Windshield wiper drive linkage arm with interior grooves

• US 20040034958A1
• Filed: 07/19/2002
• Published: 02/26/2004
• Est. Priority Date: 07/19/2002
• Status: Active Grant

• Current Assignee: Valeo Electrical Systems Incorporated (Valeo SE)
• Original Assignee: Valeo Electrical Systems Incorporated (Valeo SE)
• Inventors: Buchanan,, Harry Charles Jr.
• Granted Patent: US 7,017,224 B2
• Time in Patent Office: Days
• US Class Current: 15/250.31
• CPC Class Codes: B60S 1/24 by rotary cranks
• CPC Class Codes: B60S 1/245 with particular rod arrangements between the motor driven axle and the wiper arm axle
• CPC Class Codes: F16B 2200/63 Frangible connections
• CPC Class Codes: F16C 11/0695 Mounting of ball-joints, e.g. fixing them to a connecting rod
• CPC Class Codes: F16C 2326/09 Windscreen wipers, e.g. pivots therefore in general B60S
• CPC Class Codes: F16C 7/02 Constructions of connecting-rods with constant length
• CPC Class Codes: F16C 7/04 with elastic intermediate part of fluid cushion
• CPC Class Codes: Y10T 403/32721 Elastomeric seat
• CPC Class Codes: Y10T 74/18184 Crank, pitman, and lever
• CPC Class Codes: Y10T 74/182 Multiple levers
• CPC Class Codes: Y10T 74/2142 Pitmans and connecting rods
• CPC Class Codes: Y10T 74/2144 Yieldable
• CPC Class Codes: Y10T 74/2148 Automatic release

Abstract

This invention relates to windshield wiper system and method which utilizes a flexible member to account for compression loads in excess of a predetermined load, such as 30 percent, greater than a maximum load for the flexible member. The system utilizes a flexible pultruded composite material having a relatively low modulus of elasticity, yet relatively high elongation characteristics. The flexible arm bends to facilitate preventing damage to components in the wiper system when a compressive load applied to the flexible member is in excess of the predetermined load.

Claims

1. A windshield wiper drive linkage for use in a wiper system comprising:

a plurality of linkage arms;

at least one of said plurality of linkage arms comprising a composite flexible arm which bends to facilitate preventing damage to components in said wiper system when a compressive load applied to said at least one of said plurality of linkage arms exceeds a predetermined load as a result of a fatigue condition;

said at least one of said plurality of linkage arms comprising comprise an interior groove on each side of an end of said arm to facilitate providing an interlocking joint when a connector is overmolded onto each end.

2. The windshield wiper drive linkage as recited in claim 1 wherein said flexible arm comprises a modulus of elasticity of at least 50,000 psi.

3. The windshield wiper drive linkage as recited in claim 1 wherein said predetermined load is approximately 30 percent higher than a highest working load.

4. The windshield wiper drive linkage as recited in claim 1 wherein said predetermined load is approximately 300 Newton or higher.

5. The windshield wiper drive linkage as recited in claim 1 wherein said flexible arm comprises a pultruded composite comprising 40-60 percent (in weight) glass fibers.

6. The windshield wiper drive linkage as recited in claim 3 wherein said flexible arm comprises a length of approximately 250 mm or more.

7. The windshield wiper drive linkage as recited in claim 1 wherein said flexible arm is rectangular in cross section.

8. The windshield wiper drive linkage as recited in claim 1 wherein said a flexible arm comprises a first end coupled to a drive arm and a second end coupled to a driven arm;

said first end and said second end defining a first distance when said compressive load is less than said predetermined load and defining a second distance when said compressive load exceeds said predetermined load, wherein said second distance is less than said first distance.

9. The windshield wiper drive linkage as recited in claim 1 wherein said compressive load remains substantially constant as said flexible arm shortens at least 25 mm after said compressive load exceeds said predetermined load.

10. The windshield wiper drive linkage as recited in claim 9 wherein said flexible arm is a fiber-reinforced composite or thermoset carrier.

11. The windshield wiper drive linkage as recited in claim 1 wherein said interior groove defines a crescent shape.

12. The windshield wiper drive linkage as recited in claim 1 wherein said interior groove extends substantially parallel to an axis of said arm.

13. The windshield wiper drive linkage as recited in claim 1 wherein said connector comprises a ball socket.

14. A wiper system comprising:

a first wiper;

a second wiper;

a windshield wiper drive linkage coupled to said first and second wipers;

a drive motor coupled to said windshield wiper drive linkage; and

said windshield wiper drive linkage comprising;

a plurality of linkage arms coupled to said first and second wipers and said drive motor;

at least one of said plurality of linkage arms comprising a composite flexible arm which bends to facilitate preventing damage to components in said wiper system when a compressive load applied to said at least one of said plurality of linkage arms exceeds a predetermined load as a result of a fatigue condition;

said at least one of said plurality of linkage arms comprising an interior groove on each side of an end of said arm to facilitate providing an interlocking joint when a connector is overmolded onto each end.

15. The windshield wiper drive linkage as recited in claim 14 wherein said flexible arm comprises a modulus of elasticity of at least 50,000 psi.

16. The windshield wiper drive linkage as recited in claim 14 wherein said predetermined load is approximately 30 percent higher than a highest working load.

17. The windshield wiper drive linkage as recited in claim 14 wherein said predetermined load is approximately 300 Newton or higher.

18. The windshield wiper drive linkage as recited in claim 14 wherein said flexible arm comprises a pultruded composite comprising 40-60 percent (in weight) glass fibers.

19. The windshield wiper drive linkage as recited in claim 16 wherein said flexible arm comprises a length of approximately 250 mm or more.

20. The windshield wiper drive linkage as recited in claim 14 wherein said flexible arm is rectangular in cross section.

21. The windshield wiper drive linkage as recited in claim 14 wherein said a flexible arm comprises a first end coupled to a drive arm and a second end coupled to a driven arm;

said first end and said second end defining a first distance when said compressive load is less than said predetermined load and defining a second distance when said compressive load exceeds said predetermined load, wherein said second distance is less than said first distance.

22. The windshield wiper drive linkage as recited in claim 14 wherein said compressive load remains substantially constant as said flexible arm shortens at least 25 mm after said compressive load exceeds said predetermined load.

23. The windshield wiper drive linkage as recited in claim 14 wherein said flexible arm is a fiber-reinforced composite or thermoset carrier.

24. The windshield wiper drive linkage as recited in claim 14 wherein said interior groove defines a crescent shape.

25. The windshield wiper drive linkage as recited in claim 24 wherein said interior groove extends substantially parallel to an axis of said arm.

26. The windshield wiper drive linkage as recited in claim 14 wherein said connector comprises a ball socket.