DISPENSERS

Abstract

A dispenser has a plunger (3) operable in a pump body (4). The plunger can be locked up or locked down, and formations (88,89) of a pump plunger stem and pump body insert (6) for achieving this are described. Components of the dispenser, including a pump body cylinder/closure component (5), container neck and a pump body insert (6), are rotationally locked together with non-selective alignment and sealed by sliding-fit seals to prevent damage or leakage caused by relative turning of the components in transit.

Claims

1-10. (canceled)

11. A reciprocating dispenser pump having a locking mechanism to selectively prevent actuation of the pump and a tamper evident feature to indicate a first release of the pump from an initially locked position, the pump comprising: a pump body having a body cylinder defining a pump chamber and an insert coaxially received by the cylinder body, and a plunger having a head with a frangible extension protruding downward toward the pump body and a stem having one or more projections formed beneath, said stem extending coaxially through the insert with a lower end of the stem disposed in the pump chamber; wherein the body cylinder includes a closure plate and at least one vent hole fluidically connected to the pump chamber and positioned within a sidewall of the body cylinder; wherein the insert has: (i) a top surface with a groove positioned to receive the frangible extension and (ii) at least one downlock formation and, optionally, at least one uplock formation; wherein the lower end of the stem includes a keying projection so that, when the plunger is rotated relative to the pump body, the keying projection cooperates with the downlock formation to prevent extension of the plunger away from the pump body when the plunger is in a specific rotational alignment with the insert; and wherein the keying projection is initially engaged by the downlock formation so that the frangible extension is retained within the groove and, upon a first release of the keying projection from engagement with the downlock formation, a portion of the frangible extension detaches from the plunger to provide a tamper evident feature.

12. The pump of claim 11 wherein the lower end of the stem includes a turn stop projection positioned axially above and spaced apart from the keying projection, said turn stop projection cooperating with the insert to limit rotation of the plunger relative to the pump body.

13. The pump of claim 11 wherein the frangible extension is snap-fitted into the groove.

14. The pump of claim 13 wherein the groove is arcuate.

15. The pump of claim 13 wherein the groove includes a trap zone along a portion of the groove, said trap zone positioned relative to the specific rotational alignment so as to detach and retain the portion of the frangible extension after the first release.

16. The pump of claim 13 wherein the groove includes a top lip and the frangible extension includes a barb so that the top lip traps the barb within the groove after the first release.

17. The pump of claim 11 wherein two keying projections are positioned on opposing sides of the lower end of the stem.

18. The pump of claim 11 wherein the insert is formed to accommodate between five to ten discrete rotational alignments of the plunger and the pump body.

19. The pump of claim 11 wherein the closure plate includes inner and outer dependent skirts defining a channel to receive a container neck.

20. The pump of claim 11 wherein a movable piston is enclosed within the pump chamber, said piston selectively blocking the vent hole to control flow of compensation air when the pump is actuated.

21. The pump of claim 20 wherein a discrete end piece is positioned in the pump chamber along a bottom edge of the movable piston, said discrete end piece cooperating with an inlet valve to control flow of fluid flowing through and dispensed by the pump.

22. The pump of claim 11 wherein the plunger includes a downward skirt to sealingly engage the insert.

23. The pump of claim 11 wherein the lower end of the stem is attached to an upper end formed integrally with the head of the plunger.

24. The pump of claim 11 wherein a plurality of downlock formations and a plurality of uplock formations are provided on the insert.

25. The pump of claim 11 wherein the groove is provided in a flat collar, said flat collar integrally formed on the top surface of the insert.

26. The pump of claim 11 wherein the insert includes a floor which sealingly engages the lower end of the stem to define an upper portion of the pump chamber.

