| 摘要 |
798,007. Multiple glazing units. LIBBEYOWENS-FORD GLASS CO. Nov. 6, 1956 [Nov. 14, 1955], No. 33803/56. Class 56. Relates to the manufacture of multiple glazing units wherein a pair of spaced sheets 20 are supported by vacuum platens 35 on a carriage 29 for passage through four treatment stations A, B ... within a furnace 25, each station comprising a base 62 carrying pairs of fusion burners 59, shaping rollers 60 and finishing burners 61 between which the edges of the sheets pass for shaping and welding, the sheets being rotated through a right angle when passing between one station and the next. The invention provides for detecting and correcting any misalignment that may occur at any station between the edges of the sheets and the shaping and sealing burners and rollers. The detecting device 72 carried at the front end of the base 62 comprises two spaced blocks 78, 79 between which the edges of the sheets pass. Block 78 has two ports 84, 86 communicating with an air-pressure supply 87 and registering with ports 90, 91 in the other block 79. Port 86 is one half the size of port 84 ; ports 90, 91 communicate with opposite sides of a diaphragm 94. The normal position of the sheets is that in which the sheets block the top half of the port 84; any departure from this normal causes a differential pressure on the opposite sides of the diaphragm which causes a jet tube 98 to discharge oil under pressure from pipe 99 into one or other of the pipes 104, 106. These pipes communicate with a four-way valve 75 to control the supply of high-pressure oil from pipe 109 to an interlock valve 76 from which the high-pressure oil may be passed to a cylinder 77 either by pipe 125 or 126, depending on the position of the four-way valve 75 so as to raise or lower the base 62 which is carried by a framework 130 to which the piston rod 129 is connected. The interlock valve 76 is normally in the position shown, but on de-energization of a solenoid 124 the spring 123 puts pipes 115, 118 from the four-way valve into communication with pipes 125 and 126 respectively (through bores 121, 122). The electric circuit in which the solenoid 124 is contained includes a start switch 130<SP>1</SP> and a stop switch 139 tripped by the carriage 29 as it moves through the furnace. A slightly modified detecting device 72 is described wherein all the air ports are equal in size with the lower ones provided with baffle plates. |
