US1421853A - Pull-socket switch - Google Patents

Description

R. D. SMITH.

FULL SOCKET SWITCH.

APPLICATION FILED OCT 27,1916- RENEWED SEPT-30. 1921.

2 SHEETS-SHEET I.

Patented July 4, 1922.

R. D. SMITH.

PULL SOCKET SWITCH. .APPLICATION FILED OCT. 21, 1916- RENEWEDiSEPTJiU, 192l- 1,421,853.

Patented July 4, 1922.

2 SHEETS-SHEET 2.

UNITED STATES PATENT OFFICE,

RAYMOND D. SMITH, OF BOSTON, MASSACHUSETTS, ASSIGNOR TO SHAWMUT MACHINE WORKS, INC., .A. CORPORATION OF MAINE.

PULL-SOCKET SWITCH.

Specification of Letters Patent. Patented July 4, 1922. 7

Application filed October 27, 1916, Serial No. 128,132. Renewed September 30,1921. Serial No. 504,494.

To all whom it may concern:

Be it known that I, RAYMOND D. SMITH, a citizen of the United States, residing-at Boston, in the county of Suffolk andCommonwealth of Massachusetts, have invented certain new and useful Improvements in Pull-Socket Switches, of which the following is a specification.

This invention relates to pull sockets with their contained switch mechanisms; and has for its broad object to incorporate in such sockets, and preferably, entirely within the casing-enclosed structure thereof, in compact and durable form, suitable mountings for a plurality of lamps of different candle power arranged preferably so that their individual lighting and extinguishment may be governed by the usual socket pull chain or other switch actuating element.

Through the principles of my invention, the present commercial form of pull socket caneasily be modified to increase greatly its usefulness by providing therein such selfcontained means for varying the degree of light through manipulation of the usual switch controlling pull chain; and this modification may be made at slight increase in cost, or complication in construction, and without sacrificing any of the desirable qualities now developed and existent in this type of socket.v such as mechanical ruggedness, ease of assemblage, electrical durability, and smallness of size.

In the embodiments of my invention herein disclosed, for illustrative purposes only, I have chosen a pull socket of well known construction, having a circular series of ratchet steps or contact inclines whose bases are disposed in a plane at right angles to the axis of rotation of the usual contact bridging plate, and of its oscillatory operating wheel. Two conductive spring arms of this contact plate are adapted, as usual, to engage simultaneously with diametrically opposite contact inclines. and to leave such inclines abruptly and simultaneously, thus producing'the quick double break of the circuit recognized as the,best practice in this type of switch construction.

I have herein illustrated several novel arrangements by means of which this circifically Iemploy, in addition to the usual main lamp, a much smaller lamp rigidly mounted upon the socket body and provided with'circuit connections to the said switch contact inclines, whereby each of the said lamps may be put into circuit singly or both extinguished by successive actuation of the usual switch operating pull chain.

It will be readily appreciated that in the practical use of adouble-lamp pull-socket, as proposed above, the lighting of the smaller, or pilot, lamp relative to the usual alternate lighting and extinguishment of the main lamp, would as a rule be for somewhat special and less frequent purposes, such as for maintaining a night light in the hall or bathroom of a residence. If, however, the lighting of the pilot lamp required an independent stroke of the socket pull chain, additional to the ordinary successive strokes thereof, for alternately lighting and extinguishing the main lamp, such additional stroke would be involved in the necessary actuations for completing each operative cycle of the one-way, movable switch contact plate; or, in other words, three, rather than the usual two, separate, full strokes of the pull chain would be required between successively lighting or successively extinguishing the main lamp.

To avoid interference with conventional characteristics of socket pull chain control, such as would be occasioned by the condition above described, I have devised a simple structural arrangement, novel to the type of switch mechanism concerned, which in one' case permits the smaller lamp to be switched into circuit by an initial part of that full stroke of the pull chain which preferably lights the main lamp; the arrangement further being such that a completion of the said full stroke will extinguish the pilot lamp and light the main lamp as usual, and such that if said stroke is not completed,

the pilot lamp alone will remain established 100 in circuit. In the: case just described, the alternate full stroke of the pull chain for extinguishing the main lamp remains unconcerned; so that in my improved doublelamp pull socket, successive full strokes of 105 the pull chain operate in the usual manner alternately to light and extinguish the main lamp,-the pilot lamp, in ordinary use becoming only momentarily lighted and then extinguished during the stroke of the pull 110 referred to for producing differentsequential relationsbetween these or equivalent current-switching effects of successive pull chain strokes.

