US2127608A - Circuit controller - Google Patents

Description

Aug. 23, 1938.. L. MANLEY cmcum CONTROLLER Filed Nov. 6, 1954 INVENTOR Patented Aug. 23, 1938 UNITED STATES PATENT OFFICE mesne assignments, Philadelphia, Pa., a vania to Hugh H. Eby Inc., corporation of Pennsyl- Application November 6, 1934, Serial No. 751,679

8' Claims.

This invention relates to switches, and particularly to multiple switches controlling simultaneously a plurality of circuits.

It is among the objects of this invention: to

provide a switch of simplicity and ease of manufacture; to provide a switch of compactness and small diameter, while maintaining both low contact resistance and negligible electrostatic capacitance between adjacent contacts; to provide a switch having multiple contacts which is possessed of definite self-indexing; to provide a switch assembly arranged for, a single-hole mounting while providing a maximumnumber of contacts; to provide a multiple-contact switch with soldering connections so designed as to maintain low capacity; to provide a switch with integral connectors so designed as to reduce subsequent soldering and connecting steps or operations; to provide a multiple switch in which the clearance between contacts is such as to enable the number of contacts to be a "maximum; to reduce the cost of manufacturing and assembling multiple switches; to provide an edge of metal as a contact in a multiple switch; to provide in a multiple switch assembly a movable contactor having substantially axial pressure upon the fixed contacts; to provide a multiple switch assembly in which a contactor is so arranged with the fixed contacts as to rotate in operation, to reduce wear and friction and to reduce contact resistance;-to provide a multiple switch with terminals instaggered relation so as to facilitate attachment of connectors without increasing capacity; to provide a switch contact element with a terminal so spaced from the switch as to be directly attachable to the controlled instrumentality without the use of an intermediate connector; to provide improved contact elements in a switch; to provide contacts of a switch that are formed, instead of being punched and formed, to reduce the cost of construction; to form'switch contacts of wire; to provide switch elements that are threaded into a support instead of, being eyeletted or staked; to provide a switch with a plumetallic dust path between contacts due to normal wear; to provide a contact surface of silver or the like at low cost; to providea contact for a switch that may be punched, swaged, coined or molded so as to ofier an edge of metal to the moving contactor; and other'objects which will become more apparent as'the description proceeds.

In the accompanying drawing, forming, part 56 of this description,

rality of contacts so arranged as .to minimize the.

Fig. 1 represents a bottom or reflected plan of one form of multiple switch according to this invention;

Fig. 2 represents a vertical section taken on line 22 of Fig. 1;

Fig. 3 represents a transverse section through the form of device of Figs. 1 and 2, taken on line 3--3 of Fig. 2;

Fig. 4 represents a transverse section of the switch of the preceding figures, taken on line 4-4 of Fig. 2;

Fig. 5 represents a fragmentary section through the fixed plate of the switch with one form of contact threaded therethrough;

Fig. 6 represents a similar view with the contact element clinched into engagement with the fixed plate;

Fig. 7 represents a fragmentary section taken at line 1-1 of Fig. 2 through the moving and fixed contact elements according to one form thereof; and

Fig. 8 represents a modification and simplification of the movable contacting means and comprises a vertical section through the respective elements and contacts.

There are many situations in which it is desired to have double-throw circuit closures of 4, 6 or 8 poles, as for instance in short-wave radio receivers. The requirements for such switches are, however, quite rigid, including as necessary elements the minimum of capacity, the minimum of contact resistance, the utmost in compactness, and low cost of production with long life. It is also essential that the indexing of the switch be definite.

Switches of the type to which this invention relates may have provision for fixed or stator contacts to the number of perhaps 24, and such number or even a higher number is contemplated with this invention, although for clarity of disclosure the switch of the invention is shown as having 18 contacts. With 18 fixed contacts it is possible to obtain a six-pole, double-throw switch.

