The present invention relates to an angle adjusting arrangement for a mirror and more particularly, to an arrangement for adjusting the angle, for example, of the so-called outer or external reflecting mirror such as the fender mirror, door mirror, etc. for motor vehicles, from the interior of the motor vehicles through remote control.
Initially, for the angle adjusting arrangement of the above described type, a wire control system which effects the angle adjustments by moving the mirror through a wire was adopted, but thereafter, there has been proposed an electric driving system in which driving motors and power transmission members are accommodated on the back of the mirror in a mirror case for electrically adjusting the angles of the mirror, with further improvements being applied thereto up to the present.
Although the angle adjusting arrangement of the electric driving system as described above further includes various types of devices, it is generally arranged as described hereinbelow.
More specifically, a mirror is pivotally coupled, at its generally central portion, to a predetermined position on the outer surface of a housing or casing of the angle adjusting arrangement through a universal joint system, one end of a first mirror push-pull control shaft for vertically tilting the mirror is connected to the upper or lower side of the pivotal coupling at the rear face of the mirror and also one end of a second push-pull control shaft for inclining the mirror in the leftward or rightward direction is connected to the left or right side of said pivotal coupling through universal joint systems respectively, while the other ends of the first and second push-pull control shafts are led into the casing through inserting openings formed in said casing. In the casing, driving mechanisms including reversible motors and transmission members are accommodated for transmitting the driving force of the motors to the other ends of said first and second push-pull control shafts, and thus, by driving said driving mechanisms, the mirror is adapted to be tilted or inclined through axial displacement of the respective mirror push-pull control shafts.
Even in the mirror angle adjusting arrangement of the electrically driven type as described above, however, it is necessary that the mirror angle can be manually adjusted in the event of troubles and the like in the arrangement, and the connections between the mirror and driving mechanism are loose couplings, which may be achieved, for example, by providing each of the mirror push-pull control shafts with an elastic or resilient material such as urethane rubber, silicone rubber, natural rubber or the like, and engaging a gear having a female-threaded central opening with said control shaft, with the surface of the push-pull control shaft being finished so as to be smooth or to have a male thread thereon in loose engagement with the female thread of the gear. In the above arrangement, upon rotation of the gear by the driving mechanism, the screw thread of the gear is forced onto the surface of the push-pull control shaft, or the push-pull control shaft is axially displaced by the action of the male thread loosely engaged with the female thread of the gear, for tilting the mirror. On the other hand, when the mirror is manually moved, the female thread of the gear slides along the smooth or male-threaded surface of the push-pull control shaft so as to allow the axial displacement of the control shaft irrespective of the presence of the gear, thus making it possible to manually adjust the angle of the mirror. However, in the conventional arrangement as described above in which the push-pull control shafts are made of elastic material, there have been such problems that, since the hardness of the elastic material employed therefore tends to change due to variations in atmospheric temperatures so as to become rather soft at high temperatures and rather hard at low temperatures, smooth operation of the arrangement is undesirably obstructed due to variations in the state of coupling or the coupled portions may be broken due to undue force applied thereto particularly at low temperatures.