US3497644A

US3497644A - Electrical switches

Info

Publication number: US3497644A
Application number: US724979A
Authority: US
Inventors: William N Schink; William J Schaad
Original assignee: Indak Manufacturing Corp
Current assignee: Indak Manufacturing Corp
Priority date: 1968-04-29
Filing date: 1968-04-29
Publication date: 1970-02-24
Anticipated expiration: 1987-02-24

Description

Feb. 24, 1970 w. N, scH ET AL ECTRICAL SWITCHES 4 Sheets-Sheet 1 Filed April 29, 1968 mm 0 MW mm m willz'amlc aad 9 1/ I. 4 I I M I ,0

Feb. 24, 1970 w, scH ET AL 3,497,644

ELECTRICAL SWITCHES 4 Sheets-Sheet 3 Filed April 29, 1968 27 Run/D9122;

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Feb. 24, 1970 w. N. SCHINK ET AL 3,497,644

ELECTRICAL SWITCHES Filed April 29, 1968 4 Sheets-Sheet 4" United States Patent O F 3,497,644 ELECTRICAL SWITCHES William N. Schinlr, Crystal Lake, and William J. Schaad, Winnetka, Ill., assignors to Indak Manufacturing Corp., Northbroolr, Ill., a corporation of Illinois Filed Apr. 29, 1968, Ser. No. 724,979 Int. 'Cl. Hlh 21/78, 27/08 US. Cl. 200-11 Claims ABSTRACT OF THE DISCLOSURE This invention relates to electrical switches generally, and pertains particularly to automotive type switches, for use in automobiles, trucks, tractors and other vehicles.

Many practical applications for electrical switches, particularly in automotive service, call for multi-position switches capable of carrying out various switching functions. Moreover, there is a wide variety of requirements for multiposition switches in various situations. The requirements which switches are expected to meet are in a constant state of change from year to year and from model to model. It is diflicult to meet these requirements with existing switch constructions, particularly in the face of the additional requirements of complete dependability, long service life, and low production cost.

One object of the present invention is to produce a basic switch construction which is adaptable to produce a line of many different switches, capable of fulfilling a wide variety of needs in various applications. The various switches produced in accordance with the present invention are similar in construction, so that many components can be used in common in various switches. Nevertheless, it is easy to produce changes in the switch construction so that the various switches can perform different switching functions to meet a variety of design requirements. All of this is accomplished while maintaining dependability in their operation, long service life, and low production cost.

The switch construction of the present invention involves a carriage which is rotatable to angularly spaced switching positions within a casing. The carriage is fitted with a contactor which is engageable with a plurality of stationary contact points. The casing is provided with an insulating support for the contact points. Preferably, the insulating support is also provided with insulating bosses or dummy contacts, interspersed between the contact points. The contactor preferably comprises first and second diametrically opposite portions of different angular widths. Thus, the angular width of the second portion is preferably greater than that of the first portion, and also greater than the angular spacing between the various switching positions of the contactor. The first portion of the contactor is of such narrow width that it engages only one contact point or insulating boss in each switching position of the carriage. On the other hand, the second portion of the contactor is of sufficient angular width to engage two of the contact points or insulating bosses at one or more switching positions of the carriage. With this basic construction, a wide variety of switch designs may be produced by changing the arrangement of the contact points and insulating bosses. The number of switch- 3,497,644 Patented Feb. 24, 1970 ing positions can also be varied by changing the stops and the detents for the carriage. In each switching position, the contactor generally engages three elements, which may be contact points, insulating bosses, or dummy contacts. By changing the arrangement of the contact points, insulating bosses and dummy contacts, a wide variety of switching functions may be performed. It is easy to achieve smooth and dependable switching operations of the make before-break type. This is important in many switching operations in which it is highly desirable to avoid interrupting the circuit when switching operations are being performed. The wider portion of the contactor inherently has a make-before-break action. Moreover, the width of the narrower portion of the contactor can readily be adjusted to achieve a make-before-break action.

Whenever the circuit is broken between one of the contact points, the break occurs in the air, spaced away from the insulating support. In this way, any arcing occurs away from the board to avoid burning of the board.

The contact points are preferably spaced around a circle on the insulating support. The spacing between the contact points corresponds roughly to the spacing between the various switching positions of the contactor. However, the spacing may be nonuniform in some instances. In any particular switch design, insulating bosses or dummy contacts may be employed in locations which are occupied by contact points in other switch designs. In this way, a wide variety of switches may be produced.

