AU711499B2

AU711499B2 - Snap assembly knuckles for windshield wiper blades

Info

Publication number: AU711499B2
Application number: AU50760/96A
Authority: AU
Inventors: Edward Burton
Original assignee: Trico Products Corp
Current assignee: Trico Products Corp
Priority date: 1995-04-20
Filing date: 1996-04-18
Publication date: 1999-10-14
Anticipated expiration: 2016-04-18
Also published as: AU5076096A

Description

I/UU/U11 28/5/91 Regulation 3.2(2)

AUSTRALIA

Patents Act 1990

ORIGINAL

COMPLETE SPECIFICATION STANDARD PATENT r Application Number: Lodged: Invention Title: SNAP ASSEMBLY KNUCKLES FOR WINDSHIELD WIPER BLADES The following statement is a full description of this invention, including the best method of performing it known to us 1 SNAP ASSEMBLY KNUCKLES FOR WINDSHIELD WIPER BLADES TECHNICAL FIELD OF THE INVENTION The present invention relates to improvements in automobile wiper blade assemblies and in particular to improved pivotal connections between primary and secondary yokes.

BACKGROUND TO THE INVENTION Wiper blade assemblies comprise an articulated superstructure supporting a wiper strip, in which the superstructure comprises a plurality of yokes interconnected by pivot joints with a series of secondary yokes connected releasably to the wiper strip along its length. The yokes are commonly made of a metallic material of inverted U or inverted channel cross section so as to have a back and a pair of opposed, parallel side walls extending downwards from the back, the side walls of a primary yoke being spaced sufficient distance apart to receive the secondary yokes in a nesting relationship.

Conventionally, the pivot joints between a primary and a secondary yoke may consist of a rivet with or without a plastic spacer, or a crimp joint over a plastic knuckle. The plastic spacer or knuckle usually consists of a back or web with a pair of opposed side walls or pair of cheeks arranged between the primary and secondary yokes at the joint to prevent noise caused by metal to o.: 20 metal contact. The plastic spacer or knuckle may also in some cases act as a pivot bearing.

Any rivet joint arrangement used in the prior art provides a labour intensive assembly method and is therefore relatively costly to produce. Crimp type joints as disclosed, for example, in Australian Patent Specification No.

532733, require during assembly, that the plastic knuckle be applied over the secondary yoke so that a pair of internal trunnions engage in aligned holes in the opposed side walls of the secondary yoke. In this configuration, externally extending trunnions on the knuckle must be engaged in aligned holes in opposed side walls of the primary yoke. To achieve this, it is necessary to start with the side walls of the primary yoke splayed apart so that they will fit over the external knuckle trunnions. Thereafter, the sidewalls must be plastically deformed or crimped inwardly to position the holes over the external trunnions to finish the joint. This procedure, however, has several disadvantages in practice. Firstly, the crimping step can have a deleterious effect on the paint work of the primary yoke possibly causing cracks or other defects. Secondly, crimping is difficult to perform accurately due to metal 'spring back' effects so that the joint might be crimped too tightly or too loosely.

US Patent Specification No. 4909653 discloses a pivot arrangement where a channel shaped plastic knuckle is provided with a solid circular pivot pin extending inwardly and outwardly from each side wall of the channel shaped knuckle with the outwardly directed pins being received in circular holes in the side walls of an outer metal channel section. Relative pivoting movement of the knuckle with the outermetal channel section is prevented via an enlarged end rib of the knuckle engaging with the terminal end edge of the outer metal channel section. The smaller and inner metal channel section is formed with keyhole like slots extending from the back of the channel section part way into each side wall such that the inwardly directed pivot pins of the knuckle can be pressed into a snap fitting relationship with a part circular lower end portion of the side wall keyhole like slots.

European Patent Specification Publication No. 0631914A1 also discloses wiper pivot joint arrangement with a plastics material insert located between the two main channel shaped sections. In this disclosure the insert is adapted to be sprung over the inner channel shaped section and the outer bushing of the insert has an annular section with a thickened section joining the enlarged end edge rib such that the annular section and the thickened section each cooperate with a keyhole like slot leading from the terminal end edge of the outer channel shaped section. Finally a separate pivot pin is inserted through the annular bushings so that it connects the channel sections and the insert together in the pivot joint.

