US266910A - starr - Google Patents

Description

(No Model.)

E. T. STARR.

RHEOSTAT.

` No. 266,910. Patented O0t.31,1882.

UNIree tirarse Pett-teur @trice ELI T. STARR, OF PHILADELPHIA, IENNSYLVAITIA, ASSIGNOR 0F ONE-HALF TO WILLIAM J. PEYiUN, UF IASHING"ON, I). C.

RH EOSTAT.

SPECIFICATION forming part of Letters Patent No. 266,910, dated October 31, 1882. Application filed September 4, 1852. (No model.) Patented in England July i3, 188'), No. @,330.

tion of electro-magnetic motors employed for driving light machinerysuch as sewing-machines, lathes, {wcwhereby the speed and power ofthe machine or machines being driven may be readily controlled by the operator. Various forms ot devices have heretofore been suggested for this purpose, but none, so i'ar as I am aware, save that patented to me July 4, 1882, as No. 260,623, are as simple and etlicient as is desirable.

The object ot' my present invention is to provide an improved variable.resistance circuitcontrolling device, which is simple, inexperisive, and exceedingly ettieient.

The subject-matter claimed is particularly pointed ont at the close ofthe specification.

Some of my innnoveinents may be used without the others and in connection with electric circuits not includingelectro-magnetic motors.

The accompanying drawing` iliustrates my said improvements as organized in the best way now known to me, the figure being a sectional elevation through the variableaesistance device.

A base or stand, A, is provided with binding-screws a c for connecting the circuit-wires l 2, which lead to and from a batteryor other generator ot' electricity, said circuit including au electro-magnetic motor, it such is used.. Said binding-screws are in electrical connec tion, by wires 3 4, respectively, with the variable-resistance device, so as to constitute said device a part ofthe circuit. Said variable-resistance device consists of a vessel preferably composed of two telcscoping or expansible and contractible sections, C C', (said sections being` also preferablyofnolrcon d ucting material,such as glass or hard rubber,) held apart by a coiled spring, @,the lower or base section, C, being tirmly mounted upon the baseboard. and torining a cup or cell to contain a Huid offering comparatively high resistance to the passage of an electric current.` A conducting` wire or rod, t?, projects troni or is carried by the upper sliding section. (if, ot said vessel, so as to enter the ilnid in the. base-section G, and the depth to which this wire or conductor is made to enter the iluid controls the resistance to be oti'ered to the passage ot' the electric current, 6o and consequently the action ot' the current upon the electric motor included in the circuit. The wire I3 is connected with a binding-screw,

c, the upperend ot' which, in this example, enters slightly into the iiuid, so as to be in elecrical connection therewith and constitute a conductor, while the wire 4- is connected with the wire or conductor d, in tliisIiustanee, by way of the reacting spring c. rIhe section G of the fluid-containing vessel stands in its nor- 7o mal position at its greatest height relatively to the base-section U, with the end ofthe conductor d at its greatest distance l'rom the end ci' the conducting-screw @,anil when in this position the nmxiinnin resistance is oii'ercd to 7 the passage ot' the electric current through the resistance device. A treadle, F, pivoted upon the base-board A, connected at its front or toe end with the npperend ot' the sliding section C ot' the duid-containing vessel, and the 8o connection is pret'erably made by a slot and pin, as t'ully shown and described in my ai'oresaid patent, whereby upon depressing the treadle to vary the resistance ot the circuit the vesselsection U', carrying the conductor d, 85 moves down upon the tixed vesselsection without lateral movement. The connection bctween the treadle and vessel, in other words, is

a sliding or yielding one, and such a connection may be madein variousways. Pressure upon 9o the treadle by lthe toot ot' the operator causes the conductor d to move into the resistancetlnid and approach nearer to the end of the screw or conductor c. The nearer said conductor d approaches the conductor c the less resistance there is otiered to the passage of the current, Aas will be obvious. The resistance in tbe circuit can consequently be varied as required, and tothe slightest degree, simply by pressure of the foot, without breaking the roo circuit. As soon as the pressure is removed the spring c retracts the conductor d, and at the same time elevates the toe end ot the treadle, ready for a new depression, which is to vary the resistance offered to the passage of the current.

It will be understood, of course, that the upper section, G, of the fluid-containing vessel need not be a closed section, although the construction shown is in most cases preferable.

'A spring (not necessary to be shown) may also he used under the treadle and disconnected from the duid-vessel, either as auxiliary to or in place ofthe spring` c. I have deemed it unnecessary to show these changes in the dra'wing, as they and other changes may readily be made by a skillful meclianician, and would not constitute a departure from my invention.

I have thus descr1bed, as constructed in the hest way now known to me, a resistance device organized for use with a treadle or pivoted lever, by lwhich the resistance of an electric circuit may be varied by causing the approach and recession of a conductor relatively to another conductor, said conductors being in contact with an intermediate medium offering higher resistance to the passage of the current than said conductors.

I claim herein as of my invention- 1. The combination, substantially as hereinbefore set forth, with an electric circuit, ot' the variableresistance device consisting ot' the vessel containing a resistance-duid and the conductors in contact with said fluid, one ot' said conductors heilig movable in the iuid t0- ward and from the other, the treadle to govern the approach ot' said conductors relatively to each other, and a sprin g to return said treadle to its normal position when the pressure thereon is removed.

2. The combination, substantially as hereinbefore set forrl1,ot' the eXpansible and contractible vessel, the sections of which are each provided with a conductor, the spring to nor mally maintain said sections distended, and the resistance-fluid contained within said vessel, in which said conductors are in Contact.

In testimony whereof' I have hereunto subscribed my name this 19th day oi" July, A. D. 1882.

ELI T. STARR.

Witnesses:

E. EUGENE STARR, WM. J. PnY'roN.

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