Note: Descriptions are shown in the official language in which they were submitted.
2152~~~
TITLE
SLIDE GLASS MECHANISM AND SEAL SYSTEM
FOR VEHICULAR BACKLITE
BACKGROUND OF THE INVENTION
Field of the Invention. The present invention
relates to window frame assemblies, and in particular, to
an assembly having a sliding glass mechanism and seal
system for vehicular backlites. The assembly includes a
frame for mounting the assembly in a vehicle, a pair of
fixed side window panes secured in the frame, and one or
more sliding window panes slidingly positioned between the
fixed window panes.
Summary of Related Art. Pickup trucks and other
related vehicles have a rear window, or backlite, that is
mounted in an opening in the body panel immediately behind
the seats in the passenger compartment. The backlites are
supplied to the pickup truck manufactures as window frame
assemblies for installation on the assembly line. The
backlite assemblies typically include a metal frame, such
as aluminum, provided with a top and bottom channels to
facilitate the sliding of the glass panels.
The backlite assembly is mounted directly into the
window opening in the body panel. The assembly is secured
to the body panel with adhesives and/or mechanical
fastener devices. A urethane adhesive is frequently used
in the backlite applications, such adhesive being applied
to the mounting surface of either the opening in the body
panel or the backlite assembly prior to the moment at
which these two structures are brought into abutment.
The backlite assembly in a pickup truck can be a
source of problems, such as water leakage. The leakage
may occur at the engagement of the backlite assembly and
the body panel, which is typically caused by improper
_ 2~52~fi~
adhesive application or frame distortion. Water leakage
may also occur around the seal extending about the four
edges of the aperture in a sliding window. Two edges of
the aperture are formed by the top and bottom channel.
The other two edges are formed the internal edges of the
fixed, side windows (or a pillar mounted thereon). A
tight seal is required on all four edges of the sliding
window to ensure the integrity of the seal.
The primary configuration currently used in the
backlite assemblies consists of an assembly having a metal
bracket with two channels extending around the complete
perimeter of the assembly. The two fixed windows are
mounted in an outer channel in planar, spaced-apart
relationship with two horizontal and two vertical seals
secured in the outer channel surrounding the opening
between the fixed'windows. The sliding window is disposed
in the inner channel, adjacent the fixed windows. In the
closed position, the sliding window sealably engages the
seals to seal the opening between the fixed windows. When
moved to an open position, the sliding window slides in
the internal channel to overlap one of the fixed windows
in the outer channel.
The seals are made from rubber or other equivalent
material and include an extended lip which flexibly
engages the sliding window to prevent water and dirt from
entering around the sliding window. The rubber seals are
mounted in the outer channel between the two fixed
windows. The rubber seals facilitate the sliding of the
sliding window in a horizontal direction while maintaining
sufficient pressure at the lip of the seal to prevent
water from leaking around the seal to the interior of the
assembly and the pickup truck.
2
_ 215256.
The rubber seals require a manual production step to
properly install the seals around the opening of the
assembly. One of the needs of the window manufacturers is
to find an alternative sealing system which seals the
opening without discrete rubber seals, thereby reducing
material and labor costs during production operations and
while improving the integrity of the seal around the
sliding window.
Although rubber seals are expensive and difficult to
install, such rubber seals may still be required or
preferred in certain embodiments. If the rubber seals are
not installed properly, then water leakage may occur in
the horizontal channels or along the vertical edges of the
aperture. An improved method, such as encapsulation, for
securing the rubber seal about the aperture in the
backlite is also desired in the industry.
In addition to the sealing problem noted above, there
are several additional performance requirements which
often present problems in the use of the sliding window
assemblies in pickup trucks. In the closed position, the
backlite window assembly must maintain the wind and road
noise within acceptable limits. The seal must uniformly
seal the sliding window to eliminate outside noise. The
channel drain holes and other design features must be
designed to eliminate road noise problems.
High or variable sliding force is another concern in
backlite window assemblies. The sliding window typically
includes rubber or plastic guides to secure the slidable
window within the bottom internal channel. The slidable
window should slide freely within the guides while still
being positioned to sealably engage the lip of the rubber
sealing member. If the seals are installed improperly,
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such as misalignment, then the sliding window may
difficult to slide. The channels of the frame may also be
misaligned. The sliding characteristics of the rubber
seals and the channel guides should permit the sliding of
the sliding window while maintaining the necessary seal
force between the sliding window and the seal.
Another problem which frequently occurs with backlite
assemblies is a sliding glass rattle. When the sliding
glass is moved to an open position, the sliding glass in
the internal channel must be retained by channel guides in
order to prevent a rattle of the glass.
