Note: Descriptions are shown in the official language in which they were submitted.
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Compliant Force Distribution Arrangement for Window Wiper
Relationship to Other Applications
This application is a continuation-in-part of United States Serial No. 08/678,049, filed
July 10, 1996, which is a continuation-in-part of United States Serial No. 08/369,803 filed
5 January 9, 1995, now abandoned.
Background of the Invention
FIELD OF THE II~VENTION
This invention relates generally to arrangements for distributing an input force to a
plurality of predetermined locations, and more particularly, to an arrangement wherein an input
10 force, such as that which is applied by a windshield wiper ann is distributed to a plurality of
locations in predeterminable ma~,nitudes along a compliant member, such as a windshield wiper
blade.
DESCRIPTION OF THE RELATED ART
Conventional windshield wiper arrangements employ a plurality of metallic beams pivotally
15 coupled to one another. The respective beams, which generally are not resilient or spring-like,
are coupled to a windshield wiper blade at their free ends, and the pivoting of the beams with
respect to one another appl oximates compliant bending of the windshield wiper as it travels across
the windshield wiper. One goal to be achieved, however, is to provide a compliant support
mechanism that, within predeterminable ranges of displacement of the windshield wiper blade in
20 the direction of the windshield, cause a force to be directed by the windshield wiper blade
substantially uniformly along its len~gth onto the surface of the windshield, of a magnitude
sufficient to perform the desired windshield wiping function, and for a given u indshield contour.
The conventional windshield wiper support arrangement, with its plurality of cantilevered
beams, cannot achieve a truly compliant functionality, as it stores within itself little, if any,
25 potential energy. Instead, the arrangement of pivotally attached beams merely approximates a
truly compliant mechanism. A further problem with the known arrangements lies in the fact that
the cantilevered beams have a limited range of displacement in the direction toward the
windshield. A beam cannot be displaced beyond the point where its other end will stop against
a sequentially superior beam. The limitation on the amplitude capacity, and hence on the
30 ~ ted compliance effect, places limitations on vehicle designers, as conventional windshield
wiper support systems cannot perform adequately when the windshield surface contour has a
relatively small radius of curvature anywhere in the wiping path.
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In addition to failing to achieve a compliant function, the ~nown windshield wiper support
arrangement is implemented at significant complexity and expense. In most cases, the pivoted
beams are made of a metal, that typically is highly reflective of light and subject to corrosion upon
exposure to the elements. In order to prevent the glare of the sun on the eyes of the operator of
5 the vehicle, as well as to protect against corrosion, each such pivoted beam must have a non-
reflective coating applied thereto. This, of course, is per se a costly step that is rendered more
expensive and critical when it is realized that the coating process must be executed with accuracy
and precision lest the coating material effect adversely the inter-beam pivot couplings. There are
numerous problems that can arise when painted or otherwise coated surfaces move pivotally with
10 respect to one another. If the coating is installed prior to assembly of the product, the coating,
at least partially as a result of its thickness, will increase the width of the beams, and decrease the
size ofthe apertures through which the pivots are installed. On the other hand, if the product is
coated after assembly, the coating process is more complex to avoid leavin~ areas uncoated, and
of course, the coating will tend to accumulate at the pivot joints and at the places where the
15 beams communicate with one another. An overly thicl; coating causes interference fits and
abrasion of the coating, while a coating that is too thin will wear prematurely as a result of
exposure to the elements. Clearly, coatings will produce problems irrespective of the point in the
m~nllf~cture of the product at which they are applied.
There is a need, therefore, for a windshield wiper support arrangement that overcomes the
20 problems described hereinabove, and others.
It is, therefore, an object of this invention to provide a windshield wiper frame
arrangement that is simple and inexpensive, and whicl1 does not requirc a complex multi-pivoted
interconnection between a windshield wiper actuator arm and the windshield wiper blade.
It is another object of this invention to provide a windshield wiper frame arrangement
25 having precisely controllable compliance characteristics in terms of both, force and deflection.
It is also an object ofthis invention to provide a windshield wiper frame arrangement that
avoids the need for mechanical links and joints.
It is a further object of this invention to provide a windshield wiper frame arrangement that
can simply and inexpensively be manufactured as an integral unit, and that does not require
30 subsequent painting.
