U.S. patent application number 12/496977 was filed with the patent office on 2010-01-07 for windshield wiper arm with hemmed distal end.
This patent application is currently assigned to CONCORD TOOL & MANUFACTURING, INC.. Invention is credited to Jeff Vandine.
Application Number | 20100000282 12/496977 |
Document ID | / |
Family ID | 37909901 |
Filed Date | 2010-01-07 |
United States Patent
Application |
20100000282 |
Kind Code |
A1 |
Vandine; Jeff |
January 7, 2010 |
Windshield Wiper Arm with Hemmed Distal End
Abstract
A wiper arm (100) for a wiper assembly of an automotive vehicle,
the wiper arm (100) being formed in a single piece from a metallic
blank (100') and having an inner end portion (100a) of generally
U-shaped configuration in cross-section that is formed by drawing
the blank (100') in a progressive die, and an outer end portion
(100b) that is formed with a C-shaped configuration in
cross-section, by hemming. The outer end portion (100b) has a
central portion (130) with edge portions (132) that are reversely
folded to underlie the central portion (130), edges of the edge
portions (132) being disposed in close proximity to one another. An
end portion (100c) of the outer end portion (100b) of the wiper
(100) is reversely folded to be spaced from and underlie a portion
of the outer end portion (100b) thereabove, and the end portion
(100c) is provided with an opening (126) by which a wiper blade may
be attached to, or removed from, the wiper arm (100).
Inventors: |
Vandine; Jeff; (Macomb,
MI) |
Correspondence
Address: |
VAN OPHEM & VANOPHEM, PC;REMY J VANOPHEM, PC
51543 VAN DYKE
SHELBY TOWNSHIP
MI
48316-4447
US
|
Assignee: |
CONCORD TOOL & MANUFACTURING,
INC.
Mt. Clemens
MI
|
Family ID: |
37909901 |
Appl. No.: |
12/496977 |
Filed: |
July 2, 2009 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
11248818 |
Oct 12, 2005 |
|
|
|
12496977 |
|
|
|
|
Current U.S.
Class: |
72/256 |
Current CPC
Class: |
B60S 1/3447 20130101;
B60S 1/4006 20130101; B60S 1/3434 20130101; B60S 1/32 20130101;
B60S 1/40 20130101 |
Class at
Publication: |
72/256 |
International
Class: |
B21C 23/00 20060101
B21C023/00 |
Claims
1-4. (canceled)
5. A method of making a unitary wiper arm, said method comprising
the steps of: providing a single thickness blank adapted to be
carried through a progressive die; forming an inner portion of said
unitary wiper arm in the form of a generally upward formed
cross-section by a drawing operation in said progressive die, said
upward formed cross-section having a bight portion with extending
opposed legs; forming an outer portion of said unitary wiper arm
into a generally double thickness configuration by in-turning said
material edges that extend from opposing sides of said single
thickness layer of material by a hemming operation in said
progressive die; removing said formed wiper arm from said single
thickness blank carried through said progressive die.
6. The method as claimed in claim 5 further comprising the step of:
forming axially aligned openings in said extending opposed legs to
permit mounting of said unitary wiper arm to a mounting head.
7. The method as claimed in claim 5 further comprising the step of:
providing one of said extending opposed legs with a material
extension; and cam forming said material extension from said one of
said opposed legs into a support bracket located between said
extending opposed legs.
8. The method as claimed in claim 7 further comprising the step of:
attaching a spray nozzle to said support bracket located between
said extending opposed legs.
9. The method as claimed in claim 5 wherein said forming an outer
portion of said unitary wiper arm further comprises the step of:
forming said in-turned material edge portions over a central
material layer with no appreciable spacing between said in-turned
material edge portions and said central material later portion to
form said double thickness configuration, said free edges of said
in-turned material edge portions touching or in very close
proximity with one another.
10. The method as claimed in claim 5 further comprising the step
of: cam forming the outermost end portion of the unitary wiper arm
into a reversely folded hook portion which is spaced from and
extends parallel to a portion of the hemmed outer portion of said
unitary wiper arm, to provide a spacing for the proper attachment
of a wiper blade to the unitary wiper arm when it is required to
remove said wiper blade.
11. The method as claimed in claim 6 further comprising the step
of: final forming the width of said reversely folded hook portion
so as to enable easy fitting of said hook portion between the
cheeks of the support bracket attached to said wiper blade.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is a division of U.S. patent application
Ser. No. 11/248,818 filed on Oct. 12, 2005.
FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not Applicable
REFERENCE TO SEQUENCE LISTING
[0003] Not Applicable
BACKGROUND OF THE INVENTION
[0004] 1. Field of the Invention
[0005] This invention relates to a wiper arm for an automotive
windshield wiper system. More particularly, this invention relates
to a wiper arm of the aforesaid character of unitary construction
with a narrow, thickened free or distal end of a double thickness
that is formed by hemming.
[0006] 2. Description of the Prior Art
[0007] Typical prior art windshield wiper arm assemblies 10 used on
motor vehicles as shown in FIGS. 1 through 5 normally consist of a
mounting head 12, retainer arm 14 and wiper or arm rod 16, as well
as, a tension or a coil spring 20. The mounting head 12 is
typically manufactured of zinc or aluminum die cast. Typically the
retainer arm 14 is formed from sheet metal and stamped in a general
U-shaped configuration as shown in FIGS. 4 and 5. The windshield
wiper arm assembly 10 also has a wiper blade (not shown), which has
a support bracket system and wiper strip retainer (not shown). The
wiper blade is pivotally connected to the windshield wiper arm
assembly 10 through use of a hook like end 17 of the wiper rod 16
which engages between two lateral cheeks of the support bracket
system of the wiper blade (not shown). The fit with the support
bracket requires a sizing operation on the width of the hook like
end 17 so that it will properly fit between the two lateral cheeks
of the support bracket it engages. The connection thus formed
guides the wiper blade with the wiper strip over the glass
windshield of the motor vehicle. The jointed connection and the
support bracket system make it possible for the wiper strip to
adapt to a curvature of the windshield. A required contact pressure
of the wiper strip on the vehicle windshield is attained with at
least the tension coil of the spring 20 which braces the mounting
head 12 and the retainer arm 14 in conjunction with the wiper rod
16 through a toggle joint 21.
[0008] The shape of the individual components of the retainer arm
14 is influenced by various demands and stresses. Specifically,
they should be as torsionally rigid, deflection-resistant, and as
narrow in the field of view as possible, so that the wiper blade
can be guided without vibration and under control over the vehicle
windshield yet present little hindrance to the field of view. The
mounting head 12 transmits the drive moment from the drive axis A-A
to the wiper blade, via the retainer arm 14 and the arm rod 16. It
also forms part of the toggle joint 21, by way of which the
mounting head 12 is braced with the retainer arm 14 by the tension
spring 20 and pressed in the direction of the vehicle window. The
greatest forces or moments arise in the mounting head 12, both
parallel to the window and perpendicular to the window. Further,
deformations in the lower region of the retainer arm 14 have an
especially strong effect over the entire length and can cause
uneven wiping speeds as a result of a spring effect. The mounting
head 12 and the first portion of the retainer arm 14 must therefore
be embodied as especially deflection-resistant and
torsion-resistant.
[0009] In a wiping motion, the outward portion of the retainer arm
14 moves partly, and the wiper or arm rod 16 moves completely,
through the field of view of the driver and as a result they must
be made not only torsion and deflection resistant, but also
especially narrow so that they impede as little of the driver's
view as possible. Further, the retainer arm 14 should be shaped in
such a way that it is not lifted away from the vehicle window by
the air flow across the windshield.
[0010] To accommodate these various requirements, prior art
windshield wiper arm assemblies 10 have a wide mounting head that
may be made of zinc or aluminum die cast or sheet metal as well as
a retainer arm 14 that is also made of sheet metal which is
relatively wide in the region of the mounting head 12 that is, at
the lower edge 22 of the field of view of the driver. Often, this
portion of the retainer arm 14 is made with an inverted U-profile
that is open towards the window as shown in FIG. 5. Such profile
has a relatively strong resistance moment, and is especially
torsion and deflection resistant in this area while also being able
to accommodate the tension spring 20 which is concealed in the
U-profile. In the outward direction towards the free arm end of the
retainer arm 14 where the retainer arm 14 connects with the wiper
rod 16, the retainer arm 14 tapers so that it is narrower in the
field of view of the driver as shown in the cross-section of FIG.
3. Over the full length of the retainer arm 14, the profile has a
constant material thickness, determined by the sheet metal
thickness used. This thickness is designed in order to accomplish
the appropriate dimensional stability under the greatest material
stresses to be expected which are basically bending and torsion
stresses, specifically, perpendicular and parallel to the vehicle
window.
