Mechanism with torque-limiting device for controlling a rearview mirror

Abstract

A torque-limiting device for a mechanism controlling a vehicle rearview mirror in which the mirror is fixed on a supporting member mounted for pivoting about two perpendicular axes, on a yoke integral with a baseplate mounted in the casing. The tubular extension with the threaded portion of the control members is produced from a deformable material and is provided with at least one axial slot issuing into one of the ends of the tubular extension in such a way that any force applied axially on the control member enables the threaded end portion to disengage from the threaded hole, and the pinions are mounted on the bottom of a casing by way of a ball joint which is resiliently held in position so that the control members are always in alignment with the axis of the driving pinions.

What is claimed is: 
     
       1. A torque-limiting mechanism for operating a rearview mirror of a vehicle, said torque-limiting mechanism comprising: a casing having a cavity therein;   .Iadd.a spherical bearing adjoining said casing; .Iaddend.   a cover member mounted to said casing, said cover member having at least one opening therein;   a support member attached to said mirror, said support member further being spaced a predetermined distance from said cover member of said casing;   universal pivot joint means interposed said support member and said cover member of said casing, said universal pivot joint means adapted to allow pivoting movement of said mirror about at least one axis;   rotation to translation means mounted in said cavity of said casing, said rotation to translation means comprising:   at least one pinion gear .[.member mounted.]. .Iadd.adapted to be directly driven by a worm, said at least one pinion gear being located .Iaddend.in said cavity of said casing and .Iadd.mounted to said casing.Iaddend.;   at least one selectively movable control member having a central axis and being mounted to said at least one pinion gear .[.member.]. for movement relative thereto, said at least one selectively movable control member further having one end portion and an opposite end portion;   second pivot joint means located at said one end portion of said at least one selectively movable control member, said second pivot joint means adapted to cooperate with said support member for pivot motion of said support member relative to said at least one selectively movable control member;   a first spherical ball joint member means .[.adjoining.]. .Iadd.in one piece with .Iaddend.said at least one pinion gear .[.member.]., .Iadd.said first spherical ball joint member means being received by said spherical bearing for providing universal movement of said at least one pinion gear relative to said casing, .Iaddend.said first spherical ball joint member means being defined by a spherical radius having a center of curvature lying substantially along said central axis of said at least one selectively movable control member; and   motor means mounted in said casing at a preselected location relative to said at least one pinion gear .[.member.]. and adapted to rotate said at least one pinion gear .[.member.]..   
     
     
       2. The .[.torque limiting.]. .Iadd.torque-limiting .Iaddend.mechanism as claimed in claim 1 wherein said cover member has two openings therein and said second pivot joint means interposed said support member and said cover member of said casing is adapted to allow pivoting movement .[.to.]. .Iadd.of .Iaddend.said mirror about two substantially perpendicular axes, and further comprising: .Iadd.a second spherical bearing adjoining said casing; .Iaddend.   a second pinion gear .[.member mounted.]. .Iadd.adapted to be directly driven by a worm, said second pinion gear being located .Iaddend.in said cavity of said casing .Iadd.and mounted to said casing.Iaddend.;   a second selectively movable control member having a central axis and being mounted to said second pinion gear .[.member.]. for movement relative thereto, said second selectively movable control member further having one end portion and an opposite end portion;   third pivot joint means located at said one end portion of said second selectively movable control member, said third pivot joint means adapted to cooperate with said support member for pivot support of said support member relative to said second selectively movable control member;   a second spherical ball joint member means .[.adjoining.]. .Iadd.in one piece with .Iaddend.said second pinion gear .[.member.]., .Iadd.said second spherical ball joint member means being received by said second spherical bearing for providing universal movement of said second pinion gear relative to said casing, .Iaddend.said second spherical ball joint member means being defined by a spherical radius having a center of curvature lying substantially along said central axis of said second selectively movable control member; and   second motor means mounted in said casing at a preselected location relative to said second pinion gear .[.member.]. and adapted to rotate said second pinion gear .[.member.]..   
     
