Shunting switch

A shunting switch used in an electrical connector is formed as a bifurcated element having contact edges which are compressed between the lateral side edges of a pair of contact pins when the switch is closed. The contact edges of the shunting switch as each moves upwardly from an open condition to a closed condition occurs when the mating connector is removed causing a wiping action of the surfaces of the pins.

The present invention relates to a shunting switch used in an electrical 
connector of the type having a plurality of contact pins disposed in a row 
therein, and relates more particularly to improvements in such shunting 
switches wherein the switches are provided with contact surfaces which act 
not only to effect an electrical connection with contact pins but further 
allow relative linear movement between the contact surfaces to effect 
wiping of the pins so as to minimize buildup of debris thereon. 
Contact switches having a bifurcated form are known in the art. One such 
bifurcated form of a shunting switch is found in U.S. Pat. No. 5,470,243 
issued to Bendorf on Nov. 28, 1995. In this patent it is disclosed to 
provide a shorting switch having bifurcated contact ends that are spaced 
the same distance as the spacing of the contact pins in the row adjacent 
the sidewall of the connector. In this way the bifurcated contact end 
assures a substantially equal contact force when the contact ends are in 
engagement with the two pin contacts exposed adjacent to them. However, 
the contact pins of the bifurcated shunting switch act only at distinct 
points on each of the pin contacts. Thus there is no relative linear 
movement of switch ends along the length of the contact pins. Likewise in 
the U.S. Pat. No. 4,070,557 issued to Ostapovitch on Jan. 24, 1978, a 
bridging contact member is disclosed which includes two spaced apart 
bridging terminals which engage contact pins disposed immediately in front 
on the terminal ends. Again, this contact construction provides only 
single point co-action between the contact tips and the elongated pin 
members. 
Accordingly it is the object of the invention to provide a shunting switch 
in an electrical connector of the type of having a plurality of contact 
pins which are arranged in a row and which shunting switch is capable of 
moving linearly relative to the elongated dimension of the contact pins to 
effect wiping of the surface of the pins. 
Still a further object of the invention is to provide a shunting switch of 
the aforementioned type whereby the switch is provided with sufficient 
normal force against the transverse side of the contact pins to ensure 
proper electrical performance. 
Still a further object of the invention is to provide a shunting switch of 
the aforesaid type which can be made cost effectively. 
Other objects and advantages of the invention will become apparent from the 
following specification and the appended claims. 
SUMMARY OF THE INVENTION 
The present invention resides in an electrical connector of the type having 
a housing and a base defining a receptacle for receiving a mating 
connector therein. The connector further includes a plurality of contact 
pins arranged on the base such that a pair of the contact pins define 
surfaces which oppose one another. At least one shunting switch is 
provided and is associated with a pair of the contact pins. The at least 
one shunting switch is bifurcated to define two contact surfaces each 
respectively disposed along lateral sides of the switch and contacting one 
of the contact pin opposing surfaces and being laterally deflectable upon 
engagement with the opposing surfaces of the contact pin pair.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring to FIG. 1, there is shown a perspective view of an electrical 
connector 10 incorporating shunting switches 12, 12 of the present 
invention. Although the present invention will be described with reference 
to the single embodiment shown in the drawings, it should nevertheless be 
understood that features of the present invention could be embodied in 
many different forms of alternate embodiments. In addition, any suitable 
size, shape or type of elements or materials could be used. 
The connector 10 generally comprises an elongate housing 14 defined by a 
base 16 and two integrally connected parallel sidewalls 18, 18 disposed 
substantially symmetrically about a centerline CL. Each side wall has an 
opposed inwardly directed face 19, 19' which together with the upper 
surface of the base 16 defines a generally channel-like receptacle 17 for 
receiving a mating connector (not shown) therein. As is typical in the 
industry, the housing 14 is formed from a dielectric material as is the 
housing of the mating connector. 
The connector 10 also includes a plurality of contact pins 20, 20 each 
arranged in rows 22A, 22B, 22C and 22D extending lengthwise of the 
connector and parallel to the sidewalls 14,14. Each of the contact pins 
has an upper portion 23 which extends upwardly into the receptacle 17 to 
engage corresponding positioned contacts in the mating connector when the 
mating connector is inserted therein. Also, each of the contact pins 20, 
20 has a lower portion 24 which fixedly extends through the base 16 and 
depends therefrom to serve as a lead in electrical engagement with 
selected circuitry on a circuit board to which the connector 10 is 
connected. 
As illustrated in FIGS. 1 and 2, each of the contact pins 20, 20 of row 22A 
is equidistantly spaced from the other pins in the same row in the 
direction of the centerline CL. The successively ordered rows 22A-22B, 
22B-22C, 22C-22D, as well as the pins making up these rows, may likewise 
be equidistantly spaced from one another and so as to create a matrix of 
pin elements defining rows and columns which extend along the base 16 of 
the receptacle 15 of the connector 10. As best illustrated in FIG. 3, this 
matrix of rows and columns of the pins 20 is laterally offset from the 
centerline CL of the connector 10 so as to provide a space 32 between the 
inner face 19' of the connector and the first row 22A of the contact pins. 
Within this space 32 are located the shunting switches 12 of the present 
invention. 
