US2915755A

US2915755A - Machine for applying connectors in strip form

Info

Publication number: US2915755A
Authority: US
Inventors: Robert John Kinkaid
Original assignee: AMP Inc
Current assignee: TE Connectivity Corp
Priority date: 1957-05-31
Filing date: 1957-05-31
Publication date: 1959-12-08
Anticipated expiration: 1976-12-08
Also published as: FR1206986A; NL228287A; GB838573A; DE1402339B2; NL106561C; BE567957A; CH364966A; DE1402339A1

Description

1959 R. J. KINKAID MACHINE 50 APPLYING CONNECTORS IN STRIP FORM 2 Sheets-Sheet 1 Filed May 31, 1957 Fl G.8

INVENTOR. Roman @Ifimmmn Juan W'- Dec. 8, 1959 R. J. KINKAID MACHINE FOR APPLYING CONNECTORS IN STRIP FORM 2 Sheets-Sheet 2 Filed May 31, 195"! I w o ,8 M 3 1 m PM? F 5 INVENTOR. mummy JWJNHKAHIF M,M-M

MACHINE FOR APPLYING CONNECTORS IN STRIP FORM Robert J. Kinkaid, Harrisburg, Pa., assignor to AMP Incorporated, Harrisburg, Pa.

Application May 31, 1957, Serial No. 662,763

9 Claims. (Cl. 1--177) This invention relates in general to machines for applying solderless connectors supplied in strip form to electrical conductor wires and more particularly in such machines to improved means for severing or detaching the leading connector element from the strip.

In the production of electrical leads and harnesses for electrical equipment the practice has become widespread of applying as the connective elements for the leads solderless connectors by automatic or semi-automatic crimping machines. Commonly the connectors are supplied in strip form, that is, a series of connectors are formed integrally joined together end-t'o-end or side-byside, the crimping machine being operative to arrange the lead connector of the strip in position between the elements of a crimping die set there to receive the end of the electrical lead, to crimp the lead connector about the end end, to detach the lead connector from the strip, and then to feed the next connector into the crimping position. Such a machine is shown and described in Patent No. 2,690,562, issued October 5, 1954 to H. E. Cootes.

In severing or detaching the lead connector from the strip, the strip typically is fed across two spaced stationary plates on the bed of the machine, the facing sides of the plates terminating in shear edges across which the connecting link or strap of the strip is disposed. Cooperating with the shear plates is a shear blade which moves between the opposed faces of the plates in timed sequence with the crimping operation thereby to slugout or sever the connecting link for detaching the lead connector from the strip. In this or similar such operations it is difficult to remove or eleminate entirely the connecting link while keeping within normally acceptable machine design tolerances. In addition, regardless of any connecting link stub remaining after severing, in the nature of the operation performed there tends to be produced a burr smeared down at the severed edge, either of which excrescences may interfere with the proper use and function of the connector involved. For example, in the copending application Serial No. 400,996, filed December 29, 1953 by Kemper M. Hammell there is disclosed a sheet metal taper pin which conveniently is alfixed to the ends of associated leads through the aforesaid strip method of fabrication and application and is adapted in one condition of use to be forcefully inserted within a mating tapered socket to form a connection therewith. Any excrescences such as an outwardly turned connecting link stub and/ or burr may catch on the end edge of the socket to interfere with proper insertion of the pin, on driving the pin may score the inside surface of the mating socket, and otherwise disadvantageously act to interfere with optimum connection and seating of the connector parts.

Accordingly it is an object of the present invention to provide an improved machine for applying terminals supplied in strip form.

It is another object to provide in a terminal applying atent machine an improved mechanism for severing or detaching the connectors from the strip thereof.

It is a further object to provide in a terminal applying machine a severing mechanism wherein the burr or link stub excrescence is formed in a controlled manner so as not to interfere with the contemplated use and function of the connector element involved.

Another object is to provide in a severing mechanism for a terminal applying machine a control adjustment for varying the formation of any burr or link stub so as best to meet the conditions of a particular use for the terminal involved.

These objectives are in general attained by providing in the terminal applying machine a severing mechanism which includes a shear or slug-out blade having a pocket or recess in one side face thereof, which pocket is'brought into axial alignment with the end of the lead connector subsequent to the severing operation but prior to final crimping of the connector onto the associated lead conductor. Means are provided to shift the connector end slightly backwardly relative to the direction of strip feed so as to cause the severed link stub to overhang the edge of the stationaryv shear plate of the severing mechanism and to project into the pocket of the movable shear blade.

