US973885A

US973885A - Current-controller.

Info

Publication number: US973885A
Application number: US47951409A
Authority: US
Inventors: Frank L Sessions
Original assignee: Jeffrey Manufacturing Co
Current assignee: Jeffrey Manufacturing Co
Priority date: 1909-02-23
Filing date: 1909-02-23
Publication date: 1910-10-25
Anticipated expiration: 1927-10-25

Description

F, L. SESSIONS. CURRENT CONTROLLER.

APPLICATION FILED JAN. 7, 1904.

RENEWED FEB. 23, 1909.

' Patented 36. 25, 1910.

5 smmvsmm 1.

MAM

51 1 mantoz F. L. SESSIONS,

CURRENT CONTROLLER.

. I AIfPLIOATION FILED JAN. 7, 1904. RENEWED FEB. 23, 1909. P-

Patente 0st. 25, 1910.

5 SHEETS-SHEET 8.

625% 7/ i/gm/ P. L. SESSIONS. CURRENT CONTROLLER. APPLICATION FILED JAN}. 7, 1904. RENEWED FEB. 23, 1909.

Patented; 0st. 25, 1916.

5 SHBETS+SHEET 4.

Qmifmzoom 5 SHEEiTSSHEET 5.

F: L, sEssms,

v CURRENT GONTROZLER= APPLICATION EV'ILED JAIL 7, 1904. RENEWED FEB. 23, 1909 WD UUUDUUQUU ru CUB UH UU NW @EHUU H EH U U UNITED STATES PATENT OFFICE.

FRANK L. SESSIONS, OF COLUMBUS, QHIO, ASSIGNOR, BY MESNE ASSIGNMENTS, TO THE JEFFREY MANUFACTURING, COMPANY, A CORPORATION OF OHIO.

CURRENT-CONTROLLER.

Specification of Letters Patent.

Patented Oct. 25, 1910.

Application filed January 7, 190a, Serial No. 188,085. RenewedFebruary 23, 1909. Serial No, 479,514.

To all whom it may concern:

Be it known that I, FRANK L. SESSIONS, a citizen of the United States, residing at Columbus, in the county of Franklin and State of Ohio, have invented. certain new and useful Im. rovements in Current-ConlZIOllEFS, ofv 'WhlCh the following is a speci fication, reference being had therein to the accompanying drawing.

This invention relates to improvements in controller mechanism used with electrical apparatus, it being particularly applicable for use'in connection with electric motors employed for propelling locomotives and vehicles of that class.

Figure l is a View of the interior of the controller, the cover being removed. Fig. 2

is a section'on line 22, Fig. 1. Fig. 3 isa section on the lines 33, Fig. 1. Fig. 4

a view partly in section of the commuof wiring between a controlling mechanism embodying my invention and two motors. Fig. 8 is a diagrammatic view of the system of wiring between a controlling mechanism embodying my improvements and three motors. Fig. 9 is an end view of the pole piece of the blow-out magnets.

a In the drawin s: 1 represents the mai frame work of t e controller. It may be made of cast iron, steel or other material of high. magnetic permeability.

2, 3,, represent the end pieces or walls respectively, of. the controller, which may be secured tothe main frame 1 in any well known manner.

4 is a cover detachably secured .to flanges on the main frame and the end ieces. The end pieces are also preferably made. of a material of high magnetic permeability.

5 indicates the controlling switch as an entirety. It comprises the relatively long greater part of its length between the said end walls, the shorter cylinder 7 being arranged on the shaft near the end wall 8. The said shaft 8 is insulated from the cylinders on it by the insulating material indicated at 11. This insulating material may be arranged in any well known manner. The said commutating shells or cylinders 6, 7 are insulated from each other by the insulating disk 12 which is arranged 'between them on the shaft 8.

