US1030436A - Railway signaling system. - Google Patents

Description

L. H. THULLEN.

RAILWAY SIGNALING SYSTEM.

APPLICATION FILED MAY 16, 1904. 1,030,436, Patented June 25, 1912.

2 SHEETS-SHEET 1.

WITNESSES: Y INVENTOR CZ W MM I A I 46,11 ATTORNE COLUMBIA PMNOCIRAPH CO.,WASNXNO1'ON. D. c.

L. H. THULLEN. RAILWAY SIGNALING SYSTEM.

APPLICATION IILED MAY 16, 1904.

1,030,436, Patented June25, 1912.

2 SHEETS-SHEET 2.

WITNESSES: v INVENTOR a 1 W I Dfuo' *A J/u ATTORNEY COLUMBIA PLANOCIRAPH con WAsmNu'roN. B. c.

urn STATES PATENT OFFICE.

LOUIS HENRY TI-IULLEN, OF EDGEWOOD PARK, PENNSYLVANIA, ASSIGNOR TO THE .UNION SWITCH & SIGNAL COMPANY, OF SWISSVALE, PENNSYLVANIA, A CORPORA- TION OF PENNSYLVANIA.

RAILWAY SIGNALING SYSTEM;

Specification of Letters Patent.

Patented June 25, 1912.

To all whom it may concern:

Be it known that I, LOUIS I-I. THULLEN, a citizen of the United States, residing at Edgewood Park, in the county of Allegheny and State of Pennsylvania, have in.

' cuits) to actuate railway signals, the two currents being different in character, pref erably as regards frequency.

I employ both track rails as a return for the alternating propulsion current, and both rails as conductors for the signaling current of the track circuits, and I employ signal controlling devices which will respond to the signal current to close a local or signaling circuit but remain unresponsive to the propulsion current.

Several ways in which I accomplish the objects just stated are disclosed in the drawings, in which Figure 1 is a diagrammatic view showing a signaling system embodying my invention. Figs. 2, 3, and 4 are views showing modifications of the system shown in Fig. 1.

Referring to Figs. 1 and 2,-1 and 2 designate the parallel lines of rails of a trackway. Each line of rails is divided by insulation to form sections which I shall hereinafter refer to as block sections. 1

have shown three such block sections, 3, 4 and 5. At the ends of each block section and near the insulation points, I locate inductive or reactance bonds which I have designated 6, 7, 8 and 9. The windings of the reaotance bonds are connected with the opposite rails of their block section, and the middle points of the windings of adjacent bonds in two adjacent block sections are joined by suitable conductors; 10 and 11 designate two such conductors. This arrangement is clearly set forth in my applications filed February 5, 1904, Serial Nos. 192,145 and 192,146. The form of bond employed may be that set forth in my United States Letters Patent No. 838,916 granted Dec. 18, 1906.

12 designates a generator of alternating propulsion current, which may be of any type suitable for the purposes hereinafter stated. One terminal of the generator 12 is connected with the track rails; for example to the middle point of the winding of an inductive bond 13 bridged across the rails of a block sect-ion as shown in block section 5. The other terminal of the generator 12 is connected with a trolley wire or third rail 14 through which motive power current is conducted to a trolley 15, trolley pole 16, and a motor (not shown) of a railway vehicle 17 conventionally indicated by a pair of wheels and an axle on the rails 1 and 2. The circuit for the propulsion current from the generator 12 through a car motor and back to the generator may be traced as follows: from generator 12 through wire 14, trolley 15, trolley pole 16, motor of car 17, rails of section 3, winding of bond 6, wire 10, winding of bond 7, rails of section 4, winding of bond 8, wire 11, winding of bond 9, rails of section 5, winding of bond 13 to generator 12.

