EP0081929B1

EP0081929B1 - Sealed electrical contact assembly and electrical switch made therefrom

Info

Publication number: EP0081929B1
Application number: EP19820306233
Authority: EP
Inventors: David John Gingerich; Patrick Raymond Mccarty; David Todd Shaffer; Billy Erik Olsson
Original assignee: AMP Inc
Current assignee: TE Connectivity Corp
Priority date: 1981-12-02
Filing date: 1982-11-23
Publication date: 1988-03-02
Also published as: DE8233913U1; EP0081929A2; DE3278179D1; EP0081929A3; CA1220806A

Description

The invention relates to an electrical contact assembly and more particularly to a sealed electrical contact assembly and electrical switch made therefrom for use on a printed circuit board.
Dual in line package (DIP) switches have been used for many years. They are mounted on a printed circuit board and subjected to flow soldering to solder their pins to appropriate circuit paths on the printed circuit board. Thereafter, the soldered printed circuit board is cleaned to remove flux therefrom.
The DIP switches in undergoing the flow soldering and cleaning operations can become contaminated thereby resulting in switch failures requiring them to be replaced which is time-consuming and costly.
US-A-2 432 647 discloses a switch having three spaced stationary contact members aligned in a row in a dielectric frame. A movable electrical contact member is rockably supported on a flat surface of the middle stationary contact and is formed centrally with a flat portion with end portions inclined away from the contact row. An actuating member is pivotally supported in a housing for reciprocal pivotal movement about an axis distal from the frame and has a movable member spring biased towards and engaging the movable contact member on a side opposite the contact row. Pivotal movement of the actuating member to effect traverse of the movable member between opposite end portions of the movable contact member, and across the flat effects rocking of the movable contact member about opposite ends of the flat, and the spring bias urges alternate end portions of the movable contact member against alternate outer contacts of the row.
It is known from GB-A-1513300 to provide an electrical switch comprising a dielectric frame having a plurality of aligned stationary contact members secured therein as opposing sets of stationary contact members, movable electrical contact members to interconnect each set of stationary contact members, a housing member mounted on the frame and contact actuating members disposed in the housing member in association with respective movable contact members said contact actuating members include movable members in operative engagement with respective movable contact members to move the movable contact members from one position electrically connecting opposed stationary contact members to another position disconnecting the opposed stationary contact members.
It is an object of the invention to provide an improved switch having the features known from GB-A-1513300.
Accordingly the invention is characterised by said movable contact members being pivotally supported on pivots formed on one of the stationary contact members, a membrane member being sealingly secured onto said frame covering the sets of stationary contact members and the movable contact member associated therewith, said movable members being in operative engagement with said movable contact members through said membrane member;
said movable members being movably mounted in said contact actuating members and spring-biased towards said movable contact members, said contact actuating members being reciprocally pivotally mounted in said housing member about an axis proximate a top of said housing member distal from said frame for pivotal movement of said contact actuating member and said movable members about said axis pivotally to move the movable contact members from said one to said other positions, whereby said movable members are movable across said membrane member between positions at opposite sides of said pivots to move said movable contact members between said one and other positions, said spring bias acting between said pivotal axis and said movable members towards said movable contact members.
The invention will now be described, by way of example, with reference to the accompanying partly diagrammatic drawings, in which:-

Figure 1 is an exploded perspective view showing the various parts of the switch of the present invention.
Figure 2 is a view similar to Figure 1 of an assembled switch.
Figure 3 is a cross-sectional view taken along line 3-3 of Figure 2 with parts broken away.
Figures 4-12 illustrate the various steps in making the sealed electrical contact assembly which is then latched to a housing having contact-actuating members therein thereby completing the making of a switch.
Figure 13 is an exploded perspective view showing the various parts of an alternative switch of the present invention.
Figure 14 is a view similar to Figure 13 of an assembled switch.
Figure 15 is a cross-sectional view taken along line 15-15 of Figure 14 with parts broken away.
Figure 16 is an exploded perspective view of the rocket member, leaf spring and button.
Figure 17 is a top plan view of the elements of Figure 16 assembled together an in position in a cavity of the housing.
Figure 18 is a view similar to that of Figure 17 showing another embodiment of the invention.
Figures 19 through 29 illustrate the various steps in making the sealed electrical contact assembly which is then latched to a housing having contact-actuating members therein thereby completing the making of a switch.

