Framed Wiper Blades
Review All Models of Framed Wiper Blades:
Good visibility from the driver’s seat is an important component of safe driving. To improve visibility in adverse weather conditions, modern cars are equipped with electric windshield wipers (commonly known as “wipers”), whose task: to clean the windshield of water, snow and dirt.
Previously, the windshield of the car produced a flat shape, the beam was one – it was enough to ensure uniform pressure of the rubber tape on the glass along its entire length. With the advent of concave glasses needed more complex car wipers, which would change their curvature as you turn, again creating an even pressure on the surface to be cleaned.
Wiper blades are working elements of the wiper, experiencing mechanical, thermal and chemical effects. That is why there are strict requirements for them:
evenly and qualitatively clean from various contaminants the entire surface of not only flat, but also convex glass covered by them in a wide range of vehicle speeds and temperature conditions;
Have sufficient wear resistance (service life of quality wiper blades with observance of operating conditions is usually not less than one year);
Not to scratch (scrape) the glass.
Nowadays there are two designs of car wipers on the market – classic “frame” and modern “frameless”.
Classic Framed Wiper Blades
Classic wiper blade design includes a rigid frame, so they are called “frame”, contrasting with the modern design of “frameless” wiper blades, a review of which is presented in the article on frameless wipers.
The design of all wiper blades consists of a frame and a rubber band fixed in it, which cleans the glass. Frame design is determined by the size and curvature of the windshield: as a rule, it is a set of articulated jointed rockers, the upper of them is located on the mounting unit for the wiper arm.
Wiper belt – a rubber strip with a special profile. The profile has a working part (arrow-shaped cross-section), ending with a strictly rectangular working edge, a neck (the base of the working part) and grooves (slots) for the elastic plates (plates). Some wiper blades designs have additional longitudinal sharp edges on the side surfaces of the working part of the belt.
The main factors determining the quality of the belt are:
- the composition of rubber
- special coatings
- accuracy of geometric dimensions
The elastic plates are steel strips whose length corresponds to the length of the wipers, and their width and thickness are 1-2 mm and 0.3-0.5 mm, respectively.
The frame is a metal construction consisting of the rocker arms hinged to each other.
Elastic plates are inserted into the grooves on the sides of the belt or inside it, which gives it a certain shape and distributes the force transmitted by the frame evenly along the entire length of the belt. The tape, reinforced with plates, is connected to the frame (covered with special clamps located at the ends of the rocker arms). As a rule, one outermost clamp of the frame fixes the tape rigidly. The rest are floating, which allows the tape to move when you rotate the rocker arm. In some designs, all clamps are made free, and to hold the tape in the frame, there are stops on the ends. Due to this, the working part of the tape is pressed to the convex glass of different curvature along its entire length. The elastic plates of the wiper blades are slightly curved in the free state, so that the belt is pressed better against the glass during operation.
For framed wiper blades, the distribution of the clamping force is provided by the rocker arms. In general, more rocker arm provides a more even fit of the wipersto the glass, but it complicates the design and reduces its reliability.
Framed wiper blades can be equipped with spoilers. This improves aerodynamics, reduces noise and “rattle” in the work of the wipers that occur at high speeds.
There are winter versions of the framed wiper blades, closed with a rubber cover that prevents snow buildup and icing.
Recommendations for exploitation of classic windshield wiper blades
If the rubber has lost elasticity, and because of this there are stripes and “fog” on the glass, it must first be cleaned from dirt: wash in warm water with soap. There are more radical ways – to hold the “wipers” one or two minutes in boiling water, or use fine sandpaper (put the skin on a flat surface and go over it with a brush, tilting it at an acute angle). The rubber band sharpened in this way gets a “second breath”. But sooner or later the brushes still need to be replaced. And you should not buy separately “rubber bands” – they do not work better than the old ones.
With imported wiper blades is easier. You can buy a separate mount that serves as an adapter between the wiper arm and the axis of the large rocker “wiper. There are several types of adapters, and it is easy enough to choose the right one.
The rubber band should be elastic, its working edge thin (it fits tighter to the surface being cleaned), straight or slightly convex, but in no case concave. The latter is a sure sign that the spring has lost its elasticity or is absent at all. Such a brush will only clean the edges. Pressing a few times the working part of the brush to the upper boom, check that the “wiper” easily, without jerking took the original form, and the boom did not dangle on the axes and slide well over the carcass of the rubber band.