In summary, a backlite assembly with one or two
sliding windows must maintain a proper seal to eliminate
water leaks and wind/road noise in a closed position. The
slidable windows, without compromising the required seal,
must be easy to slide to facilitate the opening and
closing of the backlite sliding window. In the open
position, the sliding window must be secured in the
channel to prevent a rattle of the glass.
In a backlite assembly, the required features include
a tight seal and, conversely, easy sliding movement.
Adhesives are used to secure the backlite assembly in the
pickup truck and to secure the rubber seals and the guides
in the assembly. Slip coats and other lubricants are
often used to facilitate the sliding of the sliding glass
against the seal and the guide walls. Applying adhesives
and lubricants in such proximity on the same assembly adds
to the production costs and could cause quality problems
if either is applied improperly.
A window frame assembly for pickup truck backlites is
disclosed in U.S. Patent No. 5,294,168 to Kronbetter. The
Kronbetter window assembly includes a complex top and
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bottom rail with two channels, an outer channel for
mounting the two outer pieces of fixed glass and the
rubber sealing members, and an inner channel for securing
the guides and the sliding windows.
In Kronbetter, the assembly of the window frame
starts with the insertion of the guides into the inner
channels. Adhesive is applied to the outer channel to
secure the fixed window panes in the frame. The sliding
window panes are inserted into the guides and the bottom
metal frame segment and the bowed, top metal frame segment
are welded or otherwise bonded together. The sealing
members are then placed in the outer channel of the frame
to slidably and sealably engage the sliding windows in the
inner channel. The window frame assembly is then ready
for installation into a pickup truck.
The metal frame of the window assembly in Kronbetter
is expensive to manufacture and assemble. Pickup truck
manufacturers desire a less expensive window assembly that
is easier to mount and still meets all of the performance
requirements.
In recent years, motor vehicle glass suppliers have
been supplying to motor vehicle manufactures, modular
windows having urethane gaskets molded in situ by means of
a reaction injection molding (RIM) encapsulation process.
These gaskets encapsulate the peripheral edge of the glass
window and provide an effective seal between the glass and
the window opening in the metal automobile body. The
gasket is formed by inserting a glass sheet in a suitable
mold and injecting a liquid, plastic forming composition
about the periphery thereof which polymerizes and cures in
contact with the glass and tightly adheres thereto.
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Prior to the development of the reaction injection
molding process, vehicle window assemblies were comprised
of a plurality of elements, including adhesive sealants
applied around the marginal edges of the glass sheet,
suitable mechanical fasteners such as metal clips, and
exterior decorative trim strips disposed to cover the
junction between the marginal edges of the glass sheet and
the adjacent portion of the vehicle frame. These
structures were costly in both material and labor, and
were very difficult (if not impossible) to install using
robotics. In order to install the windows using robotics,
it was necessary that the windows have a gasket formed
around the perimeter thereof.
The initial vehicular window gaskets were formed from
a molded plastic material, such as polyvinyl chloride.
The relatively high pressure required for the PVC
injection molding process, however, resulted in glass
breakage and other production related problems. The PVC
window assembly process is described in U.S. Patent No.
4,072,340 to Morgan.
In the 1980's, the reaction injection molding
encapsulation process was developed to produce modular
windows which would reduce glass breakage and facilitate
the installation of motor vehicle windows by robots. U.S.
Patent No. 4,561,625 to Weaver describes the use of
polyurethane molded on the peripheral edges of the glass
at low pressures through the use of a RIM technique. The
polyurethane gasket was of great significance since it
eliminated the need for the conventional adhesive
sealants, ancillary metal clips and exterior decorative
trim strips disposed to cover the junction between the
marginal edges of the glass sheet and the adjacent
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_2152~~~
portions of the vehicle frame. The RIM encapsulated
gasket worked better than the polyvinyl chloride gasket
which was then being contemplated for use, in that the RIM
method of forming the gasket permitted it to be done at
lower pressures and accordingly substantially reduced the
incidents of breakage of the glass.
U.S. Patent No. 4,755,339 to Reilly et al. and U.S.
Patent No. 4,839,122 to Weaver disclose further details
regarding the method and apparatus for reaction injection
molding of window gaskets.
Metal brackets and spacers have been incorporated
into the reaction injection molding process to improve the
functionality of the glass. U.S. Patent No. 4,662,113 to
Weaver shows a window assembly used for door windows on
motor vehicles which is operated in a vertical manner. A
bracket is placed in the mold with the window glass and is
integrally secured to the window glass during the
formation of the gasket by the rim injection molding
process. The bracket provides a means to connect a
linkage or other drive means to the window glass to raise
and lower the window in the motor vehicle.
U.S. Patent No. 4,951,927 to Johnston et al. shows a
spacer element used to maintain spacing between two sheets
of glass. The spacer is positioned about the periphery of
the sheets of glazed glass prior to positioning the glass
in a mold for reaction injection molding to form an
encapsulating gasket around the peripheral edge portions
to produce a multiple glazed structure.
