US3214528A

US3214528A - Rotary electrical switch with movable spring contact structure

Info

Publication number: US3214528A
Application number: US330830A
Authority: US
Inventors: Jr Richard W Seabury; William A Yonkers
Original assignee: RADIO FREQUENCY LAB Inc
Current assignee: RADIO FREQUENCY LAB Inc; RADIO FREQUENCY LABORATORIES Inc
Priority date: 1963-12-16
Filing date: 1963-12-16
Publication date: 1965-10-26
Anticipated expiration: 1982-10-26

Description

1 a t 5 w m & 2, w 3 w h S 5 Oct. 26, 1965 R. w. SEABURY, JR.. ET AL ROTARY ELECTRICAL SWITCH WITH MOVABLE SPRING CONTACT STRUCTURE Flled Dec 16 1963 RICHARD m SEABURY JR. WILLIAM A. ro/v/(ERs INVENTORS T FIVE Y R. W. SEABURY, JR., ET AL ROTARY ELECTRICAL SWITCH WITH MOVABLE Oct. 26, 1965 SPRING CONTACT STRUCTURE Filed Dec. 16, 1963 3 Sheets-Sheet 2 R/GHARD W. SEABURY JR.

YO/VKERS W/LL/AM A INVENTORS A ORA/E Y Oct- 6, 1 6 R. w. SEABURY, JR.. ET A]. 3,2

ROTARY ELECTRICAL SWITCH WITH MOVABLE SPRING CONTACT STRUCTURE Filed Dec. 16, 1963 3 Sheets-Sheet 3 RICHARD W. SE ABURY JR. WILL/AM A. YO/VKERS I NVENTORS United States Patent 3,214,528 ROTARY ELECTRICAL SWITCH WITH MOVABLE SPRING CONTACT STRUCTURE Richard W. Seabury, Jr., Towaco, and William A. Youkers, Mountain Lakes, N.J., assignors to Radio Frequency Laboratories, Inc., Boonton, N.J., a corporation of New Jersey Filed Dec. 16, 1963, Ser. No. 330,830 13 Claims. (Cl. 200-11) This invention relates to electrical switches and more particularly to a multi-point rotary switch of novel construction and outstanding operating characteristics.

Rotary electrical switches of the class to which this invention is directed comprise a plurality of arcuatelyspaced fixed contacts, one or more movable contacts and an indexing mechanism for effecting step-by-step engagement of the movable contact with the stationary contacts. In many applications, it is essential that the contacts of the switch have a negligible and constant ohmic resistance and a low thermal coefficient. Also, the switch should be of rugged construction, have a high current carrying capacity, and be adapted for use in relatively high voltage circuits with complete safety to the operator. Additionally, the switch should be constructed to permit the soldering of heavy connecting leads, or cables, thereto with a minimum possibility of damage occurring during th soldering operation. I

A rotary electrical switch made as herein disclosed, provides the above-mentioned, and other, desirable characteristics.

An object of this invention is the provision of a highquality, multi-point rotary switch of rugged construction.

An object of this invention is the provision of a multi point rotary switch of relatively small size and weight, which switch has a high current carrying capacity and a low, constant contact resistance whereby the switch is adapted for use in very low voltage circuits.

An object of this invention is the provision of a multipoint rotary switch wherein the stationary contacts of the switch also constitute the terminals by means of which the switch is connectable into an electrical circuit.

An object of this invention is the provision of a multipoint rotary switch wherein electrical continuity between a common contact and a selected stationary contact is effected by means of a plurality of flexible spring members in such manner as to provide a very low, constant contact resistance.

An object of this invention is the provision of a multipoint rotary switch comprising a plurality of arcuatelyspaced, longitudinal contact rods carried by a stator member, a rotor member carrying a plurality of wire springs having inturned ends with the ends of adjacently-disposed springs being reversely disposed, spaced shafts for rotating the rotor member relative to the stator member and an indexing mechanism for positioning the rotor member such that a selected contact rod is engaged by all of the offset spring ends.

