Sliding door operator

Claim 2

A sliding door operator comprising a shaft powered for rotation oriented in the direction of door movement, a door, and an operating assembly operatively secured to said door and engaged on said shaft, said assembly including a roller bearing against said shaft to be driven thereby, said roller being mounted by said assembly for rotation about an axis normal to the surface of said shaft to effect a helical engagement of said roller on said shaft of variable pitch, roller controlling means connected to said roller to effect said rotation about said axis, positive means adapted to move said roller controlling means to rotate said roller for door movement yieldably connected to said roller controlling means, and means operative on said roller controlling means at the end of door travel to reduce the pitch of said roller engagement against said yieldable connection.

Claim 3

The combination of claim 1 wherein said pitch reduction continues to zero.

Claim 4

The combination of claim 1 wherein said assembly includes a plurality of said rollers grasping said shaft there-between, and said roller controlling means is a yoke connected to each of said rollers to move all alike.

Claim 5

The combination of claim 1 wherein said positive means is operatively connected to said roller controlling means by a spring.

Claim 6

The combination of claim 1 wherein said operative means includes a fixed cam associated with the end of door travel and a follower on said assembly.

Claim 7

A sliding door operator comprising a shaft powered for rotation, a door, and an operating assembly operatively secured to said door and engaged on said shaft, said assembly including a roller bearing against said shaft to be driven thereby, said roller being mounted by said assembly for rotation about an axis normal to the surface of said shaft variably to either side of a position where the axes of said shaft and said roller are parallel to effect a helical engagement of said roller on said shaft of continuously variable pitch in either direction, roller controlling means connected to said roller to effect said rotation in either direction, positive means adapted to turn said roller controlling means optionally in either direction, yieldable means interconnecting said positive means and said roller controlling means, and means operative on said roller controlling means at each end of door travel to turn the axis of said roller to progressively reduce the pitch of said roller engagement against said yieldable means.

Claim 8

A sliding door operator comprising a shaft powered for rotation, a door, and an operating assembly operatively secured to said door and engaged on said shaft, said assembly including a roller bearing against said shaft to be driven thereby, said roller being mounted by said assembly for rotation about an axis normal to the surface of said shaft variably to either side of a position where the axes of said shaft and said roller are parallel to effect a helical engagement of said roller on said shaft of continuously variable pitch in either direction, roller controlling means connected to said roller to effect said rotation in either direction, positive means adapted to turn said roller controlling means optionally in either direction, yieldable means interconnecting said positive means and said roller controlling means, and means operative on said roller controlling means at each end of door travel to turn the axis of said roller to progressively reduce the pitch of said roller engagement against said yieldable means.

Claim 9

The combination of claim 6 wherein said pitch reduction continues to zero to stop said door at each end of said travel.

Claim 10

The combination of claim 6 wherein said assembly includes a plurality of said rollers grasping said shaft therebetween and said roller controlling means is a yoke connected to each of said rollers to move all alike.

Claim 11

The combination of claim 6 wherein said positive means is operatively connected to said roller controlling means by a spring.

Claim 12

The combination as set forth in claim 6 including a fixed cam associated with each end of door travel and a cam follower operatively connected to said roller controlling means engageable with said cams to effect said reduction of pitch of roller engagement.

Claim 13

The combination as set forth in claim 6 including additionally adjustable means operatively connected to said roller controlling means to limit said rotation of said roller in each direction against said resilient means.

Claim 14

The combination as set forth in claim 6 wherein said positive means comprises an arm mounted for pivotal movement with respect to said shaft, and means for moving said arm through an arc.

Claim 15

The combination of claim 12 wherein said roller controlling means is rotatable througH an arc about said shaft for said roller control, and one of said members as between said arm and said roller controlling means has a spring contained concentrically with said shaft and the other of said members has a lug opposing each end of said spring to resiliently resist displacement of said roller controlling means from a predetermined angular relationship with said arm.

