US2353092A - Strand tension indicating device - Google Patents

Description

H. R. THORNTON STRAND TENsIoN INDICATING DEVICE Filed July 1o, 1943 .Ill-

July 4, 1944.

Patented July 4, 1944 STRAND TENSION INDICATING bavlca Horace R. Thornton, Baltimore, Md., assigner to Western Electric Company, Incorporated,- New York, N. Y., a corporation oi' New York Application July 10, 1943, Serial No. 494,217

7 Claims. Y (Cl. 5'1'-59)k VThis invention relates to strandrtension indicating devices and particularly to such devices for use in strand handlingmachines of the general type disclosed in co-pending application Serial No. 452,027, led July 23, 1942, the device being associated with means :for stopping the operation of the machine when a given degree of inequality of tension exists in the strands..

In the manufacture of electrical communication cable, for example, the type produced in the above-referred-to type of machine, whereinV individual conductors are twisted into pairs and the pairs are then` twisted into a cable, it is very necessary, in establishing uniformity in the in'- dividual pairs of conductors that the two twisted rpairs of conductors should, at all times, travel under similar Yand constant tensions before being twisted together. Consequently, it is necessary, when inequality of tension develops between the twisted pairs ofconductors, that it 'Y be immediately indicated and, upo'n a givendetailed description taken in conjunction with the accompanying drawing, in which Y 'Y `lig. 1 is a diagrammatic plan view of arstrand ktwisting machine showing a strand tension indicating vdevice and associatedrmeans for stopping the machine embodying. vthe featuresrof the invention; and

Fig. 2 is an enlarged longitudinal-central section of the tension indicating device and associated means shown rotated tion thereof in Fig. 1. Y

In the drawing, an embodiment of theV inven- A"tion is illustrated as applied to a strand twisting gree of inequality in such tensions' developing, y

that the machine be automatically stopped.

An object ofv this invention is to provide a simple and practicable device for indicating inequality of tensions between advancing strands associated therewith and cooperating with means for stopping ythe advance of the strands when a givendegree of inequality vof tensions exists in the strands. Y

In accordance with the above objects, the present invention, in the embodimentthereof, as applied to the above-referredto type of strand twisting machine for forming electrical communication cables, comprises a horizontally reciprocatory bar normally held in `a predetermined position relative to and extending'trans versely to the advancing twisted pairs of conductors by spring means, the bar carrying a sheave at each end over which the twisted pairs of conductors travel and anindicator movable with the bar and cooperating with indicia for indicating any movement'of the bar against the action of the spring means andthus that a condition of unequal tension has'developed in the pairs of twisted conductors advancing over.A the sheaves, and alsowhich pair has thevgreater tension. Associated with the indicator are elec-A trical limit switches effective, upon a given Aclegree of inequality of tensions, stop the machine. y

Other objects and advantages of the invention will more fully appear from the following demachine ofthe general type disclosed in the referred-to co-pending application, Serial No. 452,027, led July 23, 1942, t0 which reference maybe had for a more detailed disclosure of such machine and its operation. lnFig. 1, only such parts of the twisting machine are shown in broken lines as are necessary to a fullfunderstanding'of one use of the device of this invention, indicated'ingeneral at 5.

y The parts of the twisting machine which are shown in Fig. 1, are mounted on a base 6 having vertical housings 1. Journalled on and between the two left-hand housings 'I are two flier units, indicated in general at l0 and II, each having two'supply reels` I2,'onlyone of whichis shown,

arrangedrside by side on a commonaxis. In

the operation of the machine, Vthe ilier units Illy and II are actuated to twist conductors I3'withdrawnfrom the reels I2 included in each :ier

unit into pairs, the conductors receiving one twist per revolution ,of their respective iliers upon approaching their sheaves VI4 and another twist after passing over sheaves I5 and I6 of their flier units. The iiier units I0 and II, are driven in like directions rat speeds suliicientto place lovertwists inthe pairsvof conductors I3 to offset the tendency of a ier unit at the right hand end of the machine from untwisting the pairs when these pairsare twisted together in an opto automatically posite direction from that of their original twist.V

