US2129822A - Apparatus for controlling highway crossing signals - Google Patents

Description

' Sept. 13, 1938. w, H, CLAUS 2,129,822

APPARATUS FOR CONTROLLING HIGHWAY CROSSING SIGNALS Original Filed March 5, 1956 2 Sheets-Sheet l i L, r i

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12 1" a i a 15 {,14 .13 4 15 144 INVENTOR William Claw.

HIS ATTORNEY Sept. 13, 1938. w. H. CLAUS APPARATUS FOR CONTROLLING HIGHWAY CROSSING SiGNALS Original Filed March 3, 1956. 2 Sheets-Sheet 2 INVENTOR William H laar.

HIS ATTORNEY mally moves in both directions.

Patented Sept. 13, 1938 UNITED STATES PATENT OFFICE APPARATUS FOR CONTROLLING HIGHWAY CROSSING SIGNALS Original application March 3, 1936, Serial No.

66,835. Divided and 1937, Serial No. 146,

6 Claims.

I shall describe one form of apparatus em- 4 bodying my invention, and shall then point out the novel features thereof in claims.

In the accompanying drawings, Fig. 1 is a diagrammatic view showing one form of apparatus embodying my invention. Fig. 2 is a view, partly diagrammatic and partly in isometric projection, showing the mechanical construction of the relay R shown in Fig. 1.

Similar reference characters refer to similar parts in both views.

Referring first to Fig. 1, the reference characters 32 and 33 designate the track rails of a stretch S of railway track over which traffic nor- The rails 32 and 33 are divided, by means of insulated joints 34, to form three adjacent track sections DE, E-F, and F-G, the middle section E F being relatively short and being intersected by a highway H.

Associated with the track sections DE, E-F, and F-G is a track relay R which, as best seen in Fig. 2, comprises three electromagnets A, B, and C mounted end for end on a top plate I of suitable insulating material, such for example, as a phenol condensation product. The electromagnets A, B, and C are similar, and the corresponding parts of each are designated by the same reference characters with the distinguishing exponents a, b, and added thereto. It is believed, therefore, that a description of one electromagnet will suffice for all. Referring particularly to the electromagnet A, this electromagnet comprises two parallel cores 2 connected together at their upper ends by a back-strap 3 and provided at their lower ends with enlarged pole pieces 4 located on the underside of the top plate I. The cores 2 each carry a winding or coil 5 which windings are intended to be connected in series in the usual and well-known manner.

A non-magnetizable bracket 6 is attached to the rear sides of the pole pieces 4*, and pivotally supported on trunnion screws l mounted in depending lugs 8 provided on the ends of the bracket 6 is a tractive armature 9 which carries a plurality of contact fingers Ill H H and B When the electromagnet A is energized, the armature 9 is drawn upwardly to the position in which it is shown in the drawings, and under this application June 3, 237

these conditions the contact fingers [0 H l2 and I3 each engage an associated fixed contact member M to close front contacts lil l4 Il -4 1 l2 M and I3 -i l When, however, the electromagnet A is deenergized, the armature 9 drops downwardly under the influence of gravity, and except under certain conditions which will be described hereinafter, the contact fingers le H 82 and w then each engage an associated fixed contact member [5 to close back contacts I0 l5 Il -45 l2 --l5 and Mi -45 The contact fingers Ill li l2 and w are secured to the armature 9 by means of insulating supports Hi and it will be apparent, therefore, thatthese contact fingers are insulated from the armature and from each other.

The electromagnets l3 and C control armatures 9 and 9, respectively, which armatures are pivotally supported in a manner similar to the armature 9 andeach of which carries contact fingers which cooperate with fixed front and back contact members to close front and back contacts in the same manner that the contact fingers Ill Il I2 and I3 carried by the armature 9 co operate with fixed front contact members I l and back contact members I 5 to close front and back contacts.

