US1930926A

US1930926A - Connection for electrical appliances

Info

Publication number: US1930926A
Application number: US483814A
Authority: US
Inventors: Leroy C Doane
Original assignee: Miller Co
Current assignee: Miller Co
Priority date: 1930-09-23
Filing date: 1930-09-23
Publication date: 1933-10-17
Anticipated expiration: 1950-10-17
Also published as: FR704620A; NL31031C; CH151066A; BE374190A; DE575783C

Description

Oct. 17, 1933. L. c. DoANE CONNECTION FOR ELECTRICAL APPLIANCES Filed Sept. 23, 1930 4 Sheets-Sheet 1 INVENTOR [6/9 C 000/76. BY

ATTORNEY Oct. 17, 1933. c. DOANE CONNECTION FOR ELECTRICAL APPLIANCES INVENTOR Z erg C 30 0/76. BY I 'i 4 Sheets-Sheet 2' ATTORNEY Filed Sept. 23, 1930 1933- L. c. DOANE 1,930,926

CONNECTION FOR ELECTRICAL APPL IANCES Filed Sept. 23, 1930 4 Sheets-Sheet 3 INVENTOR v 'BYZergv C Doc/1e.

ATTORNEY I Oct. 17,1933. Q DQANE CONNECTION FOR ELECTRICAL APPLIANCES Filed Sept. 25, 1930 4 Shuts- Sheet 4 INVENTOR r C. Boa/1e.

ATTORNEY Patented Oct. 17, 1933 CONNECTION FOR ELECTRICAL APPLIANCES Leroy C. Doane, Meriden, Conn., assignor to The Miller Company, Meriden, Conn., a corporation of Connecticut Application September 23, 1930 Serial No. 483,814

18 Claims. (01. 173 -324) The present invention relates to connections for electrical appliances and is more particularly directed toward portable appliances such as floor and table lamps. Certain features of the invention are suitable for use in other allied lines.

Floor lamps, bridge lamps, floor torchiers and the like, consist essentially of a base, a' long rod, column or standard secured to the base and supporting a socket carrier of suitable type for the class of lamp intended. Table lamps are similarly made, but have a shorter column.

According to the usual practice heretofore followed, these lamps were assembled complete in the factory with the current supply cord carried from the base through a pipe inside the column and connected to the socket. Such completely assembled lamps were bulky to handle, difficult to store and required large cartonsor crates to protect them while being shipped to the dealers and distributed by them to their customers.

The manufacturer assembles the floor and table lamps from the various parts (such as, bases, columns, arms and the like) available, and these lamps, embodying the artistic notions of the manufacturer, are the articles oilered at retail. The dealer cannot maintain a complete line of the numbers which might be made up from a series of parts of varying design, and the 39 customer has no opportunity for self-expression in designing the product to be purchased.

An object of the present invention is to provide a system of interchangeable lamp parts of various styles and sizes from which one can assemble lamps of diiferent types. These different styles and sizes of parts may include, for example, bases, columns, standards, breaks, socket carriers and other ornaments commonly present in lamps. These parts may be of variant style,

, size and character, and yet are so designed that I they may be assembled in almost endless fashion.

One is able to select the desired parts from the stock available and to assemble or build up a floor or table lamp according to the individual taste of the purchaser. The number of designs available is limited only to the number of combinations possible from the individual parts at hand.

The ordinary completely assembled lamp 5! crated for shipment occupies approximately the same cubic contents as ten such unassembled lamps, thereby reducing storage space about 90% and effecting savings in transportation space and packing.

The accompanying drawings show a complete floor lamp and the various parts which may be employed in assembling the floor lamp; also a number of additional parts from which a selection may be made to build up or assemble numerous lamps. 0

In these drawings:

Figures 1 to 5 inclusive are outline views to illustrate various component parts, including bases and socket carriers with interposed columns, breaks, tubes, clocks, and the like, for 5 making up a number of floor and/or table lamps, the parts being disposed to illustrate an assembly of such a lamp;

Figures 6 to 9 inclusive are outline views of further forms of socket carriers;

Figure 10, similar to Figure 1, illustrates a bridge lamp;

Figure 11 is a fragmentary sectional view of a lamp base;

Figures 12, 13 and 14 are sectional views illustrating, respectively, the lower end of a column, an intermediate part (such as a break or tube), and a socket carrier wherein the connections are inserted from underneath;