Each shunting switch 12 is mounted within the base 16 in a receiving slot 
36 correspondingly sized and shaped to mechanically anchor the shunting 
switch 12 securely into the base 16. As illustrated in FIG. 4, each 
shunting switch 12 has a major portion 40 extending generally 
symmetrically about a major axis LA and a minor portion 42 which is 
integrally formed with the major portion 44 and disposed symmetrically 
about a minor axis MA. In the relaxed condition of the switch as shown in 
FIG. 4, the major and minor axes LA and MA intersect at an angle A, which 
in the preferred embodiment is equal to between 30 and 40 degrees. Also, 
in the illustrated relaxed condition of FIG. 4, the free end 41 of the 
switch extends a distance D1 taken perpendicularly from the major axis LA. 
The major portion 40 of the switch 12 is defined by a mounting base 44 
having a width W1 and an integrally connected elongated body portion 46 
extending upwardly from the mounting base 44 and terminating in a 
generally U-shaped bent portion 48 connecting the major and minor portions 
of the shunting switch to one another. The slot 36 has a width W2 defined 
by endwalls 35,35 which extend perpendicularly to the central axis CA of 
the connector. The dimension W2 is only slightly longer than the width W1 
of the mounting base 44 so as to maintain the mounting base 44 of the 
switch 12 in alignment with the contact pin pair associated with it. That 
is, the endwalls 35,35 of each slot are also disposed substantially 
coincidentally with one contact pin of the pair of contact pins which are 
located immediately adjacent it. 
As illustrated, the body 42 of the switch 12 has a width W3 which is 
substantially smaller in dimension than the width W1 of the mounting base 
44 so as to form a stepped shoulder 50 along the lateral sides of the 
major portion 40 perpendicularly to the major axis LA. Also, the mounting 
base 44 includes a detent 45 which is a laterally deflectable portion of 
the sheet metal from which the switch is made. As shown in FIG. 3, 
cooperating with the detent 45 is an inwardly directed stop shoulder 51 
formed in the receiving slot 36. The detent provides a stop surface 47 for 
cooperating against the stop shoulder 51 to mechanically secure the switch 
to the connector. The detent 45 yeildably tapers outwardly to its leading 
edge 47 so as to snap in place behind the shoulder 51 as the switch is 
inserted downwardly into the slot 36. In this way, each slot 36 immovably 
connects the shunting switch 12 to the connector against upward movement 
because of the detent 45 and shoulder 51 arrangement, and against wobbling 
movement through the close dimensioning of the slot 36 relative to the 
mounting base 44 of the switch. 
Referring now to FIG. 4, it should be seen that a generally V-shaped slot 
54 is formed in the minor portion 42 of the switch 12 opening at the 
free-end 41 thereof and extending longitudinally therealong symmetrically 
about the minor axis MA. The slot 54 also extends through the generally 
U-shaped bent portion 48 of the switch and partially into the body 46 of 
the major portion 40. The slot 54 thus divides the minor portion 40 of the 
switch 12 into two contact parts 58 and 60, each respectively responsible 
for engaging the inner surfaces 62,62 of the pins 20,20 of the row 22A. 
For this purpose, the first and second contact parts 58 and 60 include 
folded portions extending transversely of the minor axis MA and exteriorly 
of the lateral side edges thereof. A portion of each of the first and 
second contact parts 58 and 60 taken from points T, T and forwardly toward 
the free end 41 of each contact part is thus bent downwardly out of the 
illustrated plane P to create contact edges 66,66 which are responsible 
for contacting the side or inner surface 62 of an associated one of the 
pins 20,20. The contact edges 66,66 are disposed laterally outwardly of 
the remaining edge portion 68,68 of the contact parts 58 and 60 so as to 
be compressibly disposed between consecutively ordered ones of the pins 
20,20 in the row 22A when in the closed condition. 
Each contact edge 66,66 is connected to its associated contact part 58 and 
60 through a contact surface 70 which is bent out of the plane P. The 
surfaces 70,70 serve to cam the first and second contact parts 58 and 60 
inwardly between the opposed pairs of contact pins 20,20 when the mating 
connector is removed from the receptacle 17. That is, because the mounting 
base 44 of each switch is secured to the connector 10 at a distance D2 
from the row 22A, the minor portion 40 and the major portion 42 of the 
switch are caused to assume an angle A' which is of a dimension smaller 
than the angle A representing the relaxed condition of the switch as seen 
in FIG. 4. This is because the dimension D2 is shorter than the relaxed 
extension dimension D1 thereby causing the contact pins 20 to impinge upon 
the otherwise extended free end ares of the contact parts 58 and 60. 
Thus, in the illustrated closed condition of the switch, the contact edges 
66 engage with the inner surfaces 62,62 of the mounting pins 20,20. But 
before this happens, it should be understood that the contact parts 58 and 
60 are first deflected towards the pins 20,20 from an otherwise 
nonengagening condition when the mating connector is withdrawn from the 
receptacle 17. In so doing, the contact edges 66,66 of the contact parts 
58 and 60 are caused to move upwardly along the inner surfaces 62, 62 
until the compression force caused by the action of these surfaces stops 
the upward movement of the first and second contact parts 58 and 60 and 
thereby maintains the shorted switch condition illustrated in each of 
FIGS. 1 through 3. Through this action, the contact edges 66,66 wipe 
localized areas of the inner surfaces 62, 62 of the contact pins 20,20 
thus enhancing electrical contact therebetween. 
By the foregoing, an improved shunting switch has been disclosed by way of 
the preferred embodiment. However, numerous modifications and 
substitutions may be made without departing from the spirit of the 
invention. For example, while in the illustrated embodiment the shunting 
switch is shown disposed between two consecutively ordered contact pins, 
it is well within the purview of the invention to provide a switch which 
employs bifurcated contact parts which are spaced so as to coact against 
contact pins which are not consecutively ordered. 
Accordingly, the invention has been described by way of illustration rather 
than limitation.