GB1587051A - Screen wiper for a motor vehicle - Google Patents

Description

(54) A SCREEN WIPER FOR A MOTOR VEHICLE (71) We, ROBERT BOSCH GMBH, a German company of Postfach 50, 7 Stuttgart 1, Federal Republic of Germany, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: The invention concerns a screen wiper for a motor vehicle.

A wiper is already known in which a ball pin, prefabricated as a separate component, is riveted to a drive element. For manufacturing reasons, the ball pin is made of steel.

The disadvantage of this construction is the corrosion arising at the ball end which can only be avoided by increased manufacturing outlay such as, for example, nickel-plating of the ball end. To avoid damaging this nickel layer when the ball pin is assembled, the layer had to be put on after the ball pin was riveted to the drive element, this however being avoided on principle in electro-plating for specific reasons. Furthermore, such a process, whereby the entire drive element was also provided with a nickel layer, would be too expensive. Coating of the ball end alone would, however, require a very laborious manufacturing process.

According to the invention, a screen wiper has at least one wiper arm, a drive motor and a means for transmitting the driving movement of the motor to the wiper arm, said means incorporating at least one element operatively connected to another element by way of a ball pin and socket, the ball pin comprising a metal shaft on which a ball end manufactured in plastics material is fixed.

This wiper has, by comparison with the known wiper, the advantage that the metal shaft may be connected to the respective element without special regard for a sensitive bearing surface on the ball end. All that is then required is the fixing of the ball end on the metal shaft. It may be regarded as another advantage that the ball end may be provided during its manufacture with a satisfactory spherical surface which has optimum running properties.

Preferably, the driving movement transmitting means comprises a reduction gear and a reciprocating drive such that the wiper arm is driven to-and-fro. The reciprocating drive may take the form of a connecting-rod whose elements are operatively connected to one another by ball pins and socket cups for accommodating the ball pins. The ball pins are in two parts and each have a shaft on which a ball end is locked.

The invention is described further, by way of example, with reference to the accompanying drawings wherein: Figure 1 is a plan view of a wiper lever of a wiper arrangement having a hub part on which a ball pin is fixed, Figure 2 is a side view partially in section (along the line II-II) of the wiper lever of Figure 1, Figure 3 shows to an enlarged scale a section, a side view and a plan view of a ball end of the ball pin, Figure 4 shows to an enlarged scale a side view and a plan view of a metal shaft of the ball pin and, Figure 5 shows a section of the ball end of Figure 3 locked on the metal pin of Figure 4.

Figures 1 and 2 show a wiper lever or wiper arm 10 having a hub part 12 by means of which it may be fixed on a wiper shaft (not shown). The hub part 12 has a projecting lug 14 having a reinforcing rib 15. A ball pin 18 is disposed on the lug 14 at a distance from the hub bore 16 in the hub part 12. The ball pin 18 serves as one joint half for a linkage part of a reciprocating drive, which part is fitted with the second joint half - a socket cup. In the present embodiment, the linkage part (not shown) is used to transmit the to-and-fro movement of the first wiper arm 10 to a second wiper arm whose hub part 12 also has a lug 14 with a ball pin 18.

The two ball pins of the two wiper arms 10 are operationally connected by a link (not shown) which is pivoted by means of respective socket cups on the two ball pins 18.

Thus, a synchronous movement of the two wiper arms 10 is achieved.

The construction of the ball pin 18 is shown in Figures 3 to 5. As may be seen particularly in Figure 5, the ball pin 18 has a metal shaft 20 having a square cross-section which is connected in one piece to the lug 14 of the hub part 12. Adjacent its free end of the metal shaft 20 has an annular groove 22 extending perpendicular to the axis of the metal shaft 20. The side wall 24 of the annular groove 22 facing the lug 14 is disposed in such a manner that it, with the surface area 26, forms an obtuse angle a with the annular groove 22. A head 28 provided on the side of the annular groove 22 remote from the lug 14 is provided with a steep chamfer 30. The ball pin 18 has a ball end 32 which is shown in particular in Figure 3. The ball end 32 is made of a resilient plastics material and has a central cavity 34 whose cross-section is adapted to the shape of the cross-section of the metal shaft 20.

