US3150240A

US3150240A - Multiple contact rotary switches

Info

Publication number: US3150240A
Application number: US54175A
Authority: US
Inventors: Elmer W Voss
Original assignee: Western Electric Co Inc
Current assignee: AT&T Corp
Priority date: 1960-09-06
Filing date: 1960-09-06
Publication date: 1964-09-22
Anticipated expiration: 1981-09-22

Description

Sept. 22, 1964 E. W. VOSS MULTIPLE CONTACT ROTARY SWITCHES Filed Sept. 6. 1960 INVENTOR ELMER W. VOSS ATTORNEY United States Patent York Filed Sept. 6, 1960, Ser. No. 54,175 6 Claims. (Cl. 200-43) This invention relates to multiple contact switches, and more particularly to a rotary switch for controlling a plurality of circuits.

In many instances it is frequently desirable to have relatively large numbers of switching adjustments for se lecting proper values of electrical quantities. However, in the past, a problem has arisen in designing a switch which is relatively small but capable of performing the functions from a single control arrangement. In addition problems have arisen in the use of sliding contact switches in the form of increased contact resistance.

One object of this invention is to provide a new and simple multiple contact switch.

An additional object resides in a control by which a relatively large number of switching operations may be performed by actuation of a single element.

Another object of this invention is to provide a control arrangement for selecting any desired position from a plurality of switch positions by single control means.

A further object of this invention is to provide contact members of novel form to resiliently engage terminals thereby decreasing elfective resistance due to wear on the contacts.

A still further object of this invention is to provide a novel dial arrangement to cooperate with an axially and rotatably movable switch actuator to indicate the various axial and circumferential positions thereof.

With these and other objects in mind, the present invention contemplates an electrical switch having rotatable, slidably mounted contact members for completing any of a number of electrical connections. A rotatable, slidable plunger having bridging contact members mounted thereon is positioned within an axial bore of a cylindrical housing. A plurality of rows or rings of radially arranged terminals are axially positioned within the housing. As the plunger is axially and rotatably positioned, the bridging contact members electrically connect successive pairs of axially spaced terminals.

The invention also contemplates a dial with which the contact member cooperates to indicate both axial and rotary displacement.

Other objects and advantages of the invention will become apparent by reference to the following detailed description and the accompanying drawings illustrating a preferred embodiment thereof, in which FIG. 1 is a fragmentary sectional view of a rotary switch for making electrical connections embodying the principal features of the present invention;

FIG. 2 is a cross-sectional view taken on line 2-2 of FIG. 1 showing the radial arrangement of a ring of terminals;

FIG. 3 is a reduced scale end view of FIG. 1 disclosing the dial arrangement of the switch;

FIG. 4 is an enlarged View of abridging contact member shown in FIG. 1; and

FIG. 5 is a view of an alternate bridging contact member interchangeable with that shown in FIG. 4.

Referring now in detail to the drawings, a cylindrical housing 11, composed of Teflon or some suitable insulating material having heat resistant and minimum friction properties, has an axial bore 12 extending therethrough. Also, as shown in FIG. 2, the housing 11 is provided with a series of axially spaced, radially arranged apertures 13, extending therethrough for receiving a plurality 3,150,240 Patented Sept. 22, 1954 of rows or rings I-V of terminals or jacks 14. The terminals 14 are formed with openings 15 at the outer extremity and recesses 16 of generally hemispherical shape at the inner extremity which extend to the bore 12 of the housing 11. A hub 17 is positioned adjacent the housing 11 such that an axial bore 18 of the hub 17 is coaxial with the bore 12 of the housing 11. Positioned at the opposite end of the housing 11 is a spacer 19. Four rods 21 are brazed at one end to the hub 17 and are threaded at the opposite extremity. The housing 11 and the spacer 19 have longitudinal slots 22 formed therein for receiving the rods 21 thereby preventing a rotary slipping action of the housing 11 and the spacer 19. An end plate 23 having apertures selectively placed is positioned on the rods 21 and fastened thereto by nuts or other fastening members 24, thereby retaining the hub 17, the housing 11, and the spacer 19 in the previously described relation.

