TOILET CLEANING APPARATUS
This invention relates to a toilet cleaning apparatus, and in particular relates to a toilet brush for dispensing a predetermined volume of cleaning fluid.
Toilet brushes for cleaning the bowls of toilets are well known. In our PCT patent publication number WO 01/97654 there is disclosed a toilet cleaning apparatus comprising a toilet brash head; the toilet brush handle separated from the brush head by a brush shaft; a portion of the brush handle being adapted to contain a cleaning fluid and being in fluid communication with the brush head by a conduit; the handle being adapted to be reciprocally displaced along the conduit between a first position remote from the brush head and a second position proximate to the brush head so urging cleaning fluid from the handle to the brush head; and a non-return valve within the conduit adapted to allow the flow of fluid from handle to brush but to prevent the flow of fluid from brush to handle. This apparatus typically includes two non-return valves in the form of ball and spring valves, one preventing flow of fluid from brush to handle, and the other preventing flow of fluid from a dispensing volume back to the portion of the handle adapted to contain the cleaning fluid.
While such ball and spring valves are sound in principle, it would be desirable to have fewer moving parts. Moreover, a ball valve closes under the action of the spring and opens because positive pressure in the other direction is stronger than the force exerted by the spring. This means that the compression strength of the spring has to be very precise, which, in mass production, may not always be easily achievable.
The present invention seeks to provide a toilet cleaning apparatus improved in the above respects.
According to the present invention, there is provided a toilet cleaning apparatus of the type described wherein the non-return valve comprises a ducks beak check valve. Preferably, there is a second non-return valve between a dispensing volume and the portion of the brush handle adapted to contain the cleaning fluid. This valve preferably also comprises a ducks beak check valve.
In addition, there may be a third non-return valve located in the portion of the brash handle adapted to contain the cleaning fluid in communication with the atmosphere to allow air into the said portion when cleaning fluid is dispensed to equalise the pressure. This valve is also preferably a ducks beak check valve.
The invention will be described further, by way of example, with reference to the accompanying drawings, in which:
Figure 1 is a cross-sectional view of a toilet cleaning apparatus in accordance with PCT patent publication number WO 01/97654 with the brush handle urged towards a first position;
Figure 2 is a similar view to Figure 1, with the brash handle urged towards a second position;
Figure 3 is an exploded view of an apparatus in accordance with the present invention; and
Figure 4 illustrates a ducks beak check valve employed in the apparatus of Figure 3.
Referring to the drawings, and in particular Figures 1 and 2, a toilet brash shaft (1) is connected to a toilet brash handle (2) of a toilet cleaning apparatus according to the invention. The toilet brash shaft (1) comprises a support wall (3) defining a conduit (4) extending along the shaft (1) between the toilet brush handle (2) and the brush head (not shown). Proximate to the toilet brush head, the conduit (4) splits into a number of sub-conduits (5) which lead to apertures (6) opening at a number of points on the brush head. These ensure that the cleaning fluid which flows along the conduit (4) towards the brush head is spread evenly by the sub- conduits (5) over the brush head and onto the bristles thereof. The portion (7) of the brash shaft (1) comprising the sub-conduits (5) is connected to the remainder of the brush shaft (1) by a screw thread (8). This enables simple removal of this portion (7) should it need to be cleaned or replaced. The brush shaft (1) further comprises a threaded recess (9) for receiving a screw thread up the brash head. This enables simple separation of the brash shaft (1) and the brash head, should this be necessary, for example to clean or replace the brash head.
Extending from the opposite end of the brush shaft (1) to the brush head is the brash handle (2). The brush handle (2) comprises a hollow portion (10) for containing cleaning fluid. The outer wall (11) of this portion (10) is gripped by the user during use. Extending through the wall (11) of this portion (10) of the brash handle (2) is an air input valve (12) which allows the passage of air pressure into the hollow portion (10) when the pressure in this portion drops below ambient air pressure. The valve (12) is non-returnable so that fluid does not escape from the hollow portion (10).
In threaded engagement with the hollow portion (10) is a cylinder portion (13). The inner wall (14) of the cylinder portion (13) defines a further part (15) of the fluid conduit. This part of the fluid conduit extends between the hollow portion of the brash handle (2) and the fluid conduit (4) defined by the brash shaft (1). By means of this conduit, cleaning fluid can flow from storage in the brush handle (2) to the brash head.
The cylinder portion (13) of the brash handle (2) overlaps the toilet brash shaft (1) forming an airtight seal therebetween. When applying pressure to the brash handle (2) the handle can be slid over the shaft (1) between the first position proximate to the brash head (Figure 2) and a second position remote from the brash head (Figure 1).
Located within the conduit is a first seat member (16) forming a restriction in the conduit (4) through which the cleaning fluid must flow. A non-return valve (17) comprising a first plug (18) is urged into contact with the first seat member (16) by a first spring (19), i.e. a ball and spring non-return arrangement. The first spring (19) urges the first plug (18) into contact with the first seat member (16) in a direction away from the brush head. This ensures that when the cleaning fluid pressure on the brush head side of the non-return valve (17) exceeds that on the opposite side of the valve, the first plug (18) is urged more firmly into contact with the first seat member (16), so preventing fluid flow away from the brush head. However, when the pressure on the brash head side of the non-return valve (17) is less than that on the opposite side, the pressure urges the first plug (18) awayfromthe seat member (16). When the pressure difference is such that the cleaning fluid applies a force on the first plug (18) which is greater than the force applied by the first spring (19), the first plug (18) separates from the first seat member (16) allowing flow of cleaning fluid through the first seat member (16) towards the brush head.
