US3283558A

US3283558A - Strip feed mechanism

Info

Publication number: US3283558A
Application number: US347404A
Authority: US
Inventors: Henkel Werner Otto Peter; Over William Roderick
Original assignee: AMP Inc
Current assignee: TE Connectivity Corp
Priority date: 1963-10-18
Filing date: 1964-02-26
Publication date: 1966-11-08
Anticipated expiration: 1983-11-08
Also published as: CH414351A; NL140372B; GB1022508A; BE654334A; NL6411836A; DE1502213B2; US3266286A; DE1502213A1

Description

Nov. 8, 1966 w, O HENKEL ET AL 3,283,558

STRIP FEED MECHANISM 6 sheets shee't 1 Filed Feb. 26, 1964 Nov. 8, 1966 w. o. P. HENKEL ET AL 3,283,558

STRIP FEED MECHANISM Filed Feb. 26, 1964 6 Sheets-Sheet 2 Nov. 8, 1966 w. o. P. HENKEL ET AL v 3,283,558

STRIP FEED MECHANISM Filed Feb. 26, 1964 6 Sheets-Sheet 5 Nov. 8, 1966 w. o. PQHENKEL ET AL 3,283,558

STRIP FEED MECHANISM 6 Sheets-Sheet 4 Filed Feb. 25, 1964 Nov. 8, 1966 w. o. P. HENKEL ET AL 3,283,558

STRIP FEED MECHANISM 6 Sheets$heet 5 Filed Feb. 26, 1964 Nov. 8, 1966 w. o. P. HENKEL ET L 3,

STRIP FEED MECHANISM 6 Sheets-Sheet 6 Filed Feb. 26, 1964 United States Patent O 3,283,558 STRIP FEED MECHANISM Werner Otto Peter Henkel, New Cumberland, and William Roderick Over, Harrisburg, Pa., assignors to AMP Incorporated, Harrisburg, Pa.

Filed Feb. 26, 1964, Ser. No. 347,404 4 Claims. (Cl. 72-416) This invention relates to strip feed mechanisms for feeding terminals in strip form to a position between the dies of a crimping press.

It is an object of the invention to provide an improved mechanism for feeding terminals in ladder strip form. A further object is to provide a feeding mechanism in conjunction with a crimping press in which the feeding of the strip takes place at the end of the crimping cycle and after the crimping dies have moved apart to their fully separated positions. A further object is to provide a feeding mechanism for ladder strip terminals having improved means for maintaining the alignment of the strip relative to the crimping dies. A still further object is to provide a feeding mechanism which is actuated by a positive linkage extending from the actuating means for the press.

These and other objects of the invention are achieved in a preferred embodiment comprising a pair of feed pawls disposed in the crimping zone of the press and immediately adjacent to the fixed crimping die. One of these feed pawls is disposed downstream, relative to the direction of strip feed, from the fixed crimping die and the other pawl is disposed upstream from the fixed die. The feed pawls are mounted on the upper ends of a pair of parallel levers which are pivoted intermediate their ends for movement in a plane extending normally of the plane of the strip being fed. The opposite ends of the levers are pivotally connected by a link means so that they will oscillate in unison during the feeding operation. Oscillation of the levers is achieved by means of a pair of bell cranks, pivoted on the side of the press frame, one arm of one of the bell cranks being connected to an arm extending from one of the levers so that oscillation of this bell crank causes the levers to be oscillated about their own pivotal axes. The other bell crank is oscillated by means of a roller during the downward stroke of the movable crimping die. One of the arms of this bell crank has a roller in engagement with one arm of the first bell crank, the arrangement being such that during the downward stroke of the movable die, the first bell crank is swung about its pivotal axis in a direction such that the feed pawls retract with respect to the terminal strip and engage the strip upstream from their initial points of engagement. The feed pawls remain in their retracted position until the l ading terminal has been crimped and the movable die has moved away from the fixed die after which time the first bell crank is swung in a direction such that the feed pawls will advance to feed the strip.

