US3070144A

US3070144A - Ladder strip applicator

Info

Publication number: US3070144A
Application number: US8004A
Authority: US
Inventors: William R Evans
Original assignee: AMP Inc
Current assignee: TE Connectivity Corp
Priority date: 1960-02-11
Filing date: 1960-02-11
Publication date: 1962-12-25
Anticipated expiration: 1979-12-25

Description

Dec. 25, 1962 w. R. EVANS 3,070,144

LADDER STRIP APPLICATOR Filed Feb. 11, 1960 2 Sheets-Sheet 1 1 a- INVENTOR. l WiHiam R. Evans Dec. 25, 1962 w. R. EVANS 3,070,144

LADDER STRIP APPLICATOR Filed Feb. 11, 1960 2 Sheets-Sheet 2 ac, ac, a? 26 3,tl7tl,14ld v v LADDER TR1P APPLICATUR William K. Evans, Hershey, Pa, assignor to AMP Incorporated, Harrisburg, Pa. Filed Feb. 11, 1960, Ser. No. 8,094 1 Claim. (QB. 153 l) This invention relates to crimping devices for crimping electrical connectors and terminals in strip form onto the ends of wires.

it is common practice to manufacture electrical connectors and terminals in the form of a continuous strip and to apply the connectors to the ends of wires by means of a crimping press having a feeding device for automatically feeding the strip towards the crimping dies of the press. Conventional presses of this type usually have a fixed die or anvil, and a movable crimping die which is mounted on the ram of the press. The feeding means is commonly actuated by the press ram and is immovably mounted on substantially the same level as the fixed die of the press so that the leading connector of the strip is fed and positioned over the fixed die and in position for the crimping operation. Most of the available presses of this type are relatively large in that they are intended to be permanently mounted on a bench or the like and are not intended to be portable. A necessary feature of such presses is a shearing means for shearing the leading connector of the strip of connectors from the strip at the time of crimping. The connector strip, itself, may be either of the end-to-end variety in which the connectors are axially aligned with each other, or of the ladder strip variety in which the connectors are aligned in side-by-side parallel relationship and are secured either to each other or to a common carrier strip. The problem of shearing connectors from a carrier strip is, it might be added, somewhat more complex than the problem of shearing the leading connector from an end-to-end type of strip for reasons which will be apparent from the description of the instant invention given below.

An object of the present invention is to provide an improved crimping press for crimping electrical connectors and terminals onto the ends of wires. A further object is to provide a crimping press which is particularly adapted for ladder strip type terminals. A still further object is to provide a crimping press having an improved feed mechanism for the terminal strip which is particularly adapted for usage in a portable-type crimping press.

These and other objects are achieved in a preferred embodiment of the invention comprising a frame member which may take the form of a hydraulic cylinder having a generally C-shaped head portion integral therewith. A ram which is reciprocable within the frame or cylinder has a movable crimping die mounted on its end i for cooperation with a fixed crimping die which is mounted on the head portion of the tool. The strip feeding means is mounted on, and contained in, a support which is secured to the end of the reciprocable ram and extends laterally thereof, and which moves with the ram towards and away from the fixed crimping die during use of the tool. The strip of terminal is fed along a feed path on this support, which feed path leads to a position between the two crimping dies. The leading terminal of the strip is thus positioned between the dies and is held in this position prior to closure of the dies by virtue of its being a member of the strip. Upon actuation of the tool, the ram move toward the fixed crimping die and carries with it the terminal until the terminal is gripped between the dies so that it can not, during subsequent movements of the ram, become misaligned. The leading terminal is at that point sheared trite tats rent:

from the strip by a shearing blade which is also mounted on the ram and which moves with the ram towards the fixed crimping die. This shearing blade, however, is resiliently mounted on the ram and is provided with a stop which prevents its movement toward the fixed die during the terminal portion of the stroke, during which the shear is effected.

hi the drawing:

PiGURE l is a side view, with parts broken away, of a preferred embodiment of the invention;

FlGURE 2 is a frontal view taken along the lines 2-2 of FIGURE 1;