13 and 1 are insulating disks arranged at opposite ends of the cylinders 6 and 7 and adapted to insulate the said cylinders ,from those parts of the mechanism which are arranged on the shaft 8 near the opposite ends of said cylinders. The shells 6 and 7 are secured to the shaft 8 by means of the convexo-plano metallic plates 90 and set screws 91. Theset screws have threaded engagement with the metal of the shells and bear upon the convex side of the metallic plates 90, holding them flatly against the plane faces of the insulation 11 surround ing the rectangular shaft 8.

6' and 7' indicate lugs on the commutating cylinders 6 and 7 respectively to which the commutating segments or contact members 15, 15 and 16 are secured. The segments 15. 15 on the cylinder or shell 7 have the same peripheral length and are arranged sim larly on the said shell or cylinder relashell or cylinder 6. The lugs 6 on this cylinder are so arranged with respect to each other as to bring the segments 16 thereon successively into contact with their respective brushes as the cylinder is rotated. 17, '18 are collars mounted on the Shaft 8 outside of the insulating disks 13, 14:, re-

spectively, and, as will be hereinafter described they serve as poles for the magnetic circuits. These collars are preferably made of a material mea'bility.

possessing high magnetic per-.-

holders 41/ at their other ends.

21, 22 are pole pieces extending at right anglesto the frame 1 andarranged transversely of the shaft 8. They are composed of material of high magnetic permeability block or plate 25 serves as an insulating su'pport for the

brushes

27, 28, 29,30, 31, .32, 33, 34 and35 which are adapted to be engaged by the commutator segments on the commutating cylinders 6 and 7. These brushes may be held in position in any well knownmanner. For illustration I have shown them secured at their outer ends by means of adjusting screws 36 to the springs 38. .These 1 springs are secured at their outer ends between plates 39 and projections 40 on the brush holders 41 by means of screws 42.

137' are flexible conductors secured between the brushes and their springs 38 at one end, and between said springs and the brush These flexible conductors'are made of copper or other material which is a good conductor of electricity and are adapted to insure a good electrical connection between the brushes and the brush holders.

The springs 38 serve to hold the contact surfaces'of their respective brushes in such positions as to effect a good contact between the said surfaces and their commutator segments as the latter are rotated into operative.

engagement therewith. The deflection of each spring and the wear of its brush may be varied and its correspondingsegment be compensated byadjusting its screw 36 against the shoulder or abutment 43 on'its holder. 36 are looking nuts for securing the said screws in any position of adjustment. The brush holders 41 are secured to the insulating block 25 and have terminal sockets or binding posts 44 in which the electric conductors which lead to the brushes may be secured.

I provide a blowout magnet for blowing out the arcs between the brushes and the commutator segments as the current is. cut

out between them. 45, 46'are projections or bosses on the

end pieces

2, 3 respectively which serve as cores for the magnet coils 45, 46 respectively, indicated by dotted lines in Fig. 1. These cores may be formed integral with or separate from their respective end pieces, but

in the latter case they should be secured rigidly in place.

47 is a blow-out'magnet pole piece. It is arranged substantially parallel to the commutating cylinders 6, 7 and extends slightly beyond the opposite ends thereof. It. is sup ported by the

arms

47 ,47 of non-magnetic material which are pivoted to

thetrunnion bolts

48, 48 secured to the

opposite end walls

2, 3 of the mechanism. A bolt 49 extending through the core 46 and into the aperture 47 in the adjacent pole. arm-47 serves to hold the said pole piece in properworking position. j

