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Title:
A DISPENSER FOR DISPENSING A FLOWABLE SUBSTANCE
Document Type and Number:
WIPO Patent Application WO/2021/072491
Kind Code:
A1
Abstract:
A dispenser (10b) for a flowable substance comprises a housing (12) having a first part (14) and a second part (16) which are releasably coupled together. A coupling system (46) releasably couples the first part (14) and the second part (16) together. The second part (16) has a releasable lock (62) at one end (25). A compressed gas bias system (26p) is retained by the housing (12) and operable to force material held within a cartridge (36) which is held in the housing (12) to flow form a dispenser opening. One end of the compressed gas bias system (46) is coupled to a piston (34) that fits within the cartridge (36). An opposite end of the compressed gas bias system (26p) extends through the releasable lock (62). The releasable lock (62) is operable to allow motion of the, or a part of the, compressed gas bias system (26p) along an axis of the housing (12). A flexible hose (80) may be connected to an outlet of the cartridge (36) and fitted with a valve (86) to control flow of material from the cartridge (36).

Inventors:
BROWNE PAUL ROBERT (AU)
Application Number:
PCT/AU2020/051105
Publication Date:
April 22, 2021
Filing Date:
October 14, 2020
Export Citation:
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Assignee:
BROWNE PAUL ROBERT (AU)
International Classes:
F16N3/12; B05C17/01
Attorney, Agent or Firm:
GRIFFITH HACK (AU)
Download PDF:
Claims:
CLAIMS

1 . A dispenser for a f lowable substance comprising : a housing having a first part and a second part which are releasably coupled together the housing configured to receive a cartridge of a flowable material, the second part including a releasable lock at one end; a piston locatable within the housing, the piston arranged fit within a cartridge when received within the body and apply pressure to the material in the cartridge; a compressed gas bias system retained by the housing and operable to force material held within a cartridge to flow form a dispenser opening, wherein one end of the compressed gas bias system is coupled to the piston and an opposite end of the compressed gas bias system extends through the releasable lock, the releasable lock being operable to allow motion of the, or a part of the, compressed gas bias system along an axis of the housing; and a coupling system that releasably couples the first part and the second part together.

2. The dispenser according to claim 1 comprising a stop mechanism connected to the compressed gas bias system, the stop mechanism operable to engage an inside of the second part to limit motion of the compressed gas bias system in a direction away from the first part.

3. The dispenser according to claim 2 wherein the stop mechanism can be selectively tightened and released to allow adjustment of an axial position of the compressed gas bias system relative to the end of the second part.

4. The dispenser according to any one of claims 1 -3 wherein the compressed gas bias system comprises a pneumatic strut comprising a cylinder, a piston rod and a volume of a gas retained between the cylinder and the piston rod, wherein one of the piston rod and the cylinder is coupled to the piston and the other of the piston rod and the cylinder pass through the releasable lock.

5. The dispenser according to claim 4 wherein the piston rod is coupled to the piston and the cylinder passes through the releasable lock.

6. The dispenser according to any one of claims 1 -5 comprising a hose and a hose fixing piece, the hose fixing piece having one end and arranged to seat inside an outlet of a cartridge retained within the housing, and an opposite end arranged to couple with the hose.

7. The dispenser according to claim 6 wherein the hose fixing piece has a small diameter portion at the one end and a large diameter portion at the opposite end, wherein the small diameter portion is configured to seat inside an outlet of a cartridge retained within the housing, and the large diameter portion is arranged to fit inside the hose.

8. The dispenser according to claim 6 or 7 comprising a valve an end of the hose distant the hose fixing piece, the valve operable to control flow of material from the dispenser opening.

9. The dispenser according to claim 8 comprising an airtight closure downstream of the valve and arranged to selectively engage the dispenser opening to prevent contact of the flowable material upstream of the dispenser opening with air.

Description:
A DISPENSER FOR DISPENSING A FLOWABLE SUBSTANCE

TECHNICAL FIELD

A dispenser for a flowable substance is disclosed. The flowable substance may be in the form of a liquid, paste or highly viscous substance such as grease, sealant, adhesive or grout.

BACKGROUND ART

Grease and grout guns are widely used by tradespeople and the home handy person for dispensing flowable substances such as grease, sealants, adhesives and grout. The guns have a cylindrical body that can be opened at one end to receive a supply of a flowable substance to be dispensed. This can be by way of loading a cartridge containing the substance, or directly filling the gun form a bulk supply. The gun is formed with an outlet for the substance. The outlet may be controlled by a manually operated valve. The valve may also be part of a pump mechanism coupled with the dispenser. Alternately the outlet may act as an inlet to another type of manual or powered pump.

Within the body is a plunger assembly comprising: a piston, a coil spring, and rod or shaft. The rod passes through the spring and a keyed through hole piston. One end of the rod has a key which when aligned with the keyed hole can pass through the piston. When the rod is rotated relative to the piston so that the key is out of alignment with the keyhole the piston is retained on that end of the ride. An end of the rod opposite the plunger has a handle that lies outside of the body of the gun.

To load the grease gun with a supply of a flowable substance, whether it is in a cartridge or held directly within the body of the gun, the plunger assembly must be operated to compress the spring by pulling on the handle. This retracts the piston within the body of the gun to give space or volume for the supply of the flowable substance. A latch is often used to lock the rod and hold the spring in the compressed state during this loading process. Once the latch is released the spring pushes the piston against the flowable substance urging it towards the outlet. The rod or shaft may then be pushed into the cylindrical body and the volume of flowable substance so that the handle does not stick out from the end of the body. As this happens the rod/shaft slides through the keyed through hole, leaving the piston at the end of the flowable substance. Because the keyed hole is not sealed a small volume of the flowable substance can flow out from the hole and along the rod/shaft. This creates mess and, if it contacts the user’s hands, can make handling of the gun difficult. l The above references to the background art do not constitute an admission that the art forms a part of the common general knowledge of a person of ordinary skill in the art. The above references are also not intended to limit the application of the disclosed dispenser to any particular form of dispenser nor the type of flowable material to be dispensed.

