US873006A - Rheostat. - Google Patents

Description

PATENTED DBG. 10, 1907.

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m@ n l Hb i controlling devices of the type known as ycircuit cannot be closed except through the .that means be provided whereby if the regle', and an o ver oad magnet is provided to UNITED sTATEs PATENT oEEroE.

HENRY PRICE BALL, OF NEW YORK, N. Y., ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.-

RHEOSTAT.

Speccation of Letters Patent.

Patented Dec. 1o, 1007'.

manon.. and hmmm 21.1905. sumiso. 292.720.

To dll whom it may concern:

Be it known that I, HENRY PRICE BALL, a citizen 0f the United States, residing at New York, county of New York, State ofl vNew York7 have invented certain new-and useful Improvements in Rheostats, of which the following is a specification.

This invention relates to devices forcontrolling electric motor circuits and has for its object the provisionof a device ofthis character which will be protectedv against injury due Yeither to abnormal load conditions or careless handling and which will be simple of construction ando eration and at the same time thoroughly re iable, safe and durable.

My invention relates more specifically to starting rlieostats in which a sufficient-resistance is included vin series with the motor at starting to prevent a dangerous rush of current, resistance being lually cut out as the motor s )eeds up unter it is finally shortcircuited. n devices of this character it is essential that provision be made whereby the protecting resistance. It is also desirable sistance is cut out too rapidly so as to endanger the motor andthe starting resistance, the circuit will be opened and it will be necessary to return the controlling armto starting position before it can beagain closed.

In carrying out my invention I provide a controlling arm ada vted for sliding engage-` ment with a series o contact studs, said con trolling armbeing pivoted Aso as to move in a plane at right angles to the plane of the contacts so that the circuit may be broken at any contact without passing over the other contacts. This controlling arm I connect with a eontrollin Y handle by means of a tognockout the tog fle an( allow the controlling arm, which is iased .to open position, to Vbreak the circuit. A no-voltage magnet is also pro vided and is so arranged as to act upon a projection of the operating handle to hold the arm in operati position. Uponfailure of volta e the hand e is released and the circuit bro en. I also provide means whereby the circuit when once it opened cannot be closed without movin the controlling arm to the starting position iut which permits the/ opening of the circuit in any positlon.

My invention further consists in the 'feaN` tures of construction and the arrangement and combination of elements hereinafter set forth and particularly pointed out in the claims annexed to and forming a part of this ap lication.

n the drawings illustrating one embodiment of my invention, Figure 1 is a plan view of the device; F 2 is a side elevation of the same, part of the base being broken away; Fig. 3 is a similar view showing the position of the parts when the circuit is broken; and Fig. 4 is a diagram of circuits.

Referring to the drawingI 10 is an insulating base of slate or soapstone provided with a series of contact plates or studs 11 arranged inthe are of a circle and forming termin als of' a starting resistance 12. Mounted within' the hase and concentric with the studs 11 is a circular metallic easing 13 hav'- ing a supportingl flangel 14 which rests upon the base. A eo lar 15 is secured to the flange 14 and base 10-by means of bolts 16, ther/zontacting faces of the arts 14 and 15 being cut away so as to affor a bearing for flange 17 of sleeve 18. The controlling a 19 is pivotedat 20 in brackets' 21 of sleeve 18 and is spring-pressed in the position shown in Fig.

3 an 1n dotted lines in Fig. 2 by means of the spring 22. The arm 19 is preferably in the form of a bell crank lever, one end of which is providedwith an engaging surface or brush 23 for engaging the contact studs, the' other end being connected with anjex'tenn sion 24 of the operating handle 25 b* means of the links 26 and 27 ,forming a togg e. The handle 25 is pivotedin a bracket 280i the sleeve 18 arranged diametrically opposite to the brackets 21. The handle 25 is also )rovided with a circular extension 29 extent ing in proximity tothe sleeve 1S so as to be un( er the control of the magnet- 3() within the sleeve and concentric therewith. Directly underthis magnet is a second n'iagnet 31 within the casing 13. These magnets are concentricallv'arrangeil and a single core 32 having au enlarged head 33 on the underside` op osite tothe toggle joint when the lconf4 tro ling arm is down in engagement with the CII contact studs 11, as shown in full lines in Fig. 2. A latch 35A pivoted to the operating handle is spring-pressed toward the collar 15 by means of a spring 36 so as to engage a flange 37 thereon. This iiari'ge extendsonly a portion of the distance around the collar, as shown in Fig. 1 and is slotted at 38 so a admit the latch 35.

