US2758180A - Switch - Google Patents

Description

H. GINTOVT Aug. 7, 1956 SWITCH Filed April lO, 1953 MKM firm/WYE YS United States Patent O SWITCH Henry Gintovt, Dover, N. H., assignor to Clarostat Mfg. 'C0., Inc., Dover, N. H., a corporation of New York Application April 1li, 1953, Serial No. 347,963

9 Claims. (Cl. 200-153) This invention relates to a structurally and functionally improved switch for the control of an electric circuit.

lt is a primary object of the invention to provide a structure which will include relatively few parts, each individually simple and rugged in design and capable of manufacture by quantity production methods; such parts being capable of ready assemblage to furnish a unitary mechanism which may be very much reduced in over-all dimensions and which will, nevertheless, operate over long periods of time and in a positive manner with freedom from all diiculties.

A further object is that of designing a switch which may be combined with other units controlling the flow of electrical currents or which may be utilized as an independent mechanism; the structure being capable and ideally adapted for the production of a miniature assembly which will occupy only a very small space. Hown ever, the parts may be dimensioned to provide an assembly of any desired size. Regardless of whether the resultant switch be large or small, an extremely compact and efhcient mechanism is presented.

With these and other objects in mind, reference is had to the attached sheet of drawings illustrating practical embodiments of the invention and in which:

Fig. l is a face view of one form of switch assembly;

Fig. 2 is a partly sectional side view of the switch associated with a control which is illustrated largely in elevation;

Fig. 3 is a view showing the switch parts in a different position from that illustrated in Fig. l; and

Fig. 4 is a view similar to Fig. 3 but showing an alternative form of structure.

Primarily referring to Figs. l and 2, the numeral indicates a casing or base preferably formed of insulating material. Terminals 11 are associated with this base and as illustrated, may extend beyond the vedge of the same. The base is formed with an opening 12 through which an operating shaft 13 conveniently extends. This shaft is supported for rotation in any desired manner and may have secured to it a knob or other operating element (not shown). The base or casing 10 is conveniently closed by a cover 14 which may be retained in mounted position by, for example, securing elements 15. If the switch is to be used as an isolated unit, it may be provided with an acceptable mounting expedient whereby it is properly supported.

Frequently, however, the switch may form a part of an assembly which will include a control on the order of a variable resistance. To this end, it has in Fig. 2 been shown in association with such a control 16. Where so combined, the operating shaft may also serve to cause a functioning of the control to which end it extends through the latter and is connected to a suitable element or elements within the same. Under these circumstances, it will preferably project through a bushing 17 forming a xed part of the control and be retained against axial shifting in one direction by, for example, a split ring 18. Axial movement of the shaft in opposite direction will rice be precluded by the connection of the shaft with the element or elements of the control in accordance with well known practice. Where shaft 13 or its equivalent is provided solely for the operation of the switch, then it is apparent that structures similar to those heretofore described may be employed to rotatably support and restrain shaft 13. Also, in accordance with conventional design, the control may embody a stop portion limiting rotation of shaft 13. Again, if no control is employed, then if desired, a suitable stop portion may be associated with the switch assembly to prevent shaft 13 from being rotated through a complete circle.

A disk 19 of insulating material may be disposed within the cover 14. That disk is spaced from the face of the adjacent base or casing portion 1l). The end of shaft 13 extends into such space and conveniently terminates in a non-circular portion 2t). An actuator in the form of a hub 21 is mounted upon the end 20 of the shaft by being provided with an opening 22 which as illustrated may be formed so that a limited amount of radial lost motion can occur between the shaft and the hub. Therefore, While the actuator will rotate with shaft 13 in a plane parallel to the face of base lil, it will be appreciated that a limited amount of relative radial movement between these parts may also occur. In order for the actuator to operate the adjacent parts of the switch, certain of its surfaces are developed in the form of a radially projecting linger portion or cam 23, Any suitable form of stop structure may be provided to limit rotation of the actuator.

