Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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BAC~GROUWD OF THE INVENTION
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1. Field of the Invention
~ 'he invention relates to retracta~le window shade.s
and more particularly to such shades whicll ma~ be custom-
ized to any desired width by the user without tools
at the point of use.
2. Prior ~rt
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Retractabl~ winaow shades have been well kno~n for
many years. To provide a proper fit for the shades for
windows of various widths, it is necessary to adjust the
width of the entire shade assemblv. A retractahle shade
assembly customarily consists of a sheet of vinyl or other
material, a roller to which the sheet Oc ~aterial is
attached, a spring driven motor for driving the roller
and a light wei~ht slat inserted in a seam along the
bottom edge of the shade material to provide rigiditv.
The sheet may be made of a flexihle ~aterial such as a
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vinyl material which may be severed to facilitate fitting
of the shade to a window. Prior art shades have used
rollers and bottom slats which must be cut by a saw or
a like instrument. Furthermore, even when a prior art
shade has been provided with tear lines, the lower
edge of the material, which is folded over and seamed to
house the ~ottom slat, must be cut at the seam by a
knife or similar device.
In addition, window shade locking devices known
from the prior art have included gravity actuated pawls
pivoted about an axis parallel to the shade roller axis
and engagable with a notched cam or ratchet member.
Such devices of necessity had to be relatively large in
order to accommodate the pawls pivoting about axes a
substantial distance removed from the axis of the roller
and the ratchet member. Special axes had to be provided
to accommodate the pawls, and the pawls, pivots and
ratchet had to be manufactured in accordance with close
tolerances in the space provided.
Also taught in the prior art is a locking device
comprising a pair of matched members having elongated
slots extending in a direction parallel to the axis of
rotation and free floating pins having curved sections
inserted in holes extending in a direction transverse
to the direction to the axis of rotation. Such an
arrangement has the disadvantage that the relatively
light-weight pins, which are moved by the application of
gravitational and centrifugal forces, do not necessarily
engage or disengage the notched member at the desired
time.
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SUMMARY OF THE INVENTION
An object of this invention to provide a window
shade which may be readily adjustable in width without the
use of any tools.
A further object of the invention to provide a
window shade which may be adjusted to width and prepared
for hanging on support brackets in a few simple steps.
Another object of this invention to provide a smoothly
operating releasable automatic locking device for use in
combination with a window shade roller.
Yet a further object of this invention to provide
an enclosed substantially dust-free releasable automatic
. locking device for use in combination with a window shade
roller, which may be assembled as a unit and inserted in
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' a window shade roller without use of tools or machinery.
In accordance with the present invention,
a window shade apparatus intended for adjustment and fitting
~' at the time of installation by the ultimate user, comprises
, in combination:
a shade roller comprising interacting first and
second telescoping sections whereby the overall longitudinal
length of the roller may be adjusted within the limits of
the telescoping action;
a sheet of flexible web-like material having therein
a plurality of generally parallel spaced apart lines of weakness
extending substantially from end to end of said sheet; and
means attacning an end of said sheet to said shade
roller so that the plurality of lines of weakness extend
in a direction generally transverse to the longitudinal axis
of the shade roller.
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Preferably, the lines of weakness extend from the
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i;~ top portion to the bottom portion of the sheet and along
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at least one edge portion thereof, and are so formed that
when the sheet material is separated along one of them, a
generally clean, straight edge is formed, each of the lines
of weakness being preferably formed by a continuous cut which
penetrates into the sheet material by only a portion of its
thickness.
-~ The telescoping roller assembly may include a first
roller section, and a second roller section inserted into,
and axially slidable relative to, the first section thereby
permitting the overall length of the telescoping roller assembly
' to be adjusted.
Optionally, the apparatus may include first means
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for maintaining the sheet material fixed with respect to
the first telescoping section, and second means for maintaining
ii it fixed with respect to the second telescoping section after
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the second telescoping section has been inserted by a desired
distance into the first telescoping section.
~; 20 The first and second telescoping sections may comprise
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,'~ hollow tubular sections, and the apparatus may further comprise
; a pair of window shade support adaptors inserted in the telescoping
sections, each adaptor comprising a cylindrical body having
a diameter smaller than the inside diameter of the telescoping
sections with a plurality of longitudi.nally extending ribs
extending along its outer surface.
