Patent Publication Number: US-6981658-B2

Title: Liquid sprayers

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
   This application is a divisional patent application of U.S. patent application Ser. No. 09/624,061, to Streutker et al., filed Jul. 24, 2000, now U.S. Pat. No. 6,502,766. 

   TECHNICAL FIELD OF THE INVENTION 
   This invention relates to the field of liquid sprayers, and, more particularly, to the field of liquid sprayers having an electrical motor driving a pump. 
   BACKGROUND OF THE INVENTION 
   Sprayers have been generally used to spray liquids in order to atomize in fine droplets a liquid. The atomization of a liquid enables a better coverage of a surface by the liquid. Usually, sprayers comprise a container which is used to store the liquid and which is connected to a sprayer head. The sprayer head usually includes a trigger which activates a pump that drives the liquid to the nozzle which in turns atomizes the liquid. Those sprayers are manually activated and require the user to push the trigger several times so long as she wishes to spray the liquid. In addition to require the user to push the trigger several times, those manually activated sprayers can only maintain a uniform pattern of spray for a relatively short period of time. One of the improvements made to the sprayers was to incorporate an electrical motor connected to a switch and a portable voltage source to them. Those electrical sprayers only require the user to push the trigger once and maintain the trigger pushed as long as the user wants to spray liquid. The use of those sprayers is usually limited by the autonomy of their voltage source and as a result, one of the problems faced by an inventor is to provide an efficient mechanism which uses energy in the voltage source as to increase the service life of such a device without having to either recharge or change the voltage source prematurely. It can easily be contemplated that the use of electrical components such as a switch, a motor and a voltage source makes those electrical sprayers sensitive to liquid which might be responsible of malfunction of the device in the event the liquid comes in contact with those components. As a result, another problem faced with those sprayers is to provide a device which can limit the risk that the liquid to be sprayed might enter in contact with the electric components. 
   For the foregoing reasons, there is a need for an electrical sprayer with a higher efficiency and that limits the risk of malfunction due to contacts between a liquid to be sprayed and electrical components. 
   SUMMARY OF THE INVENTION 
   A liquid sprayer is provided. The liquid sprayer includes a bottle having an opening, a sprayer housing attached to the bottle. This sprayer housing includes an electric motor, a voltage source for powering the electric motor, a pump driven by the motor, a switch for completing an electrical circuit, a nozzle mechanism attached to the sprayer housing for spraying a liquid, a vent housing having an inner surface and an outer surface, and a translating piston disposed in the vent housing. The sprayer housing also includes a trigger movably connected to the sprayer housing for closing the switch and translating the piston, a first vent tube extending from the opening of the bottle to a first opening of the vent housing a second vent tube extending from the second opening of the vent housing to the first opening of the nozzle mechanism, a pump supply tube extending from the opening of said bottle to an inlet of the pump and a pump discharge tube extending from the outlet of the pump to the second opening of the nozzle mechanism. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     While the specification concludes with claims particularly pointing out and distinctly claiming the invention, it is believed that the present invention will be better understood from the following description taken in conjunction with the accompanying drawings in which: 
       FIG. 1  is a perspective view of the liquid sprayer showing the sprayer head connected to the bottle. 
       FIG. 2  is an exploded view of a preferred liquid sprayer made in accordance with the present invention but omitting the bottle for clarity; 
       FIG. 2A  is a fragmentary enlargement of  FIG. 2  showing the semi-circular openings on the lower housing. 
       FIG. 3  is a perspective view of the sprayer head assembled without the upper shell and one of the lower housing; 
       FIG. 4  is a cross-sectional side view along line  4 — 4  of  FIG. 5  of the vent housing of the liquid sprayer of  FIG. 2 ; 
       FIG. 5  is a side view of the vent housing of  FIG. 2 . 
       FIG. 6  is a cross-sectional side view along line  6 — 6  of  FIG. 7  of the vent piston of the liquid sprayer of  FIG. 2 ; 
       FIG. 7  is a side view of the vent piston of the liquid sprayer of  FIG. 2 . 
       FIG. 8  is a cross-sectional side view of the venting mechanism in the first position with the trigger, the switch and where the compression spring has been removed for clarity. 
