Trigger sprayer having a pump chamber with an internal spring for biasing the pump piston

Abstract: A trigger sprayer assembly for dispensing liquid from a container includes a pump element secured to a housing (480) of the assembly. The housing (480) has a portion defining a cylindrical pump chamber (512), and the pump element further comprises a piston (510) reciprocable within the cylindrical pump chamber (512) in response to actuation of a trigger (14). A spring element (514) has a base portion (516) secured to the housing (480), and a resilient arm portion (526) that extends forwardly therefrom and engages the piston (510) so as to bias the piston (510) to an extended position.

Description: Background of the Invention This invention is directed to the field of trigger dispensers, also known as trigger sprayers. The invention is particularly directed to such a sprayer having unique features that reduce the cost of the sprayer. Generally, a trigger dispenser of the type involved here is a relatively low cost pump device which is held in the hand and which has a trigger operable by squeezing or pulling the fingers of the hand to pump liquid from a container and through a nozzle at the front of the dispenser. Such trigger dispensers may have a variety of features that have become common and well-known in the industry. For example, the dispenser may be a dedicated sprayer that produces a defined spray pattern for the liquid as it is dispensed from the nozzle. It is also known to provide adjustable spray patterns such that with a single dispenser the user may select any one of several stream patterns from a stream to a fine mist. Some known trigger dispensers also include a way to seal the dispenser to prevent liquid from leaking from the nozzle orifice during shipment or non-use. A variety of sealing arrangements are known. It is also well-known to provide trigger dispensers with a means to produce foaming of the liquid as it is dispensed from the nozzle orifice. Such trigger dispensers are generally referred to in the industry as "foamers". Various types of foamers are well-known. DE-A-36 01 612 discloses a trigger sprayer where the pump element is of elastomeric material and biases the trigger to its starting position. While trigger sprayers of the type to which the present invention is directed are of relatively low cost, the various aspects of the present invention serve to further reduce costs, while at the same time providing versatility in design and reliable service. To put this into perspective, millions of trigger sprayers are sold each year for use in dispensing a wide variety of products. Because of the large volumes, a savings of only a few cents, or even one cent, is significant. So the objective of the present invention is to provide a trigger sprayer with cost-saving features relative to those presently in the marketplace while maintaining acceptable performance criteria. Summary of the Invention Accordingly, the invention provides a trigger sprayer assembly having the characterising features of Claim 1, 4 or 10. The trigger sprayer assembly spring element comprising a resilient arm portion extending forwardly of a base portion secured to the housing, and biasing the piston to an extended position represents a cost savings in a trigger sprayer utilizing a reciprocating piston pump element. Preferably the spring element is formed from an elastomeric material, thereby further reducing unit manufacturing costs. The invention will now be further described, by way of example, with reference to the following drawing. Figure 1 is a view in section showing a trigger sprayer of the present invention. The trigger sprayer shown in Figure 1 comprises a housing 480 having a front section 482 and a rear section 484. The housing has an integrally-formed bayonet connector 486 for connecting the housing to a container. The rear section 484 is pivotally attached at the bottom to the bayonet connector 486 by a living hinge 488. The upper end of the rear section 484 has a plug portion 490 formed integrally therewith and which has outwardly-extending shoulders 492. The housing 480 has a vertical cavity 494 which receives the upper end of a dip tube. A fluid passage 496 extends from the upper end of the dip tube