US3159722A

US3159722A - Rotary switch

Info

Publication number: US3159722A
Application number: US96790A
Authority: US
Inventors: Jesse M Cobb; Harry J Krol
Original assignee: Indak Manufacturing Corp
Current assignee: Indak Manufacturing Corp
Priority date: 1961-03-20
Filing date: 1961-03-20
Publication date: 1964-12-01
Anticipated expiration: 1981-12-01

Description

Dec. 1, 1964 J. M. COBB ETAL 3,159,722

ROTARY SWITCH Filed March 20, 1961 3 Sheets-Sheet l INVENTORS Jesse M. Cabb y Harry J. Krol Qfflys Dec. 1, 1964 J. M. COBB ETAL 3,159,722

I ROTARY SWITCH Filed March 20, 1961 3 Sheets-Sheet 2 INVENTORS Jsse M Cobb Harry J. Krol aizf'ys Dec. 1, 19 J. M. COBB ETAL ROTARY SWITCH Filed March 20, 1961 3 Sheets-Sheet 5 INVENTORS Jesse M. Cobb arry J. k'rol aziy's BY QM I A a u no llrhblllllll i am United States Patent 3,159,722 RQTARY SWITCH Jesse M. Cobb, Glenview, and Harry J. Krol, Arlington Heights, 111., assignors to Indak Manufacturing Corp., Northhroolr, Ill., a corporation oi Iilinois Filed Mar. 20, 1961, Ser. No. 96,790 3 Claims. (Cl. 260-41) This invention relates to new and improved switches of the rotary type and having a plurality of positions. Such switches find applications, for example, in the automotive field, for use in controlling heaters and other electrical equipment.

One object of the present invention is to provide a new and improved switch having a highly advantageous and economical detent and spring arrangement which is formed integrally with the rotor of the switch.

A further object of the present invention is to provide a rotary switch having an improved contact construction, insuring the maintenance of substantially uniform contact pressure in all positions of the switch.

Another object is to provide a new and improved switch having a contact construction which gives the eifect of three-point distribution of the contact pressure between the rotary contactor and the contact points, even though, in some positions of the switch, only two contact points may be in engagement with the contactor.

Still another object is to provide a new and improved switch which is durable in construction and eifective in operation, yet is easy to manufacture and low in cost.

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

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

FIG. 2 is a rear view of the switch.

FIG. 3 is a longitudinal section, taken generally along a line 3-3 in FIG. 2.

FIGS. 4, 5, 6 and 7 are cross sectional views, taken generally as indicated by lines and arrows 4-4, 5 5, 6-6 and 7-7 respectively, in FIG. 3.

FIGS. 8 and 9 are fragmentary sectional views, taken generally along the lines 8-8 and 99 in FIG. 7.

FIG. 10 is a rear view of the rotor for the switch of FIG. 1.

FIG. 11 is a side view of the rotor, taken as indicated by the line 1111 in FIG. 10.

FIG. 12 is a top viewof the rotor, taken as indicated the contactor in its high position, in which the contactor engages three contact points.

' FIG. 16 is a fragmentary enlarged section taken gen- ;erally along a line 16-16 in FIG. 15.

FIG. 17 is an elevational view of a modified switch, representing another embodiment of the invention.

FIG. 18 is a central longitudinal section of the switch of FIG. 17. 7

FIGS. 19, 20 and 21 are cross sectional views, taken generally along lines 19-19, 2ll20 and 21-21, re

spectively, inFIG. 18, FIGS. 19 and 21 being drawn to enlarged scales.

3,159,722 Patented Dec. 1, 1964 It will be seen that FIG. 1 illustrates a rotary switch 30 which will find many applications, but is of a general type which is often employed in automotive services for controlling electrically driven accessories such as heaters or the like. The illustrated switch 30 has a casing 32 which is generally of a square shape. A threaded bushing 34 projects forwardly from the casing 32 and may be employed for mounting the switch on a control panel bracket, or the like. The switch has a shaft 36 which extends forwardly from the bushing 34 and is rotatably mounted therein.

In this case, the rear of the casing 32 is closed by a terminal plate or board 38 which is made of electrically insulating material. The plate 38 may be secured to the casing 32 by means or" a plurality of tabs 0r flanges 48 which are formed on the casing and are bent over behind the plate 38. To locate the plate 38, notches 42 may be formed in the edges of the plate to receive the tabs 40.

The illustrated switch 30 is provided with three terminals in the form of lugs or

angle members

44, 45 and 46, secured to the insulating plate 38. However, it will be understood that the number of terminals may be varied according to the number of circuits to be controlled by the switch.

