Linear actuator with yoke actuated pitch control

Claim 2

A linear actuator with yoke actuated pitch control comprising a housing having a plurality of openings, a plurality of yokes rotatably mounted in said openings in said housing, each of said yokes including a wheel, said housing having an opening to permit the passage of a rotatable power driven shaft with each of said wheels being urged against said shaft and means to vary the pitch of said wheels with respect to the axis of said power shaft, said means including a control shaft extending through a sealed opening in said housing outwardly of said housing, said control shaft being rotatable about its longitudinal axis and including means located entirely within said housing to change the position of said yokes and thereby vary the pitch of said wheels with respect to said power shaft, and means for closing off the openings where said yokes are mounted to provide a completely sealed unit.

Claim 3

A linear actuator with yoke actuated pitch control comprising a housing having a plurality of openings, a plurality of yokes rotatably mounted in said openings in said housing, each of said yokes including a wheel, said housing having an opening to permit the passage of a rotatable power driven shaft with each of said wheels being urged against said shaft and means to vary the pitch of said wheels with respect to the axis of said power shaft, said means including a control shaft extending through a sealed opening in said housing outwardly of said housing, said control shaft being rotatable about its longitudinal axis and including means located entirely within said housing to change the position of said yokes and thereby vary the pitch of said wheels with respect to said power shaft, and means for closing off the openings where said yokes are mounted to provide a completely sealed unit.

Claim 4

A linear actuator with yoke actuated pitch control comprising a housing having a plurality of openings, a plurality of yokes rotatably mounted in said openings in said housing, each of said yokes including a wheel, said housing having an opening to permit the passage of a rotatable power driven shaft with each of said wheels being urged against said shaft and means to vary the pitch of said wheels with respect to the axis of said power shaft, said means including a control shaft extending through a sealed opening in said housing outwardly of said housing, said control shaft being rotatable about its longitudinal axis and including means located entirely within said housing to change the position of said yokes and thereby vary the pitch of said wheels with respect to said power shaft, and means for closing off the openings where said yokes are mounted to provide a completely sealed unit.

Claim 5

The invention of claim 1 including thrust bearings positioned outwardly of said yokes, and said means for closing off the openings where said yokes are mounted comprises a plate.

Claim 6

The invention of claim 1 wherein a control lever is attached to said control shaft.

Claim 7

The invention of claim 1 wherein said housing includes a bushing at each of the longitudinal ends thereof, said bushings being press fit into said housing and being replaceable so that different sizes of power drive shafts can be uTilized with said linear actuator housing.

Claim 8

A linear actuator with yoke actuated pitch control comprising a housing having a plurality of openings, a plurality of yokes rotatably mounted in said openings in said housing, each of said yokes including a wheel, said housing having an opening to permit the passage of a rotatable power driven shaft with each of said wheels being urged against said shaft and means to vary the pitch of said wheels with respect to the axis of said power shaft, said means including a control shaft extending through a sealed opening in said housing outwardly of said housing, said control shaft including means located entirely within said housing to change the position of said yokes and thereby vary the pitch of said wheels with respect to said power shaft, and means for closing off the openings where said yokes are mounted to provide a completely sealed unit, said yokes each including projections and said control means being a plurality of spheres held captive in said projections whereby the pitch of said wheels is changed simultaneously.

Claim 9

A linear actuator with yoke actuated pitch control comprising a housing having a plurality of openings, a plurality of yokes rotatably mounted in said openings in said housing, each of said yokes including a wheel, said housing having an opening to permit the passage of a rotatable power driven shaft with each of said wheels being urged against said shaft and means to vary the pitch of said wheels with respect to the axis of said power shaft, said means including a control shaft extending through a sealed opening in said housing outwardly of said housing, said control shaft including means located entirely within said housing to change the position of said yokes and thereby vary the pitch of said wheels with respect to said power shaft, and means for closing off the openings where said yokes are mounted to provide a completely sealed unit, said yokes each including projections and said control means being a plurality of spheres held captive in said projections whereby the pitch of said wheels is changed simultaneously.

Claim 10

The invention of claim 5 wherein said wheels are oriented with respect to the axis of said power shaft in order to be additive with respect to each other and contribute to linear actuation in the same sense.

Claim 11

The invention of claim 6 wherein said yokes are rotatably mounted within needle bearings.

Claim 12

A linear actuator with yoke actuated pitch control comprising a housing having a plurality of openings, a plurality of yokes rotatably mounted in said openings in said housing, each of said yokes including a wheel, said housing having an opening to permit the passage of a rotatable power driven shaft with each of said wheels being urged against said shaft and means to vary the pitch of said wheels with respect to the axis of said power shaft, said means including a control shaft extending through a sealed opening in said housing outwardly of said housing, said control shaft including means located entirely within said housing to change the position of said yokes and thereby vary the pitch of said wheels with respect to said power shaft, and means for closing off the openings where said yokes are mounted to provide a completely sealed unit, said actuator further including a fluid sensitive diaphragm in each of said openings and a source of fluid pressure in order to convey fluid pressure to said diaphragms whereby the exertion of fluid pressure against said diaphragms is conveyed to said yokes to urge said wheels against said power shaft to the extent of said fluid pressure.

Claim 13

A linear actuator with yoke actuated pitch control comprising a housing having a plurality of openings, a plurality of yokes rotatably mounted in said openings in said housing, each of said yokes including a wheel, said housing having an opening to permit the passage of a rotatable power driven shaft with each of said wheels being urged against said shaft and means to vary the pitch of said wheels with respect to the axis of said power shaft, said means including a control shaft extending through a sealed opening in said housing outwardly of said housing, said control shaft including means located entirely within said housing to change the position of said yokes and thereby vary the pitch of said wheels with respect to said power shaft, and means for closing off the openings where said yokes are mounted to provide a completely sealed unit, said actuator further including a fluid sensitive diaphragm in each of said openings and a source of fluid pressure in order to convey fluid pressure to said diaphragms whereby the exertion of fluid pressure against said diaphragms is conveyed to said yokes to urge said wheels against said power shaft to the extent of said fluid pressure.