Helical drive

Claim 2

A propelling device comprising: frame means, a drive member carried by the frame means and rotatable about an axis generally parallel with the direction of travel of the frame means, a plurality of individually rotatable members mounted on said drive member, the axes of rotation of said individually rotatable members being constrained to positions related angularly other than 90* to the drive member axis, the angular relationship between the axis of each of the rotatable members with the axis of the drive member being substantially equal.

Claim 3

A propelling device as defined in claim 1, wherein said individually rotatable members are rollers.

Claim 4

A propelling device as defined in claim 1, wherein said drive member is a cylindrical drum, a drive shaft extending through said drum and drivingly fixed thereto, each of said individually rotatable members including a roller assembly, said assembly including a resilient support fixed to said drum, a recess in said support, a roller having a coefficient of friction approximating that of rubber rotatably mounted in said recess, and thrust bearings between the ends of the rollers and the recess.

Claim 5

A propelling device comprising, frame means, a drive member carried by the frame means and rotatable about an axis generally parallel with the direction of travel of the frame means surface-engaging means releasably fixed to said drive member to move in a path angularly related to said axis, and control means for shifting said surface-engaging means to different positions defining different angular relationships between the paths and the axis.

Claim 6

A propelling device comprising, frame means, a drive member carried by the frame means and rotatable about an axis generally parallel with the direction of travel of the frame means surface-engaging means releasably fixed to said drive member to move in a path angularly related to said axis, and control means for shifting said surface-engaging means to different positions defining different angular relationships between the paths and the axis.

Claim 7

A propelling device as defined in claim 4, wherein said surface engaging means includes means for preventing significant sliding movement with respect to said surface.

Claim 8

A propelling device as defined in claim 5, wherein said surface-engaging means includes a plurality of friction rollers mounted for rotation about an axis generally transverse to a helical path.

Claim 9

A propelling device as defined in claim 6, wherein said control means increases the helix angle of said rollers by shifting each roller axially with respect to said rotatable drive member and pivoting each roller about an axis substantially perpendicular to the roller axis and lying in a radial plane of the rotatable drive member.

Claim 10

A propelling device as defined in claim 7, wherein said control means maintains each of the rollers at equal helix angles with respect to the axis of the drive member in any adjusted position thereof and makes equal changes in the helix angles of the rollers, said control means effecting an incrementally greater axial shifting movement of each roller with respect to one of its adjacent rollers for a given change in helix angle to thereby maintain the axes of the rollers substantially transverse to the helix path regardless of helix angle to assure substantially rolling motion of said rollers.

Claim 11

A propelling device as defined in claim 7, wherein said control means includes an axially expansible coil member, said rollers being part of a plurality of roller assemblies, each of said assemblies being slidably received on said coil member.

Claim 12

A propelling device as defined in claim 9, including means connecting one end of said coil member to said rotatable drive member, axially Shiftable sleeve means connected to the other end of said coil member for axially expanding the same, said roller assemblies having guide surfaces engaging said coil member so that each assembly assumes the same helix angle and the roller assemblies lie in substantially the same helical path.

Claim 13

A propelling device as defined in claim 4, wherein said surface-engaging means includes a plurality of surface-engaging members, means for releasably clamping said surface-engaging members to said drive member, said control means shifting said surface-engaging members when said surface-engaging members are released from said drive member.

Claim 14

A vehicular propelling device as defined in claim 4, wherein said surface-engaging means is movable to a path with a substantially zero helix angle providing a neutral drive.

Claim 15

A propelling device comprising: frame means, a drive member carried by said frame means and rotatable about an axis generally parallel with the direction of travel of the frame means, and surface-engaging means including means on said member movable relative to said member constrained for movement only in a path related to said axis at an angle other than 90*.

Claim 16

A propelling device comprising: frame means, a drive member carried by said frame means and rotatable about an axis generally parallel with the direction of travel of the frame means, and surface-engaging means including means on said member movable relative to said member constrained for movement only in a path related to said axis at an angle other than 90*.

Claim 17

A propelling device as defined in claim 13, wherein surface-engaging means includes a plurality of roller assemblies, means for shifting said roller assemblies including means for maintaining the roller assemblies in a generally helical path about said drum member.

Claim 18

A propelling device as defined in claim 14, wherein said roller assemblies are received in a plurality of slots in said drum member.

Claim 19

A propelling device as defined in claim 14, including interengaging means on said roller assemblies and said drum member for maintaining said assemblies in a predetermined rotational position about an axis extending through the drive member axis and substantially perpendicular to and intersecting said roller axis as a function of the axial position of the roller assemblies with respect to the drum member.

Claim 20

A propelling device as defined in claim 16, wherein said interengaging means includes a plurality of serrations on said drum member having increasing helix angles extending away from one end of the drum member.

Claim 21

A propelling device as defined in claim 14, wherein said means for shifting the roller assemblies includes a coil member, and means for axially extending and distending said coil member.

Claim 22

A propelling device, comprising: a drive member rotatable about an axis generally parallel with the direction of movement of the member, a plurality of surface-engaging means mounted on said member, said surface-engaging means each being constrained for movement relative to said member when in engagement with said surface in a path related angularly other than 90* to said axis.

Claim 23

A propelling device, comprising: a drive member rotatable about an axis generally parallel with the direction of movement of the member, a plurality of surface-engaging means mounted on said member, said surface-engaging means each being constrained for movement relative to said member when in engagement with said surface in a path related angularly other than 90* to said axis.