US2679924A

US2679924A - Strand-advancing apparatus

Info

Publication number: US2679924A
Application number: US157554A
Authority: US
Inventors: Paul R Powell
Original assignee: Western Electric Co Inc
Current assignee: AT&T Corp
Priority date: 1950-04-22
Filing date: 1950-04-22
Publication date: 1954-06-01
Anticipated expiration: 1971-06-01

Description

June 1, 1954 P. R. POWELL 2,679,924

STRAND-ADVANCING APPARATUS Filed April 22, 1950 4 Sheets-Sheet 1 FIG.

INII/ENTOR P. R. POWELL l BY ATTORNEV June 1, 1954 P. R. POWELL STRAND-ADVANCING APPARATUS Filed April 22, -1950 4 Sheets-Sheet 2 FIG. 5

lNl/ENI'OR P R. POWEL L ATTORNEY June 1, 1954 P. R. POWELL 2,679,924

STRAND-ADVANCING APPARATUS Filed April 22, 1950 4 Sheets-Sheet 3 g m I A I; rx ll llu U 73 n ,(u- M m Uh AN H 2 F MI I M g g g w Z: A. [by &;-@ W1 W MT M; h 'F Q ii "ll Q N HM Q R 1 E 1 2 I .5 N '1' E W' 0 A H [f I M, HHS EEG q l {I i1 8 V 2 MI a gr L. k E M Q E: (W M i Q I r I} Q Q WI M r F .n] I W ll M I, |H|||| 1'' I H lNl ENTOR RR. POWELL A 7' TORNE V June I; 1954 P. R. POW EL L Filed April 22, 1950 STRAND-ADVANCING APPARATUS 4 Sheets-Sheet 4 26 D\ Y 1/ FIG. 7

//v|/E/v TOR FIG. 4 F. R. POWELL A T TORNE v Patented June 1, 1954 STRAND -ADVAN GIN G APPARATUS Paul-R. Powell, Baltimore, Md., assignor to Western Electric Company, Incorporated,.New York, N. Y., a' corporation of New York Application April 22, 1950, Serial N 0. 157,554

16 Claims. 1

This invention relates to strand-advancing'apparatus, and more particularly to tractor-type capstans for advancing strands, cables and the like.

An' object of the'invention' is to'provide new and improved strand-advancing apparatus.

Another object of theinvention is to provide new'and improved tractor-type capstans for advancing strands; cables and'the like through and from'machines in which they are being processed.

A further object of'the invention'is to provide a tractor-typecapstan suitable to advance cables of different sizes.

A strand advancing apparatus illustrating certain features of the'invention, mayinclude a plurality of endless belts having gripping shoes mounted on the belts for advancing a strand through the apparatus, a plurality of guideways for guiding the belts along predetermined paths so that portions thereof face toward acommon axis, a system of pivotally mounted members for movably' supporting the guideways' so that portions of the belts are parallel to the axis, and means for selectively moving themembers to adjust the'space'between thebelts to suit the size of the strand to be'advanced'b'y the belts.

Other objects and advantages ofthe invention will appear from the followingdetailed description' ofan apparatus forming a specific embodiment thereof, when read in conjunction with the appended drawings, in which:

Fig. l is a front elevation of a tractor-type capstan embodying certain features of the invention having portions thereof broken away;

Fig; 2 is a horizontal section taken along line 22 of Fig. 1;

Fig. 3 is a rear elevation of the apparatus shown in Fig. 1 having portions thereof broken away;

Fig. 4 is an enlarged; fragmentary, vertical section taken along line 4-4 of Fig. 1;

Fig. 5 is an enlarged, perspective view of one of the gripping shoes attached to the'endless belts .shown in Fig. 4.

Fig. 6 is a plan View of a portion of the apparatus shown in Fig. 1, and

Fig. 7' is a fragmentary front elevation of the apparatus shown in Fig; 6.

Referring now in detail to the drawings and more particularly to Fig. 1, there isshown'therein a-t'ractor-type capstan'including a pair of endlesschain belts ii! and i! arranged" to travel in the same plane'in'juxtaposedpositions so spaced that the adjacent portions of the belts may engage a cable core is positioned therebetween. The cable core includes a plurality of conduc tors having several layers of impregnated paper spirally wound therearound, and-is advanced by the-capstan (Fig. 1)- from a reel'or a cable-forming mechanism (not shown).

