Creeper having lever arms providing variable mechanical advantage for inclining a back portion
AssigneeCarl Clark Auel Living Will
InventorCarl C. Auel
Life of this patent
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Abstract
A creeper having a base and an inclinable back portion and an apparatus for inclining the back, the apparatus including lever arms, pull bars, a sliding member, rocker arms and a sprocket wheel about which a length of chain attached the lever arm rolls. A point of target contact between the chain and sprocket wheel moves along the length of the lever arm resulting in a variable mechanical advantage for a force applied to the lever arm.
Claims16
In a creeper having a base and an inclinable back portion, an apparatus for inclining such back portion including:
- (a) at least one lever arm having a force receiving portion extending outwardly beyond one of opposite lateral edges of the base to allow for application of a force to said lever arm to move a force transmitting portion of said lever arm extending in the base;
- (b) at least one pull bar connected to the force transmitting portion of said lever arm for pivotal movement of said lever arm relative to said pull bar;
- (c) a force transmitter operably supporting said lever arm on said base for transmitting the force applied to said lever arm to said pull bar, said force transmitter providing a variable distance between the force receiving portion of said lever arm and said force transmitter such that a mechanical advantage is at a maximum when said back portion is in a position of minimum inclination relative to said base;
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- (d) a connector connecting said pull bar to said back portion for inclining said back portion in response to the force imparted to said pull bar by said lever arm.
In a creeper having a base and an inclinable back portion, an apparatus for inclining such back portion including:
- (a) a pair of lever arms each having a force receiving portion extending outwardly beyond one of opposing edges of the base to allow for application of a force to each of said lever arms to move a force transmitting portion of each of said lever arms extending in said base;
- (b) a pair of pull bars each connected to one of the force transmitting portions of said lever arms for pivotal movement of said lever arms relative to said pull bars;
- (c) a force transmitter operably supporting said lever arms on said base for transmitting the forces applied to said lever arms to said pull bars, said force transmitter providing variable distance between the force receiving portion of said lever arm and said force transmitter such that a mechanical advantage is at a maximum when said back portion is in a position of minimum inclination relative to said base;
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- (d) means connecting said pull bars to said back portion for inclining said back portion in response to the forces imparted to said pull bars by said lever arms.
An ever changing mechanical advantage system for a force transmitting mechanism including:
- (a) a base;
- (b) rack teeth extending along a lever arm at one end portion opposite to a force receiving end of said lever arm;
- (c) a drive including gear teeth spaced about a central axis of a circular sector secured to said base for meshing engagement with said rack teeth;
- (d) a restraint for securing said drive against pivoting about said central axis to said base;
- (e) a cage engaged for pivotal support about said central axis, said cage including spaced apart support members engagable with said one end portion of said lever arm for maintaining a meshing relation between said rack teeth and said gear teeth, whereby pivoting of said cage while said rack teeth advance along the end portion of said lever arm in response to a force applied to the force receiving end of said lever arm creates a variable length moment arm for the force applied to said lever arm such that a mechanical advantage is at a maximum when teeth of said rack teeth most adjacent the terminal part of said one end portion engage with the gear teeth of said drive.
Dependencies are inferred from the claim text.