Figures 1-3 illustrate the sealed electrical contact assembly 10 and the contact-actuating mechanism 12 that is latchably secured thereto thereby forming DIP switch S as illustrated in Figures 2 and 3. Dielectric frame 14 is molded from a suitable commercially-available plastic material and it has a series of aligned electrical contact members 16, 18 molded in place therein. Electrical contact members 16, 18 arranged in dielectric frame 14 having opposed stationary electrical contact sections 16A, 18A which are exposed in recesses 20 in the top surface of frame 14. Each of electrical contact members 16,18 have electrical terminal sections 22 extending outwardly from frame 14 for electrical connection with electrical sockets 24 disposed in proper alignment in printed circuit board 26 with electrical sockets 24 electrically connected to approp- . riate circuit paths 28 located thereon. Electrical terminal sections 22 are provided with projections 30 to limit the movement of electrical terminal sections 22 within sockets 24 in order to space switch S from board 26. Electrical contact sections 18A are provided with upwardly-directed pivot members 32 that have been stamped therefrom.
Movable electrical contact members 34 have V-shaped embossments 36 formed therein which mate with pivot members 32 and the ends are provided with contact fingers 38 to provide contact redundancy when movable contact members 34 are moved into electrical contact with stationary contact members 16 as illustrated in Figure 3. V-shaped embossments 36 in engagement with pivot members 32 positively position movable contact members 34 relative to the respective sets of contact members 16, 18 within recesses 20. Latching lugs 40 having beveled surfaces extend outwardly from the sides of frame 14 between terminal sections 22.
Membranes 42, 44 of a commercially-available plastic material are sealingly secured on the top and bottom surfaces of frame 14 by a commercially-available adhesive material. Membrane 42 covers all of recesses 20 with movable contact members 34 pivotally mounted on pivot members 32 of electrical contact members 18 and membrane 44 covers holes 45 in frame 14. As can be discerned, membrane 42 not only maintains movable contact members 34 in position in recesses 20 and on pivot members 32 of stationary contact members 18, but membranes 42, 44 also seal electrical contact assembly 10 from contaminants, especially during which the flow soldering and cleaning operations the contact assembly will be subjected and during their operating life. While membrane 44 is disclosed as covering the bottom surface of frame 14 to cover holes 46 therein, frame 14 can be molded without holes 46 therein thereby eliminating membrane 44 and using only membrane 42 adhered to the top surface of frame 14, if desired.
Contact-actuating mechanism 12 includes housing 48, rocker members 50, coil springs 52 and buttons 54. Housing 48, rocker members 50 and buttons 54 are molded from a commercially-available plastic material.
Housing 48 has separate cavities 56 which receive therein contact-operating members comprising rocker members 50, coil springs 52 and buttons 54 therein as illustrated in Figure 3. Rectangular openings 58 are located in housing 48 which communicate respectively with cavities 56. Latches 60 extend outwardly from the bottom surface of housing 48 to mate with latching lugs 40 on frame 14 to latchably secure housing member 48 onto frame 14 with the contact-operating members in position in cavities 56 thereby forming switch S as illustrated in Figures 2 and 3.
Rocker members 50 have projections 62 on the top surfaces thereof which extend through rectangular openings 58 and they have V-shaped notches 64 therein which are engaged by a probe to move rocker members 50 from a contact-actuated position as illustrated in Figure 3 to a non-contact-actuated position opposite to that illustrated in Figure 3. Projections 62 are profiled so as not to extend above the top surface of housing 48 in either one of its operated positions. Inclined surfaces 66 of rocker members 50 engage the inside top surfaces of housing 48 to limit movement of rocker members 50 within cavities 56. Pie-shaped or rectangular-shaped members 68 extend outwardly from each side of rocker members 50 and they along with the apex of inclined surfaces 66 define pivot members to enable rocker members 50 to operate in a reciprocal manner within cavities 56 to operate contact assembly 10. The apexes of members 68 and surfaces 66 engage the upper inside surface of housing 48 to define a pivot point therefor and the bottom arcuate surfaces of members 68 rock along the membrane-covered top surface of frame 14 when rocker members 50 are moved from one position to another.