Further objects, advantages and features of the invention will appear from the following description, taken with the accompanying drawings, in which:

FIG. 1 is a front view of an electrical switch to be described as an illustrative embodiment of the present invention.

FIG. 2 is a side vie-w of the switch, showing the operating key in place.

FIG. 3 is a rear view of the switch.

FIG. 4 is an elevational view showing the front or inner side of the terminal head of the switch, the view being taken generally as indicated by the line 44 in FIG. 2.

FIG. 5 is a rear view of the swtich with the terminal head removed, the view being taken generally as indicated by the line 55 in FIG. 2.

FIG. 6 is a sectional view, taken generally along the line 6--6 in FIG. 2.

FIG. 7 is a rear view of the rotary carriage for the switch.

FIG. 8 is a rear view of the casing, with the other components removed.

FIG. 9 is a diagrammatic rear view showing the Off position of the contactor, the terminal head and contacts being shown in phantom.

FIG. 10 is a diagrammatic view similar to FIG. 9 but showing the contactor in its second position, designated Run/Lights.

FIG. 11 is another diagrammatic view, similar to FIG. 9, but showing the contactor in its third position, designated Run.

FIG. 12 is another diagrammatic view, similar to FIG. 9, but showing the contactor in its fourth position, designated Start.

FIG. 13 is a longitudinal section, taken generally along the line 13-13 in FIG. 9.

FIG. 14a is a fragmentary section, taken generally along the line 14a14a in FIG. 11.

FIG. 14b is a fragmentary section, taken generally along the line 14b14b in FIG. 12.

FIG. 15a is a fragmentary section, taken generally along the line 15a 15a in FIG. 13 and showing the narrower end of the contactor.

FIGS. b, 15c and 15d are similar to FIG. 15a but show successive positions of the contactor to illustrate the rocking movement thereof as the contactor is moved between switching positions.

FIG. 15c is a fragmentary section, taken generally along the line 15e15e in FIG. 13, and showing the wider end of the contactor with the contactor in the same position as in FIG. 15a.

FIGS. 151, 15g and 15h are similar to FIG. 15e but show successive positions of the contactor, corresponding to the position shown in FIGS. 15b, 15c and 15d.

FIG. 16 is a rear view of a modified switch, to be described as a second embodiment of the invention.

FIGS. 17, 18, 19 and 20 are diagrammatic rear views of the contactor for the second embodiment, the terminal head and contacts being shown in phantom. In these views, the contactor is shown in its four successive switching positions, designated Off, Run, Run/ Lights, and Start.

FIGS. 21 and 22 are side and rear views of another modified switch, to be described as a third embodiment of the present invention.

FIGS. 23, 24 and 25 are diagrammatic rear views, showing the contactor of the third embodiment in those three successive switching positions, designated Off, Run and Start.

FIGS. 26 and 27 are rear and side views of another modified switch, to be described as the fourth embodiment of the present invention.

FIGS. 28 and 29 are diagrammatic rear views, showing the contactor of the fourth embodiment in its two switching positions, designated Off and On.

FIGS. 30 and 31 are rear and side views of still another modified switch, to be described as a fifth embodiment.

FIGS. 32 and 33 are diagrammatic rear views, showing the contactor of the third embodiment in its two switching positions, designated Oif and On.

The first embodiment, shown in FIGS. l-15, will now be described in detail. While the invention is applicable to switches of various types, the illustrated embodiment comprises a switch of the automotive type. The i1- lustrated switch 40 is particularly well adapted for use as a key type multi-position ignition switch for farm tractors or the like. Thus, the switch 40 has an operating key 42, shown in its position of use in FIG. 2.

It will be seen that the switch 40 comprises a housing or casing 44, made of metal or other suitable material. The casing 44 has a forwardly projecting axial bushing 46 which is preferably threaded for use in mounting the switch. The front end of the bushing 46 is formed with a slot 48 to receive the key 42.

As shown in FIG. 13, a carriage 50 is movably mounted within the casing 44. The carriage 50 is preferably made of a plastic insulating material, .but other suitable materials may be employed. In this case, the carriage 50 is of the rotary type. An axial shaft portion 52 projects forwardly from the carriage 50 and is rotatable within the bushing 46, which provides a bearing for the shaft portion 52. A slot 54 is formed in the shaft portion 52 to receive the key 42 so that the key may be employed to rotate the carriage 50.