In window shade apparatus in accordance with the
present invention, a pocket may be formed in the sheet of
material by folding over a portion of the sheet and seaming
it by means of a seam consisting of a plurality of sections
; having defined spaces therebetween, with the lines of weakness
passing through certain of these spaces.
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bottom slat assembly may be associated with the
lower end portion of the sheet material, the length of such
assembly being adjustable so that it can be matched to the
adjusted length of said telescoping roller assembly and to
the selected width of the sheet material by the ultimate
user. Such a slat assembly may include a first section formed
, from wood of a length no greater than the width of the flexible
material which contains no lines of weakness, and at least
one second section which is carried by the first section
and is telescopically adjustable with respect to the first
section.
The first roller section may have a constant external
diameter from end portion to end portion. The outer end
portion of the first roller section may have first means
, for supporting the window shade apparatus from a first support
location. The second roller section may have a constant
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nominal external diameter from end portion to end portion,
being telescopically and slidably receivable within the first
roller section whereby the length of the roller assembly
can be adjusted within the limits of the range of telescoping
movement. Means precluding relative rotation between the
first and second roller sections may be provided. The outer
end portion of said second roller section may have second
means for supporting the window shade apparatus from a second
support location.
The lines of weakness may comprise cut lines in
the flexible sheet material in which the depth of cut from
the end of the sheet material proximate to the roller assembly
to a location adjacent the end of the sheet material removed
from the roller assembly is less than the thickness of the
sheet material and the cut lines extend completely through
the thickness of the sheet material at one end portion of
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the sheet material, thereby to provide a plurality of individual
tabs which may be manually grasped and pulled for the purpose
of severance of a side portion of the sheet material.
In embodiments which include the optional feature
of first and second means for maintaining the sheet material
fixed with respect to the first and second telescoping roller
sections, the means for maintaining the sheet material fixed
with respect to the second telescoping section may comprise
an adhesive substance carried by the second roller section
at locations commencing at the outer end portion thereof
and extending inwardly substantially the entire length of
the second roller section when it is extended to its maximum
length with respect to the first roller section, and a temporary
protective member overlying the adhesive substance at all
points, the protective member being removable by hand from
contact with the adhesive substance throughout that portion
of the length of the second roller section which extends
beyond the inner end of the first roller section, whereby
the adhesive substance may remain unactivated until just
prior to securement of the second portion of the upper end
of the shade to the roller assembly.
The flexible sheet material is preferably composed
of a plastics material having memory properties whereby the
lines of weakness are relatively imperceptible to the naked
eye when the flexible material is viewed from a short distance
away.
The window shade apparatus may comprise releasable
automatic locking means for use with the spring driven rotatable
shade roller, comprising two matched members adapted to be
fitted together to form a cylindrically-shaped member which
is adapted to be positioned inside a hollow end section of
one of the telescoping roller sections interengaged with
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the roller, and is provided with a first recess to form a
cylindrial bore extending coaxially with the axis of rotation
of the roller and a second recess extending in a direction
radially outward from said axis and continuing in a direction
parallel thereto, with a pair of pins extending
across the second recess in a direction perpendicular to
the said axis, a pair of substantially flat, elongate plates
- pivotally mounted on the pins, and a cylinder disposed in
the bore having a toothed wheel at one end, the elongate
plates being disposed for co-operative engagement with the
toothed wheel by application of gravitational force and disen-
gageable therefrom during rotation of the roller by application
of centrifugal force. Each of the matched members may be
provided with a semi-circularly-shaped recess adapted to
receive the toothed wheel, the matched members each having
an end panel at one end adapted to form an end panel for
the roller when the members are inserted in the hollow end
section of the roller. The elongate plates may be counter-
balanced by being pivoted at a point removed from the longitudinal
extremities thereof, and the cylindrically-shaped member
may comprise means at one end thereof adapted for non-rotational
engagement with a fixed mounting arrangement external to
the roller. The apparatus may further include a helical
coil spring; the cylindrically-shaped member being adapted
to fit in one end of said window shade roller and adapted
for engagement with the roller and one end of the spring.
