MXPA96002279A

MXPA96002279A - Sprayer for trigger with ventilation depres

Info

Publication number: MXPA96002279A
Application number: MXPA/A/1996/002279A
Authority: MX
Inventors: J Barriac Jacques; B Dobbs Douglas
Original assignee: Calmar Inc
Priority date: 1995-06-15
Filing date: 1996-06-11
Publication date: 1997-08-01

Abstract

The present invention relates to a trigger pump pump, which comprises a housing assembly placed in a gas / vapor producing liquid product container, capable of generating a superatmospheric pressure in the container, the housing assembly has an assembly of pump cylinder open to the atmosphere at its outer end and having in its inner end region a pump chamber for a manually recirculated piston, the housing has assemblies for air ventilation of the container, which includes a ventilation chamber and a gate of ventilation that establish communication between the ventilation chamber and the interior of the container, the housing assemblies have inlet and outlet assemblies to supply the product inside and outside the pump chamber, a trigger lever hinged to the housing assemblies in coupling with the piston for manual reciprocation of the piston between positions without bo and pumping, assemblies on the piston to reciprocate together with it, the assemblies on the piston cooperate with the assemblies for air ventilation, to open and close the ventilation chamber to the atmosphere during reciprocation of piston between said positions, and the Air ventilation assemblies have first assemblies for pressure ventilation in an external location to the assemblies in the piston in the position without pumping to release the pressure from the container, through the ventilation damper and the ventilation chamber before movement out of the piston to the external location in response to superatmospheric pressure in the container

Description

PRESSURE VENTILATION TRIGGER SPRAYER BACKGROUND OF THE INVENTION This invention relates generally to a trigger-operated pump sprayer, and more particularly to the sprayer having assemblies for venting superatmospheric pressure of a container and from areas confined from the sprayer housing of pump when the trigger sprinkler is mounted in a container of liquid product gas / steam generator, capable of generating superatmospheric pressure in the container. Trigger or trigger sprinklers of the known type, as described in U.S. Pat. Nos. 4,747,523, 4,072,252 and 5,344,053, include assemblies for venting the container to the atmosphere during the pumping operation, for replenishing product supplied from the container with air to prevent hydraulic seizing and collapse of the container. A valve for venting of the vessel connected to the piston for movement together with it during reciprocation of the piston, slides inside a ventilation chamber having a vent gate passage communicating with the interior of the container. The seal for container ventilation responds to reciprocation of piston to allow communication and avoid communication of the interior of the container with the atmosphere through the opening / passage of ventilation and the ventilation chamber.

