US2251291A - Strand handling apparatus - Google Patents

Description

Aug 5, 1941. L. o. REICHELT s'rmmn HANDLING APPARATUS Filed Aug. 10, 1940 2 Sheets-Sheet 1 4 nv VENIUR L 0.REICHEL 7' RAwfi A rromver Patented Aug 5, 1941 OFFICE STRAND HANDLING APPARATUS Lester 0. Reichelt, Cranford, N. L, minor to Western Electric Company, Incorporated, New York, N. Y., a corporation of New' York Application August 10, 1940, Serial No. 352,054

10 Claims. (Cl. 254-135) This invention relates to strand handling apparatus, and more particularly to apparatus for advancing strands longitudinally of themselves.

In the arts which pertain to the manufacture of strands, especially of the many kinds of compound strands, cords, ropes, cables, etc., employed for both mechanical and electrical purposes, there is need for apparatus to pull the strands from or through the various devices and machines used to make or variously treat them. Generally speaking such devices fall into two principal classes, rotary capstans and tractor capstans, each with its peculiar and inherent defects and advantages. A principal advantage of the rotary capstan, which is essentially a driven drum around which the strand to be advanced is wrapped in a sufficient number of turns to effect the required frictional grip, is that a given capstan may be used without alteration or adjustment of any kind for strands having a large range of diameters. A principal inherent defect of the rotary capstan is that a strand of relatively large each other on each side of a'straight segment of the strand to be moved, and which are provided with suitable tractor blocks or other means on the belts to grip, carry along and release the strands, and with means such as suitable cam tracks to press the blocks into gripping engagement with the strand passing between them. Such tractor capstans have the inherent advantage of operating on a straight portion of strand. There is no bending of the strand under tension,

and hence no diiferential tension imposed within the strand because of bending. On the other hand, such tractor capstans have the inherent disadvantage of being capable of handling strands of practically only one diameter without a difficult and tedious removal and interchange of belts.

An object of the present invention is to provide a strand advancing apparatus generally of the tractor capstan type provided with simple,

durable, inexpensive and reliable means whereby the apparatus may be employed to advance strands having a relatively large range of diameter without interchange of parts. I

With the above and other objects in view, the invention may be embodied in a tractor capstan in which the strand gripping elements are provided with strand gripping surfaces generally cylindrical in cross-section and having portions of two separate degrees of curvature, which elements may further be composed. of resilient main accordance with the invention;

Fig. 2 is an enlarged section on the line 22 of Fig. l; i

Fig. 3 is a partial view similar to Fig. 2, showing application to a strand of minimum diameter;

Fig. 4 is a section on the line 4-4 of Fig. 2;

Fig. 5 is a view similar to Fig. 3, showing a strand of intermediate diameter; and

Fig. 6 is a partial view of a modified form of gripping member.

In the embodiment herein disclosed, a tractor capstan generally shown in Fig. 1 is provided with two tractor belts 20 and 2| of any suitable material and construction, here indicated as sprocket chains. The portions of the two belts which face each other are always parallel to each other. The belts are drivable so that the mutually facing parallel portions run at the same speed and in the same direction. The general structure and mode of operationof the capstan are no part of the present invention and so are not disclosed or described here. A suitable structure is disclosed and described in U. S. Patent No. 1,882,902 of October 18, 1932, to the present inventor, to which referencemay be had, if desired, for such information.

For present purposes all that is necessary as to r the machine generally is that the mutually facing portions of the belts 20 and 2i are drivable to :run in strict parallelism, from left to right in Fig. 1; at the same speed; that means be provided as in the patent above cited for adjusting the distance apart of the belts; and that means are present such as a hollow shaft It to lead a strand l9 to be advanced, propelled or drawn along from left to right, to enter between the belts.

As herein disclosed, each of the belts 20 and 2| consists of three distinct parallel sprocket chains, bound together at each link by transverse crossbars 22 and 23, respectively, of metal, each secured to three laterally aligned links of the three chains by being secured with rivets 25 to supporting arms 24 formed integral with the links. Each of the crossbars 22 and 23 is formed with a dovetail slot 26 running longitudinally of the bar and transversely to the belts and located in the face oi the bar away from its supporting belt.

A mounting member 21 or 28 respectively, of metal. has a base portion corresponding in width to the slotted face of the cross bar and is formed on the under side oi. its base with a dovetail to match the dovetail slot 26 and assembled therein. The base dovetail is locked into exact position in the slot 26 by a. permanent stop 29 at one end and a spring lock 30 at the other. Thus each of the mounting members 21 or 28 may be removed individually at will for exchange or repair.

