Backlash-free cam control

Claim 3

A device according to claim 1, characterized by the fact that the two guide curves (F-H) are formed by the opposite surfaces of a groove (1) into which the control part (10) engages.

Claim 4

A device according to claim 2, characterized by the fact that the guide groove (1) is milled into the tube (2) of a photographic lens and that the control part (10) is coupled with the mount (6) of a displaceable lens or lens group.

Claim 5

A device according to claim 1, characterized by the fact that the control follower (3) and the auxiliary follower (4) are arranged at a fixed distance from each other and that the control part (1) which is thereby formed, and which is rotatably supported about the control follower (3), is inserted under torsional preload in a groove (1) whose guide surfaces (F-H) are at all times a distance apart from each other which is less than the distance between the opposite sides of the followers (3-4).

Claim 6

A device according to claim 1, characterized by the fact that at least one of the two followers (3-4) is supported in ball bearings.

Claim 7

In combination, elongate guide means, and cam-drivable structure guided by said guide means and including cam-follower means adapted for cam-engaged coaction, said follower means comprising a first follower roll and a pin mounting the same for rotation in the course of tracking a first non-linear cam surface, an offset arm connected for rotation about said pin and a torsional-preload spring applying unidirectional loading to rotate said arm, an auxiliary second follower roll rotatably mounted on said arm in offset relation to said first follower roll, and a displaceable cam member having said first cam surface and an auxiliary second non-linear cam surface for tracking engagement by said auxiliary follower roll, said cam surfaces being so offset from each other and so contoured in relation to each other in terms of the path of movement of said displaceable cam member (1) that said follower rolls are at all times preloaded by said spring into engagement with their respective cams and (2) that the angle of said arm remains constant with respect to the direction of said guide means.

Claim 8

In combination, elongate guide means, and cam-drivable structure guided by said guide means and including cam-follower means adapted for cam-engaged coaction, said follower means comprising a first follower roll and a pin mounting the same for rotation in the course of tracking a first non-linear cam surface, an offset arm connected for rotation about said pin and a torsional-preload spring applying unidirectional loading to rotate said arm, an auxiliary second follower roll rotatably mounted on said arm in offset relation to said first follower roll, and a displaceable cam member having said first cam surface and an auxiliary second non-linear cam surface for tracking engagement by said auxiliary follower roll, said cam surfaces being so offset from each other and so contoured in relation to each other in terms of the path of movement of said displaceable cam member (1) that said follower rolls are at all times preloaded by said spring into engagement with their respective cams and (2) that the angle of said arm remains constant with respect to the direction of said guide means.

Claim 9

In combination, elongate guide means, and cam-drivable structure guided by said guide means and including cam-follower means adapted for cam-engaged coaction, said follower means comprising first and second follower rolls carried by said structure, said first follower roll being adapted to track a first non-linear cam surface, said second follower roll being displaceably mounted in offset relation to said first follower roll, and spring means constantly urging a single direction of such displacement, and a displaceable cam member having said first cam surface and an auxiliary second non-linear cam surface for tracking engagement by said auxiliary follower roll, said cam surfaces being so offset from each other and so contoured in relation to each other in terms of the path of movement of said displaceable cam member (1) that said follower rolls are at all times preloaded by said spring into engagement with their respective cams and (2) that the displaced condition of said second follower roll remains constant, whereby the force exerted by said spring means remains constant throughout any displacement of said cam-drivable structure.

Claim 10

In combination, elongate guide means, and cam-drivable structure guided by said guide means and including cam-follower means adapted for cam-engaged coaction, said follower means comprising first and second follower rolls carried by said structure, said first follower roll being adapted to track a first non-linear cam surface, said second follower roll being displaceably mounted in offset relation to said first follower roll, and spring means constantly urging a single direction of such displacement, and a displaceable cam member having said first cam surface and an auxiliary second non-linear cam surface for tracking engagement by said auxiliary follower roll, said cam surfaces being so offset from each other and so contoured in relation to each other in terms of the path of movement of said displaceable cam member (1) that said follower rolls are at all times preloaded by said spring into engagement with their respective cams and (2) that the displaced condition of said second follower roll remains constant, whereby the force exerted by said spring means remains constant throughout any displacement of said cam-drivable structure.