PUSH-BUTTON SWITCH

Abstract: A push-button switch including a switch base which is formed into two divisions each for mounting a switch mechanism thereon, the terminals of one circuit provided within the switch mechanism being molded in insertion in the respective division switch base, whereby the switch base is made smaller in size and simplified in assembly of the push-button switch.

Description: The present invention relates to such a push-button switch as is used in various types of electric appliances such as audio appliances or the like and more particularly, to a push-button switch, which is capable of the operation characteristics of a stable switch and is rendered smaller in size. Generally, this type of push-button switch turns on and off the switch mechanism through an operation plunger which operatively cooperates with the depressing operation of the switch. However, when the switch has been depressed, it is depressed with the operation plunger being inclined, so that the operation plunger comes into local contact against, for example, the housing which slides and guides the operation plunger, thus increasing the frictional force during the depression or causing hooking phenomenon to deteriorate the operation feeling of the switch. In addition, abrasion powder which are caused by the local contact operation are mixed into the switch mechanism to deteriorate the operation characteristics of the switch. Thus, under the existing conditions, the guide members with respect to the operation plunger increase in number or the guide member is set longer to control the inclination of the operation plunger. As the accommodation space of the housing has these guide members, the entire switches are rendered larger in size. Also, this type of push button switch is adapted to turn on and off the switch mechanism through the operation plunger which operatively cooperates with the depressing operation of the switch, but restoring springs are normally provided oppositely in the depressing direction with respect to the operation plunger to restore the operation plunger in its original position. As the terminals of such light emitting elements as turns on and off in accordance with the on and off actions of the switch mechanism were located in the vicinity position of the restoring springs built-in within the housing, the light-emitting element holders which served as electric insulating members were normally disposed considering the electric insulation property between the terminal and the restoring spring. As the light emitting element holders were arranged in construction considering the insulating property, the switches became longer in the axial length and larger in size. Also, as the restoring spring was formed in a ring shape corresponding to the inner diameter of the housing and was built-in, larger accommodating space only for the restoring spring use was required within the housing, so that the switches could not be rendered smaller in size. A push-button switch according to the preamble of claim 1 is known from FR-A-2 435 116. The invention is defined by the characterising features of claim 1. The objects and features of the present invention will become apparent from the following description taken in conjunction with the preferred embodiments thereof with reference to the accompanying drawings, in which: Fig. 1 is an exploded perspective view of an illumination push-button switch in accordance with one embodiment of the present invention; Fig. 2 is a longitudinal sectional side view of the illumination push-button switch; Fig. 3 is a longitudinal sectional front-face view of the illumination push-button switch; Fig. 4 shows views for illustrating the alternate mechanism; and Fig. 5 is an essential-portion perspective view of the switch mechanism. Before the description of the present invention proceeds, it is to be noted that like parts are designated by like reference numerals throughout the accompanying drawings. Referring now to the drawings, there is shown in Figs. 1 through 3 an illumination push-button switch. The illumination push-button switch 1 is chiefly composed of an illumination unit 2, an operation unit 3, a switch unit 4, and a housing 5 which accommodates and retains these units. The illumination unit 2 is provided as an illuminating member which serves as a push-button portion. A diffusion plate (reflection plate) 8 is internally disposed within a box-shaped color cap 6 which is colored in optional colors such as red, yellow, green, etc. and is open in the bottom face. The diffusion plate is engaged on the top face of the reflection plunger 9 corresponding to the under portion. The reflection plunger 9 is provided in its top face with rectangular open face corresponding to the bottom face open portion of the color cap 6. The engagement convex portion 10 projected from one portion of the outer peripheral side face is correspondingly engaged with the engagement concave portion 11 of the color cap 6 to serve as one