Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
cM'ElVIgNI_WINDOW HINGE WITH REDU.CED RAS11-5AQ
[0001]
BACKGROUND OF THE INVENTION
[0002] The present invention relates to casement window hinges and in
particular to a casement
window hinge reducing sash sag.
[0003] Casement window hinges allow a window to open by pivoting about a
vertical axis that
moves inward as the window opens, This combination motion is provided by
special casement
window hinges supporting the window sash. A separate operator moves the window
as mounted
on the hinges, typically using a crank mechanism.
[0004] Casement window hinges typically employ a two-bar linkage of a sash arm
and guide
arm. The sash arm is attached along the window sash, for example, by
countersunk wood screws
directed up through the sash arm into the wood of the sash. An inward end of
the sash arm is
pivotally attached Co a slide that may move along a track attached to the
window opening and
that defines the movable pivot point of the window. A center of the sash arm
is pivotally
attached to one end of a guide arm whose remaining end of the guide arm is
pivotally attached to
the track displaced from the slide.
[0005] The sash arm and guide arm can be subject to large forces, for example,
during shipping,
installation, or when the window is subject to wind loads. For this reason,
the sash arm and
guide arms are typically fabricated out of a sturdy material such as stainless
steel. They are
connected together, typically, by a metal rivet that Is lightly stakcd to
allow the parts to pivot.
Normally the slide is also riveted to the sash arm.
[0006] A typical casement window has a total sash weight of 3010 160 pounds
and when closed
may be supported by a one inch wide slide at the edge of the sash. This
support point may be 10
to 20 inches from the center of gravity of the window. The offset between the
support point and
the center of gravity tends to tilt the top of the sash downward, the hinging
side of the sash away
from the support frame, and the bottom of the sash downward towards the
support frame.
Looseness in the hinge joints or the attachment screws in the hinge track from
aging vvood, or in
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the hinge arms, will allow more tilt. Size on size attachment screws and tight
hinge joints
minimizes the tilt but nevertheless ultimately still permit the sash to sag
over time under weight
of the glass. This sagging causes a deformation of the window from a true
rectangle and can
prevent closing the window to fit within the rectangular window opening
without interference
between the window and the opening and/or the casement window hinges.
[00071 Accordingly, it is known to attach the guide arm to the track or window
opening with an
eccentric pivot pin allowing the guide arm of the lower casement window hinge
to be shortened
to provide an upward lifting force on the sash as it is closed helping to lift
it into position.
Significant amounts of sash sag over time can impose substantial compression
on the guide arm
and its pivot point, requiring stronger materials to resist buckling and pivot
pins requiring greater
adjustment forces to prevent unwanted movement of the pivot pins under greater
guide arm
forces.
BRIEF SUMMARY OF THE INVENTION
[00081 The present invention provides a casement window hinge with a thickened
guide arm that
supports the sash against the track when the window is closed to reduce window
sash sag. In one
embodiment, this thickness is obtained by a thermoplastic guide arm that can
provide the
necessary dimensions, lubricity and shape to produce the necessary support
when the window is
closed. Practical and robust hinging of the thermoplastic guide arm and sash
arm together is
provided by a wood screw that can be stabilized in the sash itself.
[00091 Specifically, one embodiment of the present invention provides casement
window hinge
having a longitudinally extending track attachable along a window opening
surface with a slide
retainable by the track for movement therealong. A sash arm is pivotally
attached to the slide at
an inner end attachable to a window sash surface opposed to the window opening
surface when
the window is closed and a guide arm is pivotally attached at one end to the
track and at the other
end to the sash arm. At least a portion of an abutting guide arm and track
substantially fills the
space between the window opening surface and the window sash surface when the
window is
closed to support the window sash surface along the portion of the guide arm.
[0010] It is thus a feature of at least one embodiment of the invention to
provide a system that
reduces sash sag by supporting the sash when it is closed against the adjacent
window opening.
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100111 The guide arm may include a thickened portion providing a surface of
the guide arm
adjacent to the window sash when the window is closed substantially aligned
and parallel with a
corresponding surface of the sash arm attached to the window sash.