A contactor 56 is mounted on the carriage 50 for rotary movement therewith. In this case, the contactor 56 is generally in the form of a metal plate which is mounted on the rear side of the carriage 50, preferably in a plane perpendicular to the axis of the carriage 50. The contactor 56 is engageable with a series of stationary contacts, which will be described in detail presently. The contacts are supported by suitable means, preferably in the form of a terminal head or board 58 which is illustrated as forming a rear wall of the casing 44. The terminal board 58 is preferably in the form of a plate made of an insulating plastic material, or some other suitable material. Suitable means are provided to secure the terminal board 58 to the casing 44. As shown, the

casing 44 is provided with a flange 60 which is spun or crimped inwardly, behind the board 58.

The illustrated carriage 50 has a rearwardly projecting axial shaft portion 62 which is rotatably supported in an opening 64 formed in the terminal board 58. Thus, the terminal board 58 provides a rear bearing for the carriage 50.

The carriage 50 preferably has an enlarged cylindrical guide portion 66, disposed just in front of the rear shaft portion 62. The guide portion 66 extends through an axial opening 68, formed in the contactor 56. Thus, the guide portion 66 assists in locating the contactor 56 on the carriage 50.

Other locating means are provided to cause the contactor 56 to rotate with the carriage 50. As shown, the contactor 56 is formed with tabs or cars 70 which are bent forwardly from the contactor and are slidably received in openings 72 formed in the carriage 50.

Means are provided to bias the contactor 56 rear wardly so that it will be pressed into engagement with the various contacts on the terminal board 58. As shown, the contactor 56 is biased rearwardly by a pair of compression coil springs 74, mounted in openings 76 which are formed in the carriage 50.

One or more sealing rings 75 are preferably stretched around the front shaft 52 to engage the inside of the bushing 46. A spring 77, affording frictional retention for the key 42, is also preferably mounted around the shaft 52.

In the illustrated switch 40 the carriage 50 has a plurality of switching positions. Detent means are preferably provided to detain the carriage in certain of these positions. Such detent means preferably comprise detent balls 78, which in this case are located in the same openings 76 which also receive the springs 74. Insulating discs or other members 80 are preferably provided between the springs 74 and the balls 78, to insulate the balls from the contactor 56.

The detent balls 78 on the carriage 50 are adapted to engage cooperating detent elements on the casing 44. As shown to best advantage in FIGS. 8 and 13, such cooperating detent elements preferably take the form of depressions or recesses 81, 82, and 83, formed in the front wall 84 of the casing 44. The detent recesses 81 and 82 are circular in shape. This is also basically true of the detent recess '83, but ramps 86 are preferably formed on one side of each recess 83, so as to enable the detent balls 78 to ride easily out of the recess 83 when the carriage 50 is rotated in one direction. The detent recesses 81, 82 and 83 are formed in pairs for engagement by the two detent balls 78.

The extent of movement of the carriage 50 is determined by a pair of

stops

88 and 90, formed on the carriage 50, and a cooperating stop 92, formed on the casing 44.

In this case, the carriage 50 is detented in its first three positions, designated Off, Run/Lights, and Run. A spring 94 is provided to return the carriage 50 from the fourth position designated Start, to the third position, designated Run. The spring 94 is of the torsion type, having a pair of prongs or arms 96, formed at its opposite ends. The arms 96 are initially positioned by an arcuate stop 98 on the carriage 50. When the carriage i rotated from the Run position to Start" position, one of the arms 96 engages a stop 98 on the casing, so that the movement of the carriage is resiliently resisted by the spring 94.

The terminal board 58 is normally provided with a plurality of active contacts, which are preferably in the form of rounded contact points, projecting from the front or inner side of the terminal board. In addition, the terminal board is preferably provided with one or more dummy contacts, which may be in the form of either insulating bosses, projecting forwardly from the board, or inactive contact points.