[0011] Generally, the wiper rod 16 is formed of a profile of
constant thickness material solid flat stock, which is either
crimped or riveted 30 as shown in FIGS. 1 and 3 to the retainer arm
14. The thickness of the wiper rod 16 is a function of drive and
contact forces, the length of the retainer arm 14, as well as the
resistant moments to the windshield wiper arm assembly 10. Further
considerations are the effect of wind engagement faces as well and
more importantly, the slender structure in the field of view of the
driver. Generally, the material stress demands are greatest at the
connection point of the wiper rod 16 to the retainer arm 14 and
because of the small cross-sectional area and unfavorable
resistance moments, the material thickness is generally determined
by the stress requirement at the connection point between the
retainer arm 14 and the wiper rod 16. For this reason, the wiper
rod 16 itself is generally a solid stock formed of a thicker
material than the retainer arm 14 thus, the arm rod 16 and retainer
arm 14 are combined in a single rigid assembly which rotates a
limited degree about drive axis A-A. As a result, in some
applications, there is unnecessarily high consumption of material,
high material costs, and high weight.
[0012] Further considerations to be made in the design of a
complete windshield wiper system is the associated windshield
washing system and considerations which need to be made with
respect to the mounting of the spraying device on the hood or the
windshield wiper arm assembly 10. The windshield washing system
consists of a washing liquid reservoir, as well as a pump (not
shown), by which washing liquid is sprayed onto the windshield to
be cleaned by a spraying device. It is known that the spraying
device may be stationarily arranged on the engine compartment hood.
Further, the windshield cleaning system-spraying device may be
fixed to the windshield wiper arm assembly 10. The advantage of
fixing the spraying device to the windshield wiper arm assembly 10
is that the washing liquid is sprayed immediately in front of the
wiper blade. In the prior art embodiment illustrated in FIGS. 1
through 5, the mounting bracket 26 for attaching a spraying or
washer nozzle 28 is riveted to one of the legs of the U-shaped
retainer arm 14. In some prior art embodiments the mounting bracket
26 may be stamped out of the profile of the U-shaped leg of the
retainer arm 14 and laterally spaced with respect to the plane of
the leg of the U-shaped retainer arm 14. This attached structure
provides a very stabile, rigid mounting surface for the spraying
nozzle 28 which provides an attractive, compact assembly in which
the fluid line or hose 24 can be dressed substantially entirely
within the cavity of the U-shaped retainer arm 14 and thereby be
out of sight from the user.
[0013] With reference to prior art FIG. 2, the details of the
spraying or washer nozzle 28 are illustrated. The washer nozzle 28
includes a body portion and a mounting flange integrally formed
therewith for mounting washer nozzle 28 with mounting bracket 26.
The fluid line 24 is connected to an inlet nipple to provide washer
fluid to an inlet port. As a result, a spray or mist is expelled
from a nozzle port of the outlet nipple.
[0014] In order to solve high cost and high weight problems, some
windshield wiper assemblies particularly teach the use of a
retainer arm and wiper rod which can be made of a number of
variable material layers which are folded upon one another in
various regions until the material thickness required for the
particular cross-section is obtained. A thin material is bent over
multiple times by approximately 180.degree. in multiple steps in
order to brace each layer. The advantage, of course, is from a
relatively thin sheet of metal, different material thickness can be
obtained in different regions and this thickness can be adapted
exactly to different stresses that arise. Unfortunately, small
material stress cracks, virtually invisible to the eye, can result
from these multiple bending operations and as a result, such minute
cracks, if they occur on the outer surfaces, can cause excessive
noise by wind passing thereover when exposed to a high wind stream.
Further, obviously, the multiple layers of metal in order to
accomplish the appropriate size requirements, may also result in
higher material costs as well as higher weights due to the multiple
layers which are necessary in order to provide the appropriate
structural rigidity for the torsion and deflection forces that are
known in selective areas of the windshield wiper assembly.
Generally, to enable the use of multiple layer assemblies, a
thinner material is used in order to make the multiple folds which
are necessary to acquire the particular cross-section needed to
resist the known deflection and torsion moments.
[0015] U.S. Pat. No. 6,505,377 B1 (Merkel et al.) discloses a wiper
arm or wiper rod, element 18, for a windshield wiper assembly, the
wiper rod being formed from multiple layers of a single thickness
component sheet of metal (column 2, lines 30-39). The free or
distal end of a one-piece wiper rod according to this reference is
formed with four thicknesses of metal by a stamping operation, FIG.
