US2937245A

US2937245A - Switch

Info

Publication number: US2937245A
Application number: US678588A
Authority: US
Inventors: Long Jasper
Original assignee: WADE ELECTRIC PRODUCTS CO
Current assignee: WADE ELECTRIC PRODUCTS CO
Priority date: 1957-08-16
Filing date: 1957-08-16
Publication date: 1960-05-17
Anticipated expiration: 1977-05-17

Description

May 17, 1960 J. LONG SWITCH 4 Sheets-Sheet 1 Filed Aug. 16, 1957 INVENT OR.

w m Z 1 n a if 2 {WM y 1960 J. LONG SWITCH Filed Aug. 16, 1957 4 Sheets-Sheet 2 24 E INVENTOR.

United States Patent SWITCH Jjasper Long, Sturgis, Mich., assignor to Wade Electric Products Co., Sturgis, MiclL, a corporation of Michigan Application August 16, 1957, Serial No. 678,588 7 Claims. Cl. 200-16) This invention relates to improvements in electrical switches and more particularly to electrical switches of the type having a movable slide block carrying bridging means relative to stationary metal contacts for controlling electrical circuits on automotive vehicles.

It is an important object of the present invention to provide an electrical switch of the type specified embodying improved means for connecting the several parts thereof, particularly the means for carrying the stationary contacts in the housing, in order to simplify and facilitate manufacture of the switch assembly.

It is another important object of the invention to provide improved stationary metal contact means and cooperating insulator housing structure for switches of the character indicated.

It is still another important object of the invention to provide an electrical switch having in combination with the foregoing construction of stationary contact means and housing therefor an improved moving contact mechanism. 7

It is a still further object of the invention to provide an improved switch particularly adapted for controlling the neutral safety and backup circuits on automotive vehicles and which is rugged in construction, reliable in operation and which may be economically manufactured and assembled on a production basis.

The above and related objects of the present invention will appear more fully during the course of the following description takenin conjunction with the accompanying drawings.

In the drawings: I

Fig. 1 is a plan view of a switch embodying the present invention; i Figs. 2and 3 are plan views of parts of the switch housing;

Fig. 4 is a plan view of a metal mounting bracket for securing together the housing parts shown in Figs. 2 and 3;

Figs. 5.and6 are plan and side elevational views respectively of one of the stationary contacts employed in the switch of the present invention;

Fig. 7 is a transverse vertical sectional view of the structure of Fig. 1 taken on the line 77 thereof;

Fig. 8 is a fragmentary longitudinal vertical sectional view of a portion of the structure of Fig. 1 taken along the line 88 thereof and showing one form of moving contact mechanism employed in the switch of the present invention.

Fig. 9 is an underside view of the bridging means for the form of moving contact mechanism shown in Fig. 8;

Figs. 10 and 11 are'front and right side elevational views respectively of the structure of Fig. 9

Fig. 12 is a plan view of the moving contact mechanism shown in Fig. 8; p

Fig. 13 is a vertical transverse sectional view of the structure of Fig. '12 taken substantially along the line 13-13 thereof;

Fig. 14 is a sectional view similar 'to Fig. 10 showing a different form of moving contact mechanism; and

2,937,245 Patented May 17, 1960 Figs. 15 and 16 are plan and left side elevational views respectively of the form of moving contact mechanism shown in Fig. 14.

In accordance with the present invention there is provided an electrical switch which is suitable for mounting on the steering column of an automotive vehicle and adapted to be actuated by the transmission gear shifting assembly for controlling the neutral safety and backup circuits on such vehicles. The switch is shown assembled in Fig. 1 and generally comprises an insulator housing which is especially constructed in two

parts

17 and 19 which together carry novel laid-in type stationary metal contacts 20-24, a mounting bracket 25 for the housing parts, a moving contact mechanism generally designated 26 consisting of a slide block 27 movable in the housing and conductive bridging means 29 carried by the slide block 27 and adapted to interconnect or dis connect two or more of the stationary contacts 20-24. An example of the type of actuating means for the moving contact mechanism of the switch assembly of the present invention is shown and described in the copending application of .Harley M. Newcombe, S.N. 475,430, filed December 15, 1954 assigned to the assignee hereof. Briefly the actuating means therein shown includes a rotatable transmission control tube which is concentrically disposed about the steering shaft of a vehicle steering column and actuable in response to the manually operable transmission control lever on the vehicle. Suitable means are provided for interconnecting the transmission control tube and the backup control switch for converting the rotary motion of the former into reciprocating motion for actuating the latter which means may be adapted for actuating the moving contact mechanism of the switch of the present invention.