As shown to best advantage in FIG. 4, the illustrated contact board 58 comprises two battery contact points 101 and 102, a magneto contact point 103, a contact point 104 for the lights, a Start contact point 105, and a ground contact point 106. In addition, there are three dummy contacts comprising an insulating boss 107 between the contact points 102 and 103, another insulating boss 108 between the

points

104 and 105, and an inactive contact point 109 between the ground contact 106 and the battery contact 101. The illustrated insulating

bosses

107 and 108 are in the form of semi-perforations, punched, extruded or otherwise formed from the insulating board 84.

The illustrated contact points 101-106 are in the form of spherically rounded heads of rivets 111-116, extending through the insulating board 58. The two

battery rivets

111 and 112 are connected together by means of a strap 114.

Terminals

121, 123, 124, 125 and 126 are mounted on the corresponding

rivets

111, 113, 114, 115 and 116. The terminals are preferably in the form of prongs, arranged to receive an appropriate connector, whereby the switch is connected into the electrical circuit of the associated vehicle.

As previously mentioned, the illustrated contactor 56 is in the form of a plate facing rearwardly on the carriage 50. It will seem that the contactor 56 is formed with first and second contacting portions or

sectors

131 and 132, on diametrically opposite sides of the axis of the carriage 50. It is the contacting

portions

131 and 132 which are adapted to engage the contact points 101-106. The contactor 56 has a central portion 133, whereby the

con tacting portions

131 and 132 are connected together.

The first contacting portion 131 of the contactor 56 is relatively narrow in angular extent. In any particular switching position of the contactor, the first contacting position 131 normally engages only one contact point, or one dummy contact. However, in passing from one contact point to another, the first contacting portion 131 normally engages both contact points simultaneously on a momentary basis, to achieve a make-before-break action.

On the other hand, the second contacting portion 132 of the contactor 56 is relatively wide in angular extent, so as to be adapted to form a bridge between adjacent contact points. Thus, in any particular position of the contactor 56, the contacting portion 132 normally engages two contacts. In some cases this will be two active contact points, but in other cases the contacts will include one active contact point and a dummy contact, or two dummy contacts.

With this construction, the switch may be designed to achieve a wide variety of switching functions. The active contact points and dummy contacts may be rearranged in many different ways, in accordance with the switching functions to be carried out.

The particular switching functions of the first embodiment are illustrated to best advantage in FIGS. 9-12., which show the contactor in its four successive switching positions. In the position of FIG. 9 designated Off, the first contacting portion 131 engages the magneto contact point 103, while the second contacting portion 132 engages the ground contact point 106 and the dummy contact point 109. In this position, the grounding of the magneto contact point 103 renders the magneto inoperative, so that the engine of the vehicle will not run.

In the position of FIG. 10 designated Run/Lights," the first contacting portion 131 engages the Lights contact point 104, while the second contacting portion 132 engages the battery contact point 101 and dummy contact point 109. Thus, the battery current is supplied to the lights. The magneto contact point 103 is no longer grounded, with the result that the magneto is rendered operative, so that the engine of the vehicle will run.

In the position of FIG. 11, designated Run, the first contacting portion 131 engages the insulating boss 108, while the second contacting portion 132 engages both of the battery contact points 101 and 102. In this position,

no circuit is established, but the magneto is in an operative condition so that the engine will run.

In the position of FIG. 12, the first contacting portion 131 engages the Start contact point 105, while the second contacting segment 132 engages the battery contact 102 and the insulating boss 107. Thus, the starting motor or other device is energized from the battery, so that the starting motor will turn over the engine.

The dummy contacts 107109 are preferably interspersed with the active contact points 101-106 in such a manner that the contactor 56 engages three contacts, either active or dummy, in all of the switching positions. The resulting tripod effect insures that firm contact pressure will be exerted between the contactor and each contact point. Moreover, the contactor is enabled to move smoothly between the successive switching positions.

Preferably, the edges of the contacting

portions

131 and 132 are bent away from the contact board 58 so as to form ramps which assist in the smooth movement of the contactor between the adjacent contacts. Thus, as shown in FIG. 14a, the contacting portion 131 is formed with ramps 141. As shown in FIG. 14b, the wider contacting portion 132 is formed with ramps 142.

The provision of the contact points and the interspersed dummy contacts insures that the contactor 56 will be spaced a substantial distance in front of the insulating board 58 in all positions of the contactor. Thus, the contactor never engages the surface of the insulating board, even when the contactor is moving away from one of the contact points, as the contactor is being moved between switching positions. In every instance the interruption of the circuit between any contact point and the contactor takes place in the air, away from the insulating board, so that any arcing produced by the interruption of the circuit will not burn the insulating board. This feature contributes to the long service life of the switch.