SUMMARY OF THE DISCLOSURE

In a first aspect there is disclosed a dispenser for a flowable substance comprising: a housing having a first part and a second part which are releasably coupled together the housing configured to receive a cartridge of a flowable material, the second part including a releasable lock at one end; a piston locatable within the housing, the piston arranged fit within a cartridge when received within the body and apply pressure to the material in the cartridge; a compressed gas bias system retained by the housing and operable to force material held within a cartridge to flow from a dispenser opening, wherein one end of the compressed gas bias system is coupled to the piston and an opposite end of the compressed gas bias system extends through the releasable lock, the releasable lock being operable to allow motion of the, or a part of the, compressed gas bias system along an axis of the housing; and a coupling system that releasably couples the first part and the second part together.

In one embodiment the dispenser comprises a stop mechanism connected to the compressed gas bias system, the stop mechanism operable to engage an inside of the second part to limit motion of the compressed gas bias system in a direction away from the first part.

In one embodiment the stop mechanism can be selectively tightened and released to allow adjustment of an axial position of the compressed gas bias system relative to the end of the second part.

In one embodiment the compressed gas bias system comprises a pneumatic strut comprising a cylinder, a piston rod and a volume of a gas retained between the cylinder and the piston rod, wherein one of the piston rod and the cylinder is coupled to the piston and the other of the piston rod and the cylinder pass through the releasable lock. In one embodiment the piston rod is coupled to the piston and the cylinder passes through the releasable lock.

In one embodiment the dispenser comprises a hose and a hose fixing piece, the hose fixing piece having one end and arranged to seat inside an outlet of a cartridge retained within the housing, and an opposite end arranged to couple with the hose.

In one embodiment the hose fixing piece has a small diameter portion at the one end and a large diameter portion at the opposite end, wherein the small diameter portion is configured to seat inside an outlet of a cartridge retained within the housing, and the large diameter portion is arranged to fit inside the hose.

In one embodiment the dispenser comprises a valve an end of the hose distant the hose fixing piece, the valve operable to control flow of material from the dispenser opening.

In one embodiment the dispenser comprises an airtight closure downstream of the valve and arranged to selectively engage the dispenser opening to prevent contact of the flowable material upstream of the dispenser opening with air.

In a second aspect there is disclosed a dispenser for a flowable substance comprising: a housing having a first part and a second part which are releasably coupled together, and discharge port on or coupled to the first part; a piston locatable within the housing, the piston being free of any axial through hole; and a bias system retainable within the housing, the piston forming a slidable seal between a flowable substance held within the housing and the bias system, the bias system operable for applying a bias to a flowable substance via the piston to urge the flowable substance toward the discharge port.

In one embodiment the dispenser is arranged to enable or otherwise facilitate, for a predetermined volume of flowable substance, a change in bias applied by the bias system to the predetermined volume flowable substance.

In one embodiment the dispenser comprises a coupling system that releasably couples the first part and the second part together, the housing having: a volume for holding the flowable substance, piston and bias system; and a length from one end to an opposite end; and wherein the coupling system is associated with the bias system wherein bias applied by the bias system to the flowable substance is adjustable by operating the coupling system to vary one or both of the volume or the length of the housing.

In one embodiment the coupling system comprises (a) a clamp; (b) complementary screw threads formed on the first part and the second part; (c) a strap, wire or other tether; (d) one or more clips.

In one embodiment the bias system comprises one or a combination of two or more of: (a) a coil spring; (b) a pneumatic spring; (c) one or more pieces or billets of a compressible and resilient material.

In one embodiment the bias system comprises one or more spacers or packers disposable within and occupying a part of the volume of the housing.

In a third aspect there is disclosed dispenser for a flowable substance comprising: a housing having a first part and a second part which are releasably coupled together, and discharge port on or coupled to the first part; a piston locatable in the housing; and a bias system retainable within the housing, the piston forming a slidable seal between a flowable substance held within the housing and the bias system, the bias system operable for applying bias to a flowable substance via the piston to urge the flowable substance toward the discharge port; wherein the dispenser is arranged to enable or otherwise facilitate, for a predetermined volume of flowable substance, a change in bias applied by the bias system to the predetermined volume flowable substance.

In one embodiment the dispenser comprises a coupling system that releasably couples the first part and the second part together, the housing having: a volume for holding the flowable substance, the piston and the bias system; and a length from one end to an opposite end; and wherein the coupling system is associated with the bias system wherein bias applied by the bias system to the flowable substance is adjustable by operating the coupling system to vary one or both of the volume or the length of the housing. In one embodiment the coupling system comprises (a) a clamp; (b) complementary screw threads formed on the first part and the second part; (c) a strap, wire or other tether; (d) one or more clips.

In one embodiment the bias system comprises one or a combination of two or more of: (a) a coil spring; (b) a pneumatic spring; (c) one or more pieces or billets of a compressible and resilient material.

In one embodiment the bias system comprises one or more spacers or packers disposable within and occupying a part of the volume of the housing.

In a fourth aspect there is disclosed a dispenser for a flowable substance comprising: a housing having a first end, an opposite second end, a discharge port located at or near the first end, the housing being configured so that a distance between the first end and the second end can be varied to provide the housing with an adjustable length; a bias system retainable within the housing operable for applying a bias to a volume of a flowable substance contained within the housing to urge the flowable substance toward the discharge port; and wherein a degree of bias applied by the bias system to the flowable substance is adjustable by either (a) interchanging one bias system with another; and/or (b) changing the length of the housing and/or (c) changing a volume of the housing.

In one embodiment of the third aspect of the coupling system is operable between the first and second ends to enable the length of the housing to be varied while the housing contains a volume of the flowable substance.

