US2683420A - Primer pump - Google Patents

Description

July 13, 1954 R. A. HILL E AL PRIMER PUMP 2 Sheets-Sheet 1 Filed Aug. 28, 1950 %Q\ 6 T H .3 QQNmRQN h sgi l INVENTOR. Robert 14. 1717/ BY @aw'a E Thomas W m @un n I ATTORNEI E" Patented July 13, 1954 UNITED STATES PRIMER PUMP Application August 28, 1950, Serial No. 181,818

6 Claims. 1.

This invention relates to an improvement in primer pumps and deals particularly with a means for and method of priming a centrifugal pump.

Centrifugal pumps are commonly used in fire engines and other fire fighting equipment. Pumps of this type must be primed before they will function, if used to draught water from a pond, river or lake. Various means have been employed for priming these pumps, one common method being to provide a priming pump of a gear type connected to the engine for actuation thereby; Such pumps tend to draw the air from the interior of the centrifugal pump, thereby drawing water through the intake of the pump. As soon as the centrifugal pump has been properlyprimed, the priming pump is disconnected.

Priming systems of this type usually require time to operate and if the pump is not properly handled, the prime will be lost. oftentimes the drive mechanism is so arranged that either the priming pump or the centrifugal pump may be selectively connected to the driving engine. When the priming pump has drawn the liquid into the centrifugal pump the'drive arrangement u must be shifted to stop the priming pump and to start'the centrifugal pump intooperation. If the prime is lost" during this process, or if a temporary interruption of the water flow into the pump intake takes place, considerable time is lost. The time required to place the equip ment in operation" is of particular importance in the type" of equipment involved.

It is an object of the present invention to provide a centrifugal pump with a priming motor which is electrically operated and which is preferably connected to the electrical system of the vehicle. As a result the priming pump may be operated simultaneously with the centrifugal pump if desired and the operation of the priming pump is discontinued when the pump is completely' primed.

A feature of the present invention lies in the fact that through the use of an electric motor drivenpriming pump, an automatic priming system may readily be provided. By providing a pressure actuated switch connected to the discharge of the centrifugal pump, the priming motor may be automatically disconnected when the centrifugal pump develops pumping pressure. At the same time, this pressure actuated switch may serve to restart the priming pump motor in the event the pressure at the pump outlet drops belowa predetermined minimum.

A feature of the present invention lies in the fact that my priming pump may be selectively connected either to the electric motor orto the vehicle engine so that it may be actuated by either source of power. In the event the electrical system shall fail for any cause, the pump may be mechanically connected to the engine driving the centrifugal pump.

These and other objects and novel features of my invention will be-more clearly and fully set forth in the following specification and claims.

In the drawings forming a part of the specification:

Figure l is a vertical sectional View through a pump of thetypein question showing the general arrangement of the parts therein.

Figure 2 is a sectional view horizontally through the drive shaft of the pump; the position of the section being indicated by the line 2 -2 of Figure 1.

Figure 3 is a sectional View through a detail portion of thestructure, the position of the section being indicated by theline' 3-3 of Figure 2.

Figured is a wiring diagram of a modified form of control system.

Figure 5 shows a' modified form of construction.

The centrifugal pump is indicated in general by the letter A. The pump includes apump housing It having a horizontally extending impeller shaft H extending therethrough. The pump includes a pair of spaced impellers i2- and i3 supported upon the shaft H in spaced relation. These impellers i2 and i3 have a central intake indicated at M and I5 respectively. The intake IA of the impeller I2 is connected to the intake manifold It within the pump housing. The intake l5 of the impeller i3 is connected to the intake manifold ll within the housing I0. Both intake manifolds i6 and H are usually connected together to a source of water supply through a suitable flexible connection such as a hose or the like.

The impeller l2- rotates within a volute I9, while the impeller it forces water into a volute 26. The pump housing It is provided with suitable passages therethrough controlled by valves, not illustrated in the drawings, toconnect the output fromthe impellers, either in series or in parallel to the discharge manifold 2|.

