Battery operated spray head retrofittable onto existing pump spray containers and producing substantially continuous spray

Abstract

A battery operated spray pump includes a piston pump having a double wave cam which is pushed by a pair of rotating cam pushers coupled to the electric motor via a gear transmission. The double wave cam has an unequal duty cycle, i.e. takes more time to expel fluid from the piston cylinder than it takes to fill the cylinder. The cam pushers rotate at a speed which, in conjunction with the duty cycle of the cam, produces a low pressure nearly constant stream.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates broadly to battery operated fluid pumps. More particularly, this invention relates to a battery operated fluid pump contained in a spray head which fits onto existing pump spray containers and which exhibits substantially continuous spray.

2. State of the Art

Many household and industrial products are sold in containers that include a sprayer. These products include cleansers, insecticides, polishes, waxes, etc. There are several kinds of sprayers used with these products. Perhaps the most common is the manual push button or trigger operated pump which is seen most frequently on liquid cleansers. It has the advantage of being environmentally friendly (i.e. it does not require a propellant) but the disadvantage of delivering fluid in a series of pulses rather than in a continuous spray. Another well known sprayer is the aerosol can which is sealed and charged with a gas propellant. This sprayer has the advantage that it dispenses fluid in a continuous spray, but has several disadvantages. One disadvantage is that the can cannot be refilled. Another disadvantage is that depending on the gas used to charge the container, the propellant can be environmentally unfriendly. While environmentally friendly propellants do exist, generally, they do not charge as well as the unfriendly gases. Still another popular sprayer is the air pump sprayer seen most frequently with insecticides and liquid garden products. The pump sprayer includes a hand operated air pump which is used to charge the container with compressed air. After it is charged, it operates much like an aerosol can. The pump sprayer is environmentally friendly but requires considerable effort to keep charged because air is not as efficient a propellant as environmentally unfriendly gases such as FREON or hydrocarbon gasses.

In recent years there has been some experimentation with battery powered pump sprayers. Most of these devices include a spray mechanism which is similar to the ubiquitous push button (or trigger) pump sprayer but which is coupled to a battery powered electric motor by some type of linkage which converts the rotary action of the motor into an oscillatory motion to drive the pump piston. Many of these battery operated pump sprayers are designed to work only with a specially constructed bottle, i.e. they are not retrofittable to existing pump spray bottles. Many also have weight distribution problems, i.e. they are top heavy and cause the bottle to which they are attached to tip over. Many of these battery powered pumps have large priming volumes, thus causing a delay between the time the pump is activated and the time liquid begins to be dispensed. Significantly, these pumps do not really provide a constant spray. They provide a continuous pulsed spray like that obtained by repeatedly squeezing the trigger of pushing the button on a hand operated spray pump.

SUMMARY OF THE INVENTION

It is therefore an object of the invention to provide a battery operated spray pump.

It is another object of the invention to provide a battery operated spray pump that is retrofittable to an existing spray bottle.

It is an additional object of the invention to provide a battery operated spray pump which produces a substantially continuous spray rather than a pulsed spray.

In accord with these objects, which will be discussed in detail below, a battery operated spray pump according to the invention includes a piston pump having a double wave cam which is pushed by a pair of rotating cam pushers coupled to the electric motor via a gear transmission. The double wave cam has an unequal duty cycle, i.e. it uses more time to expel fluid from the piston cylinder than it uses in filling the cylinder. The cam pushers rotate at a speed which, in conjunction with the duty cycle of the cam, produces a low pressure relatively constant stream. According to the presently preferred embodiment, the duty cycle of the cam is approximately 270° and the speed of the cam pushers is approximately three rotations per second.

Additional objects and advantages of the invention will become apparent to those skilled in the art upon reference to the detailed description taken in conjunction with the provided figures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a partially transparent side elevation view of a sprayer according to the invention;

FIG. 2 is a partially disassembled perspective view of the sprayer of FIG. 1;

FIG. 3 is a further disassembled perspective view of the sprayer of FIGS. 1 and 2;

FIG. 4 is an exploded perspective view of the motor drive components;

FIG. 5 is an enlarged side elevation view of the double wave cam;

FIG. 6 is an enlarged top plan view of the double wave cam;

FIG. 7 is an enlarged side elevation view of the cam pusher;

FIG. 8 is an enlarged top plan view of the cam pusher;

