Illuminated Push-Button Electrical Switch

The present invention relates to illuminated push-button electrical switches.

Such switches, for example, have operating members which are formed from a molded plastic material, the end surface of which are tranparent for passing through light from a light source. Thus, in U.S. Pat. No. 3,780,248 or U.S. Pat. No. 3,895,204, a push-button electrical switch unit is described in which the end surface of the operating member is illuminated from the interior of the switch by means of lamp.

Such push-button switches, however, are difficult to distinguish the operative condition of the switch because they indicate donditions by means of different color beams.

It would be disirable to provide illuminated push-button electrical switch units which can indicate the operative condition of the switch by means of letterings illuminated by specific color.

It is therefore an object of the present invention is to provide a new and improved illuminated push-button electrical switch which can indicate the operating condition of the switch not only by letterings, but also by color.

Another object of the invention is to provide new and improved illuminated push-button electrical switch which can indicate two diffirent colored letters by means of a single light source.

Other objects and advantages will appear from the following description in conjunction with the accompanying drawings.

FIG. 1 is an exploded perspective view of an illuminated push-button electrical switch embodying the present invention.

FIGS. 2A, 2B and 2C are sectional side elevations of essential portions for explaining the operation of the embodiment shown in FIG. 1, and

FIG. 3 is a perspective view showing an embodiment of an indicating member.

Referring to FIG. 1, the switch includes a molded synthetic resin casing 1 having a passageway 1a, bearing portions 1b and 1b, and a slot 1c. An operating member 2 is molded from a synthetic resin and slidably mounted within the passageway 1a of the casing 1. The operating member 2 has a hollow part 2a, tongue pieces 2b and 2b, and an operating arm 2c. Two filter members 3 and 4, connected each other perpendicularly by means of connecting portions 3a and 4a, are pivotably mounted on the bearing portion 1b and 1b by means of shafts 3b and 4b. The filter means 3 and 4 are made from transparent material such as acrylic resin, and are provided complementary color, for example, if the filter 3 is colored red or yellow, the filter 4 is colored blue-green or blue respectively. A cap member 5 having a through hole 5a to which a indicating plate 6 to be inserted. The cap member 5 with the indicating plate 6 is adapted to be connected with the operating member 2 by means of projections 2d and recesses 5b. The indicating plate 6 is made from transparent material such as acrylic resin and containing letterings "ON" and "OFF" as shown in FIG. 3. Two letterings are colored comprementary color, for example, "ON" is colored blue-green and "OFF" is colored red, and a remaining area is colored black. A cover member 7 having a hole 7a for mounting a lamp 8 is connected to the rear portion of the casing 1 by means of screws 11. A coiled spring 10 is interposed between the operation arm 2c of the operating member 2 and the inner wall of the casing 1 at the slot 1c. A push-button switch unit 12 is the conventional push-button switch, having a coiled spring 13 and operating rod 12a which is operable as an independent switch.

The illuminated push-button switch of the present invention operates as will now be described. FIG. 2A illustrates the state in which the operating member 2 is not depressed. Since the lamp 8 is lit up at all times and the light of the lamp 8 passes through the red colored filter means 3, only the red beam is reached to the indicating plate 6. At the indicating plate 6, the red beam can not pass through the lettering "ON" because it is colored its complementary color of blue-green while the red beam passes through the lettering "OFF" because it is colored red, and thus the letter "OFF" is illuminated in red as seen by the viewer. When the operating member 2 is depressed in this state, the operating rod 12a of the switch unit 12 is pressed down to the direction of arrow A against the spring pressure of the coiled spring 13 by the operating arm 2c of the operating member 2, and the switch 12 is changed-over. Simultaneously, the filter members 3 and 4 are turned about the pivots 3b and 4b by the movement of the tongue pieces 2b and 2b of the operating member 2. As a result, the filter 3 having been located in the path of the light moves out of the path (refer to FIG. 2c). In this state, the light of the lamp 8 passes through the blue-green colored filter 4. Therefore, only the lettering "ON" is illuminated in blue-green as seen by the viewer. FIG. 2B illustrates the state in which the switch is veing changed-over as described above.