1. A vibratory roller comprising:
(A) a chassis;
(B) at least one roller on which the chassis is supported;
(C) an exciter assembly that imparts vibrations to the roller to compact materials over which the roller travels, the exciter assembly comprising
i. an exciter housing;
ii. an exciter shaft rotatably journaled in the exciter housing;
iii. an eccentric weight supported on the exciter shaft, and
iv. a gear mounted on the exciter shaft, the gear being unlubricated and having at least an outer ring portion being formed from a non-metallic material.
2. The vibratory roller as recited in claim 1, wherein the gear comprises a composite gear having an inner metal hub and an outer ring of the non-metallic material.
3. The vibratory roller as recited in claim 2, wherein the exciter assembly comprises a first exciter subassembly of larger exciter assembly, the exciter shaft comprises a first exciter shaft, and the gear comprises a first gear, and further comprising i) a second exciter subassembly comprising a second exciter shaft rotatably journaled in the exciter housing and bearing an eccentric weight and ii) a second gear that is supported on the second exciter shaft, and that meshes with first gear, and that is of at least generally the same diameter as the first gear.
4. The vibratory roller as recited in claim 3, wherein the second gear has a metallic outer portion.
5. The vibratory roller as recited in claim 3, wherein the gears have a backlash of at least 0.20 mm (0.008 in).
6. The vibratory roller as recited in claim 5, wherein the gears have a backlash of at least 0.25 mm (0.010 in).
7. The vibratory roller as recited in claim 3, wherein the outer ring portion of the first gear is formed from a nylon-based polymer impregnated with at least one of a heat stabilizer and a lubricant.
8. The vibratory roller as recited in claim 3, wherein the second gear is a composite gear having a metal hub having an outer ring of the non-metallic material.
9. The vibratory roller as recited in claim 8, wherein the outer ring of the first gear is formed from a molded polymer.
10. The vibratory roller as recited in claim 1, wherein the eccentric weight is a fixed eccentric weight that is rotationally fixed relative to the exciter shaft, and wherein the exciter assembly further comprises a free swinging weight that is mounted on the exciter shaft so as to rotate with respect to the exciter shaft between 1) a first angular position in which the eccentricity of the free swinging eccentric weight adds to the eccentricity of the fixed eccentric weight and 2) a second angular position in which the eccentricity of the free swinging eccentric weight detracts from the eccentricity of the fixed eccentric weight.
11. A vibratory roller comprising:
(A) a chassis;
(B) first and second rollers on which the chassis is supported;
(C) an exciter housing located at least in part within the first roller and lacking an oil bath therein;
(D) an exciter assembly including first and second exciter subassemblies that impart vibrations to the first roller to compact materials over which the roller travels, each exciter subassembly comprising
i. an exciter shaft rotatably journaled in the exciter housing;
ii. an eccentric weight supported on the exciter shaft, and
iii. a gear mounted on the exciter shaft,
wherein the gears of the first and second exciter subassemblies mesh with one another and are unlubricated, and wherein at least one of the gears has at least a toothed outer portion formed from a non-metallic material.
12. The vibratory roller as recited in claim 11, wherein the first gear is a composite gear having a metal hub and an outer ring formed from a nylon-based polymer impregnated with at least one of a heat stabilizer and a lubricant, and wherein the second gear has a metallic outer portion.
13. The vibratory roller as recited in claim 12, wherein the gears have a backlash of at least 0.20 mm (0.008 in).
14. The vibratory roller as recited in claim 11, wherein each of the first and second gears is a composite gear having a metal hub and an outer ring formed from a molded polymer.
15. The vibratory roller as recited in claim 11, wherein the eccentric weight of each exciter subassembly is a fixed eccentric weight that is rotationally fixed relative to the associated exciter shaft, and wherein each exciter subassembly further comprises a free swinging weight that is mounted on the associated exciter shaft so as to rotate with respect to the exciter shaft between 1) a first angular position in which the eccentricity of the free swinging eccentric weight adds to the eccentricity of the associated fixed eccentric weight and 2) a second angular position in which the eccentricity of the free swinging eccentric weight detracts from the eccentricity of the associated fixed eccentric weight.
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 method of fabricating a stent from a wire, comprising:
(a) winding the wire on a first mandrel;
(b) heating the wound wire to form a coiled spring; and
(c) after said coiled spring has cooled sufficiently, reversing the winding direction of said coiled spring to form the stent.
2. A method as in claim 1, further comprising:
(d) placing said stent on a second mandrel; and
(e) reheating said reversed coiled spring stent for a time sufficiently short as to partially relax said stent.
3. A method as in claim 2 wherein said second mandrel is made up of at least two regions of different heat sink capacities, so that the portion of said stent overlying said at least two regions will be relaxed to different extents during said reheating.
4. A stent made by the method of claim 1.
5. A stent made by the method of claim 2.
6. A stent made by the method of claim 3.
7. A stent comprising a coiled wire characterized in that said wire includes at least one section which is wound in one sense and at least one section which is wound in the opposite sense, deployment of said stent taking place by tightly winding the stent onto a catheter and subsequently allowing the stent to resume its normal dimensions.
8. A stent as in claim 7 wherein said wire includes two sections with each of said sections representing substantially half of said wire.
9. A method of deploying a stent of claim 7 in a desired location, comprising:
(a) tightly winding said stent onto a catheter;
(b) immobilizing the two end points of said wire and at least one intermediate point on said wire;
(c) bringing said stent to the desired location where said stent is to be deployed;
(d) releasing said intermediate point on the wire, thereby allowing said stent to unwind while keeping said two end points immobilized; and
(e) releasing said two end points of said wire.
10. A stent as in claim 7 wherein said wire includes at least two sections which are wound in one sense and at least two sections which are wound in the opposite sense.
11. A stent as in claim 7 wherein said wire include a plurality of sections, each section being made up of substantially a single loop.
12. A stent as in claim 11 wherein the stent is connected to a flexible film to form a tube-like member.
13. A method of deploying a stent in a desired location, comprising:
(a) tightly winding said stent onto a catheter;
(b) immobilizing at least two tie-down points on the stent using a disconnectable thread;
(c) bringing said stent to the desired location where said stent is to be deployed;
(d) causing said thread to disconnect at one or more of said tie-down points, thereby releasing said tie-down point, wherein said disconnectable thread is meltable and said thread is disconnected by heating said thread so as to cause said thread to melt.
14. A method of heating a nitinol stent to cause the stent to shift from its martensite phase to its austenite phase and to sense the phase change, comprising:
(a) electrically connecting the stent to an electrical power supply;
(b) supplying electrical current to the stent;
(c) sensing a change in at least one electrical property to indicate the phase change;
(d) controlling said current in response to said change.
15. A method as in claim 14 wherein said electrical property is a voltage drop change.
16. A method as in claim 14 wherein said electrical property is a current change.
17 A stent comprising a coiled wire characterized in that said wire is enveloped in a material shaped so that when the stent is fully deployed, portions of said envelope material occupy gaps between adjoining coils of the stent.