Patent GB-408565-A (GB)
Title: Improvements in automatic door-closing devices
IPC: E05F3/10
Filed: 1932-07-06
Abstract: 408,565. Operating doors by springs; checks. LEVASSEUR, J. L., 9, Avenue Fontaine de Rolle, Nanterre, Seine, France. July 6, 1932, No. 19155. Void [Abridged as open to inspection under Sect. 91 of the Acts, July 8, 1932]. [Class 65 (i).] In a spring-closing and fluid-check device for doors, in which the spring bears on the check piston in the cylinder, means are provided whereby the door is unchecked during the first part of its closing movement, is then checked until nearly closed, and is finally free again to ensure closing by slight slamming ; the periods of free movement and of checking are adjustable, and the amount of checking can also be varied. The device comprises a cylinder containing a check piston 8 and a closing spring 9 acting on the piston. The piston has a hollow stem 10 attached to a rack 12 which engages with a pinion on the driving-shaft 15 ; the shaft 15 carries an arm which is connected with the door by a link or a pin-and-slot attachment. The bore of the piston stem 10 opens at one end into the checking end C of the cylinder and communicates through holes 11 with the part of the cylinder behind the piston. An obturator 27, screwed into the end-cap 7 of the cylinder, projects into the bore of the piston stem 10. The part of the bore of the stem 10 adjacent to the face of the piston is enlarged, and a washer 22, with a notched edge and a central aperture tightly fitting the largest part of the member 27, seats on the shoulder between the large and small parts of the bore, being pressed thereon by a spring bearing against a ring 26 fixed in the piston. The stem of the obturator 27 is hollow, and opens at the end into the bore of the piston stem and also communicates with the checking space C of the cylinder through an aperture 30, the size of which is adjustable by means of a screw 31. During the closing of the door, the piston moves to the right, and the first movement is unchecked, as the checking fluid can pass freely from the space C into the bore of the piston stem 10. When the piston reaches the position shown, the passage becomes throttled by the member 27, until this member completely closes the aperture in the washer 22 and the only passage for fluid is then through the throttled hole 30 in the stem of the member 27. Further movement of the piston brings the washer 22 clear of the obturator head to allow free passage of fluid again, so that the final closing of the door is unchecked. In the opening movement, when the head of the member 27 engages the washer 22 it carries the washer away from its seat, allowing free passage of the checking fluid round the washer and through the notches in its edge, until the pressure of the spring forces it off the obturator head back on to its seat to allow the fluid to pass between it and the obturator, so that the opening movement of the door is entirely unchecked. The positions in the closing stroke at which the checking and release take place may be adjusted by screwing the member 27 in or out in the cylinder head 7, a cap nut 32 serving to lock it in position and also to cover the throttling screw 31 of the hole 30 in the stem of the member 27.