US2053704A - Rail fissure detector car - Google Patents

Description

Sept 8, 1936 H. C. DRAKE ET AL RAIL FISSURE DETECTOR CAR Filed July 14, 1934 0.1. VOLTAGE 3maentors Ha rcawi: wake Fwd raddan Gtto neg Patented Sept. 8, 1936 UNITED STATES PATENT OFFICE RAIL FISSUBE DETECTOR CAR Application July 14, 1934, Serial No. 735,100 9 Claims. (01. 177-311) This invention relates to rail fissure detector cars adapted to travel over the rails in track and detect and mark for identification those rails having fissures or other internal defects. More particularly, the invention relates to the type of fissure detector mechanism embodied in the Sperry rail fissure detector cars. In said cars, the railis energized, as the car travels along the track, by means of current passed therethrough to set up an electromagnetic field surrounding the rail, and any irregularities in said field due to internal defects are detected by means of a plurality of induction coils carried at a fixed distance above the rail. On entering a region of fiaw one 01' said coils will cut a different number of lines of force from the other coil and this will generate a differential E. M. F. which after being suitably amplified may be caused to operate one or more indicating means. Such indicating means in the Sperry cars take the form oi! one or more pens operating on a travelling chart to make a record thereon and also one or more paint guns for marking the location of the fissure in the rail and marking the general location of the flssured rail in track. The rail-and-track-marking means should possess diflerent characteristics. The rail-marking means should make a short paint mark as nearly as possible'at the exact location of the fissure, while the track-marking device should make a relatively large mark in the center of the track on the ties and road-bed between the rails.

This invention has for its principal object the provision of means for insuring constant operation of the rail-marking means so that regardless of the degree 01' fissure or the extent of the induced E. M. F. caused by the fissure, the mark placed upon the rail in the vicinity of the defect will be relatively short and always or the same size.

It is a further object of our invention to provide a novel arrangement for insuring operation of the road-bed-marking means whenever the rail-marking means is actuated.

Further objects and advantages oi. this invention will become apparent in the following detailed description thereof.

In the accompanying drawing,

Fig. 1 is a side elevation of a portion of a Sperry rail flaw detector car having our invention embodied therein.

Fig. 2 is an electric wiring diagram illustrating the principle involved in our invention.

Referring to Fig. 1 of the drawing, there is disclosed a portion of the car body ll of a Sperry rail fissure detector car, from which is suspended the detector mechanism consisting essentially of a current brush carriage ll having sets of current brushes l2 and I3 for supplying current to the rail from a generator G mounted within the car body. This sets up an electromagnetic field surrounding the rail and said field will be homogeneous except in the region of fiaw, where it will be distorted. Such distortion may be detected by means of a pair 01' induction coils l4 supported on a carriage l5 at a constant distance above the o railhead so that on encountering a region of fiaw, first one and then the other 0! said coils will out a different number of lines 01' force to generate a difi'erential E. M. F. which after being amplified by an amplifier A may operate a pen P on a chart, not shown, to give an indication of the presence of a flaw. Said pen P may be operated from the amplifier A by causing the output 01 said amplifier to energize a coil 20 to attract an armature 2| and break a set of contacts 22 controlling the circuit of pen coil 23. The detector carriage l5 may be supported on the rail by means such as rollers 25 and said carriage may be mounted on the current brush carriage H by means such as loosely fitting bolts 26 and springs 21, whereby said detector carriage may adjust itself to the variations in surface of the railhead. The current brush carriage H may be supported on the rail by means such as wheels 28. Said current brush carriage is normally held in elevated position by means of cables 29 and springs, not shown, but when said carriage is to be lowered into engagement with the rail, fluid pressure is supplied to cylinders 30 to depress pistons 3| which are pivotally connected to and support the carriage 30 I i.

At the same time that the impulse from amplifier A actuates the pen P, it also operates rail-marking means in the form of a paint gun 40, and roadbed-marking means in the form of a paint gun 4|. This is accomplished by means of a relay l2 controlling a paint supply valve 43 which in turn controls the supply of paint passing through rail-marking means It and a relay 4 controlling valve 45 which in turn con- 40 trols the supply of marking fluid passing through gun ll. These paint gun relays 42 and N are connected in circuit with pen coil 23 in such manner that regardless of the input to amplifier A the paint gun 40 will be actuated to a constant to and predetermined limited degree and, secondly, the paint gun 4| will be actuated whenever paint gun 40 is actuated.