The chain belt-s l9 and II (Figs. 4. and 5) are identical in construction and operation, and include roller chains [5 and l-t'bound together at each link thereof by transverse crossbars ll-l'l. The transverse bars I'l-l'l are provided with channel-shaped ends til-l8- for detachably clamping flexible gripping shoes 2028 to the belts for exerting a frictional gripping action on the core IS. The gripping shoes preferably should be made of a flexible and elastic material which is substantially non-compressible, such as'rubber, compounds containing natural rubber; or rubber-like compounds such as polymerizedchloroprene (neoprene). A slot 23' is provided in each end of the shoes into which fit ribs'2525 provided in the corresponding ends of the'bars lll'l". The ribs'25-25-of the crossbars l"l'll key the gripping shoes til -29 to these bars and secure them to the chains 25 and Hi; The gripping shoes Zfl-Zllare inserted in the-bars Ill-11 by bending the shoes so'that the-ends thereof fit gripping surfaces and connected. together with a thin, bendable section 29 (Figs. 4 and 5).

The endless chain l5 (Figs. 2 and' l) of the belt in travels around sprockets 39 and. 3|,and the chain [6 travels around sprockets 32 and. 33.. The sprockets 31] and fifi'are secured on abushing 34 so that their teeth are aligned transversely with each other, and spaced apart a. distance equal to the spacing of the chains l5 and H3v on the crossbars 97-41. The assembly of the sprockets 3t and 32 and the bushing 34 ismounted rotatably one post 35.secured near the left-hand end of an I-shaped support 36. The

sprockets 3i and 33 areassembled in a similar manner" on a bushing 31 rotatably mounted on a post 38 securednear theright-hand end of thesupport 35? so as to be coextensive with the post 35. The support 36- (Fig. 4) is of such widththat the elongated legs of'the endless belt l9 ride on backing plates 45 and GI of the support. The plate 49 of the support 36 is positioned adjacent to the cable core I3 and serves to hold the gripping shoes 2ii29 of the belt It in positive engagement with the surface of the cable-core I3.

The chain It (Figs. 1 and 2) of the belt II travels around sprockets 44 and 45 mounted on bushings 55 and 6?, respectively, which in turn, are mounted rotatably on posts 59 and EH, respectively. The posts 50 and M are mounted coextensively on an I-shaped support 52, which is identical with the support 35. The posts 59 and i are positioned apart on the support 52 a distance equal to the distance between the posts 35 and 38. The chain of the belt I! travels around sprockets like the sprockets t4 and 45 which are secured to the bushings t6 and 4! in the same manner as that in which the sprockets 3i) and SI are secured to the bushings 34 and 31, respectively.

The support 52 is designed so that the chains i5 and it of the belt it ride on backing plates 53 and 5 3 (Fig. 1) of the support. The plate 53 of the support 52 is positioned adjacent to the cable core 13 and serves to hold the gripping shoes -29 of the belt II in. positive engagement with the cable core 13. The backing plates ti) and 53 of the

supports

36 and 52, respectively, have their end portions 5555 and 56-56, respectively, arranged to slope away from the cable core I3 to cause the shoes to engage the cable core at the entrance end of the capstan and to leave the cable core at the opposite end of the capstan without effecting any rotation of the shoes while their grooves 28-28 grip the cable core. This feature of the supports 38 and 52 prevents the gripping shoes from moving along the core it after they engage the core thereby preventing the gripping shoes from tearing the paper covering of the core.

The support 36 (Figs. 1, 2 and 3) is mounted pivotally on posts 5'i5l secured in the upper right-hand corner portions of a pair of segmental gears 5858, as viewed in Fig. 3. The gears 5858 are mounted pivotally on posts 6d6li rigidly secured in predetermined spaced relationship to a plate BI secured to a frame 54 designed to support the belts Iii and H and other moving parts of the capstan. The posts 68-60 are mounted on the plate Si in a plane which is parallel to the central axis of the belt it A link 65 holds the gears Bil-53 parallel, whereby the gears 5853 position the support 36 so that the backing plate 4| of the support is always horizontal, as viewed in Fig. 1. Consequently, the backing plate GI holds the portion of the belt I0 thereon horizontal, irrespective of the positions of the gears 58-58.

