WO2010041075A2

WO2010041075A2 - Adhesive cartridge

Info

Publication number: WO2010041075A2
Application number: PCT/GB2009/051342
Authority: WO
Inventors: Stuart Edward Saunders
Original assignee: Stuart Edward Saunders
Priority date: 2008-10-08
Filing date: 2009-10-08
Publication date: 2010-04-15
Also published as: GB0909964D0; WO2010041075A3; GB0818406D0; GB0904087D0

Abstract

A cartridge of adhesive (28) for use in an adhesive dispensing machine has a cylindrical reservoir (10) with an open end (17) and a discharge end. A piston (18) is slidably mounted in the reservoir, for discharging adhesive through a neck (13) formed as a part of an end wall (12) at the discharge end. Internal barb-shaped annular ribs (15, 16) are provided within the reservoir, one adjacent the open end and the other towards the discharge end, spaced from the end wall (12) by at least the thickness of the piston (18). The cartridge has a removable handle (26) which may be formed as a part of a screw-threaded cap (21) for the neck (13) of the end wall (12).

Description

ADHESIVE CARTRIDGE

This invention relates to a cartridge of adhesive for use in an adhesive dispensing machine and in particular, though not exclusively, to a cartridge of tiling adhesive for securing tiles to a substrate.

Though this invention may be used for adhesive other than tiling adhesive, it will hereinafter be described solely with reference to tiling adhesive. It is to be understood that this invention nevertheless is not restricted to such adhesive nor to the dispensing of adhesive expressly for tiling.

It is known to supply in a cartridge an adhesive which has been pre- mixed and is ready for use. Typically, such cartridges hold from 250ml to 500ml and are used in a cartridge gun for dispensing the adhesive, by moving a piston in the cartridge towards a nozzle at one end thereof. The gun has a rod provided with an end plate which may be moved incrementally by reciprocating a trigger hinged to a handle for the gun. The end plate of the rod engages the cartridge piston and so advances the piston into the cartridge, driving adhesive out of the nozzle.

A cartridge holding an adhesive as described above is not suitable for use in tiling a wall or floor, since the volume of adhesive within the cartridge would be sufficient for only very few tiles. Pre-mixed adhesive for tiling often is supplied in tubs holding typically 10 or 15 litres but must be applied manually to the surface to be tiled. This is usually done by trowelling the adhesive on to the surface, spreading the adhesive and then scraping it into a series of parallel beads using a toothed spreader. This takes significant skill in order to generate uniformly spaced beads of more or less constant profile and also is relatively time consuming.

There is thus a demand for a machine able to apply adhesive in parallel uniform beads on to a surface to be tiled, but this requires a suitable source of adhesive. Such a machine may be supplied with adhesive mixed either within a container of the machine or away from the machine, in which case the adhesive is then loaded into the machine. Either way, there are problems associated with uniformity and consistency of the adhesive mix, and there will be downtime for the machine, while another batch of adhesive is being mixed. Though a pre-packaged cartridge of adhesive could solve these problems, a cartridge generally similar to that for use in a gun but significantly larger cannot be made to have a sufficient capacity since the cartridge would be too heavy and unwieldy. Moreover, having regard to the relatively large size of a cartridge which may hold sufficient tiling adhesive for use in a dispensing machine, it would be relatively easy for the cartridge to be refilled after use, so losing the advantage of having a cartridge containing pre-mixed adhesive, manufactured under carefully controlled conditions.

This invention aims at resolving the difficulties associated with simply making a relatively large cartridge of adhesive, to ensure the adhesive is consistent and suitable for use and that the cartridge can be handled easily prior to insertion into an adhesive dispensing machine. According to this invention, there is provided a cartridge of adhesive for use in an adhesive dispensing machine, comprising a substantially cylindrical reservoir having an open end and a discharge end provided with an end wall formed with a neck, a piston slidably mounted in the reservoir for discharging adhesive through the neck, a first catch disposed internally at the open end of the reservoir to restrain the piston from leaving the reservoir through the open end thereof, and a second catch disposed internally adjacent the discharge end of the reservoir to restrain the piston adjacent the end wall once moved there to discharge the adhesive.