According to another aspect of the present invention,
a method of manufacturing a window shade apparatus intended
for adjustment and fitting at the time of installation by
the ultimate user, comprising the steps of
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forming a plurality of spaced apart lines of weakness
in a sheet of flexible material, extending longitudinally
between the ends of the sheet; and
attaching one end of the sheet to a support roller
comprising first and second telescoping sections whereby
the overall longitudinal length of the roller may be adjusted
within the limits of the telescoping action, with the lines
of weakness in the sheet extending transversely to the longitudinal
axis of the support roller.
The method of manufacture may further include the
additional step of providing the window shade apparatus with
various optional features, as set forth above.
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~ In the particular embodiment of the invention here-
; inafter described in detail, the telescoping sections of
the roller assembly are interlocked to avoid rotation of
one section relative to the other. A motor adaptor is provided
at one end of the roller assembly for supporting a motor
which attaches to a window shade support bracket. Further,
an end pin adaptor is provided into which is inserted an
end pin which may be supported by a second window shade support
bracket. In the production assembly of the window shade,
the roller, with the adaptors installed is extended to the
full length of the shade material, as is the extendable bottom
slat. An adhesive material is applied to the outside surface,
in the longitudinal direction, of both the inner and outer
section of the telescoping roller. The adhesive surface
on the outside surface of the inner section, however, is
covered with paper or another suitable protective material.
When the shade is initially attached to the roller it is
attached only along the adhesive surface on the outer section
of the telescoping roller.
Further, a releasable automatic locking device
is disclosed, which device is preferably manufactured in
the form of two matched lnter-locking half sections which,
when fit together, form a cylindrically-shaped body with
a bore extending therethrough along its axis and two oppositely
oriented slots extending radially outward from the axis.
A pair of dowels extend from one of the two sections across
the slot into corresponding holes in the other matched
section. The dowels serve to align the two matched
sections and serve as a pivotal axes for a pair of
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substantially flat, oblong-shaped plates having a taper
in one direction. The plates are movable in the slots
and engagable with a toothed ratchet wheel having an
axis extending into the bore of the device. The plates,
which perform the function of the pawls in the most often
used prior art devices, are provided with an opening for
pivotal engagement with the dowels. The pivotal openings
are located a substantial distance inward from the e.nds
of the plates to provide counter balance when the plates
are pivoted about the dowels. The counter balanced
pawls, which are controlled by gravitational and centrifugal
forces when the shade is rolled up or down, provide for
smoother operation of the shade.
A substantially dust-free enclosure is provided
for the moving parts. The device is provided with an
end portion of expanded diameter having an end panel,
which forms a cover for the device and forms the end
cover for a shade roller in which it ma~ be installed.
Advantageously, the matched sections may be molded from
plastic or the like material without requiring machining
to close tolerances. The outside cylindrical surface
of the half sections are provided with ribbed sec~ions
for engagement with a ribbed inner surface of a shade
roller. A shoulder portion is provided on one of the
ribbed sections to allow for attachment of one end of
the driving spring to one of the half sections. The
shade motor assembly of this invention which comprises
a ratchet, pawls, spring, and housing, may be readily
assembled as a single ~mit and inserted in a shade
roller as a unit, thereby facilitating the manufacture
of spxing driven window shades.
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In accordance with this invention, installation of a
new shade has been reduced to a few simple steps, which
may be carried out without the need of tools. A standard
size window shade made in accordance with this invention
may be marked to the desired width by holding the shade in
~ront of the window to be fitted. The inner section of
the telescoping roller may then be pushed in until the
length of the telescoping roller coincides with the
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desired width of the shade. The shade may then be
unrolled and strip of the window material corresponding
to the excess width snay be torn along the tear line most
nearly corresponding to the outer edge of the newly
; positioned inner section of the telescoping roller. The
excess material is torn along the full length of the
tear line and after the bottom slat is adjusted to the
desired width, the entire excess strip of material may
i be removed. The protective cover is then removed from
the adhesive material on that portion of the inner
section of the telescoping roller which extends beyond
the outer seCtion. ~he portion of the material over-
lapping the newly exposed adhesive is simply pressed
down and the shade may be rolled up. When the extendable
bottom slat has been adjusted to the desired length, the
shade is ready for hanging.