27. The pump of claim 26 wherein the floor serves as a seat for a biasing member, said biasing member urging the plunger into an extended position.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Embodiments of our proposals are now described by way of example, with reference to the accompanying drawings in which:

[0063] FIG. 1 is a front oblique view of a pump in a first embodiment of the invention, without a container, in the down-position;

[0064] FIG. 2 shows the same pump in the up-position;

[0065] FIG. 3 and FIG. 4 are respectively longitudinal and lateral vertical sections through the pump in the down-position;

[0066] FIG. 5 is a longitudinal vertical section in the up-position;

[0067] FIGS. 6(a), (b) and (c) are respectively a longitudinal vertical section, a front oblique view and an oblique view from below of the plunger of the first embodiment;

[0068] FIGS. 7(a), (b) and (c) are respectively a top oblique view, and side view and a vertical section through a body insert component of the first embodiment;

[0069] FIGS. 8(a), (b) are respectively a top oblique view and a bottom oblique view of the body insert, to a larger scale;

[0070] FIGS. 9(a), (b) and (c) are respectively a bottom oblique view, a top oblique view and a vertical axial section through a cylinder body component of the first embodiment;

[0071] FIG. 10 shows a special form of container neck;

[0072] FIG. 11 shows an end piece of the plunger stem;

[0073] FIG. 12 shows a piston sleeve element of the plunger stem;

[0074] FIG. 13(a) is a side view of a pump of a second embodiment in the down-position, showing without a container, and FIG. 13(b) is a front view;

[0075] FIG. 14 is a side view of the second embodiment pump with a container constituting a dispenser, and in the up-position;

[0076] FIG. 15 is a longitudinal vertical section of the second embodiment pump in the down-position;

[0077] FIG. 16 is a vertical longitudinal cross-section of the second embodiment pump and container (dispenser) in the up-position;

[0078] FIGS. 17(a), (b) and (c) are respectively a bottom oblique view, and front view and a bottom view of the plunger of the second embodiment;

[0079] FIGS. 18(a) and (b) are a side view and a top view of the body insert of the second embodiments;

[0080] FIGS. 19(a), (b) and (c) are respectively a top oblique view, a bottom oblique view and an underneath view of the body insert of the second embodiment;

[0081] FIG. 20 shows a third embodiment of dispenser in a locked-down position;

[0082] FIG. 21 shows the third embodiment on a container and unlocked, with the plunger raised and a tamper-evident element broken away;

[0083] FIG. 22 is a vertical cross-section of the third embodiment in the down position;

[0084] FIG. 23 is a vertical cross-section of the third embodiment in the up position;

[0085] FIGS. 24(a), (b) and (c) are an underneath perspective view, an underneath view and a vertical section showing the plunger head and an upper stem portion of the third embodiment;

[0086] FIG. 25 shows the cylinder body from above;

[0087] FIGS. 26(a) and (b) are a perspective view and a sectional view of the sliding seal;

[0088] FIGS. 27(a)-(d) are respectively an upper perspective view, vertical sectional view, bottom perspective view and top oblique view of the body insert component of the third embodiment;

[0089] FIGS. 28 and 29 are vertical sectional views of a fourth embodiment in the locked-down position and the locked-up positions;

[0090] FIG. 30 is a sectional view showing the plunger head and upper stem portion of the fourth embodiment;

[0091] FIGS. 31(a) and (b) are a side view of a lower stem portion and a section through the lower step portion, showing uplock/downlock formations;

[0092] FIGS. 32(a)-(c) are a transverse section through the body insert at the level of the uplock/downlock formations, a vertical sectional view through the body insert, and an enlarged detail at the circled portion of FIG. 32(b) showing a spring seat portion, and

[0093] FIGS. 33(a)(c) are a side view, top view and underneath view showing the upper part (closure portion) of the cylinder body.

DETAILED DESCRIPTION OF EMBODIMENTS

[0094] The pump module in a first embodiment of dispenser is described with reference to FIGS. 1 to 12. FIGS. 1 to 5 show the pump in up and down conditions from various viewpoints and sections, while FIGS. 6 to 12 show details of separate components. In FIGS. 1 to 5 the container of the dispenser is omitted, but the container 1 is shown in the second embodiment described later and the features are the same for the first embodiment, also details of the container neck for both embodiments are shown in FIG. 10. The general components of pump 2 are a pump body 4 and a plunger 3 reciprocable in the body in a pumping stroke. In this embodiment the pump body 4 is provided as a combination of two one-piece moulded components, namely a cylinder/closure component 5 (cylinder body) and a collar/insert component 6 (body insert). The cylinder body includes a cylinder portion 51 defining a pump chamber and a closure portion 52 by which the cylinder portion is mounted fixedly in the neck of a container 1. The drawings also show a surrounding trim piece 9; this is for shape styling at the top of the container 1 and otherwise non-functional.

