GB2203934A

GB2203934A - Lockback device for windscreen wiper arm

Info

Publication number: GB2203934A
Application number: GB08807017A
Authority: GB
Inventors: Peter Mower
Original assignee: Trico Ltd
Current assignee: Trico Ltd
Priority date: 1987-03-25
Filing date: 1988-03-24
Publication date: 1988-11-02
Anticipated expiration: 2008-03-24
Also published as: BE1001071A5; DE3809966A1; AU617308B2; GB8807017D0; GB2203934B; AU1355388A; GB8707135D0; JPS63305058A

Description

2203934 LOCKBACK DEVICE FOR THE WIPER ARM OF A WINDSCREEN WIPER This

invention relates to a lockback device for the wiper arm of a windscreen wiper..

There has become a tendency at the present time to fit the windscreen wiper drive spindle in a slot in the bodywork of a vehicle, so that, when the windscreen wiper is parked, it is no longer on view. With this type of' arrangement, the usual lockback for the wiper arm, which is provided by over centre action of the arm spring cannot be used since otherwise the edges of the slot would be fouled. Nevertheless it is desirable to lift the windscreen wiper blade from the screen both for purposes of changing' the blade and for the purposes of 6 cleaning Lhe windscreen. Also this loc---r-"w been required for assembly of the wiper system ini,tially.

Therefore there have been proposed devices for locking back the windscreen wiper arm in a somewhat raised posit.ion but these devices have been relatively complicated or consisted of parts %,inich require to be kept separately to the windscreen wiper arm and therefore are easily lost.

The present invention seeks to provide a lockback device for the arm of a windscreen wiper which is of relatively simple construction, has no loose parts and can be simply operated.

According to the invention, there is provided a lockback device for the arm of a windscreen wiper comprising an arm member, a retainer carrying the arm member, an arm head for attachment to a drive spindle. and pivotted to the retainer,, and a spring acting between che arm head and the retainer in a direction to urge the arm towards the windscreen with which_ the wiper is intended to be 2 used, the lockback device comprising a shoulder on the retainer and a slider moveable in the head between a first position in which it is Positioned in the line of movement of the shoulder to limit the pivotting movement between the arm head and retainer and a second position in which it is clear of the shoulder on the retainer and permits full pivotting of the head and retainer.

Preferably the retainer, at its end pivotted to the arm head, is of channel shaped section so as to receive the arm head in the channel thereof, the shoulder being formed on the sidewall of the channel of the retainer and the slider is arranged to slide transversely relative to the arm.

1i desired the-- slider may be spring biassed towards its second position.

ihe invention will now be described in greater detail, by way of example, wi.th reference to the drawings, in which:

Figure 1 is a perspective view of a slider used in one form of 1OCkback device in accordance with the invention; Figure 2 is a perspective exploded view of a lockback device using the slider shown in figure 1; Figure 3 is a side view of a lockback device according to figures 1 and 2; Figure 4 is 'a plan view from underneath showing the arrangement of the slider in the arm head;.

Figure 5 is a diagrammatic sectional view through a 3 variation of the lockback device of figures I to 4; Figure is a sectional view taken on the line VI-VI of figure 5, and Figure 7 -is a view similar to figure 6 but showing a different form of lockback device in accordance with the invention.

Referring firstly to figures I to 4, there is shown a part of a windscreen wiper arm 1, including a retainer 2 which carries an arm member (not shown) and an arm head 3 pivotted to the retainer 2 by means of a pivot pin 5 passing through Doth the retainer 2 and the arm head 3 anGA beitig peenel-J. over at its headless end in the form of a riveT. A spring which is used for urging t he arm towards the windscreen is indicated diagrammatically at 7.

A shoulder 10 is formed on the retainer 2 so as to lie radially of the pivot pin 5. A slider 12, sliding in a slot or slots 14 in the arm head 3 is moveable transversely to the head. it is moveable between between a first position in which a stop 16 on the slider 12 can engage behind the shoulder 10 and a second position in which the stop 16 lies outside the path of the shoulder 10 thus giving free pivotting movement of the retainer 2 relative to the head 3. The slider 12 basically comprises a trifurcated member having two outer limbs 17 and 18 parallel to each other and a middle limb 19 which is bowed at right angles to the remaining two limbs 17 and 18 so as to provide a frictional effect in the slot(s) 14 in the head 3. The slider 12 is formed with two stop elements one of which (20) is intended to retain the slide in the slot (s) 14 in the head 3 and the other of which (16) is intended to 4 engage behind the shoulder-10 on the retainer 2 as will be described in more detail hereafter. The end,of the slider 12 is bent upwardly from the plane of the outer two limbs 17 and 18, and acts both to limit movement of the slider 12 and as an operating handle 22 as will also be described hereafter.

The assembly and operation of the lockback device as described above will now be considered:

Prior to assembly of the parts 2 and 3 of the arm together, the slider 12 is slid into its slot 14.

