US2293318A

US2293318A - Electric switch

Info

Publication number: US2293318A
Application number: US390414A
Authority: US
Inventors: Thomas W Thirlwell
Original assignee: Individual
Current assignee: Individual
Priority date: 1941-04-25
Filing date: 1941-04-25
Publication date: 1942-08-18
Anticipated expiration: 1959-08-18

Description

Aug 13, 1942 T. w. THIRLWELL 2,293,318

ELECTRIC SWITCH Filed April 25, 1941 zoma's TV. Thi/"Zwaar INVENTOR ATTORN EYS Patented Aug. 18, 1942 UNITED STATES PTENT OFFICE 1 Claim.

' My invention relates to circuit' interrupters, and includes among its objects and advantages the provision of an improved general `purpose switch of the silent action type.

In the accompanying drawing:

Figure 1 "is a face view of a switch in accordance with the invention; f

Figure 2 is a View taken from the position indicated by line 2--2 of Figure 1 but showing the switch associated with the usual outlet box employed for wall installatiom Figure 3 is a sectional view taken alongthe line 3-3 of Figure 2;

Figure 4 is a sectional view taken along the line 4-4 of Figure 3;

Figure 5 isa face view of a modified form of the switch; and

Figure 6 is a sectional View taken along the line 6-6 of Figure 5.

In the embodiment selected to illustrate the invention, I make use of an insulative switch housing I0 formed of molded composition, which housing is preferably of such size and contour as to operate in conjunction with the usual outlet box II employed for wall installation and provided with the usual wall plate I2. Tubular elements I3 and I4 are molded in the end walls of the housing I0, which housing has an opening IIE in one side wall thereof. Both elements I3 and I4 are internally threaded, as at I6, for v connection with terminal screws I1 and IB.

A leaf contact I9 is xedly secured to the element I3, as by riveting 20, and this contact has an ear 2| positioned closel5r to the head of the terminal screw I1 to hold the looped end of the circuit wire closely to the shank of the terminal screw `and underneath the head thereof. To the element I4 is iiXedly secured one end of a flexible leaf contact 22, as .by riveting 23, and this contact is also provided with an ear 24 for the same lpunpose as the ear 2|.

Fig. 3 illustrates the normal open circuit position of the contact 22, which provides spacing 25 between the contacts I9 and 22. Both contacts I9 `:and 22 are electrically related to their respective elements I3 and I4.

In the front wall 26 of the housing III is .provided an opening 21 lfor the accommodation of a switch lever 29. This lever is pivotally mounted intermediate its ends on a shaft 29 lying in slots 39 in the sidewalls 3I Vof the housing. Plates 32 are secured to the walls 3I by rivets 33 molded in the material of the housing. Each lplate is provided with two ears 34 positioned at right angles to their respective plates and overlying the front face of the housing. rIvhe ears are cut away at 35 in registration with the slots 30 for accommodation of the shaft 29, and the ears of each plate have meeting tabs 33 which may be bent upwardly to permit the shaft 29 to be pressed into position and then bent downwardly over the shaft to hold it in place. Each end of the shaft is upset at 31 for coaction with theY plates 32 to restrain the shaft from relative endwise movement.

The inner end of Vthe switch lever 28 is fan shaped and lies closely to the resilient contact 22. One edge of the inner end is rounded at 38, and the contact is bent to provide a cam run 39 lyingin the path of the rounded surface 38. Fig. 4 illustrates the lev'er 28 in its two extreme positions. `In one position, the edge 40 of the lever engages the front wall 26, as at 4I, while in the other extreme position, the lever engages the rWall 26, as at 42. The lever 28 in Fig. 4 is positioned in accordance with its full line illustration of Fig. 4, fat which time the rounded surface 38 is spaced from the cam run 39 so that the contact 22 is in its normal circuit breaking yposition with respect to the stationary contact I9. Pivotal movement of the lever 2S to its dotted line position of Fig. 4 brings the rounded surface 38 into engagement with the cam run 39 and fleXes the contact 22 rrnly against the stationary contact I9 for circuit closing purposes.

Adjacent one of the side walls 3l is positioned a bowed leaf spring 43 which bears against one side of 'the switch lever 28 for pressing the latter against the other side wall to the end that the switch lever may be frictionally supported in its two positions. This spring is pressed into slots 44 in the wall 26 and the tension of the spring is such as to hold the switch lever rmly in either position.

A switch in accordance with my invention is entirely silent in its action. The contact 22 flexes easily into engagement with the stationary contact I9 and all the moving parts operate noiselessly.

Anchor plates 45 are secured to the housing YIII by rivets 45 molded in the material of the housing. These plates are provided with openings 41 for the reception of screws which may be threaded into the outlet box II for securing the housing to the box. Each plate 45 is also provided with a threaded opening 48 for the reception of screws 49 which hold the wall plate I2 in position.

Figs. 5 and 6 illustrate a diiierent form of the invention, wherein the top wall 50 and the bottom wall are molded into a unitary structure with the side walls 52, which are considerably shorter in length than the top and bottom walls. The housing of Figs. 5 and 6 conforms to the housing of Figs. l through 4 with respect to size and contour.

Tubular elements 53 are secured to the bottom wall 5| and are internally threaded at 54 for the reception of terminal screws 55. One of the tubular elements 53 is provided with a contact 56 engageable by one end of a leaf contact 51 having its opposite end xedly secured to the other element 53. Contact 51 is of the resilient type and normally spaced from the fixed contact 56.

A slot 58 is provided in the front Wall 5| for the accommodation of a lever 5.9 pivoted intermediate its ends on a shaft 60 secured to the side walls 52. A relatively flat face 6| is fashioned on the inner end of the switch lever 59 for engagement with the spring contact 51 when the latter is in the position of Fig. 6. Face 6| is so angled as to exert pressure on the spring eontact'51 for flexing the contact into engagement with the xed contact 56 when the lever 59 is pivoted to the dotted line position of Fig. 6. The face BI is provided with a curved camming face 6,2 which acts on the spring contact 51 to flex Vit to the dotted line position of Fig. 6, and the curved camming face 62 terminates in a flat face 63' whichY lies in engagement with the spring contact inthe dotted line position of the switch lever for holding the latterrmly against the xed Contact 56.

In the full line position of the switch lever 59, as illustrated in Fig. 6, the inner end hasengagement with the front wall 50, as at 64.V At the. same time, the switchv lever may have engagement with the edges of the front wall 5U so as to stop further pivotal movement of the switch lever when it reaches either of its two extreme positions. 'I'he switch of Figs. 5 and 6 also operates silently.

Anchor plates 66 are secured to the housing by rivets 61, and these plates are also provided with threaded openings 68 corresponding to the openings 48.

Without further elaboration, the foregoing will so fully illustrate my invention that others may, by applying current knowledge, readily adapt the same for use under various conditions of service.

I claim:

A switch comprising an nsulative body having a face wall provided with an opening and an interior cavity, a fixed contact secured to the insulative body inside said cavity, a flexible contact secured to said body inside said cavity and normally spaced from said xed contact, a switch lever pivoted to said body and having camming engagement with said ilexible contact when pivoted in one direction for bending the flexible Contact into circuit closingA engagement with said xed contact but relieving pressure on the flexible Contact when pivoted in theopposite direction, said flexible contact comprising a flat strap-like member lying atwise adjacent one side of the switch lever and having a cam formation lying in the path of the switch lever, and a at spring bearing flatwise against Vone side ofi-saidV switch lever for urging the latter against one wall face dening said opening for frictionallyv supporting the switch lever against accidental pivotal movement.

THOMAS W. THIRLWELL.