BRIEF DESCRIPTION OF THE DP~WING
Fig. 1 is a perspective view of a window shade
incorporating certain features of this invention;
Fig. 2 is a cross-section of the inner section
- of the telescoping roller taken along the line 2-2;
Fig. 3 is a cross-section of the inner section
- of the telescoping roller taken along the line 3-3;
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Fig. 4 is a front view of the adjustable bottom
slat;
Fig. 5 is a cross-section of the bottom slat taken
along line 5-5;
Fig. 6 is an exploded perspective view of the end
pin and adaptor;
Fig. 7 is a perspective view of the shade motor
and motor adaptor;
Fig. 8 is a front view of the shade motor adaptor;
Fig. 9 is a cross-section of the motor adaptor
taken along the line 9-9;
Fig. 10 is a front view of the end pin adaptor;
Fig. 11 is a sectional view of the end pin adaptor
taken along the lines 11-11;
Fig. 12 is an exploded perspective view of a shade
motor assembly showing a preferred embodiment of the
invention;
Fig. 13 is a cut-away side view of a roller shade
assembly showing the shade motor assembly and s~ring
attachments~
Fig. 14 shows a section along the line 14-14 of
Fig. 13;
Fig. 15 shows a section along the line 15-15 of
Fig. 14;
Fig. 16 shows a section along the line 16~16 of
Fig. 15.
DETAIhED DESCRIPTION
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In Figure 1 is shown a sheet of material 101
having a plurality of tear lines 110 paralled to one
edge of the material. The thickness of the material may
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lie in the conventional range of from about 4 1/2 th~usandth's
of an inch to about 12 thousandth's of an inch. Such tear
lines may be formed by weakening the material along these
lines. This may be done, for example, by perforation,
making slits in the material without penetrating the material,
or chemically weakening the material using an etching
solution. The end portion 111 of each of the tear lines
may be cut or scored to facilitate the tearing of the
material along the tear lines. In this illustrative
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embodiment of the invention, the shade 101 may be attached
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to the outer section 120 of the telescoping roller by
means of an adhesive area 121. An adhesive area 123 is
also provided on the outer surface of the inner section 122
of the telescoping roller. However, the area 123 is
- covered with a paper overlay 124 or similar protective
materlal and remains covered until the shade has been
adjusted to the desired width, as will be explained later
herein. Such adhesive material for the ~trips 121 and 123,
which will adhere to the shade material, i9 readily
commercially available.
Further, as shown in Figure 1, the lower portion
of the shade material is folded over to form a pocket
103. A seam is made along the upper edge of the pocket.
Such a seam may be made, for example, by known heat or
ultrasonic sealing techniques. In accordance with this
invention, in order to facilitate removal of a strip of
material torn along one of the tear lines 110, the seam
is formed in accordance with a specified pattern producinq
an interrupted seam comprising several individual sections
112 separated by sufficient distance to avoid overlap of
any of the tear lines.
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Figure 4 shows an extendable bottom slat for use with
the window shades such as may be inserted in the pocket 103.
The extendable slat consists of three sections: two c~uter
sections ~01 and 402 which are substantially identical and
may ~e made of a light weight material such as a riqid
plastic or metal; and a center section 403, which may be
made, for example, of light weight lumber or similar
material. The dimensions of the center section 4g3
are chosen such that this section will fit snugly within
sections 401 and 402 generally as shown in Figure 5.
Figure 5 is a cross-section taken along the line 5-5
which shows the general construction of the external
sections 401 and 402 and the center portion 403.
As mentioned earlier herein, the roller of the shade
assembly consists of two telescoping sections. ~ cross-
section of the outer telescoping section 120 is shown
in Figure 2, as taken along the line 2-2 in Figure 1.
Section 120 comprises a hollow tube comprising a fold
over seam 201 extending inwardly of the tube in such a
manner that the e~cternal surface of the tube is substantially
smooth and the inner surface of the tube is provided with a
protrusion having a substantially rectangular shaped cross-
section of a specified width and thickness. ~igure 3 shows
a cross-section of the section 122 which forms the inner
tube of the telescoping roller. The tube 122 is provided
with a seam 301 similar to the seam 201 of the tubular sec-
tion 120. Additionally, the tubular section 122 is provided
with a recess 302 having a substantially rectangular cross-
section and having dimensions slightly greater than the
rectangular cross-section of the seam 201 of the section 120.
When the two telescoping sections 120 and 122 are brought
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together, the seam 201 will he aligned with the recess 302
and when the section 122 is slideably engaged with the
section 120, the seam 201 and the recess 302 cooperate to
provide an interlock between the two sections to prevent
rotation of one section relative to the other.