Because of the desirable features of the gaskets
formed by reaction injection molding, the process has been
used for several additional applications. U.S. Patent No.
5,060,440 to Weaver discloses two glass sheets flexibly
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connected by adjacent gaskets joined during the reaction
injection molding process. U.S. Patent No. 4,996,808 to
Weaver discloses an encapsulated window assembly in which
a preformed sheet of plastic material is place in the mold
prior to the gasket forming process.
SUMMARY OF THE INVENTION
In accordance with the present invention, there is
provided a window frame assembly provided with a sliding
glass mechanism and seal system for vehicular backlites.
The assembly includes a pair of fixed side window panes
secured between two brackets in parallel, spaced-apart
relationship, and one or more sliding windows slidingly
positioned in the bracket channels to close and open the
aperture between the fixed window panes.
The window frame assembly includes a pair of linear
channel brackets which form the top and the bottom of the
assembly. The fixed side windows, two generally
rectangular pieces of glass, are secured to the outer
faces of the channel brackets by a reaction injection
molding process, which forms a polyurethane gasket on the
periphery of the total assembly. The fixed side windows
are spaced apart to define an aperture which is opened and
closed by a sliding window. The channels in the top and
bottom channel brackets are inwardly facing channels for
securing the sliding window.
The polyurethane gasket formed around the periphery
is used for mounting the window assembly in the opening in
the body panel of the pickup truck. The gasket provides
a flush surface for improved sealing of the opening in the
body panel.
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During the reaction injection molding process, a
single gasket is formed around the periphery of the window
assembly plus on the two vertical internal edges of the
fixed side window glass. Consequently, the aperture
between the two fixed pieces of glass has a unitary, RIM
encapsulated gasket on all four sides of the aperture.
The single gasket includes horizontal gasket segments
formed on the top and bottom channel brackets and the
vertical gasket segments formed on the internal vertical
edges of the fixed side window glass to define an
aperture.
The gaskets about the aperture are formed with a
flexible lip to sealably engage the sliding window, which
may eliminate the need for a separate rubber sealing
member. The sliding window slides in the channels of the
channel brackets and is positioned to the lips of the
gasket to seal the aperture. If sufficient force can be
maintained by the sliding glass on the lip of the channel,
the need for an internal rubber sealing member is
eliminated. The elimination of the sealing member, which
is relatively expensive to make and install, is of
significant benefit to window assembly manufacturers.
However, the application of sufficient force to
provide a sealed engagement generally restricts the
sliding motion of the sliding window in the channels. The
required sliding force may be reduced by applying a
lubricant on the lip of the urethane gasket or by coating
the edges of the sliding window.
One means for reducing the sliding force is to spring
load the sliding glass window in the top and bottom
channel. A spring loaded glass guide may be place on the
corners of the top and bottom edges of the sliding window.
9
The spring arm of the guide forces the sliding window away
from the lip of the gasket when the window is in the range
of open positions to facilitate sliding of the glass. A
cam formed in the channel bracket or other similar
mechanism may be used to compress the springs and force
the sliding glass window against the lip of the gasket to
sealingly close the aperture in the closed position.
Another embodiment for the backlite window provides a
different channel configuration for obtaining the desired
seal about the aperture. Instead of using spring loading
with a cam formed in the channel, a channel liner is
inserted in a straight channel and the leading edge of the
sliding window is provided with an angled gasket. The
backlite includes the same single gasket formed around the
periphery of the window assembly plus on the two vertical
internal edges of the fixed side window glass such that
the aperture between the two fixed pieces of glass has a
unitary, RIM encapsulated gasket on all four sides of the
aperture. The gaskets about the aperture are formed with
a flexible lip to sealably engage the sliding window.
In this embodiment, the flexible lip is treated with
a slip coat. The angled surface of the leading edge
gasket facilitates the movement of the leading edge past
the lip of the gasket on vertical internal edges of the
fixed piece of glass. A channel liner is inserted in the
channel to minimize the vibration and rattling of the
sliding window. The channel liner may be flocked as is
conventional to enhance the sealing effect provided by the
RIM encapsulated gasket and to reduce sliding friction for
the sliding window. The flocked channel liner may be
provided in different colors as an interior trim element.
The leading vertical edge of the window is provided with
_2~~~5~~
an angled gasket formed by the RIM encapsulation process
or other similar molding process.
An object of the present invention is to eliminate
the requirements for a discrete sealing member to be
mounted about the aperture in the window assembly to
prevent water leaks. The lip of the outer seal around the
periphery of the assembly can be designed to sealably
engage the slider window without the sealing member,
thereby reducing the cost of the window assembly.
