GB1568131A

GB1568131A - Screen wiper for a motor vehicle

Info

Publication number: GB1568131A
Application number: GB4760477A
Authority: GB
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 1976-11-17
Filing date: 1977-11-16
Publication date: 1980-05-29
Also published as: BE860871A; FR2371321A1; IT1088116B; FR2371321B1; DE2652334A1

Description

(54) SCREEN WIPER FOR A MOTOR VEHICLE (71) We, ROBERT BOSCH GMBH, a German company of Postfach 50, 7 Stuttgart 11, 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 wiper for cleaning motor vehicle screens which wiper comprises a wiper arm on one end of which a wiper blade is articulated, one of these two components having a connecting pin and the other component having a bore for receiving the connecting pin.

A wiper is known in which, due to unavoidable manufacturing tolerances the connecting pin is slack in the receiving bore.

Due to the particular cross-section of the connecting pin it is moreover only supported by a small part of the wall of the receiving bore which can lead to poor wiper blade guidance, to vibration marks on the windscreen to be wiped and to premature wear of the components connected to each other within the region of connection.

The present invention provides a wiper for screens of motor vehicles, said wiper having a wiper arm, a wiper blade articulated to a free end of the wiper arm by way of a connecting pin carried by one of the wiper arm and blade and a receiving bore in the other of the wiper arm and blade, the cross section of the pin, in the plane lying perpendicular to the axis thereof, being narrower in one. direction than in another and the bore having a diameter which is greater than the wider crosssectional dimension of the pin, said pin being insertable into the bore via an insertion passage having a width corresponding to the narrower cross-sectional dimension of the pin, and an intermediate piece which fits snugly in the receiving bore and embraces the connecting pin so as to substantially inhibit play of the pin within the bore in the longitudinal direction of the blade.

The wiper in accordance with the invention has by way of comparison with the known wiper the advantage that by means of the intermediate piece the slack between the connecting pin and the wall of the receiving bore is neutralised thus reducing the above - mentioned disadvantages. In particular the supporting surface area between the connecting pin and the receiving bore is enlarged which leads to a reduction of the specific surface loading.

The invention is described further, by way of example, with reference to the accompanying drawings, in which Fig. I is a partial section through a known wiper device, Fig. 2 is a perspective view of the free end of a wiper arm of a wiper according to the invention with an intermediate piece half fitted, Fig. 3 is a front view of the intermediate piece of Fig. 2, Fig. 4 is a perspective view of the wiper arm end provided with the intermediate piece, Fig. 5 is a partial section through the wiper device in accordance with the invention in which the wiper arm end and the intermediate piece are disposed opposite a connecting pin in an assembly position, Fig. 6 is a partial section through the wiper device in accordance with the invention, in which the intermediate piece is locked in position; and Fig. 7 is a partial section through a different embodiment of the wiper end arm which is locked with respect to a connecting pin by means of an intermediate piece.

Fig. 1 shows a cut-away representation of the known wiper device in which a connecting pin 11 is secured on a carrying yoke 10 of a wiper blade and serves to connect the wiper blade to a wiper arm 12.

The wiper arm 12 has at its free end a coupling member 13 which is provided with an accommodating bore 14 for the connecting pin 11. The connecting pin 11 is a cylindrical component whose surface area has two flat surfaces, 15 which lie opposite each other so that this results in a flattening of the cross-sectional surface area of the connecting pin 11. The length 16 of the cross-sectional surface area of the pin is thus greater than the distance between both flat surfaces 15 of the connecting pin 11, which lie opposite each other, the accommodating bore 14 in the coupling member 13 of the wiper arm 12 has a diameter 17 which due to technical manufacturing requirements is somewhat greater than the diameter 16 of the connecting pin 11. In this context the cross sectional surface area length 16 is to be considered as the diameter of the connecting pin 11 which is flattened in cross-section. The accommodating bore 14 of the wiper arm 12 is open at its edge by way of an assembly passage, whereby the width of the assembly passage is so matched that it is somewhat greater than the distance between both flat surfaces 15 of the connecting pin 11. By means of the particular construction of the connecting pin, described above, a relatively poor guidance of the wiper blade is obtained as the wiper blade itself abuts the inner wall of the accommodating bore 14 of the wiper arm 12 only by way of the relatively small. curved surface area section of the connecting pin 111. In so doing account is still to be taken of the fact that when the wiper device is in operation the wiper arm is spring-loaded towards the windscreen to be wiped, so that the slack between the pin diameter 16 and the diameter 17 of the accommodating bore is added towards one side. This slack is further increased in the longitudial direction of the wiper blade due te the particular construction of the connecting pin 11, which is made clear in Fig.

