SHUNT CONNECTING APPARATUS

Abstract: A shunt connecting apparatus employs a rectangular housing (21) made of insulating material, with blind holes (22a-22h) in one face (21a) in which an array of terminals (23a-23h) are fixed. Grooves (24) are formed in the other face (21b) of the housing between pairs or holes and terminals. Resilient contact pieces (25) are provided to locate the grooves to interconnect the terminals in a desired manner.

Description: FIELD OF THE INVENTION The invention relates to connecting apparatus for electrically interconnecting a plurality of terminals mounted on a printed circuit board. BACKGROUND OF THE INVENTION In one known form of connecting apparatus, illustrated in Figs. 1 and 2 of the accompanying drawings and described in more detail hereinafter, individual terminals mounted on a printed circuit board can be selectively interconnected, but only in adjacent pairs, by means of jumpers fitted onto the terminals. In another form of connecting apparatus a switchable device serves to interconnect selected terminals but such a device is complicated and expensive. SUMMARY OF THE INVENTION A general object of the invention is to provide a cheap simple connecting apparatus which has improved utility. Connecting apparatus constructed in accordance with the invention comprises a generally rectangular housing having opposed faces and sides, at least three holes formed in one face of the housing, a plurality of terminals located in the holes to project outwardly from the one face of said housing for mouting to a printed circuit board; a plurality of grooves formed to interconnect respective pairs of the holes and expose the terminals therein and at least one conductive contact piece shaped for insertion into one of the grooves to contact the terminals in the associated holes and thereby to shunt these terminals. Conveniently, the holes are blind to locate the terminals within the housing and the grooves are located in the opposite face of the housing from which the terminals project as an array. The holes and terminals may be disposed to form a matrix with rows and columns in plan view with the grooves extending between adjacent holes in both the rows and columns. By using a number of contact pieces selected groups of terminals can be interconnected and just two contact pieces will serve to contact any one terminal to two adjacent terminals. Terminals not at the boundaries of the rows and columns can be connected to more than two other adjacent terminals by using an appropriate number of contact pieces. The contact pieces can take a variety of different forms but preference is given to a structure with a resilient base portion which fits into a groove and contacts a pair of terminals with its outer regions. The distance between these outer regions can be greater than the length of the grooves to permit the contact piece to be pushed in the groove to make reliable contact and retain the contact piece in the housing until it is to be foreceably removed. To enhance the resiliency of the base portion some relief as a cutout or recess is desirable. BRIEF DESCRIPTION OF THE DRAWINGS The invention may be understood more readily and various other features of the invention may become apparent from consideration of the following description. In the accompanying drawings, Fig. 1 is a perspective view of a known form of connecting apparatus; Fig. 2 is a plan view of the connecting apparatus of Fig. 1; Fig. 3 is a perspective view of a housing part of the connecting apparatus constructed in accordance with the invention; Fig. 4 is a plan view of the housing shown in Fig. 3; Fig. 5 is a cross section of the housing taken on the line V-V of Fig. 4 and showing a contact piece inserted; and Fig. 6 is a plan view of the connecting housing of another connecting apparatus constructed in accordance with the invention. In the prior art shunt connecting apparatus shown in Fig. 1, two rows of terminals 12a to 12f are supported at specified intervals by a plate 11 and the terminals 12a to 12f are inserted through holes provided in printed circuit board 13 to connect electrically with the wiring pattern track formed on the rear side of board 13, by soldering. A plurality of separate jumpers 14 are provided. Each jumper has an insulative housing containing a metal terminal provided with two sockets, into which two adjacent terminals, for example 12c and 12d, may be inserted. As is shown in Fig. 2, any two adjacent terminals can be shunted by inserting them to the sockets of a jumper 14. With this kind of arrangement, however, the combinations of shunted terminals are restricted, and it is impossible to make connection between one terminal and two other terminals. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In Figs. 3 to 6, reference numeral 21 denotes an insulative rectangular housing conveniently formed of a synthetic resin. On the bottom face 21a of the housing 21 there are a number, typically eight (Figs. 3 and 4) or twelve (Fig. 6), blind holes 22a to 22h, of rectangular cross-section which do not extend to the other face 21b of the housing 21. The holes 22a to 22b are arranged as a matrix in plan view with two rows and four columns (Figs. 3 and 4) or three rows and four columns (Fig. 6) with equal spacing between respective holes. Conductive terminals 23a to 23h made of metal have their bases inserted in the holes 22a to 22h and the tips of the terminals 23a to 23h protrude from the side 21a of the housing 21. At least the bases of the terminals 23a to 23h have a rectangular cross section that is substantially the same as that of the holes 22a to 22h. The bases of the terminals 23a to 23h are fixed to the housing 21 by inserting them forcibly into the holes 22a to 22h. Alternatively, terminals 23a to 23h may be fastened to the housing 21 by other means such as adhesives, etc. The projecting portions or tips of the terminals 23a to 23h penetrate the holes formed in the printed circuit board (not shown) and can be soldered to the wiring pattern track on the rear of a printed circuit board. Grooves 24 are formed in the other face 21b, of the housing 21 to interconnect adjacent pairs of holes 22a to 22h. In this way, the interior portions or bases of the terminals 23a to 23h are exposed at both ends of each groove 24. The grooves 24 are narrower than the holes 22a to 22h. As generally represented in Fig. 5, one or more resilient contact pieces 25 are inserted into selected grooves 24 in order to establish connection between respective terminals 23a to 23h (e.g. 23b and 23d in Fig. 5). The contact piece 25 is formed from one sheet of thin conductive metal with a base 25a which has a greater width than the rest of the component. The base 25a is also slightly wider than the length of the grooves 24, or, in other words, slightly wider than the gap between a pair of terminals 23a to 23g, and has a thickness thinner than the width of the guide groove 24. In approximately the centre of the base 25a of the contact piece 25 a recess or cutout 26 is formed longitudinally of the contact piece 25 to permit the base 25a of the contact piece 25 to be deformed resiliently. When a contact piece 25 is inserted into one of the grooves 24, the base 25a exerts an outwardly directed expansive force in the direction of its width and its outer regions make resilient contact with the bases of the terminals 23a to 23h, exposed to the groove 24 and the terminals are thereby shunted. Although not strictly necessary, the overall length of the contact piece 25 is such that the tip protrudes from the housing 21 to facilitate its fitting and removal by hand or by using tools such as tweezers. Instead of producing the contact piece 25 from the one piece of material a composite structure can be adopted with say the top and base made from one material and the remainder from another material. In Fig. 4, if, for example, contact pieces 25 are inserted into the grooves 24 between terminal 23d and terminals 23b, 23c, 23f, then the terminals 23b, 23c, 23d, 23f, are all shunted. Thus a branch connection from one terminal to three other terminals is possible and the maximum number of terminals which can be interconnected is four. In the Fig. 6 version with three rows of terminals, if, for example, contact pieces 25 are inserted into the grooves 24 between one of the two central terminals and the surrounding terminals a branch connection from this terminal to four other terminals is established and the maximum number of terminals which can be interconnected is five. There is no limitation on the number of rows or columns of terminals which can be adopted. As is shown in Figs. 3, 4 and 6, notches 27 are cut in the two opposite longitudinal sides of the housing 21 so that a notch on one side is aligned with a corresponding notch on the other side. The notches 27 permit the housing 21 to be sub-divided into a plurality of pieces along lines between a pair of the notches 27 if the application so requires. With the connecting apparatus as described, it is possible to make a branch connection from one terminal to two or more other terminals and this greatly increases the utility of the apparatus. Since the terminals 23 do not protrude from the surface 21b of the housing 21, the structure and shape are uncomplicated and the apparatus is easy to handle. Furthermore, the contact pieces 25 do not need any holders so they occupy small space. The terminals can also be arranged close to each other, to reduce the overall size of the apparatus. The shape of the contact piece 25 is also not restricted to that shown. Any shape which permits contact with the facing terminals, when the contact piece 25 is inserted into the appropriate groove 24 can be adopted. The cross sections of the terminals 23 and the holes 22 into which they are inserted need not be rectangular and other shapes can be adopted. Although the terminals 23 are depicted as arranged in a regular matrix this again is not essential and other irregular arrangements with the terminals staggered are possible.