8, presumably to provide the wiper rod with adequate stiffness to
resist deflection or tension stresses under aerodynamic load, to
thereby maintain a wiper blade that is attached to the free end in
contact with an adjacent windshield and without requiring an
excessive wiper rod width at the outer region, which is in the
field of vision of an operator of the associated motor vehicle. A
known problem with the FIG. 8 configuration of the wiper arm or rod
of this reference is that the number of bends as a result of
stamping of the metal strip in order to achieve this configuration,
requiring a 180.degree. bend at the location of the lower detent
holes (elements 56), in addition to four 90.degree. bends to
achieve such configuration, can introduce cracking in outer surface
layers of the metal. Such surface configuration is undesirable
because it can lead to excessive noise in the associated vehicle
when the vehicle is traveling at highway speeds.
[0016] The '377 reference also discloses an alternative embodiment,
the embodiment of FIG. 9-16, in which the free or distal end of the
wiper rod is formed by a stamping operation in a triple thickness,
as shown in FIG. 14, which also requires severe bends on each of
the ends of the blank from which the rod is formed, following a
90.degree. bend in advance of each 180.degree. bend. The FIG. 14
embodiment of the invention of the '377 reference, of necessity,
will require a thickness sufficient to accommodate three (3) layers
of material, and it will require extra width of the blank from
which the wiper rod is formed to provide this triple thickness
construction. The multiple layer assembly is not cost effective
because of the additional processing steps to generate the various
bends and the resultant higher weight due to the multiple layers of
metal.
[0017] U.S. Pat. No. 6,732,401 B1 (Rapp), which shows an assignment
to the same assignee as the '377 patent, shows, in FIGS. 3 and 5, a
wiper arm assembly in which the free end has an open or box type
cross-section, presumably for added rigidity in this region. The
use of a box-type configuration in this region adds to the required
thickness of the rod or arm at a location in the field of view of
the driver, which, at the least, serves as an annoyance to the
driver and is, in any case, aesthetically unattractive. Again, such
configuration is not economical and requires additional processing
stops to obtain the various material thickness configuration of the
hook like end 21.
BRIEF DESCRIPTION OF THE INVENTION
[0018] The aforesaid and other problems associated with prior art
wiper arm constructions are avoided by a wiper arm constructed
according to the present invention that is fabricated from a single
thickness blank of a suitable material. An inner portion of the
wiper arm, which is generally U-shaped in cross-section, is formed
by a drawing operation in a progressive die. An outer portion of
the wiper arm is formed by hemming into a double thickness, a
generally C-shaped configuration with no spacing between a single
thickness layer of material of the arm and an in-turned pair of
material edges that extend from opposite sides of the single
thickness layer. Such a configuration has sufficient resistance to
deflection and torsional moments under aerodynamic loads to
maintain a wiper blade attached to the distal end of the wiper arm
in engagement with an adjacent windshield, it is sufficiently
narrow at the distal end to avoid undue visual interference to an
operator of an associated vehicle, and it is sufficiently thin in a
transverse direction to be aesthetically clean and visually
undistracting. The wiper arm of the present invention is also lower
in weight than known prior art wiper arm constructions, it is
relatively inexpensive to produce due to it's single piece
construction, and it incorporates a more accurately positioned hole
in a reverse turned hook end for accurate attachment of a wiper
blade to the wiper arm itself without the need of a resizing
operation to fit the hook like end between the cheeks of the
support bracket it engages. Further, the mounting bracket for
attachment of the spray nozzle is formed from the extended portion
of the U-shaped legs of the retainer arm so that no additional
parts or assembly operations are required to attach this mounting
bracket because additional material is provided in the original
blank that is carried through the progressive die.
[0019] Accordingly, it is an object of the present invention to
provide an improved, economical, light weight wiper arm for a
windshield wiper assembly that is fabricated from a single
thickness blank of a suitable material, that has a free or distal
end that is narrow in the line of sight of an operator of an
associated vehicle, that is both thin in a transverse direction and
is provided with sufficient resistance to deflection and torsion
moments under aerodynamic load, and can be made free of cracks and
other surface irregularities that would otherwise be noisy when the
associated vehicle is driven at highway speeds.
