Patent Application
20100104414
1. Field of the Invention
The present invention relates to a workpiece transport assembly and a method of using the same.
2. Description of the Prior Art
The present invention relates to moveable transport systems or carriers used in vehicle, tracker, airplane or other manufacturing operations which permit assembly workers to walk about the transport system and perform various assembly operations on a workpiece being moved by such transport system. These carriers are widely used to move workpieces of various shapes and sizes, such vehicle bodies or airplane fuselages, throughout manufacturing and storage facilities. It is known in the prior art to transport carriers through the manufacturing or storage area via a conveyor system. The conveyor system can include a power and free (PF) system, an overhead PF system, a friction drive system (FDS), an overhead FDS, an electrified monorail system (EMS), an overhead EMS, etc. Such conveyor systems are bulky, costly and take up much needed space in a manufacturing facility.
The subject invention relates to a workpiece transport assembly having a reaction rail that is spaced from a production floor surface. The reaction rail defines a travel path along an axis. The assembly includes an automatic guided vehicle having a guide wheel that drives the automatic guided vehicle along the production floor surface. A frame is releaseably attached to the automatic guided vehicle and defines a work area for assembling a workpiece. The automatic guided vehicle transports the frame to the reaction rail. The workpiece transport assembly includes a drive wheel assembly that is mounted to the frame. The drive wheel assembly includes a drive wheel that is movable between a drive wheel engaging position where the drive wheel engages the reaction rail to move the workpiece transport assembly along the reaction rail and a drive wheel disengaging position where the drive wheel disengages the reaction rail. The workpiece transport assembly is driven by at least one of the guide wheel and the drive wheel for movement through the assembly operation.
The present invention further provides for a method of transporting a workpiece on a workpiece transport assembly. The workpiece transport assembly includes a frame with a drive wheel assembly and at least one guide roller assembly attached thereto. The workpiece transport assembly further includes an automatic guided vehicle that releaseably attaches to the frame. To begin, the automatic guided vehicle releaseably engages the frame. The automatic guided vehicle with the frame releaseably engaged thereto is then guided into a production area having a reaction rail where the frame is aligned with the reaction rail. Next, the drive wheel of the drive wheel assembly is moved from a drive wheel disengaging position to a drive wheel engaging position. The workpiece transport assembly is then driven with the drive wheel assembly along the reaction rail. Next, the drive wheel of the drive wheel assembly is moved from the drive wheel engaging position to the drive wheel disengaging position. The frame is then guided from the reaction rail with the automatic guided vehicle.
Other advantages of the present invention will be readily appreciated, as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:
A workpiece transport assembly 20 is generally shown in the Figures for moving a workpiece through an assembly operation. The workpiece transport assembly 20 includes an automatic guided vehicle 22 for driving on a production floor surface 24, a frame 26 for attachment to the workpiece and a drive assembly for driving the workpiece transport assembly 20 as an assembly, or the frame 26 alone, against a reaction rail 28 along a travel path 30 along an axis A.
The frame 26 is releaseably attachable to both of the automatic guided vehicle 22 and the reaction rail 28. The frame 26 includes at least one crossbar 32, preferably a plurality of crossbars 32, that extends horizontally for releaseably attaching to the automatic guided vehicle 22, the workpiece and a guide roller assembly 34. The plurality of crossbars 32 define a work area 36 where the workpiece is assembled. The frame 26 includes a hitch assembly for releaseably attaching the automatic guided vehicle 22 to the frame 26. The hitch assembly is attached, or formed with, at least a part of one of the plurality of crossbars 32 at a predetermined position thereon.
The frame 26 is provided for mounting the workpiece thereto to permit workers in a certain production area to work on the workpiece while the workpiece is moving along the travel path 30. The workpiece may include for example, without limitation, a vehicle, vehicle body, furniture, tractor or airplane.