The support 52, which carries the belt II, is mounted in a similar manner on posts 6868 secured in the right-hand corner portions of segmental gears l'0-'I0 (Fig. 3) mounted pivotally on posts lI-li connected rigidly to the plate 6!. The posts 'II-II are mounted in a plane which is parallel to the central axis of the belt I i. The free ends of the gears 53-58 and 'Hl!0 are provided with conventional gear teeth which intermesh in such a manner that the gears I 0'Hl are maintained parallel. By locking the gears 5853 and IO-16 together in this manner, the support 52 is so held that the backing plate 54 thereof is parallel to the backing plate ii of the upper support 35. Consequently, the portions of the belts It and II riding on the backing plates M and 54 maintain the cable core I3 parallel thereto. This arrangement of the

supports

36 and 52 on the gears 5858 and Ill-iii maintains the juxtaposed portions of the belts i0 and H in strict parallelism. The weight of the belt it tends to turn the gears 5858 about the posts 58-45% in a clockwise direction as viewed in Fig. 3 and the weight of the belt Ii tends to turn its respective gears it-H3 about the posts E I-ll in a clockwise direction. As a result, the free ends of the gears 5858 and ill-ill tend to move in opposite directions, but since the weights of the belts are substantially equal, the force exerted on the gears is neutralized and the belts will remain in any set position of the gears 5858 and TIL-I0.

To adjust the transverse spacing between the belts ID and II to suit various sizes of cable cores or cable to be advanced by the belts, a crank 13 (Fig. 3) is secured to the gear 58 at the right of the post 60, as viewed in Fig. 3, so that it pivots about the post 56. A nut M (Fig. 2) is secured to the end of the crank and the adjacent side of the gear 58 so that it is free to swivel about the end of the crank '53. The nut 15 is designed to receive the threaded end of a shaft mounted rotatably in a thrust bearing I5 secured on the frame 56 and a handwheel 18 is secured to the shaft. The handwheel may be actuated selectively to pivot the crank 23 to move the juxtaposed portions of the belts closer together or farther apart, movement of the gear 53 imparting a corresponding movement to the other gear 58 and equal and opposite movement to the gears iiiill.

A sprocket (Fig. 1), keyed to the bushing 36 between the sprockets 3B and 32 is driven by a drive sprocket 8I through a chain 82. The drive sprocket 8! is keyed to a shaft 38 suitably journalled in the plate 6 i A spring-biased rocker arm pivotally mounted on the shaft 83 urges an idler sprocket 81, secured on one end thereof, into engagement with the chain 32, to keep slack out of the chain. A sprocket 99, keyed to the bushing 46, between the sprockets driving the chains 15 and I6 of the belt ii, is driven by a sprocket 9! through a chain 92. The sprocket 9| is keyed to a shaft suitably journalled in the plate 6! and transversely aligned with the shaft 83. A spring-biased rocker arm 96 pivotally mounted on the shaft 95 urges an idler sprocket 91 mounted on one end thereof into engagement with the chain 92 to take slack out of the chain. The free ends of the

rocker arms

86 and 95 are connected to a tension spring me.

A sprocket I03 (Figs. 2 and 3) keyed to the end of the shaft 83 and a sprocket I04 identical therewith keyed to the shaft 95 are driven in opposite directions by a sprocket 535 through a chain (06 which passes around the sprockets in the manner shown in Fig. 3. The sprocket I05 is keyed to the output shaft of a gear reducer iii! directly coupled to a motor Hit. The motor I58 is arranged to drive the sprocket I525 in a counterclockwise direction, as viewed in Fig. 3, to drive the belts I0 and II to advance the cable core I3 from right to left, as viewed in Fig. 1. An idler sprocket H0 mounted on the end of a pivotally mounted arm I I I, biased in a clockwise direction, as viewed in Fig. 3, by a tension spring I I2, keeps the chain I86 taut. This arrangement of the idler sprocket H0 permits the belts II) and II to be moved toward or away from each other without having to change the length of the chain Guide plates II3--I I3 (Figs. 3 and 4) secured to the edges of the backing plates of the supports Sit-rand i521 keep :the :endless; belts ill I] cands: I I ion: the :backing; plates; 14 I. and t53 -ofethersupports 6": andu52-g respectively. Guide channels :al I4+I I 4 i secured on the edges of the backingplates riiliand 54 include.ilongitudinalshoulders I I'3-.-! I5 which engage. thecrossbars "I 'I- I'I of the belts and keep the chains I5 andr'ltithereof inengagement with the bracket plates lt andtr. The .I-shapedsupports 36 and 52twith their associated guideiplates I I3-'. I I3 sandv guide channels. I I4-:I I4 togetherconstitute guideways for the endless belts :IIliand. I I