     
       3. The torque-limiting mechanism as claimed in claim 1 wherein said second pivot joint means further comprises a pivot center lying on said central axis of said at least one selectively movable control member and wherein said central axis of said at least one selectively movable control member and said pivot center of said second pivot joint means are aligned. 
     
     
       4. The torque-limiting mechanism as claimed in claim 1 wherein said at least one pinion gear .[.member.]. comprises a threaded hole and said second pivot joint means comprises means to prevent rotation of said at least one selectively movable control member about said central axis, and further comprising: thread means located at said opposite end portion of said at least one selectively movable control member, said thread means engaging said threaded hole of said, at least one pinion gear .[.member.]. to move said at least one selectively movable control member relative to said at least one pinion gear .[.member.]. such that as said at least one pinion gear .[.member.]. is rotated by said motor means said at least one selectively movable control member moves non-rotatably in a substantially axial direction.   
     
     
       5. The torque-limiting mechanism as claimed in claim 4 wherein said rotation to translation means further comprises resiliently yieldable means integral with said opposite end portion of said at least one selectively movable control member such that when a driving force applied to one of said at least one selectively movable control member and said at least one pinion gear .[.member.]. is opposed by a predetermined resistance to responsive movement, said resiliently yieldable means yields in a radially inward direction to disengage said thread means from said threaded hole such that said at least one pinion gear .[.member.]. is rotated by said motor means and said at least one selectively movable control member remains substantially axially stationary relative to said at least one pinion gear .[.member.].. 
     
     
       6. The torque-limiting mechanism as claimed in claim 1 wherein said casing further comprises first spherical ball joint surface means, said first spherical ball joint surface means being complementary to said first spherical ball joint member means such that said first spherical ball joint member means and said .[.first spherical ball joint surface means.]. .Iadd.spherical bearing .Iaddend.cooperate to provide a universal joint motion of said .Iadd.pinion gear and said .Iaddend.at least one selectively movable control member relative to said casing. 
     
     
       7. The torque-limiting mechanism as claimed in claim 1 wherein said one end portion of said at least one selectively movable control member extends through said at least one opening in said cover member of said casing. 
     
     
       8. The torque-limiting mechanism as claimed in claim 7 further comprising means for sealing said at least one opening in said cover member of said casing, said sealing means being attached at one end to said at least one selectively movable control member and at the other opposite end being mounted to said at least one opening of said cover member such as to seal a portion of said rotation to translation means within said casing. 
     
     
       9. A torque-limiting mechanism for operating a rearview mirror of a vehicle, said torque-limiting mechanism comprising: a casing having a cavity therein;   .Iadd.a spherical bearing adjoining said casing;.Iaddend.   a cover member mounted to said casing, said cover member having at least one opening therein;   a support member attached to said mirror, said support member further being spaced a predetermined distance from said cover member of said casing;   universal pivot joint means interposed said support member and said casing, said universal pivot joint means adapted to allow pivoting movement of said mirror about at least two perpendicular axes;   rotation to translation means mounted in said cavity of said casing, said rotation to translation means comprising;   at least one pinion gear .[.member mounted.]. .Iadd.adapted to be directly driven by a worm, said at least one pinion gear being located .Iaddend.in said cavity of said casing .Iadd.and mounted to said casing.Iaddend.;   at least one selectively movable control member having a central axis and being mounted to said at least one pinion gear .[.member.]. for movement relative thereto, said at least one selectively movable control member further having one end portion and an opposite end portion;   second pivot joint means located at .Iadd.said .Iaddend.one end portion of said at least one selectively movable control member, said second pivot joint means adapted to cooperate with said support member for pivot motion of said support member relative to said at least one selectively movable control member, said second pivot joint means further comprising a pivot center lying on said central axis of said at least one selectively movable control member; and   a first spherical ball joint .[.surface means adjoining.]. .Iadd.member in one piece with .Iaddend.said at least one pinion gear .[.member.]., .Iadd.said first spherical ball joint member being received by said spherical bearing for providing universal movement of said at least one pinion gear relative to said casing, .Iaddend.said first spherical ball joint .[.surface means.]. .Iadd.member .Iaddend.being defined by a spherical radius having a center of curvature lying substantially along said central axis of said at least one selectively movable control member such that said center of curvature of said .Iadd.first .Iaddend.spherical ball joint .[.surface means.]..Iadd.member.Iaddend., said central axis of said at least one selectively movable control member, and said pivot center of said second pivot joint means are aligned.   
     
