CA1202756A

CA1202756A - Windshield wiper blade

Info

Publication number: CA1202756A
Application number: CA000437212A
Authority: CA
Inventors: Charles T. Fritz, Jr.
Original assignee: Individual
Current assignee: Dtr Associates LP
Priority date: 1982-09-21
Filing date: 1983-09-21
Publication date: 1986-04-08
Also published as: AU546674B2; DE3333985A1; SE8305050D0; GB2127282B; GB2127282A; AU1916783A; IT1167207B; FR2533182B1; IT8322926A0; SE8305050L; GB8324702D0; FR2533182A1

Abstract

ABSTRACT OF THE DISCLOSURE
A windshield wiper blade made of a synthetic elastomeric material includes an elongated body having a longitudinal axis; at least three side by-side, longitudinally extending wiping ribs integral with the body, the wiping ribs projecting outwardly from the body and having outer ends lying in an arc which is concave toward the longitudinal axis of the body, the wiping ribs being constructed and arranged such that there is a squeegee rib with at least one scraping rib on each side thereof, the squeegee rib having a greater radial length than the scraping ribs; and a mounting rib integral with the body and projecting outwardly therefrom at a location essentially diametrically oppo-site the squeegee rib, the mounting rib providing a longitudinally extending hinge about which the body can swing in either direction, the arrangement being such that when the blade moves against a windshield the squeegee rib and the scraping rib or ribs on the side thereof facing in the direction of movement engages the windshield and the scraping rib or ribs on the other side of the suqeegee and facing in a direction opposite blade movement is out of contact with the windshield.

Description

3~ '7~
BI~C};GROUND OF T~IE I NVENTI ON

~ indshield wiper blades are u~ed to wipe ~way snow~, sleet~, rain wa~e~ or condensed moist~re alon~ wlth oil, lnsec~s, tree sap, dirt and other fore~lgn matter from a vehicle windshield. The blades should have a long, use ~ul 1 i f e to avold f requent replacement.
However~ it is well recogn;~ed that known wiper blades develop a ~endency to streak or smear and to wear out in the sense that longitudinal por~ions of the length o~
10 the blade cease to perform a useful cleaning action ~fter a relatively short period of useO ~hese disadvan-tages are difficult to eliminate because of ~he large number o~ variables, such as chemical resistance to ozone and sunlight, tear resistance, flexibilityt ten~
sile strength~ hardness, rigidity and abrasiveness of the ~lade and the uniformity o wiping pressure and con~
tac~ ~ith the windshield along the lenqth of the blade.
~any attempts have been made to improve wiper blade per-formance, as by pro~iding spec~al contours 1n the cro~s-section o~ th~ blade especially the wiplllg rib or ribs,~y selec~lon of blad~ material, by chemlcal treatment of the blade and by varying the design of the blade holder~

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Nevertheless, the problem oF s~reaking or smearing per~
sists.
The following United States patents are known to deal with various aspects of windshield wiper blades, including blade contour, material of construction and manueacturing techniques: 4,103,385; 3,903,560;
3,636,583; 3,5669432; 2,090,70~; 2,011,015; 2,179,~51;
1,940,329 and Des. 212,743.

The principal ob~ect o~ the present invention is to provide a wind~hield wiper blade which has improved non-streaking characteristics and longer operat~ng li~e than blades heretoore known. This object is achieved by providing the blade wi~h a uni~ue tubular body having a plurality of specially shaped and arranged parallel ri~ which crlgage ~he windshield in a special way during each wiping stroke. More specii-cally, the blade has a central squeegee rib of unique cross section with two scraping ribs, also of unique cross sectiQn~ on each side o the squeegee rib. The size, shape and arrangement of the ribs is such that in one direction of movement of the blade over the windshield the scraping ribs on one side of the ~queegee rib, i.e., the side facing in the direction of blade movement~ contact the glass and precede one edge of the squeegee rib across the glass, while the scr~ping ribs on the other side of the squeegee rib, i.e~, the side facing opposite to the direction of blade movement~ and `the opposite edge of the 3q~l~Ccge blade rem~in out of J5~