It will be appreciated that by having a cartridge arranged to restrain the piston adjacent the discharge end of the reservoir, once the piston has been moved there to effect discharge of adhesive from the cartridge, the cartridge cannot be refilled. In this way, the refilling of the cartridge with a locally made mix, for example at the site where tiling is being undertaken, is eliminated and so the consistency and reliability of the adhesive mix may be assured. As one cartridge becomes exhausted, a fresh cartridge of pre-mixed adhesive must be employed. The first catch may comprise at least one projection formed in the open end of the cylindrical reservoir, either at the end of the reservoir or immediately adjacent that end. The projection may be wholly continuous and thus in the form of an annular rib, or may consist of a series of individual ribs, each extending circumferentially for a limited extent, so long as there are sufficient ribs to prevent removal of the piston once inserted into the reservoir. The annular rib or each projection advantageously is barb-shaped in cross-section, to permit the piston to be inserted into the reservoir by being snapped past the projection, but which projection then prevents removal of the piston rearwardly out of the reservoir.

The second catch may be similarly formed to the first catch and so may comprise at least one projection or an annular rib formed in the reservoir, but spaced from the discharge end of the reservoir by a distance not less than the axial thickness of the piston, so that the piston may be moved fully to the discharge end of the reservoir but then may not be moved rearwardly again.

A cartridge having a volume of perhaps 15 litres will be relatively heavy, when filled with tiling adhesive. To facilitate the handling of such a cartridge, it may be provided with a handle, arranged either at the open end or the discharge end of the reservoir. Such a handle may preclude the insertion of the cartridge into a holder provided as a part of a dispensing machine and so it is preferred for the handle to be removable from the cartridge. In one embodiment, the handle may extend from a removable cap for the discharge end of the cartridge and in this case the cap may have a relatively large external diameter, more or less equal to that of the reservoir itself, whereby the reservoir may be stood on the cap for filling and storage purposes. In another embodiment, the handle is connected to a pair of diametrically opposed tabs each projecting axially from the periphery of the reservoir and each having an opposed opening in which an end portion of the handle is received.

A removable seal may be attached to the mouth of the neck, at the discharge end of the reservoir, both to protect adhesive loaded into the reservoir from deterioration and to provide quality assurance for the end user. - A -

Such a seal may comprise a foil sealed to the end of the neck, over the mouth. A similar seal may be provided over the open end of the cartridge, once filled and the piston has been inserted into the reservoir.

If the d ischarge end of the reservoir is closed before filling with adhesive, when the reservoir has been filled and the piston is fitted to the open end of the reservoir, air may be trapped between the surface of the adhesive and the piston. Such air may be eliminated by providing an air release port in the piston; the port may be open during insertion of the piston to allow the escape of air as the piston is brought into engagement with the surface of the adhesive. Then, the port may be sealed to prevent escape of adhesive, or the port may be fitted with a valve which is closed, for this purpose.

A notch or keyway may be formed in the external surface of the reservoir, to allow the correct orientation of the cartridge when fitted to a dispensing machine. Such a notch or keyway may also be used to restrain the rotation of the cartridge during filling with adhesive or even perhaps while adhesive is mixed in the reservoir during the manufacture of the finished cartridge.

By way of example only, certain specific embodiments of tiling adhesive cartridges arranged in accordance with this invention will now be described, reference being made to the accompanying drawings in which:-

Figure 1 is a cross-section of a first embodiment of cartridge;

Figure 2 shows a connector for a flexible hose, for use with the cartridge of Figure 1 ;

Figure 3 is a cross-section through an alternative embodiment of cartridge, shown connected to a flexible hose;

Figure 4 is a detail view on an enlarged scale of the neck region of the cartridge of Figure 3; and

Figures 5 and 6 show the neck region of the cartridge of Figure 3, together with a foil seal for the mouth of the neck. Referring initially to Figure 1 , there is shown a tiling adhesive cartridge which comprises a moulded plastics material reservoir 10 having a cylindrical side wall 11 and an end wall 12. The end wall defines a central neck 13 which has external threads 14, for a purpose to be described below.

