US981572A - Rheostat. - Google Patents

Description

C. D. KESTNBR.

BHEOSTAT.

APPLIOATION FILED DEO. 31, 1909.

Patend Jan. 10, 1911.

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C. D. KES/INEE.

RHBOSTAT.

LPPLIOATIOH Hmm 1120.31, v1909.

Patented Jani 10, 1911.

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- UNITED sTAriis PATENT OFFICE.

D. XESTNEB., NEW YORK, N. Y., ASSXGNOR TOTHE NtEYROWITZ MANU- FACTURING CO., A CORPR-ATION 0E NEW JERSEY. l

imnos'ran Specification of Letters Patent.

Patented Jan. 1o, 1911.

Application filed December 31, 1909. Serial No. 535,812.

To'all whom 'it may comern: p .uated for a considerable range, since here Be it known that I, CHARLES D. Kns'rnnii, the graduations atone end are undesirably a citizen. of the United States, residing in close while at the other, unnecessarily large. the .city 0f New York, in the borough of and to overcome this objectionable.feat-ureA 5 Manhattan and-State of New York. have inthe present invention has been evolved, einm es:

vented certain new and useful improve# bod ing a new form ot' rheostat which adments in Rheostats, of which the following un ,ably adaptsl itself to the required condiis a full, clear, and exact description` tions. liurther,l the device considered as a This invention relates to a lamp rheostat, whole and even more especiallyl the novel and has for its object theproduction ei' a rlicostat herein y.presented is admirably 35,

compact device. adapted to'be inserted in a adapted to various other uses. lamp or other electric circuit for the purpose The following is a description of one emof regulating the resistance tl'ierein' and bodimentcf my invention, 'which .is illusmore especially to provide a device in which trated in the accompanying drawings, like ,15 said resistance may be varied by some conparts being designated by like reference 7o venient means, such for example as a knob characters. or handle, `and securing thereto a pointer lReferring to `said drawings, Figure l is adapted to cooperate with a scale, the gradua front elevation of a socketed lamp rheoations of which should referably be substat. Fig. f2 is a vertical section taken on l0 tantiallv equally spaced? This arrangethe median line of Fig. l. Fig. 3 is a front 75 ment is or'special utility in connection with elevation, partly in section, of the device tungsten lampsand more particularly those with the scale or front plate and arbor 'rc- 'ofllow voltage. These lamps, the bulbs of moved. Fig. e is a rear elevation with the which may be very small, are used in conback plate removed. Fig. 5 is a perspective nection with various surgical appliances to view of said back plate. Fig. 6 is a. view of 8G illuminate the mouth or. nasal cavities er fthe arbor showing the insulating member likev parts', and -it becomes necessary tretherein. Fig. 7 is the rheostat proper; quently to vary the size of the bplb and shown partly in section. Fig. 8 is a vertical consequently the voltage ofthe lamp to fit section of the top socket-stein base, andcon- M 'the cavity or the instrument. When, for necting parts. 'Fig 9 is a modification of 85 example,l a six volt lamp is used, it is found the rheostat proper. necessary to .insert a given Iresist-ance into In the drawings, l designates a cylindrical A the ordinary lamp circuit to accommodate casing, preferably of sheet metal, having j a lamp of this low voltage. Upon a subsedisposed on opposite sides thereof male and '85 quent change to, kfor example, a lamp of female socketconnections respectively 2 and 90 A twelve volts, the relative travel of the mov- 3. These socket portions are carried upon able element in a rheostat of the usual type bosses or extensions 4c formed byl soldering .will not `be proportional to the change in annular members into apertures of said cas-4 voltage of' the lamp, and were afscale to be ing, and insulating base kmembers are seated 40 *used in connection with the aforesaid rcin said extensions. The upper insulator 5, 95

