Loose wheel detectors



y 5, 1967 W. A. JAMlSON ETAL 3,333,097 LOOSE WHEEL DETECTORS 2 Sheets-Sheet 1 Filed July 14, 1965 I I l v l 1 524 vou' ac. 74 j POWER SUPP mv NTOR5 h fifiA/ffifl m/sa/v M055 G. 4P1 7- 54 ATTORNEY United States Patent 3,333,097 LGQSE WHEEL DETECTORS Warner A. Jamison and Joseph G. Karlet, Roanoke, Va., assignors to Railroad Accessories Corporation, Cresskill, NJ. Filed July 14, 1965, Ser. No. 471,813 11 Claims. (Cl. 246-455) 'This invention relates to railway signalling and safety devices, and particularly to apparatus and systems for detecting and indicating the presence of a loose wheel on rail-way rolling stock. The wheels of railway cars and locomotives are normally mounted on their axles with a tight press fit, and the two Wheels and the connecting axle form an integral unit. If this original press fit should become loose, the wheel flanges, running on the inside of the pair of tracks, prevent such a wheel from slipping outward off the outer end of the axle, but often there is nothing to prevent substantial axial movement of a loosening wheel inwardly, toward its mating wheel. Loose wheels occur occasionally on railroads, and a single loose wheel moving inward and dropping off the track can derail a train. Detection of loose wheels by sensing units mounted on every axle or every truck of every railway car would be impractically expensive. The loose wheel detectors of the present invention are installed on the railroad track, preferably in pairs and for convenience usually mounted near hot-box detectors, car counters, and other control devices; however, this is not a requirement for the effective operation of the detectors of this invention. The loose wheel detector systems of this invention are inexpensive and highly effective in operation. A principal object of the present invention is to provide systems and apparatus for the detection of loose wheels on passing railway rolling stock. Another object of the invention is to provide loose wheel detection systems and apparatus permanently mounted in conjunction with other control devices at selected locations on a railroad track. A further object is to provide such systems and apparatus capable of automatically applying, directly upon a railway car, easily recognizable indications of the presence of a loose wheel thereon. Other and more specific objects will be apparent from the features, elements, combinations and operating procedu-res disclosed in the following detailed description and shown in the drawings, in which: FIGURE 1 is a perspective view of a portion of railroad track incorporating a detector assembly of the present invention; FIGURE 2 is a schematic circuit diagram showing a detector system of the present invention incorporating the assembly shown in FIGURE 1; FIGURE 3 is a top plan view of a segment of a railroad rail having a detector like the one shown in FIG- URE l mounted thereon, showing an approaching wheel; FIGURE 4 is a fragmentary side elevation view of the structure shown in FIGURE 3, showing a passing wheel; and FIGURE 5 is a cross sectional end elevation view of the structure of FIGURES 3 and 4 taken along the line 5-5 in FIGURE 4, and showing a passing loose wheel actuating the detector assembly. In the loose wheel detector systems of this invention, a resilient, insulated bowed leaf spring is supported by a detector assembly 12 near the inside of a railroad rail 14 on a level with the ball 16 of the rail 14. The bowed leaf spring is insulated from the railroad rail, and forms a part of detector circuits and systems. This insulated spring 10 is spaced inwardly away from the "ball of the rail sufficiently to allow each normal wheel 3,333,697 Patented July 25, 1967 18 on passing railway rolling stock to travel along the rail past the bowed leaf spring 10 without contacting the spring, as shown in FIGURE 3. The spring steel bows 10 are correctly adjusted when the distance from the convex face of spring bow 10 is 53%" from the inside gage surface of the opposite rail. This method will always result in a correct adjustment even though the standard rail gage spacing is slightly off. A loose wheel 29 which has moved inwardly on its axle, bringing its flange 22 inward toward the opposite rail, will engage and depress the bowed leaf spring 10 as it passes by, as indicated in FIGURE 5. The loose wheel 29 thus becomes a bridging element forming an electrical connection between the rail 14 and the bowed leaf spring 10, which is otherwise insulated from the rail. The normal railway track signal voltage employed in the signal block in which the rail 14 is incorporated may be utilized with the bowed leaf spring detectors of this invention to provide signal indications of the presence of a loose wheel. However, it is preferable to use an independent power source, such as a storage battery or an A.C. to DC. converter 24 (FIGURE 2), having one terminal connected to the rail 14 and the opposite terminal connected to the bowed leaf spring 10 of the detector 12. As indicated in FIGURE 2, a pair of such detectors are preferably mounted across from each other on the facing inner sides of a pair of rails 14 forming a track. The leaf springs 10 of both detector units may be connected to a single terminal of DC. power source 24, and the opposite terminal may be connected only to a single rail of the track pair, since the integral wheel and axle units of the train will conduct the signal voltage from one rail to the other, but the loose wheel detector signal circuit