In one embodiment the housing comprises: a first part which includes the first end of the housing, and an open opposite end; and a second part having a distal end which forms the second end of the housing, and an open opposite end, wherein the first and second parts are releasably connectable together with the open end of one of the parts received within the open end of the other of the parts.

In one embodiment the coupling system comprises one of: (a) a clamp; (b) complementary screw threads formed on the first part and the second part; (c) a strap, wire or other tether; (d) one or more clips. In one embodiment the bias system comprises: a coil spring; a pneumatic spring; one or more pieces or billets of a compressible and resilient material.

In one embodiment the second end of the housing comprises a liquid tight wall forming a barrier for flow of the flowable substance from the second end.

In a fifth aspect there is disclosed a dispenser for a flowable substance comprising: a housing having a first part provided at one end with discharge port for the flowable substance and an opposite open end, and a second part having an open end and a liquid tight closed end wherein the first and second parts are releasably connectable together with the open end of one of the parts received within the open end of the other of the parts; a bias system retained within the housing between the parts; and a piston slidingly receivable within the first part located between the bias system and the outlet; wherein a volume of the flowable substance is receivable within the housing between the piston and the outlet and the bias system is arranged to constantly bias the bias system and the flowable substance within the housing toward the discharge port.

In one embodiment the first and second parts are releasably connectable together in a manner allowing a variation in a distance between the first end of the first part and the closed end of the second part.

In one embodiment the dispenser comprises a coupling system arranged to releasably connect the first part and the second part together, wherein the coupling system comprises one of: (a) a clamp; (b) complementary screw threads formed on the first part and the second part; (c) a strap, wire or other tether.

In a sixth aspect there is disclosed a shaftless dispenser for a flowable substance comprising: a housing having a first part and a second part which are releasably coupled together, and discharge port on or coupled to the first part; a piston locatable within the housing; a bias system retainable within the housing, the piston forming a slidable seal between a flowable substance held within the housing and the bias system, the bias system operable for applying a bias to a flowable substance via the piston to urge the flowable substance toward the discharge port; and wherein the dispenser is free of a shaft connected to the piston and extending to an outside of the housing.

BRIEF DESCRIPTION OF THE DRAWINGS

Notwithstanding any other forms which may fall within the scope of the dispenser as set forth in the Summary, specific embodiments will now be described, by way of example only, with reference to becoming drawings in which:

Figure 1 is a cross-section view of a first embodiment of the disclosed dispenser with its corresponding spring in a compressed state and holding a cartridge of flowable material to be dispensed;

Figure 2 is an end view of a second part of a housing incorporated in the embodiment of the disclosed dispenser shown in Fig 1 ;

Figure 3 is a photographic representation of a partially disassembled the first embodiment of the disclosed dispenser showing an associated bias system with piston outside of the housing;

Fig 4 is a close up photographic representation of the piston shown in Fig 3;

Figure 5a is a perspective view of a washer in an upright orientation that may be used in an embodiment of the disclosed dispenser;

Figure 5b is a perspective view of the washer shown in Figure 5a but in an upside-down orientation;

Figure 5c is a section view of the washer shown in Figures 5a and 5b;

Figure 5d shows the washer of Figures 5a-5c engaged with an upper end of a grease cartridge which may be loaded into an embodiment of the dispenser shown in Figures 1-4;

Figure 6 is a photographic representation of a second embodiment of the disclosed dispenser; Figure 7 is an enlarged view of a coupling system incorporated in the second embodiment of the dispenser;

Figure 8 is an enlarged view of a second part of a housing of the dispenser shown in Figure 6 with an associated compressed gas bias system in a first position;

Figure 9 is a view of the second part shown in Figure 8 but with the compressed gas bias system in a second position;

Figure 10 is a partially disassembled view of the second embodiment of the dispenser;

Figure 11 is an end view of a hose fixing piece that may be incorporated in the second embodiment of the dispenser;

Figure 12 illustrates three of the hose fixing pieces shown in Figure 11 , one being free, another shown inserted into a cartridge that may be loaded into an embodiment of the dispenser, and another shown connected at one end with a hose; and

Figure 13 illustrates an end of the housing of the second embodiment with the hose connected to an outlet of a cartridge using the hose fixing piece shown in Figures 11 and 12.

DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS

With reference to Figures 1 -4 a first embodiment of the disclosed dispenser 10a comprises a housing 12 having a first part 14, and a second part 16. The first part 14 is provided at one end 18 with discharge port and an associated dispensing mechanism 20; and, an opposite open end 22. The discharge port in its broadest sense can be the end 18 itself. Alternately the discharge port may be considered to be a part of the dispensing mechanism coupled to the end 18 and through which the flowable substance must flow in order to reach a dispenser outlet 23. The second part 16 has an open end 24 and a closed end 25. The first and second parts 14, 16 are releasably connectable together with the open end 22, 24 of one of the parts 14, 16 received within the open end 24, 22 of the other of the parts 16, 14.

In this particular embodiment the open end 22 of the first part 14 is received within the open end 24 of the second part 16. The end 18 of the first part 14, and the end 25 of the second part 16, form or constituted opposite ends of the housing 12. A bias system 26 is retained by the housing or otherwise within the housing between the parts 14, 16. In the embodiment shown in Figures 1 -4 the bias system is shown as a single coil spring. Both the parts 14 and 16 are of a generally cylindrical configuration, although this need not be the case in all embodiments, as indeed exemplified in the second embodiment described later. The first part 14 is formed of a cylindrical tube 30 which is open at both ends, and a cap 32 that includes the outlet 23 and which is screw coupled to the end 18. This end corresponds to the end 18 of the first part 14. The dispensing mechanism 20 is integrated into or otherwise attached to the cap 32. The cap 32 and dispensing mechanism 20 may be of a generic or conventional nature. Typically, this includes an outlet chamber that in which the flowable substance is biased by the bias system 26 and a valve operated by manipulation of a trigger or lever of the dispensing mechanism 20 to open and close the valve.