On the upward stroke of the terminal applying machine ram the lower lip of the shear blade pocket, of a shape according to the manner in which the link stub is desired to be shaped, is brought into wiping engagement with the link stub thereby effecting the desired burnishing or forming of the link stub. Suitable means may be provided to secure the terminal in position during the wiping or burnishing action, such means preferably having a release time adjustment relative to the wiping or b-urnishing action advantageously to control and vary the forming of the link stub so as thus to meet the conditions of use fo the connection application involved. I

Other objects and attainments of the present inventio to which rference has not been made hereinabove will become apparent when the following description is taken in conjunction with the drawings in which:

Figure 1 is a fragmentary front view with certain parts broken away of a terminal applying machine showing the essential operative elements in position at .the beginning ofa crimping operation or cycle;

Figure .2 is a sectional side view taken at line IIII of Figure l; I Figure 3 is a view similar to Figure 2 butwith the operative elements assuming the position corresponding to the end of the down or crimping stroke of the machine ram;

Figure 4 is an enlarged view of the severing and crimping elements in the position assumed as shown in Figure 3;

Figure 5 is a view similar to Figure 2 but with the operative elements assuming a position intermediate in the upstroke of the machine ram;

Figure 6 is an enlarged view of the crimping and severing elements in the position assumed as shown in Figure 5;

Figure 7 is an enlarged view in perspective of an illustrative connector applied in accordance with the present invention; and

Figure 8 is an enlarged view in perspective of the severing blade of the terminal applying machine in accordance with the present invention.

Referring now to Figures 1 and 2 in a typical terminal applying machine there is provided a press bed or base 2 on which is supported an anvil 4 to which terminals or connectors 6 integrally joined in strip fashion are fed seriatim by strip feeding means, not shown, operative in timed sequence in each cycle of the machine as will terminal is adapted to receive the end of a conductor 10 inserted into the crimping region 12 of the machine and to be crimped thereabout, Figure 7, in electrical and mechanical engagement after the manner described, for example, in U. S. Patent No. 2,610,012, issued June 10, 1952 to James C. Macy. To this end ferrule 8 comes to rest after the strip feeding operation on die face 13 of anvil 4, which die face is part of a crimping die set also including crimping or curling die 14 carried by ram 16 that is movable toward and away from press bed 2 by power means, not shown, to complete a cycle of machine operation. To sever or detach the lead terminal from the strip a pair of shear plates 18 and 20 are fixed to bed 2 adjacent anvil 4, the shear plates being spaced to receive therebetween a shear blade 22 carried by ram 16. As the ram 16 descends towards bed 2, the crimping die 14 lightly engages ferrule 8 before severing edges 24 of blade 22 cooperate in passing with

cutting edges

26 and 28 of

shear plate

18 and 26 respectively to slug-out or sever the leading connector link 36 thereby separating the lead connector from the strip, all as is conventional and well known in the art typified by the H. E. Cootes patent aforesaid.

It is to be understood that subsequent to each crimping and severing operation the new lead terminal is advanced to crimping position automatically as a part of the cycle of operation of the machine.

It will be apparent to those skilled in the art that in the illustrative form of severing mechanism there remains after the severing operation a connecting link stump at the end of the lead connector of a length dependent upon machine design tolerances, which, together with a sharp rib or burr smeared down between shear blade 22 and shear plate 18 as they cooperate in shearing action, form an excrescence 32, as best shown in Figure 4, that at least in part projects outwardly of the operative contact surfaces defined by the tapered pin portion 34, Figure 7, of the illustrative terminal 6. As pin 34 is adapted for reception in a mating socket, not shown, which is to establish surface-to-surface engagement with pin 34, it will be readily apparent that excrescence 32 can not be tolerated.