[0012] It is thus a feature of at least one embodiment of the invention to
employ the guide arm as
a sash-supporting spacer when the window is closed.
[0013] The guide arm may be a thermoplastic material.
[0014] It is thus a feature of at least one embodiment of the invention to
provide a lightweight,
low friction material suitable for this space filling function. It is a
further feature of the invention
to provide a casement window design amenable to the use of a thermoplastic
guide arm.
[0015] The guide arm may provide a sloped surface adjacent to the window sash
when the
window is closed and angled with respect to a plane of the window sash to
guide the window
sash surface up along the guide arm as the window closes.
[0016] It is thus a feature of at least one embodiment of the invention to
provide a guide arm that
can help realign the sash as the window is closed when there is minor sash
sag.
[0017] The longitudinally extending track may have at least one countersunk
hole for receiving
wood screws for holding the longitudinally extending track to the window
opening surface and
the guide arm may provide at least one notch on a surface abutting the
longitudinally extending
track in the vicinity of at least one countersunk hole.
[0018] It is thus a feature of at least one embodiment of the invention to
provide the space filling
guide arm of the present invention without interference with mis-centered
attachment screws
protruding from the track.
[0019] The guide arm may be attached at an end of the sash arm.
[0020] It is thus a feature of at least one embodiment of the invention to
prevent interference
between the sash arm and thickened portions of the guide arm by employing a
shortened sash
arm
[0021] The casement window hinge may further include a pivot between the guide
arm and the
track comprising a boss pivotally attached to the track and received in a snap
fit with a
corresponding bore in the guide arm.
[0022] It is thus a feature of at least one embodiment of the invention to
permit rapid assembly
of the casement window hinge by snapping engagement of these parts.
[0023] The boss may be eccentrically mounted for rotation with respect to the
track.
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[0024] It is thus a feature of at least one embodiment of the invention to
provide for ancillary
correction of sash sag by compressive force exerted upward on the sash by the
guide arm.
[0025] The snap fit may be provided by an interfitting ridge and groove formed
at a
circumferential interface between the boss and corresponding bore.
[0026] It is thus a feature of at least one embodiment of the invention to
provide an assembly
technique suitable for use with thermoplastic components.
[0027] The distance between a surface of the guide arm adapted to contact the
window sash
surface and the surface of the longitudinally extending track contacting the
window opening
surface, before engagement of the snap fit between a partially assembled guide
arm and boss,
may be greater than the separation between the window opening surface and the
window sash
surface when the window is closed.
[0028] It is thus a feature of at least one embodiment of the invention to
provide a positive
indication that the boss and guide arm are not completely assembled when the
window is first
closed caused by interference between the guide arm and window. This feature
prevents
accidental sash fall out if the top guide arm is not completely assembled to
the track boss which
may happen with traditional steel casement hinges.
[0029] The exposed face of the boss includes a hexagonal bore for receiving a
hex-wrench for
rotation of the boss.
[0030] It is thus a feature of at least one embodiment of the invention to
provide a compact but
high torque method of rotating the eccentric pivot.
[0031] A second embodiment of the invention provides a casement window hinge
having a
longitudinally extending track attachable to a window opening and a slide
retainable by the track
for movement therealong. A sash arm is pivotally attached to the slide at an
inner end attachable
to a window sash and a guide arm is pivotally attached at one end to the track
and at the other
end to the sash arm. The sash arm and a guide arm are constructed of a
moldable thermoplastic
material and are joined by a wood screw passing through corresponding holes
formed in the sash
arm and guide arm to extend into the sash.
100321 It is thus a feature of at least one embodiment of the invention to
provide a casement
window hinge that may employ thermoplastic linkage arms pivotally connected to
each other and
yet robust against high casement window forces. By employing a pivot pin that
may screw into
the sash, the pivot pin is stabilized by the sash, improving strength and
stability.