Figure 7 shows a shade motor adaptor 701 and a
spring driven shade motor, which provides the necessary
power to retract the shade. Fiaure 8 represents a front
view of the motor adaptor and Figure 9 shows a cross-
section of the motor adaptor taken along the line 9-9.
The adaptor which may be made of a plastic or the like
material i5 inserted in the accessible end opening 126
of the outer section 120 o~ the telescoping roller. The
adaptor is provided with several rib-like protrusions 703
having a slanted forward section 704. The diameter ~1
indicated in Figure 8 is selected to be slightly greater
than the inside diameter of the'tu~ular section 120 to allow
for a snug fit of the adaptor inside the tube. The slanted
forward sections 704 are pro~ided to facilitate entr~
into the accessible end opening 126. The distance between
adjacent ribbed sections 702 is selected to be sufficientl~
great to accommodate the seam 201. ~hen inserted properly,
the adaptor 701 will form an interlock with the seam 201
to prevent the rotation of the adaptor relative to the
tubular section 120. A known retractor motor of fhe
type depicted generally in Figure 7, may be fitted in
the recess 901.
Figure 6 shows an end pin adaptor 1001 and an
end pin 1002. End pins similar to the one shown in
Figure 6 are well known. The adaptor has a general
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, external shape similar to that of the motor adaptor 701.
A front view of the end pin adaptor is shown in Figure 10
and a cross-section taken along the line 11-11 of Figure
10 is shown in Figure 11. The end pin adaptor may be
inserted in the accessible end 128 of the inner section ~
122 of the telescoping roller. The outside diameter ~,
D2 indicated in Figure 10 is slightly less than the inside
diameter of the section 122 to allow for a snug fit
in the tubular end section. The distance between the
ribbed sections 1003 is chosen such that the seam
301 and the recess 302 of the tubular section 122 will
fit between adjacent rihbed sections, thereby providing
a rotational interlock between the,adaptor 1001 and
the tubular section 122. The end pin 1002 may be
inserted in the center opening 1005.
Referring now to Figure 12, first and second half
sections, 511 and 512 of a shade motor assembly are there
shown. As is apparent from the drawing, each half
section is provided with a cemi-circular hore, which allows
for the lnsertion of the cylinder 513 when the two half
sections are joined. One of the half sections, 511, is
provided with pegs or dowels 514 extending from the surfaces
515 of the hal section 511. The half section 512 is
provided with corresponding surfaces 515 and with matching , , ' '
holes 516 corresponding to the pegs 514 in position on the
surfaces 515, and adapted to receive the pegs 514. The
pegs 514 and the corresponding holes 516 may be better
visualized with respect to Figs. 1~ and 16. The purpose
of the pegs is to align the two half sections and to
provide pi~otal supports for the pawls 517. Since the
surfaces 515 of both half sections 511 and 512 are recessed,
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a space is provided when the two half sections are
~- snapped together to allow for the insertion of pawls
517, as shown for example in Fig. 16. The pawls 517
comprise substantially flat, elongated plates as shown
in Fig. 12. The pawls 517 are pivotally mounted on the
pegs 514 and are movable in a direction extending
radially outward from the axis of rotation.
The cylinder 513 is provided with an opening 523
(Figs. 14 and 15) for non-rotatable engagement with one
end of the rod 518. The spring 519 is adapted to be
attached to the rod 518 at slot 534 shown in Fig. 13.
The other end of the spring Sl9 is attached to one of the
half sections 511 or 512 as discussed later herein. The
cylinder 513 is further provided with a flat portion 521
adapted to fit non-rotatably in a window shade support
bracket (not shown). The half sections, when snapped
together, are adapted to fit singly mside the window
shade roller 535, and are fixedly engaged with the inner
surface of the roller 535 by means of ribbe~ sections on
the inner qurface of the roller ~not shown).
One or both of the half sections Sll and 512 are
provided with a substantially rectangularly-shaped
shoulder section 540 near the spring end on the outer
surface of the housing. The spring 519 is provided
at one end thereof with a member 537 having a substantially
rectangularly-shaped opening, which is adapted to fit
over the shoulder section 540 as shown in Fig. 13. When
assembled, the spring 519, the rod 518, the cylinder 513,
the pawls 517, and half sections 511 and 512 together form
an independent unit which may be readily inserted into
a window shade roller.
