US2590806A - Wire feeding machine - Google Patents

Description

March 2,5, 1952 R. c. voRDERs'rRAssL- 2,590,806

WIRE FEEDING MACHINE Filed NOV. 13, 1948 v 2 SHEETS SHEIET 1 Eg. Z f

Il 1| "1| u u n 2 6b I I lul l 26 l 29 jO--3/ H J 29a I El 24C I Z4 LFE NYE? l March 2 5, 1952 R. c.. voRDx-:RsTRAssE 2,590,806

` WIRE FEEDING MACHINE Filed NOV. l5, 1948 2 SHEETS-SHEET 2 Ivy-51h22.?"

Patented Mar. 25, `1952 WIRE FEEDING MACHINE Rudolph C. Vorderstrasse, Sterling, Ill., assignor to Northwestern Steel and Wire Company, Sterling, Ill., a corporation of Illinois Application November 13, 1948, Serial No. 59,931

l Claim. l

This invention relates to an improved mechanism for periodically feeding successive identical lengths of Wire in .an axial direction relative to the Wire, and particularly to an improved cross wire feeding mechanism for use in fence making machines.

It is a well known fact in the art of fence making that one of the most critical factors in the operation of any fence making machine is the mechanism by which successive identical lengths of cross wires are fed into the machine for association with the line wires. The problems involved in such a wire feeding operation are readily apparent when it is considered that modern fence making machines operate at a rate requiring the insertion or feeding of from 50 to 100 cross Wires into a predetermined relationship with respect to the line wires each minute that the machine operates. Furthermore, the length of the successive cross wires fed into the machine must be carefully controlled, for a Wire that is too short Will result in a defective section of fence, while a wire that is too long will cause a malfunction of the fence making machine, with the attendant loss of production time required to shut down the machine and remove' the extra length of wire.

Concisely stated, the problem is that of intermittently, yet at a high cyclic rate, axially feeding'substantially identical lengths of cross Wire into a predetermined position in the fence mak-l ing machine. The fact that an intermittent feed is required necessarily means that the cross Wire must be intermittently advanced and, in order to maintain variations of the length of the wire at a minimum, this means that the wire ymust be rapidly accelerated to its normal feeding speed and then equally rapidly decelerated when sufricient length of Wire has been fed into the machine.

Cross wire feeding mechanisms have heretofore been known which employ a pair of constantly rotating feed rollers whose axes were periodically shifted relative to each other to bring the rollers into clamping engagement with the cross wire for a predetermined length of time, sufficient to accomplish the feeding of the required length of cross wire, and then such rollers were axially displaced to interrupt the feeding motion of the cross wires. This invention relates to -a feeding mechanism of this general type, but embodies certain detailed improvements in such feeding mechanisms which, although they appear to be of a detailed nature, have resulted in very substanti-al improvements in the accuracy and reliability of the cross Wire feeding operation.

Accordingly, it is an object of this invention to provide an improved mechanism for successively feeding substantially identical lengths .of

wire.

A particular object of this invention is to provide an improved cross wire feeding mechanism for use in fence making machines which will successively feed substantially equal lengths of cross wires into a fence making machine for association with the line Wires.

Another particular object of this invention is to provide an improved configuration of the wire feeding nip defined by a pair of cooperating feed rollers.

Still another object of this invention is to provide an improved cam controlled mechanism for periodically shifting the axes of the feed rollers relative to each other to effect the intermittent feeding of a cross wire through the nip thereof.

The specific nature of the invention as well as other objects and advantages thereof Will become apparent to those skilled in the art from the following detailed description of theA annexed sheets of drawings which, by way of preferred example only, illustrate one specific embodiment of the invention.

On the drawings: 4

Figure l is a plan view of a Wire feeding mechanism embodying this invention which was constructed particularly for use in a fence making machine;

Figure 2 isa side elevational view of the device of Figure l;

Figure 3 is an enlarged scale, partial elevational view, with portions thereof in section, of the feeding roll employed in the device of Figure 1;

Figure 4 is an enlarged scale sectional View of the nip portion of the feeding rolls; and

Figure 5 is a schematic diagram illustrating the shift in relative axial position of the two feed rolls accomplished by the cam controlled mechanism embodying this invention.