In circumstances where a discrete sealing member is
still required, the sealing member may be secured around
the aperture of the backlite assembly by the gasket formed
during the reaction injection molding process. The lip
for sealably engaging the sliding window is formed in the
sealing member. The polyurethane gasket secures and seals
the fixed side windows, the brackets and the rubber seal
to form an window assembly in a single reaction injection
molding process.
An object of the present invention is to simplify the
production process and improve the seal quality in a
backlite assembly. The gasket formed during the reaction
injection molding process secures the component parts in
the desired position and forms the seal around the
aperture of the backlite. In applications where a
discrete sealing member is still required, the gasket
secures the discrete sealing member about such aperture.
In any of the configurations, the seal about the aperture
is improved by the gasket, which can be formed in a single
reaction injection molding process step.
A further object of the present invention is to
simplify the metal frame required for the backlite window
assembly and to minimize the assembly costs. By using
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reaction injection molding to form a gasket around the
periphery for mounting the window assembly in a body
panel, the need for a metal frame is eliminated except to
provide a frame to connect the two fixed pieces of window
glass, and to provide a channel for positioning the
sliding glass window. A "U" or "L" shaped channel bracket
extending between the top and bottom edges of the fixed
glass windows along the horizontal path of the sliding
window is the primary requirement.
An additional object of the present invention is to
provide a sliding mechanism which makes the sliding window
relatively easy to slide and which does not rattle when
the window of the backlite window assembly is open.
Mounting the sliding window in the channel with spring
loaded glass guides separates the sliding window from the
gasket in the open position, and a cam device causes the
sliding window to sealingly engage the gaskets in the
closed position.
Another method for achieving the desired seal is to
place a lining in the channel and a sliding window gasket
on the leading edge of the sliding window. The sliding
window gasket is beveled at an angle such that the lip of
the gasket about the aperture deflects outwardly as the
sliding window is closed.
BRIEF DESCRIPTION OF THE DRAWINGS
The above, as well as other advantages of the present
invention, will become readily apparent to those skilled
in the art from the following detailed description of a
preferred embodiment when considered in the light of the
accompanying drawings in which:
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Fig. 1 is a front elevational view of the backlite
window assembly for a motor vehicle, such as a pickup
truck, as viewing the window assembly from inside the
pickup truck;
Fig. 2 is a perspective view of the top and bottom
channel brackets and the fixed side pieces of glass prior
to being placed in a mold for reaction injection molding
of the urethane gasket around the periphery of the such
parts:
Fig. 3 is a perspective view of the piece of sliding
glass with guides mounted on the top and bottom corners,
prior to insertion into the channels of the brackets;
Fig. 4 is a top view and Fig. 4A is a perspective
view of the sliding window guides with a spring portion
formed on the guides;
Fig. 5 is a front elevational view of the handle
mechanism used to open, close, and slide the sliding
window:
Fig. 6 shows a slot in the bottom bracket for
inserting the sliding window into the channel of the
bracket;
Fig. 7 is an enlarged fragmentary sectional top view
of the window assembly in Fig. 1 taken along the line 7-7
thereof:
Fig. 8 is an enlarged fragmentary sectional side view
of the window assembly in Fig. 1 taken along the line 8-8
thereof:
Fig. 9 is an enlarged sectional side view of the top
bracket showing the gasket, sliding window, and window
guide in the closed position;
13
- Fig. 10 is an enlarged sectional side view of the
bottom bracket showing the gasket, sliding window, and
window guide in the closed position;
Fig. 10A is enlarged sectional side view of a bottom
bracket showing an alternative embodiment having a
different lip configuration on the gasket, a narrower
bracket, and modified window guide in the closed position
Fig. 11 is a fragmentary view of the bottom bracket
showing the positioning of the cam and the window guide
when the sliding window is in a closed position;
Fig. 12 is top plan view of the bottom bracket
fragment in Fig. 11 taken along the line 12-12 thereof:
Fig. 13 is the top plan view of the bottom bracket
shown in Fig. 11 after the sliding window has been moved
to an open position:
Fig. 14 shows a discrete sealing member, such as a
rubber seal, which is secured about the aperture in the
backlite window assembly in an alternative embodiment:
Fig. 15 is a top plan view of the bottom bracket
fragment of a window assembly which includes the discrete
sealing member shown in Fig. 14, and shows the positioning
of the rubber seal when the aperture is closed;
Fig. 16 is a sectional side view of the bottom
bracket of the window assembly with discrete sealing
member, Fig. 16 showing the gasket, the sealing member,
sliding window, and window guide in the closed position.
