US998662A - Circuit-controlling device. - Google Patents

Description

J. B. WIARD. CIRCUIT CONTROLLING DEVICE. APPLICATION FILED MAR-25,1907.

Patenmd July 25, 1911 JJVVENTDH JOHN B.' HARD. BY t v'sjzzy'wssza' UNITED STATES PATENT OFFICE.

JOHN B. WIARD, 0F LYNN, MASSACHUSETTS, AS S IGNOB TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

CIRCUIT-CONTROLLING IlEVICE.

Specification of Letters Patent. Application filed March 25, 1907. Serial No. 364,255.

Patented July 25, 1911.

To (:71 whom it may concern:

Be it known that I, JOHN B. VVIARD, a

citizen of the United States, residing at Lynn. county of Essex, State of Massachu setts, have,inventei.l certain new and useful Improvements in Circuit-Controlling Devices, of which the following is a specification.

This invention relates to devices for controlling electric motors and has for its 0!)- jett the provision of means whereby an elu-trie motor may he started and brought to running peed in a reliable, safe and ellieient manner.

vThe invention relatesmore particularly to lie eontrolling of motors which operate fluid pressure generators. sueh as blowers, pumps and the like, one of the objects being to provide a cireuit controlling switch which is actuated by fluid pressure. l

My invention linds a special application in the starting of single-phase motors which have ditl'erent conne tions for starting and lhe press-lire-operated switeli i ate with the starts,

the pressure tln-re't'rolp lwiltaethate the switch, thearrangena-nt being! such that only a small )(ii'tir:n 1t',tli: lluid delivered from the generatorfarts upon the switeh. 'hen the motor i'eaehes; therequired speed, the siviteh cuts out the starting windings leaving the motor directly eol'meeted to the line. I i i i -ol" an inrhn-tion motor ha ving a main stator winding; It and auxiliary or starting windlug 12 and t1 The rotor It) drives, by means of a hell It or Ill any desired male neix a fluid pressure generator, such as a blower-l5, disehar;,5in s into a tank [6, there lit-lug preferably a check valve between the blower and the tank. The pressure-operated switeh l'or eontrollilfg the starting of the, motor is tapped into the pipe I? between the generator and the tank so as to makeeonnnunication with the generator.

'1 he tvxiteh consists of a tube or cylinder 18 of any desired material, provided with a piston or plunger t!) moving freely therein.

In the accompanying l'lrawi'ng, in which The cylinder is closed. at one end by a plug 20 screwed therein and provided with a. longitudinal passage lmving a valve seat 21. A nipple 22, which screws 'into this plug is also provided at one end with a valve seat 23, while at its opposite end are screw threads for tapping into the pipe 17. A ball valve 24 is arranged to play between the two valve seats 21 and 23, so that when thereis a pressure in the pipe 17, the ball will go up to the seat 21, while when the pressure is reduced it will return by gravit to the seat When the ball is on the seat 21 the passage to the cylinder is not entirely closed, there beiing small leak-holes or vents 25 in the valve seat which permit the air to leak into the cylinder. X similar arrangemet may be made in the valve 123. The upper end of the cylinder is closed hjv an insulating block 26 carrying binding posts QT and 28 fornnng the tel-annals oi eontae'ts 29 and 30 respectively. These contacts are normally bridged by a plunger eontact Ell preferably conical Ht shape and provided with a stem :52. which slides in the sleeve 33 serewed into the insulating block an. A sprin g 3t, engaging nuts on the end of the stem. forces the plunger into the position shown in Fig. l, in which thecontaets 2U andflt) are bridged. When the piston Ill reaehes the upper end of the cylinder, it engages the end of stem 33 and pushes the (UlIttHL' The operation of iniydeviee is as follows: -\\'h en the motor eircuit is closed at switch 35, the motor will be operated wi h the starting windings l2 and 13 in circuit, so as to make a three-phar-se winding for starting. The motor drives the generator 15 thereby delivering Hold to the tank m. The pr ssure from the generator immedialel hits the ball valve 24 against. the seat 21, closing the passage to the cylinder with the exception of the'leak vent 25. The "aid will therelore leakinto the. eylinder and gradually raise the piston. When the lat,- ter rem-hes the stem 33, it will move it, upward and open the circuit; of the starting windings. 'Ihe plunger having reached the switch, the pressure in the cylinder quickly rises and becomes suhslantla ly equal 'to the pressure in the main. 'I here being then pranztieally no dill'erenee in pressure between the plunger contact upward so as to break upward limit: of its travel and opened the the cylinder and the main, the ball will drop by its own weight and the apparatus will be in condition for the plunger to drop im mediately when the pressure in the main falls. When the blower 15 stops the piston 19 will drop immediately andthe spring 32 will cause the contacts 29 and 30 to be' bridged by the contact 31 thereby throwing in the starting windings.

t. will be seen that I ave provided a very simple and efficient means for changing the motor connections from starting to running, \\hich will operate automatically and positively. e i

It is clear, of course, that my invention is not limited to the particular type of motor herein shown and described, nor, to the other details of construction or arrangement of parts herein set forth, since many modifications of my device will suggest themselves to those skilled in the art without departing from the spirit of my invention, the scope of which is set forth in the annexed claims.

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

1. The combination with an electric motor having difl'erent. connections for starting and for running, of a fluid pressure generator operated by said motor, a switch for establishing running connections of the motor, a

cylin er "communicating with the generator,.

and a piston movable independently of-said switch and arranged to on age the same.

2. The combination with an electric motor, of a fluid pressure generator operated thereby, a tank for the fluid, a switch for establishing running conditions for the motor, and means for operating said switch comprising a cylinder connected between the generator and the tank, and a piston therein movable independently of said switch and arranged to engage the same at a predetermined point in its travel.

3. The combination with an electric motor of a fluid pressure generator operated thereby, a tank forthc fluid, a switch for establishing running conditions of the motor, means for operating said switch comprising a cylinder connected between the generator and the tank, a piston therein arranged to engage said switch and movable independtor, of a fluid pressure ently thereof, and means for varying the area of the passage to the cylinder.

4. The combination with an electric motor of a fluid pressure generator operated thereby, a tank for the fluid, a switch operating mechanism therefor comprising a cylinder connected between the generator and the tank, a piston therein arranged to operate the switch, and a valve controlled by the generator pressure for reducing the area of the passage to the cylinder.

5. The combination with an electric motor of a fluid pressure generator operated thereby, a tank connected with said generator, a switch for establishing running conditions of the motor, means for controlling said switch comprising a cylinder connected between the generator and the tank, a piston therein arranged to engage the switch, and a valve controlled by the pressure from the generator for varying the area of the passage to the cylinder.

6. The combination with an electric mothereby, a tank for the uid, a switch, operating mechanism therefor comprising a cylinder connected between the generator and the tank, a piston in said cylinder movgenerator operated able independently of said switch and arranged to operate the same at a predeterniined point in its travel and means whereby less than the entire discharge of fluid from the generator is admitted to the cylinder.

- 7 The combination with an electric motor having different connections for starting and running, of a fluid-pressure generator operated thereby, a tank for the fluid, a

'90 switch for establishing running connections therein arranged to engage said switch, and means controlled by the generator for vary-'4 ing the area of the passage to the cylinder.

In witness whereof, I have hereunto set, my hand this twenty-first day of March,

JOHN B. WIARD. VVit-nesses JOHN A. MoMANUs, Jr., I'IENRY O. Wns'rnNnARP,

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