US1021540A - Electric switch. - Google Patents

Description

E. T LOOKARD.

ELECTRIC SWITCH.

APPLIUATION FILED AUG. 4, 19.09. 1 1,021,540, Patented Mar. 26, 1912.

3 SHEETS-SHEET 1.

COLUMEXA PWOORAPH c0.. WASHIPWTON. D; C.

E. T. LQCKARD. ELECTRIC -SWITCH.

APPLICATION FILED AUG. 4. 1909.

Patented Mar. 26, 191 2.

3 SHEETS-SHEET 2.

COLUMBIA PLANUGRAPH 60., WASHINGTON, D. c.

E. T. LOGKARD.

ELECTRIC SWITCH.

APPLICATION FILED AUG. 4, 1909.

Patented Mar. 26, 1912.

COLUMIIA PLANOOAPH CO" 'IAIHINUTON. D. C.

EARL T. LOCKARD, 0F CINCINNATI, OI-IIO.

ELECTRIC SWITCH.

Specification of Letters Patent.

Patented Mar. 26, 1912.

Application filed August 4, 1909. Serial No. 511,130.

To all whom it may concern:

Be it known that I, EARL T. LOCKARD, a citizen of the United States, residing at Cincinnati, in the county of Hamilton and State of Ohio, have invented certain new and useful Improvements in Electric Switches, of which the following is a specification.

My invention relates to electric switches and is primarily intended for use in connection with motor-driven adding machines, but may also be employed in other relations in which it is desired to form the electric circuit while the operator of the machine to which the current is furnished is in position for using the machine, the circuit being immediately opened upon the operator leaving his position.

One of the objects of my invention is to provide a switch of novel construction which the operator must maintain closed by some action on his part so that the switch willautomatically open immediately that the operator leaves his operating position, and thus save current and avoid the operation of the motor or electric device at times when the same is not performing work.

The invention will be further readily understood from the following description and claim, and from the drawings, in which latter:

Figure 1 is a perspective view of my improved device showing the same in connectioir with a motor-driven adding machine. Fig. 2 is .a side elevation of my improved device, showing the switch open, and having the side of the casing broken away for better illustration of parts. Fig. 3 is a similar view of the same showing the switch closed in full lines, and the lever in inoperative position in dotted lines. Fig. 4 is a plan view of my improved device with the top of the casing broken away for better illustration of parts. Fig. 5 is a horizontal section on the line 22 of Fig. 2, with the cover, the levers and the catch removed. Fig. 6 is a front elevation of my improved device with the operating lever depressed and the front of the casing removed. Fig. 7 is a detail on the line yy of Fig. 4 showing the mounting of the contact-bridge; and, Fig, 8

- is a front elevation of my improved device with the operating lever depressed.

1 represents the casing of my improved switch, which is preferably portable, 2 represents an adding machine, and 3 the motor by which the adding machine is driven. The switch is electrically connected with the motor by proper conductors in a cable 4, the current being supplied from any suitable source of electricity through electric conductors in a cable 5 having at its end a suitable plug 6 fitting an incandescent lamp socket.

The casing may comprise a bottom 8 and a back 9, and a cover 10 suitably secured to the bottom and back, and having a slot 11 in its front wall.

12 is a base of non-conducting material, suitably secured to the bottom 8, upon which the operative parts of the switch are supported.

A suitable socket 15 is secured to the back 9 and receives a plug 16 to which the conductors 17 18 of the cable 5 are attached, the conductor 17 being electrically connected with the threaded part 19 while the conductor 18 is connected with the axial terminal 20 of said plug. The socket 15 comprises the threaded wall 21 with which the threaded part 19 of the plug 16 makes electrical connection, the socket also being provided with an axial terminal 22 with which the axial terminal 20 of said plug makes electrical contact.

26 27 represent separated terminals of the switch and are suitably secured to the base 12. An electric conductor 28, which is preferably a fuse, connects the terminal 26 with the lug 29 which has electric connection with the threaded wall 21 of the socket.

31 32 are electric conductors in the cable at between the switch and the point of electric application represented by the motor 3. The conductor 31 is electrically connected with the terminal 27 and the conductor 32 is electrically connected with lug 33 electrically connected with the axial terminal 22 of the socket 15.