Referring to the wiring diagram of Fig. 2, I have illustrated a method for obtaining a constant, predetermined, limited energization oi paint coil 42 regardless of the input to amplifier A or the extent of energization or de-energization of pen coil 23. For this purpose, I cause the opening of contacts 22 and consequent deenergization of pen coil 23 to induce by means of induction coils 41 and 48 a potential which is impressed upon the grid 50 of a gaseous discharge tube 5l. Said grid 50 is normally connected to the negative side oi a battery 52 and as 50 long as it is negative to a predetermined degree no current will pass through the tube, in ac-- cordance with the well known principles governing the operation of this tube. When, however, a potential is impressed upon the grid 50 to render the same less negative, current from the D. C. voltage source is permitted to flow between the anode 53 and cathode 54 of said tube to energize the coil 42 and charge a condenser 55 which is in the said D. C. circuit. The flow of current through said tube will charge condenser 55 not only to a voltage equal to the voltage of the D. C. source of supply, but to a higher voltage by reason of the inductance of coil 52. This excess voltage impressed on condenser 55 will cause the current to cease flowing through the tube and thus de-energize paint coil 62. It will thus be seen that only for the brief interval during which the current surges through the gaseous discharge tube and charges condenser 55 will paint coil 42 be energized, and it will be further seen that the time of energization will be constant each time that the above described action takes place, so that we are enabled to obtain a brief actuation of the paint coil which will r wult in a short, well-defined paint mark on the rail, of constant length, at each actuation of the paint gun 50.

As soon as the current through tube 5! has ceased to flow, it is desirable that the condenser 55 be discharged quickly in order that the device shall be ready for another actuation in response to the presence of a flaw. Ordinarily, the condenser 55 has shunted across it a high resistance 56 so that the current may gradually leak ofi said condenser. This, however, takes too long an interval of time for rail testing purposes, since the car travelling along the rails may encounter another fissure within a very short interval of time after finding one fissure. We have therefore provided the following novel arrangement for quickly de-energizing condenser 55. For this purpose there is provided a shunt circuit around condenser 55 which includes lead 55, coil M of a polarized relay, and lead 65. When condenser 55 begins to discharge, current flows through the shunt circuit in the direction of arrow B and will energize coil BI to act upon its core 62 and close a circuit between contacts 55 and to impress a voltage from the D. C.

voltage source upon a grid 66 of a triodevacuum tube 61 which is in a shunt circuit by way of anode 68 and conductor 69 around condenser 55. Said tube normally is of high resistance, while the condenser 55 is charging, but as soon as coil 6| is energized to close contacts 63 and 64 and a potential is impressed upon grid 66, the resistance of tube 61 is immediately lowered so that the condenser 55 may discharge through the said shunt circuit. Thus the tube 61 performs all of the functions of high resistance while condenser 55 is charging but does not have the inherent disadvantage of requiring a long time for discharging the condenser because the said tube 6'! by the arrangement described converts itself into a. low resistance at the proper instant to discharge condenser 55 quickly.

We have also provided an arrangement whereby energization of paint gun 40 will result in energization also of paint gun 4!. When current flows through the tube 5! to energize coil 42 and charge condenser 55, current will flow through the shunt path in the direction of arrow C, which 'is a. direction opposite to that of arrow B, and will oppositely energize coil 65 to cause contact 53 to engage contact 18 and thus impress a potential upon the grid 16 of a triode vacuum tube ll which is in the circuit of a D. 0. Voltage supply. The characteristics of tube 11 are such that low current flow is maintained in the said circuit until the potential is impressed upon grid 76, whereupon current flows by way of plate 18 tocoil M in the D. C. circuit and thus actuates paint gun valve of paint gun 4|. The contact 63 is normally centralized by any suitable centralizing spring arrangement 80.

In accordance with the provisions of the patent statutes, we have herein described the principle and operation of our invention, together with the apparatus which we now consider to represent the best embodiment thereof, but we desire to have it understood that the apparatus shown is only illustrative and that the'invention can be carried out by other equivalent means. Also, while it is designed to use the various features and elements in the combination and relations described, some of these may be altered and others omitted without interfering with the more general results outlined, and the invention extends to such use.

Having described our invention, what we claim and desire to secure by Letters Patent is:

1. In a rail flaw detector mechanism having means responsive to flaw and rail-marking means, means whereby said responsive means actuates said rail-marking means to give the same size mark on the rail regardless of the length of time or size of the response of said responsive means, said last-named means including a series circuit comprising a gaseous discharge tube having a plate, filament and grid, a discharge circuit for said tube including a condenser and said rail-marking means, and means whereby said responsive means controls the potential of said grid to control the flow of current through said tube.

2. In a rail flaw detector mechanism having flaw responsive means adapted to generate a potential when a flaw is encountered, and railmarking means, means whereby said responsive means actuates said rail-marking means to give the same size mark on the rail regardless of the length of time or size of the response of said responsive means, said last-named means including a series circuit comprising a gaseous discharge tube having a plate, filament and grid, a discharge circuit for said tube including a condenser and said rail-marking means, means for normally biasing said grid to prevent passage of current, and means whereby the potential generated by said responsive means is applied to said grid to permit current to pass.

