US2455927A

US2455927A - Electric switch

Info

Publication number: US2455927A
Application number: US606369A
Authority: US
Inventors: Stephen S Grady
Original assignee: Individual
Current assignee: Individual
Priority date: 1945-07-21
Filing date: 1945-07-21
Publication date: 1948-12-14
Anticipated expiration: 1965-12-14

Description

Dec. 14, 1948. s. s. GRADY 2,455,927

ELECTRIC SWITCH Filed July 2l, 1945 lNvEN-ron l By,

ATTORNEY Patented Dec. 14, 1948 UNITED STATES PATENT OFFICE ELECTRIC SWITCH Stephen S. Grady, New York, N. Y.

Application July 21, 1945, Serial No. 606,369

6 Claims. l

This invention relates to electric switches in general and more especially to toggle switches.

Among the objects ci the present invention, it isaimed to provide an improved electric switch of the toggle or snap switch type in which the main contacts may be disengaged without interrupting the current and thereby in turn practically eliminate the arc formation, and confine the arc formation, if any, to a quick breaking narrow area.

It is still another object of the present invention to provide an improved electric switch of the toggle or snap switch type having maink and auxiliary contacts, the auxiliary contacts being engaged nrst in circuit making action and disengaged last in circuit interrupting action to eliminate arc formation between the main contacts either during the making or breaking of the circuit.

It is still another object of the present invention to provide an improved electric switchhaving main contacts which engage face to face, one of which main contacts is yieldable to cause the contacting faces to move relative to one another while in engagement with one another during making and breaking of a circuit in turn to clean the surfaces of any accumulation of dirt or foreign material.

These and other features, capabilities and advantages of the invention will appear from the subjoined detail description of one specific embodiment thereof illustrated in the accompanying drawings in which Fig. 1 is a front elevation of the switch in closed position;

Fig. 2 is a rear elevation of the switch in closed position;

Fig. 3 is a section on the line 3 3 of Fig. 1;

Fig. 4 is a section on the line 4-4 of Fig. 1;

Fig. 5 is a rear elevation of the switch with the handle partly moved into a position before breaking the contact.

In the embodiment shown, there is provided a casing having a base i to which are connected two side walls 2 and 3, On the base there are mounted two

brackets

4 and 5 connected to the terminals (not shown) of the switch. The contact bracket .4 has the fiange 6 with an opening therein to receive a screw or the like to connect the flange 6 to the base l and the bearing bracket 5 in thev present instance has a ange 1 provided with a recess 8 to receive a screw or the like to connect the flange 'l to the base l. The

brackets

4 and 5 are in turn insulated from one anotherby, and connected to the insulation block 9. The bracket il has a connecting portion lil, double thickness in the present instance, connected ,to the block 9 by screws such as the screw ii, and the bracket 5 in turn has a flange i2 connected to the block Si by screws auch as the screw I3. The bracket l in the present instance constitutes the first Contact of the switch andy is provided with two contacting sections, to Wit, the narrow section i4 and the wide section or plate l5 connected to one another by the connecting portion it. The wide section i5, in the present instance, is separated from the connecting portion l by the slot i6, which extends down to the point Il, see Fig. l, in order that the section I is free to yield when engaged by the fdange i8 constituting one of the movable contacts ci the switch. When so yielding upon initial con tact, a wiping or rubbing action will take place between the engaging faces of the plates i5 and i8 to free the engaging surfaces from any carbon that might collect as a result of arcing during making or breaking of the circuit.

The movable contact i8 in the present instance isformed on the blade i9 pivotally connected by the pin to the flange 2l on the bracket 5. The blade IS has an opening 22 therein, the ends of which cooperate with the pin or projection 23 on the arm 24 pivotally connected at 25 to the flange 2B formed on the bracket 5. The bar 24 extends downwardly from the flange 2t and the lower edge thereof in the contact making position shown in Figs. 1 and 2 engages the narrow fixed contact area Hl of the bracket 4. The blade i9 and the 2t cooperate with the pivot pinsk 2D and 25 and the spring 2l to constitute a toggle leverage which will be locked in place to either side of the pivot pin 25 by the spring 21 in the usual way, the one end of the spring being connected to the projection 2li in the pren sent instance alining with the pinI 2?, and the other end of the'spring being connected to the projection 29 formed on the blade i9 on the other side of the pivot point 25.

Preferably for manipulating theblade i9, it is provided with a handle composed of insulating material which has the arcuate shield extensions 3| and 32 preferably integral with the handle 30 and also composed of insulating material. The shield portions 3i and 32 thus serve in a way to protect the fingers of the user from any short circuit or arc that might be created during the making or breaking of the circuit in the act of opening or closing the circuit,

The-pin 25 extends through the upper portion of the insulating block 9 from the ange 26 to 3 the contact disk 33 which is in wiping contact with the blade I9.

