US1388632A - Means for regulating the flow of fluids - Google Patents

Description

P P. DEAN.

MEANS FOR R EGUI ATING THE FLOW' OF FLUIDS. APPLICATION FILED FEB. 10, 1919.

1,388,632,- Patented Aug. 23, 1921.

INVENTOR.

A TTORNEY PATENT OFFICE. 1

PETER I. DEAN OF NEW YORK, N. Y.

MEANS FOR REGULATING THE FLOW OF FLUIDS.

Specification of Letters Patent. Patented A g. 23 1921 I Application filed February 10, 1919. Serial No. 276,008.

I To all whom it may concern:

' .tain maximum level.

Be it known that I, PETER P. DEAN, a sub- 'ect of the King of England, residing at liew York, in the county of New York and State of New York, have invented new and useful Improvements in Means for Regulating the Flow of Fluids, ofvwhich the following is a full, clear, concise, and exact description, reference being had to the accompanying drawing, forming a part of this specification.

This invention relates. to means for controlling the supply of fluids to reservoirs to maintain the fluid level in the latter within prescribed limits. 5

Where such control is desired it is now the practice to provide for supplying fluid at a given rate when the fluid within the reservoir falls to a certain level and to discon tinue the supply when the fluid attains a cer- The rate at which fluid is supplied-is constant irrespective of the rate at which fluid is discharged from the reservoir and where it is desirable to confine the fluctuations in fluid level to a narrow range, as is frequently the case, such method of control is impracticable.

The present invention has among its objects to provide simple and eflicien't control means insuring a supply of fluid approximately proportional to the discharge of fluid from the reservoir thereby enabling the variations in level in the reservoir to be confined between close limits.

Various other objects. and advantages of the invention will hereinafter appear.

The accompanying drawing illustrates schematically and diagrammatically one embodiment of the invention and the same will now'be described, it being understood that theinvention is susceptible of embodiment in other forms without departing from the scope of the appended claims.

Referring to the drawing, the same showsa tank 1 to be supplied with fluid from any suitable source through a supply pipe 2, said pipe having therein a valve 3 operable to alternatively close and open the passageway through said pipe and to graduate the supply of fluid to the tank, said valve being provided with an operating motor M connected thereto'through suitable gearing 4. In practice it is preferredto employ for the valve, a motor drive of the type disclosed in my prior Patent N0. 1,245,574, Nov. 6, 1917, but it 1s deemed unnecessary to illustrate, the same herein as other forms of drive may be employed.

The motor M is shown as having an armature A and a series field windings F, said motor being operable in one direction to open the valve and in a reverse direction to close the same and being provided with a pair of combined main and reversing switches 5 and 6. Each of the switches 5 and 6 is of the double pole type and said switches are respectively provided with electromagnetic operating wlndings 7 and 8 selectively energlzable by a switch 9'. The switch 9 comprises a contact arm 10 engaging a segment 11 and movable in opposite directions from an lntermediate position to selectively engage contacts 12 and 13 and bridge the same with the segment'll. The arm is biased to its intermediate position by springs 14 and 15 and is operable in opposite directions by a small reversible torque motor M having an armature a and a shunt field winding f, said arm being restricted to movement between contacts 12 and 13 whereby said motor is stalled in either contact engaging position of said arm. The arrangement is such that when the arm 10 engages contact 12 it completes the energizing circuit of switch 5 to start the valve operating motor M in one direction and such that when said arm en gages contact 13 it completes the energizing circuit of switch 6 to start said motor in a reverse direction. Further, the arrangement is such that disengagement of the arm 10 from either contact 12 o. 13efi'ects denergization of the closed switch to immediately disconnect the motor M from circuit. Accordingly the switch 9 affords means whereby the valve operating motor may be set in operation in either direction for opening and closing the valve to varying degrees determined by thetime during which switch 9 is maintained in an extreme position, or in other words,*determined by the duration of torque of motor M.

The motor M has its armature connected in a Wheatstone bridge including resistances R and R, forreversals of the flow of current through said armature and has its field connected in circuit for a unidirectional flow of current therethrough. The resistance R is connected to a series of contacts 16 to 21 so regulate the supply of fluid to the tank as engageable by a sliding cross head 22 to be individually bridged with a segment 23 continuously engaged by said crosshead. The crosshead 22 is connected by a rope or cable 24 with a float 25 arranged within the tank 1 to rise and fall with the fluid in said tank. The resistance R is connected to a series of contacts 26 to 31 engageable by a crosshead 32 to be individually bridged with a segment 33, continuously engaged by said crosshead. The crosshead 32 is mounted upon and operable by a screw threaded spindle driven through suitable gearing 34 by the valve operating motor M. The resistances R and R are of equal values and the steps thereof between their associated contacts are likewise of equal value, said resistances being connected in parallel to a supply line L, L and the armature of motor M being connected between segments 23 and 33 for connection to said resistances through crossheads 22 and 32 to complete the aforesaid \Vheatstone bridge.

