CA2037400A1 - Windshield wipers - Google Patents

Abstract

ABSTRACT
A mount for supporting a windshield wiper blade has first and second shells hingedly joined. The shells form an inside channel having an exterior surface. Wiper support means carried by the shells support the wiper blade disposed in the channel. The exterior surface is so shaped, disposed and arranged to provide a substantial shield against direct sunlight for the support means and for the wiper, and an external surface to react with an airstream and to be visible as a style.

Description

l 2~37~ 4299 l ¦ WINDSHIELD WIPERS

2 ¦ ipecification 3 ¦ Fleld of the Invention 4 ¦ Thi6 invention relates to windshield w~pers.

5 ¦ Backaround of the Invention 6 ¦ The wiping o~ a flat planar windshield to remove water and 7 ¦ grime does not involve any special geomeitrical problems. It i8 8 ¦ merely necesi~ary to u,iove a straight linear blade along a flat 9 ¦ siurface.
However, very signiflcant problems arise when th~ wiper i~
ll to wipe along the typeis of severely bent surface~i u3ed for l2 windshieldii of automobiles of very styliah or very 11 aerodynamically efficient shapesi. When the wiper i8 near the 14 zenith of its movement, the contact may be anywhere ~rom straiyht to gently but substantially bent. At itisi lowest point, lt often l6 extends along a very pronounced curve, and in between the~e 17 po~iitions the shape of the line contact undergoes chan~es which 18 often are rat~er complex.
19 The art has responded by making the blade quite flexible i~io it can conform to the windshield surface, and to mount it to a 21 support which will pre88 it as closely as po6slble to the 22 windsihield surface, ~nd wlth a hopefully unifor~i s~rface contact.
23 The conventional arrangement is to provide articulation~i in 24 the mounting which apply a force to the blade to pre6is it against the windE,ihield at a plurality of points - usually four or more.
26 Then the theory i8 that the short blade segments between these 27 points will follow the surface of the w~nd~hield.
28 Asi might be expected, thei~e efforts are at least partially 29 successful, but they become leas effective at higher vehicl~
speeds due to the buffeting and ~erodynamlc lift of the 31 windstream. Under these circumistance~, a 6ingle blade oft~n 32 leaves broad streaks of unwiped windshield, ~ui3t when and where ~EIlprn9~ ll mnilin~ loi I numb~ Z & r6" f Z
1 L~

2~3~0~ 4299 1 wiping i8 mo6t needed.
2 ¦ The art has r~sponded with double wipers, using two blade~
3 ¦ inste~d of one. It i8 readily theorized that a second blade may 4 ¦ well wipe where the first blade failed. Unfortunately thls 5 ¦ simplistic solution bring~ with it new problems.

6 ¦ First, because the wiper as~embly must be fitted to an 7 ¦ actuator arm which both moves the wiper acros~ the wind~hield and 81 pre~se6 the blades agalnst it, the unit loadin~ on each blade i~
9¦ reduced by half. Thu~ the efficiency of the individual blade i~

10¦ reduc~d.

11¦ Second, th~re i8 a reglon between the blades ln which grime 12¦ and water i~ moved back and forth until it either drains out the 13¦ bottom, or i8 centrifugally eJected. o~ cour~ it continues to 14¦ be replaced, and there exists between the blades a constant 15¦ "re~ervoir" of water and grlme for the les6-efflcient blades to 16¦ work against.

17 Even more, because the load on conventional wip~r motor 1 18 doubled (the drag on wipers having been doubled), the failure 19 rate of these motors i8 notlceably increased. For that matter, so is the C09t of two wiper blades instead of only on~.
21 A 6ingle blade wiper with maximum load against the 22 windshield i8 much to be pre~erred.
23 Known exlsting mounting means for ~upporting blade~ with 24 application of force at four or more locations ~hows a rather pedestrian approach. In one type of device, a rlgid housing 26 supports a palr of spring-loaded pivotal beams, each of which i~
27 attached at two polnts to ~he blade. Thi~ device ~uffers from a 28 lack of accommodation to account for severe change~ in wind~hield 29 ~hape experienced ~y the two beams.