FIG. 9 is an exploded perspective view of the piston pump components; and

FIG. 10 is a view similar to FIG. 5 but of a presently preferred double wave cam.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Turning now to FIGS. 1-3, a battery operated spray head 10 according to the invention includes an ergonomic housing 12 coupled to a threaded bottle coupling 14 and including an adjustable nozzle 16 and a trigger 18. The rear of the housing 12 includes a battery compartment 20 and extends rearward a sufficient amount to rest comfortably on the hand of the user when the user squeezes the trigger. Inside the housing 12, there are several subsystems, including the power source (batteries) 22, an electric motor 24, a transmission 26, and a piston pump 28. The trigger 18 is arranged so that when it is squeezed, it operates a double valve 30 and an electrical switch 32. One part of the double valve 30 fluidly couples the pump 28 to a tube (not shown) which extends from the valve 30 into the bottle 1 to which the bottle coupling 14 is attached. The other part of the double valve, opens an air path from the atmosphere to the interior of the bottle 1 via a tube 34 which extends from an opening (not shown) in the housing 12 to the valve 30. The double valve 30 and the electrical switch 32 are described in co-owned U.S. Pat. No. 6,752,330 to DiMaggio et al., the complete disclosure of which is hereby incorporated by reference herein.

FIG. 4 illustrates parts of the motor drive and transmission subsystems. These pieces include a front mounting bracket 40, a rear mounting bracket 42, a pinion gear 44, a reduction gear 46 with associated axle 48, a cam pusher drive gear 50 with associated axle 52 and rear spacer 54, and a double wave cam 56.

The motor 24 is coupled to the front mounting bracket 40 with its-drive shaft 24a extending rearward (see FIG. 3 as well). The pinion gear 44 is coupled to the motor drive shaft 24a. The reduction gear 46 is mounted between the front bracket 40 and the rear bracket 42 on its axle 48. The large diameter portion 46a of the reduction gear 46 engages the pinion gear 44. The small diameter portion 46b of the reduction gear 46 is engaged by the pusher drive gear 50. More particularly, the pusher drive gear 50 is mounted between the reduction gear 46 and the rear bracket 42 on the axle 52 which engages both the spacer 54 and the double wave cam 56 which is mounted in the front bracket 40. Before proceeding with the operation of the motor drive and transmission subsystems, it is advantageous to first consider details of the pusher drive gear 50 and the double wave cam 56.

Turning now to FIGS. 5 and 6, the double wave cam 56 includes an inner cylinder 56a and an outer cylinder 56b, each being formed to present a cam surface 56c, 56d, respectively, at one end thereof. The cam surfaces 56c, 56d are preferably identical in cam action (though having different diameters) and are offset from each other by 180 degrees. At the other end of the double wave cam 56, a reduced diameter cylinder 56e extends axially therefrom and a pair of arms 56f, 56g extend radially outward.

The cammed end of the double wave cam 56 is designed to interact with the pusher drive gear 50 which is illustrated in detail in FIGS. 7 and 8. The pusher drive gear 50 is generally disk shaped having a central mounting hole 50a and an outer plurality of gear teeth 50b arranged along its perimeter. A pair of cam pusher surfaces 50c, 50d are arranged on one side of the drive gear 50. These surfaces follow a circular path having the same center as the gear 50 but have unequal radii. The radii are chosen to match the diameters of the inner and outer cylinders 56a, 56b of the double wave cam 56. As illustrated, the pusher surface 50c is dimensioned to interact with the cam surface 56c of the inner cylinder 56a of the double wave cam 56. The pusher surface 50d is dimensioned to interact with the cam surface 56d of the outer cylinder 56b of the double wave cam 56.

Turning now to FIG. 9, the piston pump assembly 28 includes a generally T-shaped valve body 60 having three openings 60a-60c. Piston components 62-68 are fitted into the back opening 60a of the valve body 60. Inlet ball valve components and tube connector 70-78 are fitted in the bottom opening 60b of the valve body 60. Spray nozzle components 80-84 and 16 are fitted to the front opening 60c of the valve body 60.

The piston components include a spring 62, a piston 64, a piston rod 66, and a retainer cap 68. The spring 62 is inserted into the rear opening 60a of the valve body 60 and abuts an interior annulus (not shown). The piston 64 is inserted into the valve body 60 behind the spring which biases the piston backwards. The piston rod 66 is inserted behind the piston 64 and the retainer cap 68 is attached by force fitting to the valve body 60. The retainer cap 68 has a central opening through which the piston rod 66 extends. The piston, piston rod, and the interior of the valve body wherein the piston moves are preferably coated with a silicone lubricant (not shown).

