DISPENSING DEVICE

Abstract: A dispensing device for dispensing a measured quantity of a concentrated cleansing liquid into a spray bottle or any other suitable receptacle, is provided with means whereby the measured quantity of the liquid is pumped from a source into a holding reservoir. The dispensing device includes inhibiting means for: (a) preventing the interruption of a priming stroke as the liquid is pumped from the source into the reservoir; and (b) preventing the interruption of a delivery stroke as the liquid is pumped from the reservoir to the receptacle. The inhibiting means is provided by a pivotable lever having an arcuate rib engaged by a pair of locking members arranged to engage opposite tracks of the arcuate rib.

Description: DISPENSING DEVICE This invention is concerned with improvements in a dispensing device and is particularly concerned with the dispensing of a metered quantity of a liquid from the dispensing device in an uninterrupted method of operation of the dispensing device. Cleansing products are commonly supplied as a liquid in concentrated form which requires dilution with water before use. Thus, a measured quantity of the cleansing product is added to a known quantity of water for the most efficacious result. Normally, the measured quantity of the concentrated cleansing product is introduced into a conventional graduated spray bottle which is thereafter filled with water. The water/cleansing product mixture may entirely fill the spray bottle, or, the water may be added until an appropriate graduation mark is reached by the water/cleansing product mixture. Similarly, a measured quantity of a concentrated cleansing product may be introduced into any suitable receptacle in which, or into which, a requisite amount of water is provided. If an operative complies with the requirements for achieving the most advantageous mixture, there is little likelihood that any damage may be caused to the surfaces being cleaned or that the health of the operative may be put at risk if they are subjected to concentrations of the mixture above the recommended dosage levels. Unfortunately, it is human nature to believe that the efficacy of a mixture may be enhanced by increasing the dosage levels of a concentrate in a mixture. Thus, an operative may add double or more of the recommended dosage of a concentrated cleansing product to a mixture with deleterious results. The objects of the present invention are therefore to overcome or mitigate the drawbacks of known dispensing devices and their method of operation. Thus the present invention conveniently provides a dispensing device for delivering a metered quantity of a liquid, the dispensing device comprising a reservoir, priming means for priming the reservoir, when the dispensing device is in use, with a metered quantity of a liquid, the dispensing device also comprising a delivery means for delivering, when the dispensing device is in use, said metered quantity of said liquid from the reservoir, characterised in that, the dispensing device further comprises inhibiting means for: a) preventing the interruption and reversal of a priming stroke of the priming means; and, b) preventing the interruption and reversal of a delivery stroke of the delivery means. Preferably the reservoir comprises a piston and cylinder arrangement and the priming and delivery means comprises a lever pivotally mounted on the dispensing means, said lever being connected to a piston rod of the piston and cylinder arrangement. Conveniently the lever includes at least one arcuate surface and the inhibiting means comprises at least one locking member located on the dispensing device adjacent the arcuate surface, the locking member being movable, when the dispensing device is in use, between: a) a first operative condition in which a first arcuate surface engaging portion of the locking member is brought into engagement with the at least one arcuate surface to prevent the interruption and reversal of the priming stroke of the priming means until the priming stroke thereof is completed; and, b) a second operative condition in which a second arcuate surface engaging portion of the locking member is brought into engagement with the at least one arcuate surface to prevent the interruption and reversal of the delivery stroke of the delivery means until the delivery stroke is completed. More preferably the device comprises at least two locking members and at least two arcuate surfaces, the locking members being located one each adjacent a respective one of the arcuate surfaces, wherein, when the dispensing device is in use, the movement of the locking members into their operative conditions is arranged so that the locking members operate in concert to prevent the interruption and reversal of the priming stroke