In another type, the support itself is articulated, and its 31 articulations 60mehow exert a pressing force agalnst the blade at 32 a plurality of points. It i8 common for these ar~iculation~ to l 2~ 4299 - l be pivotally biased relatively to one anoth~r with a coil spring.
2 ¦ The problem her~ iB that the ~orce excited by the coil spring i8 3 ¦ a functlon of the relative angular position of the art~culations.
4 ¦ Thus it i~ les8 in some position~ than in others- uYually ju~t 5 ¦ when the force is most needed.

6 ¦ It i8 an ob~ect of this invention to provide an articulation 7 with spring-biasin~ means whose bias force doe~ not appreciably 8 decrease when the articulations "~old" toward one another to 9 follow a severely curved contour.
Because snow, mud and ~lush are also problems, it i8 an ll object of this invention to provide a construction which slou~h~
12 off such materials, and which tends not to pack up wi~h them.
l3 Wiper blade6 face severe conditions even when not in use.
14 One of them i8 aging that occurs when the blade is exposed to sunlight. It is an ob~ect of this invention to provide shell 16 means which substantially shield the blades from direct sunlight.
17 Yet another problem faced by wiper b~ades i8 the need for 18¦ the blade to wipe on a side respective to its instant direction l9¦ of motion, and preferably with a favorable angle of attack. Any 20¦ lifting force which moves the blade away fro~ it~ pre~erred angle 21 reduces the effectiveness of the blade. Aerodynamlc llft~ng and 22 turbulent air situations can cause these ~ituations. So can 23 uncompensated drag as the blade moves along the wind6hie~d.
2~ ¦ It i8 an object of thls invention to provide a ~hell for 25~ supporting the blade whose shape can resl6t torque cau~ed by the 26 windstream, and which can react with the air~tream to supplement 27 the force applied by the mounting arm.
28¦ ~rief Descriptio of the Invention 29 A wiper accolding to this invention includes a mounting comprising a pair of shells hinged together for relative rotary 3l movemen~ around a hinge axis. The hinge axis will normally be at 32 ¦ least reasonably parallel to the windshield, that ~6, parallel to 2~3~ 4299 l ¦ a tangent to it.
2 ¦ The mounting i8 attached to the actuating arm at the hlnge, 3 ¦ an exerts a force pre6sing the wiper toward the wind~hield in a 4 ¦ conventional manner.
5 ¦ Bias means bia6es the shell~ toward a closed position 60 as 6 ¦ to exert a ~orce again~t a wiper blade at each o~ the extreme 7 ¦ ends.
8 A rocker arm 18 pivotably mounted to the hinge wlth a branch 9 ¦ on each side of it. Thu~ lt i8 forced toward the wind~hield by 10¦ the spring ~orc~ of the actuator arm.
11¦ The above provldes few points of attachment for a wlper 12¦ blade, one at the distal end of each 6hell, and one at each free 13¦ en of the rocker arm.
14¦ According to a preferred but optional feature of the 15¦ invention, the bla~ means i8 a leaf-type spring reacting betw~en 16¦ the hinge and the 6hells, which provides a ~pring bia6 les~
17 ¦ sen~itive to the angular relation~hip of the shell~ than provided 18¦ by a conventional coil spring.
19¦ According to another preferred but optional feature of the 20¦ inven~ion, the shells provide a substantial ~hadlng 6hield 21¦ protecting the top and much of the sides of a wlper blade from 22¦ sunlight.
231 According to yet another preferred but optlonal feature of 241 the invention, the shells may be aerodynamically shaped to cause 251 a ~orce reaction with the windstrea~ tending to add to the forces 26¦ holding the wiper against the windshield, including, if desired, ~71 torque connecting sur~aces to re6ist twi~tlng of the mount by the 2~1 airstream.
291 The above and other eatures of thi~ invent~on will b~ fully 301 understQod from the following detailed descrlption and the 31¦ accompanying drawing~, in which:
321 ~//

