US1312407A - lewis - Google Patents

Description

L. V. LEWlS. RAILWAY 'CRGSSlNG SIGNAL AND CONTROL THEREOI.

APPUCATIUN HLEU AUG.2\. 9H5. 1 ,312,4:O7 Patented Aug. 5, 191-9.

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INVENTOR L. v. uzw s. RAILWAY CROSSING SIGNAL AND CONTROL THEREOF-f APPLICATION FILED AUG-2| IQIS- 1,312,407. Patented Au 5, 1919.

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PENNSYLVANIA, W

nan-waY-caos Specification of Letters I'atent.

A CORPORATION OF G 'SIGNAL CONTROL THEREOF.

Patented Aug. 5, 1919.

Application filed August 21, 1916. Serial No. 115,926.

To all whom it may concern:

Be itknown that I, LLOYD V. LEWIS a citizen of'the United States, residing at' Edge- Wood Borou h in the countyof Allegheny and State 0 ennsylvania, have invented certain new and useful Improvements in Railway-Crossing Si als andf Controls Thereof, of which the ollowing is a specification.

' My invention relates to warning signals for grade intersections of railways and highways, and the control thereof.

I shall describe one form of signal embodyingnmy invention, and then point out the novel features thereof in claims.

In the accompanying drawings, Figure 1 is a diagrammatic view showing one form of warning signal embodying my invention and one means for control ingthe signal, the signal being shown in the denergized osition. Fig. 2 is a diagrammatic view 5 owing he warning signal shown in Fig. 1 in a position wherein it indicates safety, together another form of apparatus and circuits embodyin my invention for the control of the signal: Fi 3 is a view showing the ratchet device by which blades 23 are attached to motor shaft 24:.

I Similar referencecharacters refer to simiso lar parts in each'of the views.

, Referring first to Figs. 1 and 2, the warningsi a1 here shown comprises a pendulum P having at its lower end a disk 5. The signal is located adjacent the rude intersection of a highway H and a rai way track T, the location of the signal being preferably such that the endulum P hangs over the middle of the highway'so-thatit is plainl visible by pedestrians or. occupants of vehic es using the highway. The pendulum P is the warn- 'I shall For operating the endulum I provide an induction motor M comprising windings 1 and 2, which motor may at times be operated by current supplied to one winding only, as oint out hereinafter. The rotor of is connected through reduction gearin 3 with a segmental gear 4 to which is fixe the armof pendulum'P. As thus far described, it follows that when motor M rotates in one direction or the other, the pendulum P swings in one direction or the other.

The force of gravity biasing the pendulum to the vertical position, may be augmented at times by means of a helical spring 7. Theupper end of this 5 ring is secured to a member 8 which is attac ed to the pendulum arm by a pin 8*, and the lower end of the spring is secured to a similar member 11 which is connected by a pin 11 to a bar 9,

motor front of the pendulum arm to permlt the pendulum to swing behind the spring. \Vhen the pendulum swin in either direction from the vertical position and bar 9 is held in the position shown in Fig. 1, spring 7 is stretched because the lower end of the spring is fixed, whereas the upper end of the s ring moves with the pendulum arm.

bus the spring biases'the pendulum to the vertical position as lon as bar 9 is held in fixed position. Bar 9 1s pivotally mounted at 9, and may be latched in the position shown in Fig. 1 by a latching pawl 10 pivoted on a fixed pin 10, which pawl is controlled by the armature 11 of a. magnet 12 in such manner that when the magnet is deenergized the free end of the awl 10 overhangs the free end of bar 9. he spring 7 pulls upwardly on bar 9 during each swing of the pendulum so that the free end of the bar engages the pawlwhen the pendulum swings in either direction from the vertical, the normal length of the spring being such that when the pendulum hangs vertically, the free end of bar 9 is a small distance below the lower end of pawl 10, as shown in Fig. 1. \Vhen magnet 12 is energized, the pawl 10 is turned to the right so that the bar 9 when pulled by spring 7 is free to turn upwardly, so that spring 7 is not stretched when the pendulum swings away from the PENNSYLVANIA, ASSIGNOR TO 'UIl'ION vertical position and is therefore unable to zonta the pendu um in the horizontal position,-

which retaining means may be of any suitabletype. The means I have shown in the drawing comprises blades 23 extending radially from a disk-25 (see Fig. 3) mounted to rotate freely on shaft 24 of motor M. Pawls 25 on disk 25 are biased to enga e a ratchet wheel 24 fixed tomotor shaft 2 A roller 22 mounted on the free end of a lever 21 actuated by the armature of an electromagnet is brought into the ath of springs 23,

when the pendulum is in t e safety position, shown in Fig. 2, preventing clockwise rotation of the motor shaft so that the pendulum is caused to remain in the horizontal position. That is, the ratchet device is so arranged that the pendulum may swing in counter-clockwise direction without causing rotation of disk 25, but that when the pendulum swings in the other direction the disk must move with it, whereby in the latter case if the roller is in the path of the blades the pendulum is locked.

