US1997418A - Pumping mechanism - Google Patents

Description

April ,1935. H. HORNSCHUCH E-rAL PUMPING MECHANI SM Filed Oct. 19, 1933 2 Sheets-Sheet 2 \V. 0 5 4 4 i fl 4 4 n 4 3 72 5% 5 0 7 4. 5 Q i 4d q 7V /V% THEIR ATTORNEY,

Patented Apr. 9, 1935 UNITED STATES.

PATENT OFFICE PUMPING LIECHANISM Hanns Hornschuch and Anthony L. McHugh,

Easton, Pa., assignors to Ingersoll-Rand Company, Jersey City, N. J., a'corporation of New Jersey Application October 19, 1933, Serial No. 694,212

4 Claims.

period required for priming the pump.

KLI

Another object is to prevent air-lock on the' discharge side of the pumping mechanism during the establishment of normal pumping conditions.

A further object is to cause automatic reestablishment of the parts to the positions which they occupy during normal pumping conditions after priming of the pump has been effected.

Other objects will be in part obvious and in part pointed out hereinafter.

In the drawings accompanying this specification and forming a part thereof and in which similar reference numerals refer to similar parts,

Figure 1 is a longitudinal sectional elevation of a pumping mechanism constructed in accordance with the practice of the invention, I

Figure 2 is a similar view showing a modified form of the invention with the parts in the positions which they occupy during the priming of the pump, and

Figure 3 is a sectional elevation showing the position which the parts occupy during the normal pumping operation of the pump.

Referring more particularly to the drawings and at first to Figure 1, II] designates a pumping mechanism comprising a centrifugal pump II having an impeller I2 for pumping water from an inlet opening I3 through a discharge opening I4 into a discharge chamber I5 which may, as illustrated, constitute an integral part of the casing I6 of the pump.

The impeller I2-is shown as being mounted directly upon the end of a shaft I! which may be actuated in any'well known manner, as for instance by a motor, of which only the casing I8 is indicated.

In accordance with the practice of the invention the pumping mechanism I0 is provided with a water trap I9 of which the interior or chamber communicates directly with the inlet opening I3 and also with a source of liquid supply 2| through a pipe 22. The pipe 22 is preferably connected at its upper end to the top of an upwardly extending branch 23 of the water trap and containing a strainer 24 through which the water passes before entering the pump.

The proportions of the discharge chamber I5 and the water trap l9 as well as their arrangement with respect to the pump are such that a sufficient volume of water will be readily available in the water trap IQ for priming the pump at the beginning of a period of operation.

In order to effect such priming of the pump the water trap l9 and the portion of the casing I6 constituting the discharge chamber I5 are provided with a passage 25 which opens at one end into a low point of the discharge chamber and at its other end into the water trap. Within the passage 25 is a wall 26 having a port 21 constituting a portion of the passage 25, and on one side of the wall is a seat 28 for a valve 29 which controls the passage 25.

The valve 29 is reciprocable in a chamber 30 of a casing 3I disposed upon the-water trap I9 and has a passage 'or passages 32 extending longitudinally therethrough to assure the exposure of equal areas of both ends of the valve 29 to the same pressure. On the front end of the valve is a lateral flange 8 having a pressure area 9 against which the water flowing through the passage 25 acts to assist in closing the valve.

In addition to the function described the easing 3| also serves as a guide for a rod 33 carried by the valve 29 and having attached to an intermediate portion thereof a seat 34 for an end of a spring 35 of which the opposite end seats against the casing 39.

In order to providean escape for air existing in the chamber I5 and associated channels and also such air as may find entrance into the chamber during the priming operation the discharge chamber I5 is provided at its upper end with avent 33. The vent opens into a passage 31 of a valve cage 38 which may be secured, in any suitable manner, to the casing I6. Within the valve cage 38 is a bore 39 which is coaxially.

aligned with the chamber 30 and communicates with the passage 31 through a valve chamber 4!! in the cage 38. A port M in the cage 38 and intermediate the ends of the bore affords an outlet for air entering the bore 39.

Extending into the bore 39 is a reduced end 42 of the rod 33 and a piston 43 on the end 42 seals the lowermost end of the bore 39 and also serves as a guide for the end 42 of the rod. On the end of the rod 33 extending into the valve chamber is a valve 44 adapted to seat upon a valve seat 45 in the chamber 40 to prevent communication between the passage 31 and the port 4|. The outermost end of the valve 44 constitutes a pressure area 1 against which the liquid rising in the chamber I5 acts to close the said valve. V

Preferably the rod 33 carrying the valve 44 and upon which the valve 29 is mounted is disposed loosely slidable in the valve 29 so that full seating contact of both valves 44 and 29 with their respective seats will be assured. 0n the lower end of the rod 33 is a nut 5 to abut the end of the valve 29 for opening the said valve simultaneously with the opening of the valve 44.

The operation of the device is as follows: When the pump is set in operation the water initially present in the water trap I9 is pumped therefrom into the discharge chamber I5. The amount thus pumped at the beginning of the priming operation will be insufiicient to disturb the positions of the valves 29 and 44. These valves will, therefore, be held in the opened p0sltions by the spring 35. The passage 25 will then be open so that water pumped into the discharge chamber I5 may return into the water trap l9. With the passage 25 of smaller area than that required to return the entire discharge output of the pump water will gradually accumulateln the discharge chamber l5 and the supply of fluid in the water trap l9 will, in consequence, be

diminished, thus causing a partial vacuum within the trap and the elements connecting it with the source of water supply. Water will then flow into the water trap and increase the body of priming fluid.