Various attempts have been made to devise a socket switch structure having a single switch adapted to control receptacles for a I plurality of lamps or other plug attachment devices. But socket switch structures have reached certain substantially standard forms, and such attempts have, so-far as I am aware, involved undesirable departure from, and addition to, the standard, simple, provenly-durable, and commercially accepted socket switch structures. My improvement herein described provides aJpIural-receptacle socket switch structure broadly-- and a pull socket switch specifically-possessing the desirable features of the approved forms of structures above referred to, in which substantially no departure is made from the standardized arrangement either in general form, compactness, simplicity of mechanism, or ease of assemblage in manufacture or installation. For the accomplishment of these objects my invention resides partially, but not exclusively, in the details of construction, arrangement, and combination hereinafter described and claimed, and illustrated in the accompanyin drawings.

n the drawings :Fig. 1 is a plan View of my novelly combined socket pull switch and pilot lamp, the upper insulating cap being shown omitted and the casing and insulating lining sectioned for clearness; Fig. 2 is a similar plan view taken in section on the horizontal plane 22 in Fi 3; Fig. 3 is a front view in elevation of t e complete combinedsocket switch and pilot lamp with casing cut away; Fig. 4 is a rear view in elevation of a portion of the socket structure; Fig. 5 shows'a modified arrangement of ratchet inclines and contacts; Fig. 6is a view similar to Fig. 5 showing a still different arrangement of ratchet inclines and contacts; Fig. 7 is a perspective view of the contact-bridging plate used with the construction shown in Figs. 1 to 5, inclusive; Fig. 8 is a perspective view of the actuating wheel used with the plate of Fig. 7 Fig. 9 shows a different form of contactrbridging plate adapted for use with the arrangement of inclines shown in Fig. 6; Fig. 10 illustrates a modified actuating plate for use with the plate of Fig. 9; Figs. v11 to 14, inclusive, are diagrammatic and indicate several possible arrangements of stationary contacts and circuit connections thereto, adapted for embodiment in the structure of Figs. 1 to 5, inclusive; whereby the sequence of lamp control may be varied; Figs. 15 and 16, likewise diagrammatic, indicate different operative arrangements of contacts adapted for use with the structure of Fig. 6.

Throughout the different views of the drawings identical parts are designated by like numerals.

In Figs. 1 to 4, inclusive, the shell or outer casing appears at 10 and is provided with an insulating lining 11. An upper insulating block 12 and a lower insulating block 13 are connected by standards 14, 15 and 16. The rotatable contact-bridging plate 17 has two opposite, and downwardly sloping, spring-arms 18, four equal spaced shoulders 1.9 and a hub 20. The upper surface of the lower insulating block is provided with four equally spaced inclines denoted as 21, 22, 23 and 24, in circular arrangement, each terminating in an abrupt shoulder. One of said inclines 21 has a contact leaf 25 shaped to conform therewith and to extend therefrom to contact with the base of standard 14 as usual, this standard being insulated from all other metallic parts of the socket. Another of said inclines 23, diametrically opposite, has a metal leaf 26 conforming with the surface thereof and extending to contact with a central screw 27 which screw passes upward through the lower insulating block and holds clamped to the lower surface thereof the contact tongue 28 for transmltting current to the main incandescent lamp 29.

Above contact plate 17 and concentrically pivoted therewith is the usual insulating, operating wheel 30, with four equally spaced shoulders 3l'adapted, upon full movement thereof in one direction and by ratchet engagement with the shoulders 19, to advance each of the spring arms 18 over one of a pair of diametrically opposite'inclines. A spring 33 is provided to return the wheel 30 when the usual operating chain-34 is released into a position for again actuating the contact plate. It will be noted that the centrally disposed stud 35, which acts as pivot for the plate 17 and wheel 30 is insulated from all other metallic parts of the socket and that in operating to make a circuit the plate 17" acts merely as an insulated conductor for bridging the contacts 25 and 26. All of the socket switch construction, as thus far described, being well known in the art.

On the standard 15 I have shown mounted a miniature threaded shell receptacle 40. This shell is secured by the insulated screw 41 which also holds clamped to the other side of the standard 15, and insulated therefrom, a contact leaf 42. The leaf 42 is so extended as to lie upon the incline 24 in the manner of the contacts 25 and 26. The threaded shell 40 is adapted to receive the base of a small incandescent lamp 43 and projects outwardly through the casing, being suitably insulated therefrom by a bushing such as 44.