One end of the impeller shaft I i projects from the pump casing into the gear casing indicated in general by the numeralZZ. A pinion 23 is supported upon the impeller shaft H; this pinion being in mesh with'an idler'gear M. The idler gear 23 is driven by a drive-gear zfislidably supported upon the drive shaft--26.- The driveshaft 26 is wise secured to the gear housing 22.

preferably connected to the vehicle engine or to a similar source of power supply. External teeth 2? on the gear mesh with the teeth of the idler gear 25 when the gear 25 is in proper driving position. The gear 25 is also provided with internal teeth 29 which may mesh with external teeth 99 of the driven shaft 3|, usually aligned with the drive shaft 26. When the gear 25 engages the gear 30 the engine is connected to the wheels of the vehicle.

With reference now to Figure 2 of the drawings, it will be noted that the gear 25 on the drive shaft 26 is also engageable in one position with a drive gear 32 on the drive shaft 33 of a rotary pump 34. The rotary pump 34 includes a pump casing 35 fastened to the gear casing 22 and includes a removable closure plate 36. The drive shaft 33 is supported by a suitable bearing 37 within a hollow boss 39 forming a part of the housing 35 and by a bearing 49 supported within the hollow boss 41 of the closure plate 36. A parallel shaft 42 is supported by suitable bearings 43 and 44 within the housing 35 and the closure plate 36 respectively. The shafts 39 and 34 support interengaging rotors i5 and 45 or interlocking gears, providing a positive pumping action.

The drive gear 32 is provided with a hub 4'? which encircles the drive shaft 33 and is rotatable relative thereto. A hub or sleeve 49 is keyed to the drive shaft 33 and is provided with angularly spaced inclined notches 59 in which are positioned rollers 5|. The rollers 5| are urged into engagement with the inner surface 52 of the gear hub 47 by springs 53. These rollers 5i provide an overrunning clutch which permits the drive shaft 33 to rotate freely in one direction. The purpose of this overrunning clutch is to permit rotation of the drive shaft 33 by external means, while the gear 32 is in engagement with the gear 25, without tending to drive the engine of the vehicle.

An electric motor 5a is provided with a mounting flange 55 at one end which is bolted or other- The motor shaft extends from the motor '54 and is pin connected or otherwise connected at 5? to the drive shaft 33 through the hub 49. Rotation of the motor 5 may thus rotate the hub 49 and the drive shaft 33 and consequently may drive the rotors it; and 46.

The gear 25 is moved longitudinally of the drive shaft 28 by a shifting fork 59 mounted upon a shaft (it slidable in a direction parallel to the axis of the shaft 26. This shift shaft fit may be moved longitudinally by manual means such as the shifting member 8!, partially shown in the drawings. One end 82 of the shaft 6% is preferably enclosed within a sleeve 63 which is capped as indicated at 94. Means are provided for tending to hold the shaft in any of four positions, this means including recesses 65 in the shaft to in longitudinally spaced relation and suitable spring urged means not shown in the drawings engageable in these recesses. The gear 25 is movable from pumping position shown in Figure l of the drawings to priming position shown in Figure 2 of the drawings. If the gear 251s moved to the right from its position shown in Figure 2 out of engagement with the gear 32 and not yet in engagement with the gear 30, the gear 25 is in a neutral position which is the third of the four gear positions. The fourth position is when the gear 25 is engaged with the gear 39 to drive the vehicle wheels.

A control system for controlling the priming operation of the pump is diagrammatically illustrated in Figure 2. The system includes the battery or power supply source 66, one terminal of which is grounded at 61. The other battery terminal is connected by conductors 69 and '10 to a relay terminal H. The relay arm 12 is connected by a conductor 13 to one terminal of the motor 54, the other terminal of which is grounded. Thus when the relay 14 is energized a circuit is closed to the motor 54 to drive the priming pump.