Internally within the side wall 1 1 are formed two barb-shaped annular ribs 15 and 16. Rib 15 is at the open end 17 of the side wall 1 1 and rib 16 is adjacent the end wall 1 2, spaced therefrom by a d istance equal to the thickness of a piston 18, shown in part adjacent the rib 15, in broken lines. The piston has a grooved peripheral wall and, when inserted into the side wall 11 , is a close sliding fit therein.

A closure 20 is fitted to the neck 13, that closure having a central cap 21 with an internally-threaded circular wall 22 engageable with the threads 14 of the neck 13, and also having an end wall 23. An O-ring 24 is fitted into a groove formed at the junction between the walls 22 and 23 of the cap. When fully engaged with the neck, the O-ring 24 of the cap 21 seals against the end face of the neck 13, so as to prevent leakage from the reservoir and also deterioration of the contents of the reservoir. The cap is moulded integrally with the closure 20, the external periphery of which is of the same diameter as the side wall 1 1 , and a wire handle 26 is connected to that closure such that the cartridge may easily be handled by using the handle. The cartridge may normally stand on the closure 20, both during filling (as shown in Figure 1 ) with adhesive and subsequently during storage.

As shown in Figure 1 , the reservoir of the cartridge is filled with adhesive 28 from the open end 17 of the reservoir, with the reservoir standing on the closure 20. Once filled with the appropriate quantity of pre-mixed adhesive, the piston 18 is fitted into the side wall 11 , by being snapped past the annular rib 15 to the position shown in Figure 1 . As the piston is pressed into the reservoir, any air trapped between the surface of the adhesive and the piston is allowed to escape through a port 29 in the piston. When the piston bears on the surface of the adhesive, that port is closed by way of a taper plug 30, driven into the port. Instead of a simple port as shown, an air valve may be fitted to the piston such that air may escape while the valve remains open and then, following assembly of the piston to the reservoir, the valve may be closed. When the cartridge of Figure 1 is to be used in an adhesive dispensing machine, the closure 20 is removed from the neck 13. This allows the handle 26 to be discarded and also opens the mouth of the neck 13. The cartridge is then inserted into a holder therefor (not shown) and which forms a part of the dispensing machine, and a flexible hose 32 (Figure 2) is secured to the neck by means of a connector 33. Th is connector has internal threads 34 for engagement with the threads 14 of the neck 13 and also has a central opening within which is rotatably received the end portion of the flexible hose 32. This allows the connector 33 to be turned to inter-engage its threads 34 with corresponding threads 14 of the neck, without the hose 32 also turning. As with cap 21 , the connector 33 has an O-ring 35 to effect a seal to the end face of the neck 13.

Figures 3 to 6 show a second embodiment of cartridge which is generally similar to that described above, but which differs in certain details. In Figures 3 to 6, like parts with those of the first embodiment are given the same reference numerals.

The reservoir 36 differs from that of the first embodiment in that the neck 37 is provided with internal threads 38 for receiving a connector 39 of a flexible hose 40, and is closed by a foil 41 (Figures 5 and 6) heat-sealed to the end face of the neck. Before filling, the foil is sealed to the neck but when the cartridge is to be used, the foil is stripped away from the neck so opening the reservoir. Then, the connector 39 may be threaded into the cartridge neck, to allow adhesive to be driven out of the reservoir into the flexible hose 40.

Also shown in Figures 3, 4 and 5 is an O-ring 42 fitted into an external groove 43 formed around the neck 37. On offering the cartridge into a holder therefor, the O-ring effects a seal to that holder both locating the cartridge and preventing leakage of adhesive, as shown on the left hand side of Figure 4, where part of the holder is diagrammatically illustrated at 44.