Referring now to the structure in greater detail the

housing parts

17 and 19 are shown separately in Figs. 2 and 3 respectively and each is preferably molded of phenolic and formed into an arcuate shape for reception in the bracket 25 to be described for mounting on the steering column of an automobile. The housing part 17 is flat over its length and is provided with a plurality of spaced open faced slots 30-34 which open from the long side 35 of the part 17 and are recessed from its upper face 37. The slots 30-34 interlock with the contacts 20-24 respectively and each slot has a re-entrant crosssection which conforms to the cross-sectional shape of the inner end of its respective contact. By a re-entrant cross-section is meant that the cross-sectional width of each slot at one point over its lengthis in inverse relationship to the cross-sectional width of the slot at a point on each side of the said one point so that there is interposed side wall portions of the slot and contact preventing relative movement in the plane of the contact between the latter and the housing part 17. In the instance shown each of the slots 30-34 at at least one point over its length has a crosssectional width which is smaller than the cross-sectional width at a point on each side of the said one point and for each of the slots 30-34 this one point is located intermediate its ends and indicated in Fig. 2 by the lines 40-44 respectively which pass through the said one points. It will be noted that at the point of narrowest width of the slot 30 an L-shaped' projection is formed which cooperatively engages a similarly shaped cut-away section on the contact 20 and that for each of the slots 31-34 at least one rounded projection is formed which engage rounded cutaway sections on the contacts 21-24. The slots 33 and 34 have each two such rounded projections whichcooperate with two rounded cut-away sections on the

contacts

23 and 24 respectively. By the construction thus described for the slots 30-34 and the inner ends of the contacts 20-24, the latter may each be simply. laid onto the face 37 and deposited in its re- The part 19 is an annular member provided witha. central arcuate opening 45 as shown in Fig. 3 and hasa.

mating lower face which engages the face 37 on the part 17 over; the perimeter of the latter. part 19 stand upright from the face 37 and bridgeeach of the slots 38-34 at its respective open end on the side 35- of the part 17 and at its blind end on the opposite side 46 of the part 17. The portion of the walls of the part 19 which bridges each slot engages the respective contact when the latter is disposed in the slot and completes securement of each contact in all planes. For preventing relative movement between the

parts

17 and 19 in the plane of the face 37 the part 17 isprovided with upright pins 47 formed on ears 49 which project from the ends of the part 17 and the part 19 has correspondingly located cars 51 in which slots 53 are formed for engaging the pins 47. The side walls of the part 19 and its opening 4-5 define a chamber in which operates the slide mechanism to be described and the part 17 together with the contacts 28-24 collectively define a floor for the chamber over which the slide mechanism travels. The ceiling for the chamber is provided by the arcuately shaped mounting bracket 25 the details of which are best shown in Fig. 4.

The bracket 25 is suited for forming from a blank sheet of metal and has a flat body portion 55 which engages ;the top face of the housing part 19 and closes off the opening 45 in the latter except for the longitudinally extending arcuate slot 57 in the body portion 55 which receives the operating means of the slide mechanism which is in the form of a switch arm or button 59 (Fig. 8). At suitable intervals over the sides of the body portion 55 short extensions 60 are formed which are down wardly turned to snugly receive the housing part 17 and from such extensions depend a plurality of suitably spaced tangs 61 for holding the

parts

17 and 19 together. The tangs 61 bear against the side walls of the

parts

17 and 19 and their free ends are staked over the bottom surface of the part 17 as shown and indicated at 63 in the sectional view of Fig. 7. The side wall of the part 17 may be recessed as at 65 (Fig. 2) onits side 46 and the part 19 may be recessed as at 67 (Fig. 3) on its corresponding side. The recesses 65 and 67 accommodate the tangs on the corresponding side of the bracket and prevent endwise movement of the housing parts relative to the mounting bracket. The ends of the bracket extend beyond the housing parts and on the last-mentioned side ofits body portion 55 each end is provided with a depending lug 69 in which is formed a slot 71. Another lug 73 which is flush with the body portion 55 and located on the side thereof oppositethe lugs 69 has an aperture 75 and the latter together with the slots 71 provide means for mounting the bracket to supporting structure where the switch is to be used.

