Dispenser pumps and 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 outer body and providing an external collar through which the plunger stem operates. The body insert has lock-down threads to lock down the plunger for shipping. The insert also has formations for blocking or unblocking the vent opening by rotation between the outer body and body insert, driven by rotation of the plunger head which makes a catch engagement with the top of the body insert. This plunger head rotation is the locking or unlocking action for the plunger lock-down. Blocking the vent during shipping reduces leakage.

Claims

1. A dispensing pump comprising: a plunger; and a body, having an outer body cylinder defining a pump chamber, and a body insert portion fitting into the top of the outer body cylinder; wherein the plunger includes a head, a stem and a piston and being rotatable relative to the body between axially locked and axially unlocked positions, including a locked-down position in which the plunger is held relatively retracted into the body; wherein a vent path is partially defined by a vent opening in the outer body cylinder; wherein the body insert rotates relative to the outer body cylinder between vent-blocked and vent-open relative positions in which the vent path is respectively blocked and open; and wherein the plunger initially drives relative rotation of the body insert and outer body cylinder to block or unblock the vent path and, after the body insert and outer body cylinder make a rotational stop engagement, drives relative rotation of the plunger and body insert to lock or unlock a mechanism for providing the locked-down position.

2. The dispenser pump according to claim 1 wherein the body insert has a vent-blocking portion which engages the outer body cylinder in the axially locked-down condition to block the vent opening, and is disengageable from the outer body cylinder in the axially unlocked condition to open the vent path.

3. The dispenser pump according to claim 2 wherein the body insert defines a recess or clearance which is brought into register with the vent opening of the outer body cylinder for the vent-open position.

4. The dispenser pump according to claim 1 wherein the locked-down position is provided by a threaded engagement between the plunger and the body.

5. The dispenser pump according to claim 1 wherein the body insert and the outer body cylinder each include cooperating formations or stop abutments formed at the interface between the body insert and the outer body cylinder, said formations or stop abutments engageable with one another to limit a range of relative rotational movement between the body insert and the outer body cylinder.

6. The dispenser pump according to claim 1 wherein the outer body cylinder includes a cylinder portion with a convergent upper wall having the vent opening and an annular locating flange to engage a container neck in use and wherein the body insert is secured rotatably to the outer body cylinder by way of a top retaining formation.

7. The dispenser pump according to claim 1 further comprising a securing cap attached to the body and a container for liquid product having a container neck connected to the securing cap.

8. The dispenser according to claim 7 wherein the outer body cylinder includes a locating flange to engage the container neck, said locating flange comprising a set of downward interlock projections which make an interlock engagement with the container neck to prevent rotation of the outer body cylinder relative to the container neck.

9. The dispenser according to claim 8 wherein the container neck includes cooperating projections.

10. The dispenser according to claim 7 wherein the outer body cylinder includes interlock projections which cooperate with corresponding projections on the container neck to prevent rotation of the outer body cylinder relative to the container neck.

11. The dispenser according to claim 4 wherein the threaded engagement is between the plunger and the body insert of the body.

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 is an axial cross-section of a dispenser embodying the invention, with much of the container omitted and the plunger in the extended position;

(3) FIG. 2 shows the plunger locked down in the retracted position;

(4) FIG. 3 is an oblique bottom view of a body cylinder component;

(5) FIG. 4 is a top oblique view of the body cylinder component;

(6) FIG. 5 is a top oblique view of a body insert component;

(7) FIG. 6 is a bottom oblique view of the body insert component;

(8) FIG. 7 is a bottom oblique view of a plunger head component, and

(9) FIG. 8 is a perspective view of a container neck shown separately.

DETAILED DESCRIPTION OF EMBODIMENTS

(10) FIGS. 1 and 2 show the general arrangement of a pump dispenser embodying our proposals. The dispenser consists of a pump 1 mounted on the neck 101 of a container 100 (shown only partially) which holds a liquid to be dispensed. The pump has a body 2 mounted fixedly in the neck 101 of the container by a securing cap 5 having an internal thread 51 engaging an external thread 102 of the neck. The pump body consists of an outer body or body cylinder 6 and a body insert or collar 7 fitted into the top of the outer body 6. A plunger 3 has a head 31, a stem 32 and a piston 33 which operates in a cylinder portion 61 of the body cylinder 6, defining therewith a pump chamber 9. A discharge channel is defined through the plunger stem 32, leading to a discharge nozzle 35 of the head 3 by way of an outlet check valve 34. The pump chamber 9 is supplied from the container interior via a dip tube (not shown) and an inlet with an inlet check valve 21, so that reciprocation of the plunger between the extended (up) and retracted (down) positions pumps liquid through the valve and out of the nozzle 35. A pump spring 4 biases the plunger to the extended (up) position.