Thus assuming a balanced condition of the Wheatstone bridge the several switches would occupy the positions illustrated and under such conditions the valve operating motor M is disconnected from circuit. Then assuming that the valve is at this time either closed or partially-open and that fluid is discharged from the tank tolower its level therein, the float 25 descends to lift the crosshead 22. Such operation of the crosshead, assuming proper circuit connections, unbalances the Wheatstone bridge, causing the motor M too erate the switch 9 for starting the motor in a direction to open the valve. Also, suchoperation of the motor, assuming proper driving connections, sets the crosshead 32 in motion in a direction to follow the crosshead 22, thus tending to restore the Wheatstone bridge to a balanced condi tion for release of switch 9 and arrest of motor M. However, the degree of movement of the crosshead 32 required to restore balanced condition of the Wheatstone bridge is rendered dependent upon the rate of descent of the float and consequent rate of elevation of crosshead 22 whereby with proper gear ratios the valve may be made to to render such supply ap roximately proportional to the discharge fli'oin the tank and hence maintain a substantially. constant level.

The circuit of motor M may be traced from line L to and through the left hand pole of switch 5, by conductor 35 through the motor armature, by conductor 36 through the right hand ole of switch 5, by conductor 37 throug the series field F to line L or from line L b conductor 38 to and through the left han pole of switch 6, by-conductor 36 through the motor armature, by conductor. 35 through the right hand pole of switch 6, by conductor 37 through the series field winding F to line L. Such connections, as will be apparent, provide for reversals of the flow of current through the motor armature while insuring a unidirectional flow of current through the field. The energizing circuit of switch 5 may be traced from line L switches being operated in theusual manner.

-The resistance R has one terminal thereof connected to line L by conductor 48 and its other terminal connected to line L, by conductor 49, while the resistance R is also connected between conductors 48 and 49. The armature of the motor M has one terminal connected by conductor 50 to segment 23 and its other terminal connected by conductor 51 to segment 33, while the field of said motor has one terminal connected by conductor 52 to conductor 48 and its other terminal connected by conductor 53 to con ductor 49. Thus the direction of flow of current through the field of motor M is always the same while the direction of flow of current through the armature is determined by the Wheatstone bridge. When the crosshead 22 is raised above crosshead 32 current passes throu h the armature in'one direction and when t e relation of the crosshead is reversed the direction of flow of current through the armature is also reversed.

It is, ofjcourse, to be understood that the above described embodiment of the invention is susceptible of various modifications including the substitution of a polarized relay for the motor operated switch.

What I claim as new and desire to secure by Letters Patent is:

1. The combination witha valve and a motor for operating said valve to varying degrees, of starting and stopping means for said motor, said means being responsive to changes in the fluid level within the reser-' voir for starting said motor and including means rendering the duration of operation of said motor dependent upon the degree ofchange in fluid level.

2. The combination with a valve for con-. trolling the su ply of fluid to a reservoir anda motor or operating said valve to varying degrees, of startin and stopping means for said motor including a float conment rendering the duration of operation of said motor dependent upon the degree of operation of the former element.

3. The combination with a valve for controlling the supply of fluid to a reservoir and a motor for operating said valve to varying degrees, of starting and stopping means for said motor including independently operable control elements, one of said elements being float controlled and respon' sive to variations in the fluid level within the reservoir to start said motor and the other of said elements being operable to stop said motor after operation for a varying length of time dependent upon the degree of movement of said first-mentioned element.

4. The combination with a valve for controlling the supply of fluid to a reservoir, of a motor for operating said valve to varying degrees for graduation of the supply and control means for said motor to eltect vary mg operatlons thereof according to the rate of discharge from the reservoir, said means including coacting devices; one having a float to render the same operable in response to variations in fluid level within the reservoir and the. other being operable by said motor in unison with said valve.

5. The combination with a motor operated valve for controlling the supply of fluid to a reservoir, of control means for said motor operated valve including a \Vheatstone bridge, a motor operated switch connected therein, a float operated resistance varying device for said bridge and another resistance varying device for said bridge operatively connected to said motor operated valve.

In witness whereof, I have hereunto subscribed my name.

PETER P. DEAN.

Images