     
       10. The torque-limiting mechanism as claimed in claim 9 wherein said at least one pinion gear .[.member.]. has a central axis and wherein said central axis of said at least one selectively movable control member and said central axis of said at least one pinion gear .[.member.]. are substantially coaxial. 
     
     
       11. A torque-limiting mechanism for operating a rearview mirror of a vehicle, said torque-limiting mechanism comprising: a casing having a cavity therein;   .Iadd.a spherical bearing adjoining said casing.Iaddend.;   a cover member mounted to said casing, said cover member having at least one opening therein;   a support member attached to said mirror, said support member further being spaced a predetermined distance from said cover member of said casing;   universal pivot joint means interposed said support member and said casing, said universal pivot joint means adapted to allow pivoting movement of said mirror about at least two perpendicular axes;   rotation to translation means mounted in said cavity of said casing, said rotation to translation means comprising:   at least one pinion gear .[.member mounted.]. .Iadd.adapted to be directly driven by a worm, said at least one pinion gear being located .Iaddend.in said cavity of said caving .Iadd.and mounted to said casing.Iaddend.;   at least one selectively movable control member having a central axis and being mounted to said at least one pinion gear, said at least one selectively movable control member further having one end portion and an opposite end portion;   second pivot joint means located at said one end portion of said at least one selectively movable control member, said second pivot joint means adapted to cooperate with said support member for pivot motion of said support member relative to said at least one selectively movable control member, said second pivot joint means further comprising a pivot center lying on said central axis of said at least one selectively movable control member, said one end portion of said at least one selectively movable control member extending through said at least one opening of said cover member of said casing, said second pivot joint means comprising means to prevent rotation of said at least one selectively movable control member about said central axis,   a first spherical ball joint .[.means adjoining.]. .Iadd.member in one piece with .Iaddend.said at least one pinion gear .[.member.]., .Iadd.said first spherical ball joint member being received by said spherical bearing for providing universal movement of said at least one pinion gear relative to said casing, .Iaddend.said first spherical ball joint .[.means.]. .Iadd.member .Iaddend.being defined by a spherical radius having a center of curvature lying substantially along said central axis of said at least one selectively movable control member, such that said center of curvature of said first spherical ball joint .[.means.]. .Iadd.member.Iaddend., .[.such.]. .Iadd.said .Iaddend.central axis of said at least one selectively movable control member, and said pivot center of said second pivot joint means are aligned;   helical thread means located on said at least one pinion gear .[.member.]. and at the opposite end portion of said at least one selectively movable control member, such that rotation of said at least one pinion gear .[.member.]. moves said at least one selectively movable control member nonrotatably in an axial direction;   resiliently yieldable means integral with said opposite end portion of said at least one selectively movable control member such that when a driving force applied to one of said at least one selectively movable control member and said at least one pinion gear .[.member.]. is opposed by a predetermined resistance to responsive movement, said resiliently yieldable means yields in a radially inward direction to disengage said helical thread means such that said at least one pinion gear .[.member.]. is rotated by said driving force and said at least one selectively movable control member remains substantially axially stationary relative to said at least one pinion gear .[.member.].; and   means for sealing said at least one opening in said cover .[.means.]. .Iadd.member .Iaddend.of said casing, said sealing means being attached at one end to said at least one selectively movable control member and at the other end being mounted to said at least one opening of said cover member, such as to seal a portion of said rotation to translation means within said casing.