unit. And bell-shaped reflection faces 12 whose peripheral faces are contracted into a conical shape downwardly from the top face so that the light may be upwardly guided. A cylindrical retaining portion 14 for retaining a light emitting element 13 such as a lamp, light-emitting diode or the like in the lower central portion. Vertical members each having a long hole 15 opened by a depressing stroke length along the depressing direction on its side are vertically disposed in the cylindrical retaining portion 14. Upper projections which are projected from both sides on the side face of the light emitting element 13 are respectively engaged into the long holes 15. Thus, the light emitting element 13 oppositely faces in the light emitting portion of the upper portion the top face side of the reflection plunger 9. The external terminals 18 of the lower portion of the light emitting element are mounted, being exposed under the reflection plunger 9. Also, the lower projections 19 projected from both sides on the side face of the light emitting element 13 are engaged, for preventing the draw out, with the engagement pawls 21 of the light emitting element holder 20 to be described later. Through this fixing operation, the reflection plunger 9 is allowed to be depressed by the depressing stroke length, independent of the light emitting element 13. In addition, the reflection plunger 9 is engaged detachably from the upper open face 22 and is guided in sliding contact against the inner face of the housing 5 to ensure the stable depressing operation. Pull the reflection plunger 9 externally from the upper-side open face of the housing 5 and the light emitting element is simultaneously taken out externally through disengagement between the lower projection 19 and the engagement pawl 21, thus allowing the light emitting element 13 to be easily replaced. The above-described diffusion plate 8 uniformly scatters the lights from the light emitting element 13 and reflects them, and has desired display letters, numerals or the like printed on the surface. And an operation unit 3 to be described later is disposed within the housing 5 under the above-described illumination light unit 2. The operation unit 3 is composed of an operation plunger 25 and restoring springs 26 which urge the operation plunger upwardly. The operation plunger 25 is formed into a step cylindrical unit, which has a small-diameter portion on its upper side and has a large-diameter portion on its lower side. The engagement pawls 28 of the reflection plunge 9 are respectively engaged with the opening portions 27 opened in both side faces of the small diameter portion so that both of the plungers 9 and 25 are integrally coupled to each other. The above-described restoring spring 26 is set so that a pair of right and left small-diameter coil springs may be disposed. Thus, the inner space 26c is formed between the opposite portions of a pair of right and left restoring springs 26. A top end portion of the switch unit 4 is partially interposed from below with respect to this inner space 26c so that the axial length of the switch is shortened to make the entire switch shorter in barrel. And the top end portions of the restoring springs 26 are respectively engaged with a pair of right and left spring engagement projections 26a which are vertically disposed oppositely in the diametral direction of the large-diameter lower portion to engage the top ends of the restoring springs 26 with the lower ends of the restoring springs being engaged onto the light emitting element holder 20 to be described later. And the operation plunger 25 is normally in an upwardly moving position because of the upwardly urging force of the restoring springs 26 so that the outer peripheral stage portion 29 of the operation plunger 25 is engaged with the inner peripheral stage portion 30 of the housing 5 to prevent the outer peripheral stage portion from being drawn out. Furthermore, in the large diameter portion, a vertical member 31a as a guide member with respect to the operation plunger 25, and an operation member 35 to be described later are vertically disposed in the opposite positions in the diametral direction grasping the above-described restoring spring 26 in the peripheral direction. The operation plunger 25 is smoothly advanced and retreated by both members 31a and 35 and the above-described pair of right and left restoring springs 26. In this case, the sides of both members 31a and 35 function as a peripheral-face contact operation during the advancing and retreating operations of the operation plunger 25 with the outer peripheral faces being correspondingly in contact against the inner peripheral faces of the housing 5 to regulate the inclination of the operation plunger 25 with respect to the diametral direction. Also, the sides of a pair of right and left restoring springs 26 function as the guiding operation with respect to the individually corresponding axial direction with respect to the depressing force