US465218A - spriaue - Google Patents

Description

(No Model.) 2 Sheets- Sheet 1.

P. J. SPRAGUB 8u C. R. PRATT.

ADJUSTABLE RHEOSTAT.

110.465,218. Patented Deo.15,1891.

.mm Q A 6.0 HWG .Iam n .m10

S nn U T N E V N n4: mums nuns co., mcnrumol, mnsmnnms, n. c.

(No Model.) 2 Sheets-Sheet 2. F. J. SPRAGUE 8v C. R.- PRATT.

ADJUSTABLE RHEOSTAT.

Patented Dec. 15, 1891.

- proved device.

UNITED STATES" PATENT OFFICE..

FRANK J. SPRAGUE AND CHARLES R- PRATT, OF NEV YORK, N. Y.

ADJ U STAB LIE RH EO STAT.

I SPECIFICATION forming part of Letters Patent No. 465,218, dated December 15, 1891.

Application tiled August 25, 1891. Serial No. 403,704. (No model.)

`funty and State of New York, have invented certain new and useful Improvement in Adlstable Rheostats, of which the following is hrowing more or less resistance into or out of .n electric circuit and for making and breakng such circuit.

The main object of the invention is-to provide a device of the character indicated having a large number of contact-plates in the switch, by means of which the resistance is varied, said contactplates being large, but

being so mounted that they occupy a small space, and to provide a rapidly-moving c0- operating contact.

In the accompanying drawings, Figure 1 is a side view, partially in section, of the irn- Fig. 2 is a section thereof at right angles to Fig. 1. Fig. 3 is a view of a modiiied form of switch, and Fig. 4 is a side view of the switch-arm.

Ris a resistance-conductor or a series of resistance-conductors, the terminal 1 of which is connected or adapted to be connected to the circuit-wire 2.v The opposite terminal 3 is connected by wire 4 to the irst or second contact-plate 5, of which there are forty-six, numbered from 5 to 545 on the switch apparatus, which comprises an insulating or other Suitable body 6, preferably in the form of a hollow cylinder, having a spiral groove 7 around it from end to end. On the raised thread 8 are mounted the contact-plates 5, which should be made of good conducting material and should be quite large in order to keep down the current passing between the contact-plates and the co-operating-centact per unit of surface, and in order that good contact may be obtained without the necessity of pressing the contact block or device strongly against the contact plates there should be a wide space between adjacent contact-plates. By the construction described sparking and heating are reduced.

With this switch we have in practice used a current of one hundred ampres and two hundred and forty volts without injurious sparking and without burning or welding together the contacts. The contact-block employed had a contact-surface of about two square inches, while the contact-plates were about an inch and a half square, and there were about fifty of the contact-plates. XVe do not, however, limit ourselves to these proportions or this number of plates.

From the stationary binding-posts between terminals 1 and 3 conductors 4 4', the., extend to the several spirallyarranged plates. The conductor 4 will lead to the plate 5, 4 to plate 5', and so on in regular order, all the conductors being led into the hollow cylinder and through the wall thereof to the contact-plates. It is evident that by supporting the contact-plates on the surface of the cylindrical body and leading the connectingwires thereto from the inside of the cylinder a compact and convenient construction is obtained. T0 avoid confusion in the drawings only a few of the conductors 4 are shown. One end of the insulating-body is support-ed by the bracket 10 and the opposite end is supported loosely on the end of the shaft l1, which has a bearing l2. On the shaft is a wheel 13, which may be driven by any suitable power, suchas an electric motor or by hand. To get a quick motion of the brush, speed-gearing (indicated by wheel 13') may be used. To the shaft is rigidly iixed a hub 14, carrying a riln 15, insulated by the web 1G. The rim l5 carries one or more arms 17, which pass through slots 1S in the traveler or nut 20. This traveler consists of an insulatingring cut at 21 and engaging or tting into the spiral groove er channel 7. The contactplates themselves form a spiral channel, andthe groove 7 in the body is therefore not essential. Passing through the carrier is a pin 22, on which is a sleeve 23, carryinga spring 24, one end of which presses against the lower arm 17 and is adapted to move along said arm to maintain electrical contact with it, and the other end of which carries a switch-contact block or spring.

A carbon block is shown in the drawings, and is preferred on account of its conducting properties and because of the small amount of friction which results from the rubbingcontact between the block and the contactplates. The block has a curved face adapted IOO to ride along on the spirally-arranged contact-plates and to pass on to one contact-plate before it leaves the preceding plate.

2G is a brush connected to the circuit-wire 2 and maintaining rubbing contact with the rim l5, and hence being electrically connected to arm 17, spring 24, and brush 25. Vthile -it is preferable to make the brush the movable member of the switch, this is not essential. Vhen the first wire is connected to the contact -plate 5 the first contactplate 5 (not shown in Fig. l, but shown in Fig. 3) will be deadthat is, it will have no circuit connection, so that when the switch block or brush 25 moves onto the rst contact-plate the wires 2 2 will be entirely disconnected.

The operation of the apparatusabove de-` scribed is as follows: Suppose the traveler 20,

with the parts carried thereby, to be at the right end-of the spirally grooved or channeled body, with the block 25 resting on the lfirst contact, the circuit 2 2 being open. wheel 13 is driven in the direction to move the block 25 toward the left, and when the block moves onto the second contact-plate, 2

is connected to 2 through the entire resistance between terminals l and 3. As block 25 moves onto the third contact-plate, the first section of resistance is thrown out of circuit, and as the traveler and block 25 advance the other sections of the resistance are successively cut out until, when block 25 rests on contact 545, the wires 2 2 are connected di- The rectly through the switch without including any of the resistances.

