1. Field of the Invention
The present invention relates to automotive vehicle glare reducing shields for use on vehicle sun visors.
2. Description of the Prior Art
In the past, various sun visor extensions have been devised to serve as transparent extensions of an automotive vehicle sun visor. Such vehicle sun visors are conventionally foldably located near the upper boundary of a vehicle windshield. Sun visors of conventional design are opaque and are intended to serve as an optical shield at the upper portion of a windshield to prevent solar or other reflective glare from impairing a vehicle driver's vision. While the opaque sun visors perform this function under some glare conditions, many situations arise in which glare or high light level is directed through the windshield beneath the visor to nevertheless impair a driver's visual observation of road and traffic conditions. While conventional transparent shields have been provided and fixed to a vehicle sun visor, such devices of conventional design have had certain limitations.
Many conventional transparent sun visor extension glare shields are not adapted to be folded flat into juxtaposition against an automotive vehicle sun visor when not in use. Rather, they have been affixed to the vehicle sun visor as rigid, readily noticeable, unsightly extensions thereof. Also, while useful under high glare conditions, such fixed sun visor extensions impair vision when glare is not a problem.
Other glare shield extensions which have been designed for rotation about a bracket secured to the sun visor for storage purposes have not operated satisfactorily. Many such devices are constructed with plastic hinges or knuckles which are secured by friction to an axle or rod about which they are rotated. While the force of friction of the hinge knuckles on the horizontal mounting rod will hold the glare reducing sheet folded up in a stored position the first few times it is used, the plastic hinge knuckles rapidly tend to partially lose their elasticity, so that insufficient frictional force is present between the plastic hinge knuckles and the mounting rod to hold the glare reducing sheet upright in a position stored behind the sun visor. As a result, the glare reducing shield tends to flop downward and oftentimes assumes a position somewhere between its fully extended downwardly depending position, and its fully folded position behind the sun visor. This is both annoying and dangerous to the vehicle operator, and is especially irritating when the vehicle is traveling over rough and bumpy roads. Under such conditions the visor extension tends to tilt from behind the sun visor with considerable frequency. The vehicle operator's attention is thereupon distracted to a significant degree while the vehicle is traveling over surfaces which especially warrant the operator's undivided attention.
Various attempts have been made to adjust the diameter of the visor extension hinge pin and the plastic knuckle configuration to achieve a fit which is tight enough to allow the glare reducing shield to be positioned as desired and held in place by the force of friction between the plastic knuckles and the hinge pin. However, in each case the plastic knuckles deform inelastically over a relatively short period of time so that a tight friction fit between the plastic knuckles and the hinge pin cannot be maintained.