Before the mounting bracket is assembled to the housing parts the slide mechanism is inserted into the switch chamber which may be either of the forms shown and to be described. The form of slide mechanism 26 shown in Figs. 8-13 includes the slide block 27 and the bridging means 29 previously referred to and provides the movable contacts for the switch. The slide block 27 is molded of insulating material the same as the

housing parts

17 and 19 and is formed into an arcuate shape to closely fit the inside surfaces of the side Walls of the part 19. At the four corners of the slide block on its top face rounded bosses 77 are formed for bearing againstthe inside surface of the body portion of the mounting bracket for-reducing friction therewith and for stability during movement of the slide mechanism. Adjacent its bottom face the slide block carries the conductive bridging means 29 of the slide mechanism and for purpose The walls of the are recessed from the bottom face of the slide block and spaced approximately at opposite corners thereof as can be seen in Fig. 12. Located on a diagonal with respect to the cavities 79 are a pair of open-ended apertures each of which is formed in the slide block 27 by counterbored holes 81 and 83. The hole 81 for each aperture is rectangular in shape and extends inwardly from the bottom face of the slide block. The respective hole 83 is-both rectangular andsemicircular in shape and extends inwardly from the top face of the slide block, its rectangular portion being concentric with the hole 81 so that at the intersection of the two holes 81 and 83 a shoulder 84 is formed which faces toward the top face of the slide block. Each open-ended aperture and its respective shoulder are capable of being formed in a simple mold using axially extending core pins which may be readily withdrawn at the completion of the molding operation.

The. conductive bridging means shown separately in Figs. 9-11 is in the form of a one-piece metal bridge contact provided with a body portion 85 from the inner face of which project upturned arms 87 located at diagonal corners of the body portion 85. Inwardly projecting detents 89 which are struck out from the arms 87 cooperate with the shoulders 84 when the bridge contact is assembled on the slide block. A pair of metal contact bosses 91" and 92 in the form of elongated depressions are formed as an integral part of the body portion 85 and project from opposite ends thereof at diagonal corners. Before the bridge contact is assembled on the slide block a pair of coil compression springs 93 are inserted one in each of the. cavities 79 and the bridge contact is disposed adjacent the bottom face of the slide block so that the ends of the springs 93 which project beyond the bottom face of the slide block bear against the inside surfaces of the

contact bosses

91 and 92. In this relative position of the slide block and the bridge contact the arms 87 on the latter are disposed one in each of the holes 81. The bridge contact is then forced inwardly with respect to the bottom face of the slideblock. so thatthe detents 89 which are resilient pass through the holes .81 and override the shoulders 84. The cooperative action of the shoulders 84 and the detents 89 prevent withdrawal of the bridge contact from the slide blockin a' direction away from the bottom face of the latter. The bridge contact of course is free to move inwardly toward the bottom face of the slide block against the urging of the pair of springs 93. By virtue of this construction employing a pair of springs each bearing on-one of the contact bosses of the, bridge undue tilting of the latter in its sliding movement is prevented and a more positive connect and disconnect action is effected.

It will be-noted that the. switch arm 59 previously mentioned;is moldedintegr-al with the slide block so as to upstand from its top face and is eccentrically located thereon closer to one endthan the other. When the slide mechanism is assembled it is disposed in the switch chamber of the switch assembly so that the switch arm 59 projects through the slot 57 in the mounting bracket in which position it is accessible to operating means such as that mentioned above. With the slide mechanism disposed in the switch chamber the pair of springs 93 yieldably urge the rounded bosses 79 on the top face of the slide block against the insidesurface of the body portion 55 of the mounting bracket and the bridge contact against theface 37-of the housing part 17 and the stationary contacts 20-24. carried therein. The slide mechanism is free to move within the switchcchamber endwise of the housing parts and the

contact bosses

91 and 92 move over the face37 and theinner ends of the contacts 20-24 in twoconcentricarcuatepaths with the contact boss 92 riding closer to the side 37 of the housing part 17 and with the contact boss 91 ,closer to the opposite side 46 thereof.