At least one support beam 38 extends from the work area 36 toward the reaction rail 28. In the exemplary embodiment, a plurality of support beams 38 are shown. At least one leg portion 40 extends from the work area 36 toward the production floor surface 24. In the exemplary embodiment, a plurality of leg portions 40 are shown. At least one roller wheel 42 extends from the frame 26 to engage the production floor surface 24 to move the frame 26 along the travel path 30. In the exemplary embodiment, a plurality of roller wheels 42 are shown and the plurality of roller wheels 42 engage the frame 26 at the plurality of leg portions 40. The plurality of roller wheels 42 permit the frame 26 to roll on the production floor surface 24. The embodiment shown in
At least one guide roller assembly 34 extends from the frame 26 to engage the reaction rail 28. The at least one guide roller assembly 34 includes at least two guide rollers 44 each positioned on opposite sides of the reaction rail 28 to provide lateral support to the frame 26, and more broadly to the workpiece transport assembly 20. The embodiment shown in
The guide roller assembly 34 includes a support bracket 46 that secures the guide rollers 44 to the frame 26. A guide roller support bar 48 extends from the frame 26 to the support bracket 46 for securing the guide roller assembly 34 to the frame 26.
The frame 26 may include at least one frame bumper 50 that is mounted to the frame 26. In the exemplary embodiment, the frame bumper 50 is mounted to a front portion of the frame 26, but may be mounted to any of the sides of the frame 26. It should be appreciated that such a frame bumper 50 may be useful for mounting the guidance systems 52 and/or for pushing each transport assembly along in the event of a failure of an adjacent assembly. The frame 26 may include multiple bumpers disposed on the side portions of the frame 26. Further, the frame bumper 50 may be pivotably mounted to at least one side of the frame 26 about a horizontal axis.
The frame bumper 50 may be removed from the frame 26. In this embodiment, the automatic guided vehicle 22 is permitted to move underneath the frame 26 both at a rear portion of the frame 26 and a front portion of the frame 26. As a result, it may be possible to provide for the automatic guided vehicle 22 to be driven into and out of engagement with the frame 26 in one direction. In addition, the automatic guided vehicle 22 can be driven into and out of engagement with the frame 26 in one direction even while the frame 26 is being driven by the drive wheel assembly 54. In this embodiment, it is possible to permit the frame 26 to be driven at slow speeds such as one foot per hour while detaching the automatic guided vehicle 22 from the frame 26 in order to more efficiently use the automatic guided vehicle 22 during this portion of the production area for another purpose or for use with another frame 26.
The drive wheel assembly 54 is mounted to the frame 26. The drive wheel assembly 54 includes a drive wheel 56 that is capable of moving between a drive wheel engaging position and a drive wheel disengaging position. The drive wheel 56 engages the reaction rail 28 in the drive wheel 56 engaging position for moving the workpiece transport assembly 20 along the reaction rail 28.
The drive assembly includes a drive motor, gear reducer, tensioner and a spring loaded drive wheel 56. Such an arrangement is more commonly known as a friction drive system. In
The reaction rail 28 includes a plurality of reaction surfaces 58. In the exemplary embodiment, the reaction rail 28 is generally square, but may be any shape and material known in the art. The reaction rail 28 includes a main portion 60 that is generally square and a staging portion 62 that defines a void 64. The staging portion 62 limits the contact between the reaction rail 28 and the drive wheel 56 at the staging portion 62. As seen in
The reaction rail 28 may be spaced horizontally from the work area 36 as shown in
The reaction rail 28 may be designed to inductively transmit power to the drive wheel assembly 54 and in turn also to charge a battery mounted on the automatic guided vehicle 22 while receiving power from the inductive reaction rail 28. Alternatively, the battery in the automatic guided vehicle 22 may provide power to the drive wheel assembly 54.
Automatic guided vehicles 22 (AGVs) are used throughout the material handling industry to transport loads. The term automatic guided vehicle 22 is commonly used to refer to robust vehicle designs having any of a number of available automated guidance systems 52. Automatic guided carts (AGCs) is a term commonly used to refer to a less robust vehicle used for similar but less complicated applications. Throughout this application, including the claims, the term automatic guided vehicle 22 shall mean and include both AGVs and AGCs, as well as any other vehicle that is automatically guided.
