DISPENSER PUMPS

Abstract

A dispenser pump for spraying a fine mist has a plunger (2) reciprocable in a pump body (3). The plunger has a head (4) and a stem (5). A closure (8) holds the pump in a container neck, and has an external decorative crimp sleeve (82). The plunger head has a matching external trim (72). A pump spring (7) is mounted outside the pump chamber (71), around the stem above the piston thereof. A pre-compression spring (75) acts to delay opening of the outlet piston seal until sufficient pressure builds in the pump chamber (71).

Claims

1. Dispenser pump comprising: a body having a cylinder portion and an insert portion fitting into a top of the cylinder portion, the cylinder portion defining a pump chamber having an inlet with an inlet valve, the pump chamber communicating with an outlet passage and the plunger being reciprocable relative to the body between an extended position and a depressed position in a dispensing stroke to drive liquid from the pump chamber through the outlet passage to a discharge nozzle thereof; a plunger having an actuating head and a stem portion, the insert portion of the body defining a guide opening through which the stem portion passes; and a return spring acting between the body and the plunger to bias the plunger up away from the depressed position and towards the extended position; and wherein the return spring includes a top extremity retained above an abutment of the cylinder portion, and a lower extremity retained below an abutment of the stem portion, whereby depression of the plunger stretches the return spring.

2. Dispenser pump of claim 1 wherein a top extremity of the return spring is retained in a trapping recess defined between said abutment of the cylinder portion which is an upward abutment adjacent a top mouth of the cylinder portion, and a downwardly-directed portion of the insert portion.

3. Dispenser pump of claim 1 further comprising a sliding seal member carried on the stem portion, the sliding seal member having a piston portion engaging a cylinder wall of the cylinder portion, and the sliding seal member being movable on the stem portion to either cover or uncover one or more entry openings in the stem portion which communicate between the pump chamber and the outlet passage in the stem portion.

4. Dispenser pump of claim 3 wherein the stem portion has top and bottom abutments limiting said movement of the sliding seal member, and the pump chamber comprises a pre-compression spring which acts upwardly against a downward abutment of the stem and downwardly against the sliding seal member.

5. Dispenser pump of claim 4 wherein the return spring and the pre-compression spring are provided respectively as upper and lower parts of a pump spring, the stem portion having one or more formations constituting an intermediate spring retainer which engages the pump spring between the upper and lower parts thereof.

6. Dispenser pump of claim 5 wherein the intermediate spring retainer formation comprises a downward shoulder proximate to the stem portion whereby, when the plunger is depressed, the upper part of the pump spring is stretched while the lower part tends to be compressed for pre-compression.

7. Dispenser pump of claim 5 wherein the upper part of the pump spring has a larger diameter than the lower part.

8. A dispenser pump comprising: a body defining a pump chamber having an inlet with an inlet valve, the pump chamber communicating with an outlet passage and the plunger being reciprocable relative to the body between an extended position and a depressed position in a dispensing stroke to drive liquid from the pump chamber through the outlet passage to a discharge nozzle thereof; a plunger comprising an actuating head and a stem portion; a return spring acting between the body and the plunger to urge the plunger towards the extended position, the return spring being compressed as the plunger is moved to the depressed position; wherein the return spring is a coil spring disposed around the plunger stem outside the pump chamber and wherein the body includes a pump spring abutment and an end of the return spring engaging the pump spring abutment.

9. Dispenser pump of claim 8 wherein the plunger comprises a top spring abutment to engage the top of the return spring and the body comprises a bottom spring abutment to engage a bottom of the pump spring.

10. Dispenser pump of claim 9 wherein the plunger comprises a discrete adapter piece fitted to the end of the stem portion and serving as the top spring abutment, and the actuating head of the plunger is held to the stem portion by said adapter piece.

11. Dispenser pump of claim 8 wherein the plunger comprises a dependent spring surround and the body comprises an upstanding spring surround, said dependent and upstanding spring surrounds being movable telescopically together and surrounding the return spring.

12. Dispenser pump of claim 8 wherein the dispenser pump is a spray dispenser and wherein the discharge nozzle is an atomiser nozzle.

13. Dispenser pump of claim 8 wherein the dispenser pump in which the actuating head has a socket and the top of the plunger stem portion fits into the socket.