Rocker members 50 have cavities 70 therein in which coil springs 52 and buttons 54 are disposed. ,Buttons 54 have a beveled shaft 72 disposed within coil springs 52 and a semi-spherical contact-operating member 74 that operates movable contact members 34 as illustrated in Figure 3 through membrane 42. Coil springs 52 extend between contact-operating members 74 and the bottom of cavities 70 thereby exerting pressure on contact-operating members 74 causing members 74 to springably engage movable contact members 34 through membrane 42 and to urge rocker members 50 against the upper inside surface of housing 48.
Actuating mechanism 12 can be used to move a movable member 34 via rocker member 50 from one position to another with spring-biased button 54 being maintained in one or the other positions by engagement with either side of embossment 36 to maintain movable member 34 at such position and inclined surfaces 66 limit movement of the rocker member.
In operation with reference to Figure 3, a probe (not shown) is inserted into the left-sided notch 64 for applying a force to rocker member 50. This causes the bottom arcuate surfaces of members 68 to engage the top surface of frame 14 through membrane 42 thereby causing rocker member 50 to rock about such arcuate surfaces with contact-operating member 74 being depressed inwardly against the action of coil spring 52 as it rides along V-shaped embossment 36. So long as the force applied to rocker member 50 does not enable contact-operating member 74 to extend slightly beyond the center thereof, rocker member 50 will move back to its original position. If the operating force exerted by the probe is sufficient to move contact-operating member 74 via rocker member 50 beyond the center of contact-operating member 74, the configuration of embossment 36 on pivot member 32 and that of contact-operating member 74 plus the action of coil spring 52 will move rocker member 50 to the other position from where it was located thereby providing snap action operation. Fingers 38 of movable contact members 34 are wipingly moved along stationary contact section 16A because of the downwardly bent orientation of the section of the movable contact members that begins at a location spaced outwardly from embossments 36.
The construction of DIP switch S with mem- . brane 42 in sealed engagement with the top surface of frame 14 or with membranes 42, 44 in sealed engagement with the top and bottom surfaces of frame 14 provides a DIP switch having a sealed electrical contact assembly that will protect the contact assembly from contaminants when the board 26 is subjected to conventional flow soldering and cleaning operations as well as during the normal operating life of the switch. The DIP switch S is also smaller in all dimensions than existing DIP switches thereby enabling it to be used in greater density at a lower profile.
Figures 4-12 illustrate the method of making the sealed electrical contact assembly and the switch. Electrical contact members 16, 18 are stamped and formed from a suitable metal such as, for example, brass or the like in the form of a lead frame as illustrated in Figure 4 with terminal sections 22 being connected together by sections 76 and their ends connected to the sides of carrier strip 78. Only one carrier strip 78 having the lead frame therein is shown, but the carrier strip is a continuous strip of stamped and formed lead frames with the carrier strip 78 providing a means for carrying the lead frames through gold or other precious metal plating and the manufacturing steps of making the sealed electrical contact assembly and switch made therefrom.
The lead frame is placed in a conventional mold and dielectric frame 14 is molded thereon with recesses 20 formed therein to expose exposed contact sections 16A, 18A of contact members 16, 18 as shown in Figure 5. Another carrier strip 80 has the ends of gold or other precious metal plated movable contact members 34 connected thereto as shown in Figure 6 which are sheared from carrier strip 80 and then transferred into recesses 20 of frame 14 as shown in Figure 7 so that V-shaped embossments 36 are positioned onto pivot members 32 of contact members 18. The transferring can be done by transferring members connected to a vacuum. The lead frame 78 and strip 80 of movable contact members 34 can be chemically milled or made in any other conventional manner.
