GB1574571A

GB1574571A - Attachment of windscreen wiper blade to wiper arms

Info

Publication number: GB1574571A
Application number: GB783078A
Authority: GB
Original assignee: Trico Ltd
Current assignee: Trico Ltd
Priority date: 1978-02-28
Filing date: 1978-02-28
Publication date: 1980-09-10
Also published as: JPS6333724Y2; FR2418608A7; AU4463479A; AU522550B2; JPS54130234U; BE874500A

Description

(54) ATTACHMENT OF WINDSCREEN WIPER BLADE TO WIPER ARMS (71) We, TRICO-FOLBERTH LIMITED, a British Company of Great West Road, Brentford, Middlesex, TW8 9HP, 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 perfomed, to be par ticularly described in and by the following statement:- This invention is concerned with the attachment of a windscreen wiper blade to a wiper arm by making use of an adapter, the wiper blade being of a known kind having a captive pivot pin which has a portion projecting from the side or top of the blade in the lateral sense. The projecting portion of the pin is entered in a bore in the adaptor, and the adaptor is rendered captive, for example by upsetting the outer end of the pin.

The wiper arm is also of a known kind consisting of a stiff bar of rectangular section and terminating in a hook shape, constituted by an end portion of the bar curved in a semi-cylindrical shape between the main portion of the arm and a short straight end portion lying spaced from and parallel to the main portion. The hook-shaped termination of the arm provides, in one of the parallel portions, an aperture, projection, or recess, enabling the adaptor to be retained by latching interengagement with the arm.

The adaptor is received and retained in the space defined by the hook shaped termination of the arm.

One form of adaptor which has been proposed is a plastics moulding having a bearing bush portion for receiving the pivot pin of the arm, and having two resilient adjacent shank portions which extend tangentially from the bearing bush portion. The bearing bush portion lies in contact with the semi-circular shape of the wiper arm, and the shank portions of the adpator lie in contact with the parallel portions of the hook of the arm. The adaptor is retained by interengagement of a projection on one of the shank portions with an aperture in the arm near its end, the same shank portion having an accessible end for manipulation to enable the projection to be disengaged from the aperture, The present invention provides alternative devices for attaching the kind of wiper blade to the kind of wiper arm above described.

A device according to the present invention has an external shape for reception in the space defined by the termination of the arm, and the device comprises an adaptor of rigid form and a latching member which has a resilient action, the adaptor having a bore therein for reception of the pivot pin and having side flanges or the equivalent for engagement with the sides of the arm thereby locating the adaptor laterally of the arm, and the latching member including a portion for engaging an end of the adaptor, a first means for latching engagement with the adaptor to retain the latching member longitudinally of the adaptor, and second means for latching engagement with the arm to secure the adaptor longitudinally of the arm.

Each latching means may be an element which is itself resilient, e.g. a tongue, or may be a rigid element, e.g. a half-dome, carried by a resilient portion of the latching member.

The adaptor is preferably formed with surfaces for bearing directly on the curved surface of the semi-cylindrical portion of the arm and on the straight, parallel portions of the arm which adjoin the curved surface.

Preferably the bore is disposed between the end of the adaptor which the latching member engages, and the location where the adaptor and latching member interlatch when in assembly.

Preferably the two means for latching engagement are two latching elements spaced along a limb of the latching member and formed of the material of the latching member, one such element for latching interengagement with the adaptor between its ends, and the other such element for latching interengagement with the arm.

Examples of devices embodying the present invention will now be described with reference to the drawings accompanying the Provisional Specification, in which: Figures 1 to 3 are plan, side and end views, respectively, of an adaptor, Figure 2 being a section on line 11-Il of Figure 1, and Figure 3 a view on line Ill-Ill of Figure 2; Figures 4 to 6 are plan, side, and end views, respectively, of a latching member, Figure 6 being a view on line VI-VI of Figure 5; Figure 7 is a side view, partly in section, indicating the adaptor and latching member in assembly with a wiper arm; Figure 8 is a section on line VIII-VIII of Figure 7; Figure 9 is a fragmentary section corresponding to Figure 2 but of a modified adaptor in assembly with the latching member; and Figure 10 is a plan view of Figure 9.