14. Dispenser pump of claim 8 wherein the dispenser pump in which the actuating head comprises a discrete trim component.

15. Dispenser pump of claim 12 wherein the dispenser pump in which the pump body is mounted in the neck of a container of liquid to be dispensed by means of a closure structure comprising an element in the form of a cap which closes off the gap between the pump body and container neck while orienting the pump body coaxially with the neck, and which comprises a closure trim component.

16. Dispenser pump of claim 15 in which the closure trim component is an aluminium crimp cover.

Description

DESCRIPTION OF THE DRAWINGS

[0048] Embodiments of our proposals are now described by way of example, with reference to the accompanying drawings in which:

[0049] FIG. 1 is a perspective view of a pump for a fine mist sprayer;

[0050] FIG. 2 is a side view of the pump;

[0051] FIG. 3 is an axial cross-section at III-III of FIG. 2;

[0052] FIG. 4 is an axial cross-section, perpendicular to FIG. 3;

[0053] FIG. 5 is an axial cross-section corresponding to FIG. 4, showing a part-assembly or pump module precursor of the embodiment;

[0054] FIG. 6 is an axial cross-section, corresponding to FIG. 4, of a second embodiment of our proposals, and

[0055] FIG. 7 is an axial cross-section of a third embodiment.

DETAILED DESCRIPTION

[0056] The illustrated embodiment of dispenser pump is a fine mist sprayer 1. The pump consists generally of a body 3, a plunger 2 reciprocable in the body 3 and having a head 4 and a stem 5, and a closure 8 which mounts the pump 1 and orients it coaxially in the neck path of a container. The corresponding dispenser also comprises a container 10 for liquid to be sprayed, as indicated schematically in FIG. 2. The container may be conventional.

[0057] The body 3 consists of a cylinder 31 and an insert 32. Each of these components, as is conventional, is a one-piece molding in polypropylene. The cylinder 31 has a cylinder wall 310, an inlet 312 at its bottom end with a dip tube holder 315, and at its top end or mouth an enlarged ring or collar 314. The inlet 312 includes an inlet valve which may be of any suitable type, here a nylon ball 33 seated in a valve seat 313.

[0058] The insert 32 is a generally tubular piece with a lower plug portion 34 that snaps tightly down inside the mouth of the cylinder 31, a support flange 321 projecting out to lie on top of the cylinder's top ring 314 to locate the components, and an upstanding spring surround 35, in the form of a cylindrical tube, projecting up coaxially above the rest of the pump body. Just below the flange 321 the insert 32 has an inward flange 328 surrounding a central opening through which the plunger stem 5 passes. The top of this flange constitutes a bottom pump spring abutment 36 and the bottom of the flange provides a top plunger stop abutment 324. The lower part of the insert 32 surrounds a cavity 322 which contains a pre-compression spring 75. The bottom edge of the insert forms a seal annulus 329 which, in the plunger's extended position as shown, forms a plug seal into the top of a plunger piston 62 to isolate the cavity 322. The closure 8 is a crimp closure consisting of an aluminium crimp sleeve 82 and a support/seal washer 81 which surrounds the pump body cylinder 31 and rests sealingly on the top edge of the container. The crimp sleeve 82 has a decorative outer surface, with a coloured and/or metallic finish. In a manner generally well known to the skilled person the crimped sleeve 82 is crimped onto the assembly of the container, pump body and washer 81 so that its peripheral holding collar 85 grips the outside of the container neck, a flat top portion 83 overlies the support washer 81, a crimped grip formation 86 surrounds the enlarged top portions of the pump body to hold them in place, and a flat top portion overlies the top flange 321 of the body insert 32, with the upstanding surround 35 of the insert 32 projecting up through a central opening 84 therein.

[0059] The stem 5 of the plunger is a generally tubular element defining a first outlet passage portion 52. An end piece 65 closes off this passage at the lower end, a rod 652 of the end piece fitting closely up inside the tubular stem. Channels along the rod provide flow clearances up inside the stem for the outlet passage, as seen in FIG. 3. Corresponding entry openings 66 between the bottom end of the stem and the end piece 65 enable communication between the pump chamber 71 and the first portion of the outlet passage 52.

