Note: Descriptions are shown in the official language in which they were submitted.
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GRTSTF.052VPC PATENT
REEL WITH HOUSING HAVING TRIANGULAR APERTURE FOR ENTRY OF
LINEAR MATERIAL
CLAIlVI FOR PRIORITY
[0001] This application claims priority under 35 U.S.C. 119(e) to
Provisional Patent Application No. 60/775,629, filed February 21, 2006.
INCORPORATION BY REFERENCE
[0002] The present application incorporates by reference the entire disclosure
ofU.S. Patent Application Publication No. US 2006-0266605 A1.
BACKGROUND OF THE INVENTION
Field of the Invention
[0003] The present invention relates generally to reels for winding and
unwinding linear material, and specifically to apparatuses and methods for
improving the
uniformity of wound material and ease of unwinding.
Description of the Related Art
[0004] A reel typically comprises a cylindrical reel drum onto which a
flexible
linear material (such as cord, hose, etc.) is wound. The drum ordinarily
rotates about a
central axis to wind or unwind (also referred to herein as "spooling" and
"unspooling")
the linear material with respect to the cylindrical drum surface. Some reels
include
housings that protect the drum and spooled linear material from the
environment. The
housing may include an opening or aperture=fhrough which the linear material
extends, so
that it may be pulled from the housing and =su6sequently retracted back into
the housing.
Rotation of the drum can be rnotorized or manual, such as by a hand crank or
other like
device.
[0005] Some reel housings have a portion that includes the linear material
aperture and is movable witli respect to the remainder of the housing, thereby
permitting a
user to change the position from which the linear material is pulled from the
reel. For
exarnple, U.S. Patent No. 6,279,848 to Mead discloses a cylindrical reel drum
that rotates
about a horizontal axis and is enclosed within a spherical housing comprising
upper and
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lower semispherical shell portions. The upper shell portion includes a guide
aperture for
the spooled linear material and is linked to the drum. The upper shell portion
and dnnn
together rotate about a vertical central axis with respect to the lower shell
portion. This
permits a user to pull the linear material out of the housing through the
guide aperture,
and move around the reel with the guide aperture following the radial position
of the user.
The upper shell portion and drarn form a unit that is freely rotatable (about
the vertical
axis) with respect to the lower shell portion, through 360 and more.
[0006] Another example of a reel housing having a portion that includes a
linear material aperture and is rnovable with respect to the remainder of the
housing is
shown and described in U.S. Patent Application Publication No. US 2006-0266605
A1.
That reference discloses a spherical reel housing comprising lower,
intermediate, and
upper housing portions, an internal vertical spindle member fixed with respect
to the
lower and upper housing portions, and a d.rum rotatable on the spindle member
and
sun ounded by the intermediate housing portion. In that reference, the
intermediate
housing portion includes a linear material aperture and is also rotatable,
independently of
the dn.Lm, about the spindle member.
[0007] A variety of reels, particularly non-motorized reels, include spring
return mechanisms for automatically spooling the linear material. Typically, a
coil of flat
spring steel stocle is provided with one end secured to the reel drurn and the
other end
secured to a spindle on which the drum rotates. For example, U.S. Patent No.
6,273,354
to Kovacik et al. discloses such a reel. Such reels are offten provided with a
ratchet and
pawl mechanism (or similar apparatus) for permitting the user to initiate
rewinding of the
reel by a slight tug on the linea.r material.
SUMIVIARY OF THE INVENTION
[0008] In one aspect, the present,"invention provides a reel comprising a drum
and a housing substantially enclosing the drum; The drum has a spool surface
onto which
a linear material may be wound, the spool surface having two ends. The drurn
is rotatable
about a drum axis relative to at least a portion of the housing. The at least
a portion of the
housing has a generally triangular aperture sized to receive a linear material
wound onto
the drutn. The aperture has a first side oriented generally para11e1 to the
drum axis, and
second and third sides meeting at a vertex generally midway between opposing
ends of
the spool surface of the drum.