,
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It is additionally an object of this invention to provide a windshield wiper frame
arr~n~ment that can be manufactured in a wide variety of aesthetically pleasing configurations,
while ret~ining high compliance and strength characteristics.
It is yet a further object of this invention to provide a windshield wiper frame arrangement
5 that has a compliance capacity that can easily and inexpensively be made to achieve a specific
compliance characteristic for a windshield having a predetermined surface contour, or a group of
windshields having a predetermined range of surface contours.
Summary of the Invention
The foregoing and other objects are achieved by this invention which provides, in
10 accordance with a first windshield wiper arrangement aspect of the invention, a windshield
wiper arrangement for a windshield of a vehicle, the windshield wiper arrangement being
coupled to a windshie]d wiper ann that is coupled at a first end thereof to the vehicle and at
a second end thereof to the windshield wiper arrangement for applying a force thereto with
respect to the vehicle. The force is applied in a first direction that urges the windshield wiper
15 ~rr~ngement toward the windshield, and a second force is applied which moves the windshield
wiper arrangement in a second direction across the windshield. The windshield wiper
arrangement has a windshield wiper blade coupled thereto for communicating with the
win(l~hi~ld of the vehicle. In accordance with the invention, the windshield wiper arrangement
is provided with a windshield wiper blade support system that is integrally formed of a resilient
20 material. The windshield wiper blade support system has a primary beam having first and
second and portions arranged axially distal from one anotl1er. The primary beam additionally
has a central portion between the first and second ends arranged for coupling with the
windshield wiper arm. There is additionally provided a plurality of resilient members, each
having first and second ends, the first ends of the resilient members being coupled to, and
25 axially along, the primary beam. The second ends thereof are arranged to be compliantly
displaceable along respective substantially linear paths of compliance. Each substantially
linear path of compliance is substantially parallel to the first direction, and is axially transverse
with respect to the primary beam. There additionally is provided a plurality of wiper blade
coupling arrangements, each coupled to the second end of a respectively associated one of the
30 plurality of resilient members, for coupling with the windshield wiper blade.
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In one embodiment of the invention, there is provided a plurality of resilient
interconnection elements integrally formed with the primary beam, each for coupling the
second ends of sequentially adjacent ones with the plurality of resilient members to one
another. In a further embodiment, a pair of further interconnection elements is further
5 provided for coupling predetermined ones of the second ends of the plurality of resilient
members to respective ones of the first and second ends of the primary beam.
In a further embodiment, wherein the windshield wiper is of the type having an
elongated blade support extending thereamong for a length that corresponds to the distance
between the first and second ends of the primary beam, and also has a predetermined width
10 and thickness, each of the wiper blade coupling arrangements is provided with an end pad
coupled to the second end of a respectively associated one of the plurality of resilient
members. The end pad in this specific illustrative embodiment of the invention has a width
that is predetermined in response to the width of the elongated blade support. Additionally,
there are provided first and second windshield wiper blade engagelnent members integrally
15 formed with the respective end pad and extending substantially normal to the end pad for
engaging across the width of the elongated blade support.
In a further embodiment, the first and second windshield wiper blade engagement
members are disposed in an axially staggered arrangement on the end pad.
In one specific illustrative embodiment of the invention, the resilient members are each
20 configured to form a substantially V-shaped resilient element formed of first and second
resilient beams coupled to one another to form a resiliently variable angle therebetween. The
substantially V-shaped resilient element has first and second ends. In accordance with this
embo(lim~nt, there is additionally provided a plurality of first coupling arrangements, each for
coupling an associated one of the first ends of the substantially V-shaped resilient elements to
25 the primary beam. A plurality of second coupling arrangements are provided each for
coupling an associated one of the second ends to a respectively associated one of the end pads.
Each of the substantially V-shaped resilient elements and the associated first and second
coupling arrangements are configured whereby an associated one of the end pads is
compliantly displaceable along respective counter-arcuate paths defined by respective ones of
30 the first and second resilient beams. The counter-arcuate paths combine to form the respective
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substantially linear path of compliance that is substantially parallel to the first direction and
axially transverse with respect to the primary beam.