Claims: A connecting apparatus comprising: a generally rectangular housing (21) having opposed faces and sides, at least three holes (22) formed in one face (21a) of the housing, a plurality of terminals (23) located in the holes (22) to project outwardly from the one face (21a) of said housing for mouting to a printed circuit board; a plurality of grooves (24) formed to interconnect respective pairs of the holes and expose the terminals therein and at least one conductive contact piece (25) shaped for insertion into one of the grooves (24) to contact the terminals in the associated holes and thereby to shunt these terminals. A connecting apparatus according to claim 1, wherein the grooves (24) are formed in the opposite face (21b) of the housing (21). A connecting apparatus according to claim 1 or 2, wherein said holes are blind holes, and each terminal (23) terminates at the end remote from its projecting portion within the housing. A connecting appartus according to any one of claims 1 to 3, wherein at least a base portion (25a) of said contact piece (25) is resilient and the base portion has outer regions which expand to contact the terminals in the holes associated with the groove containing the contact piece and removably retain the contact piece in said housing. A connecting apparatus according to claim 4, wherein the base portion of said contact piece is thinner than the width of each groove and the distance between the outer regions is greater than the length of each groove. A connecting apparatus according to claim 4 or 5, wherein the base portion of said contact piece is relieved with at least one recess. A connecting apparatus according to claim 4 or 5, wherein the base portion of said contact piece is bifurcated. A connecting apparatus according to any one of claims 1 to 7, wherein each terminal has at least one side flat surface for contact by the contact piece. A connecting apparatus according to any one of claims 1 to 8, wherein there are more than three holes and three terminals and a plurality of contact pieces, the holes and terminals being disposed to form a matrix with rows and columns in plan view with the grooves extending between adjacent holes in both the rows and columns whereby two contact pieces can be located in respective grooves to interconnect any one terminal to two adjacent terminals. A connecting apparatus according to any one of claims 1 to 9, wherein the cross section of each hole and terminal is substantially square. A connecting apparatus according to any one of claims 1 to 10, wherein opposed sides of the housing are provided with aligned notches (27) which permit the housing to be sub-divided along lines joining corresponding pairs of notches.

Inventors: ABE, HIROSHI
Applicants: E.I. DU PONT DE NEMOURS AND COMPANY
Application year: 1986
Main classification: H01R23
IPC codes: H01R25, H01R11, H05K3, H01R31