US2686233A - Multiple position switch - Google Patents

Description

Aug. 10, 1954 T 1 OBSZARNY 2,686,233

MULTIPLE POSITION SWITCH Filed Aug. 9, 1952 Patented Aug. 10, 1954 UNITED STATES PATENT OFFICE MULTIPLE POSITION SWITCH Tiiedore J. Obszarny, Chicago, Ill., assignor to Guardian Electric Manufacturing Co., Chicago, Ill., a corporation of Illinois Application August 9, 1952, Serial No. 303,567

(Cl. 20G- 6) 8 Claims. 1

This invention relates to multiple position switches and more particularly to a switch of the tilting contact plate type.

For rnany types of applications it is desirable to provide relatively small compact electrical switches selectively to control a plurality of electrical circuits. For example, in aircraft controls it is desirable to provide a single switch mechanism which can control operating circuits in diierent control elements, such as trim tabs and the like.

Such switches are frequently subjected to rapid operations involving a large number' or makes and breaks and often become heated to a relatively high temperature. The switches must therefore be capable of maintaining operation at high temperatures and must be easy to operate under all conditions to provide the necessary sensitivity oi control. Furthermore, in the event the contacts should stick the switch mechanism must be capable of exerting enough force thereon to insure separation thereof.

It is one of the objects of the present invention to provide a multiple position switch which satisfies all o1 these requirements and which is at the same time extremely small and compact.

Another object is to provide a switch of the tilting disc type in which a universal rotatable ball engages and acts on the disc to tilt it.

The use of a ball for this apparatus not only reduces friction and insures smooth and easy operation but also provides a point Contact with the disc to minimize transfer of heat to the handle and positively to prevent sticking of the handle to the disc.

A further object is to provide a switch in which the disc is normally urged to its tilted position by a spring pressed plunger and in which the plunger and handle are formed with interengaging parts to limit relative movement thereby to provide a positive mechanical action to break loose sticking contacts.

rEhe above and other objects and features ci the invention will be more readily apparent from the following description when read in connection with the accompanying drawing, in which:

Figure 1 is a side elevation of a switch embodying the invention,

Figure 2 is a central vertical section oi the switch,

Figure 3 is a horizontal section on the line 3-3 of Figure 2,

Figure 4 is an end view with parts broken away and in section, and

Figures 5, 6, 7 and 8 are transverse sections on lil 2 the lines 5 5, 5-S, 'I- and S-S, respectively, of Figure 2.

The switch as shown comprises a mounting bracket l0 having a flat base portion and an end portion to overlie the end of the switch housing and to form a part thereof. The end portion of the bracket is formed with a central opening rleiined by outwardly extending curved lips ii to form a part of a ball and socket joint. The end portion of the bracket is rigidly se Lired to the end of a cup-shaped housing l2 having a central opening therein donned by curved simular lips I3. Preferably a separating plate i4 is provided between the bracket and the housing and a central opening therein terminating flush with the socket defined by flanges i E and it except for a narrow projection i5 at one point therein which extends into the socket.

The socket dened by the flanges ii and i3 receives a spherical enlargement it on a tubular handle l'.' and supports the handle for universal angular movement. Preferably the spherical enn largement I6 is formed with a slot it in which the projection I5 extends to prevent the handle from turning while allowing it to swing angularly in any desired direction.

The handle Il is normally held in a centered position coaxial with the housing i 2 by means of resilient disc I9 formed of rubber or the like, which is supported in the housing between annular plates 2l and 22. The plate 2i is preferably formed with a relatively large circular opening therein through which the handle loosely extends so that the handle can move freely. The plate 22, as best seen in Figure 8, is preferably formed with a series of circumferential projections thereon to nt slidably into slots in nous ing I 2 so that the angular position or the plate 2i. is nxed. In its central part the plate is formed with an opening fitting relatively closely around the handle and having a plurality of lobes projecting radially therefrom in which tinl handle can move to its various switching positions in the form shown, four positions are conter ated and the opening in the plate 22 is provided with four lobes 25 spaced 90 from each other. rihe handle can therefore be tilted to any one oi ieu': angular operating positions, and when released will be returned to its centered inoperative posi: tion by the resilient disc The opposite end of the housing l is closed by an insulated cover disc 25 which, as best seen in Figure 4, is formed in its periphery with a plurality of spaced notches to receive integral fingers 2'I projecting from the ends of the housing. After diameter than the plunger.

the cover disc is inserted against the end of the housing with the fingers 2l extending beyond the disc, the fingers 2l are bent over against the outer surface of the disc to secure it tightly in place.