[0095] The cylinder portion 51 has a cylinder wall 52 with a convergent inlet formation 53 at its bottom end defining a dip tube socket 531 for a dip tube 72 and an inlet valve 74 with a valve ball 75. Around the valve opening a cylindrical piston stop 54, in the form of a closed cylindrical wall, projects integrally up from the convergent bottom of the cylinder portion.

[0096] The closure portion 52, formed integrally with the cylinder portion 51 as a single moulding, consists of a generally circular closure plate 57 with a peripheral downward outer securing ring 59 and a longer and more flexible downward sealing skirt 58 spaced inwardly from it, defining a channel 581 between them. FIG. 9(a) shows that the outer securing ring 59 has a circumferential series of inwardly-projecting lugs or nibs 591. As shown in FIG. 10 the neck 12 of the bottle 1 has an annular edge 13 with a smooth cylindrical inner face and on the outside a series of locking lugs 14 and recesses 15 complementary to the lugs 591 on the closure securing ring 59. These components push together to make a plug seal, with interference and some deformation of the downward sealing skirt 58, to hold and seal the cylinder body 5 onto the container 1 with rotational interlock.

[0097] The insert portion 61 of the body insert 6 fits down closely with its tubular wall 10 inside the upper part of the cylinder wall 52, held in place axially by snap ribs 611 engaging corresponding recesses in the cylinder wall. At its bottom end, the wall of the insert portion 61 turns in with a flange or floor 612 which forms a spring seat 613 on the inside for the bottom end of a pump spring 71 (here, a metal coil spring). The inner periphery of the flange 612 carries an upwardly-projecting generally cylindrical sealing skirt 58, spaced in from the wall. The downward surface of the insert flange 612 has a downwardly-projecting annular projection 615 which is part of a sealing seat and surrounds and defines a channel 616 for a sealing engagement described later. With reference to FIGS. 7 and 8, the lower interior of the insert has a set of internal uplock/downlock formations 89 to be described later, and these include a pair of downward projections 860.

[0098] At its upper part, the insert 61 projects out through the top opening of the cylinder portion 51 with a tubular upward extension 63 (FIG. 5) which connects the cylinder integrally with a collar portion 62 of the body on the outside of the pump. The collar surrounds the upper part of the plunger 3, and the head 31 of the plunger fits down against the collar 62 in the down-position. In this embodiment the upward extension 63 connects to an axial cylindrical water guard skirt 65 with an exposed upper edge, and whose lower end connects integrally with a downward trough formation 661 with a series of holes 662 through it (FIG. 8(b)) forming part of a drain structure 66. The outer wall of the trough extends back up and meets at the top with a further trim wall, forming together an outer guard wall 665 opposed to the water guard skirt 65 across the trough 661.

[0099] Beneath the collar, at the outside of the tubular wall 610 at the upper part, above the snap rib 611, the insert 61 has a circumferential series of short outwardly-projecting axially-extending locking ribs 618. The cylinder body 5, at its opening part or mouth above the snap formations (see FIG. 9(b)) has an upwardly and inwardly open circumferential series of lugs 511 with intervening recesses 510 and the ribs 618 of the body insert 6 fit down into these, so that by combination of the snap rib 611 and the interlock formations 618,510,511 the body and insert are held axially and rotationally rigidly together.

[0100] The plunger consists of a head 31, with a flat press top 311 and a laterally-projecting nozzle 312, an axial stem 32, and a piston 33 carried at the lower end of the stem on a sliding sleeve 330 and providing a pump seal 37. In this embodiment the head 31 and stem 32 are moulded together as a single piece, defining an outlet passage 76 starting at an entry opening or window 78 at the bottom of the stem and finishing at an outlet opening 77 at the end of the nozzle 312. The perpendicular outlet passage parts can be moulded by means of a withdrawing mould element. The bottom end of the stem is then open, and forms an end socket 323 with internal snap ribs to receive a discrete end piece 34 (see FIG. 11).