Fig. 17 is top plan view, similar to the top plan
view in Fig. 12, of a bottom bracket fragment for an
additional embodiment having channel line in the channel
of the bracket for engaging the sliding window, and a
gasket formed on the leading edge of the sliding window;
and
14
CA 02152561 2004-05-19
Fig. 18 is the top plan view of the bottom bracket shown in
Fig. 17 after the sliding window has been moved to an open
position.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to Fig. 1, there is shown a backlite window
assembly 14 according to the present invention, ready for
installation into an opening in a body panel of a motor
vehicle, such as a pickup truck. The backlite window assembly
14 includes a bottom channel bracket 16,a top channel bracket
18, a pair of laterally spaced, fixed windows 20, 22 and a
single sliding window 24. With a single sliding window 24, a
side latching mechanism 40 is used. In the alternative, a pair
of sliding windows with a center latching mechanism can be used
in the backlite window assembly 14.
The backlite window assembly 14 also includes a single
gasket 26 formed by a reaction injection molding encapsulation
process as disclosed in U.S. Patents Nos. 4,561,625; 4,755,339;
and 4,839,122. The single gasket 26 extends about the
periphery of the assembly and includes bottom and top segments
28, 30 and side segments 32, 34. In addition, the single
gasket 26 includes the two internal vertical segments 36, 38,
all of the segments simultaneously and integrally formed during
the reaction injection molding process of fixed glass windows
20, 22. In general, the reaction injection molding process
includes placing the individual components in Fig. 2 into a
mold (not shown). When the mold is in the open position, the
two fixed glass windows 20 and 22 are positioned on the lower
section of the mold. The bottom
21~25~
and top brackets 16, 18 are then positioned in the lower
section of the mold. Seals are placed throughout the
molds in a known manner such that the seals cooperate with
selected portions of the fixed glass windows 20, 22: the
brackets 16, 18; and the mold sections to define the
gasket forming cavities. The cavities communicate with an
inlet means or gate for receiving a flowable polymeric
gasket forming material from a nozzle member. The gasket
forming material is adapted to polymerize and cure in situ
on the peripheral portions of the fixed glass windows 20,
22 and the brackets 16, 18. The gasket may be formed by a
reaction injection molding process using an elastomeric
material such as polyurethane, for example.
The brackets 16, 18 are positioned in spaced apart
relationship with the inner surface of the horizontal
edges of the fixed windows 20, 22 and secured thereto by
the gasket segments 28, 30. In the present application,
"inner" surface refers to the surface of the window or
bracket facing the inside of the vehicle after the
backlite window assembly 14 has been mounted in a body
panel. Conversely, the "outer" surface refers to the
surface facing the outside of the vehicle after
installation.
After completion of the reaction injection molding
encapsulation process, the window assembly 14 is ready for
insertion of the sliding glass 24 with handle mechanism
40, and installation of the completed window assembly 14
into the body panel of a vehicle. The reaction injection
molding process results in a integral molding along all
peripheral edges. The molded corners of the window
assembly provide a better seal than the overlap corners
used in backlite assemblies in the prior art.
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The fixed windows 20, 22 and the sliding window 24
are standard automotive type glass with optional tinting
and other sun screen capabilities. The brackets 16, 18
are generally U-shaped in configuration with the open
sides of the channels 42, 44 facing each other for
acceptance of the sliding glass 24. The channel 42 for
bracket 16 is formed by inner and outer side walls 46, 48
and bottom segment 50. The channel 44 for bracKet 1~
includes inner and outer side walls 52, 54 and top segment
56. Identical cams 58 are formed in the inner side walls
46, 52 of the brackets 16, 18.
Figs. 3, 4, and 4A show the sliding glass window 24
and the guides 60 secured to the bottom and top edges 62,
64 of the sliding glass window 24. The guides 60 include
a flexible spring arm 66, a base 68, and a vertical
actuator surface 70 with tapered or beveled edges 72. The
guides 60 are made from a polymer material with sufficient
resiliency to maintain the necessary spring force.
When positioned in channels 42, 44, the spring arm 66
of the guides is partially compressed to ensure the proper
tension engagement in the channels 42, 44. The spring arm
66 engages the outer side wall 48, 54, and the actuator
surface 70 engages the inner side walls 46, 52 of the
brackets 16, 18. The spring arm 66 has a rounded head 74
to facilitate the sliding movement in the channels 42, 44.
The guides 60 are positioned such that the actuator
surfaces 70 engage the cams 58 when the window 24 is in a
closed position. The spring arm 66 is fully compressed in
the closed position and the slidable window engages the
segments 28, 30, 36, 38 of gasket 26 with sufficient force
to form a seal around all four edges of the slidable
window 24. When the sliding window 24 is moved to an open
17
2~5~~6~
position, the spring arm 66 is only partially compressed.
The force of the spring arm 66 expanding from a fully
compressed position in the channels 42, 44 provides
sufficient force to move the sliding glass window 24 away
from the gaskets to permit improved sliding of the window
24. The force of the partially compressed spring arm 66,
however, is still sufficient to hold the window 24 in
tension to eliminate rattles caused by vibrational
movement of the sliding window 24.