50, 51 are projections on the pole piece 47 which extend toward the axis'of the shaft 8 and are arranged between"the pairs of

brushes

27, 28 and 34, 35 respectively. 52 is an extended portion of the pole piece 47. It is arranged axially of the commutating cylinder 6 and substantially parallel to the contact surfaces of the

brushes

29, 30,

31, 32 and 33. This pole piece 47 is pivotally hung as shown inorder to provide for a be swung about the versely arranged top and bottom plates 53 and-the

edge plates

54, 95 and 96, all composed of insulating material.- The walls of these chambers are secured together in any suitable manner'and are fastened by screws 53 to lugs 53 on the pole piece 47 so that when the pole piece is swung about its pivots 48 toenable the operator to examine the commutator segments and brushes the walls of the chambers will be carried with it. Each of the remaining segments operates in a chamber 54 formed with transversely arranged top and bottom plates 53 and the

edge plates

54 and 96. The walls of these chambers are suitably secured to each other by screws and are attached to the lugs 53 v on the pole piece 52 by means of screws53. The walls of these insulating chambers 54- are likewise swung with the pole piece 47 about the pivots 48.- It will be observed that the two pairs of contact segments at either end of the controller operate in insu lated chambers, each of which is provided with a chute or chimney 97 through which the hot gases, caused by the arcing between the contact segment and brush, can be driven, while the remaining contact seg-- ments. operate in closed chambers, the relatively small size of the arcs which are formed therein not requiring a chimney or opening through which the hot gases may be expelled. v

55 indicates as an entirety theseries parallel reverse switch. 56 is the controllingallel reverse cylinder.

shaft for said switch. It is mounted in bearings 57. 58 in the

end walls

2, 3 of the mecha nism.

59 v is a cylinder made of wood or other insulating material-and secured to the shaft 56 by spurs 60 which are themselves secured the motors will be connected in series and will cause the car to move forward. 0' inch-- cates the second series of contacts on the said cylinder 59. They are so connected together that when this series is in operation the motors will be cor cted in parallel andthe car will be caused to move forward. 0 indicates the contacts of the third series on said par- They are *so con nected, that when in operative engagement with theirbrushes, the motors will be connected in'series and the car will be caused to move backward. The contacts of the'fou 'rth set on the cylinder 59 are indicated by c and are so connectepl together that when theyare in operative engagement with their brushes the motors will be connected in parallel and the car will be caused to move backward. The method of connecting up the binding posts 68 extend.

the contact. plates in each of the four series just mentioned is shown in diagram in Fig. 7.

62 indicates a brush supporting insulating plate or block arranged longitudinally of the frame 1 and secured thereto. 63 arebrush holders secured to the said block and. arranged'to hold their respective brushes so that their contact surfaces will be in the planes of rotation of the contacts on the series parallel reverse cylinder. 64 are projecting arms on the said brush holders. 65 are spring plates secured to the said arms and adapted to hold the brushes 66 so that they will yieldingly engage their respective contact pieces on the cylinder 59.

67 are flexible conductors secured between the brushes'Gti, the brush holders and the springs 65. They are made of copper or -other metal which is a good conductor of electricity, and are adapted to provide good electrical contact between the brushes and their holders.

68 are binding posts on the brush h0lders 63. v

' 69 are apertures in the frame l'through which the conductors which are secured in 69' are apertures in the said frame through which the conductors which are secured to the binding posts 44 extend.

In order to prevent the rotation of the series parallel reverse switch 55 excepting when the current is cut offfrom the motor,

or in other words, when the controller switch 5 is rotated into its off position and likewise to prevent the rotation of the controller switch 5 excepting when the switch is in. one of its fouroperative positions, I provide an interlocking device between the

shafts

8 and 56. f r

70 is acam disk secured to the shaft 8. 71 is a recess in the periphery of said disk.

72 is a disk secured to thev shaft 56 and having four sockets 73 therein.- 74 is a locking pin mounted in

bearings

75, 76 carried by .the end wall 3. 77 is an anti-friction roller mounted at one end of said locking pin Tet and adapted to engage with the periphery of the cam disk 70 on the shaft 8.

78 is a. spring abutting at one end against the bearing 7 6 and at its other end against a'shoulder on the locking pin 74. The normal tendency of this spring is to force the locking pin toward the axis of the shaft 8. hen the controlling switch 5 is in its off position the roller 6 is forcedinto the recess 71 on the disk 70 and the other end of the locking pin is withdrawn from the disk 72. so that the series parallel reverse switch may be rotated. It will be noted that the controlling switch 5 cannot be rotated until the switch 55 has been turned so that one of the sockets 73 on the disk 72 is positioned to receive the end of the locking pin 74:.

