US 5,328,235 AGranted

Pawl and ratchet assembly

AssigneeLa-Z-Boy Chair Company

InventorsJonathan R. Saul, Karl J. Komorowski, Larry P. LaPointe, Edwin J. Shoemaker

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Abstract

An improved latching mechanism for a rocking chair having an extensible leg rest assembly is disclosed. The latching mechanism is operable to releasably lock the chair frame in a rearwardly tilted position upon extension of the leg rest assembly while permitting unrestricted rocking action when the leg rest assembly is protracted. The improved latching mechanism is a pawl and ratchet latching mechanism having a spring-biased pawl member operable to lockingly engage a toothed ratchet sector for retaining the chair frame in its rearwardly tilted position. A unique actuation arrangement is disclosed having a release member that functions to pull the spring-biased pawl member to a released position. The actuation arrangement is also operable to prevent the release member from exerting any compressive biasing loading on the pawl member when the pawl member is in locked engagement with the ratchet teeth.

Claims36

Dependent claims

A rocking chair comprising:

a base;
a chair frame supported for rocking movement on said base;
a drive mechanism suspended from said chair frame;
a leg rest assembly suspended from said drive mechanism for movement between a retracted position and an extended position in response to actuation of said drive mechanism;
actuation means for permitting a seat occupant to selectively actuate said drive mechanism;
a ratchet sector secured to said chair frame and having ratchet teeth formed thereon;
a pawl member secured to said base for pivotable movement between a first position lockingly engaging said ratchet teeth wherein said chair frame is releasably locked in a rearwardly tilted position, and a second position released from said ratchet teeth for permitting unrestricted rocking movement of said chair frame;
spring means for normally biasing said pawl member toward said first position, said spring means adapted to exert an engagement force on said pawl member for maintaining locked engagement with said ratchet teeth when said pawl member is in said first position;
a first member supported on said drive means and having aperture means formed therein;
and
a release member having a first end coupled to said pawl member and a second end retained within said aperture means of said first member, said release member adapted to pull said pawl member to said second position when said drive mechanism is actuated for moving said leg rest assembly to said retracted position, said spring means being operable to urge said pawl member to said first position when said drive mechanism is actuated for moving said leg rest assembly to said extended position such that said release member is slidably movable within said aperture means for inhibiting said release member from exerting a biasing force on said pawl member whereby said release member is maintained in an unloaded condition.

8 more elements

A latching mechanism for releasably locking a chair frame of a rocking chair in a rearwardly tilted position relative to a stationary base assembly following actuation of a drive mechanism for moving a leg rest assembly from a retracted position to an extended position, said latching mechanism comprising;

a ratchet sector fixed to said chair frame and having ratchet teeth formed thereon;
a pawl member fixed to said base assembly for pivotable movement between a first position engaged with said ratchet teeth for locking said chair frame in said rearwardly tilted position and a second position disengaged from said ratchet teeth for permitting unrestricted rocking movement of said chair frame on said base assembly;
a first member supported from said drive mechanism;
a release member interconnected between said pawl member and said first member for pulling said pawl member from said first position to said second position in response to actuation of said drive mechanism causing said leg rest assembly to move from said extended position toward said retracted position;
spring means acting on said pawl member for urging said pawl member to said first position on response to actuation of said drive mechanism causing said leg rest assembly to move from said retracted position toward said exerted position;
and
means for maintaining said release member in an unloaded condition upon continued movement of said leg rest assembly to a fully extended position such that said release member does not exert a biasing load on said pawl member, said means for maintaining including aperture means formed in said first member, said release member having a first end coupled to said pawl member and a second end retained within said aperture means such that said release members is slidably confined within said aperture means.

4 more elements

a ratchet sector fixed to said chair frame and having ratchet teeth formed thereon;
a pawl member fixed to said base assembly for pivotable movement between a first position engaged with said ratchet teeth for locking said chair frame in said rearwardly tilted position and a second position disengaged from said ratchet teeth for permitting unrestricted rocking movement of said chair frame on said base assembly;
a first member supported from said drive mechanism;
a release member interconnected between said pawl member and said first member for pulling said pawl member from said first position to said second position in response to actuation of said drive mechanism causing said leg rest assembly to move from said extended position toward said retracted position;
dual torsion spring means acting on said pawl member for urging said pawl member to said first position in response to actuation of said drive mechanism, said spring means comprising a pair of laterally spaced legs having free ends arranged to engage a surface of a pawl bracket to which a first end of said pawl member is secured for pivotable movement about a hinge pin, and a transverse arm interconnecting said laterally spaced legs which engages a surface of said pawl member for exerting said biasing force thereon;
and
means for maintaining said release member in an unloaded condition upon continued movement of said leg rest assembly to a fully extended position such that said release member does not exert a biasing load on said pawl member.

4 more elements

Dependencies are inferred from the claim text.