AUSTRALIA Patents Act 1990 COMPLETE SPECIFICATION STANDARD PATENT Invention Title: A Plunger Pump Applicant: Simon Hindley The invention is described in the following statement: 2 A PLUNGER PUMP Field of the Invention. The present invention relates generally to the field of drain clearing implements and particularly to plungers and the like. 5 Background Art. A conventional plunger is used to unblock drains and the like. They normally have an elongate handle attached to a head portion which is cup-shaped and typically manufactured of rubber. The head portion has a collar on the rear of the head portion in order to receive the elongate handle. 10 A person using the plunger normally places the plunger over the opening to the drain or pipe and pushes downwardly on the handle which firstly causes the head portion to seal against the surrounding of the opening to the drain or pipe. Due to the fact that the head portion has sealed against the surrounding of the opening and the fact that the handle is depressed further, there is usually water forced 15 into the opening under pressure which is used to dislodge the blockage. Typically, the handle of the plunger is moved vertically up and down in order to repeatedly force air or water under pressure down the pipe or conduit which is blocked. According to the above use, a standard plunger can be used to push blockage matter down the drain pipe. If the handle of the plunger is moved forward 20 and backward, what typically occurs is that the blockage matter is forced forwardly in the drainpipe, and then as the handle is retracted, is drawn backwards under a vacuum force due to the seal of the cup portion with the surrounding of the opening. This is undesirable as it is preferred that the blockage material be forced down the pipe towards the ultimate outlet. 25 It will be clearly understood that, if a prior art publication is referred to herein, this reference does not constitute an admission that the publication forms part of the common general knowledge in the art in Australia or in any other country. Summary of the Invention. The present invention is directed to a plunger pump, which may at least 30 partially overcome at least one of the abovementioned disadvantages or provide the consumer with a useful or commercial choice. With the foregoing in view, the present invention in one form, resides broadly in a plunger pump having a resilient cup portion with an open forward end 3 and at least one vent opening, and a handle assembly including a barrel and an associated piston, the piston moveable between a working condition in which the at least one vent opening in the resilient cup portion is sealed and a free condition in which the at least one vent opening is at least partially clear. 5 In use, when the handle is depressed, the piston will typically seal the at least one vent opening in the cup portion and in this condition, the plunger acts as normal to compress air or water into a pipe in order to dislodge a blockage. As the handle is retracted, the seal at the vent opening is broken was that of the forward edge remains. Air or water can then enter the cup portion through the at least one inlet 10 opening without causing a vacuum effect normally associated with plungers whereby the blockage matter is drawn back towards the plunger. Each successive reciprocation of the handle forces air or water down the pipe using the plunger, forcing the blockage further down the pipe. The resilient cup portion is typically manufactured of rubber or a suitable substitute. 15 The resilient cup portion will typically have a forward sealing edge. The resilient cup portion is typically dome or hemispherical in shape although it may have any other shape. The cup portion may be integrally formed with the barrel or formed separately therefrom and attached to the barrel. Therefore, the cup portion may be 20 integrally formed with the barrel, with the barrel extending from the rear of cup portion. Alternatively, the cup portion may be provided with an opening and a collar portion with an attachment assembly to allow attachment of the barrel to the cup portion. The at least one vent opening is preferably formed in the cup portion at 25 an opposite side of the cup portion to the forward end. The at least one vent open is typically coaxial with the barrel. Normally, the at least one vent opening is formed at the zenith of the cup portion. The barrel of the preferred embodiment is typically tubular with a sidewall of any shape although it is preferred that the cross-sectional shape of the 30 barrel is substantially circular. The barrel is typically elongate. The barrel is preferably provided with at least one air inlet opening, normally through the sidewall of the barrel. Each air inlet opening may be of any 4 shape. Each air inlet opening will preferably be formed in a lower portion of the barrel, closer to the cup portion than to the handle. In this way, the at least one air inlet opening will typically be close enough to the cup portion so that the piston can be withdrawn rearwardly further than the at least one air inlet opening in order to allow 5 air into the barrel and thereby into the cup portion without removing the cup portion from the surface to which it is sealed in use. Typically, the length of the stroke of the piston will allow this to occur. The barrel is preferably also provided with a sealing seat. The sealing seat is typically provided adjacent to the vent opening in the cup portion. The sealing 10 seat will normally be shaped to provide a seal with a forward portion of the piston. Typically, the sealing seat is an annular seat with the vent opening in the centre. The sealing seat may