As shown on the drawings:

'When employed in conjunction with a fence making machine, a wire feeding device embodying this invention is generally mounted adjacent the side of the fence making machine, and since the construction of the fence making machine forms no part of this invention, it has not been shown in the drawings. A suitable articulated framework l0 is provided for supporting the varij ous elements of the wire feeding device and such framework supports a pair of spaced bearing brackets II at an elevated position, approximately adjacent the height at which it is desired to feed predetermined lengths `of cross wires into the fence making machine. Bearing brackets I I provide bearing support for a iixed roll shaft I2 to which is secured a lower feed roll unit I3 and a driving'pinion I4. Pinion I4 is driven by a chain I5 which cooperates with Ia large gear I6 mounted on a shaft II near tlie bottom of the machine and having a Igear I8 secured theretof 3 Gear I8 is driven by a pinion I9 mounted on the end of the shaft 2Il= of an electric motor 2 I. In this manner, the bottom feed roll unit I3 is continuously rotating during the operation of the feeding device.

A shaft 22 is supported in the top portions of the bearing brackets II and an eccentric sleeve 23 (Figure 3) is rotatably journaled on such shaft, the bore 23a of the sleeve being eccentrically located with respect to the external periphery of sleeve 23. A top feeding roll unit 24 is then journaled on the exterior of eccentric sleeve 23. It is therefore apparent that by angularly adjusting the sleeve 23 relative to its supporting shaft 22, the effective vertical displacement between the axis of rotation of the upper feed unit roll 24 and the lower feed roll unit I3 will be varied. Thus the effective width of the nip defined by the feed roll units I3 and 24 may be adjusted.

The feed roll units I3 and 24 are of substantially identicalconstruction and both comprise a cylindrical roll portion I3a and 24a respectively in the centers of which are formed annular wire grasping grooves |317 and 24b respectively. As is best shown in Figure 4, the grooves I3b and 24h are of generally triangular configuration and this construction is in distinct contrast to conventional arrangements which heretofore have employed a generally semi-circular cross sectional configuration of the Wire feeding groove. In addition, each roll element I3a and 24a is respectively co-rotatably secured to a gear member I3a and 24e. Such gear members are of identical size and have teeth of sufficient length to maintain the gears in continuous engagement irrespective of variations in the relative axial position of the two feed roll units which might be effected by adjustment of the eccentric angular position of the eccentric sleeve 23. Hence both feed roll units rotate at identical speeds.

The size of the wire grasping grooves I3b and 24o provided in the roll parts I3a and 24a is so proportioned as to provide a secure clamping engagement upon any length of wire W inserted therebetween, and to prevent the remainder of the peripheral surfaces of the cooperating roll parts coming into contact. In this manner, all of the biasing force that is applied between the two feed rolls to urge them toward a minimum nip position is transmitted to a clamping engagement upon the wire and, as a result, whenever the two feed roll units are shifted in their minimum nip position, the wire will be pulled through the nip at the same speed as the peripheral speed of the wire grasping grooves and little slippage will occur, even during the initial acceleration of the wire.

To periodically shift the two feed roll units I3 and 24 to their minimum nip or wire feeding position, this invention provides an eccentric operating arm 26 which has an enlarged hollow cylindrical portion 26a surrounding and keyed to a projecting portion of 'the eccentric sleeve 23. One end 2Gb of the operating arm is bifurcated and pivotally secured to a vertically extending rod 29 by a pin 30 which passes through a block 29a threadably secured to rod 29.

l The other end of the operating arm 26 engages an adjustable limit stop, such as the screw 3l mounted in a suitable bracket 32 supported on the frame II). With this arrangement, any vertical movement of the rod 29 will produce an angular shifting of the position of the eccentric sleeve 23 with respect to its supporting shaft 22 and hence produce a corresponding shift in the 4 relative axial separation of the two feed roll units I3 and 24.

The bottom end 29h of control rod 29 is pivotally'secured to one end of a link 33 which has its other end pivotally secured to a bracket 33a on frame I 0 by a pivot pin 34. A cam follower roller 35 is supported on link 32 in depending relationship by a bracket 36. A cam 31 is secured to the main drive shaft in the vicinity of the cam follower roller 35. A spring 38 is then provided, operating between the floor or any stationary part of the deviceto urge the link 33 downwardly and hence maintain the cam follower roller 35 in engagement with the periphery of cam 31. The stop 3I is suitably adjusted to permit such engagement.

The cam .31' is so contoured as to periodically effect the lifting of the cam follower roller 35 against the bias of the spring 38 and hence produce a slightangular shift in the position of the eccentric sleeve 23, hence shifting the feed roller units I3 and 24 from their proximate to their remote positions. The rate of rotation of the main drive shaft is preferably selected so that cam 31 effects the shifting of the movable feed roller 24 from its inoperative to its wire feeding position relative to the fixed feed roller I3 once during each rotation of the cam 31.