Also, confined areas of the pump housing, such as the pump chamber, the inlet passage and the discharge passage, are in communication with the interior of the vessel. When the trigger sprinkler according to any of these prior art types is mounted in a gas / vapor generating liquid product container such as a cleaning chemical capable of generating high pressure in the container, this pressure of The vessel, which is in communication with the ventilation chamber by the ventilation flap or vent passage, tends to force the pump piston out of its cylinder, exerting undue pressure against the trigger lever. Also, since the product formulation in the container is unstable, it tends to generate a certain amount of gas with a sufficient pressure to deform the side walls of the container outwardly. Before external extension of the piston, leakage of the pump chamber may occur. And, the piston that extends outwardly interferes with the function and efficient operation of the sprayer since it may require a higher force to trigger the trigger against the force of the internal pressure and may cause an unpredictable lost movement of the piston before triggering the trigger. interfere with the piston compression stroke. Further, since the superatmospheric pressure of the container communicates with confined areas of the pump housing, such as the pump chamber and the inlet and discharge passages, piston triggering is further prevented, and the product tends to discharge initially at spraying and spraying, until the pressure inside the spout system reaches atmospheric. The superatmospheric pressure under the conditions described above must therefore be ventilated to avoid leakage and achieve a trigger-operated pump sprayer that operates uniformly and efficiently. SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide an automatic pressure vent operating in the form of a pressure release valve for a trigger sprinkler mounted in a formulation vessel that can develop pressure from - of a gas generated by chemical reaction, thereby introducing a safety feature and allowing an efficient and leak-free operation of the sprayer. According to the invention, a first pressure vent in the form of a groove or a rib, extends in the direction of reciprocation of the piston, is formed in the wall of the chamber for container ventilation in an external location to the seal of Ventilation of the container to release pressure from the container through the vent gate / passage and the vent chamber before outward movement of the piston to this external location in response to superatmospheric pressure in the container. In addition according to the invention, a second pressure vent can be provided in the form of a rib or a slot extending in the direction of reciprocation of piston in the wall of the pump cylinder at a site external to the piston seal, to release pressure from the chamber of pump as well as the inlet and outlet passages around the piston seal and by the first pressure venting before the outward movement of the piston, in response to the internal pressure generated within the container. The outward movement of the piston in response to this internally generated pressure is resiliently resisted by the trigger lever which is provided with a spring-engaging effect which may be in the form of an integral spring designed as an open slot in the former. portion of the trigger that rests against the pump housing. This spring reaction tends to return the piston to its original position without pumping, ready for reciprocation by the trigger after pressure venting. The spring return for the piston can be a conventional "wet" spring located in the pump cylinder or it can be in the form of an external "dry" spring acting between the piston and the trigger lever to extract the piston during each piston return stroke. The external spring may have a pair of spring legs straddling the sides of the pump cylinder and abutting against an outer wall of the pump housing. A rod formed integrally with the piston has an active hinge and bears against the underside of the trigger, one end of the external spring engages an opening at an outer end of that rod for the spring to direct the lever relative to the piston. Other objects, advantages and novel features of the invention will be more apparent from the following detailed description of the invention when taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a vertical sectional view of a trigger sprinkler, of known construction that is mounted in a container, and that incorporates the features of the invention; Figure 2 is a view similar to Figure 1, showing an alternate external piston return spring according to the invention; and Figure 3 is a view taken substantially on line 3-3 of Figure 2. DETAILED DESCRIPTION OF THE INVENTION Turning now to the drawings, in which like reference characters refer to like and corresponding parts through the various views, the trigger sprinkler 10 illustrated in Figure 1, has a sprinkler housing 11 mounted on the neck 12 of the container, otherwise not illustrated by the arrangement of a threaded closure cap 13. The sprinkler housing is typically coated by an ornamental cover 14 coupled to it in any normal manner. The closure can be coupled by quick actuation to engage with the lower end of a cylindrical neck portion 14 of the housing, or the closure of another shape can couple the neck portion in some other convenient form that does not form part of the invention. The housing includes the pump cylinder 15 open at its outer end and having in its inner end region a pump chamber 16 for a manually reciprocable pump piston 17. An internal or "wet" coil return spring 18 extends between the end wall 19 of the pump cylinder and some convenient portion of the piston to return the piston to its inoperative position without pumping of Figure 1. An inner cylinder 21 of the spray housing holds a tube retainer 22 that suspends a dip tube conventional 23 that extends into the container. The dip tube and upper end of the tube retainer define an inlet passage 24 which is controlled by a valve through a conventional ball check valve 25 held in a valve seat at the upper end of the tube retainer.

The entrance passage terminates in an inlet gate 26 that opens in the pump chamber. A discharge gate 27 that opens from the pump chamber communicates with a discharge passage 28 which is valve controlled by an annular flap valve 29 located within a rotatable nozzle cover 31. A trigger actuator 32 is hinged to the sprinkler housing in some convenient manner as in 33, the trigger in the embodiment of Figure 1, has a hammer 34, which bears against an outer circular rim 35 of the piston. The piston has an internal annular piston seal 36, which may be in the form of a V-shaped seal directed inward, in sliding seal engagement with the pump chamber wall during pumping operation. A seal for container venting 37 in the piston, which may be in the form of an inwardly directed V-shaped seal, is spaced outwardly from the piston seal, forming an annular ventilation chamber 38 therewith. The ventilation chamber communicates with the interior of the container by means of a ventilation damper 39 located in the wall of the ventilation chamber, a passage 41 between 14 and 21 and an oval opening 42 of a packing seal 43, located between the lower end of the neck portion 14 and the upper end of the neck of the container.