An object of this invention is the provision of a multipoint rotary switch comprising a plurality of longitudinally-disposed, arcuately-spaced contacts, a central contact, a rotor carrying a plurality of flexible wire springs and providing. a low resistance electrical path between the central contact and a selected one of the arcuatelyspaced contacts, and a pair of spaced, parallel shafts for rotating the rotor.

These and other objects and advantages of the invention will become apparent from the following description when taken with the accompanying drawings. It will be understood, however, that the drawings are for purposes of illustration and are not to be construed as defining the 3,214,528 Patented Oct. 26, 1965 scope or limits of the invention, reference being had for the latter purpose to the claims appended hereto.

In the drawings wherein like reference characters denote like parts in the several views:

FIGURE 1 is an exploded, isometric view showing the components of the rotor of a switch made in accordance with this invention;

FIGURE 2 is a similar view showing the components of the stator;

FIGURE 3 is a similar view of the components forming the indexing mechanism;

FIGURE 4 is a plan view showing the first step in the assembly of the switch, namely, with the case of the rotor mounted on the bottom plate of the stator;

FIGURE 5 is a side, elevational view thereof, with certain parts broken away; I

FIGURE 6 is a side elevational view showing the second step in the assembly of the switch, namely, with the rotor cap secured to the rotor case;

FIGURE 7 is a similar view showing the third step in the assembly of the switch, namely, with the top stator plate secured in place and the indexing bushing slidably positioned over the switch-actuating rods;

FIGURE 8 is a plan view of the FIGURE 7 sub-assembly and showing other components of the switch-indexing mechanism assembled in operative position;

FIGURE 9 is a front view of the switch-operating knob;

FIGURE 10 is a side view therefore with portions shown in cross-section;

FIGURE 11 is a rear view of the knob;

FIGURE 12 is an enlarged, fragmentary plan view, showing the rotor, carrying the flexible contact springs, positioned at a point wherein the end loops of the springs lie between adjacent, stationary contacts of the switch;

FIGURE 13 is a similar view but showing the rotor rotated to a position wherein the end loops of the springs are in engagement with a stationary contact; and

FIGURE 14 is a side, elevational View of the complete switch, with certain parts broken away and certain parts shown in cross-section.-

Reference, now, is made to FIGURE 1, which is an exploded, isometric view showing the components which go to make up the rotor. The rotor comprises a housing formed by a case 10 and a cap 11 molded of a suitable plastic. The case is a unitary member comprising a base 12 and a peripheral longitudinally-extending wall 13, which wall also extends across the base to form the arcuate portion 14. Adjacent to the wall portion 14 is a cylindrical boss 15 having a longitudinal hole 16 ex tending therethrough. A generally arcuate boss 17 also extends upwardly from the base and has a hole 18 extending therethrough. The base also is provided with a central hole 19 and three holes which snugly receive the

plastic pins

20, 21 and 22. These pins serve to locate a plurality of flexible wire springs, which springs estab lish electrical contact between the common contact and the stationary contacts of the switch, as will be described in detail hereinbelow.

A plurality of similar wire springs, such as those identifie'd by the numerals 24, :24, have closed loops 25, 25' formed in the central portions thereof, relatively small loops 26, 2'6 formed at one end and relatively large open loops 27, 27' formed at the other end. The assembly of the wire springs on the rotor base 10 will be described herei-nbe'low wit'h specific reference to FIGURE 4. It is here pointed out that the closed, central loop 25, of the spring 24, is slidably inse-rtable over the pin 22, (carried by the base) while the large open loop 27 will loosely en-. circle the pin 21. Similarly, the central loop 25, of the spring 24, is slidably insertable over the pin with the large open loop loosely encircling the common pin 21.

the common contact.

