US2077812A - Rail flaw detector mechanism - Google Patents

Description

April 20, 1937. E. G. SPERRY ET AL 2,077,312

RAIL FLAW DETECTOR MECHANISM Filed March 9, 1935 10 29 f7 {20 v 25 28 I 32 v 21 2B o o 22 o o 25 3 \Hr 1 11 1 18 1'15- /5 1 F F F] F F F F F F F Fl F F g I i 4\U L Ll A 25 1 16 \l L F 25 \L Wm Edward G. Sperrg arcourt C. Drake Mung Patented Apr. 20, 1937 UNITED TAT S RAIL FLAW DETECTOR MECHANISM Edward G. Sperry, Brooklyn, and Harcourt C. Drake, Hempstead, N. Y.,' assignors to. Sperry Products, Inc., Brooklyn, N. Y., a corporation of Newyork Application March 9, 1935, Serial No. 10,142

2 Claims.

. This invention relates to rail flaw detector cars adapted to travel on railroad tracks and detect fissures inside the rails. More particularly, the invention relates to the Sperry rail flaw detector car wherein a detector mechanism is suspended from each side of the car to cooperate with the respective rail. Such mechanisms include detector means mounted on' a carriage and said carriage is in turn mounted for independent movement with respect to the car body. It has been found that the detector carriage, because of its freedom of movement, sometimes dropped into the spaces between the various parts comprising -a frog, after passing a switch, and was unable to ride up on the succeeding rails.v In some instances, the carriagewas jammed in the spaces between the parts of the frog and was severely damaged.

It is the principal object of this invention, therefore, to provide means which will prevent the detector carriage from falling into the spaces between the parts of a frog. By this means, possibility of damage to the detector carriage is avoided.

Further objects and advantages of 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 fiaw detector car showing my invention applied to the detector carriage thereof. I

Fig. 2 is a plan view, partly diagrammatic,

' showing the location on the rail of the parts of the mechanism as heretofore employed.

Figs. 3 and 4 are views partly sectioned vertically, showing the operation of this invention on a portion of a frog indicated at ll'in Fig. 2.

Fig. iii is a modified form of the invention.

Referring to the drawing, there is disclosed in Fig. I the Sperry rail flaw detector mechanism as applied to a Sperry rail flaw detector car. A portion of the car body III is disclosed, within which is supported a generator G for supplying current to the rail by means of sets of brushes II and I! to establish an electromagnetic field surrounding the rail. The flux in said field will be uniform as long as there are no .flaws therein, but when a flaw is present the flux in said field is distorted. 'Such distortion of the field is detected bymeans of a pair of induction coils l5, spaced in tandem along the rail. Said coils are of equal inductance and oppositely wound. and as the car travels along the rail they normally cut a constant and equal number of lines of force. On entering a region of flaw, one coil will cut a different number of lines of force from the other to generate a differential E. M. F. which after being suitably amplified may be I caused to operate any suitable indicator, such as a pen on a chart, and any suitable rail marking means, as, for instance, a paint gun. coils are mounted in a housing l6 carried by a detector carriage ll adapted to ride on the rail by means such as wheels l8. Said detector carriage is in turn supported on a current brush carriage 20 by means of loosely fitting bolts 2| and springs 22 which constitute a limited universal joint which permits the detector carriage to move independently of carriage 20, both laterally and vertically and thus adjust itself to irregularities in the rail surface. The current brush carriage 20 supports the currentbrushes H and i2 and may be supported on the rail by means of wheels 25 and supported on the car body by means of piston rods 28 connected to pistons operating in fluid pressure cylinders 29.

The current brush carriage 20 is normally held in raised position by means of retractile springs 3i and cables 32, 33, but when it is desired to lower the carriage into engagement with the rail, fluid pressure, such as compressed air, is admitted to the cylinders 29 todepress the pistons and thus lower the carriage against the action of the retractile springs,

In Fig. -1 it will be seen that the detector carriage is mounted on a plurality of supports comprising sets of wheels. Referringto Figs. 2 and 3, it will beseen that heretofore each of said supports comprised two narrow wheels l8 mounted on an axle, said wheels being purposely made narrow to enable said wheels to follow the contour of the rail surface and ride into each ir- I regularity so as to maintain the induction coils always at a constant distance above the rail surface regardless of the irregularities therein. Referring to Figs. 2 and 3 it will be seen that as the detector carriage approached a frog it was the opening between two parts of the frog at a point such as indicated at 4-4 because of the narrowness of the wheels, and it has been found that said wheels sometimes remained in said space without riding up on the rail portion of the switch so that the detector carriage was at times severely damaged by reason of being wedged into the said space.

To remedy the above condition. we have shown (see Fig. 4) each wheel as provided with an extension which, in one form of our invention, may take the form of a hollow cylinder 40, preferably made Said ' possible for the forward set of wheels to drop into of aluminum or other light metal so as not to add appreciably to the weight, and of somewhat smaller diameter than the wheels so as normally not to contact with the rail. It will be seen, however, that when the detector carriage approaches. a frog, one or both cylindrical extensions of the leading pair of wheels will always-ride upon the rail parts of the frog to prevent the wheels from dropping intothe space between the rail parts, thus preventing derailment of the detector carriage and damage thereto, and insuring that the wheels will ride upon the rail surface after the frog has been passed over.

In Fig. 5 we have disclosed a modified form of the invention. In this form, the extension ll tapers outwardly from the wheel portion l8", the diameter of the extension at the wheel portion being substantially the same as the wheel portion proper.

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 moregeneral 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, means responsive to flaws, a carriage for said responsive means, a support for said carriage providing universal movement thereof, said carriage having wheels adapted to ride upon the rail, each of said wheels comprising a portion adapted normally to engage the rail, said portion being so formed that it would tend to fall into the space between the rail parts of a frog, and an extension on the outside of each portion, said extension having a surface adapted to engage the parts of the frog, said surface tapering outwardly throughout its entire length from the respective wheel portion.

2. In a rail flaw detector mechanism, means responsive to flaws, a carriage for said responsive means, a support for said carriage providing universal movement thereof, said carriage having wheels adapted to ride upon the rail, each of said wheels comprising a portion adapted normally to engage the rail, said portion being so formed that it would tend to fall into the space between the rail parts of a frog, and an extension on the outside of each portion, said extension having a surface adapted to engage the parts of the frog, said surface tapering outwardly throughout its entire length from a diameter substantially equal to the diameter of the respective wheel portion.

EDWARD G. SPERRY. HARCOURT C. DRAKE.

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