79 is a wheel secured to the shaft 8.

80 are a series of recesses or notches in its periphery corresponding in number to the number of )ositions of adjustment for which the controller switch is adapted plus one.

81 is an anti-friction roller carried by one arm of the bell crank lever 82, which is pivoted at 83 to the end wall 3. The roller 81 is held in engagement with the periphery of the wheel 79 by means of a spring 84 secured at one end to the arm 85 of'the bell crank lever and at its other end to the lug 86 on the end wall 3. This arrangement of parts insures that the switching cylinder 5 will be held against rotation by a sufiicient force to prevent the accidental rotating of the said cylinder by jarring or the like and that the control which each particular recess 0r notch controls will be maintained until sufiicient power has been applied to the shaft 8 to force the roller 81 out of said notch. t

Referring to F igs; 6 and 7'the current from the line Lenters the controller through the brush 27. From the brush 27 it is conof the said resistance is connected by a con p erases ductor33 to the brush 33. The intermedi- M indicates the conductor which leads from the conductor 33' to the motors.

The energizing coils for the magnets 45, 4.6 are wound oppositely on their

respective cores

45, 46 and these coils are connected in parallel with the resistance coils R. This method of connecting said coils insuresthat they will be effective in blowing out the arcs between any of the series of brushes which are connected with the resistance andtheir commutating segments: And the said energizing coils are wound in order to so magnetize the parts of the controller mechanism that the pole piece 47 as an entirety, will be of one polarity While the

end pieces

2, 3 and the frame 1 with its

projections

21, 22 will boot the other polarity. I

Assuming that, as shown in Fig. 6, the pole piece 47 and its extensions constitute the north magnetic pole of the magnetic circuits, the lines of force passing through the magnetic cores and the said pole piece'meet in the center of the latter and are compelled to find their return circuits through the shortest pathsof the main frame 1 and its

end walls

2, 3, which may be considered the south pole of the magnetic circuit. The lines of force "which blow out the arcs between the

brushes

29, 30, 31, 32"and 33 and their respective commutator segments pass from the extended portion 52-of the pole piece 47 to the shaft 8 and thence through the

end pieces

2, 3 to the

magnet cores

45, 46. The lines of force leading from the said projection 52 to the commutating cylinder arrange themselves so as to blow outthe arcs occurring within their field on lines substantially parallel to the axis of the cylinder.

The lines of magnetic force which cross the arcs formed'by the brushes 27 28 and 34,

'35 run parallel to the axis of the commutating cylinder and are carried in such direc- 'tions as to force the arcs occurring within their field radially outward from the cylinder and away from the brushes. This blowing out of the arcs on .linesradially of the cylinder materially increases the life of-the showing flame away from the brush surface instead of along it, the flame or spark has less opportunity to attack the contact surfaces and is not forced violently against the insulations. As the arcing at the

intermediate brushes

29, 30, 31,- 32 and 33 is in no wise-as severe as that at the other four brushes, the use of a magnetic field in which the lines of force do not run parallel to the axis of the commutating cylinder will suflice for all practical purposes.

While in the diagram in Fig. 7 Lhave shown but two motors in thecontroller circuit, it will be understood that my invention may be employed for controlling the current to any number of motors. The only change necessary where more-motors are ,used is the addition, of more contacts and brushes for the series parallel reverse switch. .F or illustration, in Fig. 8 I have shown in diagram a system of wiring where three motors are controlled by a current switchin and resistance controlling mechanism em odying my improvements and it will be seen that the mere addition of contact segments in each series of contacts 0, c, 0 and 0 of the series parallel reverse-switch is the only change over the construction indicated in Fig. 7 in diagram which is necessary.

