US2158855A - Hydraulic press for cable connectors - Google Patents

Description

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. HYDRULIC PRESS FOR CABLE CONNECTORS Filed Aug. l0, 1938 Patented May 1s, 1939 PATENT OFFICE HYDRAULIC PRESS FOR CABLE CDNNECTORS Eugene D. Eby and Thomas C.'A.itchison, Pittsfield, Mass., assignors to General Electric Company, a corporation of New York Application August 10, 1938, Serial No. 224,152

6 Claims.

Electric power cablesvfof the type having enclosing lead sheaths adapted to be drawn into ducts below the surface of the street are shipped by the manufacturer in reel lengths. In installing them for service, it ls of course necessary to unite the several lengths which is commonly done in manholes located below the surface of the street where space is at a premium and where the working conditions necessarily Yare not of the best. The proper jointing of all cables is one requiring great care on the part of the operative and especially so where the cable is of the stranded multiple conductor type since the ends of the conductors to be jointed have to be splayed or separated radially before the individual connectors can be applied. Moreover, the extent to which the conductor ends can be splayed ciably affecting the other or others.

or separated is limited for various reasons. -After the connectors are applied to unite corresponding conductors, the ends of the conductors and the connectors have to .be re-insulated in such manner as to fully protect them from each other and from ground. It is desirable to secure the connectors to the. conductors by mechanically forcing metal of the connectors into the-strands of theconductors in such manner as to form good electrical and physical connection between them. Such an arrangement avoids the use of solder, blow torches and the like and the possible burning of 4the factory applied insulation on the conductors and burning of the compound with which the insulation is impregnated. This may be advantageously done by a cold process employing for the purpose anhydraulic pressand a punch which forms one or more relatively deep indentations in the connector, the metal of the indentation acting to wedge the individual strands into rm contact with each other and with the inner wall or bore of the connector; On account of the limitations above indicated, the construction of the press becomes an important factor.

One object of our inventionis the provision of an hydraulic press of improved construction by means of which indentations in the connectors of electric power cables may Ireadily be made for the purpose of lelectrically and mechanically uniting adjacent lengths of cable. More specically an object of our invention is the provision of a press so constructed andy arranged that one of the operative parts may be inserted between the splayed ends of the conductors or between spaced connectors for the purpose of successively indenting each of the connectors without appre- A further object is the provision of an improved press (Cl. 14o- 113) which is relatively light in weight, of small size yet capable of exerting great force on the indenting punch.

For a consideration of what We believe to be novel and our invention, attention is directed 5 to the accompanying description and the claims appended thereto. g

In the accompanying drawing which is illustrative of our invention, Fig. 1 is a' view of a press partly in section and partly in elevation, v

and Fig. 2 is a similar view at right angles to that of Fig. 1.

The numeral 3 indicates the head or supporting member of the press which is relatively massive because of the strains to which it is subjected when the punch II is being forced into the connector 5 and stranded conductor B. In order that the press may readily be applied over a connector and also removed when the stranded conductors are secured within the connector, the member 3 is made in the form of a hook open on one side, the size of the opening being somewhat larger than the largest connector to be punched or indented. This calls for ar considerable mass of supporting metal, as indicated, in the hook portion or part of the press. 'I'he -hook has a half round or semi-circular worksupporting seat 'I of suitable size. Located in the seat and well fitted therein is a strong half round sleeve or adapter8. By using adapters of different internal dimensions, the same press may be used for connectors of different diameters. The adapter or Work holder is held in place by suitable means such as spring pressed steel balls 9, the latter entering and engaging the walls of small recesses in the adapter. As shown the press is assumed to be hanging downwardly from a connector in which the stranded ends of two cable conductors are located. The lower end of the head or member has a tubular extension I0 which has an internal shoulder II and is also screw threaded to receive the similarly threaded end of a cylinder I2. The lower end or head of the cylinder is Amade integral with the wall thereof to avoid joints and is' tapped 45 to receive an end of a pipe I3 by means of which liquid is admitted to and received from the cylinder. Desirably the upper end of the cylinder engages the shoulder II for the purpose of definitely positioning it. vInside of the cylinder is a ram or piston I4 and a piston rod I5 of substantial cross-section to withstand the pressure exerted thereon and also to support the punch 4. The cylinder is internally screw threaded at its upper end and -threaded therein is a hollow stawork holder 2s,