As already indicated, the arrangement of contacts described enables us while using a large number of contact-plates for the purmay be arranged spirally on abody of diterent form, and that the switch-brush may be dierently operated without departing from onrinvention. One such moditicationis shown in Figs. 3 and 4. B is a suitable hase,on

which are several contact-plates 5 5', &c., corresponding to similar plates in Fig. l. These plates are insulated from each other and are arranged in a spiral line on the base. Ordinarily a large number of contact-plates will be used; but for simplicity of illustration a few only are shown. 27 is an arm mounted on ya spindle 28, which may be turned by anyv suitable means. On the arm is a carbon or other switch block 29, having projections 30, embracing the contact-plates. sistance, and 2 2 are the wires of the motor- R is the re-.

circuit, 2 being connected to the terminal post l and 2 being connected to the brush 3l, bearing against the spindle 2S, which is electrically connected with the arm 27 and block 29. The iirst plate 5 is dead; but the following plates are connected in regular order to the successive sections of the resistance by wires 4 4, &c., the last section being connected tozthe last plate 5". `When the arm 27 is moved, the switch-block will ride alongon the successive contacts and will be moved lengthwise on the arm by the spirallyarranged contact-plates acting on the projection 30 of the block in an evident manner.

1. The combination, in an adjustable rheostat, of a series of contact-plates spirally arranged and a relatively-moving switch-contact adapted to co-operate with said 'contactf plates, substantially as described.

2. The combination of a suitable body, several separate contact-plates arranged spirally thereon, and a switch contact adapted to cooperate with said spirally-arranged contacts, said contact-plates and switch-contact moving relatively in two directions, substantially as described.

3. The combination of a suitable body, several separate contact-plates arranged spirally thereon, and a switch-contact movable spi-rali y along said body Aand adapted to co-operate with said spirally-arranged contacts, substantially as described.

4. The combination, ina switch, of a stationary body, several contact-plates spirally-arranged thereon and connected or adapted Vto be connected to a circuit, and a switch-contact movable along spirally over said contactplates vand connected or adapted to be con` nected to a circuit, substantially as described.

IOO

5. The combination of 'a suitable body, a

series of contacts arranged spirally thereon, there being a channel between the turns of the spiral, and a relatively-movable switchcontact engaging or fitting into said channel so as to be moved lengthwise of the body, substantially as described.

6. The combination of a body havinga spiral groove or channel, contacts arranged spirally on said body, a traveler movable along the spiral groove or channel, and a switch-contact moved by the traveler, substantially as described.

7. The combination of a stationary cylinder, contacts arranged spirally thereon,'aJ traveler carrying a switch-contact, and means Afor turning said carrier, whereby the switch-contact is moved along over the spirally-arranged contact, substantially as described.

8. The combination -of -a resistanceconductor, several contacts connected therewith at different points, said contacts being mounted spirally-0n a supporting-body, and a switchcontact co-operating with the several spiral contacts, substantially as described.

9. The combination of a resistanccconductor, several contacts connected therewith IIO IIS

at dierent points, said contacts being rnounted spirally on a supporting-body, and a switchcontact movable spirally along said body in position to co-operate with the several spiral contacts, substantially as described.

10. The combination of a resistance-conductor, one end of which is connected or adapted to be connected to a circuit, and a switch for throwing more or less of said resistanceinto or out of circuit, said switch consisting of a suitable body on which are several contact-plates spirally arranged, and a co-op erating switch-contact adapted to make contact with the several spirally-arranged contacts, and a connection from each of said contacts to a different point in the resistanceconductor, substantially as described.

11. The combination of a hollow cylindrical I body, a series of spirally-arranged contactplates on the surface thereof, and wires leading to said plates from the interior of the body, substantially as described.

12. The combination, with a resistance-conductor, of a switch comprising a hollow cylindrical body, a series of contact-plates spirally arranged thereon, a co-operating switch-contact, and wires leading from the resistanceconductor through the cylindrical body to the contact-plates, substantially as described.

This specification signed and witnessed this 3o 11th day of August, 1891.

FRANK J. SPRAGUE. CHARLES R. PRATT. Witnesses:

IRVING S. SMITH, J. C. GRIsWoLD.

npon the application of Frank J. Sprague and Charles R. Pratt, of New Yorlvr, N "for an improvement in Adjustableheostats, errors appear in the printed sp tion requiring correction as follows: In line 46,

` the following sentence;

It is hereby eertiiied that in Letters Patent No. 465,218, granted December 15, u

page 1, a semieolon should be in after the word eontaet-plates; also after the saine word inline 48, same'page word By should` commence with a small b, making aconti andthat the said Letters atent'should. be read with thesel corr therein to conform to the papers pertaining to the casein the'Patent foe. i Y Signed, countersigned, and sealed this 29th day of v1.)eeembe13 A. D. 1891. I

- [SEAL] i 4 oYnUs BUssEY ,e V Assistant Secretary of the Interi'o 'Countersiguedz W. E. SIMoNDs,

Commissioner of Patents.

4It is hereby certified that in Letters Patent No. 465,218, granted December 15, 1891, y y upon the application of Frank J. Sprague and Charles R. Pratt, of New York, N. Y.,

for an improvement in Adjustable Rheostatsf7 errors appear in the printed specification requiring correction as follows: In line 46, page 1, a semicolon should be inserted after the word contact-plates, also after the same word in line 48, same page, and the following Word By77 should commence with a small b, making a continuous sentence; and 1that the said Letters Patent should be read with these corrections l therein to conform to the papers pertaining to the case in the Patent Office. Signed, oountersigned, and sealed this 29th day of December, A. D. 1891.

[SEAL] oYRUs BUssEY,

Assistant Secretary of the Interior. Countersigned:

W. E. SIMoNDs,

Commissioner of Patents.

Images