IL95616A - Fall detector device particularly useful for braking railroad cars - Google Patents

Description

aDn munp ηη">ί?3ί? ιητηη enn'ot? ηί?·»£)3 ·>ιί>>λϊ> ιρηη FALL DETECTOR DEVICE PARTICULARLY USEFUL FOR BRAKING RAILROAD. CARS FALL DETECTOR DEVICE PARTICULARLY USEFUL FOR BRAKING RAILROAD CARS The present invention relates to a fall detector device, and particularly to one attachable to a railroad car for automatically actuating a control device in the event of derailment of the railroad car. The control device is preferably one which automatically actuates the braking system of the train containing the railroad car, but could merely provide a signal to the train operator that a derailment has occurred whereupon the operator would actuate the braking system.

Derailment of railroad cars is one of the most serious problems which has plagued the railroad industry for a considerable period of time. There are many causes for derailment, including: excessive speed; collision with an obstacle or another railroad car; a hot bearing; excessive play in a bogie undercarriage with respect to its railroad car, or of a load-carrying wheel with respect to its bogie; and an inbalance in the load on the railroad car such that one end of the car is much more heavily loaded than the other end.

Derailment of a railroad car is very damaging to the cross-ties or sleepers, and also to the bed of 95616/2 - 2 - the railroad tracks. The damage to the track bed alone is estimated to be approximately a million dollars per kilometer of travel of the derailed car in a single-bed line, and much larger in a double-bed line. This damage is in addition to the damage caused to the car, and also to the possibility of serious personal injury or death, particularly if the derailed car overturns. Still further damage is caused by the need to closedown the line for extensive periods of time in order to repair the damaged tracks.

Various types of devices have been proposed for sensing a derailment and for automatically actuating the train braking system and/or an alarm device, in response to a derailment. One of the known systems includes an impact detector device attachable to a railroad car and comprising a housing including a weight within the housing, and a control member supported by the housing in spaced relation over the weight such that, upon derailment of the railroad car, the impact causes the weight to be displaced relative to the housing to engage a control member which actuates the train braking system and/or a signal to the train operator. Such known arrangements, however, are subject to a high rate of false alarms, since the device is sensitive to other impacts causing displacement of the weight relative to the housing, such as the wheels of the railroad car impacting agent an open juncture between rails; such impacts can actuate the signal or braking system when no derailment is involved, particularly when the train is travelling at a high rate of speed. Insofar as we are aware, no system for automatically braking a train upon derailment has yet attained widespread use, and the problem of damage caused by derailment still persists to this day.

An object of the present invention is to provide a novel device sensitive to fall, rather than impacts, for automatically detecting derailment of a railroad car, which fall detector device has advantages in the above respects.

According to the present invention, there is provided a fall detector device attachable to a railroad car for automatically actuating a control device in the event of derailment, comprising a housing including a weight within the housing and a control member supported by the housing in spaced relation over the weight; said weight being supported on a yielding member interposed between it and the housing, such that upon derailment of the railroad car, the housing and control member are moved downwardly relative to the weight, to cause the weight to engage the control member to actuate the control device.

The foregoing arrangement thus senses the fall of the railroad car upon derailment, and not impacts, and is therefore less sensitive to impacts such as may arise during the normal operation of the railroad car even when travelling at high speeds.

In the preferred embodiments of the invention described below, the yielding member is a coiled spring; also, the weight is in the form of a sphere having a diameter larger than the upper loop of the coiled spring and resting thereon.

Three embodiments of the invention are described below for purposes of example. In one described embodiment, the control member is an electrical switch actuated when contacted by the weight in the event of derailment of the railroad car. In a second described embodiment, it includes an electrical contact, and the weight is of electrically conductive material engageable with the electrical contact to actuate the control device in the event of derailment of the railroad car. In a third described embodiment, the control member is a diaphragm ruptured by the weight when contacted thereby in the event of derailment of the railroad car.

