GB1585432A

GB1585432A - Screen wiper device

Info

Publication number: GB1585432A
Application number: GB4175/78A
Authority: GB
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 1977-02-03
Filing date: 1978-02-02
Publication date: 1981-03-04
Also published as: IT7819633A0; FR2379408A1; DE2704472A1

Description

(54) SCREEN WIPER DEVICE (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 present invention relates to a wiper device for foldable vehicle windscreens.

In certain vehicles, particularly crosscountry types of vehicles, the windscreen is disposed so as to be foldable forwardly downwards. In order to fold the screen down the wiper arms with the wiper blade assemblies, which are located in front of the screen, must first be removed from the wiper drive shafts, and this gives rise to considerable expense on assembly.

It is also known to place the wiper blades and the wiper arms in a so-called extended parking position in which wiper blades and wiper arms are located below the windscreen.

This however can be achieved solely by means of a mechanism which is costly and for cross-country vehicles is too delicate.

There is provided by the present invention a windscreen wiper for a foldable vehicle windscreen, the wiper comprising a wiper arm mounted at one end on a driving member therefor and adapted to support a wiper blade assembly at the other end by means of a pivoted connection piece; the arm being either one of substantially straight form or one on which a portion terminating at said other end is bent in relation to the remainder of the arm in a plane parallel to the windscreen to position the blade on the screen, wherein said one end of the arm and the driving member in the former case, and said portion of the arm and the connecting piece in the latter case, are provided with a disengageable projection and complementary recess connection such that, on disengagement, the arm can be rotated freely on the driving member in the former case, and the connecting piece can be rotated freely on said portion of the arm in the latter case, to bring the arm or the connecting piece and the blade assembly therewith as the case may be to a position in which the windscreen can be folded down without obstruction by the wiper mechanism.

The wiper device in accordance with the invention has by way of comparison with the known devices the advantage that the normally obstrucing part of the input mechanism can be swivelled out of its operating position so that it is not necessary to dismantle that part; and that replacing it also takes place in a correspondingly simple manner. A further advantage is the fact that the wiper in accordance with the invention is very robust and also ensures a high degree of operational safety in the rough ride of cross-country motor vehicles.

Embodiments of the invention are described below with reference to the accompanying drawings in which: Fig. 1 is a partial section through the motor vehicle body in the region of the windscreen, showing a windscreen wiper according to the invention in which the wiper shaft and wiper arm are operatively connected to each other, Fig. 2 is a detail from Fig. 2, showing the wiper arm and wiper shaft uncoupled, Fig. 3 is a partial section along the line 111-111 in Fig. 2, Fig. 4 is a partial section along the line IV-IV of Fig. 2, showing a coupling disposed between the wiper arm and wiper shaft, Fig. 5 is a side elevation of a further embodiment section in the region of an articulated connection between the upper arm and wiper shaft, Fig. 6 is a plan view of the wiper arm and wiper blade in the direction of the arrow VI in Fig. 5, Fig. 7 shows another embodiment using another wiper arm joint for swivelling the wiper blade attachment point and Fig. 8 shows a still further embodiment using a still further form of wiper arm joint for swivelling the attachment for the wiper blade.

Referring now to Figs. 1 to 4, a motor vehicle has a windscreen 10, which is disposed in frame 12. Between the frame 12 and the vehicle body 14 a hinge-joint, which is not shown, is present which makes it possible to let down the windscreen 10 together with the frame 12 in the direction of the arrow 16 by at least 90 . The vehicle body 14 is apertured to allow a wiper drive shaft 18 therethrough for a wiper arm 20, in this instance, one which is substantially straight in form. Within the vehicle body 14, a rocker arm 22 is attached on the wiper shaft 18 and is part of an oscillatory drive (not shown) for the wiper. The wiper arm 20 is mounted on the outer end of the wiper shaft and secured thereon. For this purpose, the wiper arm 20 has, in the region of the wiper shaft 18, a hub part 24 which is provided with a bore 26 in which a bush 28 is rotatably guided. The bush 28 has at its end remote from the motor vehicle body 14 a ring flange 30 which has a shoulder 32 facing the wiper arm. The shoulder 32 of the ring flange 30 has a pair of pawls 34 which project in the axial direction of the bush 28 and with which are associated respective recesses 36 in the surface of the hub part 24, facing the ring flange 30 (see in particular Figs. 1 to 4). The bush 28 projects out of the part of the wiper arm hub part 24, facing the vehicle body 14, by its tubular end 38. A helical spring 40 is placed around this bush end 38 and is supported with its one end on the hub part 24 of the wiper arm and its other end on a counter shoulder which is formed by a Seeger ring 44 and by a sheet metal cap 46. The helical spring 40 is thereby pretensioned in its operating position between the hub part 24, forming the one shoulder, and the counter shoulder. Moreover the construction and arrangement of the bush 28 with its ring flange 30, of the hub part 24 as well as the arrangement of the Seeger ring 44 and the sheet metal cap 46 are such that the wiper arm 20 with its hub part 24 can be displaced against the gripping effect of the helical spring 40 in the axial direction to a greater extent than the axial length of the pawls 34. Furthermore, the pawls taper out from the shoulder 32 of the bush 28 and the shape of the recesses 36 in the hub part 24 of the wiper arm 20 is formed to complement the shape of the pawls 34 (Fig. 4).