to a check valve 498. The check valve comprises a valve seat 500 formed in the housing at the upper end of the passage 496, and a ball valve 502 which is inserted through an opening 504 in the housing above the check valve 498. The rear section 484 of the housing is secured in the closed position as shown in Figure 1 by snapping the plug portion 490 into the top of the opening 504, the opening having complementary recesses to receive the shoulders 492 in snap engagement. Hence, during assembly, the housing is moulded with the rear section 484 in a horizontal position (ie in a position at 90° clockwise to that shown in Figure 1 about the hinge 488). After the ball valve 502 is inserted through the top opening of the housing, the rear section is pivoted to the closed position and the plug portion 490 snapped into the opening to enclose the ball valve. The pump element comprises a piston 510 which reciprocates within a cylinder portion 512 formed by the housing. An elastomeric spring 514 biases the piston in the extended position shown in Figure 1. The elastomeric spring 514 is of integral construction and has a base 516 which forms an annular sleeve 518. The sleeve fits within an annular groove 520 in the housing. The annular groove defines a central cylindrical portion 522 of the housing which fits within the sleeve. The elastomeric spring has a radial portion 524 seated within a complementary groove in the housing, and a curved forwardly projecting portion 526 extending therefrom with the forward end lodged within a groove 528 formed in the rear face of the piston. The resilient elastomeric arm portion 526 of the spring element biases the piston in the extended position. The elastomeric spring element represents a cost savings in a trigger sprayer utilizing a reciprocating piston pump element. A liquid passage 530 extends from the pump chamber to passages 532 formed in the housing at the rear of the cavity 34 which houses a spinner assembly 534. The spinner assembly is of integral moulded construction with the main portion 536 of the assembly extending nearly the full length of the cavity and being relatively rigid. The front face 538 of the spinner assembly is formed in a conventional manner with tangential grooves and a spinner recess or swirl chamber for imparting a spinning motion to the liquid before exiting through the nozzle orifice to produce a spray pattern. The main portion has suitable slots 540, 542 to allow the flow of liquid through the cavity toward the orifice. At the rear of the spinner portion 536 there are radial fins 544 which fit in close proximity to the wall of the cavity to center the rear of the spinner portion 536. An axial hub 546 extends to the rear and has a flexible diaphragm disc 548 moulded integrally with the hub. With the spinner assembly mounted in the cavity 34, the diaphragm disc overlies the openings 532. The length of the spinner assembly 534 relative to the cavity 34 is such that a preload is applied to the diaphragm disc to give it a dish-shaped configuration as shown in Figure 1 after the spinner assembly is mounted in the cavity. The spinner assembly either may be moulded with the diaphragm disc flat, or in a dish-shaped configuration. To assemble the spinner assembly, the spinner assembly 534 is inserted into the cavity 34 from the front of the housing, and then the nozzle assembly 24 is attached to the housing to capture the spinner assembly within the cavity. In operation, when the trigger 14 is pulled the liquid pressure causes the diaphragm disc 548 to flex so that liquid may flow from the chamber, through the passage 530, openings 532, and past the diaphragm disc and into the cavity 34. Upon releasing the trigger 14 there is a reduction of pressure in the passage 530 and openings 532 such that the diaphragm disc seals the openings 532 to prevent the passage of liquid therethrough. Instead, liquid is drawn from the container, through the dip tube and check valve 498, passage 530, and into the pump chamber. While the present invention has been described by reference to a specific embodiment, it should be understood that modifications and variations of the invention may be constructed without departing from the scope of the invention defined in the following claims.