The ball end 32 has a spherical portion 36 whose surface corresponds to the shape of a sphere. Adjacent to the spherical portion 36 is a neck 38 whose axis lies on the axis of the central cavity 34. On the side of the spherical portion 36 opposite the neck 38, the ball end 32 has two opposing resilient lugs 40 which are each formed by two open-ended slots 42 which lie adjacent to one another but are spaced apart. Each of the resilient lugs 40 has a projection 44 integrally connected thereto which projects into the central cavity 34 of the ball end 32 and whose side 46 facing the neck 38 forms with the wall 48 of the central cavity 34 an angle ss corresponding approximately to the angle a of the metal shaft 20.

To assemble the ball pin 18, the ball end 32 is placed onto the metal shaft 20 so that the neck 38 passes over the head 28. Finally, the metal shaft 20 is inserted so far into the central recess 34 of the ball end 32 that the chamfer 30 of the pin head 28 strikes adjacent to the sides 46 of the projections 44. The ball end 32 is then strongly pushed in the direction of the arrow 49 in Figure 5 so that the projections 44 are temporarily deflected in the direction of the arrows 50 until under the influence of the initial stressing of the lugs 40 the projections 44 may spring back into their starting position when they come into the region of the annular groove 22 of the metal shaft 20 (Figure 5). In this manner, the ball end 32 is non-detachably connected to the metal shaft 20 and the ball pin 18 is formed. The resilient lugs 40 of the ball end 32 together with their projections 44 form counterlocking means for the ball end 18 which cooperates with locking means formed by the annular groove 22 of the metal shaft.

Thus, it is possible to construct the metal shaft 20 in accordance with the set requirements while the ball end may be manufactured taking into account the special requirement demanded of it as regards running properties. Moreover, by using a plastics material the ball end is insensitive to corrosion.

WHAT WE CLAIM IS: 1. A screen wiper for a motor vehicle, having at least one wiper arm, a drive motor and a means for transmitting the driving movement of the motor to the wiper arm, said means incorporating at least one element operatively connected to another element by way of a ball pin and socket, the ball pin comprising a metal shaft on which a ball end manufactured in plastics material is fixed.

2. A wiper as claimed in claim 1, in which the ball end has a cavity into which the shaft is inserted.

3. A wiper as claimed in claim 2, in which the shaft has a cross-section which departs from the circular and wherein the cross-section of the cavity is adapted to the shape of the cross-section of the shaft.

4. A wiper as claimed in claim 3, in which both the shaft and the cavity are constructed with a square cross-section.

5. A wiper as claimed in any of claims 2 to 4, in which the shaft has locking means which co-operate with counter-locking means on the ball end.

6. A wiper as claimed in claim 5, in which the locking means of the shaft are formed by a groove which extends perpendicular to the shaft axis and in which at least one projection projecting into the cavity of the ball end engages as counter-locking means.

7. A wiper as claimed in claim 6, in which the ball end is made of a resilient plastics material and the projection is disposed on a resilient lug which is integrally connected to the ball end.

8. A wiper as claimed in claim 7, in which the resilient lug is formed by two edge-open slots.

9. A wiper as claimed in any of claims 6 to 8, in which the ball end has two opposing resilient lugs with locking projections.

10. A wiper as claimed in any of claims 1 to 9, in which the shaft is integrally connected to one of said elements.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (11)

