US2677879A - Manufacture of coaxial conductor electric cables - Google Patents

Description

May 11, 1954 J. c. BEVER IDGE 2,677,879

MANUFACTURE OF COAXIAL CONDUCTOR ELECTRIC CABLES Filed March 5. 1951 2 Shets-Sheet 1 In venlor JOHN C. BE YER/06E Attorney May 11, 1954 J. c. BEVERIDGE 2,677,879 MANUFACTURE OF COAXIAL CONDUCTOR ELECTRIC CABLE S Filed March 5, 1951 2 Sheets-Sheet 2 N O m\\\\\\- Inventor JOHN C. BEVERIDGE Attorney Patented May 11, 1954 MANUFACTURE OF COAXIAL ELECTRIC CABLE John Colquhoun Bevel-id signor to Internation poration, New York, N

Delaware SONDUCTOR ge, London, Englanc'Lasal Standard Electric Cor- Y., a corporation of Application March 5, 1951, Serial No. 213,933

Claims priority, application Great Britain- March 10, 1950 3 Claims.

Thi invention relates to machines for applying insulating discs to conductors and in particular to conductors intended to form the inner conductors of coaxial communication cables.

Various methods of applying insulating discs preformed with central apertures on to conductors have been devised but the more commonly used ones involve pressing the disc onto the conductors laterally there being a radial cut in the disc to enable the conductor to pass into the central aperture.

U. S. Patent No. 2,092,487, filed April 24, 1936 and granted on September 7, 1937, there is described and claimed a machine for the continuous assembly of slotted discs in spaced relation on a" wire in the manufacture of concentric conductor cables, in which the discs are supported in a rotatingmagazine which is moved to press the discs successively into engagement with the wire by reason of the relative movement between the magazine and the wire, the magazine being arranged to=give to each disc during itsapplication to the wire substantially the'same velocity in the direction of travel of the wire as that of the Wire itself; whereby relative longitudinal movement between the disc and the wire is eliminated during the pressing operation, means being provided for supporting the wire against bending during the'application of the discs.

If the discs are made of a relatively rigid ma terial', such as ebonite, slots having a width only slightly less than the diameter of the conductors are provided. at the time Of manufacture of the discs and it is desirable that successive discs should be applied to the conductor with the slots lying in different senses so as to avoid mechanical and electrical dissymmetry. In practice this means that at least two applicator wheels are required when slotted discs are used so that alternate discs can be applied from oppositesides.

If on the other hand the discs are made of a relatively resilient material such as for example, polythene, a simple radial out or slit can be used in placeof the slot of finite Width and can be opened up sufficiently to permit the conductor to be passed into the central aperture after which the slit closes up again and the disc firmly embraces the inner conductor. When resilient discs are used the slits can be out just before they are applied so that no problem of orienting them arises as it does when slotted discs are-used. Furthermore, as the resilient" discs closeup after application it is not found necessary to arrange for the slits in alternate discs to lie in opposite senses. Hence it is possible to apply the discs chine discs provided with central apertures, butnot with sllts, are fed from a supply hopper down the discs are firmly held.

According to the cator wheel is provided with an axially project'- to the conductor from the outside of thefiange. This arrangement enables the feed hopper for the discs to be arranged'at a convenient height manufacturing a coaxial conductor electric cableouter conductor supported on core having an disc shaped insulators centrally mounted in spaced relation on ing a wheelmountedwith its axis. horizontal and carrying near its periphery a slotted flange, each slot being so shaped as to receive one discshaped insulator only, means for feeding centrally apertured insulating discs into successive slots at or near the lowest point of said wheel as it rotates, means for retaining the discs in the slots between the position at which they are fed intothe slotsand the position at which they are ap plied to the inner conductor, a knife in the path of the discs whilst they are being carried in said slots for slitting each disc from. a point on its outer oircumferenceto its central aperture, a guide member for keeping open the slits made by the knife; a wedge member foropening out an inner conductor, compris-- the slits to allow the discs to be applied to the inner conductor while it travels tangentially tosaid wheel at substantially the highest point of rotation thereof. The invention will be better understood from the following description of a preferred embodiment taken in conjunction with the accompanying drawings in which:

Figs. 1 and 2 are side and front elevations respectively of the machine.

