Rope sheave
The invention provides a rope sheave having two substantially opposed faces, each face having a plurality of ridges extending from an inner circumferential region of the face to an outer circumferential region of the face. The ridges are arranged such that those portions of the ridges on one face at the inner circumferential region substantially oppose those portions of the ridges on the opposite face at the inner circumferential region, and those portions of the ridges at the outer circumferential region on one face substantially oppose regions between those portions of the ridges at the outer circumferential region of the other face. The faces may be separable to provide two sheave parts.
1. A rope sheave comprising two substantially opposed faces, wherein:
each face has a plurality of ridges extending from an inner circumferential region of the face to an outer circumferential region of the face;
the ridges are arranged such that portions of the ridges on one face at the inner circumferential region substantially oppose portions of the ridges on the opposite face at the inner circumferential region; and
the ridges are arranged such that portions of the ridges at the outer circumferential region on one face substantially oppose regions between portions of the ridges at the outer circumferential region of the other face.
2. The rope sheave of claim 1 , wherein the ridges are provided at an acute angle to a radial line from a center of rotation of the sheave to the outer circumferential region.
3. The rope sheave of claim 1 , wherein the ridges on each face become progressively closer to each other from the outer circumferential region to the inner circumferential region.
4. The rope sheave of claim 1 , comprising a plurality of chain link engaging projections which project from the outer circumferential region.
5. The rope sheave of claim 4 , wherein one of the plurality of ridges extends outwards from each chain link engaging projection.
6. The rope sheave of claim 5 , wherein:
each chain link engaging projection has first and second faces;
a first of said faces is configured to forcibly drive a chain link in use; and
the portion of each ridge extending from the respective chain link engaging portion is disposed between said first and second faces.
7. The rope sheave of claim 6 , wherein the portion of each ridge extending from the respective chain link engaging portion is disposed closer to said second face than said first face.
8. The rope sheave of claim 1 , wherein the faces are separable to provide two sheave parts.