A sprocket :I I3:i(Figs. 2 and 3) keyedfor rotation with the shaft 83 'drives a-sprocket I I! by means of a chain H8; Thesprocket lI-l is con.- nected to the 'dr ivingside ofa-frictionclutch H9 '(Fig. ,6) which has its driven portion keyedto a shaft I23 isuitably journalled on the-upper right-hand portion-of the frame 64, as viewed in Fig. 3. The clutch I I9 is operable by a fork lever I2I pivotallymounted on the frame 64. The free end 'of the fork leverIZI is connected to a-rod I23 sli'da'bly mounted on theframe and with its free end positioned near the front of the capstan so that the clutch H9 may be actuated from the front side of the capstan. A sprocket I24 keyed to the shaft I23 (Figs. 2 and 3) is connected by a chain I25 to a sprocket I26 keyed to a shaft I27 suitably journalled in the frame 64.

The shafts I23 and I2! extend beyond'the frame 64 so that their free ends extend slightly beyond the front side of theframe. A wire rope capstan I33 (Figs. 6 and 7) is keyed tothe end of the shaft I23 and a wire rope takeup drum I3I is keyed to the front end' of the shaft I21.

The capstan I38 and the takeup drum I3I are used when it is necessary to start a cable core between the endless belts I0 and II. It is necese sary to position the cable core I3 between the belts It and II so that the entire length of the juxtaposed portions of the belts can grip the cable core in order to prevent possible injury to the gripping shoesand the core.

To start the cable core I3 through the apparatus; asuitable length of wire rope I33 is withdrawnfrom the gtakeup drum I 3! and the end thereof is connected to a. hook It i-securedto the leading end of thecable core I3., The wire. rope I33 extends from the hook I34 past a guide roller I33mounted on a spring-biased arm I35;

pivotally mounted on a bracket I33. The rope I33" extends outwardly from the roller IEE'some'distance to a. sheave I38 (Fig: '7) mounted'onacolumn I33 rigidly secured to the floor. The rope I33 passes around the sheave I33, reversing. its direction,v and passes varound a guide roller I33" positioned on the frame Mtothe capstan I33.

Itpasses around the capstan I36] several times,

drawn to the left and threads the "cable core I3 1 When the between the endless-belts Ifl'and II. leading end of the cable core I3 emerges from theflaillebd, itactuates aj latch I II torelease the roller I35 and the arm I 33;which then are moved 1 to their-broken-line positions-as viewed in Fig: 6-

so =;that 17116.36 .clear,the:.cable coreaas it passes IfBOm thfli Q t ii. At athe. entrance endzofethe frame 34,

there; is;sprovided;guide rollers- :I 4 fl tii imounted capstanr; A=guide;bushing;I5lJ .;(Fig. 1) secured in; the :exit; end iof'cthe iframel 64;; guides :the cable core-Has ityleaves the belts.

Operation The, guidei rollers ;I 431- I.43 are moved: apart-to suit the; size" of-the; cable core to 1 :be advanced by the capstan; The wire-rrope l33 isthreaded betweenaithe belts; I9; and". l I and issconnected *to the -hookl-I 34 wprovidedv on x-the rleadi-ng': end {of ;:the

cable core I 3 :and the motoni I081 is energized "to drive :thebelts I (I and :I I The handwheel i8 is turned. -ina direction which 5II:-;5B about the posts; 6fi%601=i1'l3a counterclockwisedirection-asviewed inFig. 3. This movement of the gears "5 8+58-;imparts; a nor-responde ing; movement fito the gears III-70 about their respective posts I 1-4 I 7 inra clockwise direction; When thegears 5858:.andv70ei0 move in this;

manner; the belts I Band I I amoveaway from each other;-, The rhandwheel isiturnedeguntil the space. between :the juxta.posednpont-ionsof gth'e 1b'e1ts is greatere than -thez=diameterrof :the: cable core I 3:

After sthe-belts I 0-;and:.-I I iareadjusted, in this mannereythe clutch: 5 I I 9 'is actuated to cause 1 the I capstan I36 :to pull thezwire rope I 33 :tothe left,

as viewed. in Fig; 6; and:ther.ebythread the end of the, cablecore between the juxtaposed portions of the belts :I I3 and I I When"; the leadingend of thecoreemerges from the bushing. I 50; it turns the latch I I! to allow the-springebiasedwguide:roller=I to move out of the .epath :of ttraveliofffthe core: When: the core reaches this point the'clutch' lever I2I is actuated manually-.: to @disconnect :the sprocket I I! from the shaft I23, whereuponthecapstan.I30

and 'the takeup drum :.I 3 I are irendered inoperative; The--wire;rope-l33 is removedifrom-the h'ook I34; and is coiled up.- on: the takeup .drum

I3 I by again actuating the clutch until the end ofwth'e: wire rope :133sreaches the capstan I30.

