Electrical switch

[0002] The invention relates to an electrical switch. More particularly, the invention provides an electrical switch having a height that is at least half reduced in comparison with that the prior art.

[0003] FIG. 1 is a sectional view illustrating a micro switch of the prior art, usually used in command output of mouse, keyboard, or power supply switch of electrical devices. As illustrated, the traditional micro switch principally comprises an assembly of a base 2band an upper cover 1b. First and second insertion legs 3b, 4bare arranged through the base 2b. First and second positioning portions 31b, 32bare formed on the first insertion leg 3b. A hole 11bis defined through the upper cover 1b. A conductor resilient plate 5bis further mounted over the first and second insertion legs 3b, 4b. The plate 5bincludes a first portion having a mounting part 51bmounted to the first positioning portion 31b, and a second portion provided with a contact pad 52bthat is placed vis-à-vis the second insertion leg 4b. A resilient tongue 53b, integrally formed with the plate 5b, further extends and bends toward the base 2b, the tongue 53bhaving an end portion fastened to the second positioning portion 32b. A push button 6bis mounted over the plate 5band is exposed through the hole 11b. When the user presses the push button 6b, the push button 6bconsequently presses the plate 5b. With the mounting part 51bof the plate 5belectrically connected to the first insertion leg 3b, a pressing on the push button 6bthus causes an electrical contact of the contact pad 52bwith the second insertion leg 4bby deflection of the plate 5b. An electrical switch having small contact deflection is hence traditionally constructed.

[0004] As illustrated in the drawings, mounting spaces have to be necessary left to allow pushing of the push button 6band bending of the resilient tongue 53b. As a result, the height of the traditional switch (without the insertion legs 3b, 4b) is usually 7.3 mm. As electrical equipment become increasingly smaller, a traditional approach to accommodate the above electrical switch is to reduce the thickness of the upper cover 1band the thickness of the base 2b. However, this approach negatively results in weakening the electrical switch, and causes cracks in the upper cover 1bor base 2bduring product transportation or when the user pushes on the electrical switch. As the thickness of the base 2bor/and upper cover 1bis reduced, the switch further is more subject to deformation during injection molding or assembly in its fabrication process. As a result, the yield is negatively reduced.

[0005] Moreover, the above switch suffers another disadvantage. Because the resilient tongue 53bis positioned on the second positioning portion 32bby fitting, if only the plate 5bpresents a defective deviation due to various fabrication deviations, the tongue 53beasily separates from the second positioning portion 32bafter a certain time of utilization. Moreover, because the tongue 53bis proximate to the second insertion leg 4b, the tongue 53bwhen separated thus easily contacts with the second insertion leg 4b, thereby establishing an undesirable electrical contact.

[0006] It is therefore an object of the invention to provide an electrical switch that can overcome the above deficiencies and has a height that is dimensionally reduced a half.

[0007] To accomplish the above and other objectives, the electrical switch of the invention comprises a conductor resilient plate having a resilient tongue that extends and bends toward the upper cover and is placed parallel with the push button on a same side of the conductor resilient plate. Thereby, traditional mounting spaces are not required. Furthermore, even if the resilient tongue inadvertently separates from the second positioning portion, the resilient tongue would upwardly deviate and therefore would not causes an electrical contact with the second insertion leg. A secure control of the command output is thereby achieved.

[0008] In accordance with another aspect of the invention, the base of the electrical switch further includes a reinforcement integrally formed with the base by injection molding. By means of the reinforcement, the thickness of the base and/or the upper cover can be reduced without adversely weakening the electrical switch.

[0009] To provide a further understanding of the invention, the following detailed description illustrates embodiments and examples of the invention, this detailed description being provided only for illustration of the invention.

[0010] The drawings included herein provide a further understanding of the invention. A brief introduction of the drawings is as follows:

[0011] FIG. 1 is a sectional view illustrating an electrical switch of the prior art;

[0012] FIG. 2 is a perspective view of an electrical switch according to an embodiment of the invention;

[0013] FIG. 3 and FIG. 4 are exploded views of an electrical switch according to an embodiment of the invention;

[0014] FIG. 5A is a sectional view taken along the section 5A—5A of FIG. 2;

[0015] FIG. 5B is a sectional view showing the operation of the electrical switch;

[0016] FIG. 6 is a perspective view of an electrical switch according to another embodiment of the invention; and

[0017] FIG. 7 is a sectional view taken along the section 7—7 of FIG. 6.