The relay it. includes the coil 15, one terminal of which is grounded at 16. The other coil terminal is connected by a conductor ii to one blade 73 of a switch 80, and one blade Bl of a switch 82. The cooperable blade 83 of switch is connected by conductor 84 to one terminal 85 of a single pole double throw switch 86. The arm of the switch 86 is connected by conductors 81 and 69 to the live terminal of the battery 66.

The second blade 89 of the switch 82 is connected by a conductor 99 to a terminal 91 of a single pole, single throw pressure actuated switch 92. The pressure chamber of switch 92 is connected to the discharge manifold 21 of the centrifugal pump A and is so arranged to open the switch when a predetermined pressure is reached in this manifold. For example, the switch 92 can open the circuit when a pressure of twenty-five pounds per square inch is built up within the pump discharge 2!. The arm 93 of the sw tch 92 is connected to the second terminal 94 of the double throw single pole switch 86, completing this circuit.

The switch 80 is provided with an operating lug 95 which rides upon the surface of the shaft 60. A notch or indentation 96 is provided in the shaft 69 which is engageable with the lug 95 only when the shaft 60 is in position to hold the drive gear 25 in neutral position. Thus the circuit through the switch 80 may be closed only when the pump is in neutral position. The switch 82 is mounted in the path of movement of the shaft 60 and is closed by engagement with this shaft when the pump is in pumping position. Thus the switch 92 is closed only when the pump is in pumping condition.

The two circuits described are alternative, one circuit comprising a fully automatic system, while the other comprises a semi-automatic system. When the arm of the switch 88 is against the switch terminal 85, a circuit is closed from the battery 65 through conductors 59 and El, the switch 36, conductor 94, switch 80, and conductor '2"? to the relay coil 75, the other terminal of which is grounded. Thus if the pump is in neutral position, a circuit may be closed to the relay coil 75, thus closing the motor circuit to the motor 54 and starting the priming pump. When the pump has acted to prime the centrifugal pump A, the shifting shaft 66 is moved into pumping position, thereby opening the switch 99 so that the circuit is opened to the solenoid coil 55 and subsequently to the priming motor 54 as the pump starts to function. If preferred the switch 8t can be manually broken. If it is desired to reprime the pump and if the switch 65 remains in position to close a circuit to terminal 85, the prim ng motor can again be started by merely shifting the shaft 69 to place the gear 25 in neutral position.

If the switch 35 is in its other extreme position in connection with terminal 94, a circuit is closed from the battery 96 through conductors 69 and aes'egsao @I through the switch 86 through the-normally closed pressure switch 92 and the conductor 90 to the switch 82 switch 82' is connected byth'e contluctor'li to-the relay coil 15-, the other terminal-of which isgrounded. Thus if the shaft 60 is in pumping position with the gear 25 engaged with the pump gear; as shown in Figure 1, the priming motor 5 is started as soon as the switch 86 is closed. The switch 86 is then detained closed position during the pump operation. When the pressure in the discharge manifold of the centrifugal pump reaches the necessary pressure to open normally closed pressure switch 92, this circuit is opened and the circuit to" the priming motor 5 3' is opened. However, if the pressure shall fail in the discharge of the pumpA, the switch 92" will again close and the priming motor will be restarted to again prime the pump. Thus anytime the pump shall lose its prime with the switch 86 in this position, it will be reprimed;

The system illustrated is advantageous because of the speed with which the pumpmay be primed an because of the automatic repriming operation at any time when the pump loses its prime. Even: in the semi-automatic operation of the system, the priming motor 54 will be turned off when the pump is connected to the drive shaft, thus permitting the repriming of the pump' automatica-l'ly as the shiftin member is shifted into neutral position.

In Figure l of the drawings is disclosed a manually operable control system for controlling the circuit to the priming motor 54.