and the delivery stroke of the priming means and the delivery means respectively. In one convenient arrangement provided by the present invention the locking members each comprise a triangular block pivotally mounted on the dispensing device. Conveniently, when the dispensing device is in use, the triangular blocks are moved simultaneously into their first operative condition or into their second operative condition by spring means. Preferably, the spring means comprises a generally "C" shaped leaf spring opposite ends of which leaf spring are arranged to act one on each of the triangular blocks respectively to urge the triangular blocks into their first operative condition or their second operative condition at or towards opposite ends of the arcuate surfaces associated therewith. In a further preferred arrangement provided by the present invention the dispensing device comprises stop elements located at the opposite ends of the arcuate surfaces, the stop elements being effective, when the dispensing device is in use: a) to engage the triangular blocks at a first end of the arcuate surfaces to cause the triangular blocks to pivot simultaneously about their respective fulcrum points into their first operative condition in which they are set to prevent the interruption and reversal of a subsequent priming stroke of the priming means; or, b) to engage the triangular blocks at a second end of the arcuate surfaces to cause the triangular blocks to pivot simultaneously about their respective fulcrum points into their second operative condition in which they are set to prevent the interruption and reversal of a subsequent delivery stroke of the delivery means. Conveniently, the relative positions of the respective stop elements at the opposite ends of the arcuate surfaces are variable in order to alter the length of the priming and delivery strokes of the priming and delivery means respectively. Preferably, the arcuate surface engaging portions of the triangular blocks and/or the respective arcuate tracks engaged thereby are each provided with a friction coat or surface finish to enhance the locking engagement of the triangular blocks with their respective arcuate surfaces should an operative try to interrupt and reverse the priming or delivery strokes of the priming means or the delivery means respectively when the dispensing device is in use. Conveniently, the lever includes two arcuate surfaces formed one on either side of an arcuate rib formed integrally with the lever. In a preferred embodiment provided by the present invention a centre of curvature of the arcuate rib is coincident, or substantially so, with a pivotal axis of the lever. Conveniently, the dispensing device comprises one locking member provided by a triangular block on opposite sides of the arcuate rib adjacent their respective arcuate surfaces of the arcuate rib. In another preferred arrangement, the dispensing device comprises an over-ride means for engagement with the triangular blocks, when the dispensing device is in use, to move the triangular blocks into inoperative conditions in which arcuate surface engaging portions of the triangular blocks are held out of engagement with a respective one of the arcuate surfaces. The present invention also provides a method of dispensing a metered quantity of a liquid comprising the steps of priming a reservoir with a metered quantity of the liquid and delivering the metered quantity of the liquid from the reservoir characterised in that the method also comprises the steps of: a) preventing the interruption and reversal of the priming stroke until the reservoir has received the full metered quantity of the liquid; and, b) preventing the interruption and reversal of the delivery stroke until the reservoir has been emptied of the full metered quantity of the liquid. There now follows by way of example of the invention a detailed description of a dispensing device and its method of operation which description is to be read with reference to the accompanying drawings in which: Figure 1 is a side view of the dispensing device shown in an inoperative condition; Figure 2 is a front view of the device of Figure 1 as seen in the direction of the arrow II in Figure 1 ; Figure 3 is a side view corresponding to Figure 1 with the dispensing device shown in a first operative condition; Figure 4 is a side view corresponding to Figures 1 and 3 with the dispensing device shown in a second operative condition; Figure 5 is a plan view of the device as seen in the direction of the arrow V in Figure 2; Figure 6 is a fragmentary view of some of the parts shown in Figure 1 and also showing an over-ride key for negating the inhibiting means of the dispensing device; and, Figure 7 is a side view of a lever of a priming and delivery means of the