In the drawing:

FIGURE 1 is a sectional side of a crimping press incorporating a strip feeding mechanism in accordance with the invention;

FIGURE 2 is a side view of the frontal section of the press showing the actuating means for the strip feed mechanism;

FIGURE 3 is a perspective view of a strip feed mechanism in accordance with the invention;

FIGURE 4 is a sectional frontal view of the strip feed mechanism taken along the lines 4-4 of FIGURE 2 and showing the position of the parts at the beginning of a crimping cycle;

FIGURE 5 is a view similar to FIGURE 4 but showing the positions of the parts when the forward pawls are in their retracted position midway through the crimping cycle;

FIGURE 6 is a perspective view of a short section of ladder type terminal strip;

FIGURE 7 is a plan view of the strip feed mechanism taken along the lines 7-7 of FIGURE 2;

FIGURE 8 is a sectional view taken along the lines 88 of FIGURE 5 and showing the position of the crimping die and shearing blade at the time of com- 'mencernent of shearing a contact terminal from the carrier strip;

FIGURE 9 is a view similar to FIGURE 8 but showing position of the parts after the shearing operation has been completed; and

FIGURE 10 is a view taken along the lines 1010 of FIGURE 7.

The disclosed embodiment of the invention is adapted to feed terminals in ladder strip form as shown in FIG- URE 6. The terminals 132 are disposed in side-by-side parallel relationship and are each connected to a first carrier strip 136 by means of connecting sections 134. At the time of crimping, the leading terminal of the strip is crimped onto a wire, sheared from the connecting sec tion, and the strip is advanced a distance equal to the spacing between the individual terminals to position the next adjacent terminal between the crimping dies. The carrier strip 136 is provided with spaced-apart pilot holes 138 which are formed during manufacturing of the strip and are utilized by the feeding mechanism of the instant invention. The disclosed form of terminal strip is provided with a second carrier strip which is connected to the strip 136 by means of laterally extending strip sections 142. Some forms of ladder strip have only a single carrier strip although the provision of a carrier strip on each side of the terminal as shown in FIGURE 6 is often desirable, particularly where the contact terq minals are of a relatively small size.

The invention is herein disclosed in conjunction with a crimping press which is fully described in the copending application of Stuart L. Parsons, Serial No. 317,373, filed October 18, 1963. The structure and operation of this press will be briefly described below only to the extent necessary for an understanding of the feed mechanism which comprises the instant invention. R ference is made to the above-identified application for a more thorough description of this crimping press.

Referring now to FIGURES 1 and 2, the press frame comprises a pair of spaced-

apart plates

2, 4 which are secured to and which extend from a base plate 16. A movable frame subassembly 6 is contained between the frame plates and comprises a pair of parallel plates '8, 9 which have rearwardly extending arms pivoted on a common pivot pin 12 which extends through a block 14 mounted on the base plate. The

plates

8, 9 are connected together at their forward ends by means of a spacer block 10 and suitable fasteners as indicated. A die block 18 is suspended from the spacer block 11 by means of a link 20 which is pivotally connected to the block 10 at its upper end and to the die block 18 at its lower end. A movable die 22 is mounted on the die block 18 for cooperation with a fixed crimping die 24- mounted on a lower die block 26. The die block 26 is, in turn, secured to a bolster block 29 which is contained between the frame plates at their forward ends.

Die block 18 is secured by means of a fastener 27 to a block 32 which is clamped between the ends of a pair of parallel cantilever spring plates 28, 30. At their left-hand ends, as viewed in FIGURE 1, these plates are clamped to the opposite ends of a block 34 by means of screws 36 which extend into the mounting block 14.

As explained in the Parsons application, upon relative ciockwise movement of the frame assembly 6 about its pivotal axis 12, the movable die 22 is moved relatively towards the fixed die, its path of movement being precisely defined by the spring plates 28, 30 which undergo controlled flexure as a result of their being connected together at their free ends by the block 32.