3. In a rail fiaw detector mechanism having flaw responsive means adapted to generate a potential when a flaw is'encountered and railmarking means, means whereby said responsive means actuates said rail-marking means to give the same size mark on the rail regardless of the length of time or size of the response of said responsive means, said last-named means including a series circuit comprising a gaseous discharge tube having a plate, filament and grid, 2. discharge circuit for said tube including a condenser and said rail-marking means, means for normally biasing said grid to prevent passage of current, and means whereby the potential generated by said responsive means is applied to said grid to permit current to pass to charge said condenser, road-bed-marking means, and means whereby the current passed by said tube controls said road-bed-marking means.

4. In a rail flaw detector mechanism having flaw responsive means adapted to generate a potential when a flaw is encountered and railmarking means, means whereby said responsive means actuates said rail-marking means to give the same size mark on the rail regardless of the length of time or size of the response of said responsive means, said last-named means including a series circuit comprising a gaseous discharge tube having a plate, filament and grid, a discharge circuit for said tube including a condenser and said rail-marking means, means for normally biasing said grid to prevent passage of current, and means whereby the potential generated by said responsive means is applied to said grid to permit current to pass to charge said condenser, road-bed-marking means, and means whereby the current passed by said tube renders said roadbed-marking means efiective.

5. In a rail flaw detector mechanism having flaw responsive means adapted to generate a potential when a flaw is encountered and railmarking means, means whereby said responsive means actuates said rail-marking means to give the same size marks on the rail regardless of the length of time or size of the response of said responsive means, said last-named means including a series circuit comprising a gaseous discharge tube having a plate, filament and grid, a discharge circuit for said tube including a condenser and said rail-marking means, means for normally biasing said grid to prevent passage oi current, and means whereby the potential generated by said responsive means is applied to said grid to permit current to pass to charge said condenser, road-bed-marking means, and means whereby the current passed by said tube renders said road-bed-marking means efiective, said lastnamed means comprising a circuit having a source of current supply, a thermionic tube having a plate, a filament and grid, means for normally biasing said grid to prevent passage of current, and means whereby the current passed by said discharge tube varies the bias on said last-named grid to permit current to pass.

6. In a rail flaw detector mechanism having flaw responsive means adapted to generate a potential when a flaw is encountered and railmarking means, means whereby said responsive means actuates said rail marking means to give the same size mark on the rail regardless of the length of time or size of the response of said responsive means, said last-named means including a series circuit comprising a gaseous discharge tube having a plate, filament and grid, a discharge circuit for said tube including a con- .denser and said rail-marking means, means for normally biasing said grid to prevent passage of current, and means whereby the potential generated by said responsive means is applied to said grid to permit current to pass to charge said condenser, a discharge circuit shunted around said condenser and including a thermionic tube normally oilering high resistance, and means controlled by the discharge of said condenser for lowering the resistance of said tube.

7. In a rail flaw detector mechanism having flaw responsive means adapted to generate a potential when a flaw is encountered and railmarking means, means whereby said responsive means actuates said rail-marking means to give the same size mark on the rail regardless of the length of time or size of the response of said responsive means, said last-named means including a series circuit comprising a gaseous discharge tube having a. plate, filament and grid, a discharge circuit for said tube including a condenser and said rail-marking means, means for normally biasing said grid to prevent passage of current, and means whereby the potential generated by said responsive means is applied to said grid to permit current to pass to charge said condenser, a discharge circuit shunted around said condenser and including a thermionic tube having a plate, filament and grid, means for normally biasing said grid so that said last-named tube offers high resistance to the flow of current, and means controlled by the discharge of said condenser for applying a potential to said last-named grid to lower the resistance of said tube.

8. In a rail flaw detector mechanism having fiaw responsive means adapted to generate a potential when a flaw is encountered, and railmarking means, means whereby said responsive means actuates said rail marking means to give the same size mark on the rail regardless of the length of time or size of the response of said responsive means, said last-named means including a series circuit comprising a gaseous discharge tube having a plate, filament and grid, a discharge circuit for said tube including a condenser and said rail-marking means, means for normally biasing said grid to prevent passage of current, and means whereby the potential generated by said responsive means is applied to said grid to permit current to pass to charge said condenser,

, road-bed-marking means, a discharge circuit for said condenser including means for actuating said road-bed-marking means, means whereby said preceding means is rendered efiective when the current charges said condenser, means for accelerating the discharge of said condenser, and means whereby said accelerating means is rendered eiiective when said condenser begins to discharge through said circuit.

9. In a rail flaw detector mechanism having flaw responsive means adapted to generate a potential when a flaw is encountered and railmarking means, means whereby said responsive means actuates said rail-marking means to give the same size mark on the rail regardless of the length of time or size of the response of said responsive means, said last-named means including a series circuit comprising a gaseous discharge tube having a plate, filament and grid, a discharge circuit Ior said tube including a condenser and said rail-marking means, means for normally biasing said grid to prevent passage of current, and means whereby the potential generated by said responsive means is applied to said grid to permit current to pass to charge said condenser, a discharge circuit for the condenser including a two-way control member, means

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