GB2134295A

GB2134295A - Block system in single-track section of railway

Info

Publication number: GB2134295A
Application number: GB08333470A
Authority: GB
Inventors: Yoshihiro Tsunoyama
Original assignee: Japan National Railways
Current assignee: Japan National Railways
Priority date: 1982-12-27
Filing date: 1983-12-15
Publication date: 1984-08-08
Also published as: GB8333470D0; DE3347180A1; FR2538335B1; JPS59118567A; DE3347180C2; GB2134295B; FR2538335A1

Abstract

A transmitter 5 to transmit a departure or an arrival signal and the specific number (token code) assigned to a train 7 is mounted on board the train. At each of the adjacent stations (A-B) in a single track, an appropriate device 1,2 is installed. The device comprises a receiving unit 26,26' to receive a departure or an arrival signal and the token code, a signal identification unit 30,30' to judge whether the received signal is a departure signal or an arrival signal, a train departure control unit 31, 44, a train arrival control unit 45,43; and a block locking unit 37,37'. Said devices are linked by a transmission line 16,16'. The stretch A-B is automatically blocked and locked by only sending a departure signal and the token code from the train leaving A-station, and the block of the stretch A-B is automatically unlocked when the train arriving at B-station sends an arrival signal and the token code. <IMAGE>

Description

SPECIFICATION Block system in single-track section of railway In order that trains may operate safely, reliably and rapidly, it is necessary to clear routes for trains in such a way that there can be no conflict between trains travelling in the same or opposite directions along the same route.

For this purpose it is necessary that any specific section of the line is only used by one train at a time, which can then travel safely along that section. Such a section is called a block section.

Systems for blocking between adjacent stations on a single track line are classified into four types: tablet instrument block systems, token less block systems, controlled manual block systems and automatic systems.

In tablet instrument block systems, a block device which is called the tablet instrument, is installed at each of the adjacent stations constituting the two ends of one block section on a single-track line. By coordinated action agreed upon between the two stations, one of the tablets specified for a given section is picked out of the tablet instrument installed at one of the stations, to be carried buy a train. Unless said tablet is delivered to the tablet instrument at the other station, the next tablet cannot be picked out of the tablet instrument of either station. Under this arrangement, no more than one train can travel along one block section.

In the token less block system, short track circuits are installed at both ends of a block section. Absence of a train in the block section is confirmed by tokenless instruments between the two stations. After this, a block lever is manually operated to indicate GO at the starting signal of a departure station and at the home signal of an arrival station. When a train starts and passes over the short track circuit adjacent to the departure station, a position detect signal is issued from said short circuit and causes the starting signal to indicate STOP; by a similar process when the train passes over the short track circuit adjacent to the arrival station, the home signal indicates STOP. Thus the blocking and the signalling are interlocked.

In the controlled manual block system, a block device called a block lever is located at each end of a block section. Through agreement and coordination between the two stations, the block levers are turned to effect a blocking in which the starting signal at the departure station is caused to indicate GO.

This system differs widely from the former two systems in that the blocking and the signalling are integrated, whereby a signal indicative of the location of a train in the block section is sent to the block device from a continuous track circuit extending between the two stations.

In the automatic block system the block and signal indications are automatically effected in accordance with the information on the train location detected from the continuous track circuit of the block section.

In the automatic block system for a single-track line the block lever in said controlled manual block system is provided at both ends of the block section in order to ensure oppositely travelling trains do not enter the same block section. When said block lever is operated, the automatic signal at the midpoint for one direction will indicate GO if there is no train in that section, and all the automatic signals for the other direction will indicate STOP. Thus for an opposite train, the block section is a section between two adjacent stations, and for a succeeding train the block section is split by automatic block signals.

In the tablet instrument block system mentioned above, in addition to the engine driver, personnel are needed for delivery of the tablet and handling of the tablet instrument. Since this takes considerable time, considerable inefficiency results.

Meanwhile, with the tokenless block system, the controlled manual block system and the automatic block system it is necessary to lay track circuits for the purpose of checking the presence of a train between stations. Thus these systems are found economically unfavourable as a means to block a single-track line with low density of train operation.

