US1755055A - Snap switch - Google Patents

Description

April 15, 1930. D E 1,755,055 sNA'P SWITCH Filed Feb. 1, 1928 HQ. l T

l |llll\llllllll lllllllllllhl Inventor: Frank CDeReah'ler,

1 His Attorney.

Patented Apr. 15, 1930 UNITED STATES PATENT orricr. T

FRANK C. DE REAMER, OF BRIDGEPORT, CONNECTICUT, ASSIGNOE TO GENERAL ELECTRIC COMPANY, A CORPORATIDN OF NEW YORK SNAP SWITCH Application filed February 1, 1928.

The present invention relates to small snap switches and has for its object to improve their construction. The invention is partlcularly applicable to switches for use with manually-operated devices such as vacuum cleaners, electric drills, etc. and will be described in connection with such a device although it is not to be understood as being limited thereto.

For a consideration of what I believe to be novel and my invention, attention is directed to the accompanying description and the claims appended thereto.

In the drawing, Fig. 1 is a view of the switch in side elevation showing it mounted in the tubular handle of a vacuum cleaner; Fig. 2 is a perspective view of the switch; Fig. 3 is an exploded perspective view of the frame and some of the parts; Figs. 4 and 5 are side views of the switch on an enlarged scale showing the movable contact in different positions; Fig. 6 is an end view of the switch partly in section and partly in elevation, Figs. 7 and 8 are perspective views on an enlarged scale of the actuator or trigger and illustrating how it is made and Fig. 9 is a detail view showing the mounting of the binding screws.

In making small switches the chief problems among many others are to provide a structure in which the parts are simple, cheap to construct, light and strong, and which are capable of operating for a long period of time without injury either to the electrical or mechanical elements. Also, to provide a structure the parts of which can be made in large quantities and assembled by the ordinary class of help available for the pur- 7086.

1 Having briefly outlined the principal features which a small switch should have, I will now describe the means by which they are attained.

The frame comprises a head member 10 which in this case is round but not necessarily so, and a second member 11 extending at right angles thereto and standing edgewise sald parts being riveted to each other by tongues 12 formed on the member 11 as indicated in Fig. 4. Two such tongues or rivets are pr0- vi e which ensures a. r g d. ela i n of th Serial No. 251,167.

members. The two members are punched out of sheet steel and at the same time the various v holes and notches are or may be formed. The head member is secured to a handle 13 or other support by two screws 14 located on opposite sides of the second or longitudinal-W member 11. The second member is best illustrated in Fig. 3 wherein 15 indicates an upwardl -extending -V-shaped notch the side wals of which act as stops tor the movable contactcarrying arm or element 16. The element 16 is in the form of an inverted U with the legs thereof straddling the frame member 11. Extending through said legs is a bar 17 which performs a double function,-that is to say, the central part of the bar between the legs strikes first on one wall and then on the other of the V-notch as the contact moves to open and close the circuit while the ends project beyond the legs and receive the upper ends of the coiled extension springs 18. Two such springs are provided so as to equalize the strain on the associated parts. The bar makes a looose lit in the two legs of the contact-carrying element or arm 16 and the two springs engaging the opposite ends thereof serve to hold it central. By using two relatively light springs and locating them on opposite sides of the contact-carrying element 16 and frame member 11, the assembly operation is simplified because they are easier to mount than one relatively still spring, especially if it has to be mounted between other parts as is the common practice. Below the V-notch with the walls thereof diverging in 'the opposite direction is a V-shaped or triangular opening 19. The lower bar or wall 20 of the opening forms a guiding or cam surface on its upper side and on which the trigger or actuator 21 travels the latter bein guided in its to-and-from movements by sai wall as well as by the slide surfaces of the frame member 11 as shown in Fig. 6. The portion of the wall located at the apex of the '9 opening forms the fulcrum for the actuator or trigger, as best shown in Fig. 8. The construction of the actuator or trigger is best shown in Figs. 7 and 8. It is made of thin Sheet steel and is blanked out by a die from p the frame by squeezing or legs thereof into actuate it in a manner As above stated, the trigger while it 1s not limited by the shoulders 11 vided with a second pair of out-turned or' laterally extending lugs 25, and seated in the notches thereon are the lower ends of the actuatin springs 18. The inner or bottom end 'of t e slot between the legs is enlarged to form a square or rectangular slot .30, the walls of which engage and ride on the wall or cam bar 20 of the frame member 11. The actuator or trigger is assembled in place on forcing the two contact as best shown inFig. 8, so thatone part is within the opening and engaging the fulcrum and the other part overlies the frame member and is guided thereby. From the foregoing it will be seen that the contact-carrying member 16 is carried solely by the two pivots 24 which also to be described later.

pinned to the frame nevertheless is held within the slot 19 b reason of having its two legs squeezed toget er, an arrangement which is simple yet efiective for the purpose. I The triggerQl and the contact-carrying element '16 form a toggle and the moving contact to both its closed and 0 en ositions. Itwill be seen from Fig. 6 t at t e shoulder 30 on the trigger engages that ortion 11 of the frame member which lies Eetween the bottom of the V-shaped notch and the apex of the opening 19, and that said ortion serves as a fulcrum for the trigger. lhe movements ofthe trigger are which are situated below the cam bar or guide 20.

