Railway rolling stock – Monorail
Reexamination Certificate
1999-09-01
2002-03-26
Morano, S. Joseph (Department: 3613)
Railway rolling stock
Monorail
C104S118000
Reexamination Certificate
active
06360673
ABSTRACT:
TECHNICAL FIELD OF THE INVENTION
The invention relates to an article conveying system utilizing a conveying train including a tug or locomotive and sequentially connected article conveying cars, the cars including a chassis and article tray. In particular, the invention relates to an improved chassis for the article conveying cars.
BACKGROUND OF THE INVENTION
Automated article conveying and sorting systems are widely used for receiving, transporting and discharging articles by and between receiving and discharge stations. Such systems are widely used for transporting and classifying articles in such operations as package shipment and delivery systems, warehouse storage and retrieval operations, and bulk postage handling operations.
In some applications, powered belt-type or roller conveyors are utilized for article transportation and sorting operations. Another type of article transportation and sorting system utilizes track mounted article conveying cars driven by a belt or chain which is powered by a stationary drive motor. Yet another system utilizes a conveying train including a powered tug or locomotive and sequentially connected article conveying cars for moving articles around a path including loading and discharge stations. In some cases the article conveying cars are equipped with tilting trays for receiving and discharging articles at various locations around the perimeter defined by the track. Mechanical or electromechanical devices such as cams, limit switches and location sensors may be utilized to control the tilting action of the trays during the transportation operation.
The operation of the article conveying train may be controlled by one or more microprocessors and a microprocessor may be employed to monitor and control the operation of the conveying train. Such a system may employ a stationary microprocessor and a mobile microprocessor mounted on the tug or locomotive with appropriate communication devices as well as various sensors, actuators and control devices for monitoring and controlling the operation of the system. One such system is disclosed in U.S. Pat. No. 5,632,589, titled “Apparatus for Centralized Mechanical and Systems Control in a Material Handling System,” issued May 27, 1997, and assigned to Symorex, Inc. Another such system is disclosed in U.S. Pat. No. 5,662,045, titled “Locomotive for Material Handling Train,” issued Sep. 2, 1997, and assigned to Symorex, Ltd., while another such system entitled “Track for Sortation Handling Equipment” is disclosed in U.S. Pat. No. 5,555,814, issued Sep. 17, 1996, and assigned to Symorex, Inc. The disclosures of U.S. Pat. Nos. 5,632,589; 5,662,045; and 5,555,814 are incorporated herein by reference for all purposes.
In an article sorting system utilizing a powered tug or locomotive to pull consecutively coupled article conveying cars, a monorail track is often used. In order to traverse a continuous path between loading and discharge stations, the track must incorporate arcuate sections. Additionally, depending upon the particular control system used, the speed of the conveying train must be closely controlled in order to effect the proper sequencing of loading and unloading articles. For example, if the unloading sequence is keyed or triggered by the expected location of the train or a particular article conveying car at a given time, the failure of the train to be in the proper position at the designated time may result in overloading or mis-loading a car, damaged articles or packages, clogged or jammed auxiliary chutes or conveyors and system downtime. Thus, close control of the article conveying train's speed can be a critical factor in the operation of such a system.
The cars utilized in a tug or locomotive powered train in an article conveying system as described above typically employ at least two sets of wheels for traversing the monorail track. The two sets of wheels are normally located adjacent to opposing ends of the car. Outrigger and guide wheels may also guide and stabilize the car as it traverses the monorail. In order to provide the necessary stability to the car, especially if the car is equipped with a tilting tray for discharging articles, the car must maintain a fixed position relative to the monorail track. Usually the wheels of the car are depended upon to maintain the car in the proper position relative to the track. However, if the wheels are fixed in position relative to the track and the tilting tray mechanism carried by the car, additional frictional forces will be generated between the wheels and the track as the car traverses arcuate portions of the track. The additional frictional forces generated as a plurality of such cars are pulled through an arcuate section of track will tend to slow the train, thereby interfering with operation of the conveying and sorting system. The extent of the frictional forces will depend upon the relative spacing of the car wheels along the car chassis, the radius of curvature of the arcuate track section, the type of wheels used and other factors. The problem is accentuated when a monorail track is used due to the close tolerances between the car wheels and rail required to give the car the required stability. Although the problem may be alleviated through the use of a segmented, articulated car chassis permitting independent movement of the different sections of the car, such cars are more complicated and expensive to produce and maintain and present additional problems. Additionally, article conveying cares with segmented chasses may not be suited for use in certain applications where the rigidity of conventional chassis is required.
SUMMARY OF THE INVENTION
The present invention provides an improved truck for supporting a car on a rail structure, such as a trolley car forming part of a conveyor system. Such a truck includes a carriage, a yoke connected to the carriage by a rotatable support, such that the yoke can rotate in a horizontal plane relative to the carriage, a plurality of guide wheels, fixtures that mount each wheel to the yoke optionally at horizontally offset positions with predetermined spacing to conform to the rail structure, such that rotation of the yoke relative to the carriage causes the wheels to move in unison to conform to a curve in the rail structure. An articulated yoke of the invention is specially adapted for supporting one or more wheels on opposite sides of a monorail. A conventional material carrying device may be mounted on the carriage. Such a material carrying device may be as simple as a horizontal platform, or as complex as a tilt-tray mechanism. The fixtures that mount the wheels to the yoke are preferably not mounted on casters, i.e, rotatable axles. Instead, such wheels are mounted to the yoke using a fixture that does not substantially swivel. However, the yoke uniting the wheels is mounted to the carriage in such a manner that the yoke and wheels can swivel in unison relative to the carriage about a “virtual axle” which may be offset from the actual vertical axes of the individual wheels. Such an arrangement, particularly when a pair of yokes are mounted at front and rear portions of the carriage, provides a rail-borne car which moves smoothly around curves yet is securely mounted in its associated rail or rails.
In one embodiment, a trolley car for conveying articles along a monorail having arcuate portions includes a rigid frame having a longitudinal axis and opposed ends. A pair of rotatable yokes are coupled to the frame adjacent to the opposed ends of the frame for rotational movement around an axis perpendicular to the longitudinal axis as the trolley car travels along an arcuate portion of the monorail. Each of the yokes has a pair of opposed arms extending from the mainframe and a pair of guide wheels are mounted on each of the opposed arms for rotational contact with a guide surface of the monorail. The trolley car also includes a load bearing wheel mounted adjacent to each of the opposed ends of the rigid frame. Each of the load bearing wheels is moveable around an axis perpendicular
Graefer Dominik
Herrin Richard L.
Jorgenson Edward
McCarry, Jr. Robert J.
Morano S. Joseph
Philip G. Meyers Intellectual Property Law, P.C.
Siemens ElectroCom L.P.
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