       FIG. 9  is a cross-sectional side view of the venting mechanism in the second position with the trigger, the switch is closed and where the compression spring has been removed for clarity. 
       FIG. 10  is a cross-sectional view along line  10 — 10  of  FIG. 9  of the vent housing with the translating piston. 
       FIG. 11  is a fragmentary enlargement of  FIG. 10  showing the deformation of the chevron member 
       FIG. 12  is a cross-sectional view of the fitment, the check valves and the dip tube. 
       FIG. 13  is a cross-sectional side view of the nozzle mechanism with the nozzle adapter, the discharge valve, the spin mechanics and the nozzle of the liquid sprayer of  FIG. 2 . 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Reference will now be made in detail to the present preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings wherein like numerals indicate the same elements throughout the views and wherein reference numerals having the same last two digits (e.g.,  20  and  120 ) connote similar elements. Referring to  FIG. 1 , a preferred liquid sprayer  20  comprising a bottle  22  and a sprayer head  24  is illustrated which is suitable for spraying a variety of liquid compositions. While the liquid sprayer  20  is particularly suited for use with household compositions, it is contemplated that other liquid compositions can be used with the liquid sprayer  20 . The bottle  22  preferably has a capacity of about 1 liter, although other bottle sizes can be used. 
   Referring to  FIG. 2 , the sprayer head  24  comprises the upper shell  124  and two lower housings  224  and  324  connectable with snap or screw connections. Instead of having a sprayer head out of three elements  124 ,  224  and  324 , other housing structures are possible without departing from the scope of protection. The sprayer head  24  houses the spray mechanics, including an electrical motor  26  which is directly coupled to a gear pump  28  and a venting mechanism including a vent piston  30  slidably disposed within a vent housing  32  and a spring  33  biasing the vent piston in the direction of a trigger  34 . As shown in  FIGS. 8 and 9 , a first position of the vent piston  30  in the vent housing  32  prevents venting to occur and a second position of the vent piston  30  in the vent housing  32  enables venting in the bottle. The venting mechanism will later be described in greater details. The trigger  34  is movably attached to left and right housings  224  and  324  when the liquid sprayer is assembled. The trigger  34  translates the vent piston  30  within the vent housing  32  and closes a switch  40 . Preferably, the vent piston and switch are arranged so that the vent piston  30  begins to translate before the trigger  34  closes the switch  40 . Most preferably, the vent piston  30  and switch  40  are arranged so that the vent piston is in the second position, and therefore enables venting, before the trigger  34  closes the switch  40 . When closed by the trigger, the switch  40  completes an electrical circuit between a portable voltage source, illustrated as a plurality of batteries  42 , and the electrical motor  26  and therefore activates the gear pump  28 . While the pump  28  is preferably provided in the form of a gear pump, other pumps and structures for pressurizing a liquid and delivering the liquid to the nozzle mechanism  60  can be used. For example, vane, piston, lobe, or diaphragm pumps would be acceptable for use. The gear pump  28  is maintained in position by being engaged in two slots located in each of the housings  224  and  324 . 
   In one embodiment of the invention, the first vent tube  52  is connected to the first opening  132  of the vent housing  32  and extends towards the opening of the bottle  22  while a pump supply tube  54  is connected to the inlet  128  of the gear pump  28  and also extends towards the opening of the bottle  22 . A pump discharge tube  56  interconnects the pump outlet  228  with a nozzle adapter  160  through a first passage  160   a . A second vent tube  58  interconnects the second opening  232  of the vent housing  32  with an opening of the sprayer housing wherein the vent aperture is exposed to the ambient environment. In another embodiment of the invention, the second vent tube  58  interconnects the second opening  232  of the vent housing  32  with a vent aperture  160   b  disposed on the nozzle adapter  160 , wherein the vent aperture is exposed to the ambient environment through semicircular cut-outs  62  in each of the housings  224  and  324 . The vent aperture  160   b  is located upwardly and axially away from the switch  40  so that in the event the sprayer is in a substantially downward position and a liquid has been able to enter in the venting tubes, this liquid will drop away from the switch  40  and thus substantially limit the risk of contact between the liquid and the switch. As a result, the location of the vent aperture  160   b  disposed on the nozzle adapter  160  limits the risk of malfunction of the sprayer. The nozzle adapter  160  has a hollow post which passes through larger semicircular cut-outs  66  in each of the housings  224  and  324 . Disposed within the hollow post is a discharge valve  260  and the spin mechanics  360 . A nozzle  460  is mounted on the nozzle adapter as shown in  FIG. 13 . 