**WARNING** start of CLMS field may overlap end of DESC **. the to-and-fro movement of the first wiper arm 10 to a second wiper arm whose hub part 12 also has a lug 14 with a ball pin 18. The two ball pins of the two wiper arms 10 are operationally connected by a link (not shown) which is pivoted by means of respective socket cups on the two ball pins 18. Thus, a synchronous movement of the two wiper arms 10 is achieved. The construction of the ball pin 18 is shown in Figures 3 to 5. As may be seen particularly in Figure 5, the ball pin 18 has a metal shaft 20 having a square cross-section which is connected in one piece to the lug 14 of the hub part 12. Adjacent its free end of the metal shaft 20 has an annular groove 22 extending perpendicular to the axis of the metal shaft 20. The side wall 24 of the annular groove 22 facing the lug 14 is disposed in such a manner that it, with the surface area 26, forms an obtuse angle a with the annular groove 22. A head 28 provided on the side of the annular groove 22 remote from the lug 14 is provided with a steep chamfer 30. The ball pin 18 has a ball end 32 which is shown in particular in Figure 3. The ball end 32 is made of a resilient plastics material and has a central cavity 34 whose cross-section is adapted to the shape of the cross-section of the metal shaft 20. The ball end 32 has a spherical portion 36 whose surface corresponds to the shape of a sphere. Adjacent to the spherical portion 36 is a neck 38 whose axis lies on the axis of the central cavity 34. On the side of the spherical portion 36 opposite the neck 38, the ball end 32 has two opposing resilient lugs 40 which are each formed by two open-ended slots 42 which lie adjacent to one another but are spaced apart. Each of the resilient lugs 40 has a projection 44 integrally connected thereto which projects into the central cavity 34 of the ball end 32 and whose side 46 facing the neck 38 forms with the wall 48 of the central cavity 34 an angle ss corresponding approximately to the angle a of the metal shaft 20. To assemble the ball pin 18, the ball end 32 is placed onto the metal shaft 20 so that the neck 38 passes over the head 28. Finally, the metal shaft 20 is inserted so far into the central recess 34 of the ball end 32 that the chamfer 30 of the pin head 28 strikes adjacent to the sides 46 of the projections 44. The ball end 32 is then strongly pushed in the direction of the arrow 49 in Figure 5 so that the projections 44 are temporarily deflected in the direction of the arrows 50 until under the influence of the initial stressing of the lugs 40 the projections 44 may spring back into their starting position when they come into the region of the annular groove 22 of the metal shaft 20 (Figure 5). In this manner, the ball end 32 is non-detachably connected to the metal shaft 20 and the ball pin 18 is formed. The resilient lugs 40 of the ball end 32 together with their projections 44 form counterlocking means for the ball end 18 which cooperates with locking means formed by the annular groove 22 of the metal shaft. Thus, it is possible to construct the metal shaft 20 in accordance with the set requirements while the ball end may be manufactured taking into account the special requirement demanded of it as regards running properties. Moreover, by using a plastics material the ball end is insensitive to corrosion. WHAT WE CLAIM IS:

1. A screen wiper for a motor vehicle, having at least one wiper arm, a drive motor and a means for transmitting the driving movement of the motor to the wiper arm, said means incorporating at least one element operatively connected to another element by way of a ball pin and socket, the ball pin comprising a metal shaft on which a ball end manufactured in plastics material is fixed.

2. A wiper as claimed in claim 1, in which the ball end has a cavity into which the shaft is inserted.

3. A wiper as claimed in claim 2, in which the shaft has a cross-section which departs from the circular and wherein the cross-section of the cavity is adapted to the shape of the cross-section of the shaft.

4. A wiper as claimed in claim 3, in which both the shaft and the cavity are constructed with a square cross-section.

5. A wiper as claimed in any of claims 2 to 4, in which the shaft has locking means which co-operate with counter-locking means on the ball end.

6. A wiper as claimed in claim 5, in which the locking means of the shaft are formed by a groove which extends perpendicular to the shaft axis and in which at least one projection projecting into the cavity of the ball end engages as counter-locking means.

7. A wiper as claimed in claim 6, in which the ball end is made of a resilient plastics material and the projection is disposed on a resilient lug which is integrally connected to the ball end.

8. A wiper as claimed in claim 7, in which the resilient lug is formed by two edge-open slots.

9. A wiper as claimed in any of claims 6 to 8, in which the ball end has two opposing resilient lugs with locking projections.

10. A wiper as claimed in any of claims 1 to 9, in which the shaft is integrally connected to one of said elements.

11. A wiper constructed substantially as herein particularly described with reference to and as illustrated in the accompanying drawings.