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[0033] The sash arm may include a collar portion surrounding the hole in the
sash arm and
extending into the hole in the guide arm to provide a bearing surface between
the sash arm and
guide arm separating the wood screw from the guide arm.
[0034] It is thus a feature of at least one embodiment of the invention to
provide a desirable
plastic-to-plastic interface in the pivot between the sash arm and guide arm
when using a wood
screw as a pivot.
[0035] The hole in the sash arm may be smaller than a crest diameter of
threads of the wood
screw.
[0036] It is thus a feature of at least one embodiment of the invention to
reduce pivot play by
threading the screw into the plastic of the sash arm.
[0037] The collar of the sash arm, when inserted in the guide arm, may extend
into a counter
bore for receiving a head of the wood screw in the guide arm and the end of
the collar exposed in
the counter bore may be staked over a bottom of the counter bore to retain the
engagement
between the sash arm and the guide arm without the wood screw.
[0038] It is thus a feature of at least one embodiment of the invention to
provide retention of the
sash arm and guide arm for installation before attachment using the screw.
[0039] The track may include a cantilevered cut-out deformed to extend into a
path of travel of
the slide, blocking travel of the slide unless the cantilevered portion is
depressed.
[0040] It is thus a feature of at least one embodiment of the invention to
provide a simple yet
robust stop against over-opening of the casement window.
[0041] These particular features and advantages may apply to only some
embodiments falling
within the claims and thus do not define the scope of the invention.
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BRIEF DESCRIPTION OF THE DRAWINGS
[0042] Fig. 1 is a top plan view of the casement window hinge, of a first
embodiment of the
present invention, showing the sash arm, guide arm, slide and track structures
common to hinges
of this type;
[0043] Fig. 2 is a top plan view of the slide of Fig. 1 showing an extension
with a living hinge
providing a stop for the window at full opening;
[0044] Fig. 3 is a cross-sectional view through lines 3--3 of Fig. 1 showing a
thermally formed
flange on a pivot pin attaching the sash arm to the slide, the flange received
within a counter bore
in a slide to remain recessed within the slide;
[0045] Fig. 4 is a fragmentary perspective view of a pivot mechanism
connecting the guide arm
to the track showing an eccentric mechanism for adjusting the effective guide
arm length;
[0046] Fig. 5 is a cross-section through lines 5--5 of Fig. 4 showing assembly
of the eccentric
mechanism to a coined post on the track;
[0047] Fig. 6a is a phantom view of a prior art countersunk bore in the sash
arm;
[0048] Fig. 6b is a figure similar to that of Fig. 6a showing a bore with
extended surface area
providing increased pullout resistance to wood screws;
[0049] Fig 7 is a front elevational view in partial cross-section of the track
and slide of the
present invention showing a flared track channel permitting alignment of the
slide with the track
for windows for ease of assembly;
[0050] Fig. 8 is a figure similar to Fig. 7 in side elevation, showing a
chamfer on the slide
permitting alignment of the slide and the track;
[0051] Fig 9 is a fragmentary perspective view of the extension of Fig. 2 and
corresponding stop
formed in the slide;
[0052] Fig. 10 is a top plan view of the casement window hinge, of a second
embodiment of the
present invention, showing the sash arm, guide arm, slide and track
structures;
[0053] Fig. 11 is a fragmentary detail view in partial cutaway of the track of
Fig. 10 showing an
alternative stop mechanism to that shown in Figs. 2 and 9 employing a cutout
of the track wall;
[0054] Fig. 12 is a fragmentary front elevational view of the cutout of Fig.
11;
[0055] Fig. 13 is an exploded fragmentary perspective view of an attachment
between the sash
arm and the slide providing an alternative to that shown in Fig. 3;
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[00561 Fig. 14 is an exploded perspective fragmentary view of an eccentric
boss joining the
guide arm and track in an alternative to the mechanism shown in Fig. 4;
[0057] Fig. 15 is a cross-section through lines 15--15 of Fig. 14 showing
assembly of the boss to
the track for this alternative mechanism;
[0058] Fig. 16 is a series of expanding, fragmentary cross-sections showing
support of the sash
by the guide arm when the window is closed and attachment of the guide arm to
the sash arm
with a sash engaging screw; and
[0059] Fig. 17 is a fragmentary cross-section along lines 17--17 of Fig. 16
showing support of
the sash on the guide arm when the window is closed.
