US3863039A

US3863039A - Combined potentiometer and switching structure

Info

Publication number: US3863039A
Application number: US323188A
Authority: US
Inventors: Charles M Tygard; James H Cameron
Original assignee: Spectrol Electronics Corp
Current assignee: Spectrol Electronics Corp
Priority date: 1970-06-01
Filing date: 1973-01-12
Publication date: 1975-01-28
Anticipated expiration: 1992-01-28

Abstract

A combined potentiometer and switching structure including wiper contacts fixed to a shaft and having contacting engagement with an annular resistor and a pair of switching rings. The wiper contacts are located coincident, or in phase relation. The switching rings are each provided with an interrupted area, such areas are located in an arc complemental to the arc of the resistor and are circumferentially spaced apart a distance not greater than the length of the resistor contacting surface whereby, during rotation of the shafts, circuits connected to the switch rings are opened at different positions with respect to the resistor wiping contact. alignment openings in the rings accommodate a pin to permit proper positioning of the rings relative to one another and also provide a passage for a conductor upon removal of the pin once the rings are properly positioned and secured against displacement.

Description

Tygard et al.

[ COMBINED POTENTIOMETER AND SWITCHING STRUCTURE [75] Inventors: Charles M. Tygard; James H.

Cameron, both of West Covina, Calif.

[73] Assignee: Spectrol Electronics Corporation,

City of Industry, Calif.

[22] Filed: Jan. 12, 1973 [21] Appl. No.: 323,188

Related U.S. Application Data [62] Division of Ser. No. 54,045, June 1, 1970, Pat. No. 3,679,848, which is a division of Ser. No. 828,617, May 28, 1969, Pat. No. 3,585,562.

[52] US. Cl. 200/8 A, 200/155 R, 338/172 [51} Int. Cl. H0lh 19/58 [58] Field of Search 200/155 R, 11 A, 11 D, 200/166 BB, 8 R, 8 A; 338/296, 304, 172

[56] References Cited UNITED STATES PATENTS 2,233.113 2/1941 Smith. Jr 200/8 A 3.112.377 ll/l963 Andela ZOO/ll l) 3,135,840 6/1964 Ausfeld 200/8 A 1 Jan. 28, 1975 Primary Examiner-Robert K. Shaefer Assistant Examiner-William J. Smith Attorney, Agent, or Firm-J. Raymond Curtin; Frank N. Decker, Jr.

[57] ABSTRACT A combined potentiometer and switching structure including wiper contacts fixed to a shaft and having contacting engagement with an annular resistor and a pair of switching rings. The wiper contacts are located coincident, or in phase relation. The switching rings are each provided with an interrupted area, such areas are located in an arc complemental to the arc of the resistor and are circumferentially spaced apart a distance not greater than the length of the resistor contacting surface whereby, during rotation of the shafts. circuits connected to the switch rings are opened at different positions with respect to the resistor wiping contact. Alignment openings in the rings accommodate a pinto permit proper positioning of the rings relative to one another and also provide a passage for a conductor upon removal of the pin once the rings are properly positioned and secured against displacement.

1 Claim, 6 Drawing Figures P ATENTED B SHEET 10F 3 FIG. 5

COMBINED POTENTIOMETER AND SWITCHING STRUCTURE This is a division, of application Ser. No. 54,045 filed June 1, 1970, now U.S. Pat. No. 3,679,848 which in turn is a division of application Ser. No. 828,617, filed May 28, 1969, now U.S. Pat. No. 3,585,562.

BACKGROUND OF THE INVENTION A combined potentiometer-circuit switching unit has been proposed wherein a common rotor supports both the switch actuator and the wiping contact for engaging the resistance coil of the potentiometer. When additional circuit switching functions are required, the housing becomes undesirably bulky. It has been suggested that a common mounting ring be employed for supporting two switching units. While such an arrangement will conserve space by reducing the length of the housing required, a simple inexpensive method of assembling the parts so that conductors located in inaccessible locations may be readily connected to the switch units is needed.

SUMMARY OF THE INVENTION This invention has to do with a combined potentiometer and circuit switching structure. The potentiometer is of the conventional annular type having a circular contacting surface engaged by a wiping contact fixed to a shaft. A second wiper contact is affixed to the shaft and is phased with the resistor wiper contact. This second contact engages a pair of conducting switch rings. A circuit is formed from the second wiper contact through each of the switch rings. The switch rings are formed with interrupted areas whereby, at different positions of the resistor wiper contact, the switching circuits are opened.

More particularly, the invention is directed to a structural arrangement which is economical to manufacture and convenient to assemble to produce a device having very small overall dimensions.

In addition, the invention relates to a unique method of assembling the switch rings in the switch insulator whereby welding of electrical leads to the switch rings may be easily accomplished.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational view of a structure embodying our invention;

FIG. 2 is an end elevation looking to the right, FIG.

