Method and apparatus for moulding a fluid settable material

Claim 2

Apparatus for moulding a fluid settable material, comprising: male and female mould halves which can be brought together to define therebetween a mould cavity, each said halves having flange means, sealing means interposable between said flange means for compression between said flange means on closure of said mould halves to seal said mould cavity from the atmosphere, clamping means to maintain said mould halves in a closed position, means defining at least one vacuum outlet from a mould half leading via an isolation valve to a vacuum source, means defining an inlet to said mould cavity for the introduction of a fluid settable material, and stop means on said mould halves for defining a line of closest approach of said mould halves on closure of said mould cavity, said stop means forming a pinch line located radially inwardly of said sealing means so as to define the periphery of a moulded product.

Claim 3

The apparatus of claim 1, wherein there are provided a plurality of vacuum outlets formed in the said mould half.

Claim 4

The apparatus of claim 2, wherein said plurality of vacuum outlets are spaced around the periphery of said mould cavity.

Claim 5

The apparatus of claim 1, wherein said vacuum outlets from the mould cavity include one or a plurality of ducts having a transparent duct section allowing visual inspection of the degree of filling of the mould cavity.

Claim 6

The apparatus of claim 1, wherein said inlet for introducing settable moulding material into the mould cavity is located at a point spaced from the vacuum outside by a predetermined maximum distance.

Claim 7

The apparatus of claim 1, wherein said vacuum outlets comprise mould inserts having threaded sockets for receiving an outlet duct retainer.

Claim 10

The method of claim 7, wherein said vacuum isolation valve is separated from the vacuum outlet from the mould cavity by a length of transparent ducting, and the step of closing the isolation valve is effected when the plastic resin material introduced into the mould cavity appears in the said transparent ducting.

Claim 11

Resin moulding apparatus for moulding plastic resin, comprising: first and second mould halves which can be brought together to define therebetween a mould cavity, first and second flange means projecting from said first and second mould halves respectively, around the periphery thereof, sealing means interposable between said first and second flange means of said mould halves for compression therebetween as said mould halves are brought together to close said mould cavity, clamp means engageable on said first and second flange means whereby to hold said first and second mould halves together to define said mould cavity and compress said sealing means between said first and second flange means, said clamp means clamping said mould halves together to maintain said mould cavity when resin is injected into said mould cavity under pressure, means defining at least one vacuum outlet from one of said first and second mould halves leading via an isolation valve to a vacuum source, means defining an inlet in at least one of said mould halves for the introduction of plastic resin into said mould cavity under pressure, and stop means on said mould halves for defining a line of closest approach of said mould halves on closure of said mould cavity, said stop means forming a pinch line located radially inwardly of said sealing means so as to define the periphery of a moulded product.

Claim 12

Resin moulding apparatus for moulding plastic resin, comprising: first and second mould halves which can be brought together to define therebetween a mould cavity, first and second flange means projecting from said first and second mould halves respectively, around the periphery thereof, sealing means interposable between said first and second flange means of said mould halves for compression therebetween as said mould halves are brought together to close said mould cavity, clamp means engageable on said first and second flange means whereby to hold said first and second mould halves together to define said mould cavity and compress said sealing means between said first and second flange means, said clamp means clamping said mould halves together to maintain said mould cavity when resin is injected into said mould cavity under pressure, means defining at least one vacuum outlet from one of said first and second mould halves leading via an isolation valve to a vacuum source, means defining an inlet in at least one of said mould halves for the introduction of plastic resin into said mould cavity under pressure, and stop means on said mould halves for defining a line of closest approach of said mould halves on closure of said mould cavity, said stop means forming a pinch line located radially inwardly of said sealing means so as to define the periphery of a moulded product.

Claim 13

The apparatus of claim 9, wherein there are provided a plurality of vacuum outlets formed in the said mould half.

Claim 14

The apparatus of claim 10, wherein said plurality of vacuum outlets are spaced around the periphery of said mould cavity adjacent said flanges.

Claim 15

The apparatus of claim 9 wherein said at least one vacuum outlet from the mould cavity includes at least one duct having a transparent duct section allowing visual inspection of the degree of filling of the mould cavity.

Claim 16

The apparatus of claim 9 wherein said injection point for introducing plastic resin material into the vacuum cavity is located at a point spaced from the vacuum outlets by a predetermined maximum distance.

Claim 17

The apparatus of claim 9, wherein said vacuum outlets comprise mould inserts having threaded sockets for receiving an outlet duct retainer.