US3434324A - Terminal forming machine - Google Patents

Description

March 25, 1969 F, v, Sa-r 3,434,324

TERMINAL FORMING MACHINE Filed Dec. 25, 1966 Sheet of 5 INVENTOR FRITZ v. BROSSEIT March 25, 1969 Filed Dec. 23, 1966 F. V. BROSSEIT TERMINAL FORMING MACHINE FIG. 5

Sheet I Z :52a.

FIG. 4a

FIG. 4b

United States Patent U.S. Cl. 72-324 14 Claims ABSTRACT OF THE DISCLOSURE An insulation piercing terminal forming machine in eluding an insulation piercing tab forming station comprising a punch and a cooperating die for forming an insulation piercing tab from a body of terminal material and for sharpening the tab in a first direction and an insulation piercing tab finishing station comprising a tab bending pin for bending the tab with respect to the body of terminal material, a two part member and a die for squeezing parts of the two part member into engagement with the tab and the tab bending pin to sharpen the tab in a second direction and for cooperation with the two part member to form terminal sides from the body of terminal material.

Insulation piercing terminals for electrical conductors are often fabricated in progressive punch and die mechanisms in which the various component parts of the terminals are cut and formed from a strip of terminal material at individual stations along the length of the machine. In the past the insulation piercing tabs of such terminals have been cut from the strip of terminal material, bent into a steep angle with respect to the strip and sharpened to a point at a single station. It has been found, however, that better insulation piercing tabs result and that the tab-forming portions of the terminal forming machine have a longer life and platform more reliably if the tabs are cut and sharpened in a first direction at a first station and are then bent to a steep angle and sharpened in a second direction at a second station.

Accordingly, an object of this invention is to provide an improved insulation piercing tab forming mechanism.

Another object of this invention is to provide a device for forming insulation piercing tabs which are sharp in two directions.

'In accordance with the preferred embodiment of the invention these and other objects are achieved by providing a two station terminal forming mechanism. At the [first station, two sides of a triangularly shaped insulation piercing tab are severed from a strip of terminal material and the tab is simultaneously sharpened in a direction perpendicular to the side by which the tab is attached. At the second station a two-part terminal side forming member and a cooperating die form the sides of the terminal while a tab bending member positioned in the die simultaneously bends the tab formed at the first station into a steep angle with respect to the strip. As the two-part forming member bottoms in the die, the two parts of the forming member are cammed together and the tab and the tab bending member are squeezed between the two parts. This sharpens the two unattached sides of the tab so that the tab is sharpened in two directions.

A more complete understanding of the invention may be had by referring to the following detailed description when taken in conjunction with the drawings wherein:

FIG. 1 is a front view of a terminal forming machine employing the present invention in which certain parts have been broken away more clearly to illustrate certain features of the invention;

FIG. 2 is a sectional view of the machine shown in FIG. 1 taken along the line 2-2 in FIG. 1 in the direction of the arrows;

FIG. 3 is an enlarged partial sectional view showing the details of one of the piercing stations of the machine shown in FIG. 1 in which certain components have been relocated more clearly to illustrate certain features of the invention;

FIG. 3a is an enlarged view of the piercing station shown in FIG. 3 showing the parts in a closed position;

FIG. 3b is an enlarged sectional view of the piercing pin shown in FIG. 3;

FIG. 4 is an enlarged partial sectional view showing the side forming and tab sharpening station of the machine shown in FIG. 1;

FIG. 4a is an enlarged view of the device shown in FIG. 4 showing the parts in a partially closed position;

FIG. 4b is a view similar to FIG. 4a showing the parts in a fully closed position;

FIG. 40 is an enlarged view of the parts shown in FIG. 4b;

FIG. 4d is a top View of the bending and sharpening pin employed in the station shown in :FIG. 4; and

FIG. 5 is an enlarged view of an insulation piercing tab formed by the mechanism shown in FIGS. 3 and 4.

Referring now to the drawings, wherein like reference numerals designate like parts throughout the several views, with particular reference being had to FIG. .1, there is shown a terminal forming machine comprised of a punch member 11 and a die member 12, both of which are suitably formed for mounting in a standard punch press. The die member 12 is positioned on a base plate 13 which also supports a feeder mechanism 14.

