US843814A - Means for controlling valves or other movable devices from a distant station. - Google Patents

Description

E. M. HEWLETT. MEANS FOR CONTROLLING VALVES OR OTHER MOVABLE DEVICES FROM A DISTANT STATION.

APPLICATION FILED MAY 29, 1908.

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Inventor? Edward M.Hewlett, by Wfi /Att 1v PATENTED FEB. 12, 1907.

UNITED STATES PATENT OFFICE. A

EDWARD M. HEWLETT, OF SCHENECTADY, NEW YORK, ASSIGNOR TO GEN- ERAL ELECTRIC COMPANY, A CGRPORATION OF NEW YORK.

MEANS FOR CONTROLLING VALVES OR OIHER MOVABLE DEVICES FROM A DISTANT STATION.

Specification of Letters Patent.

Patented Feb. 12, 1907.

Application filed May 29, 1906. Serial No- 319,306.

To all whom itmwy concern:

Be it known that I, EDWARD M. HEWLETT, a citizen of the United States, residing at Schenectady, county of Schenectady, State specification.

The resent invention relates to means for contro in electric motors, and particularly motors a apted to 0 erate a va ve or other device arranged to e movable within defined limits. There are many instances where it is desirable to operate one or more valves from a remote station and to have an indication available of the position which the valve occupies at any time. Where the valve and the control-station are far apart, it is advantageous to have the number of wires running between the control-station and the valve as small as possible, not only for the sake of simplifying the s stem, but in order ,to reduce the ex ense of t e installation.

The objecto the present invention is to provide a simple system of control for a motor which shall require only a mimimum number of metal conductors between the control and the valve stations, which shall operate with certainty to cause the motor to move a valve or other member in either direction step by step, and which shall indicate back to the control-station the exact position of the valve or other movable member.

To the above ends the present invention comprises a novel arrangement and organization of parts to be hereinafter described,

and particularly pointed out in the claims.

In the accompanyin drawings, Figure 1 shows 'diagrammatical y a valveoperating system arranged in accordance with the resent invention. Fig. 2 is a detail of an indicator, and Fi 3 shows an automatic circuit-breaker use in the system.

Referring to the drawin s, 1 indicates a pipe-adapted to be opene and closed by means of a gate-valve 2. p

3 is anxelectric motor having a driving connection with the valve-stem 4. This driving connection may take any suitable formf0r example, the connection ma consist of worm-gearing 5, one member 0 which is carried by the armature-shaft and the other member screw-threaded upon the valves indle. At the control-station is a source of e ectric-current supply illustrated as a threewire distribution system made u of the conductors L, L, and L A switch 6 is arranged to connect either of the sup ly-conductors L and L to the conduc or 7, which forms the sole metallic connection between the control and valve sta tions. Included in series with the conductor 7 are the coil 8 of a polarized relay 8 at the control-station, a switch 9 adjacent the valve-operating mechanism and adapted to be actuated by the valve or operating mechanism therefor, and the coil 10 of a polarized relay 11 at the valve-station.

To the movable member 12 of the relay 1 1 is connected the movable member of a double-throw switch 13, which in one posi tion connects conductor 7 to the armature of the motor 3 through the field-winding 14 and in the other position connects this con ductor to the motor-armature through the field-winding 15. The arrangement is such that in one position of switch 13 the motor runs in a direction to open the valve, while in the other position of the switch the motor operates to close the valve.

The operation is as follows: In order to open the valve, the switch 6 is moved into the position wherein it connects conductor L to the conductor 7, and thereupon current flows from supply-conductor L through conductor 7, through relay 8, through switch 9, through rela 11, to ground. The movable member of t e relay 11 is drawn to the left and switch 13 is operated into the position wherein current flows from conductor 7 through the field-winding 14, through the armature of motor, to ground. The motor therefore begins to run and the valve begins to open. After the valve has been opened a predetermined amount a pin 16 on a por-.

ouble-throw and closed until the valve has been entirely opened through a series of steps, these steps being shown on the indicator 18. 'By opening the switch 6 at any time the valve may be stopped in a partially-open position.