Upon leaving thelflier` units I ilv and II, the

Vconductors vI3 arein twisted pairs, indicated at l JB, which convergeY and pass through a hollow shaft I9 to a flier unit, indicated in general atA 20, in which a capstanZI is disposed, the flier unit 20 being journalledv on and between [the right hand vertical housingsl l. rThe capstan 2| is rotated counterclockwise, as, seen in Fig. 1, to causeadvancernent of the conductors `rI3ffrom their respective supply reels I 2V, through the ier units I(l and II, andthe pairs I 8` through the V from.` the posiv -twists to form a cable, indicated at 23, due to the flier unit 20 being driven in a direction opposite l that of the filer units I and II. Thereafter,

the cable'23 passes around the capstan 2| to effect a'pulling connection between the capstan and the cable, after which the cable is vfed over sheaves 24 and 25 to a takeup reel26. lA common power means, such as a motor 28, is provided for driving, through suitable interconnecting means, the various parts of the machine, although separate speed reducing units 29 and 30 may be employed for the left and right hand ends, respectively, of the machine.

With this general understanding of the machine and what it accomplishes and realizing the necessity of uniformity in the individual twisted pairs I6 of conductors I3 and that they should travel at all times under similar and constant tensions, attention is now directed to the strand tension indicating device of this invention and its associated means for stopping the machine when a given degree of inequality of tension exists in vthetwisted pairs of conductors. Secured to and extending horizontally from theinner vertical housing 1 at the left hand endV of the machine is a support 32 having integral vertical standards, 33 interconnected at their upper ends by a sleeve-like portion 34 with heads 35 at opposite ends. Extending freely through Vthe bore of the sleeve-like portion 34 is a reciprocatory bar or rod 36. Fixed to the rod 36 intermediate its ends is an indicator or pointer 40, which, at one end is associated with indicia 4I marked on a plate 42 carried on ,the support 32, the opposite end of the indicator being arranged Y to actuate one of two plungers 43 of normally i closed limit switches 44 carried on the support 32 upon the rod 36 being moved longitudinally a predetermined distance in either direction. As shown in Fig. 1, the limit switches 44 are connected in'parallel in the Vcircuit to the motor 28. Opposite slots 41 in the sleeve-like portion 34 permit longitudinal movement of the rod 36 with made in the adjustable means provided in the referred-to reel supporting mechanisms.

In the use of the device 5 of this invention as applied to the above-noted strand twisting machine and assuming that the twisted conductor pairs lI8 are advancing convergently from the iiier 'units I0 and II to a common point under i equal tensions over the sheaves 52 of the tension indicating device, the rod 36 will remain in its central position and the indicator 40 will, consequently, register with the center mark 48 of the indicia 4|, thus indicating that a condition of equal tension exists between the pairs I8. Whenever. a greater `tension develops in one of the pairs I8, due to any cause, the rod 36 will be shifted in the direction of the pair having the greater tension until both pairs have reached equal tension. The resultant movement of the indicator 40, moving with the rod 36, away from the mark 48, immediately indicates that a condition of unequal tension from, that desired has developed, and also which pair has developed the greater tension. Suitable adjustment is then y made through one or the other of the previously the attached indicator 40 and the arrangement is such that the rod is prevented from rotating. The lrod 36 is'normally yieldably maintained in a central position in the sleeve-like portion 34 f with the indicator 4o registered with a center mark 48 of the indicia 4I by means of similar coiled compression springs 49 surrounding the rod at opposite sides of the indicator, the opposite ends of the springs vabutting adjacent sides of the. pointer and adjustable nuts 50 threaded into the heads 35, the Vrod 36 having a sliding iit in bores 5I of the nuts 50. The nuts 50 provide meansl for adjusting the compression of the springs 48 and also to balance the indicator 40. A sheave '52 is journalled upon each end of the rod 36 and the twisted pairs I8 of conductors I3 are guided iii their advance from the flier units I0 and I I over the sheaves.