PEGURE 3 is a view showing the feed slide and lower crimping die and taken along the line 3--3 of FIGURE 2;

FlG-URES 4 and 5 are fragmentary frontal views similar to FlGURE 2 but on an enlarged scale, and illustrating the positions of the parts at different stages of the crimping cycle;

FiGURE 6 is a sectioned end view taken along lines 6-6 of FIGURE 2;

FiGURE 7 is a perspective view of a portion of a. strip of terminals of the ladder strip type;

FIGURE 8 is a fragmentary view showing a camming means for disengaging the feed pawl from the strip; and

FIGURE 9 is a fragmentary perspective view showing an ejector which forms part of the preferred embodimerit.

FTGURE 7 shows a portion of a ladder strip of the type which the disclosed embodiment of the invention is intended to apply to wire ends. The terminals 116 of the strip are secured at regularly spaced intervals to a carrier strip 1G4 and extend laterally of the carrier strip. Each terminal provides ferrule-forming portions res, 1&8 to facilitate their being crimped onto a wire, and the carrier strip provides regularly spaced openings 1695 which are engaged by a feed pawl to feed the strip towards the crimping zone of the crimping apparatus. When the leading terminal of the strip is crimped onto a wire end, this leading terminal must also be severed from the carrier strip and it is advantageous to sever the carrier strip portion which extends beyond this leading terminal into short lengths to facilitate its disposal.

The disclosed embodiment for crimping ladder strip terminals, as shown in FEGURE 1, comprises a tool body 2 in the form of a hydraulic cylinder having an integral C-shaped head 4 on its end, which head has an inwardly projecting portion 6 upon which the fixed or upper dies are mounted. A ram ill is mounted within tool body 2 and extends from a hydraulic piston 12 which is normally biased downwardly by means of a spring 8. Hydraulic fluid is supplied from any suitable source (not shown) through a hose 13 to drive the piston and ram upwardly during use.

A generally L-shaped die holder is is mounted on the end of ram lit and has a pair of fins 15 extending therefrom towards the head i of the tool. The opposed surfaces of these fins bear against flat surfaces on the sides of the tool head to maintain the ram in alignment with the fixed dies and to guide the ram toward and away from the fixed dies. A movable die mounted on die holder M by means of a die block 13 having a recess therein for the accommodation of the lower die, this die block being secured to the holder 14 by means of a fastener Upper dies 22.24 are secured to an upper die holder 2.6 which, in turn, is secured to the in ward projection e of the tool head.

The ladder strip supporting and feeding mechanism is mounted on a support having a back wall 29 from which extends an integral platform or rib 3%. A flange 32 on this rib is secured to die holder 14 by means of a fastener as shown, so that the entire support 28 moves with the ram towards and away from the fixed dies during use. Advantageously, a roller 25 is provided on a plate 58 (described below) which bears against an L-shaped plate 27 secured to the back wall 29 of the support to assist in maintaining the support in proper alignment with respect to the ram. The feed path for the terminal strip is defined by an arcuate surface 33 on housing 2.8 which advantageously has

rails

34, 35 cemented thereto to support the strip at its end and intermediate its end. These rails may be made of nylon or the like to facilitate the travel of the strip over the surface of the feed track.

Support 28 is cut away in the area immediately adjacent the die holder 14, and a housing is formed in this area for the feed finger by means of which the strip is fed. This housing is composed of a front plate 36 which is secured to rib or flange 3d, a back which is secured by fasteners through the wall of the support, and a top plate 38 secured by screws to

plates

36 and 40. The opposing surfaces of back plate id and front plate 36 have rails 44, 45 integral therewith (FIG- URE 6) to support, and define a path of reciprocation for, a slide plate 46' which may be of nylon or the like. This slide plate is biased towards front plate 36 by a spring 46:: and is pivotally connected by means of a link 48 to one end of a lever t? composed of a pair of spaced apart plates, which is pivotally mounted on its opposite end 52 in the support 28. Lover 56 is normally biased in a counterclockwise direction by means of a spring 51 but can be rotated in a clockwise direction by a stationary cam 56 secured to a plate 53 having a flange which is bolted to the top portion of housing 2 and which, therefore, does not move with the support 2%. Cam plate 56 has a cam surface 62 which bears against a cam follower 54 in the lower portion of the lever and which causes the lever to be swung in a clockwise direction during initial upward movement of the ram, as viewed in FIGURE 2. After this initial portion of the rams movement, this cam follower is engaged by cam surface 63 and is not swung further. On the return stroke of the ram, the lever Stl is maintained by surface 63 in its retracted position until it again engages cam surface 62 during the final portion of the downward stroke of the ram.

