Patent GB-190422151-A (GB)
Title: Improvements in and relating to Bulk-head Doors.
Inventor: TAYLOR DAVID WATSON
Filed: 1904-10-14
Granted: 1905-08-03
Abstract: 22,151. Taylor, D. W. Oct. 14. Bulkhead doors.-Wedging-surfaces are fitted to the door, and engage adjustable studs on the door frame, or vice versÔ, for the purpose of making the door tight when closed. The door is operated by an electric motor through mechanism which is so arranged that the door is forced into its final position with a jerk. Fig. 4 shows one of the forms of wedging- surfaces described, the stud 25 being in each case adjustable. The door is moved by a longitudinal rack 27, Fig. 1, operated by a pinion on the shaft 31, supported in a bridge above the door, which also carries the worm gearing for driving the shaft 31. When it is desired to close the door from a distant station, the switch 68 is closed, completing the circuit through the solenoid switch S and causing the solenoid to draw the bar 77<a> against the contacts 47, 55, 56. Current then flows from the main to the fields of the series motor 42 by the wire 44, returning by the wire 46 to the contact 47, and thence through the armature by the wire 49, finally returning to the main circuit through the resistance 53, wire 54, and contacts 55, 56. This starts the motor and closes the door. In order to close the door completely and bring the studs into complete engagement with the wedge surfaces, several devices are adopted, in all of which there is a certain amount of idle motion of the driving-mechanism, so that the inertia of the moving parts is brought to bear suddenly on the pinion and rack, thus jerking the door into its final position. The worm-wheel, shown in Fig. 1, can turn loosely on its shaft 31 for a quarter of a revolution, after which it comes into operation suddenly. Another device comprises a nut 84a, Fig. 15, on the motor shaft which slides on feather-ways 83 in the sleeve 82. Idle motion takes place until the nut reaches the end-plate 84. The worm may also be arranged to slide on the shaft longitudinally a short distance between the bearings for the same purpose. As the door closes, the key 73 is pressed down, short-circuiting the switch S and causing it to open ; as the whole of the current then passes through the lamp 70 in the central station, it glows, indicating that the operation is completed. The door may be opened either by hand or by the motor 42, which is then operated by the local control switch 91. The whole of the mechanism is jammed and requires a considerable force to operate it. The clutch 40, Figs. 1, 17, and 18, is provided with segmental opposing portions, each less than a quarter of the circumference, giving an idle motion of a quarter of a revolution. The movement of the worm-wheel on the shaft 31 also enables the motor to attain a speed sufficient to disengage the door. The switch 91 is turned to bring the upper set of contacts under the fingers. Current then passes through the fields in the same direction as before, by way of contacts 97, 98, to the armature, in the opposite direction to that previously taken and back to the line by way of the contact 102. The lower set of contacts, when in engagement with the fingers, causes the current to flow in the same directions as when the switch 68 at the central station is closed, thus closing the door. Compound or shunt wound motors may be used instead of the series-wound motor described.