[0101] Integrally moulded cylindrical skirts extend down from the underside of the plunger. An outer skirt 314 is provided to contour the press top exterior. Next, an intermediate downward skirt 315 (water guard skirt) extends down between the upward skirt 65 of the collar 62, in sliding contact around it, and its bottom end projects down into the trough 661 of the collar so that in the down-position (FIGS. 3, 4) it reaches nearly to the bottom of the trough while the top of the collar skirt 65 reaches up and contacts the underside of the plunger, as discussed below. In the up-position (FIG. 5) the water guard skirt 315 still contacts and overlaps the upward collar skirt 65 from the outside, so that water landing on the dispenser is kept out of the pump mechanism and can fall down into the trough 661, from where it can drain through the holes 662 and away around the trim 9 which is not in a clamped sealing engagement, so water can leak away down around the outside of the closure 52. This combination of upward and downward skirts can function as a water guard with or without the outer wall structure 665 of the collar, but the latter helps to shield the joint line against tampering and damage.

[0102] Concentrically inward of the water guard skirt 315 an inner skirt 317 extends down from the plunger head, still at a radial spacing from the central stem 32. The inner skirt 317 fits closely through the top opening of the insert body, and has a slidable outward flare or lip 3171 at its bottom edge to wipe the inside surface of the insert body tube wall. The inner skirt is sufficiently long that in the up-position (FIG. 5) its bottom end (lip 3171) is still recessed into the insert body, while in the down-position (FIGS. 3, 4) it reaches the inward flange 612 at the bottom of the insert portion 61. In conjunction with the intermediate (water guard) skirt 315, the inner skirt 317 aligns the plunger during the dispensing stroke and also houses the spring 71, which reaches up inside the inner skirt 317 to act against the underside of the plunger head just below the nozzle 312.

[0103] The central stem 32 defines the vertical part of the outlet passage 76, up to the nozzle, and carries the piston (pump seal) 37 at its bottom end. It incorporates an outlet valve function by a slidable mounting of the pump seal piston 37 on the tubular sleeve 330. It also carries uplock and downlock stem formations 88 for the uplock/downlock mechanism and, at its bottom part, contributes to sealing in the down-position. The stem exterior has a larger-diameter top portion extending down with a smooth cylindrical surface sufficiently far to plug into the upward sealing skirt 614 of the body insert for the down-position stem/body sealsee FIG. 4 and also FIG. 5 where the corresponding seal region 321 of the stem is indicated.

[0104] Below this seal region 321 the stem surface is interrupted by uplock/downlock formations 88, specifically (see also FIG. 6) a turn stop projection 85 at an upper position, a keying projection 81 at a lower position and a circumferential slot or gap 84 extending between them. In this embodiment the turn stop and keying projections 85,81 are aligned one above the other, and repeated on the opposite side of the stem for extra stability and strength, but alternative arrangements are possible as the skilled reader will understand. The keying projection has a downward shoulder 82 for uplock and upward shoulder 83 for downlock, while for the turn stop projection 85 it is the lateral (circumferentially-facing) shoulder that is functional.

[0105] The corresponding uplock/downlock formations 89 of the insert are best seen in FIG. 8 and include an identical opposed pair of keying projections integral with the insert wall, separated by a pair of axial slots 88, each projecting down slightly below the end of the insert as downward projection 860. Each keying projection features an upward shoulder 87 for uplock and a downward shoulder 86 for downlock. At one end of the upward shoulder 87 a turn stop 871 projects up.

[0106] For operation of the pump, the stem keying projections 81 align with the axial slots or paths 88 of the body insert so that the plunger can move freely up and down. For downlocking the plunger is pushed right down until the upward shoulder 83 of the stem is below the downward abutment 86 of the body insert, and turned clockwise to bring them into line so that the insert holds the plunger down. After a predetermined degree of turn the side shoulder of the stem turn stop projection 85 meets the turn stop 871 inside the insert, preventing the plunger from turning too far and rising again through the other axial slot 88. To release the downlock the plunger is turned anticlockwise through the same angle.

[0107] For uplock, the plunger at the up-position is turned clockwise. The downward shoulders 82 of the stem keying projections 81 slide around and above the fixed upward insert shoulders 87 until turn is arrested by the sides of the keying projections 81 meeting the insert turn stops 871. The plunger is then held against depression, but can be released from the uplock by turning anti-clockwise until the keying projections 81 align again with the through slots 88. This uplock and downlock functionality is provided without any increase in the number of components beyond the basic elements.