DETAILED DESCRIPTION OF THE INVENTION
First Embodiment
[0060] Referring now to Fig. 1, in a first embodiment, a casement window hinge
10 may include
a sash arm 12 that may be attached to a window sash 15 by means of mounting
holes 14
receiving countersunk head wood screws (not shown in Fig. 1) upward through
the sash arm 12
therethrough. A proximal end of the sash arm 12 is pivotally attached to a
slide 16 that may
move along a length of a metal track 18 as retained by a rolled flange 20 in
the metal track 18.
[0061] A proximal end of a guide arm 22 is pivotally attached to the track 18
at an end 23 of the
track 18 removed from the travel range of the slide 16, and a distal end of
the guide arm 22 is
pivotally attached to a midpoint 24 of the sash arm 12. The sash arm 12 and
guide arm 22 form a
two-bar linkage providing a simultaneous pivoting and translation of an
attached window sash.
The general structure of hinges of this type is described in U.S. patent
6,088,880 to LaSee,
assigned to the assignee of the present invention and hereby incorporated by
reference.
[0062] Referring now also to Fig. 2, the slide 16 includes a leftward
extending stop arm 41
whose end may abut a stop 40 formed in the track 18 to prevent the window from
opening too far
as will be described below.
[0063] A rear edge of the slide 16 and stop arm 41 supports an upwardly
extending ridge 17 that
may be captured under the rolled flange 20 of the track 18, This ridge 17
extends leftward from
a slide body 19 to provide a living hinge 27 between the slide body 19 and the
stop arm 41
allowing the latter to flex to an assembly position 38 away from the stop 40
so that the slide 16
may be assembled into the track 18 at a portion of the track 18 not having the
rolled flange 20.
Upon completion of that assembly, the natural elasticity of the living hinge
27 returns the stop
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arm 41 to the straightened position so that leftward travel of the slide 16 is
ultimately blocked by
the stop 40.
[0064] Referring now to Fig. 3, the slide 16 and distal end of the sash arm 12
include counter
bored holes 21 having a principal diameter 28 and a counter bore 26 with a
diameter 30 on their
underside diameter 30 being larger than principal diameter 28. Corresponding
pivot pins 44 on
the sash arm 12 may extend downward from the surface of the sash arm 12 to be
received within
these counter bores 26. The pivot pins 44 have a cylindrical shaft 34 with a
diameter conforming
to principal diameter 28 of the hole 21.
[0065] An end of the shafts 34 extending through the principal diameter 28 of
the bores 26 may
be thermally staked to create a flanged head 36 of diameter less than the
counter bore diameter
30 and a thickness less than the depth of the counter bore 26 to fit wholly
therein, but of diameter
greater than the principal diameter 28 of the counter bored holes 21 so as to
retain the pivot pin
44 within the counter bored holes 21. The staking process may be performed by
a number of
thermal staking techniques including ultrasonic or heated plate staking and
provides a near zero-
tolerance fit between a flanged head 36 and a seat of the counter bored holes
21 with very little
compressive force as a result of the melting of the material of the pivot pin
44.
[0066] In a second embodiment, the flanged head 36 may be preformed to a
diameter allowing a
snap fit with the counter bored holes 21. The flanged head 36 may be bored and
slotted to assist
in its compression during this snap fit.
[0067] Ideally, the pivot pins 44 are molded to be integral with the
thermoplastic sash arm 12, a
material choice for the sash arm 12 that is made possible by fabricating the
sash arm 12 of a
thermoplastic material strengthened, for example, with glass fiber. By
constructing both the sash
arm 12 and guide arm 22 out of thermoplastic, a plastic-to-plastic interface
is formed resisting
binding and destructive wear between the pivot pin 44 and the sash arm 12 or
guide arm 22.