~374~ 4299 1 ¦ Brief Descri~tion of the Drawin~s 2 ¦ Fig. 1 i~ an axial sec~ion of tAe presently-preferred 3 ¦ embodiment of the invention, taken at line 1-1 in Plg. 2, the 4 structure being symmetrical, and part of one side being deleted 5 ¦ for simpliclty of disclo6ure;
6 Fig. 2 i~ a bottom view o~ Fig. 1;
7 Fig. 3 is a v~ew slmilar to Flg. 1 ~howing the devlce ln a 8 different pO8 i tion;
9 Fig. 4 is a cros6-sectlon of the ~hell of Fig. 1, only, taken at line 4-4 in Fig. l;
11 Flg. 5 ls an axial cross-~ectlon of another embodl~ent of 12 the invention;
13¦ ~ig. 6 i8 a bottom view of Flg. 5;
14 ~ig. 7 is a cros~-section taken at line 7-7 in Fig. 5;
Fig. 8 i8 a cross-sectlon ta~en at llne 8-8 in Flg. 5;
16 Fig. 9 i~ a cross-section taken at line 9-9 in Fig. 6;
17 Fig. 10 18 a top view of another embodlment of the 18¦ invention, the structure being symmetrical, a~d part of on~ ~ida 19¦ being deleted for simpllclty of dl~closure;
Flg. 11 is a side vlew of Fig. 10 wlth the device in one 21¦ position; and 22 Flg. 12 i5 a view similar to Flg. 11 wlth the devlce ln a 23 different posltion.
241 Detailed DescriDtion of the Invention I
251 The presently preferred embodiment of a mount 20 according 26 to the invention i8 ~hown in ~ig. 1. Its purpo~e i8 to hold a 271 conventlonal wiper blade 21 against a wlndshield (not ~hown) and 28¦ draw it acro3s the wlndshield under the power o~ a conventional 29 o~cillat$ng actuator arm carried by the vehlcle.

