US2814025A - Electrical connectors - Google Patents

Description

Nov. 19, 1957 c. E. WADE ET'AL 2,814,025

ELECTRICAL CONNECTORS F1106 FIb.l 23, 1954 2 Sheets-Sheet l INVENTUM 17d/Ze- TIA/4a@ Nov. 19, 1957 c. E. WADE ET AL 2,814,025

ELECTRICAL CONNECTORS Filed Feb. 23. 1954 2 Sheets-Sheet 2 ELECTRICAL CONNECTORS Charles E. Wade, Jasper Long, and Harley M. Newcomb, Sturgis, Mich., assignors to Wade Electric Products Co., Sturgis, Mich., a corporation of Michigan Application February 23, 1954, Serial No. 411,615

4 Claims. (Cl. 339-256) This invention relates generally to connectors for electrical circuits and, in particular, is designed to improve the construction and operation of terminal connectors that are adapted to receive blade-like or spade terminals.

An important object of the invention is to provide a terminal connector construction which will resist camming out of a short spade terminal due to side thrust.

Another object is to provide a terminal connector construction having excellent conductivity, i. e., very 10W millivolt drop.

A further object is to provide a terminal connector construction which can be mass produced at low cost.

These and other objects of the invention are accomplished by means of the structure of this invention which includes a highly conductive connector body that has side barriers which engage the side edges of a spade terminal to prevent angular movementthereof relative to the connector and which therefore eliminate the possibility that the terminal will be cammed out of the connector by side thrust. The connector body has a transverse bridge portion which interconnects the side barriers to prevent them from being spread apart. The body is provided with an embossed, flat Surface of substantial area which engages one face of the spade terminal. A stamped spring strip, carried by the body, bears upon the other face of the spade terminal and holds it under pressure against the flat surface, thus minimizing the millivolt drop and promoting high conductivity as well as controlling the force required to insert or withdraw a terminal. One end of both the spring and body are flared to provide a mouth that receives the spade terminal and facilitates its insertion into the terminal connector. This in combination with the embossed surface provides optimum seating of a terminal in the connector.

The invention is illustrated in the accompanying drawings in which:

Figure 1 is an enlarged side elevation of one form of the invention;

Fig. 2 is a plan View of the construction shown in Fig. 1 with part of the spring strip broken away and showing a spade terminal prior to insertion;

Fig. 3 is a longitudinal section taken along line 3-3 of Fig. 2;

Fig. 3A is a view similar to Fig. 3 showing the spade terminal inserted in the connector;

Fig. 4 is an end view taken along line 4-4 of Fig. 2;

Fig. 5 is a plan view of a modified form of the invention with part of the spring strip broken away and the rest shown by phantom lines;

Fig. 6 is a longitudinal section taken on line 6-6 of Fig. 5

Fig. 7 is a side elevation of a modied form of the invention;

Fig. 8 is a plan View of the embodiment of Fig. 7;

Fig. 9 is an end elevation of the embodiment of Fig. 7;

Fig. 10 is a section along line 11i-10 of Fig. 8;

Fig. ll is a side elevation of another form of the invention;

States Patent() 2,814,025 Patented Nov. 19, 1957 Fig. 12 is a plan View of the embodiment of Fig. 11; Fig. 13 is an end elevation of the embodiment of Fig. 11;

Fig. 14 is a section taken on line 14--14 of Fig. 12; and

Fig. 15 is a section taken on line 15-15 of Fig. 12.

Referring first to the embodiment of the invention i1- lustrated in Figs. 1 4, the improved terminal connector has a body 1 that is formed by pressing or stamping operations from a strip of metal having high electrical conductivity, such as commercial bronze, low brass, etc. The body 1 has a bottom 3 and upstanding sides 5 that eX- tend lengthwise of the body and parallel to each other. The sides 5 are spaced from each other by a distance that is substantially equal to the width of the spade terminal T, which is illustrated in the form of a terminal described and claimed in the copending application of Jasper Long, Serial No. 69,805, filed January 7, 1949, entitled Welded Terminal Assemblies. The sides 5 are interconnected by an integral, transverse bridge 7 at the front of the body 1 which prevents them from spreading apart, and which may be formed by drawing or by bending up a sheared portion of body 1 around portions 9 and 11. The bottom 3 at the front end of the body 1 is offset downwardly at 9 and 11 to accommodate larger diameter portions T1 and T2 of the spade terminal T. The bottom 3 is embossed upwardly at 13 to provide a flat surface 15 of substantial area for interfacialcontact with one side of the spade terminal T. The rear end of the bottom 3 is adapted in a suitable manner to receive a lead wire or electrical current carrying member or to be mounted to a terminal strip or other surface, a contact rivet hole 17 and locating lug 19 being illustrated.