In the illustrated embodiment, an axial rib or slot 44 is provided at a convenient location in the wall of the ventilation chamber to break the seal between the ventilation seal 37 and that wall during the pumping operation to open the ventilation passage of the ventilation chamber. container 39, 41, 42 to the atmosphere, to admit air into the container, to replace product supplied during each pumping pressure stroke to prevent hydraulic corrugation and crushing of the container. This ventilation characteristic of the container is described in US Pat. No. 4,747,523 and the US patent. No. 4,618,077. Otherwise, the rib / slot 44 may be removed and the vent gate 39 may be located at an external site of the illustrated one such as the vent seal 37 slides through the vent gate during the pumping operation to open and close the ventilation passage to the atmosphere, without departing from the invention. This container venting feature is described in U.S. Pat. No. 4,072,252 and in the U.S. patent. No. 5,344,053, the latter having a ventilation chamber that is not coaxial with the pump chamber. According to the invention, a first pressure vent, which may be in the form of an axial rib 45 (FIG. 1) or an axial slot 46 (FIG. 2) is provided in the wall in the ventilation chamber 38 in FIG. a site external to the vent seal 37 in the inoperative position, without pumping the piston illustrated in Figures 1 and 2. In this way, when the container contains a formulation that can accumulate pressure exceeding atmospheric from a gas generated by chemical reaction or similar, that superatmospheric pressure tends to expand the walls of the plastic container outward, and to extend the piston out of its cylindrical perforation as the gas communicates with the ventilation chamber of the container through the container vent passage. As the piston is forced out under that pressure, the container vent seal 37 travels with the piston to the rib site or pressure ventilation slot 45, 46, which breaks the seal, establishing a passage or passages. for pressure ventilation to the atmosphere. The superatmospheric pressure is thus vented from the interior of the container through the container ventilation passage 39, 41, 42, the ventilation chamber 38 and the pressure vent passage (s) established as the container ventilation seal 37, either is deformed by the rib 45 or slides through the slot 46. Also, as the superatmospheric pressure inside the container causes the piston to move out of its cylinder bore, the piston tends to place the lever triggering in tension as a trigger arm 47 bears against a confronting portion of the spray housing.

This undue tension is undesirable since it interferes with the uniform and efficient operation of the pump. Leakage from the pump chamber may occur during piston movement outward equally. According to another feature of the invention, a spring acting between the spray housing and the piston is provided to resist resiliently the outward movement of the piston and to return the piston to its rest position, without pumping of Figure 1. This spring may be in the form of an integral spring, such as a leaf spring 48 formed by an open slot 49 in the arm 47 of the trigger lever. Other external or integral resilient assemblies may be provided without departing from the invention. Another pressure or second venting according to the invention is provided in the form of an axial rib 51 (Figure 1) or an axial groove 52 (Figure 2) on the wall of the pump chamber at a site external to the seal piston 36. Therefore, during external piston movement in response to high pressure within the container acting on the piston both through the ventilation chamber 38 and through the pump chamber through the inlet passage, the elevated pressure from the pump chamber 16 and from the inlet and outlet passages 24 and 28, is vented to the atmosphere as the seal between the piston seal 36 and the wall of the pump chamber breaks before coupling between the seal 36 and the rib 51 or slot 52.

The pressure from the pump chamber and the inlet and outlet passages is released to the outside by the ventilation chamber 38 and the pressure ventilation passage established by breaking the container vent seal 37 as previously described. The outward movement of the piston in response to the elevated temperature inside the container is used for automatic container pressure venting and the confined areas of the spray housing to avoid interference with a uniform and efficient pumping operation. Leakage from the pump chamber during outward piston movement is prevented as the piston is automatically returned to its initial position, without pumping by a spring force acting against the outer end of the piston. An external reciprocating piston return spring "dry" 53, illustrated in Figures 2 to 4, may be provided in accordance with the invention. The hammer 34 or trigger lever 50 is removed, and instead a coaxial rod 54 is molded into the hollow piston, the rod has an active hinge 55 which forms an outer extension 56 having an opening 57. The spring 53 may be in the form of a spring fastener having a pair of curved legs spaced 58, 59, straddling opposite sides of the pump cylinder (Figure 3) and having a sine or curved portion 61 extending from the side bottom of the pump cylinder and abuts against the outer side of the neck position 14. The legs 58, 59 each may terminate in a fastener 62 which extends through the opening 57 and which is attached in a spring elbow 63 with the main portion of the legs. Otherwise, the legs 58, 59 can be joined at the elbow 63 and the simple fastener 62 can extend from that elbow through the opening 57. The external spring resiliently couples the rod 54 of the piston against the inner face of the lever. trigger, the extension 56 bears against an internal transverse wall 64 of the trigger. In this way, compared to the spring action of the inner spring 18 which pushes the piston out of its cylinder bore during each return stroke, the external spring effectively pulls the piston out of its cylinder bore during each return stroke of the piston. piston as the external spring resiliently forces the extension 56 against the trigger lever. Extension 56 otherwise does not connect to the trigger lever, so that the internal and external springs can be easily replaced, by simply replacing the piston return springs, the pistons and the trigger levers. Otherwise, the embodiment of Figure 2 has the same characteristics for pressure venting and spring assemblies for integral trigger lever for the piston, as described with reference to Figure 1. Pressure venting according to the invention is automatic and operates whenever the elevated pressure inside the vessel requires to be ventilated, since the pressure ventilation systems take advantage of the outward movement of the piston in response to that elevated pressure. The piston is returned to its initial position, without pumping, by a resilient trigger lever, again automatically to prevent leakage of the pump cylinder and to avoid interference with a uniform and efficient pumping operation. By pressure ventilation of the container, the pump operates more efficiently without leakage from the discharge nozzle, and performs as if the trigger sprinkler was mounted in a container that does not contain a formulation that tends to accumulate pressure from gas generated by a chemical reaction of liquid ingredients in the container. Before pressure ventilation as previously described, the pump sprinkler operates and operates as a trigger-operated jet or standard trigger, since liquid product is directed to the pump chamber by the submerged tube during each suction stroke and ejected from the pump chamber. the pump chamber during each stroke or pressure stroke applied by operation of the trigger lever.

