EXTERIOR MIRROR WITH INDEXING AND CONTROL PIVOTING

摘要

1. A vehicle mirror assembly comprising: a housing assembly, a mirror unit mounted on said housing assembly, a support assembly constructed and arranged to be fixedly mounted on a vehicle and to support said housing assembly thereon in an operative position extending laterally outwardly from the vehicle so that said mirror unit serves as an exterior rear view mirror for the driver of the vehicle, a power operated pivot assembly between said support assembly and said housing assembly constructed and arranged to enable said housing assembly to be pivoted with respect to said support assembly about a generally upright axis (1) between the operative position thereof and a folded position with respect to the vehicle in response to the power operation of said pivot assembly and (2) from the operative position thereof in either direction in response to an unwanted impact blow applied in either direction thereto, said power operated pivot assembly including an electric motor and a non-self-reversing speed reduction motion transmitting assembly between an output shaft of said electric motor and said housing assembly, a spring biased pivotal control system between said housing assembly and said support assembly constructed and arranged to provide a control resistance to pivotal movement of said housing assembly about said axis which control resistance (1) does not exceed a predetermined value when said housing assembly is moved in either direction between said operative and folded positions and (2) exceeds said predetermined value when said housing assembly is moved into said operative position in a direction away from said folded position and away from said operative position in response to an unwanted impact blow applied to said housing assembly in a direction away from said folded position and a spring biased indexing system operatively associated with said motion transmitting assembly constructed and arranged to (l) transmit the movement of said motion transmitting assembly in response to a desired rotation of said motor shaft to said housing assembly to thereby move said housing assembly between said operative and folded positions with said spring pressed pivotal control system providing a control resistance to such movement which does not exceed said predetermined value in response to the desired rotation of said motor shaft and (2) allow said housing assembly to be moved from the operative position thereof relative to said electric motor in response to an unwanted impact blow applied to said housing assembly (1) in a direction to move said housing assembly from said operative position toward said folded position with said indexing system providing an indexing resistance to such movement which is independent of the control resistance provided by said control system and (2) in a direction to move said housing assembly beyond the operative position thereof away from said folded position with said indexing system providing an indexing resistance which is independent of the control resistance provided by said control system, said spring biased pivotal control system including a movable control structure connected through said motion transmitting assembly and said spring biased indexing system to move with said housing assembly and a fixed control structure mounted in fixed relation with respect to said support assembly, said control structures providing control surfaces which interengage during a final incremental movement of said housing assembly by said electric motor into said operative position in a direction away from said folded position to thereby stress the spring biased pivotal control system and establish a control bias on said housing assembly to undertake a similar incremental movement in the opposite direction, the extent of said incremental movement being greater than the incremental movement permitted by said motion transmitting assembly through backlash, said spring biased pivotal control system being constructed and arranged to enable the control bias provided thereby to stabilize said housing assembly when in said operative position (1) after having been moved therein by said electric motor in a direction away from said folded position and (2) when manually returned to said operative position after an unwanted impact blow movement therefrom. 2. A vehicle mirror assembly as defined in claim 1 wherein said spring biased pivotal control system includes an electrical circuit for said electric motor, a sensor in said electrical circuit constructed and arranged to sense a predetermined current rise therein resulting from said housing assembly meeting a resistance which exceeds said predetermined value during said movement of the housing assembly into said operative position and a controller in said electrical circuit constructed and arranged to deenergize said electric motor in response to said sensor sensing the predetermined current rise. 3. A vehicle mirror assembly as defined in claim 2 wherein said predetermined current rise is approximately 1.5 amps. 4. A vehicle mirror assembly as defined in claim 3 wherein said spring biased pivotal control system and said electric motor are constructed and arranged to enable said electric motor to stall after said final incremental movement with said control surfaces interengaged has occurred. 5. A vehicle mirror assembly as defined in claim 4 wherein said electric circuit includes a safety timer constructed and arranged to deenergize said electric motor a predetermined time after said electric motor has been energized for a few seconds beyond the expected period of normal use. 6. A vehicle mirror assembly as defined in claim 5 wherein said predetermined period is approximately ten seconds. 7. A vehicle mirror assembly as defined in claim 1 wherein said power operated pivot assembly includes a fixed inner annular member fixed to said support assembly within which said electrical motor is housed, said fixed inner annular member being formed of a metal so as to serve as a flux yoke for the electric motor housed therein. 8. A vehicle mirror assembly as defined in claim 7 wherein said power operated pivot assembly includes an outer fixed annular member fixed to said support assembly and a movable tubular member mounted between said fixed inner and outer tubular members, said movable tubular member having an upper end portion extending upwardly through an opening in an upper end of said fixed outer tubular member and fixedly connected to said housing assembly. 9. A vehicle mirror assembly as defined in claim 8 wherein said fixed outer tubular member includes a downwardly facing annular surface and a plurality of annularly spaced fixed projections having arcuate extents defined by opposite inclined surfaces and downwardly facing surfaces extending between opposite inclined surfaces, said control ring including an upwardly facing annular surface and a plurality of annularly spaced movable projections having arcuate extents greater than said fixed projections defined by opposite inclined surfaces and upwardly facing surfaces extending between opposite inclined surfaces, said annular surfaces being constructed and arranged to slidably interengage one another when said housing assembly is moved between the operative and folded positions thereof, one inclined surface of each of said fixed projections incrementally slidably interengaging one inclined surface of each movable projection when said housing assembly is moved into said operative position in a direction away from said folded position. 10. A vehicle mirror assembly as defined in claim 9 wherein another inclined surface of each fixed projection incrementally slidably interengages another inclined surface of each movable projection when said housing assembly is moved into said folded position in a direction away from said operative position, the upwardly facing surfaces of said movable projections engaging the downwardly facing surfaces of said fixed projections when said housing assembly has moved away from the operative position thereof in a direction away from the folded position after the interengaged inclined surfaces of said fixed and movable projections have moved in sliding relation to one another out of engagement with one another. 11. A vehicle mirror assembly as defined in claim 10 wherein said motion transmitting member comprises a ring gear positioned concentrically with said axis and mounted for rotational movement about said axis with respect to said movable tubular member. 12. A vehicle mirror assembly as defined in claim 11 wherein said spring biased indexing system includes indexing structure movably carried by one of said movable tubular members and said ring gear, said indexing structure being spring biased to engage another one of said movable tubular member and said ring gear. 13. A vehicle mirror assembly as defined in claim 12 wherein said indexing structure comprises an indexing ring mounted on an interior periphery of said movable tubular member for pivotal movement therewith and axial movement with respect thereto, said indexing ring being spring biased by a compression coil spring surrounded by said movable tubular member between said indexing ring and a generally radially outwardly extending surface formed in the interior periphery of said movable tubular member. 14. A vehicle mirror assembly as defined in claim 13 wherein said ring gear includes teeth on the interior periphery thereof and a plurality of annularly spaced indexing projections extending upwardly therefrom, said indexing ring including a plurality of annularly spaced recesses for receiving said projections, said recesses being interconnected with surfaces for slidably engaging said projections when not received in said recesses. 15. A vehicle mirror assembly as defined in claim 14 wherein said speed reduction motion transmitting assembly includes a stub shaft mounted between said support assembly and a lower end portion of s