dispensing device. Formulating accurate mixtures of concentrated cleansing liquids and water has always been difficult given the natural tendency of operatives to add too much of a concentrate in the erroneous belief that more of the concentrate will give better results. The dispensing device of the present invention helps to overcome this falsely held belief by ensuring that an operative can only dispense a specific quantity of a concentrate when dosing water to formulate a cleansing mixture. Thus, the invention generally provides a dispensing device 2 comprising a housing 4, see Figures 1 , 2, 3 and 4, which housing 4 provides support for a priming and delivery means 6 including a lever 8, the device 2 also comprising inhibiting means 12, whereby, when the dispensing device 2 is in use, movement of the lever 8, in effecting a priming or delivery stroke of the dispensing device 2, cannot be reversed thereby ensuring the completion of the priming or delivery stroke and thus ensuring the provision in an admixture of water and a concentrated cleansing product of the appropriate dosage of the concentrate. Specifically, the housing 4 also provides support for a reservoir 14 comprised of a piston and cylinder arrangement 16, see Figures 1 , 3, and 4, a cylinder 18 of the arrangement having a capacity in excess of the maximum priming or delivery amount which may be supplied by the priming and delivery means when the dispensing device 2 is in use. The lever 8 of the dispensing means 2 is pivotally mounted at 19 on a front wall 20 of the housing 4, the lever 8 being provided with an inwardly projecting wing portion 22, see Figures 1 , 3, 4, 6 and 7. At a right hand portion 24 of the wing portion 22, the lever 8 provides pivotal mounting for one end 26 of a connecting bar 28, an opposite end 30 of which bar 28 is pivotally connected to a piston rod (not shown) of the piston and cylinder arrangement 16, see Figures 1 , 3 and 4. Thus, when the dispensing device 2 is in use, movement of the lever 8 will cause corresponding movement of the piston and cylinder arrangement 16 as hereinafter described. The wing portion 22 of the lever 8 is provided with an arcuate rib 34 the centre of curvature of which rib 34 is arranged coincident, or substantially so, with the pivotal point 19 of the lever 8. The arcuate rib 34 comprises an inside arcuate track 36 and an outside arcuate track 38, see Figures 1 , 3, 4, 6 and 7. The inhibiting means 12 comprises two locking members 40 and 42 pivotally mounted on respective pivot pins 44 and 46 located in a bulkhead 48 of the housing 4, the member 40 being located adjacent the inside arcuate track 36 and the member 42 being located adjacent the outside arcuate track 38, see Figures 1 , 3 and 4. The members 40 and 42, see Figure 1 , comprise respective triangular blocks 50 and 52 spring urged in concert by spring means 54 into first operative conditions in which first arcuate track engaging portions 56 and 58 thereof respectively are brought into engagement with the tracks 36 and 38 associated therewith for a purpose to be more fully explained hereinafter. The triangular blocks 50 and 52, see Figure 1 , also comprise second arcuate track engaging portions 60 and 62, which portions 60 and 62, when the triangular blocks 50 and 52 are urged by the spring means 54 into second operative conditions, are brought into engagement with the tracks 36 and 38 associated therewith for a purpose to be more fully explained hereinafter. The spring means 54 is comprised of a generally "C" shaped spring 64 connected to outer lobes 66 and 68 respectively of the triangular blocks 50 and 52, to urge the blocks 50 and 52 into one or other of their first and second operative conditions. Pivotal movement of the triangular blocks 50 and 52 is limited by the provision in each of the blocks 50 and 52 of a pin 70 and 72 respectively, the pin 70 engaging in an arcuate slot 74 and the pin 72 engaging in an arcuate slot 76, the slots 74 and 76 being provided in the bulkhead 48 of the dispensing device 2 adjacent one side of the triangular blocks 50 and 52, see Figure 6. The pins 70 and 72 extend through their respective blocks to protrude therefrom on opposite sides of the blocks 50 and 52 for a purpose to be made clear hereinafter. At an inward end portion of the arcuate rib 34 there is provided an adjustable stop pin (not shown) which extends on both sides of the rib 34 for a purpose to be explained hereinafter. The dispensing device 2 also comprises a locking lever 80 spring urged into a locking position, as shown in Figure 1 , in which it prevents operation of the dispensing device 2 in the absence of a bottle or container 82 to be provided with a measured amount of a concentrated cleansing liquid. When the dispensing device 2 of the present