   In one embodiment of the invention, a fitment  44 , as shown in  FIG. 3  and  FIG. 12 , is disposed adjacent the bottom of the lower housings  224 ,  324  and comprises a bayonet-type fitment for engaging a complementary fitment on the finish of the bottle  22 . The fitment  44  is maintained in position by being engaged in two slots located in each of the housings  224  and  324 . The fitment  44  includes first and second through passages  144  and  244 . The first vent tube  52  interconnects the first through passage  144  with a first opening  132  of the vent housing  32  while a pump supply tube  54  interconnects the second through passage  244  with the inlet  128  of the gear pump  28 . A first check valve  70  is connected to the first through passage  144  and prevents a liquid from significantly exiting the bottle when the bottle is in a substantially downward position. A second check valve  72  is connected to the second through passage  244  and prevents a liquid from significantly reentering into the bottle  22  when the pump  28  is not functioning. A dip tube  80  extends from the bottle  22  and the second check valve to supply the sprayer with liquid. A dip tube filter  82  can be added at the lower end of the dip tube  80  to prevent particles which may obstruct the nozzle to reach it. In order to effectively spray a liquid, the gear pump  28  will initially need to be primed. By preventing a liquid to significantly reenter into the bottle when the user releases the trigger  34  the second check valve  72  eliminates the necessity to reprime the gear pump after each use of the sprayer and thus improves the efficiency of the liquid sprayer by saving energy in the voltage source. As a result, the check valve  72  contributes to save energy in the portable voltage source. The cracking pressure of the check valve  72  should be sufficient so that a liquid entering the pump supply tube  54  has enough energy to be driven through the gear pump  28 , through the nozzle mechanism  60  and break the fluid up into fine droplets. The first and the second check valve,  70  and  72 , may be ball valves or other type of check valves commonly known in the art, such as a membrane valves. In another embodiment of the invention, the fitment  44  includes at its lower end a leak tight seal to prevent leakage of the liquid from the bottle. 
   The electric motor  26  is preferably a direct current electric motor. The electric motor  26  has two electrical connections to which are preferably connected with electrical wires the portable voltage source, illustrated as a plurality of batteries  42  in series, with the switch  40 . When the trigger  34  is activated, the translating piston  30  comes to the second position so that venting occurs substantially before the switch  40  is closed. When the switch  40  is closed, an electrical current flows through the electric motor  26  which rotates the gears of the pump  28  to generate a pressure sufficient to open the check valve  72  so that a liquid can flow through the nozzle  60 . The occurrence of the venting substantially before the switch  40  is closed contributes to improve the efficiency of the liquid sprayer by equalizing the pressure inside the bottle with the pressure of the ambient environment before the pump is activated,. An exemplary motor is a 3 volt to 6 volt series 200 or 300 motor manufactured by Mabuchi Industry Company, Ltd. Of China. Preferably, the motor is a 4.5 volt model RS360SH manufactured by Mabuchy Industry Company, Ltd. An exemplary spray nozzle is manufactured by Calmar, INC. and more fully described in U.S. Pat. No. 4,706,888 to Dobbs et A1, issued Nov. 17, 1987, the substance of which is fully incorporated herein by reference. The sprayer housings  124 ,  224 ,  324 , nozzle mechanism  60 , gear pump  28 , fitment  44 , vent housing  32  and venting piston  30  can be injection molded using thermoplastic materials as is known in the art. Preferably, the trigger, the spin mechanics, the fitment, the vent housing are formed from polypropylene and the pump housing, the pump cap and the pump gears are formed from acetal polymer. Preferably, he sprayer housings  124 ,  224 ,  324  are formed from a mixture of acrylonytrile-butadiene-styrene and palycarbonate. Preferably, the vent piston, the nozzle and the nozzle adapter are formed from polyethylene. The voltage source  42  is preferably three AA, 1.5 volt Panasonic Alkaline batteries which are connected in series. 