A first object of the present invention is to provide an efficient block system for single-track line which requires no agreement and coordination over the telephone between adjacent stations, no delivery of tablets and no handling of tablet instruments at those stations.

A second object of the present invention is to provide an inexpensive automatic block system for a single-track line which needs no costly installation of track circuits between adjacent stations.

According to the invention there is provided a blocking system for a single-track railway line characterized in that each station at a block boundary on a single-track railway line is equipped with a station device comprising a receiving unit adapted to receive a train departure or arrival signal and a token code of the train, a signal identification unitto identify the received signal as a departure signal organ arrival signal, a departure control unit, an arrival control unit and a locking unit; and in which the departure signal and the token code from a train leaving a station (A-station) are received by the receiving unit of A-station and delivered via the signal identification unit of A-station to the departure control unit of A-station; said token code is memorized through a transmission channel in the arrival control unit of the next station (B-station); when said token code is memorized, the arrival control unit at B-station accepts the train, locks the block at B-station, turns the home signal to GO indication, and sends a train-accept signal via a transmission channel to the arrival control unit of A-station; at A-station where the train-accept signal from B-station is received, the departure control unit permits the train departure, memorizes the token code of the train earlier received, locks the block of A-station, turns the starting signal of A-station to GO indication, and returns it to STOP indication after the train leaving A-station has passed by the starting signal of A-station; the arrival signal and the token code of the train reaching B-station are received by the receiving unit of the station device at B-station; said token code is delivered via the signal identification unit of B-station to the arrival control unit of B-station; said arrival control unit correlates said token code against the token code earlier memorized; when the two codes tally, arrival is confirmed and accordingly the block of B-station is unlocked, the memorized token code is cancelled, the home signal of B-station turns to STOP indication; the token code received from the arriving train is sent to the departure control unit of A-station; the departure control unit of A-station receiving said token code correlates the received code against the memorized code; when the two codes tally arrival is confirmed and accordingly the block of A-station is unlocked, and the memorized token code is cancelled.

In the preferred embodiment, a transmitter which transmits a departure or an arrival signal and the specific number assigned to the train, is installed on a train. At each of the adjacent stations, an appropriate device is installed. The device comprises a receiving unit to receive a departure or an arrival signal from the train and the specific number assigned to the train, i.e., the token code; a signal identification unit to judge whether the received signal is a departure signal or an arrival signal; a train departure control unit; a train arrival control unit; and a block locking unit.

When the train is to depart from the departure station (A-station) toward the arrival station (B-station), a driver operates the transmitter on board the train to transmit a departure signal and the token code of the train. A departure signal from a train at A-station and the token code of the train are received by the receiving unit at A-station and sent via the signal identification unit to the departure control unit. Meanwhile the token code, transmitted via a transmission line, is memorized in the arrival control unit of B-station. If upon memorizing the token code, the arrival control unit of B-station judges the train acceptable, the block locking unit of B-station locks the block at B-station; makes GO indication at the home signal; and then sends a "train-accept" signal to the departure control unit of A-station.

Upon receiving the train-accept signal from B-station, the departure control unit of A-station understands that the train can be started; and then the token code of said train is memorized. Next, the block of A-station is locked by the block locking unit so that a GO indication of the starting signal at A-station may be maintained until the train comes inside of said signal. After the train starts and passes by the starting signal of A-station, said starting signal switches to STOP indication. The train reaches B-station, and there the driver of the train operates the transmitter on board the train to transmit the arrival signal and the token code of the train. The arrival signal from the train and the token code of the train are received by the receiving unit at B-station. The token code is given via the signal identification unit to the arrival control unit.The token code given is compared with the token code received and memorized when the train has started from A-station.

If the two codes agree, train arrival is confirmed.

Thereupon the block at B-station is unlocked by the block locking unit of B-station; the memorized token code is cancelled; the home signal at B-station switches to STOP indication; and the token code received from the arriving train is sent back to the departure control unit at A-station. At the departure control unit of A-station, comparison is made between the token code just received and the token code already memorized.