The inner ends of the-contacts 20-24 may be specially .7 constructed tocooperate with the contact bosses' on the bridge contact and in the instance shown have formed thereon arched contact surfaces 100-104 respectively. Each arched contact surface is formed by coining a portion of the inner end of the respective contact so that the metal thereof which may be of brass is reduced in thickness and cold flows. Each arched contact surface is spaced from the face 37 of the housing part 17 as shown for the contact surface 104 on the contact 24 in Fig. 7 p

which also shows the extent of the thickness reduction of the portion of the contact defining its arched contact surface. The cold working of this portion of the contact hardens it somewhat and makes it more resilient. The continual movement of the bridge contact over the inner ends of the contacts ordinarily produces considerable wear and the hardened arched contact surfaces of the metal contacts resist this wear and increase the life of the contacts. The arched surfaces may be formed straight across the stationary contact, i.e. approximately perpendicular to their longitudinal axes, as shown in Fig. 2 for the contact surfaces 101 and 102 on the contacts 21 and 22, respectively, or may be formed at a decided angle to the longitudinal axes of the contacts as shown for the contact surfaces 100, 103 and 104 on the

contacts

20, 23 and 24, respectively. Figs. 5 and 6 are separate views of one of the latter-contacts, viz., contact 24, wherein it can be seen that the arched contact surface 104 thereon extends downwardly and outwardly from the outermost rounded cut-away section on the contact.

Also from Figs. 5 and 6 theparticular construction of the outer end of the contact 104 is most clearly shown which is identical to that of the other contacts and it can be seen that a' blade portion 105 is formed on this end which has a width slightly narrower than the over-all width of the inner end of the contact. A detent aperture 107 is formed in the blade portion 105 for engaging a detent on a socket terminal, not shown, with which the contact is adapted to interlock. The tip of the blade end of the contact is coined into a taper as at 109 to facilitate entry thereof into its respective socket terminal. The outer ends of the contacts which project beyond the side 37 of the housing part 17 may be supported from beneath as shown for the contacts 21 and 22 in Fig. 1. For

this purpose arms 111 are integrally formed on the housing part 17 to project from the side 37 and provide a surface flush with the bottom surface of the slots 31 and 32 which carry these contacts. The outer ends of the contacts may also be supported from above as well as from below beyond the normal width of the housing part 19 as shown for the contacts23 and 24. For this purpose an integral abutment 113 is formed on the housing part 17 as an extension of the side 37 in the vicinity of the slots 33 and 34 which carry these contacts and a similarly shaped cooperating abutment 115 is formed as an extension of the lower part of the corresponding side of the housing part 37. Fig. 7 shows the extended support for the contact 104 derived by this construction.

Returning to a description of the construction of the inner ends of the stationary metal contacts and to the arched contact surfaces thereon, the latter are suitably located as shown in Fig. 1 so that they engage one or the other of the

contacts bosses

91 and 92 in the sliding movement of the bridge contact to keep the main body portion 85 of the latter elevated from the remaining portions of the inner ends of the stationary contacts. In the embodiment shown'the arched contact surfaces on the

contacts

22 and 24 are in the path of the contact boss 92 and the contact surfaces on the

contacts

20, 21 and 23 are in the path of the contact boss 91. Thus in the extreme position of the slide mechanism on the right side of the switch assembly as viewed in Fig. 1, the contact bo'ss'92 rests on the arched contact surface 104 of the contact 24 while the contact boss 91 rests on the arched contact surface 103 of the contact "23. The contacts. 23 and 24 are thus electrically connected or bridged in this lights and the power source therefor.

position of the slide mechanism even though the main body portion of the bridge contact is raised from the remaining portions of these contacts. Similarly in the extreme lefthand position of the slide mechanism the contact boss 92 rests on the arched contact surface 102 on the contact 22 and contact boss 91 rests commonly on each of the arched contact surfaces and 101 on the contacts 20 and 21, respectively. The three contacts 20-22 are thus electrically interconnected or bridged in this position of the slide mechanism. In the position of the slide mechanism immediately adjacent its extreme lefthand position the pair of contacts 21 and 22 are bridged by the contact boss 92 which rests on the contact surface 102 on the contact 22 and by the contact boss 91 which rests on the contact surface 101 on the contact 21. The contact 20 is electrically disconnected from the contacts 21 and 22 in this position of the slide mechanism.