On opposite sides of the frame member 11 are mounted two pieces of insulation 31 which are substantially rectangular in outline, having one corner-cut away to prevent interference with the contact carrier, or pole piece, and a notch 32 on the underside to receive the nut 33 by means of which the switch frame is secured to the tubular part 34 of the handle of the vacuum cleaner or other device to be controlled by the switch. The notches in the insulating sheets as well as the notch 35 in the frame are of T-formation. The central part of the nut occupies the larger art of the slot and the sides of the nut are nt over, all of which revents the nut from turning or bein pulle out and also acts as means to hold t e insulation in lace. The insulation is further clamped to the frame by a pair of hollow rivets 36 of usual construction.

On each side of the frame and insulated therefrom is astationary contact member 37 and a binding screw 38 for a current-carry- .faces,

the springs act to snap g ing conductor. The nut for each screw is supported by abridge piece 39 to keep the screw and conductor away from the frame,

and the ends of the brid e piece, Fig. 9, ex-

cuiting. This arrangement permits of as sembling the parts on the insulation and later fastening the her 11.

In any switch, and especially after continued euse, there is a tendency for the contact surfaces both moving and stationary to become rough due to arcing. This in time may render the switch useless. To guard against or prevent roughening of the surthe movable or bridging contact 40 which is carried by and insulated from the element 16 is given a positive rubbing or wiping movement each time it is opened and the circuit interrupted. This is accomplished by mounting the pivots 24 for the same to the frame memcarrying element 16 on the actuator or trigger instead of mounting them on the frame. As a result of the construction described, when the actuator 21 starts to move from the full line to the dotted-line position of Fig. 4, the contact-carrying element is first iven a limited movement in the direction of its length and at the same time a slight turning or twisting motion, the two said movements causing the moving and stationary contacts to rub one on the other and thus keep the surfacesbright, clean and smooth.

This is'due to the fact that trigger 21 and contact-carryin element 16 form two arms of a toggle wit the springs tending to collapse them. downwardly on account of the cam bar 20 on which it rides and since in straightening atoggle it lengthens, it follows that all of the longitudinal movement is concentrated in the contact-carrying element thereb giving the Since the trigger cannot move moving contact a wiping or rub ing engage.-

ment with the pairof stationary contacts. This movement continues until a plane passing through the end supports for each spring crosses over the pivots 24 when the springs act to com lete the movement of the contact carryin' e ement with a snap action, thereby quic ly and certainly interrupting the circuit.

The switch is thin due to the location and arrangement of the frame. member 11 and as a resultam le space is afforded for the conductors which are attached. to'the binding screws on each side thereof. To guard against short-circuiting'due to poor wiring, it is desirable to encase the switch in an insulating tube or container such as 42 which is located within the tubular part of the handle.

element is pivoted directly on the trigger or or element 16 which carries the movable con-' tact instead of being pivoted to the frame is pivoted to the trigger or actuator.

Still another distinguishing feature is the positive wiping or rubbing action of the movable contact on the stationary contactsprior to each opening movement thereof. This is due to the fact that. the contact'carrying arm or actuator and hence is positively moved in a generally longitudinal direction by it until the members of the toggle and their pivots lie in the same plane. During the straightening movements of the toggle the moving contact of coursealso turns or twists slightly with respect to the fixed contacts.

What I claim as new and desire to secure by Letters Patent of the United States, is:

l. A snap switch comprising a frame having a relatively large. opening, the wall of which defines a fulcrum, a relatively thin actuator having a part which fits into said opening and rests on the fulcrum and another part which overlies the sides of the frame,

said portions serving to hold the actuator in place, a contact and a supporting element therefor which are moved by the actuator,

, and a stationary contact carried by the frame which is engaged by the movable contact.

2. A snap switch comprising a thin,'flat frame member having a V-shaped fulcrum, a stationary contact supported by the member, a movable contact adapted to establish a circuit through the stationary contact, an actuator through which the frame member extends and which has a swinging movement on said fulcrum, an element which is pivotally connected to and supported by one end of the actuator so that when the actuator is moved it positively causes the contacts to rub one on the other, and spring means connecting the actuator and element which completes the movements of both the element and actuator, which movements are started by the actuator.

3. In a snap switch, the combination of a frame member having a V-shaped notch, the Walls of which define stops, stationary and movable contacts, a pivotally-supported element which carries the movable contact, a pivotally-supported actuator for the element, a bar which freely extends through the element and forms a stop to engage one wall or the other of said notch, and springs which connect the ends of the bar to the actuator.

4. In a snap switch, the combination of a frame having a V shaped notch, stationary and movable contacts, a supporting element for the movable contact which has apair of legs that straddle the frame, an actuator for the element mounted to swing on the fulcrum formed by said notch, a bar which freely extends through both legs of said element and alternately strikes on the walls of the notch and a pair of springs, one on each side, which connect the ends of the bar to the actuator.