If the two codes agree, train arrival is confirmed. Then the block at A-station is unlocked by the block locking unit of A-station and the token code memorized is cancelled.

Certain embodiments of the invention will now be described by way of example and with reference to the accompanying drawings, wherein: Figure 1 is a plan view illustrating the general construction of a blocking system according to the present invention.

Figure 2 is a schematic diagram showing details of the device to be mounted aboard a train and the devices to be installed at A-station and B-station.

Figure 3 is a diagram illustrating a different arrangement of the transmitter from the one in Figure 2.

Figure 4 is a circuit diagram of a different device taking the place of a timer in the departure control unit illustrated in Figure 2.

A and B in Figure 1 are adjacent stations on a single-track line. A-station is equipped with station device 1 comprising a receiving antenna 3, a receiving unit 26, a signal identification unit 30, a departure control unit 31, a block locking unit 37 and an arrival control unit 45, B-station is equipped with station device 2 comprising antenna 4, a receiving unit 26', a signal identification unit 30' a block locking unit 37', an arrival control unit 43 and a departure control unit 44.

Said departure control unit 31 and said arrival control unit 43 are electrically linked via a transmission line 16. 17 is a single track laid between A-station and B-station and 7 is a train. The train carries a transmitter 5 and transmitting antenna 6.8 is the home signal for a train coming into A-station from an adjacent station on the opposite side to B-station. 9 is the starting signal for a train starting from A-station in the direction of B-station. 10 is the home signal at B-station for a train to run from A-station toward B-station. 11 is the starting signal at B-station for a train to run from B-station towards A-station. 12 is the home signal at A-station for a train to run from B-station toward A-station. 13 is the starting signal at A-station for a train to start from A-station in the left direction in Figure 1. 14 is the starting signal at B-station for a train to start in the right direction from B-station. 15 is the home signal at B-station for a train to enter B-station from the right direction.

The following describes the case when the train 7 initially at A-station is to start toward B-station, when the stretch between A-station and B-station not blocked.

The driver of the train 7, using the transmitter 5, transmits a departure signal and the token code of the train. The transmitted signal is received via the transmitting antenna 6 by the receiving antenna 3 of the station device 1 at A-station. Only the token code passes into the departure control unit 31 via the receiving unit 26 and the signal identification unit 30. At said departure control unit 31, said token code received is transmitted over the transmission line 16 to the arrival control unit 43 of the station device 2 at B-station.

Said token code transmitted from the departure control unit 31 of A-station is memorized by the arrival control unit 43 and thus the train is accepted. Upon the train being accepted, the block locking unit 37' acts to accept the train, thereby clearing the route for the train incoming from A-station to B-station, locking the block and giving GO indication at the home signal 10 of B-station. At the same time, the train-accept signal is sent over the transmission line 16 to the departure control unit 31 of station device 1 at A-station.

At the departure control unit 31 of station device 1 at A-station, the train-accept unit acts upon receiving the permit signal from the arrival control unit 43 of station device 2 at B-station. Then the token code of the train 7 transmitted from the train 7 is memorized and at the same time the block locking unit 37 of station device 1 at A-station acts for the train to start, thereby clearing the route for the train, locking the block at A-station for the train 7 and at the same time making the starting signal 9 indicate GO. Thus the train 7 starts from A-station. After a specified time lapse the starting signal 9 automatically switches to STOP indication.

When the train arrives at B-station, the driver of the train, using the transmitter, transmits an arrival signal and the token code of the train 7 via the transmitting antenna 6. The signal thus transmitted passes to the arrival control unit 43 via the receiving antenna 4, the receiving unit 26' and the signal identification unit 30' of station device 2 at B-station. Comparison is made between the token code just received and the token code earlier transmitted from the departure control unit 31 of station device 1 at A-station and memorized at B-station. If the two codes agree, the arrival control unit acts. By the action of said arrival control unit, the token code transmitted from the train 7 to said arrival control unit 43 is given via the transmission line 16 to the departure control unit 31 of station device 1.Also by the action of said arrival control unit, the block locking unit 37' becomes inactive, causing the home signal 10 to make STOP indication and cancelling the token code memorized.

