US 3915351 A
A cordless electrically operated centrifugal pump for use in garden sprayers, fuel pumps and other applications. A cylindrical impellor is mounted for rotation within a cylindrical housing by a drive shaft connected to a battery operated motor. The impellor has a pair of diametrically directed passages intersecting at right angles at the center of the impellor. Fluid is supplied to the center of the impellor through a sealed inlet and ejected through the passages by centrifugal force as the impellor is rotated. This develops substantially high pressure within the housing for the ejection of fluid from the housing. The pump provides high pressure with a low volume output and low power requirements.
Description (OCR text may contain errors)
nited States Patent Kiralty [4 1 Oct. 28, 1975 CORDLESS ELECTRICALLY OPERATED CENTRIFUGAL PUMP Alexander Enrico Kiralfy, 823 Wellesley Ave., Los Angeles, Calif. 90049 Filed: Aug. 19, 1974 Appl. No.: 498,319
References Cited UNITED STATES PATENTS 9/1962 Ziegler 222/385 X l/l966 Page 415/113 7/1970 Conhagen 415/88 3,523,629 8/1970 Yio Dak Chi.. 222/385 X 3,647,314 3/1972 Laessig 415/206 FOREIGN PATENTS OR APPLICATIONS 1,101,771 4/1955 France 415/53 643,307 9/1950 United Kingdom 415/173 R Primary ExaminerRobert B. Reeves Assistant ExaminerFrederick R. Handren Attorney, Agent, or Firm-Robert C. Comstock  ABSTRACT A cordless electrically operated centrifugal pump for use in garden sprayers, fuel pumps and other applications. A cylindrical impellor is mounted for rotation within a cylindrical housing by a drive shaft connected to a battery operated motor. The impellor has a pair of diametrically directed passages intersecting at right angles at the center of the impellor. Fluid is supplied to the center of the impellor through a sealed inlet and ejected through the passages by centrifugal force as the impellor is rotated. This develops substantially high pressure within the housing for the ejection of fluid from the housing. The pump provides high pressure with a low volume output and low power requirements.
7 Claims, 3 Drawing Figures U.S. Patent Oct. 28, 1975 3,915,351
/2 FIG 10 O I/II/IIII Era. 2
CORDLESS ELECTRICALLY OPERATED CENTRIFUGAL IUMP BACKGROUND OF THE INVENTION 1. Field of the Invention The invention relates to a battery operated high pressure, low volume centrifugal pump which is adapted for use in garden sprayers, fuel pumps and various other applications.
2. Description of the Prior Art Centrifugal pumps are well-known, but most of the type now in use are low pressure with a relatively high volume of output. They require a substantial amount of power to operate and are not adapted to low power, high pressure and low volume applications.
Many centrifugal pumps of the type now in use have back leakage of fluid'and use close tolerances to limit the amount of the backflow. This results in a waste of power to an extent which is not permissible where the power supply is limited.
While various type of garden sprayers are on the market, some of which are battery operated, they do not provide the necessary or most desirable volume and fineness of spray.
SUMMARY OF THE INVENTION It is the primary object of the present invention to provide a cordless (battery operated) centrifugal pump which is capable of developing high pressure for use in a garden sprayer, fuel pump and various other uses for which it may be suitable.
It'is a particular object of the invention to provide such a pump which is extremely light in weight and low in friction,so that little power is consumed in the operation of the pump. I
Afurther object of the invention is to provide a pump in which the inlet is sealed, so that there is no leakage or backfiow. A related object is to provide a novel type of seal for the inlet.
Another object is to provide such a pump which provides low volume and high pressure.
A further object is to provide a pump which overcomes the deficiencies of prior devices and which is particularly adapted for use in low power applications where substantial power losses cannot be tolerated.
It is another object of the invention to provide such a device which is extremely simple in its construction and operation, so that it can be manufactured and sold at a relatively low price and requires substantially no maintenance or repair.
The invention also comprises such other objects, advantages and capabilities as will later more fully appear and which are inherently possessed by the invention.
While I have shown in the accompanying drawings, a preferred embodiment of the invention, it should be understood that the same is susceptible of modification and change without departing from the spirit of the invention.
DESCRIPTION OF THE DRAWINGS FIG. 1 is side elevational view mostly in section of a garden sprayer with my pump installed therein;
FIG. 2 is a longitudinal sectional view of the pump assembly at the bottom of the sprayer;
FIG. 3 is a partial sectional view of the impellor taken along line 3-3 of FIG. 2.
DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment which has been selected to 5 illustrate the invention comprises a battery operated garden sprayer which utilizes the centrifugal pump of the present invention. v I g The sprayer comprises a tank 10, which is adapted to hold liquid insecticide, fertilizer or other material to be sprayed. Mounted on the top of the tank is a housing 1 1 having a handle portion 12 and holding a small electric motor 13 which is connected to and operated by one or more batteries 14. The battery 14 is preferably of the rechargeable type.
15 A shaft 15 which is rotated by the motor 13 is connected to a coupling 16 which is in turn connected to a main drive shaft 17 which extends downwardly within the tank 10. The lower end of the driveshaft 17 is connected to a second coupling 18, which' is in turn connected to a pump shaft 19.
