US944785A - Rheostat. - Google Patents

Description

R. HEAD.

RHBGSTAT.

APPLICATION FILED 001*. 27, mos.

Patented Dec.28,1909.

2 SHEBTB-BHEET l.

A??? I? M 1: 7 E v. f W

ROBERT HEAD, OF NEW YORK, N.

Y., ASSIGNOB '1'0 ROBERT L. WATKINS, OF NEW YORK. N. Y.

Specification of Letters Patent.

Patented Dec. 28, 1909.

Application filed October 27, 1908. Serial No. 459,719.

To all whom it may concern:

Ilc it known that l, Roman mo, :1 cit-izen of the United States, rcsidin' at New York city. in the county of New h'ork and State of New York, have invented a new and useful Improvement in Rheostats, of which the following is a specification.

In stereopticons, photomicrographic cameras, motion picture machines and other devices employing clcetricit as a lighting medium. it is frequently ound necessary to introduce within a circuit a rhcostat or other resistance, which is usually bulky in construction and of considerable weight, therefore being exceedingly awkward to handle in transportation. It is also a fact that 'heostats, as conunonly constructed. retain the heatfor quite a long time after the electric current has been cut oil which in many instances is found to be an objectionable feature. Itis with the view of eliminating these objectionable features and roviding certain other improvements whic I will be found desirable in a rhcostat used for the pn s above mentioned.

y invention therefore relates to improvements in rheostats, of a portable nature. and the objects of my improvements are: first, to provide a rheostat that will be light in weight and compact in orm: second. to construct a rhcostat that will remain comparntively cool while an electric current passes through it; and third, to present the greatest. possible area of radiation. thus facilitating the rapid cooling of the rhcostat after the current has been cut oil. I attain these objects by the mnstruction of a rheostat as illustrated in the accompanying drawings, in which- Figure 1 is a perspective view of my improved rhcosl'at in its preferred form. when m use; Fig. :3 is a view in elevation of the middle section. or frame of some: Fig. 3 is a sectional view showing the contacts and the hinge arran cmcnt of the several sectious, and is lali cn appmximately on limi-l--3 of Fig. 2. Fig. 4 is n view similar to Fig. 3, in which two of the sections are shown in tluir closed position. which throw them out of the circuit; Fig. 5 is an enlarged dotuil view of some of the contacts. in Figs. 6 and 7, l have shown a modification of the contact and hinge nrrangcnu-nt which may la' found desirable under certain condilions.

Similar reference characters refer to like parts throughout the several views.

In the drawings illustrating one of the forms which my invention may take, I, 2, 3, 4 and designate the sections of which the rheostat is composed; thcscveral sections are similar to the extent that they each consist of a metallic frame (3. in which four strips of mica or other suitable material T, are socured. Upon each pair of the mica strips T, is wound a resistance wire 8 of exceediu ly small gage. the ends of which are elcctrica ly connected with the contact plates 9 and 9 which are suitably insulated from the frames ti.

In my rhcostat, each section or member comprises a skeleton frame, core composed of a plurality of pieces of insulating material, preferably mica, and a resistance wound on each piece of the core. T he core pieces are positioned in the frame so that the side faces-of the pieces are in the plane of, or parallel to. the corresponding side faces of the frame, said core pieces being arrai'igcd edge to edge. and practically in contact with each other. The resistance coiled on the core pieces are thus positioned in the plane of the frame. the looped parts of each resistance fitting over the edges of the cure pieces on which it is wound and contacting with the edge of the next core piece, the convolutions of one coil alternating with the couvolntions of the next coils, as shown in Figs. 1. '2 and ti. Said construction and arrangement. of parts are advantageous for a number of reasons: first, the resistance windings are fully exposm'l on the respective sides of the. frame to the circulation of air between and a round the members composing the l'licostat sccond. a very compact and economical construction is secured. and. third, the mom her of n'sistance windings made possible by the number of core )icces secures an enlurgod radiating area in each member of the rhcostat.

liigidly sccurai to the middle section 3. are angle plates l0. 10 provided with hearings it in which the trunnions of the scetions 1. 2. 4 and ii are jollrunh'd. To the underside of the plate It! is hinged a member I! having wings l2 n'onctmg at right unglus to thc l'uco lhcrool. lho member 1:! servos as a supporting leg. as llUWll in Fig. 1 when the rhcuslut is in use. and as a cla p to hold the sections together, when not in ll i'i llll use. The sections 1 and 5 are also provided with sup orts 13, adapted to be folded back against t 1e frames (3, as indicated by dotted lines in Fig. 1.

The contact vidcd with a ownward pro'ectmg tongue or ndant t) formin one o the terminals of the rheostat to \vhic may be attached one of the wires 14, of an electric circuit. The contact plate 9, of section 1 is also provided with a endant similar to 9, to which may be attac ed the wire 15, Fig. 3, to complete the electric circuit.