As shown to advantage in FIG. 3, the switch 30 has a rotor 48 which is preferably molded in one piece from nylon or some other suitable plastic material. The shaft36 may be made of metal and may be mounted in a bore 59 formed in the rotor. The illustrated shaft 36 is provided with a serrated rear end portion 52 which may be pressed securely into the bore 56 so as to be retained therein.

As clearly shown in FIG. 5, a generally ring-shaped contactor 54 is mounted on the rotor 48. It will be seen that the rotor 48 has a rear portion 56 which is received within a generally circular opening 58 in the contactor 54. Notches 60 and 61 are formed in the edge of the opening at diametrically opposite points to receive outwardly projecting keys or

lugs

62 and 63, formed on the rotor member 56. Engagement of the

keys

62 and 63 with the notches 60 and 61 insures that the contactor 54 will rotate with the rotor.

The illustrated switch 30 is provided with three

contact points

66, 67 and 68 which are mounted on the insulating plate 38 and are riveted or otherwise secured to the

terminal lugs

44, 45 and 46, respectively. In the various positions of the switch, the contactor 54 is engageable with the contact points to establish circuits therebetween, as will be described in greater detail shortly.

It will be seen that the rotor 48 has a rearwardly projecting journal or pin 70 thereon. An opening 72 is formed in the insulating plate $8 for rotatably receiving the journal 76. In the illustrated switch 30, the contactor 54 is biased rearwardiy against the contact points and 68, by means of a spring 74 which acts between the contactor and a pair of arms 76 on the front portion of the rotor. Preferably, the spring 74 is of the conical coil type tapering in diameter from front to rear. Rearwardly projecting lugs or flanges 78 are formed on the arms '76 to retain the front end of the spring 74.

The rotor 48 is movable to a plurality of positions and is detented and located in each of such positions by a novel detent arrangement 80, comprising a pair of detent projections 82, formed on the rotor 48, and a series of detent grooves or

troughs

84, 85 and 86, formed in the front wall 88 of the casing 32. In this case, there are three detent grooves to locate the rotor 48 in three diifen ent positions, but it will be understood that any desired number of detent grooves may be provided, in accordance with the desired number of positions of the switch.

to As shown to advantage in FIGS. 9 and 10, each of the detent projections 82 is formed on the central portion of a flat generally semicircular web or arm 90 which is formed integrally with the plastic rotor 48. The webs or arms 99 are sufliciently thin to be flexible and resilient,

so as to serve as springs for the detent members 82. T he detent

grooves

84, 85 and 86 are actually in the plane of the front Wall 88 and are defined by rearwardly project ing rounded humps 92 which extend between the detent grooves. As the rotor 48 is turned, the bumps )2 push the detent members 82 rearwardly, with the result that the arms 96 are flexed. The rear portion 56 of the rotor 48 engages the insulating rear plate 38 and limits rearward motion of the rotor '48. The coil spring 74 biases the rotor 48 forwardly so as to maintain the detent members 82 in snug engagement with the

detent grooves

84, 85 and 86 in the various positions of the switch.

A rearwardly projecting lug 94 is formed on the rear side of each of the webs or arms 90, to the rear of the corresponding detent projection 82. A groove 96 is provided in each of the lugs 94 to retain and locate the front coil of the spring 74.

A already indicated, the contactor 54 is ring shaped and is slidably received on the rear portion es of the rotor 48. e The

keys

62 and 63 on the rotor are of different sizes, so that the contactor 54 will fit on the rotor in only one position. p p V The contactor 54 is preferably formed from sheet metal. it will be seen that the contactor 54 has a central portion 98 which represents the original plane of the sheet metal. Three contact segments ltll, 102 and 103 are formed into a plane which is displaced rearwardly from the plane of the central portion 93, so that the

segments

101, 102 and 103 will be engageable with the contact points 66, and 68 on the insulating rear plate 38. Between the contact segments 101, N2 and 1%, the contactor 54 is formed with noncontacting segments 165, 105 and 167 which are formed into a plane which is displaced forwardly from the plane of the central portion 98.

When the switch is in its off position, as shown in FIGS. 5 and 13, the contact point 66 is opposite the .noncontacting segment 107 and thus is out of engagement with the contactor 54. Normally, the contact point 66 is connected to the hot lead of the battery, or other power source, through the lug 44. Thus,the lug 4 is marked with the letter B on the rear plate 38, as shown in FIG. 2. The lug 45 is marked with the letter L representing low, while the lug 46 is marked with the letter H, representing high. The

lugs

45 and 46 are connectedto the contact points 6'7 and 68, respectively. In the oil position, one of the arms 76 on the rotor 4S engages a stop :l ltl which is formed inwardly from one wall of the casing 32. The contact point 67 is opposite the noncontacting segment 105, while the contact point 68 is opposite the noncontacting segment 1%.