The inlet ball valve components include a ball cage 70 having interior vanes (not shown), a valve ball 72, a retainer tube 74, a tube connector 76, and an inlet elbow 78. The retainer tube 74, adapter tube 76, and inlet elbow 78 are coupled to each other by epoxy and the retainer tube 74 is force fit into the bottom opening 60b of the valve body 60 capturing the ball 72 and the ball cage 70. It will be appreciated however that some or all of the retainer tube 74, adapter tube 76, and inlet elbow 78 may be integrally formed.

The spray nozzle components include a discharge valve 80, a volume reducer 82, spin mechanics 84, and an adjustable nozzle 16. The discharge valve is a circular flapper valve having a post 80a which extends forward into the volume reducer 82. The volume reducer occupies a cylindrical space having a diameter smaller than the diameter of the valve 80. The volume reducer 82 has a forwardly extending post 82a upon which the spin mechanics 84 is mounted. All of those components are inserted into the forward end 60c of the valve body 60 and the nozzle 16 is snap fit over the forward end of the valve body 60 where it retains the other components but is free to rotate.

Referring back to FIGS. 1-4, and 9, it will be appreciated that the transmission assembly 26 is mounted behind the piston pump assembly 28 with the double wave cam 56 mounted in the front bracket 40 by the arms 56f, 56g engaging slots 40a, 40b in the forward extending arms 40c, 40d of the bracket 40. The cam 56 is arranged so that its cam surfaces 56c, 56d face and engage the pusher surfaces 50c, 50d of the gear 50. The pump assembly 28 is mounted between the arms 40c, 40d of the bracket 40 with the piston rod 66 abutting the cylinder 56e of the double cam 56.

From the foregoing, those skilled in the art will appreciate that rotation of the motor drive shaft 24a causes rotation of the pinion gear 44 which rotates the reduction gear 48 at a slower rate. The reduction gear 48 causes rotation of the drive gear 50. As the drive gear 50 rotates, the pusher surfaces 50c, 50d engage the cam surfaces 56c, 56d and cause the double wave cam 56 to reciprocate back and forth against the piston rod 66. This causes the piston 64 to move back and forth in the valve body 60. When the piston moves backwards, the ball 72 is lifted by negative pressure in the valve body 60, allowing liquid to enter the valve body from the container 1 (FIGS. 1 and 2). At the same time, the flapper valve 80 is closed, preventing air from entering the valve body through the nozzle 16. When the piston moves forward, the ball 72 drops, sealing the ball valve and preventing liquid from reentering the container 1. At the same time, liquid is pushed forward against the flapper valve 80 causing it to open. The fluid then enters the reduced volume annular chamber defined by the volume reducer 82 and the front of the valve body 60. The liquid passes through this chamber and out of the nozzle 16.

According to the presently preferred embodiment, the forward moving duty cycle (the spray duty cycle) of the piston and the rearward moving duty cycle (the fill duty cycle) of the piston are unequal. In particular, this allows the piston to move more quickly during the fill duty cycle than during the spray duty cycle. In other words, the piston spends more time expelling fluid through the nozzle than it spends drawing fluid from the container into the valve body. This helps overcome the “pulsing” nature of certain prior art pumps and results in what appears to be a more continuous spray. According to the presently preferred cam arrangement, a 270° spray duty cycle and a 90° fill duty cycle is utilized. This arrangement is illustrated schematically in FIG. 10 which is similar to FIG. 5 with similar reference numerals (increased by 100) referring to similar parts. It can be seen in FIG. 10 that the cam surface 156d has a downward sloped portion 156d-1 of approximately 90° and an upward sloped portion 156d-2 of approximately 270°. Though not shown in FIG. 10, it will be appreciated that the cam surface 156c has the same configuration as surface 156d, but offset by 180°. Although the presently preferred embodiment uses a 270°/90° duty cycle, those skilled in the art will appreciate, however, that other unequal duty cycles could be used to obtain similar results. In particular, the duty cycle can be optimized for different kinds of fluids, optimizing the spray characteristics vs. the perceived pulsation of the spray. For example, if the fill duty cycle is longer than the spray duty cycle, this allows for a higher pressure spray resulting in finer atomization and/or greater spray distance at the cost of perceived pulsation.

Further, according to the presently preferred embodiment, the transmission 26 is arranged so that the piston 64 cycles between two and ten cycles per second, and most preferably between 2.5 and 4 times per second. This, together with the spray duty cycle discussed above, results in an apparently constant stream at a relatively low pressure (5-200 psi).