The armatures 9 and 9 are interlocked by interlocking mechanism comprising two arms 36 and 3l which are attached, respectively, to these armatures, and which cooperate with a locking dog I1 pivotally mounted on a shaft I8 The dog I'l is provided, with a horizontal arm I9 and a vertical arm 26 and is biased to rotate, in a counterclockwise direction, to an inoperative position in which the vertical arm 20 engages a stop arm 38 by a counterweight M which is secured to the outer end of the horizontal arm N3 The inner end of the arm I9 is provided with an upstanding projection 22 which cooperates with a resilient strip 23 attached to the interlocking arm 3| When the armature 9 is released and drops, the flexible strip 23 engages the projection 22 of the horizontal arm I9 of the dog il shortly after the armature passes its mid-stroke position, and during the remainder of the downward stroke of the armature, the dog I'l is rotated in a clockwise direction, in opposition to the bias exerted by the counterweight 2 I to an operative position in which the upper end of the vertical arm 26 is in the path of downward movement of an offset portion 24 forming a part of the arm 30 If armature 9 is then released, the downward movement of this armature will be limited by engagement of the offset portion 24 with the upper end of the vertical arm 20 The parts are so proportioned that when the oifset portion 24 engages the vertical arm 20 in this manner, the armature 9a will be held at approximately its mid-stroke position, and both the front and back contacts controlled by the armature 9 will then be open. Furthermore, when the offset portion 24 engages the vertical arm 20 in this manner, a tip 25 formed on the end of a retaining spring 26 attached to the arm 30 extends downwardly past the outer edge of the upper end of the vertical arm 20 thus holding the dog in place underneath the ofiset portion 24 and thereby insuring that armature 9 cannot move to the position in which it back contacts are closed. When electromagnets A and B again both become energized, so that the armatures 9 and 9 are both moved to their upper positions, the counterweight 2l returns the dog H to its inoperative position against the stop rod 38 in which position the vertical arm 20 is out of the path of movement of the offset portion 24 If armature 9 is released and drops before armature 9 the offset portion 24 will move downwardly past the upper end of the arm 20 of the dog I'l but the tip 25 of the retaining spring 26 will engage the upper end of the arm 20 The retaining spring 26 however, is very flexible, and it will be apparent, therefore, that it will offer very little resistance to the downward movement of the armature 9 so that the armature will close its back contacts under these conditions with substantially the same contact pressure as would be the case if the interlocking arm 30 were not attached to the armature.

The armatures 9 and 9 are interlocked by interlocking mechanism which is similar in all respects to, and which operates in the same manner as, that just described for interlocking the armatures 9 and 9 The various parts of the mechanism for interlocking the armatures 9 and 9 are designated by the same reference characters as the corresponding parts of the mechanisms for interlocking the armatures Q and 9 but with the exponent 2 added, and it is believed, therefore, that a detailed description of the mechanism for interlocking the armatures 9 and 9 is unnecessary.

It should be pointed out that the dogs I1 and I! are very light in weight and are loosely pivoted on the associated shafts I8 and I8 so that the force required to drive these dogs is small. The flexible strips 23 and 23 need only be stifi enough to drive the dogs I1 and I! without causing deflection of the strips, and it will be apparent, therefore, that these strips may be constructed to bend under sufiiciently small pressures so that they will not prevent the armature 9* from closing its back contacts even though one of the dogs I1 or H is prevented from rotating to its full operative position due to the armature 9 or the armature 9 having previously been released. If desired, back-stops 28 and 28 of rigid material may be provided to determine accurately the position at which the strips 23 and 23 will engage the associated dogs I1 and I! during the downward stroke of the armature 9 Furthermore, topstops 29 and 29 may also be provided with clearance above the strips, so that if some unusual resistance to the movement of the dogs should develop that would cause abnormal deflection of the strips 23 and 23 the associated topstop 29 or 29 would engage the strips and would limit the amount of deflection of the strips so that the corresponding locking dog would still be driven into the path of movement of the associated offset portion 24 or 24 and past the tips 25 and 25 of the retaining springs 26 and 26 It will be seen that with a relay constructed in the manner described, if either electromagnet A or electromagnet C becomes deenergized before electromagnet B, the armature 9 or the armature 9, as the case may be, will drop to its lowermost position in which the associated back contacts are closed, but that, if either electromagnet A or electromagnet C becomes deenergized subsequently to electromagnet B, the armature 9 or the armature 9, as the case may be, will be prevented from dropping past the position in which the associated front and back contacts are all open.

Referring now again to Fig. 1, section D-E is provided with a track circuit comprising a battery 35, connected across the rails adjacent the end of the section which is farthest away from the highway H, and the magnet C of interlocking relay R connected across the rails, at the end nearest the highway H, in series with front contact l -M of relay R Section F-G is provided with a similar circuit which includes a battery 36, the rails of the section, magnet A of relay R and front contact I l l 4 of relay R Section EF is provided with a track circuit which includes a bat tery 31 connected across the rails at one end of the section, and the magnet B of relay R connected across the rails at the other end of the section.