The operating position of the wiper device is shown in Fig. 1. It can be seen from this Figure that the wiper arm with its bush 28 is mounted on the wiper shaft 18 of the wiper device. The attachment of the wiper arm 20 on the wiper shaft 18 is achieved by means of a known splining 50 and a threaded lug 52 of the wiper shaft, whereby a nut 54 is screwed onto the threaded lug which projects out of the bush 28. The bush 28 is thus in this manner firmly connected to the wiper shaft 18. The ring flange 30 of the bush 28 forms with the pawls 34 the half of a claw coupling which in the position shown in Fig. 1 is kept in engagement with the counter coupling half, which is formed by the recesses 36 in the hub part 24, by means of the pretensioned helical spring 40. This claw coupling, formed from the two aforementioned coupling halves, thus ensures a positively locked connection between the bush 28 and the wiper arm 20 so that the wiper arm can be driven by the oscillatory drive.

If the windscreen 10 is now to be let down forwards in the direction of the arrow 16, a pressure must be applied to the wiper arm in the direction of the arrow 56 (Figs. 1 and 2), by means of which the hub part 24 on the bush 28 is displaced against the force of the helical spring 40 so that the pawls 34 come completely out of the recesses 36. Thereafter the wiper arm 20 or the hub part 24 on the bush 28 can be swivelled so far that the wiper arm 20 with its wiper blade comes to lie completely outside the edge of the windscreen 10. Thereafter the windscreen can be swivelled forwards without difficulties and let down onto the radiator cover of the vehicle, which is not shown. To place the wiper arm 20 in its operating position the wind-screen 10 is initially brought again into its upright position and secured there, whereafter the wiper arm 20 can be swivelled back into its normal position without further preparations. By means of the pretensioning of the helical spring 40 the pawl 34 is automatically pressed in its recess 36 when they lie opposite one another.

For design reasons, however, in the case of many wiper systems, the wiper arm is bent in a plane parallel to the windscreen. Such an arrangement is shown in Figs. 5 and 6. The wiper arm 20 extends from its end connected to the wiper shaft up to a bent portion 60 and comprises an end section 62 which is formed with an attachment or connecting piece 64 for a wiper blade 66. Between the bent portion 60 and the connecting piece 64, the wiper arm 20 has a joint 68 by means of which the end section 62 can be swivelled relative to the wiper arm 20. In the embodiment of Fig. 5, thejoint 68 is formed by a pin 70 on which the end section 62 can be swivelled. The wiper arm 20 has at its outermost end a recess 72 which in the operating position of the wiper arm fits exactly over a recess 74 in the end section 62.

At the same time a leaf spring 76 is secured on the wiper arm by the pin 70 and engages by means of notched projection 78 into the two recesses 72 and 74 of the wiper arm 20 and of the end section 62 so that these parts are secured in their operating position. In order to unlock this operating position described the leaf spring 76 is deformed in the direction of the arrow 80 against its pretensioning so that the notched projection 78 comes at least out of the recess 74, whereafter the end section 62 can be swivelled relative to the wiper arm so that the attachment point 64 for the wiper blade can be swivelled approximately into an imagined extension of the wiper arm section connected to the wiper shaft. By means of this step it is possible to let down the windscreen also when the wiper is bent in the manner described above.