At the departure control unit 31 of A-station which receives the token code from B-station, comparison is made between the token code just received and the token code of said train memorized at the time of its departure. When the two codes agree, the departure control unit becomes active, unlocking the block earlier locked by the locking unit 37 and at the same time cancelling the token code of the train 7 earlier memorized.

Preferred embodiments of the invention will now be described in detail with reference to Figures 2-4.

In Figure 2, 5 denotes generally the transmitter mounted on the train 7. Token code memory unit 18 which stores the token code assigned to said train 7, is connected to the transmitting antenna 6 via departure signal generating unit 21 and arrival signal generating unit 22 connected in parallel, and via the modulation circuit 23 and the amplifier 25. 19 and 20 denote respectively switches inserted between the departure signal generating unit 21 and the arrival signal generating unit 22 on one hand and the token code memory unit 18 on the other.

The departure signal, the arrival signal and the token code may be expressed by means of, say, frequencies fO and fl. Namely the departure signal is given as fO, the arrival signal is given as fl and the token code is given as a combination of the two frequencies fO and fl, as follows: Departure signal Arrival signal Token code fo fl fo f, fo f, fo 1 2 4 8 16 For instance, the departure signal of a train bearing the token code 10 may be produced by transmitting fo, the second f and the fourth fin succession.When the departure signal of the train 7 is to be transmitted, the switch 19 is closed by a driver, whereupon a signal mentioned above modulates a carrier-wave at the modulation circuit 23, is amplified at the amplifier 25, and then transmitted from the transmitting antenna 6.

When the arrival signal is to be transmitted, the switch 20 has only to be closed by a driver. 24 in the transmitter 5 denotes a carrier-wave oscillator. 26 is a receiver installed in the station device 1 at A-station. A signal transmitted from the antenna 6 is received at the receiving antenna 3, amplified at the amplifier 27, and after being demodulated at the demodulator 28, it goes into the signal identification unit 30. 29 is the oscillator for demodulation. The signal identification unit 30 serves to identify the output from the receiver 26 as a departure signal fO or as an arrival signal f.If it is a departure signal fO, the token code of the train will be given as an input to the departure control unit 31; if it is an arrival signal fl, said token code will be given as an input to the arrival control unit 45. 32 in the departure unit 31 is the token code memory unit. 33 is a token code comparing unit to compare the token code stored in said memory unit 32 with the token code of the train 7 transmitted, as mentioned later, from the arrival control unit 43 at B-station when said train arrives.If the stored code agrees with the transmitted code, said code comparing unit yields an output which actuates the arrival acknowledge unit 34. 35 is the departure permit unit which is actuated upon receiving a train-accept signal transmitted through the action of the train-accept unit 39 in the arrival control unit 43 at B-station. 36 is a delayed action timer which begins to act after a specific time lapse from reception of an input. 37 is the block locking unit and 42 is the block locking relay of the same construction as the block locking relay 42' to be described later. 34a and 34b are the action and drop-away contacts of the arrival acknowledge relay 34. 35a, 35a', 35a", and 35a"' are the action contacts of the departure-permit relay 35. 36b is the drop-away contact of the timer 36. 42a, 42a' and 42a" are the action contacts of the block locking relay 42, while 42b and 42b' are the drop-away contacts of the block locking relay 42.

4 is the receiving antenna installed in the station device 2 at B-station, and 26' is the receiver installed at B-station. These are of the same construction as the receiving antenna 3 and the receiver 26 installed in the station device 1 at A-station. 27', 28' and 29' at B-station respectively correspond to 27,28 and 29 at A-station. 30' is the departure-arrival identification unit of the same construction as the departure-arrival identification unit 30 at A-station; and the output side of this unit is connected, in the same way as at A-station, to the input side of the code comparing unit 40' of the arrival control unit 43 and to the input side of the departure control unit 44 of the same construction as the departure control unit 31 at A-station. 37' is the block locking unit of the same construction as the block locking unit 37 at A-station.