A signal L which, as here shown, is an electric bell, is located adjacent the intersection of the highway H and the stretch S, and this signal is provided with a circuit which includes a battery J and back contacts B -l5, l3 l5 and I3-I5 of relay R connected in parallel. It will be apparent, therefore, that when all of the back contacts l3 l5 |3 -l5 and l3l5 are open, the bell L will be silent, but that, when any one of these contacts is closed, the bell L will ring.

The operation of the apparatus shown in Fig. 1 as a whole is as follows: When a train moving from right to left enters section F-G, the train shunt will cause magnet A to become deenergized, and back contact I3=-I5 of relay R will therefore become closed and will cause bell L to start to ring. When the train enters section E-F, magnet B will become deenergized and will cause the front contacts of relay R controlled by this magnet to open and the back contacts controlled by this magnet to become closed. The opening of front-contact i ?l4 will interrupt the circuit for magnet A, and will thus cause magnet A to remain deenergized as long as magnet B remains deenergized. The opening of front contact Ni -M will interrupt the circuit for magnet C, and will thus cause magnet C to also become deenergized. The energization of this latter magnet will cause the front contacts of relay R controlled thereby to open, but the back contacts controlled thereby will remain open due to the interlocking mechanism. The closing of back contact l3 --l5 will close the circuit for bell L at this Contact, but since the circuit for bell L is already closed at back contact l3 l5 the closing of back contact |3 -|5 will have no eifect of the remainder of the apparatus. As the train continues to traverse the stretch S, no further change in the apparatus will take place untilthe rear end of the train clears section E-F. When this happens, magnet B will become energized and will cause the back contacts controlled thereby to open and the front contacts controlled thereby to close. The closing of front contact li -44 will restore the circuit for magnet A, while the closing of front contact NF -l4 will restore the circuit for magnet C. Magnet A will then pick up and open its back contacts and close its front contacts, but magnet will remain deenergized due to the train shunt. When back contact I3 -l opens, back contacts i3 -|5 and l3--l5 will both be open, and as a result, the circuit for bell L will become interrupted, so that the bell will stop ringing. When the train departs from section D-E, magnet C will become energized and will cause the front contacts controlled thereby to become closed. All parts of the apparatus will then be restored to the positions in which they are shown in the drawings.

When a train traverses the stretch S from left to right, the operation of the apparatus is similar to that just described, and it is believed that this operation will be apparent from the foregoing description and from an inspection of the drawings without further detailed description.

It will be seen from the foregoing that a train approaching the crossing H in either direction will cause the bell L to start ringing as soon as the train enters either section D-E or F-G, and the bell will continue to ring until the train has completely passed section EF.

It will be noted that as shown in the drawings the magnets A and C are slow releasing magnets. The reason for making these magnets slow releasing is to insure that the armatures controlled by these magnets will not drop quickly enough to cause the interlocking apparatus to fail to function when either of these magnets becomes deenergized due to the previous deenergization of magnet B. The relay will, however, usually function in the proper manner when the magnets A and C are of the ordinary acting type.

It should also be noted that since the .deenergization of magnet B causes the circuits for both magnets A and C to become interrupted, back contact |.'-l' *l5 or back contact I3-l5 will always be closed when contact l3l5 is closed, and as a result, the bell L will function in the manner described Whether or not contact I3 -I 5 is included in the circuit for bell L, the only reason for including this contact in the circuit for bell L being to provide an additional degree of protection against improper operation of the apparatus.

One advantage of controlling a highway crossing signal in the manner described above is that the directional selection for cutting off the operation of the highway crossing signal is made at the crossing proper, thus eliminating circuit lockouts due to train movements in sections D-E and F-G. This is particularly desirable where a switch is located in either section D-E or section FG, since the reversal of the switch while a train is in the other section, or the entry of a train into the other section while the switch is reversed, will not prevent a warning from being given at the crossing as long as the train has not proceeded past the crossing to the position in which it clears section EF.

Although I have herein shown and described only one form of apparatus embodying my invention, 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:

1. In combination, a stretch of railway track divided into first, second, and third consecutive track sections, a highway intersecting said second section, an interlocking relay comprising first, second, and third armatures controlled by first, second, and third electromagnets, respectively, said armatures being interlocked in such manner that movement of said second armature away from said second electromagnet restricts the subsequent movement of said first and third armatures away from said first and third electromagnets, a source of track circuit current connected with each of said track sections, means for connecting said second magnet with said second section, means for connecting said first and third magnets with said first and third sections when and only when said second magnet is energized, and a highway crossing signal located adjacent the intersection of said highway and said stretch and controlled by said interlocking relay.