[0108] The piston and other functions of the lower end of the stem 32 are now described. The bottom end of the stem has a reduced-diameter end portion 324 constituting a slide track for the sleeve 330 carrying the piston. A downward shoulder 335 forms a top stop of the slide track. The piston/sleeve element 33 (FIG. 12) has an inward annulus 336 that slides on the stem track 324, and a bottom seal ring 333 and top seal ring 334 which are each slightly spaced from the stem exterior. A pump seal 37 projects out around the sleeve 330 and has a top lip 331 and bottom lip 332 which engage sealingly against the cylinder wall; this component is desirably made of a softer material such as LDPE.

[0109] The bottom of the stem 32 is partly closed off by the end piece 34 (see FIG. 11). The end piece has a set of spaced clip legs 341 engaging the snap ribs inside the stem socket 323, a disc-shaped closure body 346 spaced slightly out from the stem end, and an upward seal ring 342. The underside of the closure body 346 carries a central nose 344 surrounded by a downward sealing skirt 345 which, in the down-position (FIGS. 3, 4), slidingly plugs sealingly into the inlet formation 53 of the cylinder body, around a cylindrical sealing surface 56 thereof, and stopped by inward nib projections 561, blocking communication between the inlet and the pump chamber 79. The piston sleeve 330 has limited travel between upper and lower positions relative to the stem 32. In the upper position (see also FIG. 15 of the second embodiment, where the structures are the same) the inward annulus 336 meets the top slide stop 325 and the bottom seal ring 333 of the sleeve 330 is axially spaced from the upward seal ring 342 of the end piece, leaving a window 78 for liquid product to enter the outlet passage through the bottom of the stem 32 during the downstroke of the pump, in which the piston sleeve takes the upper position because of friction against the cylinder wall. In the downward relative position of the sleeve seen in FIG. 5, the window 78 is closed by the bottom ring 333 of the sliding seal making a plug seal against the upward ring seal 342 of the end piece, which includes an internal deformable lip to make this a plug seal with interference. This isolates the pump chamber 79 from the outlet passage 76.

[0110] In the up-position (FIG. 5) the top seal ring 334 of the sleeve also plugs into the downward seal channel 616 of the body insert, between its sealing annulus 615 and the downward projections 860 which help to locate it, isolating the space above the pump seal 37 from the central opening of the body insert (which cannot be sealed directly at that position because the uplock/downlock formations must pass). In this position the pump seal 37 also blocks the side vent holes 55 through the cylinder wall, so that liquid cannot enter the cylinder from the container interior.

[0111] So, in both the up-position and the down-position, and in particular when the corresponding uplock and downlock mechanisms are actuated, the pump structure provides a set of internal seals preventing the entry of container liquid into the pump, and preventing the escape of any liquid already in the pump to the exterior of the pump.

[0112] As part of the pump, and again without increasing the component count, means are provided for inhibiting rotation of the plunger 3 relative to the body 2. This can help to keep the pump in the down locked condition. In shipping, it also helps to prevent relative rotation which, as mentioned, may disturb internal seals or damage packaging. In this embodiment a plunger lock inhibiting release of the downlock mechanism is provided by interlock formations 64 acting between the top edge of the upward water guard skirt 65 of the collar 62 and the underside of the plunger head. As seen in FIG. 7, the top edge of the upward collar skirt 65 has a series of castellations 641, i.e. multiple upward block-form projections with slots between, slightly narrower than the projections. The top corners of these are slightly chamfered or rounded. This formation 64 is engaged in use by a downwardly-projecting radially-extending rib 313 of the underside of the plunger head, in line with the nozzlesee FIG. 5 (and also FIG. 17(c) of the second embodiment showing a corresponding rib, although it is not functional in the second embodiment). More than one rib may be used, but frequently the lowermost counter-surface beneath the head will be the surface beneath the nozzle and a single rib is convenient. When the plunger is pushed down and turned to the downlock position on assembly, the rib can easily engage into one of the slots between the many castellations 41, without positional selectivity. This interlock then inhibits unintended rotation of the plunger back out of the downlocked position. Conveniently, the interlock formations are completely hidden inside the water guard skirts 65,315.