38' is the token code memory unit which stores the token code transmitted via the signal identification unit 30 and the departure control unit 31 and the transmission line 16.39' is the train-accept relay which acts when the token code memory unit 38' memorizes a token code. 40' is the token code comparing unit.The token code transmitted from the transmitting antenna 6 of a train arriving at B-station is received via the receiving antenna 4, the receiver 26', and the departure-arrival identification unit 30'; and when the received token code and the token code stored in the token code memory unit 38' agree, the arrival acknowledge relay 41' acts. 42' is the block locking relay which holds in action when the train-accept relay 39' is in action and the arrival acknowledge relay 34' and 41' is in inactive state; in this condition the block is unlocked upon action of the arrival acknowledge relay 41 '. 41 'a, 41 'a' are the action contacts of the arrival acknowledge relay 41 '.41 'b is a drop-away contact of arrival acknowledge relay 41 39'a, 39'a' and 39'a" are the action contacts of the train-accept relay 39. 45 in Figure 2 is the arrival control unit at A-station of the same construction as the arrival control unit 43 at B-station. 44 is the departure control unit at B-station of the same construction as the departure control unit 31 at A-station.Elements denoted by the same number have the same construction; for instance, 32', 33' in the departure control unit 44 in the B-station correspond to 32,33 in the departure control unit 31 in the A-station and 38,39 in the arrival control unit 45 in the A-station correspond to 38', 39' in the arrival control unit 43 in the B-station. It will be understood that when the departure control unit 31 and the arrival control unit 43 are in active state, the departure control unit 44 and the arrival control unit 45 are in inactive state, and vice versa. 35'a"' is the action contact of the departure permit relay 35' in the departure control unit 44.

The action of the above arrangement will now be described for a situation in which a stationary train at station A is to depa rt for Station B.

In this case it is assumed that the block between the stations A and B is unlocked.

When the driver of the train 7 closes the switch 19 for the starting signal, the departure signal generated from the departure signal generating unit 21 and the token code of said train stored in the token code memory unit 18 are delivered in the form of a combination of frequencies such as fO, fO, f, fO, f, fO, to the modulation circuit 23, where they modulate a carrier wave. The resultant signal is then amplified by amplifier 24, transmitted from the transmitting antenna 6, and received by the receiving antenna 3 of the station device 1 at A-station.The signal thus received is amplified at the amplifier 27, demodulated at the demodulator 28 and then passed to the signal identification unit 30, where it is identified by fO as the departure signal and as the token code. Only the token code passes to the token code memory unit 38' via the dropaway contact 42b the transmission line 16, and the drop away contact 42'b' of said relay 42' of the station device 2 at B-station, to be stored in the token code memory unit 38'. Thereupon an output from the token code memory unit 38' actuates the train accept relay 39'. When said relay 39' acts, its action contact 39'a" closes.

Then since the dropaway contacts 34'b, 41 'b of the arrival acknowledge relay 34', 41' are in closed state, the block lock relay 42' acts to lock the A - B block at B-station. At the same time the action contact 39'a' of the train accept relay 39' closes and the action contact 42'a" of the block locking relay 42' closes, thereby causing the home signal 10 at B-station to indicate "GO". Meanwhile, upon action of the train-accept relay 39', its action contact 39'a closes and in consequence the train-permit signal fb from B-station goes via the transmission line 16 and the filter 351, which passes only the fb signal to the departure-permit unit 35 of the station device 1 at A-station, and actuates said departure-permit unit 35.Thereupon the action contact 35a of the departure-permit relay 35 closes and the token code from the signal identification unit 30 goes into the memory unit 32. At the same time, the action contact 35a"' of the departure-permit unit 35 closes, while the dropaway contacts 34b, 41 b of the arrival acknowledge relay 34, 41 in inoperative state are in closed state.

Therefore the block lock relay 42 becomes active to lock the block at A-station in the direction for the train to start from A-station towards Station.