Another embodiment is shown in Fig. 7. In this, in place of the leaf spring 76, a helical spring 82 is disposed so as to be pretensioned between a counter shoulder 84 and the wiper arm 20. A pin 86 is located in the centre of the helical spring 82 and is rotatable in a bore of the wiper arm 20. The wiper arm 20 also has at its outermost end a notched projection 88 which in the operating position shown of the wiper device projects into a recess 90 in the end section 62 and thus secures the end section 62 against rotation in the bore for the bolt 86. By pressing against the helical spring 82 in the direction of arrow 92, the notched projection 88 can be brought out of the recess 90. Thereafter the end section 62 can be swivelled into a position in which the windscreen can be let down without difficulties.

In the embodiment shown in Fig. 8, the connecting piece 64 for the wiper blade is disposed so as to be directly rotatable in the wiper arm 20. For this purpose, the connecting piece has a pivot axle 96 which is guided in a bore 98 of the wiper arm 20. The axle 96 projects by its end remote from the connecting piece 64 from the bore which is provided with a guide collar, and is there provided with a counter shoulder which is formed from a retaining ring 100 and a sheet metal cap 102. A helical spring 104 is disposed between the counter shoulder and the wiper arm 20 and is supported in a pretensioned manner on these two components and forces the connecting piece 64 against the wiper arm 20. The connecting piece 64 has on its side facing the wiper arm 20 a notched projection 106 which like the pawls 34 of the bush 28 lies in a recess of the wiper arm 20.

Thus in the case of this joint, as well, a kind of claw coupling is formed which is in engagement in the operating position of the wiper device and is kept in this operating position by the force of the helical spring 104.

By pressing on the sheet metal cap 102 in the direction of the arrow 108 the claw coupling is taken out of engagement so that the connecting piece 64 can be swivelled in accordance with requirements.

WHAT WE CLAIM IS:1. A windscreen wiper for a foldable vehicle windscreen, the wiper comprising a wiper arm mounted at one end on a driving member therefor and adapted to support a wiper blade assembly at the other end by means of a pivoted connection piece; the arm being either one of substantially straight form or one on which a portion terminating at said other end is bent in relation to the remainder of the arm in a plane parallel to the windscreen to position the blade on the screen, wherein said one end of the arm and the driving member in the former case, and said portion of the arm and the connecting piece in the latter case, are provided with a disengageable projection and complementary recess connection such that, on disengagement, the arm can be rotated freely on the driving member in the former case, and the connecting piece can be rotated freely on said portion of the arm in the latter case, to bring the arm or the connecting piece and the blade assembly therewith as the case may be to a position in which the windscreen can be folded down without obstruction by the wiper mechanism.

2. A wiper in accordance with claim 1, in which the driving member is mounted on the wiper drive shaft and is in the form of a bush guided in a bore in the one end of the wiper arm.

3. A wiper in accordance with claim 2, wherein the bush has a shoulder facing the one end of the wiper arm, which forms one half of a coupling and the other half of the coupling is formed by an axial projection of the one end of the wiper arm.

4. A wiper in accordance with claim 3, wherein the shoulder of the bush has at least one pawl which projects in the axial direction thereof and with which is associated a recess in the one end of the wiper arm.

5. A wiper in accordance with claim 4, wherein the pawl tapers in the direction from the shoulder of the bush and in that the recess in the wiper arm end is complementary in shape to the shape of the pawl.

6. A wiper in accordance with any of claims 3 to 5, wherein the two halves of the coupling are drawn against each other by the force of a spring and are thus held in engagement with each other.

7. A wiper in accordance with claim 6, wherein the spring is a helical spring which is disposed around an end section of the bush, the end section being on the side remote from the shoulder of the bush and axial projection of the one end of the wiper arm.

8. A wiper in accordance with claim 7, wherein the helical spring is disposed so as to be pretensioned between the wiper arm end and a counter shoulder formed at an end section of the bush.

9. A wiper in accordance with claim 1, wherein said portion of the arm provides a bore passing transversely therethrough, and said connecting piece is formed with a pivot axle to pass through the bore; means being provided to hold the axle in position in the bore.

10. A wiper in accordance with claim 9, wherein the connecting piece provides projections radially of said axle and facing the

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Claims

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the wiper arm so that the attachment point 64 for the wiper blade can be swivelled approximately into an imagined extension of the wiper arm section connected to the wiper shaft. By means of this step it is possible to let down the windscreen also when the wiper is bent in the manner described above.