Referring to the drawings, particularly to Figures 1 to 3, an adaptor 10 is a moulded plastics block of rigid form, and of external shape for reception in the space defined by a hook-shaped termination of a wiper arm 11, shown in Figure 7. Accordingly the adaptor 10, as shown in Figure 2, has upper and lower parallel surfaces 12, 13 joined by a semicylindrical end surface 14. These surfaces 12 to 14 interfit with the wiper arm 11 as later described.

In the region of the axis of generation of the -semi-cylindrical surface 14, and parallel to it, is the axis of a cylindrical bore 15 which extends through the adaptor 10 from side to side for reception of a pivot pin (not shown), captive on a wiper blade (not shown).

The adaptor 10 is formed with two side flanges 16 which extend in planes at right angles to the surfaces 12 to 14, and to the bore 15. The flanges 16 are for engaging opposite sides of the termination of the wiper arm 11 and thereby locating the adaptor laterally of the arm 11.

The surfaces 12 to 14 are formed with a shallow groove 17, of uniform width throughout and of uniform depth where it extends round the semi-cylindrical surface 14, and above and below the bore 15 as seen in Figure 2, the depth corresponding to the thickness of a latching member 18 (see Figure 5, described below) to be assembled on the adaptor 10. To the right of the bore 15 as seen in Figure 2, the depth of the groove 17 varies in a symmetrical manner on opposite sides of a horizontal plane which, in this example, passes through the two axes mentioned above. Thus the depth of the groove 17 changes abruptly to form oppositely disposed recesses 19 between edges 20, 21, but otherwise, to the right of kinks 22, the groove 17 steadily increases in depth to edges 23 disposed at the right-hand end of the adaptor.

In lateral aspect, as can be seen in Figures 1 and 3, the groove 17 extends centrally between the flanges 16, and is of width somewhat greater than the width of the latching member 18, as seen in Figures 4 and 6, so that the latching member can easily enter the groove.

The latching member 18 is of rectangular section metal spring strip, the unstressed shape of which appears from Figure 5. In this example, the member 18 is symmetrical, having a preformed semi-cylindrical end portion 24 of an inner curvature corresponding to the curvature of the groove 17 where it extends around the semi-cylindrical surface 14 of the adaptor 10, and having equal limbs 25, 25a extending away from the end portion 24. The latching member 18 would however fulfil its purpose, about to be described, if it comprised merely the curved end portion 24 and a single limb 25.

The limb 25, or each limb 25, 25a as shown, is outwardly convex adjacent to its free end 28a (Fig. 5).

Between the end portion 24 of the member 18 and the free end 28a of each limb 25, 25a, are spaced lugs 26, 27 (27a), each formed by cutting and pressing out a tongue from the respective limb to which the tongue inclines in the longitudinal sense. The lugs 26, 27 (27a) are oppositely directed, the free end of lug 26 being directed inwards towards the end -portion 24 whereas the free end of the lug (27a) is directed outwards away from the end portion 24.

The wiper arm 11, of which only the hookshaped termination is shown in Figure 7, is of rectangular section and has a portion 28 curved in a semi-cylindrical shape so that a short straight end portion 29 lies spaced from and parallel to the main portion 30 of the arm 11. The short portion 29 is formed with an aperture 31 in this example, for latching engagement with the member 18. The space defined by the termination lies on the inside of the curved portion 28 and between the short straight portion 29 and the main portion 30 opposite it.

Preparatory to assembling the adaptor 10 on the wiper arm 11, the latching member 18 is pushed by hand into place on the adaptor 10, the free ends of the member 18 being entered in the groove 17 at the shallow parts which are seen above and below the bore 15 in Figure 2, and moved to the right, until the lugs 26 snap into latching engagement with the recesses 19. In this position the semi-cylindrical end portion 24 of the latching member 18 embraces and contacts the end surface 14 in an arc around the bore 15.

The assembled adaptor 10 and latching member 18 are then assembled on the wiper arm 11 by presenting the curved end surface 14 and portion 24 to the open end of the hook-shaped termination of the wiper arm.

The position of the wiper arm relative to the sub-assembly of adaptor 10 and member 18 is indicated in broke lines in Figure 7 Assembly is completed by causing relative longitudinal movement of the arm and sub assembly, until the adaptor 10 and member 18 make contact with the curved end portion 28 of the arm, the side flanges 16 guiding the adaptor 10 along the side of the hook of the arm into position. Just before such contact is made, the lug 27 adjacent to the short straight portion 29 of the arm snaps into latching engagement with the aperture 31.