Before passing to a description of the operation of the switch assembly of the present invention the construction of the form of slide mechanism shown in Figs. 14-16 and generally designated 126 should be noted as it is also usable therein. The slide block for the slide mechanism 126 is indicated at 127 and the bridge contact therefor at 129. The slide block 127 is provided with an eccentrically located switch arm 159 and rounded bosses 177 which project from the top face of the slide block as in the previous form of slide mechanism. A pair of open-ended apertures are formed through the body of the slide block 127 and spaced thereon as shown in the plan view of Fig. 15. The open-ended apertures are formed by ccunterbored holes 181 and 183 which intersect to form shoulders 184 similar to the shoulders 84 previously described. Inwardly projecting detents 189 are formed on arms 187 which are inturned from the main body portion 184 of the bridge contact 129. The shoulders 184 cooperate with the detents 189 for retain ing the bridge contact assembled on the slide block. The slide block 127 in this form is provided with a single centrally located cavity 179 in which operates a coil spring 193 for biasing the slide block against the inside surface of the body portion 55 of the mounting bracket and the bridge contact 129 against the face 37 of the housing part 17 and against the stationary contacts 20-24. The bridge contact 129 has a shape in plan as shown in Fig. 15 and at approximately'three corners of the same there are formed contact bosses 191 in the form of an elongated depression and 192A and 192B each in the form of a rounded depression. The contact bosses 191 and 192A-192B define three separate paths over the face 37 of the housing part 17 and the inner ends of the contacts 20-24 during the sliding movement of the slide mechanism 126 within the switch chamber. inner ends of the contacts 20-24 may be modified as would be obvious to one familiar with what is taught herein so that the same sets of contacts as are bridged by the bridge contact 29 are also bridged by the bridge contact 129 in corresponding positions of the latter.

In the operation of the switch of the present invention stationary contacts 20-22 on one side of the switch may be connected in series with the conventional push-button starter switch and the starter motor for the automotive vehicle on which the switch is mounted and the

contacts

23 and 24 may be connected in series between the backup More specifically the terminals 20 and 21 may be commonly connected through socket terminals and lead-in wires, not shown, to one side of the push-butt0n starter switch and the contact 22 may be similarly connected through a socket terminal and lead-in wire not shown to one side of the starter motor. Similarly one of the

terminals

23 and 24 may be connected to one side of the backup lights circuit and the other connected to power source therefor. With the switch arm of the slide mechanism disposed so as to The.

move within the switch chamber inaccordance, with thegpositionof the manually operated transmission shift lever; Suitablemeansmay be provided external of the switchassembly described by one familiar with present day automobiles for biasing the slide mechanism toward one end of the switch chamber in a direction to yieldably oppose the actuating means on the transmission gear shifting assembly. When the manually operated shift lever isinrcverseposition the slide mechanism is in its extreme position on the right side of the switch

assembly bridging thecontacts

23 and 24 and thus energizing backup lights for the Vehicle. In this position and in all other positions of the slide mechanism except the extreme position on the lefthand side of the switch assembly corresponding to'the Neutral position of the shift leverand the one immediately adjacent thereto corresponding to thePark position of the shift lever the starter switch is rendered inoperative. When the slide mechanism is actuated through the shift lever to the left in positions corresponding to Low and Drive positions the contact bosses'on the bridge contact leave the contacts 23 .and Hand tie-energize the backup lights. In these positions the bridge contact of the slide mechanism rides on the insulator face 37 of the housing part 17 between the sets of contacts. on each side thereof. Continued movement of the slide mechanism to the left causes the bridge contact on the slide mechanism through its contact bosses to electrically interconnect the terminals 21 and 22 and thus complete the circuit between the starter switch and the starter motor. In this position which corresponds to the Park position of the shift lever the starter switch is rendered inoperative so that the starter motor can be energized upon depression of the push-button starter switch. Further movement of the slide mechanism to its extreme left position corresponding to the Neutral position of the shift lever interconnects the three contacts 20-22 retaining the starter switch operative.