As shown in the drawings, the wires 14 and 15 terminate in slotted plugs 14: and 15' and connection is established with the rheostat by forcing the ndants 9'-' of the contact plates 9 and 9, o the sections 1 and 5 respectively, into the slots of the tplugs 14 and 15 It is obvious however at many other methods of connecting the wires 14 and 15 to the rhcostat may be employed within the scope of my invention.

In Fi 5, which is snbstantiall an enlarged view of Fi 4, with two the sections eliminated, have shown in diagrammatic form the electric circuit and the manner in which the resistance of the middle section is cut out.

If the full resistance of the rheostat is desired, all the sections are opened, as shown in Figs. 1 and 3, in which sition the electric current will be for to traverse the resistance wires of all the sections. be current may enter the rheostat through either of the terminals, but for the purpose of illustration we will assume it enters through the contact plate of section 1 and pames along the resistance wire 8 thereof to the contact plate 9 of section 1, thence to contact plate 9 of section 2, along its resistance wire 8 to the contact plate 9 thereof and so on throughout the several sections of the rheostat leaving some by the contact late 9 of the last section 5. If however it IS desirable to cut out the resistance of one or more of the sections, they may be returned to their closed position, as shown in Fi s. 4 and 5.

n Fig. 4, the resistance of sections 2 and 3 is shown as cut out of the circuit, but for the purpose of better illustrating the method thereof, reference may be made to Fig. 5 wherein the resistance of the middle section is in like manner cut out of the circuit.

It will be seen by referring to Fig. 5 that the current will enter the rheostnt b the contact plate 9 of the first. section an pass through the I'CnlStlllNB 8 thereof, to the contact late H of same, as previously stated; hut in the :resout. instance the current is shunted to tie contact plate 9 of the next section, via the rivet 6 and contact. 17, thus avoiding the insist-name of that mrtlculnr section. The contact plale E) of tie motion late 9 of section 5 is pro just referred to and the plate 9 of the next section 5, being in contact with each other, the electric current will continue along the resistance 8 of section 5 and to the terminal thereof. It is evident therefore that the different degrees of resistance offered by a. rheostat as ascribed, will be proportionate to the number of sections contained in the rheostat; it. is also evident that at least one of the sections will always be included in the circuit.

For purposes requiring a uniform resistance, I prefer to construct the rheostat as shown in Figs. 6 and 7 wherein the 6 frames of each of the sections 1, 2, 3, 4 and 3 are pro vided, respectively, with two insulated members 20 and 20 21 and 21, 22 and 22. 23 and 23,- 24 and 24 which in addition to forming terminals for the resistance wires of the several sections, also serve as hinge cr swivel joint, connecting the sections both mechanically and electrically to the post 25. The post 25 is made in two parts insulated from each other at 26. In the end of the u per part of the post 26, and in the side 0 the lower part, I provide sockets 27 and 28 to reeeive t e plugs 14 and which form the terminals of the wires 14 and 15. In a rheostat of the above descri tion. the electric current passes through tie resistance wires 8 of all the sections at the same time, entering via the terminals 20, 21 22, 23 and 24 from the upper part of the post 25, and leaving the several sect ions via the terminals 21, 22 23, and 24 to the lower section of the post 25, or vice versa.

As a convenient means of elevating the rheostat slightly above the surface upon which it. may be resting. I extend the front stile of the frames 6 of sections 1 and F- sli htly beyond the lower edge of the frames, an in like manner the lower part of the post is extended, thus providing three legs or supports, 6 and 25.

As shown in Fi 6 insulating pads 29 and 30 are secured to t hc ends of the legs 6 and 25 In a rheostat of the construction shown in Figs. 6 and 7, the resistance will be constant regardless of the relative position of the several sections. therefore the only ap parent object in hinging the sections together. is that of compactness, which is the chief object sought in the resent. invention. and may be attained by to ding the sections together, lmokwiso. when the rhcostnt is not in use.

\Vhile l have shown but two of the forms. my invention may take. I do not care to be limited thereto, as it is obvious that several modifications may be made without departing from the spirit of my invention.

am aware t mtrhrostnts of u more or loss bulky form, which usually hrcmuc a permuuout. fixture when intrmlured into an electric circuit are in general use, l am also aware that rheostats of both constant and variable resistances are in use. but I am not aware that heretofore any such improvements have been made in rheostats. as are emlmdicd in my resent invention. nor for the purposes herein set forth.

'Iherefore what I claim as new and desire to secure by Letters Patent is:

I. In a rbeostat, a plurality of frames. suitable supporting strips carried wit-hm said frames, resistance coils mounted apan the supporting strips and means operat b the relative movement of said frames for controlling the flow of current through said resistance coils.