be shaped to direct air into the cup portion. The barrel is typically also provided with at least one portion of a retention mechanism in order to releasably attach the handle and piston to the barrel, 15 to prevent removal of the piston from the barrel. The retention mechanism may be a simple mechanism such as a threaded fastener or grub screw inserted through the sidewall and which mates with a slot or rebate portion in the handle/piston. Other mechanisms may be used such as a removable elongate finger inserted into the handle/piston and which rides in a close-ended elongate slot in the sidewall of the 20 barrel. The barrel has an associated piston which is typically provided at an end of a handle opposite the handle. The handle is used to manually reciprocate the piston between the working condition and the free condition. The piston is typically provided with a sealing member or arrangement 25 in order to temporarily seal the piston against the sealing seat of the barrel. Typically, the sealing member or arrangement is resilient in order to form a better seal. The handle is preferably provided with an elongate stem with the piston at one end opposite the handle at the other end of the stem. The stem will preferably guide movement of the handle and the piston in a reciprocating manner within the 30 barrel. Normally, the stem will have features allowing for interaction with the barrel. For example, corresponding features of the stem will be provided to engage the mechanism to attach the handle to the barrel. According to the two preferred 5 embodiments outlined above, the stem may therefore have a slot in which to receive a threaded faster or an opening to receive an elongate finger. The stem will also preferably have portions of reduced dimension adjacent to the air inlet openings in order to allow passage for the air to communicate 5 with the cup portion. Apart from any portions of reduced dimension, the stem will typically be closely received within the barrel to allow a reciprocating movement but to minimise other movement in the barrel. Guide means may be provided. According to an alternative embodiment, the cup portion may be 10 provided with an opening and a collar portion with an attachment assembly to allow attachment of the barrel to the cup portion. Preferably, the barrel is attached with a screw or threaded portion. Normally, the collar will extend from a rear portion of the cup. A collar is preferably substantially tubular and provided with an internally threaded portion in order to 15 attach the barrel thereto removably. The barrel is preferably provided with an externally threaded portion in order to attach it to the collar. The barrel is also normally provided with at least two openings therein, the openings allowing a user to set a mode of operation. There will preferably be at 20 least two modes of operation namely an agitation mode in which the piston is locked relative to the barrel with the piston in the working condition and a suction/pressurisation mode in which the piston is movable relative to the barrel between the working condition and the free condition. The plunger when in the suction/pressurisation mode can be operated to provide suction or positive pressure. 25 Preferably, a pair of opposed openings are provided in the barrel for the agitation mode and a further pair of opposed openings are provided in the barrel for the suction/pressurisation mode with the respective pairs of opening offset from one another. The mode openings are normally spaced longitudinally along the barrel from the air inlet openings. 30 Typically, a guide pin is associated with the piston portion which engages with the barrel and which selectively engages either the agitation mode openings or the suction/pressurisation mode openings. The guide pin is movable at the user's selection between the two modes.
6 The agitation mode openings are typically discreet or point openings designed and dimension to receive portions of the guide pin therein closely to prevent movement of the piston relative to the barrel. The suction/pressurisation mode openings are preferably elongate 5 openings or slots and more preferably are angled in relation to the longitudinal dimension of piston. In this way, the suction/pressurisation mode openings guide a reciprocal rotation of the piston between the working condition and the free condition. It is preferred that each of the openings has a periphery, with a portion of a wall of the barrel separating the openings from one another. Preferably, user 10 manipulation of the guide pin is required in order to change the mode of operation of the plunger. The guide pin is preferably associated with the piston and preferably, is associated with the piston in a fixed configuration such that rotation of the piston rotates the guide pin as well, within the barrel. It is preferred that the guide pin is 15 located within a tubular piston. Preferably, the guide pin is provided with at least one and normally a pair of opposed pin ends which are biased outwardly. According to a particularly preferred embodiment, the guide pin is provided as a pair at least of tubular telescopic portions with a biasing means (normally a spring) located therein in order to bias the 20 portions apart. Normally, there is a pin end located on the outward end of each end of the guide pin. The pin ends can therefore be depressed into the barrel against the biasing force of the spring, forcing the pin ends away from the periphery of the openings in the barrel in which they sit. The plunger can then be rotated until the pin ends align with openings in the barrel and are then biased outwardly, locking the 25 piston into the designated