US 3894783 A
A spring grip contact and an associated housing are disclosed for zero on-zero off engagement with appropriate fixed terminal pins. The housing has a base portion adapted to receive a plurality of spring grip contacts therein and a mating cover portion. Each spring grip contact has a conductor engaging portion and a terminal engaging portion, the former being of conventional configuration and the latter having an arcuate or bowed longitudinal configuration with elongated holes spaced apart towards opposite ends thereof. The terminal engaging portion of the contact, in its relaxed state with the housing open, allows easy passage through the spaced holes by a terminal pin. When the cover portion of the housing is closed down against the contacts, they are biased into locking engagement with the terminal pins. The assembly is removed simply by opening the housing to release the contacts.
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Description (OCR text may contain errors)
United States Patent n91 Messner  Appl. No.: 458,603
 US. Cl. 339/91 R; 339/97 R; 339/258 R [5|] Int. Cl. 01R 13/54  Field of Search r. 339/91 R, 9] F, 9| P. 19,
339/22 B. 97 R, 198 J, 198 H, 241, 243, 252 R, 252 P. 252 S, 95 D, 256 C, 256 S, 258 P, 258 RR, 273 S, 277 R  References Cited UNlTED STATES PATENTS 3.4l7,362 l2/l968 Reynolds 339/9l R X 3,705,376 l2/l972 Kinkaid et al. 339/95 D X 3.808.578 4/1974 Hansen .l 339/258 P X Primary Examiner-Roy Lake Assistant E.raminerDeWalden W. Jones Attorney, Agent, or FirmRussell J. Egan, Esq.
[451 July 15, 1975  ABSTRACT A spring grip contact and an associated housing are disclosed for zero on-zero ofi' engagement with appropriate fixed terminal pins. The housing has a base portion adapted to receive a plurality of spring grip contacts therein and a mating cover portion. Each spring grip contact has a conductor engaging portion and a terminal engaging portion, the former being of conventional configuration and the latter having an arcuate or bowed longitudinal configuration with elongated holes spaced apart towards opposite ends thereof. The terminal engaging portion of the contact, in its relaxed state with the housing open, allows easy passage through the spaced holes by a terminal pin. When the cover portion of the housing is closed down against the contacts, they are biased into locking engagement with the terminal pins. The assembly is removed simply by opening the housing to release the contacts.
18 Claims, 11 Drawing Figures PATENTED JUL 15 ms SHEET I D II 1T, L
SPRING GRIP CONTACT ASSEMBLY BACKGROUND OF THE INVENTION 1. The Field Of The Invention The present invention relates to a spring grip contact assembly and in particular to a zero on-zero off spring grip contact and its associated housing.
2. The Prior Art There are many instances when it is highly desirable to have a low insertion force for mating electrical contacts. Many attempts have been made to solve this problem with various contact and housing configurations designed for mating with different arrays of fixed terminals.
An earlier example of a low insertion force spring grip connector can be found in US. Pat. No. 1,221,713. This spring contact has a body member G with a slotted spring member H bent over the body G and with resilient hooked member J projecting into the slot of member H. When member H is depressed, there is clear passage for a wire through the hooked member I. The wire is held between members J and H when the latter member is released. This arrangement is suitable only for mating with terminals or conductors extending normal to the axis of the contact.
U.S. Pat. No. 2,610,996 shows another type of zero insertion force arrangement in which the wires 29 are passed through slots 20 in contacts 19 before the contacts are driven by screw means 21 into engagement with the wire. Such an arrangement has the obvious defects of being very slow and cumbersome to use.
U.S. Pats. Nos. 3,526,870 and 3,609,634 show other spring tension devices for connecting individual wires to wire wrap posts and the like. However, these devices are intended for making separate connections between specific wires and posts and are not readily adapted for making gang connections.
SUMMARY OF THE INVENTION The present invention concerns a spring grip contact assembly for zero on-zero off engagement with fixed pin terminals. The assembly includes a housing and a plurality of spring grip contacts mounted therein. Each contact has a conductor gripping portion and a terminal gripping portion. The conductor gripping portion has wire and insulation gripping members. The terminal gripping portion, in side elevation, has an arcuate or bowed configuration with a pair of elongated holes spaced apart near opposite ends thereof. The housing has a base portion with a plurality of grooves adapted to receive the contacts in parallel spaced apart relation and a terminal pin receiving aperture opening to the longitudinal axis of each groove and a cover portion mating with the base portion. The contacts, in their relaxed condition with the housing open, allow the terminal pin to penetrate through both of the elongated holes. When the housing is closed, the cover portion of the housing biases the contact into engagement with the terminal pin at each end of the elongated apertures to provide a good electrical and mechanical connection therewith.