Figure 15 is a longitudinal sectional view 30 through an adjustable or telescoping tube;

Figure 16 is a sectional view of the base assembly, the parts being separated;

Figure 17 is a top plan view with parts in section along the line 17 of Figure 16, the right 5 half indicating the appearance of the upper end of the base, and, in general, indicating the appearance of the upper end of anyof the intermediate parts;

Figure 18 is a sectional view through the socket carrier parts shown in Figure 14, the parts being separated;

Figure 19 is an inverted plan view showing the lower end of the socket carrier of Figure 18, and, in general, illustrating the lower end of all the socket carriers and intermediate parts;

Figure 20 is a perspective view illustrating two of the washers employed in the socket car riers and elsewhere;

Figure 21 is an exploded perspective view showing a threaded metallic bushing and an insulated bushing;

Figure 22 is an elevational view of a modified form of housing used in some socket carriers and intermediate parts;

Figure 23 is a fragmentary sectional view illustrating one way of securing a lamp socket yoke to the housing of Figure 22;

Figure 24 is a sectional view through a porno 'tion of a socket carrier wherein the connections are inserted from above;

Figure 25 is a vertical sectional view through an intermediate part having swivel connections and a clock;

Figure 26 is a sectional view on the line 26 of Figure 25;

Figures 27, 28 and 29 are sectional views of modified forms of housings for socket carriers and the like;

Figure 30 is an inverted plan view of Figure 29; and

Figures 31 and 32 are sectional and top plan views of a modified form of base.

The lamps illustrated in outline in Figures 1 to 5 and 10 may be of the usual size with any desired ornamentation and shape. The parts employed may include a number of bases B, columns C, breaks Br, intermediate parts, known as standards or tubes T, and socket carriers S0. The bases, columns, tubes and breaks may be of varying size, ornament and material, but may be made so that each accomplishes substantially the same function as any one of the other corresponding parts. The socket carriers are the units which give varying character to the lamps. These may include a cluster, a single candle, torchier unit, or an imitation oil lamp unit, as indicated in Figures 1 to 5 inclusive, or various forms of semi-indirect units, as shown in Figures 6 and 7, a number of candles, as shown in Figure 8, an illuminated smoking stand, as shown in Figure 9, or a bridge arm, as shown in Figure 10. The set of interchangeable parts may also include other units, as an electrical clock E, indicated in Figure 5, or an electric fan, cigar lighter or convenience outlet.

Each of these various parts is a complete unit and saleable as such. The bases are all adapted to be provided with a current supply cord, and any socket carrier or any one of the intermedi ate parts may be secured directly to the base or any of the intermediate parts may be interposed between the selected base and socket carrier. To accomplish this all the intermediate parts are provided with threaded connections at both ends, the socket carriers and bases are provided with threaded parts cooperable therewith, and each of the parts is provided with electrical connections automatically completed to the adjacent part, when the parts are threaded together.

Figures 11, 16 and 17 show the parts employed in a typical base B. The cast base shown is provided with a central hole 10, shouldered at 11, and internally threaded at 12. The upper part of the opening is made non-circular, preferably octagonal as indicated at 13 (Fig. 17) A metal bushing 14 has an octagonal flange 15 received in an octagonal recess 16 in an insulating bushing 17, the upper reduced end 18 of which is octagonal and adapted to be received within the octagonal hole 13, so as to non-rotatably support the metal bushing 14 in place. This bushing is threaded as indicated at 19 and projects above the upper face 20 of the base.

The bushing 14 carries a split pin 21 which, with a tubular conducting member 22, passes through an insulating washer 23. The lower end of the tubular member 22 has a lateral extension 24 which carries a pin 25 similar to the pin 21. The extension and pin are received in an elongated opening 26 in an intermediate washer 27, and both

pins

21 and 25 pass through holes in another washer 28. These parts pass upwardly through the opening' 10 and are clamped against the shoulder 11 by a threaded shell 29. An insulating bushing 30 is then pressed down into the opening in the bushing 14 to center and insulate the tubular conductor 22.

The cord .31 passes through a bushing 32 and is tied as indicated at 33. Each wire has a receptacle 34 adapted to be passed onto one of the pins or plug

contacts

21 or 25. This permits easily renewing or changing the current supply cord.