In accordance with a further windshield wiper arrangement aspect of the invention,
there is provided a windshield wiper arrangement for a windshield of a vehicle, the windshield
5 wiper arrangement being coupled to a windshield wiper arm that is coupled at a first end
thereof to the vehicle. a second end of the windshield wiper arm is coupled to the windshield
wiper arrangement for applying a force thereto with respect to the vehicle in a direction that
urges the windshield wiper arrangement toward tl1e windshield, and which moves the
windshield wiper arrangement across the windshield. The windshield wiper arrangement has
10 a windshield wiper blade coupled thereto for communicating with the windshield of the
vehicle, and, in accordance with the invention, there is provided a windshield wiper blade
support formed of a resilient material. The windshield wiper blade support has a primary
beam arranged to couple with the windshield wiper arm. There is additionally provided a first
compliant beam having a first end for coup]ing to the primary beam, a second end for coupling
15 to the windshield wiper blade, and a resilient portion between the first and second ends for
bending resiliently in response to a force applied between the primary beam and the
windshield wiper blade.
In one embodiment of this second aspect of the invention, the first compliant beam has
a substantially elongated configuration with an axis thereamol1g~ The first compliant beam is
20 arranged with respect to the windshield wiper blade whereby a principal component of the
force applied by the windshield wiper blade to the first compliant beam is applied substantially
transverse to the axis of the first compliant beam.
In an alternative embodiment of the invention, the force applied by the windshield
wiper blade to the first compliant beam is applied substantially axially at the second end of the
25 first compliant beam.
In accordance with a further embodiment of the invention~ there is additionally
provided a first resilient coupling portion for resiliently coupling the first compliant beam to
the primary beam. There is additionally provided a second compliant beam coupled to the first
compliant beam. In a specific illustrative embodiment of the invention, the second compliant
30 beam is arranged intermediate of the first compliant beam and the windshield wiper blade, and
is provided with an arrangement for couplil1g with the windshield wiper blade.
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In a still further embodiment, there is provided a second resilient coupling portion
integrally formed with a first compliant beam for resiliently coupling the second compliant
beam with the first compliant beam. In this embodiment, the first end of the second compliant
beam is adopted to engage with the windshield wiper blade.
In accordance with a further aspect of the invention, a compliant force distribution
arrangement is formed by an inventive process, the process including the steps of:
forming a primary beam member;
forming a first compliant beam member integrally with the primary beam member,
forming a plurality of force output portions integrally with said first compliant beam
member, said force output portions each being resiliently displaceable in response to the
application of a force across said first compliant beam member.
In one embodiment of this aspect of the invention, the first compliant beam member comprises
a resilient element having a substantially S-shaped configuration.
In a further embodiment, there is provided the step of forming a second compliant beam
member resiliently coupled to, and integrally formed with, the first compliant beam member. The
first and second compliant beam members form, in this specific illustrative embodiment of the
invention, a substantially V-shaped resilient element.
In an alternative embodiment, there is provided the step of forming a second compliant
beam member resiliently coupled to, and integrally fonned with, the first compliant beam member
to form a tiered arrangement of resilient elements. Persons of skill in the art can configure
multiple-tier resilient beam arrangements that rely on the integrally fonned resilient coupling
portions to provide the necessary compliance characteristics the relatively firm subordinate
beams. Such resilient beams can be tiered, wl1ereby the overall compliance characteristic of the
windshield wiper blade support arrangement is responsive to the resilience characteristics of the
beams themselves.
In an advantageous embodiment, the steps of forming a primary beam member, forming
a first compliant beam member integrally with the primary beam member, and forming a second
compliant beam member integrally with said first compliant beam member are, in one embodiment,
performed simultaneously during performance of a step of molding. That is, the process can
incorporate the various forming steps in a molding operation. Alternatives to the molding step,
also wherein the various portions of the apparatus are simultaneously formed, include extrusion,
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casting, stamping, or any other process of manufacture that. in light of the teaching herein, is
deemed appropriate by persons of skill in the art.
Attention on the part of the designer should be directed to the choice of materials,
particularly in regard of certain physical and mechanical properties. ~ hese include, for example,
flexural strength, tou~ghness (i.e., impact strength), percentage of elongation, density, weather
resistance, resistance to the effects of ultraviolet li~ht, water absorption, temperature at which
heat distortion occurs, resistance to creep, density stability, and dimensional stability. Flexural
strength is a measure of the magnitude of a load that can be imposed before the material breaks.