In accordance with the present invention the sheared end of the lead connector is subjected to a controlled frictional wiping or burnishing action to turn up within the operative surfaces extended of terminal 6 and to smooth down or burnish any excrescence 32 remaining after the severing operation. To this end shear blade 22 is provided with a pocket or recess 36 having at its lower margin or lip a generally arcuate camming surface 38, Figure 8, adjacent severing edges 24, pocket 36 being located so as to be in axial alignment with the sheared end of the lead terminal during the final stages of the crimping or downward stroke of ram 16, as shown in Figure 3. By mechanism to be described, upon disposition of pocket 36 in alignment with terminal 6, the sheared end is moved slightly backwardly relative to the direction of strip feed in timed sequence in the crimping cycle so as to cause excrescence 32 to overhang shear edge 26 of plate 18 and to project within pocket 36, Figure 4. On the upward stroke of ram 16, Figures and 6, the lead terminal is secured in position for a predetermined time while shear blade 22 is lifted to bring cam 38 into wiping and burnishing engagement with excrescence 32, the terminal being released upon the desired degree of forming of the pin end having been accomplished.

To control the movement of and operation on the lead terminal, the upper, or ram crimping die assembly includes a tool holder block 40 which, together with shear blade 22 and a cover plate 42, is rigidly afiixed to an open wall 44 of ram 16 as by bolts 46. Crimping die 14 is slidably mounted between cover plate 42 and block 40 within a channel 48 in the front face of block 48, the limits of sliding movement being defined in one directlon by end wall 56 of channel 43 and in the other direction by an adjustment screw 52 threadedly received through a side of cover plate 42, stem 54 thereof projecting into channel 48 within stop notch 56 in the side of die 14-. One side 58 of notch 56 is inclined substantially linearly downwardly whereby on retracting or advancing screw 52, notch side 58 comes into engagement after more or less travel respectively of die 14 away from channel end wall 50, thus to adjust the lower limit of sliding movement of the crimping die for reasons to become apparent hereinafter.

Crimping die 14 is resiliently biased against screw stem 54 by coil spring 61 received in well 62 defined in part in cover plate 42 and in part in block 40, one end of spring 60 bearing against an adapter plug 64 which in turn abuts the upper end 66 of die 14.

In the rear of block 4-8 is a channel 66 in which is slidably received adjacent shear blade 22 a hold down plate 68 movable between the limits defined by the end wall 70 of channel 66 and the engagement of stem 72 of bolt 74 with the end wall of slot 76 in block 40, bolt 74 being threaded in plate 68 as shown. Coil spring 78 disposed in well 86 of ram 16 serves, through adapter plug 82 bearing on the end of pin 84 slidably extending through a passageway in block 40 to abut against the end of plate 63, to bias plate 68 downwardly until stem 72 is arrested at the end of slot 76.

As thus constructed, the cyclical operation of the illustrative terminal applying machine is initiated from the rest position of the elements as shown in Figures 1 and 2 wherein: the ferrule-forming portion 8 of the lead terminal is disposed in crimping position on die face 13 in position to receive the end portion of the conductor wire 19 inserted into target area 12; connecting link 30 is disposed in bridging relation across

shear edges

26 and 28; and the ram assembly is in the up position relative to the press bed. In this connection in the strip feeding operation the trailing end of the lead terminal preferably is advanced a few thousandths of an inch to avoid any unfortunate accumulation of design tolerances which Would result in placing any portion of the operative surfaces of the lead terminal in the path of shear blade 22.

As ram 16 moves downwardly toward bed 2 and the end of the crimping stroke illustrated in Figures 3 and 4, crimping die 14 first grips ferrule portion 8 to initiate application of the crimp and to stabilize the terminal while shear blade 22 engages and shears through connecting link 36 to slug out a section 30 thereof thus to detach the lead terminal from the strip. During final movement of the ram to complete crimping or compressing the ferrule onto the conductor, the pressure of crimping and engagement of end face 86 of hold down plate 68 cause die 14 and plate 68 to move to their upward positions against

channel walls

50 and 70 respectively, thereby compressing

springs

62 and 78. Spring 78, however, is light enough so that the pressure of face 86 results in no distortion of the terminal.

To effect optimum crimping, the crimping pressure exerted by die 14 is sufiicient to result in longitudinal extrusion of the metal of the ferrule thus tending to shift the trailing end of the terminal slightly backwardly, to the right in Figure 4. For example, in a terminal designed to receive a #20 wire, American wire gauge, the amount of extrusion may be of the order to move the trailing end 0.015 inch, the terminal end moving without interference by virtue of pocket 36 coming into alignment therewith, thus to overhang excrescence 32 relative to shearing edge 26 in the path of travel of camming surface 33. In addition it is contemplated that the crimp length will be less than the length of ferrule portion 3 whereupon a bell-mouth configuration is imparted to the ferrule ends thus to provide a shoulder 88 in abutment with the rear face of die 14 as best shown in Figure 4 or 6.