Upon the action contact 35a' being closed by the action of the departure-permit relay 35, the delayed action timer 36 is set for action. Meanwhile, when the action contact 42a is closed by the action of the block lock relay 42, the action contact 35a" is closed by the action of the departure permit relay 35 and when the dropaway contact 36b of the timer 36 is closed, the starting signal 9 at A-station indicates GO. After the starting signal 9 indicates GO, the train leaves A-station for B-station, passes by the GO-indication starting signal 9 of the A-station, and reaches B-station. After a delay time contacts 36b open to set signal 9 to STOP.

When the train arrives at B-station, the driver operates the arrival switch 20 of the transmitter 5 on board.

Thereupon the arrival signal f and the token code of the train fO, fl, fO, fi, fo modulate a carrier wave in the modulation circuit 23, which is amplified in the amplifier 25, and is transmitted from the transmitting antenna 6. The signal transmitted is received by the receiving antenna 4 installed in the station device 2 at B-station, amplified by the amplifier 27', demodulated by the demodulator 28', and passes to the signal identification unit 30', while the token code, distinguished from the arrival signal by the initial fl, passes to the arrival control unit 43 at B-station. Said token code goes into the token comparison unit 40', which compares said token code with the token code stored in the token code memory unit 38'.When the two codes tally, the arrival acknowledge relay 41' acts. When the two codes do not tally, the arrival acknowledge relay 41' remains in the inactivated state and the stretch A-B remains locked in blocked state.

When the arrival acknowledge relay 41' acts, the dropaway contact 41 'b opens, the block lock relay 42' drops to unlock the block at B-station, and with the action contact 42'a" of the block lock relay 42' opened, the home signal 10 of B-station turns to STOP indication. Upon the action contact 41 'a of the arrival acknowledge relay 41' being closed, a cancel signal is given to the token code memory unit 38', thereby cancelling the storage in the token code memory unit 38'.At the same time, with the closing of the action contact 41 'a' in the arrival relay 41 ', the token code out of the signal identification unit 30' goes into the token code comparison unit 33 in the departure control unit 31 of A-station via the filter 331 which passes only the signal fO, f1. In said comparison unit 33, said token code is compared with the token code stored in the token code memory unit 32. When the two codes tally, the arrival acknowledge relay 34 acts. The action of said relay 34 opens the dropaway contact 34b and causes the block lock relay 42 to drop, thereby unlocking the block. When the action contact 34a of the arrival acknowledge relay 34 closes, a cancel signal is given to the token code memory unit 32 to cancel the storage in said token code memory unit 32.In consequence the original state before the train 7 left A-station is restored at A- and B- stations.

The starting signal 9 at A-station gives GO indication during the inaction of the timer 36, action of the departure permit relay 35 and the action of the block lock relay 42 and it turns to STOP indication through an action of the timer 36 which comes into action after a predetermined time period after the action of the departure permit relay 35. The delay is made sufficiently long for the train 7 to depart and pass the starting signal 9 after the starting signal 9 indicates GO.

When the train 7 is to depart from B-station toward A-station, the same actions described above take place between the departure control unit 44, installed in the station device at B-station, of the same construction as the departure control unit 31 at A-station and the arrival control unit 45 of the same construction as the arrival control unit 43 of B-station, said control unit 45 being installed in the station device 1 at A-station and connected with said control unit 44 via the transmission line 16'. Thus in a similar manner, locking of the block to enable trains to travel safely from B to A, and subsequent unlocking of the block is achieved.

The case described above is one when the control units 31,43 and 44,45 in the station devices of A-station and B-station comprise electric circuits. However, the invention is not intended to be so limited, since it is obvious that the functions of these elements could be performed equally well by microcomputers.

In the above example the transmission line 16 linking the departure control unit 31 of A-station and the arrival control unit 43 of B-station and the transmission line 16' linking the arrival control unit 45 of A-station and the departure control unit 44 of B-station are separately laid. However, multiple transmission could equally well be achieved by frequency splitting or time splitting over a paired transmission line.