The bottom and top edges 62, 64 of the sliding window
24 may include two or more guides 60 in spaced-apart
relationship on each edge. The guide may also be formed
in an elongate fashion such that only a single guide may
be used to facilitate the movement of a sliding window 24.
In the closed position, when the actuator surfaces 70
of the guides 60 engages the cams 58, the sliding window
24 is compressed against the gasket segments as noted
above. The polyurethane gasket 26 restricts the movement
of the sliding glass window 24 such that up to 20 pounds
of force may be needed to move the sliding glass window 24
the final distance to close the sliding window 24. In an
effort to reduce the closing force required to slide the
window 24 to a fully closed position, the handle mechanism
40 is designed to provide additional leverage to close the
window 24.
The handle mechanism 40 includes a fixed base 76
attached to the vertical gasket 38. The fixed base 76 is
provided with a groove 78 formed in the base 76 which
extends into sliding base 80. The sliding base 80 is
provided with an angle arm 82 pivotably connected to the
base 80 at pivot point 84. Rotating the handle 86 about
the pivot point 84 causes the tracking head 88 to move
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2~525~~
from a locked, close position to an open position and vice
versa. The handle mechanism 40 provides the additional
leverage needed to overcome the closing force of the
window 24 when the actuator surfaces 70 of the guides 60
engages the cams 58 in the closed position.
Other styles and configurations of handle mechanisms
40 may be used if sufficient force is generated to close
the sliding glass window 24. In addition, other styles
and configurations of guides 60 may be used to create the
proper forces to seal the edges of window 24 in the closed
position, and to force the window 24 away from the gaskets
28, 30, 36, 38 for improved sliding of the window 24 while
maintaining the desired stability in the channels 42, 44.
After the reaction injection molding process is
complete, the sliding glass window 24 with guides 60 must
be positioned between the bottom bracket 16 and the top
bracket 18. The sliding window 24 may be positioned
between the brackets 16 and 18 in the RIM molds such that
no gasket forming material is deposited and cured on the
sliding window 24. Another means of installing the
sliding glass window would be to temporarily flex open the
inner side walls 46 and 52 of the brackets 16 and 18 and
to wedge the sliding glass window 24 in place. Fig. 6
shows a gap 90 formed in bracket 16 by removing a segment
of the inner side wall 46. The window 24 may be inserted
into the brackets 16, 18 at the gap 90 and slid into
position. The sliding glass window 24 may also be
installed from one end of the brackets 16, 18 by
temporarily removing gasket 34 from the ends of the
brackets 16, 18 to facilitate the insertion of the sliding
glass window 24.
19
21525~~
The completed window assembly 14 is shown in greater
detain in Figs. 7-10. The gasket 26 includes a notch 92
on the inner edge of the gasket 26 for seating the
assembly 14 in a side panel of a pickup truck (not shown).
The outer surface 94 of the sliding window 24 engages the
tip 98 of lip 96 formed in gasket 26 about the aperture
between the fixed windows 20, 22. The lip 96 is formed on
all four sides of the aperture and provides an excellent
means for sealing the aperture so long as the force of the
sliding window 24 is sufficient to sealing engage lip 96.
The gasket 26 may have different body configurations in
various segments, such as the bottom gasket segment 28
shown in Fig. 10 and the top gasket segment 30 shown in
Fig. 9. However, the lip 96 provides the same sealing
affect around the periphery of the aperture between the
two fixed windows 20, 22.
The lip 96 is integrally formed with the gasket 26
during a single reaction injection molding process. The
lip 96 is formed on the full length of the vertical gasket
segments 36, 38 and on the center portions of horizontal
gasket segments 28, 30. Because no separate sealing
pieces are required to be inserted in an additional
channel and sealed in such channel, the integrity of the
seal in the present invention is superior to seals in the
prior art. In addition, the labor and material needed to
provide an acceptable seal is substantially reduced.
In Fig. 7, the positioning and relationship of the
cams 58 and the guides 60 are shown. The cams 58 urge the
sliding glass 24 toward the lip 96 to completely seal the
aperture between the fixed windows 20, 22. The lip 96 is
formed from an elastomeric material which has sufficient
flexibility and resiliency to exert a pressure to seal the
215256
perimeter of the aperture without breaking the sliding
window 24, and to maintain the desired seal over an
extended period of operation.
Figs. 8-10 show the positioning of the guides 60 in
brackets 16, 18, and the engagement of the gasket lip 96
and the outer surface 94 of the sliding window 24. The
lip 96 formed on the bottom and top 28, 30 segments of
gasket 26 is the same configuration as the lip 96 on the
vertical segments 36, 38 of the gasket 26.