The present windshield wiper application requires r elatively low flexural strength. The toughness
characteristic relates to the magnitude of the energy required to break a plastic material, and is
used to measure impact strength. Impact strength is not a measure of the stress required to break
a sample, but rather a measure of the energy needed, or absorbed, in breaking the specimen. A
relatively large value of impact strength is required in the present windshield wiper application.
The combined effects of temperature, light radiation, moisture, gases, and other chemicals
in the environment can cause dimensional and other physical changes in plastic materials. The
"weatherability" of a plastic material relates to its ability to withstand direct sunlight, or the
application of artificial weathering conditions. Ultraviolet radiation, in conjunction with water and
other environmental oxidants, may cause color fading, pitting, crumbling, surface cracking,
crazing, or brittleness. Heat stabilizers, that are well-known to persons of skill in the plastics art,
can be added to the polymers to retard the damagin~ effects of heat, light energy, oxidation, or
mechanical shear. "Deflection temperature," or "heat distortion temperature," represent the
characteristically highest continuous operating temperature that the material will withstand. In
the present windshield wiper application, the material should be effective within a range of
approximately -50 ~F to l 50 ~F.
The compliant, force distributing arrangements of the present invention, in embodiments
thereof that are applicable to windshield wiper systems, can be made of a variety of materials.
These include, for example, Xenoy (from GE Plastics), low density polyethylene, polypropylene,
PVC, aromatic polyesters, polycarbonate, fluoroplastics, ABS, polyallomers, and polystyrene.
Some of the referenced materials are considered to be guite expensive, notwithstanding their
excellent mechanical and physical properties. For example, PTFE is about fifty times more
expensive than polyethylene.
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From the standpoint of economy of manufacture, it is self-evident to persons of skill in the
art that, for a given mold configuration, a lower density material will yield more parts per pound.
It is nececs~ry, therefore, to compare costs on a unit volume basis. The plastic materials (without
limitation), arranged in order of increasing cost per unit volume, are: polyethylene; polypropylene;
polystyrene; ABS (polypropylene with 30% glass fill); and PTFE. Polyethylene, preferably of
the low density type, or polypropylene, appear to be well-suited for the present windshield wiper
application. Both such materials are characterized with low specific gravity ~polyethylene is
approxinlately 0.917; and polypropylene is approximately 0.904), excellent molding qualities, very
low cost, high impact strength, and low flexural modulus. Although subject to degradation upon
exposure to W radiation, UV absorbers and other additives known to persons skilled in the art
can reduce the effects of UV radiation and improve creep resistance.
Polypropylene, polystyrene, and polyethylene do not absorb water and therefore are good
candidates for the windshield wiper application. Nylons, polyesters, polycarbonates, and ABS
absorb moisture and therefore are not recommended. From the standpoint of cost and flexural
strength, polypropylene is a better choice as it costs less thal1 $0.50 per pound and has a flexural
modulus of approximately between 100,000 and 150,000 psi. Polyacetal (trade name "Delrin")
and polyethylene terephthalates (PET) are also good choices.
From the standpoint of manufacture, injection molding appears preferred, although
extrusion is a cost-effective alternative. During molding. care should be taken that a knit line is
not produced. A knit line is on along which two fi onts of polymer flow meet. Knit lines produce
a line of weakness that is susceptible to failure dul ing impact.
Brief Description of the :l~rawing
Comprehension of the invention is facilitated by reading the following detailed description,
in conjunction with the annexed drawing, in which:
Fig. 1 is a schematic plan view of a windshield wiper support frame embodiment of the
invention wherein highly compliant, integrally formed coupling portions are utilized;
Fig. 2 is a schematic plan view of a windshield wiper support frame embodiment of the
invention wherein resilient, hinge-like elements are integrally t'ormed with the beams, there being
provided eight equally spaced force distribution points;
Fig. 3 is a schematic plan view ofthe configuration of a small resilient, hinge-like element;
Fig. 4 is a schematic plan view ofthe configuration of a larger resilient, hinge-like element,
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Fig. 5 is a schematic plan view of a windshield wiper support frame embodiment of the
invention wherein resilient, hinge-like elements are integrally formed with the beams, with eight
equally spaced force distribution points, and with greater flexibility than the embodiment of Fig.