In this instance, thevehicle battery 66 or other source of current supply, has one terminal grounded as indicated at 91'. The other battery terminal connected by conductor 99 to a normally open manually closed switch [60. Theother terminal of. the switch I is connected by conductor Hill to a relay coil Hi2, which in turn is grounded at I03. Thus when the switch lfillis manually closed, the relay coil I02 is energized. The relay ar-m I04 is connected by conductor M to the priming motor 56, the other terminal of which is grounded at N16. The arm Ifidwhen energized is engageable with a terminal It! connected by conductors I69 and 99 to the battery 65. Thus when the relay coil Hi2 is energized the motor 5 -3 is: set into operation. The motor remains in operation until the manual switch Hit is manually released to open the circuit.

In Figure 5 of the drawings we disclose a modified form of construction which differs slightly from the construction shown in Figures 1 and 2 of the drawings. The main point of difference of this form of construction lies in the fact that the electric primin motor is mounted on the opposite side of the gear case from the form of construction previously described. This arrangement is somewhat more awkward in appearance and somewhat less compact in design, but has the advantage that the motor may be added to a conventional pump with fewer mechanical changes.

The pump B illustrated in Figure 5 is virtually identical with the pump A, except for the shape of the gear casing and the motor mounting. The drive shaft H0 acts to rotate a drive gear ill which is spline connected thereto and which is provided with external teeth H2 engageable in one position with a drive gear H3 on a parallel shaft IE4. An over-running clutch H5 is interposed between the gear I I3 and the shaft I M for a purpose which will be understood.

The shaft H4 is supported by suitable bearings l- IB-in an internally extending boss 1 I 1 and is al'so supported by bearings H9 supported within the pump casing [20 The shaft H4 extends intoa hollow" boss I2! on the pump housin l=20 opposite the bearing H9. suitable flexible connection 22. connects the shaft H4 with the shaft l23of the-primingmotor i2 4.

Agear I25 is provided on the shaft H4 which meshes with asimilar gear I 26 on a countershaft I21. The counter-shaft I27 is supported by a bearing I29 in the pump housing and by an aligned bearing- I3-ll in the pump housing cover plate I32 of which the hollow boss [2 l' is a part.

In: other respects the pump similatesthe pump A and the drive gear ill is connected by-suitable gear means to the impeller shaft to drive the impellers precisely in the manner illustrated in Figure 1. Thus the structure of Figure 5 differs from the structure of Figure z'mainily in themanher in which the electric motor is connected thereto.

The motor i24 is controlled similarly to the motor 54 and accordingly the wiring diagram shown in Figure 2 is not repeated in Figure 5. The structure of Figure 2 illustrates the motor 54 attached directly to the gear housing 22'. As a result some modification of the gear housing is necessary to accommodate the electric motor 54. However, this arrangement is compact and" the motor 54 is attached to the shaft 33 at the end thereof opposite the end extending into the plmp housing 35. On the other hand, the construction illustrated in Figure 5' may be produced bymere- 1y changing the design of the pump closure plate, such as I32, and by changing the construction of the shaft H4. Thus it is somewhat less costly to modify conventional pumps to produce the construction shown in Figure 5 than to produce the construction shown in Figure 2.

In accordance with the patentstatutes, the principles of construction and operation of the primer pump have been described, and while it has been endeavored to set forth the best embodiment thereof, it is desired to have it understood that obvious changes may be made within the scope of the following claims without departing from the spirit of th'e'invention.

We claim:

1. A priming system for priming a centrifugal pump, the pump including an impeller shaft and gear means for driving said shaft and connected thereto, a drive shaft, a drive gear slidably supported on said drive shaft and movable into or out of engagement with said gear means, a priming pump, a gear connected to said priming pump for actuating the same, said gear being engageable with said drive gear in one position thereof, an electric motor connected to said priming pump for selectively actuating the same, an overrunning clutch interposed between said gear connected to said priming pump and said priming pump, said clutch acting to disengage said last named gear from said priming pump when the rotative speed of said motor is greater than the rotative speed of said gear.

