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A switch section of a sliding-type DIP switch includes a slider and a pair of opposing contacts each consisting of a resilient metal plate member and having a V-shaped urged portion and a linear portion connected to the urged portion. When the slider is slid, each opposing side wall thereof presses the distal end of the respective urge portion of one contact into contact with the linear portion of the other contact to achieve a reliable electrical switching action. A number of these contact pairs are integrated with the bottom portion of a housing by insert molding to facilitate fabrication.

1. A sliding-type DIP switch comprising:

a housing having a bottom portion, first and second spaced apart and opposed side wall portions extending from said bottom portion, a pair of spaced apart and opposed end wall portions extending from said bottom portion between said first and second opposed side wall portions, and a cover plate provided opposite said bottom portion on said wall portions, said cover plate having at least one slot means extending therethrough, said slot means extending in a direction between said side wall means;

a pair of opposing contacts each of which extends from said housing at said first and second side wall portions respectively and has a free end,

one of said pair of opposing contacts having a first portion extending from said housing at said first side wall portion, an urged portion bent away from and then towards the other opposing contact and a contact portion extending from said urged portion terminating at the free end of said one contact,

said other contact having a first portion extending from said housing at said second side wall portion of said housing, an urged portion bent away from and then towards said one contact and a contact portion extending from said urged portion thereof terminating at the free end thereof;

a slider slidably mounted to said housing for sliding in said direction in which said slot means extends, said slider having a lower portion located in said housing, said lower portion comprising first and second spaced apart and opposed side walls defining a cavity therebetween through which said opposing pair of contacts extend, each of said first and second side walls having a recess open to said cavity,

said slider being slidable between a first position adjacent said first side wall portion of said housing in which said urged portions of said opposing pair of contacts are situated in a respective said recess of each of said side walls of said slider and said pair of opposing contacts do not contact each other to a second position adjacent said second side wall portion of said housing in which said urged portions of said opposing contacts are each engaged by a respective one of said side walls of said slider for urging each of said pair of opposing contacts towards one another such that each contact portion of said pair of opposing contacts makes contact with said first portion of the opposing contact; and

a respective terminal connected at one end thereof to each of said first portions of said opposing contacts.

2. A sliding-type DIP switch as claimed in claim 1 wherein,

said bottom portion comprises a bottom wall having an insulating plate insert molded thereto, said insulating plate located directly beneath said pair of opposing contacts; and

said contacts being integral with said terminals and extending transversely thereto, said contacts each further comprising a finger integrally formed therewith and located between said insulating plate and said bottom wall portion for securing said contacts to said insulating plate and said housing.

Description of the Prior Art

An example of a conventional DIP switch of the above type is described in the specification of Japanese Patent Application Laid-Open No. 57-165926 and is illustrated in the sectional view of FIG. 3 (a). As shown, the DIP switch includes a box-shaped housing 2 insert molded about a set of fixed terminals 1, 1 each formed from a metal member die-punched in advance. When the insert molding operation is performed, a free end of each fixed terminal 1 is held firmly in position in a molding die and is formed into a contact portion 1a by the action of the die. This contact portion 1a is exposed above the floor surface of the housing 2, with the arrangement being such that the contact portions 1a, 1a of the respective fixed contacts 1, 1 oppose each other. A sliding contact 4 held by a slider 3 is slid back and forth between the opposing contact portions 1a, 1a to open and close these contacts, thereby performing a switching action.

Another example of the above-described DIP switch is described in the specification of Japanese Patent Application Laid-Open No. 56-45523 and illustrated in the sectional view of FIG. 3(b). As shown, the DIP switch includes a first base 12 in which a fixed contact terminal 11 is insert molded in advance, a second base 14 disposed on the first base 12 and in which a resilient movable contact terminal 13 having a movable contact 13a is insert molded in advance, and a slider 15 provided with a projecting portion 15a. The movable contact 13a is pressed against and released from the fixed contact terminal 11 by the projecting portion 15a, thereby closing and opening the switch.

The DIP switch having the structure shown in FIG. 3(a) is disadvantageous in terms of contact resistance and stability. Specifically, since the contact portion 1a of fixed terminal 1 is formed by the die for insert molding, it is necessary that a soft material capable of being molded be used as the material constituting the fixed terminal 1. Accordingly, self-actuation of the switch by relying upon its resilience is difficult, so that it is necessary to open and close the switch by a bridging or engaging-disengaging action performed by the separate contactor. Consequently, contact is made at a plurality of locations in series fashion, thus resulting in a large contact resistance. Furthermore, since the contact portion 1a is pressure molded by the molding die, contact instability is caused by the occurrence of scratches on the contact portion or by the adherence of dust or insulating substances such as the molding material to the contact partion. Another problem is the large number of component parts, which makes it difficult to assemble the switch.

In accordance with the illustrated embodiment, a number of the contacts 24 are attached to the insulating plate 27 while being retained by the interconnected frames X, Y. The contacts 24 are then fixed in position by forming the wall and bottom portions of the housing 21 about the insulating plate by means of insert molding. Accordingly, in a case where a number of contact groups are to be assembled at one time, the position at which each contact is disposed can be accurately maintained to make possible the very simple assembly of even miniature DIP switches. In addition, since each switch section of the DIP switch is constituted by a pair of the contacts, contact resistance is reduced in comparison with the prior art of FIG. 3(a), which employs a separate contactor. Furthermore, since the linear portion 24a of one contact 24 touches the contact portion 24b of the other, the two contacts 24 of the pair contact each other at two points in the manner of a parallel connection, thereby reducing contact resistance and enhancing contact reliability over the prior-art arrangement in which contact is obtained at only one point. Moreover, each time a switch section of the DIP switch is actuated, the opposing contacts clean each other to provide more stable contact. Since the DIP switch is sealed tightly by the ultrasonically welded housing 21 and cover plate 26, there is no danger of dust or other contaminants invading the interior of the switch. This assures even greater reliability of operation.

Further, with conventional DIP switches having the structures of the type shown in FIGS. 3(a) and 3(b), there is the danger that gaps will form between the molded housing and the terminal members when there is a sudden rise in temperature when soldered. The gaps result due to a difference in thermal expansion between the terminal members and the molding material constituting the housing. Such gaps would permit the invasion of molten solder or flux, which might then reach the coplanar contact and terminal portions. This would tend to cause contact failure. With the present invention, on the other hand, the contact portions are not flush with the terminal portions but are disposed at a higher level, thus eliminating or greatly reducing the possibility of such contact failure.

Since the DIP switch of the present invention has few component parts and is easy to assemble, mass production is possible at a low cost.