US2343008A - Electric switch - Google Patents

Description

Feb. 29, 1944.

L. GROSSMAN ET AL 2,343,008

ELECTRIC SWITCH Filed April 3, 1941 2 Sheets-Sheet 1 49 v a 4 22 .i 15 20 10 Z F I:

7f .9 2.9 1 O I 28 51 qslr NVENTORS {geomrdl fl Mm-L V ATTORNEY Patented Feb. 29, 1944 2,343,008 ELECTRIC SWITCH Leonard Grossman, Newark, and Alfred F.

Bahlke, Scotch Plains, N.

Electric Corp., tion of New .iersey East Newar 1., assignors to Utility N. 1., a corpora- Application April 3, 1941, Serial No. 386,640 2008) 4 Claims.

This invention. relates to new and useful improvements in electric switches and more particularly to a multiple electric snap switch.

It is the object of the present invention taprovide a multiple snap switch of simple and inexgrammatic representation of the circuits;

Fig. 2 is a vertical cross-section along lines 2 -2 of Fig. 1;

Fig. 3 is a plan view of the cover plate} Fig. 3a is a vertical cross-section of a modified switch operating handle; a

Fig. 4 is a view corresponding to Fig. 2 of a second embodiment of the invention;

Fig. 5 is a sectional view along lines 5-5 of Fig. 4; and

Fig. 6 is a circuit diagram to illustrate the operation of Figs. 4 and 5.

The switchproper is enclosed within a molded casing composedoi' has formed in it a central cavity 3 and three slots 4, 5, and 6. Within each of these slots is held by friction the double-back end of a contact spring, the free end of each contact spring standing out substantially at right angles. The three contact springs are numbered I, 8, and 9.

The movable switching or ratchet device consists of a square metal stud III on which is mounted a metal disc ll between preferably two fiber discs [2 and I 3. The disc II has three cam surfaces l4, l5, and [6 which project outside of the edges of the fiber discs I2 and I3 and may be engaged by the free ends of springs 1, 8, and 9, which project tangentially with respect to the discs and are tensioned so as to press against the cam surfaces towards the stud Ill. The two fiber discs have each a cam surface ll, l'la which projects beyond a cutaway portion of the metal disc II and on which the contact springs 1, 8,

and 9 may ride.

Within a cavity of the bottom half i of the casing is placed a small electric lamp l8, in the present instance a gaseous discharge lamp. One of the electrodes IQ of the lamp is connected witha wire 20 which runs through the switch casing thereof. The other to the outside at both ends electrode zl'is connected with a wire 22, the end of which isplaced within the central cavity 3 below a. carbon resistor 23. The lower end of the stud HI rests on resistor 23. The upper end of the stud is held in a square cavity 24 of a rotatable knob 25 mounted within an opening of the cover 2. A coiled spring 26 within the cavity 24 pushes the stud I0 down into contact with the a bottom I and a cover 2..

resistor 23 when the two sections l and 2 of the casing are clamped together by screws 21. A wire 28 projects through one end of the cas- 9, respectively, in the same manner as wire 28 is fastened to spring 1. The wires are connected with two resistances 32 and 33 of a heat pad or the like. One of these resistances may give low heat, the other medium, and the two together high heat.

When the switch is in the position illustrated in Fig. l, a circuit is closed from one terminal of the plug 28 over conductor 28, spring I resting the cams ll of the fiber discs l2 and [3, conductor 30, resistance 32, conductor 20, to the other terminal of the plug 29. The resistance 32 will heat up and in parallel with it the lamp l8 islighted, the lamp being connected from conductor 20 over the electrodes l9 and 2|, conductor 22, resistance 23, stud HI, disc H, spring 1, to conductor 28.

By rotating the knob in a clockwise direction, one can alter the above traced circuit connections. In the next position, the contact spring energized and the lamp I8 is extinguished.

In the following position, the conductor 28 is connected over spring 1 which is now resting on the cam surface I8 against the fiber cam H, the

on cam surface is against the cam i6, conductor 3i, resistance 33, conductor 20. Both resistances 32 and 33 will, therefore, be energized and the lamp it will be lighted over the same parallel path that was previously traced.

Upon the rotation of the knob by an additional step, the contact spring 8 will come to rest on the fiber cam N. This will open the circuit of the resistance 32, but-'the resistance 33 will remain in the circuit over spring 9. The letters L, H, and M, which are cut in the cover and covered with a transparent plastic, are illuminated by lamp l8, the rays of which are reflected by the bottom half I of the casing. The

'knob 25 is suitably marked so that the user can determine its angular position with respect to the cut-out letters which indicate low, high,- and medium heat.

Instead of the above described arrangement, the visual indication of the position of the on and oif positions of the switch can be efiected in the manner illustrated in Fig. 3a. As shown in this figure, the handle or knob 25a is divided into four compartments, one of which is 2 301.. Letters or numerals or other indicia of the switch positions are cut into the handle as indicated at 2511. Since the compartments are shutoff from one another by walls, only the cut-out 25b of the compartment which is above the lamp l8 will be illuminated and will thus indicate the position of the switch.

Instead of this arrangement, or in addition thereto, an opening 2b may be cut in the cover 2a throughwhich the illuminated or extinguished condition of the lamp it can be determined.