The inner,

small loops

26, 2 6', of the two springs, are designed to encircle the common stationary contact of the switch, as will be described here'inbelow. Although only the two

springs

24, 24 are shown in FIGURE 1, the total number of such springs to be asembled on a given rotor base will depend upon the diameter of the spring wire and the height of the wall portion .14. A total of fourteen (14) springs has'been found to be sufficient for a switch of general utility. Adjacent springs will be reversely disposed relative to each other, with the central closed loops of the odd-numbered springs disposed over the pin 20 and the central loops of the even-numbered springs disposed over the pin 22. All springs will have their large open loops loosely disposed over the comm-on pin 21 and their small, open loops disposed over the common stationary contact of the switch.

The rotor cap 1 1 is a unitary member molded of a suitable plastic, and comprisesa circular base 129 (having a diameter correspoding to that of the case and a collar 30. The base ,is provided with three holes 31-33 for receiving the respective pins 22, '21 and (of the case 10) and the means for rotating the rotor (in the assembled switch) comprises the two

plastic rods

34 and 35 which are force-fitted through holes extending completely through the cap 111. After the flexible wire springs have been mounted on the rotor case 10, the cap .1 1 is inserted over the case \10, with the pins 20- 22 passing into the corresponding holes 31-3 3 and the

rods

34, 35 passing into the

case holes

16 and 18. 'Ihe rods are then pressed into the case holes until the end surfaces thereof 'lie flush with the outer surface of the base 12. This eifectively closes the case 10, except, of course, for that portion lying [beyond the wall portion :14. It is apparent that the wire springs will now be held captive on the pins 20 22 and that the rotor may be rotated by a suitable knob attached to the free ends of the

plastic rods

34 and 35. The described assembly has been accomplished without the use of screws or other fastening means.

Reference, now, is made to FIGURE 2, which illustrates the components which go to make up the stator. The complementary lower plate 38 and upper plate 39 preferably are made of a hard silicone-filled asbestos. "The plate '38 is provided with a central hole and a plurality of equally-spaced margina-l'holes corresponding in number to the number of stationary contacts of the particular switch, which, in the case illustrated, will be a twelve point switch. The stationary contacts comprise metal rods 40-51, whereas the center rod 52 constitutes All of these rods are ttorced-fitted through the holes and initially extend from the plate (to the right) a distance somewhat greater than that of the radial thickness of the assembled rotor, for purposes which will become apparent as the description proceeds. The rotor plate 39 is provided with marginal bores, not visible in the drawing, which bores receive the ends of the rods 40-51 when the switch is assembled. The plate 3 9 also is provided with four holes 53-56 for receiving the internally-threaded, metal inserts 57-60. These in serts, provided with knurled outer surfaces, are forced into the holes and the ends then are spun outwardly so that the inserts will :not turn relative to the plate. Two diametrically-opposed inserts serve to secure the indexing plate to the switch whereas the other two inserts serve as means for mounting the complete switch on a panel. A bushing 60 is force fitted over the center rod 52 and into contact with the surface of the lower plate 38. This bushing has an outside diameter so as to fit nicely into the central hole 19 of the rotor case 10 (see FIG- U RE 1) and serves as the lower bearing for the rotor.

FIGURE '3 shows the components of the indexing mechanism. A metal collar '64 (having an outside diameter) cor-responding to that of the collar 30 of the rotor cap, (see FIGURE 1) has a pair of metal bushings 65, 66' :torcefitted into appropriate holes formed therein. The internal diameters of the bushing holes are slightly larger than the diameters of the operating

rods

34, 35 of the rotor so that the collar may be slidably inserted over the rods. The collar is also provided with a transverse hole 67, which hole communicates with the

longitudinal grooves

68, 69 having arcuate bottom walls. A com pression spring 70 is positionable within the collar 'hole 6 7, whereas the

grooves

68 and 69 are adapted to receive the metal rollers 71 and 712. *In the assembled switch; the spring presses the rollers into diametrically opposed notches formed in the metal indexing plate 73, which plate includes four holes corresponding in location to the holes 53 formed in the upper stator plate 39 (see FIGURE 2). An inner spacer Washer 74, made of plastic, is p0 sitionable over the circular base portion of the collar 64, thereby to position the indexing plate 73 centrally with respect to the rollers. A generally similar plastic Washer 75 is positionable over the indexing plate 73.

