This disclosure generally relates to guideway systems, and more particularly, to a guideway switching mechanism for a guideway system.
A guideway system generally refers to a type of transportation system in which automated transport vehicles are guided along predetermined paths using a guideway made of structurally rigid materials including metal and/or concrete. While typical railway systems use a pair of elongated steel rails that are spaced apart a specified distance from one another and configured to guide its associated transport vehicles using flange-shaped wheels, guideway systems utilize a single elongated guideway for guidance of its associated transport vehicles. The guideway provides guidance of the automated transport vehicle along specified paths and may include running surfaces for support of the wheels of the automated transport vehicle.
According to one embodiment, a guideway switching mechanism includes an elongated section of flexible guideway coupled to a switch plate. The flexible guideway has a first end that may be coupled to a first elongated guideway and a second end that may be selectively coupled to one of a multiple quantity of alternative guideways. The switch plate provides selective coupling of the flexible guideway to multiple alternative guideways by movement through an arcuate path such that the automated transport vehicle may selectively move from the first elongated guideway to either of the alternative guideways.
Some embodiments of the disclosure may provide numerous technical advantages. Some embodiments may benefit from some, none, or all of these advantages. For example, according to one embodiment, flexible guideway may provide motive force the automated transport vehicle while moving through the guideway switching mechanism. This may be due, at least in part to the properties of the guideway that remain essentially continuous throughout the guideway switching mechanism. For linear induction motors, therefore, that generate motive force using the guideway, the automated transport vehicle may remain under power while transitioning through the guideway switching mechanism.
Other technical advantages may be readily ascertained by one of ordinary skill in the art.
A more complete understanding of embodiments of the disclosure will be apparent from the detailed description taken in conjunction with the accompanying drawings in which:
Guideway systems incorporating a single elongated guideway may provide certain advantages over railway systems having multiple rails. For example, guideways may be used in conjunction with linear induction motors to provide a motive force for movement of transport vehicles along the guideway. Switching of the transport vehicle among multiple guideways or paths is not easily accomplished, however, due to their obstruction of the wheels of transport vehicle when extending in a path that is different from the chosen path of the transport vehicle.
Automated transport vehicle 24 may be any type of vehicle suitable for movement along first guideway 16, alternative guideways 22a, 22b, and 22c, and flexible guideway 12. In one embodiment, motive force for movement of automated transport vehicle 24 may be provided by a linear induction motor (not specifically shown) in which first guideway 16, alternative guideways 22a, 22b, and 22c, and flexible guideway 12 serves as a stator portion of the linear induction motor. Certain embodiments of the present disclosure may provide an advantage in that the flexible guideway 12 may continue to provide motive force for automated transport vehicle 24 while transitioning through the guideway switching mechanism 10.
In one embodiment, guideway switching mechanism 10 may be implemented such that automated transport vehicle 24 diverges from one first guideway 16 to one of multiple alternative guideways 22a, 22b, or 22c. In another embodiment, guideway switching mechanism 10 may be implemented such that the automated transport vehicle 24 merges from multiple alternative guideways 22a, 22b, and 22c into a single first guideway 16. That is, the switching function of the guideway switching mechanism 10 may be reversed to provide a merging operation from among a plurality of alternative guideways 22a, 22b, and 22c as opposed to diverging from a single first guideway 16 to multiple alternative guideways 22a, 22b, and 22c.
The term “pre-fabrication” may be referred to, in this disclosure, as the act of creating support substrate 30 at one location, and subsequently installing and using the created support substrate 30 at a different location. In one embodiment, guideway switching mechanism 10 may be fabricated in multiple sub-sections 32a through 32f (
Bending of flexible guideway 12 may be provided by a switch plate 18. Switch plate 18 is disposed in a generally arc-shaped cavity 34 that allows the switch plate 18 to freely move in a generally lateral arcuate path. An actuator 36 may be provided for movement of the switch plate 18. The actuator 36 may be any suitable type, such as a hydraulic piston, a servo mechanism, or an electric motor.
