US2221575A - Circuit interrupter - Google Patents

Description

' Nov. 12,1940. E. K. CLARK CIRCUIT INTERRUPTER Filed Aug. 3, 1938 ATTORNEY INVENTOR WITNESS'ES: V

Patented Nov. 12, 1940 CIRCUIT INTERRUPTER Earl K. Clark, Mansfield, Ohio, assignor to Westinghouse Electric & Manufacturing Company, East Pittsburgh, Pa., a corporation of Pennsylvania Application August 3, 1938, Serial No.- 222,800

3 Claims.

, My invention relates to a circuit interrupter, and more particularly to a relatively thin switch for use in domestic appliances and the like.

With the modern trend in styling of appliances,

such as sandwich grills and coffee makers, it has been practically impossible to adapt present control switches to the particular structures thereof in view of the physical dimensions of such switches. The mere reduction in size of the switches, while maintaining suflicient currentcarrying capacity thereof, resulted in ineflicient structures, the parts of which would bind or become generally inoperative with repeated operations.

It is, therefore, an object of my invention to provide a thin, compact appliance switch capable of handling at least 1300 watts, without the cooperating parts thereof binding after repeated operations in the field.

Another object of my invention is to provide a thin, compact appliance switch having an operating arm operating in one plane which is capable of moving a contact in a plane normal to such control arm without any binding action 25 therebetween.

A further object of my invention is to provide an efiicient, rugged, inexpensive, compact, thin appliance switch which has a positive contact pressure.

Other objects of my invention will either be pointed out specifically in the course of the following description of a device embodying my invention, or will be apparent from such description.

In the accompanying drawing,

35 Figure 1 is a perspective view of a device embodying my invention in its open position,

Fig. 2 is an end view of the operating lever,

Fig. 3 is a view similar to Fig. 1 showing the device in its closed position,

, Fig. 4 is a side elevational view of the device shown in Fig. l, and;

Fig. 5 is a perspective view of the resilient contact supporting member.

Referring to the accompanying drawing, I

5 show a thin appliance switch l0 comprising a base or supporting structure l2, a manually operable operating lever I4, a resilient contact supporting member l6 associated therewith, a movable contact l8 rigidly attached to member I6,

50 stationary contacts mounted on the base, a contact operating pin 22 on member l6 and a fulcrum-supporting pin 24 for attaching the operating lever l4 and resilient member I to the supporting structure.

55 The supporting structure I2 is preferably formed from a strip of sheet metal, and has a base 25 and a relatively short upwardly extending flange 26 located at one end thereof. A slotted aperture 28 is located in the flange 26 substantially at its junction with the base 25 to permit the operating lever I4 to extend therethrough, as hereinafter described. A notch 30 is positioned in the upper edge of the flange 26 substantially at the midpoint thereof. The notch 3ll is substantially as long as the width of the resilient contact supporting member I6 so as to receive such member and to prevent horizontal movement thereof, substantially as hereinafter described. However, it is tobe understood that the base l2 may be formed in any other manner which permits the cooperative action of the operating handle l4 and resilient contact supporting member lli substantially as hereinafter described.

'I'heoperating lever l4 comprises a handle portion 32 and a fan-shaped portion 34. The op- 20 erating lever I4 is swingably attached intermediate the ends thereof, preferably near the apex of fan-shaped portion 34, to the base 25 of the supporting structure l2 by means of a fulcrum pin 24, substantially as hereinafter de- 25 scribed. The operating handle portion 32 extends, substantially parallel to the base 25, through the aperture 28 in the flange 26, whereas the fanshaped portion 34 is located substantially parallel to the base 25 and is positioned over such base 30 to cooperate with operating pin 22, as hereinafter described. It, therefore, follows that as the handle portion 32 of the operating lever I4 is moved in a plane substantially parallel to the base 25, the operating lever M will be rotated about the fulcrum supporting pin 24 and the fan-shaped portion 34 of the lever l4 will likewise be moved in a plane parallel to the base 25.

An upwardly extending tapered flange portion or ledge is positioned along a portion of the G outer edge of the fan-shaped portion 34 of the operating lever l4, see Figs. 1 and 3. The flangeshaped portion or ledge 35 tapers upwardly from substantially the midpoint of the outer edge of the flat fan-shaped portion 34 and along the ed e of the fan-shaped portion 34, and cooperates with the contact operating pin 22 so as to move it substantially normally to the base 25 with the rotative movements of handle l4, as hereinafter described.

