Patent GB-197653-A (GB)
Title: Improvements in moving platforms
IPC: B65G23/00
Filed: 1923-04-03
Abstract: 197,653. Continuous Transit Co., (Assignees of Putnam, H. St. C.). May 15, 1932, [Convention date]. Transferring persons to or from trains and other conveyances in motion. - An endless moving platform composed of articulated elements is driven electrically by current supplied from a polyphasa generator to primary windings adapted to create a shifting field placed at intervals along the track. Short circuited secondary windings are mounted on each element of the platform, the arrangement being such that a secondary winding is always in inductive relation to a primary winding. Where a series of parallel platforms is used and each platform is driven at a speed intermediate the speeds of adjacent platforms, means are provided for reducing the speed of, or stopping, the more rapidly moving platforms, if the drive for one or more of the platforms becomes inoperative. Each platform element 1, Fig. 8, has circular ends and is provided with a supporting member 19 having at one end a pair of wheels 21 and at the other a coupling 22 by which it can be pivotally connected to the axle of the next element. Each primary winding 3 is composed of coils 7, 10, 12, Fig. 3, received in slots in a laminated core 13, Fig. 5, mounted in insulating material 6 in a, casing 5 secured to a cross-tie 4 of the track. Each secondary winding is composed of laminations 15, Fig. 6, having slots to receive a continuous copper plate 17, or copper bars having their ends electrically connected. Adjacent secondary windings are preferably electrically connected. The electric circuits employed with three parallel platforms 25, 26, 27 running at different speeds, e.g. 3, 6 and 9 miles per hour are shown in Fig. 11. The primary windings of the platforms 25, 26, 27 are supplied with current through conductors 38, 39, 40 and and cables 35, 36, 37 by polyphase generators 32, 33, 34 producing current at 20, 40, and 60 cycles, respectively. The apparatus is started by closing the switches 41, 42, 43, 44. The consequent energizing of the magnet 45 closes the switch 46 and the current supplied to the primary windings of the platform 25 from the generator 32 causes it to move at 3 miles per hour. On closing the switch 47, the circuit is completed from the conductor 38 to the primary windings of the conductor 26 through the conductor 50, and this platform moves at 3 miles per hour. Similarly by closing the switch 51, the platform 27 is started at 3 miles per hour. The switch 52<a> is next closed, thus opening relay 52 which breaks the circuit to relay 48 controlling switch 49 and closes the circuit through a retarded relay 53 controlling switch 54. The closing of the lastmentioned switch connects the conductor 39 to the primary windings of the platform 26 and the speed increases to 6 miles per hour. By closing the switch 63, the speed of the platform 27 is increased to 9 miles per hour. In order that the platform 26 shall not be operated at 6 miles per hour unless the platforms 25, 27 are both in operation, it is arranged that the circuit of the relay 53 is not completed unless the following contacts are closed, viz. auxiliary contacts 55 of switch 56 or auxiliary contacts 57 of switch 58, auxiliary contacts 59, 60 associated with switches 43, 41 and the auxiliary contacts 62 associated with switch 46. In a similar manner it is arranged that the platform 27 cannot be actuated at maximum speed unless the other platforms are moving at normal speed. If the circuits controlling the platform 25 are deranged, the switch 41 is opened by either the underload release coil 69 or the overload release coil 70 and the opening of the auxiliary contacts 60 replaces the supply of 40 cycle current to the platform 26 by 20 cycle current, while the opening of the contacts 67 effects a similar change in the current supplied to the platform 27. If the switch 42 is opened by the overload release coil 74, platform 26 is stopped, but if the supply of 40 cycle current fails, the switch 42 is not effected, but the circuit changes caused by the dropping of the no-voltage relay 73, connects this platform and platform 27 to the supply of 20 cycle current. If the supply of 60 cycle current fails, platform 27 is supplied with 20 cycle current, but platform 26 is still supplied with 40 cycle current. If the supply of 20 cycle current fails the underload release coils 69, 72 and 77 will trip the switches- 41, 42, 43 and each platform will stop.