invention is in use, an operative places a bottle 82 in a holder 84 located beneath a dispensing outlet 86 of the piston and cylinder arrangement 16, as shown in Figure 3. In placing the bottle 82 as aforesaid the locking lever 80 is displaced to the right, viewing Figure 3, into a position in which it no longer prevents the operation of the dispensing device 2. For this purpose the locking lever 80 is provided with an inwardly protruding 'T shaped pin engaging member (not shown) which pin engaging member, as the locking lever 80 is moved to the right as aforesaid, engages with the pins 70 and 72 to enable the dispensing device 2. When the dispensing device is enabled, the "C" shaped spring 64 acts on the triangular blocks 50 and 52 to urge them into a first operative condition, as shown in Figure 3, in which a priming stroke of the dispensing device 2 may be effected. In order to effect the priming stroke the operative moves the lever 8 to the left from the position shown in Figure 3 to the position shown in Figure 4, During movement of the lever 8 the connecting bar 28 acts on the piston rod of the piston and cylinder arrangement 16 to move it downwardly to draw concentrated cleansing liquid from a source, not shown, into the cylinder 14 of the arrangement 16. As this priming stroke is effected, although the arcuate rib 34 has an unhindered passage between the triangular blocks 50 and 52 until completion of the priming stroke, if the operative stops the priming stroke and attempts to reverse the lever 8, the first track engaging portions 56 and 58 bite into their respective tracks 36 and 38 to prevent such reversal. Under such circumstances the operative has no alternative but to continue with the priming stroke of the dispensing device 2. At the end of the priming stroke the stop pin at the end of the arcuate rib 34 engages the pins 70 and 72 of the triangular blocks 50 and 52 to cause the blocks 50 and 52 to pivot about their respective pivot pins 44 and 46 from their first operative conditions into their second operative conditions in which respective second arcuate track engaging portions 60 and 62 thereof engage their respective tracks 34 and 36, see Figure 4. The operative then moves the lever 8 to the right viewing Figure 4 thereby reversing the stroke of the piston rod of the piston and cylinder arrangement 16 and effecting delivery of the measured amount of the concentrated cleansing liquid into the bottle located under the dispensing outlet 86 of the dispensing device 2. As the delivery stroke of the device 2 is effected, although the arcuate rib 34 has an unhindered passage between the triangular blocks 50 and 52 until completion of the delivery stroke, if the operative attempts to interrupt the delivery stroke of the device 2 in order to reverse the delivery stroke, the second arcuate track engaging portions 60 and 62 will bite into their respective tracks 36 and 38 to prevent such reversal. Under such circumstances the operative has no alternative but to continue the delivery stroke of the dispensing device 2. At the end of the delivery stroke the operative may remove the bottle 82 from the dispensing device 2 whereupon the locking lever 80 is spring urged against a damping mechanism (not shown) back into its locking condition as shown in Figure 1 and the dispensing device 2 is ready for the next bottle 82 to be placed in the holder 84 to repeat the sequence of operations. Although the stop pin at the end of the arcuate rib 34 is described as a fixed pin, in an alternative arrangement the pin may be adjustable in order to vary the length of the priming and delivery strokes of the dispensing device 2 and thus the quantity of the concentrated cleansing liquid delivered to a bottle 82. In addition, in order to enhance the effect of the triangular blocks 50 and 52, the track engaging portions thereof may be provided with a rough surface or they may be provided with a coating of friction material, for example polytetrafluoroethylene. Likewise, the tracks 36 and 38 of the arcuate rib 34 may be coated in addition to the track engaging portions of the blocks 50 and 52 or instead of so coating those portions. The dispensing device 2 may be provided with an over-ride key 90 as shown in Figure 6, which over-ride key 90 is adapted to engage with the triangular blocks 50 and 52 to move and locate them in an ineffectual position mid-way between the positions of their first and second operative conditions. PARTS LIST dispensing device 64 "C" shaped sprinc housing 66 outer lobe priming & delivery means 68 outer lobe lever 70 pin 72 pin inhibiting means 74 arcuate slot reservoir 76 arcuate slot piston & cylinder arrangement 78 stop pin cylinder 80 locking lever pivot 82 bottle (container) front wall 84 holder inwardly projecting wing portion 86 dispensing outlet right hand portion (of wing) end (of 28) connecting bar opposite end (of 28) piston rod arcuate rib inside arcuate track outside arcuate track locking member (of 12) locking member (of 12) pivot pin pivot pin bulkhead triangular block triangular block spring means ("C" shaped) first arcuate track engaging portion first arcuate track engaging portion second arcuate track engaging portion second arcuate track engaging portion