To engage the contacting segments 101, 1&2 and 103, insulating plate 38 is formed with a plurality of forwardly projecting insulating points or member'slll, 112, 113 and 114 which may be produced by partially punching or extruding disc shaped elements from the plate. In this case there are four insulating points, but the number may be varied to suit the requirements of the switch. In the oil position of the switch, the

contact'segments

101, 102 and 103 are engagedby the insulating

points

111, 112 and 113, respectively. Thus, these are three points of contact with the contactor 54. This arrangement insures that the contactor will not have any tendency to rock relative to the rotor 48.,

In the next position of the switch, which may be designated the low position, the rotor '43 is turned to bring the contactor 54 to the position shown in FIG. 14. The battery contact point at now engages the contact segment 101, so that b'att ery current is supplied to the contactor 54. The contact segment 102 engages the contact point 68.

so that this contact point and the lug 46 are connected to the battery. The contact point 67 is still opposite the noncontacting segment 105. To provide for three point contact with the contactor 54, the insulating point 114 engages the contact segment 103. The insulating

points

112 and 113 are opposite the noncontacting segments 1G7 and 166, respectively, and thus are out of engagement with the contactor. The insulating point 111 is opposite the contact segment 161 but does not engage such segment because the insulating point projects forwardly to a lesser extent than the contact point 66 which is in engagement with the segment 181.

In the third position of the switch, which may be designated the high position, the rotor 48 is rotated until the arm it engages a second stop 116 formed inwardly from the casing 32. The battery contact point 66 still engages the contact segment 101, as shown in FIG. 15. However, the contact point 68 is now opposite the noncontacting segment Th7 and thus is out of engagement with the c'ontactor 54. The contact point 67 engages the contact segment 193 so that the contact point 67 and the lug 45 are connected to the battery terminal 44'. The Contact segment 16 2 engages the insulating point 113 to provide for three point contact with the contactor. The other insulating points are out of engagement with the contact'or.

It will be apparent that the arrangement of the insulating point 111-114 insures that there will be three points of engagement with the contactor 54 in all of the 'positions of the switch. In this way, the contact pressure between the contact points and the contacto'r will be 'evenly distributed, and there will be no tendency for the contactor to rock relative to the contact points.

FIGS. 17-21 illustrate a modified switch 130 which is the same as the switch 3601f FIGS. 1-16, except that the shaft 36 is replaced with a shaft 136 which is slidable longitudinally through the rotor 148. The rear end 'of the shaft 136 is connected to a flexible resilient wire 202 which is adapted to operate a push-pull type control, such as an air control valve or deflector for an automotive heater or the like. The wire 202 is slidable within a protective flexible sheath 2% which may be in the form of a closely coiled helical wire. The rear portion of the shaft 136 isslidab-le within .a tubular guide 295 secured to the insulating plate 138. It will be seen that one end of the sheath 2% is received within and secured to the rear end of the tubular guide 206. A coupler 2% is employed to connect the rear end of the shaft 136 to the front end of the wire 262.

The shaft 13s is noncircul-ar in cross section and is slidable within an opening 210 of corresponding shape in the rotor 148. In this instance, the shaft 136 has a flat 212 on one side and a keywa'y 214 on the opposite side. The opening 219 receives the shaft 136 with a close sliding fit so that the rotor 14% will rotate with the shaft 136.

In all other particulars, the switch may be the same as the switch 30. To the extent that the switches are the same, the same reference chanacters are employedin FIGS. l7-2l as in FIGS. 1-16.

It will be apparent that each of the illustrated switches is provided with an effective and economical detent arrangement in which the detent inl'ernber's 82 are connected to the rotor by the integral flexible arms 90 which serve as springs for the detent members. Another important feature resides in the manner in which the insulating points 111-114 insure that the contac'tor will be engaged the true spirit and scope of the invention, as exemplified in the foregoing description and defined in'the following claims.

We claim:

1. In a switch, the combination comprising a casing, a plastic insulating rotor mounted in said casing for rotation to a plurality of positions, contact means operable by said rotor, a plurality of detent channels on said casing corresponding to said positions of said rotor, a pair of plastic detent members engageable with said detent channels, and \a pair of thin flexible generally semicircular plastic arms resiliently connecting said detent members to said rotor; each detent member being disposed sub stantially midway between the ends of the corresponding semicircular arm, the ends of each arm being connected to said rotor; said rotor, said arms and said detent memhere being formed integrally from resilient plastic material.