Thus, the object of this invention is to provide an improved form of interconnection between the pivot joints of a wiper blade assembly which will permit improved assembly mechanisation and provide an effective joint construction while limiting the number of parts required and minimizing or avoiding the drawbacks noted above associated with existing arrangements.

SUMMARY OF THE INVENTION Accordingly, the present invention provides an improved pivot joint in a wiper blade assembly, said pivot joint including: a primary channel member having a base wall and a side wall depending from each longitudinally extending edge of said base wall; a secondary channel member having a base wall and a side wall depending from each longitudinally extending edge of said base wall located such that said secondary channel member nests within said primary channel member; an insert member of channel configuration having a base wall and a side wall depending from respective opposed edges of said base wall with said insert member located between said primary and secondary channel members; said insert member having a circular solid trunnion extending from each said insert member side wall and engaged within a circular bearing aperture in 15 a respective said side wall of either said primary or said secondary channel member permitting pivotal movement between said insert member and the primary or the secondary channel member engaged thereby; and said insert member further having a non-circular projection extending from each said insert member side wall in a direction opposite to the circular 20 solid trunnion, each said non-circular projection being engaged in a slot in a respective said side wall of either the primary or the secondary channel members by movement only in a direction transverse to longitudinal axes of the primary or the secondary channel members, said non-circular projection being complementary in shape to at least part of the slot in which it is engaged whereby rotation of said non-circular projection in said slot is prevented, said slots opening onto either an upper or a lower edge of the side wall in which the slot is formed and said slots further including retention means to retain the noncircular projections operationally engaged therewith.

According to a further preferred aspect, the present invention provides an improved pivot joint in a wiper blade assembly, said pivot joint including: a primary channel member having a base wall and a side wall depending from each longitudinally extending edge of said base wall; a secondary channel member having a base wall and a side wall depending from each longitudinally extending edge of said base wall located such that said secondary channel member nests within said primary channel member; an insert member of channel configuration having a base wall and a side wall depending from respective opposed edges of said base wall with said insert member located between said primary and secondary channel members; said insert member having an inwardly directed circular solid trunnion extending inwardly from each said insert member side wall and engaged within a circular bearing aperture in a respective said secondary channel member side wall permitting pivotal movement between said insert member and the secondary channel member engaged thereby; said insert member further having a non-circular projection extending *o* outwardly from each said insert member side wall, said non-circular projections 15 being engaged in a slot in a respective said primary channel member side wall by movement only in a direction transverse to a longitudinal axis of said primary channel member, said non-circular projection being complementary in shape to at least part of the slot in said primary channel member side wall in which it is engaged whereby rotation of said non-circular projection in said slot is 20 prevented, said slots in said primary channel member side walls opening onto a lower edge of said primary channel member side walls and said slots further including retention means to retain the non-circular projections operationally engaged therewith.

By the pivot arrangement defined above, ease of assembly is achieved by the insert member being capable of flexing over and fitting with the secondary channel member and this subassembly being capable of mechanised assembly with the primary channel member simply by pushing the non-circular projections into the apertures in the side walls of the primary channel section in a direction transverse to the channel sections rather than a more complicated and difficult procedure of mechanised assembly in a longitudinal direction of the channel members. Further the use of separate pivot pins are avoided thereby avoiding a separate assembly step and of course also avoiding the possibility that such separate pivot pins could become disengaged during use of the wiper blade assembly. Finally no metal forming or crimping steps are required with the primary or secondary channel members thereby ensuring against damage to paint work and of course ensuring that this difficult and extra assembly task does not have to be carried out.

According to a still further aspect, the present invention provides an improved insert member for use in a pivot joint of a wiper blade assembly of the type including a primary channel member having a base wall and a side wall depending from each longitudinally extending edge of said base wall, a secondary channel member having a base wall and a side wall depending from each longitudinally extending edge of said base wall located such that said secondary channel member nests within said primary channel member with the insert member located therebetween, said insert member being of channel configuration having a base wall and a side wall depending from respective 15 opposed edges of said base wall, said insert member further including a circular solid trunnion extending from each said insert member side wall adapted for engagement with a circular bearing aperture in a respective side wall of either the primary or secondary channel members of the pivot joint, said insert member further having a non-circular projection extending from each said insert member 20 side wall in a direction opposite to a said circular solid trunnion, each said noncircular projection being adapted for engagement with a slot on a respective side wall of either the primary or the secondary channel members by movement only in a direction transverse to a longitudinal axis of the insert member, said slot opening onto either an upper or a lower edge of the side wall in which the slot is formed, each said non-circular projection further being configured for retention in a said slot by cooperation with said slot and having a shape complementary in shape to at least part of said slot whereby rotation of said non-circular projection in said slot is prevented.