In this case also, the cut-outs should be covered or filled with transparent plastic material to prevent intrusion within the switch casing.

When the device to be controlled has three resistances which must be switched in one after another, then the arrangement shown in Figs. 4-6 may be used. For ready comparison with the embodiment illustrated in Figs. 1-3, we have designated the various parts by adding 100 to each reference numeral.

One of the terminals with wire H20 and the other terminal with wire l28. Wire are is connected in parallel with one end of each of three resistances, H2, H3, and i 50, and also to one electrode of lamp H8. The other terminal of resistance H2 is connected to a contact spring ifll. Similarly, the resistances we and M6 are connected to contact springs Hi3 and N39. The contact springs llii, its, and H39 are arranged in the same manner as contact springs l, 8, and 9 in Fig. 1. In

addition to these contact springs, there is a third contact spring llli mounted in the lower half of the casing NH. The contact spring MI is permanently connected with the conductor 42S and rests against a circular brass disc M2 mounted on square stud shaft H just below fiber disc H3. The contact spring ltll will engage the contact disc M2 at all times and complete the circuit therethrough except in the offposition where spring Ml engages an insulated portion $3 of the disco The arrangement of the fiber discs H3 and H2, and a brass disc Hi held between the two fiber discs on of plug H9 is connected the stud H0, is substantially the and H9 can come into engagement while the ratchet is being rotated. On the other hand, the two fiber discs H2 and H3 are provided with three such cam surfaces, H4, H5, and H5. Whichever spring is in engagement with the cam surface Ill will connect its associated resistance 132, 633, or Hill with the disc Hi and, thence, through shaft Ho, disc M2, contact spring 86!, and conductor i28, to the plug I29.

Thus, one resistance after the other can be connected in circuits in parallel with the lamp H8. In the oif position of the switch in which the three springs HIT-I09, rest on the cam surfaces of the fiber discs, the spring 14! rests on insulated segment I63 of the disc I42, breaking the circuit of the lamp H8.

It will be obvious to those skilled in the art that the invention may be modified in many respects without departing from the spirit thereof.

- slot, a rotatable For example, the electric lamp may be omitted, the switch may be used to control other devices than heating pads equipped with two or three resistances, the number of switch positions may be increased or decreased, etc.

What is claimed is:

1. In an electric snap switch, a casing of insulating material consisting of a bottom and a cover, a central cavity and a plurality of slots in the bottom, a resistor within said central cavity, and a flat contact spring frictionally held in each knob mounted in the cover, a stud of conducting material positioned within said central cavity in contact with said resistor and engaging said knob to be rotated thereby, a ratchet consisting of a disc of conducting material and at least one disc of insulating material above and below the conducting disc mounted on said stud to be rotated. therewith, cam surfaces on said discs in engagement with said contact springs so cut as to permit rotation of the ratchet only in one direction, a second conducting disc on said shaft, an electric lamp within said casing and visible from the outside through openings cut in said cover, a connection from said lamp to said resistor, and a plurality of conductors, one for each spring and one for the lamp, projecting from said casing.

2. In an electric snap switch, a casing of insulating material consisting of a bottom and a cover, a central cavity and a plurality of slots in the bottom, a resistor within said central cavity, and a flat contact spring frictionally held in each slot, a knob mounted in the cover and rotatable from the outside, a stud of conducting contact with said resistor and engaging said knob to be rotated thereb a ratchet consisting of a disc of conducting material and at least one disc of insulating material above and below the conducting disc mounted on said stud to be rotated therewith, camsurfaces on said discs in engagement with said contact springs so cut as to permit rotation of the ratchet only in one direction, a second conducting disc on said shaft, an additional contact spring mounted in the bottom and resting against the second disc, an insulating segment in the second disc arranged to engage said additional contact spring in a certain angular position of said stud, an electric lamp within said casing and visible from the outside through openings cut in said cover, a connection from said lamp to said resistor, and a plurality of concluctors, .one for each spring and one for the lamp, projecting from said casing.

3. In an electric snap switch, a casing of insulating material, a resistor and a plurality of contact springs in said casing, a rotatable knob mounted on the casing, a stud of conducting material in contact with said resistor and engaged by said knob to be rotated thereby, a

ratchet conssting of a disc of conducting mate rial and a disc of insulating material mounted on said-stud to be rotated therewith, cam surfaces on said discs in engagement with said contact springs so cut as to permit rotation of the ratchet only in one direction, an electric lamp within said casing and visible from the outside through openings cut in said cover, a connection from said lamp to said resistor, and a plurality of conductors, one for each spring and one for the lamp, projecting from said casing.

4. In an electric snap switch, a casing 01' insulating material consisting of a bottom and a cover, a resistor and a plurality of contact springs irictionally held in said bottom, a rotatable knob mounted on the cover, a stud of conducting material in contact with said resistor and engaging said knob to be rotated thereby, a ratchet consisting of a d sc of conducting material and at least one disc of insulating material above and below the conducting disc mounted on said stud to be rotated therewith, cam surfaces on said discs in engagement with said contact springs so cut as to permit rotation of the ratchet only in one d rection, an electric lamp within said casing and visible from the outside through openings cut in said cover, a connection from said lamp to said resistor, and a plurality of conductors, one for each spring and one for the lamp, projecting from said casing.

LEONARD GROSSMAN. ALFRED F. BAHLKE.

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