In this embodiment the second part 16 is in the form of a cylindrical tube having a closed end

25 opposite its open end 24. The closed end 25 may be in the form of a circular planar wall. By being a closed end, the planar wall has a continuous surface, i.e. does not include any through holes. That is the closed end 25 is liquid-tight. For this reason, it is not possible for the flowable substance to leak out of the housing from the end 25. However, in an alternate embodiment the end 25 may have one or more openings provided it otherwise has some mechanism such as a shoulder or crossbar to form a stop for the bias system 26 and otherwise prevented from falling out of the housing 12.

A piston 34 is slidingly receivable within the housing and located between the bias system

26 and the end 18. When the bias system 26 is a coil spring, it is configured to maintain a pre-load when the piston 34 is immediately adjacent the end 18. That is, the bias system 26 may be arranged to always be under a degree of compression when there is a flowable substance within the housing 12; and thus, always apply bias urging the flowable substance toward the discharge port or dispensing mechanism 20.

In this embodiment the dispenser 10a is arranged to receive a cartridge 36 that holds a volume of flowable substance. Such cartridges are well-known in the art and do not form a part of the present disclosure. These cartridges often have a removable cap or peel off seal at one end that in use is located adjacent the end 18, and a peel off seal, a removable cap or possibly a slidable plug 38 at an opposite back end. A radial lip is also formed about the front end. This lip is clamped between the upper end of the cylindrical tube of the part 14 and the cap 32. In any event the disclosed dispenser is able to operate and function as intended with all currently know cartridges. When a volume of the flowable substance, for example by insertion of a cartridge 36, is contained within the housing 12 between the piston 34 and the one end 18 the bias system 26 is arranged to constantly bias the piston 34 and the flowable substance within the housing toward the discharge port or dispensing mechanism 20.

The piston 34 has a body 40 that can be coupled to one end of the bias system 26 and a resilient seal 42. The seal 42 is arranged to form a circumferential seal about an inside wall of the cartridge 36 as the plug 38 advances toward the outlet 18 when the flowable substance is dispensed from the dispenser 10a. As shown in Figure 4 the seal 42 has a cup like shape with a resilient peripheral wall 44 that contacts an inside surface of the cartridge 36 and lie in advance of body 40 with reference to the direction of travel through the housing 12.

The piston 34 does not have a through hole for a rod or shaft as in the prior art. This is because the bias system in the disclosed dispenser is not compressed by applying a pulling force from outside of the housing, to pull the piston back against the bias of the bias mechanism. For this reason, embodiments of the disclosed dispenser may also be considered to be a shaft-less dispenser. That is the bias system does not require a shaft that connects to the piston and extends to outside of the body, and is pulled, for compressing the bias system.

A coupling system 46, in this embodiment in the form of a clamp, enables the first part 14 and the second part 16 to be releasably coupled together. Additionally, in this, but not necessarily all embodiments, the coupling system allows adjustment of the overall housing length and thus the pressure that can be applied by the bias system 26. More particularly the coupling mechanism 46 enables the distance between the ends 18 and 25 of the housing to be varied. This is equivalent to enabling the length L of the housing 12, or the volume of the housing, to be changed or varied. Because of this, these embodiments of the coupling system enable a user to change the degree of bias provided by the bias system 26 by adjusting the length L of the housing 12, i.e. varying the distance between the opposite ends 18 and 25. Flowever as describe later it is not essential in all embodiments that the coupling system enables the housing length or volume to be varied to enable a change in bias.

It is believed that this may be helpful to ensure positive flow of the flowable substance to the discharge port at all times and particularly when the amount of flowable material remaining within the cartridge 36 is relatively low, for example less than say 30%, or less than 15%.

The ability to adjust the bias provided by the bias system 26 (whether this is by action of the coupling systems, or by action or operation of the bias system itself independent of any change in housing length or volume) may be helpful when dispensing flowable substances of different inherent viscosity and/or in different temperature conditions, for example in cold temperatures which may increase the viscosity of the substance.

The ability to adjust the bias is also available by using bias systems 26 of different spring constant or higher compression ratios. For example, instead of a 15 kg spring used in conventional grease guns a 30 kg spring can be used. Alternately the spring can be left unchanged and one or more spacers or packers can be placed within, and occupying a part of the volume of, the housing to thereby change the bias applied by the bias system 26. In these embodiments the bias system 26 includes incorporates one or more spacers or packers in addition to a bias mechanism. If a packer is used, the packer also be inflatable for example by a gas (e.g. air) or a liquid. This can be achieved by use of an external pump connected to a coupling that may be attached to the housing.

The ability to vary the bias by either changing the bias mechanism itself, or by inserting one or more spacers, is facilitated, at least in some embodiments, by the manner of coupling between the parts 14 and 16 which enables the user to more easily apply forcible pressure to initially compress the bias system 26. Of course, it follows from the above that due to the structure of the disclosed dispenser the degree of bias applied to the flowable substance can be changed by only changing the bias system while keeping the overall length of the housing the same.

Thus, embodiments of the disclosed dispenser enable adjustment of bias by any one of a) interchanging between bias systems (or bias mechanism of the bias system) of different spring constant or compression characteristics while keeping the housing length L and the housing volume unchanged; b) maintaining the same bias system but varying the length of the housing; c) maintaining the same bias system and keeping the housing length constant but changing the housing volume for example by inserting one or more spacers or packers in the housing; d) maintain the same bias system, keeping the housing length constant and inserting an inflatable packer and subsequently inflating the packer while maintaining the housing length constant; e) changing the bias system and varying one or both of the length of the housing and/or the volume of the housing. One method of using the dispenser 10a may be as follows. Assume as a starting condition that the dispenser 10a has been used to fully dispense the flowable substance within a cartridge 36. To install a fresh cartridge 36 a user may either (a) releases the coupling system 46 enabling the length of the housing 12 to be extended and more particularly the first part 14 to be withdrawn from the second part 16; and then unscrew the cap 32 to remove the spent cartridge 36; or (b) unscrew the cap 32 to remove the spent cartridge 36 and then release the coupling system 46 enabling the length of the housing 12 to be extended and more particularly the first part 14 to be withdrawn from the second part 16.