1 by the reference numeral 19.

The coupling member 30, shown in Fig.

2 and belonging to the wiper arm, is substantially identical in construction with the coupling member 13 (Fig. 1). It also possesses an accommodating bore 31, which is open at its edge by way of an assembly passage 32. An intermediate piece 33 is, however, able to be inserted into the accommodating bore 31, and is constructed substantially in a cylindrical shape. The inermediate piece 33 has on its surface area a projection 34 which is directed substantially in a radial manner. The intermediate piece 33 has further a longitudinal groove 35 open at its edge, whose width is matched to the width of the connecting pin.

As can be seen from Fig. 3, the projection 34 and the longitudinal groove 35 of the intermediate piece 33 enclose with each other and angle a of bore than 900 - In order to insert the intermediate piece 33 in the accommodating bore 31 of the wiper arm the intermediate piece 33 is rotated in -such a manner that the projection 34 of the intermediate piece can be guided from the side into the assembly passage 32 of the wiper arm (Fig. 2). When the intermediate piece 33 is now fully located in the accommodating bore 31, the former is rotated, whereby the projection 34 moves into a recess 36 in the coupling member 30.

The projection 34 on the intermediate piece 33 forms together with the recess in the coupling member 30 a safety mechanism which prevents the intermediate piece from wandering out of the accommodating bore 31 in an axial direction. The recess 36 in the coupling member 30 is such that the intermediate piece 33 can be rotated in the accommodating bore 31 about an angle of 90 . The arrangement of the longitudinal groove 35 and the projection 34 is so made that the intermediate piece, guided in the accommodating bore 31, can be brought into an assembly position, in which the longitudinal groove 35 forms an extension of the assembly passage 32 (Fig. 5). The width of the longitudinal groove 35 is matched in such a manner to the width 37 of the cross-sectional surface area of a connecting pin 39, anchored in a carrying yoke 38 of a wiper blade, that side walls 40 of the longitudinal groove 35 abut tightly the flat surfaces 41 of the connecting pin 39, which lie opposite each other. The depth of the longitudinal groove 35 is such that it is greater than the length 42 of the cross-sectional surface area of the connecting pin 39. A particularly advantageous fit, substantially free from slack in the longitudinal direction of the blade, of both the connecting pin 39 in the longtudinal groove 35 of the intermediate piece and of the intermediate piece 33 in the accommodating bore 31 of the coupling member 30 is achieved if the intermediate piece is produced from an elastic plastic material, so that the side walls 40 of the longitudinal groove 35 abut at once free of slack the flat surfaces of the connecting pin. Furthermore, however, a bearing, free from slack, of the intermediate piece 33 in the accommodating bore 31 is achieved without thereby causing a disadvantageous tight fit of the intermediate piece 33 in the accommodatingbore 31.

When the wiper arm is to be connected to the wiper blade, the intermediate piece 33 is rotated in the accommodating bore 31 of the coupling member 30 in such a manner that the longitudinal groove 35 forms an extension of the assembly passage 32 (Fig.

5). Then the connecting pin 39 of the wiper blade is inserted in the direction of the arrow 43 through the assembly passage 32 into the longitudinal groove of the intermediate piece 33. The depth of the longitudinal groove 33 is thereby so matched that the axis of the connecting pin 39 is located on the axis of rotation of the intermediate piece 33. The wiper arm is then pivoted in relation to the wiper blade from its assembly position, indicated in Fig. 6 by dash-dot lines, into its operating position, shown in Fig. 6. A rotation of approximately 90Q thereby occurs between the coupling member 30 and the intermediate piece 33, whereby the assembly passage 32 is rotated with respect to the longitudinal groove 35 of the intermediate piece 33 in such a manner that the connecting pin 39 and thus the carrying yoke 38 of the wiper blade are undetachably connected to the wiper arm.