Claims: CLAIMS 1. A dispensing device for delivering a metered quantity of a liquid, the dispensing device comprising a reservoir, priming means for priming the reservoir, when the dispensing device is in use, with a metered quantity of a liquid, the dispensing device also comprising a delivery means for delivering, when the dispensing device is in use said metered quantity of said liquid from the reservoir, characterised in that, the dispensing device further comprises inhibiting means for: a) preventing the interruption and reversal of a priming stroke of the priming means; and, b) preventing the interruption and reversal of a delivery stroke of the delivery means. 2. A dispensing device according to Claim 1 characterised in that the reservoir comprises a piston and cylinder arrangement and the priming and delivery means comprises a lever pivotally mounted on the dispensing means, said lever being connected to a piston rod of the piston and cylinder arrangement. 3. A dispensing device according to Claim 2 characterised in that the lever includes at least one arcuate surface and the inhibiting means comprises at least one locking member located on the dispensing device adjacent the arcuate surface, the locking member being movable, when the dispensing device is in use, between: a) a first operative condition in which a first arcuate surface engaging portion of the locking member is brought into engagement with the at least one arcuate surface to prevent the interruption and reversal of the priming stroke of the priming means until the priming stroke thereof is completed; and, b) a second operative condition in which a second arcuate surface engaging portion of the locking member is brought into engagement with the at least one arcuate surface to prevent the interruption and reversal of the delivery stroke of the delivery means until the delivery stroke is completed. 4. A dispensing device according to Claim 3 characterised in that the device comprises at least two locking members and at least two arcuate surfaces, the locking members being located one each adjacent a respective one of the arcuate surfaces, wherein when the dispensing device is in use, the movement of the locking members into their operative conditions is arranged so that the locking members operate in concert to prevent the interruption and reversal of the priming stroke and the delivery stroke of the priming means and the delivery means respectively. 5. A dispensing device according to either one of Claims 3 and 4 characterised in that the locking members each comprise a triangular block pivotally mounted on the dispensing device. 6. A dispensing device according to Claim 5 characterised in that, when the dispensing device is in use, the triangular blocks are moved simultaneously into their first operative condition or into their second operative condition by spring means. 7. A dispensing device according to Claim 6 characterised in that the spring means comprises a generally "C" shaped leaf spring opposite ends of which leaf spring are arranged to act one on each of the triangular blocks respectively to urge the triangular blocks into their first operative condition or their second operative condition at or towards opposite ends of the arcuate surfaces associated therewith. 8. A dispensing device according to Claim 7 characterised in that the dispensing device comprises stop elements located at the opposite ends of the arcuate surfaces, the stop elements being effective, when the dispensing device is in use: a) to engage the triangular blocks at a first end of the arcuate surfaces to cause the triangular blocks to pivot simultaneously about their respective fulcrum points into their first operative condition in which they are set to prevent the interruption and reversal of a subsequent priming stroke of the priming means; or, b) to engage the triangular blocks at a second end of the arcuate surfaces to cause the triangular blocks to pivot simultaneously about their respective fulcrum points into their second operative condition in which they are set to prevent the interruption and reversal of a subsequent delivery stroke of the delivery means. 9. A dispensing device according to Claim 8 characterised in that the relative positions of the respective stop elements at the opposite ends of the arcuate surfaces are variable in order to alter the length of the priming and delivery strokes of the priming and delivery means respectively. 