Abstract:
Disclosed is a two-motion push-button switch which comprises first and second switch portions, each switch portion including a movable contact piece 4 or 6 formed of an elastic thin metal plate and having a reversing portion provided with a movable contact portion and arms formed to grip the reversing portion therebetween and fixed contact portions 2a,3a or 8a,9a formed in a case 1 or 7 at the position confronting said movable contact portion, and one slider 5 slidably arranged in the case, wherein the movable contact pieces are reversed by said slider to drive said two switch portions so that the reversing force of the moving contact piece of the first switch portion is made different from that of the movable contact piece of the second switch portion.

Description:
BACKGROUND OF THE INVENTION 
     (1) Field of the Invention 
     The present invention relates to a push-button switch. More specifically, the present invention relates to a push-button switch of the momentary motion type in which the thickness of the switch is reduced, a light switching touch is obtained and two-motion changeover operation is possible. 
     (2) Description of the Prior Art 
     A two-motion push-button switch is used for various purposes. For example, it is used in a tape recorder or the like to perform the switching operation of the running speed of the tape to move the tape at an ordinary speed or a higher speed, and in adjusting the indicating hands of an electric clock, the two-motion push-button switch is used for performing the switching operation of the rotation speed and turning the hands at a higher speed. Furthermore, the two-motion push-button switch is combined with an electric circuit and is used as a pulse-generating switch. 
     Various push-button switches of this type differing in structure have heretofore been proposed. However, these switches typically have a complicated structure and are often large in their dimensions. In the field of electronic appliances such as radio sets and television sets, diversification of the functions, reduction of the size and enhancement of the quality and capacity have been desired, and development of a push-button switch of this type which is reduced in the size and can be operated by a small driving force with a good operation touch is desired. 
     SUMMARY OF THE INVENTION 
     The present invention is to provide a two-motion push-button switch meeting the above requirement. More specifically, in accordance with the present invention, there is provided a two-motion push-button switch of a simple structure in which movable contact pieces formed by a thin, electrically conductive metal plate high in resiliency are arranged in parallel to construct reversing spring contact pieces exerting a pressing action in the direction parallel to the planes thereof, a light switching operation touch is given by the reversing motion of the reversing spring contact pieces, and the pressing force of one reversing spring contact is made different from that of the other movable contact piece so that changeover is possible between two motions. 
     The present invention will now be described in detail with reference to the accompanying drawings illustrating one embodiment of the present invention. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a fragmentary perspective view illustrating one embodiment of the two-motion push-button switch according to the present invention. 
     FIG. 2 is a sectional side view of the push-button switch shown in FIG. 1. 
     FIGS. 3-(a) to 3-(c) are sectional side views illustrating the operations of the push-button switch shown in FIG. 1. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to the drawings in which FIG. 1 is a fragmentary perspective view showing the structure of the push-button switch of the present invention, FIG. 2 is a sectional view of the push-button switch of the present invention and FIG. 3 is a diagram illustrating the operations of the push-button switch of the present invention, a first case 1 is molded from a synthetic resin and comprises an open concave portion 1a, an opening 1b formed in the upper side wall shown in FIG. 1 and a side wall 1c confronting said opening 1b and projecting outward at a right angle from a bottom 1e. Grooves 1d and 1d&#39; having a V-shaped section are formed on the side wall 1c, and poles 1f are formed at the four corners of the side walls for attachment of a second case described hereinafter. In the bottom of the concave portion 1a are fixed contact pieces 2 and 3 providing fixed contacts 2a and 3a&#39; and external connection terminals 2b and 3b connected to the fixed contacts extend from the surface of the bottom 1e of the case 1. Incidentally, the fixed contact pieces 2 and 3 are fixed to the case simultaneously with the molding of the case by arranging the contact pieces in a mold and insert-molding a synthetic resin in the mold. A movable contact piece 4 forming a movable contact of a first switch portion is integrally formed from a thin, electrically conductive metal plate high in resiliency, and the movable contact piece 4 comprises a pair of arms 4a and 4a&#39; formed on respective ends of the contact pieces and a bent portion 4b held between the arms 4a and 4a&#39;. A part of the bent portion 4b is punched to comprise a movable contact portion 4d divided with a plurality of segments and having tongue pieces 4c formed by bending the contact portion 4d in the direction B in the drawings, and also comprises connecting portions 4e. When a force is applied to the arms 4a and 4a&#39; in the direction indicated by arrow A, the bent portion 4b is projected in the direction B perpendicular to the direction A. In order to promote this projecting action, the arms 4a and 4a&#39; are slightly folded with a certain angle on the bases thereof. A slider 5 comprises a pushbutton portion 5a, notches 5b to be engaged with the projections 1g formed on the case 1 and jaw portions 5c and 5c&#39; formed on respective faces of the lower end of the push-button portion 5a. The length lc of the notches 5b is larger than the length lp of the projections 1g, so that the slider 5 moves in an out along a length (lc-lp) within the concave portion 1a of the case 1. A movable contact piece 6 constituting a movable contact of a second switch portion is integrally formed from a thin, electrically conductive metal plate high in resiliency. The movable contact piece 6 comprises arms 6a and 6a&#39; formed on respective ends of the movable contact piece 6 and a reversing portion 6b held between both the arms 6a and 6a&#39;. A part of the reversing portion 6b is punched and the reversing portion 6b comprises a movable contact portion 6d divided in a plurality of segments and having tongue pieces 6c formed by bending the contact portion 6d in the direction C in the drawings and also comprises connecting portions 6e. When a force is given by the arms 6a and 6a&#39; in the direction indicated by arrow A, the reversing portion 6b is reversed and projected in the direction C. In order to promote this reversing action, the arms 6a and 6a&#39; are slightly folded with a certain angle on the bases thereof. A second case 7 constituting a switch case in combination with the above-mentioned first case 1, which has a substantially channel shape, comprises a concave portion 7a, projections 7b and holes 7c corresponding to the concave portion 1a, projections 1g and poles 1f of the first case 1. Fixed contact portions 8a and 9a are exposed to a bottom 7d of the concave portion 7a and as in the first case 1, fixed contact pieces 8 and 9 having external connection terminals 8b and 9b are integrally formed by insert-molding. 