The automatic guided vehicle 22 includes a guide wheel 66 that is driven by a guide motor to move or guide the automatic guided vehicle 22 along the production floor surface 24. The automatic guided vehicle 22 may be used to transport the frame 26 on the production floor surface 24 from one area of a production facility, such as the end of an assembly area, to another production area such as the beginning of the assembly area, or a storage location. The automatic guided vehicle 22 is releaseably attached to the frame 26 to provide for interchangeability of an automatic guided vehicle 22 with any given frame 26.
A guide wheel lifter 68 may be provided on the automatic guided vehicle 22 or mounted to the frame 26 to selectively lift the guide wheel 66 into or out of engagement with the production floor surface 24. It should be appreciated that the guide wheel 66 may also be engaged and disengaged by other known means besides the guide wheel lifter 68. In the exemplary embodiment, the guide wheel lifter 68 is secured to the frame 26 for moving the guide wheel 66 between the guide wheel 66 engaging position and the guide wheel disengaging position. In an alternative embodiment, as shown in
As is the case with most automatic guided vehicles 22, the automatic guided vehicle 22 can be provided with on-board or off-board electronics including, for example, on-board computer and on-board guidance systems 52 or off-board guidance systems 52. The guidance system 52 in communication with the automatic guided vehicle 22 for controlling the movement of the automatic guided vehicle 22 along the production floor surface 24.
In the exemplary embodiment, the guidance system 52 is shown mounted to the frame 26, but the guidance system 52 may be mounted to the automatic guided vehicle 22. A variety of guidance systems 52 may be used with the automatic guided vehicle 22. These guidance systems 52 generally include inertial guidance, magnetic guidance, active guide wire guidance, laser guidance and optical guidance systems 52. Magnetic guidance systems 52 typically include magnetic tape or magnetic devices installed on the factory floor permitting the automatic guided vehicles 22 to follow the tape using magnetic sensors. Laser and optical guidance systems 52 generally search for targets installed on the walls or other support structures of a production facility. By finding and triangulating or comparing the location of these targets, the guidance system 52 determines the location of the automatic guided vehicle 22 Also, some automatic guided vehicles 22 use inertial guidance as the primary guidance system 52 for each automatic guided vehicle 22. Other guidance systems 52 may be used with the present invention including the use of some combinations of the above systems such as the use of an inertial guidance system 52 in communication with one or more laser systems.
In the exemplary embodiment, the guidance system 52 is mounted with the frame 26 and includes an optic beam mounted in a bumper like arrangement on at least one end of the frame 26. In operation, the automatic guided vehicle 22 is positioned below the frame 26 and releaseably attached thereto. It should be appreciated that the automatic guided vehicle 22 may be programmed to automatically drive underneath the frame 26 into the appropriate mating position with the frame 26. As is known in the industry, the automatic guided vehicle 22 may be operated at speeds ranging from 10 feet per minute to 300 feet per minute. After the automatic guided vehicle 22 is attached to the frame 26, the automatic guided vehicle 22 may further drive the entire workpiece transport system to a production area for alignment of the guide roller assembly 34 and the drive wheel assembly 54 with the reaction rail 28. When the automatic guided vehicle 22 is appropriately aligned and positioned with the reaction rail 28, the guide wheel lifter 68 is engaged causing the guide wheel 66 to no longer be engaged with the production floor surface 24 and the drive wheel assembly 54 is engaged to apply a load against the reaction rail 28 to thereby cause the workpiece transport system to be driven by the drive wheel assembly 54 along at least a portion of the production area having the reaction rail 28. The workpiece transport system when driven with the drive wheel assembly 54 can be driven at extremely slow speeds such as one foot per hour. It should be appreciated that the speed selection depends on many different factors including, for example, the size and weight of the workpiece, and/or the amount of operations required at a certain portion of the travel path 30. At the end of the reaction rail 28, the guide wheel lifter 68 is disengaged causing the automatic guided vehicle 22 drive wheel 56 to engage the floor surface thereby causing the workpiece transport system to be driven by the automatic guided vehicle 22 drive wheel 56 and not the drive wheel assembly 54 on the frame 26. At this point, for example, the automatic guided vehicle 22 may assist in the production work flow by, for example, transporting the frame 26 to another portion of the production area such as the beginning of the production line.
