NZ245498A - Trigger-operated hand pump; pump chamber comprises a resilient flexible tube with a corrugated bellows section - Google Patents

Description

245 498 Patents Form # 5 NEW ZEALAND Mi* ;• »v %\ ;Patents Act 1953 fa J, ;^ Of! ;mMPr.ETE SPECIFICATION V, % ;AFTER PRQVTSTQNAT.NQ: 245498 TITLE: Pumps ;We, Dynapak Holdings Limited ;Address: 18 Broadway, Newmarket, Auckland, New Zealand ;Nationality: New Zealand hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: ;-1- ;PF05JWP ;FEE CODE -1050 ;<-) K n r. n £ U ;-2- ;The present invention relates to pumps and is applicable particularly, but not ;According to one aspect of the present invention there is provided a pump including a pump chamber, an inlet valve to said chamber, the pump chamber comprising a resilient flexible tube, and a pressure pad movable substantially radially of said tube to compress the tube and discharge fluid from said chamber and in which the tube is formed with a corrugated bellows section at at least one end of the chamber, to enable limited bending of the tube without the tube closing. ;Preferably the tube is formed with one of the corrugated bellows sections at each end of the chamber. ;Conveniently an external surface portion of the flexible tube adjacent the inlet valve is sealingly fitted into a closed vessel, and in which a member hinged to said pad is adapted to move a part of said external surface portion away from the adjacent portion 25 of the closed vessel, to provide a temporary air bleed into the closed vessel. ;Advantageously the pump includes an outlet valve element, which at least in part is moulded as an integral part of said tube, and including a discharge hole or nozzle ;30 ;downstream of the outlet valve element and a spiral, radially inwards directed duct connecting the outlet valve to said hole or nozzle. ;Conveniently the pump includes means to enlarge or by-pass said duct. ;5 exclusively to hand pumps. ;15 ;20 ;35 ;/M * 2 August 1995/4920AMSP.795/BS/ms 245498 It is an object of the present invention to go at least partway towards providing novel or improved pumps, or at least to provide the public with a useful choice.

The following is a description of one preferred form of the present invention, given by way of example, with reference to the accompanying drawings in which: Figure 1 illustrates the preferred embodiment of the present invention in side view and cross-section, Figure 2 shows the embodiment of Figure 1 with the trigger squeezed, and Figure 3 illustrates the flexible tube element of the preferred embodiment as moulded.

The preferred form of the present invention comprises a trigger-operated hand pump, of the type commonly used as an alternative to aerosols or squeeze-bottles for dispensing liquid from a bottle. Such pumps are found to be useful in that they allow liquid to be dispensed in a relatively high pressure jet or spray, without the need for a pressurized propellant. However, the pumps hitherto available for this purpose have often been relatively complex mechanisms, and accordingly expensive to produce and somewhat liable to damage or failure. As shown in Figure 1, the mechanism of the present invention can be relatively simple and accordingly easy to manufacture.

As shown in Figure 1, the trigger pack 10 is comprised of a housing 11 mounted on a rotatable screw-cap 12, by which it may be sealingly fitted onto the top of a bottle or other container 13, and having a nozzle 14 and trigger 15. The screw-cap 12 is provided with a sleeved central aperture 16, having an inwardly projecting flange 17 at the upper rim. // 2 August 1995/4920AMSP.795/BS/ms -4549B The nozzle 14 is described in more detail hereafter but may as illustrated have a narrow jet outlet, a wide-spray outlet, or an adjustable outlet, in a cap 18 with a hinged lid 19. When the hinged lid 19 is open or removed, the outlet is exposed; when the lid 19 is fitted in place, the outlet is covered and accidental use or misuse is thereby prevented. As an alternative to the lid 19, an insert may be placed behind the cap 18 to block the outlet, which must be removed before use.

The pump mechanism is comprised by a flexible tube 22, extending from the sleeved aperture 16 in the cap 12 to the nozzle 14. As shown in Figure 3, the tube 22 is moulded substantially straight with two bellows sections 23 and 24, by which it can be bent in two substantially 45" bends to complete a substantially 90" turn, from the cap 12 to the nozzle 14. The tube 22 is preferably formed from a material which is resiliently flexible, and slightly elastic. The preferred material at present is a flexible PVC based alloy, which is resistant to a wide variety of household solvents. The bellows sections 23 and 24 allow the tube to bend without crimping, and furthermore define specific areas at which bending occurs, thereby preventing crimping or stretching of other parts of the tube. The three areas of the tube defined by the bellows sections 23 and 24 comprise an upstream valve section 25, a pumping chamber 26, and a downstream valve section 27.

The upstream valve section 25 is comprised of a constricted "bottleneck" portion 28, and a number of fingers 29 projecting into the flowpath to hold a ball 30 adjacent to the bottleneck portion 28. The ball 30 is acted on by fluid pressure to seat against the bottleneck portion 28 preventing backward flow, or to seat against the fingers 29 allowing forward flow past the bottleneck portion 28 and the ball 30, through the fingers 29.

