Switch Operating Mechanism

This invention relates to a switch operating mechanism and more particularly an operating mechanism for actuating a switch of the type directly incorporated into a panel or a base plate.

Generally, in such electronic musical instrument as an electronic organ, such various control switches as a power switch, a tone color preset switch, an autorythm switch, a sustain switch or the like are disposed beneath a control panel and ON/OFF-controlled by operating members mounted on the panel.

FIG. 1 illustrates one example of a prior art switch operating mechanism of the type described above. As shown, switch operating members 3 are rotatably mounted with a pivot shaft 4 inserted and received in openings 2 respectively. When the operating members 3 are depressed, touch switches 6, for example, disposed beneath the operating panel 1 are operated through actuators 5. The two ends of the pivot shaft 4 are secured to the rear surface of the operating panel 1 through fittings 7.

In the prior art switch operating mechanism described above, however, as it is necessary to insert the shaft 4 through the shaft openings 8 of the operating members 3 and to secure the fittings 7 to the rear surface of the operating panel 1 with set screws 9, not only the assembling and disassembling operations are troublesome, but also the number of the component parts increases.

Accordingly, it is an object of this invention to provide an improved switch operating mechanism having a simple construction and requiring a small number of component parts.

Another object of this invention is to provide a switch operating mechanism especially suitable for mounting side by side a plurality of switches on a base plate.

A further object of this invention is to provide an improved switch operating mechanism capable of readily and rapidly mounting component parts on the base plate.

According to this invention there is provided a switch operating mechanism of the type wherein at least one switch is mounted on a base plate, the base plate is provided with at least one opening for accommodating an operating member for actuating the switch, and one end of the operating member is pivotally supported, characterized in that there are provided a bearing member projecting from a portion of the rear surface of the base plate near the opening and overlying the same, a pair of supporting members projecting in opposite directions from the operating member, the distance between the outer sides of the supporting members being larger than the width of the opening, an engaging member located near the opening for rotatably engaging said bearing member when the operating member is mounted, and an actuator operated by the operating member for actuating the switch.

In the accompanying drawings:

FIG. 1 is a perspective view, partly in section, showing one example of a prior art switch operating mechanism;

FIG. 2 is a side view, partly in section, showing one embodiment of the switch operating mechanism according to this invention;

FIG. 3 is a perspective bottom view, partly exploded, of the switch operating mechanism shown in FIG. 2;

FIG. 4 is a perspective bottom view showing a modification of the operating mechanism embodying the invention;

FIG. 5 is a side view, partly in section, showing a modified shaft support;

FIG. 6a is a side view, partly in section, showing still another embodiment of this invention;

FIG. 6b is a perspective bottom view showing a state before mounting an operating member on the panel;

FIG. 7 is a plan view showing another modification in which a plurality of operating members are mounted on a single shaft;

FIG. 8 is a perspective view showing a seesaw switch operated by an operating member; and

FIGS. 9a, 9b, 10a and 10b are side views, partly in section, showing still other embodiments of this invention having simplified constructions.

A preferred embodiment of this invention is illustrated in FIGS. 2 and 3 in which a plurality of operating members 13 (only one of them is shown) are freely inserted in rectangular openings 12 provided at prescribed positions of an operating panel or base plate 11 of a switch structure 10 with their upper portions projected upwardly. Each operating member 13 is made of a synthetic resin and its rear end 13a is pivotably supported by a shaft 14, while a stop member 20 is formed on the lower surface of the front end 13b for preventing the operating member 13 from disengaging from the opening 12. Each operating member 13 is shaped as a trough 13c having a rectangular cross-section and a groove extending in the longitudinal direction thereof. A pair of actuators 15 are formed on both side walls of the trough 13c at about the longitudinal center thereof so as to actuate a push button switch 21 to be described hereinafter. At the rear end 13a of the trough shaped operating member 13 is integrally formed a rotary or pivot support 23 comprising a pair of inverted U shaped or semicircular projections 24a and 24b projecting from both side walls. The rotary support 23 is further provided with grooves 25 for receiving the shaft 14.

On the bottom surface 11a of the operating panel 11 and on the center line of the openings 12 for accommodating the operating member 13 is formed a bearing means or a shaft support 26 integrally with the panel 11 near the rear ends of the openings 12. The fore end 26a of the shaft support 26 is spaced from the bottom surface 11a of the panel 11 by a suitable distance G and lies above the rear portion of the opening 12 so as to support an intermediate portion of the shaft 14 on the upper surface of the fore end 26a. Semicircular notches 28a and 28b are provided for the rear surface 11a of the panel 11 on both sides of the rear end of each opening 12 for rotably receiving upper curved portions b or the pair of projections 24a and 24b comprising the rotary support 23.