The columns, breaks and ordinary tubes are of various sizes and shapes, as will be apparent from the drawings. Each has an outer tubular body 40, (usually cast metal or a drawn tube), and adapted to carry the circuit forming parts completely insulated from one another and from the body. Figure 13 shows one such complete part.

As shown in Figure 13, a pipe 41, threaded at its upper and lower ends 42 and 43, carries a bushing 44, shown in detail in Figure 21. It is threaded to the desired position and then preferably brazed in place and is received within an insulating bushing 45, identical with the bushing 17, (see Fig. 21). A seating member 46 surrounding the bushing 45 is received within a recess 47 in the body 40 and is held against rotation by a prong 48 entering a slot 49. These parts are inserted into the tubular body 40 from above together with a paper lining 50.

A sheet metal seating 51, similar to the seating 46 but without the prong 48, and a bushing 52, identical with the bushing 45, are then passed upwardly onto a recess in the lower end of the break or other part. An internally threaded bushing 53 is then threaded onto the pipe 41, the seating ring 51 and insulating bushing 52 turning with the metal bushing 53. Holes 54 in the bushing permit swedging the pipe outwardly to lock the parts, as indicated at 55.

A length of heavy, slow-burning, solid copper wire 56 is axially disposed along the inside of the pipe 41. Its ends 56' and 56 are secured to female contact 57 and male contact 58, in the form of a split pin. The contact 57, like the contact 22, is received within an insulating bushing 30. The male contact 58 is held in place by an insulating bushing 59, forced into the pipe.

The internally threaded bushings 53 form female contacts adapted to receive the upwardly extending threaded bushings carried by the base or at the upper end of any of the intermediate parts and, hence, any column, break or tube may be threaded onto any base or onto any other column, break or tube, thus mechanically connecting the parts together and continuing the circuit connections to the concentric male and

female contacts

42 and 57.

The housing 60 of the socket carrier of Figures 14 and 18 has an opening 61, internally threaded at 62 and shouldered at 63. One of the circuit wires 64 passes through an eccentrically located hole in an insulating washer 65 and is connected with a short stamping 66 adapted to be received within an elongated slot 67 in another insulating washer 68. This stamping 66 is riveted to a split pin 69 which passes through a third washer '70. The other circuit wire '71 passes through another hole in the washer 65 and into a hollow rivet '72, (see Figure 18), securing the washers 68 and '70 together and having an exposed face opposite the flange 73 oi. a bushing 74, identical with bushing 44. The bushing 74 is received within an insulating bushing '15, the same as the bushings 17 and 45. This assemblage is secured in the housing 60 by a threaded locking ring 76 having an octangonal opening to accommodate the octagonal end of the bushing 75. If desired, the insulating

washers

65, 68 and 70 may be secured together by an insulating pin 77, and the ring 76 locked by peening the threads as indicated at 77'.

The housing 60 of Figure 18 is adapted to be part of a casting, such as a cast bridge arm, while the housing 60 of Figure 22 is in the form of a turning intended for use with socket carriers made up of assembled parts such as those indicated in Figures 1, 3, 6, '7 and 9, in telescopic tubes such as in the adjustable cluster of Figure 1, and in current consuming units such as the clock unit of Figure 25. It is threaded at the upper end as indicated at 78 and this threaded extension is employed to connect the housing with the superposed part or directly with the cap of a metal shell lamp socket or with the yoke '79 of a porcelain base lamp socket, this being shown in Figure 23. Where used directly for supporting sockets and socket covers, a threaded ring 80, brazed or soldered to the body 60', is adapted to receive a locking ring 81 to clamp the socket cover 82 in place.

The housing and terminal arrangement shown in Figure 24 employs many of the same parts as that shown in Figure 18, except that the' housing 83 is threaded from above, as indicated at 85, and the lower end 01' the housing is provided with an octagonal opening 86 to receive the octagonal insulated bushing 75. The locking ring indicated at 87 is in all respects like the ring shown at 76 in Figure 18. This form of housing is intended for use in socket carriers which employ tubular socket carrying arms and vertically extending shade supports, as indicated in Figures 2 and 8.

As shown in Figures 2 and 15, one of the intermediate parts is in the form of a telescopic tube 90, designed to permit adjusting the height of the socket carrier. The body. of the telescopic tube has an outer tubular part '91 secured to a lower female assembly indicated at 92 and adapted to receive a smaller or inner tube 93, secured to an upper assembly 94.