A plunger 25, composed of a suitable insulating material, has electrical connecting means mounted thereon in the form of a pair of resiliently urged bridging contact members 2%? and is slidably positioned within the

axial bores

12 and 18 of the housing 11 and the hub 17, respectively. The bridging contact member 26, as shown in FIG. 4, is of a generally T-shaped form and has axially spaced projections 27 on a cross bar 28 and an opening 29 in a lower leg 31. An alternate arrangement of the bridging contact member 26, for example as shown in FIG. 5, is also of a generally T-shaped form and has cup-like recesses 32 formed in a cross bar 33 for receiving spherical members 34 and an opening 35 in a lower leg 36. The spherical members 34 are composed of a hard material of high electrical conductivity such as beryllium copper. The plunger 25 has a pair of cutaway sections or slots 37 for receiving the bridging contact members 26. A spring 38 is positioned within the openings 21? of the bridging contact members 25 to resiliently urge the projections 27 outwardly from the plunger 25.

The plunger 25 is formed with a circumferential groove 39 for receiving a retaining means or ball check 41 which is contained within a partially threaded aperture 42 in the housing 11. There is also formed on the plunger 25 a pair of rows of circumferentially arranged

recesses

43 and 44 of generally hemispherical shape where the recesses of each row are interconnected by slots 45. The

rows are positioned on each side of the groove 39 for receiving the ball check 41 upon axial positioning of the plunger. The ball check 41 consists of a spherical member 46, a spring 47, and an adjustable set screw 48 positioned in a threaded section of the aperture 42, as shown in FIG. 1. The spring 47 acts on the spherical member 46 to insure resilient engagement of the ball check 41 with the groove 39 or the

recesses

43 and 44. A lock ring 49 is mounted in a groove formed in the plunger 25 and cooperates with an enlarged section 51 of hub bore 18 to limit the axial positioning of the plunger 25.

A dial arrangement, as shown in FIG. 3, consists of a disk 52 concentrically positioned about the plunger 25 adjacent to a threaded portion 53 of the hub 17 and attached thereto by a pair of lock nuts 54 and 59, an annulus 55 firmly attached to the disk 52, and a knob 56 secured to the plunger 25 and having a pointer 57 fastened thereto being rotatable with the plunger 25. The arrangement of the disk 52 and the annulus 55 could be machined from a single piece. As shown in FIG. 3, the disk 52 and the annulus 55 are provided with indicia representative of the various positions of the bridging contact members 26. The switch, as shown in FIG. 1, may be mounted on a cabinet frame 58 and fastened thereto by the cooperation of lock nuts 54 and 59 and the threaded portions 53 of the hub 17.

In operation of the switch, a number of circuits may a be connected to the switch by the insertion of plug connectors into the openings 15 of the terminals 14. It is to be understood that the circuits may also be connected to the switch by soldering wire leads to the terminals 14. The plunger 25 then can be adjusted to any one of three axial positions. In a first position, the plunger 25 is positioned such that the ball check 41 engages one of the recesses 43 of the plunger 25. The projections 27 of a first of the bridging contact members 26 engages the recesses 16 of a pair. of axially spaced terminals 14 of rings I and II, thereby providing an electrical connection between the terminals 14'. Additionally, a second bridging contact member 26 electrically connects another pair of axially spaced terminals 14 of rings III and IV. in the same manner. Each connection is designated as a switch position and is represented by indicia as shown on disk 52 and indicated by pointer 57. Therefore, as the plunger 25 is maintained in the position as previously described, switch positions 2 and 10, as shown in FIG. 3, indicate the position of bridging contact members 26 with terminals 14 of rings I and II, and III and IV, respectively. Rotation of plunger 25, as controlled by knob 56, further positions bridging contact members 26 at positions which 1 position where the groove 39 of the plunger 25 receives 7 the ball check 41 thereby preventing sliding movement of the plunger 25 regardless of the rotary position of the plunger. As the plunger 25 is moved as described, the projections 27 of bridging contact members 26 disengage With the recesses 16 of terminals It and rest on the bore Wall 12 of the housing 11 thereby placing the switch in a neutral or non-connecting position. This is indicated by the position of the pointer 57 being midway between the surface of the disk 52 and the upper surface of the annulus 55. The resilient action provided by the springs 38 or" the bridging contact members 26 decreases the wear on the contacting elements resulting from sliding contact thereby decreasing the effective resistance of the contacts due to wear.