The resistance of the two lines of rails being substantially equal, the alternating propulsion current will normally divide itself equally between them; but any one qual distribution of current between the rails will cause an unbalancing of the current in the windings of the inductive bonds 6, 7, 8 and 9. The propulsion current traverses both lines of rails in the same direction; but the adjacent bonds having the centers of their windings connected together, the current from one rail traverses one half of each Winding in one direction and the current from the other rail traverses the other half of the winding in the opposite direction, whereby the currents in the two halves of the windings neutralize each other in their magnetizing action on the cores of the said bonds. The cores are, therefore, unaffected by the propulsion current, provided it be equal in each line of rails, and the voltage across the terminals of the bonds 6, 7, 8 and 9 is zero. If, however, the propulsion current be unequal in I the two lines of rails of a block section, a counter electro-motive force due to the unbalancing of the current would be set up in the inductive bonds of that block section,

and a difference of potential of propulsion connected with that block section if the relay were constructed to respond to current of the frequency of the propulsion current. This relay must not, therefore, be operative by any difference of potential of the propulsion current across the rails of the block sections.

18 designates a generator of alternating signaling current differing in character from the current generated by the generator 12, the diflerence being preferably in frequency. The terminals of the generator 18 are connected with mains 19 and 20. For each block section I provide a transformer, 21 having its primary winding connected with the mains 19 and 20, and its secondary winding connected with the rails of the block section.

The current from transformer 21 of each block section traverses the windings of the bonds 6, 7, 8 and 9 in one direction, and the bonds are therefore inductive to such current.

For each block section I provide a relay 23 which is adapted to close a local circuitthat is to say, it closes the local circuit when energized by alternating current intended for its operation, and opens the local circuit when the alternating signaling current is shunted from it and also when the relay is improperly energized by the alternating propulsion current. I therefore provide means at some point in each track circuit which acts to prevent the alternating propulsion current from improperly energizing the relay to cause itto close the local circuit when the local circuit should be open. Referring now to Fig. 1, one lead 25 to the relay 23 is divided into two branches 26 and 27, the former branch including a condenser 28 and the latter an inductive winding 29. In Fig. 2, the lead 25 to the relay.

23 is branched in the same manner, but in this case each of the branches has acondenser 28 and 30, having different sizes or values, and each branch also has an impedance or inductive winding 31 and 32,

. center and the other winding on the other side of the center thereof. A connecting wire between the, two windings 33 and 34 than the other and .will actuate the armature to close the local or signaling circuit, while if car propulsion current traverses the divided circuit the energization of the two windings will be equal and opposite, and they will, therefore, have no rotative effecton the relay armature.

In the system embodying my invention, the propulsion current has one frequency, and the signaling current a different frequency. For example, the frequency of the propulsion current might be twenty-five cycles per second, and that of the signaling current sixty cycles per second.

In the system shown in Fig. 1, the condenser 28 and the inductive winding 29 are so proportioned that current of the frequercy of the propulsion current traverses both equally, that is, the current through them varies equally as the difference of potential varies. Hence any change in the potential of the propulsion current across the terminals of the inductive bonds, and therefore across the terminals of the relay, will not unbalance the currents in the branches 26 and 27, and the action of the windings 33 and 34 on the armature remains balanced. But if the apparatus is thus proportioned for equal currents through the two windings 33 and 34 at one frequency, the currents in these two windings will be unbalanced at any other frequency. This is for the reason that the current through a condenser increases in proportion to the frequency at a given voltage, while under the same condition the current through an inductive circuit decreases. If, therefore, a current of a frequency higher than that of the propulsion current be impressed on the terminals of the relay, the current in the branch 26 which includes the condenser 28, will increase, while that in the branch 27 which includes the impedance 29 will decrease. The currents in the windings 33 and 34 being therefore unbalanced, the armature will be operated to close the local circuit for the signal 38.

In the system shown in Fig. 2, the condensers 28 and 30 and the impedances 31 and 32 are so proportioned that, as described for the preceding system, at one frequency, preferably at the frequency of the propulsion current, the currents in the two branches 26 and 27 are equal and the relay contact is free to open. At a higher frequency, however, the balance is destroyed and the relay is operated to close the local circuit for signal 38.