As is more fully described in the copending application of F. V. Brosseit entitled, Terminal Attaching Machine, Ser. No. 604,350, filed of even date herewith, the feeder 14 advances two strips of stock S in the form of narrow bands of terminal material from a pair of supply rolls 15 (only one of which is shown) through the terminal forming machine along two parallel paths. The terminal forming machine operates on the two strips of stock S in the manner of a progressive punch and die mechanism to form the two strips into terminals. In the portion of the terminal machine to the right of the parts shown in section in FIG. 1, the strips are separated into unitary terminal sections by slits extending transversely partially through the strips. In the portion of the terminal forming machine shown in section the strips are formed into terminal blanks by the mechanism shown in FIGS. 3 and 4. In the portion of the terminal forming machine shown to the left of the parts shown in section in FIG. 1, a wire is fed transversely to the paths of the strips and is cut to length, after which the terminal blanks are attached to the wire by crimping. Finally, the terminals are completed and a finished part comprised of a wire having a finished terminal attached to each of its ends is ejected from the left end (FIG. 1) of the terminal forming machine.

Referring now to FIGS. 1 and 2 the details of the punch member -11 and the die member 12 may be seen. The punch member 11 is comprised of a punch shoe 20 suitably formed for attachment to the ram of an ordinary punch press. An upper stripper 21 is slidably mounted on the ram 20 by upper stripper retaining screws 22 and is urged away from the punch shoe 20' by upper stripper springs 23 which surround the upper stripper retaining screws 22. Attached to the middle of the punch shoe 20 are heavy backer springs 24 which are normally spaced from the upper stripper 21 and which serve to restrain movement of the upper stripper 21 toward the punch shoe 20.

The punch member 11 supports a plurality of punch elements some of which are supported by the punch shoe and others of which are supported by the upper stripper 21. Those punch elements which are mounted on the punch shoe 20 are secured thereto by a pair of punch holders which are suitably spaced from the punch shoe 20 by a pair of spacer plates 27. The punch elements which are supported by the upper stripper 21 are retained thereon by a pair of retainer plates 28 which are fixed to the upper stripper 21.

The die member 12 includes a spacer plate 30 attached to the base plate 13 and a pair of die shoes 31 attached to the spacer plate 30. A pair of die holders 32 are attached to the die shoes 31 by means of screws 33 and serve to retain a plurality of die elements on the die shoes 31. A lower stripper 34 is slidably mounted on the die shoes 31 by lower stripper retaining screws 35 and is normally held in a spaced relationship to the die shoes 31 by means of lower stripper springs 36. Mounted on the upper surface of the lower stripper 34 are stock retainers 37 which serve to define a pair of parallel strip paths through the terminal forming machine.

As the strips of stock S are passed through the terminal forming machine shown in FIG. 1, they are initially slit into unitary strip sections which are in turn formed into terminal blanks. The initial operation in the formation of the terminal blanks is the cutting of insulation piercing tabs into the strips of stock S. Two such tabs are cut into each of the strips, however, for the sake of clarity only one of the tab cutting stations will be described.

Referring now to FIG. 3 the details of one of the insulation piercing tab cutting stations is shown. In FIG. 3 an upper stripper retaining screw 22, an upper stripper spring 23, a heavy backer spring 24, a lower stripper retaining screw 35 and a lower stripper spring 36 have been relocated so that their function in the operation of the device may be more readily understood. It should be remembered, however, that the components actually occupy the positions shown in FIGS. 1 and 2.

The insulation piercing tab cutting mechanism is comprised of a tab cutting punch pin 40 mounted in the die holder 32 and positioned with respect thereto by a set screw 41 secured in the die shoe 31. The tab cutting punch pin 40 is guided and supported in the die holder 32 by a lower cutting pin guide 42 and is guided and supported in the lower stripper 34 by an upper cutting pin guide 44. Mounted in the retainer plate 28 is a sharpening die 45.

As the ram of the punch press to which the terminal machine is attached closes, it moves the punch shoe 20 toward the die shoes 31. This causes the upper stripper 21 to move toward the lower stripper 34 thereby bringing the retainer plate 28 into engagement with the strips of stock S supported on the lower stripper 34. After this engagement, the upper stripper springs 23 compress thereby reducing the gap between the punch shoe 20 and the upper stripper 21 until the heavy backer spring 24 comes into engagement with the lower surface of the punch shoe 20. After this engagement, the combined springs 23 and 24 temporarily prevent further narrowing of the gap between the punch shoe 20 and the upper stripper 21. Therefore, as the punch shoe 20 moves further toward the die shoe 31, the lower stripper 34 is forced downwardly thereby compressing the lower stripper springs 36. This action continues until the lower stripper 34 comes into engagement with the die holders 32.

As the lower stripper 34 moves toward the die holders 32 the stock is lowered into engagement with pin 40 and the cutting of an insulation piercing tab in the strip of stock S begins. As is best seen in FIG. 3b the punch pin 40 is triangular in cross-section so that a triangularly shaped tab having one of its sides attached to the strip of stock S and having the other two of its sides free thereof is formed in the strip of stock S.