[0113] FIGS. 13 to 19 show a second embodiment. The elements of the pump, rotational interlocks and seals are all as in the first embodiment and are indicated by corresponding reference numerals, except that the structure and relation between the underside of the plunger and the top of the collar differ.

[0114] Firstly, the water guard function is provided not by a pair of opposing skirts, but by an integral seal lip projection 67 around the mouth opening of the collar 162, directly wiping the cylindrical outer surface of the inner skirt 317 of the plunger. This supplements the sealing or containment effect already provided by the bottom end of this inner skirt 317 sliding down the interior of the body insert.

[0115] Instead of the rotationally non-selective rotational interlock between the collar top and plunger underside in the first embodiment, the second embodiment provides a rotationally-selective rotational interlock which also constitutes a tamper-evident feature of the dispenser. An intermediate downward skirt 316 from the plunger is shorter in length than in the first embodiment, so that in the down-position of the pump (FIG. 15) its bottom edge just meets the flat upper surface 68 of the collar 162. Over a specified sector (between a quarter and a half of the full circumference) of the top surface 68 of the collar 162 is an arcuate locking groove 36 which, at least over a trap region 383 thereof (FIG. 18(b)) has an overhanging top lip 381 (FIG. 16). At a corresponding radial position beneath the nozzle 312 of the plunger, the intermediate skirt 316 carries a dependent break-off element 36 consisting of an arcuate rib body 362 connected to the skirt edge above through a pair of frangible links 361 (see FIGS. 17(a),(b)). The rib body 362 tapers downwardly in section (FIG. 16) so that on assembly it can be pushed with a snap down into the groove 38. The groove 38 is sufficiently long (FIG. 18(b)) that the plunger head can then be turned to the downlocked position, with the rib 361 sliding along the groove 38 internally, and moving past a barb or tooth 382 projecting across the groove 38 (FIG. 18(b)) and delimiting the trap zone 383. The rib body 362 cannot travel back pass the tooth/barb 382 and holds the plunger head in the downlocked rotational position. To release the plunger head to undo the downlock the frangible links 361 must be broken, leaving the broken-away rib body in the groove 38. As well as retaining the locked and sealed condition of the pump for shipping and transit, this also provides a visual tamper-evident feature.

[0116] FIGS. 20 to 27 show a third embodiment, in which again the general components correspond to those of the first two embodiments but with the following differences.

[0117] Firstly, the plunger stem is formed with an upper portionintegral with the plunger head as seen in FIG. 24and a separate lower stem portion which snaps onto the upper stem portion. The lower stem portion carries the opposed pair of uplock/downlock rectangular lands, the top and bottom surfaces of which provide the down-locked and up-locked positions shown in FIGS. 22 and 23, by engagement with the inward projections on the insert component (FIG. 27). As before, the insert component lockdown formations include tracks for passage of the lands on the plunger stem, and stop formations, which are engaged by the ribs seen on the sides of the upper stem portion (FIG. 24). By providing the uplock/downlock formations on a separate stem piece, moulding of the stem and head components is simplified. The lower stem portion keys rotationally with the upper stem portion so that it will always turn with it.

[0118] This embodiment has a simpler structure for the annular seal protection on the end of the stem, which plugs into the inlet structure above the inlet ball valve in the down position (FIG. 22).

[0119] A further difference is an upward inner extension of the body insert (see also FIG. 2(a)), whichsee FIG. 22makes a seal in the down-position with a downward inner skirt beneath the plunger top.

[0120] A further difference is in the tamper-evident component. See FIG. 24(a)a breakoff ring goes all the way round the bottom of the plunger's outer skirt, connected by a few frangible links. It fits into a corresponding annular trough which goes all the way round the top of the bottom collar: see FIGS. 27(a), (b), (d). The bottom of the breakoff ring has downward teeth which engage corresponding upward teeth (FIG. 27(d)) in the trough to prevent relative rotation. A downward tooth around inside the trough (see FIG. 27(b)) holds the ring down after initial forced insertion, so that the plunger cannot be turned or lifted without breaking the frangible links. This construction provides a barrier against initial unlocking of the plunger, and also a tamper-evident feature which can be neater than the second embodiment (above) in that a trough is filled with the detached breakoff ring all the way round.

[0121] The body insert locks rotationally into the top of the body cylinder in the same manner as before: see FIGS. 25 and 27(c).