In accordance with a still further aspect, the present invention also provides an improved insert member for use in a pivot joint of a wiper blade assembly of the type including a primary channel member having a base wall and a side wall depending from each longitudinally extending edge of said base 6 wall, a secondary channel member having a base wall and a side wall depending from each longitudinally extending edge of said base wall located such that said secondary channel member nests within said primary channel member with the insert member located therebetween, said insert member being of channel configuration having a base wall and opposed side walls, said insert member further including a circular solid trunnion extending inwardly from each said insert member side wall with a non-circular projection extending outwardly from each said insert member side wall, each said non-circular projection being adapted, in use, for engagement with a slot in a side wall of the primary channel member by movement only in a direction transverse to a longitudinal axis of the insert member, said slot member opening onto a lower edge of the side wall in which the slot is formed, each said non-circular projection being further configured for retention in a said slot by cooperation S with said slot and having a shape complementary in shape to at least a part of S 15 said slot whereby rotation of said non-circular projection in said slot is prevented.

Several preferred embodiments of the present invention will now be described with reference to the accompanying drawings, in which: Figure 1 is a perspective exploded view of a first preferred embodiment of 20 a pivot joint assembly according to the present invention; Figure 2 is a perspective view similar to Figure 1 showing a second preferred embodiment; ~Figure 3 is a perspective view similar to Figure 1 showing a third preferred embodiment; and Figure 4 is a perspective view similar to Figure 1 of a fourth preferred embodiment.

Figure 1 illustrates a pivot joint 10 in a wiper blade assembly. Any wiper blade assembly might include a plurality of such pivot joints 10, each comprising a primary channel member 11 having a base wall 12 and depending opposed side walls 13. The pivot joint 10 further includes a secondary channel member 14 adapted to nest, when assembled, within the primary channel member 11.

6a The secondary channel member 14 has a base wall 15 and opposed depending side walls 16. Generally the primary and secondary channel members 11,14 are formed from metal sheet or plate as illustrated. An insert member 17, normally moulded from a suitable plastics material is provided for location between the primary and secondary channel members 11,14 such that the pivot point 10 is formed by the members 11,14 and the insert member 17. The insert member 17 is generally of a U shaped configuration with a base wall 18 and two opposed side walls 19,20. The base wall 18 may have a number of cut out regions 21,22 to limit the amount of plastics material utilized and to improve the ability of the side walls 19,20 to flex toward or away from one another.

As shown in Figure 1, the side walls 19,20 of the insert member 17 include a pair of solid circular trunnions 23 extending a short distance inwardly 00 0* 0 *00 a *o of the member such that these trunnions can be engaged in circular bearing apertures 24 in the side walls 16 of the secondary channel member 14. This sub assembly may be achieved by flexing the side walls 19,20 outwardly slightly and clipping the insert member 17 over the secondary channel member 14 to engage the trunnions 23 in the apertures 24. On the outer face 25 of each of the side walls 19,20 a non-circular projection 26 is provided which in this preferred embodiment conveniently has an outline shape generally configured like an A with two outer side edges 27,28 converging towards one another in an upward direction. The lower portion of the projection 26 has a recess 29 formed therein to create legs 30,31 which may conveniently also be spaced from the main outer face 25 of the side walls 19,20. This arrangement increases the flexibility of movement of at least the lower sections or legs 30,31 of the projection 26 toward one another. It will of course be appreciated that in another embodiment the projection 26 might be formed by a block with side edges 27,28 converging as 15 illustrated, no undercuts and top and bottom edges generally parallel to one another and to the base wall 18. The projection 26 is so configured that it will fit into a slot 32 in a respective part of side wall 13 of the primary channel member 11. The slots 32 open onto a lower edge 33 of the side walls 13 and their upper S•ends 34 are shaped to closely engage around the side edges 27,28 and the top edge of the projection 26.