Reference, now, is made to FIGURES 4 and 5, which illustrate the first step in the assembly of the switch. As stated hereinabove, the center contact rod 52 and the arcuately-spaced contact rods 40-51 are force-fitted through the hole formed in the lower statorplate 38 and initially extend forwardly, as Viewed in FIGURE 4, a distance somewhat greater than the axial thickness of the rotor. The rotor case 10 is first positioned on the lower stator plate 38 with the bearing 61 disposed within the central hole formed in the case. The flexible wire springs are now mounted intoposition, one by one, with adjacent such springs reversely disposed relative to each other. Only two such springs 24, 24' are shown in FIGURE v4 whereas the complete pile up .of the springs is shown in FIGURE 5. Further, for clarity .of presentation, only two

contact rods

40 and 46 are shown in FIGURE 5. The large, open loops of the springs loosely encircle the common pin 21 and the small, open loops fit snugly around the center contact rod 52. It is here pointed out that the springs are so formed that the distance between the spring end loops is greater than that between the pin 21 and the center rod 52 Consequently, whenthe closed center loops of the springs are inserted over the

respective pins

20 and 22, the spring ends must be flexed toward each other in order to insert the end loops over the pin 21 and the center rod 52. The resulting spring tension provides good electrical contact between the center rod 52 and the encircling spring loops and, at the same time, biases the large spring loops outwardly so that these loops abut against the common 'pin 21. As shown in FIGURE 4, however, the large loops of the springs are in contact with the fixed contact rod 40, whereby electrical continuity is established between this contact rod and the center rod 52.

The next step in the assembly of the switch is shown in the side elevational view of FIGURE 6.. The base portion 29, of the rotor cap 11, is placed over the rotor case 10, with the three pins passing into the holes provided for this purpose, only the two

pins

20, 21 being visible in the side view presented in FIGURE 6. The operating

rods

34, 35, which are aligned with the

holes

16 and 18 of the case (see FIGURE 4) are now driven through such holes until the rod ends abut against the lower rotor plate 38. Inasmuch as these rods are also force-fitted through the holes provided in the rotor cap, the rotor assembly, essentially, is a unitary structure which is closed, except for the peripheral opening in the side wall of the rotor case, through which opening are visible the flexible springs and the associated supporting pins. It will be noted that the rotor cap is provided with a central hole accommodating a bearing 78, with the central contact rod 52 passing through this bearing. It will now be clear that the assembled rotor is rotatable about the center rod 52 in response to a force couple applied to the operating

rods

34 and 35. i

The upper stator plate 39 is now placed into position as shown in FIGURE 7. The assembly is placed in a suitable fixture and pressure applied to the two stator plates, whereby the ends of the arcuately-spaced rods are forced into the bores provided in the upper plate 39. When the rod ends are fully seated within such holes, the collar portion 30, of the rotor cap, is disposed within the central clearance hole formed in the upper stator plate 39. The amembly described to this point results in a complete multi-point rotary switch, except for the indexing mechanism.

The indexing mechanism is assembled to the switch by inserting the operating

rods

34, 35 through the

bushings

65, 66 of the metal collar 64, as shown in FIGURE 7. The base of the collar abuts against the integral collar 30 of the rotor cap. The compression spring is positioned within the hole 67 and the spacer washer 74 (see also FIGURE 3) is positioned over the collar 64 and into face contact with the upper stator plate 39.