contact with the glas~. When the direction of the blade is reversed by the wiper mechanism, ~he blade rotates slightly about an axis parallel to the longitudinal dlmension of the blade and thereby brings the scraping ribs on the ~pposite side of the squeegee rib into con-tact with the windshield in position to precede the opposite edge o~ the squeegee rib across the glass.
Rotation o~ the blade also brings the tubular body into proper position Eor pushing heavy debris or snow ahead o~ the blade an~ supporting the blade against lateral distortion.
The blade configuration comprises a tubular body portion made up of two seml-circular sections of different diameter connected by radially extending shoulders. ~ive ribs project from the smaller diameter sections generally radially with cespect to the longitu-dinal axis o~ the bodyO The middle rib of the five constitutes the squeegee rib and is longer radially than the two scraping ribs. Diametrically opposite the sgueegee rib ls a T-shaped mounting rib which serves the dual purpose o providing a means by whi h the blade is attached to the windshield wiper mechanismj and Ellnc-tioning as a hinge which allows ~he blade to rotate at the reversal point o~ each wiping stroke so as to engage the scraping ribs on opposite sides of the squeegee rib with the windshield in the manner described above~
The preferred material for the blade is synthe-tic rubber r particularly an ethylenepropylene-diene polymer, such as "Nordel~ manu~actured by E. I~ duPont de Nemours ~ CoO, Inc. This material has been found to ~p 7 1- L~
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have an excellen~ combination of physical and chemical properties and it can be extr~ded in the multi-ribbed configurat1on described above~ In particular~ this material has been ~ound to be ex~remely durable in both the mechanical and chemical sense and to have an excellent balance o~ hardness, rigidity, flexibility, abrasive characteristics and resilience, such that a constructed embodiment of the present invention as described herein exhibits superior performance in terms of non~smear, non-squeak operation and long service life.
The extruded mul~i-ribbed blade of this inven-tion is further unique in that it can be very easily used to replace worn-out wiper blades o~ any design or length by cutting the required length from a longer length and then attaching the cut length to an existing wiper blade backing member with a simple universal clip.
The seller does not need to stock a large number o~ dif-~erent pre-cut lengths; he merely purchases ~rom the manufacturer a supply of clips and a long length of extruded blade in roll ~orm or individual packayes of a blade which would be the longest needed ~or any windshield (automotive, marine or aircraft). Whatever length ls required by the customer is cut to size and then attached to the customer's existing wiper blade holder. The blade does not h~ve to be contoured to fit an existing wiper blade holder because the clips are designed to cooperate with the previously mentioned mounting rib. The clips are also designed to cooperate with all or essentially all existing wiper blade 31.. ~2 V;Z~ r~5 ~
IlOlders. As a result, ~he blade is a universal replacement blade in tha~ it can be cut to the necessary length and easily attached to substantially all ex:istlng wiper blade holders In summary of the above, therefore, the present invention may be broadly defined as providing a windshield wiper blade made of a synthetic elastomeric material com-prising an elongated body having a longitudinal axis, a longitudinally extending squeegee rib integral with the body and extending radially therefrom, a plurali-ty of longitudinally extending scraping ribs integral with the body, -the scraping ribs projecting radially outwardly from the hody and having outer edges lying generally in an arc generated about the longitudinal axis, the squeegee rib having a greater radial l.ength than the scraping ribs, and a mounting rib integral with the body and projecting radiall.~ outwardly therefrom in a direction and at a location diametrically opposite the squeegee rib, the body comprising an upper semi-circular sectlon Eor the support of the mounting rib and a lower

2~ semi-circular section of relatively smaller diameter than the upper section for the support of the scraping and squeegee ribs, the upper and lower sections of the body being connect~d by a pair ~f radi.ally extending shoulders to effect latera stiffenlng of the blade, the inherent flexibility of the mounting rib providing a longitùdinally extending hinge about which the body can s~ing in either direction, the arrangement being such that ~hen the blade moves against a windshield the squeegee rib and at least one scraping rib on the side thereof facing in the direction of movement of the ~lade engage the ~:indshiel~.