The mount include~ a pair of shells 25,26 which are hinged 31 together by a hinge pin 27. The hlnge pln has a central shaft 28 32 and flanges 29,30 to hold the shells together and enable th~m to 2~37~ 4299 1 ¦ ro~ate relative to one another around hinge axi8 3~. In 2 ¦ operation, the hinge aX18 Will be as close to parallel a~
31 pos~ible to a tangent to the wlnd~hield. Of cour~e thi~
4 situation will vary, depending on the geometrles of th~
sl situation.
6 A bias spring 35 ("bias mean~") p~eferably formed as a leaf 7 spring, has a central portion 36 that bear~ aga~nst the hinge 8 shaft and two arm~ 37,38 whlch fit into respective recesses 9 39,40, in the shells. As 3hown in Figs. 1 and 3, the efPect of the blas means 18 to tend to "fold" the shell~ toward one 11 another, thereby tending to press the ends 41,42 of the shell3 12 toward the wind~hield. In the drawing~, the end portions of 13 shell 25 have been omitted. They ar~ the ~irror lma~e of the end 14 portions of ~hell 26.
A rocker beam 45 i8 pivotally mounted to the shaft of the 16 hinge pin. It rocks around the hinge pin~, and i~ bia~ed toward 17 the windshield by force exert~d on the hin~e pin by the actuato~
18¦ arm. The rocker beam has ar~a 46,4~ on opposite ~des oP the 19¦ hinge pin.
This conRtruction provides four polnts of attachment ~or the 21¦ wiper blade, points 50,61 (point 50 being on the un~hown end o~
22 shell 25) at the end~ of the shells, and 52,53 at the ends of the 2~ rocker beam.
2~ This i~ a fully functional wlper mount whlch wlll properly press a flexible blade against a wide range of windshield 26¦ contours.
27 As best ~hown in Fig~. 1 and 4, the shells have a 28 longitudinally extending central portion 60 which faces into the 29 air~tream. ~ skirt 61,62 on each slde of the Gentral portlon makes a reasonabl~ clo~e approach ~o the windshield ~o as to 31 provide as much ~hielding of the wiper blade from ~unllght as 321~ pos~ible- o cour8e there must be ouffici~nt clearanc~ that the ~ 203740~ 4299 1 ¦ shell does not contact the wind~h~eld, and to permit exit of 2 ¦ water and grime. Thi~ forms a channel 65 in the shell~ to 3 ¦ receive support means for a wiper blade and much of the wiper 4 ¦ blade itself. End flange~ such a~ flange 65a clo~e the in~ide 5 ¦ channel~ in the shells.
6 ¦ ~f deaired, a 6poiler tab 66,67 can extend longitudlnally 7 ¦ along the shells at one side thereof. It ~lopes upwardly and 8 ¦ away from the windshield side~ of the mount. Its aerodyna~ic 9 ¦ effect is to add force to hold the mount toward the wind~hield 10¦ when subjected to an alrstream. This counters some of th~ llft 11¦ which the airstream may have given to the mount.
12¦ The mount of Fig. 3 shows a gap 70 between the ends of the 13¦ ~hell. In the more styl~h application~, this ~8 unde~irable.
1~¦ Figs. 10-12 shows the u~e of a flange 71 on one ~hell 72 15¦ overhanging part of shell ~3 ~o as to present a more agreeable 16¦ appearance.
17¦ Also, especially for hlgher velocity installations, 18¦ additional stabillty at the tips is sometimes desirable in order 19¦ to counter the torque exerted by the spoiler. Figs. 10-12 20¦ show the use o~ a ~kirt tab 75 at the end of the ~hells. The~e 21¦ are configured to apply an addltlonal force on the tlps to force 22¦ them toward the windshield and to counter torque.
231 As best ~hown in F1~. 5-9, the central portion 80 of ~hell6 241 81 and 82 shell may have rounded external surface 83, almost 251 s~mi-circular, extendlng in the longltudlnal directlon. This 26¦ configuration, wh11e also suitable for forwardly facing 271 windshield~, finds it6 be6t applicatlon as a rear window wiper, 28¦ because it reduces the effects of turbulence on it. It holds to 291 the ~urface better, and sheds mud, ice and snow.
301 The term "windshield" a~ used herein includes any surface 31¦ expo6ed to airstream~ generated by movement of the vehlcle. Thls ~21 includes not only the forwardly-facing windshield, but al~o rear ~ 2~3~ 4299 1 ¦ shields 8uch a~ rear window~, and windows on hatchbacks or rear .
2 ¦ doors, for example.
3 ¦ The use of a leaf spring al~o offers advantages in that it8 4 ¦ end~ which bear against the plastic shell material have a 5 ¦ substantial bearing area. ~here re~ults much le65 long-term 6 ¦ damage to the shell material, compared with the thin-wire contact 7 ¦ made by the ends of a coll spring. ~owever, coil spring~ are 8¦ included herein within the definition of "bia~ means"
9¦ The shells can be made of a 61ick-surfaced plastic, for 10¦ example nylon, which tend~ to shed snow, mud and ice. A180 11¦ importantly, it can readily be molded to shape~ which are 12¦ attractive and efflcient. The concept of using a shell enables a 13 whole new fleld of styllng and performance concepts to be 1~¦ employed 15¦ This invention is not to be limlted by the embodiment~ shown 16¦ in the drawings and de~cribed in the description, which i~ given 17¦ by way of example and not of limitation, but only in accordance with the sco e of the appended claims.

Claims (8)

1. A mount for supporting a windshield wiper blade comprising: a first and a second shell; hinge means hingedly joining said shells for rotation around a hinge axis, said shells forming an inside channel and having an exterior surface; wiper support means carried by said shells to support said wiper blade disposed in said channel, said exterior surface being so shaped, disposed and arranged to provide a substantial shield against direct sunlight for said support means and for said wiper, and an external surface to react with an airstream and to be visible as a style.

2. A mount according to claim 1 in which said exterior surface includes a spoiler tab extending along each said shell, so disposed and arranged as to press said shell against the windshield when reacted on by an airstream.

3. A mount according to claim 2 in which a trim skirt is formed on each said shell on its side opposite from said spoiler to counteract torque caused by said spoiler.

4. A mount according to claim 1 in which a flange on one of said shells projects over the other said shell to cover the region where the hinge pin is located.

5. A mount according to claim 1 in which bias means said biases said shells towards a closed position.

6. A mount according to claim 5 in which said bias means comprises a leaf spring opposed between said hinge pin and said shells.

7. A mount according to claim 1 in which a rocker beam is disposed in said channel and hinged to said hinge pin, said rocker beam having a pair of arms, whereby a wiper blade can be mounted to both of said arms and to the free ends of the shells to forced against a windshield.

8. A mount according to claim 1 in which said shells are rounded in lateral cross-section, the better to resist accumulation of mud, ice and snow.