The length of travel of the switch plate 18 may be based upon the quantity of alternative guideways 22a, 22b, and 22c implemented and the breadth of the wheels of automated transport vehicle 24. For example, to provide for clearance between the wheels of automated transport vehicle 24 and an adjacent alternative guideway 22a, 22b, or 22c, each alternative guideway 22a, 22b, and 22c may be placed at least half the wheel breadth of automated transport vehicle 24 apart.
The speed at which the actuator 36 is operable to alternatively couple alternative guideways 22a, 22b, and 22c may be directly proportional to the rate at which automated transport vehicles 24 move through guideway switching mechanism 10. In one embodiment, actuator 36 moves switch plate 18 at a speed of approximately 10 feet-per-second such that automated transport vehicles 24 moving at approximately 90 feet-per-second may be properly guided to their desired alternative guideway 22a, 22b, or 22c.
As best shown in
Lateral bending of rigid sub-sections 42a and 42b relative to one another may be provided by articulation along a joint 44. A multiple quantity of joints 44 configured on flexible guideway 40 allows it to bend along an arc for selectively coupling second end 14b to either of alternative guideways 22. The stiffness of joint 44 may also be controlled from a relatively low stiffness to allow bending to a relatively high stiffness for guiding automated transport vehicle 24 along its selected path.
Selective stiffness of joint 44 may be provided by any suitable approach. In the particular embodiment shown, two pistons 46 are included that are coupled at either end to adjacent sub-sections 42a and 42b. Pistons 46 have a length L that varies proportionally with articulation of joints 44 and have an adjustable stiffness. The stiffness of pistons 46 generally refers to their level of resistance to a change in its length L. Thus, by controlling the stiffness of pistons 46, the relative stiffness of joint 44 is effectively controlled. In the particular embodiment shown, two pistons 46 are used to control the stiffness of joint 44; however, any quantity of pistons 46, such as one piston, or three or more pistons may be used to control the stiffness and thus lateral articulation of their associated joint 44.
In one embodiment, pistons 46 may be filled with a magneto Theological fluid to control its stiffness. A magneto Theological fluid is a substance having a viscosity that varies according to an applied magnetic field. Typical magneto Theological fluids include ferro-magnetic particles that are suspended in a carrier fluid, such as mineral oil, synthetic oil, water, or glycol, and may include one or more emulsifying agents that maintain suspension of these ferro-magnetic particles in the carrier fluid. Pistons 46 may operate, therefore, in the presence of a magnetic field to control the stiffness of pistons 46 and thus, the stiffness of joint 44 to which they are coupled.
Modifications, additions, or omissions may be made to guideway switching system 10 without departing from the scope of the disclosure. The components of guideway switching system 10 may be integrated or separated. For example, flexible guideway 12 may be integrally formed with switch plate 18 such that actuator 36 is directly coupled to flexible guideway 12. Moreover, the operations of guideway switching system 10 may be performed by more, fewer, or other components. For example, support substrate 30 may include other structural features not specifically described to support the weight of automated transport vehicle 24 and/or maintain flexible guideway 40 in proper alignment with first elongated guideway 16 and alternative guideways 22. Additionally, operations of actuator 36 and/or pistons 46 may be controlled by a suitable controller that may include, for example, logic comprising software, hardware, and/or other suitable forms of logic. As used in this document, “each” refers to each member of a set or each member of a subset of a set. Additionally, the drawings are not necessarily drawn to scale.
Although the present disclosure has been described with several embodiments, a myriad of changes, variations, alterations, transformations, and modifications may be suggested to one skilled in the art, and it is intended that the present disclosure encompass such changes, variations, alterations, transformation, and modifications as they fall within the scope of the appended claims.
This application claims priority to U.S. Provisional Patent Application Ser. No. 60/978,958, entitled “GUIDEWAY SWITCHING MECHANISM,” which was filed on Oct. 10, 2007.
Number | Date | Country | |
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60978958 | Oct 2007 | US |