Patent Application
20110146527
This patent disclosure relates generally to railroad track construction, maintenance, and service equipment and, more particularly, equipment for sorting and orienting tie plates that are retrieved from a rail bed before being placed between a rail and rail ties.
Equipment for mechanically placing tie plates between rails and rail ties has been proposed in the past. One example of a proposed tie plate placer machine can be found in U.S. Pat. No. 5,655,455 (“the '455 patent”). The tie plate placer disclosed in the '455 patent includes a mobile frame travelling on a railroad track that collects loose tie plates from the rail bed and places them in a magazine for holding and for later positioning on a selected rail tie and underneath the rail. A rail jack lifts the rail away from the tie to allow insertion of the tie plate, and an insertion arm and plate urge a tie plate from the magazine into position between the tie and the rail.
In the device disclosed in the '455 patent, tie plates are retrieved from the rail bed and stored in a collection bed. Operators manipulating magnetic frames sort and orient the collected tie plates into magazines, which are associated with the mechanism that places the tie plates between the rail and the rail ties. Such manipulation of tie plates is susceptible to operator error, and, in part because it requires a dedicated operator for each side of the track during operation, it has an increased cost of operation.
Another example of a known automated tie plate orientation sensor arrangement and a known tie plate sorting and orientation device are shown, respectively, in U.S. Pat. Nos. 4,727,989 (“the '989 patent”) and 4,907,686 (“the '686 patent”). The device disclosed in the '989 patent is used for determining the current orientation of tie plates using a series of spaced fingers that are pivotable relative to a bar and are arranged across a conveyor carrying the tie plates. Contact between the tie plates and the fingers causes pivotal displacement of the fingers, which act as whiskers to determine the contour and, thus, the orientation of the plates carried by the conveyor. When re-orienting the plates, the device disclosed in the '686 patent includes an inclined conveyor having devices that arrest the descent of individual tie plates along the conveyor. Actuators then flip each tie plate to a correct orientation.
Such and other proposed devices for sensing the orientation of tie plates, whether operating in a manual or automatic fashion, are time consuming and/or involve complicated mechanisms that can be unreliable, inaccurate, costly, and/or inefficient to operate when sorting and orienting tie plates at a high rate for prolonged periods or in inclement weather conditions.
In one aspect, the disclosure describes a machine for automatically orienting railroad tie plates that includes a sensing region having at least one optical sensor adapted to sense a physical feature of a tie plate. An electronic controller is connected to the optical sensor and is disposed to receive a sensor signal indicative of the physical feature of the tie plate when the tie plate is in the sensing region. The electronic controller further determines an orientation of the tie plate based on the sensor signal, compares it to one or more predetermined or possible orientations, and provides a command to at least one actuator adapted to perform at least one tie plate orientation operation to change the orientation of the tie plate based on the comparison of the orientation of the plate with the predetermined orientation.
In another aspect, the disclosure describes a machine for placing tie plates between rails and rail ties in a railroad. The machine includes a tie plate depositor and a tie plate collector arranged to collect individual tie plates strewn along a rail bed. A machine frame includes wheels riding on the railroad, an engine arranged to power the wheels, and an operator cab. A sorting and orientation portion of the machine includes at least one plate orientation actuator, a sensing region, and a conveyor system extending between the collector, the sensing region, the sorting and orientation portion, and the tie plate depositor. At least one optical sensor is associated with the sensing region and is connected to the machine. The at least one optical sensor is adapted to sense a physical feature of at least one tie plate passing through the sensing region while transported by the conveyor system. An electronic controller receives a sensor signal indicative of the physical feature of a tie plate as it passes through the sensing region. The electronic controller is arranged to determine an orientation of the tie plate based on the sensor signal, designate one of four predetermined orientations to each tie plate that passes through the sensing region, and provide a command signal to the at least one plate orientation actuator to change the orientation of the tie plate based on the designated predetermined orientation before the tie plate is provided to the tie plate depositor by the conveyor system.
