What is claimed is:
1. An inner diameter grinding wheel (4) provided with a doughnut-shaped main body having a bore portion, comprising a plurality of annular grinding grooves (13) stacked together in a longitudinal direction of said bore portion of said doughnut-shaped main body to form an inner peripheral surface of said bore portion, wherein each of said annular grinding grooves (13) assumes a trapezoidal shape in cross section, wherein said inner peripheral surface of said bore portion is coated with abrasive grains having been fixed to said inner peripheral surface, said abrasive grains being diamond or other similar hard abrasive material.
2. The inner diameter grinding wheel (4) as set forth in claim 1, wherein a part of said inner peripheral surface of said bore portion of said main body is constructed of a plain peripheral surface grinding area (17), said plain peripheral surface grinding area (17) being combined with said annular grinding grooves (13) to form said inner peripheral surface of said bore portion.
3. The inner diameter grinding wheel (4) as set forth in claim 1, wherein said annular grinding grooves (13) differ from each other in substance andor grain size of said abrasive grains.
4. A grinding apparatus using an inner diameter grinding wheel (4) to grind a cylindrical workpiece (12), the apparatus comprising:
a grinding wheel axle support cylinder (5) for supporting a sleeve-shaped grinding wheel axle (6) on which said inner diameter grinding wheel (4) is mounted, said inner diameter grinding wheel (4) being provided with a plurality of annular grinding grooves (13) in its inner peripheral surface, wherein said sleeve-shaped grinding wheel axle (6) is rotatably mounted in said grinding wheel axle support cylinder (5) to vertically pass through said grinding wheel axle support cylinder (5) and is provided with an upper surface on which said inner diameter grinding wheel (4) is fixedly mounted;
a rotatably driving means for rotatably driving said sleeve-shaped grinding wheel axle (6);
a workpiece axle support sleeve (18) provided with a lower workpiece clamp (20) in its upper end, to which clamp (20) said cylindrical workpiece (12) is attracted by the suction, wherein said workpiece axle support sleeve (18) is freely passed through said sleeve-shaped grinding wheel axle (6);
said grinding wheel axle support cylinder (5) andor said workpiece axle support sleeve (18) being capable of moving vertically and horizontally.
5. The grinding apparatus as set forth in claim 5, wherein said inner diameter grinding wheel (4) provided with a doughnut-shaped main body having a bore portion, comprising a plurality of annular grinding grooves (13) stacked together in a longitudinal direction of said bore portion of said doughnut-shaped main body to form an inner peripheral surface of said bore portion, wherein each of said annular grinding grooves (13) assumes a trapezoidal shape in cross section, wherein said inner peripheral surface of said bore is coated with abrasive grains having been fixed to said inner peripheral surface, said abrasive grains being diamond or other similar hard abrasive material.
6. The grinding apparatus as set forth in claim 5, wherein a part of said inner peripheral surface of said bore portion of said main body is constructed of a plain peripheral surface grinding area (17), said plain peripheral surface grinding area (17) being combined with said annular grinding grooves (13) to form said inner peripheral surface of said bore portion.
7. The grinding apparatus as set forth in claim 6, wherein said annular grinding grooves (13) differ from each other in substance andor grain size of said abrasive grains.
8. The grinding apparatus as set forth in claim 4, wherein the grinding apparatus further comprises an upper workpiece clamp (27) which is coaxially arranged with said lower workpiece clamp (20) to hold said workpiece from above, wherein said lower workpiece clamp (20) and said upper workpiece clamp (27) are integrally rotated.
9. The grinding apparatus as set forth in claim 4, wherein the grinding apparatus is provided with an inner peripheral surface grinding wheel (33), wherein said inner peripheral surface grinding wheel (33) is rotatably supported by an inner peripheral surface grinding wheel axle support cylinder which is vertically and horizontally movable, said inner peripheral surface grinding wheel (33) being advanced to the interior of each of said upper workpiece clamp (27) and said lower workpiece clamp (20).
10. The grinding apparatus as set forth in any one of claims 4 to 9, wherein the grinding apparatus further comprises a reverse rotation means for rotatably driving said workpiece axle support sleeve (18) in a direction opposite to that of said sleeve-shaped grinding wheel axle (6).
