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US 6,637,575 B2Granted
Apparatus and method for thin profile ratchet actuator
AssigneeL&P Property Management Company
InventorsJintao Liu, Alfred Stadlbauer
Life of this patent
Estimating the term…
Abstract
A ratchet actuator for an ergonomic device has a thin profile due to the combination of multiple functions into single parts. A ratchet drive gear also has drive fingers for operating a clutch. A clutch stator has high and low steps for engaging and disengaging ratchet pawls.
Claims21
A ratchet actuator comprising:
- a lever;
- a ratchet arm having a drive axis and a ratchet axis, said ratchet arm being fixed to said lever at said drive axis;
- a ratchet comprising:
- a ratchet post, said ratchet post being coaxial with and fixed to said ratchet arm ratchet axis;
- a first pawl having a first end in rotating communication with said ratchet post and having a second end, said second end having teeth and a pin;
- at least one second pawl having a first end in rotating communication with said ratchet post and having a second end, said second end having teeth and a pin;
- a pawl spring biasing said first pawl second end towards said second pawl second end;
- a drive gear having teeth, said drive gear teeth being dimensioned to mesh with said first and second pawl teeth and said drive gear being disposed to engage said pawls, said drive gear having at least two fingers projecting perpendicular to the plane of the gear;
- a ring having a high step and at least one low step;
- each of said steps being disposed to mediate said pawl spring biasing of each of said pawls towards the other of each of said pawls by sliding contact with said pins;
- such that when one of said first or second pawl pins is in contact with said at least one low step, the other of said pins remains in contact with said high step;
- said low step being dimensioned to mesh said teeth of said one of said pawl ends having said pin contacting said low step with said teeth of said drive gear;
- and
- said high step being dimensioned to keep said teeth of said other pawl end having said pin contacting said high step disengaged from said drive gear teeth;
- a hub having at least two bosses defining at least two spaces between said bosses;
- said hub having at least two edges forming one side of each of said spaces and
- said each of said edges being dimensioned with a first hub distance and a second hub distance from a center of said hub with said edge being graduated from said first distance to said second distance,
- said hub being circumscribed by said ring, said ring having an inner surface, said inner surface being in sliding rotational communication with said bosses, said inner surface defining another side of each of said spaces, and
- said at least two spaces receiving said at least two fingers from said drive gear;
- at least two locking rollers, disposed in said spaces said locking rollers being narrower in diameter than a distance between said ring inner surface and said hub edge first distance and said rollers being wider in diameter than a distance between said ring inner surface and said edge second distance;
- and
- at least two springs disposed between said bosses and said locking rollers such that said springs bias said locking rollers from said first distance and toward said second distance;
- a traction element anchor;
- and
- a housing encapsulating said ratchet arm, said ratchet, said drive gear, said ring, said hub, said springs and said traction element anchor.
22 more elements
A ratchet actuator for an ergonomic device comprising:
- a housing;
- a pulley rotatable within said housing, said pulley being adapted to draw a traction element;
- a locking clutch encapsulated by a ring in said housing and disposed to control rotation of said pulley;
- a drive gear in rotationally driving communication with said pulley through said clutch;
- a ratchet in driving communication with said drive gear, said driving communication being mediated at least one step in said ring;
- a lever in driving communication with said ratchet and rotationally fixed to said housing;
- and
- a traction cable having a first end fixed to said pulley and a second end adapted to engage an ergonomic device;
- whereby a first rotation of said lever in a first direction draws said traction cable to a position held by said clutch, and a second rotation of said lever removes said traction cable from said position.
6 more elements
A method of actuating an ergonomic device comprising:
- rotating a pulley via a lever, a ratchet and a drive gear;
- controlling said rotating step by a clutch interaction step comprising:
- freewheeling of said rotation in a selected first rotational direction upon application of rotational force in said selected first rotational direction;
- locking said pulley from rotating in a second rotational direction opposite said selected first rotational direction upon removal of said rotational force in said first direction;
- selectively releasing said locking of said clutch upon application of rotational force in said second rotational direction;
- selectively applying rotational force in said first rotational direction or said second rotational direction with said lever and said ratchet by moving a first of two pawls into driving engagement with said drive gear in said first rotational direction while disengaging a second of said two pawls from said drive gear and by moving a second of said two pawls into driving engagement with said drive gear in said second rotational direction while disengaging said first of said two pawls from said drive gear;
- mediating said selective application of rotational force via a high step and a low step on a ring circumscribing said clutch;
- returning said lever to a neutral position via a spring in a housing channel when rotational force is released;
- transferring said rotational force to tractive force via a cable having a first end attached to said pulley and a second end attached to said ergonomic device.
6 more elements
Dependencies are inferred from the claim text.