Pump dispensers

Abstract

A dispenser pump has a plunger operable in a body including an outer cylinder body having a vent opening in its sidewall and a body insert fitting into the top of the body cylinder and providing an external collar through which the plunger stem operates. The body insert has a lock-down thread to lock down the plunger for shipping. The insert also has an undulating annular vent-control bead extending right round its cylindrical outer surface, engaging the cylinder wall with interference for either blocking or unblocking the vent opening, according to whether the vent-control bead lies above or below the interior vent opening, by rotation between the body cylinder and body insert. The rotation can be driven by rotation of the plunger head, which makes a catch engagement with the top of the body insert. Blocking the vent during shipping reduces leakage.

Claims

1. A dispenser pump comprising a plunger and a body, wherein the body includes a body cylinder and a body insert received within a top portion of the body cylinder; wherein the plunger includes a head, a stem and a piston and wherein the plunger is rotatable relative to the body and axially movable between a locked-down position in which the plunger is held relatively retracted into the body and an unlocked position extended away from the body; wherein a vent path is defined by a radial clearance between the body insert and body cylinder, said vent path communicating with a vent opening formed in the cylinder, and wherein the body insert includes a projecting, at least partially circumferential vent-control formation which engages a wall of the cylinder, said vent-control formation having high and low portions lying respectively axially above and axially below the vent opening and wherein the body insert is rotatable relative to the body cylinder so as to align the high portion of the vent-control formation circumferentially with the vent opening when the vent path is open or so as to align the low portion of the vent-control formation below the vent opening when the vent path is closed.

2. A dispenser pump of claim 1 in which the vent-control formation is an annular rib or bead projecting radially from a generally cylindrical outer surface of the body insert.

3. A dispenser pump of claim 1 in which the vent-control formation defines sinuous or undulating circumferential line around the body insert.

4. A dispenser pump according to claim 1 in which the vent-control formation engages the body cylinder with radial interference.

5. A dispenser pump according to claim 1 in which the vent opening comprises a through-opening through the wall of the body cylinder communicating with a recess on an interior surface of the wall, said recess extending axially below the through-opening.

6. A dispenser pump according to claim 1 in which a threaded engagement between the plunger and the body maintains the locked-down position.

7. A dispenser pump according to claim 5 in which the body insert rotates in concert with the plunger based upon engagement of the plunger and the body insert.

8. A dispenser pump according to claim 6 in which engagement of the plunger and the body insert is at a relative rotational alignment corresponding to a fully locked-down position, and further comprising a catch mechanism on one or both of the plunger and the body to resist relative movement away from the relative rotational alignment.

9. A dispenser pump according to claim 6 in which engagement of the plunger and the body insert is provided by a flexible rib, fin, lug or projection at or on the underside of the head and an upwardly-directed surface of the body insert having a shoulder abutment and a ramp leading to the shoulder abutment so that the flexible rib, lug, or projection slides over the ramp upon rotation and is retained behind the shoulder abutment.

10. A dispenser pump according to claim 1 in which the body insert and body cylinder each include cooperating limit formations or stop abutments to limit a range of relative rotational movement between the body insert and the body cylinder.

11. A dispenser pump according to claim 6 wherein rotation of the plunger initially drives relative rotation of the body insert and body cylinder to block or unblock the vent path, until the body insert and body cylinder make a rotational stop engagement therebetween so that further relative rotation of the plunger and body insert drives the threaded engagement thereof.

12. A dispenser pump according to claim 1 in which the body cylinder comprises a cylinder portion with a wall having the vent opening, an annular locating flange to engage a container neck in use, and a top retaining formation, the body insert being secured relatively rotatably to the top retaining formation.

13. A dispenser comprising a container for liquid product and having a neck, and a dispenser pump according to claim 12 connected to the container neck.

14. A dispenser according to claim 13 in which the body cylinder of the pump comprises a locating flange to engage the container neck, the locating flange comprising a set of downward interlock projections which make an interlock engagement with the container neck to prevent rotation of the body cylinder relative to the container neck.

15. A dispenser pump according to claim 1 in which a continuous seal is formed between the body insert and the body cylinder, the continuous seal including the vent-control formation.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Embodiments of our proposals are now described by way of example, with reference to the accompanying drawings in which:

(2) FIG. 1 and FIG. 2 are side views of a dispenser pump embodying the invention, respectively in the locked-down and plunger-up positions;

(3) FIG. 3 and FIG. 4 are axial cross-sectional views of the pump in the plunger-up and locked-down positions;

(4) FIG. 5 is a radial cross-section of FIG. 3 (plunger-up position) at V-V;

(5) FIG. 6 is a corresponding cross-section of FIG. 4 (locked-down position);

(6) FIG. 7 is an exploded view showing all the main components of the pump;

(7) FIG. 8 shows the underside of the detached plunger head;

(8) FIG. 9 is an oblique view of the body insert component;

(9) FIG. 10 is an enlarged view of the top end of the body cylinder component;

(10) FIG. 11 is an enlarged axial cross-section showing the positions of structures near the pump vents with the plunger locked down, as in FIGS. 1 and 4; and

(11) FIG. 12 is a corresponding view with the plunger up as in FIGS. 2 and 3.