The contact leaf. 25 is extended to occupy also the incline 22 so that the contact plate 17 may alwa s have one spring arm in contact with this leaf, the opposite arm lying either. in contact with the leaf 26 or 42 dependent upon the position of the said plate. In Fig. 3it will be apparent that both the large, threaded receptacle 45 for the main lamp, and the small threaded receptacle 40 are permanently in electrical connection with the standard 15 which standard, in

'turn, is constantly alive with one lead from the supply circuit at the binding-post screw 47 the other supply lead being attached to the standard 14 at the binding-post screw 48.

From the above description the operation is obvious, it being plain that in place of the usual lighting and extinguishment of the main lamp, the main lamp is extinguished and the pilot lamp lighted by one actuation of the switch, and' that subsequent actuation lights the main lamp and extin-- guishes the pilot lamp, all parts being selfcontained, durable in construction and as compactly arranged as in the present com- H mercial form of single lamp socket.

I may, however, vary the number and relation of ratchet inclines and contacts with or without altering other parts of the switch mechanism and. thereby obtain a greater number of operative effects through the same actuating agency of single pull element.

For instance, as shown in Fig. 5 I may subdivide each of the two old quadrant inclines 22 and 24 into two smaller inclines. This arrangement is shown diagrammatically in Figs. 11 and 12 where the inclines 21 and 23 with their respective contact leaves 25 and 26 remain unchanged, but where two'new incline steps 50 and 51 occupy the quadrant formerly devoted to the single incline 22 and where the two new incline steps 52 and 53 occupy the quadrant formerly devoted to the single incline 24. The arrangement of contacts will be evident from the diagram, it being noted that the inclines 50 and 52 are left blank, thus providing for a position of the contact late 17 in which both main and pilot amps are out of circuit.

Figs. 13 and 14 indicate a similar division of each of the original inclines 21 and 28 into two separate inclines 55, 56, 57 and 58, respectively, with different arrangements *of circuit connections. It should be borne in mind that the contact plate 17 and operating wheel 30 (shown detached in Figs. 7 and 8) are provided with four equally spaced ratchet-shoulders for producing a rotation of substantially ninety degrees at each full stroke of the chain, so that arrangements of inclines and contacts as indicated in Figs.

,alone lighted (by. necessary full actuation).

Pilot lamp alone lighted to main lamp alone lighted (by partial actuation) or back to both lamps out (by full actuation).

Fig. 14.--B0th lamps out to main lamp alone lighted (by necessary full actuation) main lamp alone lighted to pilot lamp alone lighted (by partial actuation) or back to both lamps out (by full actuation).

In Figs. 6, 15 and 16, by substituting for the six unevenly divided inclines of Figs.v 5, and 11 to 14, inclusive, six equally spaced inclines 21, 23, and 60 to 63, inclusive, and by providing a corresponding arrangement of six squally spaced ratchet shoulders 49 on the plate 17 and corresponding shoulders 59 on the wheel 30 as shown in Figs. 9 and 10, I am able to obtain the same. operative effects of switching into circuit each of the lamps singly and of cutting out both lamps; but here, three complete actuations of the switch are necessary to complete one operative cycle, Figs. 15 and 16 showing merely a difference in contact arrangement for varying the sequence of operation.

Although all of the above-described modi- F fications for varying the sequential relation of lamp lighting and extinguishment contemplate specifically the connection of each lamp singly to the supply circuit, it will be obvious to those skilled in the art that such modifications would be available in systems of electrical connection where both lamps, for one position of the switch, are connected to the supply circuit in series relationsuch systems "of connection, however, being merely a matter of choice and well known in the art pertaining to plural lamp socket switches.

It is immaterial to the spirit of my invention what type of socket structure is employed, either as to its precise switch mechanism or outward form and provision therein for mechanical and electrical connection to the means of support. Those skilled in the art will appreciate that my invention may be as readily embodied in that type of socket-switch commonly known as an adapter, as in the herein illustrated permanent or fixture form of socket.

Without, therefore, limiting the scope of my invention to the precise form and mechanical arrangement of pull socket-switch herein described and illustrated, what I claim as new is I 1. In a pull-socket having a body structure comprising a top insulating block and a bottom insulating block secured together in spaced relation, in combination; a double break pull switch embodying a two-armed t electrical connection to one of a different pair of said contacts and opening outwardly at the side of said structure.