The guide 60 engages the outer wall 48, 54 and inner
wall 46, 52 of the respective channels 42, 44. When the
sliding window 24 is closed, the guide 60 engages the cam
58 to urge the window 24 towards the lip 96 to compress
the spring arm 66 and increase the seal between the lip 96
and the window 24.
When the sliding window 24 is open, the guide 60 does
not engage the cam 58 and the spring arm 66 is only
partially compressed to maintain the guide 60 in tension
in the channels 42, 44. Such tension minimizes any
vibration or rattles as the vehicle is being driven. The
tension force is transverse to the sliding path of the
window 24. Consequently, the spring tension of the guides
60 does not restrict the sliding of the window 24 or
increase the sliding force required to slide the sliding
window 24.
As the force of the sliding window 24 against the lip
96 increases to increase the integrity of the seal, the
force required to slide the window 24 also increases.
Consequently, the cam 58 is positioned such that the extra
force to seal the aperture is applied only after the
leading edge 104 of the sliding window 24 has cleared the
lip 96 of vertical gasket segment 38 as the window 24 is
21
_215~~61
being closed. As a result, the extra force is added only
at the point of closing.
When the window is opened and the guide 60 disengages
the cam 58, the spring arm 66 pushes the sliding window 24
away from the lip 96 to reduce the force needed to slide
the window 24 along the range of open positions.
The design parameters effecting the sealing forces
and the sliding forces, such as spring force of the guide,
the width of the channels, and the length and shape of the
lip, can be adjusted to achieve the desired sealing and
sliding performance characteristics using the single
gasket formed by a single reaction injection molding
process. Figs. 10 and l0A show two configurations of the
bottom bracket 16. Fig. 10 is the cam 58, guide 60 and
lip 96 shown in Figs. 4-9. In Fig. 10A, the bracket 106
has a narrower channel 108 and a guide 110 with no or very
little spring. The cams 112 have been significantly
reduces in size. The overall tighter fit of the sliding
window 100 in the channel 108 may reduce rattles and
provide a tighter seal, but the required force for sliding
the window is increased.
In order to reduce the sliding force, the tip 114 of
the lip 96 had been rounded. A lubricant can be added to
the lip 96 or the outer surface 102 of the window 100 to
reduce the required sliding force to open the window 100.
Various coatings may be applied to outer surface 102 of
window 100 or the lip 96 in a standard production process.
Silicon based coatings and other slip coatings are known
in the art.
As shown in Fig. 10, the bottom bracket 16 includes a
drain provision 116 for directing any water to a plurality
of miniature weep holes 118 in the drain 116. Because the
22
_2~525~~
present invention does not require a rubber gasket or
other full length guide in the channel 42, the weep holes
118 can be positioned at appropriate intervals and can be
make significantly smaller to reduce wind noise which can
occur at the drain holes.
In Figs. 11-13, the impact of the cam action at the
closing point is shown in greater detail. The single, RIM
encapsulated gasket segment 38 of gasket 26 is secured
about fixed window 22. The actuator surface 70 engages
the cam 58 to compress the spring arm 66 when the window
24 is closed. The lip 96 of both the vertical gasket
segment 38 and the bottom gasket segment 28 engages the
outer surface 94 of the window 24. When the window is
opened and the actuator surface 70 clears the cam 58, the
spring arm 66 forces the window away from the lip 96 to
reduce the frictional force of the window 24 sliding
against the lip 96. The spring effect is highlighted in
Fig. 13 by showing a slight gap 120 along the outer
surface 94 if the window 24. In actual operation, the
window 24 will remain in contact with the lip 96, but with
substantially less engagement force in the open position.
Some vehicle manufacturers still prefer a discrete
rubber gasket for sealably engaging the sliding window in
a backlite window assembly. Figs 14-16 show an additional
embodiment having a discrete sealing member 132 for
inclusion in a assembly 130 (shown only in fragmentary
views of Figs. 15-16). The brackets 16, 18; the fixed
windows 20, 22; the sliding window 24; and the brackets 60
shown in assembly 14 and assembly 130 are identical and
the same reference numbers are used in both embodiments.
The primary differences between the first and second
embodiments are the addition of a discrete sealing member
23
_ 2~.~25~
132 and a change in the configuration of the gasket 138,
140 about the aperture in the assembly 130 in the second
embodiment.
The sealing member 132 is typically made from rubber
or other similar sealing material. The sealing member
includes a body portion 134 and an extended lip 136. The
extended lip 136 is similar in function to the lip 96
formed by the encapsulated gasket of window assembly 14.
In window assembly 130, the reaction injection
molding process includes the proper positioning of the
sealing member 132 in the mold. The sealing member 132
defines the aperture in window assembly 130.