Obviously, many modifications and variations of the present invention are possible in light of the above teachings. Therefore, it will be understood that within the scope of the appended claims, the invention may be practiced otherwise as specifically described. WHAT IS REVINDED IS:

Claims

CLAIMS 1. Trigger-operated pump dispenser, comprising a housing assembly placed in a gas / vapor producing liquid product container, capable of generating a superatmospheric pressure in the container, the housing assembly has a pump cylinder assembly open to the atmosphere at its outer end and having in its inner end region a pump chamber for a manually reciprocable piston, the housing has assemblies for air ventilation of the container, which includes a ventilation chamber and a ventilation hatch that communication between the ventilation chamber and the interior of the container is established, the housing assemblies have inlet and outlet assemblies for supplying the product inside and outside the pump chamber, a trigger lever hinged to the housing assemblies in engagement with the piston for manual reciprocation of it between positions without pumping and pumping, assembly s in the piston to reciprocate in conjunction with it, the assemblies in the piston cooperate with the assemblies for ventilation of air, to open and close the ventilation chamber to the atmosphere during reciprocation of piston between said positions, and the ventilation assemblies of Air have first mounts for pressure ventilation in an external location to the assemblies in the piston in the position without pumping to release the pressure from the container, through the ventilation damper and the ventilation chamber before movement out of the piston to the location external in response to superatmospheric pressure in the container.
2. A dispenser according to claim 1, wherein the assemblies in the piston comprise an annular vent seal.
3. Dispenser according to claim 1, wherein the first press vent assemblies comprise a slot in a wall of the air vent assemblies containing the vent gate, the slot extends in the reciprocating direction of the piston. .
A dispenser according to claim 1, wherein the first press vent assemblies comprise a rib in a wall of the air ventilation assemblies containing the vent gate, the rib extends in the reciprocating direction of the piston .
5. A dispenser according to claim 1, further comprising resilient assemblies acting between the housing assemblies and the piston to resist resiliently the outward movement of the piston and to return the piston to the position without pumping.
The dispenser according to claim 5, wherein the resilient assemblies are integral with the trigger lever.
A dispenser according to claim 5, wherein a portion of the lever rests against the housing assemblies, the lever portion having an open slot defining the resilient assemblies.
8. Dispenser according to claim 2, wherein the piston has an annular piston seal, the vent seal is axially spaced from the piston seal, to define the ventilation chamber therebetween.
9. Dispenser according to claim 1, wherein the piston has an annular piston seal, the cylinder assemblies have second assemblies for pressure ventilation, in a location external to the piston seal in the non-pumping position to release the pressure from the pump chamber and the inlet and outlet assemblies through the first assemblies for pressure ventilation before movement of the piston. A dispenser according to claim 9, wherein the second press vent assemblies comprise a rib in a wall of the cylinder assemblies, the rib extends in the reciprocal piston direction. A dispenser according to claim 9, wherein the second press vent assemblies comprise a slot in a wall of the cylinder assemblies, the slot extends in the reciprocal piston direction.