In yet another aspect, the disclosure describes a method for automatically sorting and orienting tie plates in a tie plate placing machine. The method includes sensing at least one physical feature of each tie plate by scanning a portion thereof with an optical sensor. A signal indicative of the physical feature is provided to an electronic controller that determines an orientation of each tie plate based on the signal. The orientation of each tie plate is compared to one or more possible, predetermined orientations, and an orientation designation is assigned to each tie plate. Each plate is thereafter re-oriented based on the orientation designation.
This disclosure relates to machines and equipment for use during installation, replacement, service, and/or maintenance of railroad tracks. Routine maintenance of a railroad track includes replacement of certain railroad ties. Railroad tie replacement can include various operations, such as removing spikes that secure the tie plates to the cross ties, replacing the cross ties beneath the rail, and retrieving and reinstalling the tie plates, which have typically been strewn on the rail bed beside the track during the removal phase. Machines and devices for removing and reinstalling spikes and cross ties, as well as machines for collecting tie plates strewn on the rail bed along the track, but the inventors herein know of no commercially successful machines that are known to be currently on the market. The present disclosure relates to a system and method for automatically sorting, checking, and/or orienting tie plates collected from the rail bed for proper orientation during rail installation or re-installation. The embodiments described herein are presented as part of a fully automated machine that can travel along a railroad track while collecting, sorting, and installing tie plates. Although such a machine is useful in railroad track maintenance and installation, other applications are well suited for the systems and methods disclosed. For example, a machine of a different type, or a static installation used for sorting and loading loose tie plates into magazines or other containers, may benefit from the disclosed systems and/or methods.
A partial view of a tie placing machine 100 from a top perspective during operation along a railroad track 101 is shown in
A collector 115 disposed on either side of the machine 100 collects tie plates 103 from the rail bed 105 as the machine 100 moves along the rails 111. The collected tie plates 103 are provided to a conveyor system 117, which in the illustrated embodiment includes two transverse conveyors 119 that carry tie plates 103 from the collectors 115 toward a longitudinal conveyor 121. The direction of motion of tie plates 103 along the conveyor system 117 is denoted by arrows although it can be appreciated that other types of conveyors may be used. Alternatively, other devices or systems may be employed for the transfer of tie plates 103 from one location of the machine 100 to another. In the embodiment illustrated in
In the illustrated embodiment, tie plates 103 are delivered to a sensing portion 125 disposed around at least a portion of the conveyor system 117 as they travel along the longitudinal conveyor 121. In alternate embodiments, the tie plates 103 may pass through the sensing portion 125 by different means, for example, by sliding along an inclined surface.
The sensing portion 125, two embodiments of which are described in more detail relative to
The plate sorting and orientation portion 129 includes actuators 131 that can appropriately orient the tie plates 103 for delivery to one of two tie plate depositors 133 of the machine 100. The tie plate depositors 133 may include a magazine or collector that can receive properly-oriented tie plates 103 for placement under the rails 111 by any known device, for example, the actuator arms and associated structure disclosed in the '455 patent. The actuators 131 may operate in response to commands from the electronic controller that is in communication with the sensors 127, such that each tie plate 103 may be uniquely manipulated to achieve a specific orientation before entering into each tie plate depositor 133. The actuators 131 may perform additional functions, such as distributing tie plates 103 to the right or left side of the machine 100, as required, reject plates found to be defective, and so forth. As illustrated, the machine 100 may further include other structures, for example, a rail lifting structure 135 for lifting the rails 111 away from the ties 107 during insertion of tie plates 103, an operator cabin 137, an engine, and others.