A substantially at spring istrip 25 is disposed below the cover 14 so that its at surface is arranged substantially parallel to the base of face 10 and perpendicular to shaft 13. One end ofthis strip may be widened as at 26 to provide a relatively rigid mounting portion. The strip is arranged to encircle the actuator and to that end its inner edge is preferably of arcuate shape and is enlarged so as to present integrally formed internal radial cam surfaces. The central portion of the strip should extend to encompass an arc conveniently not less than The inner edge of the strip adjacent that end which is opposite to mounting portion 26 is developed to provide a cam Asurface 27. The latter may be continued to furnish a recessed portion 28. Beyond this point, the extreme end of the strip terminates in an edge portion 29 providing a contact surface. That surface is engageable with an adjacent surface 30 of a conductor plate 24. In the interest of economy, and also to provide for'ease of assembly, this plate, as well as the mounting portion 25, may be formed integrally one with each of the terminals l1. Strip 25, from its contact surface 29, through to its mounting portion 26, may extend approximately through 210.

A force-distributing lever 31, made of any suitable insulating material, has its body interposed between actuator 21 and the cam surface 27 of the spring strip 25. It is mounted for pivotal movement conveniently by having a rounded outer end 32. The edges of the latter bear against the edges of arcuate recesses 33 conveniently formed in the terminals 11 or the portions adjacent thereto. Within its inner edge and adjacent its free end, this lever may be formed with a projection 34. The cam surface vin advance of the latter is engaged by the finger 23 as the actuator 21 is turned. Finally, with regard to this portion of the structure, it is to be noted that the lever is provided in its inner edge and adjacent the projection 34 with a relatively recessed or dwell part 35.

In the switch assembly as yshown in Figs. l, 2 and 3, the parts are constructed and arranged so that the switch normally maintains a closed position. In other words, disregarding the cam and actuator functions of parts 23,

27 and 34, the resiliency of the spring strip tends to maintain its surface 29 in firm electrical engagement with surface 3u of the conducting portion forming a part of plate 24. However, as the actuator rotates, its finger Z3 will move in a clockwise direction so that as it wipes against the inner edge of lever 3l over the cam surface of that lever in advance of projection 34, it will cause the lever to swing in a clockwise direction around its end portion 32. Thus shifted, the opposite edge portion of the lever will bear slidingly against the cam surface 27 of strip 25 and will shift into the recess Z8.

So actuated, the parts will move from the position shown in Fig. l, to that illustrated in Fig. 3 in which the end presenting surface 29 has moved outwardly along surface 30 and then upwardly away from surface 30. Due to the nature of this movement and the configuration of the parts, the separation of the contact surfaces will include an initial sliding or wiping action. With such movement, the circuit between terminals lll will be interrupted by a quick break. Under this position of the parts, finger 23 will lie within the dwell portion 35 so that the switch may be maintained in open condition. Finger 23 will always tend to center itself with respect to the dwell portion incident to the urging of strip 25 against lever 3i which will thus yieldingly press against finger 23, and due to the lost motion connection existing between actuator 21 and shaft end 20 will serve to assure this result. It will, of course, be understood that finger Z3 in conjunction with projection 34 will serve as a detent for the parts. Regardless of this, however, it will again be understood, due to the lost motion connection existing between the operating shaft or equivalent element and the actuator 21, that finger 2.3 will move beyond aligned position with respect to projection 34 because of the camming effect between the surfaces.