The indexing plate is then positioned over the collar '64 (into face contact with the spacer washer) and secured in place by two screws 79, as shown in the front elevational view of FIGURE 8. These screws pass through the aligned holes in the indexing plate 73 and the underlying spacer washer, and are threaded into diametricallyspaced inserts carried by the upper stator plate 39, as, for example, the

inserts

57 and 59 shown in FIGURE 2. The assembly is completed by inserting the metal rollers 71 and 72 into place between the ends of the compression spring and the indexing plate. As stated hereinabove, the purpose of the spacer washer is to position the indexing plate in a plane which substantially bisects the rollers. The considerable pressure applied to the rollers by the spring normally presses the rollers firmly into the diametrically-opposed notches formed in the indexing plate and prevents the rollers from moving, axially, out of the assembly.

The washer 75 (see FIGURE 3), preferably made of insulating material, is positioned over the indexing plate 73. Such washer 75 is provided with four holes cor responding to the holes in the indexing plate 73 and the underlying spacer washer. Thus, the mounting screws by which the switch is secured to a panel, may pass through the available aligned holes in the two washers and the indexing plate and threaded into the available inserts carried by the upper stator plate 39.

A knob 80, for rotary operation of the switch, is shown in FIGURES 9-11. The knob is molded of suitable plastic and includes two

bores

81, 82, for receiving ends of the switch-operating rods, and a threaded hole for receiving a locking screw 83. Actually, the locking screw merely serves to prevent axial separation of the knob from the switch-operating rods, or shafts, since it is obvious the two-shaft construction precludes a turning of the knob relative to the shafts.

Reference, now, is made to FIGURES 12 and 13 which are enlarged, fragmentary, plan views presented to illustrate the action of the flexible springs. In FIGURE 12, the rotor is shown in a position wherein the common pin 21, carried by the rotor case 10, lies in a position midway between adjacent

stationary contact rods

40 and 41 ,carried by the lower stator plate 38. All of the oddnumbered springs, represented by the spring 24,have their closed, center loops '25 inserted over the pin 21, inner loops 26 snugly encircling the center, common rod 52, and the relatively large open loops 27 loosely disposed over the common pin 21. All of the even-numbered springs, represented by the spring 24', also have their end loops encircling the center rod 52 and the common pin 21 but their closed center loops 25' are inserted over the pin 22. As stated hereinabove, the springs originally are so formed that the normal spread between the loops of each spring is greater than the radial distance between the center rod 52 and the common pin 21. Hence, when the springs are mounted, as shown, spring tension (tending to spread apart the spring end loops) maintains a good electrical contact between the rod 52 and the loops carried thereon. At the same time, such spring tension causes the outer, relatively large spring loops to abut against the common pin 21. The outermost surfaces of the latter spring loops (that is, those encircling the common pin 21) lie on a radius (r), which radius is greater than the radius (r of a circle which touches the innermost surface portions of the

stationary contact rods

40 and 41. The reverse orientation of adjacent spring loops about the common pin 21 results, effectively, in the formation of a longitudinal trough identified by the letter X.

'Upon rotation of the rotor relative to the stator, in one or the other direction, the outer spring loops come into engagement with a stationary contact rod and the springs flex inwardly. This results in a sliding, or rubbing, action between the spring loops and the rod as the rotor moves to the position shown in FIGURE 13. In the case of .a switch wherein the rotor is provided with fourteen (14) springs, twenty-eight such sliding contacts are established with the rod 40, thereby resulting in a very low, ohmic contact resistance. Inasmuch as the contact rods and the spring loops present reversely curved surfaces to each other, these members engage each other along point contacts, which reduces wearing to .a minimum and results in a constant contact resistance. Rotation of the rotor also results in a rubbing contact between the center contact rod 52 and the spring loops snugly encircling same, thereby also promoting a good, low, constant resistance between these members.