5. A snap switch comprising a frame member having-an opening one wall of which forms a cam surface, a trigger mounted to move on the said surface, a stationary contact, a movable contact, a contact-carrying element, a pivot means carried by the trigger carried by one end of the trigger, a contact,-

acarrying element therefor, the legs of which are supported by the pivots, a pair of sta-, tionary contacts which are bridged by the moving contact, anda pair of springs which connect the element to the trigger and which move the contact when in their they cross said pivots.

7. A snap switch comprising a flat member which stands edgewise and has a notch in one edge and an opening near the other,

the lower wall of said opening forming a cam surface, a trigger which is partly located in said opening and has a portion which rides on the surface .of the cam, the trigger, bridging contact, a U-shaped element which carries the bridging contact and is itself solely supported by the pivots on the trigger, said trigger and element forming a toggle, the endwise movements of which are limited by said cam to the element, and a spring connected to the trigger and element which actuates the bridging contact as it moves across the pivots of the element. I

8. A snap switch comprising stationary contacts and a bridging contact, an element which carries the bridging contact, a trigger on which the element is pivoted, said element and trigger forming a toggle, a fixed fulcrum for the trigger, an overset spring for actuating the element when the trigger is moved, a support for the parts. and a cam means which confines the endwise movement of said toggle parts to theelement when the trigger movement 1.05. pivots carried by 1 a pair of stationary contacts, a

is moved from one of its positions to the has a V-shaped notch in one edge and an opening near the other edge,one wall of which opening forms a cam, a trigger which moves back and forth in the opening and is guided inits movement by the cam, a U-shaped element which straddles the frame and is pivotally connected to the trigger, stationary con-' tacts carried by and insulated from the frame, a bridging contact carried by the element, and springs locatedon opposite sides of the frame member which cause the element and its contact to move with a snap action when the trigger is actuated.

10. In a snap switch, the combination of. a frame member, a trigger which straddles the frame, a cam surface on the frame. which holds the trigger against endwise movement and guides it in its to and fro movements, an element which straddles the frame and trigger, pivots independent of the frame which connect the adjacent, ends of the trigger and element, a pair of stationary contacts carriedby the frame member, a bridging contact carried by the element, and a pair of springs one on each side of the. frame, which cause said element to move when the trigger is actu' ated.

11. In a snap switch, the combination of a frame member having stops, a trigger which straddles the frame, a cam surface on the frame which holds the trigger against endwise movement and guides its swinging movements, an element which straddles the frame and trigger, pivot-s which connect the adjacent ends of the trigger and element, a bar which extends through the element and is arranged to strike said stops to limit the movements of the element and which also serves as attaching means for the actuating springs, and a pair of springs one on each side of the element and trigger which connect them and serve to move said element when the trigger is actuated.

12.-In a snap switch, the combination of a thin, flat frame member, stationary contacts carried thereby, a movable contact, an element on which the movable contact is supported and which straddles the member, a trigger which is pivotally supported on the frame member and through which trigger th frame member extends, said trigger having a pair of outwardly-extending pivots on which the said element is supported and a pair of outwardly extending lugs, and springs which are attached to said lugs at one end and to said element at the other. i

13. A snap switch having a frame comprising a head on one end, and a single piece flat member extending perpendicular there to, said parts being united, a contact-carrying element, a trigger, both of which straddle the frame member and form parts of a toggle, cam means for guiding the trigger in its movements, pivots for said element which are carried by the trigger, stationary.con-

tacts carried by the framemember, a contact on said element, and springs which connect said element and trigger whereby movement of the trigger is imparted to the element and the contact carried therebyi; v

14. In a snap switch, the'combination of a frame member having an opening one portion of which is shaped to form a fulcrum, an ac tuator, a portion of which is located within the opening and is held in place thereby, one part of said portion resting on the fulcrum, a pivoted contact-carrying element, spring means connecting the actuator and element, and a contactfa'vhich is adapted to be engaged by the one oirthe element when the actuator is moved.

15. In a switch, the combination of a. flat frame member, insulating material mounted on the sides thereof, said member and material having a T-shaped slot, a nut mounted in the slot and having bent-over edges which prevent the ,nut from turning, a casing, and a screw which passes through the casing into the nut for uniting the parts.

16. A snap switch comprising a thin, flat frame member, a fixed contact supported thereby, a movable contact, an element which carries the movable contact and straddles the frame member, an actuator pivoted on the frame member for moving the element and through which the frame member extends, said element straddling the actuator, a pivot for the element which is carried by the actuator and forms its sole support, said actuator and element forming a toggle, and a coil spring connected at one end to the element and at the other end to the actuator, which spring when it crosses the dead center moves the element with a snap action to open or close the circuit and which also completes the movements of the actuator. I

In witness whereof, I have hereunto set my hand this thirtieth day of January, 1928.

FRANK C. DE REAMER.

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