It is therefore an object of the present invention to produce an improved spring grip contact assembly for zero on-zero off engagement with fixed pin terminals.
It is another object of the present invention to produce an improved spring grip contact having an arcuate configuration with elongated apertures spaced at opposite ends of the arc, whereby the contact, in a relaxed condition, freely receives a terminal pin through the apertures and, in a biased condition, firmly and mechanically and electrically engages the terminal pin.
It is still another object of the present invention to produce a zero on-zero off spring grip connector assembly having a plurality of bowed spring grip contacts mounted in a housing with the housing arranged to bias the spring grip contacts from a relaxed condition, wherein terminals pins may be received therein, to a biased condition in which the spring grip contacts mechanically and electrically engage pins inserted therein.
It is a further object of the present invention to produce a spring grip contact assembly for electrically and mechanically mating with a plurality of fixed terminal pins aligned in single or multiple parallel rows.
It is a still further object of the present invention to produce a zero on-zero off spring grip contact assembly which can be readily and economically manufactured.
The means for accomplishing the foregoing objects and other advantages, which will be apparent to those skilled in the art. are set forth in the following detailed description taken with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded perspective view of the preferred embodiment of the subject invention;
FIG. 2 is a side elevation of the subject connector as sembly showing the housing in an open condition;
FIG. 3 is a side elevation of the subject connector assembly showing the housing in a closed condition, the latching mechanism being shown in partial section;
FIG. 4 is a vertical transverse section taken along line 4-4 of FIG. 2;
FIG. Sis a vertical transverse section taken along line 5-5 of FIG. 3;
FIG. 6 is an enlarged detailed view of a portion of the contact engaging the terminal pin, as shown in FIG. 5;
FIG. 7 is a horizontal section taken along line 77 of FIGS. 2 and 4',
FIG. 8 is an exploded perspective view. similar to FIG. 1, showing an alternate embodiment of the housing for the subject connector assembly;
FIG. 9 is a vertical transverse section through a second alternate housing for the subject invention showing an alternate contact configuration;
FIG. 10 is a plan view ofa blank for forming the subject spring grip contact; and
FIG. 11 is a side elevation of the subject spring grip contact after being formed to an alternate configuration.
DESCRIPTION OF THE PREFERRED EMBODIMENT The subject spring grip terminal assembly includes a two-part housing 10 having a base portion 12 and a cover portion 14. The base portion 12 includes a back wall 16 having a plurality of integral spacer blocks 18 projecting therefrom defining therebetween a plurality of parallel, spaced apart contact receiving grooves 20. A contact alignment groove 24 is formed at the upper end of each contact receiving groove 20 extending into each block 18. The bottom wall 24 of the base portion 12 has a plurality of terminal receiving apertures 26, each leading to one of the slots 20. A plurality of locking lance receiving apertures 28 are formed in the back wall 16, each aperture 28 lying within a groove 20. Front wall 30 is integral with bottom wall 24 and extends parallel to and spaced from blocks 18 to define a cover receiving recess 32 therebetween. At each end of the base portion there is an outwardly directed locking latch member 34, 36, each including a latching shoulder 38 and release ear 40.
The cover portion 14 of the housing includes a front wall 42 having a contact engaging skirt 44 depending therefrom and channel shaped end portions 46, 48 each adapted to at least partially enclose the opposite ends of the base portion 12. Each end portion 46, 48 includes a latch member passage 50 and latching detent 52. The latch ear 40 projects above the latch detent 52 when the housing is closed and allows release of the cover portion.
The blank for forming contact 54, see FIG. 10, is preferably die stamped from a continuous strip of metal, not shown, in conventional fashion. The contact blank 54 is shown in FIG. 10 as it would appear after being severed from a carrier strip, not shown, and before being formed. The contact includes, from left to right, a pair of insulation gripping flanges 56, an insulation displacing, wire receiving slotted portion 58, a pair of contact orientation ears 60, a locking lance 62, first and second spaced elongated apertures 64, 66 and the free end 68 of the contact.