The lower assembly 92 includes a body 95 similar to the body 60, except that it is internally threaded to receive the tube 91. The parts enclosed within this body 92 are the same as those shown in Figures '14, 18 and 19 and the same reference characters are employed.

The upper assembly 94 utilizes the sub-assembly of insulating washer and a split pin, the same as at the bottom, and designated by the same reference characters. The male threaded connection of this upper assembly utilizes the same parts employed in the base and described above in detail.

The inner tube 93 is slotted, as indicated at 96, to receive a cross bar 97 secured to the outer tube 91 by a screw 98 and ring 98. A split ring 99 keeps the split tube in an expanded position and limits the length to which the tube may be extended. A locking ring 100, threaded on the upper end of the tube 91, acts to hold the parts in extended position.

The intermediate part E shown in Figures 25 and 26 is designed to embody a current consuming device, such as a clock, fan or the like, which is automatically connected into the circuit when the part is threaded onto the supporting part. As it is desirable to have clocks, fans or such devices face in a certain direction, and as the threaded parts tighten at various angular positions, these intermediate parts are designed to permit orienting the clock by turning it back without unloosening the threads which secure the various parts together.

The lower end of the unit is indicated at 110. It has an outer housing 111, generally like the housing 60'. The parts included within it are the same as those shown in Figures 14 and 18 and the same reference characters are employed. An externally threaded cup-shaped stamping 112 is clamped to the body by nut 113 and lock washers 114. This stamping has a downwardly extending tongue 115 adapted to enter an annular groove 116 in the body of the member 110 and to engage a pin 11'? carried by the body member. A clock supporting ring 118 is threaded onto the cup-shaped stamping 112 and locked in place by a screw 119. The clock unit E is secured to the top of a lamp base column or intermediate part by threading it on in the usual manner. The clock may then be turned backward nearly an entire revolution without starting to unloosen the threads. This arrangement is also used on socket carriers, such as the desk lamp unit shown in Figure 5, so that they may be oriented relative to the base.

The upper end of ring 118 is connected to the upper assembly 120 in the same manner as to the lower assembly, the same reference characters being employed for the corresponding parts. The electrical assembly inside the upper housing 1 111 is the same as that inside the housing 94 shown in Figure 15 and the same reference characters are employed. This upper assembly permits turning the element supported above the same backward without unthreading these ele- 1 ments.

In the modified form shown in Figure 27, the housing 130 is shorter than the housing 83 of Figure 24. It is recessed from below as indicated at 131 to receive the washers and bushings in 120 the same manner as shown in Figure 14, but, instead of securing these parts in place by an octagonal locking ring threaded into the recess, one employs a ring 132, non-circular to fit the insulating bushing and internally threaded at t a stamping 138 having an octagonal hole to receive the insulating bushing.

In Figures 29 and 30, the housing 140 is drilled to receive rivets 141 which pass through a circular ring or washer 142 having an octagonal hole 142 to fit the insulating bushing. The rivets are countersunk so as to provide a flat surface.

Figure "31 shows a base 145 drilled to receive rivets 146 which pass through a ring or washer 147 (like the washer 142) to secure the washers and bushings in place as shown.

The constructions just described make it unnecessary to provide the housings and bases with octagonal holes such as 13 in Figure 1'7 or 86 in Figure 24.

Certain of the features illustrated herein form the subject matter of applications for patent Serial Nos. 483,815, 483,816, 483,817, filed September 23, 1930.

It is obvious that the invention may be em- 2.

bodied in many forms and constructions within 156' the scope of the claims, and I wish it to be understood that the particular forms shown are but a few of the possible embodiments. Various modifications and changes being possible, I do not limit myself in any way with respect thereto.

I claim:

1. In an electrical appliance, a metallic support having an internally threaded housing having a shoulder beyond the threads, a threaded metallic bushing, an insulating member which supports the metallic bushing in the housing, an axially disposed conducting pin, a plurality of insulating washers for supporting the pin projecting toward the open end of the housing and insulating it from the bushing and support, a conductor extending through the washers and contacting with the bushing, a second conductor connected to the pin, and threaded means cooperating with the threaded housing for clamping the parts together and against the shoulder.