It will be-seen that the sets of movable contact members on the series parallel reverse switch cylinder are so arranged that the sets for connecting the motors in series ahead and series reverse are adjacent to each other and'that the sets for .-connecting the motors in parallel ahead and parallel reverse are outside of the sets for connecting the motors inseries. This arrangement permits of the movement of the handle from the ofi' position first to the series position then to the parallel position for the same direction of travel so that the operator becomes accustomed always to turn the series parallel reverse switch in one direction for forward motion of his car,.and in the opposite direction for the rearward travel of his car. The final break ofthe circuit within the current switching and resistance controlling mechanism occurs at the pairs of stationary brushes 27-28 and 3ft35 at the opposite ends respectively-of the commutator switch 5. The disadvantageous arcing effect incident to the breaking of the elecat a single contact.

I claim- 1. In a controller for electrical apparatus the combination of a current switching and resistance controlling-mechanism, the recontrolling mechanism, and having their.

energizing coils connected in, parallel with theresistance, substantially as set forth.

2. In a controller for electrical apparatus the combination with the resistance. coils,

of a series of stationary contacts connected therewith, a series of movable contacts for engaging with said stationary contacts sucoessively and the-blow-out magnets arranged at either end of the series of stationary contacts and having their energizing coils oppositely wound on their respective cores and connected in parallel with the resistance, substantially as set forth.

- 3. In a controller for electrical apparatus, the combination of a current-switching and resistance-controlling mechanism, a casing in which said mechanism is mounted, re-

sistance controlled by said mechanism, and the blow-out magnets arranged near either end of said mechanism and having a common core and their energizing coils connected in parallel withsaid resistance.

4. In a controller for electrical apparatus, the combination with the resistance coils, of a series, of stationary contacts connected therewith, a series of movable contacts for engaging withsaid stationary contacts, and

stationary blow-out magnets for extinguishing the arcs formed at'all of said contacts, mechanically independent of the movable contacts and having their energizing coils connected 'in parallel with said resistance coils. I

5. The combination incontrojller for electrical apparatus .of the framework made of magnetizable metal, the pole piece arranged longitudinally between the end walls thereof, the magnet cores at the opposite ends of said pole piece and the pole pieces arranged transversely of and secured to said frame work between its ends, the latter pole pieces and the frame forming the return circuits for the lines of force which emanate from the longitudinally arranged pole piece, substantially as set forth.

6. The combination in a controller for electrical apparatus of the frame work made of magnetizable metal, the pole piece extending between the end walls ofsaid frame and having inwardly extending plates or projections formed integrally therewith, the magnet cores arranged'at the opposite ends of said pole piece, and the plates or pole pieces arranged transversely ofand secured to the frame and on either side ofsaid inward projections on the longitudinally arof said stationary contacts, and the pole 1 cores, sai

ity to the said projections on the first de-- scribed pole piece.

8. In a controller for electrical apparatus, the combination with the frame work formed of inagnetizable metal, afseries of pairs of electrical contacts arranged therein, each pair comprising a movable member and a stationary one, of blow-out magnets arranged at either end of said series of electrical contacts having a pole piece extending between their respective cores and provided with integrally formed projecting plates which extend between the adjacent pairs of electrical contacts at either end of saidseries', substantially as set forth.

9. The combination in an electrical apparatus with the frame work-and a series of pairs of electrical contacts arranged therein,

each pair comprising a movable and a stationary member, of blow-out magnets arranged at either end of said series of electrical contacts and having a pole piece extending be-' tween their cores, said pole piece having an inward projection at either end thereof extending between the pairs of stationary members at the opposite end of said series of electrical contacts and an inward exten sion arranged adjacent to and substantially parallel with the contact surfaces of the in termediate stationary members of the series of electrical contacts, substantially as set forth.