' By omitting contact or by failure to attach connectors as desired, any smaller number of poles may be used. I

For purposes of illustration an embodiment of the invention will be presumed to have a relatively fixed and immovable plate 25 made of an insulating material such as fiber or a phenolic condensation product. upon the reduced end 26 of a bushing or sleeve'2'l having a threaded shank 28 arranged to be moved axially into a single opening of a panel or the, like. to center and anchor the switch in the man- The plate 25 is mounted ner commonly employed withsuch devices. The bushing 21 has an axial bore 30 and the reduced portion 26 is turned over or fianged upon a disc 3| as at 32. Disc 3| has a pair of spaced upstanding ears or stops 33 and 34, and, if desired, a depending ear 35 disposed in a suitable opening in the stator plate 25, to anchor the disc. Plate 25 carries fixed contacts to be described.

The movable part of the switch assembly includes a shaft 36 rotatably disposed in the bushing 21, having peripheral groove 31 into which a C washer 3B is inserted to abut the end of sleeve 27 and thereby to prevent axial shaft movement in one direction. The shaft 36 extends axially beyond the flange 32 of the bushing 21 and has a shoulder 40 against which the stop disc 4| having the integral radial lug 29 is frictionally held by the insulating plate 42 formed of any suitable material, such as fiber or a phenolic condensation product or the like, and which in turn is frictionally held by a washer 43, the latter being suitably secured to the end 'of shaft 36, as at 44. It will be understood that a suitable knob or other rotating means (not shown) will be attached to the free end of shaft 36, and that the radial lug or stop 29 will be positioned between the upstanding stops or ears 33 and 34, so as to positively limit the oscillations of plate 42. In a common form or switch, the cooperating stops are so spaced as to permit oscillation of the movable plate through an arc corresponding to the.distance between adjacent contacts on fixed plate 25.

A unique feature of the present invention is that no connections are made to moving contactors, eliminating the necessity for inefficient and troublesome spring or pig-tail means for establishing a positive electrical path to moving contact members. Plate 42 carries contactors to be described, but these contactors function as bridging members to establish an electrical connection between a pair of fixed contacts.

Present-day switches not only have widely disproportionate contact resistance between adjacent circuits, but the fixed contacts, owing to their wide lateral extent, are so limited in number that the maximum number of poles for double-throw circuit control is inadequate for the requirements of the art. is limited by the necessity for maintaining a wide gap or clearance between the side edges of the fiat contacts in order to keep the inter contact electrostatic capacity at a minimum. As such switches are constructed, it is impossible to increase the relatively small number of poles available without an undesirable increase in one or more dimensions of the switch unit, or without an even less desirable increase in capacity. In some types, knife edges operating relatively to the flat contacts are resiliently connected to eccentric anchors, so that the resilient urge is asymmetrical of the fixed contacts and therefore uneven and varied, and also causes a train of metal dust to be formed across fixed contacts. This obvious disadvantage becomes worse as the gap between the fixed contacts is reduced by increasing the number of circuits to be controlled by the switch without greatly increasing the size of the switch.

It is a broad feature of this invention to provide fixed contacts exposing an edge to the moving contactor, and having small area in the direction of movement of the moving contactor. This is satisfactorily accomplished by the use of wires as contacts.

In the form of contact shown in Figs. 5 and 6,

'The number of contacts the gap between the for example, the disc-shaped plate 25 has an annular row or series of equally spaced apertures 45, close to its periphery, and in number as many as the maximum number of contacts to be employed. A second annular series of apertures 46 is more closely grouped inwardly of and with each aperture in radial alignment with the respective outer apertures. Each pair of radially spaced apertures 45 and 46 forms the locating and anchoring means for an associated contact. A wire or drawn conductor 41 of suitable metal of any desired cross section, such as square or polygonal for instance, is formed or bent to the profile shown in Fig. 5, in. which a short leg 48 merges at substantially a right angle into the contact area 50, at the outer end of which the wire is bent downwardly at 5| in substantial parallelism with the leg 48. The leg 5| may be short and be formed into a soldering terminal. In the same operation that shapes the contact initially to the form shown in Fig. 5, or in a separate operation, the angular edges of the contact area 50 may be rendered less sharp, as by rounding them, for instance as shown in section in Fig. 7, or by coining. Contacts 4! may be plated with silver or other metal to improve their surface conductivity.