The operating members 13 are mounted on the shaft 14 from the side of the bottom surface 11a of the operating panel 11. More particularly, as shown in FIG. 3, the shaft 14 is inserted into the gap G between the bottom surface 11a of the panel 11 and the fore end 26a of the shaft support 26 from the lefthand side as viewed in FIG. 3. The gap G is sized such that after the shaft 14 is inserted into the gap, the shaft is clamped between bottom surface 11a and fore end 26a. Then the grooves 25 of the pairs of projections 24a and 24b of the operating members 13 are fitted to the shaft 14 from the bottom surface 11a the operating panel 11. According to another method, after prefitting the shaft 14 into the grooves 25 of the operating member 13, the shaft 14 is inserted into the gaps G. Thereafter the operating members 13 are rotated about the shaft 14 in the counter clockwise direction as viewed in FIG. 2 to cause the fore ends 13b to project above the openings 12. At this time, the upper curved portions b of the projections 24a and 24b would be received in the notches 28a and 28b on both sides of the rear end of each opening 12 so as to support the shaft 14 at three points by the pair of grooves 25 and the fore end 26a of the shaft support 26. Then, the rear end 13a of each operating member 13 is prevented from moving in the left and right direction and fore and aft directions (in the directions of A and C shown in FIG. 3) by the engagement of the projections 24a and 24b with the notches 28a and 28b, whereas in the vertical direction by the shaft 14, thereby preventing the rear end 13a of each operating member 13 from disengaging the opening 12. Disengagement of the fore end 13b of each operating member 13 from the opening 12 is prevented by a stop member 20.

A switch mounting member 30 is secured to the base plate 11 with a suitable supporting member 30a at a suitable distance from the bottom surface 11a of the operating panel 11, and well known push button switches 21 are mounted on the upper surface of a switch mounting member 30 to confront respective actuators 15 of the operating members 13. Each push button switch 21 comprises a switch 21A, an actuating rod 21B free to move in the vertical direction, and a return spring 21C normally pusing the actuating rod upward towards the actuator.

When the operating member 13 is depressed by an operator, the actuator 15 moves downwardly so that the actuating rod 21B would be locked in the depressed state to close the switch 21A. Thereafter, when the operating member 13 is depressed again, the actuating rod 21B is released and returned to the original position by the return spring 21C thus opening the switch 21A.

As above described, according to this invention, a rotary support 23 constituted by a pair of U shaped projections forming grooves 25 which face downward are integrally provided on both sides of the lower surface of an operating member 13. A shaft 14 secured to the rear surface 11a of an operating panel 11 is fitted into the grooves 25 so that it is possible to mount the operating member 13 with a single operation, thus simplifying the assembling operation. Moreover, as portions of the rotary supports 23 are projected in the lateral direction of the operating member 13, and the projected portions 23 are fitted in the notches or recesses 28a, 28b provided for the operating panel 11, it is possible to prevent disengaging and the lateral movement of the operating member 13, thus enabling stable operation of the switch 21. Further, shaft supports 26 are integrally provided for the rear surface 11a of the operating panel 11 with their fore ends 26a overlapped with the openings 12 for accommodating the operating members 13 to hold the shaft 14 between the fore ends 26a and the rear surface 11a of the panel 11 so that it is possible to readily mount the shaft 14 on the operating panel 11.

Although in the above described embodiment, the shaft 14 is supported at three points by the pair of grooves 25 and the fore end 26a of the shaft support 26 so as to maintain a suitable distance H (see FIG. 2) with respect to the rear surface 11a of the operating panel 11, the shaft 14 may be supported at three points with the fore end 26a of the shaft support 26 and a pair of projections 29a and 29b integrally formed on the rear surface 11a of the operating panel 11 as shown in FIG. 4. In this case, the shaft 14 is pushed into the gap G defined between the rear surface 11a of the operating panel 11 and the fore end 26a of the shaft support 26 by slightly elastically deforming these elements for mounting the shaft 14 on the operating panel 11 with the central portion of the shaft 14 supported by the fore end 26a and with the both ends abutted against the lower surfaces of the shaft holding projections 29a and 29b. In this embodiment, the upper curved portions b at the upper portions of a pair of projections 24a and 24b of each operating member 13 are received in the notches 28a and 28b in the same manner as in the previous embodiment.

As shown in FIG. 5, where the width of the gap G is decreased by the height of the projections 29a and 29b so as to elevate the fore end 26a it is possible to directly support the both ends of the shaft 14 with the bottom surface 11a of the operating panel 11 without using the projections 29a and 29b shown in FIG. 4.

Thus, with the switch operating mechanism embodying the invention, it is possible to readily mount the shaft 14 on the panel 11 independently of the operating members 13 instead of establishing an opening in the operating member, passing the shaft through the opening or removing a fixture for the shaft. This not only reduces the number of assembly steps and the component parts but also facilitates disassembling at the time of inspection and repair. Moreover, as the operating members 13 are prevented from disengaging and moving laterally, it is possible to stably depress the operating members, in other words, the switches can be operated positively. Moreover, as it is possible to make uniform the gap width between each operating member 13 and an opening 12 for accommodating the same, the appearance of the panel surface can be improved. Moreover, as the shaft 14 is secured by a pair of grooves 25 formed by the rotary supports 23. The shaft 14 is further secured by the fore end 26a of the shaft 26.

