Patent Application
20130068570
The present invention generally involves a system and method for operating a locomotive parking brake. In particular embodiments of the present invention, the system and method may detect and measure the force or tension applied by a take-up device to a wheel brake.
Locomotives generally include an air brake system for stopping the locomotive and a separate parking brake system for holding the locomotive in place over long periods. For example, U.S. Pat. Nos. 6,427,811 and 7,347,306, assigned to the same assignee as the present application, disclose various embodiments of parking brakes suitable for use with locomotives. As shown in each patent, the parking brake generally includes a manual or automated take-up device connected by rigging to a brake shoe. The take-up device is often remote from the brake shoe, and operation of the take-up device applies force or tension to the rigging to draw the brake shoe directly against a wheel to prevent the locomotive from moving. The take-up device may be manually operated, for example by using a hand wheel or lever, or a motor may be used to assist in applying the force or tension to the rigging needed operate the parking brake.
A reliable indication of the actual status of the parking brake is important for both equipment and safety reasons. A parking brake that has not been adequately set may allow inadvertent and/or uncontrolled movement of the locomotive. Conversely, a parking brake that has not been adequately released may result in damage to the locomotive wheel and/or parking brake if the locomotive is subsequently moved.
Although various devices and methods have been developed to determine the status and position of the parking brake, the remote location of the take-up device, the potential for interference with the rigging, and the general lack of direct access to the brake shoe individually and collectively can create uncertainty in the parking brake status. For example, the rigging may become bound at some point between the take-up device and the brake shoe. As a result, the amount of force or tension applied by the take-up device and/or rigging may not accurately reflect the amount of force or tension that is actually applied by the brake shoe against the wheel. Therefore, continued improvements in systems and methods for operating a locomotive parking brake would be useful.
Aspects and advantages of the invention are set forth below in the following description, or may be obvious from the description, or may be learned through practice of the invention.
One embodiment of the present invention is a system for operating a locomotive parking brake that includes a wheel brake, a coupling connected to the wheel brake, and means for applying force to the coupling. A sensor connected to the coupling measures a force applied to the coupling and generates a signal reflective of the force applied to the coupling.
Another embodiment of the present invention is a system for operating a locomotive parking brake that includes a coupling to the parking brake and a sensor connected to the coupling. The sensor measures a force applied to the coupling and generates a signal reflective of the force applied to the coupling.
The present invention may also include a method for operating a locomotive parking brake that includes applying a force to a coupling connected to a wheel brake, measuring the force applied to the coupling, and comparing the force applied to the coupling to a first predetermined limit. The method further includes indicating that the force applied to the coupling is equal to or greater than the first predetermined limit.
Those of ordinary skill in the art will better appreciate the features and aspects of such embodiments, and others, upon review of the specification.
A full and enabling disclosure of the present invention, including the best mode thereof to one skilled in the art, is set forth more particularly in the remainder of the specification, including reference to the accompanying figures, in which:
Reference will now be made in detail to present embodiments of the invention, one or more examples of which are illustrated in the accompanying drawings. The detailed description uses numerical and letter designations to refer to features in the drawings. Like or similar designations in the drawings and description have been used to refer to like or similar parts of the invention. As used herein, the terms “first”, “second”, and “third” may be used interchangeably to distinguish one component from another and are not intended to signify position, location, or importance of the individual components unless specifically stated in the claims.
Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that modifications and variations can be made in the present invention without departing from the scope or spirit thereof. For instance, features illustrated or described as part of one embodiment may be used on another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents.
Various embodiments of the present invention provide a system and method for operating a locomotive parking brake 10. As shown in
The wheel brake 12 generally includes a brake disc or brake shoe suitably shaped and sized to engage a complementary surface on a locomotive wheel 22, as shown in
In particular embodiments, the means for applying force or tension to or through the brake force unit 20 may include different and/or additional devices or structures that provide a suitable mechanical advantage in setting and releasing the parking brake 10, and one or ordinary skill in the art will readily appreciate that embodiments of the present invention are not limited to any particular take-up device 16 or means for applying force or tension to or through the brake force sensing unit 20 unless specifically recited in the claims. For example, as shown in
The sensor 42 may any suitable instrument or device known to one of ordinary skill in the art for measuring dynamic forces applied to a structure. For example, the sensor 42 may be a strain gauge attached to the coupling 40 to measure a change in electrical potential or current flow produced by elastic deformation of the coupling 40. As another non-limiting example, the sensor 42 may be a fiber optic cable or interferometer that measures a change in optical frequency associated with elongation of the coupling 40. The sensor 42 may thus measure the force or tension applied to the coupling 40 and generate a signal 46 reflective of the force or tension applied to the coupling 40.
The processor 44 receives the signal 46 reflective of the force or tension applied to the coupling 40. The signal 46 may have a magnitude on the order of millivolts. As a result, the processor 44 is generally located proximate to the sensor 42 to minimize any noise or other electromagnetic interference that might interfere with or distort the signal 46. For example, as shown in
The processor 44 converts the signal 46 to a force or tension measurement and transmits a digital output 50 for further use by the brake force sensing unit 20 and/or take-up device 16. As shown in
The technical effect of the processor 44 and/or controller 60 is to convert the signal 46 produced by the sensor 42 into a quantity that can then be compared to the one or more predetermined limits. As used herein, the processor 44 and/or controller 60 may include any combination of microprocessors, circuitry, or other programmed logic circuit and are not limited to any particular hardware architecture or configuration. Embodiments of the systems and methods set forth herein may be implemented by one or more general-purpose or customized processors 44 and/or controllers 60 adapted in any suitable manner to provide the desired functionality. The processor 44 and/or controller 60 may be adapted to provide additional functionality, either complementary or unrelated to the present subject matter. For instance, one or more processors 44 and/or controllers 60 may be adapted to provide the described functionality by accessing software instructions rendered in a computer-readable form. When software is used, any suitable programming, scripting, or other type of language or combinations of languages may be used to implement the teachings contained herein. However, software need not be used exclusively, or at all. For example, as will be understood by those of ordinary skill in the art without requiring additional detailed discussion, some embodiments of the systems and methods set forth and disclosed herein may also be implemented by hard-wired logic or other circuitry, including, but not limited to application-specific circuits. Of course, various combinations of computer-executed software and hard-wired logic or other circuitry may be suitable, as well.
The controller 60 may store results of previous comparison between the digital output 50 and the one or more predetermined limits for subsequent review and analysis. For example, the controller 60 may store set and release events by the date, time, and actual force applied for subsequent review and analysis. Alternately or in addition, the controller may display the results of the comparison between the digital output 50 and the one or more predetermined limits on one or more visual indicators 62 shown in
In particular embodiments, the controller 60 may further selectively enable operation of the take-up device 16 and/or means for applying force to the coupling 40. For example, the controller 60 may enable operation of the motor 32 shown in
The particular embodiments described and illustrated in
This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they include structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.