FIGS. l5a-l5h illustrate the manner in which the contactor 56 moves between the successive contact points with a rocking action, whereby there is an effective wiping action between the contactor and the contact points. The wiping action insures that good electrical contact will always be established between the contactor and each contact point. Moreover, the wiping action keeps the contact points clean and spreads the wear on the contact points over a considerable area thereof.

The controlled rocking action between the contactor and the contact points is due to the arrangement whereby the narrower portion or sector 1310f the contactor engages one contact point, while the wider sector 132 engages a pair of contact points, at each switching position. Thus the contact points are not diametrically opposite one another, but are arranged with a single contact point diametrically opposite from the space between each pair of contact points. This arrangement results in a construction in which there are an odd number of positions for the contact points around the circle defined by the centers of the contact points. Thus there are nine positions for the contact points in the switch of FIGS. l15h. Some of these positions are occupied by contact points, while others are occupied by insulating bosses or other dummy contacts.

FIGS. 15a and 15.2 represent one of the switching positions of the contactor 56. In this case, the narrower contacting sector 131 engages the contact point 103, while the wider contacting sector 132 engages the contact points 106 and 109. FIGS. 15b, 15c and 15d represent transitional positions of the narrower contacting sector 131 as the contactor is moved to the next switching position in which the narrower sector engages the contact point 104. In FIG. 15b it will be seen that the sector 131 has rocked in one direction into the valley between the contact points 103 and 104. In FIG. 15c, the sector 131 has returned to an even keel, in which the sector engages both contact points 103 and 104. In FIG. 15d, the sector 131 has rocked in the opposite direction as it moves away from the contact point 103 toward its next switching position, in which it is centered over the contact point 104.

FIGS. 151, 15g and 15h correspond to FIGS. 15b, 15c and 15d, respectively, and show the same rocking movement as it affects the wider segment 132. In FIG. 15 the sector 132 is rocking into the valley between the contact points 106 and 109. In FIG. 15g, the sector 132 has returned to an even keel and is centered over the contact point 109. In FIG. 1511, the sector 132 has rocked into the valley between the contact points 109 and 101. In the next switching position the sector 132 is centered between the contact points 109 and 101 and is on an even keel, much the same as in FIG. 152.

In FIGS. 15b and 15 the contactor 56 is viewed from its opposite ends. This accounts for the opposite inclination of the contactor in the two views, which actually represent the same position of the contactor. Similarly, the oppositely inclined angles of the contactor in FIGS. 15d and 1511 are due to the fact that the contactor is being viewed from opposite ends.

To provide for the tilting or rocking movement of the contactor 56, the driving ears or lugs 70 are tapered, as shown in FIGS. 14a and 14b. Thus the ears are able to rock in the openings 72.

The flexibility and versatility of the basic switch construction will be illustrated by describing several modified embodiments. The second embodiment is shown in FIGS. 16-20 It comprises a modified ignition switch 200 having four switching positions, shown in FIGS. 17-20. The switch 200 may be the same in construction as the switch 40, except for the fact that the contact points and dummy contacts are rearranged on the insulating board 58. Thus, as shown, in FIGS. 17-20, the switch 200 comprises two battery contact points 201 and 202, a magneto contact point 203, a contact point 204 for the lights, a start contact point 205, and a ground contact point 206. There are three dummy contacts comprising an insulating boss 207 between the contact points 203 and 204, an insulating boss 208 between the points 204 and 205, and an insulating boss 209 between the

points

206 and 201.

In the position of FIG. 17, designated Off, the first contacting portion 131 of the contactor 56 engages the ground contact point 206. The wider contacting portion 132 engages the magneto contact 203 and the insulating boss 207. Thus the magneto contact is grounded so that the engine of the vehicle will not run.

In the position of FIG. 18 designated Run, the first contacting portion 131 engages the insulating boss 209. The second contacting portion 132 engages the insulating boss 207 and the contact point 204. Thus no circuit is established. The engine will run, because the magneto contact is not grounded.

In the position of FIG. 19, designated Run/Lights, the contacting portion 131 engages the battery contact 201. The wider contacting portion 132 engages the Lights contact 204 and the insulating boss 208.

