BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an exploded perspective view of a sealed pushbutton switch in accordance with the present invention;
FIG. 2 is a perspective view of an actuator as shown in FIG. 1;
FIG. 3 is a perspective view of a movable contact as shown in FIG. 1;
FIG. 4 is a perspective view of a base as shown in FIG. 1;
FIG. 5 is an assembled perspective view of the sealed pushbutton switch as shown in FIG. 1, with the base and the fixed contacts being removed; and
FIG. 6 is an assembled perspective view of the sealed pushbutton switch as shown in FIG. 1.
DETAILED DESCRIPTION OF THE INVENTION
Reference will now be made to the drawing figures to describe the present invention in detail. Referring to FIG. 1, a sealed push button switch 1 in accordance with the preferred embodiment of the present invention comprises an insulative housing 2 defining a cavity 25, an actuator 3 retained in the cavity 25 of the insulative housing 2, a movable contact 6, a seal 4, a coil compression spring 5 bearing against the actuator 3, a base 8 attached to the insulative housing 2, and a pair of fixed contacts 7 mounted on the base 8.
Referring to FIG. 1, the insulative housing 2 is a substantially rectangular case, comprising a front wall 23, a top wall 21, a bottom wall 24 opposite to the top wall 21, a pair of side walls 22 extending rearwardly from the front wall 23 to thereby define the cavity 25 therebetween. The top wall 21 has a circular through hole 26 defined in a central portion thereof. Each side wall 22 has a recess 221 defined in an inner surface thereof. A pair of protrusions 241 are symmetrically formed on the bottom wall 24, each with a free end thereof extending upwardly.
Referring to FIG. 2, the operator 3 comprises a body portion 32 and a button 31 extending upwardly from a top of the body portion 32. The button 31 includes a columnar portion 311, and a guiding portion 312 having a conical shape for facilitating insertion into the through hole 26 during assembly. The button 31 defines therearound an annular groove 313, which is positioned adjacent to the body portion 32. The body portion 32 is provided with a rectangular primary wall 320, a pair of periphery walls 321 perpendicular to opposite sides of the primary wall 320, and a columnar post 33 extending downwardly from the primary wall 320 for engaging the spring 5. A nose portion 322 configured as a flat plane projects rearwardly from a center of an upper portion of the primary wall 320, and is flush with a top surface of the primary wall 320 for upholding the button 31. A slot 324 is defined at a bottom of the nose portion 322 in a longitudinal direction. A tongue portion 323 extends horizontally below the nose portion 322.
Referring to FIG. 3, the movable contact 6 is formed by bending a punched metal plate, comprising a retention portion 61 and a pair of elastic beams 62. The retention portion 61 has a primary plate 612, an insertion plate 611 extending parallel to the primary plate 612 and positioned a certain distance above the primary plate 612. The insertion plate 611 has a pair of click projections 6110 formed at opposite edges thereof. A connection plate 613 extends in another direction perpendicular to the extending direction of the primary plate 612 for connecting the insertion plate 611 and primary plate 612 together. The pair of elastic beams 62 extend symmetrically horizontally firstly from a center of opposite sides of the primary plate 612 and then outspread obliquely downwardly. A contact portion 621 having a semi-circular curved surface is formed on a free end of each elastic beam 62.
Referring to FIG. 1, each fixed contact 7 comprises a body portion 71, a pair of soldering portions 74, and a pair of connection portions 72 connecting the corresponding soldering portions 74 to the body portion 71. The body portion 71 is configured as a lying “L”, with one end thereof protruding laterally therefrom to form an engaging portion 711. The body portion 71 has an indentation 73 defined beside the engaging portion 711.
Referring to FIG. 4, in conjunction with FIG. 1, the base 8 is substantially flat, comprising an inner face 81, an outer face 82 opposite to the inner face 81, four side faces 83 and a pair of tubers 831 formed at two opposite side faces 83 thereof. The inner face 81 has a plurality of slots 811 interconnected as a substantial “C” shape and each defined along a side edge thereof. The inner face 81 has a pair of retaining channels 841 symmetrically defined therein. The outer face 82 defines therein two pairs of insertion channels 142 respectively communicating with corresponding retaining channel 841 for extension of the soldering portions 74 of the fixed contacts 7.
Referring to FIGS. 5-6, in conjunction with FIG. 1, in assembly of the sealed pushbutton switch 1, the movable contact 6 is fastened to the body portion 32 of the actuator 3 firstly. The retention portion 61 of the movable contact 6 is confined between the nose portion 322 and the tongue portion 323 of the actuator 3, with the insertion plate 611 thereof being inserted into the slot 324 and the click projections 6110 thereof frictionally engaging with the slot 324. The pair of elastic beams 62 are positioned between the pair of periphery walls 321. The spring 5 is assembled to the actuator 3 by encircling around the post 33. Secondly, the actuator 3 together with the movable contact 6 and the spring 5 is received in the cavity 25 of the insulative housing 2, with the button 31 extending outside the top wall 21 through the through hole 26. The seal 4 is then inserted into the annular groove 313 for preventing leaks between the actuator 3 and the insulative housing 2.
Thirdly, the pair of fixed contacts 7 are assembled to the base 8. The body portions 71 of the fixed contacts 7 are respectively partially retained in corresponding retaining channels 841, with engaging portions 711 thereof being exposed on the inner face 11, the connection portions 72 thereof inserted into the corresponding insertion channels 142, and the soldering portions 74 thereof extending outwardly through the insertion channels 142. Finally, the base 8 together with the fixed contacts 7 is attached to a rear portion of the insulative housing 2, with the inner face 81 exposed in the cavity 25. The side faces 83 of the base 8 are conglutinated to the walls 21, 22, 24 of the insulative housing 2 by glue or epoxy. Glues through any gaps (not shown) between the side faces 83 of the base 8 and side edges of the walls 21, 22, 24 of the insulative housing 2 is then confined in the slots 811 of the base 8 and therefore would not creep into other portions of the assembled sealed detect switch 1.
Referring to FIGS. 5 and 7, in a normal position, the spring 5 is located between the actuator 3 and the bottom wall 24 of the insulative housing 2, with a lower portion thereof fixed between the pair of protrusions 241. The pair of elastic beams 62 of the movable contact 6 are positioned between the fixed contacts 7, with the contact portions 621 thereof respectively contacting with the corresponding engaging portions 711. An electrical connection between the fixed contacts 7 is established, via an engagement between the contact portions 621 and the engaging portions 711 of the fixed contacts 7. The sealed pushbutton switch 1 is in the closed position.
In operation, when the button 31 of the actuator 3 is downwardly pushed by exerting an external force, the movable contact 6 is driven to move downwardly together with the actuator 3 to thereby move the contact portions 621 away from the engaging portions 711 and into the indentations 73. The sealed pushbutton switch 1 is caused to be in an electrically opened position, when the electrical connection between the engaging portions 711 of the fixed contacts 7 is broken. At the same time, the spring 5 is compressed. When the external force is removed, the pushbutton switch 1 restores itself to a normally closed position, due to an elastic force provided by the compressed spring 5.
Naturally, the slots 811 could be defined at the side faces 83 of the base 8, or be defined on side edges of the walls 21, 22, 24 of the insulative housing 2, if only be defined near the gaps for containing the glue.
However, the disclosure is illustrative only, changes may be made in detail, especially in matter of shape, size, and arrangement of parts within the principles of the invention.
Patent Application
20070261945