Membranes 42, 44 are then adhesively and sealingly secured onto the top and bottom sur- . faces of frame 14 as shown in Figure 8. Membrane 42 maintains movable contact members 34 in position in recesses 20. Figure 8 illustrates the completed sealed electrical contact assembly 10 which is inverted as shown in Figure 9 and latchably secured onto housing 48 having the contact-operating members positioned in cavities 56 thereof via latches 60 latchably engaging latching lugs 40 as shown in Figure 10. Sections 76 are sheared from between terminal sections 22 and the ends of terminal sections 22 are sheared from carrier strip 78 as shown in Figure 11 and then bent into a proper orientation for matable engagement with sockets 24 of board 26. The completed electrical DIP switch S, as illustrated in Figure 12, can then be tested and packaged in tubes in the same manner as integrated circuits and they can be loaded into printed circuit boards by automated insertion equipment. Adjacent members 68 can be interconnected when formed or via a suitable adhesive and cavities 56 so profiled to enable gang switching if desired.
Figures 13 through 15 illustrate the sealed electrical contact assembly 110 and the contact-actuating mechanism 112 that is latchably secured thereto thereby forming DIP switch SA as illustrated in Figures 14 and 15. Dielectric frame 114 is molded from a suitable commercially-available plastic material and it has a series of aligned electrical contact members 116, 118 molded in place therein. Electrical contact members 116, 118 are arranged in dielectric frame 114 having opposed stationary electrical contact sections 116A, 118A which are exposed in recesses 120 in the top surface of frame 114. Each of electrical contact members 116, 118 has an electrical terminal section 122 extending outwardly from frame 114 for electrical connection with plated through holes 124 disposed in proper alignment in printed circuit board 126 with holes 124 electrically connected to appropriate circuit paths 128 located thereon. Plated through holes 124 can be sockets if desired. Electrical terminal sections 122 are provided with projections 130 to limit the movement of electrical terminal sections 122 within holes 124 in order to space switch SA from board 126 to facilitate cleaning after soldering operation. Electrical contact sections 118A are . provided with upwardly-directed pivot members 132 that have been stamped therefrom.
Movable electrical contact members 134 have V-shaped embossments 136 formed therein which mate with pivot members 132 and the ends are provided with contact fingers 138 to provide contact redundancy when movable contact members 134 are moved into electrical contact with stationary contact sections 116A as illustrated in Figure 15. V-shaped embossments 136 in engagement with pivot members 132 positively position movable contact members 134 relative to the respective sets of stationary contact sections 116A, 118Awithin recesses 120. Latching lugs 140 having beveled surfaces extend outwardly from the sides of frame 114 between terminal sections 122.
Membranes 142, 144 of a commercially-available plastic material are sealingly secured on the top and bottom surfaces of frame 114 by a commercially-available adhesive material. Membrane 142 covers all of recesses 120 with movable contact members 134 pivotally mounted via V-shaped embossments 136 on pivot members 132 of electrical contact members 118 and membrane 144 covers holes 146 in frame 114. As can be discerned, membrane 142 not only maintains movable contact members 134 in position in recesses 120 and on pivot members 132 of stationary contact members 118, but membranes 142, 144 also seal electrical contact assembly 110 from contaminants, especially during the flow soldering and cleaning operations to which the contact assembly will be subjected and during their operating life. While membrane 144 is disclosed as covering the bottom surface of frame 114 to cover holes 146 therein, frame 114 can be molded without holes 146 therein thereby eliminating membrane 144 and using only membrane 142 adhered to the top surface of frame 114, if desired.
Contact-actuating mechanism 112 includes housing 148, rocker members 150, leaf springs 152 and buttons 154. Housing 148, rocker members 150 and buttons 154 are molded from a commercially-available plastic material. Leaf springs 152 are stamped and formed from a suitable metal having the necessary spring characteristics.
Housing 148 has separate cavities 156 which receive therein contact-operating members comprising rocker members 150, leaf springs 152 and buttons 154 therein as illustrated in Figure 15. Rectangular openings 158 are located in housing 148 which communicate respectively with cavities 156. Latches 160 extend outwardly from the bottom surface of housing 148 to mate with latching lugs 140 on frame 114to latchably secure housing member 148 onto frame 114 with the contact-operating members in position in cavities 156 thereby forming switch SA as illustrated in Figures 14 and 15.