The piston 34 which would be frictionally held in the cartridge 36 is slid out by pulling on the back end of the bias system 26.

A fresh cartridge 36 is now loaded in through the end 18. The cartridge 36 may include a radially extending lip (not shown) at an end opposite to that containing the plug 38. The cartridge 36 is loaded with the end having the plug 38 first so that the radially extending lip sits on the upper end of the tubular body of the first part 14. The cap 32 is screwed back onto the tubular body which also clamps against the radially extending lip. This forms a seal preventing the flowable substance from flowing back down the housing between the outside surface of the cartridge 36 and inside surface of the first part 14, or through the threads between the cap 32 and part 14.

Next, the bias system 26 is loaded into the second part 16 with the piston 34 facing away from the end 25. The parts 14 and 16 are now brought into axial alignment and the piston 34 seated within or adjacent the plug 38. A force is applied between the ends 18 and 25, compressing the bias system 26 to allow: the first part 14 to slide inside of the open end 24 of the second part 16; or equivalently, the second part 16 to slide over the open end 22 first part 14. The user at this time can adjust the degree of bias provided by the bias system 26 dependent upon the degree of insertion of the parts 14 and 16 one into the other, i.e. dependent on the overall length L of the housing 12. The coupling system 46 is now operated to releasably lock the parts 14 and 16 together. This keeps the overall length L of the housing 12 fixed until either adjusted by the user or, when replacing the cartridge 36.

During use of the dispenser 10a if the flow rate of the flowable substance from the opening 23 is not considered appropriate for a particular application, a user may release the coupling system 46, change the overall length of the housing 12 to vary the bias provided by the bias system 26 and then using the coupling system 46 fix the length of the housing by clamping the parts 14 and 16 together. Now that the first embodiment has been described, it should be appreciated that the dispenser 10a maybe embodied in many other forms. For example, the coupling system 46 is described in this embodiment as being in the form of the clamp. However, many different forms are possible. For example, coupling system 46 may be in the form of complimentary screw threads formed on the first part 14 and the second part 16. The threads enable the parts 14 and 16 to be connected together, and to be screwed in or out with respect to each other there by varying the overall length L of the housing 12.

In another embodiment the coupling system 46 can be in the form of a strap, wire or other tether that extends about the housing 12 in the length direction and can be lengthened or shortened. For example, the mechanism 46 in the form of a strap that is fixed at the end 25 extends up along one side of the housing 12 passes over the opposite end 18 and then engages a fastening mechanism at or near the end 25. The fastening mechanism can be formed to enable a variation in the length of the strap between the end 25 and the fastening mechanism. In one example the fastening mechanism can be in the form of a buckle. In another example of the fastening mechanism may include a spool about which one end of the strap wraps, a handle lever for retaining the spool and releasable ratchet mechanism holding the rotational position of the spool.

Further, although the bias system 26 is depicted in this embodiment has a coil spring, it may take many other forms such as, but not limited, a compressed gas or pneumatic system such as an air spring or air damper (i.e. a pneumatic strut) an example of which is described later in relation to the second embodiment; or one or more billets or pieces (e.g. discs) of compressible and resilient material such as rubber or foam; to which the piston 34 may be attached. When using an air spring or air damper, one end may be provided with a screw thread that screws into a blind hole of the piston 34, or indeed a through hole. In the case of a through hole, the engagement of threads seals the hole so that flowable substance cannot pass through the piston 34. It should also be understood that in this instance the air spring or damper does not apply a pulling force on the piston 34, but rather a pushing force.

The bias system 26 may provide substantially greater pressure to the cartridge 36 then is provided by traditional grease guns and the like dispensers. This may cause issues such as leakage or collapse of the cartridge 36. With a view to circumventing these issues embodiments of the dispenser 10a also contemplate the incorporation of a rigid support ring or washer 35 (shown in Figures 5a-5d) which engages with a front end of a grease cartridge 36. The washer 35 is in the general form of an annulus having a circumferential inner wall 37, a circumferential outer wall 39 and an annular circular plane the bottom wall 41 , but also having shaped upper wall 43 which includes a circumferential flange 45 that extends radially beyond the outer wall 39 and an optional tapered portion 47 at slopes down to meet the inner wall 37. This taper may assist in concentrating seal pressure between the top of the washer 35 and a rubber/plastic/cork washer seated inside the cap 18. A semicircular notch or recess 49 may also formed in the bottom wall 41 is shown in Figure 5b. Also, as shown by phantom line 37b, a bottom of the wall 37 may be tapered to facilitate removal of the washer 35 with a screwdriver or similar tool from the cartridge 36.

The washer acts 35 to prevent the cartridge 36 collapsing at its discharge end when extra pressure is exerted by screwing the cap 32 more tightly to prevent leakages. Additionally, the washer 35 may act to hold the cartridge open and prevent it collapsing from pressure exerted by the bias system 26. The washer 35 seats on the inside of the upper lip of the cartridge 36. The lip of the cartridge lies in the shoulder formed between the flange 45 and the outer wall 39, with the outer wall 39 applying radially outward pressure on the inside wall of the cartridge 36. Many cartridges 36 are formed with a ridge 53 on the upper wall 51 , as shown in Figure 5d. This is accommodated in the notch 49 of the washer 35. The washer 35 aids in sealing by exerting an even downward pressure on the lip of the cartridge 36 and outward pressure on the inner wall of the cartridge just beneath the lip. Also, some cartridges 36 do not have a lip all the way around the circumference. In these situations, the outward pressure from the firm fit provided by the washer 35 gives a good seal which would otherwise be unavailable. This seal is the one between the lip of the cartridge, the inside surface of the cap 32 and inside wall of the first part 14. Without this good seal grease is able to flow backward between the inside surface of the housing and the outside surface of the cartridge and potentially leak from the back end of the housing 12.