A relay R is provided for the control of motor M and magnets 12 and 20, which relay is responsive to the approach of railway cars or trains to the highway crossing. As shown in Fig. 1, relay R is controlled by the track circuit of a section of track a-b adjacent the intersection of the highway and the railway, this control (well understood in the art) being such that relay R is energized or denergized according as the section is unoccupied or occupied.

Alternating current for operating the motor M and electromagnets 12 and 20 is furnished by a transformer N supplied from an alternator not shown on the drawing.

For a description of the operation of the signal I shall first assume that the section of track 01-5 is unoccupied so that relay R is energizedfand that hand switch S is open as shown in Fi 1 so that the motor M and magnets 12 an 20 are denergized, allowing pendulum P to hang in the vertical position because of its bias.

When switch S is closed, relay R remaining energized, the pendulum is moved to the horizontal position by the motor M. The

circuit for winding 2 of the motor is as follows: from transformer N, through switch S, wire 26, winding 2, wire 38, electromagnet 12, wire 32, contact 33, contact segment 33 on gear 4, contact 33, wire 34,-, contact 35-36 of relay R, and wire 37 to transformer N. The current in this circuit energizes,

therefore, not only winding 2, but also electromagnet 12, which magnet closes at contact 28-31 the following circuit for motor windin g 1: from transformer N, through switch wire 26, winding 1, wire 27, contact 28-31 of magnet 12, wire 32, contact finger 33', segment 33", contact finger 33, wire 34, contact 35-36 of relay R, and wire 37 to transformer N. Because of the inductance of magnet 12 in series with winding 2, the current in winding 2 lags behind the current in winding 1, so that motor M has two-phase action and turns counterclockwise, moving pendulum P to the horizontal position shown in Fig. 2. This movement of the pendulum is not opposed by spring -7 because magnet 12, being energized,- has withdrawn latch 10 from the path of bar 9. Motor M and magnet 12 are deenergized by the disengagement of finger 33" from segment 33 just before the pendulum reaches the horizontal position, but the inertia of the moving parts 15 sufiicient to carry the pendulum far enough to cause segment 33" to close at contact 33' the circuit for the holding magnet 20, which circuit is as follows: from transformer N, through switch S, wires 26 and 42, magnet20, wire 43, contact finger 33", segment 33", contact finger 33, wire 34, contact 35-36 of relay R, wire 37 to transformer N. The motor is at this time rotatin counterclockwise, so that one of the bla cs 23 engages the left side of roller 22 when the electromagnet lifts the roller into the path of the blades, causing the ratchet t'o sli until the motor comes to a standstill an. begins to turn in the opposite direction, due to the weight of the pendulum. A third of a revolution of the 'motor brings another blade 23 into contact with the right side of roller 22, as shown in Fig.2, whereupon the ratchet prevents further clockwise rotation of the motor, locking pendulum P in the safety position, as shown in F ig. 2.

When the signal is in this position, if a train approaches the. highway crossing in the direction of the arrow (Fig. 1) and enters section o-b, relay and opens at contact 35-36 the circuit for holding magnet 20, so that the roller 22 drops out of engagement with the blade 23 and ermits the motor to be turned olockwise y the force of gravity actin on the pendulum P. The relay R- has in t e meanwhile closed at its back contact 39 the following circuitfor winding 1 of motor M: from trgnsformer Ngthrough switch S, wire 26, winding, 1 of motor M, wire 27, contact 28-29, wire 30, contact 39-36 of relay R and wire 37 to transformer N. Winding 2 remains deiinergized. Motor M, therefore, has single-phase action, and exerts torque in the dlrection in which it is rotated by the swing of the pendulum, as soon as the endulum has accelerated it to the pic -up speed. As the pendulum passes the vertical position bar 9 is caught under the latching R is denergized finger 10 of the magnet 12 because this magnet is now denergized so that spring 7 1s stretched as the "pendulum continues its swing toward the left. The motor now drives the endulum against the force of gravity and the spring tension, both of which continue to increase until the motor is stalled in some position such as indicated by the dotted line :0 in Fig. 1. The biasing forces on the pendulum then drive the pendulum and the motor in the reverse direction. The motor is soon brought up to the pick-up speed and again exerts its torque in the (11- rection in which it has been started, until it is a The again stalled, in similar manner when the pendul um reaches a position suchas y. In-

this manner the pendulum P is caused to swing back and forth from w to y to give the danger indication while there is a car or train in section (1-6.