While preferred embodiments of the invention have been shown and described it is to be understood that various modifications and changes may be made without departing from the spirit thereof or from the scope of the appended claims.

What is claimed is:

1. In an electrical switch, an insulator housing for carrying stationary metal contacts comprising a member having a plurality of spaced slots each opening from one side and recessed from one face thereof, a metal contact having'itsinner end engaged in each slot and its outer end projecting beyond said one side, each slot having a re-entrant cross section conforming to the cross section of the inner end of its respective contact so as to prevent relative movement in the plane of the contact between the latter and said member but permitting the contact to be lifted from said face and another member laid over the first-mentioned member and having portions engaging "saidface and bridging each of said slots at spaced points adjacent both its open and blind end so as to prevent the contacts from being lifted from said face and to expose the portion of each contact between said spaced points so that electrical contact can be made therewith.

2. In an electricalswitch, an insulator housing comprising a member having a plurality of spaced slots each opening from one side and recessed from one face thereof, stationary metal contacts corresponding to the number of slots each having its inner end disposed in one of said slots and its outer end projecting from said one side, each slot having a. re-entrant cross, section and the inner end of its respective contact conforming to its slot cross section so that relative movement int-he plane of the contacts between thelatter and said first member is prevented by the cooperative structure on the side walls of the slots and the contacts, means for preventing the contacts from being lifted from said face and means defining a chamber with said member, a slide block of insulating material slidablycarried nsaidchamber, the face of said member and thecontacts: collectively defining. a. floor, for, said chamber over which the slide-block moves, a. metal bridge:

carried by said slide block so as to slidably engage said contacts, a coil spring. carried in the slide block having one end bearing against said bridge and yieldably urging it'in'one direction against the; chamber floor, shoulders on the-slide block and detents onthe bridge cooperatively preyenting withdrawalof the bridge from the slide block in saidone direction, and means for guiding the movement of the slide block within said chamber.

3. In an electrical switch, an insulator housing comprising amember having a plurality of spaced slots each opening from one side and-recessed from one face thereof, stationary metal contacts corresponding to the number of'slots each having its inner end disposed in one of said slots and its outer end projecting from said one side, eaclrslot having a re-entrant cross section and the inner end of its respective contact conforming to its slot cross section so that relative movement in the plane of the contacts between the latter and said first member is prevented by the cooperative-structure on the side walls of the slots and the contacts, means for preventing the contacts from being lifted from said face, and means defining a chamber with said member, a slide block of insulating material slidably carried in said chamber, the face of said member and the contacts collectively defining a floor for said chamber over which the slide block moves, a metal bridge carried by saidslide block so as to slidably engage said contacts, a pair of spaced depressed contact bosses on the bridge, a pair of coil springs each having one end bearing against one of said contact bosses and yieldably urging the bridge in one direction against the chamber floor, shoulderson the slide block and detents on the bridge cooperatively preventing withdrawal of the bridge from the slide block in said one direction, and means for guiding the movement of the slide block within-said chamber.

4. In an electrical switch, an insulator housing comprising a member having a pluralityof spaced slots each opening from one side and recessed from one face thereof, stationary metal contacts corresponding to the number of slots each having its inner end disposed in one of said slots and its outer end projecting from said one side, each slot having a re-entrant cross section and the inner endv of its respective contact conforming to its slot cross section so that relative movement in theplane of the contacts between the latter and said first member is prevented by the cooperative structure on the side walls of the slots and the contacts, means for preventing the contacts from being lifted from said face, and means defininga chamber with said member, a slide block of in: sulating material slidably carried in said chamber, the face of said member and the contacts collectively defining a floor for said chamber over which the slide block moves, a metal bridge carried by said slide block so as to slidably engage said contacts, a depressed contact boss on the bridge at approximately each of three corners thereof, a coil spring having one end bearing against the bridge centrally of said contact bosses and yieldably urging said bridge in one direction against the chamber floor, shoulders on the slide block and detents on the bridge cooperatively preventing withdrawal of the bridge from the slide block in said one direction, and means for guiding the movement of the slide block within said chamber.

