BACKGROUND OF THE INVENTION
FIELD OF INVENTION
The invention relates to a crank and slider mechanism which is employed to automatically operate the windshield wiper of a motor vehicle.
BACKGROUND OF THE PRESENT INVENTION
An automobile windshield wiper generally consists of an arm, pivoted at one end with a long rubber blade attached to the other. The blade is swung back and forth over the glass of the windscreen, pushing water from its surface. The speed is normally adjustable, with several continuous speeds and often one or more "intermittent" settings. Most automobiles use two synchronized radial type arms, while many commercial vehicles use one or more pantograph arms. Mercedes-Benz pioneered a system called the monoblade in which a single wiper extends outward to get closer to the top corners, and pulls in at the ends and middle of the stroke, sweeping out a somewhat 'W'-shaped path. Wipers may be powered by a variety of means, although most in existence today are powered by an electric motor through a series of mechanical components, typically two 4-bar linkages in series or parallel. Inside that gearbox on the motor is a simple worm gear, spinning a ring gear and bellcrank that translate the motor's circular motion to a linear one, back-and-forth. Simple joints attach the transmission arms to the -wiper pivot shaft, which is fixed to the cowl by some sort of pillow block. Lack of lubrication, ice buildup or simple corrosion takes its toll and can slow things down and cause severe problems in current automobile windshield wiper systems. A loose joint will leave lost motion, which can cause the blades to flop around or, worse yet, catch each other and get tangled. We have developed a new mechanical crank and slider arrangement to drive the windshield wiper which will minimize the occurrences of these problems. In addition, the
operation will be improved.

EP 2738054 A2
The invention relates to a crank and connecting rod mechanism for a wiper system comprising of a crank which is configured to be connected to an output shaft of a driving assembly of the wiper system and is configured for outputting a rotational movement of the output shaft; a connecting rod which is configured to be connected to a wiper arm of the wiper system and is configured for driving the wiper arm to perform a reciprocating swinging movement; and a joint assembly which is configured for connecting the crank and the connecting rod, the joint assembly comprising: a ball pin connected to the connecting rod; and a slider, the ball pin being connected to the slider, and the slider and the output shaft being connected to two opposite ends of the crank, wherein the slider and the connecting rod connected thereto slides in a direction along the length of the crank relative to the crank in a state that a force in the direction transferred to the slider via the connecting rod and the ball pin is greater than a certain critical value. The invention also relates to a wiper system comprising the above crank and connecting rod mechanism.
US 4701971 A
This invention describes a wiper system for motor vehicles in which the wiper arm is radially retracted and extended during the to-and-fro motion, so that in comparison with conventional systems an enlarged wiping area is achieved. The coupled gear for retracting and extending a slide mounted in a guide member and connected with the wiper arm is arranged outside the guide member. The coupled gear drives a shaft operatively connected with the slide, which shaft is mounted in a bore of the actual drive shaft for driving the guide member in pendulum-fashion. Thereby the overall height and the weight of the guide member are reduced.

IND PATENT
The invention relates to a wiper system having at least one wiper bearing which is fastened to a vehicle body of a vehicle via at least one supporting region. It is proposed for the bearing housing of the wiper bearing to have three supporting regions, specifically a first supporting region which includes a longitudinal axis of the bearing housing and is provided at one end which faces a wiper a second supporting region and third supporting region, which are provided relative to the first supporting region and offset axially with respect to the other end, and with respect to each other are arranged approximately diametrically with respect to the longitudinal axis of the bearing housing.
SUMMARY OF THE INVENTION
In accordance with the present invention, there is provided a windscreen wiper comprising an arm having an end rotatably supported near the glass, a wiper blade fixed to the sliding member, a crank and slider actuating mechanism for actuating the arm to reciprocally rotate. A single slider crank chain is a modification of the basic four bar chain. It consists of one sliding pair and three turning pairs. This type of crank slider mechanism converts rotary motion of the crank wheel into reciprocating motion of the slider.
THE OVERALL ASSEMBLY WORKS AS FOLLOWS:
A handle is fixed to the crank wheel toy means of a shaft and the handle can be manually operated or connected to a motor. The crank wheel starts to rotate when the handle is turned though a small angle. The crank wheel is connected to the slider with the help of a connecting rod. The crank wheel converts the rotational motion of the handle into reciprocating motion of the slider by means of the crank slider mechanism. The reciprocating slider also produces the reciprocating motion of the rack. Two pinion spur gears are in a mesh with the teeth of the rack. The reciprocating motion of the rack causes
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both the pinions to rotate. The two windshield wipers are attached to the respective pinions, such that they produce sliding motion when the pinions rotate. When the user or the motor rotates the handle the wiper starts sliding without any hesitation.
BRIEF DESCRIPTION OF THE DRAWING
Further objects and advantages of this invention will be more apparent from the ensuing description when read in conjunction with the accompanying drawings and wherein:
Figure 1 is a CREO model of overall assembly of Automobile windshield wiper system based on crank and slider mechanism. Figure 2 is an orthographic view of overall assembly.
DETAILED DESCRIPTION OF THE DISCLOSED EMBODIMENT
The following description details the preferred embodiments of the disclosed invention, it is to be understood that the invention is not limited in its application to the details of construction and arrangement of the parts illustrated in the accompanying drawings, but includes all variations and modifications within the scope of claims.
Rack and Pinion (1) is a pair of gears which convert rotational motion into 'linear motion or vice-versa. The straight ;line gear is called rack and the circular wheel is called pinion.
Wiper (2) blades are like squeegees. The arms of the wiper drag a thin rubber strip across the windshield to clear away the water. When the blade is new, the rubber is clean and has no nicks or cracks and it wipes the water away without leaving streaks.

Slider (3) is used to convert the rotary motion of the crank wheel into reciprocating motion of the rack by the crank slider mechanism. The reciprocating slider thus produces the reciprocating motion of the rack.
Connecting rod (4) is used to connect the crank wheel to the reciprocating slider. The crank wheel converts the rotational motion of the handle into reciprocating motion of the slider by means of the crank slider mechanism.
Crank wheel and handle (5) A handle is fixed to the crank wheel by means of a shaft and the handle can be manually operated or connected to a motor. The crank wheel can be rotated by turning the handle though a small angle. The crank wheel is connected to the slider with the help of a connecting rod.
Base (6) houses all the components of the crank slider mechanism, rack and pinion arrangement and the wipers.

CLAIMS
1. We claim an automobile windshield wiper system based on a crank and
slider mechanism comprising:
(i) Wiper (2) connected to the centre of the pinion (1) by using bolt and nut.
(ii) Rack and Pinion (1) is in mesh with each other.
(iii) Rack (1) is coupled with the slider (3) which in turn is attached to the
connecting rod (4) by arc welding.
(iv) Connecting rod (4) is attached to the crank wheel (5) with the help of
fasteners.
(v) Handle (5) is connected to the centre of the crank wheel by means of a
shaft.
2. We claim a method for operating the windshield wiper, said method
comprising:
(i) rotating the crank wheel by turning the handle though a small angle.
(ii) generating linear motion of the slider and the rack from the rotary motion
of.the crank wheel by means of the crank slider mechanism.
(iii) rotating the pinion from the linear motion of the rack.
(iv) generating the sliding motion of the windshield wipers due to rotation of
the two pinions.