2;
Fig. 6 is a schematic plan view of a windshield wiper support frame embodiment of the
invention wherein resilient, hinge-]ike elements are integrally formed with the beams, there being
provided an odd number of unequally spaced force distribution points for each half of the support
~ame;
Fig. 7 is a schematic plan view of an illustrative embodiment of the invention wherein a
plurality of resilient coupling elements couple a primary beam to a flexible working beam,
Fig. 8 is a schematic plan view of the embodiment of Fig. 7 showing the flexure of the
resilient coupling elements in response to flexure of the flexible working beam toward the primary
beam;
Fig. 9 is a schematic plan view of a further illustrative embodiment of the invention
wherein a plurality of resilient coupling elements couple a primary beam to a respective plurality
of end pads with blade coupling elements extending therefrom;
Fig. 10 is an en]arged schematic isometric representation of a portion of the embodiment
of Fig. 9 showing certain details of the end pads with the blade coupling elements extending
therefrom; and
Fig. 11 is an enlarged schematic isometric representation of a portion of a further specific
embodiment of the invention showing certain details of the end pads with the blade coupling
elements extending therefrom and a single beam resilient element.
Detailed Description
Fig. l is a schematic plan view of a windshield wiper support frame I 0 wherein highly
compliant, integrally formed coupling portions I I-16 are utilized for interbeam coupling, as will
be described hereinbelow. A primary beam 20 is coupled to a secondary beam 2 l via coupling
portion 13. Similarly, the primary beam is coupled to a further secondary beam 22 via coupling
portion 16. Coupling portion l 1 couples secondary beam 21 to a tertiary beam 23 . Similarly, on
the other half of the windshield wiper support frame, coupling portion 14 couples secondary beam
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22 to a further tertiary beam 26. Coupling portions 12 and 15 are shown to couple their
respectively associated secondary beams 21 and 22 to tertiary beams 24 and 25.
In this specific illustrative embodiment of the invention, output forces, which correspond
to predeterminable proportions of an input force that is represented by vector 30, are provided
at tertiary beams 23 -26, and at secondary beams 21 and 22. More specifically, the output forces,
that are represented by vectors 31-36, sum up to the magnitude of vector 30. Vectors 31-36
therefore represent a distribution of the input force represented by vector 30. The force
represented by vector 30 is supplied in this embodiment by a windshield wiper actuator arm (not
shown) that is conventionally coupled to the windshield wiper motor (not shown) of a vehicle (not
shown) and to the windshield wiper support frame, illustratively at aperture 40 through primary
beam 20. Although not specifically shown in this figure, the terminations of the secondary and
tertiary beams where the output forces are provided are adapted (not shown in this figure) in a
conventional manner to be coupled to a windshield wiper blade. The windshield wiper blade may
be of the conventional single blade type, or of the dual blade type.
As indicated, the primary, secondary, and tertiary beams, along with their respectively
associated compliant coupling portions, are formed inte,rally with one another. The coupling
portions, such as coupling portions 13 and 16, perll1it their respectively associated secondary
beams to pivot. Moreover, terminations of the secondary and tertiary beams where the output
forces are produced are tr~ncl~t~ble along paths that are parallel to the input force vector.
Persons of skill in the art will readily recognize that the magnitudes of the forces represented by
vectors 31-36 can be made not to be equal to one another, as required by the particular
application. Proportions of the force magnitudes amongst the vectors are responsive to the
location of the coupling portions along the respective beams, the mechanical properties of the
compliant coupling portions, and the mechanical properties of the beams themselves. Persons of
skill in the art can configure these characteristics in light of the teaching herein
Fig. 2 is a schematic plan view of a windshield wiper support frame 50 wherein resilient,
hinge-like portions 51-56 are integrally formed with the beams, there being provided eight equally
spaced force distribution points. As shown, a primary beam 60 is resiliently coupled via integrally
formed resilient coupling portions 52 and 55 to respective secondary beams 61 and 62. Each
secondary beam is coupled via respective integrally formed resilient coupling portions 51 and 53,
and 54 and 56, to respective tertiary beams 64-67. In this specific illustrative embodiment of the
- 10-
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invention, the tertiary beams are coupled to a windshield wiper blade, which is schematically
represented in the figure by structural element 69. The windshield wiper blade can, in certain
embodiments, be coupled to the force output points of the tertiary beams using any of several
known wiper blade coupling arrangements (not shown), or it can be formed integrally with the
5 windshield wiper support frame.