The slots 32 further include retaining ledge means 35 that engage with the lower corners 36 of the projection 26 once the projections 26 have been forced up into the slots 32 into the upper end zone 34. Assembly of the pivot joint 10 is therefore achieved by relatively moving the subassembly of the secondary channel member 14 and insert member 17 into the channel of the primary channel member 11 with sufficient force to connect the projections 26 into the retaining zones 34 of the slots 32. In this condition a substantial bearing surface is established between the projection 26 and the edges of the slot 32 that prevent rotation of the insert member 17 relative to the primary channel member 11. At the same time, pivoting of the secondary channel member 14 relative to the primary channel member 11 is achieved by the pivotal action of the trunnions 23 in the bearing apertures 24.

Figure 2 illustrates a similar arrangement to that which is shown in Figure 1 but with an alternative preferred form of non-circular projections 26 and cooperable slots 32 in the primary channel member 11. In this embodiment, the non-circular projection 26 is formed by an upper circular boss section 50 and a lower section 51 having parallel vertical side edges 52,53 generally perpendicular to the lower edges 33 of the side walls 19,20 of the insert member 17. The width between the side edges 52,53 is slightly less than the diameter of the boss section 50 so as to form retaining corners 40,41 which are engagable with retaining ledge means 35 in the slots 32. The outlined shape of the slots 32 in this embodiment are generally the same as the outline shape of the projection 26. Figure 3 illustrates another very similar embodiment to that which is shown in Figure 2. In this further embodiment, the boss section 50 of the non-circular projection 26 includes a groove or recess 42 so as to improve the flexibility or capability of the laterally opposed edges 43,44 of the boss section 50 moving 15 towards one another to ease passage of the boss section 50 up the smaller lower section 45 of the slots 32 and thereafter enable them to spring back once the boss section 35 enters the upper section 46 of the slots 32. In both the embodiments of Figures 2 and 3, assembly is achieved by forcing the projection 26 into the slots 32 in a direction transverse to the longitudinal direction of the primary and secondary channel members until the boss section 35 is retained in the upper section 46 of the slots 32. It will of course be appreciated to those skilled in this art that other configurations of the non-circular projections 26 could also be utilized.

Figure 4 illustrates a still further preferred embodiment. In this case, a non-circular projection 26 similar to that shown in Figure 2 is provided extending inwardly of the side walls 19,20 of the insert member with the section 36 extending from the upper inner corner of the member 17 to the circular boss section 50. Further the secondary channel member 14 has slots 47 in the side walls 16 formed extending downwardly from the corners between the base wall 15 and the side walls 16. The circular trunnions 48 are in this embodiment arranged extending outwardly from the side walls 19,20 to be engaged in circular bearing apertures 49 in the side walls of the primary channel member 11. Assembly of such an arrangement is achieved by clipping the insert member 17 into the primary channel member 11 and thereafter forcing this subassembly and the secondary channel member together by engaging the noncircular projection 26 into the slots 47 in the side walls 16 of the secondary channel member. It will of course be further appreciated that the shape of the non-circular projection 26 and its cooperating slot 47 might be similar to any of the other embodiments disclosed herein or any other similar configuration.