A plurality of contact elements according to Fig. 5 is operatively associated with appropriate pairs of apertures, as by threading the longer shank 5| of each contact downwardly through an outer hole 45, until its short leg 48 seats in hole 46, and thereupon, as by a single punching operation, the longer leg or shank 5| is bent around as at 52 in Fig. 6 to be clear of the plate 25, and in one form the end is bent to form the soldering connection 53 of the form shown, or of any desired form. The end of short leg 48 is bent over toward the outer opening 45, and clinched to the plate to firmly anchor the contact. It is a feature of this assembly that the inner ends of the contacts are bent radially outwardly instead of inwardly, since the preferred bend does not cause the increase in total inter-contact capacity of the contact assembly which would result were the ends to be still more closely clustered by such inward radial bending.

The hooked end 53 of the contact element may assume any form desired in accordance with requirements, and it is a feature that, whereas one contact may have the form shown in Fig. 6, the adjacent contact may have a terminal end of a different outline, or may be bent up or down out of lateral registration with the first-mentioned hook, so that alternate terminals may be vertically staggered to facilitate attaching of connectors (not shown). It will be understood that where desired the terminal lug may be obviated and the contact extended as a connector.

It is a feature of importance in the forms of fixed plate which have been described, and in the many obvious modifications thereof that those skilled in the art may evolve, that the contacts may be attached to a previously prepared plate, and this may be a single or a gang operation, as desired; or the contacts may be suitably held in a mold, and the plate molded into anchoring engagement with the contacts.

The form of fixed contact disclosed is relatively thin transversely in a direction parallel to the upper surface of plate 25, and is preferably of such thickness perpendicular of the plate that the upper contact surface is well spaced from said plate surface. Regardless of the transverse width, it is preferable that the vertical or perpendicular dimension be such as to form ample clearance for the middle of the moving contactor, to be described, especially while the edges thereof are engaging the contact surfaces.

Referring to Figs. 2 and 7, there is shown one form of substantially universally adjustable rotatable contactor that is of economical and'eflicient construction and operation. The movable plate 42, already described, is provided with an annular series of equally spaced apertures. The apertures are preferably the same in number as the maximum number of poles in the switch. Each opening 66 may form a guide surface of itself or it may be provided with a guiding eyelet such as that shown at 61, having a flange 58 on the contact side of the plate 42, and serving as a guide for the slidable shank, pin or support 10 of a moving contactor. Pin 10 has a pointed head H, arranged to engage recess E4 in contactor 12. Contactor 12 may have any profile or outline. desired, but is preferably a single-based spherical segment.

The shank 10 has a flange 1011 or other suitable device to check axial motion of conically coiled spring 13, and is surrounded by the spring 13, the small end of the spring abutting the flange 10a, and the large end of. the spring engaging the flange 68 of the eyelet 61, if provided, or the lower surface of the movable plate 42 if the opening 66 is the guide of itself. It will be observed, in Fig. 7, that the contactor I2 is evenly spaced from and is symmetrical relative to the contact portions 50 of a pair of wire or edged contacts, and that the thrust of the spring 13 is axial with respect to the shank I and thus symmetrical relative to the spaced contacts. The contactor 12 might be cooked so as to be asymmetrical, but owing to symmetrical axial pres-sure, the contact resistance is equalized and good contact is established with each of the spaced contacts.