[0068] As will be understood in the art, the slide 16 may also be molded from
a thermoplastic
material and typically is molded about a steel spine 43 which, in this case,
may include a hole
amply sized to allow the molding of the counter bored hole 21 into the slide
16.
[0069] Referring now to Figs. 1, 4 and 5, the attachment of the proximal end
of the guide arm 22
to the track 18 (constructed of sheet metal in the present invention) is
obtained through a molded
thermoplastic boss 46 attached to the track 18 (as will be described) and snap-
fitted into a
corresponding bore 48 in the proximal end of the guide arm 22. The boss 46 has
a generally
8
cylindrical outer surface and thus may rotate within the guide arm 22 when
twisted by a
screwdriver inserted into a slot 49 cut in the upper face of the boss 46. The
boss 46 provides a
rotation axis SO with respect to its attachment to the track 18 (as will be
described) that is
eccentric with respect to an outer circumference of the boss 46. Thus,
rotation of the boss 46
with respect to the guide arm 22 causes an effective change of the length of
the guide arm 22 as
may correct for sash sag as described generally in U.S. patents 4,790,106 and
5, 017,075,
assigned to the same assignee as the present invention,
100701 Referring to Fig. 5, the attachment of the boss 46 to the track 18 is
provided by means of
a coined protrusion in the track 18 providing an upwardly extending, upwardly
open tube 52
integrally formed in the track 18. The inside of this open tube 52 may be
threaded to receive a
pan head, hex drive, machine screw 60 whose head may retain the boss 46
against axial
movement with respect to the track 18 while allowing rotational movement of
the boss 46 about
the machine screw 60
[0071] The snap connection between the boss 46 and the guide arm 22 is
provided by opposed
downwardly cantilevered spring fingers 54 molded into the inner diameter of
the bore 48 of the
guide arm 22 receiving the boss 46. Teeth 56 at the lower edge of the spring
fingers face inward
to receive a corresponding outwardly open rim 57 in the lower edge of the boss
46.
[0072] Referring now to Figs. 6a and 6b, in a prior art, hole 14 receiving
countersunk head
wood screws to attach the sash arm 12 to a window sash provided an amply.sized
countersink
bore 63' cut through the sash arm 12 avoiding interference between a shaft of
the wood screw
and a too-small bore in a metallic sash artn 12. Limited conical
countersinking 62' is provided so
that the head of the wood screw would be flush with a surface of the sash arm
12 to prevent
interference in the opening and closing of the window by a protruding screw
head.
10073j In the present invention, the radius of the countersink bore 63 is
significantly reduced to
equal or be slightly less than the expected diameter of the shaft of a wood
screw. This reduction
in radius increases the total area of the conical countersinking 62 as a
square of the reduction in
radius to provide sufficient pullout resistance in the plastic of the sash arm
12. The conical
countersinking 62 provides a frustro-conical surface having an upper base of
greater diameter
and a lower base of lesser diameter. In the preferred embodiment, the radius
of the upper base is
no less than substantially twice the radius of the smaller base. The increased
risk of interference
between the smaller hole sin of the smaller base and the shaft of the wood
screw is remedied by
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the soft characteristic of the plastic material allowing the wood screw to
slightly enlarge this hole
as needed. The present inventor has determined that this radius reduction
provides a sufficient
pullout resistance to allow construction of the sash arm 12 from a reinforced
plastic material.
[0074] Referring now to Fig. 7, the slide 16 may be pulled upward by an amount
72 when sash
arm 12 is attached to a sash (not shown) in a window sash that is
dimensionally shorter than
expected. This can make it difficult to insert a guide ridge 17 of the slide
16 under the rolled
flange 20. For this reason, the present invention provides for an upward
flaring of the rolled
flange 20 to provide a funneling of the guide ridge 17 of the slide 16 into
the rolled flange 20
when the slide 16 is first assembled onto that track 18. Similarly, as shown
in Fig. 8, a rear edge
of the slide 16 includes a chamfer 76 so that, in the opposite situation,
where the slide 16 is
displaced downward when used with a window sash that is dimensionally taller
than expected,
the chamfer 76 guides the slide 16 up onto the surface of the track 18.