Rocker members 150 have actuating members 162 which extend through rectangular openings 158 and they have V-shaped notches 164, 165 therein which are engaged by a probe to move rocker members 150 from a contact-actuated position as illustrated in Figure 15 to a non-contact-actuated position opposite to that illustrated in Figure 15. Actuating members 162 are profiled so as not to extend above the top surface of housing 148 in either one of its operated positions. Notches 164 enable operation of rocker members 150 from above whereas notches 165 enable operation of rocker members 150 from the sides. Inclined surfaces 166 of rocker members 150 engage the inside top surface 167 of housing 148 to limit movement of rocker members 150 within cavities 156. Pie-shaped or rectangular-shaped members 168 extend outwardly from each side of rocker members 150 and the apexes thereof along with the apex of inclined surfaces 166 define a pivot to enable rocker members 150 to operate thereabout in a reciprocal manner within cavities 156 to operate contact assembly 110. The apexes of members 168 and surfaces 166 engage the upper inside surface of housing 148 to define a pivot point therefor and the bottom arcuate surfaces of members 168 rock along the membrane-covered top surface of frame 114 when rocker members 150 are moved from one position to another.
Rocker members 150 as shown in Figures 16 and 17 have slots 169 and recesses 170 therein in which leaf springs 152 and buttons 154 are disposed. Buttons 154 have rounded ends 172, 173 and projections 174 that are disposed in recesses 170 to guide movement of buttons 154 in rocker members 150 and to operate movable contact members 134 as illustrated in Figure 15 through membrane 142. Leaf springs 152 are arcuate shaped and have projections 153 extending outwardly therefrom which are disposed in recesses 170 when the leaf springs are positioned in slots 169. The ends of leaf springs 152 extend along actuating members 162. Buttons 154 engage leaf springs 152 thereby exerting pressure on buttons 154 causing rounded ends 172 to springably engage movable contact members 134 through membrane 142 and to urge rocker members 150 against the upper inside surface 167 of housing 148.
Figure 18 illustrates an alternative embodiment of the invention whereby leaf springs 152A are interconnected at necked-down sections 155 between projections 153A of adjacent leaf springs. In this way, leaf springs 152A are interconnected and they are readily positioned within slots 169A of rocker members 150A. The necked-down sections 155 do not effect the operation of rocker members 150A and, after a number of actuations of the rocker members, the necked-down sections are susceptible to breaking which will not affect the operations of the rocker members.
Actuating mechanism 112 can be used to move a movable member 134 via rocker member 150 from one position to another upon forces being applied to actuating members 162 with spring-biased button 154 being maintained in one or the other positions by engagement with either side of embossment 136 to maintain movable member 134 at such position and inclined surfaces 166 limit movement of the rocker member.
In operation with reference to Figure 15, a probe (not shown) is inserted into the left- sided notches 164 or 165 for applying a force to rocker member 150. This causes the bottom arcuate surfaces of members 168 to engage the top surface of frame 114 through membrane 142 thereby causing rocker member 150 to rock about such arcuate surfaces with button 154 being depressed inwardly against the action of leaf spring 152 as it rides along V-shaped embossment 136. So long as the force applied to rocker member 150 does not enable button 154 to extend slightly beyond the center thereof, rocker member 150 to move back to its original position. If the operating force exerted by the probe is sufficient to move button 154 via rocker member 150 beyond the center of button 154, the configuration of embossment 136 on pivot member 132 and that of rounded end 142 plus the action of leaf spring 152 will move rocker member 150 to the other position from where it was located thereby providing snap action operation. Fingers 138 of movable contact members 134 are wipingly moved along stationary contact section 116A because of the downwardly bent orientation of the section of the movable contact members that begins at a location spaced outwardly from embossments 136.
The construction of DIP switch SA with membrane 142 in sealed engagement with the top surface of frame 14 orwith membranes 142,144 in sealed engagement with the top and bottom surfaces of frame 114 provides a DIP switch having a sealed electrical contact assembly that will protect the contact assembly from contaminants when the board 126 is subjected to conventional flow soldering and cleaning operations as well as during the normal operating life of the switch. The DIP switch SA is also smaller in all dimensions than existing DIP switches thereby enabling itto be used in greater density at a lower profile.