The arcuate movement of the frame assembly 6 about the pivotal axis 12 is achieved by means of a pair of tangentially superimposed roller 38, 40 which are rotatably mounted between the opposed faces of a pair of

parallel arms

42, 44 contained between the opposed faces of the

plates

8, 9. At their rearward ends, these plates are secured to a block 46 which has a yoke 47 extending from its underside in which a low friction nut 48 is mounted. A power screw 50 is threaded through this not and is coupled at its rearward end to the output shaft of an electric motor 52 secured to a motor mounting block 54 on the base plate 16. The upper roller 38 moves over a surface on a cam plate 56 which extends between the opposed faces of the

frame plates

2, 4. The lower roller 40 moves over the camming surface on a camming plate 58 which extends between and is secured to the

plates

8, 9 of the inner frame assembly 6. When the parts are in the position of FIGURE 1, the surface of the plate 58 extends convergently towards the surface of the plate 56 so that upon rightward movement of the rollers from the position of FIGURE 1, the inner frame assembly will be swung in a clockwise direction about it pivotal axis 12 to move the die 22 towards the fixed die 24.

The terminal strip feeding mechanism is actuated from the power screw 50 by means of a pair of

rolls

62, 64 mounted on the shaft 60 on which the lower roll 40 is mounted. The shaft extends through a slot 66 in the frame plate 4 and the two

rolls

62, 64 are mounted on the external portion of the shaft for engagement with the actuating mechanism of the feed. This actuating mechanism comprises a pair of

hell cranks

68, 78, the bell crank 68 having one arm 76 which extends alongside the slot 66 in the frame plate 4. The roll 62 moves 'over the upper edge of this arm which is contoured in a manner such that the bell crank 68 will be swung in a counterclockwise direction during the first portion of the forward (i.e., rightward) stroke :of the shaft 60. During :a final portion of the stroke of this shaft, the roll 62 moves over an edge portion 71 having a slope such that no further rotation of the bell crank takes place. Bell crank 68 has a relatively short depending arm 72, the end of which is connected by means of a tension spring 74 to an upwardly extending arm 76 of a bell crank 78. The bell crank 78 is pivoted at 80 to the frame plate 4 adjacent to the base plate 16 and has a forwardly extending arm 84 notched as shown at 86 on its end. A rocker arm 88 extending from the feed mechanism is received within the notch 86 so that upon oscillation of the bell crank 78 about its pivotal axis, the arm 88 will be lowered and raised as is apparent from FIGURES 4 and 5.

The end of the arm 7 of bell crank 68 is provided with a roller 82 in engagement with the rearwardly facing edge of the arm 76 of the bell crank 78. By virtue of this arrangement, when the roll 62 moves rightwardly from the position of FIGURE 1, and the bell crank 68 is swung in a counterclockwise direction about its pivotal axis, the bell crank 78 will be caused to swing in a clockwise direction about its pivotal axis 88 as this roller moves downwardly of the edge of the arm 76. When the shaft 60 moves left-wardly to its initial position, that is the position of FIGURE 2, the roller 64 will move against the forwardly facing edge of the arm 76 at the end of the rearward stroke of this shaft and swing the bell crank 78 in a counterclockwise direction about its pivotal axis. The arm 88 extending from the strip feed mechanism is thus lowered during forward motion of the shaft 60 and raised at the end of the rearward stroke of this shaft.

Referring now to FIGURES 3 and 4, the terminal strip is advanced by means of a pair of aligned spaced apart feed

pawls

98, 92 which have

teeth

94, 96 on their upper sides and which are mounted on the ends of first and second levers 98, 98'. The pawls are positioned beneath the ladder strip and the

teeth

94, 96 and are adapted to enter the pilot holes 138 of the strip, the trailing sides of the teeth having a relatively gentle SlJOPG with respect to the plane of the strip so that the pawls can move out of the pilot holes and ride over the underside of the strip during their retractile movement. The pawl is pivotally mounted on a pin 102 in a slot 100 on the upper end of lever 98. Pawl 90 is biased in a clockwise direction about its pivotal axis 102 by means of a flat spring 104 secured to the lever 98 on the left-hand side thereof as viewed in FIGURE 4. Lever 98 is pivotally mounted intermediate its ends at 186 on a pin extending from the die mounting block 26. The pawl 92 is similarly mounted on a lever 98 which is identical to the lever 98 except for the provision of the laterally extending arm 88. Lever 98' is pivoted intermediate its ends at 106 for inverting block 26. The lower ends of the levers 98, 98' are slotted as indicated at 110, and are connected together by means of a link 108 having its ends received in these slots and pivotally connected to each of the levers as shown at 109, 109'.