The pump shaft 19 is rotatably mounted in a bearing 20 which extends into a substantially cylindrical pump housing 21. A locknut 40 extends around the bearing 20 adjacent to the top of the housing 21. The lower end of the pump shaft 19 is connected to a circularimpellor 22, which is mounted for rotation within the housing 21.
The lower end of the impellor 22 is provided with a projection 23, around the lower portion of which the upper end of a tubular plastic seal 24 is friction fit. The lower end of the seal 24 makes a light leak-proof engagement with the upper end of a hollow bearing 25, which extends upwardly through an opening in the bottom of the housing 21. A locknut 41. secures the bearing 25 to the housing 21. The bearing 25 is disposed adjacent to the bottom of the tank 10 and serves as an inlet for fluid entering from the tank 10 into the pump housing 21. A support tube 26 extends between the housing 21 and the top of the tank 10,- to support. the housing2l. f
An outlet 27 extends vertically upwardly from. the housing 21. A hose 28 is connected atits lower end-to the outlet 27 and at its upper end to one end of a tube 29. The opposite end of the tube 29 is connected to a hose 30 which is in turn connected at its opposite end to a conventional spray nozzle.
Liquid entering the inlet bearing 25 flows through the seal tube 24 and then through an outwardly flared opening 31 formed within the projection 23 on the bottom of the impellor 22. The upper end of the opening 31 is equal in diameter to a starting chamber 32 formed in the center of the impellor 22. Four narrow liquid flow passages 33 extend radially outwardly from the starting chamber 32 to openings formed in the periphery of the impellor 22.
Four stationary fan blades 34 may be provided within the starting chamber 32 to assist in the flow of liquid from the inlet 25 to the passages 33, thereby facilitating the starting operation of the pump.
A normally open ball type air bleed valve 35 may be provided in the upper wall of the housing 21 for the purpose of providing an outlet for air within the pump assembly to facilitate the initial flow of fluid from the housing 21 before the pump is first started. The starting of the pump might otherwise be delayed by air lock if the outlet hoses or tubes are blocked by the presence of stored stationary liquid. Once the pump is in operation, the pressure within the housing 21 closes the bleed valve 35 and maintains it closed during the time the pump is operating.
In use, liquid flows from the inlet to the impellor 22 and out through the passages 33. Due to centrifugal force, pressure is quickly built within the housing 21 surrounding the impellor 22, such area acting as a pressure chamber. This pressure causes the flow of liquid through the outlet 27 under substantially high pressure. The liquid travels through the outlet assembly and passes through the outlet nozzle in the form of a fine spray.
The seal 24 is preferably dimensioned so that it fits loosely around the inlet bushing 25 when the pump of housing 21 is not under pressure. As soon as pressure is generated within the housing 21, such pressure causes the seal 24 to tighten automatically into sealing engagement with the bushing 25. This arrangement provides a minimum amount of friction loss during rotation of the impellor. The positioning of the seal 24 can be varied in order to provide a simple means of adjustment to compensate for manufacturing tolerances.
The entire pump assembly and particularly the impellor and other rotatable parts can easily be made of lightweight metal or molded plastic. The parts require no machining and no close tolerances.
With the embodiment illustrated in the drawings, it is possible to operate the impellor at a speed of approximately 8,000 r.p.m. to generate a pressure up to 20 pounds per square inch with a flow rate of to gallons per hour.
1. A centrifugal pump which includes a cylindrical housing, a cylindrical impellor mounted for rotation within said housing by a drive shaft connected to a battery operated motor, said impellor having its outer periphery spaced a short distance from the inner periphery of said housing, said impellor having a plurality of passages extending outwardly from the center thereof, inlet means for supplying fluid to the center of said impellor, said impellor upon rotation ejecting said fluid into said passages by centrifugal force to develop sub- 4 stantially high pressure within said housing, and outlet means for ejecting said fluid from said housing under pressure, said inlet means being sealed to prevent any backflow or leakage into the interior of said housing, said seal for said inlet means comprising a piece of plastic tubing disposed within said housing beneath said impellor, said tubing having one end thereof fitting around a projection formed on the bottom of said impellor adjacent to the center thereof and its other end fitting around a fluid inlet extending into the center of the bottom of said housing.
2. The structure described in claim 1, and a drive shaft extending through the top of said housing adjacent to the center thereof, said drive shaft being connected to said impellor, said drive shaft being substantially aligned vertically with said plastic tubing seal.
3. The structure described in claim 2, the upper end of said fluid inlet forrnin g a bearing for said plastic tubing seal upon rotation of said impellor, said tubing fitting loosely around said fluid inlet when the interior of said housing is not under pressure, said seal being tightened by pressure within said housing to form a light leak-proof engagement with said inlet.
4. The structure described in claim 1, said impellor having two diametrically directed passages intersecting at right angles at the center of said impellor.
5. The structure described in claim 4, and four stationary fan blades disposed at the center of said impellor, said fan blades being constructed and arranged to direct fluid from said inlet into said passages.
6. The structure described in claim 4, said housing having an air bleed valve which is open when said housing is unpressurized, said bleed valve adapted to be closed by pressure within said housing during operation of said pump.
7. The structure described in claim 4, said pump being mounted adjacent the bottom of a tank holding a supply of fluid, said battery and motor being mounted adjacent the top of and outside said tank, and spray nozzle means connected to the output of said housing. l