The invention relates to a switch device which includes a cam groove and a lock pin, and has the function of holding an operating member in two positions.
A so-called push lock-type switch device has the following construction. A cam groove, having, for example, a heart-shape, is formed in one of a device body and an operating member movably mounted on the device body, while a lock pin is provided at the other, and the lock pin slides in the cam groove in accordance with the movement of the operating member so as to hold the operating member in two positions (an original position and a pushed-in position). A holding spring for urging the lock pin toward the cam groove is provided together with this lock pin.
FIG. 6 shows the portion of the operating member of the above conventional construction including the lock pin and the holding spring. The operating member 51 is mounted on the device body (not shown) for reciprocal movement in directions of arrow Q. A proximal end portion 52a of the lock pin 52 is fitted in a fitting hole 51a formed in the operating member 51. A distal end portion 52b of the lock pin 52 is held in sliding contact with the cam groove (not shown). The holding spring 53 has a linear shape, and has opposite end portions fitted respectively in fitting grooves 51b and 51b. The holding spring 53 serves to urge the lock pin 52 toward the cam groove.
In this construction, when mounting the operating member 51 on the device body (not shown), there is a fear that the lock pin 52 drops, and the assembling operation must be carried out while taking care not to allow the lock pin to drop. And besides, since this switch device itself is small, there has been encountered a disadvantage that the efficiency of the assembling operation is low.
This invention has been made under the above circumstances, and an object of the invention is to provide a switch device in which a device body and an operating member can be assembled together while preventing the dropping of a lock pin, and besides the lock pin can be moved in a predetermined manner after the assemblage.
In order to solve the aforesaid object, the invention is characterized by having the following arrangement.
(1) A switch device comprising:
a device body;
an operating member, for operating a switch portion by movement thereof, reciprocally movably mounted on the device body;
a cam groove portion formed in one of the device body and the operating member;
a lock pin which includes a proximal end portion mounted on the other of the device body and the operating member, and a distal end portion which can slide in the cam groove portion so as to releasably hold the operating member in two positions;
a holding spring for urging the lock pin toward a bottom surface of the cam groove portion, mounted on the other of the device body and the operating member with its opposite end portions fitted therein;
a pin engagement portion, for engaging the lock pin to prevent the dropping of the lock pin in a condition before the operating member is mounted, formed on the other of the device body and the operating member; and
an engagement cancellation portion, for disengaging the lock pin from the pin engagement portion in a mounted condition of the operating member, formed on the one of the device body and the operating member.
(2) The switch device according to (1), wherein a holding spring engagement portion for preventing the dropping of the holding spring in the condition before mounting the operating member is formed on the other of the device body and the operating member.
(3) The switch device according to (1), wherein
the lock pin is adapted to rotate about the proximal end portion,
the distal end portion of the lock pin is moved within a movement range of the cam groove when the operating member performs the switching operation, and
the pin engagement portion is provided outside the movement range.
(4) The switch device according to (1), wherein
an engagement cancellation portion for disengaging the lock pin from the pin engagement portion is formed on the one of the device body and the operating member.
(5) The switch device according to (4), wherein
when the operating member is assembled to the device body, the engagement cancellation portion disengages the lock pin from the pin engagement portion and move the lock pin to the movement range.