The contact 54 is attached to a conductor 69 in the conventional way by forcing the free end of the conductor into the wire receiving slot 58 and crimping the insulation engaging flanges 56 about the insulation. A plurality of contacts are then loaded into the housing by slipping them through the contact receiving grooves 20 until the cars 60 engage in the grooves 22 to hold the contacts in the proper alignment. The locking lance 62 of the fully inserted contacts will project through the locking lance receiving aperture 28 to lock the contact in place. It is forseeable that the contacts could be first loaded into the housing and the conductors then attached to the contacts.
The operation of the subject spring grip contact assembly in achieving zero on-zero off mating will be described with reference to FIGS. 4 to 6. FIG. 4 shows the housing 10 in the open condition and the contact is in a relaxed bowed shape. In this condition the elongated apertures 64, 66 are so aligned with aperture 26 that a clear passage is formed allowing the terminal pin 70 to easily pass therethrough without engaging the contact 54 at any point therealong. However, when the cover portion 14 of the housing I is brought into the closed condition with base portion 12, as shown in FIGS. 3 and 5, the skirt portion 44 engages the contacts 54 at the crest of the bowed portion between apertures 64, 66 and biases the contact downwardly into engagement with the terminal pin 70. The contact 54 floats in the groove 20 during this movement, the amount of float being limited by the locking lance 62 in aperture 28. The free end 68 of the contact also moves in the slot to allow compression of the bowed configuration. An enlarged detailed view of a portion of the engagement of the contact and terminal is shown in FIG. 6. The sharp edges 72, 74 forming ends of the elongated aper tures 64, 66, respectively, actually penetrate into ll terminal 70 to make a tight mechanical and electrical engagement. The penetration of the contact into the terminal takes place at both ends of the elongated apertures. The housing is held in the closed condition by the engagement of the latching members 34, 36 with the latching detents 52. The cover is released by simply depressing the latching ears 40 and removing the cover.
An alternate embodiment of the housing is shown in FIG. 8. The most distinctive feature of this housing 76 is that it includes a double row of contacts. This housing includes a base portion 78 and a cover 80. The base portion 78 is almost a double sided modification of base 12. However, the front wall 30 and recess 32 have been replaced by a plurality of dove tailed portions 80 integral with the bottom ends of the spacer blocks 84. The cover 80 is similar to a doubled embodiment of cover 14 with skirt 44 being replaced by dove tailed portions 86 which mate with portions 82. The remainder of the structure of this housing, the contacts and the operation are identical with the preferred embodiment.
Another alternate embodiment of the subject housing is shown in FIG. 9. This is a one piece housing 88 enclosing a modified contact 90. This embodiment of the housing 88 has a base wall 92 with contact apertures 94, 96 therein. A resilient latching member 98 extends integrally and normally from one side of the base wall 92. A terminal receiving wall portion 100, having a plurality of terminal apertures 102, extends normally from the base wall parallel to and spaced from latching member 98. A latching cover 104 is hingedly connected to the wall portion by hinge portion 106 and has a gripping handle portion 108 spaced from the hinge. The free end of the cover 104 is adapted to engage with the latching member 98. The contact 90 includes a pair of terminal portions 110, 112 depending from a body 114 and an arcuate bowed portion 116 bent back upon the body and having elongated apertures I18 and 120 therein. The terminals I10, 112 are solder connected to a circuit board 122 and the contact 90 is arranged to be engaged with terminal pins 124 fixed to a chassis 126. The contact operates in substantially the same fashion as the preferred embodiment in that in the initial relaxed condition, as shown, the elongated apertures ll8, 120 provide sufficient clearance for the free passage of the terminal pin 124 therethrough. When the cover 104 is closed to its latched position, the arcuate portion 116 of the contact 90 is stressed to bring the edges of the elongated apertures 118, I20 into good mechanical and electrical engage ment with the terminal pin 124.
A further modification of the subject spring grip contact is shown in FIG. I]. Instead of a smooth curved or bowed configuration, terminal gripping portion of this embodiment has three distinctively arced segments 128, I30 and 132. The particular advantage of this embodiment is the ends of the elongated apertures approach the mating terminal at an angle substantially normal to the terminal to achieve a good electrical and mechanical engagement therewith.
The present invention may be subject to many modifications and changes without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive.
I claim I. A spring grip electrical connector assembly for low force mating with a plurality of closely spaced, fixed, parallel terminal pins, said assembly comprising:
a housing having a contact carrying base portion and a cover portion mating with said base portion. and
a plurality of spring grip contacts mounted in said contact carrying base portion of said housing in parallel spaced relationship, each said contact including a conductor engaging portion and a resilient terminal pin engaging portion of arcuate longitudinal section with an elongated aperture at each end thereof, said contact adapted to receive an associated terminal pin axially through said apertures whereby said cover portion, in the closed position, engages said conductor engaging portion of said contacts and biases said contacts into engagement with said terminal pins.