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In the completed shade assembly, the motor adaptor
701 together with the motor 702 and the end pin adaptor
1001 tagether with the end pin 1002 will be inserted in
the openings 126 and 128, respectively, of the telescoping
roller. The telescoping roller will be extended to a
length corresponding to the total width of the shade
material 101 and the upper section of the shade 101,
will be attached to the adhesive area 121 of the outer
tubular section 120. The bottom slat, (Fig. 4)
will be inserted in the slat pocket 103 and extended to
the full width of the shade material 101. In installing
the shade, the ~esired width of the shade ma~ be
de~ermined and the shade may be torn along one o the
tear lines 110 to obtain the desired width of the shade.
After the bottom slat (Fig. 4) is removed or moved
to one side, the shade may be torn along its full length
without the use of any tools. ~n additional step in
preparing the shade for mounting is to push the inner
tqlescoping section 122 into the outer telescoping section
120 until the total length of the telescoping roller
assembly corresponds to the width of the window. Thereafter,
the overlay 124 is removed from that portion o~ the adhesive
area 123 which is not covered by the outer telescoping
section 120. The upper portion of the shade material 101
which overlaps the newly exposed adhesive area 123, may be
; attached thereto. The bottom slat may be reinserted and
adjusted to a length corresponding to the new width of
the shade by sliding the end sections 401 and 402 toward
each other.
After the window shade 536 is installed and rolled
down, the portion of the spring attached to one of the
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half sections at 540, will rotate with the shade roller
while the other end of the spring will remain fixed in
its original position by virtue of its attachment to the
rod 518 at 534. When the shade is rolled down, the roller
535 and the snapped together half sections 511 and 512
engaged thereto will be rotated in the counter-
clockwise direction, and, if the shade has been properly `
installed, the end piece 521 of the cylinder 513 will be
engaged with a stationary window support bracket (not shown).
Consequently, the ratchet wheel 522 will remain stationary
when the roller 530, the half sections 511 and 512, and
the pawls 517 revolve around the axis of the roller. As is
apparent from the drawing, the ratchet wheel 522 is
designed to allow free rotation of the roller in the
counter-clockwise direction, allowing the shade to be
rolled down. During rotation of the roller, centrifugal
force will tend to hold the pawls 517 away from the
ratchet wheel 522. When rotation is stopped, one of
the pawls will engage with the ratchet wheel due to
gra~itational force. A clockwise rotational force
will be exerted by the spring 519 holding the pawl
against the teeth of the ratchet wheel 522. ~hen the
shade is to be raised any distance, the shade is first
rolled down in the counter-clockwise direction and
then released to be raised by means of the rotational
force of the spring exerted in the clockwise direction.
Advantageously, in accordance with this invention, the
pawls 517 are counter balanced such that a relatively
small rotational speed will provide sufficient centri-
fugal force to hold the end portions 517a away fxom
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the ratchet wheel 522. The counter balance aids in
releasing the ends 517a of the pawls from the ratchet
wheel 522 and provides for smoother operation of the
roller shade. Due to the counter balance of the pawls 517,
a larger number of stopped positions are available for
the roller shade. The ratchet wheel 522 shown in Fig. 16,
has six teeth. Customarily, shade motors relying on
centrifugal force to hold the pawls away from the ratchet
wheel generally have only two or four stopping posit~ons,
since non-counter balanced pawls re~uire a substantially
greater rotational speed to be held away from the ratchet
wheel and a larger surface without teeth or notches has
to be provided on the ratchet wheel.
The two half sections 511 and 512 each have a raise2
edge 528 and a front cover 524. The edge 528 is desi~ned
to fit snugly against the end of a shade roller as shown
in Fig. 13 and the front surface 524 provides a cover
for the motor assembly and for the roller. As is
apparent from the drawing, when the two half sections
511 and 512 are fit together, an enclosed unit is formed.
The wheel 522 is housed in the recess 525 and the
pawls 517 are housed in the recesses 515, thus
substantially reducing the accummulation of dust or
lint on the moving parts.
It will be understood that the above-described
arrangement is merely an illustrative embodiment of
the principles of the invention and that other arrange-
ments may be devised by those skilled in the art
without departing from the spirit and scope of the
invention.
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