[0020] It is a further object of the present invention to fabricate
an improved wiper arm for a windshield wiper assembly that is
economical to manufacture by hemming the wiper rod portion of the
retainer arm and provide additional material in the single piece
blank to enable fabrication of the mounting bracket for the
attachment of the spray nozzle out of the single piece blank.
[0021] For a further understanding of the present invention and the
objects thereof, attention is directed to the drawing and the
following brief description thereof, to the detailed description of
the invention and to the appended claims.
BRIEF DESCRIPTION OF THE DRAWING
[0022] FIG. 1 is a plan view of a prior art construction of a
windshield wiper arm assembly,
[0023] FIG. 2 is a partial view of the prior art wiper arm assembly
shown within Circle 2 of FIG. 1;
[0024] FIG. 3 is an cross-sectional view of the prior art wiper arm
along lines 3-3 of FIG. 1;
[0025] FIG. 4 is a cross-sectional view of the prior art wiper arm
taken along line 4-4 of FIG. 1;
[0026] FIG. 5 is a cross-sectional view of the prior art wiper arm
taken along line 5-5 of FIG. 1;
[0027] FIG. 6 is a plan view of a blank strip for a progressive die
from which the wiper arm according to the present invention is
fabricated;
[0028] FIG. 6A is a cross-sectional view taken along line 6A-6A of
FIG. 6;
[0029] FIG. 6B is a cross-sectional view taken along line 6B-6B of
FIG. 6;
[0030] FIG. 6C is a cross-sectional view taken along line 6C-6C of
FIG. 6;
[0031] FIG. 7 is a bottom plan view of a single piece wiper arm
according to the present invention after it has been fabricated
from the blank strip of FIG. 6;
[0032] FIG. 8 is a side elevation view of the wiper arm according
to the present invention;
[0033] FIG. 9 is a cross-sectional view rotated 90.degree. taken
along line 9-9 of FIG. 7;
[0034] FIG. 10 is a cross-sectional view, rotated 90.degree., taken
along line 10-10 of FIG. 7;
[0035] FIG. 11 is a cross-sectional view taken along line 11-11 of
FIG. 8; and
[0036] FIG. 12 is a cross-sectional view taken along line 12-12 of
FIG. 8.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT OF THE
INVENTION
[0037] FIG. 6 is a strip layout of the stages of development of the
blank for the retainer and wiper arm as it moves through the
various stations within the progressive die which fabricates the
one-piece wiper arm. The strip is laid out so that two pieces are
carried on either side of the center carrier and from the initial
blanking station in the first several stages of the tool the
mounting bracket is partially formed upwards. Thereafter, both edge
portions of the blank are formed upward at an approximate
90.degree. angle as shown in FIG. 7 in order to create the U-shaped
form of the retainer arm. In subsequent stations, the hemming of
the arm rod portion of the retainer arm is accomplished in a two
stage operation shown in FIGS. 6B and 6C wherein the first stage
hems the edges of the blank to approximately a 45.degree. angle
which is thereafter finished in the next station to completely hem
both edges so that the hemmed edges overlie and are in direct
contact with the underlying surface of the underlying material
layer as shown in FIGS. 6C and 11. Thereafter, the mounting bracket
for the attachment of the spray nozzle is cam formed to its final
position shown in FIG. 12 within the two legs of the U-shaped
retainer arm in two separate stations. To finalize the completed
one piece retainer arm a slot is pierced into the rod end (FIG. 10)
which is thereafter cam formed and sized into the hook like end of
the rod arm, shown in FIGS. 9 and 10, to enable the hook like end
to fit between the cheeks of the support bracket of the wiper
blade. In the final stages of the progressive die, the part is
separated from the strip so as to present the one piece wiper arm
assembly incorporating all the necessary structural elements to
provide attachments for the remaining elements of a complete
windshield wiper arm assembly.
[0038] The one-piece wiper arm as illustrated in FIGS. 6 through 12
according to the preferred embodiment of the present invention is
identified by reference character 100 in bottom plan and side
elevational views of FIGS. 7 and 8 respectively. The one-piece
wiper arm 100, as earlier described, is formed in a single piece
from a blank 100' carried by a strip through a progressive die,
with an inner end portion 100a that is formed from the blank 100'
by progressively moving through the various stages in the
progressive die as earlier described. An outer or distal end
portion 100b is developed through the same progressive die by
hemming operations as earlier described. The inner end portion 100a
of the one-piece wiper arm 100 generally has the configuration of a
downwardly facing .andgate. with a flat central or bight portion
104 that, when mounted on the vehicle is spaced away from the
windshield (not shown) of an associated vehicle in the assembled
state of the one-piece wiper arm 100. The inner end portion 100a is
formed into a U-shaped configuration having opposed legs 106, 108
extending normally from the flat central or bight portion 104.
