GB2173833A - Syphon unit for flushing w.c. cistern - Google Patents

Abstract

A syphon unit includes a demountable coupling (14) that enables the pipe to be separated into two parts. The coupling may be of the compression type or the snap- fastening type. <IMAGE>

Description

SPECIFICATION Waste water preventer system This invention relates to waste water preventer (WWP) systems.

In the conventional design of WWP syphon the syphon is secured to the cistern in a watertight fashion where the syphon pipe penetrates the bottom wall of the cistern. For this purpose the syphon pipe is provided with an external flange which is directly or indirectly clamped against the internal surface of the bottom wall of the cistern by means of a nut screw-threadedly engaged on the part of the syphon pipe protruding beneath the bottom wall.

From time to time access may be required to the internal moving parts of the syphon, for instance, to replace a damaged diaphragm.

With the conventional design of WWP syphon this access can only be gained by removing the syphon from its cistern. This in turn entails gaining access to the securing nut used to secure the syphon to the cistern. This usually presents little difficulty where the cistern is connected to a pan by way of a flush-pipe, but in the case of close-coupled systems access to this securing nut is denied until the cistern is separated from the pan. Servicing of the WWP syphon would be very much easier to perform if this separation were not necessary, and this invention is particularly concerned with a modified design of WWP syphon which enables access to be gained to its internal moving parts without having first to gain access to the securing nut by which in use the syphon is secured in its cistern.

According to the present invention there is provided a waste-water preventer syphon that includes a generally U-shaped syphon pipe one end of which communicates with a chamber containing the syphon plunger, and the other end of which is provided with an external flange near its extremity beyond which flange the syphon pipe is externally screw-threaded, wherein between the chamber and the flange, the syphon pipe is provided with a demountable coupling that enables the pipe to be separated into two parts.

There follows a description of a WWP syphon embodying the invention in a preferred form. The description refers to the accompanying drawing which depicts a schematic cross-section through the syphon.

Referring to the drawing, a plunger 1 with an associated diaphragm 2 is slidably fitted in a chamber 3. Optionally a return spring 4 is provided to bias the plunger to the bottom of the chamber. The syphon is operated by means of a flushing arm (not shown) acting by way of a linkage 5 to raise the plunger 1 in the chamber 3. The linkage 5 is engaged through a hole near the top of the plunger stem 6.

Communicating with the top of the chamber 3 is one end of a syphon pipe 7 having the general form of an inverted 'U' tube. Optionally the two limbs of the 'U' tube may be linked by one or more webs 8. The end of the syphon pipe remote from the chamber 3 is formed with a flange 9 beneath which the pipe is provided with an external screw-thread 10. This flange 9, the threaded portion 10 of the pipe, and a co-operating nut 11 and gasket 12 provide means by which the syphon may be secured in a watertight fashion in the bottom of a cistern with the outlet of the syphon pipe protruding through its bottom wall 13. Conveniently, though not essentially, the plunger, chamber and syphon pipe are formed of moulded plastics material.

At a point between the chamber 3 and the flange 9 the syphon pipe includes a demountable union indicated generally at 14. This union may for instance be a snap-action fastening coupling or, as illustrated, a conventional plumbing type plastics compression coupling with the two parts of the union being secured by means of a nut 15 and a watertight seal being formed with the aid of an O-ring gasket 16.

The presence of this union means that, if desired, at some time after the syphon has been fitted in its cistern, the portion of the syphon including the chamber can be detached and removed from the cistern for servicing without any requirement to gain access to the securing nut 11.

1. A waste-water preventer syphon that includes a generally U-shaped syphon pipe one end of which communicates with a chamber containing the syphon plunger, and the other end of which is provided with an external flange near its extremity beyond which flange the syphon pipe is externally screw-threaded, wherein, between the chamber and the flange, the syphon pipe is provided with a demountable coupling that enables the pipe to be separated into two parts.