If the wiper blade is to be separated again from the wiper arm, these components are pivoted to each other in such a manner that the wiper arm again adopts the position, shown in Fig. 6 by dash-dot lines, in which position the longitudinal groove 35 of the intermediate piece 33 again forms an extension of the assembly passage 32, Then the wiper blade can be removed from the wiper arm counter to the direction of the arrow 43 (Fig. 5).

In the operating position shown in Fig.

6, of the wiper device, the intermediate piece 33 thus encloses the connecting pin 39 on three sides, substanfially free from slack in the longitudinal direction of the blade, and simultaneously fills out the open areas (Fig. 1), located between the accommodating bore 14 and the connecting bolt 11, in the case of the Prior Art, where this is of importance in avoiding the aforementioned disadvantages. The bearing pressure coming from the wiper arm ensures that the connecting pin 39 abuts properly on the floor of the longitudinal groove 35 and holds the wiper blade in contact with the windscreen to be wiped with the required pre-stressing.

As regards the cross-section of the intermediate piece 33, this possesses two equal cap-shaped halves which are connected to each other by way of a narrow segment.

The construction of the intermediate piece can also be arranged in such a manner that this narrow connecting segment can be made so thin that it functions at a film joint, which can contribute to economical production of the intermediate piece.

In the embodiment of the invention shown in Fig. 7 the connecting pin 50 is provided with only a single flat surface 51, so that the connecting pin 50 has a thicker cross section. The assembly passage 52 is also in this emhbodiment matched to the smallest width of the cross-section of the connecting pin 50. The intermediate piece 54, which sits in the accommodating bore 53, is thereby also constructed in such a manner that it encloses substantially free from slack in the longitudinal direction of the blade the connecting pin 50 on three sides and fills out the remaining open areas between the wall of the accommodating bore 5t and the connecting pin 50 to the extent that is required in order to avoid the aforementioned disadvantages. In this embodiment as well, the intermediate piece is seated free from slack, but rotatably, in the accommodating bore 53 of the coupling member 55 so that the longitudinal groove 56 of the intermediate piece 52 can be brought into alignment with the assembly passage 52 of the coupling member 55.

Particularly when the wiper arm and the coupling member 30 and 55 are manufactured from an elastic plastics material, the intermediate piece 33 and 54 can even be produced from a non-resilient material, for example a metal.

WHAT WE CLAIM IS: 1. A wiper for screens of motor vehicles, said wiper having a wiper arm, a wiper blade articulated to a free end of the wiper arm by way of a connecting pin carried by one of the wiper arm and blade and a receiving bore in the other of the wiper arm and blade, the cross section of the pin, in the plane lying perpendicular to the axis thereof, being narrower in one direction than in another and the bore having a diameter which is greater than the wider cross-sectional dimension of the pin, said pin being insertable into the bore via an insertion passage having a width corresponding to the narrower cross-sectional dimension of the pin, and an intermediate piece which fits snugly in the receiving bore and embraces the connecting pin so as to substantially inhibit play of the pin within the bore in the longitudinal direction of the blade.

2. A wiper as claimed in claim 1, in which a yoke of the wiper blade is provided with the connecting pin and in which the wiper arm contains the receiving bore for the connecting pin.

3. A wiper device as claimed in claim 1 or 2, in which the intermediate piece is generally cylindrical and has a radially directed longitudinal groove and in which the intermediate piece is rotatable in the receiving bore to rotate the groove into and out cf a position wherein the groove forms an extension of the insertion passage.

4. A wiper as claimed in claim 3, in which the depth of the longitudinal groove is greater than the wider cross-sectional dimension of the connecting pin.