2. In a pull-socket having a body structure comprising a top insulating block and a bottom insulating block secured together in spaced relation, in combination; adoublebreak pull switch embodying a two-armed ratchet-driven current distributor pivotally mounted to rotate :between'said blocks, said switch including three or more stationary contacts mounted in circular arrangement on the upper surface of. the bottom block and so spaced that predetermined pairs of said contacts may be conductively bridged by said distributor; a main lamp receptacle depending from the lowersurface of said bottom insulating block and having electrical connections to one of said pairs of contacts; and an auxiliary plug receptacle mounted on the pull socket body structure adjacent the said distributor, said auxiliary receptacle having electrical connection to one of a diflerent pair of said contacts and opening outwardly at the side of said structure.

3. In a pull-socket having a body structure comprising a top insulating block and a bottom insulating block secured together in spaced relation, in combination; a doublebreak pull switch embodying a two-armed ratchet-driven current distributor pivotally mounted to rotate between said blocks, said switch including three or more stationary contacts mounted in circular arrangement on one of said blocks and so spaced that predetermined pairs of said contacts may be conductively bridged by said distributor; a main lamp receptacle depending from the lower surface of said bottom insulating block and having electrical connections to one of said pairs of contacts; and an auxiliary plug receptacle mounted on the pull socket body structure between the said two insulating blocks and peripherally adjacent the said distributor, said auxiliary receptacle having electrical connection to one of a different pair of said contacts and opening outwardly at the side of said structure.

4. In a pull-socket having a body structure including circular top and bottom insulating blocks secured together in spaced relation with rigid conductive members extending between said insulating blocks at the peripheral edges thereof, in combination; pull switch mechanism mounted to operate in the space between said insulating block and between said rigid conductive members, including stationary con tacts mounted on one of said blocks; a main lamp receptacle depending from the lower surface of said bottom insulating block; and an auxiliary plug receptacle mounted rigidly on one of said conductive members between said insulating blocks and laterally of the pull switch mechanism, each of said receptacles bein electrically connected to respectively di erent ones of said stationary contacts thereby to be electrically governed through the said switch mechanism.

5. In a pull-socket having supply circuit terminals and including a body structure comprising top and bottom insulating blocks secured in spaced relation by conductive brackets extending therebetween, the combination with said structure, of a pawl-and-ratchet-actuated switch mechanism mounted between said blocks and including an oscillatory driving device with means to limit its stroke to a' partial rotation and resilient means tending to restore it to a definite position at one end of the designed stroke; a rotatable conductive, double-ended current-switching member pivoted to be rotated by said device; a plurality of circuit contacts arranged to be successively engaged by said member in diametrically opposite pairs, with insulating supports for said contacts arranged cooperatively with said member to restrict retrogressive movement thereof between successive contacts; a main two-terminal lamp receptacle depending from the lower surface of said bottom insulating block; an auxiliary two-terminal plug receptacle carried by said body structure;

insulated ,fixed circuit connections between one, terminal of each of said receptacles and a common supply circuit terminal; and separate circuit connections between the other terminal of each of said receptacles and members of different pairs of said stationary contacts; together with insulated fixed circuit connection between the related members of said lastmentioned pairs and another supply circuit terminal ;-more than one of the said pairs of contacts being successively disposed within the travel of said member caused by a full stroke of said device, whereby different connection of said receptacles to the supply circuit may be had through a full or partial stroke respectivelyof said device.

6. In a pull-socket having a body structure comprising a top and a bottom insulating block secured together in spaced relation, in combination double-break! current switching mechanism mounted to operate between said blocks and embodying an oscillatory actuator with means to limit its stroke and resilient means tending to restore it to the beginning of its stroke; a two-armed current-switching member arranged to be r0tatively advanced by successive strokes'of said actuator, and three or more stationary contacts fixedly mounted on insulating step formations and circularly arranged to be conductively bridged by said member in diametrically opposite pairs; a main lamp receptacle depending from the lower surface of the bottom insulating block; and an auxiliary plug receptacle carried laterally of the pull-socket body structure ;-each of said receptacles being electrically connected to one of respectively different pairs of contacts thereby to be electrically energized in respectively different positions of said current-switching member.