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[0009) In another aspect, the present invention provides a method comprising
rotating a drnm about a drum axis to wind a linear material onto a spool
surface of the
drum or unwind the linear material from the spool surface of the drum. During
the step of
rotating the drum, the linear material is drawn through a generally triangular
aperture in a
housing substantially enclosing the dram, the drum being rotatable about the
dnun axis
with respect to a portion of the housing that includes the aperture. The
aperture has a first
side oriented generally parallel to the drum axis, and second and third sides
meeting at a
vertex generally midway between opposing ends of the spool surface of the
drum.
[0010] In another aspect, the present invention provides a reel comprising a
drum and a housing substantially enclosing the drum. The drum has a spool
surface onto
which a linear material may be wound, and is rotatable about a drum axis
relative to at
least a portion of the housing. The at least a portion of the housing has a
generally
triangular aperture sized to receive a linear material wound onto the ctrum.
100111 ln other aspect, the present invention provides a method comprising
rotating a drum about a drum axis to wind a linear material onto a spool
surface of the
drum or unwind the linear material from the spool surface of the drum. During
the step of
rotating the drum, the linear material is drawn through a generally triangular
aperture in a
housing substantially enclosing the drum, tlie "drum being rotatable about the
drum axis
with respect to a portion of the housing that iiicludes the aperture.
[0012] For purposes of summarizing the invention and the advantages
achieved over the prior art, certain objects and advantages of the invention
have been
described above and as further described below. Of course, it is to be
understood that not
necessarily all such objects or advantages may be achieved in accordance with
any
particular embodiment of the invention. Thus, for example, those skilled in
the art will
recognize that the invention may be embodied or camed out in a manner that
achieves or
optimizes one advantage or group of advantages as taught herein without
necessarily
achieving other objects or adva.ntages as may be taught or suggested herein.
[0013] All of these embodiments are intended to be within the scope of the
t=t::.
invention herein disclosed. These and otlier embodiments of the present
invention will
become readily apparent to those skilled in the art from the following
detailed description
of the preferred embodirnents having reference to the attached figures, the
invention not
being limited to a.ny particular preferred embodiment(s) disclosed.
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BRTEF DESCRIPTION`OF THE DRAWINGS
[0014] Figure 1 is a perspective view of a reel according to one embodiment
of the present invention.
[0015] Figure 2 is an exploded top perspective view of the reel of Figure 1.
[0016] Figure 3 is an exploded bottom perspective view of the reel of Figure
1.
[0017] Figure 4 is a top perspective view of the reel of Figure 1, with the
upper housing portion removed.
[0018] Figure 5 is a bottom perspective view of the drum of the reel of Figure
1. =
[0019] Figure 6 is a front view = of a triangular aperture according to one
embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Overview
[0020] ' Embodiments of the present invention provide a reel comprising a reel
drum substantially enclosed within a housing having a portion with a
triangular aperture
for receiving and guiding linear material onto a spool surface of the drum as
the drum
rotates relative to the housing about a drum axis. In sorne embodiments, the
housing
portion having the triangular guide aperture is also rotatable about the drum
axis, relative
to the drum. In some embodiments, the rotatable housing portion having the
triangular
guide aperture is also rotatable, about the drum axis, with respect to one or
more other
portions of the housing. In other words, the drum and housing portion with the
triangular
guide aperture are preferably independently rotatable with respect to the
rernainder of the
housing. In preferred embodiments, the housing portion with the triangular
guide aperlure
is freely rotatable through at least 360 , and preferably any fraction or
multiple thereof,
with respect to a remainder of the housing. In preferred embodiments, the reel
is adapted
to spool electrical cord. However, skilled artisans will appreciate that reels
of the present
invention can spool other types of linear rnaterials, such as hoses, ropes,
and the like.
[0021] Reels that employ a drum that rotates about a vertical axis are
susceptible to the problem of non-uniform winding. In other words, the linear
material
wound upon the drum tends to form a non=uniform spool. This is because the
linear
material tends to wind upon the lower portion of the drum, due to the effects
of gravity.