Fig.3 is a schematic plan representation of the configuration of a small resilient, hinge-like
portion 70, which corresponds to coupling portions 51, 53, 54, and 56, shown in Fig. 2. Fig. 4
is a schematic plan view of the configuration of a larger resilient, hinge-like portion 80, which
corresponds to coupling portion 55 in Fig. 2. Coupling portion 52 in Fig. 2 is the mirror image
of coupling portion 55. Referring once again to Fig. 3, hillge-like portion 70 is formed with first
and second resilient members 71 and 72, that couple beams 74 and 75 resiliently to one another.
When beam 75 is urged in the direction of arrow 77, first resilient member 71 is subjected to a
compression force, and second resilient member 72 is subjected to tension. Conversely, when
beam 75 is urged in the direction of arrow 78, first resilient member 71 is subjected to a tensile
force, and second resilient member 72 is subjected to compression force. In this regard, without
limitation, the present invention is distinguishable from the mere pivoting function of the
interbeam couplers of the conventional windshield wiper support frames.
The larger resilient, hinge-like portion 80 of Fig. 4 that corresponds to coupling portion
55 in Fig. 2, functions in a manner similar to the hinge-like portion described with respect to Fig.
3. More specifically, when beam 85 is urged in the direction of arrow 87, first resilient member
81 is subjected to a compression force, and second resilient member 82 is subjected to tension.
Conversely, when beam 85 is urged in the direction of arrow 88, first resilient member 81 is
subjected to a tensile force, and second resilient member 82 is subjected to compression force.
Fig. 5 is a schematic plan view of a windshield wiper support frame 100 embodiment of
the invention wherein resilient, hinge-like portions are integrally fonned with the beams, with
eight equally spaced force distribution points, and with greater flexibility than the embodiment of
Fig. 2. As shown in this figure, windshield wiper support frame 100 is provided with resilient,
hinge-like portions 101-106 are integrally formed with the beams. A primary beam 110 is
resiliently coupled via integrally formed resilient coupling portions 102 and 105 to respective
secondary beams 111 and 112. ~ach secondary beam is co~lpled via respective inte;,rally formed
resilient coupling portions 101 and ]03, and 104 and 106, to respective tertiary beams 114-117.
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The embodiment of Fig. 5 achieves a greater degree of compliance over that of Fig. 2 in that the
resilient coupling portions are not only longer, but thinner. Thus, when materials having relatively
high stiffness characteristics are employed in the manufacture of the product, desired compliance
characteristics can be achieved by controlling the size and thickness of the resilient coupling
S portions. In this specific illustrative embodiment of the invention, the force output portions (not
spe~ific~lly (lesi~n~ted in this figure) are shown schematically to be coupled to a windshield wiper
blade 120. As previously noted, the windshield wiper blade can, in certain embodiments, be
coupled to the force output points using any of several known wiper blade coupling arrangements,
or it can be formed integrally with the windshield wiper support frame
10Fig. 6 is a schematic plan view of a windsllield wiper support frame 130, which is a
specific illustrative embodiment ofthe invention whelein resilient, hin;,e-like portions 131, 132,
133, and 134 are integrally formed with the beams. In this embodiment, there are provided an
odd number of unequally spaced force distribution poh1ts for each half of the support frame.
More specifically, a primary beam 136 is resiliently coupled via integrally formed resilient coupling
15portions 132 and 133 to respective secondary beams 137 and 138. Each secondary beam is
coupled via respective integrally formed resilient coupling portions 131 and 134 to respective
tertiary beams 140 and 141. In this specific illustrative embodiment of the invention, the tertiary
beams are coupled to a windshield wiper blade, whicll is schematically represented in the figure
by structural element 143. As previously stated, the windshield wiper blade can, in certain
20 embodiments, be coupled to the force output points of the tertiary beams using any of several
known wiper blade coupling arrangements (not shown), or it can be formed integrally with the
windshield wiper support frame.
Fig. 7 is a schematic plan view of an illustrative embodiment of a windshield wiper support
arrangement 150 constructed in accordance with the invention. As shown, a primary beam 151
25 which in this specific illustrative embodiment of the invention is c-lrved is shown to be coupled
resiliently to a flexible working beam ] 53 by a plurality of resilient coupling elements 161 - 167.