Figures 19 through 29 illustrate the method of making the sealed electrical contact assembly and the switch. Electrical contact members 116,118 are stamped and formed from a suitable metal such as, for example, brass or the like in the form of a lead frame as illustrated in Figure 19 with terminal sections 122 being connected together by sections 176 and their ends connected to the sides of carrier strip 178. Only one carrier strip 178 having the lead frame therein is shown, but the carrier strip is a continuous strip of stamped and formed lead frames with the carrier strip 178 providing a means for carrying the lead frames through gold or other precious metal plating and the manufacturing steps of making the sealed electrical contact assembly and switch made therefrom.
The lead frame is placed in a conventional mold and dielectric frame 114 is molded thereon with recesses 120 formed therein to expose exposed contact sections 116A, 118A of contact members 116, 118 as shown in Figure 20. Another carrier strip 180 has the ends of gold or other precious metal plated movable contact members 134 connected thereto as shown in Figure 21 which are sheared from carrier strip 180 and then transferred into recesses 120 of frame 114 as shown in Figure 22 so that V-shaped embossments 136 are positioned onto pivot members 132 of contact sections 118A. The transferring can be done by transferring members connected to a vacuum. The lead frame 178 and strip 180 of movable contact members 134 can be chemically milled or made in any other conventional manner.
Membranes 142, 144 are then adhesively and sealingly secured onto the top and bottom surfaces of frame 114 as shown in Figure 23. Membrane 142 maintains movable contact members 134 in position in recesses 120. Figures 23 through 25 illustrate loading rocker members 150 with leaf springs 152 and buttons 154. Rocker members 150 are positioned within aligned carrier members 182. The leading carrier member 182 is moved to a station as shown in Figure 24 so that carrier strip 184 on which leaf springs 152 are located can position leaf springs 152 in slots 169 of rocker members 150. Leaf springs 152 are then severed from carrier strip 184.
Carrier member 182 is then moved to another station as shown in Figure 25 so that buttons 154 in tubes 186 are serially inserted therefrom into slots 169 of rocker members 150. Carrier member 182 with fully assembled rocker members 150 is then moved to a further station as shown in Figure 26 whereat carrier member 182 is tilted to slide assembled rocker members 150 in cavities 156 in housing 148.
An alternative approach would be that in molding the rocker members 150, they can be molded to a carrier member at spaced intervals therealong. Leaf springs are then inserted in slots 169 and severed from carrier strip 184 whereafter buttons 154 are inserted in slots 169. Then the loaded rocker members 150 can be positioned within cavities 156 of housing 148 whereafter they are severed from the carrier member.
Figure 23 illustrates the completed sealed electrical contact assembly 110 which is inverted as shown in Figure 27 and latchably secured onto housing 148 having the rocker members 150 positioned in cavities 156 thereof via latches 160 latchably engaging latching lugs 140 as shown in Figure 27. Sections 176 are sheared from between terminal sections 122 and the ends of terminal sections 122 are sheared from carrier strip 178 as shown in Figure 28 and then bent into a proper orientation for matable engagement with holes 124 of board 126. The completed electrical DIP switch SA, as illustrated in Figure 29, can then be tested and packaged in tubes in the same manner as integrated circuits and they can be loaded into printed circuit boards by automated insertion equipment. Adjacent members 168 can be interconnected when formed or via a suitable adhesive and cavities 156 so profiled to enable gang switching if desired.
The configuration of leaf springs 152 on carrier strip 184 and of buttons 154 enables them to be easily positioned within rocker members 150, and fully-loaded rocker members 150 are easily drop- . ped into the respective cavities 156 of housing 148. This enables actuating mechanism 112 to be readily secured onto sealed contact assembly 110 which itself is readily assembled as illustrated in Figures 19 through 23.
The projections 153 of leaf springs 152 and projections 174 of buttons 154 in recesses 170 of rocker members 150 maintain leaf springs 152 and buttons 154 in position in rocker members 150 and guide the movements of springs 152 and buttons 154 during operation of rocker members 150.