The actual feeding of the strip is accomplished by a feed pawl 64 which is pivotally mounted at 66 between upstanding ears on a plate 68, which, in turn, is secured to slide 46. A spring 76 normally biases this feed pawl upwardly and into engagement with the carrier strip, as shown in FIGURE 2. The end of the feed pawl 71 has a pointed tip portion which enters into the spaced openings 105 of the carrier strip we so that upon movement of this feed pawl, the strip is advanced toward the crimping zone. In order to prevent retractile movement of the terminal strip during retraction of the slide plate 46 and the feed pawl, there is provided a holding pawl 85 which is clamped to top plate 38 and which extends downwardly to engage between the terminals of the strip. An extension 87 extends upwardly from this drag pawl through an opening in the top plate so that it can be lifted out of engagement with the strip if it becomes necessary to withdraw the end of the strip from the crimp ing zone. It is also necessary to disengage feed pawl 64 from the strip of terminals when the strip is manually retracted. To this end, there is provided a pin 59 on the feed pawl which extends towards the front plate. A cam plate 61 in a groove 63 in the front plate has an inclined surface engageable with this pin so that upon rightward movement of the plate (as viewed in FIGURE 8), it engages the pin and depresses the feed pawl. A screw 65 in plate 61 extends through a slot in the front plate to permit the plate to be manually moved and a spring washer 67 retains the screw and plate in position when it is moved rightwardly.

As shown best in FIGURES 2 and 6, the terminal strip is supported by means of the surface of an L-shaped plate 72 which is secured to the back plate of the housing, and by means of a slot or groove which is formed by an inward projection on the front plate and by a depending projection 73 of the top plate. This slot receives the carrier strip Iii-t of the ladder strip and guides the strip toward the crimping Zone. It will be noted that the depending flange '73 of the top plate provides a slot for the accommodation of the tip '71 of the feed pawl which may extend through the spaced openings of the ladder strip and into this slot.

Referring now to FIGURES 2, 3 and 4, there is provided on the front of die holder 14 a generally L-shaped plate 74 which is secured in place by means of fastener 26, previously referred to. A fixed shear block 7% is mounted in the die holder and between plate 76 and die block 18, and a relatively movable shearing block 80 is provided above this fixed shearing block, the relatively movable block being normally biased upwardly by means of a spring 82 disposed within a recess in the movable block and which acts between a pin '77 in plate 74 and the block itself. The movable shearing block is guided for movement towards and away from the fixed shearing block by a flange 76 on plate 74. The blocks 78, 89 provide a pair of cooperating shearing edges 81, 83, the edge SI being on an upward projection of the fixed shearing block and the edge 33 being defined .by a recess within the movable block which receives the projection on the fixed block. In normal use, the scrap carrier strip will extend beyond these edges when the parts are in a position of FIGURE 4 and upon relative upward movement of the fixed block, the projecting portion of the carrier strip will be sheared from the running length thereof. Movable shearing block 39 also provides an arm 86 extending inwardly towards the crimping dies and substantially over the feed path of the carrier strip. A shearing edge 84 on this arm is substantilly in the plane of the face of fixed die 16 so that, when the die moves upwardly relative to the fixed die, a shear is affected in the plane of the face of the die 16. This shear removes the terminals being crimped from the carrier strip.

Relative movement of the movable shearing block is achieved during the terminal portion of a stroke of the ram towards the fixed dies by means of a stop 38 on the top of the movable block. During the upward stroke of the ram, this stop comes to rest against the die block 26 and prevents further upward movement of the movable block. During the remainder of the stroke, the movable die moves upwardly relative to the block and the terminal is sheared, as shown in FIGURE 5.