35 is a lever pivoted at 36 to standards 37 secured to the base. This lever is preferably of non-conducting material, for instance non-conducting fiber. A bridge 38 is secured to the lever for electrically spanning the gap between the terminals 26 27. This bridge preferably comprises a curved spring-bar 39 shown bent in the form of an arc, to the respective ends of which shoes 40 41 are secured, these shoes being arranged to respectively engage the terminals 26 27 for electrically spanning the gap between said terminals. The bar is secured to the lever preferably by means of a U-clip 42, the

shanks of which are received loosely through apertures 43 in said bar, the bar and clip eX- tending longitudinally of the lever, by which means I obtain a rocking motion between the shoes and insure that proper electric connect-ion be made between both shoes and their respective terminals. At the same time the relative movement between the bridge and lever is limited so that the shoes may not drag upon either terminal.

46 is an operating lever pivoted at 47 to standards 48 secured to the base 12. This operating lever comprises an operating arm 49, shown as a treadle, and an arm 50 from which the lever 35 is operated, these arms having a connecting member 51 between them. A spring 52 normally draws the operating lever into inoperative position. When in inoperative position, a spring 53 between the base and the lever 35 moves the latter lever into inoperative position for removing the contacts thereon from the separated terminals of the switch.

If the operator desires to operate the adding machine, he will place his foot on the treadle 49, thereby depressing the treadle and holding the same depressed until he has completed his additions on the adding machine. The treadle is shown as a thin flat bar, so that the same may remain under the foot of the operator without inconvenience to him. The depression of this treadle will force the forward end of the lever 35 upwardly, thereby depressing that end on which the electric contacts are located, placing the contacts into electric connection with the separated terminals 26 27, a pin 54 on said latter end being received under a latch 55 pivoted at 56 to a plate 57 secured to the base and urged into interfering position with the pin by a spring 58. The latch has a receding face 59 against which the pin engages in its passage under the latch.

61 is a rod which connects the latch with the operating lever. The rod passes loosely through an aperture 62 in the shank of the latch and has a head 63 which limits the movement of the rod toward the lever. The rod also passes loosely through an aperture 64 in a lug 65 on the operating lever, there being nuts 6667 received over the threaded end 68 of said rod. The object of the connection between the latch and the operating lever is to control the release of the switch for causing the same to release with a snap movement to prevent arcing in the switch. When the treadle is moved into depressed position the lug 65 will pass longitudinally of the rod for providing a space 69 between he will remove his foot from the operating lever, causing the same to spring up by reason of the spring 52. During the first part of its movement the lug 65 will pass through the space 69. In the meantime the inner end of the operating lever is moving away from the contactlever 35 which is held in place by the latch 55. At approximately the limit of upward movement of the treadle, the lug 65 will have made contact with the nut 66 and moved the same and the rod 61 sufficiently to trip the latch 55, causing the same to move out of range of the pin 54:, whereupon the lever 35 is released and the shoes 4:0 ll spring upwardly from the separated terminals of the switch. The bottom and base are provided with a slot 7 0 for receiving the operating lever when depressed, the slot 70 registering with the slot 11 in the front wall of the cover.

Having thus fully described my invention, what I claim as new and desire to secure by Letters Patent is:

In an electric switch of the character described, the combination of a casing provided with a bottom, normally separated electric terminals therein, a connecting part for said terminals, an operating lever pivoted to said casing and provided with an operating treadle projecting outside said casing, a lock for said connecting part for maintaining the same in contact with said terminals, there being a spaced connection between said lock and operating lever for permitting the first part of the movement of said operating lever to be idle with relation to said lock, the said connection arranged to release said lock during the latter part of said movement of said operating le-' ver, and means for maintaining said operating treadle in normally elevated position, and said operating treadle arranged to be depressed by the foot of the operator into substantial line with said bottom, said op erating treadle when so depressed being located below the horizontal plane of said terminals, substantially as described.

In testimony whereof, I'have signed my name hereto in the presence of two subscribing witnesses.

EAR-L T. LOCKARD. Witnesses:

LILLIAN BURNETT. CARL LEI-IMANN.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G.

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