1987 patent.
The specification of the 1989 patent claims the advantages to be derived from the valve arrangement in the
same terms as the specification of the 1987 patent. Claim 1 of the former specification reads as follows:
"1.
A valve means for use in sanitary plumbing, the valve comprising a housing, having
(a)
an inlet connectable to a pipe,
(b)
sealing means at the said inlet whereby the inlet can be sealed to the said pipe,
(c)
a crossplate across the housing,
(d)
a plurality of apertures through the said crossplate, and
(e)
a plurality of one way valves respectively controlling fluid flow through the said apertures, at least one of such
valves permitting flow through its associated aperture in one direction only and the other said valve permitting
flow through its associated aperture in the opposite direction only."
It will be apparent from the aforegoing that essentially the invention to which these patents relate is the twoway
valve means as utilised in a sanitary (or lavatory) plumbing arrangement. The arrangement, in so far as it comprises
a toilet pan, a watertrap, a waste disposal pipe and a waste pipe extension, is wellknown and commonplace and
could not possibly constitute subjectmatter for a patent. And the main advantage claimed for the twoway valve
means is that it enables one to dispense with a relatively long waste pipe extension.
I turn now to the issue of anticipation. By reason of the view which I take of the matter it is necessary to refer
only to the Blau patent specification. It is not disputed that this document formed part of the state of the art
immediately
Page 6 of [1996] 1 All SA 1 (A)
before the priority date of the 1987 and 1989
View Parallel Citation
patents and that it consequently qualifies as a document which could legally anticipate. The vital question is
whether it does anticipate. This involves a comparison between the claims which I have highlighted and the Blau
specification.
It is appropriate to now take a closer look at the Blau specification which was published in 1973 and in terms of
which a patent was granted by the Patent Office, London. The specification, entitled "Closure Cap", states that:
"The present invention relates to a closure cap for a container or which may be used as a pipe socket closure in which
excess internal or external pressures in the interior can be compensated automatically by valve members mounted in the
closure."
After referring to various other known closure devices, the specification proceeds:
"It is an object of the present invention to provide a simplified structure and mounting of automatically acting valve
members relative to a rigid insert plate having air vents and sealing tori, and whereby both excess internal and external
pressures are automatically compensated.
According to the present invention, there is therefore provided a closure cap comprising a rigid insert plate having vent
holes provided therethrough, which vent holes are adapted to be opened and closed by valve members subject to the action
of compression springs, at least one valve member allowing air or gas to pass through at least one vent hole in one direction
and at least one other valve member allowing air or gas to pass through another vent hole in the opposite direction, the
valve members being constituted by a sealing plate supported against annular toroidal supports pressed out of the insert
plate, one such sealing plate being located above the insert plate and a second sealing plate being located below the insert
plate such that when the pressures on opposite sides of the insert plate are not equal, one sealing plate is removed from its
supports and air or gas passes through the thus opened vent hole.
Preferably, the vent holes are eccentrically disposed in the insert plate.
Advantageously, the vent holes allowing the passage of air or gas through the insert plate in one direction are located
diametrically to but on opposed sides of the centre of the insert plate from the vent holes allowing the passage of air or gas
through the insert plate in the opposite direction."
There follow examples or embodiments, accompanied and illustrated by drawings. In describing one illustrated
embodiment the specification states:
"Over the inner circumference of the closure cap 1, there is mounted a rigid insert plate 2 having a sealing ring 3. The
sealing ring 3 is located around the circumferential edge of the closure cap and is retained in a hollow 4 provided in the
lower portion 4 of the closure cap which is pressed thereunder in the region of the rim portion 1 of the closure cap. Against
the outer surface thereof, a sealing ring 5 is supported between the closure cap and the edge of a socket (not shown) of a
container or pipe socket part. In the embodiment shown the lower portion 4 is drawn cupshaped similar to the closure cap.
In a known manner, a bayonet catch bridge member is mounted thereon which is subject to the action of a compression
spring. The invention is, however, applicable to any kind of closure cap, such as screw threaded sockets to be fastened
downwardly or even simple stopper closures."
Page 7 of [1996] 1 All SA 1 (A)
And finally, claim 1 of the patent reads: