Push switch device

#1. Field of the Invention

#The present invention relates to a push switch device for switching contact elements by pushing an actuation body projecting from a housing. More particularly, the present invention relates to a push switch device for actuating a contact element switching mechanism by rotating an actuating member spline coupled with a cam follower by converting the movement of an actuation body in an axial direction into the rotation of the cam follower through a latchet mechanism.

#2. Description of the Related Art

#FIG. 1 is a front elevational view showing a push switch device according to an embodiment of the present invention;

#FIG. 2 is a sectional view showing a non-actuated state of the push switch device;

#FIG. 3 is a sectional view showing a pushed-state of the push switch device;

#Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a front elevational view showing a push switch device according to an embodiment of the present invention; FIG. 2 is a sectional view showing a non-actuated state of the push switch device; FIG. 3 is a sectional view showing a pushed-state of the push switch device; FIG. 4 is an exploded perspective view of the push switch device; FIG. 5 is a plan view of a case provided with the switch device; FIG. 6 is a bottom view of the case; FIG. 7 is a sectional view of the push switch device taken along the line VII—VII of FIG. 5; FIG. 8 is a view of a guide portion formed to the case and explains the guide portion by developing it; FIG. 9 is a front elevational view of an actuation body of the push switch device; FIG. 10 is a bottom view of the actuation body; FIG. 11 is a view of a first latchet tooth formed to the actuation body and explains the latchet tooth by developing it; FIG. 12 is a plan view of a cam follower provided with the push switch device; FIG. 13 is a front elevational view of the cam follower; FIG. 14 is a bottom view of the cam follower; FIG. 15 is a view of a second latchet tooth formed to the cam follower and explains the latchet tooth by developing it; FIG. 16 is a plan view of a movable contact element provided with the push switch device; FIG. 17 is a plan view of a wafer provided with the push switch device; FIG. 18 is a front elevational view of the wafer; FIG. 19 is a side elevational view of the wafer; FIG. 20 is a bottom view of the wafer; FIG. 21 is a sectional view of the wafer taken along the line XXI—XXI of FIG. 17; FIGS. 22A to 22G are views explaining the changes of phase of the first latchet tooth and the second latchet tooth; FIGS. 23A to 23E are views explaining the contacting/departing states of the movable contact element to respective stationary contact elements; FIG. 24 is a perspective view showing the state that three external terminals are connected to the push switch device; FIG. 25 is a view explaining the connecting state of the three external terminals to connector terminal groups; FIG. 26 is a perspective view showing the state that four external terminals are connected to the push switch device; FIG. 27 is a view explaining the connecting state of the four external terminals to connector terminal groups; FIG. 28 is a sectional view showing the connecting state of an external terminal to a first connector terminal; FIG. 29 is a sectional view showing a connecting state of the external terminal to the second connector terminal; and FIGS. 30A and 30B are plan views showing modifications of the wafer.

#As shown in FIGS. 1 to 4, the push switch device 1 according to the embodiment includes a case 2 having a hollow internal structure, an actuation body 3 that can rises and falls in the up/down direction of the case 2, a cam follower 4 that can be moved in a rotational direction and the up/down direction by the rising/falling movement of the actuation body 3, a first coil spring 5 interposed between the actuation body 3 and the cam follower 4 and acting as an elastic member, an actuating member 6 that is spline coupled with the cam follower 4 and can be rotated integrally with it, a second coil spring 7 interposed between the cam follower 4 and the actuating member 6 and acting as a return spring, a wafer 8 rotatably supporting the actuating member 6, and a cover 9 for closing the lower opening end of the case 2, and a housing 10 is composed of the case 2 and the cover 9.

#The case 2 is molded of a synthetic resin material such as polybuthylene telephthalate (PBT) and the like and has a rectangular base 2a with its lower surface opened and a cylindrical portion 2b standing from the upper surface of the base 2a as shown in FIGS. 5 to 8. Four bosses 2c suspend downward from the inside of the base 2a, and a circular hole 2d is formed at the center on the upper surface of the cylindrical portion 2b. Four guide projections 11, which extend in an axial direction, are formed on the inner circumferential surface of the cylindrical portion 2b at equal intervals, and guide grooves 12 are formed between the respective guide projections 11. The guide projections 11 and the guide grooves 12 act as a guide portion for guiding the actuation body 3 in the up/down direction, and tapers 11a are formed the guide projections 11 at the lower end thereof.