US2722859A - Crimping tool with a rotatable work head - Google Patents

Description

Nov. 8, 1955 H. c. STOLTZ CRIMPING TOOL WITH A ROTATABLE WORK HEAD 2 Sheets-Sheet 1 Filed Oct. 16, 1952 Nov. 8, 1955 H. c. STOLTZ CRIMPING TOOL WITH A ROTATABLE WORK HEAD 2 Sheets-Sheet 2 Filed Oct. 16, 1952 BY M w ATTO l E fi limited mien CRIMPING root. ITH A ROTATABLE Wonk HEAD This invention is in the field of portable hand-operated tools for crimping electrical connectors or terminals onto wire conductors. The invention has particular utility for making connections on existing transmission and feeder lines and on wires where the working space is cramped or awkward.

For example in working on existing overhead or underground lines there are many places where the conductor is accessible only from one side and the tool must be held at an angle, so that it is extremely awkward or often impossible to make a satisfactory connection with the tools available today and even where a connection can be made, it is unduly fatiguing to the workman. Moreover, a large portion of such work is on large size wires and cables under service conditions where the connection is required to have a high mechanical strength and a large current-carrying capacity. Thus, during the crimping operation, to insure a high quality connection, the die assemblies must be maintained in accurate predetermined alignment with respect to each other and with respect to the wire and they should be susceptible to full closure relatively easily regardless of the limited space or angle in which the crimping tool must be held.

The present invention is described as embodied in a hydraulically operated hand tool in which the head of the tool can be freely rotated with respect to the hydraulic cylinder and tool handles and with the die assemblies keyed to the head so that they remain in proper alignment with respect to each other and with the head, and the operator can work the tool handles from a convenient angle.

One aspect of this embodiment permits the tool to be used in making connections on the standing part of a wire where no ends are available over which to slide the tool head. This feature also saves time in making connections near the center of long loose wires, for the head of the tool may be snapped quickly around the wire rather than threading the wire through the tool head or disassembling the head and reassembling it around the wire.

An additional advantage of this embodiment is that the head of the tool can be unlatched and the dies quickly removed and replaced by a different size or type of die. Thus, a single tool may be used for several different sizes of wire and for making difierent types of connections. Moreover, a'single tool together with a set of dies is relatively light in weight; so that a lineman can carry these up a pole or into a manhole and work on several difierently sized cables without exchanging his tool.

Another advantage of the described embodiment is that the die assemblies are maintained in precisely accurate alignment regardless of the way the operator may twist and turn the tool handles to obtain the most convenient operation during crimping.

' It is an object of the present invention to provide a handy crimping tool capable of producing the high crimping pressures necessary for work on intermediate and large size conductors, and having the dies accurately positioned to produce connections having a high mechanical strength and a high electrical performance, and yet which can be readily used in cramped locations and at various angles with respect to the conductor being crimped.

The various aspects, objects, and advantages of the present invention will be in part pointed out and in part apparent from the following description taken in conjunction with the accompanying drawings.

Figure 1 is a perspective view of a hand-operated hydraulic crimping tool, generally-indicated at 10, embodying the present invention;

Figure 2 is a perspective view of a crimped connection such as may be made by the tool 10;

Figure 3 is a partial axial sectional view of the head and of the hydraulic cylinder of the tool 10, taken along the line 3-3 in Figure 1, showing the die assemblies in fully closed crimping position;

Figure 4 is a partial view showing the head of the tool in unlatched position and the ease with which the impression die and nest die may be removed;

Figure 5 is a cross sectional view of the base portion of the head;

Figure 6 is another view of the base portion of the head shown in Figure 5;

Figure 7 shows a portion of the die assembly which may be used in the tool 10;

Figure 8 is a partial axial sectional view of the head base swivelly connected to the cylinder of a differently arranged tool; and

Figure 9 is a cross sectional view of the swivel joint taken along the line 9-9 of Figure 8.

The embodiment of the tool 10 as illustrated is adapted to make connections of the type formed by telescoping a sleeve or ferrule portion 11 (Figure 2) of a connector 12 over the bared end (not seen) of a conductor 13, the insulation 14 being shown broken away to reveal the conductor 13. The connector and conductor are placed within the head 15 of the tool 10 and the connection is made by crimping the walls of the sleeve against the conductor, for example, as more fully described in U. S. Patent No. 2,535,013 to Thomas C. Freedom, issued December 19, 1950. Moreover, by simple changes in the die assemblies as described hereinafter, this tool may be adapted for use with various size conductors and for making connections to the intermediate portions of existing electrical lines where an end of the line is not available. The top of the head of the tool, as explained hereinafter, in detail, can be unlatched and quickly snapped around any wire on which a connection is to be made.