[0122] FIGS. 28 to 33 show a fourth embodiment. As in the third embodiment, the plunger stem has a discrete lower stem portion carrying the uplock and downlock formations, for ease of moulding. The plunger head is relatively simple, with a single downward skirt engaged by a water-resisting inward sealing bead around the mouth of the insert component. As seen above, the bottom end of this plunger skirt makes an outward seal against the inside of the insert component. As in the third embodiment, the cylinder body is sufficiently short above its bottom convergence that in the down position, it pushes the sliding seal up into its closed position relative to the outlet windows.

[0123] FIGS. 30 and 31 show the integrated head and upper stem portion (FIG. 30) and the lower stem portion (FIG. 31), including axially toothed interlocking formations above the snap ribs so that they are rotationally locked.

[0124] A particular feature in this embodiment is the transfer of more of the uplock/downlock functionality to the exterior of the plunger stem, rather than the interior of the insert component. Thus, the insert component (FIG. 32) has a pair of simple uplock/downlock lugs which are simply shaped, with flat top and bottom surfaces (see also FIGS. 28, 29), a steeply-inclined stop face directed clockwise, and a gently-inclined ramp face directed anti-clockwise, and a rounded inward tip. Otherwise, the inner face of the insert is a plain cylinder.

[0125] The stem exterior carries an upper downlock projection and a lower uplock projection, one above the other and of similar form, with flat axially-directed abutment surfaces which, in the locked positions, engage above or below the locking lugs of the insert. In addition, the plunger stem has a radially-projecting stop formation at one (circumferential) end of each abutment, shaped to fit against the steep stop face of the insert lug, and a more gently-inclined stop formation facing in the opposite direction about one quarter turn away from the lug. These formations are repeated on opposite sides of the stem, as before. Moreover the stop formations and associated featuresdescribed beloware continuous up and down the stem which makes for ease of moulding and also provides for a good user action as now described.

[0126] Specifically, adjacent the locking turn stop formation (at one end of the lug on the stem) the stem surface has a recess i.e. a local reduction in diameter, approached by smooth surfaces. The lug of the insert fits into this recess, without interference. Adjacent the recess the diameter increases slightly, so that there is a larger-diameter land region between the turn stop for the lock position and the turn stop for the unlock position (which as mentioned is about a quarter-turn or third-turn away). Adjacent the turn stop for the unlock position, there is again a slight diameter reduction recess in which the insert lug fits without interference. Between these positions however there is appreciable interference between the rounded tip of the insert lug and the raised land on the stem surface, so that when the plunger is turned and reaches one of the stop positions, the user feels an appreciable relaxation, click or settling into the defined position. This tactile reinforcement assists the user to feel confidence in the positions of the plunger. Since the recesses continue up and down the stem, they provide a guide for up and down movement of the plunger without rotation so that the plunger does not accidentally shift between the locked and unlocked positions, and rises and falls freely in use unless deliberately turned. The stem surface can easily be moulded with smoothly curving surfaces providing these features so that the parts can turn freely and without damage even when there is radial interference.

[0127] FIGS. 32(e), (c) show a further refinement. The spring seat region at the bottom of an insert has an inwardly-inclined or conical surface, with a raised outer edge which prevents sideways or outward displacement of the spring during its movement. This is an independent proposal herein and helps to ensure free movement of the plunger skirt opened to down the interior of the body insert. See also FIGS. 28 and 29.

[0128] The fourth embodiment shows a different rotational lock formation for the underside of the closure part of the cylinder body and to engage the container neck (not shown). The formation shown has a set of eight downward projections, outwardly spaced from the inner sealing skirt as before. This is the feature disclosed in our GB1608596.1 filed on 16 May 2016, the disclosure of which is incorporated herein by reference. It is designed to cooperate with a container neck having an upward plug sealing skirt as before, and a pair of two opposed outward projections immediately below the skirt, to engage the body flange lugs shown. In addition to the usual thread, the container neck has directional pawls below the thread to engage flexible directional lugs which project in around the bottom periphery of the outer securing cap (see FIGS. 28 and 29) resulting in a very secure, tamper-resistant closure that will resist considerable agitation and impact e.g. during shipping, without damage or leakage.