GB1595217A - Syphonic flushing cistern - Google Patents

Description

(54) SYMPHONIC FLUSHiNG CISTERN (71) We, FORDHAM PRESSINGS LIMI TED, a British Company of Dudley Road, Wolverhampton, West Midlands, do 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: This invention relates to syphonic flushing cisterns.

All cisterns currently sold in the United Kingdom provide either a single 9 litre flush only or an optional 9 litre flush or two 4.5 litre flushes. Whether a cistern is of a single flush only type, which provides the possibility of only a single 9 litre flush, or is of a dual flush type, which provides the possibility of either a single 9 litre flush or two 4.5 litre flushes, is determined during manufacture.

To-day the provision of dual flush citerns is being encouraged by Water Authorities particularly for domestic use as a 4.5 litre flush is adequate for most purposes and hence leads to a saving in water consumption. If in any case it should not be sufficient then either a second 4.5 litre flush can be performed or, if it is thought initially that a large flush will be required, the cistern can be operated to provide a single 9 litre flush.

However in certain applications such as in hospitals where swabs or the like need to be flushed away a dual flush type cistern would not be allowed but only a single 9 litre flush only type cistern so as to ensure an adequate flush initially.

Hitherto a purchaser of a cistern has had to state what type of flush he requires at the time of order since cisterns have not been interchangeable from one type of flush to another.

.It is accordingly an object of the invention to provide a new and improved syphonic flushing cistern which can be converted from either a single flush only type to a dual type and vice versa, and another object of the invention is to provide a method of converting a synphonic flushing cistern from a single flush only to a dual flush capability.

According to one aspect of the invention we provide a syphonic flushing cistern comprising a cistern, a piston operated syphon unit having a body with a piston in sealing engagement therewith and movable therein by means of a linkage which extends externally of the housing and is connected to an operating means, aspirator means in said body, aspirator closure means which close said aspirator means to permit syphonic flushing to be initiated and which maintain said aspirator means closed when the piston is in a first position whereby the cistern may provide a full flush, and which open the aspirator means when the piston is not in its first position to permit air to enter the housing of the syphonic flushing unit to interrupt flushing whereby the cistern provides a partial flush only, a sealing element which may be sealingly engaged with said aspirator means to close said aspirator means without having to separate or otherwise disconnect the linkage from the piston to convert said cistern from a dual flush capability to a single flush capability only.

According to a second aspect of the invention we provide a method of converting a dual flush capability syphonic flushing cistern to a single flush capability only, said dual flush capability cistern comprising a piston operated syphoning unit having a body with a piston in sealing engagement therewith and movable therein by means of a linkage which extends externally of the housing and is connected to an operating means, aspirator means in said body, aspirator closure means which close said aspirator means to permit syphonic flushing to be initiated and which maintain sad asprator means closed when the piston is in a first position whereby the cistern may provide a full flush, and which open the aspirator means when the piston is not in its first position to permit air to enter the housing of the syphonic flushing unit to interrupt flushing whereby the cistern provides a partial flush only, said method comprising engaging a sealing element with said aspirator means without separating or otherwise disconnecting the linkage from the piston.

According to a third aspect of the invention we provide a piston operated syphon unit for use in a syphonic flushing cistern, the unit comprising a body with a piston in sealing engagement therewith and movable therein by means of a linkage which extends externally of the body and is adapted to be connected to an operating means, aspirator means in said body, aspirator closure means which may close said aspirator means to permit syphonic flushing to be initiated and which may maintain said aspirator means closed when the piston is in a first position and which open the aspirator means when the piston is not in its first position, a sealing element which may be sealingly engaged with said aspirator means to close said aspirator means without having to separate or otherwise disconnect the linkage from the piston to convert said piston operated syphon unit from a dual flush capability to a single flush capability only.

Preferably, the aspirator means comprise a boss projecting from the body of the piston operated syphon unit, said boss having an aperture in its side surface, the sealing element comprising a sleeve mounted in or on the boss to close the aperture.

The sleeve may be made of rubber.

The body of the piston operated syphon unit may be of generally inverted U-shaped with one leg mounted at a discharge outlet in the base of the cistern and the other leg terminating in a syphon bell which contains a reciprocable piston mounted on a stem which passes through an aperture in the upper surface of the bell and is connected to said linkage the piston being movable upwardly on operation of an operating lever.

One example of the invention will now be described in more detail by way of example with reference to the accompanying drawing which is a transverse cross-sectional view through a syphonic flushing cistern embodying the invention.

Referring to the drawing a syphonic flushing cistern is indicated generally at 10 and comprises a cistern 11 having side walls 12, a base 13 and a removable cover 14.

The cistern may be made in any suitable material but plastics material is preferred.

Secured to the bottom wall 13 of the cistern is a stand pipe 27 which has at its lower end a threaded spigot 28 which passes through an aperture in the bottom wall 13 and is secured in position by means of a nut 29 with sealing washers, not shown, being provided to ensure that the joint is watertight. The upper end of the stand pipe 27 carries a float operated valve 30 for admission of water into the cistern.