[0075] Referring now to Figs. 1 and 9, opening of the sash 15 such as would
move the sash 15
leftward 74 beyond a perpendicular orientation with respect to the track 18 is
stopped by
abutment of the stop arm 41 of the slide 16 against the stop 40. This portion
of the track 18 near
the stop 40 does not have a rolled flange 20 allowing the stop arm 41 to be
flexed by means of a
living hinge 27 away from the stop 40 for disassembly.
Second Embodiment
[0076] Referring now to Fig. 10, in a second embodiment, a casement window
hinge 110 may
include a sash arm 112 attached to a window sash 15 by means of mounting holes
114 in the sash
arm 112 receiving four pan head wood screws (not shown in Fig. 10) upward
through the sash
arm 112 into the sash 15. A proximal end of the sash arm 112 is pivotally
attached to a slide 116
that may move along a length of a metal track 118 as retained by a rolled
flange 120 in the metal
track 118.
[0077] An optional metal reinforcement strip 119 may be placed between the
proximal end of
the sash arm 112 and the slide 116 to add more stiffness to the sash arm on
very wide casement
sashes.
[0078] A proximal end of a guide arm 122 is pivotally attached to the track
118 at an end 123 of
the track 118 removed from the travel range of the slide 116, and a distal end
of the guide arm
122 is pivotally attached at the end 124 of the sash arm 112. As before, sash
arm 112 and guide
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arm 122 form a two-bar linkage providing a simultaneous pivoting and
translation of an attached
window sash.
[0079] Referring now also to Figs. 11 and 12, the track 118 may include a cut
out 140, for
example, produced by a die cutting operation and formed in its vertical rear
wall. The cut out
140 provides a cantilevered finger 141 separated from the track 118 on three
of four sides so that
it may be bent outward to extend flexibly into the path of the slide 116. The
cantilevered end of
the finger 141, extending from the track 118, prevents the slide 116 from
passing the finger 141
when the slide 116 approaches the finger 141 from the left, as shown, during
opening of the
window and thus prevents opening of the window too widely. The slide 116 may
be maneuvered
past the finger 141 in this direction, for disassembling of the window, by
using a slide release
lever 143 attached to the slide 116 by a living hinge, being molded with the
slide 116 from
thermoplastic, the slide release lever pressing the finger 141 into alignment
with the rest of the
track 118 against the natural spring resilience of the material of the finger
141. During assembly
of the window, the orientation of the finger 141 is such that motion of the
slide leftward naturally
presses the finger 141 into the track 118 allowing free passage of the slide
116.
100801 As shown in Fig. 7 above, the rear edge of the slide 116, like slide
16, supports an
upwardly extending ridge 17 that may be captured under the rolled flange 120
of the track 118.
100811 Referring now to Fig. 13, the slide 116 may include and in-molded steel
plate 136
positioned in a horizontal portion of the slide 116. A bottom of the steel
plate 136 is exposed at
the base of an upwardly extending counter bore 130 to receive the head 143 of
a brass rivet 144
so that the head rests directly against the steel plate 136. A shaft of the
rivet 144 may extend
through a hole centered in the counter bore 130 and pass through the steel
plate 136 and the slide
116 to engage a corresponding hole in the strip 119 and the sash arm 112 and
extend
therethrough. A shank of the rivet 134 may then be staked over the sash arm
providing a
pivoting connection between the sash arm 112 and the slide 116. Sliding motion
of the rivet 144
is largely limited to the interface between the rivet 144 and the slide 116 to
limit wear that might
otherwise occur between the rivet 134 and the sash arm 112.