Another embodiment is shown in Fig. 7. In this, in place of the leaf spring 76, a helical spring 82 is disposed so as to be pretensioned between a counter shoulder 84 and the wiper arm 20. A pin 86 is located in the centre of the helical spring 82 and is rotatable in a bore of the wiper arm 20. The wiper arm 20 also has at its outermost end a notched projection 88 which in the operating position shown of the wiper device projects into a recess 90 in the end section 62 and thus secures the end section 62 against rotation in the bore for the bolt 86. By pressing against the helical spring 82 in the direction of arrow 92, the notched projection 88 can be brought out of the recess 90. Thereafter the end section 62 can be swivelled into a position in which the windscreen can be let down without difficulties.

In the embodiment shown in Fig. 8, the connecting piece 64 for the wiper blade is disposed so as to be directly rotatable in the wiper arm 20. For this purpose, the connecting piece has a pivot axle 96 which is guided in a bore 98 of the wiper arm 20. The axle 96 projects by its end remote from the connecting piece 64 from the bore which is provided with a guide collar, and is there provided with a counter shoulder which is formed from a retaining ring 100 and a sheet metal cap 102. A helical spring 104 is disposed between the counter shoulder and the wiper arm 20 and is supported in a pretensioned manner on these two components and forces the connecting piece 64 against the wiper arm 20. The connecting piece 64 has on its side facing the wiper arm 20 a notched projection 106 which like the pawls 34 of the bush 28 lies in a recess of the wiper arm 20.

Thus in the case of this joint, as well, a kind of claw coupling is formed which is in engagement in the operating position of the wiper device and is kept in this operating position by the force of the helical spring 104.

By pressing on the sheet metal cap 102 in the direction of the arrow 108 the claw coupling is taken out of engagement so that the connecting piece 64 can be swivelled in accordance with requirements.

WHAT WE CLAIM IS:1. A windscreen wiper for a foldable vehicle windscreen, the wiper comprising a wiper arm mounted at one end on a driving member therefor and adapted to support a wiper blade assembly at the other end by means of a pivoted connection piece; the arm being either one of substantially straight form or one on which a portion terminating at said other end is bent in relation to the remainder of the arm in a plane parallel to the windscreen to position the blade on the screen, wherein said one end of the arm and the driving member in the former case, and said portion of the arm and the connecting piece in the latter case, are provided with a disengageable projection and complementary recess connection such that, on disengagement, the arm can be rotated freely on the driving member in the former case, and the connecting piece can be rotated freely on said portion of the arm in the latter case, to bring the arm or the connecting piece and the blade assembly therewith as the case may be to a position in which the windscreen can be folded down without obstruction by the wiper mechanism.
2. A wiper in accordance with claim 1, in which the driving member is mounted on the wiper drive shaft and is in the form of a bush guided in a bore in the one end of the wiper arm.
3. A wiper in accordance with claim 2, wherein the bush has a shoulder facing the one end of the wiper arm, which forms one half of a coupling and the other half of the coupling is formed by an axial projection of the one end of the wiper arm.
4. A wiper in accordance with claim 3, wherein the shoulder of the bush has at least one pawl which projects in the axial direction thereof and with which is associated a recess in the one end of the wiper arm.
5. A wiper in accordance with claim 4, wherein the pawl tapers in the direction from the shoulder of the bush and in that the recess in the wiper arm end is complementary in shape to the shape of the pawl.
6. A wiper in accordance with any of claims 3 to 5, wherein the two halves of the coupling are drawn against each other by the force of a spring and are thus held in engagement with each other.
7. A wiper in accordance with claim 6, wherein the spring is a helical spring which is disposed around an end section of the bush, the end section being on the side remote from the shoulder of the bush and axial projection of the one end of the wiper arm.
8. A wiper in accordance with claim 7, wherein the helical spring is disposed so as to be pretensioned between the wiper arm end and a counter shoulder formed at an end section of the bush.
9. A wiper in accordance with claim 1, wherein said portion of the arm provides a bore passing transversely therethrough, and said connecting piece is formed with a pivot axle to pass through the bore; means being provided to hold the axle in position in the bore.
10. A wiper in accordance with claim 9, wherein the connecting piece provides projections radially of said axle and facing the

adjacent surface of said portion of the arm, and said portion of the arm provides complementary recesses to receive the projections.
11. A wiper in accordance with claim 9 or 10, wherein said means comprise a spring resiliently to bias the axle in position in the bore.
12. A wiper for a foldable vehicle screen, substantially as hereinbefore described with reference to Figs. 1 to 4 or to Figs. 5 and 6 or to Fig. 7 or to Fig. 8 of the accompanying drawings.