The spray head of the invention is well balanced, small, and is retrofittable to many existing fluid containers taking the place of a manual spray pump.

There have been described and illustrated herein several embodiments of a battery operated spray head retrofittable to existing pump spray containers. While particular embodiments of the invention have been described, it is not intended that the invention be limited thereto, as it is intended that the invention be as broad in scope as the art will allow and that the specification be read likewise. It will therefore be appreciated by those skilled in the art that yet other modifications could be made to the provided invention without deviating from its spirit and scope as claimed.

Claims

1. A battery operated liquid sprayer for use with a fluid container, said sprayer comprising:

a piston pump;

an electric motor; and

a transmission coupling said electric motor to said piston pump, said transmission including a double wave cam, wherein:

said piston pump has an intake cycle in which fluid is drawn from the fluid container and a spray cycle in which fluid is expelled from said pump,

said intake cycle and said spray cycle being of unequal duration.

2. The sprayer according to claim 1, wherein:

said spray cycle is of longer duration than said intake cycle.

3. The sprayer according to claim 1, wherein:

said spray cycle is approximately three times the duration of said intake cycle.

4. The sprayer according to claim 1, wherein:

said intake cycle and said spray cycle each occur at least twice per second but fewer than ten times per second.

5. The sprayer according to claim 1, wherein:

said intake cycle and said spray cycle each occur between 2.5 and 4 times per second.

6. The sprayer according to claim 1, wherein:

said double wave cam includes a pair of concentric cylinders each having a cam surface disposed 180° relative to the other.

7. The sprayer according to claim 6, wherein:

said transmission includes a pair of rotating cam pusher surfaces, each engaging a respective one of said cam surfaces.

8. The sprayer according to claim 7, wherein:

said cam pusher surfaces are coupled to a gear which is coupled to said electric motor.

9. The sprayer according to claim 1, further comprising:

a first one way valve coupled to an inlet of said piston pump, said first one way valve allowing liquid to enter through said inlet but not exit through said inlet; and

a second one way valve coupled to an outlet of said piston pump, said second one way valve allowing liquid to exit through said outlet but not enter through said outlet.

10. The sprayer according to claim 1, wherein:

said spray cycle is of shorter duration than said intake cycle.

11. A battery operated liquid sprayer for use with a fluid container, said sprayer comprising:

a pump;

an electric motor; and

a transmission coupling said electric motor to said pump, wherein

said pump has an intake cycle in which fluid is drawn from the fluid container and a spray cycle in which fluid is expelled from said pump,

said intake cycle and said spray cycle each occur between 2 and 10 times per second.

12. The sprayer according to claim 11, wherein:

said spray cycle is of longer duration than said intake cycle.

13. The sprayer according to claim 11, wherein:

said spray cycle is approximately three times the duration of said intake cycle.

14. The sprayer according to claim 11, wherein:

said intake cycle and said spray cycle each occur between 2.5 and 4 times per second.

15. The sprayer according to claim 11, wherein:

said intake cycle and said spray cycle each occur approximately three times per second.

16. The sprayer according to claim 12, further comprising:

a first one way valve coupled to an inlet of said pump, said first one way valve allowing liquid to enter through said inlet but not exit through said inlet; and

a second one way valve coupled to an outlet of said pump, said second one way valve allowing liquid to exit through said outlet but not enter through said outlet.

17. The sprayer according to claim 11, wherein:

said spray cycle is of shorter duration than said intake cycle.

18. A battery operated liquid sprayer for use with a fluid container, said sprayer comprising:

a piston pump;

an electric motor; and

a transmission coupling said electric motor to said pump, wherein

said pump delivers a substantially constant stream at a pressure between 5 and 200 pounds per square inch.

19. The sprayer according to claim 18, wherein

said pump has an intake cycle in which fluid is drawn from the fluid container and a spray cycle in which fluid is expelled from said pump,

said intake cycle and said spray cycle being of unequal duration.

20. The sprayer according to claim 19, wherein:

said spray cycle is of longer duration than said intake cycle.

21. The sprayer according to claim 19, wherein:

said spray cycle is approximately three times the duration of said intake cycle.

22. The sprayer according to claim 19, wherein:

said intake cycle and said spray cycle each occur at least twice per second but fewer than ten times per second.

23. The sprayer according to claim 19, wherein:

said intake cycle and said spray cycle each occur between 2.5 and 4 times per second.