In order to close the valve, switch 6 is brought into the position wherein conductor 7 is connected to supply conductor L Current now flows through the conductor 7 in the opposite direction, and the movable members of the relays are swung to the right instead of to the left, and field-coil instead of coil 14 of the motor is brought into action. The motor now runs in the opposite direction and the valve is'closed step by step in the same manner that it was previously opened.

The indicator may take any desired form whereby a step-by-step indication is obtained in synchronism with the step-by-step f opening and closing movements of the valve.

oted double pawl 23.

For example, the indicator may be come posed of a movable graduated disk 19, -copperating with a fixed pointer 20, the disk being provided with ratchet-teeth 21 on the periphery. An arm 22, pivoted at the center of the disk, carries at its outer end a piv- When the arm is moved in either direction from the central position, one of the pawls engages with teeth 21 and carriesthe disk with it. The other pawl, however, is held out of engagement I with the teeth bymeans of one of the pins 24.

. particular purpose.

Therefore when the arm is moved in one direction from the normal position the disk isgiven a clockwise rotation, while upon theother direction of movement of the arm from the central position a counter-clockwise rotation of the disk results.

It will thus be seen that the present invention provides a simple and positive means for opening or closing the valve slowly through a series of steps and making an indication at the distant control-station of the exact position which the valve occupies without the use of more than a single conductor between the valve-station and the control-station.

Although I have described the invention as applied to the operation of valves, it is of course not limited in its application to this What I elaimas new, and desire to secure by Letters Patent of the United States, is- 1. In a system of control, a motor, a re versing-switch, a polarized relay for operating said reversing-switch, a control-station,

a sin le wire conductor and a return connec-' tion etween said motor and relay and said control-station, and means for causing current to flow in either direction through said conductor.

2. In a system of control, a'motor, a reversing-switch, a control-station, a single wire conductor and a return connection between said motor and relay and said controlstation, means at the control-station forcaus ing current to flow in either direction through said conductor, an indicator at the control-i station, a second polarized relay for operating said indicator' and having a-coil in series with said conductor, and means con-- motor, a switch for connecting said conductor to the motor through either field-windin a polarized relay for operating said switc and having a coil in parallel to the switch, and means at the control-station for producing a flow of current in either direction throu h said conductor.

4. n a system of control, a motor havin independent field-windings for forward an reverse rotation, a control-station, a single conductor connecting said control-station to said motor, a switch for connecting said conductor to the motor through either fieldwinding, a polarized relay for operating said switch having a coil connected in parallel to said switch, means at the control-station for producing a flow of current in either direction through said conductor, an indicator at the control-station, asecond polarized relay for operating said indicator and having a coil in series with said conductor, and means controlled by the motor for momentarily interrupting the circuit through said conductor after each predetermined number of revolutions of the motor.

5. In combination, a movable member, a motor for operating said member, a controlstation, 'a single conductor connecting said motor to said control-station, a reversingswitch between said conductor and the motor, a polarized relay for operating said switch and having a coil connected in parallel to said switch and said motor, a circuitbreaker in series with said conductor, means for momentarily opening said circuit-breaker when the said member reaches predetermined positions, and means at the controlstation for causing current to flow in either direction through said conductor.

6. In combination,a movable member, a motor for operating said member, a controlstation, a smgle conductor connecting said motor to said control-station, a reversingswitch between said conductor and the mo- .tor, a polarized relay for operating said switch having a coil connected in parallel to for operating said indicator, said latter relay 10 said switch and said motor, a circuit-breaker l havinga coil in series with said conductor.

in series with said conductor, means for In Witness whereof I have hereunto set my momentarily opening said circuit-breaker hand this 28th day of May, 1906.

when the said member reaches predetermined positions, means at the control-sta- EDWARD HEWLETT tion for causing current to flow in either di- Witnesses:

rection through said conductor, an indicator BENJAMIN B4 HULL,

at the control-station, and a polarized relay HELEN ORFORD.

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