US2748452A - Methods and blanks for making connectors - Google Patents

Description

June 5, 1956 F, P|ERE 2,748,452

METHODS AND BLANKS FOR MAKING CONNECTORS Filed May 7, 1955 2 Sheets-Sheet l INVENTOR fk/r/wr Z. fleece ATTOR EYS.

METHODS AND BLANKS FOR MAKING CONNECTORS Frank L. Pierce, Natick, Mass., assiguor to Aircraft- Marine Products, Inc., Harrisburg, Pa., a corporation of New Jersey Application May 7, 1953, Serial No. 353,518

4 Claims. (Cl. 29-15555) This invention is in the field of solderless electrical terminals. More particularly it relates to methods and blanks for forming strips of joined terminals made from continuous flat strips of metal and making them into terminations for wires and relates to the strips of terminals themselves. This application is a continuation-in-part of my copending application Serial No. 7547, filed February 11, 1948 now abandoned.

Continuous strips of joined electrical terminals are used in many terminal forming operations rather than individual loose terminals. The strips are readily stored and handled by rolling into reels and lend themselves to automatic and semi-automatic machine application.

In the past, in making terminations for wires from a strip of terminals the strip commonly was fed to a pair of shears or cutting plates. The end terminal was sheared from the rest of the strip, and either simultaneously or subsequently the severed terminal was crimped onto a wire. This shearing or cutting operation is one of the critical limiting factors in the use of automatic and semiautomatic machinery. After a period of use, the opposed cutting edges of the shears become turned over and dulled, resulting in ragged edges where the terminal is severed from the strip. Sometimes the shears become sprung slightly apart, causing a tearing action rather than a cutting action, and again jagged edges result.

Thus, in the operation of such machines, there are intervals of down time when the machine is out of production in order to sharpen or replace the shear blades.

The present invention greatly reduces the down time in the use of such automatic machinery. smoother edge on the terminal along the line of severance. It enables the use of an automatic machine in which a pair of opposed breakers are used for breaking off the end terminal from the strip. A relatively smooth edge along the line of severance is obtained even if the edges of the breakers are turned over and rounded and even if they are sprung apart. In fact, where desired, these breakers may be provided with a slight clearance between their adjacent faces (i. e. unlike shears), thus reducing the amount of wear and allowing the machine to run without interruption for extended periods of time.

in the described embodiments of the present invention a generally V-shaped notch is swaged at intervals across the flat surface of the strip to provide a weakened region between each two adjacent terminals. This notch enables the use of blunt breakers, as mentioned, and provides for a clean line of severance. Also, it is advantageous in controlling the contour of the ends of the terminal adjacent the separation line.

An aspect of a described embodiment of the invention provides a tapered end or lead on a tab-type terminal when it is severed, making the terminal easier to insert into its socket. r

An advantage of the presentinvention is the automatic provision of a complete bell mouth portion on certain forms of terminals which have been broken off from the strip.

It provides a nited States Patent r 2,748,452 Cg Fatented June 5, 1956 These and other objects, aspects, and advantages of the present invention will be in part pointed out and in part apparent from the following description taken in conjunction with the accompanying drawings, in which:

Figure 1 is a perspective view of a strip, generally indicated at 26, of ring-tongue type terminals for application in a machine wherein the terminals are broken off one by one and applied to wires;

Figure 2 is a cross sectional view of the strip 20 taken along the line 22 of Figure 1, along the bottom of a V-shaped breaking-off notch;

Figure 3 is a partial side view of strip 2t), shown on enlarged scale;

Figure 4 is a partial sectional View, on enlarged scale, showing the bared end of a wire resting in the ferruleforming portion of a terminal from strip 2% prior to crimping;

Figure 5 is a partial sectional view, on enlarged scale, showing a strip of terminals such as strip 2% being fed into the breaking and crimping portion of an automatic machine and showing the end terminal in the process of being broken oii Within the machine and crimped;

Figure 6 is a perspective view of a termination formed on a wire with one of the terminals from strip 2%;

