Patent GB-190607962-A (GB)
Title: Safeguards for Automatic Railways
Inventor: CARPENTER BENJAMIN FOWLER
Filed: 1906-04-03
Granted: 1907-02-28
Abstract: 7962. Carpenter, B. F. April 3. Points and switches; pneumatic railways.-Relates to means for ensuring the safe working of railways in which the cars are propelled through a tunnel or tube without any attendant, the safe-guards consisting in the use of (a) two independent devices for operating each of the signals, points, doors, and other movable appliances upon the railway, (b) automatic mechanism for locking the appliances when moved until the vehicles have passed over a certain section of the track, and (c) means, at the junctions, whereby the vehicles, after passing, automatically operate the points so as to direct the succeeding vehicle to the other track. Fig. 1 shows a diagrammatic plan of a railway station comprising a number of junctions and doors fitted with the safety arrangements. The points N' can be automatically operated by on-coming vehicles through either the tread lever 0, rock-shaft v<1>, and the bar D of the controller, shown in greater detail in Fig. 4, or the treadlever P<1>, solenoid P, which is electrically connected to the tread-lever, and the lever c. These two methods of operation are entirely independent, thus giving greater safety. The tread-levers for the different junctions are arranged at different points in the width of the track, and the vehicles are furnished with an adjustable wheel which can be set to operate any particular set of tread-levers, The bar D, Figs. 1 and 4, is arranged to move over another bar d, both having slots through which project the stud c<1> formed on the levÞr c. The plate d has inclined projecting surfaces d<1> adapted to raise or lower the bar D when operated by the corresponding solenoid N, N' which becomes energized when the vehicles pass on to the insulated rail - sections 7. The point tongues are connected to the lever c through the rods a, b. The spring l<4> locks the points by dropping into either of the two slots formed in the rod a. Inclined slots in the rod b are adapted to unlock the rod a when necessary. The points are normally set for the main line by means of a spring. After the vehicles have operated the points, they pass over the short insulated rails 3, thus energizing the solenoid N, which causes the projections on the bar d to raise the bar D clear of the stud c'. The points cannot then be again operated through the bar D until the vehicle has withdrawn the bar d by energizing the solenoid N'. The withdrawal of the bar d also operates the lever c to unlock the points and permit them to return to their normal position. The gates are also shown with two agencies to safeguard their operation. The gate M is operated by two pneumatic cylinders r, r', Figs. 1 and 3, the valves s, s<1> of which are controlled by the vehicles through tread-levers P<4>, O<4> and rods P<1>, P<2> in one case and through the solenoids t, t<1> and insulated rails 12, 13 in the other case. The gate is normally closed, and is opened or closed by admitting or exhausting compressed air to or from the cylinders. To balance the air pressure on the sides of the gate, which always resists its opening movement, a diaphragm W is connected with a sliding ram W<1> which acts on the lower part of the door as shown. The end of the ram is formed with a spring coil to reduce shock when the door is closing. The valve s may also be operated by connexion with the bar D, Fig. 4, through the wire p<1>. At junction points, such as F, F<1>, Figs. 1 and 5, means consisting of a modified arrangement of the device shown in Fig. 4 are used for automatically reversing each switch after the car has passed When a oar passes on to the switch F or F<1>, it automatically completes the circuit through the solenoid D', thus causing the rod d to be retracted. This raises the plate D clear of the stud c<1> and renders it impossible for the solenoids R', R<2> to operate the points. The spring p<4> re-sets the bar d when the car has passed off the switch. The car then passes over one of the insulated rails 8 or 9 and energizes the corresponding solenoid R<1> or R<2>, which reverses the switch. The next car is thus passed on to the opposite set of lines to that on which the last car passed. The arrangement also prevents a second car, which follows the first too closely, from encountering partly opened or closed points.