Patent GB-410868-A (GB)
Title: Improvements in and connected with door checking devices
IPC: E05F3/14
Filed: 1932-10-31
Abstract: 410,868. Door closing and check devices. ADAMS, J. S., 3, Emerald Street, Bloomsbury, London. Oct. 31, 1932, No. 30637. [Class 65 (i).] A spring-closing and fluid-check device for doors comprises a pair of separate rotatable members, one of which by its rotation operates or sets the spring closing-means when the door is opened while the other effects relative rotation between a fluid-containing chamber and cooperating fluid check means within that chamber. In the form shown, the device is applicable to doors opening both ways, the spring and check coming into action correctly for either direction ot motion. The spring used is of the spiral or clock type, and is contained in a drum 6, rotatably mounted, the inner end of the spring being attached to a ratchet wheel 15 which is prevented from moving by a pawl 16 pivoted on the cover of the housing 1 which contains the apparatus. The check device comprises a fixed member 23, bored to form cylinders for three spring-pressed plungers 25, contained in an oil chamber formed by a rotatable drum 20 of which the inner wall is formed with cam surfaces 27 to engage balls carried by the ends of the plungers 25 ; the inner ends of the cylinders in which the plungers work open into a common chamber communicating with the oil reservoir formed by the drum through a check valve, which almost entirely obstructs the passage of the oil on the inward movement of the plungers, and tubes 29. The plungers 25 engage the ends 27<a> of the cam tracks to limit the motion of the door. The door engages with, and rotates, a spigot 3 carried by a gear wheel 5, which has a set of teeth 5b on its lower part to engage with teeth on the lower part of the check drum 20, and another set of teeth 5<c> on its upper part to engage with teeth on the upper part of the spring drum 6 ; the two sets of teeth 5b, 5<c> are formed on different parts of the periphery of the wheel 5, and only overlap by two teeth 5<a> which extend the full depth of the wheel and form part of both sets of teeth 5b, 5<c>. The teeth on the gear-wheel 5 are normally out of engagement with the teeth on the drums 6, 20, but upward extensions of the teeth 5<a> engage cam-plates 37 fixed on top of the two drums so that there is no backlash when movement commences. The drums 6, 20 are geared together by pinions 18, 19, to rotate in opposite directions. If the door is opened so that the wheel 5 rotates anti-clockwise, the teeth 5<a> on the wheel 5 rotate the drum 6 in the direction of the arrow, to wind up the spring, acting first on the cam plate 37 on drum 6 and then on the teeth on the drum, the teeth 5<c> on the wheel then coming into mesh with the teeth on the drum 6 to continue the motion ; this motion is transmitted to drum 20 through pinions 18, 19, so that the cam surfaces 27 are rotated to allow the plungers 25 to be pressed out of their cylinders by their springs, the teeth on drum 20 being clear of all teeth on wheel 5. On release of the door, the spring in drum 6 acts to close it, the motion of this drum causing reversed motion of the check drum 20 so that the cam surfaces. press the plungers 25 into their cylinders against the resistance afforded by fluid leaking through the check valve. When the door opens in the opposite direction, the wheel 5 engages directly with the check drum 20 only, the spring drum 6 receiving its motion from the latter through the pinions 18, 19 ; the two drums are thus rotated in the same direction as before, although the motion of wheel 5 is reversed. If the door has a large angle of opening, the check may be provided with only two cylinders and plungers 25, diametrically opposed, and corresponding cam surfaces 27. The Provisional Specification describes a check device in which the drum 20 has a truly cylindrical inner surface and the members 23 is also cylindrical, and both the drum and the member 23 have substantially radial vanes bearing on the surface of each other, one set of these vanes being provided with check valves preventing, or considerably restricting, passage of fluid in one direction ; contact between the vanes may be prevented by a stop on the housing 1 engaging an end tooth on the drum 20. In a modification of this form, passages are formed in the central member 23, with a single check valve, taking the place of the valves in the vanes. For doors opening in one direction only, one of the drums 6, 20 is permanently in engagement with the wheel 5, the other being driven from the first one.