7. In a pull-socket including a body structure comprising top and bottom insulating blocks secured in spaced relation by con-' ductive brackets extending therebetween, the combination with said structure of a pawland ratchet actuated, current supplied, switch mechanism mounted between said blocks and embodying an oscillatory driving device with means to limit its stroke and resilient means tending to restore it to a definite position at one end of the designed stroke; a rotatable current-switching memher arranged to be rotated by said device; a plurality of circuit contacts with insulating support formations arranged to be successively engaged by said member in its rotative movement and arranged co-operatively therewith to restrict retrogressive movement thereof; a main lamp receptacle depending from the lower surface of said bottom insulating block; an auxiliary lamp receptacle carried by said body structure between said top and bottom insulating blocks, and disposed laterally thereof; and independent electrical connections between each of said two lamp receptacles and a separate 'one of said contacts ;more than-one of the said contacts being disposed within the full stroke limit of said device and member driven thereby, whereby selective circuit control through said member may be had by a full or partial stroke of said device.

8. In a pull-socket including a body structure comprising top' and bottom insulating blocks secured in spaced relation by 'conductive brackets extending therebetween; the combination with said structure of a pawland ratchet actuated, current supplied, switch mechanism mounted between said blocks and embodying an oscillatory driving device with means to limit its stroke to a partial rotation and resilient means tending to restore it to a definite position at one end of the designed stroke; a rotatable currentswitching member arranged to be rotated by said device; a plurality of circuit contacts with insulating support formations arranged to be successively engaged by said member in its rotative movement andarranged co-op-- erat-ively therewith to restrict retrogressive movement thereof; a main lamp receptacle depending from the lower surface of said bottom insulating block; an auxiliary lamp receptacle rigidly mounted on one ofsaid brackets substantially between said two insulating blocks and disposed to extend outwardly and laterally thereof; and independent electrical connections between each of said two lampreceptacles and a separate one of said contacts ;-more than one of. the said contacts being disposed within the full stroke limit of said device and member driven thereby, whereby selective circuit control through said member may be had by a full or partial stroke of said device.

9. A pull socket switch having two plpg receptacles controlled by a single switch and embodying two parallel-positioned, substantially circular, insulating plates held in spaced concentric relation; two rigid conductive brackets extending between said plates and adjacent the peripheries thereof; a switch concentrically mounted on and between said plates and having a concentrically-pivoted, pull-actuatable rotative two-- armed wiper, and also a plurality of co-operative pairs of diametrically opposite, stationary contacts mounted on one of said plates and circularly arranged so that the co-operative pairs thereof are conductively bridged in different rotative positions of the wiper; a, two-pole rim-and-centre-contact plug receptacle concentrically mounted on the outer face of one of said plates; and a second and similar two-pole plug receptacle mounted laterally of the switch on one of said brackets ;-the two poles of each of said receptacles having fixed electrical connection to different stationary contacts and to said last mentioned bracket, respectively;- together with fixed electrical connection from the other of said brackets to the cooperative stationary contacts that are diametrically opposite the said different stationary contacts.

10. A pull socket switch having two plug receptacles controlled by a single switch and embodying two parallel-positioned, substantially circular, insulating plates held in spaced concentric relation; two rigid conductive brackets extending between said plates and adjacent the periphery thereof a switch concentrically mounted on and between said plates and having a double-ended, concentrically-pivoted, pull-actuatable rotating, conductive wiper, and also a plurality of co-operative pairs of diametrically opposite, stationary contacts mounted on one of said plates and circularly arranged, to be bridged by the wiper;--a plug receptacle concentrically mounted on the outer face of said plates ;-a fixed connection from the center contact of said plug receptacle extending from beneath the switch pivot to one of a pair of said stationary contacts ;-a second plug receptacle mounted laterally of the switch and conductively on one of said brackets;a bracketinsulated, center holding screw and contact for said, last mentioned receptacle, conductively connected to one of another pair of said stationary contacts;fixed' conductive connection from said bracket to the other receptacle ;and fixed conductive connections from the other bracket to the opposite members of each of said last mentioned two pairs of stationary contacts.

11. A current-supplied pull socket switch mechanism for governing plural circuits embodying, in combination, an oscillatory switch-operating device with means to limit its rotative stroke and resilient means tending to restore it to a normal position at one end of its limited stroke; a rotatable current-distributing member arranged to be intermittently advanced through pawl-andratchet driving engagement therewith by said device; a plurality of fixed contacts connected in respectively different load circuits and arranged to be engaged successively by said member for energizing the loads; and detent means arranged to prevent retrogressive movement of said member between contacts more than one of the said contacts being disposed within the path of travel of said member as caused by the said limited stroke of said device, whereby a full stroke and a partial stroke of said device operate respectively to establish said member in engagement with different ones of said fixed contacts, thereby to energize respectively different load circuits.