The laterally extending arm 88 of the lever 98 has a leaf spring 113 secured to its upper side which functions as a motion take-up device between the end of the bell crank arm 84, and the lever arm 88. As is apparent from the drawing, the notch 86 in the end of the bell crank arm is somewhat oversized relative to the thickness of the 'lever arm 88 and the spring 113 functions to maintain the lower side of the lever arm 88 against the lower side of the notch 86.

A stationary stop pawl 112, which may be identical to the

pawls

90, 92, is pivo -tally mounted on the upper end of the block 114, the mounting being substantially similar to the mounting of the

pawls

90, 92 of the upper ends of their respective levers. Block 114 is mounted beneath the terminal strip by means of a pin 116 and an adjustment screw 118, the pin 116 extending through an L-shaped mounting block 122 and into the block 114 and the adjusting screw 118 extending through the block 122, through a threaded spacer 124- and into a threaded opening in the block 114. L-shaped block 122 is mounted on the die block 26- as is shown :at 123. -In order to vary the position of the stop pawl 112, it is merely necessary to rotate the screw 118 to cause movement of the block 114 leftwa-rdly or rightwardly depending upon the direction of rotation of the screw.

In order to guide the terminal strip from the crimping Zone of the press after the terminals have been removed therefrom, it is advantageous to provide a guide block 128 which is secured to the upwardly extending arm of the mounting block 122. This guide block has an arm 129 which extends over the

pawls

96, 112 towards the crimping zone of the press and has a groove 130 extending therethrough through which the scrap carrier strip is fed. As is shown in FIGURE 4, this block is recessed at 131 and 133 for the accommodation of the strip engaging teeth of the

pawls

92, 112.

At the time of crimping it is necessary to remove the leading terminal of the strip from the carrier strip 136 by shearing transversely across the slug 134 adjacent to the rearward end of the terminal 132. This shearing operation is elfected by means of a shear plate 142 extending from a supporting arm 144, see FIGURE 7. A depressor 143 mounted in front of the movable die 22 engages the upper surface of the shearing plate 142 during downward movement of the die and presses downwardly on the upper surface of the strip section 134 while the terminal is being crimped. Shearing plate 142 has a laterally extending arm 144 which projects parallel to the direction of stripped feed and is clamped by means of a crimping block 146 for the terminal strip as is shown in FIGURE In the disclosed embodiment, a probe or detector 152 is provided in alignment with the lower crimping die or anvil 24. This probe forms a component of a tripping circuit for actuating the press. The circuit may, for example, be of the type disclosed in the copending application of Robert Karl Grebe and Earl Raymond Kreinberg for Wire-Sensing Means, Serial No. 325,321.. Where a tripping circuit of this type is employed, the arrangement is such that when the end of the wire is positioned against the probe 152, the electric motor 52 is energized to drive the press through a complete crimping cycle. Probe 152 is secured by means of a clamp bar 154 to an arm 1'53 extending from a mounting plate 150; this mount-ing plate being secured to the upper surface of the block 156 as shown in FIGURE 7.

In use, the parts will normally be in the positions of FIGURES 1, 2, 3 and 4 at the beginning of an operating cycle. The operator first positions the stripped end of a wire between the crimping dies and in alignment with the open-U ferrule portion of the terminal 132 which is located between the crimping dies. Thereafter, the press is actuated by touching the detector 152 with the end of the wire. The power screw 50 is first rotated in one direction to drive the nut 48 forwardly until the dies move toge'ther and then in the opposite direction to retract the nut 48. During forward motion of the nut 48, the rolls 38, 40 and the shaft 60, the bell crank 68 is swung in a counterclockwise direction about its pivotal axis by the roller 62. The roller 82 on .the end of the arm 70 of this bell crank rides over the rearwardly facing edge of the arm 7-6 of the bell crank 78 causing this bell crank to be swung in a counterclockwise direction with downward movement of the arm 84 and the notch 86. The downward movement of bell crank arm 84 causes the arm '88 to be moved downwardly from the position of FIGURE 4 to the position of FIGURE and the levers 98, 98' are swung in unison in a counterclockwise direction as viewed in FIG- URE 4 about their pivotal axes 106, 106'. As a result, the