2. In an electrical appliance, a metallic support having an internally threaded housing having a shoulder beyond the threads, a reduced non-circular opening beyond the shoulder, an insulating bushing non-rotatably carried in the non-circular opening, a threaded metallic bushing non-rotatably supported in the non-rotatably carried insulating bushing, an axially disposed conducting member supported on an insulator and projecting toward the open end of the housing, a conductor extending through the insulator and contacting with the bushing, a second conductor connected to the member, and thread ed means cooperating with the threaded housing for clamping the parts together and against the shoulder.

3. In an electrical appliance, a metallic support having an internally threaded housing having a shoulder beyond the threads, a reduced non-circular opening beyond the shoulder, an insulating bushing non-rotatably carried in the non-circular opening, a threaded metallic bushing non-rotatably supported in the non-rotatably carried insulating bushing, an axially disposed oonducting member, a plurality of insulating washers for supporting the member projecting toward the open end of the housing and insulating it from the bushing and support, a conductor extending through the washers and contacting with the bushing, a second conductor connected to the pin, and threaded means cooperatiing with the threaded housing for clamping the parts together and against the shoulder.

4. A base for self-wiring lamps or the like, comprising a body having a vertical hole, an insulating member carried within the hole and supporting an externally threaded tubular con-'- ducting member extending above the upper surface of the base, a tubular insulating liner inside the tubular conducting member, the conducting member and liner being open at the top, a second tubular conducting member within the liner, a plurality of insulating washers for supporting the second tubular conducting member and insulating it from the first conducting member and the body, terminals connected with the conducting members and extending downwardly underneath the base, and means for securing all said parts in place in said hole.

5. A base for self-wiring lamps or the like, comprising a body having a vertical hole, an insulating member carried within the hole and supporting an externally threaded tubular conducting member extending above the upper surface of the base, a tubular insulating liner inside the tubular conducting member, the conducting member and liner being open at the top, a second tubular conducting member within the liner, an insulating support for the second tubular conducting member, downwardly extending conducting pins secured to the conducting members and extending underneath the base, and a current supply cord having receptacles on the ends of the wires thereof to receive the pins. 1

6. In self-wiring lamps, or the like, a body having a vertical, internally threaded hole extending to a reducing shoulder and being noncircular beyond the shoulder, an insulating bushing fitted in the non-circular portion of the hole and cooperating with the shoulder, a threaded metallic bushing non-rotatably carried by the insulating bushing, a locking ring threaded into the body, and three insulating washers interposed between the ring and bushing, the ring bearing on the washers to hold the insulating bushing against the shoulder, the middle washer carrying a conductor extending through the washer adjacent the bushing and disposed axially thereof, the washer adjacent the bushing carrying a conductor in contact with the metallic bushing and extending out through the other washers.

7. In self-wiring lamps, or the like, a bony having a vertical, internally threaded hole extending to a reducing shoulder and being noncircular beyond the shoulder, an insulating bushing fitted in the non-circular portion of the hole and cooperating with the shoulder, a threaded metallic bushing non-rotatably carried by the insulating bushing, a locking ring threaded into the body, three insulating washers interposed between the ring and bushing, the ring bearing on the washers to hold the insulating bushing against the shoulder, the middle washer carrying a conductor extending through the washer adjacent the bushing and disposed axially thereof and secured to a pin extending through the other washer, the washers being apertured, and a pin secured to the bushing and extending out through all the washers.

8. In an electrical appliance, a metallic support having an internally threaded housing having a shoulder beyond the threads, a.threaded metallic bushing, an insulating member which supports the metallic bushing in the housing, a plurality of insulating washers closing the housing behind the bushing, an axially disposed rigid conductor passing through one washer, non-rotatably supported in an intermediate washer and insulated from the support by a third washer, a Wire passing through the washers and con tacting with the end of the bushing, and a lock ing ring threaded into the housing for clamping the parts against the shoulder.

9. In an electrical appliance, a metallic support having an internally threaded housing hav ing a shoulder beyond the threads, a threaded metallic bushing, an insulating member which supports the metallic bushing in the housing, a plurality of insulating washers closing the housing behind the bushing, an axially disposed rigid conductor insulatedly supported by the washers, a conductor passing through the washers and contacting with the end of the bushing, and a threaded locking ring for clamping the parts against the shoulder.