mode. When in the suction/pressurisation mode, in order to use the plunger to create suction, the piston is depressed, deforming the resilient cup while the piston is rotated into the free condition. This allows air to escape outwardly through the events. The piston is then rotated to the working condition and the piston drawn outwardly 30 which creates a suction force in the cup provided that the cup is sealed against the surface about an opening anything in the opening towards the cup. When in the suction/pressurisation mode, in order to use the plunger to create a positive pressure, the piston is rotated to the working condition as it is 7 depressed and rotated in the opposite direction to the free condition on the upstroke in order to release the airlock. Brief Description of the Drawings. Various embodiments of the invention will be described with reference 5 to the following drawings in which Figure 1 which is a schematic side elevation view of a plunger according to a preferred embodiment of the present invention. Figure 2 is an axonometric view of a plunger according to a second preferred embodiment of the present invention. 10 Figure 3 is a side view of the plunger illustrated in Figure 2 with the guide pin locked in the agitation setting. Figure 4 is a sectional view of the plunger illustrated in Figures 2 and 3 along line A-A illustrated in Figure 5. Figure 5 is a top view of the plunger illustrated in figures 2 to 4. 15 Figure 6 is a detailed side view of the guide pin assembly according to a preferred embodiment. Figure 7 is a side view of a plunger illustrated in Figure 2 with the guide pin located in suction/pressurisation setting. Figure 8 is a sectional view of the plunger illustrated in Figures 2 and 3 20 along line A-A illustrated in Figure 5 with the vents closed. Figure 8 is a sectional view of the plunger illustrated in Figures 2 and 3 along line A-A illustrated in Figure 5 with the vents opened. Detailed Description of the Preferred Embodiment. According to a preferred embodiment, a plunger is provided. 25 As illustrated in Figure 1, the preferred plunger 10 has a resilient cup portion 11 with an open forward end 12. It also has a handle assembly 13 including a barrel 14 and an associated stem or piston 15, with the piston 15 moveable between a working condition in which a vent opening 16 in the resilient cup portion 11 is sealed and a free condition in which the vent opening 16 is at least partially clear. 30 The resilient cup portion 11 is typically manufactured of rubber or a suitable substitute and has a forward sealing edge 17, which in use, will make contact with the surround of an opening of a pipc or conduit (not shown) which is at least partially blocked.
8 The resilient cup portion 11 illustrated is dome or hemispherical in shape. According to the illustrated embodiment, the cup portion 11 is integrally formed with the barrel 14. Therefore the barrel 14 extends upwardly from 5 the rear of cup portion 11. According to the illustrated embodiment, a single vent opening 16 is formed in the cup portion 1 at an opposite side of the cup portion 11 to the forward sealing edge 17. The vent opening 16 is coaxial with the barrel 14. The barrel 14 of the illustrated plunger is tubular with a cross-sectional 10 shape. The barrel 14 of the plunger illustrated is provided with a pair of air inlet openings 18 through the sidewall of the barrel 14. Each air inlet opening 18 is normally formed in a lower portion of the barrel 14, closer to the cup portion 11 than to the handle 19. In this way, the air inlet openings 18 are close enough to the cup 15 portion 1 I so that the sealing portion 20 of the piston 15 can be withdrawn rearwardly further than the air inlet openings 18 in order to allow air into the barrel 14 and thereby into the cup portion 11 without removing the cup portion 11 from the surface to which it is sealed in use. Typically, the length of the stroke of the piston 15 allows this to occur. 20 The unitary barrel 14 illustrated is also provided with a sealing seat 21. The sealing seat 21 is provided adjacent to the vent opening 16 in the cup portion 11. The sealing seat 21 is shaped to provide a seal with the forward sealing portion 20 of the piston 15. The sealing seat 21 is an annular seat with the vent opening 16 in the centre. 25 The illustrated barrel 14 is also provided with part of a retention mechanism in order to releasably attach the handle 19 and piston 15 to the barrel 14, to prevent removal of the piston 15 from the barrel 14. The retention mechanism of the illustrated embodiment is a simple mechanism including a threaded grub screw 22 inserted through the sidewall and which mates with a rebate portion 23 in the piston 30 15. The handle 19 is used to manually reciprocate the piston 15 between the working condition and the free condition. The handle 19 illustrated is formed integrally with an elongate piston 15. The sealing portion 20 is provided at the end 9 opposite the handle 19. The elongate piston 15 guides movement of the handle 19 and the piston 15 in a reciprocating manner within the barrel 14. Normally, the stem or piston has features allowing for interaction the barrel 14. The stem has portions of reduced dimension 24 adjacent to the air inlet 5 openings 18 in order to allow passage for the air to communicate with the cup portion 11. Apart from the portions of reduced dimension 24 and the rebate portion 23, the stem is closely received within the barrel 14 to allow a reciprocating movement but to minimise other movement in the barrel 14. 