A mechanical compression system such as a threaded bolt or shaft can be incorporated in the housing to compress the bias system from within the housing.

In the above-described embodiment the flowable substance is held within a cartridge 36 that is loaded into the housing 12. However, in an alternate embodiment the flowable substance may be loaded directly into the first part 14 so that the piston 34 and associated seal 42 would slide along and directly contact the inside surface of the first part 14. In one example, if the substance is sufficiently viscous, the first part 14 could be filled with the substance by removing the cap 32, inserting the end 18 into a bucket of the substance to fill the part 14 to a level short of the end 22, removing the parts 14, attaching the end cap 32 and then assembling the remainder of the dispenser 10a.

A second embodiment of the disclosed dispenser 10b will now be described with reference to Figures 6-13. In this embodiment the same reference numbers are used as in the first described embodiment 10a to denote the same or functionally similar features. The second embodiment of the dispenser 10b is particularly well-suited to use with cartridges 36 of a type having an centrally located threaded outlet 48 (see in particular Figures 11 and 12). When the dispenser 10b is used with such cartridges, the dispenser 10b does not use or require the cap 32 of the first embodiment. This embodiment may be used in place of a traditional caulk gun.

The dispenser 10b comprises a housing 12 having a first part 14, and a second part 16. The first part 14 is provided at one end 18 with a circumferential lip 50 (shown in Figure 13). The lip 50 extends in a radial inward direction and forms a stop which abuts the cartridge 36 preventing it from being pushed out of the first part 14 from the end 18. An opposite end 22 of the first part 14 is open.

The second part 16 has a first or piston end 24 and an opposite end 25. The first and second parts 14, 16 are releasably connectable together with the end 24 of second part 16 fitting over and onto first part 14 from its end 22. The end 18 of the first part 14, and the end 25 of the second part 16, form or constituted opposite ends of the housing 12. As in the first embodiment bias system 26 is retained within the housing between the parts 14, 16. Flowever as a point of difference in the second embodiment of the dispenser 10b the bias system 26 uses, instead of a coil spring, an air spring or air damper in the form of a pneumatic strut 26p. Such struts are readily commercially available and are used in numerous applications such as for cupboard doors and vehicle bonnets. In the present embodiment suitable struts 26p may apply between 30kg and 60kg of force.

In the illustrated form of the second embodiment the second part 16 comprises two parallel arms 52. The arms 52 are connected at one end by a plate 54 at the end 25. The opposite ends of the arms 52 are connected together by the coupling system 46. The pneumatic strut 26p has an outer cylinder 56 and a piston rod 58. An end of the cylinder 56 from which the piston rod 58 extends passes through a centrally located hole in the plate 54 and is retained by a stop mechanism 60. The hole is centred on a central axis of the first part 14 and dimensioned or configured to provide a loose fit for the cylinder 56. The stop mechanism 60 operable to engage an inside of the second part 16 to limit motion of the strut 26p in a direction away from the first part 14. This prevents the pneumatic strut 26p from being pulled or pushed out from the end 25 of second part 16. In particular the stop mechanism 60 engages the plate 54 from the inside of the second part 16. The “pushing” could arise from a reaction to the compressive forces acting on the pneumatic strut 26p from inside of the housing 12; the “pulling” by gripping and pulling on the pneumatic strut 26p from outside of the housing 12. In this, but not necessarily every, embodiment the stop mechanism is in the form of a clamp 60. The clamp 60 can be selectively tightened and released to allow adjustment of the axial position of the strut 26p relative to the end 25 of the second part 16.

The second part 16 also incorporates a spring lock 62. The spring lock 62 includes a bar 64 that is pivoted near one end by a threaded shaft 66. The shaft 66 is fixed to the plate 54 and passes through a hole in the bar 64. The hole is dimensioned or configured (for example by being in the form of a slot) to give a loose fit to enable the bar 64 to be pivoted. The bar 64 is retained on the plate 54 by a nut 68 (Fig 10). The cylinder 56 passes through a hole formed in the bar 64. A coil spring 70 encircles a portion of the cylinder 56 between the plate 54 and the bar 64. The spring 70 is biased to push the bar 64 away from the plate 54 so that it is inclined to the perpendicular of the cylinder 56 to in effect form a friction lock.

The piston 34 is attached to the opposite end of the piston rod 58. The piston 34 has a body 40 provided with at least one circumferential groove (not visible) for seating a seal 42 in the form of an O-ring. The groove in which the O-ring 42 sits can be tapered so that the diameter of the groove increases in a direction toward the piston rod 58. The tapered groove has the effect of expanding the O-ring 42 in a radial outward direction as is pushed further into a sliding end cap, beard metal or plastic of a cartridge 36 held within the dispenser 10b. The body 40 of the piston 34 is of a diameter that provides a loose or clearance fit with the inside of cartridge 36, with the O-ring 42: contacting and forming a sliding seal against an inner circumferential wall of the cartridge 36; or applying an outward force or support to the side walls of a sliding end cap of a cartridge 36. In this way the piston either directly or indirectly (via the sliding end cap) assists in forming or maintain a sliding seal against the inner wall of the cartridge 36.

With particular reference to Figures 11-13 the dispenser 10b is provided with an optional hose fixing piece 74. The hose fixing piece has one end arranged to seat inside the outlet 48 of a cartridge 36 retained within the housing 12, and an opposite end arranged to couple with a hose 80. In this embodiment the piece 74 is in the form of a tube having a small diameter portion 76 at the one end and a large diameter portion 78 at the opposite end. The small diameter portion 76 fits inside of the outlet 48 with the large diameter portion 78 sitting on and extending from an end of the outlet 48. The piece 74 is used to assist in the attachment of a dispensing hose 80 to outlet 48. The idea here is to use two separate clamps to attach the hose 80 to the outlet 48. To attach the hose 80 to the cartridge 36, end 76 is inserted into the outlet 48 and an end of the hose 80 is fitted over the large diameter end 78. The end 76 helps to create an airtight seal and prevents the outlet 48 from collapsing or distorting its shape when the clamp 84a is tightened. The hose 80 may be of any desired length which is practical in the context of the present disclosure. For example, trials have shown that lengths of between 300mm-500mm appear to have no adverse effects on output or flow rates. A benefit of the inclusion of the hose 80 is greater control, judgement and accuracy of placement of the outlet for longer periods of time because a user only needs to hold and controlling the outlet end with one hand rather than the whole dispenser 10b.

