Patent GB-272007-A (GB)
Title: Improvements in fluid pressure apparatus for operating bulkhead and other doors
IPC: B63B19/00
Filed: 1926-04-26
Abstract: 272,007. Neville, H., and Watkins, W. P. April 26, 1926. Operating and controlling doors hydraulically and pneumatically and by toothed-gear mechanism: indicating and signalling operation of doors.-Bulkhead and other doors are operated by a ram cylinder at the door and a control slide valve connected with the ram cylinder, the casing of the valve having a pressure connection and an exhaust connection, the pressure admitted to the casing acting constantly on the ram area, a releasable detent being provided that normally engages with and prevents the ram from reversing the elide valve, and local control means whereby the slide valve can be controlled without interfering with the bridge or other central control, the detent being releasable by flexible connections from the bridge control. The slide valve d, Fig. 1, controls the admission of pressure fluid from the pipe f to a double-acting cylinder c with a ram b attached to a slidable door a, f<1> being the exhaust pipe. The usual toothed gearing g is provided for enabling the door to be operated by the handshaft h. The valve d is a double-faced throughported valve and has a stem j operable by a hand-lever l through a crank arm k on the spindle k<3>. In the position shown, the valve allows pressure fluid to pass through the port x and pipe e, the pipe e<1> being placed to exhaust. The bypass valve m provides that, in the event of pressure failing or being cut off, the spring q depresses the valve and short-circuits the pipes e, e', the door being then operable by the hand-gear. In the lowered position of the valve d the stem j rests upon a small ram r, to the lower end of which pressure fluid is constantly admitted through a duct s. An offset part r<1> of the ram r is engaged by a spring-operated detent s<1>, and the engaging members have bevelled faces, as shown. A revoluble disc t with a trigger-lever t<1> connected by a cable v to a bridge control lever z is mounted eccentrically of the stem of the detent s<1> and formed with a peripheral recess t<2> that is normally out of alignment with the said stem. The detent s<1> retains the ram r in the depressed condition so that the door responds to the local control. When the control lever z at the bridge is released, the spring u operates the crank t<1> and turns the disc t so that the recess t<2> is opposite the stem of the detent s<1>. The pressure under the ram r then forces it upwardly to move the detent against its springs so that its stem enters the recess t<2>, and this upward movement of the ram r lifts the stem j and valve d into the door-closing position. Bells and indicator switches may be provided to indicate this operation. In the valve device shown in Fig. 2, a tubular part 3 is pressed by a spring against the lock of the slide valve d, as described in Specification 29310/11. The pressure fluid passes through a tubular part 4a to the underside of the ram r, beneath which is placed a spring 9. The ram r is held by the detent s<1> at such an elevation that the valve d is blanked when it comes to rest, and the hand-lever must be turned to open or close the door. When the bridge control handle is released, a spring (not shown) pulls down the rod v<2> and the upper end of the slot v<1> engages the arm t<1> and depresses it against the action of the spring t<3>. This movement of the arm t<1> turns the member t and the engagement of the stem of the detent s' with the recess t<2> is permitted, the ram r moving upwardly to operate the slide valve d. The length of the slot v<1> allows the officer at the bridge to reset his control lever in spite of the arm t' being locked. Instead of the lost-motion device provided by the slot v', the rod v<2> may be pivotally connected to the crank t' and the cable v may include a tension spring.