DETAILED DESCRIPTION

(12) With reference to the figures, a dispenser pump 1 has a pump body 3 and a plunger 2 reciprocable in the body cylinder 4 of the body 3. The body 3 also comprises a body insert 5 fitted into the top of the body cylinder 4. A threaded retaining cap 7 fixes the body into the neck of the container 100 (shown fragmentarily and schematically in FIG. 3). The pump body projects down into the container interior.

(13) Considering these components in more detail, the body cylinder component 4 includes a cylinder 41 with a cylinder wall 42, and defining an inlet 412 at its lower end (for example, to take a dip tube) and having a valve 413. Near its top the body cylinder component 4 has a projecting support flange 43 with an array of downward interlock formations in the form of projections 44 which engage corresponding projections on the neck of the container (not shown) as described in our above-mentioned Indian application and in our earlier PCT/EP2017/061611, to hold the body securely against rotation, and particularly anticlockwise rotation, relative to the container neck for reasons discussed below.

(14) The body insert 5, seen particularly in FIGS. 7 and 9, comprises a lower insert tube 51 having a tube wall 52 with an outer cylindrical surface 521. At the top of the body insert is a radially enlarged top collar 53, which snaps down over an upwardly-projecting fixing skirt 45 of the body cylinder 4 having corresponding snap formations 451, to hold the assembly together axially while allowing relative rotation. The collar and flange trap between them the top inward flange 71 of the retaining cap 7, which also has an outer securing skirt 72 with inward threads 73 to fix on the neck of the container 100. The underside of the support flange 43 of the body cylinder 4 has an annular plug sealing skirt 49 which fits with interference into the container neck to make a seal without a separate seal ring being required.

(15) The top collar 53 of the body insert 5 has an inner skirt 531 making the snap engagement with the body cylinder skirt 45 and an outer skirt 532 carrying an external thread 54 which constitutes a lock-down formation for the plunger, discussed below.

(16) Immediately beneath the support flange 43 the cylinder 41 has a pair of diametrically-opposed vent holes 46 communicating through the cylinder wall 42 between the container interior and the interior of the cylinder 41. A slight radial clearance 88 is defined between the cylinder 41 and the body insert tube 51. See FIG. 10: at the inner surface of the cylinder the vent through-hole 46 communicates into a downward extension channel 461 recessed into the cylindrical surface of the cylinder wall and providing an interior opening extending substantially below the through-hole of the vent 46.

(17) Around the inside of the top fixing skirt 45 of the body cylinder 4 is a set of spaced rotational stops 47 in a form of vertical bars, and these can engage with corresponding insert stop ribs 58 around the underside of the collar 53 of the body insert 5: see FIG. 7.

(18) The plunger 2 comprises a head 21 with a nozzle 22, projecting as an actuator for manual pressing at the top of the dispenser, and an axial stem 26 defining an internal outlet passage 28 and carrying a piston 27 that works in the cylinder 41. In this embodiment the piston 27 is formed as a sliding valve member over stem entrance openings 29 for the outlet passage 28, so that piston friction against the wall operates an outlet valve function. The piston also closes the outlet passage when the pump is locked down.

(19) The plunger head has a conventional outer shell or shroud 23, and a set of stiff radial ribs 25 beneath the shroud (see FIG. 8). The internal edge of the shroud has a female lock-down thread 24 to engage with the corresponding male thread 54 on the body insert collar 53.

(20) The body insert 5 and plunger head 21 also have structures to make a security catch engagement supplementing the lock-down function. To reduce the possibility that the lock-down thread engagement might work free, e.g. during shipping or transit of the product which might entail substantial vibration, a catch mechanism is provided to resist turning away from the fully locked-down position. It includes a pair of catch teeth 55 on the top flange 533 of the collar 53, each tooth 55 having a perpendicular abutment face 551 and a gently sloping ramp face 552 facing in opposite directions. For lock-down the plunger is pushed down and then turned clockwise to engage the screw threads 24,54. As the thread engagement approaches completion, a pair of the radial ribs 25 beneath the plunger head come into engagement with the ramp faces 552 of the respective catch teeth 55 on the collar, and ride over then with interference until they click down behind the abutment faces 551. In conjunction with the friction of the thread engagement, this imposes a substantial threshold force which must be overcome to unlock the plunger by anticlockwise rotation. This is why the pump body cylinder 4 engages the container neck by the interlock formations 44; to prevent it from turning so that the downlock can reliably be released by applying the threshold turning force, without undesirably turning the cylinder 4 in the container neck. The turning force of the plunger head on unlocking is applied to the body insert 5 initially primarily through the catch teeth 55, until they are overridden and release. The thickness, resilience and interference of these structures are adjusted so that the release torque or threshold force for the catch engagement is greater than the force required to turn the body insert 5 relative to the body cylinder by frictional sliding. Accordingly it is the insert that turns first, and this rotation continues, e.g. for about 40°, until the stop ribs 58 of the body insert 5 meet the corresponding stop ribs of the body cylinder 4 and relative rotation must cease, whereupon the applied force rises to the catch threshold, overcomes the engagement of ribs 25 and catch teeth 55 and the plunger starts to unscrew from the locked-down position on the body insert 5. The body insert then holds its rotational orientation relative to the cylinder 4. Secondary retainer projections 48 (see FIGS. 10 and 5) define retaining grooves next to some of the stop ribs 47, so that routine or casual clockwise turning of the plunger, e.g. when in the up position, does not cause accidental shifting of the insert 5 clockwise relative to the cylinder 4.