100821 Referring now to Figs. 10, 14 and 15, the attachment of the proximal
end of the guide
arm 122 to the track 118 may be obtained through an eccentric pivot 146, for
example, machined
brass. The eccentric pivot 146 may be attached to a hole 152 in the track 118
receiving a
cylindrical stud 153 extending downward from the eccentric pivot 146. The end
of this stud 153
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passing through the track 118 may be staked over to capture the material of
the track 118 as
shown in Fig. 15 permitting rotation of the eccentric pivot 146 about the axis
of the stud 153.
This rotation may be facilitated by hexagonal flats 154 in the body of the
eccentric pivot 146 to
be turned by an open end wrench or the like.
[0083] The eccentric pivot 146 further includes an upwardly extending
cylindrical pivot pin 156
having a circumferential groove 157. An axis of this cylindrical pivot pin 156
is offset from the
axis of the stud 153 to provide a point of pivot that may be adjusted
eccentrically about the hole
152 by rotation of the eccentric pivot 146. A hex socket 158 may be cut into
the upper surface of
the cylindrical pivot pin 156 to augment the flats 154 for rotation of the
eccentric pivot 146.
[0084] Referring to Fig. 15, a bore 160 in the end of the guide arm 122 may
receive the outer
surface of the cylindrical pivot pin 156. The bore 160 may include flexing
fingers 162 having
radially inwardly extending teeth 164 that may engage the cylindrical groove
157 to provide a
snap fitting between the guide arm 122 and the eccentric pivot 146. Prior to
full engagement
between the guide arm 122 and the eccentric pivot 146, when the bore 160 only
partially receives
a cylindrical pivot pin 156, the height of the guide arm 122 above the track
118 will be such as to
cause interference in the closing of the window as will be described.
[0085] As previously described, rotation of the eccentric pivot 146 with
respect to the guide arm
122 causes an effective change of the length of the guide arm 122 as may
correct for minor sash
sag.
[0086] Referring now to Fig. 16, a window 170 of the type suitable for use
with the present
invention may include one or more glass panes 172 surrounded by a rectangular
sash 15 typically
of wood or the like. The sash 15 may fit into a window frame 176 defining a
window opening
by its internal periphery. Generally, when the window 170 is closed, there
will be a separation
distance 180 between the outer surface of the sash 15 and the window frame
176, above and
below the sash 15, in which the casement window hinges may rest.
[0087] The guide arm 122 in this embodiment of the invention may have a
vertical thickness 182
such that when an outer surface 184 (lower surface in Fig. 16) of the guide
arm 122 abuts the
inner (upper) surface of the track 118, when the latter is supported by the
window frame 176, the
inner surface 186 of the guide arm 122 abuts the lower surface of the sash 15
supporting the sash
15 over the length of the guide arm 122. Typically, this extent of support
will be on the order of
7 inches, or greater than 4 inches, or greater than 70% of the length of the
guide arm 122. As
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noted, the guide arm 122 may be constructed of a thermoplastic material
providing low friction
between its sliding contact with the track 118 and the sash 15.
[0088] The vertical thickness of the guide arm 122, which together with the
thickness of the
track 118, essentially fills the distance 180, ensures that any incomplete
attachment of the guide
arm 122 to the eccentric pivot 146 may be instantly detected as the window is
closed as the extra
height of the guide arm 122 above the track 118 will cause interference with
such closure,
something that may not occur with standard guide arms permitting such
misassembly to go
undetected.
[0089] Referring momentarily to Fig. 17, the inner surface 186 of the guide
arm 122 may be
beveled or canted in cross section with respect to the plane of the lower
surface of the sash 15 to
provide a guiding wedge surface lifting the sash 15 upward should sash sag
cause the separation
between the sash 15 and the frame 176 to drop below distance 180.
[0090] Referring again to Fig. 16, the lower surface 184 of the guide arm 122
may include
periodic notches 190 providing clearance with protruding heads 192 of wood
screws 194
attaching the track 118 to the frame 176. These notches 190 permit the close
sliding interaction
between the guide arm 122 and the track 118 allowing for support of the sash
15.