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The present inventors have discovered that' Iiliis tendency is reduced
significaantly by a
linear material guide or housing aperture 'ihat is located generally midway
between
opposing ends of the spool surface of the drum. During winding, a guide or
aperture so
positioned causes the linear material to wind more evenly on the spool
surface. However,
when the direction of drum rotation is reversed, the centrally located guide
or aperture can
substantially impede or slow down the process of unwinding the linear
material, due to
the restrictive position and size of the aperture relative to the length of
the spool. In many
cases, the linear material tends to become stuck or immovable during
unwinding.
[0022) As used herein, the terms "winding" and "spooling" refer to -the
process of rotating the drum in a direction to accumulate the linear material
onto the spool
surface of the drurn, and "unwinding" and "unspooling" refer to the process of
retracting
the linear material from the drum, which involves rotating the drum in the
opposite
direction.
[0023] The present invention addresses this problem by providing a reel
having a housing with a generally triangular guide aperture for the linear
material. A first
vertex of the triangular aperture is preferably located generally midway
between the ends
of the spool surface of the drum. The first vertex points in the direction in
which the
linear material is wound so that, during winding, the linear material tends to
slide against
the first vertex. Thus, during winding, the linear material is guided onto the
drum from a
position generally midway between the opposing ends of the spool surface,
advantageously producing more even and uniform winding as explained above. The
side
of the triangular aperture that is opposite; the first vertex is preferably
oriented
substantially parallel to the drum's axis of rotation and has a length
preferably large
enough to significantly improve the ease of unwinding. During unwinding, the
linear
material is free to slide against the full length of this side of the
triangle, advantageously
reducing the likelihood of the linear material getting stuck.
-Exemplary Reel
[0024] In order to provide a fuller understanding of the invention, the
following paragraphs describe an exemplary reel and reel housing that are
particularly
suited to having a triangular aperture as taught herein. While the illustrated
reel 10 is an
electrical cord reel, triangular apertures of the invention can be provided
for reels adapted
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to wind different types of linear materials. Further details of the
illustrated reel 10 are
shown and described in U.S. Patent Application Publication No. US 2006-0266605
Al.
[0025] Figure 1 shows a reel 10 comprising a housing 11 enclosing a rotatable
reel drum 20 (Figures 2, 3, and 5) onto which a flexible linear material2 can
be spooled.
, ,.
In the illustrated embodiment, the linear rnaterial 2 comprises an electrical
cord with a
female plug connector 3, as known in the art. The housing 11 comprises a first
or lower
housing portion 12, a second or upper housing portion 14, and a middle housing
portion
16 interposed therebetween. In the illustrated embodiment, the housing
portions 12, 14,
and 16 collectively form a substantially spherical' shape. However, the
housing 11 can
have other shapes, giving due consideration to the goal of collectively
substantially
surrounding and preferably enclosing the drum 20. The reel 10 also includes a
first or
lower support stracture 18 mounted to the lower housing portion 12, as well as
a second
or upper support structure 19 mounted to -the upper housing portion 14. The
lower
support structure 18 is configured to support tlie reel 10 on a lower support
surface. In a
: r
preferred embodiment, the reel is capable of operating upside down, and the
upper
= ,i,.: ~
support stracture 19 is also configured to sup'.port the reel 10 on a lower
support surface.
As explained in further deta.il below, the middle housing portion 16 includes
a triangular
aperture 15 through which the linear rnaterial2 can extend.
[0026] As mentioned above, in a preferred embodiment the reel 10 is adapted
to spool electrical cord 2. Preferably, the reel 10 provides electrical power
to the cord 2
from an external electrical power outlet. In the embodiment of Figure 1, the
reel 10
includes an electrical cable 13 that extends out of a lower opening (not
shown) of the
lower housing portion 12. The cable 13 preferably includes a standard
electrical plug 17
that is adapted to plug into a standard electrical power outlet. The cable 13
preferably
provides power to the electrical cord 2 sppoled on the reel 10. While the
illustrated
connectors 3 and 17 are respectively female andr male, these "genders" can be
reversed.
