Infinitely adjustable linear actuator

Claim 2

A linear actuator for a vehicle seat including a track assembly formed of a lower track fixedly mounted to a vehicle, an upper track movably mounted in the lower track for translation with respect to the lower track, and a seat back frame member mounted to one of the upper track and the lower track, the linear actuator comprising: a rotatable shaft adapted to be coupled to one of the upper track, the lower track and the seat back frame member; a housing mounted about the rotatable shaft and fixedly coupled to another of the upper track, the lower track and the seat back frame member; a rotatable element disposed within the housing about and fixedly coupled to and rotatable with the rotatable shaft; first and second bearing means, mounted at opposite ends of the housing, for providing bearing surfaces for the rotatable element, the first and second bearing means spaced apart to permit axial movement of the rotatable element therebetween into rotatable engagement with one of the first and second bearing means under axial loads on the rotatable shaft permitting rotation of the rotatable shaft; and means, mounted in the housing, for displacing the rotatable element from engagement with the first and second bearing means to a non-rotatable position disengaged from both of the first and second bearing means and inhibiting rotation of the rotatable shaft.

Claim 3

The linear actuator of claim 1 wherein the displacing means comprises: first and second moving members disposed in the housing, each movable from a first engaged position with the rotatable element in which the first and second moving members disengage the rotatable element from both of the first and second bearing means and a second disengaged position with respect to the rotatable element; and means, mounted in the housing and coupled to the first and second moving members, for moving the first and second moving members between the first and second positions.

Claim 4

The linear actuator of claim 2 wherein the moving means comprises: bidirectional rotatable drive means, mounted in the housing and connected to first and second moving members, for driving the first and second moving members between first and second positions.

Claim 5

The linear actuator of claim 3 wherein moving means further comprises: guide means, formed on first and second moving members and the housing, for guiding movement of first and second moving means between first and second positions.

Claim 6

The linear actuator of claim 4 wherein the guide means comprises: a pair of guide slots formed in opposite sides of the housing, the guide slots disposed at a non-perpendicular angle with respect to a longitudinal axis of the housing; and ramp surfaces formed on opposite sides of each of the first and second moving members, each ramp surface slidably engaging one of the guide slots for guiding the first and second moving members toward and away from the rotatable element.

Claim 7

The linear actuator of claim 3 further comprising: biasing means, acting on the drive means, for biasing the drive means to a position driving the first and second moving members to the first engaged position with the rotatable element.

Claim 8

The linear actuator of claim 2 wherein the rotatable element comprises: a body fixedly mounted on and rotatable with the rotatable shaft; and a radially enlarged collar formed between opposite ends of the body, first and second opposed side surfaces formed on the collar.

Claim 9

The linear actuator of claim 6 wherein: the first and second moving members are disposed adjacent the first and second side surfaces of the collar, respectively; and the first and second moving members each including an engaging surface engageable with one of the first and second side surfaces of the collar when the first and second moving members are disposed in a first position.

Claim 10

The linear actuator of claim 2 further comprising: means for interconnecting the first and second moving members for simultaneous movement of the first and second moving members by the moving means.

Claim 11

The linear actuator of claim 9 wherein the interconnecting means comprises: a first projection formed on and extending outward from each of the first and second moving members; an aperture formed in each of the first and second moving members; and the first and second moving members being disposed in a reversed relationship within the housing such that the first projection on each of the first and second moving members slidably engages the first aperture in the other of the first and second moving members.

Claim 12

The linear actuator of claim 10 wherein the moving means comprises: a drive member rotatably mounted in the housing; a release lever fixedly coupled to the drive member for bidirectionally rotating the drive member upon bidirectional pivotal movement of the release lever; and a second projection extending outward from at least one of the first and second moving members; and drive finger means, mounted on the drive member and engaging the second projection, for moving the interconnected first and second moving members between first and second positions during bidirectional rotation of the drive member.