As shown in Figure 13 one clamp 84a fits over the outlet 48 and clamps the outlet 48 against the small diameter portion 76. A second clamp 84b clamps the hose 80 onto the end 78. Using the piece 74 enables firm clamping force is to be used in the outlet 48 that may otherwise crush, break, or distort the outlet 48. The hose 80 may be a flexible hose made of a plastics material. It may be of benefit if the plastics material is transparent or translucent to allow a user to visualise the flow of material from the cartridge 36 through the hose 80. It may further be of benefit for the hose to filter UV radiation which for some materials to be dispensed may cause them to cure and harden; or at least increase their viscosity, notwithstanding an air tight seal.

Looking at Figure 6 the dispenser 10b is also provided with a hand operable dispensing valve 86 at an end of a hose 80 distant the outlet 48. The valve 86 enables a user to stop the flow of material substantially instantly without the need to release the pressure on the material from the strut 26p. Forward of the valve 86 is a nozzle 88 with a dispenser opening (not visible) through which material held within the cartridge can be dispensed. The dispenser 10b also includes an airtight nozzle closure 90 downstream of the valve 86. The purpose of the closure 90 is to close the disperser opening, i.e. the end of the nozzle 88 so that material upstream of the dispenser opening; and more particularly between the valve 86 and the end of the nozzle 88 is sealed from contact with the air with a view to preventing the setting of that material.

The nozzle closure 90 can take several different forms. In the illustrated embodiment the closure 90 is in the form of an elastic band 92 that can be stretched to fit over an opening in the nozzle 88. In another embodiment the elastic band 92 can also be provided with a short stop that can be inserted with an interference fit into the nozzle opening. In yet another embodiment the closure 90 may be in the form of a cap that fits over the nozzle 88 with an interference fit.

One way of using the dispenser 10b is as follows. The parts 14 and 16 in a disassembled from each other. The spring lock 62 is pushed against the bias of the spring 70 and the cylinder 56 is pulled so that the clamp 60 abuts the plate 54 as shown in Figures 8 and 10. If the piece 74 is used, its end 76 is inserted into the outlet 48, and its end 78 is inserted into the hose 80. The clamps 84a and 84b are applied to hold the piece 74 in the outlet 48 in the hose 80 the piece 74. Indeed, in a slight variation the hose 80 can be pushed over the outlet 48 so that hose 80 overlies the full length of end 78 and at least a portion of the length of end 76 that is inside the outlet 48. The clamp 84a now clamps the hose 80 onto the outlet 48 in which the end 76 is inserted. This then clamps the hose 80 to outlet 48, and clamps the piece 74 to the outlet 48, and helps prevent the hose 80 form detaching form the outlet 48. The cartridge 36 with the attached hose 80 is inserted into the first part 14 from the end 22 until the forward end of the cartridge 36 abuts the inside of the lip 50 as shown in Figure 13. The hose 80 extends from the end 18 as shown in Figures 6, 10 and 13.

The second part 16 can now be attached to the first part 14. If necessary to ensure that the piston 34 is behind of the clamping system 46 the spring lock 62 can be released and the cylinder 56 and thus the piston rod 58 pulled away from the end 22 of the first part 14.

The coupling system 46 can be at least partially tightened. Now the piston 34 can be fitted into the back end of the cartridge 36. This can be done by simply releasing the spring lock 62 so that the cylinder 56 can slide relative to the second part 16 and allowing the piston 34 and strut 26p to be freely manipulated. The coupling system 46 can now be operated to firmly retain the second part 16 on the first part 14.

To apply a compressive force or bias to the material within the cartridge 36 a force is now applied to the free end of the strut 26p. Optionally this may be done with the valve 86 initially open to allow bleeding of air from the hose 80. This compresses air within the cylinder 56 as the cylinder now slides relative to the piston rod 58 in a forward direction through the plate 54, for example as shown in Figure 9. Upon release of the compressive force the spring lock 62 automatically operates locking the cylinder 56 in place and prevented it from sliding in an opposite direction through the plate 54 away from the first part 14.

To dispense the material from the cartridge 36 the valve 86 and the closure 90 are opened. Material is now free to flow through the hose 80 and out from the dispensing nozzle 88. If is required to increase the pressure on the material being dispensed the user can apply further compressive force on the free end of the cylinder 56. Additionally, or alternately the pressure on the material in the cartridge 36 can be increased by releasing the coupling system 46 and sliding the second part 16 further along the first part 14 toward the end 18. Thus, the dispenser 10b has at least two separate mechanisms that can work individually or together for varying, including increasing the pressure on the material to be dispensed from the cartridge 36, namely apply a compressive force onto the free end of the strut 26b, or, while keeping the position of the cylinder 56 fixed, releasing the coupling system 46 and sliding the second part 16 relative to the first part 14 so that the overall length of the housing 12 is reduced.

The clamp 60 can also be used to vary the pre-tensioning of the strut 26p and thus the pressure on the material within the cartridge 36. This can be done by releasing the clamp 60, relocating it at a position intermediate of the ends of the cylinder 56, and then retiming the clamp 60. This may also be considered as a third mechanism for varying the pressure on the material to be dispensed.

