US 5,299,853 AGranted

Vehicle seat assembly with linear actuator

AssigneeHoover Universal, Inc.

InventorsLes Griswold, William H. Jones, Marc D. Hewko, Joanne H. Cole

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Abstract

A vehicle seat assembly with a linear actuator is disclosed in which the actuator is used to adjust the relative position of two relatively movable components of the seat assembly. The actuator includes a first part attached to one of the seat assembly components in the form of a lead screw with an external helical screw thread. A second part of the actuator is attached to the other seat component that is relatively movable and includes a housing containing a spin nut threaded onto the lead screw. The second part further includes means for axially capturing the spin nut to prevent the spin nut from rotating along the lead screw and means for selectively releasing the spin nut from its axial capture to permit rotation about the lead screw and thereby relative movement of the actuator second part relative to the first part. A cam is mounted to the second part to selectively engage and release the spin nut from its axial capture.

Claims17

Dependent claims

An actuator for a motor vehicle seat assembly, said seat assembly having a base member for attachment to a motor vehicle, a seat member mounted to said base member for translational movement relative to said base member and a back member mounted to said seat member for rotation relative to said seat member, said actuator holding one of said seat member or back member in position relative to said base member or said seat member respectively, said actuator comprising:

an elongated lead screw having a pair of ends and defining central linear axis of said actuator, said screw being attached to one of said base member, seat member and back member, said screw having a threaded portion comprising a plurality of threads which extend in a helical fashion around the outside of said screw;
a spin nut having a central bore with a complementary threaded portion, said nut being threadably coupled to said screw and being axially movable along said screw in response to rotation of said spin nut about said axis, and said nut having axial end walls disposed in planes at a right angle to said central axis;
a housing having two ends mounted to another of said base member, seat member and back member, and containing said spin nut therein, said housing having an end wall at one end with an inner face in confronting juxtaposition with one end wall of said nut and said housing being open at the other end;
an end cap slidably disposed in said housing open end having an inner face in confronting juxtaposition to the other end wall of said spin nut to axially capture said nut between said inner faces, said cap further having an outer face opposite said inner face, said end cap being axially slidable in said open end between a lock position in which said inner faces forcefully engage said end walls of said spin nut to prevent rotation of said spin nut about said central axis and a release position in which said inner faces do not engage said end wall thereby permitting said nut to rotate about said axis;
bearing means within said housing to promote free rotation of said nut with respect to said screw;
yieldable resilient means within said housing to urge said end cap to said release position and to urge said nut away from said inner faces whereby said nut is free to rotate;
a cam rotatably mounted to said housing having a cam surface engaging said outer face of said cap, said cam having a first position in which said cam holds said end cap in opposition to said yieldable resilient means in said lock position of said end cap and said cam having a second position in which said end cap is allowed to be moved to said release position by said yieldable resilient means;
bias means for urging said cam to said first position whereby said nut is frictionally held from rotation;
and
release means for rotating said cam in opposition to said bias means to said second position whereby said nut is permitted to rotate about said screw.

7 more elements

In a seat assembly for a motor vehicle having a base member for attachment of said seat assembly to a motor vehicle, a seat member mounted to said base member for translational movement:

relative to said base member and a back member mounted to said seat member for rotational movement relative to said seat member, an actuator for holding two of said relatively movable members in position, said actuator comprising first and second portions mounted to opposite members of said relatively movable members, an annular element defining an axis and being disposed in said second portion and having transverse end faces at opposite axial ends thereof, means axially capturing said element on said second portion, said means axially capturing said element comprising capturing portions which are relatively adjustable to one condition permitting said element to rotate about said axis relative to said first and second portions of said actuator and to another condition preventing such rotation, said element and said first portion of said actuator comprising an operative connection between them which is effective, when said capturing portions are in said one condition and axial forces are concurrently applied to said actuator, to initiate rotation of said element about said axis relative to said first and second portions of said actuator, and said rotation of said element is in turn effective to permit translation of said first portion relative to both said element and said second portion thereby to change the relative positions of said relatively movable members, said capturing portions being disposed in confronting juxtaposition to said end faces of said element and operable in said another condition to apply axial capturing frictional forces against both said end faces great enough to prevent said element from rotating with respect to said first and second portions of said actuator in response to axially applied forces, bearing means and yieldable resilient means disposed in said second portion, said bearing means being urged by said yieldable resilient means to provide bearing support to promote free rotation of said element with respect to said first and second portions when said capturing portions are in said one condition, said yieldable resilient means yielding when said capturing portions are in said another condition so as to allow said capturing portions to apply said axial capturing forces against said end faces to prevent said element from rotating with respect to said first and second portions;
said capturing portions including a housing forming a recess within which said element is disposed and a housing cap covering said recess and being axially slidable relative to said housing, said cap having a first side being disposed in confronting juxtaposition to one end face of said element to apply said capturing frictional forces thereto and a second side opposite said first side and axially spaced therefrom, a cam mounted to said housing having a cam surface engaging said second side of said cap and said cam being movable to apply varying axially forces to said cap second side to move said cap between a first position corresponding to said one condition of said capturing portions and a second position corresponding to said another condition of said capturing portions.

Dependencies are inferred from the claim text.