2. A syphon as claimed in claim 1, wherein the demountable coupling is a compression type coupling.

3. A syphon as claimed in claim 1, wherein the demountable coupling is a snapfastening type coupling.

4. A waste water preventer syphon substantially as hereinbefore described with reference to the accompanying drawing.

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

Claims (4)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Waste water preventer system This invention relates to waste water preventer (WWP) systems. In the conventional design of WWP syphon the syphon is secured to the cistern in a watertight fashion where the syphon pipe penetrates the bottom wall of the cistern. For this purpose the syphon pipe is provided with an external flange which is directly or indirectly clamped against the internal surface of the bottom wall of the cistern by means of a nut screw-threadedly engaged on the part of the syphon pipe protruding beneath the bottom wall. From time to time access may be required to the internal moving parts of the syphon, for instance, to replace a damaged diaphragm. With the conventional design of WWP syphon this access can only be gained by removing the syphon from its cistern. This in turn entails gaining access to the securing nut used to secure the syphon to the cistern. This usually presents little difficulty where the cistern is connected to a pan by way of a flush-pipe, but in the case of close-coupled systems access to this securing nut is denied until the cistern is separated from the pan. Servicing of the WWP syphon would be very much easier to perform if this separation were not necessary, and this invention is particularly concerned with a modified design of WWP syphon which enables access to be gained to its internal moving parts without having first to gain access to the securing nut by which in use the syphon is secured in its cistern. According to the present invention there is provided a waste-water preventer syphon that includes a generally U-shaped syphon pipe one end of which communicates with a chamber containing the syphon plunger, and the other end of which is provided with an external flange near its extremity beyond which flange the syphon pipe is externally screw-threaded, wherein between the chamber and the flange, the syphon pipe is provided with a demountable coupling that enables the pipe to be separated into two parts. There follows a description of a WWP syphon embodying the invention in a preferred form. The description refers to the accompanying drawing which depicts a schematic cross-section through the syphon. Referring to the drawing, a plunger 1 with an associated diaphragm 2 is slidably fitted in a chamber 3. Optionally a return spring 4 is provided to bias the plunger to the bottom of the chamber. The syphon is operated by means of a flushing arm (not shown) acting by way of a linkage 5 to raise the plunger 1 in the chamber 3. The linkage 5 is engaged through a hole near the top of the plunger stem 6. Communicating with the top of the chamber 3 is one end of a syphon pipe 7 having the general form of an inverted 'U' tube. Optionally the two limbs of the 'U' tube may be linked by one or more webs 8. The end of the syphon pipe remote from the chamber 3 is formed with a flange 9 beneath which the pipe is provided with an external screw-thread 10. This flange 9, the threaded portion 10 of the pipe, and a co-operating nut 11 and gasket 12 provide means by which the syphon may be secured in a watertight fashion in the bottom of a cistern with the outlet of the syphon pipe protruding through its bottom wall 13. Conveniently, though not essentially, the plunger, chamber and syphon pipe are formed of moulded plastics material. At a point between the chamber 3 and the flange 9 the syphon pipe includes a demountable union indicated generally at 14. This union may for instance be a snap-action fastening coupling or, as illustrated, a conventional plumbing type plastics compression coupling with the two parts of the union being secured by means of a nut 15 and a watertight seal being formed with the aid of an O-ring gasket 16. The presence of this union means that, if desired, at some time after the syphon has been fitted in its cistern, the portion of the syphon including the chamber can be detached and removed from the cistern for servicing without any requirement to gain access to the securing nut 11. CLAIMS

1. A waste-water preventer syphon that includes a generally U-shaped syphon pipe one end of which communicates with a chamber containing the syphon plunger, and the other end of which is provided with an external flange near its extremity beyond which flange the syphon pipe is externally screw-threaded, wherein, between the chamber and the flange, the syphon pipe is provided with a demountable coupling that enables the pipe to be separated into two parts.

2. A syphon as claimed in claim 1, wherein the demountable coupling is a compression type coupling.

3. A syphon as claimed in claim 1, wherein the demountable coupling is a snapfastening type coupling.

4. A waste water preventer syphon substantially as hereinbefore described with reference to the accompanying drawing.