Patent GB-260010-A (GB)
IPC: B61L23/24
Abstract: 260,010. Roberts, W. S., Burton, J. H., and Railway Signal Co., Ltd. May 18, 1925. Staff, tablet, and ticket systems.-To minimize the risk of improper operation in a token system of railway tratfic control, the token is partly or wholly in the form of a key adapted to co-operate with locking plungers in a lock barrel of the token instrument to free the barrel for rotation to insert or withdraw a token. Figs. 1, 3, 5, 6, 7 show an instrument for "absolute" working. The insertion and withdrawal of a token 3 is controlled by a rotary lock barrel 1 having plunger locking elements 12, 14, similar to those described in Specification 236,675, co-operating with spring- pressed plungers 11, 13 in the barrel casing 8. Two key apertures 2, 4 are provided, the token key 9 being shown inserted in the upper hole 2 as in inserting or withdrawing the token. The key occupies the lower hole when the barrel is in position for transferring a token to or from the receptacle 5, removal of the token from the instrument in this position being prevented by a part 50 of the receptacle. The token has collars 6 co-operating with ribs 7 of the receptacle to prevent improper removal. Intermediate plungers 15 are provided in the barrel 1 whereby insertion of the key 9 in either aperture 2, 4 operates both sets of locking plungers to release the barrel. The barrel 1 is mounted on a shaft 16 so that its rotation may be controlled by an electric locking mechanism operated by current from the other end of the line section. The shaft 16 carries a disc 17 Fig. 6 having a cam groove 18 and a locking disc 23 having notches 24, 25 and recesses 26, 27. Projecting lugs 37, 49, are also provided on the face of disc 23 adjacent to the notches 24, 25. A lever 33 pivoted at 28 has a hook 32, a pin 35 engaging in the cam grooves 18, and a projection 36 normally engaging the lug 37 to prevent clockwise rotation of shaft 16. A lever 29 also pivoted at 28 rests on lever 33, is formed with a projection 34 normally engaging in the notch 24 and carries a rotary polarized electric lock mechanism 30, the free end of lever 20 being connected by links 38, 39 to a shaft 40 which can be oscillated by a tappet key 41, Fig. 1. Shaft 40 carries a. commutator 42 cooperating with fixed contacts 43. Shaft 16 carries a gear wheel meshing with a gear-wheel 45 on a shaft 46 which carries a. commutator 47 co-operating with fixed contacts 48. When the tappet key 41 is depressed, commutator 42 makes connections conveying any current received from the other end of the section to lock 30, and also raises lever 29. With no current or current of wrong polarity lever 29 moves idly, but with current of proper polarity, a hook 31 on the rotary member of the lock is moved to engage the hook 32 on lever 33, so that lever 33 is raised by the lever 29 and the projection 36 is withdrawn from the path of lug 37 allowing the shaft 16 and barrel 1 to be rotated clockwise to withdraw a token. 'The recess 26 co-operating with the projection 84 allows lever 29 to fall and disengage the hooks 31, 32 before the barrel 1 has rotated through 180‹, and the cam slot engaging pin 35 positively lowers lever 33 so that projection 36 engages lug 49 to limit the barrel movement to a half-rotation. The above arrangement also prevents return of commutator 42 to its intial position for sending current when tappet kev 41 is released until the movement of barrel 1 has been completed and levers 29, 33 are lowered. On returning a token, free anti-clockwise rotation of the barrel 1 is allowed by a bevelled face on projection 34 riding up an inclined face of notch 24, thus raising lever 29, the lever 33 being raised by a pin 35 and the cam groove. A modification is described employing two lock barrels, one controlling the withdrawal and the other the return of the tokens, means being provided to lock one barrel whilst the other is being operated. The intermediate plungers 15 are omitted, and one set of plungers in each barrel casing is ineffective to lock the barrel, these plungers merely preventing insertion or removal of the token except when the barrel movement is completed. A form of instrument for permissive working is described using two lock barrels, one controlling the insertion and withdrawal of the tokens, and the other, operated after each withdrawal or insertion by a withdrawn token, controlling a counter which indicates the number of tokens withdrawn. The lock mechanism in this form of instrument are preferably of the kind described in Specification 233,070. The indicator barrel also operates a step-by-step stop mechanism controlling the " cancellation " of tokens in conjunction with received current. A further modification is described adapted for unidirectional working as described in Specification 236,675, the tokens being transferred from the receiving to the sending instrument in a locked portable magazine as described in that Specification. A preferred form of magazine is illustrated. An alternative form of electric lock is described in which the rotary members of the lock mechanism operates a sliding abutment. A limited rotation of shaft 16 is allowed, during which a cam raises a lever, spaced from which is a catch member normally in the part of a projection on a disc carried by the shaft. When no current or current of wrong polarity is received, the lever moves idly, but with current of proper polarity the sliding abutment is introduced between the lever and the catch, whereby the movement of the lever withdraws the catch and frees the shaft to complete its movement. Token of the form contemplated by the invention may be used to release or operate various control devices such as points, signals, swing-bridge operating mechanism, or devices for switching out token instruments of short block sections as described in Specification 188,097. Fig. 27 shows an indicator which may be used with the various instruments described. A flag moveable about a pivot 152 has two parts 150, 151 respectively bearing the words " Token out, train coming," and " Token in, line clear," and is normally held by a balance arm to display the latter indication through apertures in a plate 147. A second flag 153, bearing the words " Token out, train going " is normally held in invisible position by a pin 156 on an arm 157 (pivoted at 152 and supporting one end of flag 153) engaging a notch in one arm 155 of a V- shaped member 155, 159 pivoted at 158. Flag 150,151 is controlled by a rotary polarized electromagnetic mechanism so that when a token is removed from an instrument at the other end of the section the received current causes the part 150 to be exhibited. When the token is returned to either instrument, so that the two instruments are in phase, received current causes the exhibition of the part 151. A second rotary mechanism energized in series with the coil controlling release of the tokens from the instrument moves an arm 163 so that a pin 164 thereon engages the arm 159 and rocks the member 155 to release the pin 156 allowing flag 153 to fall in front of flag 150, 151, and be exhibited through the plate apertures, a lip 166 on a flag 153 engaging and carrying with it the flag 150, 151. The flags are both returned to normal position when the instruments are again in phase on the return of the token to either. Specification 199,891 also is referred to.