Themotor: I08 is. deenergized to stop the belts,

and: the :handwheel 'l8siszactuated" to :move the belts-'13 and "I I toward each other until the thin center= portion-=29 of rthe. gripping-shoes.- 20:40

ridingaonthe backingiplates dfisiand 53' exerts a pressurevon th eicablefiore suificient'to bend the gripping shoes andocause the. edge portions of of "contact about ;the periphery of the core as indicatedjbn the; arcs designated 'A, B,';C.and Din Fig 4. Thus, the gripping; shoes apply equal pressure. to. the core. at;opp9sit e points around its.

periphery, here y.pre nti s hel s Wa llfrom crushing or. damaging the core I3.

This construction of each gripping. shoe produces, in effect; a pair of, opppsed'jawspivotable centrally thereof and 'having arcuate gripping surfaces, and alever connectin-g the jaws-together-ad-jacent=to their -pivot-pointp When the will pivot the gears 7 belts l and l I are adjusted as described, the core pushes the lever inwardly and thereby pivots the jaws toward each other so that the arcuate gripping surfaces engage the core.

After the belts I0 and H have been adjusted in this manner, the motor l08 again is energized to drive the belts through the sprockets its and I94 and the chain I06, as seen in Fig. 3. When the belts are driven in this manner they advance the cable core 13 through the capstan from right to left as seen in Fig. l. The

inclined end portions

55 and 58 of the

supports

36 and 52, respectively, cause the gripping shoes 2=32il on the belts l0 and H to travel in gradually sloping paths as they approach and as they recede from the core I 3, thereby preventing relative longitudinal movement between adjacent shoes on the belts in gripping and releasing the cable core.

The gripping shoes -20 are designed so that the radius of the grooves 2828 is slightly greater than the radius of the largest cable core to be advanced by the endless belts I ii and l i. When the largest cable cores ar advanced by the belts, only a minimum deformation of the gripping shoes is required to cause the belts to grip the cable core with sumcient force to advance it from left to right, as viewed in Fig. 3. When cable cores having a diameter slightly less than that of the largestsize core are to be advanced by the belts, the belts are moved toward each other so that the gripping shoes are deformed to a greater degree and cause the entire curved surface thereof to contact the core. When it is desirable to advance a cable core having a diameter beyond the range that the gripping shoes can be deformed to grip the cable core, the gripping shoes 2i5-20 are replaced by other gripping shoes provided with a concave gripping surface having a radius designed to suit the range of core sizes in which that core falls. The gripping shoes 202B may be readily removed from their respective crossbars ll-Il' when necessary without having to remove the endless belts in and H from the respective sprockets.

The supports 36 and 52 are mounted pivotally on the segmental gears 58-58 and Til-10, which are tied together by the connecting link $55 so that their respective weights are balanced against each other, whereby the belts remain in any set position. When the belts l0 and H are adjusted to advance the cable core, the pressure of the gripping shoes 2020 caused by the belt tends to turn the gears 5858 about the posts Gib-60 in a counter-clockwise direction as viewed in Fig. 3. At the same time the pressure of the gripping shoes of the belt H tends to move the belt H away from the cable core and thereby turn the gears l0l'& about their respective posts ll-H in a clockwise direction. Since the gears 5858 and 10-10 are intermeshed, the tendency of each belt to move away from the cable core is counteracted by an equal opposite force existing in the other belt which tends to hold it against the cable core. Therefore, when the belts are properly adjusted, the traction that the gripping members exert on the cable core does not cause the belts to separate and relax their grip on the cable. This arrangement of the

supports

36 and 52 and the gears 58-58 and illill provides a very efiicient and simple mechanism for adjusting the space between the belts to suit the size of the cable core to be advanced thereby, and maintains an accurate adjustment of the belts throughout long periods of operation.