[0060] A piston/outlet valve assembly 6 comprises a sliding seal member 61 consisting of a sealing sleeve 63 around the bottom of the stem 5 and a piston seal 62 carried on the sleeve 63 and bearing sealingly against the cylinder wall 310. The sealing sleeve 63 can slide relative to the plunger stem between a lower stop 651 on the end piece 65 and an upper stop 54 provided by a downward shoulder on the stem 5. Further up, the stem 5 provides an upper stop 56, in the form of a circular flange, for the top of the pre-compression spring 75. The bottom of the pre-compression spring 75 acts against the top of the sealing sleeve 63, pressing it down towards the lower stop 651. Immediately above the pre-compression spring stop, the piston stem 5 reduces to a smooth uniform cylindrical outer diameter, and in this form projects up through the central hole defined by the flange 328.

[0061] The upwardly-projecting stem 40 5 finishes at a top end 53 with a plain circular opening of the outlet passage 52. Into this opening a spring retainer or spring-retaining adapter 9 is fixed. With reference in particular to FIG. 5, the spring retainer 9 takes generally the form of a deep, inverted U-channel with an inner tube 91 that plugs down inside the stem, engaging by a snap formation 94, a top wall or radial flange 92 projecting out from the top 53 of the step, and an outer tube or depending surround 93. The depending surround 93 is cylindrical in form and extends down so as just to overlap axiallyin the extended position shownthe top edge of the upstanding surround 35 of the pump body. They fit telescopically with the upstanding surround on the inside. The upstanding and depending surrounds 35,93 enclose and define, in concert with the top spring retainer wall 92 and the central piston stem 5, an enclosed pump spring chamber 76 in which a pump spring 7 is enclosed. The bottom of the pump spring 7 acts against the top of the inner body flange 328, and the top of the pump spring 7 acts against the underside of the top wall or radial flange 92 of the spring retainer 9.

[0062] The inner tube 91 of the retainer 9 defines a part of the outlet passage.

[0063] The plunger head 4 comprises a main head piece 40 or button with a top push surface 41, a peripheral cylindrical skirt defining the outer form of the head and a downwardly-directed central socket 44 shaped to fit closely and fixedlyby a snap engagement not indicateddown over the spring-retaining adapter 9 at the top of the plunger stem 5. Specifically, the socket includes an inward cylindrical surface which fits down around the outward cylindrical surface of the outer tube or depending surround 93 of the spring-retaining adapter 9.

[0064] The plunger head piece 40 defines a second outlet passage portion 42 which extends as a continuation of the first outlet passage portion 52 in the stem and leads to a radially-directed atomiser nozzle 43 which is the discharge nozzle for the pump. The atomiser nozzle 43 may be conventional. An external trim 72 or outer cover for the plunger head fits closely over the head piece 40 (with a hole at the nozzle 43) and, like the closure crimp sleeve 82 provides a decorative finish to the plunger head 4. This is well-known. In particular, these trim components may be of aluminium which is readily provided with a variety of attractive finishes such as anodised colour finishes. The printing of logos and names is also convenient.

[0065] The operation of the pump as a pump is generally conventional and readily understood. The figures show the plunger 2 in the extended position. When the plunger head 4 is depressed, the plunger stem moves down and progressively compresses the pump spring 7. The sliding seal member 61 experiences friction at the piston seal 62 tending to move it up on the stem, but the force of the pre-compression spring 75 overcomes this and keeps it at the bottom of its travel against the lower stop 651 on the end piece 65, keeping the openings 66 shut. The pump chamber 71 contains liquid from a previous priming or dispensing stroke, so the inlet valve is held shut and pressure rises in the pump chamber. After an initial downward (pre-compression) movement, the rising counter-pressure of the liquid overcomes the pre-compression spring 75, and the sealing sleeve 63 moves up along the stem 5 to the upper stop 54, opening the entry openings 66 for rapid flow of the pressurized liquid from the pump chamber 71 along the outlet passage 52,42 and out through the spray nozzle 43.

[0066] As the plunger head 4 descends the dependent spring surround 93 slides telescopically down around the upstanding surround 35, continuing to enclose the pump spring 7, until the plunger end point is reached.

[0067] When the plunger is released the plunger stem and piston rise, refilling the pump chamber through the inlet valve. The pump spring 7 re-expands, but at even the extended position remains fully enclosed by the tubular surrounds 35,93.