2. A spring grip electrical connector assembly according to claim 1 wherein each said spring grip contact comprises:
a stamped and formed integral metallic body memher,
said conductor engaging portion including means for crimp connection to a conductor, and
said arcuate terminal pin engaging portion having a smooth bowed configuration.
3. A spring grip electrical connector assembly according to claim 1 wherein said arcuate terminal pin engaging portion comprises at least three interconnected arcs whereby each end of each elongated aperture is substantially normal to the terminal pin passing therethrough.
4. A spring grip electrical connector assembly according to claim 2 wherein:
said resilient terminal pin engaging portion extends back along said body above said conductor engaging portion.
5. A spring grip electrical connector according to claim 1 further comprising:
a locking lance on each said contact, and
a plurality of locking lance receiving apertures in said base, said locking lances adapted to engage in said apertures in said housing base to thereby limit longitudinal movement of said contacts.
6. A spring grip electrical connector according to claim 1 further comprising:
at least one integral locking car extending transversely of each said contact, and
a recess in said housing base, said ear engaging in said recess thereby preventing rotation of each said contact about its longitudinal axis.
7. A spring grip electrical connector assembly according to claim 1 wherein:
said contact carrying base portion of said housing comprises:
a back wall,
a plurality of parallel, spaced apart spacer blocks integral with said wall defining a plurality of contact receiving recesses therebetween,
a terminal pin receiving aperture communicating with one end of each said recess along the longitudinal axis thereof, and
latching means adapted to hold said cover portion in a closed condition.
8. A spring grip electrical connector assembly ac cording to claim 7 wherein base portion and said cover portion of said housing are separate members, said base portion further comprising:
a wall spaced parallel from said spacer blocks to define a groove therebetween,
said cover portion having a depending flange adapted to be received in said groove, and
said latching means detaehably securing said base and cover portions together in the closed condition.
9. A spring grip electrical connector assembly according to claim 1 wherein said housing comprises a unitary member including base portion and said cover portion.
10. A spring grip electrical connector assembly according to claim 7 further comprising:
a groove in each said spacer block opening into each said contact receiving recess, and
each said contact further comprises at least one integral ear engaging in said groove thereby preventing movement of said contact about its longitudinal axis.
11. A spring grip electrical connector assembly according to claim 7 further comprising:
a plurality of apertures in said base, each aperture opening into a respective one of said contact recesses, and
each said contact having an integral locking lance engaging in said aperture thereby limiting longitudinal movement of said contacts.
12. A spring grip electrical connector assembly according to claim 1 wherein said contacts are mounted in said base in at least two parallel spaced rows.
13. A spring grip electrical connector assembly for zero force mating with a plurality of closely spaced, fixed, parallel terminal pins, said assembly comprising:
housing means including a base portion having a plurality of parallel spaced apart contact receiving recesses and a terminal receiving aperture at one end of and aligned with the longitudinal axis of each said recess, and a cover portion adapted to close on said base portion;
a plurality of spring grip contacts, each contact including a conductor engaging portion and a terminal pin engaging portion, said terminal pin engaging portion having a normal relaxed bowed configuration in longitudinal section with an elongaged aperture at each end thereof, each contact being mounted in a respective one of said recesses with at least part of said bowed configuration extending therefrom and adapted to receive said terminal pins along their longitudinal axis through said elongated apertures; and
said cover of said housing, in a closed condition, engaging said terminal pin engaging portion and deforming the bowed configuration thereof whereby opposite ends of said apertures are driven into mechanical and electrical engagement with terminal pins received therein.
14. A spring grip electrical contact for zero force engagement with a fixed terminal pin, said contact comprising:
an elongated, unitary metallic member having a conductor engaging portion and a terminal pin engaging portion,
said conductor engaging portion having means for fixedly engaging an associated conductor,
said terminal pin engaging portion having a normal,
relaxed bowed configuration in longitudinal section and an elongated aperture adjacent each end thereof, whereby a terminal pin can freely pass through said apertures in said normal condition and said contact biased into engagement with said pin.
17. A spring grip contact according to claim 14 further comprising:
a locking lance integral with said contact.
18. A spring grip contact according to claim 14 furwherein said conductor engaging portion comprises an thcr comprising:
insulation displacing slot and insulation gripping flanges.
locking ears extending transversely of said contact. =l=