US1353675A - Switch-handle - Google Patents

Description

G. B1. THOMAS.

SWITCH. HANDLE.

APPLICATION FILED Novv.2a.19Is.

353,675., mamas@ 21,1920.

I OFI 1:4mm/vica',` GEORG E B. Thum@ 51 GEGRGE B. THOMAS, 0F BRIDGEPORT, CONNECTICT, ASSIG-NOR TCTHE BRYANT ELEC- TRIO COMPANY, OF BRIDGEPORT, CONNECTICUT, .A CORPORATION 0F CONNECTICUT.

A SWITCH-HANDLE.

To all whom z't Imay con-cem `Be it known that I, GEORGE B. THOMAS, a citizen of the United States of America, residing at Bridgeport in the county of Fairfield and State of Connecticut, have invented certain new and useful Improvements in Switch-Handles, of which the following is a specification.

Mv invention relates to switch handles, and .particularly to handles Ifor rotary snap switches, the object of my invention being to provide a handle of such construction that while it is attached to the switchspindle by a screw thread connection, it 1s not possible to unscrew the handle by rotating it in reverse direction. l

In the accompanying drawings- Figure 1 is a broken side elevation of a rotary snap switch to which a handle embodying my invention in one form is at-y tached-the handle being shown 1n a position of partialreverse rotation;

Fig. 2 isa sectionbn the line 2-2 Fig. l; and l Fig. 3 is a dropped perspective of certain of the handle elements.

The switch illustrated is. of the usual rotary snap type comprising an insulating base 5 upon which the switch mechanism is mounted and housed within a sheet metal cover 6 resting on the base. The switch f spindle 7 is provided at its upper end with a threaded boss 8 of reduced diameter, on which the tapped lower end of the stem 9 of the switch handle is screwed. The body of the switch handle consists of an insulating thumb piece 10 centrally pierced by a rectangular well 11, which, at the outer end of the handle, is continued by a cylindrical opening 12 of less diameter, while at its inner end the well is shouldered to afl'ord a seat 13 lfrom which extend opposite bays 14 Jfor a purpose hereinafter explained.

Fast on the stem 9 of the handle is a washer 15, having oiset lugs 16 which serve as dogs to engage the ratchet faces 17 of a rectan lar driving nut 18. .The latter is slipped.Ll upon the outer end of the stem and is engaged by the walls of the rectangular well 11 so as to rotate with the switch handle 10. A light coil spring 19 bears at its lower end against the driving nut 18, to maintain the latter in operative relation to the dogs 16 of the washer 15. The upper end of this spring bears against a rectangu- Spec'ication of Letters Patent. Patented. Sept. 21., i920. Application led November 28, 1919. Serial No. 341,042.

lar Washer 20 seated against the upper end of the well 11, but pierced at 21 -to permit tlie reduced end 22 of the stem 9 to pass therethrough. A shoulder` 23 limits the downward movement of'the Washer on the stem. The outer end of the stem is slotted at 24 to receive a screw driver, by which the switch handle maybe turned' on the switch spindle 7 in reverse direction to remove it. I`he driving nut 18 is preferably recessed on its upper face to aiiord a spacin lHange 25, which prevents the spring 19 groinl being compressed sufficiently. to render the parts rigid with relation to each other, in case the washer20 by accident slips over the shoulder 23.

' Below the flange 15 on the switch stem is arranged a bushing 260i rectangular shape, having a cylindrical neck 27 which bears against and supports the flange 15. This bushing is maintained within the lthumb piece 10 by'a washer 28 resting against the seat 13 at the inner end of the handle and having wings 29 which are sprung into the bays 14, above mentioned, and serve to maintain 'the stem and its associated parts in permanent engagement with the thumb' piece. -Below the washer 28 is a spring 30 and a bearing washer 31, the latter resting upon the ferrule 32 at the mouth of the boss 33 on the 4switch cover 6, and serving to hold the latter in position on the base 5 in the assembled position of the parts.l

The operation of the device is as follows: The switch handle elements havin been assembled as shown in Fig. 1, thei screwed upon the threaded boss 8 of the ,switch spindle 7 by the usual clockwise rotation. Obviously the stem 9 is rotated with the switch handle in this direction by rea.- son of the engagement of the dogs 16 with the ratchet shoulder 17 of the driving nut 18 in the rectangular recess 11 of' the handle. To actuate the switch the handle is turned further in the same direction. Upon reverse or counter-clockwise rotation of the handle, however, the drivin nut 18 rides over the ratchet dogs 16 without rotating the stem-9, since thev spring 19 is intentionally made soclight that the frictional drag between the ratchet elements is quite insufficient to loosen the screw connection between the switch spindle and the stem of the thumb piece. If the operator should press 'down the thumb piece in an attempt to compress andle is l the spring 19 sufliciently` torender the parts rigid with relation to each other, he isv halted by the engagement of the-washer\20 on the narrow shoulder 23 of the stem'm9. This shoulder is intentionally made of sueh'slight width that the rictional engagement between the washer 20 and the shoulder is insuicient to overcome the resistance afforded by the threaded connection between the switch spindle and the-stem of the thumbI piece. If, on the contrary, the handle is pulled outward in order tosecure a rigid engagement between the sleeve 27 of the bushlng 26 and the Washer 15 on the switch stem, it is `still. impossible to render the parts suiiciently rigid with relation to each other to unscrew the stem since the sleeve 27 is intentionally made so thin that its end bearing surface is very much reduced, and

this fact, coupled with the fact that it bears against only a small area of the washer 15, so reduces the frictional engagement between the parts that it also is insuiiicient to overcome the resistance offered by the threaded connection between the stem 9 and the switch spindle. By reason of the fact f that the washer 20, bushing 26, and nut 18 are rectangular, as well as by reason of the fact that the washer 28 closely engages the switch handle, it is impossible to tilt the latter with relation to the switch stem suiiiciently to cramp the parts in this way suiiiciently to nullify the action of the ratchet. The only way in which the switch handle can be removed from the switch spindle is by unscrewing the stem 9 with a screw driver, or slmilar instrument, through the opening` 12, and directly engaging the slit end of the stem. Accidental removal of the handle is thus prevented.

Various modifications in details of construction, which do not depart from what l claim as my invention, will readily occur to those skilled in the art. Moreover, while l have shown a construction which operates in the manner described without the use of any lubricant between the parts, the desired action is made still more certain if a suitable lubricant is applied to the'coperating bearing surfaces.

inserted assente y A handle for rotary snap switches comprlslng a thumb piece recessed to form a well non-.circular in cross' section, a stem arranged 1n said well, a ratchet element fast onsaidstem, a coperating ratchet element .freely mounted kgn said stem, but engaged in sald well, a spring for maintaining said ratchet elements in cooperating position, 'and means on said stem accessible from the outer end of the Switch handle for rotating said stem, together with screw means at the opposite end of said stem fom connecting \the handle to the spindle of the switch op- ,erated thereby. t

2. rotary switch handle comprising a centrally apertured thumb piece, a stem arranged therein, a ratchet element fast on said switch stem, a cooperating-ratchet element free on said stem, but engaged in said well, a spring for pressing said free ratchet element into engagement with the ratchet element on the stem, and a bearing for the opposite end of said sprin together with a shoulder on said stem limiting the endwise movement ot said bearing on the stem to prevent undue compression of the spring.

3. A rotary snap switch handle comprising a thumb piece centrally recessed, a stem arranged in said recess, a flange fast on said stem, a bushing engaging said flange, a washer engaging the switch handle and maintaining said bushing interposed between the same and the iiange on the switch stem, together with means at the switch end GERGE B. THOMAS.

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