Claim 13

The linear actuator of claim 1 wherein: the rotatable shaft is an externally threaded shaft; the linear actuator further including: a drive nut having an internally threaded bore engaged with the rotatable shaft, the drive nut translating along the rotatable shaft as the rotatable shaft rotates; and a linkage connected to the seat back frame member and the drive nut for pivoting the seat back frame member during translation of the drive nut along the rotatable shaft.

Claim 14

The linear actuator of claim 1 wherein the first and second bearing means comprise at least one of a plurality of bearings mounted in a bearing seat formed in the housing and a low friction bearing surface formed in the housing.

Claim 15

The linear actuator of claim 1 wherein: the housing is adapted to be mounted to the upper track of a vehicle seat; and one end of the rotatable shaft adapted to be rotatably connected to the upper track of the vehicle seat.

Claim 16

The linear actuator of claim 1 wherein: the rotatable shaft is adapted to be rotatably mounted on the lower track of a vehicle seat; a threaded drive nut is threadingly mounted about the rotatable shaft; and a bracket rotatably carrying the drive nut is adapted to be fixedly connected the upper track of a vehicle seat such that rotation of the rotatable shaft causes translation of the drive nut along the rotatable shaft and translation of the upper track relative to the lower track.

Claim 17

The linear actuator of claim 1 further comprising: biasing means for biasing the displacing means to a position in which the displacing means displaces the rotatable element from engagement with the first and second bearing means.

Claim 18

A linear actuator for a vehicle seat including a track assembly formed of a lower track fixedly mounted to a vehicle, an upper track movably mounted in the lower track for translation with respect to the lower track, and a seat back frame member mounted to one of the upper track and the lower track, the linear actuator comprising: a rotatable shaft having a plurality of external threads formed thereon, the rotatable shaft adapted to be coupled to one of the upper track, the lower track and the seat back frame member; a rotatable element fixedly coupled to and rotatable with the shaft; an enlarged annular collar formed on the rotatable element, the annular collar having opposed side surfaces extending radially outward from an exterior surface of the rotatable element; a housing having opposed ends, the rotatable element mounted in the housing, the housing adapted to be fixedly coupled to another of the upper track, the lower track and the seat back frame member; first and second bearing means, mounted at the opposite ends of the housing, respectively, for providing first and second low resistance bearing surfaces for the rotatable element; first and second moving members disposed in the housing, each of the first and second moving members disposed adjacent to one of the opposed side surfaces of the annular collar on the rotatable element; and means, mounted on the housing, for moving the first and second moving members between a first position in which the first and second moving members engage the opposed side surfaces of the annular collar and disengage the rotatable element from both of the first and second bearing means and form a high friction connection with the rotatable element preventing rotation of the rotatable element and the rotatable shaft, and a second position in which the first and second moving members are spaced from the annular collar to permit axial movement of the rotatable element into engagement with one of the first and second bearing means under an axial load acting in one direction on the threaded shaft and thereby rotation of the rotatable element and the rotatable shaft.

Claim 19

A linear actuator for a vehicle seat including a track assembly formed of a lower track fixedly mounted to a vehicle, an upper track movably mounted in the lower track for translation with respect to the lower track, and a seat back frame member mounted to one of the upper track and the lower track, the linear actuator comprising: a rotatable shaft having a plurality of external threads formed thereon, the rotatable shaft adapted to be coupled to one of the upper track, the lower track and the seat back frame member; a rotatable element fixedly coupled to and rotatable with the shaft; an enlarged annular collar formed on the rotatable element, the annular collar having opposed side surfaces extending radially outward from an exterior surface of the rotatable element; a housing having opposed ends, the rotatable element mounted in the housing, the housing adapted to be fixedly coupled to another of the upper track, the lower track and the seat back frame member; first and second bearing means, mounted at the opposite ends of the housing, respectively, for providing first and second low resistance bearing surfaces for the rotatable element; first and second moving members disposed in the housing, each of the first and second moving members disposed adjacent to one of the opposed side surfaces of the annular collar on the rotatable element; and means, mounted on the housing, for moving the first and second moving members between a first position in which the first and second moving members engage the opposed side surfaces of the annular collar and disengage the rotatable element from both of the first and second bearing means and form a high friction connection with the rotatable element preventing rotation of the rotatable element and the rotatable shaft, and a second position in which the first and second moving members are spaced from the annular collar to permit axial movement of the rotatable element into engagement with one of the first and second bearing means under an axial load acting in one direction on the threaded shaft and thereby rotation of the rotatable element and the rotatable shaft.

