Abstract The invention concerns a moulding apparatus provided with a cooling system and comprising at least one mould chamber having walls defining a mould cavity, at least one wall defining a wall cavity and also defining a plurality of apertures to allow communication between the mould cavity and the wall cavity; a steam distribution means comprising a steam distributor pipe having a first and a second section; a plurality of steam connecting pipes extending from the first and second sections of the steam distribution pipe and connected to the said wall to communicate with said wall cavity thereof; a coolant inlet pipe connected to the distribution pipe to define a junction between said first and second sections thereof; a coolant output means comprising a coolant outlet pipe connected to the first section of the steam distribution pipe; a multi position shut-off valve mounted at the junction of the first and second sections of the distribution pipe with the coolant inlet pipe and having at least two shut-off positions, a first position to shut off the coolant inlet pipe and a second position to shut off the first section of the steam distribution pipe; and a multi position shut-off valve switch-over means for switching from first said shut-off position to second said shut-off position and vice versa.
A molding apparatus for molding blocks of rigid plastic foam provided with a cooling system and comprising, at least one molding chamber being bounded by a pair of concentric walls which define a wall cavity, said walls having a plurality of apertures therein to allow communication between said wall cavity and said chamber, said at least a wall cavity being connected by connecting pipes to a generally vertical steam distribution pipe which is connected to a steam source, said steam distribution pipe having upper and lower portions which are connected at a junction, a coolant inlet pipe connected to said distribution pipe at said junction, a coolant extractor connected to a coolant outlet pipe having a coolant shut-off valve, said coolant outlet pipe being connected to said upper section of said steam distribution pipe, a steam shut-off valve disposed in said upper section of said distribution pipe between said source and said coolant outlet pipe, a multiposition shut-off valve mounted at said junction and being movable between a first position in which said coolant inlet pipe is shut off and a second position in which the upper portion of said distribution pipe is shut off, means for switching said valve from said first position to said second position, said coolant shut-off valve having valve operating means associated therewith which valve operating means comprises a pressure sensor interposed in the coolant outlet pipe between the coolant extractor and the coolant shut-off valve and which operating means is effective to open the coolant shut-off valve when a predetermined reduced pressure is sensed.
Claim 2
Dependent Claim
260 words
A molding apparatus for molding blocks of rigid plastic foam provided with a cooling system and comprising, at least one molding chamber being bounded by a pair of concentric walls which define a wall cavity, said walls having a plurality of apertures therein to allow communication between said wall cavity and said chamber, said at least a wall cavity being connected by connecting pipes to a generally vertical steam distribution pipe which is connected to a steam source, said steam distribution pipe having upper and lower portions which are connected at a junction, a coolant inlet pipe connected to said distribution pipe at said junction, a coolant extractor connected to a coolant outlet pipe having a coolant shut-off valve, said coolant outlet pipe being connected to said upper section of said steam distribution pipe, a steam shut-off valve disposed in said upper section of said distribution pipe between said source and said coolant outlet pipe, a multiposition shut-off valve mounted at said junction and being movable between a first position in which said coolant inlet pipe is shut off and a second position in which the upper portion of said distribution pipe is shut off, means for switching said valve from said first position to said second position, said coolant shut-off valve having valve operating means associated therewith which valve operating means comprises a pressure sensor interposed in the coolant outlet pipe between the coolant extractor and the coolant shut-off valve and which operating means is effective to open the coolant shut-off valve when a predetermined reduced pressure is sensed.
Claim 3
Dependent Claim
61 words
The molding apparatus of claim 1 wherein said means for switching said multiposition shut-off valve comprises a pressure sensor interposed in the coolant outlet pipe between the coolant shut-off valve and the steam distribution pipe, said switching means being effective to switch said multiposition shut-off valve from said first position to said second position when a predetermined reduced pressure is sensed.