10. An electrical connector comprising a housing having an opening therethrough, there being a reducing shoulder in the opening, a plurality of insulating washers in the opening, the rear.

washer engaging the shoulder, a forwardly extending, axially disposed terminal supported by the washers, an off center contact carried by the front face of the front washer, a threaded bushing having a portion which engages with the off center contact, an insulating ring enclosing the bushing, and means engaging with the insulating ring for clamping the bushing against thecontact and the washers against the shoulder.

11. An electrical connector comprising a housing having an opening therethrough, there being a reducing shoulder in the opening, a plurality of insulating washers in the opening, the rear washer engaging the shoulder, a forwardly extending, axially disposed terminal supported by the washers, an oif center contact carried by the front faceof the front washer, a threaded bushing having a portion which engages with the off center contact, an insulating ring nonrotatably enclosing the bushing, and means for non-rotatably securing the insulating ring in the opening, the ring clamping the bushing against the contact and the washers against the shoulder.

12. An electrical connector comprising a housing having an opening therethrough, there being a reducing shoulder in the opening, an insulator in the opening with its rear engaging the shoulder, a forwardly extending, axially disposed terminal supported by the insulator, an of! center contact carried by-the face of the insulator, a non-circular bushing having a portion which engages with the off center contact, an insulating bushing enclosing the metal bushingand having a non-circular outer portion, and means for clamping the metallic bushing against the contact and the insulator against the shoulder, said means holding the insulating bushing against rotation. v

13. An electrical connector comprising a threaded housing having an opening therethrough, there being a reducing shoulder in the opening, an insulator in the opening with its rear engaging the shoulder, a forwardly extending, axially disposed terminal supported by the insulator, an off center contact carried by the face of the insulator, a non-circular bushing having a portion which engages with the 011 center contact, an insulating bushingenclosing the metal bushing and having a non-circular outer portion, and a threaded ring non-rotatably receiving the insulating bushing and acting to clamp the metallic bushing against the contact and the insulator against the shoulder. 14. An electrical connector comprising a threaded housing having an opening therethrough, there being a reducing shoulder in the opening, a plurality of insulating washers in the opening, the rear washer engaging the shoulder 9. forwardly extending, axially disposed terminal supported by the washers, an of! center contact carried by the front face of the front washer, a non-circular metallic bushing having a portion which engages with the off center contact, an insulating bushing enclosing the metal bushing and having a non-circular outer portion, and a threaded ring non-rotatably receiving the insulating bushing and acting to clamp the metallic bushing against the contact and the washers against the shoulder.

15. An electrical connector comprising a threaded metallic bushing having a non-circular flange, an insulating bushing having a non-circular recess to receive the flange and a reduced non-circular periphery at its opposite end, a terminal assembly having an insulating body carrying an off center contact engageable with the flange on the bushing and an axial contact inside the metal bushing, a housing adapted to receive the bushing and terminal assembly, and means to clamp the terminal assembly against the metal bushing and to non-rotatably secure the insulating bushing in the housing.

16. An electrical connector comprising a threaded metallic bushing having a non-circular flange, an insulating bushing having a non-circular recess to receive the flange and a reduced non-circular periphery at its opposite end, a terminal assembly having an insulating body in the form of a plurality. of washers carrying an 011 center contact engageable with the flange on the bushing and an axial contact inside the metal bushing, a threaded housing, and a locking ring threaded to the housing for clamping the terminal assembly against the metal bushing, the insulating bushing being non-rotatably secured in place.

17. In an electrical fitting, three washers arranged face to face and having aligned of! center holes, a conductor extending through the three holes, one outer washer having a central hole while the other outer washer has a second oil? center hole, the center washer having a slot disposed opposite both said latter mentioned holes, a rigid conductor passing through the center hole and having a lateral extension in the slot, and a conductor extending through the second off center hole and secured to the extension.

18. In an electrical fitting, three washers ar-- ranged face to face and having aligned of! center 1 holes, a conductor extending through the three holes and secured to a rivet which rivets the outer washer and the middle washer together, one outer washer having a central hole while the other outer washer has a second ofl center hole, the center washer having a slot disposed opposite both said latter mentioned holes, a rigid conductor passing through the' center hole and having a lateral extension in the slot, a conductorextending through the second 011' and secured to the'extension, and an insulating pin holding the three-washers together.

' LEROY C. DOANE.

center hole