It is to be understood that the capstan also may be used in conjunction with cable-making apparatus for drawing a finished cable, such as a lead-sheathed cable, from various cable-forming mechanisms and delivering it to a takeup reel. It will be obvious, of course, that tractor-type capstans embodying features of this invention are capable of numerous other uses.

While the above-described capstan is particularly well adapted for advancing cable cores through or from apparatus in which the cable is being processed, it may be readily adapted for ad vancing various types of elongated articles, such as wire rope, stranded cables, lead-sheathed cables, and the like without departing from the spirit and scope of the invention.

It is to be understood that the endless belts IS-!B also may be provided with gripping members designed to act as dies for forming cables and tubular articles into desired shapes. The apparatus is readily adaptable for these and other operations relating to elongated articles by the mechanism provided for adjusting the spacing between the belts to suit the size of the article positioned between mutually-facing portions of the belts.

What is claimed is:

l. A strand-advancing apparatus, which comprises a plurality of endless belts, a plurality of guideways for guiding the belts along predetermined paths, a plurality of gripping shoes secured on the endless belts for engaging a strand to be advanced through the apparatus, a system of interconnected pivotally mounted members for supporting the guideways so that portions of the belts travelling thereon face toward a common axis and are parallel to said axis, said members being so designed that movement of any one of them imparts equal and opposite movement to the guideways with respect to said axis, and means for selectively moving the members to adjust the space between the belts to suit the size of the strand to be advanced by the belts.

2. A strand-advancing apparatus, which cornprises a plurality of endless belts, a plurality of guideways for guiding the belts along redetermined paths, one for each belt, a plurality of pairs of spaced pivotally mounted levers for movably supporting the guideways, one pair of levers for each guideway, said guideways being arranged on the levers so that a portion of their respective belt faces toward a common longitudinal axis, a link connecting the pivotally mounted levers of one of the belts together so that a portion of the belt supported thereby is parallel to said common axis, means for connecting free ends of all the levers together in such a position that portions of the belts supported by the other pairs of levers are parallel to the longitudinal axis, a plurality of gripping shoes secured on the endless belts ior engaging a strand to be advanced along the common axis, said pivotally mounted levers being so connected that movement of any one of the levers imparts equal movement toward or away from the common. axis, and means for selectively moving one of the levers to adjust the space between the belts and the common axis to suit the size of a cable to be advanced by the belts.

3. A strand-advancing apparatus, which comprises a pair of elongated members having opposed guideways, sprockets mounted on opposite ends of each of the guideways, a pair of endless chain belts arranged to travel on the guideways and around the associated sprockets thereof, one belt for each guideway, a pair of pivotally sea-a4 same plane and are disposed in spaced relationship; said levers being connected to maintain the opposed portions ofthe'belts parallel and so that mov'ementof anyone of the'levers imparts equal and opposite transversemovement to the guideways, a plurality of gripping shoes'secured on the belts for engaging a strand to be advanced by theopposedportions of thebelts, and'means for selectively moving the levers to adjust the space between the opposed portions of the belts to suit the size of the strand to beadvancedby the belts.

4. A capstan for advancing cables longitudinally of their length,which comprises a'pair of endless belts, a plurality of cable gripping members secured to the moving belts for engaging a cable longitudinally positioned between the belts, a pair of lT-sha'ped supports'one for each belt,'a pair of pivotally mounted levers for supporting one of the supports, a second pair of pivotally mounted levers for supporting the other support, a connecting link for maintaining the first-mentioned pair of levers in such a position that one portion'of the belt supported thereby is maintained parallel to the longitudinal axis of a cable positioned between the mutually facing portions of the belts, means for connecting the free ends of the second pair of levers to the free ends of the first-mentioned levers so that the secondpair of levers maintain a portion of the belt carried thereby parallel to the longitudinal axis of the cable, saidle'vers being so linked together that movement of any one of its levers about its pivot point imparts equal and opposite transverse movement to the supports carrying the belts, and means for moving one of the pivotally mounted levers in either direction to adjust the space between the mutually-facing parallel portions of the belts to suit the size of the cable to be advanced thereby.