The operation of my device will be clearly understood from the foregoing -description from which it will be seen that the controlling arm 19 is normally biased away from the contact studs and is forced vinto contact therewith by means of the handle 25. With the parts in the position shown in Fig. 3, the circuit is broken and the latch 35 is in engagement with the liange 37 so as to hold the operatinghandle and hence the controlling arm in the position shown. The controlling arm cannot, therefore, be forced into erigagement with the studs until it is turned to the left from the position shown in Fig. 1, sufficieritly to allow the latch 35 to pass through the slot 38. This will be the starting position of the rli'eostat. When this point is reached the handle may be drawn up and the toggle being straight, the operating arm will lbe moved. against the tension of thespring 22. As soon as contact is made between the arm and the` studs the magnet 30 is energized and its core 30 attracts the extension 29 lof the operating handle, as shown in Fig.-

2. The controlling arm may now be moved along tothe right by means of the handle to cut out resistance.` At any position of the controlling arm, should the load become eX- cessive, dilo to too rapid movment of the arm .or to other causes or when the arm `has reached the short-circuited position on the last stud, the overload magnet 31 willattract the head 33 against the tension of'the spring 34 andthe projecting end 32 'will' strike the toggle joint and break the same allowing the controlling arm to take the position shown mdotted lines in Fig. 2. Likewise upon failure of voltage from any cause or-with the arm in any position, the rio-voltage magnet 30 will release the extensionY 29 of the operating handle and allow the parts to assume the position shown in Fig. 3; In either case, after the circuit has beenbroken, it will be impossible, as before stated, to again close the circu'ituntil the' arm has been moved to starting position Withthe operating handle opposite the'slot 38.

The arrangement ofthe circuits is shown in Fig. 4 and is extremely simple. In the arrangement shown the magnet 31 is arranged in series with the starting resistance and the armature so that 'When the starting 'arm is moved on to the first stud, current passes from a line at L through the magnet coil 31, controlling arm 19, resistance 12, conductor 39 to armature A and back` to line 6e at Ll, theicurrent to the shunt field passing "a rheostat which it is impossible to destroy from the pivotalpoint of the controlling arm at 4]. through thc magnet 30 and lield l" back I to line.

It will thus he seen that .l have provided either by improper handling or from overloads due to other causes. The opening of the circuit through the cntrolling arm is independent of the operating handle so that on any stud for too long a time, the circuit will be broken without movement` of the handle., It vill then he necessary that the arm be again moved to starting position before the circuit can be closed.

While I have described a specific construction and arrangement of parts, it should be understood that I do not limit my invention thereto, since various modifications may be made therein without departing from the spirit ofiny invention, the scope of which is set forth in the claims hereto annexed.

What I claim as new and desire to secure by Letters Patent of the United States, is,-

1. A rheostat comprising a series of contacts, a `controlling arm mounted for sliding engagement therewithto vary the resistance,

and means for breaking the circuit at any of said contacts by disengaging said arm therefrom upon the occurrence of underload or 9 overload conditions.

2. A starting rheostat comprising a series of contacts, a controlling arm mounted to successively engage the same to vary the resistance, means for disengaging said arm 100 from any of said contacts toY break the circuit upon. thel occurrence oi underload or overload conditions, and, means for prevent- Airiga rengagement until the arm is brought to starting position.