During the cutting operation, the upper cutting pin guide 44 moves downwardly with the lower stripper 34 toward the lower cutting pin guide 42 mounted in the die holder 32. The mounting of the guide 44 in the lower stripper 34 assures full support for the cutting pin 40 during the entire cutting operation and allows the relatively small diameter pin 40 to easily cut the strip S in a manner similar to the piercing of a coin by a needle supported in a cork.

After the lower stripper 34 is bottomed on the upper surface of the die holder 32 further downward motion of the punch shoe 20 causes compression of the upper stripper springs 23 and the heavy backer spring 24. This action causes extreme pressure to be placed on the com ponents of the terminal forming machine and causes the upper pointed end of the insulation piercing tab pin 40 to swage the tab formed in the strip of stock S into a sharp point in a direction extending longitudinally of the strip of stock S. After the swaging operation, the ram which is attached to the punch shoe 20 returns to its initial position during which movement the parts of the terminal forming machine open in a pattern which is exactly the reverse of the closing pattern just described.

Upon completion of the cutting of a first insulation piercing tab in the strips of stock S, the strips are advanced to a second tab cuting station whereat a second insulation piercing tab is formed in the strips of stock S just to the rear of the tab formed at the station shown in FIG. 3. The two tab cutting stations appear to be aligned in FIG. 1 but are actually slightly displaced so that upon completion of the two tab cutting operations each unitary strip section has two tabs formed in it, these tabs being aligned with each other along a line extending transversely of the strips of stock S.

After the forming of the second insulation piercing tab the strips of stock S are moved to a terminal forming and tab sharpening station one of which is shown in FIG. 4. At the forming and sharpening station a die having a U-shaped die cavity 51 formed in its upper surface is mounted on the die shoe 31 and is retained thereon by the die holder 32. The die 50 serves as a guide for a bending and sharpening member 52 which is slidably mounted in the die 50 and which is urged upwardly by a bending and sharpening member spring 53 positioned in the die shoe 31 between the bending and sharpening member 52 and a set screw 54 mounted in the spacer plate 30. As is best shown in FIG. 40. the bending and sharpening member 52 has a pair of tab engaging points 52a and 52b suitably spaced for engagement with the tabs formed at the tab cutting stations.

In the punch member 11 a two-part forming member having jaws 61 is pivotally mounted in the retainer plate 28 over the die 50 by a pair of trunnions 62 (shown in FIG. 2). The two-part forming member 60 is urged into an open position by a forming member opening spring 63 mounted in the punch shoe 20 which acts upon the two-part forming member 60 by means of a forming member opening pin 64. Mounted in the punch member 11 adjacent the forming member 60 is a stock retainer 65 which is urged downwardly toward the lower stripper 34 by a spring 66 that acts upon the stock retainer 65 through a pin 67.

As the punch shoe 20 descends, the punch member .11 moves toward the die member 12 until the retainer plate 28 engages the lower stripper 34. During this action the stock retainer 64 shown in FIG. 2 engages and grips the strips of stock S against the action of the spring 65. At the time of engagement of the retainer plate 28 with the lower stripper 34 the components occupy the position shown in FIG. 4a wherein the strip S is gripped between the retainer plate 28 and the lower stripper 34 and wherein the two-part forming member 60 is in engagement with the upper surface of the strip.

Further downward movement of the punch shoe 20 causes the retainer plate 28 and the lower stripper 34 to move downwardly carrying the strip of stock S. This movement also drives the two-part forming member 60 into the die cavity 51 in the upper surface of the die 50. This action forms one unitary strip section into a U- shaped wire receiving configuration, this action being made possible due to slits formed between the unitary sections at the initial stations of the terminal attaching machine shown in the right-hand portions of FIG. 1.

The movement of the unitary section of stock into the cavity 51 brings the tabs of the section into engagement with bending and sharpening member 52. The bending and sharpening member 52 bends the insulation piercing tabs formed at the tab cutting stations upwardly so that they stand substantially vertically with respect to the strip of stock S. Upon completion of the bending operation the insulation piercing tabs and the upper portions of the members 52 are positioned between the jaws 61 of the forming member 60.

The movement of the two-part forming member 60 into the die cavity 51 causes the two parts of the forming member to be cammed together against the action of the forming member opening spring 63. As the jaws 61 of the two-part forming member 60 come together they squeeze the bending and sharpening member 52 and the tabs formed at the tab cutting stations in the manner shown in FIG. 4a. This action swages the sides of the tabs which are not attached to the strip of stock S and causes them to be sharp so that the finished tabs are sharp in two directions, one of which extends longitudinally of the strip of stock S and the other of which extends transversely with respect thereto. The finished tab is shown in FIG. 5 wherein the arrow 70 represents the longitudinal direction of the strip of stock S in which the tab was initially sharpened and wherein the arrow 71 represents the transverse direction of the strip of stock S in which the tab is sharpened by the squeezing action of the two-part forming member 60.