Claim 16

A sliding door operator comprising a shaft powered for rotation oriented in a direction of door movement, a door, and an operating assembly operatively secured to said door and engaged on said shaft, said assembly including a plurality of rollers grasping said shaft therebetween, each of said rollers being mounted by said assembly for rotation about an axis normal to the surface of said shaft variably to each side of a position where the axes of said shaft and said rollers are parallel to effect a helical engagement of said rollers on said shaft of continuously variable pitch in either direction, a roller yoke rotatable concentrically with said shaft to rotate said rollers all alike about said axes, a servo yoke rotatable concentrically about said shaft, means yieldably connecting said servo yoke and said roller yoke to cause said roller yoke normally to track said servo yoke, a servo mechanism for moving said servo yoke in both directions through a predetermined arc, control means for energizing said servo mechanism to move said servo yoke alternately between the ends of said arc upon energization thereof, and means adjacent the end points of travel of said operating assembly to impose said parallel axis position on said roller yoke against said yieldable connection.

Claim 17

A sliding door operator comprising a shaft powered for rotation oriented in a direction of door movement, a door, and an operating assembly operatively secured to said door and engaged on said shaft, said assembly including a plurality of rollers grasping said shaft therebetween, each of said rollers being mounted by said assembly for rotation about an axis normal to the surface of said shaft variably to each side of a position where the axes of said shaft and said rollers are parallel to effect a helical engagement of said rollers on said shaft of continuously variable pitch in either direction, a roller yoke rotatable concentrically with said shaft to rotate said rollers all alike about said axes, a servo yoke rotatable concentrically about said shaft, means yieldably connecting said servo yoke and said roller yoke to cause said roller yoke normally to track said servo yoke, a servo mechanism for moving said servo yoke in both directions through a predetermined arc, control means for energizing said servo mechanism to move said servo yoke alternately between the ends of said arc upon energization thereof, and means adjacent the end points of travel of said operating assembly to impose said parallel axis position on said roller yoke against said yieldable connection.

Claim 18

A linear actuator comprising a shaft powered for rotation, and an operating assembly engaged on said shaft for relative linear movement therebetween, said assembly including a plurality of rollers grasping said shaft therebetween, each of said rollers being mounted by said assembly for rotation about an axis normal to the surface of said shaft variably away from a position where the axes of said shaft and said rollers are parallel to effect a helical engagement of said rollers on said shaft of continuously variable pitch, a roller yoke rotatable concentrically with said shaft to rotate said rollers alike about said normal axes, and means movable between limits yieldably connected to said roller yoke to cause said roller yoke to track said movable means normally, said roller yoke being movable against the resistance of said yieldable connection in non-tracking relationship with said movable means.

Claim 19

A linear actuator comprising a shaft powered for rotation, and an operating assembly engaged on said shaft for relative linear movement therebetween, said assembly including a plurality of rollers grasping said shaft therebetween, each of said rollers being mounted by said assembly for rotation about an axis normal to the surface of said shaft variably away from a position where the axes of said shaft and said rollers are parallel to effect a helical engagement of said rollers on said shaft of continuously variable pitch, a roller yoke rotatable concentrically with said shaft to rotate said rollers alike about said normal axes, and means movable between limits yieldably connected to said roller yoke to cause said roller yoke to track said movable means normally, said roller yoke being movable against the resistance of said yieldable connection in non-tracking relationship with said movable means.

Claim 20

The combination of claim 15 wherein said rollers are rotatable in either direction away from said paralleled axis position and said yieldable connection permits non-tracking movement of said roller yoke in either direction.

Claim 21

The combination of claim 15 wherein said movable means is operatively connected to said roller yoke by a spring.

Claim 22

The combination of claim 15 wherein said movable means is arcuately movable about said shaft.

Claim 23

The combination of claim 18 wherein one of said members as between said yoke and said movable means has a spring contained concentrically with said shaft and the other of said members has a lug opposing each end of said spring to resiliently resist displacement of said yoke from a predetermined angular relationship with said movable means.