Fig. 3 is an enlarged representation of part of the main applicator wheel shown in Fig. 2.

Fig. 4 is a section along the line IV-IV shown in Fig. 3.

Fig. 5 is a section along the line V-V shown in Fig. 3.

Fig. 6 is a section along the line VIVI shown in Fig. 3.

Fig. 7 shows five sections along lines lettered a, b, c, d, e in the upper part of Fig. 3.

In Fig. 1 there is a supply hopper i which is kept supplied with discs 2 of insulating material, the discs being made with a central aperture of the correct size to fit on the inner conductor. The discs are transferred from the hopper I to the pick-up trough 3 by means of a travelling belt conveyor 4 which is preferably operated intermittently so as to keep the discs agi tated. A hub 5 mounted in the trough 3 carries four, identically shaped arms 6, 7, 8 and 9. The hub 5 with its arms is rotated and each of the arms is formed with a channel so that it picks up a number of the discs 2.

The arm 6 is shown when it has picked up four discs. In the position shown for arm 1 the end of the channel in the arm is directly above a slot in a fixed central boss H! which can best be seen in Fig. 2.

From the slot in the boss H) the discs enter a chute H and travel downwards under gravity until they are delivered to the inner side of the flange [2 of the main applicator wheel l3 which will be more fully described later. When the chute II is full any surplus discs delivered to the slot in the boss H! are bypassed through a gate and full back into the trough 3.

It can be seen that the applicator wheel I3 carries a flange [2 as shown in Fig. l. The operation of the machine is primarily dependent on the functioning of this flange. The method of rotating the wheel is indicated and need not be more closely described. In Fig. 2 it can be seen that the flange I2 is in fact built up of a number of sections 14 separated by slots l5, and these sections 14 together form the applicator ring. In Fig. 3 there is shown in enlarged form part of the applicator wheel with details of associated equipment. Fig. 6 is a section through VI-VI shown in Fig. 3 and it can be seen that the section cuts the main wheel and the sup porting arrangements IE but does not cut any sections M as the section line passes through one of the gaps i5 between adjacent sections 14. In Fig. 6 it will be seen that there is a groove H in the section [4 and this, which occurs in every section I4, is also shown in Fig. 1. Effectively thefiange or applicator ring 12 has a groove 11 on its outer surface all the way round. The purpose of the groove will become clear later.

Fig. 4 is a section through IV-IV shown in Fig. 3, and should be studied in conjunction. therewith and also with Fig. 1. In this the discs 2 are seen approaching the lower end of the chute H while the section [4 is shown as cut by the section line the discs not being shown as cross hatched for clarity. As one of the slots 15 passes under the lower end of the chute H a disc falls in, the next disc in the chute being retained until another slot is in position.

Shortly after a disc has been dropped into one of the slots the continued rotation of the applicator ring brings it up against the slitting knife [8 which slits it from the circumference to the central aperture. An arcuate guide mem ber 19 outside the applicator ring prevents the discs from falling through the slots and out of the applicator ring while a second arcuate guide member 20 on the inner side of the ring prevents the discs from falling out in the inward direction as they approach the upper position of the ring.

' The guide members [9 and 20 are mounted on the fixed part of the machine by means of supports 2|.

Fig. 5 is a section through V-V Shown in Fig. 3 and shows the knife [8 actually in the process of slitting a disc. Part of the external arcuate guide member I9 is formed as ridge or key 22, best seen in Fig. 7 (a).

This key 22 holds the slit in the disc 2 slightly open and prevents the disc from rotating, and in conjunction with guides 19 and 20 holds the disc in position in its slots l5 until the time has come when it is to be applied to the inner conductor 23. This ridge or key 22 is shown as a continuation of the knife l8.