The encapsulated gasket is formed in a single
reaction injection molding encapsulation operation. The
resulting gasket is a one-piece gasket formed about the
periphery of the window assembly 130 and the aperture
between the fixed windows 20, 22. The one-piece formation
provides a unitary gasket which significantly reduces
leakage problems.
The main difference between the gasket in the second
embodiment and the gasket in the first embodiment is in
the segments around the aperture between the fixed windows
20, 22. The gasket includes a vertical segment 138 to
sealably join the sealing member 132 and the fixed windows
20, 22. The horizontal segments 140 of the gasket
sealably join the sealing member 132 to the brackets 16,
18.
The reaction injection molding encapsulation process
eliminates the need for a two channel bracket and improves
the seal about the aperture.
In addition to the reaction injection molding process
for forming a polyurethane gasket, other molding processes
24
and materials can be used to form the gasket. An elastic
polyvinyl chloride material could be used to form a gasket
for the window assembly of the present invention.
Figs. 17-18 show an additional embodiment of a window
assembly 142 (shown only in fragmentary views). The fixed
windows 20, 22: the sliding window 24 with vertical edge
104 and outer surface 94: the gasket 26 with gasket
segments 28, 38; and the lip 96 in window assembly 142 are
identical to the windows and gaskets of the prior
embodiments (same reference numbers). The window assembly
142 includes a top and bottom bracket 144 with a straight
channel 146. The integral gasket 26 is formed as noted
above in a single process step. However, in this
embodiment, no cams are required in the channel 146 and no
guides are required on the top and bottom edges of the
sliding window 24.
A channel liner 148 in channels 146 continuously
engages the horizontal top and bottom edges 62, 64 of the
sliding window 24 and maintain the sliding window 24 in
tension in the channels 146 without the use of the guides.
The overall tighter fit of the sliding window 24 in the
channel 146 reduces rattles and provides a tighter seal.
The channel liner 148 is a flocking material or other
similar material used to support and seal vehicle windows.
A leading edge gasket 150 is formed on the vertical
edge 104 of the sliding window 24 to facilitate a sliding
movement past the lip 96. The leading edge gasket 150 is
provided with a beveled or tapered outer edge 152 to
slidingly engage the sealing lip 96 of the gasket 38 as
the sliding window 24 is being closed. Without the gasket
150, the edge 104 of the sliding window 24 would have a
tendency to bend the lip 96 inside the channel 146, which
would prevent the sliding window 24 from closing properly.
When the sliding window 24 is being closed, the tip 98 of
the lip 96 slides up the beveled surface 152 and along the
outer edge 154 of the gasket 150. When the sliding window
is closed, the lip 96 engages to outer surface 94 of the
sliding window 24 to seal the aperture.
To improve the sliding characteristics of the window
assembly 142, the lips 96, the gasket 150, and/or the
outer surface 94 of the window 24 may be treated with a
slip coat. Silicon based coatings and other slip coatings
are known in the art.
The edge 156 of the gasket 150 on the outer surface
94 may be beveled to facilitate the flexing of the lip 96
during the movement of the sliding window 24 from a closed
position to an open position. The gasket 150 may be made
by using the RIM encapsulation process or other similar
molding process.
The slidable window engages the segments 28, 30, 36,
38 of gasket 26 with sufficient force to form a seal
around all four edges of the sliding window 24. The outer
surface 94 of the sliding window 24 engages the tip 98 of
lip 96 formed in gasket 26 about the aperture between the
fixed windows 20, 22. The lip 96 is formed on all four
sides of the aperture and provides an excellent means for
sealing the aperture so long as the engagement force of
the sliding window 24 against the gasket 26 is sufficient
to sealing engage lip 96 formed about the aperture.
When the sliding window 24 is open, the channel liner
148 maintains the sliding window 24 in tension within the
channels 146. Such tension minimizes any vibration or
rattles as the vehicle is being driven. A latch 40 is
used to latch the window 24 is a closed position.
26
_2~~~~~1
The design parameters effecting the sealing forces
and the sliding forces, such as the channel liner
material, the width of the channels, and the length and
shape of the lip, can be adjusted to achieve the desired
sealing and sliding performance characteristics using the
single gasket formed by a single reaction injection
molding process.
The window assembly 142 with channel liner 148 and
leading edge gasket 150 shown in Figs. 17-18 could also be
combined with the discrete sealing member 132 having a
body portion 134 and sealing lip 136 shown in Figs. 15-16.
The open and closing feature of the leading edge gasket
150 would remain the same. The lip 136 of the discrete
sealing member 132 engages the outer surface 94 of the
sliding window 24 to seal the aperture.
In accordance with the provisions of the patent
statutes, the present invention has been described in what
is considered to represent its preferred embodiment.
However, it should be noted that the invention can be
practiced otherwise than as specifically illustrated and
described without departing from its spirit or scope.
30
27
