US902061A - Motor-controller. - Google Patents

Description

H.'F. EL SHOFF. MOTOR CONTROLLER. AgrLmA Tlon FILED .'I UNE so, 1006.

Patented Oct. 27,1908.

INVENTOR WITNES s55 citizen of the United N1TED STAT is AT ;EENRY EL SHOFF, OF NORWOOD, OHIO, ASSIGNOR TO ALLIS-OHALMERS COMPANY, A (lOR- enrich.

PORATION OF NEW JERSEY, AND THE BULLOCK ELECTRIC MANUFACTURING COMPANY,

' A oonronn'rlon oronio.

moron-commence.

Patented Oct. 27, 1908.

implication filed June 30, 1906. Serial No. 324,175.

To all whom it may concern:.

Be it known that I, HENRY Ff ELsHoFF,

States, residing at Nor- 1 wood, in the county of Hamilton and State of Ohio, have invented certain new and useful Improvements in Motor-Controllers, of which the following is a full, clear, and ex act specification.

My invention relates to controllers.

In the patent to Dunn No. 797,271, granted Aug. 15, 1905, there is described a multiple-voltage controller in which afixed resistance is temporarily out into the arms.- ture circuit whenever the connections of the armature are changed from one set of mains to another. This resistance, now com-- mcnly known as a butler resistance, serves to prevent excessive surges of current through the armature when the impressed Volta e thereon is either increased. or decreased. %n the Dunn atent this buffer resistance is in-v sorted in circuit by raising one of the'contact fingers from the controller drum, thereby.

ggening a short-circuit around the resistance. iis is found to be unsatisfactory, because of the double movement of the drum and the finger and because there is only a point or line contact between the finger and its co" crating contact segment on the drum. The present invention is intended to overcome this difliculty by having the buffer resistance insorted by a switch so arate from the controller drum. and its fingers, ut operated hy thedrum in its rotation. l

one aspect my invention comprises a controller consisting of a rotatable drum and a switch arranged to be 0 )ened by said drum when the latter s move between certam positions, together with means which tends close said switch and clockwork. mechanism ror retarding such closing.

ln s more specific aspect my invention comprises, in combination, a multiple-voltage controil er, a motor controlled thereby, a resistance in the armature circuit of said motor, a switch normally closed to ehortcircuit said resistance, said switch from the controller drum but arrange to he opened thereby to break said short-circuit whenever the armature connections are changed from one set of mains to smother,

and clockwork mechanism for retarding the closing movement of said switch.

multiple-voltage eration of the device,

ates. of on its periphery. jections are so located that they engage with being crate Other features of my invention will appear hereinafter.

Figure 1 is an elevation of a part of a corn troller embodying my invention, with the casing partly brolien away in order to Show the operating mechanism. Fig. 2 is a section on the line 2-2 of Fig. 1. Fig. 3 is a diegrammatic view SllOWl g a development of the controller.

In the drawings, 31 is the controller drum operable by theusual handle 32.

plicalole to any form of multiple-voltage con:

troller. The controller drum has contact segments 33 arranged to cooperate with the contact fingers 34. to 39 inclusive, to connect For the sake of simplicity the connections of the 0033-.

the armature of motor M to different sets of I the mains 0,5, 0 and d. The drum also has a ring 40 and contact segments 41 arranged to cooperate with contact fingers 42 to 48 in elusive to vary the resistance r in the field circuit of motor M. Mounted on the shaft of the controller drum is a cam wheel 49, on the peri hery of which rides a roller 50 carried b a lever 51. The cam wheel 49 is shown dove oped in Fig. 3, hut in order to show more clearly the opit is shown as it its cam rejections were on its u ese cam mand move roller 50 as the armature comicstions are being changed from one set of mains to another. Lever 51 is connected to a switch 52 by a rod 53 and link 54. A spring 55 tends to close theswitch 52 and-hold it closed. The bar 53 is provided with teeth 56 to form a rack, some of these teeth Being cut away, at 57 for a purpose hereinafter explained. Arranged to engage with the teeth 56 is a inion 58. Integral with pinion 58 or otherwise firmly attached thereto is a ratchet wheel 59, whose cooperating pawl 60 is on a gear wheel 61 mounted to turn on the same axis as the wheels 58 and 59 but not fixed to said wheels. The gearwheel 61 meshes with pinion 62,-ihte rel: or otherwise attached to wheel 63, Wide cooperates with an escape Iper surface in-- .1

connections are varied,

ment 64. The escapement is provided with a weight in order to slow its action. By reason of the pawl and ratchet 59 and 60 the train of gearing or clockwork mechanism retards only the closing movement of the switch 52, its movement in the other direction being free or unretarded. The switch 52 when closed short-circuits a resistance R in the motor armature circuit, but when opened breaks the short circuit to effectively include the resistance in said armature circuit.