10 In use, when the handle 19 is depressed, the piston 15 seals the vent opening 16 in the cup portion I1 and in this condition, the plunger 10 acts as normal to compress air into a pipe in order to dislodge a blockage. As the handle 19 is retracted, the seal at the vent opening 16 is broken whilst that of the forward edge 12 remains. Air can then enter the cup portion 11 through the air inlet openings 18 15 without causing a vacuum effect normally associated with plungers whereby the blockage matter is drawn back towards the plunger. Each successive reciprocation of the handle 19 forces air down the pipe using the plunger, forcing the blockage further down the pipe. According to the alternative embodiment of the invention illustrated in 20 Figures 2 to 9, the cup portion 11 may be provided with an opening 16 and a collar portion 25 with an attachment assembly to allow attachment of the barrel 14 to the cup portion 11. As illustrated in Figure 4 in particular, the barrel 14 is attached with an externally threaded lower portion. The collar 25 extends from a rear portion of the cup 25 11. The collar 25 is substantially tubular and has an internally threaded portion in order to attach the barrel 14 thereto removably. The barrel 14 also has pairs of openings therein to allow a user to set a mode of operation. The illustrated embodiment has two modes of operation namely an 30 agitation mode illustrated in Figure 3 in which the piston 15 is locked relative to the barrel 14 with the piston 15 in the working condition and a suction/pressurisation mode illustrated in Figure 6 in which the piston 15 is movable relative to the barrel 14 between the working condition and the free condition. The plunger 10, when in the 10 suction/pressurisation mode, can be operated to provide suction or positive pressure to a pipe or similar as required. A first pair of opposed openings are provided in the barrel 14 for the agitation mode and a further pair of opposed openings are provided in the barrel 14 for 5 the suction/pressurisation mode, with the respective pairs of opening offset from one another. A guide pin 26 is associated with the piston 15 which engages with the barrel 14 and which selectively engages either the agitation mode openings 27 or the suction/pressurisation mode openings 28. The guide pin 26 is movable at the user's 10 selection between the two modes. The agitation mode openings 27 are point openings designed and dimension to receive portions of the guide pin 26 therein closely to prevent movement of the piston 15 relative to the barrel 14. The suction/pressurisation mode openings 28 are elongate openings or 15 slots and more angled in relation to the longitudinal dimension of piston 15. In this way, the suction/pressurisation mode openings 28 guide a reciprocal rotation of the piston 15 between the working condition and the free condition. Each of the openings has a periphery with a portion of a wall of the barrel 14 separating the openings from one another. User manipulation of the guide 20 pin 26 is required in order to change the mode of operation of the plunger. The guide pin 26 is associated with the piston in a fixed configuration such that rotation of the piston, 15rotates the guide pin 26 as well within the barrel 14. It is preferred that the guide pin is located within a tubular piston as illustrated in Figure 4. 25 The guide pin 26 has a pair of opposed pin ends which are biased outwardly. According to the illustrated preferred embodiment, the guide pin 26 is provided as a pair at least of tubular telescopic portions with a biasing spring located therein in order to bias the portions apart. The pin ends can therefore be depressed into the barrel 14 against the biasing force of the spring, forcing the pin ends away from 30 the periphery of the openings in the barrel 14 in which they sit. The piston 15 can then be rotated until the pin ends align with openings in the barrel 14 and are then biased outwardly, locking the piston 15 into the designated mode.
11 When in the suction/pressurisation mode, in order to use the plunger to create suction, the piston is depressed, deforming the resilient cup while the piston is rotated into the free condition. This allows air to escape outwardly through the events. The piston is then rotated to the working condition and the piston drawn outwardly 5 which creates a suction force in the cup provided that the cup is sealed against the surface about an opening anything in the opening towards the cup. When in the suction/pressurisation mode, in order to use the plunger to create a positive pressure, the piston is rotated to the working condition as it is depressed and rotated in the opposite direction to the free condition on the upstroke in 10 order to release the airlock. In the present specification and claims (if any), the word "comprising" and its derivatives including "comprises" and "comprise" include each of the stated integers but does not exclude the inclusion of one or more further integers. Reference throughout this specification to "one embodiment" or "an 15 embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, the appearance of the phrases "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or 20 characteristics may be combined in any suitable manner in one or more combinations. In compliance with the statute, the invention has been described in language more or less specific to structural or methodical features. It is to be understood that the invention is not limited to specific features shown or described since the means herein described comprises preferred forms of putting the invention 25 into effect. The invention is, therefore, claimed in any of its forms or modifications within the proper scope of the appended claims (if any) appropriately interpreted by those skilled in the art.