Certain types of tie plates, especially those used in modern railroad tracks that are suitable for high speed rail traffic, are asymmetrical and require installation in a specific orientation. A cross section of a typical tie plate 200 installed between a rail 202 and a rail tie 204 is shown in
As is more particularly shown in
The rail seat portion 212 is part of a channel that accommodates the base 216 of the rail 202. When the rail 202 is disposed within the channel on the rail seat portion 212 of the tie plate 200, the rail 202 is inclined at the camber angle α relative to vertical. As can be appreciated, the rail seat portion 212 requires the tie plate 200 to be installed at a unique orientation when positioned onto the rail tie 204. Hence, the tie plate 200 itself has a gage side 218 and a field side 220 as dictated by desired positioning of the rail seat portion 212 on one side of the rail tie 204 or the other. This asymmetry of the tie plate 200 is taken under consideration when orienting tie plates that are collected from the rail bed or are provided to a tie plate placing machine in bulk and enter the machine in random orientations. As can be seen in
A partial outline view of the sensing portion 125 (
In an alternate embodiment, the sensors 301 may include a visual image acquisition device, such as a digital camera or, in general, a charge coupled device (CCD) image sensor or complementary metal oxide semiconductor (CMOS) technology to capture visual representations or pictures of the tie plate in a digital format. This digital image of the tie plate may be stored in an appropriate memory device and used in subsequent operations as described below.
In the embodiment illustrated in
Together, the two sensors 301 are arranged to sense the contour of each side of the tie plate 200 along the lines 313 “painted” by the beams 307 or, alternatively or in addition thereto, based on visual data or pictures of the tie plate acquired from the sensors 301. In the illustrated embodiment, the beams 307 emanating from the emitters 303 are arranged to impinge onto the surface of the plate 200 at an angle relative to the receiver portions 305 such that a clear view of the painted line on the surface of the plate 200 is provided for the receiver portion 305 of each sensor 301. In the illustrated embodiment, the beams 307 impinge perpendicularly onto the plate 200 to provide the painted line 313, which is then viewed and captured by each receiver portion 305. Visual acquisition of the painted line 313 is analyzed to provide a set of points from each side of the plate 200 for further processing. In regard to the bottom side of the plate, points on the contour are collinear so a subset of all visible points may be selected. However, points on the rail side contour of the plate may be selected to illustrate various areas of interest of the plate, such as the locations of the edges of the plate, the peaks of the shoulders surrounding the rail seat portion of the plate, and so forth.
The contour information gleamed from the tie plate 200 is provided to the electronic controller 309. In addition to the contour information, other information about the tie plate 200 may be acquired from the signals provided by the sensors 301. For example, the length or total dimension of the tie plate 200 may be determined. Further, the thickness of the tie plate 200 at the various portions thereof may be calculated by comparing the signals provided by the two sensors 301. In one embodiment, the beams 307 may sweep the entire surface on either side of the tie plate 200 by sweeping the beams 307 vertically along the height of the tie plate 200 as it passes through the sensing region 311. Such sensor operation may provide additional information about the tie plate 200, such as the presence of foreign matter on the tie plate 200, the planarity of the various portions thereof, the presence of bent portions or chipped-off corners, the surface finish as an indication of corrosion of the tie plate 200, the presence of cracks, and/or any other quality-related aspect of the tie plate 200 as an indication of suitability for its use or reuse. Use of the sensing systems described herein, as well as other types of sensors, advantageously possesses adequate resolution to adequately discern subtle features of the tie plate, such as the angle of the rail seat portion, which can be as little as 1.43 degrees (see, for example, discussion relative to
A partial outline view of an alternative embodiment of a sensor arrangement in the sensing portion 125 (
A block diagram for one embodiment of a control system 500 used to determine the orientation of tie plates based on sensor input is shown in
In the illustrated embodiment, the control system 500 is operably connected to and arranged to receive information from one or more sensors 502, for example, the sensors 301 shown in
In the illustration of
Returning now to
Given the four possible orientations of plates entering the sensing region 311, the plate orientation determinator 506 considers the orientation of the sensed plate contour 510, which is compiled based on the information provided by the sensors 502, and assigns to each plate 200 an orientation designation in accordance with, for example, the information tabulated in Table 1 table, which is shown below, or a similar collection of information:
For instance, in the orientation of the plate 200 shown entering the sensing region in
The plate orientation determinator 506 may specifically determine the certain plate orientation operations that are required for each plate based on the predetermined orientation designation. For example, a plate having a designation orientation of “3” may be inverted if the plate is destined for installation on the right side of the machine as it travels along the track. This and other predetermined orientation operations can be accomplished by allowing the plate to proceed through the machine and by appropriately commanding one or more actuators to invert and/or rotate the plate in a single or in multiple successive operations before the plate is provided to portions of the machine performing its installation beneath the rail, for example, the plate depositors 133 (
Following the determination of the specific plate orientation steps that should be performed at the plate orientation determinator 506, the control system 500 may optionally determine which side of the railroad track or which side of the machine 100 (
A first orientation process 522 may adjust the top-to-bottom orientation of the plate. In other words, the first orientation process 522 may be activated when plate orientation determinator 506 determines that the sensed plate is inverted relative to an appropriate installation orientation. In these instances, the first orientation process 522 may command an inversion actuator 524 to invert the plate as the plate travels through a sorting system of the machine 100 (
Returning now to
After plate orientation is sensed and adjusted, the tie plates are delivered to one or more plate depositors, for example, the plate depositors 133, or may alternatively or additionally be loaded onto a magazine (not shown) at 530. Examples of depositors can be found in the '455 patent discussed above. Magazines for use with railroad tie plates are also known in the art.