If the parts are proportioned and arranged as in Fig. 4, then a structure is provided in which the switch elements normally provide a gap so that the switch is open, as in dash lines in that figure. By proper operation of the assembly, the switch is caused to close. Thus, in this View the parts are generally similar to those just described. However, the spring strip 36 is caused to expand in an outward and slightly upward direction when actuator 37 is turned to cam finger 38 against the projection of lever 39. Thus, the outer contact surface 40 of strip 36 is shifted into engagement with the contact edge or surface 41 of the terminal plate 42 from the position indicated in dash lines to that shown in full lines. In this connection, it will be understood that the inner edge of the strip 36 adjacent its end surface 40 is formed with a cam surface against which the end of lever 39 rides or bears. The several surfaces may have dwell portions incorporated in them so that the closed position of the switch parts may be maintained. As is apparent, as soon as finger 38 shifts to a position where it no longer retains lever 39 in an outward position expanding strip 36, that strip because of its resiliency will move inwardly. Thus, the dotted line position of the parts will be established so that the circuit will be interrupted. Again, in this form of apparatus, a wiping engagement of the contact surfaces occurs so that these surfaces are maintained in clean condition.

As is apparent, the present teachings might be embodied in switches of diverse types. Also, the spring strip may be made of any desired metal. Preferably it is formed of beryllium copper or Phosphor bronze either of which combine the required qualities of conductivity and resiliency. Such resiliency will be adequate whether the strip is normally held in a condition of restraint within a circumscribed or restricted space and tends to expand or retract insofar as its contact surface is concerned. The saving of space which becomes possible by the use of this construction is, of course, apparent. This is not along true because of the split washer type of configuration which is employed but also because the i functions of a conductor and spring are combined in this unit. This, of course, is in addition to the lead and terminal which may form a part of the element, aside from the fact that one of its surfaces provides the desired contact area.

The great liexibility of this structure is evident from the number of combinations which can be obtained from minor changes in the incidence of the cam surfaces, the contact surfaces, and changes in the configuration, Width, or thickness, and of the materials, of the actuator, lever and spring.

In both illustrated forms of the invention all parts move in the same plane as the largest dimension of the bow spring or strip. Also, all cam surfaces are perpendicular to this plane or parallel to the actuator axis. As a consequence, the great flexibility of this structure is obvious in that a number of desired combinations may be obtained by minor changes in coniiguration of the several cooperating surfaces. To this end, the character of the materials employed and the thickness or width of the parts might be varied.

Thus, among others, the several objects of the invention as aforenoted are achieved. It is obvious that numerous changes in construction and rearrangement of parts may be resorted to without departing from the spirit of the invention as defined by the claims.

I claim:

l. A switch including in combination a mounting, an actuator rotatable with respect to said mounting and in a plane parallel thereto, a fiat contact fixed with respect to said mounting, a substantially flat strip of resilient metal disposed adjacent said mounting and at least partially encircling said actuator, the ilat surfaces of said contact and said strip being disposed in the plane of movement of the actuator an end portion of said strip being engageable with an edge portion of said contact and means whereby in response to movement of said actuator, said strip portion will shift with respect to said contact to establish and interrupt electrical connection with the same.

2. A switch including in combination a mounting, an actuator rotatable with respect to said mounting and in a plane parallel thereto, a iiat contact fixed with respect to said mounting, a substantially flat strip of resilient metal disposed adjacent said mounting and at least partially encircling said actuator, the flat surfaces of said contact and said strip being disposed in the plane of movement of the actuator a portion of said strip being engageable with said contact as said strip is flexed and means whereby in response to rotation of said actuator, said strip portion will flex toward and away from said contact.

3. A switch including in combination a mounting, an actuator rotatable with respect to said mounting and in a plane parallel thereto, a flat contact fixed with respect to said mounting, a substantially flat strip disposed adjacent said mounting and at least partially encircling said actuator, the flat surfaces of said contact and said strip being disposed in the plane of movement of the actuator a portion of said strip being engageable with said contact, means securing one end of said strip against movement with respect to said mounting, said strip being formed of spring material, the opposite end of said strip presenting a portion engageable with said contact and means whereby in response to rotation of said actuator, the body of said strip will be flexed to shift the opposite strip end in an oblique direction to have said strip portion move into and out of electrical engagement with said contact.