(11) For shipping or extended periods of non-use the plunger can be locked down as shown in FIG. 2. The plunger head 3 (see also FIG. 7) has a tubular connector portion 39 into which the stem 32 is plugged, with an external lock-down thread 37 and a pair of fins or ribs 36 whose function is described later. The body insert 7 has an inner skirt 72 with a complementary (female) lock-down thread 722. By pushing the plunger 3 down and then turning clockwise to engage the lock-down threads 37,722, through e.g. about three-quarters of a turn, the plunger can be locked down and in this position the inlet valve 21 is held shut to prevent escape of liquid through the dispensing path.

(12) The body cylinder 6 is shown in more detail in FIGS. 3 and 4. It is a one-piece moulding, with the cylinder portion 61 formed integrally with a radial locating flange 62, which rests against the top of the container neck, and an upward annular retainer projection 65 carrying outer snap ribs 651 which engage corresponding inward snap ribs on an outer skirt 71 of the body insert 7. The retaining projection 65 projects up through a central hole of the securing cap 5, the surrounding flange of which presses the body flange 62 down onto the neck edge. In this embodiment the body flange 62 and container neck are specially formed to make an interlock preventing their relative rotation, by means of spaced downward interlock projections 64 from the flange 62, each with a circumferentially-directed abutment face. The container neck 101 (see FIG. 8) has a thinner region adjacent the edge forming an inward step on the outer side, and having a diametrically-opposed pair of body interlock projections 103 formed integrally, at the same thickness as the main thickness of the neck tube (i.e. only as an interruption of the step formation). As explained in our earlier PCT/EP2017/061611, the disclosure of which is incorporated herein by reference, by forming the projections 103 only at the position of a mould split line, or only at positions orthogonal to that line, projections with reliably perpendicular flat faces can be moulded giving a strong interlock at small bulk. Also, they leave a wide clear segment above the step formation into which the downward interlock projections 64 can fit on assembly without specific component alignment being needed. Plural interlock formations 64 are provided (six in this embodiment, as two evenly-spaced sets of three each) to reduce the angle turned between the components before a fixed position is reached. The projections 64 lie close in against the neck edge, and an inwardly prominent retaining band region 53 around the interior of the cap 5 surrounds them closely in the assembled condition (FIGS. 1 and 2) so that the projections 64 cannot bend outwardly out of engagement. This mechanism prevents the outer body/body cylinder 6 from rotating relative to the neck. For further security, in this embodiment the neck is formed with a pair of directional cap interlock projections 104 (see FIGS. 1 and 8) engaged by inwardly-directed pawls or directional teeth 54 around the bottom of the cap 5 to prevent accidental unscrewing of the cap.

(13) Inwardly of the interlock projections 64 a flexible plug skirt 63 projects down from the flange 62: this fits with interference inside the container neck edge to make a seal, obviating the conventional seal washer used here.

(14) Around the inside of the upstanding retaining projection 65 of the body cylinder 6 is a series of spaced limit stops 67, four in this embodiment, presenting abrupt circumferentially-directed faces.

(15) Below the locating flange 62 the cylinder portion 62 has a downwardly converging region 68 of the upper wall through which a pair of vent holes 66 are formed, through which air from the exterior can pass to the container interior around the plunger stem during operation (or in some embodiments between the retainer projection 65 and body insert skirts, e.g. through grooves provided for this purpose). This mode of venting is known in itself. The vent holes are exposed to the container interior, so the potential exists for liquid product to penetrate the pump cylinder above the piston 33 and perhaps escape through the top body opening and/or accumulate in the cylinder 6 above the piston. In either case, such liquid might undesirably emerge from the top of the pump such as when the plunger is unlocked after transit.

