Patent GB-1452593-A (GB)
Title: Adjustable mirrors for vehicles
IPC: B60R1/072
Filed: 1975-04-18
Abstract: 1452593 Vehicle rearview mirrors TENNA CORP 18 April 1975 [16 May 1974] 16131/75 Heading B7J An adjustable rearview mirror comprises a fixed housing 22, a mirror 24, means for adjustably securing the mirror in the housing for movement relative to the housing, and means 38 carried with the mirror adjacent its perimeter and yieldable biased into slidable contact with the housing 22 for damping vibration of the mirror. The damping means consists of spring fingers 38 mounted on the mirror backing plate 25. Alternatively, the damping means consists of hinged plastics tubes secured to or formed integrally with the backing plate and urged by springs into engagement with the interior surface of the housing 22, Fig. 10 (not shown). The spaced plastics tubes may be replaced by a peripheral skirt on the backing plate. The mirror is adjusted by means of a rigidly mounted motor 30 driving a flexibly mounted worm gear 44 movable by a solenoid 31 to engage gear 46 or 47. The gears drive screws 35, 36 attached to the mirror backing plate 25. The mirror backing plate is formed from a flexible polyester material and includes a central region 25a rigidly secured to the motor housing 28 by press-stud connections 90, 91. The backing plate is slotted at 78, 79 and 83, 84 to provide hinges 86, 87 and 81, 82 permitting the outer region 25b of the backing plate to pivot relative to the central region 25a about mutually perpendicular axes. The screws 35, 36 are secured to members 102 mounted in cut-outs in the backing plate. The worm gear 44 arrangement consists of a tubular member 127, which is a push fit on the motor output shaft, a ring 124 mounted on the member 127 by a pair of diametrically opposed flexible lugs 140, and a worm gear 134 carried by a hollow tube 132 secured to the ring 124 by a pair of diametrically opposed flexible lugs 142. The open end 135 of tube 132 engages a projection on a frame 49 pivotally mounted in the motor casing whereby actuation of the solenoid 31 flexes the tube 132 to bring the worm gear into driving engagement with gear 46 or 47. Each gear is rotatably mounted between the walls 28a, 28b of the motor housing, Fig. 11, and has a central aperture receiving a screw 35 or 36. The gear has three grooves 179 spaced around the screw, each groove receiving a captive spring-loaded toothed member 186 rotatable with the gear to move the screw in a longitudinal direction and adjust the position of the mirror. Only one member 186 is in full engagement with the screw, the other two members being offset in opposite directions to apply opposing loads on the screw and prevent vibration thereof, Figs. 12-14 (not shown). In the event of the screw reaching an end position, or of the mirror being prevented from moving by snow or ice, the members 186 slip relative to the screw to prevent damage to the motor. In a modification, the members 186 carry nylon bristles or fur in place of the teeth. The motor is wrapped in a foam strip to deaden vibrations. The solenoid and motor are operated through a single electric switch movable between four positions to engage the motor-driven worm gear 44 with the gear 46 or 47 and rotate the gear 44 in one direction or the other to retract or extend the associated screw and adjust the position of the mirror.