   In accordance with one aspect of the present invention, the venting mechanism will now be described in greater detail with reference to  FIGS. 4  through  FIG. 11 . The venting mechanism includes a vent housing  32  and a translating piston  30 . The vent housing is preferably a hollow cylinder closed at one end and having two openings  132  and  232  located on the cylinder&#39;s wall. Preferably, the two openings are spaced apart along the axis A—A of the vent housing as shown in  FIG. 4 . The other end of the vent housing is left open to enable the translating piston  30  to enter the vent housing. As shown in  FIG. 6 , the translating piston  30  is substantially a cylinder whose diameter is smaller than the inner diameter of the vent housing so that it can slide within the vent housing  32 . When used in accordance with this invention, one extremity of the translating piston is closed and the other extremity is in contact with the trigger  34  so that motion of the trigger will translate the piston within the vent housing. The translating piston also comprises a first and a second deformable component having a portion that has a surface in contact with the inner surface of the vent housing and is capable of being deformed to leave a gap. The first deformable component is located on the translating piston so that when the piston is in a first position as shown in  FIG. 8 , and a second position as shown in  FIG. 9 , air cannot flow between the second opening  232  and the open end of the vent housing  32 . The second deformable component is located on the translating piston  30  so that when the piston is in a first position as shown in  FIG. 8 , air cannot flow between the first and second opening,  132  and  232 , and when the piston is in a second position as shown in  FIG. 9 , air can flow between the first opening  132  and the second opening  232  of the vent housing  32 . In one embodiment of the invention, those deformable components are a first and a second chevron shaped member (herein after “chevron member” for simplicity)  130  and  230 , located on the outer surface of the translating piston. As defined with regard to this invention, a chevron member is preferably a flexible ring with one edge connected to the outer surface of the translating piston. The chevron member has a V shape when view from the side. Those chevron members can also be formed onto the surface of the piston when the piston is molded. The largest diameter of those chevron members is longer than the inner diameter of the vent housing so that the other edge of the chevron members is substantially in contact with the inner surface of the vent housing when the translating piston slides in it. As a result, air cannot flow through those chevron members and thus provide a sealing effect. In one embodiment of the invention, the vent housing includes means for deforming the second chevron member  230 , and located on the inner surface of the vent housing between the first and the second opening. When the trigger  34  is activated, the translating piston leaves its first position and moves towards the deforming means. When the second chevron member  230  encounters the deforming means, it is deformed and leaves a gap and thus the piston reaches the second position. Because of the gap created by the deformation of the chevron member, air can flow between the first and the second opening of the vent housing to enable venting. This deforming means is so that it will keep the second chevron member deformed at least until the trigger  34  closes the switch  40 . Such deforming means can be for instance at least one element projecting from the inner surface of the vent housing. Such element can be in the form of a fin or a rib  332  located in the inner surface of the vent housing between the first and the second opening of the vent housing but other elements may be used to provide the same effect. The element can be either fixed or directly molded on the inner surface of the vent housing. Preferably, The inner surface of the vent housing has four of those elements as show in  FIG. 4 . In another embodiment of the invention, the venting mechanism also includes a compression spring located in the vent housing and biasing the translating piston so that when the user releases the trigger, the translating piston comes back to its first position. In one embodiment of the invention, the compression spring is kept centered in the vent housing by fins  432  extending from the closed end of the vent housing towards its opened end. 
   In another embodiment of the invention, the portable voltage source  42  is composed of rechargeable batteries connected by electric wires to a printed circuit board  84  comprising a battery charger jack  86  extending through the sprayer housing. Once the batteries are discharged, the user can connect the charger jack to a charger and thus recharge the batteries. 
   The foregoing description of the preferred embodiments of the invention have been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Modifications or variations are possible and contemplated in light of the above teachings by those skilled in the art, and the embodiments discussed were chosen and described in order to best illustrate the principles of the invention and its practical application. It is intended that the scope of the invention be defined by the claims appended hereto.