Patent GB-190908379-A (GB)
Title: Improvements in Door Operating Appliances.
Inventor: SHOEMAKER FRANK
IPC: F23M7/00
Filed: 1909-04-07
Granted: 1909-11-04
Abstract: 8379. Shoemaker, F. April 27, 1908, [Convention date]. Operating sliding doors. -Relates to means for operating doors, and more particularly furnace doors, by pivoted levers actuated by compressed air. The doors 20, 21 slide in guides and are connected by studs 22, 24 to levers 27, 26. The lower member of the bell-crank lever 26 is connected by a link 36 to the lever 27, which may be operated by hand when desired. The lever 26 is also connected by a pitman 15 to a piston-rod 13, which is operated by compressed air when it is desired to open the doors mechanically. The piston-rod 13 is formed in two parts secured together by a nut 66, and carries pistons of different diameters. The larger piston is formed of disks 52, 65 secured together and provided with a seat in the edges for packing-rings 54, 55 and a resilient split ring 53. The smaller piston is similarly formed and works in the narrower chamber 74 of the cylinder 11. Heads 43, 79 are detachably secured to the ends of the cylinder, and in the former is formed a chamber 50 which communicates by channels 47, 44 with the upper inlet chamber 5. A set-screw 7 having a lock-nut 46 is mounted in the head 43 and is coned to fit a similarly -formed seat 45 between the channels 44, 47, so that the area of communication between these channels can be adjusted. The exhaust-valve casing 6 has a perforated screw cap 61, which receives the threaded stem of an adjusting-screw 60 adapted to control the valve 62. The valve 41 in the inlet chamber 5 is of similar form, but is made with a small axial hole 40 to afford limited communication between the channel 44 and a pipe 38 which connects both valve casings with the pipe 4. The supply pipe 2 is connected to the chamber 56 by the port 84 and to the pipe 4 through the valve chamber 97, Fig. 4. The stem 92 of the valve 88 is supported on the lever 94, which is operated to remove the valve from its seating 89. The stem 92 is perforated transversely at 90, 99, the perforations being connected by an axial boring 96. The lower perforation opens into an annular groove 91, which is connected to an exhaust port 100 and to the pipe 4 by the port 98 when the valve is seated. The pipe 2 communicates with the chamber 87 by the port 95. When the valve 88 is raised, compressed air enters through the port 95, passes through the channels 90, 96, 99, 91, pipe 4, and inlet chamber 5, and depresses the piston 52 so that the doors open. When the operator releases the lever 94, the valve 88 descends and cuts off the air passage 90. The ports 98, 100 are now in communication and provide a vent for exhausting air from the chamber 56 through the valve 62 and pipe 4. The lower chamber 74 has a vent port 75 which opens into a valve chamber 12. In addition to the valve 78 a narrow orifice 76 is made in the chamber 12. When the lower piston descends, the air slowly escapes through the orifice 76 ; and during the latter part of the upward movement of the upper piston, similar elastic cushioning takes place owing to the slow escape of air through the orifice 40.