Thereafter the water chamber 15 will become gradually filled, and as the water rises in the chamber 15 the air which it displaces flows through the vent 36 and associated passages to the atmosphere, or to such other point wherewith the port 4| may be connected.

After the discharge chamber [5 becomes filled with water under pressure so that water flows through the passage 25 at greatly accelerated velocity the current of water will act against the pressure area 9 of the valve 29 and, by overcoming the force exerted by the spring 35, draw said valve to its seat. At the same time the pressure of the liquid in the discharge chamber l5 and associated passages will act against the pressure area 1 of the valve 44 and augment the pressure acting against the pressure area 9 of the valve 29 to overcome the lifting force of the spring 35. The valves 29 and 44 will then be closed and will remain in that position as long as the pressure of the liquid in the chamber l5 and associated passages exceeds that value at which the spring 35 is calibrated to act for opening the valves 29 and 44.

In the modified form of the invention illustrated in Figure 2 means are provided for positively maintaining the valves 29 and 44 in the opened positions during the priming of. the pump. To this end a toggle 46 is disposed between the casing 3| and the spring seat 34 to prevent movement of the valves toward their seats before the pressure in the discharge chamber I 5 approximates normal discharge pressure.

The toggle 46 comprises a link 41 and a bell crank 48, an end of the link 41 being pivotally connected to the angle of the bell crank 48, as at 49, and the opposite end of the link 41 being connected, in like manner, to the spring seat 34. The end of one arm of the bell crank 48 is mounted or connected to a pivot 50 seated in the casing 3|, and the other end or arm 5| of the bell crank extends, in the operative position of the toggle, to a point adjacent the discharge chamber l5. The arrangement of the toggle is such that when the spring 35 acts toopen the valves 29 and 44 the link 41 and the bell crank 48 will also be moved into their operative positions for resisting pressure a flange or plate 55 to assure an ample area of contact between the rod and the arm 5| of the bell crank. The opposite end of the rod 54, which extends beyond the piston 53, is in the form of a valve 56 for controlling a port 51 in the end of the cylinder 52 and through which discharge fluid may flow from the chamber I5 into the cylinder 52.

The end of the valve 51 constitutes a pressure area 58 which is constantly exposed to the pres sure of the medium in the discharge chamber l5 for opening the valve 56, and a spring 59 in the cylinder 52 serves to close the valve 55 and maintain it closed at a certain predetermined pressure.

In the operation of this form of the invention, whenever the pressure in the discharge chamber l5 falls below that at which the spring 35 is intended to act, the said spring will open the valves 44 and 29. At the same time the toggle 46 is rocked into position to maintain the valves in the open positions. The arm 5| will then be moved into approximate abutment with the plate 55, thus as the pressure in the chamber l5 increases the liquid acting against the pressure area 58 will move the piston 53 toward the bell crank and the water then acting against the large area of the piston 53 will trip the bell crank out of its bracing position. Thereafter when the pressure within the chamber l5 and'the velocity of the water through the passage 25 reach those values which may overcome the force of the spring 35v the valves 29 and 44 will be moved to their seats to cause the pump to operate normally.

We claim:

1. Pumping mechanism comprising a pump having a discharge chamber and a vent for the discharge chamber, a casing having a water trap constituting an inlet for the pump, said casing having a passage for conveying fluid from the discharge chamber to the water trap, a valve to control the passage and having equal opposed end areas subjected to the same pressure, a second valve for controlling the vent, a rod on said second valve extending slidably through'the first said valve and being adapted to lift said first valve to its open position simultaneously with the opening of the second said valve, a spring on the rod to open the valves and hold both valves open during the priming of the pump, and a flange on the first said valve against which the current of fluid discharged by the pump acts for drawing the valves to their closed positions.

- 2. Pumping mechanism comprising a pump having a discharge chamber and a passage leading from the discharge to a source of priming fluid, a valve controlling the passage, 2. spring for opening the valve, toggle means for maintaining the valve open, a plunger actuated by discharge fluid for tripping the toggle means to release the valve, and a pressure area onthe valve against which discharge fluid acts for closing the valve.

3. Pumping mechanism comprising a pump 7 having a discharge chamber and a vent for the discharge chamber, means affording a passage for conveying priming fluid from the discharge chamber to a source of priming fluid, valves to control the passage and the vent, means connecting the valves together in spaced relationship, a

spring for opening the valves, toggle means for maintaining the valves open during the priming of the pump, means actuated by discharge fluid for tripping the toggle means to release the valves, and pressure areas on the valves against which discharge fluid acts for closing the valves.

4. Pumping mechanism comprising a pump having adischarge chamber and a vent for the discharge chamber, means affording a passage for conveying priming fluid from the discharge chamber to a source, of priming fluid, valves to control the passage and the vent, means connecting the valves together in spaced relationship, a spring for opening the valves, toggle means for maintaining the valves open during the priming of the pump and being actuated into operative position by the spring, means actuated by discharge fluid for tripping the toggle means to release the valves, and pressure areas on the valves against which discharge fluid acts for closing the.

Images