FIG. 3 is an enlarged sectional view taken on a line corresponding to line 3-3, FIG. 2.

FIG. 4 is a sectional view taken on line 4-4, FIG. 3;

FIG. 5 is an exploded view of the switch rings and resistor illustrating the orientation of such parts; and

FIG. 6 is a schematic diagram illustrating an arrangement of the resistor and switching rings.

DESCRIPTION OF THE PREFERRED EMBODIMENT The apparatus consists ofa casing having sections l0, 11. The section 10 is formed with an end wall 12 having an inwardly extending cylindrical hub 13. The hub 13 is provided with a central aperture forming a bearing in which an enlarged portion 14 of an actuating shaft 15 is journaled.

The casing section 11 is provided with a discoidal closure 16 which is formed with a central aperture arranged in axial alignment with the aperture in the hub 13 and forming a second bearing for the shaft 15. The end member 161s attached to the section 11 by a clamp ring 17.

A resistor 18 of substantially annular configuration is fixedly mounted in the section 11. The inner surface 20 of the resistor is a contact surface over which a wiper contact 21 is moved. The contact 21 is fixed on one end of an arcuate spring member 22, the opposite end of which is fixed to an arm 23 which, in turn, is fixedly secured to a sleeve 25 of insulating material fixedly secured to the shaft 15. A collector ring 27 is attached in conductive relation to the arm 23 and is connected to a terminal 28 by a brush 30.

The casing section 10 is formed at its inner end with a cylindrical flange 33 formed with an annular shoulder 34. The casing 11 is formed with a circular flange 35 snugly engaging the flange 33 and abutting against the shoulder 34. The sections are held together by a clamp ring 37;

A pair of

switching rings

38, 40 are fixedly mounted in the flange 33 of the casing section 10. In the arrangement disclosed, the switching rings are mounted in an annular insulation member 41, fixedly mounted in the flange 33 and having a flange or central rib 43 extending radially inwardly between the

switch rings

38, 40. The inner contacting surfaces of the switch rings are engaged by a wiper contact 45 fixed on one end of an arcuate leaf spring member 46, the opposite end of which is fixed to an arm 47 which, in turn, is fixed to the sleeve 25. A collecting ring 50 is fixed in conducting relation to the arm 47, and is connected to a terminal 53 by a brush 54. The collector rings 27, 50 are separated by a ring of insulating material 55.

The contacting surface 20 of the resistor 18 extends circumferentially less than 360 in the structure shown about 325. The switching rings 38, 40 are each formed with an interrupted area in their inner contact ing surfaces. For economy in manufacture, these interrupted areas are preferably in the form of a notch 58 in ring 38, and a notch 60 in ring 40. The switch rings 38, 40 are fixed in the insulating member 41 with the

notches

58, 60 spaced apart circumferentially a distance less than the circumferential extent of the effective contacting surface 20 of the resistor 18. It will be

apparent rings

38 and 40 are duplicate parts. To obtain the relationship shown in FIG. 5, it is only necessary to invert one of the rings through an angle of 180.

The switch ring 40 is connected to a terminal by wire 71 conveniently extended through the

apertures

63, 64 in the switching rings and member 41, see FIG. 3. The switching ring 38 is connected to a terminal 72 by wire 73. One end of the resistor 18 is connected to a terminal 75 by wire 76. Accordingly, a switching circuit is established from terminal 53 to terminal 70 through switching ring 40, and a second switching circuit is established through terminal 53 and terminal 72 through switch ring 38.

To provide for convenience in assembling the switch rings with the interrupted areas in the desired phase relation, the rings are formed with through apertures 63. The member 41 is formed with a through aperture 64 in the flange or central rib 43. The

apertures

63, 64 are aligned and a pin is extended through the apertures. The rings are pressed into the member 41, or otherwise secured therein, and the member 41 is pressed or otherwise secured as by applying adhesive material to the rings prior to the insertion of the pins, in the section 10. The alignment pin is then removed and the wire 71 is run through the apertures and fixed to the ring 40. The sections 10, 11 are oriented and fixedly clamped together by the band 37.

In FIG. 6, the interrupted areas in the

rings

38, 40 are indicated at 58, 60 and as being located coincident with the ends of the resistor 18. The

wiper contacts

21, 45 are fixed in phase relation, see also FIG. 4. Accordingly, when the resistor wiper 21 is positioned at the right end of the resistor, the contact 45 is in register with the notch 58in the switch ring 38. When the resistor wiper has been moved to the left end of the resistor, the contact 45 is in registration with the notch 60 in the switching ring 40. At intermediate positions of the wiper contacts, both switching circuits are energized.

It will be apparent that the interrupted areas of the switching means may be phased to provide interruption of the switching circuits at various preselected positions of the resistor wiper contact 21.