[0018] Wherever possible in the following description, like reference numerals will refer to like elements and parts unless otherwise illustrated.

[0019] Referring to FIG. 2, FIG. 3, and FIG. 4, various perspective and exploded views illustrate an electrical switch according to an embodiment of the invention. As illustrated, the electrical switch comprises a base 2aand an upper cover 1athat assemble with each other. On sidewalls of the upper cover 1aand base 2aare respectively formed projections 22 and recessed portions 12 that correspondingly engage with one another. The base 2ais integrally formed by injection molding, and includes a reinforcement 21 projecting toward the upper cover 1a. Once the upper cover 1aand the base 2aare fastened to each other via the engagement of the projections 22 and the recessed portions 12, the reinforcement 21 supports and reinforces either the upper cover 1aor the base 2athat may be weakened due to a reduced thickness. First and second insertion legs 3a, 4aare further arranged through the base 2a. First and second positioning portions 31a, 32a, “<” shaped, are integrally formed on the first insertion leg 3a. A hole 11ais further defined through the upper cover 1a, and a conductor resilient plate 5ais mounted over the first and second insertions legs 3a, 4awithin the base 2a. The plate 5ais provided with a mounting part 51athat fits the first positioning portion 31a, and a contact pad 52ais placed vis-à-vis the second insertion leg 4a. Integrally formed with the plate 5a, a resilient tongue 53aextends and bends toward the upper cover 1a. A notch 531 is defined at an end of the tongue 53ato be fastened to the second positioning portion 32a. The plate 5ais further provided with a push button 6athat is externally exposed through the hole 11a, enabling a pressing of the plate 5a.

[0020] By placing the resilient tongue 53aand the push button 6aon a same upper side of the plate 5a, the push button 6abeing placed parallel to the tongue 53a, the height of the electrical switch can be substantially reduced. An electrical switch hence constructed can therefore satisfy the requirements of reduced mount space.

[0021] Referring to FIG. 5A and FIG. 5B, two sectional views illustrate the operation of the electrical switch according to an embodiment of the invention. As illustrated, the mounting part 51aand the notch 531 are respectively positioned and mounted to the first and second positioning portions 31a, 32a(in order to accommodate the tongue 53a, the bending direction of the second positioning portion 32adiffers from that of the prior art). In order to prevent any separating displacement before the upper cover 1ais mounted, an opposite end of the plate Sa extends below the reinforcement 21 of the base 2ato be thereby restrictedly positioned. Once the upper cover 1ais mounted to the base 2a, the user can turn the switch by pressing the push button 6a. The push button 6aconsequently pushes the plate 5athat, via the rotation points respectively formed by the mount of the mounting part 51ato the first positioning portion 31aand the mount of the notch 531 to the second positioning portion 32a, deflects and causes the contact pad 52ato electrically contact with the second insertion leg 4a. The first and second insertion legs 3a, 4aare thereby electrically connected to each other.

[0022] As shown in the drawings, since the tongue 53aand the push button 6aare placed on a same side, the height of the switch can be favorably reduced. For reference, the height of the switch of the invention (without considering the insertion legs 3a, 4a) can be optimally 3.6 mm, which is about a half of the conventional switch height of 7.3 mm. The electrical switch of the invention can therefore satisfy the requirements of dimensional reduction. Furthermore, even if the tongue 53ainadvertently separates from the second positioning portion 32a, a consequent upward deviation of the tongue 53awill be restricted by the reinforcement 21, and inadvertent electrical contact with the second insertion leg 4ais thereby prevented. A secure control of the command output can be therefore achieved.

[0023] It should be apparent to those skilled in the art that the above description is only illustrative of specific embodiments and examples of the invention. For example, FIG. 6 and FIG. 7 are a perspective view and a sectional view that illustrate another variant embodiment of the invention where the first and second insertion legs 3a, 4amay be fabricated by SMT (surface mount technology).