C; d /'`".

5~
r~Rl]~F D~C~RlP'l'lON OF ~ DR~WINGS
Fi~ure 1 is a side elevatiorl~l view of the wiper blade of the ~resent invention mounted in a complementary wiper arm.
Figure 2 is a transverse cross-sectional view of the blade taken along the line 2-2 of Fig. 1.
Figure 3 is a view similar to Fig. 2 with the blade in con-tact with a windshield and moving to the left.
Figure 4 is a view similar to Fig. 3 with the blade movin~ to the right.
Figure 5 is a cross-sectlonal view of a blade in a universal mountin~ clip.

DETAILED DESCRIPTION OF THE PR~FERRED
EMBODIMENT OF THE I~VENTION
A wiper blade 10 in accordance with a constructed embodiment of the instant invention comprises an extruded synthetic polymeric elastomer blade adapted to be accepted in a wiper blade holder 12. The blade 10 comprises five integral ribs 14, 16, 18 t 20 and 22 which e~tend the length of the blade 10 and Froject generally radially relative to a longitudinal ax s 24 of an upper tubular body portion 25.
The central rib 18 co~prises a squeegee rib and the two ribs 14, 16 and 20, .';dt,' . ~ Sll~-2~7S~

22 on opposite sides of the squeegee rib 18 are scraping ribs, As will be described in greater speci~icity, the squeegee rib 18 is slightly longer than the scraping ribs 14, 16, 20 and 22.
~ eferring to Fig. 2, the dimensional rela-tionships between the upper tubular body portion 25, a support rib 26, a lower tubular body portion 27, and the ribs 14-22 are important to peoper unction of the blade 10 .
In a constructed embodiment Oe the invention, the dimensions set forth in the following ta~le, as applied to the dimensions of Fig. 2 of the drawing, resulted in a wiper blade ~hat exhibi~ed exceptional wiping characteristics:
Dimension Measurement in Inches a .300-.315 b .210-.225 c .160 d ~165 e .250 ~ .350 :9 .095 It is to be noted that the angle between the ribs 14, 16, 18, 20 and 22 is approxlmately 30 and the included angle of the points on the ribs 14, 16, 20 and 22 is approximately 45.
It is also to be noted that the squeegee rlb 18 has a concave end face 32 whereby a relatively sharp edge is presented to the surface being wiped.

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The radially projecting generally T-shaped sup-port rib 26 is de~ined by a leg portion 28 and a top flange portion 30. The leg portion 28 is su~ficiently ~lexible to serve as a hinge when the top portion 30 is fixedly secured in the wiper blade holder 12~ This form of hinge is known in the art as shown in, for example~
the aforemen~i~ned patents No. 3,903,560 and 4,103,385.
The flange portion 30 of ~he support rib 26 may be con~
toured as desired, provided that the contour can be gripped by the blade holder 12 in a manner that preclu-des relative rotation therebetween, As seen in Fig. 1, the blade holder 12 is o~
channel~shaped cross section having inwardly facing spaced-apart cllp portions 40 for retention o the top flange 30 of the blade 10. A web portion 42 of the blade holder 12i is adapted to be connected to the arm (not shown) of the wiper drive mechanism in the conven-tional manner.
~ s seen in Fig. 5, the wiper blade 10 of the present invention may be secured to a conventional blade holder S0 by individu~l spaced-apart clips 52 which are complementary to the T-shaped rib 26 on the blade 10.
The external configuration of the clips 52 may be adapted to any desired armO
As discussed previously, the preferred material for the blade 10 is extruded synthetic rubber, par~
ticularly ethylene-propylene-diene polymerO Such material and others are disclosed for wiper blade use in the aforementioned patent No. 4,103t385.