will not be closed until a loose wheel engages the bowed leaf spring detector as shown in FIGURE 5. The detector systems of the present invention may include pen recorders, signal lamps, buzzers or other indicators to indicate defects at local or remote locations. A preferred embodiment of the invention incorporating an automatic car marking system is illustrated in FIG- URE 2; this system sprays a jet of paint or bright-colored dye directly on the car carrying the loose wheel. Thus the buzzer or light indicator permits the train to be halted promptly, while the dye marking on the car allows the loose wheel to be identified immediately. Loose wheel sensing assembly The loose wheel detector sensing assembly 12 shown in the figures incorporates a spring supporting plate 26, to the ends of which are attached downwardly extending rods 28 bent in an L-sliaped configuration extending beneath the plate 26 toward the web 3! of rail 14. The rods 28 are secured to but insulated from the rail 14. Thus, as shown in the drawings, the horizontally extending legs of rods 28 are preferably threaded and inserted through suitably spaced apertures passing through the web 30 of the rail. Rods 28 are insulated from the web by flanged plastic bushings 32 of nylon or other suitable weatherproof insulating material. The bushings are anchored in their installed position by lock washers and nuts 34, and the terminal of the DC power supply 24 is preferably connected to detector assembly 12 by a terminal eye 35 anchored under one of these nuts 34, as shown in FIGURE 5. An alternate preferred method of connecting the power to the insulated loose wheel detector is to use a screw type clamp similar to a ground rod clamp to secure the current carrying wire to L-shaped rod 28 shown in FIGURE 1. The plate 26 is elongated in the longitudinal direction, parallel to the rail, and its length is the same order of magnitude as the diameter of the Wheel 20 to be detected. The plate 26 is supported in a substantially vertical plane parallel to the side of the ball or head 16 of rail 14 and inwardly spaced therefrom by the L-shaped rods 28 anchored to the web 30 of rail 14, as shown in FIGURE 3. A pair of spring retainers 36 are mounted on the ends of plate 26 facing each other and forming concave cavities 38 shaped to receive loosely the movable free ends of the bowed leaf spring 10. The ends of the spring 10 are positioned within these cavities 38 near the ends of plate 26, and the central portion of the bowed leaf spring 10 protrudes in its normal bowed curve toward ball 16 of rail 14, all as indicated in the figures. The spring retainers 36 in the illustrated embodiment are formed as U-shaped flat strap members whose ends are welded to the upper and lower end edges of plate 26, as shown in FIGURES 1, 3 and 5. The central portions of these spring retainers 36 are angular ly displaced from the plane of plate 26, and are substantially parallel to the ends of bowed leaf spring 10 accommodated therein. Anchored to the mid-portion of the bowed leaf spring 10 is a protruding alignment rod 40 extending inwardly toward and through a suitable aperture 42 passing through the plate 26, and provided with an elastic stop nut 44 threaded thereon on the opposite side of plate 26. A compression coil spring 46 is sandwiched between plate 26 and leaf spring 10 surrounding the alignment rod 40. In the normal position of assembly 12, the leaf spring 10 is bowed towardthe rail 14 and urged in that direction by the compressed coil spring 46. By adjusting the two lock nuts 34 together along each threaded rod 28, the plate 26 and leaf spring 10 may be moved toward or away from ball 16 of rail 14, to leave ample clearance C (FIGURE 3) for the passage of normal wheels, making allowances for normal wear and conventional tolerances on the distances between pairs of wheels and rails. A final or fine adjustment of the how 10 can be accomplished by turning elastic stop nut 44. When the inner face of flange 22 of a loose wheel 20 is too far from the central plane of the rail 14, however, it contacts leaf spring 10 (FIGURE By setting the assembly 12 at the desired clearance distance C from rail 14, the safe operating limits of wheel separation are automatically employed to signal the presence of any pair of wheels closer together than such desired limit. By employing two detectors 12 directly opposite each other, such a faulty pair of wheels will be detected no matter which wheel is riding normally and which is riding on the outer edge of its rim, like wheel 22 in FIGURE 5. Car marking and signalling system As shown in the schematic diagram of FIGURE 2, the DC. power supply 24 has one terminal connected to one rail 14 of the pair, and its other terminal connected to each of the leaf springs of a pair of loose wheel detector assemblies 12 secured to and insulated from each of the rails 14 in the manner illustrated in FIGURE 1. Interposed between the leaf springs 10 and the power supply 24 is a D.C. relay 48 with suitable operating characteristics. When a loose wheel bridges the gap between rail 14 and detector assembly 12, as shown in FIGURE 5, this has the effect of closing the circuit and applying the voltage of the power supply via rail 14, wheel 20, spring 10, assembly 12 and terminal eye 35 directly across the relay 48, closing its contacts 50 and 52. The contacts 50 of relay 48 apply A.C. voltage from the A.C. line 54 directly to a solenoid-controlled valve 56 incorporated in a colored dye spray-head 58 