12. A current-supplied pull socket switch mechanism for governing plural circuits embodying, in combination, an oscillatory switch-operating device with means to limit its rotative stroke and resilient means tending to restore it to normal position at one end of its limited stroke; a rotatable currentdistributing member arranged to be intermittently advanced through pawl-andratchet driving engagement therewith by said device; a plurality of fixed contacts connected in respectively different load circuits and arranged to be engaged successively by said member for energizing the loads; and insulating formations supporting said contacts and formed co-operatively With said member as incline steps with abrupt shoulders for normally positioning the latter and for preventing retrogressive movement of said member between contacts; more than one of the said insulating formations with its supported contact being disposed within the path of travel of said member as caused by the said limited stroke of said device, whereby a full stroke and a partial stroke of' said device operate respectively to establish said member in engagement with different ones of said fixed contacts, thereby to energize respectively different load circuits.

13. In a pull socket switch structure, in combination, an oscillatory operating device with means to limit its rotative stroke and resilient means tending to restore it to a normal position at one end of its limited stroke a rotatable current-switching member arranged to be intermittently advanced by successive forward strokes of said device through paWLand-ratchet driving engagement therebetween; and a plurality of fixedly mounted contacts positioned to be successively engaged by said member in its rotative advance; means to prevent retrogressive movement of said member between contacts; and a plurality of current-translative electric load units mounted on the socket structure and electrically connected respectively to different ones of said contacts; more than one of the said contacts being disposed within the path of travel of said member as caused by the said limited stroke of said device, whereby different circuits through said units may be operated respectively by a full stroke and by a partial stroke of said device.

14. In a pull socket switch structure, in combination, an oscillatory operating device with means to limit its rotative stroke and resilient means tending to restore it to a normal position at one end of its limited stroke; a rotatable current-switching member arranged to be intermittently advanced by successive forward strokes of said device through pawl-and-ratchet driving engagement therebetween; and a plurality of fixedly mounted contacts positioned to be successively engaged by said member in its rotative advance; insulating formations supporting said contacts and formed cooperatively with said member as detent steps for normally positioning the same and for preventing retrogressive movement of said member between contacts; and a plurality of current-translative electric load units mounted on the socket structure and electrically connected respectively to different ones of said contacts ;more than one of the said contacts being disposed within the path of travel of said member as caused by the said limited stroke of said device, whereby diiferent circuits through said units may be operated respectively by a full stroke and by a partial stroke of said device.

15. In a pull socket switch, the combination with an insulating block having incline formations, and leaf contacts carried on the incline surface of selected formations for governing different circuits through the switch; of a rotatable contact plate having downwardly extending conductive arms which are adapted to engage either the incline formations or the said leaf contacts carried thereon, in diametrically opposite pairs; a pull-actuatable operating plate mounted to oscillate and adapted to engage with said contact plate for positively impelling the same intermittently in a constant rotative direction, thereby to advance said plate arms successively'over said incline formations; and a spring acting to retainthe said contact plate and said operating plate in operative position and to return the operating plate to its normal position after each forward stroke thereof; together with stop means arranged to limit the full stroke of said operating plate to such path and extent of rotative travel relative to the position and spacing respectively of said incline formations, that said full stroke is operative to ad- Vance said contact plate arms over a plurality but limited number of consecutive incline formations, whereby a full and a partial pull-actuation of said operating plate may position said arms for engagement with respectively different pairs of incline forformations, and leaf contacts carried on the incline surface of selected formations for governing different circuits through the switch; of a rotatable contact plate having downwardly extending conductive arms which are adapted to engage either the incline formations, or the said leaf contacts carried thereon, in diametrically opposite pairs; a pull-actuatable operating plate mounted to oscillate and adapted to engage with said contact plate for positively impelling the same intermittently in a contact rotative direction, thereby to advance said plate arms successively over said incline formations; and a spring acting to retain the said contact .plate and said operating plate in operative position and to return the operating plate to its normal position after each forward stroke thereof; one'of the said leaf contacts being formed and extended to occupy a plurality of the said incline formations whereby said extended leaf contact may be connected electrically with different ones of' the other leaf contacts in respectively different rotative positions of said contact plate. Signed at Boston, Massachusetts, this 26th day of October, 1916.

RAYMOND D. SMITH.

, Witnesses:

JAMES D. GORDON, E. LILLIAN MOFADDEN.

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