In this specific illustrative embodiment of the invention flexible working beam 153 functions to
support a windshield wiper blade (not shown). The resilient coupling elements are distributed
over the length ofthe primary beam and are coupled thereto on the concave side of the curvature.
30 Flexible working beam 153 is shown in this specific illustrative embodiment of the invention to
be straight when undisturbed. The variations in the distance between the curved primary beam
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,
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and the straight flexible working beam is accommodated by employing resilient coupling elements
of varying sizes. Thus, resilient coupling elements 161 and 167 are smal1er than resilient coupling
elements 162 and 166, e~C., resilient element 164 being the largest in this embodiment.
Fig. 8 is a schematic plan view of the embodiment of Fig. 7 showing the flexure of the
resilient coupling elements 161-167 in response to a bending flexure in tlle central region of
flexible working beam 153 toward primary beam 151. As shown, as the distance between the
primary beam and the flexible working beam is decreased by the application of force (not shown)
on the flexible working beam toward the primary beam, resilient coupling elements 162-166 are
shown to become compressed and somewhat elongated along the direction of the primary beam.
In this specific illustrative embodiment of the invention, the flexible working beam separates away
from the primary beam at its extremities as it is urged toward the primary beam in its central
region.
In the embodiment of Figs. 7 and 8, primary beam 151 is formed so as to be fairly rigid,
i.e., that it will not bend significantly in response to the forced contemplated by the designer to
be applied thereto and to flexible working beam 153. Resilient coupling elements 161-167 are
formed of a resilient material, such as polypropylene, polystyrene, and polyethylene, as described
above.
Fig. 9 is a schematic plan view of a further illustrative embodiment of a windshield wiper
support arrangement 180 constructed in accordance with the invention. As shown, a primary
beam 181 which in this specific illustrative embodiment of the invention is curved is shown to be
coupled resiliently to respective first ends of a plurality of resilient coupling elements 183- 188.
In this specific illustrative embodiment of the invention, the resilient coupling elements are
distributed over the length of the primary beam and are coupled thereto on the concave side of
the curvature of primary beam 181. Each ofthe resilient coupling elements is coupled at a second
end thereof to a respective one of end pads 190- 195, shown from the side thereof in this figure.
Each of the end pads has extending therefrom, in this specific illustrative embodiment of the
invention, a pair of blade engagement members, such as en~agement members 200 and 201, which
will be described in greater detail hereinbelow with r espect to Fig. 10.
In the embodiment of Fig. 9, each of end pads 190- 195, shown from the side thereof in
this figure, is coupled to a sequentially adjacent one of the end pads by a coupling element, in the
form of, for example, coupling element 203 which is connected at one end to end pad 192, and
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at its other end to end pad 193. Primary beam 181 has a first end 205 and a second end 206. In
this specific illustrative embodiment of the invention, the respective ends are couple to their
inwardly proximal end pads by coupling elements 208 and 209, respectively. That is, coupling
element 208 couples first end 205 to end pad 190, and coupling element 209 couples second end
206 to end pad 195. The end pads are shown in this embodiment to be arranged in a substantially
straight-line relation to one another. This facilitates installation of conventional windshield wiper
blades. However, curved arrangements for specialized windshield contours can be provided
within the scope ofthe invention. In such specialized embodiments, the windshield wiper blades
can themselves be fabricated to have a predetermined curvature that easily would be installed in
the correspondingly curved windshield wiper SUppOIt arrangell1ent.
The variations in the distance between the curved primary beam and the straight flexible
working beam is accommodated by employing resilient coupling elements of varying sizes. Thus,
resilient coupling elements 183 and 188 are smaller than resilient coupling elements 184 and 187,
which are smaller than resilient coupling elements I 85 and l 86 which are the largest in this
embodiment.
Fig. 10 is an enlarged, fragmented schematic isometric representation of a portion of the
embodiment of Fig. 9 showing certain illustrative details of end pad 190 with blade coupling
elements 200 and 201 extending therefrom. As shown~ end pad 190, as are the other end pads
in this embodiment, is wider than the couplin~ elements~ illustratively coupling element 208 which
couples end pad 190 to first end 205 of primary beam l ~ l The blade coupling elements are
shown in this specific illustrative embodiment of the invention to be arranged axially offset from
one another on the end pad, and are provided with respective inwardly directed protuberances 210
and 211 which engage with an elongated support (not shown) of a conventional windshield wiper
blade (not shown).
