US965609A - Electric pump-governor. - Google Patents

Description

U. W. TOWNSEND. ELEGTIRIC PUMP GOVERNOR. APPLICATION FILED JUNE 18, 1900.

Patented July 26, 1910.

2 BHEETS-SHEET l.

m/dfl A/ G W. TOWNSEND. ELECTRIC PUMP? GOVERNOR. myuouron FILED mm: 1a, 1906.

Patented July 26, 1910.

2 8HEETS-SEEET 2.

- UNITED. STATES PATENT orrron.

crrARLEsw. 'rowivsnnnor sr, .LoUIs, mrssouar, nssrenon TO THE WESTINGHOUSE AIR BRAKE COMPANY, OF PITTSBURG, PENNSYLVANIA, A CORPORATION OF PENN-4 r SYLVANIA.

ELECTRIC PUMP-GOVERNOR.-

Specification of Letters Patent. Patented July 26, 1910.

Application filed June 18, 1906. Serial No. 322,194

To all whom itimay concern: V

Bejit known that I, CHARLES W. Town- SEND, a citizen of the United States, resid ing at St. Louis, in the State of Missouri,

have invented certain new and useful Imcrating to open and close the electric circuit to stop and start the motor according to the degree of air pressure produced by the com.-

pressor. v

The principal object of my inventionis to simplify the construction of governors of this type,-.to greatly lessen the cost ofmanufacture and at the same time produce a governor which shall be durable and thor oughly reliable in its operation.

With this object in view, my present form of apparatus is composed of few parts, connected together in a simple and com act design, which may be readily adjuste to operate under any desired service conditions, all as hereinafter more fully described and set forth in the claims. r

In the accompanying drawings, Figure 1 is a side elevation of one form of my improvement, the pressure cylinder being indicated 1n scctronrFw. 2 1m end view of the same; Fig. 3- a sectional view of amodified form of my invention; Fig. 4a side view showing still another modification; and Figs. 5 and (5 a plan and end view respectively of the modified construc tion shown in Fig. 4;.

As shownin Figs. 1 and 2, my improved device comprises a base portion '7, having at or near one end a flange S, on which may 'be mounted a pressure cylinder 10 having movable abutment or piston 11., and an admission port 12 for coinn'uuncatiiig with the ump orreservoir of fluid underlpressure.

he iiston rod 11 which extends out through.

the ange or head 8, has a collar 16 fixed thereon, and another collar 14 mounted for longitudinal movement and adapted to be adjusted by a screw 15' mounted in the upright flange 9 for varying the tension of the coiled spring 17 located between said collars.

vThe switch mechanism for opening and closing the'electric circuit may comprise a bell-crank lever, supported 1n any eon'-.

venient manner, such as pivoted upon a bracket secured to the cylinder head 8, and having a long arm 22 carrying a contact bar 24 for engaging the stationary contact fingers 25 and 27connected respectively to the binding posts 26 and 28 of the electric circuit. The short arm 23 of the bell-crank lever is operated by the movement of the piston rodand is pxreferably provided with a recess engagingt e-fiXed collar 16 on said rod. By means of this construction the switch for controlling the circuit is opened and closed by the movement of the piston,

which is subject to the opposing forces of the fluid-pressure from the pump or rmervoir on one side, and of the'adjustable :spring upon .the other.

In order'to effect a'quick and sudden movement of'the .piston and its rod at the times of opening and closing the switch to cut'out and cut in the pump, a retarding spring 19 is preferably provided, formed of a strip of flexible metal rigidly secured at one end and having an ad ust1ng nut or screw 21 for adjusting the position of said spring. On the strip sprin 19 is formed a hump or projection 20, which is adapted to en age wlth a V-shaped projection 18 on the co lar. 16 of the piston rodand thereby exert a certain additional resistance to the movement' of said rod at'this point of its movement in both directions. Y

The amount of resistance exerted by the .on the spring which en ages the V-shaped projection 18 on the co lar, which amount may be adjusted by means of the adjusting screw .21 to any degree desired. This willdetermine the diiierence between the cutting in pressure and the cutting out pressure of the governor, as will be readily understood.

When the s rings 17 and 19 are adjusted to the desired amounts, and there is little or no pressure in the cylinder, the switch is norma ly closed, as shown in the drawing, and, as the current is turned on,the pump starts to work compressing air and accumtb lating pressure in the cylinder 10 of the governor. As this pressure increases to the degrcc for which the main spring 17 is adjusted, the piston 11 is moved out slightly,

sgJhat-(iheV-shaped' projection engages the hump on the retarding spring, and'the additional resistance-thus ofiered to the movemen't'ofthe piston rod holds the same at this 5 point without-moving the switch until the pump pressure. has increased an additional am0unt,"sufiicient to depress the retarding spring and carry the V-shaped projection 'over the hump 20. As the resistance exerted 1.0

by the retarding spring then ceases the piston moves outwith a quick and positive movement, compressing the main spring 17 and throwing the bell-crank lever to its upper position, thereby opening 'the switch with a-sudden and snap-like action, which '1 prevents injurious arcing at the contact points of. the'circuit.

After the pump stops the pressure in the cylinder 10 falls'and the main spring 17 starts the piston on its return movement, but the li -shaped projection then engages on the other side of the hump 20 of the retarding spring and holds the parts in this position until the pressure in the cylinder acting on piston 11 has vfallen to such a degree that the tension of spring 17 issuiticient to overcome both the fluid pressure and'the effect of the retarding spring, whereupon the pistop, with its rod and collar, move inward with a quick positive action, causing the sud: den movement of the bell-crank lever to close the switch and start the pump. It will be I .noticed that the arm of the bell-crank c'arry-' ing the switch contact'ismuch longer than theone connected. to the piston rod, so that the extent and rapidity of its movement are multiplied to give very quick action.