After completion of the crimp, ram 16 starts on its return or upstroke in the initial portion of which camming surface 38 isbrought into wiping engagement with the overhanging excrescence 32, Figures 5 and 6. During this period springs 62 and 78 cause die 14 and plate 68 to slide relative to ram 16, thus to remain or dwell in engagement with terminal 6. The dwell engagement of die 14 serves to maintain a frictional loading on the terminal and shoulder 88 in abutment therewith thus securing the terminal against longitudinal movement while camming surface 38 burnishes the relatively rigid link stub 32 to the desired degree. In the dwell period of hold down plate 68, face 86 provides support at the terminal end adjacent the burnishing operation to prevent bending or other distortion of the terminal under the transverse bending moment applied by camming surface 38.

Ferrule 8 is released and the dwell time of die 14 ends when upward movement of ram 16 brings stem 54 into lifting engagement with inclined side 58, at which time further applied pressure of camming surface 38 on the link stub merely forces the terminal in a direction, to the left in Figure 6, longitudinally out of the crimping region with no further forming of the metal of the pin. It will be apparent, therefore, that the dwell time control afforded by adjustment screw 52 provides a means for controlling the degree of burnishing or forming of excresence 32 which may be subjected toonly a light burnish or may be pushed wholly back into the nose of the terminal according to the conditions of the particular terminal application.

Toward the end of the ram upstroke the connector strip is advanced by one unit length to prepare the assembly for the next cycle of machine operation.

In the foregoing specification there has been described in detail a preferred embodiment of the present invention; it is to be understood, however, that this embodiment is not intended to be exhaustive or limiting of the invention but is given for purposes of illustration in order that others skilled in the art may fully understand the invention and the principles thereof and the manner of applying it in practical use so that they may modify it in various forms, each as may be best suited to the conditions of a particular use. For example, the strip of terminals may be joined in ladder strip fashion requiring only a single edged severing blade, or each unit in the strip may simply comprise a connector ferrule for joining a plurality of wires in which event the necessity for hold down plate 68 may be obviated.

I claim:

'1. In a machine for applying connectors in strip form to electrical conductors, each connector being integrally joined at an end portion thereof to the adjacent connector in the strip, a shear plate having a shear edge, a shear blade cooperable with said shear plate to form a shear for severing the strip at the end portion of the leading connector along the line defined by said edge, means for moving said blade toward and away from said plate to sever the strip and return said blade respectively in a cycle of severing operation, means operable after the severing movement of Said shear blade to shift the connector end portion towards said edge to dispose any excrescence remaining after the severing operation at an overhanging position relative to said shear edge and in the path of return movement of said shear blade, and lip means on said shear blade operative in the return movement thereof to engage and burnish the excrescence.

2. In a machine for applying connectors in strip form to electrical conductors, each connector having an integral connecting link extending from an end portion thereof for joining the connectors in the strip, a shear plate having a shear edge, a shear blade cooperable with said shear plate to form a shear for severing a connecting link disposed across said edge, means for moving said blade toward and away from said plate to sever the link and return said blade respectively in a cyle of substantially continuous operation, means operable after the severing movement of said shear blade to shift the connecting link stump on the end portion to an overhanging position on said shear plate in the path of return movement of said shear blade, and lip means on said shear blade operative in the return movement thereof to engage and burnish the overhanging link stump toward the longitudinal axis of the connector.

3. In a machine for applying connectors in strip form to electrical conductors, each connector having an integral connecting link extending an end portion thereof for joinin the connectors in the strip, a shear plate having a shear edge, a shear blade cooperable with said shear plate to form a shear for severing a connecting link disposed across said edge, means for moving said blade toward and away from said plate to sever the link and to return said blade respectively in a cycle of severing operation, means operable after the severing movement of said shear blade to shift the connecting link stump on the end portion to an overhanging position on said shear plate in the path of return movement of said shear blade, burnishing means comprising a lip on said shear blade operative in the return movement thereof to engage and burnish the overhanging link stump toward the longitudinal axis of the connector, and holding means operative to secure the connector in position for a predetermined time in the return movement of said blade during engagement of the link stump by said burnishing means.