positioned alongside the track 14 near the loose wheel detector assembly 12. r The spray-head 58 is operatively connected through a conduit 60 to a dye reservoir 62 containing a quantity of paint or brightly-colored dye, and pressurized by such means as a cylinder of compressed gas 64 connected to the top of reservoir 62, as shown in FIGURE 2. For example, this may be a type K cylinder of dry nitrogen supplying a regulated gas pressure of 45 p.s.i. to the dye reservoir. The solenoid valve 56 on spray-head 58 may be an Asco solenoid spray valve with a time delay relay producing a three second hold, for example, spraying a suitable jet of brightly-colored dye aimed at the side of the car directly above the loose wheel detected by the system as described above. The slight time delay of two or three seconds holding time for the relay can be obtained by connecting two suitable capacitors in parallel across the 24 volt D.C. relay as shown in FIGURE 2. This method would be in lieu of using a mechanical-type time delay relay. The contact 52 of the relay 48 connects the A.C. line 54 directly across an A.C. relay coil 66, energizing this relay 66 to close itscontacts 68 and 70. Relay contact 68 is a holding contact, bypassing the contact 52 of relay 48 to connect the A.C. line 54 directly across the relay coil 66, and thus maintaining A.C. relay 66 energized until the reset button 72 is pushed, to de-energize relay 66. Contact of A.C. relay 66 is closed by this energizing of the relay, applying the A.C. line voltage across a signal lamp 74 or such other signal devices as recorders or audible alarms. For example, the third or marker pen of a pen recorder may be connected to record actuation of assembly 12 by a loose wheel. Operation Every normal wheel 18 rolling along rail 14 will bypass the leaf spring 10 of the detector assembly 12 without touching it, since its flange extends inward from the rail a distance less than predetermined permissible maximum clearance C, as shown in FIGURE 3. The detector thus draws no current and suffers no abrasion or wear with the passage of normal wheels. A loose wheel slipping inwardly on its axle, such as wheel 20 shown in FIGURE 5, will touch and depress the leaf spring 14) momentarily as it passes the detector assembly 12 as indicated in FIGURE 5, thus briefly closing the circuit of DC. power supply 24 and placing its entire DC. potential across the DC. relay 48. As a result of the operation of relays 48 and 66, as described above, the lamp 74 or other signal devices are'energized, and if desired, as shown in FIGURE 2, the solenoid valve 56 is actuated to spray a jet of brightly-colored dye directly on the car to indicate the location of the loose wheel detected by the system. One preferred method of determining the location of the loose wheel in the train is useful with a dual-pen recorder, such as those used with dual hot box detectors mounted alongside both rails of a track. A passing hot box is indicated on such recorders by a deflected peak on one recorded pen line. In this preferred method, the loose wheel detector is connected to cause both pens or stylii of the recorder to be deflected simultaneously. This can be accomplished as follows: When a loose 'wheel moves inwards on the axle and contacts the springsteel bow 10, a circuit i completed which causes a relay to close momentarily while the flange of the wheel is rubbing against the bow. This momentary closing of contacts can be used to close another circuit and cause a voltage pulse to be delivered to the recorder in such a manner 'as to cause the pen or stylus for'eac'h rail to be deflected simultaneously. This simultaneously high deflection of both pens or stylii will indicate on the chart the exact location of the loose wheel in the train. From FIGURES 3, 4 and 5 it may be seen that the arched leaf spring 10 forms a contact ramp facing the adjacent lateral surface of each passing wheel 18 or 20. The ramp slants toward the plane of rotation of'the flange-side of each approaching wheel, and each succeeding portion of the contact ramp from each end, held in spring retainer 36, to the center of leaf spring '10 is successively closer to this plane, providing a double ramp accommodating wheels approaching in either direction. The center of leaf spring 16 thus constitutes a final region of the contact ramp, spaced beyond the path of normally aligned wheels 18 (FIGURE 3) and in the path of misaligned wheels 29 (FIGURE 5) for contact with their facing lateral surfaces. While the objects of the invention are efficiently achieved by the preferred forms of the invention described in the foregoing specification, the invention also includes changes and variations falling within and between the definitions of the following claims. We claim: 1. A track-guided wheel detector positioned facing adjacent lateral surfaces of passing wheels for sensing and indicating the presence of any passing faulty wheel misaligned away from its intended track-guided position in a direction transverse to the plane of rotation of a normal Wheels adjacent lateral surface, comprising, in combination (A) a contact ramp slanting toward said plane of rotation and having successive regions positioned progressively closer to said plane in the direction of travel of the track-guided wheels, (B) with a final region being spaced transversely from said plane by a preselected maximum clearance distance placing the final portion beyond the path of normally aligned wheels and in the path of misaligned wheels for contact with the facing lateral surfaces thereof, (C) and indicating means responsive to each contact of a misaligned wheel with the contact ramp. 2. The detector of claim 1 including means resiliently urging the contact ramp toward a predetermined position at the preselected maximum clearance distance from said plane to counteract deflection of the final portion of the contact ramp away from the predetermined position by a laterally-misaligned passing wheel. 