tionary nut I6 that acts as a guide for the piston rod and as an abutment for a spring. Between the stationary nut and the ram is a coiled compression spring I1 which acts in opposition to the fluid pressure to return the ram after each of its working strokes. The upper end of the piston rod is screw threaded to receive the threaded shank I8 of the removable punch. The punch has a shoulder I9 resting on the end of the piston rod to take the load, the shoulder also serving as an abutment for the coiled compression spring 20. The upper end of the punch is desirably well rounded to prevent cutting of the connector when fluid pressure is applied to the ram. From the rounded end the side walls 2| gradually diverge. The length of the rounded end of the punch in the axial plane of the connector is such as to produce the desired length of indentation. Its length will be determined in large part by the length of the connector itself, bearing in mind that two cable ends are to be united by the connector. The punches are made removable so that other punches ofthe same or of different shape and size may be substituted.

Located within the cylindrical part of the head is a reciprocating follower 22 of cylindrical shape which at its upper en d has a semi-cylindrical .seat to support the second half round adapter or the latter being held in the position shown by spring pressed steel balls 2l which engage the side walls of recesses in the adapter. The follower has an opening 25 through which the punch is permitted to pass. The adapter likewise has an opening 26 registering with opening for the same purpose. It is necessary to prevent the follower from turning and also the punch. For this purpose, the follower has a slot 21 in one side and located therein for engagement with opposite walls thereof is a pin 28 carried by a screw. To prevent the punch from turning, the follower has two other walls of the two slots are screws 30 which are threaded into the enlarged shoulder i9 at the bottom of the punch.

It is important to. preserve the round contour of the connector 5 during the .pressing operation for the reason that any distortion thereof makes it more difficult to insulate and may, affect its electrical characteristics. This is accomplished -by the two half -round or semi-cylindrical adapters 8 and 23. The adapter 8 is fully backed up by the massive metal part of the book. The ends of the side walls of the follower 22 are'subject to a spreading tendency due to the dislocation of the metal forming the inset or indentation 3l by the punch. To prevent spreading, the vertical wall 32 of the part of the head or supporting member containing the follower is extended upwardly parallel to the axis of the upper half adapter. The end part 33 of the follower is in engagement with the wall 32 which effectively prevents` spreading in this region. To prevent the right hand side of the adapter from spreading, it is first backed up by the part 3| of the follower and second by the wall of a shoulder or socket 35 formed in the tip of the hook. These arrangements effectively hold the second or lower half adapter against distortion. Since ers are prevented from distorting it follows that the connectors are likewise prevented from distorting.

Assuming the stranded conductor ends to be inserted in the ends of the connector which at "this stage has an unbroken cylindrical surface,

.ent size,` the same slots 29 arranged at right angles to slot 21, and located in and engaging the follower to the level ofthe4 the adaptthe hook end of the shown in Fig. 1. forced under pressure into the cylinder through the pipe I3. As the cylinder fills, the ram or piston I4 rises and with it the punch 4, follower 22 and lower half adapter 23. Under the circumstances, the half adapter first engages the under side of the connector, then as the ram continues to rise, the spring 2l)` about the punch is compressed and in so doing firmly presses the adapter half adjacent the connector.A At this stage, the connector is firmly supported above and below. Continued upward movement of the ram causes the punch l to pass through openings 25 and 26 and form the indentation 3|, the metal so displaced being forced into and between the strands of thev conductor firmly wedging them against each other and against the inner wall of the connector thereby ensuring good electrical and mechanical engagement. In this connection it is to be noted that initially there are small spaces between the strands, and that by the action of the punch the strand' spaces are largely eliminated. After the indentation is made, pressure on the ram is released and springs i1 and 20 return the parts tothe position shown. Assuming that one or more other indentations are desired, the press is moved along the connector to the next position and the operation of the ram and punch is repeated. By using adapters of differpress may be used for a number of different size connectors and different diameter conductors. Y

A press of the construction described is capable of exerting great pressures. As an illustration, the one shown is capable of exerting a pressure of the order of eleven tons. The weight of such a press is ofthe order of nineteen pounds. Moreover, it is of a size that can be conveniently handled within a manhole or other congested place, being onlyr of the order of thirteen and one-half inches in length. As an illustration the press shown is suitable for indenting connectors for 750,000 c. m. stranded conductors.