of the operation plunger. Especially when the switch has been end-depressed, the restoring spring 26 on the side where the stronger depression is performed is strongly repulsed to regulate the end depression. Accordingly, the operation plunger 25 smoothly slides through the multiplication effect of both the members 31a and 35 and the restoring springs 26 to ensure the stable operation characteristics and operation feel of the switches. In addition, the large diameter portion has a long hole 31 opened for the depression stroke length along the depression direction. The operation plunger 25 is regulated in the depression stroke through the corresponding engagement between the long hole 31 and the engagement projection 34 of the switch cover 33 to be described later. Also, the large diameter portion has an operation member 35 vertically disposed to turn on and off the switch at the lower end during the depressing operation. The operation member 35 is provided with an opening window 36 which is shaped as an inverted L and is largely opened in the longitudinal length. The alternate mechanism 38 is composed of the window 36 and a cam 37 which is guidingly regulated for the free rotation by the window. The operation plunger 25 is regulated in the depression lock position and the depression lock releasing position by the alternate mechanism 38. The operating function of the switch and the opening window 36 as the alternate mechanism are efficiently provided through the formation of the opening window 36 in the operation member 35 so that the operation plunger 25 is made smaller in size. Also, even if the operation plunger 25 is tiltingly depressed in accordance with the end depression of the switch, the operating member 35 and the opening window 36 normally operate in synchronous relation, with the operating member 35 and the opening window 36 being provided in the same peripheral position, to correspondingly operate the switch mechanism and the alternate mechanism correctly. The alternate mechanism 38 is composed of the above-described opening window 36 and a small piece of cam disposed within the opening window 36. The opening window 36 has the top-face central portion within the window 36 notched further into a concave portion. One angular portion in contact against the top face of the notched concave portion 39 is provided in a first top-face angular portion 40 formed into a circular arc shape. The other angular portion is provided in a second top face angular portion 41 formed into a slightly higher position. The above-described cam 37 is rotatingly regulated by each angular portion 40, 41 and 42, the intermediate angular portion 42 of the lower L-shaped intermediate portion is opposite to the first top-face angular portion 40. The above-described cam 37 has the central portions on the sides of both the rectangular shorter sides described respectively in the V-shaped cam groove 43 for the corresponding engagement use with the above-described angular portions. The cam 37 has the inner-face side of the central portion pivoted for the free rotation on the fixed projection of the switch cover to be described later. Then, the operating condition of the alternate mechanism 38 will be described with reference to Figs. 4(a) through 4(h). Normally, as shown in Fig. 4(a), the cam 37 is longitudinally long and is rotatably regulated along the opening side face of the opening window 36. When the illumination unit 2 is depressed, the opening window 36, opened by the plunger, together with the operation plunger 25 moves downwardly. As shown in Figs. 4(b) and 4(c), the first top face angular portion 40 comes into contact against the top-face end portion of the cam 37 to tilt the cam 37 so that the cam groove is correspondingly engaged with the second top-face angular portion 41 to regulate the downward motion of the operation plunger 25. When the depressing force is released, the opening window 36 integral with the operation plunger 25 performs its upward motion slightly as shown in Figs. 4(d) and 4(e) to correspondingly engage the intermediate angular portion 42 with the cam groove 43 on the lower side thereby locking the depressed condition of the operation plunger 25. When the depressing operation is performed again, the second top-face angular portion 41 comes into contact onto the top face of the cam 37 through the downward motion of the opening window 36 as shown in Fig. 4(f) to tilt the cam 37 so that the operation plunger 25 is regulatingly depressed in the horizontal condition of the cam 37 as shown in Fig. 4(g). Then, when the depressing force is released, the cam 37 is raised in its side face by the intermediate angular portion 42 through the restoring operation (upward motion) of the opening window 36 as shown in Fig. 4(h), is half-rotated and is restored to its original condition again in Fig. 4(a). The switch unit 4 is composed of a light emitting element holder 20, a switch cover 33, and a switch base 44. The light emitting element holder 