In crimping the type of connectors shown, at the end of the crimping operation the crimped terminal will usually, if not always, be lodged within the recess in the fixed die and will be removable therefrom only upon its being pushed downwardly. While this operation can be performed manually, it is desirable to provide an automatic ejector as shown at 96. This ejector comprises a small plate having an arm which extends past the recess of the fixed die 24 and is normally disposed below the level of this recess. A spring 98 within a spacer 92 normally biases the arm downwardly, as viewed in FIG- URE l, but permits upward movement of the ejector during crimping. An additional spacer 94 is provided in the block to properly position the ejector and the crimping dies relative to the fixed crimping die and the terminal. Since the spring 98 will normally not be willciently strong to push the terminal out of the upper die, there is provided a plate Itlfi on the die block 18 which has an arm I02 projecting toward the fixed clie. An inward extension on this arm passes over a lateral extension on the ejector so that, during the final portion of the downward stroke of the ram, arm 162 pulls the ejector downwardly thereby forcing the terminal out of the fixed die.

In use, and assuming the parts are in the position shown in FIGURES 1 and 2, the operator first positions the end of a wire in line with the terminal and preferably within the recesses of the fixed dies 22, 24, the ejector which extends down beyond the recess of die 24 functioning as a stop for the end of the wire. Thereafter, the operator actuates the hydraulic system to supply fluid to the cylinder 2 and to drive the ram upwardly. During the initial portion of the upward stroke of the ram, the arm 50 is swung in a counterclockwise direction by cam surface 62 to retract the slide 46 and the feed pawl 64. During the terminal portion of the upward stroke, this lever does not, of course, move. During the upward stroke of the ram, the support 28 and the entire feed mechanism is carried upwardly until this terminal is gripped between the fixed dies and the movable die. At this point in the cycle, stop 88 comes to rest against block 26 and further upward movement of the carrier strip portion which extends past the dies is prevented, while the terminal itself is pushed upwardly and further into the upper portion of fixed dies to complete the crimping operation. During this portion of the cycle, the terminal is crimped. At the same time, the previously fed section of the carrier strip which extends beyond the edges 81, 83 is sheared and drops through this slot shown in the fixed shearing block. Upon return movement of the ram back to the position of FIGURE 1, the lever 50 is permitted to swing at a counterclockwise direction to feed the strip and position the next adjacent terminal in crimping position.

While I have disclosed a preferred embodiment of the invention, obvious modifications thereof, which fall within the proper scope of the appended claims, will be apparent to those skilled in the art. It is contemplated, for example, that the principles of the invention including the reciprocable support for the feed mechanism, be adapted to applicators for end-to-end type of strip terminals. It is also contemplated that alternative types of linkages might be used to actuate the feeding means for the strip.

I claim:

A portable crimping apparatus for crimping terminals in ladder strip form onto wires comprising, a cylinder, a generally C-shaped head integral with said cylinder, a fixed crimping die mounted on said head, a ram in said cylinder reciprocable towards and away from said fixed crimping die, a movable crimping die mounted on said ram, supporting means mounted on, and extending laterally of, said ram, said supporting means having a terminal strip feed track thereon leading to a location between said dies whereby the leading terminal of a strip fed along said track is positioned between said dies, feeding means for said strip comprising a spring biased lever pivotally mounted on said support, a fixed cam engageable with said lever during movement. of said ram away from said fixed crimping die to actuate said feeding means, a spring loaded shearing blade mounted on said ram and having a shearing edge normally extending past said fixed die, and a stop for said shearing blade efiective during movement of said ram towards said fixed die to prevent movement of said shearing blade during the terminal portion of the stroke of said ram whereby, said movable crimping die moves past said shearing blade and the leading terminal of said strip is sheared from the carrier strip thereof.

References Cited in the file of this patent UNITED STATES PATENTS 2,592,276 Hackbarth Apr. 18, 1952 2,727,236 Klumpp Dec. 20, 1955 2,845,108 Hammell et al. July 29, 1958