[0091] Referring still to Fig. 16, the pivoting attachment between the guide
arm 122 and the sash
arm 112 may be made by means of a wood screw 198 passing through both the
guide arm 122
and the sash arm 112 and into the sash 15. Stabilization of screw 198 in the
sash 15 protects the
thermoplastic sash arm 112 from forces imposed on it by the guide arm 122 such
as are
conducted into the sash 15 by the wood screw 198. The stabilization of the
screw 198 further
resists torsional deflection of the sash arm 112 and the guide arm 122 to
which it is attached.
[0092] The sash arm 112 may include an outwardly extending collar 200
surrounding the shaft
of the wood screw 198 as it passes both through the sash arm 112 and through
the guide arm 122.
A bore through this collar 200 may be smaller than a crested diameter 202 of
the threads of the
screw 198 so that the threads cut into the thermoplastic material of the bore
of the collar 200 may
reduce any play between the sash arm 112 and screw 198. The collar 200 further
provides an
outer bearing surface 204 between the sash arm 112 and the guide arm 122
receiving the collar to
provide reduced wear between these two components. The collar 200 may pass
through a bore
205 in the guide arm 122 and into a counter bore 206 in the guide arm 122
intended to receive
the head of the screw 198. There a protruding lip 207 of the collar 200 may be
swaged radially
13
CA 02738253 2011-04-27
outward to grip the bottom of the counter bore 206 thereby retaining the sash
arm 112 in
connection with the guide arm 122 prior to installation, simplifying assembly.
Screw 198 is then
tightened down onto the exposed lip 207 to be fully received within the
counter bore 206. The
collar 200 and lip 207 prevent rotation forces of the guide arm 122 from
unscrewing screw 198.
[0093] Referring still to Fig. 16, the pan head wood screws 113 used to attach
the sash arm 112
to the sash 15 (other than screw 198), may also fit into slightly undersized
holes through the
sash arm 112 to prevent shifting of the sash arm 112 along the sash 15. The
heads of the screws
113 may fit tightly against the surface of the sash arm 112 to also help
prevent slippage. In the
prior art, such slippage can permit sash sag on both the top and bottom hinges
caused by forces
generated by the offset center of gravity of the window sash.
[0094] Certain terminology is used herein for purposes of reference only, and
thus is not
intended to be limiting. For example, terms such as "upper", "lower", "above",
and "below"
typically refer to directions in the drawings to which reference is made.
Terms such as "left",
"right", "front", "back", "rear", "bottom" and "side", describe the
orientation of portions of the
component within a consistent but arbitrary frame of reference which is made
clear by reference
to the text and the associated drawings describing the component under
discussion. Such
terminology may include the words specifically mentioned above, derivatives
thereof, and words
of similar import. Similarly, the terms "first", "second" and other such
numerical terms referring
to structures do not imply a sequence, or order unless clearly indicated by
the context.
[0095] When introducing elements or features of the present disclosure and the
exemplary
embodiments, the articles "a", "an", "the" and "said" are intended to mean
that there are one or
more of such elements or features. The terms "comprising", "including" and
"having" are
intended to be inclusive and mean that there may be additional elements or
features other than
those specifically noted. It is further to be understood that the method
steps, processes, and
operations described herein are not to be construed as necessarily requiring
their performance in
the particular order discussed or illustrated, unless specifically identified
as an order of
performance. It is also to be understood that additional or alternative steps
may be employed.
[0096] Various features of the invention are set forth in the following
claims. It should be
understood that the invention is not limited in its application to the details
of construction and
arrangements of the components set forth herein. The invention is capable of
other embodiments
and of being practiced or carried out in various ways. Variations and
modifications of the
14
CA 02738253 2011-04-27
foregoing are within the scope of the present invention. It also being
understood that the
invention disclosed and defined herein extends to all alternative combinations
of two or more of
the individual features mentioned or evident from the text and/or drawings.
All of these different
combinations constitute various alternative aspects of the present invention.
The embodiments
described herein explain the best modes known for practicing the invention and
will enable
others skilled in the art to utilize the invention.
