US2090531A

US2090531A - Surgeproof pilot switch

Info

Publication number: US2090531A
Application number: US704196A
Authority: US
Inventors: Charles N Hardin
Original assignee: WILLIAM A EMERSON
Current assignee: WILLIAM A EMERSON
Priority date: 1933-12-27
Filing date: 1933-12-27
Publication date: 1937-08-17
Anticipated expiration: 1954-08-17

Description

Aug. 17, 1937. c. N. HARDIN SURGEPROOF PILOT SWITCH Filed Dec. 27, 1933 ad IIN.

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)P ,rv u@ vut L in HEEEM Patented Aug. 17, 1937 `UNITED STATES SUBGEPBOOF PILOT SWITCH Charles N. Hardin, Sulphur, Okla., assigner o! one-eighth to William A. Emerson, Sulphur,

Okla.

applicatie December e1, 1933, serai No. '104,196

3 Claims.

This'invention relates to a surge-proof pilot switch, one field of use for which is in connection with city water-pumping equipment with a view toV maintaining the water in the stand pipe 5 within a few feet of that recommended by the manufacturer of the equipment. At the same time, it is to be understood that the invention is capable of general use and application and is therefore not to -be limited to the specific purpose mentioned.

A more specific object is to provide a pilot switch for controlling the motor of the pumping equipment and which switch is operable according to the pressure of the water pumped by that equipment.

An important object is to provide such a pilot switch as is controlled by vacuum tube apparatus.

Another important object is to provide a cono struction wherein the time required for the necessary heating and cooling of the cathode is variable and may be regulated, thus giving any desired time lag, and rendering the switch unaected by pressure surges.

'I'he more specific objects and advantages will become apparent from a consideration of the description following taken in connection with accompanying drawing illustrating an operative embodiment. y

In said'drawingz- The view shows the apparatus in electrical diagram.

Referring specifically thereto, alternating current from any suitable source is conducted by wires III to the primary LI of a transformer I2 having secondary wiring or coils at I3 and I4.

For example, primary I I may receive electric cur-- rent of 110 volts, 60 cycles, while the secondary I3 receives electric current of 6.3 volts, .4 ampere and the secondary I4 receives 220 volts, .05 ampere.

Vacuum tubes I5 and IG, for instance of type 237 as used in radio telephony, are shown employed, the cathodes I1 thereof being connected by a conductor I3 from which a conductor I9 leads to the secondary I4. From the same secondary I4, -a conductor 2li leads to a conductor 2| having

coils

22 and 23 therein respectively adapted to actuate and being associated with

relays

24 and 25. From the conductor 2|, conductors 26 and 26' lead to the plates 21 and 21' within the tubes I5 and I8.

The filaments or heaters 23 of the tubes Iii and I3 are connected by a conductor 2l and from the filament 23 of the tube I5 a conductor 33 leads to a contact 3i of a pressure gauge 32. A conductor 33 leads from the filament 23 of the tube I6 to a contact 34 of said pressure gauge 32.' In the conductors 3l and 33, heavy duty rheostats 35 and 3la`are incorporated as shown. A conductor 35' connects conductor 23 to the secondary I3 and from the same secondary a conductor 36, grounded at 31, leads to a movable contact 33 of the said pressure gauge 32. While a pressure gauge has been specifically referred to, yet it is to be understood that the element 32 may represent contacts or a relay in a light sensitive cell circuit or be any other means or lead to any other means of making and breaking an electric circuit at high and low pressure or vacuum.

The

relays

24 and 23 may be a type as manufactured by Struthers Dunn Inc., Philadelphia, Pennsylvania, according to Patent No. 1,646,888. Any other type of relay, however may be used.

It will be realized that when the

coils

22 and 23 are deenergized, the contacts 23h of the relay 24 are closed while the contacts 23a ofthe relay 25 remain in normally open position. A conductor 39 connects one side of both relays and has a conductor 43 leading therefrom while conductors 4I and 4I lead from the other side of each relay. The conductors 43, 4I and 4I are adapted to be operatively connected to the operating motor M of the centrifugal pumping mechanism previously referred to or to the line starter for that motor in the diagrammatic or conventional manner shown, 42 being a line switch having an interlock 43. An actuating coil is provided for said switch 42 at 44.

When the water pressure reaches the low point, the pressure gauge operated by that water, moves contact 33 into engagement with contact 34, causing current to flow through the filament 23 of tube I6. As a result, the cathode of vacuum tube I6 is heated and the coil 23 is energized closing the switch 23 which has the effect of closing the line starter for the motor of the pump, such action being equivalent to pushing an on button of a line starter.

When such motor starts and the pump begins discharging, the pressure is immediately increased by the amount of the friction head which is sufficient in any case to open the contacts 33 and 34, allowing the vacuum tube I6 to immediately cool oil.' and remain idle until the next start is performed.

When the pressure builds up to the high point, the contact 33 engages contact 3I of the pressure gauge, causing a similar action to take place in the relay 2l and vacuum tube i5, which has the effect oi.' moving the starter switch for the motor of the pump to an o position. When such motor stops, the pressure then decreases by the amount of the friction head which opens the high pressure contacts and the vacuum tube I 5 cools off, and remains cool until the next stop is performed. l.

In both of said operations the rheostats 35 determine the time required for the cathode to heat and may be varied, for example, from approximately seventeen seconds to one andonehalf minutes, however, the time necessary for the cathode to cool will remain approximately the same at any setting of

relays

24 and 25 and is approximately nine seconds. Such diierence of time necessary for heating and cooling of the cathode renders the present device successful and not aected by pressure surges.

Attention is called to the fact that the present invention is also adaptable among other uses, to acting as an automatic starter for electric motor driven centrifugal pumps installed in deep wells such as are used in irrigated areas and in the oil fields. For such use,t the time delay periods may be increased over that previously suggested to Cil say to one and one-half to two or more minutes.

This can be accomplished by connecting two or more of the vacuum tubes in circuit in series.

Various changes may be resorted to provided they fall within the spirit and scope of the inven.

tion.

I claim as my invention:-

1. In combination with a control device having a gauge for pressure developed therein, a pressure moveable arm on said gauge, vacuum tubes of the two element type having a common conductor connected to their cathodes, each tube having another conductor connected to the gauge and to their filaments and engageable one at a time by said arm, a conductor connecting the filaments, a conductor having relay coils therein connected to the plates of said tubes, ilrst and second windings, said first conductor branching to the last mentioned conductor through the iirst winding. a conductor connecting the iliaments branching through the second winding to said arm, the closing of one relay operating the device to on position and the closing of the position,

connected to their cathodes, each tube having another conductor connected to the gauge and to their filaments and engageable one at a time by` said arm, a conductor connecting the iliaments, a conductor having relay coils therein connected to the plates of said tubes, first and second windings, said' first conductorvbranching..`

to the last mentioned conductor through the first winding, a conductor connecting the iliaments branching through the second winding to said arm, the closing of one relay operating the device to on position and the closing of the other relay moving the device to oi position, and means to energize said windings, each conductor connected to the filaments having a rheostat therein.

3. In combination with a control device having a gauge for pressure developed therein, a pressure movable arm on said gauge. vacuum tubes-of the two element type having a common conductor connected to their cathodes, each tube having another conductor connected to the gaugeand to their laments and engageable one at a time by said arm, a conductor connecting the filaments, a conductor having relay coils therein connected to the plates of said tubes, said iirst conductor branching to the 'last mentioned conductor, and the conductor connecting the iliaments branching to said arm, and means to supply current, the closing of one relay operating the device to on position and the closing of the other relay moving the device to off position.

CHARLES N. HARDIN'.