The spade terminal T is held in at, forcible engagement against flat surface 15 by a spring strip Z1. The strip is formed from a metal having a higher yield strength than the metal from which body 1 is made and will therefore have lower conductivity. Spring steel may be used but Phosphor bronze is preferred since it is more resistant to corrosion and because it has a better conductivity. The strip 21 is formed by stamping or pressing from a longer strip and has a free or unstressed shape which, to the naked eye, is the same as shown in Fig. 3. Most of the strip 21 is almost as wide as the bottom 3, as will be seen in Fig. 2. The spring strip 21 has a flat central portion 23 that is designed to engage the upper face of the spade terminal T and press it against surface 15. The strip 21 has a rear end portion 25 that is inclined upwardly from portion 23 and a front end portion that is also inclined upwardly from portion 23 at about the same angle as portion 27. The front end portion includes an upwardly olfset inclined section 27 that passes under bridge 7 and engages the underside of the bridge. The extreme front end section 29 is reduced in width and ared upwardly and engages the front side of the bridge '7. It will be seen that the front end of the strip 21 and the sections 9 and 11 of the body bottom 3 cooperate to provide a ared mouth for the terminal connector which facilitates insertion of the spade terminal T.

The spring strip is held in place in the body 1 in such a manner that it must be deflected a slight amount before it can be removed; in other words, it is snapped into place. This is achieved by fulcruming the strip 21 on an upturned tab 31 at the rear of embossment 13 and catching the end of rear portion 2S under the lateral tang 33 of the upturned spring retainer tab 35. It will be observed from Figs. 2 and 3 that tabs 31 and 35 are complemental sections formed upwardly from the flat bottom 3. These various structural features are preferably arranged so that the flat section 23 is parallel to surface 15 and spaced above it by a distance slightly less than the thickness of the spade. This distance is, of course, controlled by the height of tab 31. It may also be controlled by the depth of detent indentations 37 in the strip 21 and embossment 13 that fit in terminal detent hole T3 and which may engage each other to space the section 23 above surface The strip is prevented from sliding lengthwise out of the front end of the body 1 by tangs 39 that are bent up from the sides of the front end of section 27 so that they catch on the inside of the bridge 7 and also by the latching action of tab 29 in the recess at the lower edge of bridge 7. It will therefore be seen from Fig. 3 that it is necessary to deliect the front end of the strip 21 down- `wardly so that tangs 3:9 and the front edges of section 27 clear bridge 7 before the strip 21 can be removed from the body. The tangs 39, however, are slanted so that they engage bridge 7 to cam the strip down to permit easy insertion and assembly of the strip 21 with the body 1.

When the terminal T is inserted into the connector, the front and rear inclined ends of the strip 21 will be deflected slightly to increase the spacing between section 23 and surface 15. This will stress the strip and the reaction will force the spade terminal T tightly against surface 15, thus minimizing the millivolt drop. The pressure applied by the strip 21 to the terminal T will be substantially uniform over the area thereof because the strip 21 can shift lengthwise (and transversely, for that matter) to properly adjust itself in accordance with the stress distribution. The side edges of the terminal T engage the sides 5 which will prevent it from being cammed out by a side thrust or transverse force applied to the terminal. It will be noted from Fig. 4 that the embossment 13 elevates the terminal T above the radii 41 at the bottoms of the sides so that an effective, squared engagement between the sides 5 and terminal blade is obtained to prevent any substantial relative angular movement of the terminal T and the terminal connector. The detents 37 in conjunction with the pressure applied by spring 21 prevent accidental disconnection of the terminal from the connector. It will be seen that the shape of the mouth at the front end of the connector accommodates the shape of the terminal and facilitates its insertion. The tab 31 acts as a stop to limit insertion and, in the event that it is not used, the transverse shoulders between sections L and 11, and 9 and 13, and the corresponding shoulders on the strip 21 can serve as stops to control the extent of insertion.