Claims

1. An electrical switch comprising a dielectric frame (14, 114) having a plurality of aligned stationary contact members (16, 18, 116A, 118A) secured therein as opposing sets of stationary contact members (16, 18, 116A, 118A), movable electrical contact members (34, 134) to interconnect each set of stationary contact members (16,18,116A, 118A), a housing member (48,148) mounted on the frame (14, 114) and contact actuating members (50, 150) disposed in the housing member (48, 148) in association with respective movable contact members (34, 134) said contact actuating members (50, 150) include movable members (72, 172) in operative engagement with respective movable contact members (34, 134) to move the movable contact members (34,134) from one position electrically connecting opposed stationary contact members (16, 18, 116A, 118A) to another position disconnecting the opposed stationary contact members (16, 18, 116A, 118A), characterised by said movable contact members (34, 134) being pivotally supported on pivots formed on one of the stationary contact members (16, 18, 116A, 118A), a membrane member (42, 142) being sealingly secured onto said frame (14, 114) covering the sets of stationary contact members (16, 18, 116A, 118A) and the movable contact member (34, 134) associated therewith, said movable members (72,172) being in operative engagement with said movable contact members (34, 134) through said membrane member (42, 142);
said movable members (72, 172) being movably mounted in said contact actuating members (50, 150) and spring-biased (52,152) towards said movable contact members (34, 134), said contact actuating members (50, 150) being reciprocally pivotally mounted in said housing member (48, 148) about an axis proximate a top of said housing member (48, 148) distal from said frame (14, 114) for pivotal movement of said contact actuating members (34, 134) and said movable members (72, 172) about said axis pivotally to move the movable contact members (34, 134) from said one to said other positions, whereby said movable members (72, 172) are movable across said membrane member (42,142) between positions at opposite sides of said pivots (32) to move said movable contact members (34, 134) between said one and other positions, said spring bias (52, 152) acting between said pivotal axis and said movable members (72, 172) towards said movable contact members (34, 134).

2. A switch as set forth in claim 1 characterised in that said frame (14, 114) has membrane members (42, 142, 44, 144) secured onto the top and bottom surfaces thereof.

3. A switch as set forth in claim 1 characterised in that said stationary contact members (16, 18, 116, 118) have terminal sections (22, 122) for electrical connection with socket members (24, 124) in a printed circuit board (26, 126).

4. A switch as set forth in claim 1 characterised in that the free ends of said movable contact members (34, 134) have contact fingers (38, 138).

5. A switch as set forth in claim 1 characterised in that said spring-biased members (54) include button members (74) and coil springs (52) disposed in openings (70) of said movable members (50) and onto shafts (72) of said button members (74).

6. A switch as set forth in claim 1 characterised in that said spring-biased members (154) include button members (154) having rounded ends (172, 173) and projections (174), leaf springs (152) disposed in slots (169) in said movable members (150) and having projections (153), said projections (174) of said button members (154) and said projections (153) of said leaf springs (152) disposed in recesses (170) in said movable members (150) with said leaf springs (152) urging said button members (154) within an outward direction relative to said movable members (150).

7. A switch as set forth in claim 1 characterised in that said movable members (50,150) are rocker members and have triangular-shaped projections (68, 168) extending outwardly from the sides of the rocker members (50, 150), with the apexes of the triangular-shaped projections (68, 168) being urged against an inside surface of said housing member (48,148) by said spring-biased members (54, 154) and the bases of said triangular-shaped projections (68, 168) being radiussed.

8. A switch as claimed in any preceding claim, characterised in that said movable contact members (34, 134) have inverted V-shaped embossments (36,136) mated with respective pivots (32).

9. A switch as claimed in any preceding claim characterised in that end portions of the movable contact member (34) on opposite sides of the pivot (32) are downwardly bent towards respective stationary contacts (16A, 18A).