Double enveloping worm and gear seat recliner

Claim 1

A device for adjusting the relative inclination of two elements comprising: a first member; a second member; pivot means for connecting the first member to the second member and for allowing adjustable inclination of the first member relative to the second member; and double enveloping gear and worm means formed at least in part of intermeshing double enveloping plastic teeth for adjustably driving the first member through a predetermined range of inclination relative to the second member, said gear means having a gear pitch diameter less than a pitch diameter of said worm means and a variable center to center distance between said gear pitch diameter and said worm pitch diameter allowing more plastic teeth to be brought into contact with one another under high load conditions.

Claim 2

A device for adjusting the relative inclination of two elements comprising: a first member; a second member; pivot means for connecting the first member to the second member and for allowing adjustable inclination of the first member relative to the second member; and double enveloping gear and worm means formed at least in part of intermeshing double enveloping plastic teeth for adjustably driving the first member through a predetermined range of inclination relative to the second member, said gear means having a gear pitch diameter less than a pitch diameter of said worm means and a variable center to center distance between said gear pitch diameter and said worm pitch diameter allowing more plastic teeth to be brought into contact with one another under high load conditions.

Claim 13

A device for adjusting the relative inclination of two elements, and in particular a back of a seat relative to a base of the seat, said device comprising: a base member; a back member; pivot means for connecting the base member to the back member and for allowing adjustable inclination of the back member relative to the base member; enveloping gear means pivotally connected to the base member for selective movement relative to the base member through a predetermined arc, said gear means having plastic concave teeth formed thereon with a first pitch diameter; motion transfer means for moving the back member in response to movement of said enveloping gear means; and enveloping worm means, rotatably connected to the base member and in double enveloping engagement with the enveloping gear means, for driving the gear means selectively along the predetermined arc, the worm means having a plastic concave worm with at least a single thread, the thread having a second pitch diameter smaller than the first pitch diameter of the gear means allowing more plastic teeth to be brought into contact with one another under high load conditions.

Claim 14

A device for adjusting the relative inclination of two elements, and in particular a back of a seat relative to a base of the seat, said device comprising: a base member; a back member; pivot means for connecting the base member to the back member and for allowing adjustable inclination of the back member relative to the base member; enveloping gear means pivotally connected to the base member for selective movement relative to the base member through a predetermined arc, said gear means having plastic concave teeth formed thereon with a first pitch diameter; motion transfer means for moving the back member in response to movement of said enveloping gear means; and enveloping worm means, rotatably connected to the base member and in double enveloping engagement with the enveloping gear means, for driving the gear means selectively along the predetermined arc, the worm means having a plastic concave worm with at least a single thread, the thread having a second pitch diameter smaller than the first pitch diameter of the gear means allowing more plastic teeth to be brought into contact with one another under high load conditions.

Claim 22

A device for adjusting the relative inclination of two elements, and in particular, the relative inclination of a back member of an automotive seat pivotally connected about a rotational axis to a base member of the seat for movement through a predefined arc, the device comprising: at least an enveloping gear sector for pivotal connection to said base member about an axis generally co-axial with said rotational axis, said gear sector having plastic concave teeth formed thereon with a first pitch diameter; an enveloping worm for rotatable connection to said base member, said worm formed of at least one plastic concave worm having at least a single thread, said worm in double enveloping engagement with the gear sector and the thread having a second pitch diameter smaller than the first pitch diameter of the gear sector by approximately 20 percent; a rotatable cam pivotally connecting the gear sector to said base member, the rotatable cam pivotal along a predefined arc about an axis of rotation generally co-axial with said rotational axis of said back member; a spring biasing the rotatable cam in a rotational direction such that the gear sector is urged into positive engagement with the worm at any angular position of movement; a motion transmitting member connecting the gear sector to said back member at a position radially spaced from the rotational axis and generally disposed between the rotational axis and the teeth of the gear sector; drive means for rotating the worm in clockwise and counterclockwise directions; and releasable lock means for preventing unintentional movement of the worm in either rotational direction.

Claim 23

A device for adjusting the relative inclination of two elements, and in particular, the relative inclination of a back member of an automotive seat pivotally connected about a rotational axis to a base member of the seat for movement through a predefined arc, the device comprising: at least an enveloping gear sector for pivotal connection to said base member about an axis generally co-axial with said rotational axis, said gear sector having plastic concave teeth formed thereon with a first pitch diameter; an enveloping worm for rotatable connection to said base member, said worm formed of at least one plastic concave worm having at least a single thread, said worm in double enveloping engagement with the gear sector and the thread having a second pitch diameter smaller than the first pitch diameter of the gear sector by approximately 20 percent; a rotatable cam pivotally connecting the gear sector to said base member, the rotatable cam pivotal along a predefined arc about an axis of rotation generally co-axial with said rotational axis of said back member; a spring biasing the rotatable cam in a rotational direction such that the gear sector is urged into positive engagement with the worm at any angular position of movement; a motion transmitting member connecting the gear sector to said back member at a position radially spaced from the rotational axis and generally disposed between the rotational axis and the teeth of the gear sector; drive means for rotating the worm in clockwise and counterclockwise directions; and releasable lock means for preventing unintentional movement of the worm in either rotational direction.