Referring now to Figs. 3 and 4, I have here shown systems similar to those of Figs. 1 and 2, except that in each of the branches 26 and 27 of the relay circuit is included a primary winding 41 of a transformer 40, these windings being in the same direction for each branch. A relay 42 has a single controlling winding 43 which is connected with a secondary winding 44 of the transformer 40. In Fig. 3, the branches 26 and 27 include, respectively, a condenser 28 and an impedance 29 which are adjusted to balance at the propulsion current frequency as heretofore described for the system shown in Fig. 1. As long as the currents in both primary windings of the transformer 40 are equal there will be no current induced in the secondary winding 44; but a current of a higher frequency will unbalance the currents in the two primary windings 41 and will therefore cause a current to be induced in the secondary winding 44 which Will operate the relay 42 to close its local or signaling circuit. The system of Fig. 4 is similar to that of Fig. 3, except that the condenser 28 and the impedance 29 are included in one branch as 26, and are so adjusted that currents in the two branches 26 and 27 are balanced at propulsion current frequency but are unbalanced at another frequency.

Referring to all of the figures, when a train enters any block in which there is no other train, the wheels and axles thereof shunt the signal controlling devices in an obvious manner, causing the local circuit to be opened and the signal to be thrown to indicate danger. As soon as the train has left the block, the current will at once be restored to the signal controlling devices, whereupon the local circuit will be closed and the signal operated to indicate a clear track.

I do not desire to limit myself to the particular appa 'atus described and illustrated herein, as the same may be varied while still retaining the spirit of my invention, which is the safe-guarding of the relay against the effects of the propulsion current, and the means for safe-guarding may be located either in the relay or at some other point in the track circuit.

Having thus described my invention, I claim:

1. In a signaling system for an electric railway the trackway of which is included in the circuit for the propulsion current, a source of alternating propulsion current, a

track circuit, a source of alternating signaling current connected with said track circuit and dlfli'ering in character from the propulsion current, a relay having two windings each of which is connected with the track circuit, and means included in the circuits of the said windings for balancing the flow of propulsion current and for unbalancing the flow of signaling current in the two windings.

2. In a signaling system for an electric railway the trackway of which is included in the circuit for the propulsion current, a plurality of block sections formed by insulations in the rails of the trackway, a source of alternating propulsion current, means connecting the block sections for permitting the passage thereover of the propulsion current, a track circuit for each block section, a source of alternating signaling current con nected with each track circuit and differing in character from the propulsion current, a relay for each track circuit having two windings each of which is connected with the track circuit, and means included in the circuits of the said windings for balancing the flow of propulsion current and for 1111- balancing the flow of signaling current in the two windings.

8. In a signaling system for an electric railway the trackway of which is included in the circuit for the propulsion current, a source of alternating propulsion current, a track circuit, a source of alternating signaling current connected with said track circuit and differing in frequency from the pro pulsion. current, a relay having two windings, each of which windings is connected with the track circuit, and means comprising inductance and capacity included in circuit with the said windings for balancing the flow of current of the propulsion frequency and for unbalancing the flow of current of the signaling frequency in the two. windings.

4. In a signaling system for an electric railway the trackway of which is included in the circuit of the propulsion current, a source of alternating propulsion current, a source of alternating signaling current differing in frequency from the propulsion current, a track circuit, a transformer having its primary connected with the source of signaling current and its secondary with the rails of the track circuit, a relay having two windings, each of which is connected with the track circuit, and means comprising inductance and capacity included in circuit with the said windings for balancing the flow of current of the propulsion frequency and for unbalancing the flow of current of the signaling frequency in the two windings.

5. In a signaling system for an electric railway the trackway of which is included in the circuit of the propulsion current, a source of alternating propulsion current, 'a source of alternating signaling current differing in frequency from the propulsion current, a track circuit, a transformer having its primary connected with the source of signaling current and its secondary with the rails of the track circuit, a relay having two windings each of which is connected with the track circuit, and means comprising inductance and capacity interposed between the said windings and the track circuit for 10 balancing the flow of current of the propulsion frequency and for unbalancing the flow of the current of the signaling frequency of the two windings.