20 is provided in its top-face central portion with insertion holes 45 into which the external terminals 18 of the light emitting element are inserted, and is provided in its both sides of the top face with the projected engagement pawls 21, which engage the lower projections 19 of the light emitting element through a given retaining force to prevent the lower projections from being drawn out. And small concaved spring engagement grooves 26b which sink the restoring springs 26 and accommodate, support them are respectively formed in both the outer positions of both the engagement pawls 21. The lower portions of the above-described restoring springs 26 are respectively inserted into the spring engagement grooves 26b and are supportingly guided. The small restoring springs 26 are stably and elastically engaged between the above-described spring engagement projections 26a and the spring engagement grooves 26b. Also, the terminal contact guiding faces 20a are formed on both sides of the lower face. The guiding faces 20a function to depress the top-end contact members 51 of the light emitting element/connecting terminal to be described later against the above-described outer elements 18 to force them to come into contact against them. In addition, a pair of support projections 48 are projected in the diametral direction on both sides of the holder 20. The support projections 48 are supported on the switch cover 33 to be described later. The above-described switch cover 33 has the support projections 48 of the above-described holder 20 guided supportingly on the support guiding faces 49 formed on both side faces of the upper portion. In addition, light emitting element connecting terminals 50 are engaged into the terminal engagement grooves 33a formed on the side portion of the switch cover 33. The leaf spring shaped upper-end contact members 51, which are bent in the top ends of the light emitting element connecting terminals 50, are disposed in the insertion space portions 52, into which the light emitting element external terminals 18 are inserted, within the switch cover 33 so that the top-end contact members may be correspondingly brought into contact into the insertion space portions 52. As the insertion space portions 52 are provided with respect to the above-described inner spaces 26c which have wide accommodation spaces, the top-end contact members 51 of the light emitting terminals 50 which are inserted into the insertion space portions 52 may be disposed in a shape suitable between the terminals, setting to the sufficient, corresponding contact length. And an engagement projection 34, which is engaged into the long hole 31 of the operation plunger 25, is projected from the external peripheral face, also a fixed projection 53 which supports the cam 37 as the alternate mechanism 38 is projected from the external peripheral face on the side opposite to the engagement projection. It is to be noted that a lower engagement projection 54 is used to be integrally coupled to the switch base to be described later. In addition, vertical members 54a as the portal coupling leg portions are respectively disposed vertically on both sides of the switch cover 33. Regulating members 54 which serve as reinforcing members to regulate the oscillation of the coil spring in contact with the coil spring of the switch mechanism to be described later are vertically disposed between these vertical members 54a. The regulating members 54 reinforce the vertical members 54a on both sides to efficiently improve the strength. And the lower engagement projections which are used to integrally couple to the switch base to be described later for temporary assembly are projected from the lower-end inner face side of these vertical members 54a. The above-described switch base 44 has switch base halves 44a and 44b combined integrally and is used in a disc shape, the switch base halves 44a and 44b being each shaped into a half moon. To manufacture these switch base halves 44a and 44b, each terminal of the switch mechanism of one circuit to be described later is integrally molded in insertion during the resin molding in a metallic mold, so that the efficient engagement with respect to the switch base 44 is performed. It is to be noted that these base halves 44a and 44b are separately manufactured to simplify the manufacturing operation with respect to the metallic mold, thus allowing the insertion-molding to be performed. And these switch base halves 44a and 44b have on the mutual connection opposite faces a pair of engagement projection 46 and engagement concave 47, which are adapted to be engaged with each other. In addition, band-shaped convexes 46a along the projection direction are provided around the engagement projection 46. Ultrasonic wave welding is performed with the engagement projection 46 being engaged into its opposite engagement concave 47, so that the convex 46a is meltingly adhered to the inner face of the engagement concave 47 to integrate both divided