Reference, now, is made to FIGURE 14, showing the complete switch. This figure shows the indexing plate 73 disposed between the inner spacer member 74 and the outer washer 75, and the knob attached to the operating

rods

34, 35 for imparting rotation to the rotor. As a protection against the deleterious action of dust, fumes, etc., the electrical operating portions of the switch are enclosed within a housing. Such housing comprises the spaced

rotor plates

38, 39 and a thin plastic sheet 35 (which spans the space between the stator plates) and an overlying, relatively thick, resilient band '86 made preferably of an elastomeric silicone. Thus, the only exposed metal parts are the protruding ends of the stationary contact rods. These rod-s, having a diameter of approximately /8 inch, serve not only as the switch contacts but also constitute the terminals to which relatively heavy cables can be soldered as, for example, the cable 87 having an end soldered to a tubular connector 88, which connector is insertable over the end of the rod 42 for soldering thereto.

Although the various components of the switch may be made of any materials compatible with the intended end use of the switch, the spring contacts and the stationary contact rods preferably are made of a silver alloy thereby precluding the development of objectionable thermal voltages and resulting in excellent electrical properties. A twelve point switch, made as herein described and having fourteen (14) wire springs, had a contact resistance of 0.004 ohm, which value changed only an insignificant amount after, 1,000,000 switch operations.

The two stator plates preferably are made of a siliconeasb stos compound which has a high dielectric strength and a low moisture absorption. Such material withstands the high temperatures required for soldering heavy connection leads to the switch. The rotor bearings preferably are made of a plastic compound sold under the trademark Teflon and the rotor case and cap are made of an acetal resin sold under the trademark Delrin, which material has a low temperature coeflicient of expansion, low moisture absorption, high dielectric strength and a low, constant coeflicient of starting and running friction.

The use of the above materials in a switch, constructed as disclosed herein, results in a high quality switch having a high current carrying capacity and one which is particularly adapted for use in low voltage circuits. Rotation of the rotor is effected by means of the two rods positioned on either side of the rotor axis, thereby facilitating switch operation with a minimum possibility of jumping the indexing mechanism beyond the desired point. The cylindrical, or circular, shape of all metal components, reduces to a minimum the capacitance between such com ponents whereby the switch is adapted for use in high frequency circuits. Although the switch illustrated and described is of the break-before-make type, it is apparent that the outer spring loops can be formed to provide a make-before-break operation without any other change in the switch construction.

Having now giving a detailed description of the invention, those skilled in this art will be able to make various changes and modifications to meet specific requirements without'thereby departing from the scope and spirit of the invention as recited in the following claims.

We claim:

1. A rotary electrical switch comprising,

(a) a stator member carrying a center contact rod and a plurality of longitudinally-extending contact rods equally spaced from the center contact rod,

(b) a rotor member mounted for rotation about the said center contact rod, and

(c) a plurality of flexible contact members carried by the rotor member, said contact members each having one end engaging the said center contact rod and the other end adapted for sequential engagement with the longitudinally-extending rods upon rotation of the rotor member.

2. The invention as recited in claim 1, wherein the said flexible contact members are wire springs, each spring having a loop formed at one end, which loops are adapted for the stated engagement with the longitudinally-extending rods.

3. The invention as recited in claim 2, including an insulator pin carried by the said rotor member and extending through the loops of the wire springs.

4. The invention as recited in claim 1, including a pair of spaced, parallel shafts of insulating material carried by said rotor member and extending axially therefrom, and an operating knob removably attached to the free ends of the said shafts.

5. The invention as recited in claim 4, including cooperating elements carried by the said rotor and stator members, said elements forming an indexing mechanism for positioning the ends of the flexible contact members in engagement with a selected one of said longitudinallyextending rods.

6. A rotary electrical switch comprising,

(a) a stator member carrying a center contact rod and a plurality of longitudinally-extending contact rods equallyspaced from each other and the center contact rod,

(b) .a rotor member mounted for rotation about said center contact rod, said member carrying a longitudinally-extending insulator pin,

(c) a plurality of flexible contact springs carried by the rotor member, each spring having an end in engagement with said center contact rod and a loop formed at the other end and loosely positioned over the said pin, the spring loops being positioned for engagement with said longitudinally-extending rods upon rotation of the rotor member, and

.(d) operating means carried by the rotor member for effecting rotation thereof relative to the stator member.