3. A starting rheostat comprising a series of contacts, a controlling arm adapted for sliding engagement with said contacts but biased therefrom and pivoted for movement in a plane at an angle to the plane of said 110 contacts, and means for preventing engage- .mentbetweeri said arm andsaid contacts until the former is' moved to the starting position. f

4. A rheostat comprising aseries of con- 115 tacts, a controlling arm adapted for sliding yengagement Awith said contactsbut biased therefrom and pivoted for'movernent in a plane at an angle to the plane of said contacts, means for holding said arm in engage- 120 merit withsaidcontacts during normal operation, and means for releasing the same in any position upon the occurrence of underload or overload conditions.

5. A starting rheostat comprising a series 125 contacts, means for preventing engagementV 130 87eme :e former is moved to the starting position, 'i means ,for releasing the same in any' position upon the occurrence of underload or overload conditions.v v

6. A starting rheostat comprising a series olt rv-intacts, a controlling 'arm adapted for slidinff engagement with said. contacts but Ui ser therefrom and pivoted lfor movement in a piano at an an le to the lane of said contacts, means for olding said arm in enelnent with said contacts during normal operation, means for releasing the Vsame in air-Y position upon vthe occurrence of underpreventing engagementy between said arm and said contacts until the former is moved to the starting position.

7. A rheostat comprising a series of contacts, a controlling arm plvoted for movement in a plane at an angle to the plane of said contacts and adapted to successively engage the same but biased from the contacts', means for holding said arm in engagement with said cont-acts during normal operaLion, an operating handle, and inc-ins for releasing said arm independently of said handle.

A rheostat .comprising a series of con-- tacts, a controlling arm adapted for sliding engagement with said contacts but biased th ,reronn moans forholding said arm in en gageinent with said contacts duringr normal operation, an operating handle, and an electromag. device for releasing said arm independcntly of' said handle.

f). A rlioostat comprising a series of contacts, a f ntrolling arm therefor', an operating handie, toggle connections between said arm and said handle and means for opening thc circuit upon the occurrence of abnormal conditions therein.

1li'. A rire stat comprising a series of conrolling arm therefor biased to t position, an operating handle, inectons between said arm and ile, and a rio-volta c magnet acting l. handle to hold arm in opera rheostat comprising a of con- -ntrolling arm adapted for sliding with said -contacts but biased Y, au operating handle, toggle conM vload or overload conditions, and means for nections between said arm and said liandle for holding the former in engagement with4 $5 said contact-s during normal operation, and an overload device acting lupon said toggle to release said. arm. y

12. A rheostat comprising a ries of contacts, a' controlling varm therefor biased to open circuit position, an operating handle, toggle connections between said arm and said handle, a no-voltagc magnet acting upon `said handle to hold said arm in operative position, and an overload device acting upon said toggle to release said arm.

i3. A starting rheostat comprising a series of contacts, a controlling arm therefor biased to open circuit position, an operating handle, tog rle connections betweenY said arm and sai hadle,.a 11o-voltage magnet acting upon said handle to hold said arm in closed circuit position, and means for preventing movcmen t of the arm to the closed circuit position until it has been moved tc the starting positionv f 14. A rheostat com rising a series of contacts, a movable mein er mounted to rotate in a plane parallel to the plane vof the contacts, a controliing clement pivoted thereto for movement in a plane at an angle to the plane of the contacts, a similarly pivoted operating handle, liek connections between said han ie and snif "rm, and an electromagneiic device i holding said arm in operative position and or rceasing the saine upon the occurrence oi undcrload conditions.

15. A rheostat comprising a series of contacts, a movable inem.' mounted to rotate in a plano pa l to the piane of t contacts, a conxfsolllv element pivotod thereto for movement in a piano ai. an angle to the sirniiarliT pivoted op- 4 o, tom `Vrmnections between said handle and i l zu'in, and elcctromagnotie dcvic im' holding said arm in operan tive position ai i Vor rol asing the same upon 'the occurrence oi nndcr'ood or overload con ditions.

ln witness 3reni i ve hereunto set my hand. this 15in day rm december. IQCS.

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