In the present embodiment the piece 74 and the hose 80 a separate from the housing 12 until coupled by a cartridge 36 received within the housing 12. In one variation the piece 74 can be permanently or releasably attached to a crossbar that extends across the front end 18 of the first part 14. In such an embodiment when the cartridge 36 is inserted into the first part 14 the outlet 48 is pushed onto the small diameter portion 76 of the piece 74. The hose 80 can be pre-attached to the large diameter portion 78. This then requires only the application of the clamp 84a about the outlet 48.

In a further possible variation, the second part 16 of the dispenser 10b can also be provided with a tubular body rather than the arms 52. In such variations the plate 54 would extend across one end of the tubular body and the clamping system 46 coupled to the opposite end. Also, in a further variation to the dispenser 10b the piece 74 can be in the form of a tube having a constant inner and a constant outer diameter. A difference in the outer diameter at opposite ends of the pieces 74, and in particular the incorporation of a large diameter portion 78 is dependent on the inner diameter of the hose 80. It should also be noted that the form of the cartridge 36 is not an aspect or feature of the present embodiments. Embodiments of the disclosed dispenser have used with a variety of cartridges which hold a flowable substance and an outlet at one end. For example, while the outlet 48 of the cartridge 36 is shown in the accompanying Figures as having a threaded outer surface, embodiments of the disclosed dispenser may equally be used with cartridges having a non-threaded outlet. In one possible enhancement to the second embodiment 10b, an extension shaft may be coupled onto the cylinder end of the strut 26p. To facilitate this the blind end of the cylinder 56 can be provided with a and axially extending threaded start on to which the extension shaft is screwed. Preferably the extension shaft has an outer diameter the same as that of the cylinder 56 so that it can pass through the plate 54 and the bar 64 and be engaged by the spring lock 62. This allows the assembly of the strut 26p and the extension rod be adjusted and moved further into the cartridge 36 and/or housing 12 effectively increasing the ‘stroke length’ of the gas strut 26p.

A magnetic latch may also be incorporated in the spring lock 62 to hold the spring lock 62 in an unlocked or released position. The magnetic latch may be in the form of a magnet attached to or embedded in one or both the plate 54 and the bar 64. When the bar 64 is pressed to compress the spring 72 releasing the spring lock 62, the magnet(s) would engage holding the bar 64 down against the bias of the spring 72 keeping the spring lock 62 in the unlocked or released position. To return the spring lock 62 to the locked position a user would need to physically pivot the bar 64 away from the plate 54 to overcome the magnetic force.

In a further variation to the spring lock 62 can be modified by removing the threat shaft 66 and nut 68 and reconfiguring the plate 64 to include spaced apart fingers that extend from an end distant the cylinder 56 and curl underneath the plate 54. This forms a loose hinge like arrangement allowing the bar 64 to pivot in substantially the same way as described above enabling the spring lock 62 to move between locked and unlocked positions.

A gravity operated locking ring similar in operation to the spring lock 62 can also be incorporated in the second part 16. This would take the form of a ring having an inner diameter that is greater than the outer diameter of the first part 14 and hinged or otherwise pivotally mounted to and 24 or the coupling system 46. This ring fits over the first part 14 and when the dispenser 10b is held with this longitudinal axis being vertical the ring would pivot by the action of gravity so that it lies in an inclined plane. This has no effect in moving the coupling system 46 over the outside of the first part 14 when connecting the second part 16 to the first part 14. However, it will act as a locking mechanism to prevent the sliding or movement of the second part 16 in an opposite direction. The benefit of this is that it acts as a self acting lock to hold the second part 16 onto the first part 14 potentially against the pressure applied by the strut 26p to enable the user to more easily tighten the coupling system 46 because there is no need to physically hold the first part 14 and the second part 16 together simultaneously when tightening the coupling system 46. The action of the locking ring can be easily overcome by simply pushing it to pivot toward the end 22 of the first part 14 so that it lies in a plane closer to a radial plane of the first part 14.

It is believed that embodiments of the present dispenser may provide one or more of the following benefits and advantages:

• as there is no need for a shaft passing through the piston 34 for retracting the bias system 26, 26p and maintaining the position of the piston within the housing, one source of possible leakage about the shaft is obviated;

• for the embodiment of the dispenser 10a provision of the cup like seal 42, which is directly opposite to the configuration of the seals used in conventional grease guns, provides a higher quality and more reliable seal with the inside surface of the housing 12 or cartridge 36;

• the embodiments of the dispensers 10a, 10b enable the use of interchangeable bias systems allowing the pressure applied to the substance to be changed to suit the physical characteristics of the substance;

• allows the bias system 26, 26p to be increased by pushing the parts 14 and 16 of the housing 12 together rather than pulling on a handle. For example a person may use their body weight to compress the bias system 26, 26p which in turn may facilitate the use of bias systems with higher spring constant or pressure rating than used in conventional dispensers including grease guns;

• with the embodiment of the dispenser 10b provides improved safety and ease of use because the second part 16 can be attached to the first part 14 without the need to also compress the bias system 26p. This can be achieved by sliding the cylinder 56 along the length of the second part 16 through the spring lock 62 or by releasing clamp 64;

• the hose 80 in the dispenser allows easier access to otherwise difficult to reach places, as well as taking away the need to hold the housing 12 and associated substantive weight of the dispenser, at least by hand because the dispenser could be rested on a surface, or hooked on say a user’s belt while allowing application of the material by only holding the nozzle or hose by one hand;

• the combined use of the hose fixing piece 74, the clamp is 84 a and 84 B, and hose 80 firmly attached to the valve 86 insures an airtight seal to prevent the flowable substance from setting or otherwise “going off”; • due to the greater pressures available by use of the bias mechanism 26, for example 30 kg or more by the spring 26 or from 30 to 60 kg for the strut 26p, the speed of application of the material can be increased by 2 to 3 times. In the claims which follow, and in the preceding description, except where the context requires otherwise due to express language or necessary implication, the word “comprise” and variations such as “comprises” or “comprising” are used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the system and method as disclosed herein.