The cover disc 2E carries a central contact seat 28 which, as shown, is circular in outline with a flat central seating surface and a circular upstanding peripheral ange 29. The contact seat is rigidly secured to the cover disc and carries a connector lug 3| by which it may be connected to a common lead for the several circuits to be controlled. For example, the connector lug 3l might be connected to one side of a source of power, such as a battery. A plurality of xed contacts 32 are carried by theclosure disc 26 and are spaced around the contact seat 28. Each of the fixed contacts 32 carries a connector lug 33 by which it may be connected into any desired circuit such as a circuit controlling motors-for operating trim tabs or the like. As shown, four xed contacts 32V are provided uniformly spaced around the contact seat 28 and registering in position with the vlobes 25 of the opening in `the disc 22.

vThe contact seat is adapted to supporta tiltable contact disc having a at circular base portion 3 to seat against the flat surface of the seat within the nange 29. The disc terminates in a peripheral ilange 35, which overlies and is normally spaced from the Vfixed contacts 32, as shown in Figure 2. The opposite surface of the disc is provided with a concave disheol cavity St which may be arcuate but which is preferably substantially parabolic as shown.

vTo tilt the disc the tubular handle ll slidably receives a plunger 3l formed of an insulating material, such as a relatively hard plastic. The plunger is urged outwardlyv of the handle toward the Contact disc by a spring 38 and is adapted to exert pressure on the disc when the handle is tilted to tilt the disc to one f its contact positions as seen in Figure 3.

It has been found that when the end of the plunger, such as the plunger 3l, is located to engage the contact disc directly it tends to wear rapidly and, further, tends to soften under the relatively high temperatures which may be developed in operation. Therefore, according to the present invention the plunger 3l carries a metallic cup member 39 which is of slightly larger external A ball lili, such as a conventional steel bearing ball is mounted in the cup member 3.13 for universal rotation therein and engages the concave surface 35 of the contact disc.

In use, when the handle Il is released it will center, as shown in Figure 2, tohold the contact vdisc against the seat 28 in its nat centered position outof engagement with all of the fixed contacts. When the handle is swung to one of its angular operating positions, as shown, for example, in Figure 3, the ball will ride up on the concave surface 36 and will tilt the disc so that the ange portion 35 thereof engages one of the xed contacts 32. At this time the selected one of the circuits will be completed to eiect a selected operation. It will be noted that in its operated position the spring 38 is compressed to a greater extent than when the switch is in its centered position so that the disc will be held against the selected iixed contact with a relatively high pressure. This insures good contact with a minimum of resistance in the circuit and with a vminimum chance of arcing. It .will also be noted vthat with this construction a snap action of the Adisc is produced during both makingand break- 4 ing of the circuit due to the fact that the disc will tilt sharply about its edge in one direction or the other as soon as the line of force exerted by the plunger thereon crosses the edge of the disc base.

With a ball tl as shown engaging the disc surface the friction between the disc and the plunger is reduced to an absolute minimum in all directions of operation so that the switch can be operated smoothly and easily. Furthermore, be-

cause the ball will have substantially a point contact with the disc, transfer of heat from the disc to the handle is minimized so that the handle portion of the switch will not be overheated. Also with a metal ball contacting a metal disc surface the possibility of binding or sticking is eliminated so that the switch will operate prop- -erly under all conditions.

In the event a contact should stick tending to hold a circuit closed after the handle is released, `the handle can be swung in an opposite direction vto exert a breaking force on the contact. Under these conditions the plunger will be moved inward of the handle until the enlarged cup member 39 strikes the end of the handle after which no further movement will be permitted. rIherefore as the handle is swung a positive mechanical force will be exerted on the disc to tilt it and this force can be made large enough to break loose a sticking contact without any difiiculty. Therefore even if the contacts should stick dueto an overload, the switch can still be released by exerting manual pressure on the handle in the direction opposite to that required to close the sticking parts.

While one embodiment of the invention has been shown and described in detail, it will be understood that this is for the purpose of illustration only and is not to be taken as a denition of the scope of the invention, reference being had for this purpose to the appended claims.

What is claimed is:

l. A multi-position switch comprising a housing, a central Contact seat carried by one end of the housing, at least three fixed contacts spaced around the contact seat and carried by said one end of the housing, a contactrdisc having a base portion supported on the contact seat, said disc having a ilange portion overlying and normally spaced from the nxed contacts and a concave dished surface facing the other end of the housing, a handle extending through the other end of the housing and supported therein for universal angular movement, a plunger slidably carried by the handle, a spring urging the plunger outward of the handle toward the contact disc, and a ball carried by the outer end of the plunger for universal rotation thereon and engageable with the dished surface of the contact disc to tilt the disc on the contact seat and move the `flange portion thereof into engagement with one of the iixed contacts when the handle is swung from a centered position.

2. A multi-position switch comprising a housing, a central contact seat carried by one end of the housing, at least three iixed contacts spaced around the contact seat and carried by said one end or the housing, a contact disc having a base portion supported on the contact seat, said disc having a ilange portion overlying and normally spaced from the iixed contacts and a concave dished surface facing the other end of the housing, a handle extending through the other end of the housing and supported therein for universal angular movement, a-plunger lslidably carried by the handle, a spring urging the plunger outward of the handle toward the contact disc, a ball carried by the outer end of the plunger for universal rotation thereon and engageable with the dished surface of the Contact disc to tilt the disc on the contact seat and move the flange portion thereof into engagement with one of the fixed contacts when the handle is swung from a centered position and interengaging parts on the plunger and the handle to limit movement of the plunger inward of the handle whereby a positive pressure can be exerted on the disc to tilt it in the event of contact sticking.