2. In a switch, the combination comprising a casing, a plastic insulating rotor mounted in said casing for rotation to a plurality of positions, a contactor rotatable with said rotor, a plurality of detent channels on the front portion of said casing and corresponding to said positions of said rotor, a pair of plastic detent members engageable with said detent channels, a pair of thin flexible generally semicircular plastic arms resiliently connecting said detent members to said rotor, each of said arms having its ends connected to said rotor, each of said detent members being disposed substantially midway between the ends of the corresponding semicircular arm, said arms and said detent members being formed integrally with said rotor,

contact means in said casing to the rear of said rotor and engageable by said contactor, and a spring acting between said contactor and said rotor for biasing said contactor rearwardly against said contact means, while biasing said rotor forwardly to urge said detent members against said detent channels.

3. In an electric switch, the combination comprising a casing, a rotor rotatably mounted in said casing, a contactor rotatable with said rotor and having a plurality of imperforate arcu-ate contact segments, an insulating member mounted on said casing to the rear of said rotor, a spring biasing said contactor toward said insulating member, .a plurality of conductive contact points on said insulating member and engageable by said contact segments of said contactor, said contact points projecting forwardly from said insulating member, a plurality of insulating points projecting forwardly from said insulating member and disposed thereon between said contact points and engageable by said contact segments, and detent means for detaining said rotor in a plurality of operative positions, said detent means being separate from said contact segments and said contact point-s and insulating points, certain of said contact segments being engageable with certain of said insulating points while other of said contact segments are simultaneously engageable with certain of said contact points in at least one of said operative positions of said rotor, the engagement of said insulating points with said contact segments being effective to maintain three-point contact with said contactor to prevent excessive and uncontrolled rocking of said contactor in its various operative positions.

References Cited in the file of this patent UNITED STATES PATENTS 1,663,779 Soreng Mar. 27, 1928 1,696,744 Wynran Dec. 25, 1928 1,828,433 Norviel Oct. 20, 1931 1,855,612 Salinas Apr. 26, 1932 2,519,215 Appleton et a1. Aug. 15, 1950 2,530,006 Ellithorpe Nov. 14, 1950

Claims

3. IN AN ELECTRIC SWITCH, THE COMBINATION COMPRISING A CASING, A ROTOR ROTATABLY MOUNTED IN SAID CASING, A CONTACTOR ROTATABLE WITH SAID ROTOR AND HAVING A PLURALITY OF IMPERFORATE ARCUATE CONTACT SEGMENTS, AN INSULATING MEMBER MOUNTED ON SAID CASING TO THE REAR OF SAID ROTOR, A SPRING BAISING SAID CONTACTOR TOWARD SAID INSULATING MEMBER, A PLURALITY OF CONDUCTIVE CONTACT POINTS ON SAID INSULATING MEMBER AND ENGAGEABLE BY SAID CONTACT SEGMENTS OF SAID CONTACTOR, SAID CONTACT POINTS PROJECTING FORWARDLY FROM SAID INSULATING MEMBER, A PLURALITY OF INSULATING POINTS PROJECTING FORWARDLY FROM SAID INSULATING MEMBER AND DISPOSED THEREON BETWEEN SAID CONTACT POINTS AND ENGAGEABLE BY SAID CONTACT SEGMENTS, AND DETENT MEANS FOR DETAINING SAID ROTOR IN A PLURALITY POSITIONS, SAID DETENT MEANS BEING SEPARATE FROM SAID CONTACT SEGMENTS AND SAID CONTACT POINTS AND INSULATING POINTS, CERTAIN OF SAID CONTACT SEGMENTS BEING ENGAGEABLE WITH CERTAIN OF SAID INSULATING POINTS WHILE OTHER OF SAID CONTACT SEGMENTS ARE SIMULTANEOUSLY ENGAGEABLE WITH CERTAIN OF SAID CONTACT POINTS IN AT LEAST ONE OF SAID OPERATIVE POSITIONS OF SAID ROTOR, THE ENGAGEMENT OF SAID INSULATING POINTS WITH SAID CONTACT SEGMENTS BEING EFFECTIVE TO MAINTAIN THREE-POINT CONTACT WITH SAID CONTACTOR TO PREVENT EXCESSIVE AND UNCONTROLLED ROCKING OF SAID CONTACTOR IN ITS VARIOUS OPERATIVE POSITIONS.