The invention also provides a braking system for railroad cars which includes braking means, a source of compressed air, an air brake line, and a brake actuator automatically responsive to a drop in pressure in the air brake line to actuate the braking means, characterized in that the braking system further includes a fall detector device as described above for automatically venting the pressure in the braking line to the atmosphere to actuate the braking means in the event of derailment of the railroad car.

Further features and advantages of the invention will be apparent from the description below.

The invention is herein described, by way of example only, with reference to the accompanying drawings, wherein: Fig. 1 schematically illustrates one form of railroad car braking system constructed in accordance with the present invention; Fig. 2 illustrates one form of fall detector device that may be used in the braking system of Fig. 1 for detecting derailment of a railroad car; and Figs. 3 and 4 illustrate two other forms of fall detector devices which may be used in the braking system of Fig. 1 for detecting derailment of the railroad car.

Fig. 1 illustrates a railroad car 2, e.g., a freight car, supported by two bogie undercarriages 4 at this opposite ends. Each bogie undercarriage 4 includes four load-carrying wheels 6 movable along a pair of tracks 8. The wheels are connected together by axles 10 extending transversely of the cars and are mounted to the bogie undercarriages by springs (not shown) as well-known in railroad car constructions.

As also well-known, such railroad cars include brakes, schematically shown at 14, which are automatically actuated by a brake actuator 16 in case of a drop of air pressure in an air brake line 18 supplied by a source 20 of compressed air. In the conventional railroad braking system, the air brake line 18 extends the complete length of all the cars of the train such that if the pressure in the air brake line 18 drops for any reason, the braking devices 14 are automatically actuated to brake all the cars in the train.

According to the present invention, the air brake system includes a derailment detector device 30 and a control device 40 which is automatically actuated by the detector device in the event of derailment of a railroad car; actuation of the control device vents the air brake line 18 to the atmosphere and thereby causes a drop of air pressure in the line to actuate the brakes 1 via the brake actuator 16. As shown in Fig. 1 , one detector device 30 is to be attached to a wheel on the front bogie 6 on one side of the railroad car, and a second dector device 30 is to be attached to one of the wheels of the rear bogie on the other side of the railroad car, such that one or the other detector device 30 detects derailment of a wheel on one or the other side of the railroad car with respect to its railroad track 8.

Fig. 2 illustrates one form of derailment detector device 30 which may be used in the system of Fig. 1. Thus, detector device 30 illustrated in Fig. 2 comprises a housing 32 attachable to one of the wheels 6 on the railroad card, e.g., to its outer bearing, in any convenient manner. Housing 32 includes a weight 34 supported within the housing on a yielding member 36, in the form of a coiled spring, interposed between it and the housing, and a control member 38 supported by the housing in spaced relation over the weight 34, such that upon derailment of the railroad car, the housing 32, and the control member 38 supported thereby, abruptly fall downwardly by gravity. The weight 34 however, because of the upward force of the coiled spring 36, falls at a velocity less than that of the housing, thereby causing the weight to impact against the control member 38, to actuate the control device 40, and in turn to actuate the automatic brakes 14 via the brake actuator 16.

It will thus be seen that this arrangement, wherein the weight 34 is supported within the housing 32 by a yielding member 36, decreases the sensitivity of the device 30 to impacts not involving a derailment, such as the impacts applied to the wheels when bridging an open juncture between two rails, even when the train is travelling at a high rate of speed. On the other hand, the illustrated arrangement including the yielding means 36 makes the device sensitive to the abrupt drop or fall of the housing 32, and thereby of the wheel to which the housing is attached, as would occur upon a derailment of the railroad car.

In the arrangement illustrated in Fig. 2, the yielding member 36 is in the form of an open coiled spring, and the weight 34 is in the form of a metal sphere of slightly larger diameter than the upper loop of the coiled spring 36 so as to stably rest on the upper end of the coiled spring. Also, the control member 38 is in the form of a mechanical switch which is actuated upon impact by the weight 34 to close an electrical circuit, schematically indicated by conductors 39, to the control device 40, such as a solenoid valve. The control device 40 vents the air brake line 18 to the atmosphere thereby causing a drop of pressure in the air brake line to actuate the brakes 14 via the brake actuator 16.