The resilient contact supporting member I6 is, in this instance, a long flat spring which is attached to the base or supporting structure l2 intermediate its ends by means of the fulcrum supporting pin 24. One end of the resilient memher l6 ispositioned within the notch 36 in flange 26. The notch 20, being substantially the same length as the width of the resilient member l6, functions incooperation with the fulcrum supporting pin 24 and prevents any movement of the resilient member I 6 about the fulcrum. pin. Resilient member [6 has a preset downwardly extending arch, as shown in .Fig. 5, which, ensures a positive downward biasing action of the free end of such member. The free end thereof will thus be biased towards the base 25 at all times and the movable contact l8 operatively associated therewithwill likewise be biased toward the stationary contacts 20.

The movable contact I8 comprising a looselymounted contact plate 38 is insulatedly attached to the free end of the resilient contact-supporting member l6 by means of an insulated rivet structure 36. The rivet structure 36 is rigidly attached to the free end of the resilient member l6. However, the contact plate 38 is loosely attached to the rivet 36 to ensure positive uniform bridging contact with the stationary contacts 26. It, therefore, follows that as the resilient member I6 is biased downwardly, as hereinabove described, the movable contact l8 operatively associated therer with will likewise be biased downwardly towards the base 25 of the supporting structure I12, and will exert a positive uniform'con'tact pressure on the stationary contacts 20.

The stationary contacts 26 include contact members 40 insulatedly attached to the supporting structure l2. The contact members 46 are, in this instance, strips of an electrical conducting material such as silver surfaced aluminum or copper, which are insulatedly attached to the base 25 by means of rivets 42 and an insulating gasket 44. The contact members 40 of contacts 20 are positioned so that there is a gap located therebetween which is bridged by the movable contact l8 as the resilient member l6 biases or actuates such movable contact into engagement i therewith.

If desired, suitable terminals (not shown.) may be operatively associated with the contacts 20 to permit the switch to be readily inserted in a circuit to be controlled. However, the stationary contacts 20 may be attached to an appliance, such as a sandwich grill or percolator, by having the conductors thereof directly attached to the can tact members 40, as by soldering thereto or in any other desirable manner.

The contact-operating pin or cam roller pin 22 comprises a shaft 23 and a disc-shaped cam or roller 21. The shaft 23- is mounted substantially normal to the base 25 and the resilient member l6, and is journalled in the base 25 at one end thereof and within the resilient member l6 at the other end. The shaft 23 is then free to rotate about the longitudinal axis thereof and also to move longitudinally along such axis because of the length of the shaft. The cam or roller 21 is rigidly positioned upon the shaft 23 intermediate the end thereof, being located between the resilient member [6 and the fan-shaped portion 34 of the operating lever l4.

Therefore, as the operating lever I4 is rotated about the fulcrum pin 24 as an axis, the upwardly extending ledge 35, positioned below the cam 26 of operating pin 22, forces the pin 22 upwardly, this, in turn, forcing the resilient member l6 upwardly. Inasmuch as the pin 22 is journalled within resilient member l6 and base 25, and is mounted substantially normal thereto and to the operating handle [4, such pin will be rotated I aaansn about its axis as the operating handle is moved. In addition, the rotation of the operating pin 22 will eliminate or reduce the horizontal component of the force action between the lever l4 and the pin 22 to substantially a minimum value. It, therefore, follows that as the handle I4 is rotated about the fulcrum pin 24, the pin 22 will be moved vertically without any horizontal binding action between the handle l4, the base 25 or the resilient member l6.

The fulcrum-supporting pin structure 24, operatively associated with the operating handle 14 and resilient member l6, as hereinafter described, comprises, in this instance, a one-piece construction including a main body portion 46, a lower sleeve portion 48, an upwardly extending rivet portion 49 and a downwardly extending rivet portion 50 which rigidly attaches the structure to the base 25. The fulcrum pin 24 attaches the operating handle l4 and resilient member I6 to the base in substantially the following manner. The lower sleeve portion 48 of fulcrum pin 24 is inserted through an aperture 56 in the operating lever l4 while the main body portion 46 thereof supports the resilient member [6 above the handle l4, with the upwardly extending rivet portion 49 passing through an aperture 58 in the resilient member IS. The downwardly extending rivet portion 50 is then inserted through the base 25, whereupon the upper and lower ends of rivet portions 49 and 50, respectively, may be spun or riveted over upon resilient member l6 and base 25, respectively, to form a rigid structure. If desired, a washer 60 may be positioned upon resilient member l6 to permit the pin 49 to be spun over thereon without injuring the resilient member I6 in any manner. In addition, a washer or spacer 59 may be positioned on the sleeve portion 48 intermediate the operating lever 14 and the base 25 to space the lever l4 from the base 25.