3. A wheel detector mounted beside a wheel-carrying rail and positioned to detect the passing of a laterally misaligned wheel, comprising, in combination (A) a contact member having a central surface portion arched convexly toward the head of the rail, (B) support means adjustably positioning the central surface portion beside the head of the rail at a predetermined position spaced therefrom by a preselected maximum clearance distance placing the arched surface portion beyond normally aligned wheels and in the path of laterally misaligned wheels for contact therewith, (C) and indicating means responsive to each contact of a misaligned wheel with the arched surface portion of the contact member. 4. The detector of claim 3 including means resiliently urging the arched surface portion toward the predetermined position to counteract deflection of the arched surface portion away from the predetermined position by a laterally-misaligned passing wheel. 5. The combination defined in claim 3 in which the contact member and the rail are electrically insulated from each other by the support means, and are electrically connected only by a passing misaligned wheel simultaneously contacting both the rail and the central surface portion, and in which the indicating means is connected to the rail and the contact member for actuation by each simultaneous contact of a misaligned wheel with both rail and contact member. 6. A loose railway Wheel detector mounted beside a railroad rail and comprising, in combination (A) a thin curved member having its central portion nogmally arched convexly toward the head of the rar (B) support means adjustably positioning the arched central portion beside the head of the rail at a predetermined position spaced therefrom and incorporating (1) restraining means positioning the curved member for guided movement away from the rail (2) and resilient means urging the curved member toward the predetermined position, (C) and indicating means responsive to each contact of the curved member by a misaligned loose wheel protruding beyond the predetermined spaced position from the head of the rail. The combination defined in claim 6 wherein the resilient means includes a compressed coil spring interposed between the curved member and the support means. 8. The combination defined in claim 6 wherein the thin curved member is a leaf spring positioned for flexing displacement by a misaligned wheel contacting the arched central portion thereof. 9. A loose wheel detector positioned facing the adacent lateral surfaces of wheel flanges beside the inner side of the head of one of a pair of railroad rails and comprismg, in combination (A) thin elongated curved leaf spring having its central portion normally arched convexly toward the head of the rail, (B) electrically insulated support means adjustably positioning the arched leaf spring convexly presented beside the rails head at a preselected maximum clearance distance therefrom, and including retainers loosely confining the ends of the arched leaf spring, and an adjustable alignment rod guiding a central portion of the arched leaf spring for flexing movement toward and away from the rails head, (C) and indicating means activated by simultaneous contact of a misaligned wheel with both the rail and the leaf spring to indicate the presence of the misaligned wheel. 10. The combination defined in claim 9 including a second, separate curved leaf spring oppositely positioned by electrically insulated support means beside the inner side of the head of the opposite rail of a pair of rails and connected to the same indicating means. 11. The combination defined in claim 1 wherein the indicating means includes a dye-spraying system, actuated by a contact of a misaligned wheel with the contact ramp, and positioned to direct a jet of colored dye on the side of a railway car having the actuating misaligned wheel mounted thereon. References Cited UNITED STATES PATENTS 521,455 6/1894 Alsop 246-255 527,099 10/ 1894 Alsop 246-246 1,194,981 8/1916 Faubel et a1. 246-255 FOREIGN PATENTS 2,455 of 1898 Great Britain. 3,620 of 1906 Great Britain. ARTHUR L. LA POINT, Primary Examiner. S. T. KRAWCZEWICZ, Examiner.



Download Full PDF Version (Non-Commercial Use)

Patent Citations (5)

    Publication numberPublication dateAssigneeTitle
    GB-189802455-AJanuary 28, 1899Robert Burn, Alfred Charles BrownImprovements in Electric Contacts, suitable for Railway Signalling and other Purposes.
    GB-190603620-AJanuary 31, 1907Joseph Henry HollyerImprovements in Contacts for use in connection with Electric Warning Signals for Railways and the like
    US-1194981-AAugust 15, 1916Electric bail way-signal
    US-521455-AJune 19, 1894Charles richard alsop
    US-527099-AOctober 09, 1894Charles richard alsop

NO-Patent Citations (0)


Cited By (2)

    Publication numberPublication dateAssigneeTitle
    US-4407072-AOctober 04, 1983Southern Railway CompanyThin flange and loose wheel detection system
    US-6564467-B1May 20, 2003Aea Technology PlcRailway wheel monitoring