An example of such connections where this unlatching of the head is a great advantage is the connection of new feeders to an existing distribution line by using so-called T-tap and X-tap types of connections such as are described in the application of William R. Evans, Serial No. 299,201, filed July 16, 1952. These T-tap or X-tap connectors have a generally U-shape which can be hooked onto the existing wire and then slid onto a new line from the side and crimped closed to form a junction.

The tool 10 shown in Figures 1 through 7 comprises, generally, a body 16, the head 15, which is free to rotate with respect to the body, and a pair of handles 17 and 13. The tool is hydraulically operated, that is, during crimping the movable handle 17 is manually pressed toward the fixed handle 18 with a series of pumping strokes, and a piston rod 19 forces a hydraulic fluid into the ram chamber 20 within the cylinder wall 21 (see Figure 3) and behind the rear of ram 22 to drive it toward the head 15'. Figure 3 shows the ram 22 fully advanced toward the head 15 after completion of the crimping operation. The details of the operation and construction of the movable handle 17 and the fixed handle 18 and of the hydraulic circuit of this tool may be similar to those de scribed in the application of Kenneth E. Peterson, Serial No. 167,459, filed June 10, 1950, now Patent No. 2,696,- 850, issued December 14, 1954. The compression spring 24, which acts to-returnithe ram 22 to-its-initial posit-ion when a pressure release valve .(not shown) is manually unseated :by turning a release-knob 25 ,(see Figure 1') following a'crimping operation, fits within-the cylinder 21 between anannular recess-26-in theb'ase 28 of the head -15 and rpushes against a :shoulder iltl on the ram 22. To retain the fluid within chamber 24), the shoulder 30 .has a peripheral ,groove 32 holding-an --ring backed up by va-leather washer.

In order to support and drive adie assembly, generallydndieated at-3'4, comprisinga dieholder-36 and'an impression die piece 38, the faceof-the ram 2211215 a sooket40 into which the d-ie holder 3'6 is-pivotallysecured bya shoulder screw 42. The die assembly 34 is held together as a-unit by -a stem 44 .(see also Figure 4) on the impression die 38 whieh slides into .a recess'or hole 46 in the-dieholder, and-a spring-biased ball'detent 4-8 (Figure 7') snaps into a -groove=50 in the stem 44 to lockit in place. As -shown, the-stem44 may be provided with an additional retaining groove to adapt the impression die piece for use in other tools.

To prevent the impression die-38 from twisting in the die holder 36, a channel 52 (see Figure 7) is cut across the end of the die holder into which snugly fits the rectangular base 53 (Figure 4) -of the impression diepiece 38. A smaller channel-54m right angles thereto co-operates with a relieved area- 56 in the base of the die 38 to provide clearance so that when'the-dies are to be changed, thedie 38 may be started with a screw driver blade or the like, ifnecessary. Thus, the impression die piece 38 and its die holder 36 are locked together -s a unit and are free to rotate with respect to screw 4.. turning independently of but bearing upon the ram 22.

As indicated above, the'tool 1-0 is particularly adapted for use in the maintenanceand construction of electrical power distribution systems and for work oft-intermediate and large size wires where the performance requirements of the connections are high. In the formation of crimped connections such as those described .above, it is known that-the form of the-crimp and the accuracy with which it is'made-are extremely important .factors indetermining its performance. Thus inthe-typeof work discussed above, the connections must be very accurately 'made andthis is done by maintaining the nest die and impression die piece inaccurate alignment atall times during the-crimping stroke. During crimping the die holder 3-6 slides along the Walls 58 (see Figures and'6) of acentral opening in the head base 28, so that the die assembly 34 is maintained in accurate-alignment with the-head. A keyway 60 is cut in the wall 58 parallel with the path of movement of the die assembly 34, and a dovetailed key 62, as shown in Figure 7, is force fitted into an undercut keyway in the-die holder-36 to slide in the keyway 60 and preventthe-die assemblyfrom rotating in the head 15.

Mounted in the head :opposed to'the die piece 38 is a nest die 64 having a stem 66 held in a hole 68 in the top 70 of the head 15 by a spring-biased ball detent 72 which snaps into a retaining groove 74 in the stem 66. Additional grooves may be provided in the stem 66 to adapt the nest die64 .for use in other tools. The nest die 64 is prevented'from twisting in the top 78 by its rectangular base 76 which snugly fits into a recess 77 in the underside of the top 70. One edgeof the base 76 is rabbeted at 78 to provide clearance for a screw driver blade to be inserted between the die 64 and the top 70, in case the die should stick when it is to be changed.