This latching engagement maintains the position of the adaptor longitudinally of the arm.

The lug 27a, having in this example no aperture in the main portion of the arm 11 to engage, does not latch with the arm. Indeed the portion of limb 25a on which lug 27a is formed is held clear of the main portion of the arm by engagement of the curved free end of limb 25a of the latching member, the groove 17 allowing limb 25a to be deflected away from the arm as the adaptor and latching member are being pushed into the space withinthe termination of the arm. The presence of the lug 27a is however useful in that it enables the latching member to be used 1800 rotated about its axis of symmetry, thereby facilitating fitment, lug 27 then being otiose.

It is apparent from Figures 7 and 8 that, when the adaptor 10 and latching member 18 are in position on the arm, i.e. making contact with the curved end portion 28 of the arm, the adaptor and member fit the space within the termination of the arm.

The kind of fit acceptable is a push fit. This applies also to the fit between the side flanges 16 and the sides of the arm.

Moreover, because the adaptor is of rigid form and because of its fit in the arm, with the surfaces 12 to 14 bearing directly on the arm, the bore 15 is well supported.

The device can easily be disassembled from the arm in a manner which will be described with reference to Figure 7. The free end 28a of limb 25 of latching member 18 is moved by hand or by a tool away from the short arm portion 29, to disengage the lug 27 from the aperture 31. The device is then withdrawn from the termination of the arm.

It is believed at this stage of development of the present invention that it is unnecessary to back up the semicylindrical end portion 24 of the latching element through 1800 by the adaptor 10: the adaptor groove 17 could be deepened in the manner indicated at 32 in Figures 9 and 10 but a residual nose 33 having the width of the groove 17 could support the latching member 18. Moreover, continuous side flanges 16 may be unnecessary. Lateral location of the adaptor on the arm could be provided by spaced projections at the sides of the adaptor.

Any form of device which has been described may be modified so that, in effect, the width of the groove 17 extends up to the side flanges 16, and the width of the latching member 18 is correspondingly increased.

The adaptor will then bear indirectly on the arm by means of the latching member.

WHAT WE CLAIM IS 1. A device capable of attaching a windscreen wiper blade having a captive pivot pin which has a portion projecting from the side or top of the blade in the lateral sense to a wiper arm consisting of a stiff bar of rectangular section and terminating in a hook shape, constituted by an end portion of the bar curved in a semi-cylindrical shape between the main portion of the arm and a short straight end portion lying spaced from and parallel to the main portion, the device comprising an adaptor of rigid form and a latching member which has a resilient action, the adaptor having a bore therein for reception of the pivot pin and having side flanges or the equivalent for engagement with the sides of the arm thereby locating the adaptor laterally of the arm, and the latching member including a portion for engaging an end of the adaptor, a first means for latching engagment with the adaptor to retain the latching member longitudinally of the adaptor, and second means for latching engagement with an aperture, projection, or recess in one of the parallel portions of the hookshaped termination of the arm.

2. A device according to claim 1, in which the adaptor is formed with surfaces for bearing directly on the curved surface of the semi-cylindrical portion of the arm and on the straight, parallel portions of the arm which adjoin the curved surface.

3. A device according to claim 1 or claim 2, in which the bore is disposed between the end of the adaptor which the latching member engages, and the location where the adaptor and latching member interlatch when in assembly.

4. A device according to any of claims 1 to 3, in which the two means for latching engagement are two latching elements spaced along a limb of the latching member and formed of the material of the latching member, one such element for latching interengagement with the adaptor between its ends, and the other such element for latching interengagement with the arm.

5. A device according to any of claims 1 to 4, in which the latching member is of metal spring strip.

6. A windscreen wiper arm consisting of a stiff bar of rectangular section and terminating in a hook shape, constituted by an end portion of the bar curved in a semicylindrical shape between the main portion of the arm and a short straight end portion lying spaced from and parallel to the main portion, with an aperture, projection or recess provided in one of the parallel portions, the arm being in assembly with a device according to any of claims 1 to 5.

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

Claims

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

28 of the arm, the side flanges 16 guiding the adaptor 10 along the side of the hook of the arm into position. Just before such contact is made, the lug 27 adjacent to the short straight portion 29 of the arm snaps into latching engagement with the aperture 31.