Axially aligned openings or holes 110 are provided in the legs 106,
108 by which the one-piece wiper arm 100 may be fastened to a
mounting head, not shown, similar to the prior art arrangement of
FIG. 1. The openings or holes 110 are stamped in the blank 100'
formed in the very beginning stations of the progressive sequence
as shown in FIG. 1.
[0039] One of the legs of the U-channel section, shown in FIG. 2 as
leg 106, is provided with extended material from which the mounting
bracket is fabricated to enable the attachment of the spray nozzle
28 as well as one end of the tension spring 20 as shown in prior
art FIG. 1. As more clearly shown in FIG. 12, the extended material
portion or support bracket 112, upon processing through the
progressive die, is of generally L-shaped configuration with a leg
portion 112a extending back towards the central portion 104 of the
U-shaped channel as well as a second leg portion 112b extending
from an inner end of the leg portion 112a generally transverse to
the leg 106 towards the leg 108 and parallel to the central bight
portion 104 but spaced therefrom. The support bracket 112 has an
opening 114 by which an end of a coil tension spring (not shown)
may be attached to provide tension on the wiper blade (not shown)
so as to bias the wiper blade against the windshield. Opposite the
opening 114 is a leg extension 116 of the support bracket 112
wherein is formed a detent 118 to enable mounting of the spray head
and locking the spray head in place on the support bracket 112
again, similar to the illustration of the prior art in FIG. 1.
[0040] As is shown in FIG. 11, the hemmed outer end portion 100b of
the one-piece wiper arm 100 is of a double layer construction with
the configuration of a C. This outer end portion 100b has a central
material layer portion 130 with in-turned material edge portions
132 that extend parallel to the central material layer portion 130,
and with no appreciable spacing between the in-turned material edge
portions 132 and the central material layer portion 130, the free
edges of the in-turned material edge portions 132, which face the
windshield of an associated vehicle during the operation of the
one-piece wiper arm 100, are touching or in very close proximity to
one another. This configuration minimizes the width of the outer
end portion 100b, for minimal obstruction to the view of an
operator of an associated vehicle. It is of a minimal thickness in
a perpendicular direction for a clean, aesthetic appearance and
optimum viewing characteristics, and imparts sufficient resistance
to deflection under aerodynamic load to maintain an associated
wiper blade engagement with a windshield of a vehicle even when the
vehicle is traveling at highway speeds. Further, the FIG. 11
configuration can be formed with two hemming operations in the
progressive die as shown in FIGS. 6B and 6C. The first operation
hems the material at approximately a 45.degree. angle as shown in
FIG. 6B. The second stage of hemming completely hems both ends so
that the hemmed ends come into complete contact with the central
material layer portion 130 and with each other. The hemming
operations do not result in any surface irregularities in that
portion of the blank 100' and the objectionable noise is not
experienced that can result in a wiper arm having external surface
cracks when the associated vehicle is traveling at highway
speeds.
[0041] An outermost end portion 100c of the outer end portion 100b
of the one-piece wiper arm 100 is reversely folded by a cam form
operation to form the hook end 120 which is spaced from and extends
parallel to a portion of the outer end portion 100b that is
thereabove. This outermost end portion 100c of the outer end
portion 100b is the portion of the one-piece wiper arm 100 that is
provided with the opening 126, and the spacing between the
outermost end portion 100c and the portion of the outer end portion
100b thereabove provides a clearance for the proper attachment of a
wiper blade to the one-piece wiper arm 100 and for the easy removal
of the wiper blade when it is required to replace the wiper blade.
The progressive die operation final sizes the width of the hook end
120 in order to fit the hook end 120 between the cheeks of the
support bracket of the wiper blade.
[0042] Although the best mode contemplated by the inventor for
carrying out the present invention as of the filing date hereof has
been shown and described herein, it will be appreciated by those
skilled in the art that suitable modifications, variations, and
equivalents be made without departing from the scope of the
invention, such scope being limited solely by the terms of the
following claims and the legal equivalents thereof.
* * * * *