Figure 7 is a perspective view of a strip, generally indicated at 22, of tab-type terminals for application in a manner similar to the manner of strip 2%;

Figure 8 is a cross sectional view, on enlarged scale, of strip 2?. taken along the line 8-8 in Figure 7, along the bottoms of a pair of V-shaped breaking-off notches;

Figure 9 is a partial side view of the strip of terminals 22 shown, on an enlarged scale;

Figure 10 is a perspective view, on an enlarged scale, showing a tab terminal after being broken off from the strip 22 and crimped onto a wire and about to be inserted into a socket;

Figure 11 is a perspective view of a strip, generally indi cated at 24, of eyelet-type terminals for application in a machine;

Figure 12 is a cross-sectional view thereof taken along the line 1212 in Figure 11;

Figure 13 is a top view of the strip of terminals 24;

Figure 14 is a side view, on enlarged scale, of a portion of strip 24;

Figure 15 is a perspective View of an eyelet termination formed from one of the terminals in strip 24;

Figure 16 is a perspective view of a strip, generally indicated at 26, of another form of eyelet-type terminals for application in an automatic machine;

Figure 17 is a cross-sectional view thereof taken along the line 17-17 in Figure 16;

Figure 18 is a top view of the strip of terminals 26;

Figure 19 is a side view, partially in section, of strip 25; and

Figure 20 is a perspective View of an eyelet termination formed from one of the terminals in strip 26.

In Figures 1 through 6 is shown a process for forming solderless terminations on electrical wires for connecting the wires to other conductors of electricity. A fiat strip of metal is stamped or formed into a plurality of joined ring-tongue terminals, each generally indicated at El). These terminals 30 each have a flat ring portion 34 adapted to be used for making electrical connection with a threaded stud conductor 35, as indicated in phantom view in Figure 6, and they each have a ferrule-forming portion, generally indicated at 36, with a pair of upstanding side ears 37 which are adapted to be curled around a wire for securing the terminal to the wire, as explained in detail hereinafter. The terminals in strip 20 are longitudinally joined, end-to-end, so that in following along the strip from the left end (Figure 1) toward the right end, one

' finds in succession the ferrule-forming portion 36, the flat ring portion 34, and a pre-formed weakened breaking-off line, generally indicated at 38, extending in a direction across the flat surface of the strip near the fiat portion 34.

For application to a wire, the bared end of a wire is inserted into the U-shaped region 39 (see Figure 2) between the pair of ferrule-forming ears 37 from the left (see Figure 4). Hence, the left edges of cars 37 as seen in Figures 1, 3 and 4, are referred to as the wire-receiving edges or mouth edges of the ears. Strip 20 has a continuous unbroken bottom surface 49, as seen best in Figure 3.

During the forming operation, the inner corners of the wire-receiving edges of ferrule-forming ears 37 are swaged or chamfered at 44 along their entire lengths so as in effect to provide a bell mouth on the ferrule-forming portion 36. This bell mouth acts to gather in and guide the bared strands 46 as the end of an insulated wire 48 is inserted therein, as shown in Figure 4, preparatory to the crimping operation. The bell mouth enables an extremely tight crimp to be made with the ears 3'7, which often are harder metal than the wire strands 46, without the wire-receiving edges of the ears cutting into and weakening the outside strands as they pass into the ferrule. Moreover, the bell mouth supports the strands of the wire so that if any fiexure of the wire 43 takes place subsequent to crimping, there is less tendency for them to be cut by the wire-receiving edges of ears 37.

At the same time as the chamfer 44 is formed, that is, before ears 37 are turned up, the transverse breaking-off line 38 is formed by swaging a generally V-shaped notch 50 across the flat surface of strip 20 (see Figures 1 and 3) which forms the end of the ring-tongue after terminal 30 is broken from strip 20. This notch St) has a rather abruptly sloped surface adjacent the flat ring portion 34 of terminal 30, as seen in Figure 3. The other more gradually sloping surface 51 of notch t) acts to form a continuation of the inner edge of the bell mouth, as seen in Figure 4.