Additional movement of plunger 25 to the right, as shown in FIG. 1, places the plunger 25 in a third position where the ball check 41 engages one of the recesses 44 of the plunger 25 and also positions the pair of bridging contact members 26 to engage and electricflly connect axially spaced terminals 14 of rings II and III, and 1V and V, respectively. Again, as shown in FIG. 3, the positions of bridging contact members 26 are indicated by the position of the pointer 57 in cooperation with the indicia on the annulus 55. Rotation of the plunger 25 further positions the bridging contact members 26 to other positions which are indicated by the indicia on the annulus 55. As previously described, the engagement of the ball check 41 with the recesses 44 of the plunger 25 provides a restraining action as the plunger 25 is indexed.

By increasing the diameter of the housing 11, additional terminals 14 may be added thereby increasing the number of possible switch positions. Further, the bridging contact members 26 may be radially arranged such that no two sets of terminals shall be in contact at the same time.

The miniature structure of the switch readily permits the use of the switch in precision operations for potentiometers, attenuators,'and capacitor tuning circuits. Additionally, the switch is extremely useful in selectively connecting vast arrays of circuit components in a circuit.

It is to be understood that the above described arrangements are simply illustrative of an application of the prin- 4. ciples of the application. Numerous other arrangements may be devised by those skilled in the art which will embody the principles of the invention and will fall within the spirit and scope thereof.

What is claimed is:

1. In arotary switch,

a housing having an axial bore;

a plurality of pairs of axially spaced rings of radially disposed terminals mounted in said housing and extending to said bore of said housing;

an insulating plunger mounted within said bore of said housing, and axially movable inwardly and outward 1y relative to said bore, and rotatably movable within said bore; and

means mounted on said plunger and responsive to:

the axial inward and outward movement of said plunger for engaging and electrically interconnecting successive pairs of said rings of said terminals, and

the rotational movement of said plunger for electrically interconnecting a selected pair of terminals in said interconnected rings.

2. In a rotary switch, a housing having an axial bore,

a pair of axially disposed rings of radially displaced ter minals mounted in said housing and extending to said bore, a plunger mounted Within said bore of said housing for axial and rotational movement, and a spring-tensioned cross bar mounted on said plunger and having a pair of axially spaced spherical members mounted thereon for engaging successive pairs of axially displaced terminals upon axial and rotational movement of said plunger thereby electrically connecting said terminals.

3. In a rotary switch, a housing having an axial bore,

a plurality of axially spaced rows of radially disposed terminals having recessed contact portions that are spaced apart equal angular distances, a plunger mounted in said bore having resilient contact elements mounted thereon, said resilient contact elements being complementary to said recessed contact portions, means mounted in said housing for resiliently engaging said plunger, said plunger having a circumferential row of recesses each of which is spaced apart an angular distance equal to the angular distance between said terminals, and means for rotating sa d plunger to engage said resilient contact elements with said recessed contact portions and to engage said recesses in said plunger With said means mounted in said housing. 4. In a rotary switch, a housing having an axial bore, a pair of rings of terminals mounted in the housing and extending to said bore, a plunger mounted Within said bore for axial and rotational movement and having bridg- 1ng means resiliently mounted thereon for engaging and electrically connecting an axially displaced pair of terminals of said rings, said plunger having formed therein a circumferential groove and a circumferential row of recesses ad acent said groove, a spring-tensioned spherical member mounted Within said housing and engaging said circumferential groove in said plunger for retaining said bridging means in a disengaged position, and said spherical member upon axial movement of said plunger engaging said circumferential row of recesses of said plunger for providing a restraining action upon indexing of said plunger. 7