This conductor is drawn tangentially across the applicator ring at its top point and at the same speed as the tangential speed of said top point and the conductor is pressed into the groove ll by the support 24. It will have been noticed from Fig. 5 that the knife I8 projects into the groove 11 so that the slit in the disc is formed in the groove and will be held there by the key 22 all the time from the moment it leaves the knife (8 until it reaches the conductor 23. Fig. '7 (a) shows as explained above how this key 22 holds the disc. Just before the disc reaches the inner conductor 23 however the key 22 is widened out to a wedge shape as shown in Figs. '7 (b), '7 (c) and '7 (d) so that the slit in the discs is opened further and further as the disc approaches the conductor until finally the key or wedge 22 tapers away to nothing and the slit in the disc closes over the conductor as shown in Fig. 7 (e). The disc is now mounted on the conductors and passes away for the applicator ring to the next stage of the operation, normally the applying of an outer conductor. It is to be noted that the chute l I leading from the pick-up trough 3 to the rotating flange 12 on the applicator wheel l3 given two gentle bends in diiferent planes, one to enable it to pass from the pick-up trough past the upper portion of the applicator wheel flange and into position to deliver the discs to the inner surface of the lower portion of the flange, the other to enable it to pass from the hub of the rotating pick up arms without interfering with the arms. These bends are such however, that the discs are able to fall under gravity down the chute and into the slots between the axially projecting portions of the applicator wheel and the chute is in fact substantially vertical.

While the principles of the invention have been described above in connection with specific embodiments and particular modifications thereof, it is to be clearly understood that this description is made only by way of example and not as a limitation on the scope of the invention.

What I claim is:

1. In a device of the character described, the

combination with a conductor drawn at uniform speed through a linear path, and means for gravity feed of centrally apertured circular discs to a point below said cable, of an annular and rotatably driven applicator for sequentially moving each disc from the point of feed upwardly and onto said moving conductor at a circumferential speed equal to the linear speed of the conductor, said applicator comprising a rotatably mounted and driven member provided with a plurality of laterally extending block-like elements disposed in circumferential configuration at spaced intervals to define a plurality of slots, equally spaced circumferentially, for the reception of a disc when in registry with said feed means, each said block-like element being centrally provided in the outermost wall thereof with a longitudinally extending slot, said slot being positioned in circumferential registry, guide means disposed between said feed point and the point of interception of said conductor for retention of each disc in its slot, means for feeding said discs to the inside of said block-like elements and into said slots, means adjacent said feed point and disposed in the path of said circurnferentially registered slots for cutting each disc in the plane of applicator rotation and radially outwardly of the axis of applicator rotation, means for progressively spreading the slit portion of said disc as it is moved toward said conductor, and means adjacent the point of termination of said spreader means for directing said moving conductor into the path of said circumferentially registered slots and into the center of each disc, and said applicator applying said discs from the outside of said slots to said conductor, the slots serving as a passage-way through the block-like elements.

2. Apparatus for the sequential application of annular discs to a conductor comprising in combination, a rotatably mounted annular applicator peripherally provided with a laterally extending slotted flange, the slots providing a passageway through the flange, means for sequentially feeding a disc to the inside of the flange into each slot thereof, guide means for retainin the discs so each disc along the outermost radius as positioned by the applicator, annularly disposed spreader said conductor.

3. The apparatus according to claim 2, wherein said slotted flange comprises a plurality of arcuate block-like elements disposed in equally spaced annular configuration to define equally spaced disc receiving slots therebetween, said block-like elements each being provided in the moving cable being tangentially directed into said block channels and centrally of each annular disc to permit, upon termination of said spreader means, snug fit application of each successive disc to said conductor.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 482,542 Butler et a1 Sept. 13, 1892 915,542 Biertuempfel Mar. 16, 1909 1,627,601 Goebel May 10, 1927 2,075,050 Nowinski Mar. 30, 1937 2,333,940 Kuehlman Nov. 9, 1943 2,355,832 Wagner Aug. 15, 1944 2,404,782 Berggren et al July 30, 1946 2,4 6,623 Larsen Sept. 2, 1947 2,579,468 Brillhart Dec. 25, 1951 FOREIGN PATENTS Number Country Date 631,914 Great Britain Nov. 11, 1949

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