10. In a controller for electrical apparatus the combination with the series of pairs of electrical contacts,- each'pair comprising a movable and a stationary member, of blowout magnets arranged at either end of said series of contacts and having a pole piece extending between their cores and provided with projections which extend between the pairs of stationary contacts at the opposite ends ofsaid series of electrical contacts and.

with a'T shaped projection arranged to have its longer arm be adjacent to and substantially parallel with the contact surfaces of the stationary members intermediate of the two pairs of stationary contacts at either end of said series, substantially as set' forth.

11. In a controller for electrical apparatus, the combination with a series of pairs of electrical contacts each pair'comprising'a movable and a stationary member, of the oppositely wound blow-out magnets arranged at either end of said series of elec trical'contacts and having a longitudinally arranged Cpole piece exending between their pole piece having ntegral projections arranged to extend between .each

member of the pairs of stationary members at either end of the series of electrical contacts, and the pole pieces arranged on opposite sides of said pairs of. stationary members at either ,end of the series of electrical contacts adapted to be of-opposite polarity to the longitudinally arranged pole piece, whereby the lines of force in the magnetic fields set up between saidextensions on said longitudinally arranged pole piece and their cooperating pair of pole pieces respectively, will run substantially parallel to the contact surfaces of the stationary contact members in their respective fields, substantially as 'set forth.

12. In a controller for electrical apparatus the combination of a controller switch having a series of electrical contact seg 'ments thereon, a series of stationary contact members with which the said segments on the controlling switch are adapted to engage, the stationary contacts being connected up substantially as described whereby the final break of the circuit when the current is cut otfwill occur between the.

' either end of the series, the oppositely woundblow-out magnets arranged near either end ofthe series of stationary contact members and having a pole piece longitudinally arranged between their respective cores, said pole piece, having projections at either end which extend between the contacts of each pair of stationary cont-act members at opposite endsof the series of contact members, and pairs of pole pieces arranged transversely of said switching cylinderon either sideof the said end pairs of stationary contacts, whereby the lines of force in the magnetic fields in which the arcs occur when the current is entirely cut out, run in lines substantially parallel tothe axis of said cylinder, substantially as set forth. 1

13. In a controller for electrical apparatus, the combination of a controller switch having aseries of contact segments thereon, a series of stationary contacts'with which the said segments on the controlling switch are adapted to engage respectively, the stationary contacts being connected into the circuit substantially as set forth, whereby the final break of thecircuit when'the current is cut off will occur between the members of-the pairs of stationary contacts and their re-' spective segmcntsat either end of the series, and the blow out 'magnets'associated with said stationary contacts.

14. In a controller for electrical apparatus, the combination of a rotary controller switch having a series of contact segments thereon,-

(a series of stationary contact segments with which the said segments on the controlling switch are-adapted to engage respectively, the stationary contacts being connected in the resistance circuit substantially as set forth, whereby the final break of the circuit when the current is c ut ofi will occur be- J erases and the "blowout magnets arranged near either end of the said series of stationary contacts.

15. In a controller for electrical apparatus, the combination of a controller switch having a series of contact segments thereon, a series of stationary contacts with which the said segments on the controlling switch are adapted to engage respectively, a blow-out magnet, and a pole piece. for saidblow-out magnet extending longitudinally of said series of said stationary contacts and having a series of integrally formed projections extending between saidhstationary contacts to the region in which arcs occur between them and the movable contact segments 16. In a controller for-electrical apparatus, the combination of a controller switch having a series of contact segments thereon, a series of stationary contacts with which the said segmentson the controlling switch are adapted to engage respectively, and a blowoutmagnet-having a pivotally mounted pole piece extending longitudinally of said series of stationary contacts and having a series of integral projections extending between said stationary contacts to the region of arcing between them and the movable contacts.