(21) The significance of the controlled relative rotation between the body insert 5 and body cylinder 4 is in controlling the operation of the vents 46. As mentioned, the purpose of these is to allow equalisation of pressure in the container 100 after dispensing of liquid, by allowing air entering the pump—through the top opening of the collar, around the fitting skirt 226 of the plunger head—down through the insert 5 and the opening through its base (defined through a lower spring support flange 64) and up around the insert 5 through the clearance 88. For shipping, the plunger is locked down as seen in FIGS. 1, 4, 6 and 11. In this position the vents 46 cannot be blocked by the plunger piston as they are in some dispensers. In any case, the vents in this construction are at the top of the cylinder body where the piston could not reach them. Accordingly, there is a risk that liquid from the container interior can enter the narrow clearance 88 through the vent holes 46 and get down into the cylinder space above the piston with the risk of then leaking to the exterior around the stem when the plunger is unlocked and raised.

(22) To prevent this, a vent-control formation is provided on the body insert and can best be seen in FIGS. 7 and 9. It takes the form of a projecting bead or rib 56, extending right around the otherwise cylindrical outer surface 521 of the insert tube 51, and being smoothly curved in a sinuous undulating form having two relatively high or upper regions 561 and two relatively low or lower regions 562. The bead 56 is moulded integrally with the wall of the body insert 5, and dimensioned so as to fit with slight interference into the cylinder 41, causing slight flexion of the cylinder wall 42 and making an effective seal. Because the bead 56 has the same radial projection extent all around the pump, the circular form is not distorted so the seal is less prone to leakage and sticking than circumferentially-localised blocking lands.

(23) The interaction of the vent-control bead 56 with the two vents 46 can be understood from FIGS. 9 and 10, and seen directly in FIGS. 11 and 12. In the locked-down position of FIG. 11, the body insert 5 is at its clockwise extreme relative to the cylinder 4 and the low regions 562 of the bead 56 are circumferentially aligned with the interior openings of the respective vents 46. These low regions 562 are below the level of the interior openings of the vents, even considering the downward opening extension channels 461 thereof. Accordingly, in this position as clearly seen in FIG. 11, the vent-control bead 56 completely blocks any communication from the container interior to the interior of the cylinder 41 through the vents 46. This because it extends below the vent openings and seals right around between the insert and cylinder. The skilled person can devise other specific paths for one or more vent-control formations such as elongate beads or ribs in line with these proposals. The problem of escaping liquid during transit is thereby avoided.

(24) The position after release of the lock-down, with the body insert turned to its anticlockwise extreme relative to the cylinder 4, is seen in FIG. 12. In this orientation, part of a high region 561 of the vent-control bead 56 is brought into circumferential register with each of the vents 46. By virtue of the downward extension channels 461 the level of the upper bead portion 56 lies above at least a portion of the vent interior opening so that venting communication is established between the container interior and the clearance 88 between the cylinder 4 and insert 5, leading down into the cylinder interior. The vents 46 accordingly become functional for dispensing.

(25) The high position of the actual through-holes of the vent 46, leading from the container interior, minimises liquid access to the vents. However, this position is part of the thicker-section material adjacent to support flange 43. Interference of the vent-control bead of the insert 5 at this position might involve excessive force and low dimensional tolerance. Extending the effective interior opening position downwards by means of the channel recesses 461, the bead 56 can lie at a level corresponding to a lower, more flexible part of the cylinder wall 42.

(26) While the continuous rib or bead type formation is a preferred embodiment herein, the skilled person will appreciate that the combination of features providing controlled rotation of the body insert driven from the plunger as disclosed herein, especially in a down-locking pump and more especially one with a catch for the rotational downlock, can be used with alternative vent-control (vent-blocking or vent-isolating) formations acting between the insert and cylinder body. These might be e.g. blocking lands, or rib-form formations which surround the vent without extending all around the insert. Such constructions are also contemplated as an aspect of our proposals herein.