1. A rim of non-uniform thickness, manufactured from a rim material of non-uniform thickness, the non-uniform thickness of the rim varying in an axial direction of the rim;
wherein the rim material includes a first material portion which forms an axially curved portion of the rim and a second material portion which forms an intermediate portion between adjacent axially curved portions of the rim;
the axially curved portion of the first material portion including portions A, B, C, D, E and F, wherein portion A is a curved portion between a first flange portion located at a first end of the rim and a first bead seat portion connected to the first flange portion, portion B is a curved portion between a side-wall portion located on the first side of the rim and a drop portion, portion C is a curved portion between a side-wall portion located on a second, opposite side of the rim and the drop portion, portion D is a curved portion located at a root of a hump portion, portion E is a curved portion located at a top of the hump portion, and portion F is a curved portion between a second flange portion located at a second, opposite end of the rim and a second bead seat portion connected to the second flange portion;
each of portions A, B, C, D, E and F of the first material portion has a parallel-surface portion including opposite surfaces parallel to each other and having a larger thickness than portions connected to the parallel-surface portion, the parallel-surface portion having a width greater than a maximum amount of an axial dislocation of the parallel-surface portion expected to occur when the parallel-surface portion is formed to a corresponding curved portion, the parallel-surface portion having a width of equal to or greater than 2 mm and equal to or smaller than 10 mm in an axial direction of the rim; and
the second material portion has a thickness varying portion.
2. The rim of claim 1, wherein the thickness varying portion includes a surface having a configuration defined by a line, which connects ends of parallel-surface portions located on opposite sides of the thickness varying portion.
3. The rim of claim 2, wherein the line is a straight line, a slightly curved line, a composite line of a straight line and an arc located on at least one end of the straight line, or a composite line of a slightly curved line and an arc located at least one end of the slightly curved line, or any combination thereof.
4. The rim of claim 1, wherein the angle defined between the surface of the thickness varying portion and the surface of the surface-parallel portion is equal to or smaller than 25 degrees.
5. A method for manufacturing a rim of non-uniform thickness, comprising the steps of:
producing a rim material of non-uniform thickness;
coiling the rim material;
butt-welding opposite ends of the coiled rim material to form an annular material;
trimming a welded portion of the annular material;
flaring axially opposite end portions of the annular material; and
roll-forming the annular material flared at the axially opposite end portions to a rim configuration,
wherein during the step of producing a rim material, a rim material is produced which includes:
(a) a first material portion which forms an axially curved portion of the rim after the rim material is formed to the rim and a second material portion which forms an intermediate portion between adjacent axially curved portions after the rim material is formed to the rim, the axially curved portion of the first material portion including portions A, B, C, D, E and F, wherein portion A is a curved portion between a first flange portion located at a first end of the rim and a first bead seat portion connected to the first flange portion, portion B is a curved portion between a side-wall portion located on the first side of the rim and a drop portion, portion C is a curved portion between a side-wall portion located on a second, opposite side of the rim and the drop portion, portion D is a curved portion located at a root of a hump portion, portion E is a curved portion located at a top of the hump portion, and portion F is a curved portion between a second flange portion located at a second, opposite end of the rim and a second bead seat portion connected to the second flange portion;
(b) wherein each of portions A, B, C, D, E and F of the first material portion has a parallel-surface portion including opposite surfaces parallel to each other and having a larger thickness than portions connected to the parallel-surface portion, the parallel-surface portion having a width greater than a maximum amount of an axial dislocation of the parallel-surface portion expected to occur when the parallel-surface portion is formed to a corresponding curved portion, the parallel-surface portion having a width of equal to or greater than 2 mm and equal to or smaller than 10 mm in an axial direction of the rim; and
(c) the second material portion having a thickness varying portion.
6. A method for manufacturing a rim having a non-uniform thickness according to claim 5, wherein the thickness varying portion includes a surface having a configuration defined by a line, which connects ends of parallel-surface portions located on opposite sides of the thickness varying portion.
7. The method of claim 6, where the line is a straight line, a slightly curved line, a composite line of a straight line and an arc located on at least one end of the straight line, or a composite line of a slightly curved line and an arc located on at least one end of the slightly curved line, or any combination thereof.
8. The method of claim 5, wherein the rim material has a first surface which is flat and a second, opposite surface which is a convex and concave surface.
9. The method of claim 5, wherein the rim material has a first surface and a second, opposite surface, each of the first and second surfaces being a convex and concave surface.