2. In combination, a stretch of railway track divided into first, second, and third consecutive track sections, a highway intersecting said second section, an interlocking relay comprising first, second, and third armatures controlled by first, second, and third electromagnets, respectively, said armatures being interlocked in such manner that movement of said second armature away from said second electromagnet restricts the subsequent movement of said first and third armatures away from said first and third electromagnets; a source of track circuit current connected with each of said track sections, means for connecting said second magnet with said second section, means for connecting said first and third magnets with said first and third sections when and only when said second magnet is energized, a highway crossing signal located adjacent the intersection of said highway and said stretch, and a circuit for said signal including a back contact controlled by said first armature connected in multiple with a back contact controlled by said third armature.

3. In combination, a stretch of railway track divided into first, second, and third consecutive track sections, a highway intersecting said second section; an interlocking relay comprising first, second, and third armatures movable toward and away from first, second, and third electromagnets, respectively, and each provided with front contacts which are closed when and only When such armature is moved toward its associated electromagnet and with back contacts which are closed when and only when such armature is moved its full stroke away from its associated electromagnet, said first and third armatures being mechanically interconnected with said second armature in such manner that said first and third armatures are prevented from moving their full strokes away from the associated electromagnets if said second armature is first moved away from said second electromagnet, a track circuit for said first section including said first magnet and a front contact controlled by said second magnet, a track circuit for said second section including said second magnet, a track circuit for said third section including said third magnet and a front contact controlled by said second magnet, and a highway crossing signal located adjacent the intersection of said highway and said stretch controlled by back contacts of said magnets.

4. In combination, a stretch of railway track divided into first, second, and third consecutive track sections, a highway intersecting said second section; an interlocking relay comprising first, second, and third armatures movable toward and away from first, second, and third electromagnets, fespectivelyQand each provided with front contacts which are closed when such armature is moved toward its associated electromagnet and with back contacts which are closed when and only when such armature is moved its full stroke away from its associated electromagnet, said first and third armatures being mechanically interconnected with said second armature in such manner that said first and third armatures are prevented from moving their full strokes away from the associated electromagnets if said second armature is first moved away from said second electromagnet, a track circuit for said first section including said first magnet and a front contact controlled by said second magnet, a track circuit for said second section including said second magnet, a track circuit for said third section including said third magnet and a front contact controlled by said second magnet, a highway crossing signal located adjacent the intersection of said highway and said stretch, and an energizing circuit for said signal including a back contact controlled by said first armature connected in multiple with a back contact controlled by said third armature.

5. In combination, a stretch of railway track divided into first, second, and third consecutive track sections, a highway intersecting said second section; an interlocking relay comprising first, second, and third armatures movable toward and away from first, second, and third electromagnets, respectively, and each provided with front contacts which are closed when such armature is moved toward its associated electromagnet and with back contacts which are closed when and only when such armature is moved its full stroke away from its associated electromagnet, said first and third armatures being mechanically interconnected wth said second armature in such manner that said first and third armatures are prevented from moving their full strokes away from the associated electromagnets if said second armature is first moved away from said second electromagnet, a track circuit for said first section including said first magnet and a front contact controlled by said second magnet,

a track circuit for said second section including said second magnet, a track circuit for said third section including said third magnet and a front contact controlled by said second magnet, a highway crossing signal located adjacent the intersection of said highway and said stretch, and an energizing circuit for said signal including a back contact of said first armature connected in multiple with a back contact of said third armature and a back contact of said second armature.

6. In combination with a stretch of railway track which is crossed by a highway and divided into three consecutive sections the central of which includes the length of track which said j crossing embraces; a protective signal associated with said crossing; an interlocking relay comprising three electromagnets, an armature which moves towards each of said magnets when the magnet is energized and away therefrom when the magnet is deenergized, interlocking means which prevent the first and third of said armatures from moving their full strokes away from the first and third of said magnets if the second armature is first moved away from the second magnet, a back contact operated by said first armature, a back contact operated by said third armature, and two front contacts operated by said second armature; means for supplying track circuit energy to the rails of each of said sections;

a circuit through which the second magnet of said relay is at all times connected to the rails of said central track section; a circuit including one of said front contacts of the relay through which said first magnet of the relay is connected to the rails of one of said two remaining track sections only when said second winding is energized; a circuit including the other of said front contacts through which said third magnet of the relay is connected to the rails of the third track section also only when said second winding is energized; and a circuit including said two back contacts of the relay through which said crossing signal is supplied with operating energy whenever either of said first and third armatures 4

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