The disclosure further provides a method for automatically sorting tie plates collected from the field during construction, repair, or maintenance of railroad tracks. The automation of the tie plate sorting process presents a considerable advancement of the current state of the art, which relies on manual sorting and operations. The current manual operations are time consuming, prone to operator error, and further place workers close to large equipment having numerous moving parts. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context.
A flowchart for a method of sorting and adjusting the orientation of tie plates is shown in
The classification of tie plates can be used to sort tie plates as they are collected from the field, and to reject incorrect-type tie plates that may be accidentally mixed in with the proper type of tie plate for a certain application and/or reject other metallic debris that may have been collected, such that the tie plate installation process is not needlessly delayed. Moreover, the system may detect bent or damaged tie plates and reject them before they enter a supply stream of plates provided to tie plate depositors on a machine, such as those shown in
The visually acquired and/or otherwise sensed physical dimensions and attributes of each individual tie plate collected from the field may be further used to determine the orientation of each tie plate at 604. The orientation determination may occur before, after, or concurrently with the determination of the tie plate type at 602. Although the orientation of a tie plate may be adjusted to a desired orientation for placement on a railroad track, defective tie plates and/or debris collected from the rail bed, such as spikes, other metallic components, and so forth, are rejected at 606 following an evaluation or decision at 608. The decision to accept or reject a tie plate or other objects being scanned may be based on a comparison of one or more physical attributes of the object being scanned, such as a digital photograph, a measurement of length or thickness of the object, the presence or absence of a particular feature, such as a slanted rail seat surface, and so forth, with a predetermined feature or aspect that is stored in an appropriate form at within an electronic controller.
Following successful acceptance of a tie plate at 608, the tie plate may be assigned to a track side of a tie plate depositor machine at 610 before or after the tie plate undergoes a re-orientation process at 612. Having determined the orientation of a tie plate at 604, and considering that asymmetrical tie plates may be used on either side of the track of a railroad, it can be appreciated that a reversal and/or rotation of a tie plate may be required before it is provided to a tie plate depositor device or placed in a stack or magazine for later deposition. The assignment to a track side 610 may be selectively made based on the requirements of a depositor operation. Alternatively, the assignment to a track side at 619 may be made based on the orientation of a particular tie plate as it is collected from the field. This alternate embodiment may advantageously increase the speed of the machine by eliminating at least one re-orientation operation of the plate when applicable. Orientation of a tie plate may include one or more active re-orientation operations performed to change the top-to-bottom or field-to-gage side orientation of a tie plate.
After each tie plate has been successively scanned, sorted, and/or properly oriented, it is delivered to a tie plate depositor portion of a machine, for example, the tie plate depositor 133 (
It will be appreciated that the foregoing description provides examples of the disclosed system and technique. However, it is contemplated that other implementations of the disclosure may differ in detail from the foregoing examples. All references to the disclosure or examples thereof are intended to reference the particular example being discussed at that point and are not intended to imply any limitation as to the scope of the disclosure more generally. All language of distinction and disparagement with respect to certain features is intended to indicate a lack of preference for those features, but not to exclude such from the scope of the disclosure entirely unless otherwise indicated.