In orderto facilitate themakingofcrimps without the necessity-for threadingthe wire-through the head 15 between the nest die 64 andtheimpression die 38, the top 70 of the head is hinged at 79 (see Figure 4) on a pivot bolt 80 so that'it may'be swung open. On the opposite side of the top 70 from the pivot 80 is a latch 82 hinged on a pivot 83 and having a hook 84 which catches under a tab or lip 86 on the head base 28. The latch 82 is biased toward closed position by a spring 88 which is held in a slot in the latch 82 and is compressed between a lip 90 on the top 70 and the bottom 92 of the spring slot. A stop 94 prevents the latch from being swung too far open.

The top 70 is freely hinged on the'pivot 80, and hence when the head 15 is elevated above the handles, as for example when a lineman on a pole reaches up to hook the top around a line, it may swing down toward closed position. As seen in Figure 4, the top 70 is balanced on its hinge 79 so that when it is fully open and the tool 10 is held in a more or less vertical position with the head 15 above the body 16, the top will remain open. However, when the top begins to swing closed, its center of gravity passes over the pivot 80 and gravity then pulls it toward its closed position. The hook 84 slides down the inclined outer face of the lip 86, and when it has cleared the extremity of the lip, the bias spring 88 pushes the latch 82 into its closed position with the hook 84 under the lip 86. A latch stop 95 holds the latch in a position so that the hook 84 can engage this inclined surface of lip 36 as the top 70 is dropping toward closed position.

Thus, the lineman can reach up holding one ofthe handles with only one hand and latch the tool in crimping position on an overhead line. This overhead latching can be performed with one sweeping motion, saving the time and effort which is required with other tools for the lineman to climb further up the pole, adjust his safety belt, and put the tool in place. In using the tool it), he first unlatches the top and holds the head of the tool downwardly so that the top swings open, or opens the top with his other hand, and then with an upward swing the tool is latched in place.

Moreover, as described and claimed in the co-pending Peterson application, identified above, this tool 10 may be provided with a quick take-up piston which is operated from the end of the handle 18 (not shown). Thus, as soon as the tool has been latched in place as described above, the quick take-up piston is depressed, causing the dies to close until they take an initial grip on the connector, preventing the tool from being accidentally slid off from the end of the connector.

As can be seen in Figure 3, the lip 86 has a slightly downwardly curved overhanging portion and a clearance is provided between the stop portion 95 of the lip 86 and the portion of the top 70 near pivot 83 so that the top 70 can move down toward the head base 28 the extra amount necessary for the hook 84 to catch under the lip. When the quick take-up plunger is actuated, the hook 84 becomes positively engaged behind the overhanging portion of the lip.

Still another advantage of this embodiment is the ease with which the die pieces can be removed and changed for other size ranges of wire when the top 70 is in open position, as indicated in Figure 4.

As seen in Figure .6, the head base 28 has three hinge plates 96. 97, 98 which mate with a correspondingpair of plates 1% (see Figure 3) on the top 70 and the hinge bolt 80 passes through these five plates. Thus, the top 70 is securely fastened to the base 28 of the head 15 to resist the large crimping thrust delivered by the ram 22, and these two parts of the head are maintained in accurate alignment during crimping. The latch 82 has a pair of hinge plates 1102 and 104 (Figure-1) to provide rigidity and strength and is of the same width as the hinge 79, for it must carry approximately one half of the total crimping force, and ,it serves further to align the die surfaces during cirmping.

As seen in Figure 5, the inside of the lip 86 and the inside of the hinge 79 are milled out at 106 to provide clearance for the nest die 64 when the top 70 is latched into closed position.

In order to attach the head 15 to the body 16 and to allow it to swivel thereon the cylinder 21 is provided with a flange 110. A recessed collar 112 having an internal shoulder or flange 114 on one end fits over the flange 110 and screws onto the head base 28 where it is locked in place by a set screw 116. With this swivel connection, the operator is free to orient the handles and body of the tool at any angle with respect to the conductor 13 to select the most convenient angle at which to work. Moreover, the head of the tool is free to swivel a full 360 and the dies are always maintained in accurate alignment with each other and with the head.

In Figures 8 and 9 are shown another swivel connection and a different impression die assembly, for use in a tool similar to the tool 10 described above. Parts performing functions corresponding to those in tool 10 have in certain instances been given the same reference numeral as in the previous description followed by the sufiix A.

As shown in Figure 8, a ram 128 is formed with a recess 130 to receive the stem 132 of an impression die assembly, generally indicated at 134, comprising an impression die 136 and a dovetailed key 138 which is forcefitted into a keyway in the side of the die 136. The die assembly 134 is free to rotate on the ram 128, being held only by the spring-biased detent 140. The key 138 slides along the keyway 139 in the wall 58A of the head base 28A, so that the die assembly 134 is always properly aligned with respect to the head base 28A.