7~i6 In accordance with one feature of the instant invention, the upper portion of the tubular bady portion 25 o~ the blade 10 is larger in diameter than the lower portion 27 thereof so as to function as a snow and ice pusher, reducing scraping loads on the scraping ribs 14, 16 or 20, 22. Moreover, because the lower tubular body portion 27 is smaller in diameter than the upper body portion 25, it provides in conjunction with a pair of oppositely radially extendinq shoulders 34 and 36, a relatively stable ~upport plateorm for the ribs 14-22.
Figs. 3 and 4 illustrate the blade 10 as it moves in opposite directions over a windshield 60. In Fig. 3, the blade 10 is moving to the left as indicate~
by the arrow. In this mode, the body 25 of the blade 10 has rotated slightly counterclockwise due to the fric-tion between it and the windshield 60 and due to the flexibility of the neck portion 28 of the support rib 26. In this posi~ion the scraping ribs 14 and 16 and the squeegee rib 18 are in contact with the windshield 60~ In the event of snow on the windshield 60, the upper body por~ion 25 of the blade 10 functions as a pusher. Moreover, the shoulders 34 and 36 ~unction to stiffen the blade 10 against lateral deflectlon insuring proper contact of the ribs 14, 16 and 18 with the windshield 60.
The primary action o~ the ~craping ribs 14 and 16 ls to clear away heavy Eain~ snow, sleet and Eoreign material such as insects and road dirt. Ordina~ily, the ribs 14 and 16, being shorter and hence less 1exible than the rib lB, are flexed to a lesser extent ~han the 7~

rib lB due to contact with the windshield 60. The edge of the squeegee rib 18 in contact with the windshield 60 performs a squeegee action, i.e., removal of essentially all liquid Erom the windshield 60.
When the blade lO reaches the end o~ its stroke and reverses direction, as illustrated in Flg. 4, the blade 10 rota~es clockwise as a result oE friction bet-ween the blade 10 and the windshield 60, ~lexibility of the neck portion 28 of the support rib, and the inherent resilience o~ the blade 10 due to its tubular construc-tion, It is also to be noted ~hat the unique tubular cross section of the blade 10 maximizes the abillty thereof to conform to contours of the windshield 60 while minimizing lateral deflec~ion and its resul~ant d~stortion of the ribs 14 22~ It will be seen that the edges of all the ribs are sharp at ~he point o~ contact with the windshield.

While the preferred embodiment of the inven-tion has been disclosed, it should be appreciated that the invention is susceptible of modiication without departing ~rom the scope of the following claims.

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Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A windshield wiper blade made of a synthetic elastomeric material comprising an elongated body having a longitudinal axis, a longitudinally extending squeegee rib integral with said body and extending radially therefrom, a plurality of longitudinally extending scraping ribs integral with said body, said scraping ribs projecting radially outwardly from said body and having outer edges lying generally in an arc generated about said longitudinal axis, said squeegee rib having a greater radial length than said scraping ribs, and a mounting rib integral with said body and projecting radially outwardly therefrom in a direction and at a location diametrically opposite said squeegee rib, said body comprising an upper semi-circular section for the support of said mounting rib and a lower semi-circular section of relatively smaller diameter than said upper section for the support of said scraping and squeegee ribs, the upper and lower sections of said body being connected by a pair of radially extending shoulders to effect lateral stiffening of said blade, the inherent flexibility of said mounting rib providing a longitudinally extending hinge about which said body can swing in either direction, the arrangement being such that when said blade moves against a windshield the squeegee rib and at least one scraping rib on the side thereof facing in the direction of movement of said blade engage the windshield.

2. A wiper blade as in claim 1 wherein there are two scraping ribs on each side of said squeegee rib.

3. A wiper blade as in claim 1 or 2 wherein said shoulders are substantially the same lengths as said scraping ribs.

4. A wiper blade in accordance with claim 1 or 2 wherein said squeegee rib has a concave surface at the windshield engaging end thereof defining two relatively sharp edges, one of said edges being engageable with said windshield upon movement of said blade in one direction and the other of said edges being engageable with said windshield upon movement of said blade in the opposite direction.

5. A wiper blade in accordance with claim 1 or 2 wherein said scraping ribs have a sharp edge defined by the intersection of a rib sidewall extending generally radially with respect to a central axis of said upper and lower semi-circular sections and an end face extending at an angle of approximately forty-five degrees to said rib sidewall and angled toward said squeegee rib.