It should be noted that the terminal blank forming mechanism shown in FIGS. 3 and 4 operates to form insulation piercing tabs in two distinct and separate steps. In the step carried out at the tab cutting stations the tab is cut and sharpened in a first direction. However, no attempt is made to bend the tab to an upright position nor is any attempt made to sharpen the tab in a second direction. At the bending and sharpening station shown the tabs are bent to an upright configuration by the bending and sharpening pin and are sharpened in a second direction by the squeezing action of the two-part forming member. The separation of the cutting and bending steps in the formationof the insulation piercing tabs contributes greatly to the length of life of the cutting pin 40 and the bending and sharpening pin 52 and results in a greatly improved insulation piercing tab.

Although a particular embodiment of the invention is shown in the drawings and described in the foregoing specification it will be understood that the invention is not limited to that specific embodiment, but is capable of modification and rearrangement, and substitution of parts and elements without departing from the scope of the invention.

What is claimed is:

1. A device for forming terminals comprising:

a first station including a punch and a cooperating die for forming an insulation piercing tab and for sharpenin g the tab in a first direction; and

a second station including:

means for bending the tab formed at the first station into an upstanding configuration; a two-part forming member;

a die for cooperation with the two-part forming member to form the sides of the terminal; and means for squeezing the bending means and the tab between the two parts of the forming member to sharpen the tab in a second direction.

2. The terminal forming device according to claim 1 wherein the first station also includes guide means for sup- 6 porting the punch during the forming and sharpening of the tab.

3. The terminal forming device according to claim 1 wherein the two-part forming member is a pair of spring loaded jaws which push the sides of the terminal into engagement with the cooperating die and which are cammed together by the die to squeeze the bending means and the tab together to sharpen the tab in the second direction.

4. The terminal forming device according to claim 1 wherein the insulation piercing tab has a triangular crosssection and is attached to the terminal by one of its sides, wherein the punch and die of the first station sharpen the tab to a point in a direction perpendicular to the side by which the terminal is attached and wherein the squeezing of the bending means and the tab by the two-part forming member sharpens the two unattached sides of the tab.

5. A device for making terminals for wires including:

means for cutting an insulation piercing tab from a terminal blank and for sharpening the tab in a first direction;

means for bending the tab into an upright position with respect to the blank, and

means for sharpening the upright tab in a second direction.

6. The device according to claim 5 wherein the means for sharpening the upright tab in a second direction is a two-part squeezing member which squeezes the tab and the bending means between its two parts to sharpen the tab.

7. The device according to claim 5 wherein the insulation piercing tab has at least three sides and is attached to the terminal blank by one of its sides; wherein the cutting means sharpens the tab in a direction perpendicular to the side by which the tab is attached, and wherein the means for sharpening the tab in a second direction sharpens two unattached sides of the tab.

8. A mechanism for forming terminals from strips of terminal material in which the sides of the terminals have been severed one from the other and in which insulation piercing tabs have been previously cut including:

a die member;

forming means for cooperation with the die member to form the side walls of the terminal; and

means on the forming member for sharpening the tabs of the terminals. 9. The mechanism according to claim 8 further including means for bending the tabs into a substantially rightangle with respect to the strip prior to the sharpening of the tab by the forming member.

10. The punch and die set according to claim 9 wherein the forming member is comprised of two parts and wherein the die member squeezes the two parts of the forming member together with the bending means and the tab between the parts to sharpen the tab.

11. An insulation piercing terminal forming mechanism including:

an insulation piercing tab forming station comprising a punch and a cooperating die for cutting an insulation piercing tab from a body of terminal material and for sharpening the tab in a first direction, and

an insulation piercing tab finishing station comprising a punch and a cooperating die for bending the tab with respect to the body of terminal material and for sharpening the tab in a second direction.

12. The mechanism according to claim 11 wherein the die of the insulation tab finishing station is comprised of two parts and further including means for squeezing the tab between the two parts of the die to sharpen the tab in the second direction.

13. The mechanism according to claim 11 wherein the tab finishing station further includes a second punch having the tab bending and forming die formed in it and a second die having the tab bending and forming punch mounted in it positioned for cooperation with the second 7 8 punch to form terminal sides from the body of terminal References Cited matenal- UNITED STATES PATENTS 14. The mechanism according to claim 11 wherein the punch and die of the tab forming station cuts a triangularly shaped tab from the body of terminal material that is attached to the body of material along one of its sides and 5 CHARLES LANHAM Examine sharpens the tab in a direction extending perpendicularly B. J. MUSTAIKIS, Assistant Examiner. to the attached side and wherein the punch and die of the tab finishing station sharpens the tab in a direction extend- US ing parallel to the attached side. 29 630; 113 119 2,613,743 10/1952 Bangerter 72325

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