US 4,230,414 AGranted

Ratchet-action hinge device

AssigneeUop LLC

InventorErnest L. Cheshire

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Abstract

A hinge device for supporting an armrest on a vehicle seat includes a ratchet mechanism in which ratchet teeth are disposed around the inside of a ratchet ring for engagement with a pawl carried by a rotor within the ring. A blocking ring coaxial with the ratchet ring is overlapped by the pawl and is carried along by engagement of the pawl in a recess of the blocking ring as the pawl ratchets over the teeth. After clearing the ratchet teeth, the pawl is lifted by cam action from the recess on to the inner surface of the blocking ring which masks the ratchet teeth and allows the pawl to be returned to its starting position where it is restored by cam action to its recess in the blocking ring wherein it can once again engage the ratchet teeth.

Claims3

Dependent claims

A hinge device for pivotally interconnecting two parts and including a ratchet mechanism comprising

a first ring member secured to one of said parts and carrying a row of ratchet teeth on its inner periphery,
a rotor member secured to the other of said parts for movement relative to the ratchet teeth about the axis of the hinge device, said rotor member being located concentrically within said first ring member,
a pawl carried by said rotor member and engageable with any selected one of said teeth to support said parts relative to each other in any selected one of a plurality of predetermined angularly-spaced positions corresponding to the angular spacing between the teeth of the ratchet mechanism,
de-activating means operable after the pawl has ratcheted across the last tooth in said row, as a result of relative rotation of said parts in one direction, to maintain the pawl out of engagement with the ratchet teeth and thereby allow relative rotation of said parts in the opposite direction until the pawl has cleared the ratchet teeth in said opposite direction,
said de-activating means comprising a second ring which is concentric with the first ring member and is engageable with the pawl in response to movement of said members into a first relative position, is disengageable from the pawl in response to movement of said members into a second relative position, and holds said pawl away from said ratchet tooth over the path of movement of said members between said first and second positions, said second ring being mounted for movement with said pawl along a path disposed adjacent said ratchet teeth, said second ring including a radially inwardly projecting detent behind which said pawl can engage in response to movement of the pawl as said members enter said first relative position, the said second ring being coupled to said rotor member for movement therewith between said first and second positions, the detent holding the pawl at a radial distance from the hinge axis at which it clears the ratchet teeth, movement of the pawl into said second position causing release of the pawl from the detent, the second ring being disposed adjacent the first ring in the axial direction, the pawl being elongate axially to bridge across both said rings and engage either said ratchet teeth or said detent.

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Dependencies are inferred from the claim text.

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Abstract

A hinge device for pivotally interconnecting two parts and including a ratchet mechanism comprising

a first ring member secured to one of said parts and carrying a row of ratchet teeth on its inner periphery,
a rotor member secured to the other of said parts for movement relative to the ratchet teeth about the axis of the hinge device, said rotor member being located concentrically within said first ring member,
a pawl carried by said rotor member and engageable with any selected one of said teeth to support said parts relative to each other in any selected one of a plurality of predetermined angularly-spaced positions corresponding to the angular spacing between the teeth of the ratchet mechanism,
de-activating means operable after the pawl has ratcheted across the last tooth in said row, as a result of relative rotation of said parts in one direction, to maintain the pawl out of engagement with the ratchet teeth and thereby allow relative rotation of said parts in the opposite direction until the pawl has cleared the ratchet teeth in said opposite direction,
said de-activating means comprising a second ring which is concentric with the first ring member and is engageable with the pawl in response to movement of said members into a first relative position, is disengageable from the pawl in response to movement of said members into a second relative position, and holds said pawl away from said ratchet tooth over the path of movement of said members between said first and second positions, said second ring being mounted for movement with said pawl along a path disposed adjacent said ratchet teeth, said second ring including a radially inwardly projecting detent behind which said pawl can engage in response to movement of the pawl as said members enter said first relative position, the said second ring being coupled to said rotor member for movement therewith between said first and second positions, the detent holding the pawl at a radial distance from the hinge axis at which it clears the ratchet teeth, movement of the pawl into said second position causing release of the pawl from the detent, the second ring being disposed adjacent the first ring in the axial direction, the pawl being elongate axially to bridge across both said rings and engage either said ratchet teeth or said detent.

2 more elements