Fig. 3 illustrates a modification in the construction of the derailment detector device 30 of 95616/2 - 9 - Fig. 2. For ease of understanding, corresponding elements in the modification of Fig. 3 carry the same reference numerals as the elements in Fig. 2, except followed by the suffix "a". Thus, in the modification of Fig. 3, the spherical weight 34a, yieldably supported within the housing 32a by the coiled spring 36a, constitutes one contact of an electrical switch; and the control member 38a, engaged by the sperical weight 34a upon derailment, constitutes the other electrical contact of a switch, such that the electrical circuit indicated by conductors 39a is closed by the engagement of metal ball 34a with control member 38a upon a derailment, to close the electrical circuit to the control device 40 in Fig. 1.

Fig. 4 illustrates a further modification in the construction of the derailment detector device, therein designated 30b. In this modification, the control member 38b is in the form of a diaphragm which is ruptured by the weight 34b supported within the housing 32b by coil spring 36b. In this case, the weight is non-spherical and carries a pointed upper tip 35; also, the upper end of the housing 32b above the diaphragm 38b is vented to the atmosphere, as shown by opening 39b, whereas the lower end of the housing below the diaphragm is connected to the air brake line 18, as shown by pipe 39b'. The arrangement is such that when the diaphragm 38b is ruptured by the weight 34b in the event of a derailment, the air brake line 18 is vented to the atmosphere to thereby actuated the brakes 14 via the brake actuator 16.

While the invention has been described with respect to several preferred embodiments, it will be appreciated that many variations may be made. For example, the location of the control member (38, 38a or 38b) may be made adjustable to vary the magnitude of the fall to actuate the system. Adjustments for similar reasons may be made with respect to the force of the spring, or the magnitude of the weight. In addition, the invention, although especially useful for detecting derailment, can also be used in other forms of detectors, such as to detect an excessive downward speed of an elevator to actuate an automatic brake. Other variations, modifications and applications of the invention will be apparent.

Claims (9)

WHAT IS CLAIMED IS;

1. A fall detector device attachable to a railroad car for automatically actuating a control device in the event of derailment, comprising a housing including a weight within the housing and a control member supported by the housing in spaced relation over the weight; said weight being supported on a yielding member interposed between it and the housing, such that upon derailment of the railroad car, the housing and control member are moved downwardly relative to the weight, to cause the weight to engage said control member to actuate the control device.

2. The device according to Claim 1 , wherein said yielding member is a coiled spring.

3. The device according to Claim 2 , wherein said weight is in the form of a sphere having a diameter larger than the upper loop of the coiled spring and resting thereon.

4. The device according to any one of Claims 1-3, wherein said control member is an electrical switch actuated when contacted by said weight in the event of derailment of the railroad car.

5. The device according to any one of Claims 1-3, wherein said control member includes an electrical contact, and said weight is of electrically conductive material engageable with said electrical contact to actuate said control device in the event of derailment of the railroad car.

6. The device according to any one of Claims 1-3, wherein said control member is a diaphragm ruptured by said weight when contacted thereby in the event of derailment of the railroad car.

7. A braking system for railroad cars including braking means, a source of compressed air, an air brake line, and a brake actuator automatically responsive to a drop in pressure in said air brake line to actuate said braking means, characterized in that the braking system further includes a fall detector device according to any one of Claims 1 -6 for automatically venting the pressure in the air brake line to atmosphere to actuate said braking means in the event of derailment of the railroad car.

8. A fall detector device attachable to a railroad car, substantially as described with reference to and as illustrated in the accompanying drawings.

9. A braking system for railroad cars substantially as described with reference to and as illustrated in the accompanying drawings. Advocate, Patent Attorney P.O.B. 23008 Tel-Aviv, 61 230