The block 9 is provided with a slot 34 to form a clearance for the pin 23, and, see Fig. 4, is also provided with a slot 35 to form a clearance for the lower end of the arm 24 by eifectively insulating the lower end of the arm 24 from the bracket 4 when the switch is in open position. Preferably as shown, the insulating block may be composed of two parts, the part 36 and the angle strip 31 having the web 38 secured to the bottom of the part 36 and the web 39 spaced from the bottom of the part 36 to form a clearance between the web 39 and the part 36 for the lower end of the arm 24.

The lower portion 40 of the insulation part 36, as is clearly shown in Fig. 4, separates the arm 24 from the blade I9 so that, see Fig. 3, after the switch has been closed, both the flange I8 engages the plate I5, and the blade 24 engages the portion I4 of the bracket 5. Then upon starting to open the switch, see Fig. 5, the blade I9 will rst cause the flange I8 to clear the plate I5 when the current will continue to llow from one terminal to the other through the arm 24 and contact portion I4 of the bracket 5 and the switch will not be opened until the blade I9 has moved the abutment 29 of the spring 21 so that the spring 21 will pass to the other side of the dead center or pivot pin 25 to cause the arm 24 quickly to snap out of contact with the portion I4 and move over into the open position where the pin 23 approaches the other end of the recess 22, namely the end 4I, when the lower end of the arm 24 will engage the inner face of the bracket 4.

When again actuating the blade I9 to close the switch, the end 4I of the recess 22 will first move into engagement with the pin 23 and after engaging the same cooperate with the spring 21 to swing the lower end of the arm 24 into engagement with the contact portion I4 of the bracket 4, the spring 21 of course entering into play as soon as it passes the dead center or pivot pin 25 in the well known action of a toggle. In the final position of the blade I9, see Fig. 2, the spring 21 will also operate or function to cause the flange I to engage the plate I5.

In operation it will thus be seen that when the switch is closed, the current will pass from a terminal of the conductor, not shown, connected to the bracket 4 either through the plate I8 to the flange I5 of the blade I9, then from the blade I9 through the bracket 5 to the other terminal or else when the blade I9 has caused the flange I8 to be spaced from the plate I5 then the current will pass from the bracket 4 through the contact portion I4 to the arm 24 and then from the arm 24 pivotally connected to the bracket 5 through the bracket 5 to the other terminal of the conductor. In this way, when the blade I 9 is in its closed position as shown in Fig. 2, the extended area of the flange I5 will cooperate with the blade I8.

From the foregoing it will thus appear that the initial make and break of the circuit will be effected by the edge of the arm 24 engaging the portion I4 of the bracket 4, a comparatively narrow surface, :and the make and break with the edge of the arm 24 will be an exceedingly fast one so that if an overload did occur, before it could cause any harm to the switch, in the opening of the switch, the spring 21 would come into play to cause the switch to open immediately, and in turn, when closing the switch, also while the arm 24 may be the first to establish a current through the :area I4 of the bracket 4, the successive contact between the flange I8 and plate I5 will follow so quickly after initial contact is made that no harm can come to the switch, and on the other hand, when the extended face of the flange I8 engages the plate I5, then a sulliciently large Iarea will be in contact to reduce the resistance and effectively take care of an ordinary overload without injury to the switch- In turn, upon opening of the switch, due to the fact that the arm 24 will still be in contact with the portion I4 of the bracket 4 when an extended surface of the flange I8 recedes from the plate I5, see Fig. 5, no arc will take place during this opening movement. Furthermore, if any dirt or foreign material should have collected on the faces of the flange I8 and plate I5, such dirt or foreign material will be wiped off or rubbed off, due to the yieldability of the plate I5 and relative movement of the plate I5 and flange I8 as :a result of this flexibility while the ilange I8 is making contact with the plate I5 or leaving the plate I5. In other Words, when the flange I8 initially engages the plate I5, before the two come to rest, there will be a surface movement of one relative to the other due to the yieldability of the plate I5 which surface movement will again occur when the blade I9 is started on its movement to open position.

It is obvious that various changes and modiiications may be made to the details of construction without departing from the general spirit of the invention as set forth in the appended claims.

I claim:

1. The combination of a bearing bracket con stituting one terminal of an electric circuit, a blade and an arm pivotally connected at spaced apart portions of said bearing bracket, a spring connected at one end to said arm and at its other end to said blade, a contact bracket constituting the other terminal of an electric circuit, the spring being positioned to one side of 'the pivotal connection of said arm when said blade and arm are spaced from said contact bracket, said contact bracket having a flexible contact plate, and a contact flange on said blade, the spring being positioned to one side of the pivotal connection of said arm when said arm and blade are maintained in open switch position and said spring being positioned to the other side of the pivotal connection of said arm when said spring yieldably maintains the free end of said arm in contact with said contact bracket and the flange of said blade in contact with said flexible plate, said blade being movable relative to said arm so that said flange may be withdrawn out of contact with said flexible plate before the free end of said arm is withdrawn from contact with said contact bracket.