In the fourth position of FIG. 20, the narrower contacting portion 131 engages battery contact 202. The wider contacting portion 132 engages the Start contact 205 and the insulating boss 208.

The first and

second embodiments

40 and 200 are in the form of four position switches. The third embodiment shown in FIGS. 21-25, is in the form of a threeposition switch 300. Here again, the switch 300 is basically the same as the switch 40, except that the contact points and dummy contacts have been rearranged. Suitable changes are also made in stops and detents, so as to accommodate the three operating positions. As shown in FIGS. 2325, the terminal board 58 of the modified switch 300 is provided with first and second battery contact points 301 and 302, first and second Start contact points 303 and 304, and first and second ignition contact points 305 and 306. In addition, there are two dummy contacts comprising an insulating boss 307 disposed between the contact points 304 and 305, and an insulating boss 308 between the contact points 301 and 306, and somewhat closer to the contact point 301.

In the first switching position, shown in FIG. 23 and designated Off, the narrower contacting portion 131 of the contactor 56 engages the insulating boss 307. The wider contacting portion 132 engages the battery contact point 301 and the insulating boss 308. Thus no circuit is established.

In the position of FIG. 24, designated Run, the narrower contacting portion 131 engages the ignition contact point 305. The wider contacting portion 132 engages the battery contact points 301 and 302. Thus the ignition circuit is energized from the battery.

In the-position of FIG. 25 designated Start, the narrower contacting portion 131 engages the second ignition contact point 306. The Wider contacting portion 132 engages the battery contact 302 and the Start contact 303.

As before, the contactor 56 is spring returned from the Start position of FIG. 25 to the Run position of FIG. 24. During the return movement of the contactor, the ignition'circuit is maintained without interruption by virtue of the make-before-break action of the contactor 56. The wider contacting segment 132 is wide enough to engage both battery contact points 301 and 302 simultaneously, so that the circuit to the battery is inherently maintained. In the Start position of FIG. 25, the contactor engages only the second battery contact 302, while engaging both

battery contacts

301 and 302 in the Run position of FIG. 24.

The narrower contacting portion 131 is wide enough to engage both of. the

ignition contacts

305 and 306 on a momentary basis during the return movement in which the contactor moves between the

contacts

305 and 306. Thus there is no interruption of the ignition circuit.

FIGS. 26-29 illustrate a fourth embodiment in the form of a two-position switch 400. Here again, the switch is basically the same as before, except that the contacts are rearranged. Moreover, suitable changes are made in the stops and detents to produce a two-position switch.

As shown in FIGS. 28 and 29, there are only two active contact points 401 and 402, which are in adjacent positions on the terminal board 58. There are three dummy contacts, comprising insulating

bosses

407, 408 and 409.

In the switching position of FIG. 28, designated Off, the narrower contacting portion 131 of the contactor 56 engages'the insulating boss 407. The wider contacting segment 132 engages the contact point 401 and the insulating boss 409. Thus no circuit is established.

In the switching position of FIG. 29, designated On, the narrower contacting portion 131 engages the insulating boss 408. The wider contacting portion 132 engages the contact points 401 and 402.

FIGS. 30-33 illustrate still another embodiment in the form of another two-position switch 500. As shown in FIGS. 32 and 33, the switch 500 comprises contact points 501, 502, 503 and 504. The terminal board 58 is also provided with dummy contacts in the form of insulating

bosses

507 and 508, adjacent the contact points 501 and 503. As before, the contact points 501-504 are preferably in the form of rounded heads of

rivets

511, 512, 513 and 514. The first terminal 521 is mounted on the

rivets

511 and 512, while the second terminal 522 is mounted on the rivets 513 and 514. Thus the contact points 501 and 502 are connected together by the terminal 521. Similarly, the contact points 503 and 504 are connected together by the terminal 522.

In the switch 500 the contact points 501-504 are of large size to provide high current carrying capacity. The

terminals

521 and 522 are also of large size.

In the switching position of FIG. 32, designated Off, the narrower contacting portion or segment 131 engages the insulating boss 508. The wider contact segment 132 engages the contact point 501 and the insulating boss 507. Thus no circuit is established.