[0068] The container interior is vented through the pump in the conventional way, viz. a small hole (not shown) through the cylinder wall at the level of the piston in the extended position.

[0069] FIG. 5 shows a pre-assembly or pump module precursor consisting of the pump body, the plunger stem and piston/outlet valve assembly 6, and the pump spring 7 fitted into position and held by the spring retainer 9 so that the spring is securely retained and also fully enclosed to protect it from fouling. This headless pump pre-assembly is universal or standard in that it lacks the visually-distinctive outer components of the closure and plunger. All other functional components are present.

[0070] In use, at a facility where the dispensers are filled and assembled, closures and plunger head finishes of the desired type are selected and matched. The assembly of the pumps is completed by application of the closures 8 and by fitting the heads. The heads are fitted by pushing them down onto the spring retainers 9 which act as fitting adapters for this purpose, fitting the head sockets 44. In this procedure the spring need be neither exposed nor released.

[0071] Where there is no need to accommodate a variable finish of the closure, such as where the closure is a plastics cap connected to or integral with the pump body, the retaining end enclosure of the spring and the possible variation of the plunger head, are still useful features.

[0072] Plunger heads may alternatively be selected for different function or type rather than on decorative grounds.

[0073] The upstanding spring surround may be formed as part of a closure rather than part of the pump body.

[0074] FIG. 6 shows a second embodiment. Reference numerals generally refer to the same components as in the first embodiment, or to similar or analogous components. The second embodiment differs from the first embodiment in the manner retention and accommodation of the spring 7. Instead of the spring-retaining adapter 9 which snaps down inside the top of the plunger stem 5, this embodiment has a thick external retaining ring 109 which snaps down around the top of the plunger stem 5 after the spring 7 is positioned thereon, seating fixedly in an annular groove 55 around the top of the stem, so that it can hold the spring 7 in position in the situation of a pump module precursor as shown in FIG. 5 for the first embodiment. The ring 109 shown has a generally rectangular cross-section with rounded edges for sliding to the snap fit. It may be made of engineering thermoplastics such as acetal polymer (Delrin). The downward socket of the plunger head 4 is formed with a corresponding inwardly-directed annular groove 144 into which the retaining ring 109 snaps when the head is pushed on, as shown in the figure. The use of this harder polymer ring can hold the head on more securely. In this embodiment the spring 7 is not housed or enclosed by any extension of the pump body. Adequate protection is provided by the downward extent of the side skirt of the decorative trim 72 on the head.

[0075] FIG. 7 shows a third embodiment with a substantially different structure. Here the socket 244 of the plunger head 104 snaps directly onto the top of the plunger stem 105 in the conventional fashion, without an intervening adapter or ring. The pump spring 107 is mounted entirely inside the body cylinder 131, and held down in the enclosed cavity beneath the discrete insert or plug portion 132 (which as before is itself enclosed by the top of the external decorative aluminium closure crimp 82).

[0076] The pump spring 107 provides restoring force for the plunger 104,105 and pre-compression force for the sliding piston or seal member 162 using two portions of the same metal coil spring. The spring 107 has a lower part or pre-compression part 172 of smaller diameter and an upper part or plunger-return part 171 of larger diameterin this embodiment of gradually diverging diameter. The top annulus of the spring is trapped between the underside of the insert plug 132 and an upward ledge just beneath the mouth of the cylinder 131, these forming a trapping recess 1311 fixing the top of the spring axially. The top coils of the lower, smaller-diameter part 172 are trapped below a downward shoulder 152 defined around the stem, which constitutes an intermediate spring retainer. The bottom end of the lower, smaller-diameter part 172 acts downwardly against the sliding seal 162.

[0077] A distinctive feature here is that the upper spring part 171 is stretched against its resilience by depressing the plunger, because its lower extremity is trapped beneath the intermediate spring retainer 152, and so acts in tension as a return spring to bias the plunger to the extended position. Conversely the lower spring part 172 acts in compression as the pre-compression spring in the conventional manner. By this economy of space and means a single pump spring for a pre-compression spray pump can be entirely housed within the pump body cylinder portion, and thereby be free from obstruction and contamination while also being outside the liquid product path so that there is no metal contact with the liquid product.