The upstanding body oi each mounting member 21 is relatively wide, as herein shown spanning all three chains of the belt 2i. The depending body of each member 28 is relatively narrow, spanning, in the structure disclosed, substantially only the middle chain of the belt 20. The top surface of the member 21 and the bottom surface of the member 28 are each curved to a radius somewhat greater than that of the largest strand to be handled by the particular assembly, and each of these faces is formed with a correspondingly arcuate dovetail slot 3| or 32 respectively.

A gripping member 33 or 34, preferably of rubber or the like material, is formed, pressed and Vulcanized into each slot 3| or 32 respectively to be securely gripped therein. Each of the members 33 has in its upper face a semi-cylindrical slot or groove 35 whose radius is that of the largest strand to be handled, except at the bottom. Here there is a further groove 36 cut into the bottom of the groove 35 with a radius equal to that of the smallest strand in view, and preferably with a width of about 90, the sharp intersection of the two curved surfaces being smoothly faired away. The bottom face of each gripping member 34 is curved to the radius of the largest strand in view, as at 31. In the preferred form, as noted above, the members 33 or 34 are of some relatively softly resilient material such as rubber. They may then be molded in place as described to be substantially homogeneous. Or they may, in some instances preferably, be partiallypreformed of laminations of fabric impregnated with uncured rubber material and cured after being put in place in the members 21 or 28. Or in other instances the members 21 and 33 or 28 and 34 or both may be made integral and of metal, while preserving the particular contours of the gripping surfaces 35 and 36 or 31 as described.

The operation of the members 33 and 34 in gripping a strand to be advanced is thought to be self-evident from the above description of the apparatus. It may be noted that in any given case the distance apart of the belts 20 and 2| will be adjusted to an optimum value which will be related to the diameter of the particular strand in question in a manner dependent upon the structure and nature of the particular strand, the severity of the grip upon the strand in turn depending upon the difference between the ungripped diameter of the strand and the empty distance between the opposed faces of the gripping members. Generally, both the members 33 and 34 on the one hand and the strand gripped by them on the other, will be more or less deformed by the gripping pressure. At one extreme is the case where the members 33 and 34 are of relatively soft rubber and the strand a solid rod of metal or a closely laid cable of hard metal strands, in which case there is no deformation of the strand. At bers 33 and 34 of relatively soft and such case, there will gripping members.

deformable the other extreme the memmay be of metal and the strand material. In

be no deformation of the In the particular case of the handling of compound strands such as telephone cable cores,

composed of a plurality of wires intertwisted together as a whole or in pre-twisted groups, the

invention has its principal practical value.

cores, in practise, at various stage Such s of manufacture, may be simply such compound strands of intertwisted wire, or they may have a binder strand wound about pitch, or they may, as illustrated the strand ill, have a wrapping completely covering them. Such them at relatively short in the case of of paper tape cores will endure a certain amount of deformation under transverse squeezing obviously not a great deal.

without material injury but When a maximum diameter core, such as i9,

is gripped as in Figs. 2 and 4, the

gripping pressure is applied over something like two thirds of the circumference of the core, the resilient surfaces 35 and relatively soft,

31 accommodate themselves not only to the general contour of the core but also to the minor irregularities, and a relatively heavy tractive effort may applied to the core.

In the case of a minimum diameter core illustrated in Fig. 3, the surface 36 makes contact with the core over a quarter of the be harmlessly I l, as close circumference without any deformation of either; and only a slight and negligible deformation at the upper contact of the core is n the surface 31 and the core con over another quarter of the circumference. cases where extreme tenderness of action is quired, the upper member with a secondary in the member 33, erally, however, this is The most common trated in Fig. 5, where the core I groove I36 like ceded to make form together In 34 may even be formed the groove 36 as illustrated in Fig. 6. Gennot found to be necessary. intermediate case is illus- 6 has a diameter intermediate between the least and greatest. The figure illustrates, as do the others also, an impossible state in which there is no deformation of any of the elements involved. there will be both a flattening of In actuality the core l6 at the top and a deepening of the surface 31 under the gripping pressure. But a in will show that only a practically formation of the strand is requir the concomitant deformation of t to spread the tangency gripping members from the idea oments study negligible deed, in view of he surface 37,

of the core and upper 1 line contact illustrated over a very considerable angular portion of the circumference of the c ore. The case at the bottom is similar. Ideally the core makes contact with the member 33 only along two lines where the surface 36 35. In actuality only is faired off into the surface negligible mutual deformations are required to flatten down the faired ridges and correspondingly shallowly indent the core so that contact between the gripping member and the core is established over the whole surface 36, the faired ridges and considerable angular fractions of the surface 35 on both sides.