6. In a signaling system for an electric railway the trackway of which is included in the circuit of the propulsion current, a plurality of block sections formed by insulations in the rails of the trackway, asource of alternating propulsion current, means connecting the block sections for permitting the passage of the propulsion current thereover, a source-of alternating signaling current differing in frequency from the propulsion current, a track circuit for each block section, a transformer for each "track circuit having its primary connected with the source of signaling current and its secondary with the rails of the track circuit, a relay for each track circuit having two windings, each of which windings is connected with the track circuit, and means comprising inductance and capacity included in circuit with the said windings for balancing the flow of current of the propulsion frequency and for unbalancing the flow of current of the signaling frequency in the two windings.

7. In a signaling system for an electric railway the trackway of which is included in the circuit of the propulsion current, a source of alternating propulsion current, a track circuit, a source of alternating signaling current connected with said track circuit and differing in frequency from the propulsion current, a relay having two windings each of which is connected with the track circuit, and means comprising inductance and capacity included in the circuits of said windings and so proportioned that the energy in the two windings will vary. equally upon variations of voltage of the propulsion frequency, but unequally upon variations of voltage of the signaling frequency.

8. In a signaling system for an electric railway the trackway of which is included in the circuit of the propulsion current,

sources of alternating propulsion and signaling currents differing in frequency, a track circuit connected with the source of signaling current, a signal for said track circuit, a relay for the control of said signal and comprising two windings each of which is connected with the track circuit, inductance and capacity included in the circuits with said windings and so proportioned that the flow of current of the propulsion fre- 'quency will be equal and the flow of current of the signaling frequency will be unequal in the two windings. I

9. In a signaling system for an electric railway the trackway of which "is included in the circuit for the propulsioncurrent, a plurality of block sections formed by insulations in the rails of the trackway, a source of alternating propulsion current, means connecting the block sections for permitting the passage thereover of the propulsion current, a signal for each block section, a track circuit for each block section, a source of alternating signaling current connected with each track circuit and differing in frequency from the propulsion current, a relay for the control of each signal and comprising two windings each of which is connected with the corresponding track circuit, and means comprising inductance and capacity included in circuit with the said windings for balancing the flow of current of the propulsion frequency and for unbalancing the flow of current of the signaling frequency in the two windings.

10. In a signaling system for an electric railway the t-rackway of which is included in the circuit for the propulsion current, a source of alternating propulsion current, a track circuit, a source of alternating signaling current connected with said track circuit and differing in frequency from the propulsion current, a relay comprising a movable member and two windings which windings are connected with the track circuit, and means comprising inductance and capacity included in the circuits of said windings for balancing the effect on the movable member of propulsion current in the windings, and for unbalancing the effect on the movable member of signaling current in the wind ings.

11. In a signaling system for electric railways the track rails of which are included in the circuit for the propulsion current, a source of alternating propulsion current, a track circuit, a source of alternating signaling current connected with said track circuit and differing in frequency from the propulsion current, a relay comprising a movable member and two windings, which windings are connected with the track circuit, and means comprising inductance and capacity in the circuits of said windings for balancing the flow of propulsion current and.

cuit and differing in frequency from the propulsion current, a relay comprising a movable member and two windings, which windings are connected with the track circuit and are arranged to tend to move the movable member in opposite directions, and means comprising inductance and capacity included in the circuits of said windings for balancing the flow of propulsion current and for unbalancing the flow of signaling current in the said windings.

13. In a signaling system for electric railways the track rails of which are included in the circuit for the propulsion current, a source of alternating propulsion current, a track circuit, a source of alternating signaling current connected with said track circuit and difiering in frequency from the propulsion current, a relay comprising a movable member of non-magnetic electro-conductive material and two windings, which windings are connected with the track circuit and are arranged to tend to move the movable member in opposite directions, and means comprising inductance and capacity included in the circuits of the said windings for balancing the flow of propulsion current and for unbalancing the flow of signaling current in the said windings.

Signed at Pittsburgh this 7th day of May, 30

LOUIS HENRY THULLFN.

Witnesses M. A. BUSHMAN,

F. N. BARBER.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, I). 0"

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