In the manner above described, the gov- .ernorcontinues to operate to cut the pump in and out, and thereby maintain a certain rangeof fluid pressure in the reservoir.

This form of my device is particularly adapted for use with small potentialcurrents, but for governing motors Working .under heavier currents I prefer the modified formof my improvement shown in Fig.

3 ofthe' drawings. According to this modification, the movable contact bar 24 of the switch is carried by rod 36 of piston operating-against-the spring 37 in the cylinder 34, the admission of fluid under pressure to and its release from said cylinder being controlled by a. small slide valve 30 operated by the piston 11 and governor mechanism previously described.

The. operation ofthis form of my improvement will be readilyunderstood; fluid under pressure from the pump 'or reservoir being admitted through port 12 to valve chamber 29 acts upon the piston 11 and causes the same to move outward with a; quick positive movement, when the pressure I rises to a point sufiicient to overcomeboth the regulating spring 17 and the retarding spring 19. as before described. This moveinent carries the slide valve 30 to such a position asto open wide the supply port- 31 to the cylinder 34 whereupon the full reservoir pressure acting on piston 35 throws the same together with thecontact bar 2L of 'the switch to its outer position and thereby opens-the circuit with a quick and positive movement. Any suitable or preferred form of blowout device may also be employed, if desired, for assisting in extinguishing the arcs at the switch contact points. When the pressure acting on the piston 11 has diminished to the predetermined amount, the regulating spring 17 forces the piston back to its former position with quick and sudden movement, as previously described, and thereby returns the slide valve 30 to suclrposition that the cavity 33 opens communication from the port 31 to exhaust port '32 and releases fluid under pressure from cylinder 34: to the atmosphere, so that the spring 37 immediately returns the piston 35 and closes have illustrated another modification, in.

which an electro-magnet is used forzthis purpose. Th1s construction corresponds substantially with that shown in Figs. 1 and 2,;

except that in lieu of the retarding sprim mechanism an electro-magnet lS',I)1'OVld6 having coils 3;) and 40, and a contact piece or armature 38 carried by thearm 22 of the bell-crank lever. The coils of the electromagnct are located in the motor circuit, as

indicated, so that when the governor is cut in with the circuit closed, the coils are energized and the armature attracted thereto with a certain magnetic pull.

When the pressure acting on piston 11 rises to a point sufficient to overcome the tension of the spring combined with the pull of the magnets, the piston-moves outward and starts the bell-crank lever toward its open-or cut out position. I The instant that the circuit is broken, the pulling effect of the magnets eeases, so that the switch arm 22 is car ried to its open position, indicated in dotted lines, with a quick and positive movement by the excess of air pressure over that of the spring. As the pressure then diminishes the spring operates to close the switch in the usual way, but the instant thatthe circuit is again closed the magnets are energized and thexswitch is then held closed by thecombined force of the spring and magnets. This requires a certain increase in pressure before the switch can again be opened, and the range or difference between the cutti and cutting out pressures is determine by the pull of the magnets, which may be varied by adjusting the position ofthe 'm'agnets and armature with reference to to give any; desired range, and operates with:

a quick and snap-like action to open the circult and cut out the pump when the maxi- 10' mum degree is reached. r

Having now described my invention, what I claim as new and desire to sec-ureby' Lej'.

ters'Patent, isz- A 1. An electric pump governor fi xed ons'aid rod, a coiled spring bearing against said collar, a bell-crank lever having a long arm carrying a contact bar for open- .ing and closing an electric circuit, and a ,2 short arm engaging withsaid fiized collar on the piston IOdu i 2; An electric pump governor comprising a cylinder, pistonv androd, a coiled s ring surrounding said rod, a laterally flexib e re: 25 tardin spring, and a projection carried by the ro for engaging said retarding spring. 3.- An electric pump governor comprising a cylinder, piston and rod, -a coiledspring surrounding said rod, a laterally flexib e re- 0 tarding spring having an adjusting screw,

and a projection carried by the rod for engaging said retarding spring.

4t. An'electric pump governor comprising a cylinder, piston, and rod, an adjustable 515 spring surrounding said rod, a laterally flexible retarding spring having a hump portion, and means operated by the movement of the piston rod for engaging said hump portionj ,5. An electric pump governor comprising a cylinder, piston, and rod, an adjustable sprm flexib e retarding spring having a hump and a- V-shaped'projection carried by the piston rod for engaging'said surfaces. 6. An electric pum governor'comprising surroundin said rod, a stationary retardin spring, an a. projection carried by the r0 for engagin' said retarding spring. 7. In an e ectric pump overnor, thecomv hination-with a piston su ject to the fluid '15 a pressure cylinder,'p1ston and rod,.a collar-"- ressure, an adjustable regulating sprin a L55.

projection operated bythe movement of the aterally flexible retardings rmg, an a piston for engaginsaid retardin s rin of. a switch operati n .piston and cyl inde r:

' controlling the supply of fluid to the switch operating cylinder. 1 1 v I A 8. An electric pump governor comprising a pressure cylinder, plstonand rod, a collar fixed on said rod, a coiled ring bearing against said collar,'a bell-era lever having W. G'msoow CLARK, S. W. HA'Y vns.

surrounding said rod, a laterally portion with inclined resistance surfaces,

and a valveactuated y the first piston for.

"a-cylinder, piston an rod, acoiled spring a long-arm carrying a contactbar for oPtm-I I

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