F ig u re 3 also shows a wire hand le 45 con nected to a pa ir of diametrically opposed tabs 46 projecting from the end wall 12 of the reservoir. Those tabs typically have openings into which the end portions of the handle are pressed. When the cartridge is to be used, the handle 45 is pulled away from the tabs 46 and is discarded, such that the handle does not interfere with the fitting of the cartridge to the dispensing machine. Also as shown in Figure 3, the handle could instead be fitted to the open end of the reservoir, tabs 47 being instead provided for that purpose.

The piston 48 of the second embodiment is shown having a valve 49 fitted to a port 50 extending therethrough, for the same purpose as has been described above with reference to port 29 of the first embodiment.

The open end of the cylindrical side wall of the cartridge may be provided with a rectangular notch 53 as shown in Figure 7, for engaging a corresponding peg 54 within a cylindrical holder 55 for the cartridge. When the peg 54 has engaged in the notch 53, the free end of the cartridge bears on an annular rib 56 provided within the holder, the cartridge then being held against rotation relative to the holder.

Claims

1. A cartridge of adhesive for use in an adhesive dispensing machine, comprising a substantially cylindrical reservoir having an open end and a discharge end provided with an end wall formed with a neck, a piston slidably mounted in the reservoir for discharging adhesive through the neck, a first catch disposed internally at the open end of the reservoir to restrain the piston from leaving the reservoir through the open end thereof, and a second catch disposed internally adjacent the discharge end of the reservoir to restrain the piston adjacent the end wall once moved there to discharge the adhesive.

2. A cartridge as claimed in claim 1 , wherein the first catch comprises at least one projection formed in the open end of the reservoir, internally thereof.

3. A cartridge as claimed in claim 2, wherein the projection comprises a substantially continuous annular rib.

4. A cartridge as claimed in claim 2 or claim 3, wherein the projection is barb-shaped in cross-section, to permit the insertion of the piston into the reservoir but to restrain movement of the piston out of the reservoir.

5. A cartridge as claimed in any of the preceding claims, wherein the second catch comprises at least one projection formed internally of the reservoir, spaced from the discharge end thereof by a distance not less than the axial thickness of the piston.

6. A cartridge as claimed in claim 5, wherein the projection comprises a substantially continuous annular rib.

7. A cartridge as claimed in claim 5 or claim 6, wherein the projection is barb-shaped in cross-section, to permit movement of the piston fully to the discharge end of the reservoir but to restrain movement of the piston away from the discharge end.

8. A cartridge as claimed in any of the preceding claims, wherein the cartridge has a detachable handle arranged at either the open end or the discharge end of the reservoir.

9. A cartridge as claimed in claim 8, wherein the handle is defined by a pair of d iametrically opposed tabs each projecting axially from the periphery of the reservoir and each having an opposed opening, and a handle component fitted into said openings of the tabs and removable therefrom.

10. A cartridge as claimed in any of claims 1 to 7, wherein the neck of the reservoir is closed by a removable cap, threaded to the neck.

1 1 . A cartridge as claimed in claim 1 0, wherein the cap has an enlarged outer periphery of a diameter comparable to that of the reservoir, and a handle is secured to that outer periphery.

12. A cartridge as claimed in any of the preceding claims, wherein a removable seal is attached to at least one of the mouth of the neck and the open end of the reservoir.

13. A cartridge as claimed in claim 12, wherein the seal is in the form of a foil heat-sealed to the end face of the neck, around the mouth thereto.

14. A cartridge as claimed in any of the preceding claims, wherein the piston includes a through-port, to allow the egress of air from within the reservoir.

15. A cartridge as claimed in claim 14, wherein the port is closed by one of a plug or a valve including a manually operable valve member.

16. A cartridge as claimed in any of the preceding claims, wherein the reservoir includes a notch or projection engageable with a corresponding projection or notch respectively, on a holder for the cartridge thereby to restrain rotation of the cartridge relative to the holder when fitted thereto.