4. In a machine for applying connectors in strip form to electrical conductors, each connector having an integral connecting link extending an end portion thereof for joining the connectors in the strip, a shear plate having a shear edge, a shear blade cooperable with said shear plate to form a shear for severing a connecting link disposed across said edge, means for moving said blade toward and away from said plate to sever the link and to return said blade respectively in a cycle of severing operation, means operable after the severing movement of said shear blade to shift the connecting link stump on the end portion to an overhanging position on said shear plate in the path of return movement of said shear blade, burnishing means comprising a lip on said shear blade operative in the return movement thereof to engage and burnish the overhanging link stump toward the longitudinal axis of the connector, and adjustable holding means operative to secure the connector in position for a variable predetermined time in the return movement of said blade to control the degree of burnish imparted to the link stump by said burnishing means.

5. In a machine for applying connectors in strip form to electrical conductors, each connector having an integral connecting link extending from an end portion thereof for joining the connector in the strip, a shear plate having a shear edge, a shear blade relatively movable toward and away from said shear plate and cooperative therewith to form a shear for severing a connecting link disposed across said shear edge, a recess in said blade having a marginal camming surface arranged to be positioned adjacent the connector end upon movement of said shear plate past said shear edge, and means for moving the link stump remaining after severing across said shear edge and into said recess for wiping engagement by said camming surface upon return movement of said shear plate.

6. In an applicator for electrical connectors in strip form, each connector including a ferrule-forming portion adapted to be crimped onto a conductor upon operation of the applicator and an integral connecting link extending from an end portion thereof for joining the connector in the strip; a reciprocating ram; a crimping station including means coupled to said ram operative in the forward stroke of said ram to crimp the ferrule portion of the lead connector to a conductor and to shift the end portion longitudinally; and a severing station including means for severing in said forward stroke the connecting link of a connector disposed in said crimping station before operation of said crimping station means is completed, and lip means on the severing means responsive to longitudinal shifting of the end portion and operative in the return stroke of said ram to wipe the connecting link stump remaining after the severing operation toward the longitudinal axis of the connector.

7. In an applicator for electrical connectors in strip form, each connector including a ferrule-forming portion adapted to be crimped onto a conductor upon operation of the applicator and an integral connecting link extending from an end portion thereof for joining the connector in the strip; a reciprocating ram; a crimping station including die means coupled to said ram operative in the forward stroke of said ram to crimp the ferrule portion of the lead connector to a conductor and to shift the end portion longitudinally; a severing station includ ing blade means for severing in said forward stroke the connecting link of a connector disposed in said crimping station during operation of said crimping station means, and burnishing means comprising a lip on said blade means responsive to longitudinal shifting of the end portion and operative in the return stroke of said ram to burnish the connecting link stump remaining after the severing operation toward the longitudinal axis of the connector; and control means for causing said die means to dwell for a predetermined time in engagement with the ferrule portion in the return stroke of the ram to secure the connector in position during engagement thereof by said burnishing means.

8. An applicator according to claim 7 wherein said control means includes an adjustment for varying the dwell time of said die means whereby to vary the degree of burnishing of the link stump.

9. In an applicator for electrical connectors in strip form, each connector including a contact portion, a ferrule-forming portion adapted to be crimped onto a conductor upon operation of the applicator and an inte gral connecting link extending from the end of the contact portion for joining the connector in the strip; a reciprocating ram; a crimping station including die means coupled to said ram operative in the forward stroke of said rarn to crimp the ferrule portion of the lead conncctor to a conductor and to shift the end of the contact portion longitudinally; a severing station including blade means for severing in said forward stroke the connecting link of a connector disposed in said crimping station during operation of said crimping station means, and burnishing means on said blade means responsive to longitudinal shifting of the pin portion and operative in the return stroke of said rarn to wipe the connecting link stump remaining after the severing operation toward the longitudinal axis of the contact portion; control means for causing said die means to dwell for a predetermined time in engagement with the ferrule portion in the return stroke of the ram to secure the connector in position during engagement thereof by said burnishmeans; and supporting means movable into engagement with the connector contact portion adjacent the end thereof for at least said predetermined time to support the connector against distortion during the burnishing operation,

References Cited in the file of this patent UNtTED STATES PATENTS 805,578 Parker Nov. 28, 1905 1,368,233 Becker Feb. 15, 1921 2,069,231 Findlay Feb. 2, 1937 2,289,177 Chandler July 7, 1942 2,522,440 Freter Sept. 12, 1950 2,690,562 Cootes Oct. 5, 1954 2.778.097 Berg Jan. 22, 1957