When the car or train asses ofl' this'section, relay R is reiinergized, o ening the last-mentioned circuit for wmdmg 1, and closing the circuits hereinbefore described for magnet 12 anbboth windings of motor M. The pendulum -is then driven to and held in the horizontal position, as hereinbefore explained, so that the signal again gives 'the safet indication.

In case of failure of the power supply for transformer N or in case of derangement of some portions'of the apparatus, the pendulum falls to the vertical position due to its bias, and remains there, no matter whether ornot a train is approaching the crossing.

endulum hanging vertically is a danger indication, separate and distinct from the warning given by the pendulum when oscillating, and serves to inform users of the highway that the signal is out of order, and to caution such persons to ascertain for themselves whether or not a train is approaching.

Referring now to Fig. 2, the signal controlling apparatus here shown comprises a track 'trcadle 50,1ocated a distance in the rear of the crossing, This treadle is adapted to be operated by the wheel flanges of a passi car or train, and governs a contact 51 which controls the circuit of relay R, as I shall describe hereinafter. A cam 52 is caused to oscillate with pendulum P, being fixed to the pivotal shaft therefif, as indicated diagrammatically by a dotted line. Springs 53 and 54 are biased to follow the cam surface, the former of these constituting part of a contact 55 and the-latter one operating a ratchet wheel 56. The shape 1f cam 52is such that at the end of each swir g of the pendulum from right to'left, contact spring 53 engages contact 55 and each swi 1g of the pendulum in the reverse direction advances ratchet 56 one tooth. A cam 58 is fixedto ratchet wheel 56 and controls a c mwire 61, relay R, wire 66, contact 67, wire 65, contact 51, to battery 60. From these C11- cuits it is apparent that for the energizetion of relay R, both of the cam-controlled contacts on the signal must be closed as well as the treadle controlled contact 51,

whereas, once energized, this relay remains closed by current flowing through its own contact 67, until the hoiding circuit is broken-by the opening of treadle contact 51.

For a description of the operation of the signal with the controlling apparatus shown in Fig. 2, I shall assume at the outset that relay R is energized by current in its holdin circuit, so that the pendulum P is in the sa ety position as hereinbefore explained.

When a train approaching the crossing operates treadle 50, contact 51 opens the holding circuit of relay R, whereupon this relay opens contact 35-36 and closes contact 36-39, so that the signal begins to oscillate as hereinbefore described, indicating thereby the approach of the train to the crossing. As soon as the train has passed the tread 50, contact 51 closes but relay R remains'deenergized because its pick-up circuit is open at the "cam-controlled contacts 53-55 and 59-57. The former of these is closed at every swing'of the pendulum to the'left, but the latter remains open until the pendulum has oscillated a predetermined number of times, according to the number of teeth on ratchet wheel 56. After the said number of oscillations, the contact 57-59 closes, during a swing of the pendulum from left to right,

and during the next reverse swing of the opened. Relay B is now held closed through the holding circuit as hereinbefore explained,

and the signal apparatus is again in the position assumed. at the outset.

It will be noted that the pendulum is caused to oscillate for a definite length of time after a train passes treadle 50, and the distance of this treadle from the crossing and the number of teeth in the ratchet with each stroke of' the pendulum should be relatively so proportioned that for trains of average speed the danger indication continues until the train reaches the crossing.

Although I have herein shown and described only one form of signal embodying my invention and certain arrangements of apparatus for the control thereof, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is: r

1. A railway crossing signal com rising a warning member mounted to osci late and .biased to an intermediate position, an induction motor capable of operation in either direction on current supplied to one winding only thereof, and means interposed between the rotor of said motor and said -warning member for positively connecting the two, said arts being so proportioned that as said mem r approaches said intermediate osition it causes the motor to rotate at pic -u speed and that the biasing force on sai member overbalances the motor torque after the member passes said intermediate position whereby the operation is then reversed.

2. A railway crossing si al comprising a member mounted to oscilla e, and an induction motor operatively connected to said member, said motor comprising two windings, one for maintaining oscillations of said member to give a danger indication, and the other for coasting with said first winding to move said member away from its middle position to give a safety indication.

3. A railway crossmg signal comprising a member mounted to oscillate, an induction motor having a plurality of windingsifor driving the member to a safety position, and

means or energizlng at times a single winding of said motor to maintain the oscillation of said member to indicate danger.