     Assembling of the push-button switch of the present invention will now be described. One arm 4a of the movable contact piece 4 forming the first switch portion is engaged with and fitted in the groove 1d formed on the side wall 1c of the first case 1. Then, the slider 5 is arranged in the opening 1b of the concave portion 1a of the case 1, and the other arm 4a&#39; is engaged with the jaw portion 5c of the slider 5. One arm 6a of the movable contact piece 6 forming the second switch portion is engaged with and fitted in the other jaw portion 5c&#39; of the slider. In this state, the slider 5 is slightly pushed in the direction pressing the movable contact pieces 4 and 6 to engage the notches 5b with the projections 1g of the case 1. The slider 5 is always urged upwardly by the spring forces of the movable contacts 4 and 6, and the central part of the mountain-shaped movable contact portion 4d of the movable contact piece 4 is brought into close contact with the surface 5d of the slider 5 and the slider 5 is pressed to the bottom surface 1e of the case 1 by the spring force of the movable contact piece 4. Accordingly, in this state, the respective elements are not disassembled fragmentarily. Then, the poles 1f of the case 1 are inserted into the holes 7c of the second case 7, and the case 7 is placed on the top face of the case 1, and both the cases are bonded and fixed by an adhesive or the like to complete assembling of the push-button switch of the present device, see FIG. 2. 
     The operations of the push-button switch of the present invention will now be described with reference to FIGS. 2 and 3. 
     In the state where the push-button portion 5a is not depressed as shown in FIGS. 2 and 3(a) since the movable contact pieces 4 and 6 are engaged with the grooves 1d and 1d&#39; of the case 1 and the jaw portions 5c and 5c&#39; of the slider 5, the slider 5 is urged upward (in the direction indicated by arrow D), the contact portions 4d and 6d of the movable contact pieces 4 and 6 of the first and second switch portions are kept in the non-contact state with the confronting fixed contact portions 2a, 3a and 8a, 9a. 
     When the push-button portion 5a is depressed in this state in the direction opposite to the direction of arrow D, that is, in the direction of arrow A, since the arms 4a and 4a&#39; of the movable contact piece of the first switch portion are slightly folded with a certain angle on the bases thereof to promote bending and the reversing force of the movable contact piece 4 is smaller than that of the movable contact piece 6, the movable contact piece 4 is bent in the direction of arrow B and also the movable contact piece 6 of the second switch portion is bent in the direction of arrow C, see FIG. 3(b). When the push-button portion 5a is further depressed, bending of the movable contact piece 4 is increased, and the connecting portions 4e and movable contact portion 4d are reversed in a moment in the direction of arrow B. The respective tongue pieces 4c of the movable contact portion 4d are pressed by the repulsive force of the fixed contact portions 2a and 3a to produce the switch-on state, see FIG. 3(b). 
     When the push-button portion 5a is further depressed in this state, as shown in FIG. 3(c), also the movable contact piece 6 is reversed and the movable contact portion 4d is projected in the direction of arrow C, and while the tongue pieces 4c and 6c of the movable contact portions 4d and 6d are pressed to the fixed contact portions 2a, 3a and 8a, 9a, the slider 5 is caused to slide with deformation until the resiliency of the tongue pieces 4c and 6c are restricted. The moving region of the slider can be adjusted by appropriately changing the length lc of the notches 5b and the length lp of the projections 1g. When the pressing force is released in the state where the push-button portion 5a is pressed to the last extremity, the state shown in FIG. 3(a) is restored to produce the switch-off state. 
     According to the present invention, the first switch portion and second switch portions are arranged in parallel, the respective contact pieces are integrally molded from a thin, electrically conductive metal plate high in resiliency to form two movable contact pieces of bent springs differing in the reversing force and the switching operation is accomplished by the contact pieces of said reversing springs. Accordingly, the switching operation can be performed by a small depressing force with a very light switching touch. Furthermore, if there is provided a time difference between the reversing operations of the two reversing springs, two-motion changeover becomes possible. Therefore, the present invention provides a push-button switch of a simple structure which can be utilized in various fields.