2. In a rheostat, a plurality of frames carrying supporting strips, suitable resistance material mounted upon said supports, means for yieldingly connecting the frames, and means operated by the movement of the frames relative to each other for electrically connecting the resistance material of the several frames in series.

3. In a rheostat, the combination of a plurality of sup )orting frames, a hinge member connecting the several frames,- supporting members secured within said frames, resistance. material mounted upon the supporting members, insulated contact plates forming terminals for the several sections of resistance; the contact plates of the various frames adapted to be thrown in or out of electrical contact with the plates of the frames adjacent thereto, substantially as shown.

4. In a rheostat, the combination of a plurality of supporting frames, a hinge eonneeting the several frames, supporting members secured within said frames, resistance material mounted upon the supporting mem bers, insulated contact. plates forming terminals for the several sections of resistance: the contact. plates of the various frames adapted to be thrown in or out of electrical contact with the plates of the frames adjacent thereto. and supporting members or elevating the rhcostat, adapted to be folded laterally against. the frames substantially as shown and set forth.

5. lo a rhcostat. a plurality of sections consisting of a suitable resistance material mounted upon supporting strips, said strips secured within a frame. a pillar or support consisting of two insulating sections, means for yieldingly connecting the sections to the pillar, and means for establishing electrical connection between the resistance material and the pillar substantially as shown and described.

(1. In a rheoslat. a member comprising an open frame. a core composed of a plurality of pieces of insulating; material. said core being positioned within the frame. and the pieces composing the euro being assembled edge to edge with reference to each other, and a plurality of resistances wound individually on the core pieces, said l'wislanccs lying substantially in the planes of the respective faces of 1 10 frame.

7. In a rheostat, a member comprising an open frame, a plurality of core pieces positioned within said frame, said core pieces being assembled edge to edge with respect to each other and lying substantially in the planes of the respective faces of the frame. and a )lurality of resistance windings coiled individually on the core pieces.

8. In a rhcostat, a member comprising an open frame, a plurality of mica cores positioned within said frame. said mica cores being assembled in edge to edge order, and substantially in contact. along their edges. and a plurality of resistances wound individually on said cores.

9. In a rheostut, a member comprising an open frame, a lurality of flat core pieces socured in said nune and positioned edge to edge with respect to each other, and resistance coils wound on said core pieces, the windings of one resistance coil alternating with the convolutions of the next adjacent coil.

10. In a rhcostat, a member comprising, a core composed of a sheet of mica divided to produce a series of lengths, said lengths bemg disposed in edgewise opposing relation, and a resistance com iosed of a. metallic winding supported by t as mica sheet.

11. In a rheostat, a plurality of members flexibly connected for adjustment relative to each other, whereby said members may be spaced for the circulation of air between them, each member having a resistance exposed to the air, and means operated by the adjustment of said members for regulating the flow of current through the resistances.

12. In a rheostat, a plurality of resistance members llexiblv connected for adjustment into compact relationship and adapted to be separatet for the circulation of air between and around said members, and means dcendcnt upon the movement of said memms for controlling the flow of current into the resistances thereof.

[3. In a rheostut. a plurality of resistance ca rrying members adjustable into compact relationship and adapted to be relatively separated. and means dependent upon the positions of the members for controlling the flow of current through the resistances.

14. In a rheostul, a plurality of resistance carrying members adjustable into compact relationship and into spaced order, and means controllable by the adjustment of said members for cutting them into and out of an electric circuit.

15. In a rheostat, a plurality of adjustable resistance carrying mcuda-rs. and means coutrollahlc by the adjnsluu-nt of said members for cutting them into and out of an clorlrio circuit.

16. In a rheostab, a plurality of movable carrying members each havin on resistance, and means contro able by the movement of said members for cutting the resistances into or out of an electric circuit.

17. In a rhcostat, a plurality of movable resistance members, means for sup orting the same, and means controllable y the movement of said members for including them into an electric circuit.

18. In a rheostat, a plurality of movable resistance members eaci adapted to be exsed for the free circulation of air in contact therewith, and means 0 rated by the movement of. said members or cutting the resistances into and out of an electric circuit.

19. In a rheostat, a plurality of resistance members movable with respect to each other,

members hinfiedly connecte whereby said members may be separated laterall and means operated by the movement 0 said members for cutting them into or out of an electric circuit.

20. In a rheostat, a pluralit of resistance for lateral movement WIT, respect to each other, and swatch devices operated by the movement of said members for cutting them into or out of an electric circuit.

In witness whereof I have hereunto set my hand this 24th do of October 1908 in the presence of two su ribing witnesses.

ROBERT HEAD lVitnesses J. M. Mammm'r, Ronmrr L. Wxrxms.

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