In order to provide a swivel connection between the head A and the body 16A a flange 110A is provided on the end of the cylinder 21A. The head base 28A has an annular hp 142 which fits over the flange 110A. A groove 144 is provided on the inside of the lip 142 and a split retaining ring 146 is compressed and slid into the groove 144 where it expands and locks the head 15A firmly on the body 16A. Figure 8 shows the ram 128 and the die assembly 134 in retracted position.

As shown in Figure 9, a plurality of small holes 148 are drilled through the lip 142 into the groove 144 so that the split ring 146 can be compressed and slid out of the groove 144 when the head of the tool is to be removed from the body.

Thus, the tool shown in Figures 8 and 9 is also well adapted for work in crimped or awkward places and the dies are held accurately aligned no matter at which angle the tool is held. Moreover, the tool is capable of delivering a high crimping force so that it may be used on the intermediate and larger size wires with convenience and accuracy.

It is thus seen that I have provided a tool for crimping connectors and terminals that is well adapted to attain the ends and objects hereinbefore set forth, and which is subject to a variety of modifications so that it may be best fitted for a particular use. It is to be understood that the description and drawings are for the purpose of illustrating the invention in accordance with the statutory requirements.

I claim:

1. In a hand-operated hydraulic tool for crimping connectors to wire wherein a pair of dies carried in the head of the tool are forced toward each other with great force, apparatus providing for rotation of the head with respect to the body of the tool and for maintaining said dies in accurate orientation with respect to each other comprising: a body portion of the tool including hydraulic force generating means, a head portion of the tool, a swivel connection between said body and head enabling said head to be freely rotated with respect to said body, a fixed die held in said head in fixed position, a ram within said body and having a portion actuated by said hydraulic means to move said ram along a path toward said fixed die, a die-assembly-supporting portion on said ram, a die assembly including a die holder rotatably secured to said supporting portion, an impression die, die gripping means securing said impression die to said die holder to prevent rotation of the die on the holder, a key on said die holder, said head having a keyway therein parallel to the path of said ram, and said key projecting into said keyway, whereby said fixed die, die holder, impression die and head all rotate as a unit on said body.

2. In a hand-operated hydraulic tool for crimping connectors to wire wherein a pair of dies carried in the head of the tool are driven toward each other with great force, apparatus providing for rotation of the head with respect to the body of the tool and for maintaining said dies in accurate orientation with respect to each other comprising: a body portion of the tool including a hydraulic ram ,chamber containing hydraulic fluid, a head portion of the tool, a swivel connection between said body and head enabling said head to be freely rotatable with respect to said body, a fixed die held in said head in fixed position, a ram within said chamber and having a rear portion exposed to said fluid to move said ram along a path toward said fixed die, a front portion of said ram having a die-assembly-supporting cylindrical recess, a die assembly including a die holder rotatably secured in said recess and having a channel cut in its face with a hole behind said channel, an impression die sitting in said channel and having a stem fitting into said hole, said channel preventing rotation of the impression die on the holder, a key on said die holder, said head having a keyway therein parallel to the path of said ram, and said key projecting into said keyway, whereby said fixed die, die holder, impression die and head all rotate as a unit on said body.

3. In a tool for crimping connectors onto wire wherein a pair of dies carried in the head of the tool are forced toward each other with great force, apparatus providing for rotation of the head with respect to the body of the tool and for maintaining the dies in accurate orientation with respect to each other comprising: a body portion of the tool including force generating means, a head portion of the tool, a swivel connection between said body and head enabling said head to be freely rotated with respect to said body, a die piece held in said head in fixed position, a ram in said body drivable by said force generating means to move the ram along a path toward said fixed die piece, a movable die assembly having a crimping surface, swivel means rotatably connecting said movable die 2 assembly to said ram, said die assembly being freely rotatable with respect to said ram, means for permitting relative longitudinal movement but preventing relative rotational movement between the head and the movable die.

4. A device as set forth in claim 1, wherein the swivel connection between the body and the head includes a flange on one of the members that mates with a recess on the other member.

5. A device as set forth in claim 1 wherein the swivel ,connection between the body and the head includes a recess on one of said members, a flange in the other member and a split ring fitting in the recess and gripping the flange.

References Cited in the file of this patent UNITED STATES PATENTS 1,837,689 Sunde Dec. 22, 1931 2,158,855 Eby et a1 May 16, 1939 2,202,125 Temple May 28, 1940 2,400,140 Sargeson May 14, 1946 2,424,849 Rogofi et al. July 29, 1947 2,453,597 Sarver Nov. 9, 1948 2,557,495 Bily June 19, 1951

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