Located within the cistern 11 is a piston operated syphon unit 15 in the form of an inverted U-tube having limbs 16 and 17 joined by a cap 18. At the bottom of the limb 16 is an adaptor 19 which has a threaded spigot 20 which passes through a discharge outlet 1 3a in the bottom wall 13 and which is secured in position by means of a nut 21 and sealing rings 22 and 22' being provided so that the joint is water tight.

At the bottom of the limb 17 is a bellhousing 23 in which is reciprocable a syphon piston 24 connected to a piston rod 25 which projects through an opening 26 at the top of the housing.

This piston rod 26 is connected by a link 31 to a pivoted lever 32 which is connected by a link 33 to the lower end of a rod 34 mounted for reciprocable movement by means of a bearing 35 and a boss 36 depending from the cover 14 and having at its upper end a manually engageable member 37 so that pressing of the member 37 causes downward movement of the rod 34 and hence pivotal movement of the lever 32 and lifting of the piston 24 to initiate a syphonic flushing action.

A boss 38 of generally cylindrical configuration and having a closed upper end 39 is formed in the wall of the housing 23 at its upper end and is provided with a radial aperture 40 to provide an aspirator means.

The piston 24 has a lead weight 41 mounted on the rod 25 and also mounted on the piston rod 25 above the weight 41 is an aspirator member closure means comprising a member 42 having a relatively soft abutment member 43 mounted thereon and which is adapted, when the piston is in a first, upper position, to engage the wall of the housing 23 around the lower end of the boss 38 thereby to close the aspirator means. Thus, if a full flush is required the member 37 is maintained depressed to maintain the piston 24 in its first or uppermost position with the member 43 in engagement with the wall of housing 23 so as to seal the aspirator means so that flushing continues until the water level falls to the bottom of the housing 23.

If however, a partial flush is required, then once flushing has been initiated, the member 37 is released permitting the piston to fall to its "at rest" position thereby opening the aspirator means 40 and causing the syphonic action to cease when the water level falls to the level of the aperture 40.

By providing a generally cylindrical rubber sleeve which can be engaged with the external surface of the boss 38 to seal the aperture 40 the cistern above described can be easily and conveniently converted from a cistern having a full flush only capability to a single/dual flush capability.

Therefore manufacturers of the cistern need produce only one type of cistern which can be easily converted to provide the capability required by the customer merely by the provision or absence of the sleeve 44.

It will be appreciated that once a cistern has been installed it can be converted from one capability to the other should this need arise during service merely by fitting or removing the rubber sleeve 44.

Although the sealing element for the aspirator means has ben described above in the form of a rubber sleeve it will be appreciated that if desired any other means may be provided for sealing the aspirator means and if desired the aspirator means may be provided in some manner other than by means of a boss of cylindrical configuration.

WHAT WE CLAIM IS: 1. A syphonic flushing cistern comprising a cistern, a piston operated syphon unit having a body with a piston in sealing engagement therewith and movable therein by means of a linkage which extends externally of the housing and is connected to an operating means, aspirator means in said body, aspirator closure means which close extends externally of the housing and is flushing to be initiated and which maintain said aspirator means closed when the piston is in a first position whereby the cistern may provide a full flush, and which open the aspirator means when the piston is not in its first position to permit air to enter the housing of the hyphonic flushing unit to interrupt flushing whereby the cistern provides a partial flush only, a sealing element which may be sealingly engaged with said aspirator means to close said aspirator means without having to separate or otherwise disconnect the linkage from the piston to convert said cistern from a dual flush capability to a single flush capability only.

2. A method of converting a dual flush capability syphonic flushing to a single flush capability only, said dual flush capability cistern comprising a piston operated syphoning unit having a body with a piston in sealing engagement therewith and movable therein by means of a linkage which said aspirator means to permit syphonic connected to an operating means, aspirator means in said body, aspirator closure means which close said aspirator means to permit syphonic flushing to be initiated and which maintain said aspirator means closed when the piston is in a first position whereby the cistern may provide a full flush, and which open the aspirator means when the piston is not in its first position to permit air to enter the housing of the syphonic flushing unit to interrupt flushing whereby the cistern provides a partial flush only, said method comprising engaging a sealing element with said aspirator means without separating or otherwise disconnecting the linkage from the piston.

3. A piston opearted syphon unit for use in a syphonic flushing cistern, the unit comprising a body with a piston in sealing engagement therewith and movable therein by means of a linkage which extends externally of the body and is adapted to be connected to an operating means, aspirator means in said body, aspirator closure means which may close said aspirator means to permit syphonic flushing to be initiated and which maintain said aspirator means closed when the piston is in a first position and which open the aspirator means when the piston is not in its first position, a sealing element which may be sealingly engaged with said aspirator means to close said aspirator means without having to separate or otherwise disconnect the linkage from the piston to convert said piston operated syphon unit from a dual flush capability to a single flush capability only.