When the controller is moved to change the armature connections from one set of mains to another, the cam projections on cam wheel 49 move lever 51 to open the switch 52 and to include the resistance R in the motor armature circuit. During this opening movement of the switch the teeth of rack 56 en age with those of pinion 58 to rotate the wieels 58 and 59. Because of the pawl and ratchet 59 and 60, the rest of the clockwork mechanism remains stationar during this opening movement of the switch 52 and conse uently does not retard such movement. is soon as the change of armature connections has been made, the spring 55 begins to expand to force the switch 52 toward closed position. This movement of the switch, however, is at first retarded by the clockwork mechanism, the amount of this retardation depending upon the rapidity with which the escapement 64 can operate.

When the switch is nearly closed, the teeth 56 pass out of engagement with pinion 58, bringing the cutaway ortion of rod 53 adjacent said pinion. his allows the final closin movement of switch 52 to be unretarded so that a quick engagement of the switch contacts may be secured. In the controller shown the resistance R is included in circuit when the controller passes between positions 7 and 8,14 and 15, 18 and 19, 21 and 22, and 23 and 24, and also when it passes to or fron1 o1f position. Between the positions just mentioned the armature connections are changed from one set of mains to another. Between any other two adjacent positions the controller merely varies the resistance r in the field circuit of the motor. This field resistance is arranged to be increased as the controller is moved forward between those adjacent. positions where the armature connections are not varied, thus increasing the speed of the motor, but to be cut out whenever the armature thus insuring a strong field whenever a higher voltage is imvaried as desired, and

pressed on the armature. I'l desired, instead of having some of the teeth on the rack 56 cut away, one or more of the teeth on pinion 58 may be cut away.

It is obvious that the part of the controller which controls the field resistance may be that the part which controls the armature connections may be adapted to any multiple-voltage system and arranged if desired to reverse the armature current. These modifications as well as many others which readily occur to one skilled in the art may be made without departing from the spirit of my invention, and are intended to be covered by the following claims.

What I claim as new is:-

1. In a controller, a rotatable drum, a switch biased toward closed position but arranged to be 0 ened by said drum when the latter is moved )ctween certain positions, and clockwork mechanism for retarding part of the closing movement of said switch only.

2. In a controller, a rotatable drum, a switch arranged to be opened by said drum when the latter is moved between certain positions, means which tends to close said switch, and clockwork mechanism arranged to retard the first art of the closing movement of said switch but to allow the last part of the closing movement and all of the opening movement thereof to be unretarded.

3. A multiple-voltage controller, a motor controlled thereby, a resistance in the armature circuit of said motor, a switch normally closed to short-circuit said resistance, said switch being separate from the controller drum but arranged to be opened thereby to break said short-circuit whenever the armature connections are changed from one set of mains to another, and a train of gearin with an escapement for retarding the c osing movement of said switch. 1 I

4. A multiple-voltage controller, a motor controlled thereby, a resistance for the armature circuit of said motor, a switch normally closed to short-circuitsaid resistance, said switch being, separate from the controller drum but arranged to be opened thereby to include said resistance in the armature circuit whenever the armature connections are changed from one set of mains to another, means tending to close said switch, and a clockwork escapement for retarding such closure.

5. A n1ultiplevoltage controller, a motor controlled thereby, a resistance for the armature circuit of said motor, a switch normally closed to short-circuit said resistance, said switchbeing separate from the controller drum but arranged to be opened thereby to effectively include said resistance in the armature circuit whenever the armature connections are changed from one set of mains to another, means tending to close said switch, and clockwork mechanism for retarding such closure, but arranged to allow a free opening movement of the switch.

6. A multiple-voltage controller, a motor, controlled thereby, a resistance in the armature circuit of said motor, a switch normally closed to short-circuit said resistance, said switch being separate from the controller drum but arranged to be operated thereby to,

open said short-circuit whenever the arma-, ture connections are changed from one set of; mains to another, and clockwork mechanlsm for retarding part of the closing movement of said sw tch. V

7. A multiple-voltage controller, a motor controlled thereby, a resistance in the armature circuit of said motor, a switch normally closed to short-circuit said resistance, said switch being separate from the controller drum but arranged to be operated thereby to open said short-circuit whenever the annature connections are changed from one set oi' mains toanother, and clockwork mechan- 'drum but arranged to bee ened thereby to include said resistance in t e armature circuit whenever the armature connections are changed from o'ne'set of menus to another,

' means tending to close said switch, and clockwork mechanism for retarding such closure while allowing a free opening movement of I.

the switch.

9. In a motor control system, multiplevoltage mains, amotor, a drum controller for connecting the motor armature to different sets of the mains, a resistance in the armature circuit of the motor, a switch separate from thecontroller and biased to closed position to short-circuit said resistance, means whereby a movement of the controller between certain positions opens said switch, and clockwork mechanism for retarding theclosure of said switch.

In testimony whereof in the presence of two witnesses. i

' HENRY F. ELSHOFF. Witnesses:

GEO. B. SoHLEY, FRED J KINSEY.

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