The portion 25 of the tube 22 is in use fitted through the sleeved aperture 16 in the cap 12, as shown in Figure 1 and 2, and in normal use the flange 17 at the upper rim of the aperture 16 seals against the outer surface of the tube, to prevent leakage of fluid from the container 13. For fluid to be dispensed however, it is desirable for air to be admitted to the container 13 to avoid a pressure imbalance. Consequently, a hinged bar 31 is provided on the trigger 15, and as shown in Figure 2, this acts to push against the tube 22 adjacent the flange 17 when the trigger 15 is squeezed. This opens a gap between the flange 17 and the outer surface of the tube 22, breaking the 4920CSX.N93/1U 245498 seal and allowing air into the container 13.

Pumping of fluid from the container 13 is achieved by compression of the chamber 26 5 with the trigger 15. The trigger 15 is comprised of a lever handle 32, pivoted at a pivot point 33 as close as practically possible to the top of the housing 11. A head 34 projects into the housing 11 from the side of the lever, as far down from the pivot point 33 as practically possible. As shown in Figure 2, when the trigger 15 is squeezed, the head 34 acts to compress the pumping chamber 26 against detents 35, closing the ball-valve 10 25 and expelling the contents of the chamber 26 through the valve portion 27 (described hereafter) and nozzle 14. When the trigger 15 is released, the resilience of the tube 22 acts to return the chamber 26 and trigger 15 to the original configuration of Figure 1, drawing fluid from the container 13 through the valve 25 past the ball 30, to refill the pumping chamber 26.

The valve section 27 downstream of the pumping chamber 26 is held in place at the nozzle 14 by a coacting flange 36 on the tube 22 and annular channel 37 in the housing 11. The nozzle 14 is fitted into the neck of the section 27, and is comprised of two parts. The outer part 18, as mentioned above, comprises a cap with a hinged lid 19. The 20 inner part 38 fits within the outer cap 18 as shown, and has a projecting annular flange 39 which in use seals against the inside surface of the section 27 of the tube 22, to prevent leakage from the nozzle when the unit is not in use. When the trigger 15 is squeezed, and pressure applied to the pumping chamber 26, the valve section 27 is caused to expand away from the flange 39, allowing fluid to pass along channels 40 and 25 41 in the part 38 to the nozzle 14. When the trigger is released, the chamber contracts onto the flange 39, and reseals the nozzle. The channels 41 on the front face of the inner part 38 spiral inward to the nozzle 14, so that a rifling effect is given to the stream emitted from the nozzle, creating a narrow jet. To provide a wide spray, the cap 18 is simply spaced slightly away from the front face of the inner part 38. Fluid can then 30 pass from the channels 40 to the nozzle 14 across the whole front face of the part 38, negating the rifling effect and thereby allowing dispersion of the stream. To further disperse the stream or cause foaming, a fine mesh insert might be provided across the nozzle 14.

By the action of the tube 22, flow is facilitated in one direction and prevented in the opposite direction, providing a relatively simple pump mechanism. It should be 2 August 1995/4 920AMSP.795/BS/ms 2 4 R & 0 g appreciated that a wide variety of changes and modifications might be made to this example within the general spirit and scope of the invention.

The dimensions of the various elements might easily be considerably modified to suit different applications, limited by the capabilities of the materials used. It will be appreciated that the mechanism relies to some extent on the resilience of the tube 22, and this may limit the dimensions of the tube in practice. Similarly, if the pump mechanism is intended for one-hand manual operation, as illustrated in the example, the 10 range of possible variations may be limited by practical considerations such as hand size or strength. Embodiments of the invention intended for other than manual operation may be modified to suit a particular purpose and mode of operation.

The valve mechanisms illustrated, while preferred at present, may be substituted by any 15 of a wide range of alternative systems, and similarly a variety of other changes and modifications might be made within the scope of the invention.

Claims (1)

1. WHAT WE CLAIM IS: A pump including a pump chamber, an inlet valve to said chamber, the pump chamber comprising a resilient flexible tube, and a pressure pad movable substantially radially of said tube to compress the tube and discharge fluid from said chamber and in which the tube is formed with a corrugated bellows section at at least one end of the chamber, to enable limited bending of the tube without the tube closing. A pump according to claim 1, in which the tube is formed with one of the corrugated bellows sections at each end of the chamber. A pump according to claim 1 or 2 in which an external surface portion of the flexible tube adjacent the inlet valve is sealingly fitted into a closed vessel, and in which a member hinged to said pad is adapted to move a part of said external surface portion away from the adjacent portion of the closed vessel, to provide a temporary air bleed into the closed vessel. A pump according to any of claims 1, 2 or 3, including an outlet valve element, which at least in part is moulded as an integral part of said tube, and including a discharge hole or nozzle downstream of the outlet valve element and a spiral, radially inwards directed duct connecting the outlet valve to said hole or nozzle. A pump according to claim 4 including means to enlarge or by-pass said duct. A pump constructed and arranged and adapted to operate substantially as described herein and as shown in the accompanying drawings. A fluid container incorporating a pump according to any preceding claim. JAMES W PIPER & CO Attorneys for the Applicant DYNAPAK HOLDINGS LIMITED