US2440560A

US2440560A - Two-stage pump

Info

Publication number: US2440560A
Application number: US712632A
Authority: US
Inventors: Allan G Sheppard
Original assignee: American La France Foamite
Current assignee: American-la France-Foamite Corp
Priority date: 1946-11-27
Filing date: 1946-11-27
Publication date: 1948-04-27
Anticipated expiration: 1965-04-27

Description

April 27, 1948. A. s. SHEPPARD TWO-STAGE PUMP Filed Nov. 27, 1946 6 Sheets-Sheet 1 1 nvmvrox. Er- /4//a/7 GJ/vepparz/ ATTORNEYJ April 27, 1948. A. G. SHEPPARD 2,440,560

' 'rwo-smen mar Fuedum 27, 1946 6 Sheets-Sheet z 4//a/1 6. Me a card ATTORNEXJ April 27, 1948. A. e. SHEPPARD TWO-STAGE Puur Filed Nov. 2'7, 1946 e Sheets-sheaf;-

llllfll /l/l/I/ g I! IN V EN TOR.

a M w J N ATTORNEYS April 27, 1948. A. G. SHEPPARD TWO-STAGE PUMP Filed Nov. 27, 1946 6 Sheets-Sheet 4 INVENTOR.

//c7/7 GJ/zeppara' M April 27, 1948.

A. G. SHEPPARD TWO-STAGE PUMP Filed NOV. 27, 1946 s Sheets-Shed. 5

INVENTOR. AUG/'1 G. Jbe o oar'a BY AT TO/PNE VS April 1943' A. G. SHEPPARD 2,440,560

TWO-STAGE PUMP Filed NOV. 27, 1946 6 Sheets-Sheet 6 IN VFJV TOR.

/4//0/1 6. J/lep oard j ATTO/PA/EVJ Patented Apr. 27, 1948 TWO-STAGE PUMP Allan G. Sheppard, Elmira, N. Y., minor to American-La France-Foamlte Corporation, Elmira, N. Y., -a corporation of New York Application November 21, 1946, Serial No. 212,632

6 Claims. 1

v This invention relates to water pumps of the appropriate for fire department use and has for its primary object the provision of an improved multi-stage pump of high efliciency and so organized as to be quickly convertible from series to parallel stage operation.

With the foregoing and other objects in view, as will hereinafter appear, the invention comprises the devices, combinations and arrangements of parts hereinafter set forth and illustrated in the accompanying drawings of a preferred embodiment of the invention, from which the several features of the invention and the advantages attained thereby will be readily understood by those skilled in the art.

In the drawings:

Fig. 1 is an elevation of a preferred form of pump acording to the invention;

Fig. 2 is a top plan view, partially broken out and sectioned;

Fig. 3 is a section on the line III--III of Fig. 1;

Figs. 4 and 5 are sectional views on the lines IV-IV and V--V, respectively, of Fig. 2; and

Fig. 6 is a section on the lines VI--VI of Fig. 2.

In the illustrated embodiment, and as is preferred, the pump includes a main housing of elongated form appropriate for mounting transversely upon a truck chassis with the water inlets 2 and 3 located at opposite ends of the housing so that either one may :be conveniently hose-coupled to the water supply source for the P mp.

Within the housing, and cast integrally with it, for example, are two casings, generally designated 4 and 5, in which are mounted first and second stage impellers B and 1, respectively. The impellers are secured to a common shaft 8 which may be journaled at its ends in the hous ing side walls 9 and I0.

The casings 4 and 5 are spaced from each other and from the housing side walls so that, with their wall extensions I, l2, l3, and I4, they constitute partitions extending throughout the major portion of the length of the housing and provide intervening spaces l5, l6 and II. The latter may conveniently be designated water inlet spaces, all three of them opening at their opposite ends into the end portions of thehousing supplied by the water inlets 2 and -3. For convenience, the designations first and secand are sometimes used herein to identity the spaces, passages and so forth, associated with the first and second stage units, respectively.