Thus by the employment of gripping members preferably of resilient material, which are mutually approximable for coaction, and

whose strand gripping surfaces are primarily curved to fit the largest strand in view and of which may have a portion secondarily cu either or both rved to fit the smallest strand contemplated, it is possible satisfactorily to grip and exert tractive effort on a strand of any of a large range of diameters without material injury to either the strand or the apparatus and without need for interchangeable gripping members.

The embodiment of the invention disclosed is illustrative and may be variously modified and departed from without departing from the spirit and scope of the invention as pointed out in and limited only by the appended claims.

What is claimed is:

1. In apparatus of the general character described, a pair of opposed and mutually approximable gripping members for gripping therebetween a strand of any diameter between and including predetermined maximum and minimum values, each such gripping member having a strand gripping surface .primarily cylindrically curved to fit a strand of maximum diameter.

2. In apparatus of the general character described, a pair of opposed and mutually approximablegripping members for gripping therebetween a strand of any diameter between and including predetermined maximum and minimum values, each such gripping member having a strand gripping surface primarily cylindrically curved to fit a strand ,of maximum diameter, and each such gripping member being composed of elastically resilient material.

3. In apparatus of the general character described, a pair of opposed and mutually approximable gripping members for gripping therebetween a strand of any diameter between and including predetermined maximum and minimum values, each such gripping member having a strand gripping surface primarily cylindrically curved to fit a strand of maximum diameter, one of the gripping members also having its said strand gripping surface further formed over a portion thereof with a cylindrical curvature to fit a strand of minimum diameter.

4. In apparatus of the general character described, a pair of opposed and mutually approximable gripping members for gripping therebetween a strand of any diameter between and including predetermined maximum and minimum values, each such gripping member having a strand gripping surface primarily cylindrically curved to fit a strand of maximum diameter, one of the gripping members also having its said strand gripping surface further formed over a portion thereof with a cylindrical curvature to fit a strand of minimum diameter and having the junctures of the two portions of difierent curvature faired away.

5. In apparatus of the general character described, a pair of opposed and mutually approximable gripping members for gripping therebetween a strand of any diameter between and including predetermined maximum and minimum values, each such gripping member having a strand gripping surface primarily cylindrically curved to fit a strand of maximum diameter, each of the gripping members also having its said strand gripping surface further formed over a portion thereof with a cylindrical curvature to fit a strand of minimum diameter.

6. In apparatus of the general character described, a pair of opposed and mutually approximable gripping members for grippin therebetween a strand of any diameter between and including predetermined maximum and minimum values, each such gripping member having a strand gripping surface primarily cylindrically curved to fit a strand of maximum diameter, each of the gripping members also having its said strand gripping surface further formed over a portion thereof with a cylindrical curvature to fit a strand of minimum diameter and having the junctures of the two portions of different curvature faired away.

7. In apparatus of the general character described, a pair of opposed and mutually approximable gripping members for gripping therebetween a strand of any diameter between and including predetermined maximum and minimum values, each such gripping member having a strand gripping surface primarily cylindrically curved to fit a strand of maximum diameter, one of the gripping members also having its said strand gripping surface further formed over a portion thereof with a cylindrical curvature to fit a strand ofminimum diameter and each such gripping member being composed of elastically resilient material.

8. In apparatus of the general character described, a pair of opposed and mutually approximable gripping members for gripping therebetween a strand of any diameter between and including predetermined maximum and minimum values, each such gripping member having a strand gripping surface primarily cylindrically curved to fit a strand of maximum diameter, one of the gripping members also having its said strand gripping surface further formed over a portion thereof'with a cylindrical curvature to fit a strand of minimum diameter and having the junctures of the two portions of different curvature faired away and each such gripping member being composed of elastically resilient material.

9. In apparatus of the general character tie-'- scribed, a pair of opposed and mutually approximable gripping members for gripping therebetween a strand of any diameter between and including predetermined maximum and minimum values, each such gripping member having a strand gripping surface primarily cylindrically curved to fit a strand of maximum diameter, each of the gripping members also having its said strand gripping surface further formed over a portion thereof with a cylindrical curvature to fit a strand of minimum diameter and each such gripping member being composed of elastically resilient material.

10. In apparatus of the general character de scribed, a pair of opposed and mutually approximable gripping members for gripping therebetween a strand of any diameter between and including predetermined maximum and minimum values, each such gripping member having a strand gripping surface primarily cylindrically curved to fit a strand of maximum diameter, each of the gripping members also having its said strand gripping surface further formed over a portion thereof with a cylindrical curvature to fit a strand of minimum diameter and having the junctures of the two portions of different curvature faired away and each such grippin member being composed of elastically resilient material.

LESTER o. REICHELT. I

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