The outer corners of the extremities of the upstanding cars 36 are swaged along substantially their entire length to form a chamfer 52 (Figure 3), which leaves these extremities sharper and enables them to be driven in among the strands of a wire. The small outer corner 53 which remains unchamfered abuts against the corresponding corner on the other side during crimping and causes the ears to curve inwardly at the desired angle, as seen in Figure 6. The inner surface of ferrule-forming portion 36 may be transversely scoured, as shown in Figure l, to provide a better grip on strands 46 after crimping.

During the application of terminals 30 to Wires, such as wires 4, terminal strip 2%) is fed along a path (see Figure 6) in the direction of arrow 54 on top of a frame guide 55 into a breaking-off and crimping zone, generally indicated at 56, of a machine shown partially in section. Strip 2%} is fed along intermittently with the bell-mouth edges of ears 37 leading. This strip may conveniently be unwound from a large reel (not shown), and resilient means may be provided intermediate the reel and the crimping zone 56 to absorb the shock of the intermittent feed. The details of such resilient means are shown in the copending application of Harold E. Cootes, Serial No. 65,645, filed December 16, 1948, now Patent No. 2,690,562.

Strip is fed along path 54 past a transverse junction plane or line of demarcation, indicated by the dotted line 53 between a zone of support, provided by a stationary breaker blade 66, and an open or free zone of no support,

generally indicated at 61, beneath a movable breaker blade 62.

Strip 20 is arrested with one of the notches 5t) substantially in this transverse junction 58, and with at least a portion of one of the flat ring portions 34 in the open zone beneath movable breaker blade 62. In order to separate the end terminal from the remaining terminals in strip 20, the flat portion 34 is struck with the blunt lower surface 64 of the blade 62 and is driven downwardly in a direction substantially parallel with the upstanding ears of the succeeding terminal. A smooth break occurs along the line of separation 38, following the bottom of notch 50.

As shown in Figure 5, the adjacent opposed edges of the breaker blades 60 and-62' may each be rounded and the two breakers 6t) and 62 may have clearance therebetween without any detrimental effect upon the smoothness of the break which is made.

Among the advantages of the form of notch 59 is that after the terminals are separated from each other, its sloping surface 51 (Figure 4) adjacent the bell mouth of ferrule-forming portion 36 forms a continuation of the bell mouth underneath strands 46 of wire 48. Thus in'etfect, the bell mouth is provided on all sides of the wire.

in the semi-automatic machine partially shown in Figure 5, the ferrule-forming portion 36 of the end terminal is curled around the strands of the Wire 43 during the same operation as that which-breaks the end terminal off from the strip. The two ears 37 are curled toward each other and are crimped back in among the strands 46 (Figure 6) by a recessed crimping die 66 (Figure 5) which drives ferrule-forming portion 36 down against an anvil 68.

The bared end of wire 48 is fed into ferru1e-forming portion 36 through a vertically elongated hole in a guard plate 74 which prevents the operator from accidentally catching anything between die plate 66 and anvil 68 as they close. A stationary stripper plate 72 is placed adjacent die plate 66 so that if the ferrule portion 36 should happen to stick in die 66, stripper 72 knocks it out as die 66 is raised.

A second stationary breaker plate 74 is provided in zone 56 beneath stripper 72 and adjacent the open zone. Plate 74 is used when the machine is modified to remove slugs of metal from certain types of terminal strips during the severing operation, as explained in detail hereinafter. In order to provide clearance for such slugs to allow them to fall freely away from the portion of the machine shown in Figure 5, breaker plate 60 may be set at a slight angle to the vertical as shown.