The first stage unit is of a dual inlet type and, in this instance, though of the same diameter,

is of double the capacity of the second stage unit, which is of a single inlet type. As indicated, the first stage unit incorporates dual inlets I8, I! on opposite sides of the casing 4 and communicating with the first stage inlet spaces It and I6, respectively; and the second stage unit incorporates a single inlet 20 communicating with the first stage inlet space H. As shown particularly in Figs. 4 and 5, the first and second stage casings are provided with discharge-passages 2| and 22, respectively, and valve means are provided whereby the two units may .be connected, in series or in parallel, to a discharge header 23 to supply a number of

hose outlets

24, 25.

To control the coupling of the units to the header there is provided a manually operable valve the construction and operation of which will be apparent from Figs. 2 and 4 of the draw- 20 ings. In the position illustrated in Fig. 4, the

head 28 (constituting the valve proper) occupies its extreme left hand position abutting a seat 21 and the discharge from the first stage unit flows through passage 2| into header 23 as indicated by the full-line arrow. The second stage unit likewise (and at all times) will be discharging directly into the header by way of passage 22. In other words, the units are coupled in parallel.

To convert to series operation the valve-2B is withdrawn by handwheel 28 to its extreme right hand position abutting a seat 29, thereby shutting oil the first stage discharge passage 2| from direct communication with header 23. The valve 28 is shown so positioned in Fig. 2. As the valve is thus withdrawn from seat- 21 it opens a port 30 and provides an outlet from discharge passage 2| into a passage 3|, as indicated by the broken-line arrow in Fig. 4. As appears in Figs. 2 and 3 the passage 3| discharges into the second stage inlet space H.

To complete the conversion to series operation, means are provided for closing off the second stage inlet space from the housing, so that the second stage supply is derived solely from the first stage discharge (by way of passage 3|, as above described). Such means is preferably automatic in the sense of requiring nothing more of the operator than the manipulation of hand wheel 28, and, as shown, may comprise a pair of flow-controlled, hinged valves 32, 33. As will be understood, these valves will be moved to and held in their open position during parallel operation of the units, as a result of the inflow of water from the housing and throughinlet space H to the second stage inlet 20; whereas when the units are coupled in series in the manner described, the valves will be moved to and held in their closed position by the greater fiow (representing the discharge from the larger capacity first stage unit) which enters space I! from passage 3 I In addition to the structural advantages inherent in the described form and the hydraulic balance effected by the described arrangement of the impellers, the invention lends itself to more eflicient operation than can lie-achieved by any of the customary two stage or four stage pump arrangements. For instance, the impellers may be designed so that when pumping in parallel, approximately 70% of capacity is taken through the double suction first stage and the 30% balance through the single suction second stage. These two stages, representing substantially the practical equivalent of three impellers but without their complexity and space requirements, can satisfy lift conditions not possible witha conventional two stage pump, can provide ample suction to deliver, say 1500 gallons per minute at 150 p. s. i.; and, when converted to series operation, the double inlet first stage impeller has ample suction capacity to ensure net deliveries of 70% of capacity, or 1050 gallons per minute, at 200 p. s. i., and 50%, or 750 gallons per minute at 250 p. s. 1. These capacities are available for delivery on a ten foot lift using two lengths of standard six inch suction hose to supply the pump.

In the light of the foregoing description the following is claimed:

1. A two-stage, series-parallel pump comprising: an elongated housing having a water supply inlet at each end; first and second stage impeller casings mounted within the housing and laterally spaced from each other and from the housing sidewalls to provide first stage inlet spaces between the first stage casing and its proximate housing side wall and between the casings, and a second stage inlet space between the second stage casing and its proximate housing side wall, said three inlet spaces all opening at their opposite ends into the end portions of the housing; a. large capacity first stage impeller and a smaller capacity second stage impeller mounted in the respective casings and secured to a common shaft journalled in the said housing side walls; dual casing inlets to the opposite sides of the first stage impeller communicating with said first stage inlet spaces, and a single casing inlet to the second stage impeller communicating with said second stage in-let space; a discharge header; a first discharge passage from the first stage casing communicating with the header and with the second stage inlet space, and a second discharge passage from the second stage casing to the header; a. manually operable valve movable to one position to direct the water flow in the first discharge passage to the header only and to another position to direct such flow to the second stage inlet space only; and valve means responsive to movement of the said manually operable valve to its said positions, respectively, to open and to close off communication between the said end portions of the housing and the second stage inlet space.