sistance, as an indicating means ot the is formed with vertically disposed recesses amount thereof in circuit, the fnfaduations adapted to receive conductive sleeves 6, and, upon said scalf, would be unequally spaced i the lugs 7 of a vthreaded conductive shell 8. so that at one "ad thereof the division lines lions 9 and l0 extend through apertures 'in 3F would be spaced. far apart, while at the other said .lues and through the lower portion of 1Go end they would be disproportiomitcly close the i` lating base, and are respectively together. For convenience in use therefore, g .flidly into the liber strips lll-419.. it is desirable that some means be provided i (j ps if; and M, preferably ot' brass, are A whereby when for example the required i'oltimlcpentlently secured to strips l1 and 1:2, age is-to be doubled trebled or quadrupled being positioned one on either side of the the handle and pointer shall preferably travcenter line of the base; the bolt 9 contacting erse distances proportional to the voltage re with clip i3. The fiber strips servelto space quired, thereby permitting of less care in the clips 'foin a conductive bar lo, united the adjustment of the rheostat. Partitur to the insulating base by a riveted extension upon metallic through-bolt 16, the head 17 1X0 l5 larly is this the case where the scale is grad of which is positioned onthe top of the base and together with the threaded shell aforesaid, forms the male socket connections. The lower insulating base 18 carries upon the lower portion thereof a threaded shell 19, said shell being secured to said socket by screws 20, 21. Said screws extend upward from the base and through a fiber block 22; screw 20 threading into a nut 23, and screw 21 threadin .into a metal bar 24. Said bar may be furt 1er secured to the liber block 22 by screws 25 if desired. Extending upward through the base 18 is a contact screw 26 threaded into a. bar 27. The fiber block 22 being recessed for the reception of said bar. 'lransversely positioned in said casing is the rheostat proper, in this instance formed by winding a coil of conductive material 29, preferably German silver wire, upon an insulating core or base 28, in this instance of fiber, having` theV form substantially of a truncated conc.- The various turns of the coil are substantially insulated from each other by a coating of lacquer, or other insulating medium, and the said core and coils positioned thereupon are in this instance shownv flattened, as at 30, along one side thereof, the insulating coating being scraped from the exposed surfaces of the coil along this flattened portion. The core 28 tapers gradually from the end 31, which is secured to the casing by screw B2, and the opposite or reduced extremity of said core is flanged as at 33 to better retain the wire wrapping, said end in turn being secured to the casing by a'screw 34. This exem lification of my rheostat is merely one o many possible diverse forms thereof, and should the exigencies of the case require a structure of other shape than that of a truncated cone, as for example that shown in Fig. 9 such structure would be considered within the purview of my invention.

One modification of my rheostat is illustrated in Fig. 9, wherein the core is omitted, the wire forming the rheostat being of sufficient rigidity to permit dispensing with the said core. The metallic parts 35 in this form of device may be supported by loops 36 adapted to be engaged by screws or like means secured to the walls of the casing; the coil vbeing of course properly insulated by strips of mica or the like.

Positioned on the front of casing 1 is a tace plate 37, secured in position upon the casing by lugs 38. Said plate carries upon the outer face thereof a scale A pointer 40 carried upon a sleeve 41 cooperates with said scale. An arbor 42 having a reduced portion 43 adapted to be seated in an aperture 44 in said face plate, carries the sleeve 41 upon an extension 45 thereof; a knurled nut 46, preferably of insulating material, clamping said sleeve firmly in position upon the arbor and thereby securing said arbor in its bearing. The rear end of the arbor is recessed for the reception of an insulating fiber block 47, and said block carries in the slotted extremity 48 thereof a resilient conductive finger 49, preferably of rolled copper or like material. The upper extremity 50 of said finger is dished for reasons hereinafter set forth, and said finger is secured to said block by a screw 51.

A perforated rear or back plate 52 formed or provided with a stiffening flange 53 preferably soldered thereto, completes the casingl proper; said .plate being secured to the casing by struck-up lugs 54, similar to those on the front plate. These lugs may be threaded for the reception of securing screws -55. The resilient strip 56 is secured by a screw 57 to the bar 24, and extends obliquely upward therefrou'rtoward the inner extremity of arbor 42. The end of said strip is cupped at 58 to engage a considerable surface of screw 5l carried by the said arbor. The connections of the several arts above described can be best explaine while describing the course of current through the apparatus. Assuming that the socket stem 2 has been screwed into` position in the usual lamp socket, current will enter let us say, at 17, passing thence down through conductor 16 to bar 15. A wire 59 connects said bar with bar 27, current thence proceeding throu h contact screw 26 to the center contact o a lamp; returning from the lam) through shell 19, screw 21, bar 24, the resilient member 56, screw 51 into finger 49; then according to the osition of said finger upon the rheostat coi through a greater or less extent of said coil to a lead 60 extendin therefrom to the L-shaped bar 13, and rom thence through screw 9 and sleeve 6, back to the shell 8, completing the circuit.