4. The invention according to any one of the preceding claims wherein the aspirator means comprises a boss projecting from the body of the piston operated syphon unit, said boss having an aperture in its side surface, the sealing element comprising a sleeve mountable in or on the boss to close the aperture.

5. The invention according to Claim 4 wherein the sleeve is made of rubber.

6. The invention according to any one of the preceding claims wherein the body of the piston operated syphon unit is of generally inverted U-shape with one leg mounted at a discharge outlet in the base of the cistern and the other leg terminating in a syphon bell which contains a reciprocable piston mounted on a stem which passes through an aperture in the upper surface of the bell and is connected to said linkage, the piston being movable upwardly on operation of an operating lever.

7. A syphonic flushing cistern substantially as hereinbefore described with reference to and as shown in the accompanying drawings.

8. A method of converting a dual flush

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (9)

**WARNING** start of CLMS field may overlap end of DESC **. the aperture 40 the cistern above described can be easily and conveniently converted from a cistern having a full flush only capability to a single/dual flush capability. Therefore manufacturers of the cistern need produce only one type of cistern which can be easily converted to provide the capability required by the customer merely by the provision or absence of the sleeve 44. It will be appreciated that once a cistern has been installed it can be converted from one capability to the other should this need arise during service merely by fitting or removing the rubber sleeve 44. Although the sealing element for the aspirator means has ben described above in the form of a rubber sleeve it will be appreciated that if desired any other means may be provided for sealing the aspirator means and if desired the aspirator means may be provided in some manner other than by means of a boss of cylindrical configuration. WHAT WE CLAIM IS:

1. A syphonic flushing cistern comprising a cistern, a piston operated syphon unit having a body with a piston in sealing engagement therewith and movable therein by means of a linkage which extends externally of the housing and is connected to an operating means, aspirator means in said body, aspirator closure means which close extends externally of the housing and is flushing to be initiated and which maintain said aspirator means closed when the piston is in a first position whereby the cistern may provide a full flush, and which open the aspirator means when the piston is not in its first position to permit air to enter the housing of the hyphonic flushing unit to interrupt flushing whereby the cistern provides a partial flush only, a sealing element which may be sealingly engaged with said aspirator means to close said aspirator means without having to separate or otherwise disconnect the linkage from the piston to convert said cistern from a dual flush capability to a single flush capability only.

2. A method of converting a dual flush capability syphonic flushing to a single flush capability only, said dual flush capability cistern comprising a piston operated syphoning unit having a body with a piston in sealing engagement therewith and movable therein by means of a linkage which said aspirator means to permit syphonic connected to an operating means, aspirator means in said body, aspirator closure means which close said aspirator means to permit syphonic flushing to be initiated and which maintain said aspirator means closed when the piston is in a first position whereby the cistern may provide a full flush, and which open the aspirator means when the piston is not in its first position to permit air to enter the housing of the syphonic flushing unit to interrupt flushing whereby the cistern provides a partial flush only, said method comprising engaging a sealing element with said aspirator means without separating or otherwise disconnecting the linkage from the piston.

3. A piston opearted syphon unit for use in a syphonic flushing cistern, the unit comprising a body with a piston in sealing engagement therewith and movable therein by means of a linkage which extends externally of the body and is adapted to be connected to an operating means, aspirator means in said body, aspirator closure means which may close said aspirator means to permit syphonic flushing to be initiated and which maintain said aspirator means closed when the piston is in a first position and which open the aspirator means when the piston is not in its first position, a sealing element which may be sealingly engaged with said aspirator means to close said aspirator means without having to separate or otherwise disconnect the linkage from the piston to convert said piston operated syphon unit from a dual flush capability to a single flush capability only.

4. The invention according to any one of the preceding claims wherein the aspirator means comprises a boss projecting from the body of the piston operated syphon unit, said boss having an aperture in its side surface, the sealing element comprising a sleeve mountable in or on the boss to close the aperture.

5. The invention according to Claim 4 wherein the sleeve is made of rubber.

6. The invention according to any one of the preceding claims wherein the body of the piston operated syphon unit is of generally inverted U-shape with one leg mounted at a discharge outlet in the base of the cistern and the other leg terminating in a syphon bell which contains a reciprocable piston mounted on a stem which passes through an aperture in the upper surface of the bell and is connected to said linkage, the piston being movable upwardly on operation of an operating lever.

7. A syphonic flushing cistern substantially as hereinbefore described with reference to and as shown in the accompanying drawings.

8. A method of converting a dual flush

capability syphonic flushing cistern to a single flush capability only substantially as hereinbefore described with reference to the accompanying drawings.

9. A piston operated syphon unit sub stantially as hereinbefore described with reference to and as shown in the accom panying drawings.