Positioned between the first seat member (16) and the brash head is a valve (32) made of resiliently deformable material, preferably silicone. The valve comprises a base sealingly attached to the conduit wall surrounding the valve. Positioned within the base is a deformable crown comprising self-sealing lips. This seal prevents fluid dripping from the conduit onto the brush head if the brash is left standing in a vertical position for a long period. The air input valve (12) comprises an identical valve for allowing entry of air into the hollow portion (10) of the valve handle.
Also located within the conduit (4) is a piston (20) which defines a dispensing volume (21) within the shaft (1). The dispensing volume (21) is connected to the hollow portion (10) by a refill conduit (24) to enable cleaning fluid to flow from the handle (2) to the dispensing volume (21). Extending from the conduit (24) is a piercing member (25). The piercing member (25) includes a conduit (26) to complete the connection between the hollow portion (10) and the dispensing volume (21). The joint between the piercing member conduit (26) and the refill conduit (24) defines a refill seat (27) which carries a non-return valve (28) in the form of a plug or ball (29) urged into contact with the refill seat (27) by means of a refill spring (30). When the fluid pressure within the dispensing volume (21) exceeds that in the handle (2), the refill plug (29) is urged further into contact with the refill seat (27), so preventing flow along the conduit (24). If, however, the pressure in the handle (2) exceeds that in the dispensing volume (21) by a sufficient degree to overcome the action of the refill spring (30), then the refill plug (29) will separate from the refill seat (27) allowing fluid to flow from the handle into the dispensing volume (21).
Finally, also positioned within the conduit (4) is a piston spring (31) which urges the shaft (1) away from the handle (2). In use, the handle portion (10) containing cleaning fluid is threadably engaged with the associated cylinder portion (13). As the portions (10,13) are screwed together, the piercing member (25) pierces a thin foil cap (not shown) allowing cleaning fluid to flow from the hollow portion of the handle (2). The handle (2) may be supplied as a separate refill bottle, as well as being supplied with the initial brash apparatus.
Initially, cleaning fluid will flow along the piercing member conduit (26) to the refill valve (28). If the fluid pressure in the handle portion (2) is greater than that in the dispensing volume (21), the fluid pressure will open the valve (28) allowing fluid to flow into the dispensing volume (21) until the fluid pressures in the handle (2) and the dispensing volume (22) are substantially equalised.
As no force is being applied to the handle (2), the piston spring (31) urges the piston (20) and thus the handle (2) away from the brush head, as shown in Figure 2.
In order to dispense cleaning fluid from the handle (2) to the brush head, the brush head is held stationary and the handle (2) urged towards the head (to the position shown in Figure 1). The spring (31) is compressed as the cylinder portion slides over the shaft (1) towards the brush head. This reduces the dispensing volume (21), causing the fluid pressure within the dispensing volume to rise until it is sufficient to allow the first plug (18) to separate from the first seat (16) against the force of the spring (19). This enables the cleaning fluid to flow from the dispensing volume (21) through the diaphragm (32) along the sub-conduits (5) and onto the brash head. During this time the refill valve (28) remains closed preventing the flow of cleaning fluid back into the handle. Hence, as the cleaning fluid flows onto the brash head, the fluid pressure within the dispensing volume (21) drops until the valve (17) closes. The amount dispensed is determined by the travel between the first and second positions and is hence substantially constant; and its volume is determined by the size of the dispensing volume (21).
To complete the action the handle (2) is then urged to the second position away from the brush head (Figure 2). This is aided by the resilience of the spring (31). The dispensing volume (21) increases lowering the pressure therein and ensuring that the valve (17) closes to prevent fluid coming back from the direction of the brush head. Naive (28) opens allowing cleaning fluid from the hollow portion (10) to refill the dispensing volume (21). Once the fluid pressure in the dispensing volume (21) is substantially equal to that in the handle, the refill valve (28) closes under action of the spring.
Finally, since cleaning fluid is passed from the handle (2) to the dispensing volume (21), the fluid pressure within the hollow portion (10) will have dropped. The air input valve (12) opens allowing air to flow into the hollow portion (10) of the handle (2) until the pressure within returns to ambient, thus completing the dispensing cycle.
Turning now to Figures 3 and 4, the apparatus in accordance with the present invention operates on exactly the same principles as described above. However, the ball and spring nonreturn valves (17,28) are replaced with ducks beak valves (40) as described more fully hereinafter. In addition, the diaphragm (32) can normally be dispensed with since the ducks beak valve is more efficient in preventing dripping than the ball and spring valve previously used. This enables the housing to be shortened, if desired.
Finally, the air input valve (12) can be replaced with a ducks beak valve (40) as shown in Figure 3.
As is illustrated in Figure 4, the ducks beak valves (40) comprise a flange (42) for securing them in place, and a generally cylindrical portion (44) terminating with two inclined surfaces (46) defining between them a slot (48). The valve (40) is made from a resilient material and operates as follows. Pressure from the flange end of the valve tends to push against the inside of the surfaces (46), opening the slot (48) and allowing fluid to flow. Pressure from the other direction, however, presses against the outside of the surfaces (46) urging them together and thus closing the slot (48). The greater the pressure of the fluid in this direction, the more the valve "beak" compresses, thus actually increasing its sealing properties.
The ducks beak valves are manufactured, preferably in one integral piece, e.g. by moulding, from a resilient material such as a rubber or plastics material. The modification in accordance with the invention allows the cleaning apparatus of our above mentioned PCT patent application to be manufactured more simply and cheaply and yet be more reliable in use. However, the advantages of this apparatus are retained, namely that a measured, relatively small, aliquot of cleaner/disinfectant is dispensed to the brash greatly reducing waste and damage to the environment. The brush of the invention is considerably more economical on cleaner/disinfectant use than conventional brashes as with these the user is always tempted to pour far too much into the bowl when cleaning.