5. A capstan for advancing cables longitudinally of their length,'which comprises a pair of endless belts, a plurality of resilient gripping shoes secured on the'endlessbelts for'engaging a cable to be advanced thereby, a pair of movable supports one for each belt, a system or levers connecting the supports together so that the endless belts travel in the sameplane with their juxtaposed portions parallel to the longitudinal axis of the cable to be advanced by the belts, said system of levers being designed so that movement of any one of the levers imparts equal endopposite transverse'movement' to the supports, and means for selectively positioning the system of levers toadjust the space between the juxtaposed portions of the belts to suit the size'of a'cable to be advanced thereby.

6. A capstan for advancing cables, which comprises a pair of endless belts arranged to travel in the same plane and disposed in spaced relationship, a plurality of resilientgrippingshoes secured on the endless belts 'foren'gaging a-c'able positioned longitudinally between the mutuallyfaeing portions of the belts, apair'of spaced pivotally mounted levers for movably supporting one of the belts, a second pair of spaced pivotally mounted levers for movably supporting the other belt, a connecting link for holding the first-mentioned pair of levers in such a position that a portion of the belt supported thereby is parallel to the longitudinal axis of the cable to be advanced by the belts, said levers having gear teeth formed on their nee" 'ends' whichihtermesh with ea h other anemia the remnants" or reversin such a position that a portion of the belt supported byis parallelto the longitudinal axis or the cable engaged by the belts, said pivotally mounted levers'being arranged so' that movement'of any one of the levers imparts" equal and opposite transverse'movem'ent to the'belts, and'means for "selectively positioning the levers-so as to" adjust the space between the mutually-facing parallel portions 'of the'belts to suit the size of the cable being advanced by the belts.

'7. A capstan for advancing cables, which comprises a pair of endless belts arranged to travel inthe same plane'and' disposed in spaced rela- "tionship, a plurality of gripping members secured on 'the'endless belts for engaging a cable longitudinally positioned between the mutuallyfac'ing portionsfof the'belts, a pair of pivotally mounted leversfformovably supporting one of thebelts, a secondpair or spaced pivotally mounted'levers for movably supporting the other belt, a connecting linli'for' holding thefirst-mentioned levers in such a position that one portion of the belt supported thereby is parallel to the longitudinal 'axisbf the" cable'to be advanced by the belts, said levers having gear teeth formed on 'their'adjacent ends which intermesh with each other so" as to hold the second pair of levers in such a position that a, portion'of the belt supported thereby is parallel to the'longitudinal axis of the cable engaged by the belt, said pivotally mounted levers being arranged so that the weight of the belts tends 'to' turn theirrespective levers in opposite directions'whe'reby movement of any one of the'levers imparts equal and opposite transverse movement to the'belts, a crank connected to one of the levers, and means for selectively actuating'the crank so as to turn the lever about its pivot "point andthe'reby'adjust the spacing between the mutually-facing parallel 'po'rtionsof thebelt to suit the size of the cable being advanced thereby.

, 8. A strand advancing'apparatus, which comprisesa pair of endless belts having strand-engaging surfaces thereoma' pair of g'uideways for guiding the belts along predetermined paths, a group of segmental gears 'mou'nted' on fixed pivotal axes, pivotal mounting 'means'positioned offcenteron the gears'connecting one of the beltguideways to the gears to' support the guideway thereby, a "second group of I segmental gears mounted onfi'xed pivotal aiaes and intermeshed withthegears of the first inkntioned group of gears, pivotal mounting means connecting the other guideway'to the gears of the second-mentioned group to support that guideway thereby, means linkingtog'eth'er the gears supporting one of theguideways to orient all the gears in positionssuch that portions of the belts carried bytheguidewaysface a common axis and are parallel to said axis, said'pivotal mounting means being'so connected to the gears that movement of' any one of thegea'rs imparts equal and opposite movements of thebelts'w'ith respect to said o'on irnon"axis,and.meansfor turning one of the "gears"about"itspivot"point to adjust the space between the belts to suit the size of the strand to be advanced by the apparatus.

9. A strand-gripper, which comprises a pair of legs having generally opposed gripping surfaces formed on the free end portions thereof, and a flexible web connecting the legs together at points thereon between the gripping surfaces and the opposite ends of the legs for pivoting the legs 1 1 to bring the gripping surfaces into engagement with a strand when the strand is pressed against the web.

10. A gripping shoe for strand-advancing apparatus, which comprises a flexible, but substantially non-compressible rubber block having thick opposed end portions provided with arcuate strand gripping surfaces, and a substantially thin web connecting the end portions for causing the end portions to turn inwardly and grip a strand when the strand is pressed against the web.