3. A multi-position switch comprising a housing, a central contact seat carried by one end of the housing and formed with a flat seating surface and an upstanding peripheral flange, at least three fixed contacts carried by said one end of the housing spaced around the contact seat, a contact disc having a flat base portion tting within the peripheral flange and seating against the seating surface, said disc having a flange portion overlying and spaced from the fixed contacts and a concave dished surface facing the other end of the housing, a tubular handle extending through the other end of the housing and supported therein for universal angular movement, a plunger slidable in the handle, a spring in the handle urging the plunger outward thereof toward the contact disc, and a ball mounted on the end of the plunger for universal rotation thereon and engageable with the concave surface of the disc to tilt the disc on the contact seat and move the ange portion thereof into engagement with one of the fixed contacts when the handle is swung from a centered position.

4. A multi-position switch comprising a housing, a central contact se-at carried by one end of the housing and formed with a flat seating surface and an upstanding peripheral flange, at least three xed contacts carried by said one end of the housing spaced around the contact seat, a contact disc having a flat base portion fitting within the peripheral flange and seating against the seating surface, said disc having a flange portion overlying and spaced from the fixed contacts and a concave dished surface facing the other end of the housing, a tubular handle extending through the other end of the housing and supported therein for universal angular movement, a plunger slidable in the handle, a spring in the handle urging the plunger outward thereof toward the contact disc, the plunger being formed of insulating material and of a uniform external diameter to lit slidably in the handle, a metal cup member carried by the outer end of the plunger, and a ball mounted in the cup member for universal rotation therein and engageable with the concave surface of the disc.

5. The construction of claim 4 in which the cup member is of larger diameter than the plunger to seat on the end of the handle and limit movement of the plunger into the handle.

6. A multi-position switch comprising a housing, a central contact seat carried by one end of the housing and formed with a flat seating surface and an upstanding peripheral ange, at least three fixed contacts carried by said one end of the housing spaced around the contact seat, a contact dise having a dat base portion fitting within the peripheral flange and seating against the seating surface, said disc having a flange portion overlying and spaced from the fixed contacts and a concave dished surface facing the other end of the housing, a tubular handle extending through the other end of the housing and supported therein for universal angular movement, a plunger slidable in the handle, a spring in the handle urging the plunger outward thereof toward the contact disc, a ball mounted on the end of the plunger for universal rotation thereon and engaging the concave surface of the disc to tilt the disc when the handle is swung from a centered position, and a disc of resilient material in the housing fitting over the handle to seal the housing and to urge the handle resiliently to its centered position.

7. A multi-position switch comprising a housing, a central Contact seat carried by one end of the housing and formed with a at seating surface and an upstanding peripheral flange, at least three fixed contacts carried by said one end of the housing spaced around the Contact seat, a contact disc having a flat base portion fitting within the peripheral flange and seating against the seating surface, said disc having a flange portion overlying and spaced from the fixed contacts and a concave dished surface facing the other end of the housing, a tubular handle extending through the other end of the housing and supported therein for universal angular movement, a plunger slidable in the handle, a spring in the handle urging the plunger outward thereof toward the contact disc, a ball mounted on the end of the plunger for universal rotation thereon and engaging the concave surface of the disc to tilt the disc when the handle is swung from a centered position, a disc of resilient material in the housing tting over the handle to seal the housing and to urge the handle resiliently to its centered position, and a rigid disc overlying the resilient disc and formed with an opening through which the handle projects having lobes corresponding in number and angular spacing to the fixed contacts to guide the handle in its tilting movements.

8. A multi-position switch comprising a housing, a central contact seat carried by one end of the housing and formed with a flat seating surface and an upstanding peripheral flange of circular contour, at least three fixed contacts carried by said one end of the housing spaced around the contact seat, a contact disc having a fiat base portion of circular contour fitting within the peripheral flange and seating against the seating surface, said disc having a flange portion overlying and spaced from the fixed contacts and a concave dished surface facing the other end of the housing, a tubular handle extending through the other end of the housing and supported therein for universal angular movement, a plunger slidable in the handle, a spring in the handle urging the plunger outward thereof toward the contact disc, and a ball mounted on the end of the plunger for universal rotation thereon and engageable with the concave surface of the disc to tilt the disc on the contact seat and move the flange portion thereof into engagement with one of the fixed contacts when the handle is swung from a centered position.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,912,624 Douglas June 6, 1933 2,400,849 Stearns May 21, 1946 2,469,336 Kohl May 3, 1949 2,506,196 Bourne May 2, 1950

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