FIGS. 6a and 6b show still another modification which is different from the foregoing embodiments in that the fore end 26a of the shaft support 26 is provided with a bearing 27 in the form of a circular arc or a U shaped groove. Other parts are identical to those of the foregoing embodiments so that they are designated by the same reference charactors to omit their description. With this modified embodiment, since the shaft 14 is fitted into the bearing 27, the fore and aft movement (in the direction of arrow C shown in FIG. 6a) is prevented, shaft 14 can be maintained in position. This construction can eliminate the notches 28a and 28b on the rear surface 11a of the operating panel 11 thus simplifying the construction. Thus, the movement of the rear end 13a of the operating member 13 in the vertical direction (that is in the direction shown by an arrow B in FIG. 6a) is limited by the engagement of the upper curved portions b of a pair of projections 24a and 24b against the rear surface 11a of the operating panel 11, while the movement of the operating member 13 in the left and right direction (in the direction shown by an arrow A in FIG. 6b) is prevented by the engagement of the side walls 13d and 13e of the operating member 13 against the side walls of the opening 12, thus preventing the rear end 13a of the operating member 13 from disengaging from the opening 12.

Although the foregoing embodiments have been described mainly with reference to a single operating member, as shown in FIG. 7, a plurality of operating members 13A, 13B, 13C . . . may be supported by a single shaft 14. In this case too, shaft supports 26 as shown in FIG. 2 are provided for the operating panel 11 respectively corresponding to the openings 12a, 12b and 12c for accommodating the operating members 13. Other component elements, and the method of mounting the shaft 14, and the operating members 13A, 13B, 13C . . . are identical to those described above.

Although the foregoing embodiments were described with reference to operating members for ON/OFF-controlling push button switches 21, it should be understood that the invention is not limited to this particular construction. For example, as shown in FIG. 8, an operating element may be used to actuate a two contact driving type seesaw switch. In this case, rotary supports 23 are formed at about the center of both sides of the lower surface of the operating member 40, and a pair of actuators 15 are provided near the both ends of the lower surface of the operating member 40. Substantially T shaped shaft supports 41 are integrally formed with the rear surface 11a of the operating panel 11 to cross substantially the central portions of respective openings 12. On the upper surface of one leg 41a extending in the longitudinal direction of the opening 12 is formed a groove shaped bearing 27 adapted to fit with the shaft 14. Where a plurality of operating members 40 are mounted on a single shaft 14 as in this embodiment, the shaft supports 41 are provided for only the openings on the two ends to support the two ends of the shaft 14, while the central portion of the shaft 14 may be supported by the bottom surface 11a of the operating panel 11.

Of course, various embodiments described above may be combined suitably. For example, in the foregoing embodiments, although the operating member is supported by a shaft 14, such shaft may be omitted where the mounting structure is constructed as shown in FIGS. 9a and 9b, 10a and 10b.

For example, in the construction shown in FIG. 9a and 9b, like the preceding embodiments, a pair of opposed projections 24a and 24b (only 24a is shown) are provided for both side surfaces of an operating element 13. It is to be noted that, different from the proceding embodiments, these projections are not provided with grooves for bearing but provided with curved portions b on their upper surfaces. In the same manner as the embodiment shown in FIGS. 2 and 3, these curved portions b are received in recesses 18a and 18b of base plate 11 provided for the outer edges of the opening 12. Further, according to this embodiment, a projection 50 is provided within the trough 13c of the operating member 13 adjacent to the rear end 13b thereof. The outer end of the projection 50 projects from the side wall or the bottom surface of the operating member 13 to pivotally engage the inner wall of the fore end 26a of a supporting member 26 projecting from the rear surface of the panel 11 to overlie an opening 12. The recesses 18a and 18b (only 18a is shown) of the base plate 11 are shaped such that the rear end 13b of the operating member 13 can be inserted while sliding between the front end 26a of the support 26 and the bottom surface of the base plate 11.

This construction can eliminate the shaft 14 thus decreasing the number of the component parts and moreover as the projection 50 can be integrally formed with the operating member, the number of manufacturing steps can be reduced.

FIGS. 10a and 10b show simplified constructions of FIG. 9 in which the function of the projection shown in FIG. 9 is provided by the rear wall of the rear end 13b of an operating member 13 and a pair of projections 24a and 24b (only 24a is shown) are provided to oppose each other with the rear wall interposed therebetween. These projections 24a and 24b are adapted to engage the recesses 18a and 18b (only 18a is shown) provided for on the base plate 11. The modified operating members shown in FIG. 10 can be formed with much simpler mold. Of course, in the embodiments shown in FIGS. 9 and 10, the recesses 18a and 18b of base plate 11 may be omitted or these recesses 28a and 28b may be formed on the projection of the shaft support 26 in the same manner as in FIG. 6.