pawls

90, 92 are swung in a counterclockwise direction about their

pivotal axes

102, 102 and the

teeth

94, 96 on these pawls move relatively out of the pilot holes in which they were initially positioned and leftwardly over the underside of the strip. When each tooth moves into registry with the next adjacent upstream pilot holes, they enter these upstream holes under the influence of the

springs

104, 104. This swinging of the levers and the retraction of the feed pawls takes place while the roll 60 is moved over the portion 69 of the bell crank arm 70 so that during the final portion of the forward stroke of the roll 62 (i.e., during the final portion of the downward stroke of the movable crimping die), the feed mechanism and the feed pawls remain stationary.

During the return stroke of vthe shaft 60, the feed mechanism remains in the position shown in FIGURE 5 until the roll 64 moves against the forwardly facing edge of the bell crank arm 78 at which time this bell crank is swung in a counterclockwise direct-ion resulting in upward movement of the lever arm 88 and clockwise swinging motion of the

levers

98, 98. During such movement of the levers, the two feed pawls advance the strip to move the leading uncrimped terminal of the strip to a position between the crimping dies.

The stop pawl 112 is swung in a clockwise direction when the strip is being advanced and its tooth is disengaged from the pilot hole in which it was previously positioned and engages the next adjacent pilot hole when it comes into registry therewith. This stop pawl prevents retractile movement of the strip while the feed pawls are moving leftwardly over the underside of the strip and thereby maintains the position of the strip when it is not being held by the feed pawls.

The invention presents several advantages for electrical terminal crimping presses where feeding must be precise and accurate and must not interfere with the operation of crimping the terminals onto Wires. One noteworthy advantage is that the feeding of the strip, that is the movement of the feed pawls from the position of FIG- URE 5 to the position of FIGURE 4, takes place after the crimping dies have moved completely apart. This feature is distinctly advantageous in that the possibility of jamming an uncrimped terminal between the crimping dies by reason of a lack of adequate clearance for movement of the terminal is avoided.

An additional feature of the invention is that the linkage, by means of which the feed mechanism is driven, is positive in all respects; that is to say, the

levers

98, 98 are positively controlled by means of the bell cranks which in turn are controlled directly by the

rolls

62, 64 on the shaft 60. The starting and stopping of the strip is, therefore, precise and abrupt as compared to the action achieved when feeding or retracting of the feed finger is achieved by means of springs.

The arrangement of having two feed pawls for ad vancing the strip, has the advantage of maintaining the alignment of the strip in its own plane so that the ferrule forming portion of the terminals will be positioned beneath the movable crimping die. In other words, the strip will be held by. the two feed pawls with its longitudinal axis extending normally of the axis of the crimping die 24 and is not permitted to become cocked (i.e., to extend diagonally) with respect to the die 24. The tWo feed pawls also prevent the strip from buckling, an important consideration where the strip is of extremely thin and flexible stock metal. Buckling is prevented because of the fact that one pawl pulls the strip while the other pawl pushes it.

Changes in construction will occur to those skilled in the art and various apparently difi'erent modifications and embodiments may be made without departing from the scope of the invention. The matter set forth in the foregoing description and accompanying drawings is offered by way of illustration only. The actual scope of the invention is intended to be defined in the following claims when viewed in their proper perspective against the prior art.