Claims: A trigger sprayer assembly for dispensing liquid from a container, said assembly comprising: a housing (480) having a liquid passage (34) therein a nozzle at the front of the passage (34) and having an orifice through which liquid is dispensed; a trigger (14) secured to said housing (480) for actuation thereof relative to said housing; a pump element secured to said housing (480) and which is operable in response to actuation of said trigger (14) for pumping liquid from a container and through said liquid passage (34) and said orifice; said housing (480) having a portion defining a cylindrical pump chamber (512), said pump element further comprising a piston (510) reciprocable within said cylindrical pump chamber (512) in response to actuation of said trigger (14); and a spring element (514) which has a base portion (516) secured to the housing (480), and a resilient arm portion (526) that extends forwardly therefrom and engages the piston (510) so as to bias the piston (510) to the extended position, said resilient arm portion (526) flexing upon actuation of said trigger (14). A trigger sprayer assembly as claimed in Claim 1 wherein the spring element (514) is elastomeric. A trigger sprayer assembly as claimed in Claim 1 or Claim 2, wherein said spring element (514) is positioned within said cylindrical pump chamber (512). A trigger sprayer assembly for dispensing a liquid substance from a container, the assembly comprising: a housing (480) having a liquid passage (34) extending between a first and a second end; a nozzle positioned at the first end of the passage (34), the nozzle having an orifice through which the liquid substance is dispensed; a pump element secured to the housing (480), the pump element having an internal volume which varies in response to actuation of the pump element between an extended position wherein the internal volume is maximized and a contracted position wherein the internal volume is minimized, the pump element drawing the liquid substance from the container in response to an increase in the pump element internal volume and expelling the liquid substance through the nozzle orifice in response to a decrease in the pump element internal volume; and a spring element (514) secured to the housing (480), the spring element (514) including a curved elastomeric leaf (526) extending from the housing (480) to the pump element for biasing the pump element toward the extended position and a base (516) attached to the leaf (526) for securing the spring element (514) to the housing (480); wherein the housing (480) has a groove (520) adjacent the spring element (514) and the spring element (514) includes a tab (518) extending from the base (516), the tab (518) being configured to engage in the housing groove (520) to secure the spring element (514) to the housing (480). A trigger sprayer assembly as claimed in Claim 4 wherein the spring element (514) is positioned within the interior volume of the pump element. A trigger sprayer assembly as claimed in Claim 4 wherein the housing groove (520) and the spring element base tab (518) are annular. A trigger sprayer assembly as claimed in Claim 4 wherein the spring element (514) further includes a radial portion (524) extending between the base (516) and the curved elastomeric leaf (526). A trigger sprayer assembly as claimed in Claim 4 wherein: the pump element is comprised of a cylinder (512) formed in the housing (480) and a piston (510) configured to reciprocate within the cylinder (512); and the curved elastomeric leaf (526) of the spring element (514) extends from the housing (480) to the piston (510) to bias the pump element toward the extended position. A trigger sprayer assembly as claimed in claim 8 wherein the cylinder (512) defines the interior volume of the pump element and the spring element (514) is positioned within the pump element cylinder (512). A trigger sprayer for dispensing a liquid substance, the trigger sprayer comprising: a housing (480) having an orifice through which the liquid substance is dispensed; a pump positioned within the housing (480) for pushing the liquid substance through the housing orifice in response to actuation of the trigger, the pump being configured to reciprocate between a contracted and an extended position, the pump having an interior volume which varies in response to reciprocation of the pump; a spring (514) having an arm (526) extending between the pump and the housing (480) for biasing the pump toward the extended position, the spring (514) further including a base (516) positioned adjacent the sprayer housing (480); and a fastener configured to secure the spring to the housing, the fastener including a projection (518) extending from the spring base (516) and a recess (520) formed in the housing (480), the recess (520) being configured to accept and retain the spring base projection (518) within the recess (520). A trigger sprayer as claimed in Claim 10 wherein the spring base projection (524) and the housing recess (520) are annular. A trigger sprayer as claimed in Claim 10 wherein the spring (514) further includes a radial portion (524) connecting the arm (526) to the base (516). A trigger sprayer as claimed in claim 10 wherein the spring (514) is positioned within the interior volume of the pump. A trigger sprayer as claimed in claim 10 wherein the pump is comprised of a cylinder (512) and a piston (510) configured to reciprocate within the cylinder (512) in response to actuation of the trigger sprayer.

Inventors: FOSTER DONALD D, NELSON PHILIP L, FOSTER, DONALD D., NELSON, PHILIP L.
Applicants: CONTINENTAL SPRAYERS INT INC, CONTINENTAL SPRAYERS INTERNATIONAL, INC.
Application year: 1993
Main classification: B05B11
IPC codes: B05B11, B05B1