10. A dispensing device according to any one of Claims 5 to 9 characterised in that the arcuate surface engaging portions of the triangular blocks and/or the respective arcuate tracks engaged thereby are each provided with a friction coat or surface finish to enhance the locking engagement of the triangular blocks with their respective arcuate surfaces should an operative try to interrupt and reverse the priming or delivery strokes of the priming means or the delivery means respectively when the dispensing device is in use. 11. A dispensing device according to any one of Claims 3 to 10 characterised in that the lever includes two arcuate surfaces formed one on either side of an arcuate rib formed integrally with the lever. SUBSTTTUTE SHEET (RULE 26) 12. A dispensing device according to Claim 11 characterised in that a centre of curvature of the arcuate rib is coincident, or substantially so, with a pivotal axis of the lever. 13. A dispensing device according to either one of Claims 11 and 12 characterised in that the dispensing device comprises one locking member provided by a triangular block on opposite sides of the arcuate rib adjacent their respective arcuate surfaces of the arcuate rib. 14. A dispensing device according to any one of Claims 5 to 13 characterised in that the dispensing device comprises an over-ride means for engagement with the triangular blocks, when the dispensing device is in use, to move the triangular blocks into inoperative conditions in which arcuate surface engaging portions of the triangular blocks are held out of engagement with a respective one of the arcuate surfaces. 15. A method of dispensing a metered quantity of a liquid comprising the steps of priming a reservoir with a metered quantity of the liquid and delivering the metered quantity of the liquid from the reservoir characterised in that the method also comprises the steps of: a) preventing the interruption and reversal of the priming stroke until the reservoir has received the full metered quantity of the liquid; and, b) preventing the interruption and reversal of the delivery stroke until the reservoir has been emptied of the full metered quantity of the liquid. 16. A dispensing device substantially as hereinbefore described with reference to the accompanying drawings. SUBSTTTUTE SHEET (RULE 26) AMENDED CLAIMS [received by the International Bureau on 05 October 2000 (05.10.00); original claims 1-16 replaced by new claims 1-14 (4 pages)] CLAIMS 1. A dispensing device for delivering a metered quantity of a liquid, the dispensing device comprising a reservoir, priming means for priming the reservoir, when the dispensing device is in use, with a metered quantity of a liquid, the dispensing device also comprising a delivery means for delivering, when the dispensing device is in use said metered quantity of said liquid from the reservoir, wherein the dispensing device further comprises inhibiting means for: a) preventing the interruption and reversal of a priming stroke of the priming means; and b) preventing the interruption and reversal of a delivery stroke of the delivery means, and wherein the priming and delivery means comprises a lever pivotally mounted on the dispensing device, characterised in that the lever includes at least one arcuate surface and the inhibiting means comprises at least one locking member located on the dispensing device adjacent the arcuate surface, the locking member being movable, when the dispensing device is in use, between: a) a first operative condition in which a first arcuate surface engaging portion of the locking member is brought into engagement with the at least one arcuate surface to prevent the interruption and reversal of the priming stroke of the priming means until the priming stroke thereof is completed; and, b) a second operative condition in which a second arcuate surface engaging portion of the locking member is brought into engagement with the at least one arcuate surface to prevent the interruption and reversal of the delivery stroke of the delivery means until the delivery stroke is completed. 2. A dispensing device according to Claim 1 characterised in that the device comprises at least two locking members and at least two arcuate surfaces, the locking members being located one each adjacent a respective one of the arcuate surfaces, wherein when the dispensing device is in use, the movement of the locking members into their operative conditions is arranged so that the locking members operate in concert to prevent the interruption and reversal of the priming stroke and the delivery stroke of the priming means and the delivery means respectively. 