Claim 20

The linear actuator of claim 17 wherein the moving means comprises: bidirectional rotatable drive means, mounted in the housing and connected to first and second moving members, for driving the first and second moving members between the first and second positions.

Claim 21

The linear actuator of claim 18 wherein moving means further comprises: guide means, formed on first and second moving members and the housing, for guiding movement of first and second moving means between the first and second positions.

Claim 22

The linear actuator of claim 19 wherein the guide means comprises: a pair of guide slots formed in opposite sides of the housing, the guide slots disposed at a non-perpendicular angle with respect to a longitudinal axis of the housing; and ramp surfaces formed on opposite sides of each of the first and second moving members, each ramp surface slidably engaging one of the guide slots for guiding the first and second moving members toward and away from the rotatable element.

Claim 23

The linear actuator of claim 18 further comprising: biasing means, acting on the drive means, for biasing the drive means to a position driving the first and second moving members to the first engaged position with the rotatable element.

Claim 24

The linear actuator of claim 17 wherein: the first and second moving members each have an engaging surface engageable with one of the first and second side surfaces of the collar when the first and second moving members are disposed in a first position.

Claim 25

The linear actuator of claim 17 further comprising: a drive nut having an internally threaded bore engaged with the rotatable shaft, the drive nut translating along the rotatable shaft as the rotatable shaft rotates; and a linkage adapted to be connected to the seat back frame member and the drive nut for pivoting the seat back frame member during translation of the drive nut along the rotatable shaft.

Claim 26

The linear actuator of claim 17 further comprising: means for interconnecting the first and second moving members for simultaneous movement of the first and second moving members by the moving means.

Claim 27

The linear actuator of claim 24 wherein the interconnecting means comprises: a first projection formed on and extending outward from each of the first and second moving members; an aperture formed in each of the first and second moving members; and the first and second moving members being disposed in a reversed relationship within the housing such that the first projection on each of the first and second moving members slidably engages the first aperture in the other of the first and second moving members.

Claim 28

The linear actuator of claim 25 wherein the moving means comprises: a drive member rotatably mounted in the housing; a release lever fixedly coupled to the drive member for bidirectionally rotating the drive member upon bidirectional pivotal movement of the release lever; and a second projection extending outward from at least one of the first and second moving members; and drive finger means, mounted on the drive member and engaging the second projection, for moving the interconnected first and second moving members between first and second positions during bidirectional rotation of the drive member.

Claim 29

The linear actuator of claim 17 wherein the first and second bearing means comprise at least one of a plurality of bearings mounted in a bearing seat formed in the housing and a low friction bearing surface formed in the housing.

Claim 30

The linear actuator of claim 17 wherein: the rotatable shaft is adapted to be rotatably mounted on the lower track of a vehicle seat; a threaded drive nut is threadingly mounted about the rotatable shaft; and a bracket rotatably carrying the drive nut and adapted to be fixedly connected the upper track of a vehicle seat such that rotation of the rotatable shaft causes translation of the drive nut along the rotatable shaft and translation of the upper track relative to the lower track.

Claim 31

The linear actuator of claim 17 further comprising: biasing means for biasing the moving means to a position in which the moving means moves the first and second moving members to the first position engaging the annular collar on the rotatable element.

