Park safe mechanism for wiper systems

A wiper system comprising:

• a first wiper and a second wiper;
• a drive motor for moving the first and second wipers between an inwipe position, an outwipe position, and a park position;
• and
• a windshield wiper drive linkage coupled between the first and second wipers and the drive motor, the windshield wiper drive linkage including a crank arm connectible to an output shaft of the drive motor, a drive arm pivotably connected to the crank arm for movement between first and second angular positions with respect to one another, and a flexible composite rectangular plate spring to be subjected to bending load while extending between the crank arm and the drive arm, the flexible composite spring preloaded into an initial arcuate position and bendable from the initial position to facilitate preventing damage to components in the wiper system when a load applied to the arms exceeds a predetermined load.

A windshield wiper system for a motor vehicle comprising:

• a first wiper and a second wiper;
• a drive motor for moving the first and second wipers between an inwipe position, an outwipe position, and a parked position;
• and
• means for automatically shortening an effective length of a crank in response to a load applied to the crank exceeding a predetermined load to allow continued rotation of an output shaft of the drive motor, the shortening means connectible between the first and second wipers and the drive motor, wherein the shortening means includes a flexible composite rectangular plate spring to be subjected to bending load while preloaded to an arcuate position and extending between the crank and a pivotally connected drive arm.

A windshield wiper system for a motor vehicle comprising:

• a first wiper and a second wiper;
• a drive motor for moving the first and second wipers between an inwipe position, an outwipe position, and a parked position;
• means for automatically shortening an effective length of a crank in response to a load applied to the crank exceeding a predetermined load to allow continued rotation of an output shaft of the drive motor, the shortening means connectible between the first and second wipers and the drive motor;
• and
• a windshield wiper drive linkage coupled between the first and second wipers and the drive motor, the windshield wiper drive linkage including a crank arm connectible to an output shaft of the drive motor, a drive arm pivotably connected to the crank arm for movement between first and second angular positions with respect to one another, and a flexible composite rectangular plate spring to be subject to bending load while extending between the crank arm and the drive arm, the flexible composite spring preloaded into an initial arcuate position and bendable from the initial position to facilitate preventing damage to components in the wiper system when a load applied to the arms exceeds a predetermined load, the crank arm and the drive arm defining the first angular position when the load is less than the predetermined load and defining the second angular position when the load exceeds the predetermined load, wherein the second angular position is less than the first angular position, thereby effectively shortening a length of the crank allowing continued rotation of the output shaft of the drive motor.