Torque limiter mechanism

• US 3,986,634 A
• Filed: 10/18/1974
• Issued: 10/19/1976
• Est. Priority Date: 06/05/1974
• Status: Expired due to Term

• Current Assignee: General Motors Corporation (General Motors Company)
• Original Assignee: General Motors Corporation (General Motors Company)
• Inventors: Williams, Donald L., Smith, Claude A.
• Primary Examiner(s): Price, William
• Assistant Examiner(s): Hart, Ro E.
• Application Number:
  US05/516,032
• Time in Patent Office: 732 Days
• Field of Search: 220/288, 220/200, 220/296, 220/304, 220/203, 220/39, 215/220, 215/9, 192/46
• US Class Current: 220/288
• CPC Class Codes: B60K 15/0406 Filler caps for fuel tanks
• CPC Class Codes: F01P 11/0214 Mounting
• CPC Class Codes: F01P 2011/0228 Sealing

Abstract

A two piece torque release mechanism includes a metal cover having a peripheral flange with a plurality of circumferentially spaced, cam surfaces each including ramp and notch segments intersecting at a sharp radius point radially inwardly of a land segment; a plurality of integrally formed fingers on a driven member are sprung radially outwardly into operative engagement with the cam surfaces. Each finger has a sharp radius tip portion formed by the intersection of a flat radial surface and an inclined slip surface; the radial surfaces and notches define a positive interlock between the cover and the driven member for removing the driven member; the slip surfaces are mateable with the cam ramp segments to produce a torque release couple between the cover and the driven member to prevent overtightening of the driven member and to produce a reverse slip movement of each finger following torque release for parking the tip portions against the cam land segments so as to maintain the fingers in an unstressed position when the driven member is in place.

Claims

1. A torque release clutch mechanism comprising cover means having a top portion and a continuously formed circumferential flange thereon, a plurality of circumferentially spaced cam surfaces on the interior of said flange, each of said surfaces including a cam ramp and a cam notch having a land portion formed therebetween, a curved peak joining each of said ramps to an adjacent cam notch, a driven member having a head portion thereon with a peripheral flange received within said cover for rotation relative thereto, means for connecting said cover means and driven member against axial separation, a plurality of fingers formed integrally with said peripheral flange and of material tending toward a cold set distortion under prolonged stress, each finger having a root directed radially outwardly of said peripheral flange, each of said fingers including an arcuate segment joined to said root and having a tip biased radially outwardly of said peripheral flange and compressible radially inwardly toward said peripheral flange, each of said tips including a flat radially inwardly directed stop surface thereon engageable with said cam notches to interlock said cover with said driven member upon a first relative rotation therebetween, each of said tips further including an inclined surface thereon, a sharp radius curve on said tip joining said stop surface and said inclined surface, said sharp radius curve being mateable with each of said cam ramps and movable thereacross to produce a limited resistance to relative rotation between said cover and said driven member upon rotation of said cover in a direction opposite to said first relative rotation and a torque release between said curved peaks and said sharp radius curves, to assure movement of said fingers radially outwardly to an unstressed park position on said land portion following movement of said fingers radially inwardly on said cam ramps, said inclined surface and said cam ramp having an angle of inclination whose tangent exceeds the coefficient of friction between said inclined surface and said cam ramp whereby said fingers will slip radially outwardly on said cam ramps if they are located thereon following cap tightening to assume an unstressed park position on said land portions following cap tightening, said flange having lugs formed integrally thereof at spaced circumferential points thereon to space said finger roots from said cover means, a plurality of ribs formed on said driven member engageable with said cover to space said finger tips axially of said cover means whereby said fingers are free to flex between said peripheral flange and said cam surfaces during movement thereof across said cam surfaces between torque released positions on said cam ramps and unstressed park positions on said land portions.