switch bases 44a and 44b through the ultrasonic wave welding operation. Furthermore, new rising connection faces 44d which are risen upwardly from the connection face 44c of the adjacent base thickness and are used for connection of the divided faces. The ultrasonic wave welding operation is performed with the mutual rising connection faces 44d being connected with each other. The combining performance is efficiently improved by the mutual bonding function between the connection face 44c having the sectional area of the above-described base thickness and these rising connection faces 44d, thus resulting in sturdy switch base 44, which is not divided by external forces. Engagement concaves 55 are respectively notched on both sides of the side face of the switch base 44 integrated as described hereinabove. The lower engagement projections 54 of the above-described switch cover 33 are respectively engaged into these engagement concaves 55 for integral coupling operation. The switch base 44 is integrated with the switch cover 33 to simplify the handling operation as the switch and to extremely simplify the accommodating operation with respect to the housing 5. In this case, the switch base 44 is adapted to be inwardly depressed from the lower-end open face of the housing 5 to be accommodated. Several rising connection faces, which are to be connected with the inner peripheral face of the housing 5, are erected in the peripheral direction on the top face of the switch base 44. The stable accommodating conditions are provided with respect to the housing 5 by the multiplication effect of the connection supporting operation with respect to the axial direction by the rising connection faces and the connection supporting operation of the peripheral direction by the external peripheral face of the switch base 44. Therefore, the reduced thickness of the switch base 44 may be set to make the switch smaller in size. In addition, engagement pawls which are correspondingly engaged with the engagement openings of the housing 5 are respectively projected from the top ends of these rising connection faces 44e. Thus, the switch base 44 is secured to the housing 5 not to be drawn out by the engagement function. It is to be noted that the smoother accommodation is performed without any application of the excessive load upon the mutual connection members, because the entire rising connection face 44e is elastically deformed even if a gap corresponding to the engagement pawl 44g is not provided between the switch base 44 and the housing 5. And the switch mechanism 56 of the two-circuit bi-disconnection type is mounted on the same plane of the top face of the above-described switch base 44. As shown even in Fig. 1(c), in the switch mechanism 56, a first top terminal 58 and a first lower terminal 59 with contact members 57 being oppositely disposed up and down, a second top terminal 60 and a second lower terminal 61 with contact members 57 being oppositely disposed up and down in parallel to these terminals are molded in insertion and are planted on the switch base 44. A first movable member 62 broad in width which comes into contact commonly in the horizontal direction is disposed between these upper and lower opposite faces. The first movable member 62 has the contact members 63 disposed in parallel, which correspondingly comes into contact against the contact member 57 of each terminal of both the upper and lower portions. The first movable member 62 with the V-groove 62a at its one end being engaged with the notch 65 of th planted member 64 erected on the switch base 44 has the engagement projection 66 at the other end engaged into an engagement hole 68 formed into one end of a second movable member 67, the other end of the second movable member 67 engaged with the lower end of the above-described operation member 35. An erected member 69 which is partially bent and erected is provided on the other end of the second movable member 67. The erected member 69 is engaged with the longitudinal groove 70 formed in the lower end of the operation member 35 and is regulated in its upward motion. Also, one end of the coil spring 71 is engaged with the erected member 69, the other end thereof is engaged with the upper portion of the planted member 64. The lower end of the above-described regulating member for regulating the oscillation of the coil spring 71 is in contact against the intermediate portion to perform the positional regulation with respect to the movable members 62 and 67 through the coil spring 71 so that the temporary assembly may be performed in accordance with this positional regulation. And through the feeding operation of the tensile function of the spring 71, the first movable member 62 urges the other side downwardly with the side of the V groove 62a as a support point, also the second movable member 67 urges the other side downwardly in its inclined condition with the lower end of the operation member 35 as a support point. The condition is normally