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
What is claimed is:
1. A structure for a telecommunication antenna, comprising:
a concealment panel, the concealment panel comprising a foam core having a low-dielectric constant expanded poly-vinyl-chloride foam sheet disposed on at least one surface of the foam core.
2. The structure of claim 1, further comprising means for mechanically interlocking together ends of the concealment panels.
3. The structure of claim 1, wherein the foam core comprises polystyrene.
4. The structure of claim 1, wherein the foam core has first and second sides, and wherein a first low-dielectric constant expanded poly-vinyl-chloride foam sheet is disposed on the first side and a second low-dielectric constant expanded poly-vinyl-chloride foam sheet is disposed on the second side.
5. The structure of claim 4, wherein the form core forms a tongue portion along one edge of the panel, and wherein the first and second low-dielectric constant expanded poly-vinyl-chloride foam sheets form a groove portion along another edge of the panel.
6. The structure of claim 1, wherein the low-dielectric constant expanded poly-vinyl-chloride foam sheet is attached on the at least one surface of the foam core by an adhesive or a tape.
7. The structure of claim 6, wherein the adhesive comprises urethane forming a layer between the low-dielectric constant expanded poly-vinyl-chloride foam sheet and the foam core and having a thickness of approximately 3 to 10-mils.
8. The structure of claim 1, wherein the low-dielectric constant expanded poly-vinyl-chloride foam sheet has a dielectric constant equal to or less than two.
9. The structure of claim 1, wherein the low-dielectric constant expanded poly-vinyl-chloride foam sheet has a thickness of approximately 4 to 10-mm, and wherein the foam core has a thickness of approximately 2-inches.
10. A structure for a telecommunication antenna, comprising:
a plurality of concealment panels for concealing a portion of the antenna, the concealment panels at least partially composed of an expanded poly-vinyl-chloride foam having a dielectric constant equal to or less than two.
11. The structure of claim 10, further comprising means for mechanically interlocking together ends of the concealment panels.
12. The structure of claim 10, wherein the panels comprise a first sheet of expanded polyvinyl-chloride foam.
13. The structure of claim 12, wherein the panels comprise a foam core disposed on a side of the first sheet of expanded poly-vinyl-chloride foam.
14. The structure of claim 13, wherein the foam core comprises polystyrene.
15. The structure of claim 13, wherein the panels further comprise a second sheet of expanded poly-vinyl-chloride foam disposed on side of form core opposing the first sheet.
16. The structure of claim 10, wherein the foam core is attached to the first sheet of expanded poly-vinyl-chloride foam by an adhesive or a tape.
17. The structure of claim 10, wherein the concealment panels define curved surfaces by thermoforming or vacuum forming a substantially flat sheet.
18. The structure of claim 17, wherein the panels with the curved surfaces have a smaller thickness at edges of the panels than at a center of the panels.
19. A structure for a telecommunication antenna and for a flag with a rope, the structure having a mounting spool with a flange, comprising:
a plurality of concealment panels;
a mounting ring connecting to the flange;
means for mechanically connecting the concealment panels on the mounting ring;
an adapter coupling to the mounting ring and flange and having a mounting plate, the mounting plate extending beyond the flange and defining a first opening;
a cap coupling to the mounting plate and defining a second opening;
a truck including a shaft and an arm, the shaft installing in the second opening of the cap and coupling to the first opening of the adapter, the arm rotatable about the shaft and having the rope for the flag connected thereto.
20. The structure of claim 19, wherein the concealment panels are at least partially composed of an expanded poly-vinyl-chloride foam having a dielectric constant equal to or less than two.
21. The structure of claim 19, wherein the adapter includes a plurality of wings coupling to the flange with fasteners and having the mounting plate extending from substantially in a center of the wings.
22. The structure of claim 19, wherein the cap includes a rim fitting over an edge of the flange and over ends of the concealment panels.
23. The structure of claim 19, wherein the cap couples to the mounting plate with a plurality of fasteners installed in holes in the cap and the mounting plate.
24. The structure of claim 19, wherein the truck includes head integrally connected to the arm and having the shaft positioned therethrough, the head having bearings for rotating about the shaft.
25. The structure of claim 19, wherein the arm of the truck includes a pulley to which the rope for the flag is connected.
26. The structure of claim 25, wherein the pulley is adjustable along a length of the arm.