We claim:

1. A crimping press having a strip feeding mechanism for feeding terminals in ladder strip form, said press comprising a fixed crimping die and a movable crimping die, said fixed crimping die having a supporting surface for supporting the leading terminal of said strip, first and second levers pivotally mounted intermediate their ends on parallel spaced-apart axes, said axes being disposed on each side of said fixed crimping die and extending transversely of the direction of movement of said movable die, the ends of said levers which are adjacent to said terminal supporting surface having strip engaging means thereon on each side of said surface for engagement with said ladder strip, and the ends of said levers which are remote from said surface being pivotally linked together whereby said levers are oscillable in unison about their pivotal axis, movable die actuating means for moving said movable die relatively towards and away from said fixed die, and feed actuating means acting between said movable die actuating means and said levers for swinging said levers in a first direction to retract said strip engaging means relative to said strip during movement of said movable die towards said fixed die, and for swinging said levers in a second direction to advance said strip after said leading terminal has been crimped onto a wire, said strip engaging means on said first and second levers functioning to push and pull said strip during feeding and thereby maintain the alignment of said strip in said first direction.

3. A device as set forth in claim 1 wherein said feed actuating means comprises a rocker arm extending from one of said levers, a bell crank having one arm in en- 10 gagernent with said rocker arm, and means on said movable die actuating means for oscillating said bell cr-ank.

4. A device as set forth in claim 1 including stop means downstream from said levers in engagement with said 3 strip, said stop means being effective to prevent retractile movement of said strip while permitting feeding of said strip by said strip engaging means.

References Cited by the Examiner UNITED STATES PATENTS 3,004,581 10/ 1961 Krol et al. 29203 3,101,765 8/1963 Batcheller 29203 3,154,234 10/1964 Cootes 29203 CHARLES W. LANHAM, Primary Examiner.

R. D. GREFE, Assistant Examiner.

Claims

1. A CRIMPING PRESS HAVING A STRIP FEEDING MEACHANISM FOR FEEDING TERMINALS IN LADDER STRIP FORM, SAID PRESS COMPRISING A FIXED CRIMPING DIE AND A MOVABLE CRIMPING DIE, SAID FIXED CRIMPING DIE HAVING A SUPPORTING SURFACE FOR SUPPORTING THE LEADING TERMINAL OF SAID STRIP, FIRST AND SECOND LEVERS PIVOTALLY MOUNTED INTERMEDIATE THEIR ENDS ON PARALLEL SPACED-APART AXES, SAID AXES BEING DISPOSED ON EACH SIDE OF SAID FIXED CRIMPING DIE AND EXTENDING TRANSVERSELY OF THE DIRECTION OF MOVEMENT OF SAID MOVABLE DIE, THE ENDS OF SAID LEVERS WHICH ARE ADJACENT TO SAID TERMINAL SUPPORTING SURFACE HAVING STRIP ENGAGING MEANS THEREON ON EACH SIDE OF SAID SURFACE FOR ENGAGEMENT WITH SAID LADDER STRIP, AND THE ENDS OF SAID LEVERS WHICH ARE REMOTE FROM SAID SURFACE BEING PIVOTALLY LINKED TOGETHER WHEREBY SAID LEVERS ARE OSCILLABLE IN UNISON ABOUT THEIR PIVOTAL AXIS, MOVABLE DIE ACTUATING MEANS FOR MOVING SAID MOVABLE DIE RELATIVELY TOWARDS AND AWAY FROM SAID FIXED DIE, AND FEED ACTUATING MEANS ACTING BETWEEN SAID MOVABLE DIE ACTUATING MEANS AND SAID LEVERS FOR SWINGING SAID LEVERS IN A FIRST DIRECTION TO RETRACT SAID STRIP ENGAGING MEANS RELATIVE TO SAID STRIP DURING MOVEMENT OF SAID MOVABLE DIE TOWARDS SAID FIXED DIE, AND FOR SWINGING SAID LEVERS IN A SECOND DIRECTION TO ADVANCE SAID STRIP AFTER SAID LEADING TERMINAL HAS BEEN CRIMPED ONTO A WIRE, SAID STRIP ENGAGING MEANS ON SAID FIRST AND SECOND LEVERS FUNCTIONING TO PUSH AND PULL SAID STRIP DURING FEEDING AND THEREBY MAINTAIN THE ALIGNMENT OF SAID STRIP RELATIVELY TO SAID FIXED DIE AND PREVENT BUCKLING OF SAID STRIP DURING FEEDING.