Claim 32

A linear actuator for adjusting and immobilizing a movable part relative to a support, the linear actuator comprising: a rotatable shaft adapted to be coupled to the movable part; a housing adapted to be connected to the support and mounted about the rotatable shaft; a rotatable element disposed within the housing about and fixedly coupled to and rotatable with the rotatable shaft; first and second bearing means, mounted at opposite ends of the housing, for providing bearing surfaces for the rotatable element, the first and second bearing means spaced apart to permit axial movement of the rotatable element therebetween into rotatable engagement with one of the first and second bearing means under axial loads on the rotatable shaft permitting rotation of the rotatable shaft; and means, mounted in the housing, for displacing the rotatable element from engagement with the first and second bearing means to a non-rotatable position preventing rotation of the rotatable shaft.

Claim 33

A linear actuator for adjusting and immobilizing a movable part relative to a support, the linear actuator comprising: a rotatable shaft adapted to be coupled to the movable part; a housing adapted to be connected to the support and mounted about the rotatable shaft; a rotatable element disposed within the housing about and fixedly coupled to and rotatable with the rotatable shaft; first and second bearing means, mounted at opposite ends of the housing, for providing bearing surfaces for the rotatable element, the first and second bearing means spaced apart to permit axial movement of the rotatable element therebetween into rotatable engagement with one of the first and second bearing means under axial loads on the rotatable shaft permitting rotation of the rotatable shaft; and means, mounted in the housing, for displacing the rotatable element from engagement with the first and second bearing means to a non-rotatable position preventing rotation of the rotatable shaft.

Claim 34

The linear actuator of claim 30 wherein the displacing means comprises: first and second moving members disposed in the housing, each movable from a first engaged position with the rotatable element in which the first and second moving members disengage the rotatable element from both of the first and second bearing means and a second disengaged position with respect to the rotatable element; and means, mounted in the housing and coupled to the first and second moving members, for moving the first and second moving members between the first and second positions.

Claim 35

The linear actuator of claim 31 wherein the moving means comprises: bidirectional rotatable drive means, mounted in the housing and connected to first and second moving members, for driving the first and second moving members between first and second positions.

Claim 36

The linear actuator of claim 32 wherein moving means further comprises: guide means, formed on first and second moving members and the housing, for guiding movement of first and second moving means between first and second positions.

Claim 37

The linear actuator of claim 32 further comprising: biasing means, acting on the drive means, for biasing the drive means to a position driving the first and second moving members to the first engaged position with the rotatable element.

Claim 38

The linear actuator of claim 31 wherein the rotatable element comprises: a body fixedly mounted on and rotatable with the rotatable shaft; and a radially enlarged collar formed between opposite ends of the body, first and second opposed side surfaces formed on the collar.

Claim 39

The linear actuator of claim 35 wherein: the first and second moving members are disposed adjacent the first and second side surfaces of the collar, respectively; and the first and second moving members each including an engaging surface engageable with one of the first and second side surfaces of the collar when the first and second moving members are disposed in a first position.

Claim 40

The linear actuator of claim 31 further comprising: means for interconnecting the first and second moving members for simultaneous movement of the first and second moving members by the moving means.

Claim 41

The linear actuator of claim 37 wherein the moving means comprises: a drive member rotatably mounted in the housing; a release lever fixedly coupled to the drive member for bidirectionally rotating the drive member upon bidirectional pivotal movement of the release lever; and a projection extending outward from at least one of the first and second moving members; and drive finger means, mounted on the drive member and engaging the projection, for moving the interconnected first and second moving members between first and second positions during bidirectional rotation of the drive member.

Claim 42

The linear actuator of claim 30 wherein the first and second bearing means comprise at least one of a plurality of bearings mounted in a bearing seat formed in the housing and a low friction bearing surface formed in the housing.

Claim 43

The linear actuator of claim 30 further comprising: biasing means for biasing the displacing means to a position in which the displacing means displaces the rotatable element from engagement with the first and second bearing means.