In the above example a signal comprising a departure signal or an arrival signal together with the token code of the train is transmitted by radio from the transmitting antenna 6 on board the train to the receiving antenna 3,4 in the station device on the ground from where the signal transmitted passes the control unit in the station device of the station where the train stays. However, the object of the present invention may be achieved equally well using an arrangement in which cards which memorize the departure signal or the arrival signal and the token code in bar code form are stored on board, and a bar code reader is included in the station device.Thus when the train leaves or arrives, the driver operates the bar code reader in the station device to read such card, and the station device then delivers the departure signal or the arrival signal together with the token code of the train to the signal identification unit 30 or 30' in Figure 2.

Further instead of the transmitter 5 on board in the above example, an array of ceramic resonance elements 46 matching the token codes of trains may be provided as illustrated in Figure 3; and instead of the receivers 26, 26' in the station device, a transceiver 47 which transmits a sweeping wave with timevariable frequency may be provided. Said sweeping wave is transmitted from said transceiver 47 via the antenna 3 or 4 to said ceramic resonance element 46 when the train 7 leaves or arrives; a reflected wave produced through resonance of said sweeping wave with said ceramic resonance element 46 is received by the antenna 3 or 4; and after being amplified and decoded, it passes to the signal identification unit 30 or 30'.

Alternatively a voice recognizer may be employed which transmits a specific frequency signal when it recognizes a human voice. This is installed in the station device and the driver with the aid of the voice recognizer uses his voice to give a departure or an arrival signal and the token code signal to the signal identification unit 30 or 30' of the station device.

Alternatively an ultrasonic wave or an infrared ray may be utilized to transmit a departure signal or an arrival signal and the token code from on board the train to the station device. The ultrasonic wave or the infrared ray transmitted from on board is modulated through amplitude-modulation or phase-modulation and is then received by the receiver of the station device. After demodulation it is delivered to the signal identification unit 30 or 30'.

Further alternative is to replace timer 36 in Figure 2, by a short track circuit T laid at A-station as illustrated in Figure 4. Instead of the dropaway contact 36b of said timer 36, a dropaway contact of the track relay 48 of said track circuit T is employed. When the train 7 leaves A-station and passes over said track circuit, the track relay 48 comes into action and said dropaway contact opens, and thereupon the departure signal 9 turns to STOP indication.

According to the present invention, for instance, when the train 7 at A-station is to leave for B-station and for this purpose the stretch A-B must be blocked, what is to be done is merely for the train 7 to transmit an arrival signal or departure signal and the token code of said train to the departure control unit 31 of the station device at A-station. Thereupon said signal will be memorized in the token code memory unit of the station device at B-station, the train will be accepted, and the block at B-station will be locked, at the same time switching the home signal 10 of B-station to GO indication and sending an accept signal from B-station to A-station.At A-station which receives said accept signal, the token code of the train 7 already transmitted to the station device 1 of A-station is memorized and at the same time A-station is locked and the starting signal 9 turns to GO signal to allow the train 7 to leave A-station. When the train 7 reaches B-station, said train sends an arrival signal and the token code to the arrival control unit 43 of the station device at B-station.

Thereupon said token code is compared with the token code stored in the arrival control unit 43 of B-station.

If the two codes tally, arrival is confirmed and the block of B-station is unlocked. At the same time the home signal 10 changes to STOP indication; the token code stored in the arrival control unit 43 is cancelled; the token code transmitted from the train 7 arriving at B-station is transmitted to the departure control unit 31 of A-station. Then the token code transmitted to A-station is correlated against the token code stored in the departure control unit 31 of A-station. When the two codes tally, the block of A-station is unlocked, the token code stored in the departure control unit 31 of A-station is cancelled, and the original state at A- and B-stations before the train has left A-station are restored.

Under this arrangement of the present invention: 1) The stretch A-B is automatically blocked and locked by only sending a departure signal and the token code from the train leaving A-station, and the block of the stretch A-B is automatically unlocked when the train arriving at B-station sends an arrival signal and the token code. Therefore unlike in the conventional systems such as the tablet instrument block system, tokenless block system and controlled manual block system, there is no need for talk and coordination over the telephone to block the stretch A-B; and unlike in the tablet instrument block system there is no need for such a procedure that the tablet is taken out of the tablet block device at one station and carried to go into the tablet block device at the other station. Thus the handling for locking and unlocking the block is extremely simplified.