11. A gripping shoe for strand-advancing apparatus, which comprises a block of flexible, but substantially non-compressible material having a concave strand-gripping surface of a radius greater than that of the maximum size strand to be engaged by the shoe and a recess centrally positioned in the side thereof opposite the concave surface, said concave surface and recess forming a thin wall between the opposed outer portions of the shoe which bends when the shoe is engaged by a strand and pulls the outer portions of the concave surface inwardly into gripping engagement with the strand.

12. A strand-advancing apparatus, which comprises an endless belt movable along a predetermined path, a plurality of holders secured transversely on the belt, and a plurality of flexible strand-gripping shoes insertable in the holders for engaging a strand to be advanced by the apparatus, each of said gripping shoes having a concave strand-engaging surface of a radius greater than that of the maximum size strand to be engaged thereby and the central portion thereof being a flexible web yieldable toward the belt to cause the outer portions of the concave surface to tightly grip strands of different diameters.

13. A strand-advancing apparatus, which comprises an endless belt, a plurality of sockets secured transversely to the belt, and a plurality of resilient gripping shoes insertable in said sockets for engaging a strand to be advanced by the apparatus, said sockets having means thereon for keying the gripping shoes to the belt, each of said gripping shoes having a concave groove Whose radius is greater than that of the maximum size strand to be advanced by the belt and a recess centrally positioned in the side thereof opposite to the groove, said recess permitting the gripping shoe to be bent toward the belt and cause the outer portions of the concave surface to grip tightly strands of any diameter between and including predetermined maximum and minimum values.

14. A strand-advancing apparatus, which comprises an endless belt having a portion thereof travelling parallel to a strand to be advanced by the apparatus, a holder secured on the belt and having channel-shaped ends provided with inwardly extending ribs and a flexible but substantially non-compressible rubber gripping shoe positioned in the holder and having slots in the sides thereof for receiving the ribs of the holder, said gripping shoe having a concave groove in its strand gripping surface whose radius is greater than that of the maximum size strand to be advanced by the apparatus and a recess centrally positioned in the opposite side thereof, said recess being provided in the gripping shoe so that it may be flexed sufficiently to be inserted into the channel-shaped ends of the holder and the shoe can be bent toward the belt, whereby opposed portions of the concave groove tightly grip strands of any diameter between and including predetermined maximum and minimum values.

15. A capstan for advancing cables, which comprises a pair of endless belts, means for supporting the endless belts in the same plane and in spaced relationship, means for selectively positioning the supporting means so as to adjust the space between the mutually-facing parallel portions of the belt to suit the size of a cable to be advanced by the belts, and a plurality of flexible, but substantially non-compressible gripping shoes detachably secured on the endless belts for engaging the cable positioned between the mutuallyfacing portions of the belts, each of said gripping shoes having a concave cable engaging surface of a radius greater than that of the cable to be engaged thereby, and a recess centrally positioned in the side thereof opposite the groove, said recess being designed so that the shoes bend toward the belt when they engage the cable in such a manner that each pair of opposed shoes exerts maximum gripping force on the cable at four diametrically opposed arcs of contact about the periphery of the cable.

16. A capstan for advancing cables longitudinally of their length, which comprises a pair of endless belts, each of said belts includes a pair of endless chains having bars secured transversely across the alternate lengths of the chains, means for movably positioning the belts so that they travel in the same plane with juxtaposed portions disposed in spaced relationship to suit the size of a cable to be advanced by the apparatus, said bars having channel-shaped ends provided with an inwardly extending rib, and a flexible gripping shoe positioned in each transverse bar and having a slot in each end thereof for receiving the corresponding ribs of its respective transverse bar, each of said gripping shoes having a concave groove in its cable griping surface whose radius is greater than that of the maximum size cable to be alvanced by the apparatus and a recess positioned centrally in the opposite side thereof, said recess being provided in the gripping shoes so that they may be flexed sufiiciently to be inserted into the channel-shaped ends of the bars and so that they will bend in the center as they engage the cable and grip tightly cables of any diameter between and including predetermined maximum and minimum values at four diametrically opposed arcs of Contact about the periphery of the cable.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,904,885 Seeley Apr. 18, 1933 2,135,806 Fermann et al. Nov. 8, 1933 2,212,132 Shear Aug. 20, 1940 2,251,291 Reichelt Aug. 5, 1941