In the switching position of FIG. 33, designated On, the narrower contacting segment 131 engages the contact point 503. The wider contacting segment 132 engages the contact points 501 and 502. Thus a circuit is established between the terminal 521, connected to the

points

501 and 502, and the terminal 522, connected to the point 503.

It will be evident that the switch construction of the present invention is extremely versatile and may readily be adapted to produce a line or series of switches capable of performing a wide variety of switching functions. New switching functions can be achieved by rearranging the active contact points and the dummy contacts on the terminal head. This can readily be done, particularly in view of the fact that all of the active contact points may be in the form of rivet heads. Thus the tooling cost involved in rearranging the contact points is quite low.

The same basic contactor construction can be employed for many different switches. Moreover, the casing and the carriage can be basically the same for a Wide variety of switches. Only the detents and stops need be changed to produce new switches. The tooling costs involved in relocating the detents and the stops may be quite low. Normally, the carriage is molded from an insulating plastic material. The stops may be produced by using removable inserts in the mold. In this way, the stops can readily be relocated.

The casing is normally die cast. The detent recess may be formed by using movable inserts in the die or mold so that the detent recess may readily be relocated when new switches are to be produced.

In any particular switching position, the contactor may engage one, two or three contact points. Thus the narrower contacting segment of the contactor may engage one contact point. Alternatively, it may engage the insulating boss or other dummy contact. The wider contacting segment may engage two contact points in some instances. In other cases, the wider contacting segment may engage one contact point and an insulating boss, or two insulating bosses.

Several embodiments have been disclosed in detail, but it willbe realized that many other new switches may be produced, using the basic switch construction of the present invention. The switching functions involved in a great many situations may be performed by the switches of the present invention.

Various other modifications, alternative constructions and equivalents may be employed without departing from the true spirit and scope of the invention, as exemplified in the foregoing description and defined in the following claims.

I claim:

1. An electrical switch, comprising a casing,

an insulating carriage rotatable in said casing to a plurality of angularly spaced positions,

an insulating support mounted on said casing opposite said carriage,

a plurality of angularly spaced contact points mounted on said insulating support,

a contactor mounted on said carriage for movement therewith and engageable with said contact points, and spring means mounted on said carriage and biasing said contactor toward said contact points,

said contactor being in the form of a fiat conductive plate mounted on said carriage and substantially perpendicular to the axis of rotation thereof,

said contactor having first and second diametrically opposite portions constituting sectors of said conductive plate,

said first portion of said contactor being of such narrow angular extent as to be engageable with only one of said points at each position of said carriage,

said second portion of said contactor being wider than said first portion and of such angular width as to engage two of said points in at least one position of said carriage,

said first and second portions of said contactor being symmetrical about a common diametrical axis,

2. A switch according to claim 1,

in which the angular spacing between adjacent positions of said carriage corresponds to one-ninth of a complete revolution,

said contact points being correspondingly spaced.

3. A switch according to claim 1,

including at least one dummy point projecting from said insulating support toward said carriage for engagement by said contactor,

the spacing between said dummy point and the adjacent point corresponding to the spacing between the successive positions of said carriage.

4. An electrical switch, comprising a casing,

a carriage rotatable in said casing to a plurality of angularly spaced positions,

a rotatable operating shaft extending forwardly from said carriage and out of said casing,

an insulating support mounted on said casing to the rear of said carriage,

a plurality of contact points mounted on said insulating support,

a contactor mounted on the rear side of said carriage for movement therewith and engageable with said contact points,

and spring means biasing said contactor rearwardly relative to said carriage,

said carriage having an axially disposed cylindrical guide portion projecting rearwardly therefrom,

said contactor having an axially disposed guide opening slidably receiving said cylindrical guide portion of said carriage,

said contactor having at least one locating tab projecting forwardly therefrom,

said carriage being formed with a locating opening slidably receiving said locating tab to establish the operating position of said contactor relative to said carriage.

5. A switch according to claim 4,

in which said contactor is formed with a plurality of such locating tabs,

said carriage being formed with a plurality of locating openings slidably receiving said tabs.

References Cited UNITED STATES PATENTS 2,715,661 8/1955 Miller 2004 XR 3,239,615 3/1966 Schink et al. 200-44 3,334,198 8/1967 Bedocs et al.

ROBERT K. SCHAEFER, Primary Examiner J. R. SCOTT, Assistant Examiner US. Cl. X.R. 200-44