate at which the feeding means feeds wire, and a liner removably mounted in said shaft and having an axial opening which closely receives the wire and locates it substantially coincident with the axis of the shaft.

13. In a machine for forming wire or the like into a helix, a wire-bending unit, means supporting said unit for rotation about an axis, means for feeding wire longitudinally of itself to said unit along a line coincident with such axis, said unit including a series of wire-engaging members spaced from each other axially of the unit, adjacent ones of said members being offset oppositely from each other transversely of the axis of unit rotation to cause progressive bending of the Wire fed through the unit, and means for rotating said unit about its axis in timed relation to the rate at which the feeding means feeds the wire, said bending unit including two rods parallel to and on opposite sides of the axis of unit rotation, cross-members extending between and slidable along said rods, a yoke associated with each cross-member and pivotally supported therefrom for rotative movement about an axis perpendicular to the axis of unit-rotation, each of said wire-engaging members comprising a roller rotatably supported from one of said yokes, and means for releasably securing each of said cross-members in a fixed position of adjustment along said rods.

14. In a machine for forming wire or the like into a helix, a wire-bending unit, means supporting said unit for rotation about an axis, means for feeding wire longitudinally of itself to said unit along a line coincident with such axis, said unit including a series of wire-engaging members spaced from each other axially of the unit, adjacent ones of said members being offset oppositely from each other transversely of the axis of unit rotation to cause progressive bending of the wire fed through the unit, and means for rotating said unit about its axis in timed relation to the rate at which the feeding means feeds the wire, said bending unit including a support for each of said wire-engaging members, each of said supports having an opening extending perpendicularly to the axis of bending-unit rotation, a sleeve slidably mounted in said opening for movement toward and away from such axis, means for holding said sleeve in adjusted position along its path of sliding movement, and a yoke having a shank received in said sleeve for pivotal movement about an axis perpendicular to the axis of bendingunit rotation, each of said wire-engaging members comprising a roller rotatably mounted in one of said yokes.

15. In a machine for forming wire or the like into a helix, a rotatable shaft, a wire-bending unit located at one end of said shaft and operatively connected thereto for rotation therewith, said shaft having an axial opening through which wire may be fed to the bending unit, wire-feeding means located at the other end of the shaft for feeding Wire through said opening to and through the bending unit, said bending unit including a series of wireengaging members spaced from each other axially of the bending unit, adjacent ones of said members being offset oppositely from each other transversely of the axis of unit rotation to cause progressive bending of wire fed through the unit, and means operatively connected to said shaft for rotating it and the unit in timed relation to the rate at which the feeding means feeds wire, said last named means being power-operated and adjustable to vary the speed of bending-unit rotation.

References Cited in the file of this patent UNITED STATES PATENTS 600,790 Jones Mar. 15, 1898 1,260,799 Porath Mar. 26, 1918 1,262,120 Smurr Apr. 9, 1918 FOREIGN PATENTS 66,479 Sweden June 27, 1927

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