5. A wiper as claimed in any preceding claim in which the connecting pin is part

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

Claims

**WARNING** start of CLMS field may overlap end of DESC **. arrow 43 through the assembly passage 32 into the longitudinal groove of the intermediate piece 33. The depth of the longitudinal groove 33 is thereby so matched that the axis of the connecting pin 39 is located on the axis of rotation of the intermediate piece 33. The wiper arm is then pivoted in relation to the wiper blade from its assembly position, indicated in Fig. 6 by dash-dot lines, into its operating position, shown in Fig. 6. A rotation of approximately 90Q thereby occurs between the coupling member 30 and the intermediate piece 33, whereby the assembly passage 32 is rotated with respect to the longitudinal groove 35 of the intermediate piece 33 in such a manner that the connecting pin 39 and thus the carrying yoke 38 of the wiper blade are undetachably connected to the wiper arm. If the wiper blade is to be separated again from the wiper arm, these components are pivoted to each other in such a manner that the wiper arm again adopts the position, shown in Fig. 6 by dash-dot lines, in which position the longitudinal groove 35 of the intermediate piece 33 again forms an extension of the assembly passage 32, Then the wiper blade can be removed from the wiper arm counter to the direction of the arrow 43 (Fig. 5). In the operating position shown in Fig. 6, of the wiper device, the intermediate piece 33 thus encloses the connecting pin 39 on three sides, substanfially free from slack in the longitudinal direction of the blade, and simultaneously fills out the open areas (Fig. 1), located between the accommodating bore 14 and the connecting bolt 11, in the case of the Prior Art, where this is of importance in avoiding the aforementioned disadvantages. The bearing pressure coming from the wiper arm ensures that the connecting pin 39 abuts properly on the floor of the longitudinal groove 35 and holds the wiper blade in contact with the windscreen to be wiped with the required pre-stressing. As regards the cross-section of the intermediate piece 33, this possesses two equal cap-shaped halves which are connected to each other by way of a narrow segment. The construction of the intermediate piece can also be arranged in such a manner that this narrow connecting segment can be made so thin that it functions at a film joint, which can contribute to economical production of the intermediate piece. In the embodiment of the invention shown in Fig. 7 the connecting pin 50 is provided with only a single flat surface 51, so that the connecting pin 50 has a thicker cross section. The assembly passage 52 is also in this emhbodiment matched to the smallest width of the cross-section of the connecting pin 50. The intermediate piece 54, which sits in the accommodating bore 53, is thereby also constructed in such a manner that it encloses substantially free from slack in the longitudinal direction of the blade the connecting pin 50 on three sides and fills out the remaining open areas between the wall of the accommodating bore 5t and the connecting pin 50 to the extent that is required in order to avoid the aforementioned disadvantages. In this embodiment as well, the intermediate piece is seated free from slack, but rotatably, in the accommodating bore 53 of the coupling member 55 so that the longitudinal groove 56 of the intermediate piece 52 can be brought into alignment with the assembly passage 52 of the coupling member 55. Particularly when the wiper arm and the coupling member 30 and 55 are manufactured from an elastic plastics material, the intermediate piece 33 and 54 can even be produced from a non-resilient material, for example a metal. WHAT WE CLAIM IS:

1. A wiper for screens of motor vehicles, said wiper having a wiper arm, a wiper blade articulated to a free end of the wiper arm by way of a connecting pin carried by one of the wiper arm and blade and a receiving bore in the other of the wiper arm and blade, the cross section of the pin, in the plane lying perpendicular to the axis thereof, being narrower in one direction than in another and the bore having a diameter which is greater than the wider cross-sectional dimension of the pin, said pin being insertable into the bore via an insertion passage having a width corresponding to the narrower cross-sectional dimension of the pin, and an intermediate piece which fits snugly in the receiving bore and embraces the connecting pin so as to substantially inhibit play of the pin within the bore in the longitudinal direction of the blade.

cylindrical having at least one flattened longitudinal surface.

6. A wiper as claimed in claim 5, in which the connecting pin has two flattened longitudinal surfaces which lie parallel to each other

7. A wiper as claimed in any of claims 1 to 6, in which the intermediate piece has means which cooperate with said other of the wiper arm and blade so as to prevent the intermediate-piece from wandering out of the receiving bore in an axial direction.

8. A wiper as claimed in claim 7, in which the means are formed by a projection located on the surface of the intermediate piece, which projection engages within a recess if said other of the wiper arm and blade.

9. A wiper as claimed in claim 8, in which the projection is insertable into the insertion passage in the axial direction of the receiving bore and is movable into the recess by rotation of the intermediate piece.

10. A wiper as claimed in any 6f claims 1 to 9 in which the intermediate piece is manufactured from an elastic, plastics material.

11. A wiper constructed substantially as herein particularly described with reference to and as illustrated in Figs. 1 to 6 or Figs.

2 to 6 when modified by Fig. 7 of the accompanying drawings.