2. The combination of a bearing bracket con- Stitutllg one terminal of an electric circuit, a blade and an arm pivotally connected to said bracket. a spring connected at one end to said arm and at its other end to said blade, a contact bracket constituting the other terminal of an electric circuit, the spring being positioned to one side of the pivotal connection of said arm when said blade and arm are spaced from said contact bracket, said contact bracket having a flexible contact plate, a contact flange on said blade, the spring being positioned to one side of the pivotal connection of said arm when said arm and blade are maintained in open switch position and said spring being positioned to the other side of the pivotal connection of said arm when said spring yieldably maintains the free end of said arm in contact with said Contact bracket and the flange of said blade in contact with said flexible plate, said blade having an opening therein with abutments at the ends thereof, and a projection on said arm extending into said opening and cooperating with said abutments and said spring to snap said arm and blade into open or closed position immediately that said spring passes the pivotal connection of said arm.

3. The combination of a bearing bracket constituting one terminal of an electric circuit, a blade and an arm pivotally connected at spaced apart portions of said bearing bracket, a spring connected at one end to said arm and at its other end to said blade, a contact bracket constituting the other terminal of an electric circuit, the spring being positioned to one side of the pivotal connection of said arm when said blade and arm are spaced from said contact bracket, said contact bracket having a flexible contact plate, a Contact flange on said blade, the spring being positioned to one side of the pivotal connection of said arm when said arm and blade are maintained in open switch position and said spring being positioned to the other side of the pivotal connection of said arm when said spring yieldably maintains the free end of said arm in contact with said contact bracket and the flange of said blade in contact with said flexible plate, and an insulated extension on said blade to serve as a handle for actuating the blade.

4. The combination of a bearing bracket having two flanges at its opposite ends and constituting one terminal of an electric circuit, a blade pivotally connected to one of said flanges and extending to and beyond the other flange, an arm pivotally connected to said other flange and extending parallel to said one flange, a spring connected at one end to said arm below its pivotal connection with said other flange and connected to said blade beyond said other flange, a contact bracket constituting the other terminal of the electric circuit, a flexible plate formed on said Contact bracket, and a flange formed on said pivotal blade and contacting said flexible plate when the spring is positioned to one side of the pivotal connection to close the circuit when the free end of said arm also contacts said contact bracket.

5. The combination of a bearing bracket having anges at its opposite ends and constituting one terminal of an electric circuit, a blade pivotally connected to one of said flanges and extending to and beyond the other flange, an arm pivotally connected to said other flange and extending parallel to said one flange, a spring connected at one end to said arm below its pivotal connection with said other flange and connected to said blade beyond said other flange, a contact bracket constituting the other terminal of the electric circuit, a flexible plate formed on said contact bracket, a flange formed on said pivotal blade and contacting said flexible plate when the spring is positioned to one side of the pivotal connection to close the circuit when the free end of said arm also contacts said contact bracket, there being an opening in said pivotal blade having abutments at its opposite ends, and a projection on said arm cooperating with said abutments and said spring to snap said arm and pivotal blade into and out of closed position.

6. The combination of a bearing bracket having flanges at its opposite ends and constituting one terminal of an electric circuit, a blade pivotally connected to one of said flanges and extending to and beyond the other flange, an arm pivotally connected to said other flange and extending parallel to said one flange, a spring connected at one end to said arm below its pivotal connection with said other flange and connected to said blade beyond said other flange, a contact bracket constituting the other terminal of the electric circuit, a flexible plate formed on said contact bracket, a flange formed on said pivotal blade and contacting said flexible plate when the spring is positioned to one side of the pivotal connection to close the circuit when the free end of said arm also contacts said contact bracket, there being an opening in said pivotal `blade having abutments at its opposite ends, and

a projection on said arm cooperating with said abutinents and said spring to snap said arm and pivotal blade into and out of closed position, said pivotal blade being movable relative to said arm to withdraw said flange from said flexible plate before said arm is withdrawn from said contact bracket in circuit interrupting operation, and said flexible plate and flange being movable relative to o-ne another when in contact with one another to remove any deposits of dirt or foreign material.

STEPHEN S. GRADY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,155,157 Lewis Sept. 28, 1915 1,383,695 Comboni July 5, 1921 1,407,603 Timmons Feb. 21, 1922 1,829,514 Grossman et al. Oct. 27, 1931 2,308,026 Rawlins Jan. 12, 1943