This latching engagement maintains the position of the adaptor longitudinally of the arm.

The lug 27a, having in this example no aperture in the main portion of the arm 11 to engage, does not latch with the arm. Indeed the portion of limb 25a on which lug 27a is formed is held clear of the main portion of the arm by engagement of the curved free end of limb 25a of the latching member, the groove 17 allowing limb 25a to be deflected away from the arm as the adaptor and latching member are being pushed into the space withinthe termination of the arm. The presence of the lug 27a is however useful in that it enables the latching member to be used 1800 rotated about its axis of symmetry, thereby facilitating fitment, lug 27 then being otiose.

It is apparent from Figures 7 and 8 that, when the adaptor 10 and latching member 18 are in position on the arm, i.e. making contact with the curved end portion 28 of the arm, the adaptor and member fit the space within the termination of the arm.

The kind of fit acceptable is a push fit. This applies also to the fit between the side flanges 16 and the sides of the arm.

Moreover, because the adaptor is of rigid form and because of its fit in the arm, with the surfaces 12 to 14 bearing directly on the arm, the bore 15 is well supported.

The device can easily be disassembled from the arm in a manner which will be described with reference to Figure 7. The free end 28a of limb 25 of latching member 18 is moved by hand or by a tool away from the short arm portion 29, to disengage the lug 27 from the aperture 31. The device is then withdrawn from the termination of the arm.

It is believed at this stage of development of the present invention that it is unnecessary to back up the semicylindrical end portion 24 of the latching element through 1800 by the adaptor 10: the adaptor groove 17 could be deepened in the manner indicated at 32 in Figures 9 and 10 but a residual nose 33 having the width of the groove 17 could support the latching member 18. Moreover, continuous side flanges 16 may be unnecessary. Lateral location of the adaptor on the arm could be provided by spaced projections at the sides of the adaptor.

Any form of device which has been described may be modified so that, in effect, the width of the groove 17 extends up to the side flanges 16, and the width of the latching member 18 is correspondingly increased.

The adaptor will then bear indirectly on the arm by means of the latching member.

WHAT WE CLAIM IS 1. A device capable of attaching a windscreen wiper blade having a captive pivot pin which has a portion projecting from the side or top of the blade in the lateral sense to a wiper arm consisting of a stiff bar of rectangular section and terminating in a hook shape, constituted by an end portion of the bar curved in a semi-cylindrical shape between the main portion of the arm and a short straight end portion lying spaced from and parallel to the main portion, the device comprising an adaptor of rigid form and a latching member which has a resilient action, the adaptor having a bore therein for reception of the pivot pin and having side flanges or the equivalent for engagement with the sides of the arm thereby locating the adaptor laterally of the arm, and the latching member including a portion for engaging an end of the adaptor, a first means for latching engagment with the adaptor to retain the latching member longitudinally of the adaptor, and second means for latching engagement with an aperture, projection, or recess in one of the parallel portions of the hookshaped termination of the arm.
2. A device according to claim 1, in which the adaptor is formed with surfaces for bearing directly on the curved surface of the semi-cylindrical portion of the arm and on the straight, parallel portions of the arm which adjoin the curved surface.
3. A device according to claim 1 or claim 2, in which the bore is disposed between the end of the adaptor which the latching member engages, and the location where the adaptor and latching member interlatch when in assembly.
4. A device according to any of claims 1 to 3, in which the two means for latching engagement are two latching elements spaced along a limb of the latching member and formed of the material of the latching member, one such element for latching interengagement with the adaptor between its ends, and the other such element for latching interengagement with the arm.
5. A device according to any of claims 1 to 4, in which the latching member is of metal spring strip.
6. A windscreen wiper arm consisting of a stiff bar of rectangular section and terminating in a hook shape, constituted by an end portion of the bar curved in a semicylindrical shape between the main portion of the arm and a short straight end portion lying spaced from and parallel to the main portion, with an aperture, projection or recess provided in one of the parallel portions, the arm being in assembly with a device according to any of claims 1 to 5.
7. A device according to claim 1, sub

stantially as described with reference to Figures 1 to 8 of the drawings accompanying the Provisional Specification, or modified as in Figures 9 and 10.
8. An arm and device according to claim 6, substantially as described with reference to Figures 1 to 8 of the drawings accompanying the Provisional Specification, or modified as in Figures 9 and 10.