It should be appreciated that the automatic guided vehicle 22 may releaseably attach and detach from the frame 26 at any point during the assembly operation. For example, the automatic guided vehicle 22 may be configured to drive under the frame 26 to releaseably attach to the frame 26 at a first location and to detach from the frame 26 at a second location to drive-out from under the frame. The first location may include, but is not limited to, a storage location, an end of the assembly operation, or any point along the assembly operation. The second location may include, but is not limited to a storage location, the beginning of the assembly operation, or any point along the assembly operation.
Electronic communications between the automatic guided vehicle 22, the frame 26 and a central production area control may also be provided to monitor and/or control certain operations of the automatic guided vehicle 22 and the frame 26 including, for example, the location in the production area, determining which frame 26 is mounted to which automatic guided vehicle 22, relationship guidance between other workpiece transport assemblies 20 moving in the production area, signaling when to operate the driven wheel assembly or the automatic guided vehicle 22 drive wheel 56.
The present invention further provides for a method of transporting a workpiece on a workpiece transport assembly 20. The workpiece transport assembly 20 includes a frame 26 with a drive wheel assembly 54 and at least one guide roller assembly 34 attached thereto. The workpiece transport assembly 20 further includes an automatic guided vehicle 22 that releaseably attaches to the frame 26. To begin, the automatic guided vehicle 22 is guided along a production floor surface 24 to a position adjacent to the frame 26. Next, the automatic guided vehicle 22 is releaseably engaged to the frame 26. The automatic guided vehicle 22 with the frame 26 releaseably engaged thereto is then guided into a production area having a reaction rail 28 where the frame 26 is aligned with the reaction rail 28. The frame 26 includes a guide roller assembly 34 for aligning the frame 26 with the reaction rail 28.
The drive wheel 56 of the drive wheel assembly 54 is next moved from a drive wheel disengaging position to a drive wheel engaging position. The method includes the optional step of moving the guide wheel 66 of the automatic guided vehicle 22 from a guide wheel 66 engaging position to a guide wheel disengaging position. This step can be performed at any time relative to the step of moving the drive wheel 56 from the drive wheel 56 disengaging position to the drive wheel engaging position, but in the exemplary embodiment, these steps are performed simultaneously. The workpiece transport assembly 20 is then driven with the drive wheel assembly 54 along the reaction rail 28.
The drive wheel 56 of the drive wheel assembly 54 is next moved from the drive wheel engaging position to the drive wheel disengaging position. The method includes the optional step of moving the guide wheel 66 of the automatic guided vehicle 22 from a guide wheel disengaging position to a guide wheel engaging position. This step can be performed at any time relative to the step of moving the drive wheel 56 from the drive wheel engaging position to the drive wheel 56 disengaging position, but in the exemplary embodiment, these steps are preformed simultaneously. The frame 26 is then guided from the reaction rail 28 with the automatic guided vehicle 22.
It should be appreciated that the workpiece transport assembly 20 can be used in a variety of applications beyond the illustrated applications.
The foregoing invention has been described in accordance with the relevant legal standards, thus the description is exemplary rather than limiting in nature. Variations and modifications to the disclosed embodiment may become apparent to those skilled in the art and fall within the scope of the invention.
This utility patent application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/107,995 filed Oct. 23, 2008, entitled “Workpiece Transport Assembly and Method of Using Same,” the entire disclosure of the application being considered part of the disclosure of this application, and hereby incorporated by reference.
| Number | Date | Country | |
|---|---|---|---|
| 61107995 | Oct 2008 | US |