With'this form of contactor, lateral thrust on the wiping surface is resisted both by the side walls of the eyelet 61, and by the conical form of the resilient element. It is desirable that contactor 12 be as close to movable plate 42 as. reasonably possible so as to decrease the tendency toward lateral sway. To this end the spring may be compressed to a point where the turns of the coil lie in the form of a flattened cone or even in a plane, and the spring is preferably so designed that the coil may be compressed to lie in a plane without coil interference. It is also contemplated that the contactor l2, pivotally engaging the shaped head II of the shank 10, may also carry directly the flange a against which the spring 13 abuts.

In the previously discussed forms of contactor mountings, the contactor is prevented from moving any substantial amount in the line of wiping relative to movable plate 42. In each case the lateral thrust on the contactor is transmitted through the axial pin. In Fig. 8 there is shown a modification of the bridging contactor that is not only simpler and less expensive to make, but which also has greater universal resilience and freedom, and in which all thrust is transmitted directly by a spring element.

In one form of this modification, as shown in Fig. 8, a conical coil spring 15, which may be of wire, flat ribbon or wire tape, has its large end seated within the hollow contactor 16, the rim 11 of which is spun, bent, crimped or turned into engagement with the large end of spring 15 so as to anchor the latter in the contactor.

A short pin I8 has a flange 8B and on the upper side has a stud 8| arranged to engage frictionally in an aperture 66 of plate 42, so as normally to be retained therein, and may have the depending stud 82 of slightly greater diameter than the inner diameter of the small end 83 of coil spring 15, so as to be frictional-1y engaged thereby. when the stud 82 is forced into the small end.

In the assembly of Fig. 8 the axial thrust is "spread over the entire area of the contactor l6,

and the contactor is therefore completely free to adjust itself to any condition of seating that may be required, thus insuring good electrical contact.

By forming the coil spring of ribbon, interference between adjacent turns is preventedduring compression of the spring, and the spring is substantially self-aligning. The latter feature enables it to resist lateral deformation, thereby improving the operation of the switch in which it is used by maintaining the contactors substantially in their normal positions relative to plate 42. Referring to Fig. 8, the large end of spring 15 applies a substantially uniform pressure to contactor l6, insuring even pressure on the contacts.

A feature of interest and importance in a preferred form of the invention, in which electrical connection between fixed contacts is accomplished by means of a universally adjustable rotatable contactor, is the fact that rotation of the contactor is secured during the switching operation. Each contactor is normally in electrical contact with a pair of fixed contacts including a pole contact, and oscillation of plate 42 moves the contactor over the pole contact, to engagement with the other pair including the same pole contact. The fixed contacts are normally disposed radially on the plate 25, and they are therefore outwardly divergent. With the rotatable contactor in engagement with. a pair of outwardly divergent contacts, the axial pressure urging the contactor downwardly between the fixed contacts has a resultant force in a direction substantially bisecting the angle between the adjacent contacts. If the play in the contactor is appreciable, there may be a movement in the direction of this force. When the contactor slides over the pole contact and away from the outside contact of the first pair, this force is effective to establish a contact point between the contactor and the pole contact, that is out of alignment with the axis of the contactor in its line of oscillation, thus causing rotation of the contactor about this point as a pivot. As these points are constantly shifting with switching operations, there is continued oscillation and rotation of the contactor to maintain uniformly distributed wear.

The pressure exerted by the conical spring urges the contactor downwardly between adjacent fixed contacts. During rotation of the rotor in operation of the switch, the spring is further compressed as the contactor passes over the intervening contact. Due both to the force exerted by the spring and to the relative shapes of the contactor and the contact, the switching mechanism moves with a definite mechanical and audible snap from one conductive position to another, and thus urges the contactor toward and into a position intermediate two adjacent contacts. The resulting automatic self-indexing is an important feature of the present invention.