2. A two-stage, series-parallel pump comprising: a housing; first and second stage impeller casings mounted within the housing and laterally spaced from each other and from the housing side walls to provide first stage inlet spaces between Q a smaller capacity second stage impeller mounted in the respective casings and secured to a common shaft joumalied in the said housing side walls; dual casing inlets to the opposite sides of the first stage impeller communicating with said first stage inlet spaces, and a single casing inlet to the second stage impeller communicating with said second stage inlet space; a discharge header; a first discharge passage from the first stage casing communicating with the header and with the second stage inlet space; and a second discharge passage from the second stage casing to the header; a manually operable valvemovable to one position to direct the water fiow in the first discharge passage to the header only and to another position to direct such flow to the second stage ininlet' space only; and valve means responsive to movement of the said manually operable valve to its said positions, respectively, to open and to close oif communication between the said portion of the housing and the second stage inlet space.

3. A two-stage, series-parallel pump comprising; a housing; first and second stage impeller casings mounted within the housing and laterally spaced from each other and from the housing side walls to provide first stage inlet spaces between the first stage casing and its proximate housing side wall and between the casings, and a second stage inlet space between the second stage casing and its proximate housing side wall; a water supply inlet to a portion of the housing normally in communication with all three of said inlet spaces; a large capacity first stage impeller and a smaller capacity second stage impeller mounted in the respective casings and secured to a common shaft; dual casing inlets to the opposite sides of the first stage impeller communicating with said first stage inlet spaces, and a single casing inlet to the second stage impeller communicating with said second stage inlet space; a discharge header; a first discharge passage from the first stage casing communicating with the header and with the second stage inlet space, and a second discharge passage from the second stage casing to the header; a manually operable valve movable to one position to direct the water fiow in the first discharge passage to the header only and to another position to direct such flow to the second stage inlet space only; and valve means movable to open and to close oil communication between the said portion of the housing and the second stage inlet space.

4. A two-stage, series-parallel pump comprising: a housing; first and second stage impeller casings mounted within the housing and laterally spaced from each other and from the housing side walls to provide first stage inlet spaces between the first stage casing and its proximate housing side wall and between the casings, and a second stage inlet space between the second stage first stage impeller communicating with said firststage inlet spaces, and a single casing inlet to the second stage impeller communicating with said second stage inlet space; a discharge header; a first discharge passage from the first stage casing communicating with the header and with the second stage inlet space, and a second discharge passage from the second stage casing to the header; and valve means adapted for coupling the said casings and discharge passages to the header in series or in parallel.

5. A two-stage, series-parallel pump comprising: a housing; first and second stage impeller casings mounted within the housing and, with the housing, forming first and second stage inlet spaces; a water inlet to the housing adapted to supply both said spaces; a large capacity first stage impeller and a smaller capacity second stage impeller mounted in the respective casin'gs and secured to acomrnon shaft journalled in the said housing; a casing inlet to the first stage impeller communicating with said first stage inlet space, and a casing inlet to the second stage impeller communicating with said second stage inlet space; a discharge header; a first discharge passage from the first stage casing communicating with the header and with the second stage inlet space, and'a second discharge passage from the second stage casing to the header; a manually operable valve movable to one position tov direct the water fiow in the first discharge passage to the header only and to another position to direct such flow to the second stage inlet space only; and valve means responsive to movement of the said manually operable valve to its said position, respectively, to open and to close 0d communication between the housing and the second stage inlet space.

6. A two-stage, series-parallel pump comprising: a housing; first and second stage impeller casings mounted within the housing and, with the housing, forming first and second stage inlet spaces; a water inlet to the housing adapted to supply both said spaces; a large capacity first stage impeller and a smaller capacity second stage impeller mounted in the respective casings and secured to a common shaft; a casing inlet to the first stage impeller communicating with said first stage inlet space, and a casing inlet to the second stage impeller communicating with said second stage inlet space; a discharge header; a first discharge passage from the first stage casing communicating with the header and with the second stage inlet space, and a second discharge passage from the second stage casing to the header; and valve means adapted for cowpling the said casings and discharge passages to the header in series or in parallel.