2) When the train 7 is about to leave A-station and there is a preceding train in the stretch A-B, the starting signal 9 at A-station will remain at STOP indication, because the lock relay 42 of the locking unit 37 at A-station is active and its dropaway contact 42b is open; in consequence, even if the train 7 issues a departure signal and the token code, they will not be memorized in the memory units 32,38'; and accordingly the control units at both A-station and B-station will be inactive. The block will be unlocked for the train 7 and the starting signal 9 at the A-station will change to GO indication, when the preceding train reaches B-station; an arrival signal and the token code are transmitted from said train to make the control units 31 and 43 of A-station and B-station active and the locking units 37,37' inactive.

When the train 7 is about to leave A-station and there is an opposite train leaving for A-station, in the same way as above the starting signal at A-station will continue to indicate STOP even if the train 7 sends a departure signal and the token code, because the locking units 37,37' are active and the block remains locked until the opposite train reaches A-station and sends an arrival signal and the token code. Thus in all cases, an appropriate, highly reliable and safe blocking is ensured.

3) With no track circuit laid between the stations unlike in the conventional tokenless block system, controlled manual block system and automatic block system, the blocking can be done highly economically.

Claims

1. A blocking system for a single-track railway line characterized in that each station at a block boundary on a single-track railway line is equipped with a station device comprising a receiving unit adapted to receive a train departure or arrival signal and a token code of the train, a signal identification unit to identify the received signal as a departure signal or an arrival signal, a departure control unit, an arrival control unit and a locking unit; and in which the departure signal and the token code from a train leaving a station (A-station) are received by the receiving unit of A-station and delivered via the signal identification unit of A-station to the departure control unit of A-station; said token code is memorized through a transmission channel in the arrival control unit of the next station (B-station); when said token code is memorized, the arrival control unit at B-station accepts the train, locks the block at B-station, turns the home signal to GO indication, and sends a train-accept signal via a transmission channel to the arrival control unit of A-station; at A-station where the train-accept signal from B-station is received, the departure control unit permits the train departure, memorizes the token code of the train earlier received, locks the block of A-station, turns the starting signal of A-station to GO indication, and returns it to STOP indication after the train leaving A-station has passed by the starting signal of A-station; the arrival signal and the token code of the train reaching B-station are received by the receiving unit of the station device at B-station; said token code is delivered via the signal identification unit of B-station to the arrival control unit of B-station; said arrival control unit correlates said token code against the token code earlier memorized; when the two codes tally, arrival is confirmed and accordingly the block of B-station is unlocked, the memorized token code is cancelled, the home signal of B-station turns to STOP indication; the token code received from the arriving train is sent to the departure control unit of A-station; the departure control unit of A-station receiving said token code correlates the received code against the memorized code; when the two codes tally arrival is confirmed and accordingly the block of A-station is unlocked, and the memorized token code is cancelled.

2. A blocking system as claimed in claim 1, characterized in that the train carries a transmitter which transmits, using a switch means, a departure signal and token code information or an arrival signal and token code information via a modulation circuit and a transmitting antenna; and the information thus transmitted is received via a demodulation circuit by a receiving unit of the station device.

3. A blocking system as claimed in claim 1 characterized in that the train carries a number of ceramic resonance elements corresponding to the train's token code; a sweeping wave of time-variable frequency is issued from the station and said ceramic elements on board the train resonate with said sweeping wave to produce a reflected wave, which is received by the station device through a decoding circuit.

4. A blocking system as claimed in claim 1 characterized in that the station is equipped with a voice recognizer which recognizes the human voice and yields a specific electric signal as the output and a token code signal is issued depending on the driver's voice and this signal is received by the receiving unit of the station device.

5. A blocking system as claimed in claim 1 characterized in that the driver is provided with a card which records the token code of the train in the form of a bar code; and the station device is equipped with a bar code reader so that the card information can be received by the receiving unit through said bar code reader.

6. Blocking systems for a single track railway line substantially as hereinbefore described with reference to the accompanying drawings.