Resilient element 183 is shown to have a substantially V-shaped configuration~ wherein
a first end thereof is coupled to primary beam 181, and a second end is coupled to end pad 190.
The structure of the resilient element of this specific illustrative embodiment of the invention is
comprised oftwo resilient beams 213 and 214 which are resiliently coupled to one another at a
resilient coupling 215. As end pad 190 is displaced toward primary beam 181 by the application
of a force in the direction of arrow 220, resilient beams are urged toward one another, effectively
counter-rotating about their respective couplings to the primary beam and the end pad. The
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WO 98101329 PCT/US97/12289
effective displacement path (not shown) ofthe end pad in response to the application of the force
is substantially linear. In this embodiment, the entire structure is integrally formed by any of a
variety of known rn~nllf~ctllring techniques, such as injection molding. A practicable embodiment
has been formed of Xenoy, a compound that is commercially available from GE Plastics.
Fig. 11 is an enlarged fragmented schematic isometric representation of a portion of a
filrther specific embodiment of the invention showing certain details of the end pads with the blade
coupling elemPntc extending therefrom and a single-beam resilient element. Elements of structure
that are analogous to those discussed hereinabove with respect to Fig. 10 are similarly designated.
Fig. 11 shows, as does Fig. 10, certain illustrative details of end pad 190 with blade coupling
elements 200 and 201 extending therefrom. As shown in Fig. l 1, end pad 190~ as are the other
end pads (not shown) in this embodiment, is wider tl-an the coupling elements, illustratively
coupling element 208 which couples end pad 190 to first end 205 of primary beam 181. As
previously discussed, the blade coupling elements are shown in this specific illustrative
embodiment of the invention to be arranged axially offset from one another on the end pad, and
are provided with respective inwardly directed protuberances 210 and 21 I which engage with an
elongated support (not shown) of a conventional windshield wiper blade (not shown).
In the various embodiments of the invention, a plurality of apertures, such as aperture 250,
are be provided through primary beam ~ 81 to permit 11igh speed air to flow therethrough during
vehicle operation. Such air flow will impin;,e upon the windshield wiper blade urging same
toward the windshield (not shown).
A resilient element 241 is shown in the embodiment of Fig. l 1 to have a substantially S-
shaped configuration, wherein a first end thereof is coupled to primary beam 181, and a second
end is coupled to end pad 190. The structure of the resilient element of this specific illustrative
embodiment ofthe invention is comprised oftwo resilient bends ~43 and 244 which are resiliently
interconnected by a resilient beam 246. As end pad 190 is displaced toward primary beam 181 by
the application of a ~orce in the direction of arro\~ 2~0, resilient beam 246 is caused to bend
resiliently. In this embodiment, the entire structure is integrally formed, as previously noted.
In addition, persons of skill in the art can config,ure multiple-tier resilient beam
arrangements, similar in appearance to the embodilllent showll in Fig. ~, but instead of relying on
the integrally formed resilient coupling portions ~ ., 51 and 53) to provide the necessary
compliance to the relatively firm subordinate beams (~ ., 61 and 64), resilient beams of the type
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WO 98/01329 PCT/US97/12289
described in connection with Figs. 9-l l can be tiered (not shown), whereby, as previously stated,
the overall compliance characteristic of the windshield wiper blade support arrangement is
responsive to the resilience characteristics of the beams themselves. In still further embodiments,
the resilient coupling elements, such as coupling element 208 which couples end pad l90 to first
5 end 205 of primary beam l 8 l in Figs. 9- l l, can themselves be configured to distribute force to
the windshield wiper blade (not shown), in regions intermediate of the end pads. In such
embodiments, the resilient connectors between the end pads, or between an end pad and an end
of the primary beam, has a preformed curvature that applies a resilient force to the windshield
wiper blade.
Although the invention has been described in terms of specific embodiments and
applications, persons skilled in the art can, in light of this teaching, generate additional
embodiments without exceeding the scope or departing from the spirit of the claimed invention.
Accordingly, it is to be understood that the drawing and description in this disclosure are
proffered to facilitate comprehension of the invention, and should not be construed to limit the
15 scope thereof.
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