10. The method of claim 5, wherein when or after the rim material is rolled, the rim material is formed so that a thickness center line thereof is wavy so as to be convex andor concave in a direction perpendicular to the axial direction of the rim.
11. The method of claim 5, wherein an angle defined between a surface of the thickness varying portion (14) and a surface of the surface-parallel portion is equal to or less than 25 degrees.
12. The method of claim 11, wherein the angle defined between the surface of the thickness varying portion and the surface of the surface-parallel portion is equal to or less than 15 degrees.
13. The method of claim 11, wherein during the step of trimming, a trimming cutter is moved following a configuration of the annular rim material in an axial direction of the annular rim material.
14. The method of claim 5, wherein the rim is used on a bus or a truck.
15. A rim material for a rim having a non-uniform thickness, including a first material portion which forms an axially curved portion of the rim after the rim material is formed to the rim and a second material portion which forms an intermediate portion between adjacent axially curved portions after the rim material is formed to the rim, the axially curved portion of the first material portion including portions A, B, C, D, E and F, wherein portion A is a curved portion between a first flange portion located at a first end of the rim and a first bead seat portion connected to the first flange portion, portion B is a curved portion between a side-wall portion located on the first side of the rim and a drop portion, portion C is a curved portion between a side-wall portion located on a second, opposite side of the rim and the drop portion, portion D is a curved portion located at a root of a hump portion, portion E is a curved portion located at a top of the hump portion, and portion F is a curved portion between a second flange portion located at a second, opposite end of the rim and a second bead seat portion connected to the second flange portion;
wherein each of portions A, B, C, D, E and F of the first material portion has a parallel-surface portion including opposite surfaces parallel to each other and having a larger thickness than portions connected to the parallel-surface portion, the parallel-surface portion having a width greater than a maximum amount of an axial dislocation of the parallel-surface portion expected to occur when the parallel-surface portion is formed to a corresponding curved portion, the parallel-surface portion having a width of equal to or greater than 2 mm and equal to or smaller than 10 mm in an axial direction of the rim; and
the second material portion has a thickness varying portion.
16. The rim material of claim 15, wherein the thickness varying portion including a surface having a configuration defined by a line, which connects ends of parallel-surface portions located on opposite sides of the thickness varying portion.
17. The rim material of claim 16, where the line is a straight line, a slightly curved line, a composite line of a straight line and an arc located on at least one end of the straight line, or a composite line of a slightly curved line and an arc located on at least one end of the slightly curved line, or any combination thereof.
18. The rim material of claim 15, wherein an angle defined between a surface of the thickness varying portion and a surface of the surface-parallel portion is equal to or less than 25 degrees.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A buffer for absorbing impacts, said buffer comprising:
an elastic buffer element made of a material having a first e-module, and
a force take-up axis,
said buffer element being compressible at least in the direction of said force take-up axis,
wherein
at least one additional element having a second e-module is enclosed in said buffer element, said second e-module being larger than said first e-module.
2. The buffer according to claim 1, wherein said additional element is elastic.
3. The buffer according to claim 2, wherein the additional element is elastically deformable by 300-700%, preferably by 400-600%.
4. The buffer according to claim 1, wherein the buffer element has a first compression module and the additional element has a second compression module, said second compression module being larger than said first compression module.
5. The buffer according to claim 1, wherein the additional element is incompressible in volume.
6. The buffer according to claim 1, wherein the additional element has the shape of a frustum of a circular cone, the base surface of the additional element extending orthogonally to force take-up axis of the buffer element.
7. The buffer according to claim 6, wherein the lateral or outer surfaces of the additional element extend at an angle from 20\xb0 to 80\xb0, preferably at an angle from 30\xb0 to 60\xb0, relative to force take-up axis of the buffer element.
8. The buffer according to claim 6, wherein the additional element has the shape of a frustum of a right circular cone.
9. The buffer according to claim 6, wherein the additional element has the shape of a hollow frustum of a circular cone.
10. The buffer according to claim 1, wherein least two additional elements, spaced from each other in the longitudinal direction of the buffer element, are enclosed in the buffer element.
11. The buffer according to claim 1, wherein the buffer element is made of foamed plastic material.
12. The buffer according to claim 1, where in the buffer element is compressible by 80 to 90% in the direction of the force take-up axis.
13. The buffer according to claim 1, wherein the material of the buffer is volume-compressible and with regard to the volume has an air content of about 50 to 80%, preferably 60 to 70%.