3. A dispensing device according to either one of Claims 1 and 2 characterised in that the locking members each comprise a triangular block pivotally mounted on the dispensing device. 4. A dispensing device according to Claim 3 characterised in that, when the dispensing device is in use, the triangular blocks are moved simultaneously into their first operative condition or into their second operative condition by spring means. 5. A dispensing device according to Claim 4 characterised in that the spring means comprises a generally "C" shaped leaf spring opposite ends of which leaf spring are arranged to act one on each of the triangular blocks respectively to urge the triangular blocks into their first operative condition or their second operative condition at or towards opposite ends of the arcuate surfaces associated therewith. 6. A dispensing device according to Claim 5 characterised in that the dispensing device comprises stop elements located at the opposite ends of the arcuate surfaces, the stop elements being effective, when the dispensing device is in use: a) to engage the triangular blocks at a first end of the arcuate surfaces to cause the triangular blocks to pivot simultaneously about their respective fulcrum points into their first operative condition in which they are set to prevent the interruption and reversal of a subsequent priming stroke of the priming means; or, b) to engage the triangular blocks at a second end of the arcuate surfaces to cause the triangular blocks to pivot simultaneously about their respective fulcrum points into their second operative condition in which they are set to prevent the interruption and reversal of a subsequent delivery stroke of the delivery means. 7. A dispensing device according to Claim 6 characterised in that the relative positions of the respective stop elements at the opposite ends of the arcuate surfaces are variable in order to alter the length of the priming and delivery strokes of the priming and delivery means respectively. 8. A dispensing device according to any one of Claims 3 to 7 characterised in that the arcuate surface engaging portions of the triangular blocks and/or the respective arcuate tracks engaged thereby are each provided with a friction coat or surface finish to enhance the locking engagement of the triangular blocks with their respective arcuate surfaces should an operative try to interrupt and reverse the priming or delivery strokes of the priming means or the delivery means respectively when the dispensing device is in use. 9. A dispensing device according to any one of Claims 1 to 8 characterised in that the lever includes two arcuate surfaces formed one on either side of an arcuate rib formed integrally with the lever. 10. A dispensing device according to Claim 9 characterised in that a centre of curvature of the arcuate rib is coincident, or substantially so, with a pivotal axis of the lever. 11. A dispensing device according to either one of Claims 9 and 10 characterised in that the dispensing device comprises one locking member provided by a triangular block on opposite sides of the arcuate rib adjacent their respective arcuate surfaces of the arcuate rib. 12. A dispensing device according to any one of Claims 3 to 11 characterised in that the dispensing device comprises an over-ride means for engagement with the triangular blocks, when the dispensing device is in use, to move the triangular blocks into inoperative conditions in which arcuate surface engaging portions of the triangular blocks are held out of engagement with a respective one of the arcuate surfaces. 13. A method of dispensing a metered quantity of a liquid from a dispensing device according to any one of Claims 1 to 12, the method comprising the steps of priming a reservoir with a metered quantity of the liquid and delivering the metered quantity of the liquid from the reservoir characterised in that the method also comprises the steps of: a) preventing the interruption and reversal of the priming stroke until the reservoir has received the full metered quantity of the liquid; and, b) preventing the interruption and reversal of the delivery stroke until the reservoir has been emptied of the full metered quantity of the liquid. 14. A dispensing device substantially as hereinbefore described with reference to the accompanying drawings.

Inventors: BARNETT DAVID GRANT, BUNOZ ETIENNE VINCENT, EWANS JOHN FRAYN, SALLOWS GEOFFREY, BARNETT, DAVID, GRANT, BUNOZ, ETIENNE, VINCENT, EWANS, JOHN, FRAYN, SALLOWS, GEOFFREY
Applicants: BARNETT DAVID GRANT, BRIGHTWELL DISPENSERS LTD, BUNOZ ETIENNE VINCENT, EWANS JOHN FRAYN, SALLOWS GEOFFREY, BARNETT, DAVID, GRANT, BRIGHTWELL DISPENSERS LIMITED, BUNOZ, ETIENNE, VINCENT, EWANS, JOHN, FRAYN, SALLOWS, GEOFFREY
Application year: 2000
Main classification: G01F11
IPC codes: B67D5, G01F11