In Figures 7 through 10 is shown a strip 22 of tab terminals adapted for forming a termination by a process similar to that described in connection with Figures 1-6. A strip of metal is stamped or formed into a plurality of joined tab terminals, each generally indicated at 80. These terminals each have a fiat tab portion 82 for making electrical connection with a tab socket, as indicated in Figure 10, and they each have a ferrule-forming wiregripping and insulation gripping portion, generally indicated at 84. This portion 84 includes two pairs of upstanding side ear portions. The pair of ears 86 adjacent the tab 82 form the conductive ferrule for crimping onto the bared end of a wire, and the other pair of ears 88 forming the insulation-gripping ferrule (Figure 10). These latter ears 88 are longer and spread further apart than ears 86, as seen most clearly in Figure 8, in order to accommodate the wire plus its insulation.

The tab terminals in strip 22 are joined end-to-end, so that in following along the strip from the left end (Figure 7) toward the right end, one finds in succession ferruleforming portion 84, flat tab portion 82, and a pre-formed weakened breaking-off plane, generally indicated at 90, extending in a direction across the flat surface of the strip near fiat tab portion 82.

In forming strip 22 the weakened line 90 is formed by swaging a pair of opposed generally V-shaped notches 92 across both the top and bottom fiat surfaces of the strip adjacent tab 82. Notches 92 each have an abrupt face adjacent tab 82, to form. a tapered lead on the end thereof after separation from the rest of strip 22. The

more gradual sloping faces of notches 92 taper into a small neck portion 94 between breaking-off plane 90 and a plane 96 adjacent the end of ferrule portion 84 and extending parallel to the insulation-receiving edges of ears $3. This neck or slug 94 is broken off and severed out of strip 22 when the terminals are separated from the strip.

The machine shown in Figm'e 5 can readily be used with strip 22 in which the neck or slug 94 of metal between planes 92 and 96 is broken out during the severing operation. The stroke of movable breaker plate 62 is extended so that it moves down a small distance between plate 60 and plate 74 and coacts with both of these plates.

During the application of terminals 80 to wires, such as the wire 98 shown in Figure 10, strip 22 is intermittently fed along a path, like path 54 (Figure 5). The strip is arrested with plane 96 (Figure 9) coincident with junction 58. Plane 52 coincides with a junction 100 between breaker blade 62 and plate 74. In its downward stroke, blade 62 strikes a Hat surface of neck 94; it first severs the neck 94 along plane 96 from ferrule portion 84 and then in conjunction with plate 74 breaks slug 94 free from tab 82 of the end terminal.

In order to crimp the insulation gripping ears S8 at the same time as the ears 86, an additional crimping die plate (not shown) may be mounted adjacent plate 66, and guard plate 71 moved further to the left to accommodate the additional die.

Among the advantages of swaging the double V-shaped notches 92 are those which result from the fact that when the tab 82 is cleared of the slug 94, a tapered lead 102 is available on the end of tab 82, as shown in Figure 10. in completing a connection, tab 32 is inserted into a socket 104 on a wire 1116, and tapered lead 102 helps to guide theend of the tab into its socket. A circular recess 1117 in tab 152 snaps over a raised lug 108 in the bottom of the socket when it is fully inserted to hold the tab more firmly connected to the socket.

121 Figures 11 through 15 is shown a strip of eyelet terminals, each generally indicated at 110, and adapted for forming a termination by a process similar to that described in connectionwith Figures l6. Each of the eyelet terminals includes a central flat web portion 112 having an aperture 114 therein adapted to receive the shank of an attaching screw, or binding post. A pair of upstanding side ear portions 115 are provided on opposite sides of flat web 112 for forming ferrules for crimping. At least one of these ferrule-forming ears 115 may be crimped around the bared strands 116 of a wire 118 to complete a termination. The other ear is bent over and curled under to provide a resilient abutment 121') of approximately the same height as the ear 122 which is crimped around a wire end. This resilient abutment 120 assists in holding a clamping screw or nut tight even against considerable vibration and allows a maximum compression stress to be placed on the other ferrule 122, as explained in detail in my copending application mentioned above.

As seen in Figure 12, during the forming of strip 24, the outer or end edges of ears 115 may be tapered or beveled to facilitate their curling during crimping.