5. In a rotary switch, a housing having terminals mounted therein and extending to an axial bore thereof, a plunger mounted within said bore for axial and rotational movement and having bridging means'mounted thereon for engaging and electrically connecting said terminals, means for shifting said plunger into two axial positions and a plurality of rotary positions whereby said connections are completed, a dial mounted on said housing concentric with said plunger having a pair of scales at different planes and radially arranged indicia on each scale where each scale is representative of an axial position of said plunger and said indicia is representative of a rotary position of said bridging means, and a pointer fixedly mounted on and rotatable with said plunger positioned adjacent said scales for cooperating separately With each of said scales to indicate the axial position'of said plunger and the rotary position of said bridging means.

6. In a rotary switch, a housing having an axial bore, a pair of axially spaced rings of radially disposed terminals mounted in said housing and extending to said bore, a plunger mounted Within said bore for axial and rotational movement, said plunger having formed therein a circumferential groove and a pair of circumferential rows of recesses, one on each side of said groove, a spring- .tensioned cross bar mounted on said plunger and having a pair of axially displaced spherical members mounted thereon for engaging successive pairs of axially spaced terminals and completing an electrical connection thereof, a sprin -tensioned'spherical member mounted in said housing and first engaging said circumferential groove of said plunger for retaining said pair of spherical members from engagement with said terminals and second upon axial movement of said plunger engaging one recess of said pair of circumferential rows of recesses of said plunger for providing a restraining action upon rotational movement of said plunger whereby said pair of spherical members engage and electrically connect a given pair of axially spaced terminals, a dial mounted on said housing and concentric with said plunger having a pair of scales at diiierent planes With radially arranged indicia on each scale, and a pointer fixedly mounted on and rotatably and axially positionable with said plunger for cooperating With each of said scales to indicate the rotary position of said plunger and said pair of spherical members.

References Cited in the file of this patent UNITED STATES PATENTS 285,778 Adams Oct. 2, 1883 1,118,024 Lawrence Nov. 24, 1914 1,350,924 Eaton Aug. 24, 1920 1,671,196 Larson May 29, 1928 1,684,650 Tuttle Sept. 18, 1928 1,744,626 Getchell Jan. 21, 1930 1,908,204 Winning May 9, 1933 1,999,313 Alexonis Apr. 30, 1935 2,263,754 Batcheller Nov. 25, 1941 2,452,916 Fleischmann Nov. 2, 1948 2,576,836 Hilsinger Nov. 27, 1951 2,710,317 Pearl June 7, 1955 2,927,168 Brown Mar. 1, 1960 3,011,041 Bakels Nov. 28, 1961 FOREIGN PATENTS 33,851 France Oct. 28, 1928 (Addition to Fr. Pat. 620,182) 1,160,431 France July 15, 1958

Claims

1. IN A ROTARY SWITCH, A HOUSING HAVING AN AXIAL BORE; A PLURALITY OF PAIRS OF AXIALLY SPACED RINGS OF RADIALLY DISPOSED TERMINALS MOUNTED IN SAID HOUSING AND EXTENDING TO SAID BORE OF SAID HOUSING; AN INSULATING PLUNGER MOUNTED WITHIN SAID BORE OF SAID HOUSING, AND AXIALLY MOVABLE INWARDLY AND OUTWARDLY RELATIVE TO SAID BORE, AND ROTATABLY MOVABLE WITHIN SAID BORE; AND MEANS MOUNTED ON SAID PLUNGER AND RESPONSIVE TO: THE AXIAL INWARD AND OUTWARD MOVEMENT OF SAID PLUNGER FOR ENGAGING AND ELECTRICALLY INTERCONNECTING SUCCESSIVE PAIRS OF SAID RINGS OF SAID TERMINALS, AND THE ROTATIONAL MOVEMENT OF SAID PLUNGER FOR ELECTRICALLY INTERCONNECTING A SELECTED PAIR OF TERMINALS IN SAID INTERCONNECTED RINGS.