off with the first movable member 62 being in contact against the first and second lower terminals 59 and 61. And the upper side of the second movable member 67 in the inclined condition is downwardly moved through the depressing operation of the operation member 35. When the second movable member 67 has exceeded the horizontal straight-line condition with respect to the first movable member 62, the connecting portion of both movable members 62 and 67 upwardly moves to change over the switch into the ON operation. It is to be noted that in the depression locking condition of the operation plunger 25 by the above-described alternate mechanism 38, the switch mechanism 56 is set into the ON condition, also the switch mechanism 56 is set into the OFF condition through the restoring operation of the operation plunger 25. Also, the above-described operation unit 3 and the switch unit 4 are inserted from the lower face opening portion of the housing 5 for the mounting operation. In the drawing, a clamping nut 72 for use in the wall-face mounting is screwed on the outer peripheral face of the housing. In the illumination push-button switch of such construction as described hereinabove, the operation member 35 of the operation plunger 25 together with the reflection plunger 9 is downwardly moved in accordance with the depressing force through the depression of the color cap 6 face of the illumination unit 2 with fingers to downwardly depress the second movable member 67. Through the operative cooperation of it, the first movable member 62 is upwardly moved in the contact side with the tensile force of the coil spring 71. Thus, the conduction is performed between the first and second upper terminals 58 and 60 through the first movable member 62 to effect the ON operation. The light emitting element 13 emits the light by such a depression input signal as described hereinabove, and is illuminated. Also, the depression input signal is inputted into a preset given electric appliance. It is to be noted that the ON condition is locked by the alternate mechanism 38 and is retained until the lock is released. And the lock of the alternate mechanism 38 is released by the depressing operation of the illumination unit 2 again. Thus, the illumination unit 2 and the switch mechanism 38 are restored to the respective original positions so that the condition may be changed over to the OFF condition. Although the present invention has been fully described by way of example with reference to the accompanying drawings, it is to be noted here that various changes and modifications will be apparent to those skilled in the art. Therefore, unless otherwise such changes and modifications depart from the scope of the present invention, they should be construed as being included therein.

Claims: A push-button switch comprising a switch mechanism (56) including a switch base (44) consisting of two parts (44a, 44b) each provided with an insert-molded terminal of a single circuit (58, 59, 60, 61), a movable piece (62) having a contact member (63) for switching the circuit upon engaging or disengaging with a contact member (57) of the terminal (58, 59, 60, 61); a light emitting element holder (20) disposed above the switch mechanism (56) and provided with a light emitting element (13) having external terminals (18) extending towards the switch mechanism; an operation unit (3) for operating the switch mechanism (56) and disposed above the light emitting element (13); and a housing (5) accommodating the switch mechanism (56); light emitting element connecting terminals (50) for connecting to the external terminals (18) of the light emitting element (13) extending at the periphery of the switch base (44) characterized in that each of the-two parts (44a, 44b) of the switch base (44) is formed as a half disk shape at the halving plane on which half disks there are provided a projection portion (46) and a re-entrant portion (47) for positioning the parts so as to form the switch base (44) as a full round shape; a switch cover (33) fitted to the switch base (44) is provided at the outside of which the light emitting element connecting terminals (50) extend, said connecting terminals (50) having tip portions which are guided by the light emitting element holder (20) so that the external terminals (18) of the light emitting element (13) are sandwiched between a tip portion of the switch cover (33) and the tip portion of the light emitting element connecting terminals (50); and the housing (5) is of cylindrical shape so that a lower portion of said connecting terminals is sandwiched between the switch base (44) and the housing (5).

Inventors: BINGO, HIDEYUKI OMRON TATEISI ELECTRONICS CO, HAYAKAWA, TOMOHIKO OMRON TATEISI ELECTRONICS CO, HAYASHI, MITSUJI OMRON TATEISI ELECTRONICS CO, HONDA, SUEAKI OMRON TATEISI ELECTRONICS CO, NIWA, TAKASHI OMRON TATEISI ELECTRONICS CO
Applicants: OMRON TATEISI ELECTRONICS CO.
Application year: 1985
Main classification: H01H13
IPC codes: H01H13, H01H1