Patent Application
20070213188
1. Field of the Invention
The present invention relates to a glass substrate transferring apparatus and more specifically, to an impression wheel for use in a glass substrate conveying system.
2. Description of the Related Art
During the fabrication of LCD monitors, glass substrates are delivered by a mechanical conveying system. In such a mechanical conveying system, an impression cylinder is provided to impart a proper downward pressure to each glass substrate being delivered so that each glass substrate is smoothly delivered to the assigned place.
The aforesaid cylindrical wheel body 10 wears quickly with use. When the cylindrical wheel body 10 starts to wear, it cannot give a pressure to the whole surface of the glass substrate 13 in a balanced status. Giving an uneven pressure to the glass substrate affects delivery stability. Therefore, when the cylindrical wheel body 10 starts to wear, the cylindrical wheel body 10 must be immediately replaced. It is not economic to frequently replace the cylindrical wheel body of the impression cylinder. It causes a waste to throw away a cylindrical wheel body that has only a small local damage.
The present invention has been accomplished under the circumstances in view. It is the main object of the present invention to provide an impression wheel assembly for transferring glass substrates, which allows replacement of every part thereof that starts to wear. It is another object of the present invention to provide an impression wheel assembly, which does not damage the surface of the glass substrate being delivered. To achieve these and other objects of the present invention, the impression wheel assembly comprises a wheel axle fixedly supported between two brackets of a glass substrate conveying system, and an impression wheel supported on said wheel axle. The impression wheel is comprised of a plurality of roller units mounted on the wheel axle and connected to one another. Each roller unit is comprised of a roller wheel frame and a roller wheel body mounted around the roller wheel frame. The roller wheel frame comprises a hub, a rim concentrically spaced around the hub, and a plurality of spokes equiangularly and radially connected between the hub and the rim. The rim has an annular mounting groove extending around the periphery thereof for supporting the associating roller wheel body. The roller wheel body has an outer diameter greater than the outer diameter of the rim so that the periphery of the roller wheel body configures a glass substrate contact surface. When the roller wheel body of one roller unit starts to wear, the user can replace the damaged roller wheel body without changing the whole impression wheel. Further, the roller wheel body covers the peripheral edge of the rim so that the roller wheel frame of each roller unit is prohibited from touching each glass substrate being delivered.
Referring to FIGS. 2˜6, an impression wheel assembly 20 in accordance with the present invention is shown comprised of a wheel axle 21 and an impression wheel 22. The impression wheel 22 is supported on the wheel axle 21. The impression wheel 22 is formed of a plurality of roller units 30 arranged in parallel and abutted one against another.
Each roller unit 30 comprises a roller wheel frame 40, and a roller wheel body 50 mounted on the roller wheel frame 40. The roller wheel frame 40 comprises a hub 41, a rim 43 concentrically spaced around the hub 41, and a plurality of spokes 42 equiangularly and radially connected between the hub 41 and the rim 43. The rim 43 has two sidewalls 432 arranged in parallel, and an annular mounting groove 431 extending around the periphery. The hub 41 has a first coupling structure 44 at one end, namely, the first end, and a second coupling structure 45 at the other end, namely, the second end. The first coupling structure 44 is comprised of two coupling notches 441 symmetrically formed on the first end of the hub 41 at two sides. The second coupling structure 45 is comprised of two coupling lugs 451 symmetrically formed on the second end of the hub 41.
The roller wheel body 50 is an annular member molded from an elastomeric material, for example, PU (polyurethane). The inner diameter A of the roller wheel body 50 is equal to or slightly smaller than the diameter B of the bottom wall of the annular mounting groove 431 of the rim 43. The outer diameter C of the roller wheel body 50 is greater than the outer diameter D of the rim 43. The periphery of the roller wheel body 50 configures a glass substrate contact surface 52 that has a smoothly arched contour. The width E of the roller wheel body 50 is not less than the width F of the annular mounting groove 431 of the rim 43.
The roller wheel body 50 is mounted in the annular mounting groove 431 of the rim 43. Because of the elastomeric material property and the feature that the inner diameter A of the roller wheel body 50 is equal to or slightly smaller than the diameter B of the bottom wall of the annular mounting groove 431 of the rim 43, the roller wheel body 50 is firmly secured to the annular mounting groove 431 of the rim 43 between the two sidewalls 432. Because the outer diameter C of the roller wheel body 50 is greater than the outer diameter D of the rim 43, the glass substrate contact surface 52 of the roller wheel body 50 protrudes over the rim 43 of the roller wheel frame 40.
Referring to
When a glass substrate is moved over the bottom side of the impression wheel 22, the glass substrate contact surface 52 of the roller wheel body 50 of each roller unit 30 is forced into contact with the surface of the glass substrate, enabling the glass substrate to be moved smoothly forwards. Because the roller wheel body 50 is made of an elastomeric material and the glass substrate contact surface 52 has a smoothly arched contour, the roller wheel body 50 does not cause any damage the surface of the glass substrate.
In case the impression wheel 22 starts to wear after a long use, the user can detach the damaged roller wheel body 50 from the associating roller wheel frame 40 of the associating roller unit 30 for a replacement without changing the whole impression wheel.
Glass substrates of different thicknesses may be used for making different products. The gap between the conveying system and the impression cylinder 22 must allow pass of glass substrates of the smallest thickness, and the roller wheel body 50 is slightly compressed when touching the surface of a glass substrate of the smallest thickness. Because the roller wheel body 50 is made of an elastomeric material, glass substrates of different thicknesses within a certain range can be moved through the gap between the conveying system and the impression wheel 22 over the bottom side of the roller wheel body 50 of each roller unit 30. When a relatively thicker glass substrate is moved over the bottom side of the roller wheel body 50 of each roller unit 30, the roller wheel body 50 will be compressed relatively heavily. Because the roller wheel body 50 covers the peripheral edge 432 of the associating rim 43, the rim 43 of each roller unit 30 is prohibited from touching the glass substrate being delivered over the bottom side of the impression wheel 22. Therefore, the invention prevents the rim 43 of each roller unit 30 from scratching the surface of the moving glass substrate.
Although particular embodiments of the invention have been described in detail for purposes of illustration, various modifications and enhancements may be made without departing from the spirit and scope of the invention. Accordingly, the invention is not to be limited except as by the appended claims.