4. A switch including in combination a mounting, an actuator rotatable with respect to said mounting and in a plane parallel thereto, a flat contact fixed with respect to said mounting, a substantially flat strip disposed adjacent said mounting and at least partially encircling said actuator, the at surfaces of said contact and said strip being disposed in the plane of movement of the actuator a portion of said strip being engageable with said Contact, means securing one end of said strip against movement with respect to said mounting, said strip being formed of spring material, the opposite end of said strip presenting a surface engageable with said contact, cam surfaces associated with said strip and actuator and said cam surfaces cooperating as said actuator is rotated whereby to cause iiexing of said strip to shift its opposite end in an outward direction to shift said strip surface into and out of electrical engagement with said Contact.

5. A switch including in combination a mounting, an actuator rotatable with respect to said mounting and in a plane parallel thereto, a flat contact fixed with respect to said mounting, a substantially iiat strip disposed adjacent said mounting and at least partially encircling said actuator, the ilat surfaces of said contact and said strip being disposed in the plane of movement of the actuator a portion of said strip being engageable with said contact, means securing one end of said strip against movement with respect to said mounting, said strip being formed of spring material, the opposite end of said strip presenting a surface engageable with said contact, cam surfaces in the adjacent edges of said actuator and strip, a lever pivotally supported by said mounting and the body of said lever being disposed to lie between and cooperate with the cam surfaces of said strip and actuator whereby as the latter is rotated, said lever will oscillate to cause oblique displacement of said strip and movement of said surface thereof into and out of electrical engagement with said Contact.

6. A switch including in combination a mounting, an actuator rotatable with respect to said mounting and in a plane parallel thereto, a flat contact fixed with respect to said mounting, a substantially at strip disposed adjacent said mounting and at least partially encircling said actuator, the flat surfaces of said contact and said strip being disposed in the plane of movement of the actuator, a portion of said strip being engageable with said contact, means securing one end of said strip against movement with respect to said mounting, said strip being formed of spring material, the opposite end of said strip presenting a surface engageable with said contact, cam surfaces in the adjacent edges of said actuator and strip, a lever pivotally supported with respect to said mounting and the body of said lever extending between said strip and actuator to cooperate with the cam surfaces thereof as said actuator is rotated to cause a tangential shifting of said strip surface into and out of electrical engagement with said contact.

7. A switch including in combination a mounting, an actuator rotatable with respect to said mounting and in a plane parallel thereto, a pair of terminals supported by said mounting, a lever pivoted at a point to one side of the center of rotation of the actuator, a ilat contact connected with one terminal, a flat bow spring curved in the plane of its flat surface connected with the other terminal and movable into and out of engagament with said contact, the flat surfaces of said contact and said spring being disposed in the plane of movement of the actuator, and said lever being interposed between said spring and actuator for transmitting movement from the latter to the former.

8. A switch including in combination a mounting, an actuator rotatable with respect to said mounting, a pair of conducting portions relatively movable with respect to each other to move into and out of electrical engagement, a lever having a rounded end, the adjacent edges of said conducting portions being arcuately recessed and spaced to receive said end portion and pivotally support said lever, and said lever being interposed between one of said conducting portions and actuator for transmitting movement from the latter to the former.

9. A switch including in combination a mounting, an actuator rotatable with respect to said mounting, an electrical conducting C-shaped spring member having integrally formed internal radial cam surfaces, an end of said spring member forming a contact, means to fix said contact rigidly to said mounting, a second contact xedly mounted on said mounting in the plane of said spring member and having a cam surface thereon, a cam surface on the second end of said spring member, said cam surface being relatively movable with respect to said second contact to move into and out of electrical engagement with the cam surface thereon, a lever having a rounded end, the adjacent edges of said first and second contacts being arcuately recessed and spaced to receive said end portion and pivotally support said lever, and said lever being interposed between said actuator and the cam surface of said spring member for transmitting movement from the latter to the former.

References Cited in the le of this patent UNITED STATES PATENTS 2,482,206 Pratt Sept. 20, 1949 2,528,841 Morrison et al Nov. 7, 1950 2,574,034 Heimann Nov. 6, 1951 2,660,913 Frisby Dec. 1, 1953

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