Ventilating holes 61 provided in the walls of the casing, together with the perforated back plate afford a sufiicient circulation of air to prevent the device from becoming overheated when in use. As a matter of precaution to avoid any possibility of shortcircuiting, a layer of mica 62 is provided between the arbor and conductive bar 27.

To afford a finished appearance to the exterior of the bottom socket member7 a metallic sleeve or ring 63 is placed in position thereupon, engaging the flange 64 of the insulating base, and being. secured in position by a knurled nut 65.

As it may not always be desirable or possible to use my device' in connection with a lamp socket, l have provided threaded binding posts 66, 67, upon the face thereof. Said posts are insulated from the face plate by washers 68; post 66 being screwed into the short leg of L-shaped clip 13, while ost 67 is correspondingly screwed into c ip, 14. This latter bar is not in electrical connection with the shell of the socket stem, since the wise.

lead Wires/69 connect the ends of bai 14 withbar 24 and screw 57, therebyplacing blnding post- 67 in electrical connection with finger49. Bar 13 is connected by lead GO with the rheostat coil in a manner already' described, and hence the circuit is adapted to be completed between said binding posts,

through the medium of said rheostat.

` The operationof the rheostat proper is obvious` and it may be merely added that it is possible by varying the sizes of the vari ous turns of the coil to effect any predeter mined changes of resistance desired While :permitting the scale used in connection therewith to be graduated evenly or otheru It will be noted also that the rheostat 1s adapted to operate as a switch, since if .the revoluble arm 49 be rotated to the ex- .throw of said arm, and the end of saidV arm 1s dished as hereinbefore mentioned to bet.-

ter permit a sharp line contact with the respective turns of the resistance coll.

"The .equal .spacing of thescale obviates the. objections to the use of an unevenly.

raduated one, to wit the difliculty of reading and, interpolatinwhen the lines of the scale are `most close y spacedv and the liability of the operator to turn the controlling knob to an' improper position for a given lamp, which may cause the burning out-thereof; the interpolation abovereferred to being in such case necessitated by' the fast that when the graduations are close the4 designating numerals or marks cannot all be applied, since such figures would be too small, and interpolation. must be re sorted to, with the consequent liability of erroneously adjusting the rheostat.

' What. I clan is:-

l. In a rheostat, a tapering insulating.

core, a conductive member wound thereon,

ter-iai, hav-ing 'the turns thereof of unequal size, and a. member adapted'to contact with various turns of said coil when iela'tlve movement occurs between sa-idcoil and said member.

A rheostatcomprising a rigid tapered coil of coi'nluctive material in combination with a contact adapted to malte successive connection ywith the turns thereof.

et. A rheostat coniprisinga rigid coil. having the 'turns thereof of varying size and aninsulating base' therefor in combination with a Contact adapted to malte successive connectionwith the turns thereof.

A rheostat comprising a tapered coil, iatteued upon one side, a revoluble arbor disposed substantially at right angles to the axis of said coil, and an arm carried by said arbor and having a protuberance adapted to resilientiy engage Avarious portions of said flattened portion. l

(i. A lamp rheostat comprising a scale, a coil having the various turns thereof of differing` si'ze,p a revoluble member carrying an arm and a pointer, said arm being adapted to engage Various turns of said coil, and

said pointer indicating'upon said scale when the arm is in proper position foruse with a given lamp.

7. A- lamp rheostat coi'nprising a casing having means for connecting-said rhe'ostat in circuit/with a` lamp, a nonconductive core having the shape substantially of a truncatedcone secured to a. side of said casing, a resistance wire wound thereupon, and-means for engaging the turns of said coil for adapting the current to the lamp to be used'.v r

S. A rheost-at comprising a non-conductive base the successive vtransverse sections of which are of varying areas, a coiled con ductive member mounted upon and con forming to the Variations of the base, and an arm adapted for engagement with the turns of said member.

In witness whereof, I subscribe my signature.y in the presence of two witnesses.

Louis Pn. Garen.'

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