With the main body portion 46 of fulcrum pin 24 being somewhat larger than the sleeve portion 48, such main body portion will prevent the operating handle i 4 from moving vertically along pin 24, while the sleeve 48 will permit the handle to be rotated about such pin as a fulcrum or axis. It is, therefore, obvious that the fulcrum pin 24 rotatably supports the operating handle H with respect to the base 25.

The top surface of the main body portion 46 of the fulcrum pin 24 is somewhat below the level of the notch 36 located in flange 26. Accordingly, inasmuch as the resilient member I 6 is operatively associated with notch 36 and rigidly attached to the main body portion 46, of pin 24, such member l6 will be held at substantially an angle to the base 25, extending downwardly from the flange 26 to the stationary contacts 26. The prearched shape of resilient member l6 then produces a downward biasing action of the free end thereof at all times and, therefore, ensures a positive contact pressure between the movable contact l8, located on the free end of the resilient member l6, and the stationary contacts 26.

It is, therefore, obvious that the operating handle I 4, rotatably attached substantially parallel to the base 25, through the cooperative action of operating pin 22, will move the free end of resilient contact supporting member I 6 upwardly and will permit it to move downwardly, as the handle is moved from one position to another, to effect engagement and disengagement of the movable contact ill with the stationary contacts 20.

When operating the appliance switch In cmbodying my invention, the operating handle I4 is manually moved substantially in the plane of such operating handle from, say, an on" position shown in Fig. 3 to an "ofP position shown in Fig. 1 or vice versa. The upwardly extending ledge of the fan-shaped portion 34 in the handle I4 then, as the handle I4 is moved from an on to an off position, forces the operating pin 22 substantially vertically upwards. As the pin 22 is moved vertically along its axis, it forces the free end of the resilient member l6 upwardlv. against its downwardly biasing action, and, inasmuch as the pin 24 is journalled within the resilient member l6 and base 25, such pin 22 will rotate therein without any binding action therebetween. As the free end of the resilient member ID is moved upwardly by pin 22, the movable contact l8 operatively associated with the free end thereof, is disengaged from the stationary contacts 20, whereupon the switch is in an inoperative position.

To reengage the contacts I8 and, or have the switch returned to an operative position, the operating handle I4 is moved in the opposite direction substantially in its plane, whereupon the up the pin 22, permitting such pin 22 to rotate and to be vertically moved toward the base 25, by :the downward biasing action of resilient member l6.

As the ledge 35 is completely removed from under roller 26 of the operating pin 22, the movable contact [8 will again reengage the stationary contacts 20. The downward biasing action of the resilient member l6 thus ensures a positive contact pressure between the cooperating contacts l8 and 20.

It is, therefore, obvious that the switch or circuit interrupter embodying my invention-is exceptionally thin and compact, inasmuch as the overall height thereof is substantially determined by the relatively short upwardly extending ledge 26, and that such switch is operated by an operating arm operating in the plane of the switch by moving a contact positioned normal to the plane thereof without any binding action between the cooperating parts.

Various modifications may be made in the device embodying my invention without departing from the spirit and scope thereof, and I desire, therefore, that only such limitations shall be placed thereon as are imposed by the prior art and the appended claims.

I claim as my invention:

1. A circuit interrupter including, in combination, a supporting structure, a plurality of concomprising the moving arm for moving the pin I along its axis to eiiect the movement of the movable contact into engagement with or disengagemeat from the stationary contact.

2. A thin appliance switch including in combination, a supporting base, contact means com- I prising at least one movable contact, a flat inherently resilient member attached and extending substantially parallel to the base and adapted to insulatedly support the movable contact and to bias it toward the base, an operating pin journaled within the base and the resilient member, said pin being adapted to rotate about an axis normal to the base and to move longitudinally along such axis, a manually swingable operating arm attached substantially parallel to the base and adapted to be moved in its plane, and means comprising a cam surface on the moving arm for engaging an intermediate surface of said pin to convert swinging movement of the operating arm and cam surface to a vertical movement of the pin along its axis in opposition to said flat resilient member.

3. A thin appliance switch comprising in combination, a supporting base including a short upwardly extending flange, contact means comprising at least one movable contact, a resilient member operatively associated with the flange attached to the base and adapted to insulatedly support the movable contact and to bias the contact toward the base, an operating arm rotatably attached to the base and adapted to be moved in its plane, an upwardly extending ledge integral with the arm, an operating pin journaled within the base and the resilient member being adapted to rotate therein, an engageable member positioned intermediate the ends of the pin, said en'- gageable member being operatively associated with theledge and adapted to convert rotational movement of the operating arm and ledge to a vertical movement along its axis, and means responsive to rotatable movements of the operating arm for vertically moving the pin, resilient member and movable contact substantially normal to the base to efiect engagement and disengagement of the contact means.

EARL K. CLARK.

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