Assuming the case of three-conductor cables, the ends of the conductors are separated or splayed so that they stand in 120 relation to each other, the distance between each pair of conductors being approximately the same. The spacing of two adjacent connectors must be suiicient to allow the hooked end of the press to be inserted between them. All of the connectors may be 'mounted in place before the indenting operation or as each is applied, it may be indented. The shapeand size of the hook end of the press is such that it can be inserted between connectors and its operation performed. Because of the 120 relation of the conductors and connectors, the angular position of the press with respect to the axis of the cable for each operation on the same end of a connector is different but the procedure is the same. After the connectors are applied and properly insulated, theyv with the connected conductors may be moved inwardly somewhat toward the axis of the cable so as to reduce the outside diameter of the assembly. In this connection, the usual practice in such matters may be followed.

What we claim as new and desire to secure by Letters Patent of the United States is:

l1. A press comprising a supporting member having a cylindrical bore and a semi-cylindrical seat for the work, a cylinder supported by the member adapted to receive fluid under pressure, a ram in the cylinder actuated by the uid press is mounted thereon as Liquid, as from a pump, is

2,158,855 `therein, a retracting means for the ram, a rod for the ram, a follower movable axially within the bore of the member, a punch detachably secured to the rod and normally located within the follower, means within the follower for retracting the punch, a second semi-cylindrical -seat for the work carried by the follower and having an opening for the punch, means car-- ried by the member fo'r preventing the follower from turning, means carried by the follower for preventingl the punch from turning, and a conduit for admitting fluid under pressureto the cylinder.

` 2. A press comprising a supporting member having a cylindrical bore and a semi-cylindrical seat for the work, a cylinder supported by the member adapted to receive uid under pressure, a ram in the cylinder actuated by the iiud therein, a retracting means for the ram, a rod for the ram, a slotted follower movable axially within the bore of the member, a pin carried by a wall'of the member engaging the walls of a slot in the follower to prevent it from turning, a punch detachably secured to the rod and normally located within the follower, a spring Vwithin the follower for retracting the punch,

means carried by the punch and follower for preventing relative angular movements between them, a second semi-circular seat for the work carried by the outer end of the follower having an opening for the punch, and a conduit for admitting iiuid under pressure to the cylinder.

3. A press comprising a hook-shaped supporting member having a cylindrical bore, a seat yformed in the hook, a semi-circular adapter located in the seat, a cylinder supported by the member adapted` to receive fluid under pressure, a ram in the cylinder actuated by the fluid therein, a rod for the ram, a follower movable axially within the bore of the member having a seat at its outer end, a reciprocating punch de-` tachably secured to the rod, and normally located within the follower, retracting springs for the ram and punch, a second semi-circular adapter carried by the seat of the follower, the follower and second adapter having aligned openings registering with the punch and through which it passes, means preventing the follower and the adapter carried thereby from turning, and a conduit for admitting fluid under pressure to the cylinder to actuate the ram. y 4. A press comprising a hook-shaped supporting member having a cylindrical bore and a semi-cylindrical seat. a shoulder formed on the tip of the hook, an adapter located in the seat, a cylinder supported by the member, a ram in the cylinder, a rod moved by the ram, a follower located inthe bore of the member having a recessed seat at its outer end, the portion of the follower on one side of the seat being backed up by the wall of the bore and that on the other side by engaging theshoulder on the tip of the hook when the ramis actuated, a reciprocating punch detachably secured to the rod and normally located within the follower, retracting springs forthe ram and punch. a second adapter carried by the:I follower, the seat and adapter having aligned openings through which the punch passes, and a conduit for admitting fluid under' pressure to the cylinder for actuating theL ram. i

5. A press comprising a supporting member having a cylindrical bore and terminating in a hook, a movable follower located in the bore, the hook and follower between them defining a seat. an adapter located in one of the seats to receive and hold the work, a cylinder supported by the member, a, ram in the cylinder for moving vthe follower, a reciprocating punch also moved by the ram and located inside the follower, means for preventing the follower and punch from turning with respect to each other and the supporting member, and a conduit adapted to convey fluid under pressure to the cylinder to actuate the ram.

6. A press comprising a supporting member having a cylindrical bore and terminating in a hook having a work supporting seat, a cylinder supported by the member, a reciproci'iting ram in the cylinder, a follower having a central bore and a second work supporting seat, a punch actuated by the ram located in the bore of the fol-V lower and arranged to extend through it and the second seat, a rst springcompressed by the outward movement of the ram and punch for moving the follower toward the seat in the hook to receive vand hold the work, a second spring for reti-acting the ram after each working stroke, the springs being so related thatthe follower and punch move as a unit until the follower-engages the work and thereafter the punch alone moves, and a conduit admitting fluid under pressure to the underside of the ram to actuate it.` v Y EUGENE D. EBY. V THOMAS C. AITCHISOYN.-

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