Thereafter head and retainer parts of the arm are assembled in the usual way using the pivot pin 5. -it will be seen that, due to the fact that the retainer 2 extends around the outside of the head 3 and re.dialj.y further outward of the pivot than the end of the slots 14, once the arm has been assembled the slider 12 will be captivated in the slots 14 and thus be prevented from being lost.

in order to lock the arm in the lockback position, the retainer 2 is pivotted- about the arm head 3 in a direction away- from the windscreen (anticlockwise in figure 3) until the shoulder 10 passes the slot 14.

With the retainer 2 and arm head 3 held in this position, the slider 12 is pulled out using the handle portion 22, sothat the retaining stop 16 is p ositioned behind.the shoulder 10 of the retainer 2. The retainer 2 is then allowed to pivot baCK under the acion of the spring 7 whereupon, when the shoulder 10 engages the stop 16 in the slider, this will prevent it from pivotting any further and will maintain the arm in a position with the windscreen wiper blade spaced from the windscreen.

To unlock the lockback device, the retainer 2 is again pulled back in an anticlockwise direction against the action of the spring 7 so as to move the shoulder 10 away from the retaining stop on the slider, thus releasing the slider 12. The slider 12 can then be pushed back into the arm head 3 so that the retaining stop!6 is moved out of the path of the shoulder 10, and, on release of the retainer, the pivotting of the retainer 2 relative to the head 3 is unrestricted so that the windscreen wiper blade will be returned to the windscree for operation.

Figures 5 and 6 show a modified arrangement in which the slider 12 is urged - to its non-operative position 13 v 15) meai-is olf' a com.pression spring 30. This spring 30 acts between the slider!2, and one side of the arm head 3.

the slider 12 being provided with a projection 32 on which the compression spring 30 is located.

With this embodiment, the retainer 2 must be released while the slider 12 is held out to achieve lockback, the force of the shoulder 10 acting on the retaining stop 16 of the slider being sufficient. to counteract the bias of the compression spring 30. in order to release the wiper arm, th4-retainer 2 is pulled back, releasing the slider 12 which is then moved by the spring 30 back into its non-operative position. When the retainer 2 is again released, full pivotting can be carried out.

in a further version of the arrangement shown in figure 7,. this spring 30 is again omitted and the necessary t friction for the slider 12 is provided by means of a rubber or soft plastics insert 40 which engages the slider 12, thus doing away with the 'necessity for the bowed central arm 19 of the slider i2. in this way the slider i2 can be made as a solid sheet member.

6 it will be appreciated that various modifications may be made to the above described embodiments without departing from the scope of the invention. For example, the slider can be of any suitable shape, such -as round, the slider being provided with, the appropriate projections as stops for engagement with the shoulder.

7

Claims

V' CLAIMS

1. A lockback device for the wiper arm of a windscreen wiper comprising an arm member, a retainer carrying the arm member, an arm head for. attachment to a drive spindle and pivotted to the retainer, and a spring acting between the arm head and the retainer in a direction to urge the arm towards the windscreen with which the wiper is intended to be used, wherein the lockback device comprises a shoulder on the retainer and a slider moveable in the head between a first position in which it is posit - ioned in the line of movement of the shoulder to limit the pivotting movement between the arm head and retainer and a second position in which it 15. is clear of t-he shoulder or, the rletainer and p4=rm.i-ts- full pivoLlt-ing of the head and retainer.

2. A lock back device as claimed in claim 1, wherein the retainer, at its end pivotted to the arm head, is of channel shaped section so as to receive the arm head in the channel thereof, the shoulder being formed on the sidewall of the channel of the retainer and the slider is arranged to slide transversely relative to the arm.

3. A lockback device as claimed in claim 1 or 2, wherein the slider slides in one or more slots in the arm head.

4, A lockback device as claimed in claim 3, wherein the slider 12 is a trifurcated member having two outer limbs parallel to each other and a middle limb which is bowed am right angles to _the remaining two limbs so as to provide a frictional effect in the slot in the head.

5. A lockback device as claimed in claim 4, wherein the end of the slider away from the free ends of the limbs is bent upwardly from the plane of the outer two limbs and acts as an, operating handle

6. A lockback device as claimed in claim 3, 4 or 5, wherein the slider is formed with two stop elements one of which is intended to retain the slider in Tne slot(s> in the arm head and the other of' which is intended to iO engage behind the shoulder on the retainer.

7. A lockback device -as claimed in claim I or 2, wherein the slider is spring biassed towards its second position.

i5

8. A lockback device for the wiper arm of a windscreen wiper substantially as described herein- with reference to the drawings.

Published 1986 at The Patent office, state House, 66.71 High HOIbOrn, London WCIR 4TP. Further COPies may be obtained froin Salles The Paten e Branch, St Mary Cray. Orpington, Kent BR5 ome 3RD. Printed by MultiPlex terhniclues; Itd, St Mary Cray, Kent. con. 1/87.