4. A railway crossing si :11 comprising a member mounted to oscil ate, single base means for oscillating the member to in icate danger and polyphase means for actuating the member ton safety position.

5. A railway crossing signal comprising a member mounted to oscil ate, single base means for oscillating the member to in icate danger and polyphase means for actuating the member to a safety position, and means for retaining said member in the safety pdsition.

6. A railway crossing signal comprising a member mounted to oscillate, and an induction motor operatively connected to said member, said motor compris' two windings, one ior causing oscillation of said member to give a den r indication, and another for coacting wit said first winding to drive said member to a safety position, and

means for retaining said member in the safety position, said means comprising a latch and an electromagnet for operating when in one position and to indicate danger when oscillating about another position, resilientmeans for limitin the angle of oscillation of said member 9. out the last mentioned position, and means for at times rendering said resilient means inefl'ective in its control of said member in order to permit movement of said member to said safety position.

8. A railway crossing signal comprising a pivoted member adapted to indicate safety when in one sition and to indicate danger when oscillating about another position, resilient means for limiting the angle of oscillation of said member about the last-mentioned position, a latch for at times. rendering said resilient means ineffective in its control of said member, and an electromagnet for controlling said latch.

9. A railway crossing signal, comprising a pivoted member adapted to indicate safety when in one position and to indicate danger when oscillating about another position, resilient means for limiting the angle of oscillation of said member about the lastmentioned position, a motor for driving said member beyond said limited angle of oscillation to the safety position, electrom etic means for renderin when energize said resilient means ine ective in its control of said member, electromagnetic means for retaining when energized said member in the safety position, and circuits controlled by said member for deiinergizing said motor and said first-mentioned electron] etic means and for energizing said retaining means when said member reaches the safety position.

10. A railway crossing signal comprising a. member mounted to oscillate, single phase means for oscillating the member about one position to indicate danger, resilient means for limiting such oscillation to a given angle, lyphase means for actuating the member biiyond said angle of oscillation to the safety sition, electromagnetic means for rendermg said resilient means inoperative in its control of the member, and electromagnetic means for retaining said member in the saflety osition.

1. a member inounted to oscillate, an induction motor operatively connected to said member,

and comprising a single winding for oscillating said member about one position-to indicate danger and a plurality of windings for driving said member to another position to indicate safety, resilient means for biasing said member to said first-mentioned porailway crossing signal comprising 7 sition, a latch for rendering said resilient means ineflective to bias said member, an

I electromagnet for controlling said latch, and

, connected with the rotor of said motor, and

means for at times energizing one winding and at other times both windings of motor.

13. A signal comprising an induction motor having two stator windings, a member mounted to oscillate and biased to a middle position and operatively connected with the rotor of said motor, means for energizin both windings of said motor to move said member away from its middle position, and means for energizing one winding only to cause said member to oscillate.

14. A railway crossing signal comprising a. member mounted to oscillate and biased to an intermediate position by gravity, normally active mechanical means for increasing the force biasing said member to said position, an induction motor having two stator windings and'having a rotor operatively connected with said member, and means for at times energizing only one winding of said motor and for at other times energizing both windings of said motor and rendering said mechanical means inactive.

15. A railway crossing signal comprising an induction motor having two stator windings", ainember mounted to oscillate and operatively connected with the rotor of said motor, a source of alternating current, two

said

,relays 12 and R; a circuit for one motor winding including said source, the winding of relay 12 and a front contact of relay R; a circuit for the other motor winding including a front contact of relay 12 and a front contact of relay R and said source, and a branch for said latter circuit around the said relay contacts and including a back contact of relay 12 and a back contact of relay R. 16. A railway crossing signal comprisin a member mounted to oscillate and biase b gravity toian intermediate position, mechanical means for increasin the force biasing said member to said position, an induction motor havin the rotor of sai motor being operatively connected with said member, a source of alternating current and two relays R and 12; a circuit for one motor winding including said source, the winding of relay 12 and a front contact of relay R a circuit for the other motor winding including a front contact of relay 12 and a front contact of relay R, a branch for said latter circuit around said relay contacts and including a back contact of relay 12 and a back contact of relay R, and means controlled by the armature of relay 12 for rendering said mechanical means operative or inoperative according as the relay is deenergized or ener ized. a

n testimon whereof I aflix my signature in presence 0 two witnesses.

LLOYD V. LEWIS. Witnesses:

A. HERMAN WEGNER, IETHEL C. DURHAM.

two stator windings and-

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