7; The invention as recited in claim 6, wherein the said operating means comprises a pair of spaced parallel rods of insulating material extending from the rotor member.

8. The invention as recited in claim 7, including cooperating elements carried by the rotor and stator members and forming an indexing mechanism for positioning the spring loops in engagement with a selected one of the said longitudinally-extending rods.

9. The invention as recited in claim 6, wherein .ad? jacent spring loops are laterally offset relative to each other to thereby form a longitudinally-extending trough lying in a plane which includes the said center contact rod and insulator pin.

10. The invention as recited in claim 9, wherein each spring has a loop formed at the other end and encircling the said center contact rod.

11. A rotary electrical switch comprising,

(a) a pair of axially-spaced discs of insulating material,

(b) a plurality of longitudinally-extending contact rods force-fitted through spaced, marginal holes formed in one disc and into corresponding bores formed in the other disc,

(0) a common contact rod force-fitted through a central hole formed in the said one disc,

'(d) a rotor case having an open end and mounted for rotation about said common contact rod,

(e) a first insulator pin carried by the rotor case and lying in a reference plane which includes the said common contact rod,

(f) second and third insulator pins carried by the totor case and lying on either side of said reference plane,

(g) two sets of substantially-identical wire springs hav ing loops formed at each end and a closed loop formed intermediate of the end loops, the center loops of .one set of springs encircling the said second pin, the center loops of the other set of springs .encircling the third pin, corresponding end loops of all springs positioned over and engaging the common contact rod, and the (other corresponding end loops of all springs loosely positioned over the said first pin, the latter loops having surface portions lying in the path of travel of the longitudinally-extending contact rods upon relative rotation of the rotor case,

(h) a rotor cap closing the open end of the rotor case, said cap provided with three holes receiving-ends of the said three pins, and an axially-extending collar rotatably positioned within a central hole formed in the said other disc, and

(i) a pair of spaced, insulator shafts extending from said rotor cap.

12. The invention as recited in claim 11, including cooperating elements carried by the said other disc and the said shafts, said elements forming an indexing mechanism for retaining the open loops of the springs in engagement with a selected one of the longitudinally-extending rods.

13. The invention as recited in claim 11, including an indexing mechanism comprising,

(a) a collar member slidably mounted on the said shafts, said collar member having a diametrical hole communicating with diametrically-opposed, longitudinal grooves,

(b) an indexing plate positioned over the collar member and secured to the said other disc, said indexing plate having radially-extending notches formed therem,

(c) a roller pin inserted in each of said longitudinal grooves, and

(d) a compression spring disposed in the said diametrical hole and biasing the roller pins toward the said notches.

KATHLEEN H. CLAFFY, Primary Examiner.

Claims

1. A ROTARY ELECTRICAL SWITCH COMPRISING, (A) A STATOR M EMBER CARRYING A CENTER CONTACT ROD AND A PLURALITY OF LONGITUDINALLY-EXTENDING CONTACT RODS EQUALLY SPACED FROM THE CENTER CONTACT ROD, (B) A ROTOR MEMBER MOUNTED FOR ROTATION ABOUT THE SAID CENTER CONTACT ROD, AND (C) A PLURALITY OF FLEXIBLE CONTACT MEMBER CARRIED BY THE ROTOR MEMBER, SAID CONTACT MEMBERS EACH HAVING ONE END ENGAGING THE SAID CENTER CONTACT ROD AND THE OTHER END ADAPTED FOR SEQUENTIAL ENGAGEMENT WITH THE LONGITUDINALLY-EXTENDING RODS UPON ROTATION OF THE ROTOR MEMBER.