scribed and disclosed in the above-referred-to co-pending application, for causing the conductors I3 to travel from the reels I2 of the flier units l0 and II vand'thereafter in the form of twisted pairs I8 under like and constant tensions. At times, due to various causes, the two pairs I8 of conductors I3 may not be under the same tension and, in such case, suitable adjustment is referred-to means associated with the reel Supporting mechanisms to again cause -thev desired degree of equality of tension betweentl-ie twisted conductor pairs I8.v Whena given ydegree fof inequality of tension develops betvl/'een the'jpairs I8, the opposite end of the'indic'ato'r 4I)y will lengage and actuate one or the other of the plung- -ers 43 of the normally'closed limit'switches 44 and thereby open the power circuit to the motor 28 to cause an immediate stoppage ofthe twistlng machine. l f` Fromthe foregoing description; it will'be ap- Y parent that a simple and practicable strand tension indicating device is provided for "use in strand twisting machines,v which is effective to provide a visual indication of Vany inequality of tension between advancing strands or variations from desired different tensions between such strands, if such is the case. Also, in the case of such equalities or variations exceeding a predetermined degree, means cooperating with the tension indicating device is eiective to cause an immediate stoppage of the machine. Y

It will be understood that the embodiment herein described is merely illustrative of the invention and one application thereof and that modifications can be made and'it is capable oi other applications.

' What is claimed is:

, 1. A tension indicating devicefor a plurality of spaced strands during handling in a strand handling machine comprising a reciprocably mounted member, yieldable means for maintaining said member in a predetermined position, opposite portions of said member adapted to be engaged by said strands, and means including an indicator movable with said member for indicating movement thereof against the action of said yieldable means when undesired tensions exist in the strands.

2. A tension indicating device for strands being advanced in a strand handling machine comprising a reciprocably mounted member, yieldable means for maintaining said member in a predeterminedposition, rollers carried upon opposite ends of said member over which the strands advance, and means including an indicator movable strands in a strand handling machine comprising an apertured support, a reciprocable member movable longitudinally therein, said member having an enlargement intermediate its ends, apertured means at opposite ends of said support for guiding said reciprocable member, coiled compression springs surrounding said member at each side of and abutting at their adjacent ends opposite faces of said enlargement, the opposite ends of said springs abutting said apertured means, opposite ends of said member adapted to be engaged by said strands,4 and means including an indicator carried by and intermediate said faces of said enlargement for indicating movement thereof against the action of said springs when undesired tensions exist in the strands.

4. A device for indicating tension in advancing strands in a strand handling machine which includes power actuating means therefor comprising a reciprocably mounted member, lyieldable means for maintaining said member in a predetermined position, opposite portions of said member adapted to be engaged by said strands, means including an indicator movable with said member for indicating movement thereof against the action of said yieldable means when undesired tensions exist in the strands, and means responsive to la predetermined movement of said indicator when a given degree of undesired tensions exists in the strands to interrupt the operation of the power actuating means of the machine.

5. A tension indicating device for a machine in which spaced strands are advanced convergently to a common point comprising a reciprocably mounted member movable transversely of the direction of advance of the strands, means including yieldable elements eiective for maintaining said member in a predetermined position, opposite portions of said member adapted to be engaged by said advancing strands, and means including an indicator movable with said member for indicating movement thereof against the action of said yieldable elements when unequal tensions exist in the strands.

6. A tension indicating device for a machine in which spaced strands are fed convergently to a common point comprising yieldably mounted means engaging the spaced strands and movable in opposite directions transversely of the direction of advance and in accordance with the differential of the tensions in the strands, and

means cooperating with said strand engaging chine.

HORACE R. THORNTON.

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