It should be particularly noted that with the described arrangement, the feeding of the wire W takes place only when the cam follower roller 35 is contacting the low portions, of the cam 31. The on cam positions of the cam follower roller 35, i. e., when the cam follower roller 35 is engaged by the high portions of the surface of cam 31 effects the shifting of the movable feed roller 24 to 'its non-feeding position. This arrangement has been found to be particularly desirable and to yield greatly improved performance as compared with mechanisms wherein the wire feeding or minimum nip positions of the two feed rolls corresponds to an on cam position of the cam follower roller. The reason for such difference is believed to lie in the fact that when the l.g5 feeding movement is accomplished during the off cam position of the cam follower roller 35, the full force of the spring 38 is available to press the fed rolls into biting engagement with the wire W, and there is no tendency of the feed rolls l to chatter andthus intermittently decrease their biting engagement with the wire W and permit the slight slipping of the wire. This condition cannot be realized with on cam feeding of the wire, in as much as very slight irregularities in 5 5 the cam surface will then be effective to reduce the biting engagement of the feed rolls with the wire, and furthermore, the amount of force available for grasping the wire is determined strictly by the accuracy of the cam design and the maintenance of proper dimensions in. all portions of of the rolls will be maintained at a minimum.

The sensitivity of the relative axial position of the feed rolls with respect to the contour of cam,

37 is more clearly shown in the schematic diagram of Figure 5, where in the solid lines indicate the position of the feed rolls in their minimum nip, or Wire feeding position and the dotted lines indicate their relative position in their inoperative or non-feeding position. The corresponding angular positions of the eccentric arm 2B are similarly shown in solid and dotted lines, and it will be noted that a substantial angular displacement of the arm 26 is required to produce a relatively slight axial displacement of the two feed roll units.

As was heretofore stated, the improvements in the wire feeding mechanism accomplished by this invention appear in retrospect to be of rather detailed nature but the results achieved thereby have been really amazing from the standpoint of greatly increased accuracy and reliability of performance. The described feeding mechanism will successively feed substantially identical lengths of wire into a fence making or similar machine operating at high cyclic rates and will maintain its accuracy over a long period without requiring shutdowns for adjustment or repair purposes.

It will, of course, be understood that various details of construction may be modified through a wide range `without departing from the principles of this invention and it is, therefore, not the purpose to limit the patent granted hereon otherwise than necessitated by the scope of the appended claim.

I claim as my invention:

An intermittent wire feeding apparatus for successively feeding predetermined lengths of cross wire to a fence welding machine comprising a frame, a feed roll journaled on said frame, a motor, a main drive shaft driven by said motor and a positive drive connection from said shaft to said feed roll, a cooperating feed roll journaled on said frame and with said first mentioned feed roll defining a nip therebetween, a gear coaxial with and rotated by said first feed roll, a second gear coaxial with and rotating said cooperating feed roll andmeshing with said first mentioned gear, the mounting for said second gear and cooperating feed roll on said frame comprising a shaft parallel to the axis of said first feed roll and mounted on said frame with its longitudinal axis offset from the center of said roll, a sleeve on said shaft, the center of said sleeve being eccentric of the center of said shaft and concentric with the center of said gear and roll, and said sleeve having said gear and cooperating feed roll journaled thereon, an arm secured to said sleeve, a cam rotatably driven by said main drive shaft, a second 'rocking arm spaced beneath said rst arm and pivoted to said frame, a follower on said rocking arm engaging said cam to one side of the' center thereof, a link operatively connecting saidarms together, and a spring connected to the free end of said second arm and yieldably engaging said follower with said cam, whereby rotation of said cam will periodically pivot said first arm and eccentric sleeve and vary the nip relationship between said rolls into periodic feeding engagement with the cross wire therebetween.

RDOLPH C. VORDERSTRASSE.

REFERENCES CITED The following references are of record inthe file of this patent:

UNITED STATES PATENTS Number Name Date 220,224 Everson Oct. 7, 1879 343,928 Stambaugh June 15, 1886 357,228 Pocock Feb. 8. 1887 540,543 Ebert June 4, 1895 1,093,578 Sommer Apr. 14, 1914 1,151,784 Herman Aug. 31, 1915 1,275,984 Bailey Aug. 13, 1918 1,300,704 Drewes Apr. 15, 1919 1,612,159 Sommer Dec. 28, 1926 1,733,557 Pfannenstiehl Oct. 29, 1929 1,857,116 Dina` May 3, 1932

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