5. In an electrical switch, an insulator housing comprising a first member having a plurality of spaced slots each-openingfrom one side and recessed from one face thereof, fiat one-piece stationary metal contacts corresponding. to the number of slots each having its inner end disposed in one of said slots and its outer end projecting from said ,one side, each slot having a re-entrant crosssection and the-inner end of its respective contact conforming to its slot cross section so that relative movement in; theplane of the contacts between thelatter and said, first :member is \prcventediby. the-:cooperative structure on the side walls of the slots and the contacts, a second member laid over the first member and having wall portions engaging said face and bridging each of said slots at their open and blind ends so as to prevent the contacts from being lifted from said face, said second member being an annular member disposed about the perimeter of said first member and defining therewith a chamber, a slide block of insulating material slidably carried in said chamber, the face of the first member and the contacts collectively defining a floor for said chamber over which the slide block moves, a metal bridge carried by said slide block so as to slidably engage said contacts, a coil spring carried in the slide block having one end bearing against said bridge and yieldably urging it in one direction against the chamber floor, shoulders on the slide block and detents on the bridge cooperatively preventing Withdrawal of the bridge from the slide block in said one direction, and means forming a top wall for said chamber and securing the first and second housing members together, said last-mentioned means having an opening through which actuated means on the slide block extends for moving the slide block within said chamber;

6. In an electrical switch, an insulator housing comprising an arcuately shaped first member having a plurality of spaced slots each opening from one side and recessed from one face thereof, fiat one-piece stationary metal contacts corresponding to the number of slots each having its inner end disposed in one of said slots and its outer end projecting from said one side, each slot having a re-entrant cross section and the inner end of its respective contact conforming to its slot cross section so that relative movement in the plane of the contacts between the latter and said first member is prevented by the cooperative structure on the side walls of the slots and the slots and the contacts, an arcuately shaped second member laid over the first member and having wall portions engaging said face and bridging each of said slots at their open and blind ends so as to prevent the cont-acts from being lifted from said face, said second member being an annular member disposed about the perimeter of said first member and defining therewith a chamber, a slide block of insulating material slidably carried in said chamber, the face of the first member and the contacts collectively defining a floor for said chamber over which the slide block moves, a metal bridge carried by said slide block so as to slidably engage said contacts, a coil spring carried in the slide block having one end bearing against said bridge and yieldably urging it in one direction against the chamber floor, shoulders on the slide block and detents on the bridge cooperatively preventing withdrawal of the bridge from the slide block in said one direction, a metal mounting bracket having a body portion forming a top wall for said chamber and securing the first and second housing members together, the body portion of the bracket having an opening through which actuated means on the slide block extend for moving the slide block within said chamber.

7. In an electrical switch, an insulator housing comprising a member having a plurality of spaced slots each opening from one side and recessed from one face thereof, stationary metal contacts corresponding to the number of slots each having its inner end disposed in one of said slots and its outer end projecting from said one side, each slot having a re-entrant cross section and the inner end of its respective contact conforming to its slot cross section so that relative movement in the plane of the contacts between the latter and said first member is prevented by the cooperative structure on the side walls of the slots and the contacts, and bridging means extending across each of the slots at spaced points adjacent each end thereof to prevent the contacts from being lifted from said face whereby the portion of each contact between said spaced points is exposed so that electrical connection can be made therewith.

References Cited in the file of this patent UNITED STATES PATENTS 1,738,140 Despard Dec. 3, 1929 2,714,140 Spicer July 26; 1955 FOREIGN PATENTS 832,844 France July 11, 1938 640,110 Great Britain July 12, 1950 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 2 937 245 May 17 1960 Jasper Long It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 9, lines 34 and 35 strike out "and the slots".

Signed and sealed this 27th day of December 1960.

(SEAL) Attest:

KARL AXLINE ROBERT c. WATSGN Attesting Oificer Commissioner of Patents UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 2,937,,245 May 17 1960 Jasper Long 7 It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction and that the said Letters v Patent should read as corrected below.

Column 9, lines 34 and 35 strike out and the slots".

Signed and sealed this 27th day of December 1960.

(SEAL) Attest: I, I a

KARL Ha AXLINE ROBERT c. WATSON Attesting Oificer Commissioner of Patents