US1247009A - Rheostat. - Google Patents

Description

T. RHODUS.

RHEOSTAT.

APPLICATION FILED luNE 23.1917.

1 ,247,009. Patented Nov. 20, 1917.

THOMAS RHODUS, OF CHICAGO, ILLINOIS.

nHEosTA'r.

Specivcation of Letters Patent.

Patented Nov. 20, 191 7 Application led June 23, 1917. Serial No. 176,463.

To all whom t may concern.'

Be it known that I, THOMAS RHonUs, a citizen of the United States of America, and a resident of Chicago, in the county of Cook, State of Illinois, have invented certain new and useful Improvements in 'Rheostats, of which the following is a specication. The yinvention relates to that type of adjust-ablel rheostat which constitutes the subject matter of my prior Letters Patent...No. 1,053,219, dated February 18, 1913, and' No. 1,154,728, dated September 28th, 1915, and the present improvement has for its various objects To provide a structural formation and combination of parts in the wire wound resistance element of a rheostat, involving a plurality of subwindings connected in series and having progressively different electrical resistance, the a'rangement being adapted to introduce aY multiple step-bystep -increase or decrease of resistance in the circuit-of the rheostat as the movablecontact member is moved in one or the other direction upon and in contact with said resistance element. To provide a duplex arrangement of the wire windings of the resistance element of a rheostat, with the respective divisions of saidV windings connected in multiple in the electric circuit of the rheostat, and in connection therewith the provision of a movable contact member of the duplex type with the respective contacting ends of said contact member individualto and making contact with the corresponding duplex windings of the resistance element aforesaid. The advantages resulting from the described arrangement being a division of the current to the duplex windings with less liability to fusion of the resistance element.

To provide a simple and effective structural formation-and arrangement of parts by means of which the movable contact arm or arms of an adjustablerheostat, are yieldingly connectedto a central operating shaft in a durable, eficient and economical manner, all as will hereinafter more fully appear.

The accompanying drawing is an elevation of a rheostat having the present improvement ap lied, the central operating shaft and the lnclosing casing being shown in section.

.Referring to the drawing, 1, designates a base orspider providing a support for the oriced inclosing casing 2, the insulating rail or support 3, and other portions of the rheostat, hereinafter described in detail.

4 designates the supporting core of the stationary resistance element of the rheostat.4 Said core is of the usual ring form and having overlapping ends by which it is secured to a supporting bracket 5 on the insulating rail 3 aforesaid.

6 designates the series of fiat, open spiral windings of the stationary resistance element, wound upon the core aforesaid. In the present improvement said spiral tindings comprise a plurality of groups or subwindings-7, 8, 9 connected in series, with each group having progressively different electrical resistance, and attained by an increase or decrease in the cross-sectional area of the individual `convolutions of a subwinding, as lshown in the drawing.

In the preferred type of the present invention, two spiral windings 6 are applied to the ring form core 4 in opposed relation to each other, and connected in multiple' in the circuit of the rheostat, as shown.

10 designates a centrally arranged 4shaft revolubly mounted on the insulating slab 3 aforesaid, in any usual manner, to constitute the operating member of the rheostat. 11 designates a cross-head preferably of the H shape shown, liXedly secured to the aforesaid operating shaft 10, and formed with a pair of orificedguide flanges 12.

13, 13, designate counterpart sliding bars arranged to have sliding movement in the guide flanges 12 aforesaid, and located at opposite sides of the shaft 10 and in approXimately parallel relation to eachother.

14, 14, designate counterpart contact rollers journaled in any Suitable manner to the 'outer ends of the aforesaid sliding bars 13, 13, and adapted to have rolling contact with the inner faces of the resistance windings 6 aforesaid; one of the bars 13 with one of the contact rollers 14 forming a working contact member. In the construction shown therollers 14, 14 have electric connection /in common kwith the cross-head 11, which in turn has electric connection with'one side or wire of the circuit of the rheostat.

15, 15 designate springs adapted to impart outward movement to the sliding bars 13, 13 and. the associated contact rollers 14, 14 aforesaid.

In the preferred form of the present ine.`

vention shown in the drawing, the two groups of sub-windings are so arranged in the electric circuit that the sub-windings of the respective groups having thelowest resistance, will be disposed next adjacent to the respective line.wires of the circuit so as to remain longest in said circuit. rIhe described arrangement is intended for use with the three wire system of electric wiring and in connection'with twin electrical appliances in which an' increase in current in one appliance is required with a simultaneous decrease in current to the companion appliance, and vice-versa.

Having thus fully described my said/ invention, what I claim as new and desire to secure by Letters Patent, is

l. In a rheostat, the combination of a resistance element formed of groups of subwindings of resistance wire, arranged in series, the wire of one group differing in cross-sectional area from the wire of another group, a contact member making contact upon said resistance element, and means for effecting movement between said parts, substantially as set forth.

2. In a rheostat, the combination of a curved resistance element comprising a plurality of resistance windings arranged in opposed relation and connected in multiple in the circuit, contact members individual to and making a contact upon said windings, and means for effecting movement between the parts, substantially as set forth.

3. In a rheostat, the combination of a curved resistance element comprising a plurality of resistance windings arranged in opposed relation and connected in multiple in the circuit, each of -said plurality of windings comprising groups of sub-windings arranged in series and having progres- 1 s ively dierent electrical resistance, contact members individual vto and making contact upon said windings, and means for effecting.

ythe circuit to the line wire terminals, contact members individual to and making contact on said windings, and means for effecting movement between the parts, substantially as set forth.

5. In a rheostat, the combination of a curved resistance element comprising a plurality of resistance windings arranged in opposed relation and connected in multiple in the circuit, contact members individual to and making contact upon said windings and mounted on a common carrying head, and means for imparting a turning movement to said head, substantially as set forth.

6. In a rheostat, the combination of a curved resistance element comprising a plurality of resistance windings arranged in opposed relation and connected in multiple in the circuit, Contact members individual to and making contact upon said windings, a cross-head adapted to support said Contact members in spaced relation, springs for moving said contact members, and an operating shaft connected to said cross-head intermediate of the aforesaid contact members, substantially as set forth.

Signed at Chicago, Illinois, this 21st day of June, 1917.

THOMAS RHODUS.

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