The eyelet terminals 110 in strip 24 are joined end-toend and have a pre-formed weakened line between successive terminals, as generally indicated at 123, to facilitate severance by equipment which does not have to be maintained as an accurate shear. These weakened lines 123 are formed by swaging a generally V-shaped notch 124 across the flat surface of the strip adjacent flat web portions 112. Strip 24 has a continuous unbroken bottom surface 126, as seen in Figure 14.

During the application of terminals 110 to wires, strip 26 is intermittently fed along a path, like path 54 (Figure 5). The strip is arrested with one of the notches 124, usually the notch between the end terminal and the rest of strip 24 coincident with a junction, such as junction 58, between a zone of support and an open zone. At least a portion of the flat web 112 in the open zone is struck by a breaker blade, such as the blade 62, breaking the end terminal cleanly and smoothly from the strip. In the same operation, one of the ferrule-forming ears 115 may be wrapped around a wire, as explained in my co- '6 pending application, mentioned above, to complete a termination as shown in Figure 15.

In Figures 16 through 20 is shown a strip of eyelet terminals, each generally indicated at 130 and adapted for performing a termination by a process similar to that described in Figures 11 through 15. Each of the eyelet terminals 130 includes a central flat web portion 132 having an aperture 134 formed therein and adapted to receive the shank of an attaching screw or a binding post.

This strip 26 is conveniently formed from a strip of sheet metal with lateral side ear portions 136 struck up, and adapted to be rolled over to form ferrules as shown in Figure 20. An advantage of this form of strip is that there is substantially no wasted stock, the central aperture 134 being formed by a struck up tab 138 which is curled to form a wire-gripping ferrule 140, as shown in Figure 20.

The two side ear portions 136 are bent over and curled under to provide resilient abutlnents 141 which assist in holding a clamping screw or nut firmly in engagement with ferrule 140, as explained in detail in my copending application, mentioned above.

During the forming of the strip 26, a weakened line or joint 142 is formed between each of the terminals. This line 142 is formed by swaging a generally V-shaped notch 146 across the flat surface of the strip adjacent flat web portions 132. Each of these notches has a sloping face 148 extending between the bottom ends of upstanding ears 136, and the other sloping face is adjacent flat webs 132 of terminals 130. Thus, the bottoms of V-shaped notches 146 are substantially in the same plane as the edges of upstanding ferrule-forming ears 136. Similarly, in connection with the strip shown in Figures 1-6, the bottoms of V-shaped notches 50 are substantially in the plane of the wire-receiving edges of ferrule-forming ears 37. Among the advantages of this substantially coplanar arrangement of the bottoms of the V-shaped notches and the edges of ferrule-forming ears are those which result from the fact that the upstanding ears in these two ,cases act to add rigidity to the nearby metal lying between them. Hence, when a breaker hits the next terminal to break it off, the metal between the cars is stiffened at both sides near the bases of the ears, and a smoother separation line results. There is added rigidity adjacent the line of the break to prevent the metal therealong from being rolled over the edge of the nearby breaker.

It should be noted that terminals 130 differ from terminals in that during the crimping of a tab 133 around the hated end 50 of a wire 152, the wire is inserted from a direction transversely of strip 26, which is seen by comparing Figures 18 and 20. This transverse insertion of the wire lends itself more readily to high speed fully-automatic machine operation.

In order to break the end terminal from strip 26, a portion of flat web portion 132 is arrested in an open zone, with V-shaped notch 146 between the end terminal and the rest of the strip coinciding with a junction, such as junction 58, between this open zone and a zone of support. Flat web 132 is struck in the open zone, breaking the end terminal cleanly and smoothly from the strip. During this same operation, tab 138 may be wrapped around the bated end of a wire, as shown in Figure 20, to complete the termination.