- 17. In a controller for electrical apparatus,

the combination with a casing, a controller.

switch mounted therein and carrying a series of contact segments, and a series of'stationary contacts with which said movable segments are adapted to engage respectively, of a blow-out magnet having a pole piece ex- 2 tending longitudinally of said stationary contacts and provided with an integral projection adapted to lie adjacent tothe arcing region of certain of said cooperating pairs of contacts, and a series of integral projections arranged to extend between certain of said stationary contacts to the region of arcing, and pole pieces carried bysaid frame andarrang'ed-to extend between certain of said stationary contacts into the region of arcing-and to cooperate withthe adjacent,"projections carried by the 'pole piece for the blow-out magnet.

c 18. In a controller for electrical apparatus; the'combination with a framework and cur- 1 the combination with a framework and-cur rent switching and resistance controlling :mechanism mounted therein, of a blow-out ranged tobe moved into position between the said coils, and means for holding the pole piece in the latter position, substantially as set forth.

20. The combination in a controller for electrical apparatus, of a rotary shaft of.

polygonal cross section, insulating facing plates upon the sides of the said shaft, a cylindrical sleeve surrounding the shaft and insulating plates, conveXo-plano metallic plates interposed between the insulatingplates and the sleeve, and resting flatly against the said insulating plates, means carried by the sleeve for forcing the said conveXo-plano plates against the insulating plates, contact segments carried by the sleeve, and stationary contact brushes adapted to engage the said contact segments.

21. The combination in a controller for electrical apparatus, of the rotatable shaft polygonal in cross section, the insulating fact ing surrounding said shaft, the sleeve disposed about the shaft and clamping plates interposed between the insulating facing and the sleeve, contact segments carried by the sleeve, and stationary contact brushes adapted to engage with the contact segments.

22. The combination in a controller for electrical apparatus, of a rotatable shaft of polygonal cross section, a sleeve surrounding said shaft and having a cylindrical interior surface, means interposed between the sleeve and shaft for-preventingrelative rotation of the sleevewlth respect to the ,shaft and for securing the sleeve to the shaft, contact segments carried by the sleeve, and stationary contact brushes adapted to engage with the said contact segments.

23. The combination in a controller for electrical apparatus, of a rotatable metallic shaft of rectangular cross section, a hollow rectangular insulating sleeve snugly fitting over the said rotatable shaft, a sleeve surrounding said insulating sleeve having an interior cylindrical surface, clamping plates bearing upon the insulating sleeve, means carried by the outer sleeve for forcing the clamping plates against the insulating sleeve, contact segments carried by the outer sleeve, and stationary contact brushes adapted to engage with the contact segments.

The combination in a controller for electrical apparatus, of a rotatable shaft, two sleeves mounted upon the shaft and insulated therefrom and from each other, two contact segments carried by one of the sleeves and two'stationary contact brushes coact-ing therewith adapted to provide two breaks in the circuit as the controller is turned to the off position, a plurality of contact segments mounted upon the other sleeve, a plurality of contact brushes suitably connected with resistance and adapted to engage with the said contact segments to vary the resistance in the circuit, two of said plu rality of contact segments being adapted to engage with the said contact segments to break engagement with their corresponding contact brushes simultaneously with the contact segments upon the first mentioned sleeve, said two contact segments being mounted at the end of the second sleeve farthest removed from the said first mentioned sleeve.

25. The combination in a controller for electrical apparatus, of resistance coils, a

series of stationary contacts connected there-- with, a series of movable contacts for engaging the said stationary contacts, a pair of arc dividing contacts, a pair of movable contacts mounted rigidly with the said series of movable contacts and adapted to engage with said are dividing contacts, means for blowing out the arcs formed between said stationary and movable contacts, a frame work of plates ofinsulating material forming chambers around the places where the said arcs occur and mounted pivotally on an axis parallel to the axis about which the said movable contacts rotate, the insulating chambers formed about the arc dividing contacts being provided with openings through which the arc is adapted to be blown, and the insulating chambers formed about the resistance varying contacts being closed upon all sides.

In testimony whereof I ailix my signature in presence of two witnesses.v

FRANK L. SESSIONS. Witnesses:

1 CARIZ D. SLoo'rnMYER,