0*

Claims

2. A pivot joint in a wiper blade assembly, said pivot joint including: a primary channel member having a base wall and a side wall depending from each longitudinally extending edge of said base wall; 11 a secondary channel member having a base wall and a side wall depending from each longitudinally extending edge of said base wall located such that said secondary channel member nests within said primary channel member; an insert member of channel configuration having a base wall and a side wall depending from respective opposed edges of said base wall with said insert member located between said primary and said secondary channel members; said insert member having an inwardly directed circular solid trunnion extending inwardly from each said insert member side wall and engaged within a circular bearing aperture in a respective said secondary channel member side wall permitting pivotal movement between said insert member and the secondary channel member engaged thereby; out wasaid insert member further having a non-circular projection extending outwardly from each said insert member side wall, said non-circular projections S"being engaged in a slot in a respective said primary channel member side wall by movement only in a direction transverse to a longitudinal axis of said primary channel member, said non-circular projection being complementary in shape to at least part of the slot in said primary channel member side wall in which it is engaged whereby rotation of said non-circular projection in said slot is prevented, said slots in said primary channel member side walls opening onto a lower edge of said primary channel member side walls and said slots further 2.including retention means to retain the non-circular projections operationally engaged therewith.
3. A pivot joint according to claim 1 or claim 2 wherein each said non- circular projection has lateral side edges extending generally transverse to the longitudinal axes of said primary and secondary members, each said non- circular projection having at least one widened section between said lateral side edges and at least one narrowed section between said lateral side edges, and wherein said widened section cooperates with said retention means to prevent removal of said non-circular projection from a said slot in which it is engaged.
4. A pivot joint according to claim 3 wherein said non-circular projection includes recess means located between said lateral side edges in the vicinity of a said widened section to improve the ability of said lateral side edges to flex inwardly at at least the vicinity of said widened section. A pivot joint according to claim 3 or claim 4 wherein at least part of the non-circular projection includes an undercut region.
6. A pivot joint according to any one of claims 3 to 5 wherein the lateral side edges converge from a said widened section at one end to a said narrowed section at the other end of each said side edge. .o S7. A pivot joint according to any one of claims 3 to 5 wherein the non- 0* circular projection includes a semi-circular section and a block section with the block section extending transversely toward either an upper or a lower edge of the insert member side wall, said block section having a width less than the diameter of said semi-circular section.
8. An insert member for use in a pivot joint of a wiper blade assembly of the type including a primary channel member having a base wall and a side wall .depending from each longitudinally extending edge of the base wall, a secondary channel member having a base wall and a side wall depending from each longitudinally extending edge of said base wall located such that said secondary channel member nests within said primary channel member with the insert member located therebetween, said insert member being of channel configuration having a base wall and a side wall depending from respective opposed edges of said base wall, said insert member further including a circular solid trunnion extending from each said insert member side wall adapted, in use, for engagement with a circular bearing aperture in a respective side wall of either the primary or secondary channel members of the pivot joint, said insert member further having a non-circular projection extending from each said insert 13 member side wall in a direction opposite to a said circular solid trunnion, each said non-circular projection being adapted, in use, for engagement with a slot in a respective side wall of either the primary or the secondary channel members by movement only in a direction transverse to a longitudinal axis of the insert member, said slot opening onto either an upper or a lower edge of the side wall in which the slot is formed, each said non-circular projection further being configured for retention in a said slot by cooperation with said slot and having a shape complementary in shape to at least part of said slot whereby rotation of said non-circular projection in said slot is prevented.
9. An insert member for use in a pivot joint of a wiper blade assembly of the type including a primary channel member having a base wall and a side wall depending from each longitudinally extending edge of said base wall, a secondary channel member having a base wall and a side wall depending from each longitudinally extending edge of said base wall located such that said secondary channel member nests within said primary channel member with the insert member located therebetween, said insert member being of channel configuration having a base wall and opposed side walls, said insert member further including a circular solid trunnion extending inwardly from each said insert member side wall with a non-circular projection extending outwardly from each said insert member side wall, each said non-circular projection being *adapted, in use, for engagement with a slot in a side wall of the primary channel member by movement only in a direction transverse to a longitudinal axis of the insert member, said slot opening onto a lower edge of the side wall in which the slot is formed, each said non-circular projection further being configured for retention in a said slot by cooperation with said slot and having a shape complementary in shape to at least a part of said slot whereby rotation of said non-circular projection in said slot is prevented. An insert member according to claim 8 or claim 9 wherein each said non- circular projection has lateral side edges extending generally transverse to the longitudinal axis of said insert member, each said non-circular projection having at least one widened section between said lateral side edges and at least one narrowed section between said lateral side edges.
11. An insert member according to claim 10 wherein said non-circular projection includes recess means located between said lateral side edges in the vicinity of a said widened section to improve the ability of said lateral side edges to flex inwardly at at least the vicinity of said widened section.
12. An insert member according to claim 10 or claim 11 wherein at least part of the non-circular projection includes an undercut region.
13. An insert member according to any one of claims 10 to 12 wherein the lateral side edges converge from a said widened section at one end to a said narrowed section at the other end of each said side edge.
14. An insert member according to any one of claims 10 to 12 wherein the ova* non-circular projection includes a semi circular section and a block section with the block section extending transversely toward either an upper or a lower edge of the insert member side wall, said block section having a width less than the **diameter of said semi-circular section. 9 9 A pivot joint in a wiper blade assembly substantially as described herein with reference to the accompanying drawings.
16. An insert member for a pivot joint in a wiper blade assembly substantially as described herein with reference to the accompanying drawings. DATED this 18th day of August, 1999. TRICO PRODUCTS CORPORATION WATERMARK PATENT TRADEMARK ATTORNEYS 290 BURWOOD ROAD HAWTHORN VICTORIA 3122 AUSTRALIA SKP/ML/JC DOC 7 AU50760/96 *sea 19C 00404