(16) To prevent this, the pump is provided with a vent blocking/unblocking mechanism and function as follows. As mentioned, the vent holes 66 are formed through the convergent upper wall 68 of the body cylinder 6 which provides a generally conical annular inner surface. The body insert 7 has a vent control skirt 73, projecting downwardly between the inner and outer skirts 72,71 mentioned above, which has a vent control surface 735 of conical form generally complementing that of the body wall 68, and contacting it. The vent control surface is characterised by a set of lands 731, each of a smooth conical segment form, which will fit closely against the body wall 68 and block a vent opening 66 if opposed to it. Between the lands are recesses or notches 732 which open downwardly so that, when brought into opposition to a vent opening 66, the vent opening communicates into the upper cylinder space so that the vent path is open. The outside of this vent control skirt 73 also carries a set of four limit stops 74 which, as can be seen, will fit between and interact with those on the inside of the cylinder retainer projection 65 so that with the components inserted and snapped together, the insert 7 is limited to a rotation arc or sector of slightly less than 90 degrees relative to the outer body 6, but can be turned between these limits by overcoming the modest sliding friction at the snap joint. At the anti-clockwise limit of the body insert (seen from above) the vent is closed, while at the clockwise limit the vent is open since the limit stops 67,74 accurately position the recesses 732 over the vent holes 66.

(17) Next, the role of the plunger 3 is described.

(18) The top face of the body insert 7 interacts with the underside of the plunger head 31 to constitute a plunger catch mechanism which inhibits initiation of the unlocking (anti-clockwise) movement of the plunger head e.g. when subject to impacts in transit. The top face of the body insert 7 has a generally conical indentation, with a conical track 76 interrupted by two retaining formations 75. There could be only one retaining formation, or more than two, but two is convenient and effective for obvious reasons. Each retaining formation 75 consists of a generally radial slot 77 whose bottom is level with the conical track 76, bordered to either side by a circumferentially-directed abutment face 79, from which a ramp 78 extends down in either direction to join the level of the conical track 76.

(19) The downward edges 361 of the ribs or fins 36, formed solidly with the plunger head's connector portion 39, are inclined up and out to conform with the conical track surface 76, and so that as the plunger is being turned to lock it down, they come into engagement with that surface. Approaching the fully locked-down position, the ribs ride up a corresponding pair of the ramps 78 (the opposed pair which rise in the anti-clockwise direction), forcing some resilient bending thereof, and then drop or click down into the slot 77, recovering from the bending. From this position, a substantial threshold turning force is required to push the fins 36 past the abutments 79 and initiate unscrewing of the down-lock threads. By providing the catch mechanism and formations in a recessed surface of the body top, a compact and concealed mechanism is achieved. The oppositely-directed abutment 79 and ramp 78 provide that for tightening (clockwise) turning of the plunger head a similar threshold force must be overcome for head rotation to release co-rotation of the body insert 7.

(20) The threshold force to overcome the catch mechanism is substantially greater than the force required to turn the body insert 7 in the body cylinder 6.

(21) The operation of the features can now be understood. When the dispenser is assembled on the production line, the plunger is depressed and turned clockwise to lock it down. On or soon after its initial engagement with the body insert 7, the ribs 36 of the plunger head carry the body insert 7 around, rotating it relative to the outer body 6 (which is held against rotation relative to the neck 101 by the interlock between them). They turn relatively until the limit stops 67,74 meet, assuring blocking of the vent holes 66. The reaction of the abutted limit stops then easily overcomes the engagement force for the catch mechanism, so that the ribs or fins 36 ride up the ramps 78 with deformation and click into the catch slots 77 (if they have not already done so). The pump is then able to be shipped, sent by mail etc. without leakage through the vent holes.

(22) When the pump is to be used, the user turns the plunger head forcibly anti-clockwise. On initial rotation, the plunger head carries the body insert 7 anti-clockwise with it until the opposite faces of the limit stops 74,67 meet, preventing further rotation of the insert 7. The insert recesses 732 are then aligned with the vents 66, so that the vents are open and the pump can operate. The abutting of the limit stops overcomes the threshold release force of the plunger head catch, so that continued turning of the head releases the catch and unlocks the down-locked thread engagement, allowing the plunger to rise for use.

(23) The illustrated embodiment has a pump of the kind in which the pump spring is in the pump chamber. The body insert can be of small length, extending only a short distance down into the body. As is well known, some pumps have a longer tubular insert extending down into the outer cylinder, and often housing the spring in the insert (to avoid product contacting the spring). The same principles can be used to block or unblock a vent hole formed through the wall of the outer cylinder using the insert. The vent holes in this case may be formed further down the cylinder wall, because the insert reaches further down. For example, the insert will typically have a plain cylindrical outer surface with a slight clearance from the outer body wall—as is conventional—so that venting proceeds through the hole and the gap between them. However in line with the invention the plain cylindrical surface of the insert can be interrupted by a land or wall formation (however many are required to correspond to the vents provided) which, by turning the insert relative to the outer body, can be brought to cover or block the vent opening in the outer wall in the similar way to that described above.