I claim: I

1. A multiple switch including plural contacts formed of wire and radially self-secured at equal intervals around a circle upon an insulating element, plural spherically rounded contactors of size suificient to bridge two adjacent contacts and simultaneously actuated by a movable insulating disc, pins in said insulating disc, a conically coiled spring anchored to each of said contactors and positioned at its small end upon one of said pins to urge said contactor toward said contacts, whereby said switch is automatically indexed into each of its conductive positions, each said contactor being out of direct physical contact with its pin and arranged for self seating on adjacent contacts and for limited response to the resultant thrust radially of said circle pursuant to axial thrust on divergent contacts to secure firm electrical engagement and low contact resistance.

2. A multiple switch having plural contacts formed of wire and radially self-secured and equally spaced in a circle upon a fixed insulating plate, plural spherically rounded contactors large enough to electrically connect two adjacent contacts, and means for simultaneously actuating all of said contactors including a movable insulating plate, pins equally spaced in a circle upon said movable plate, and a resilient member anchored to each of said contactors and positioned upon one of said pins to permit independent motion of said contactor toward and into a position intermediate adjacent contacts, and into a circuit closing position of small contact resistance with two adjacent divergent contacts out of alignment with the initial thrust of the resilient member.

3. A multiple switch including a stator and a rotor, divergent radial contacts on the stator, a contactor on the rotor engaging a pair of said divergent contacts, the rotor and contactor being resiliently connected in operative association and the contactor having a contact surface substantially curved in the direction of relative movement of the rotor and stator so as simultaneously to engage juxtaposed divergent contacts with part of the curved contact surface below the level of adjacent divergent contacts, the operative association of the rotor and contactor being such that the contactor may respond to and adjust itself in intimate electrical engagement with the said juxtaposed divergent contacts as a resultant of substantially axial pressure on divergent fixed contacts, of the radial outward urge on the con tactor due to such axial pressure, of the relative rotative urge on said disposed contacts mounted upon the stator, a rotor, a domed contactor, means resiliently operatively associating the contactor with the rotor so as to impart a thrust substantially axially of the contactor to urge the latter to intimate contact with a pair of said livergent contacts, said contactor including means rendering it capable. of rotation, lateral shifting and turning relative to said rotor and arranged for self seating in engagement with said pair of contacts as a resultant of the axial thrust and the reaction of the domed contactor from the divergent contacts.

5. In switches a wiping contact assembly including a substantially hemispherical segment, a tapered helical coiled spring having its larger end engaged with the segmental contact, a rotor having a pin, the smaller end of the coil engaging said pin, the coil and contact arrangement being such as to enable axial movement, bodily lateral movement and oscillation about an axis transverse of the axis.

6. In switches, in combination a stator and a rotor, the stator comprising an insulating member and a plurality of radially disposed relatively divergent fixed substantially rounded elongated contacts, the rotor comprising an oscillatable member having a wiping movement relative to the fixed contacts of the stator, the member comprising a substantially arcuate surface arranged to simultaneously engage adjacent fixed contacts with a portion of the arcuate surface below the level of the fixed contacts and arranged to slidingly wipe such adjacent contacts, resilient means arranged to impart substantially axial thrust on the member to urge it to frictional engagement with adjacent divergent radial stator contacts, said member and resilient means being so arranged that the said member can oscillate about an axis substantially radial of the axis of said rotatable member.

7. A contact member comprising a hemispherical hollow dome having an inturned flange, a tapered coil spring having its large end engaged in the dome beneat the flange, a pin en gaging the small end of the spring, rotor means having an aperture, said pin disposed in the aperture, the connection between dome and pin being only through the spring.

8. In switches, a self seating wiping contactor having driven arcuate switching movement and a curved contact surface, said contactor comprising a driving member, means resiliently coupling the member and the contactor in such a manner as to enable motement of the contactor to a seated contacting position as a resultant of substantial axial pressure on the contactor, lateral bodily pressure in one direction, transverse tilting pres sure on the contactor in another direction and rotative torque of the contactor, and a stator, divergent radial contacts on the stator arranged to be engaged by the contactor and having such clearance between contacts and between the contact peaks and the stator as to contribute by reaction toward the development of said pressure and torque.

LEE L. MANLE'Y.

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