While we have described a preferred embodiment of our invention, it is to be understood the invention is not limited thereto since it may be otherwise embodied within the scope of the following claims,

We claim:

1. A switch assembly comprising:

l. a casing;

2. a rotary shaft mounted for rotation within said cas- 3. a switch module secured with said casing, said switch module comprising:

a. a non-conductive mounting ring mounted coaxially in said casing and having an annular rib extending radially inwardly from the inner surface thereof, said rib having an axially extending locating aperture therein;

b. a first annular metallic switch ring disposed in said mounting ring on one side of said annular rib, said first switch ring having an axially extending aperture formed therein which is aligned with said aperture in the annular rib of the mounting during assembly therewith;

c. a second annular metallic switch ring disposed in said mounting ring on the other side of said annular rib, said second annular metallic switch ring having an axially extending aperture formed therein which is aligned with said aperture in the annular rib of the mounting ring during assembly therewith;

d each of said annular switch rings having a relieved portion formed on the inner surface thereof which is positioned in a predetermined relationship with the relieved portion of the other switch ring by alignment of said axially extending apertures;

4. a first switch terminal having an electrical conductor extending therefrom through the aligned axial apertures in one of said switch rings and said annular rib, said electrical conductor extending into the aperture in the other of said switch rings and being secured in electrical contact therewith;

5. a second switch terminal having an electrical conductor extending therefrom into electrical contact with said one switch ring; and

6. a spring biased wiper contact carried by said rotary shaft, said wiper contact being biased into engagement with the unrclieved portion of the annular inner surface of both of said switch rings for electrical contact therewith, and a collector terminal having conductor means in electrical engagement with said collector member for making electrical contact with the collector member, whereby rotation of said rotary shaft selectively makes and breaks electrical connection between said collector terminal and said first and second switch terminals in accordance with the preselected phase relation between said switch rings.

Claims

1. A switch assembly comprising: 1. a casing; 2. a rotary shaft mounted for rotation within said casing; 3. a switch module secured with said casing, said switch module comprising: a. a non-conductive mounting ring mounted coaxially in said casing and having an annular rib extending radially inwardly from the inner surface thereof, said rib having an axially extending locating aperture therein; b. a first annular metallic switch ring disposed in said mounting ring on one side of said annular rib, said first switch ring having an axially extending aperture formed therein which is aligned with said aperture in the annular rib of the mounting during assembly therewith; c. a second annular metallic switch ring disposed in said mounting ring on the other side of said annular rib, said second annular metallic switch ring having an axially extending aperture formed therein which is aligned with said aperture in the annular rib of the mounting ring during assembly therewith; d. each of said annular switch rings having a relieved portion formed on the inner surface thereof which is positioned in a predetermined relationship with the relieved portion of the other switch ring by alignment of said axially extending apertures; 4. a first switch terminal having an electrical conductor extending therefrom through the aligned axial apertures in one of said switch rings and said annular rib, said electrical conductor extending into the aperture in the other of said switch rings and being secured in electrical contact therewith; 5. a second switch terminal having an electrical conductor extending therefrom into electrical contact with said one switch ring; and 6. a spring biased wiper contact carried by said rotary shaft, said wiper contact being biased into engagement with the unrelieved portion of the annular inner surface of both of said switch rings for electrical contact therewith, and a collector terminal having conductor means in electrical engagement with said collector member for making electrical contact with the collector member, whereby rotation of said rotary shaft selectively makes and breaks electrical connection between said collector terminal and said first and second switch terminals in accordance with the preselected phase relation between said switch rings.

2. a rotary shaft mounted for rotation within said casing;

3. a switch module secured with said casing, said switch module comprising: a. a non-conductive mounting ring mounted coaxially in said casing and having an annular rib extending radially inwardly from the inner surface thereof, said rib having an axially extending locating aperture therein; b. a first annular metallic switch ring disposed in said mounting ring on one side of said annular rib, said first switch ring having an axially extending aperture formed therein which is aligned with said aperture in the annular rib of the mounting during assembly therewith; c. a second annular metallic switch ring disposed in said mounting ring on the other side of said annular rib, said second annular metallic switch ring having an axially extending aperture formed therein which is aligned with said aperture in the annular rib of the mounting ring during assembly therewith; d. each of said annular switch rings having a relieved portion formed on the inner surface thereof which is positioned in a predetermined relationship with the relieved portion of the other switch ring by alignment of said axially extending apertures;

6. a spring biased wiper contact carried by said rotary shaft, said wiper contact being biased into engagement with the unrelieved portion of the annular inner surface of both of said switch rings for electrical contact therewith, and a collector terminal having conductor means in electrical engagement with said collector member for making electrical contact with the collector member, whereby rotation of said rotary shaft selectively makes and breaks electrical connection between said collector terminal and said first and second switch terminals in accordance with the preselected phase relation between said switch rings.