I claim:

1. A process for forming solderless terminations on electrical wires for connecting the wires to other condoctors of electricity comprising the steps of forming a continuous long, flat strip of metal into a plurality of joined electrical terminals, each terminal having a flat portion adapted to be used for making connection with another conductor of electricity and having at least a pair of side portions adapted to be bent upwardly approximately perpendicularly to the plane of said flat portion and adapted to be curled around, swaging a generally V-shaped notch transversely to the fiat surface of said strip near each of said flat portions, said notch being in the junction between each of said terminals, feeding said strip of terminals along a path past a transverse plane of demarcation between a zone of support and a free zone, arresting said strip with one of said notches lying in said plane of demarcation and with at least a part of one of said fiat portions in said free zone, striking said one flat portion over an area adjacent to and extending parallel to said notch by a force directed substantially parallel to said plane of demarcation and substantially perpendicular to said fiat portion to drive said one fiat portion substantially parallel to said plane of demarcation to break off one of said terminals along the line of said notch, andcurling at least one of said side portions around.

2. A process for forming solderless terminations on electrical wires for connecting the wires to other conductors of electricity comprising the steps of forming a continuous long, fiat strip of metal into a plurality of joined electrical terminals, each terminal having a flat portion adapted to be used for making connection with another conductor of electricity, and having at least a pair of side ear portions adapted to be knocked upwardly approximately perpendicularly to the plane of said flat portion and adapted to be curled around, forming a joint between terminals by swaging a generally V-shaped notch transversely to the fiat surface of said strip and near each of said flat portions, each of said notches having a first sloping surface at least partially between said ear portions, feeding said strip of terminals along a path past a transverse junction between a zone of support and an open zone, arresting said strip with one of said notches parallel to and lying in said junction and with one of said flat portions in said open zone, striking said one flat portion on an area extending parallel to said notch to break ofi one of said terminals along the line of said notch, and curling at least one of said side portions around in a direction toward said first sloping surface at least partially between said ear portions, to form a conductorreceiving ferrule with said first sloping surface forming a bell mouth portion at the inner edge of said ferrule.

3. A process for forming solderless terminations on electrical wires for connecting the wires to other conduetors of electricity comprising the steps of forming a continuous long, flat strip of metal into a plurality of joined electrical terminals, each terminal having a flat portion adapted to be used for making connections with another conductor of electricity by insertion into a socket and having at least a pair of side portions adapted to be bent upwardly approximately perpendicularly to the plane of said flat portion and adapted to be curled around, swaging a generally V-shaped notch transversely to the fiat surface of said strip near each of said fiat portions, said notches being in the junctions between each of said terminals, and each having a first abruptly sloping surface adjacent each of said flat portions and a more gradually sloping surface toward said side portions, feeding said strip of terminals along a path past a transverse plane of demarcation between a zone of support and a free zone, arresting said strip with one of said notches lying in said plane of demarcation and with at least a part of one of said fiat portions in said free zone, striking said one fiat portion on an area adjacent to and extending parallel to said notch to break off one of said terminals along the line of said notch with said first abruptly sloping surface forming a tapered lead on the end of said one flat portion, and curling at least one of said side portions around.

4. A flat metal strip formed into a plurality of joined terminals, each terminal having a flat portion adapted to be used for making connection with another conductive element and a ferrule-forming portion including at least a pair of opposed side portions adapted to be bent in the same direction and to be curled over toward each other to form a ferrule, each of said side portions having edges adapted to form the mouth of the ferrule when said side portions are curled over toward each other, said terminals being joined together in succession along said strip by a series of transversely weakened breaking off lines formed by at least one generally V-shaped notch swaged across said strip intermediate said flat portions of each of the terminals and said ferrule-forming portions of adjacent terminals, each of said notches having a sloping surface extending out along the corners of said edges facing in said direction, whereby when said side portions are bent in said direction and curled over said corners are toward the inside and form a bell mouth for said ferrule.

References Cited in the file of this patent UNITED STATES PATENTS 2,242,967 Carlile May 20, 1941 2,406,079 Krueger Aug. 20, 1946 2,452,932 Johnson Nov. 2, 1948 2,494,137 Martines Jan. 10, 1950 2,508,782 Carlile May 23, 1950

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