The modified form of connector shown in Figs. 5-6 is very similar to the connector just described and like features are designated by like reference numerals. In this connector the rear portion 71 of the body 73 is turned up at substantially a right angle whereby it is adapted for connection to a different type panel than is the body 1. in this form the strip 21 is fulcrumed on a tang 75' that is sheared out of the bottom 77 of the body 73 and bent upwardly. It also serves as a stop to limit insertion of the terminal T. An inwardly bent tab 79 serves as a catch for the end of the strip 21.

1t will be seen that in the foregoing structure the spring strip 21 will force a substantial area of the spade T into an efcient electrical engagement with the embossment face 15. The Spring strip in combination with the detents 37 also serves to control the forces required to insert or withdraw the terminal from the connector and prevents accidental disengagement. A detent 37 could, of course, be sheared out like tang 75 so as to provide a permanent connection between the terminal T and the connector. The side barriers 5 engage the side edges of the terminal T to guide its entry and prevent substantial angular move ment thereof, as about the center of hole T3. In case some angular movement does occur due, for instance, to a poor it between the terminal and connector, the sides of the terminal section T1 will abut the sides of the bridge 7 (front ends of barriers 5) to positively prevent camming out due to side thrust.

Referring to the embodiment of Figs. 7-10, it will be seen that it is similar in principle to the embodiment of Figs. 1-4. In this case, the body 1tl1 can be formed by bending and shearing flat stock so as to obtain the side barriers 103 and the front bridge 10S along with rear bridge 107. The blade contacting face 109 is embossed upwardly and the inlet portion 111 of the body is flared downwardly as shown. The hole 113 will receive a contact rivet or the like and trough 115 may be used to house a lead wire. A spring strip 117 is bent slightly as it lits under bridges HB5 and 107 and fulcrums on a tang 119 bent from its surface.

The embodiment of Figs. 11-14 is similar in principle to the embodiment of Figs. 1-4. The body 131 has side barriers 133 and a rather low front bridge 135. The blade contacting portion 137 is embossed upwardly and the inlet to it is flared downwardly as shown at 139. In this embodiment, however, the spring strip 143 extends crosswise rather than lengthwise of the connector and is caught in notches 145 in the side barriers. The strip has a tab 14.7 that catches under bridge 135, these various connections acting to slightly bend the strip so that it will hold a blade with spring pressure against face 137. ln order to illustrate that a lead wire may be spot welded or otherwise attached to the female terminals (as they are with the male terminal), We show the flared stranded end 201 confined between upright side barriers and clamped by arms 20S. The end 261 is spot welded to the bottom of the metal piece. This is in lieu of rivet connection through the hole, such as 113.

in the two embodiments of Figs. 7-14, as in the other embodiments, the spring strips may have a higher yield strength than the body to provide optimum elastic action. In Figs. 11-14, the shorter terminal does not have the inlet throat of the other embodiments to receive the enlarged portion T1 of the spade terminal.

What is claimed is:

1. An electrical terminal connector for flat terminals comprising a body member of conductive metal having a bottom portion and side barriers extending lengthwise along opposite sides of said bottom portion, one end of said body comprising an inlet end for receiving a terminal, a transverse bridge at said inlet end and spaced above the bottom portion and interconnecting said side barriers to prevent spreading apart thereof, a part of said bottom portion being adapted to engage a terminal, a spring strip retained by said body member and located above said part to press a terminal against said bottom, one end of said strip including portions extending under said bridge and engageable with opposite sides thereof to retain said strip in said body, said bridge being spaced from said bottom by a distance such that it spaces the strip from thc part by a distance less than the thickness of a terminal.

2. The invention set forth 'in claim 1 including a tab struck from said body member and engaging an intermediate part of said strip and serving as a fulcrum therefor and abutment means on the body member engaging the other end of said strip to resist movement thereof away from the bottom portion, said bridge, tab, abutment means, and strip being arranged so that said strip can be inserted in and removed from place by movement length- Wise of the body through said bridge accompanied by bending of a portion of the strip toward said bottom portion.

3. The invention set forth in claim 2 wherein said tab is located adjacent the inner end of said part and serves as a stop to limit insertion of a terminal.

4. The invention set forth in claim l, 4including a second bridge formed in said body, the other end of said strip extending under and engaged with said bridge.

References Cited in the file of this patent UNTTED STATES PATENTS 2,550,636 Bergan Apr. 24, 1951 2,591,909 Riche Apr. 1, 1952 2,731,617 Doane Jan. 17, 1956

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