2. A priming system for priming a centrifugal pump, the pump including an impeller shaft and gear means for driving said shaft and connected thereto, a drive shaft, a drive gear slidably supported on said drive shaft and movable into or out of engagement with said gear means, a priming pump, a gear connected to said priming pump for actuating the same, said gear being engage able with said drive gear in one position thereofI an electric motor connected to said priming pump for selectively actuating the same, means for sliding said drive gear on said drive shaft from a neutral position into selective enmeshment with either said gear means or said primin pump gear, and means engageable with said drive gear sliding means for energizing said electric motor only when said drive gear is in said neutral position.

3. A priming system for priming a centrifugal pump, the pump including an impeller shaft and gear means for driving said shaft and connected thereto, a drive shaft, a drive gear slidably supported on said drive shaft and movable into or out of engagement with said gear means, a priming pump, a gear connected to said priming pump for actuating the same, said gear being engageable with said drive gear in one position thereof, an electric motor connected to said priming pump for selectively actuating the same, means for sliding said drive gear on said drive shaft from a neutral position into selective enmeshment with either said gear means or said priming pump gear, and means engageable with said drive gear sliding means for energizing said electric motor only when said drive gear is in mesh with said gear means.

4. A priming system for priming a centrifugal pump, the pump including an impeller shaft and gear means for driving said shaft and connected thereto, a drive shaft, a drive gear slidably supported on said drive shaft and movable into or out of engagement with said gear means, a priming pump, a gear connected to said priming pump for actuating the same, said gear being engageable with said drive gear in one position thereof, an electric motor connected to said priming pump for selectively actuating the same, and a control system for controlling the operation of said electric motor, said control system including a manually operable switch, a normally closed pressure switch operable by an increase in pressure at the centrifugal pump discharge to open the circuit to said electric motor, and an interlocking switch in series with said pressure control switch and closed only when said drive pinion is in mesh with said gear means.

5. A priming system for priming a centrifugal pump, the pump including an impeller shaft and gear means for drivin said shaft and connected thereto, a drive shaft, a drive gear slidably sup ported. on said drive shaft and. movable into or out of engagement with said gear means, a primin pump, a gear connected to said priming pump for actuating the same, said gear being engageable with said drive gear in one position thereof, an electric motor connected to said priming pump for selectively actuating the same, a double control circuit for controlling the electric motor, said double control system including a two position switch movable into position to control either of two circuits of said double circuit, one of said two circuits including a switch closed only when said drive gear is in neutral position and operable when the drive gear is in said neutral position to close a circuit to said electric motor, and the other circuit of said double circuit including a switch closed only when said drive pinion is in engagement with said gear means and a pressure switch connected to the discharge of the centrifugal pump to open the circuit upon an increase in pressure of the centrifugal pump discharge, said second circuit portion also closing the circuit to said electric motor.

6. A pump priming system comprisin a centrifugal pump including a casing, an impeller shaft supported by said casing, a gear on said impeller shaft, a priming pump mounted on said casing, and in fluid communication with said centrifugal pump, said primin pump having an operating shaft supported by said casing, a gear on said operating shaft, a drive shaft supported by said casing and adapted to cooperate with said impeller shaft, a source of power connected to the drive shaft, gear means on said impeller shaft and the gear on said operating shaft, an electric motor connected to said operating shaft, said motor being operable to drive said priming pump while said impeller shaft is connected to said source of power through said drive shaft.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,475,994 Havens Dec. 4, 1923 1,682,331 Goyne Aug. 28, 1928 2,033,980 Durdin Mar. 17, 1936 2, 07,575 Boyles July 9, 1940 2,216,690 Madden Oct. 1, 1940 2,329,495 Van Pelt Sept. 14, 1943 2,468,008 Yocum Apr. 19, 1949

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