[0027] Figures 2 and 3 are exploded top and bottom views, respectively, ofthe
reel 10. The reel 10 includes a spindle member 22 having a first end 24 and a
second end
26 (Figure 4). The first end 24 is connected to, and preferably integrally.
formed with, the
lower housing portion 12. In this embodiment, the spindle mernber 22 is
configured to
extend through an opening 28 (Figure 5) in the dram 20 so that the drum is
rotatable
about a spindle axis 31 (also referred to herein as a"drum axis") defined by
the spindle
member 22. Preferably, the opening 28 is sized to closely receive the spindle
member 22.
-6=-. .
. f,
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The spindle member 22 is also configured to extend through an opening 30
(Figure 4) of
the middle housing portion 16. Preferably, the opening 30 is sized to closely
receive the
spindle member 22. In one embodiment, the spindle member 22 has a lower larger
diameter portion for a close fit with the opening 28 of the drum 20, and an
upper smaller
diam.eter portion for a close fit with the opening 30 of the middle housing
portion 16, it
being understood that the opening 28 is larger than the opening 30. In another
embodiment,, the o.penings 28 and 30 are approximately the same size, and the
spindle
member 22 has a substantially uniform diameter. Skilled artisans will
appreciate that
other configurations of the spindle member 22 and openings 28 and 30 are
possible,
keeping in mind the goal of permitting both the middle housing portion 16 and
drum 20 to
rotate with respect to the spindle member 22 and independently with respect to
each other.
(0028] With reference to Figures 2-4, the upper housing portion 14 is
preferably adapted to connect to the second end.26 of the spindle member 22
when the
member 22 extends through the 'dram 20. Preferably, the upper housing portion
14 and
the spindle member 22 are detachably secured to one another so that they
cannot rotate
with respect to each other. In the illustrated embodiment, the upper housing
portion 14
includes four through-holes 32 sized and configured to receive screws 34
(Figure 4) that
are in turn adapted to screw into threaded holes 36 in the second end 26 of
the spindle
member 22. Skilled artisa.ns will appreciate that any of a wide variety of
ineans can be
employed for detachably securing the upper housing portion 14 to the spindle
member 22.
[0029] The reel 10 thus permits the middle housing portion 16 and drum 20 to
rotate freely about the spindle member 22 and independently with respect to
each other.
In order to assist or facilitate the rotation of the drurn 20 and/or middle
housing portion
16, rotation-assistance elements such as ball bearings, rollers, and the like
may (but need
not) be provided at interfaces between the housing portions 12 and 16, between
the
housing portions 14 and 16, between the middle housing portion 16 and the drum
20,
.-~, ~ :
between the lower housing portion 12 and the'drurn 20, between the spindle
member 22
.,;:=;..
and the drum 20, and/or between the spindle member 22 and the middle housing
portion
~;.., .
16. Also, tracks or other guide means can be provided to control the relative
movement
of these members. Lubricants can also be used to reduce friction at these
interfaces.
[0030] With continued reference to Figares 2 and 3, each of the upper and
lower housing portions 12 and 14 preferably includes an annular wa1139 a.nd a
plurality of
radial ribs 37 for added strength. Alternative configurations for internal
walls and ribs are
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also possible, keeping in mind the goal of improving the strength and rigidity
of the
housing portions 12, 14. In other embodiments, the housing portions 12 and 14
do not
have any internal rnembers for added strength.
[0031] In the disclosed embodiments, the upper and lower support structures
18 and 19 are (but need not be) substantially similar. Accordingly, only the
lower support
structure 18 is described in detail herein. With reference to Figures 2 and 3,
the lower
support structure 18 preferably comprises two mounting portions 40 and two
handle
portions 38. The illustrated mounting portions 40 comprise elongated tubular
members
that are configured to be mounted on opposing sides of the lower housing
portion 12.
Skilled artisans will appreciate that the mounting portions 40 can
alternatively have non-
tubular shapes. In a preferred embodiment, the lower housing portion 12
includes
recesses 42 that are sized and shaped to receive the mounting portions 40. The
mounting
portions 40 can be secured (preferably detachably) to the lower housing
portion 12 by any
of a wide variety of ineans, such as by screws, nut and bolt combinations, and
the like.
For example, the illustrated mounting portions 40 include vertical internally
threaded
stubs 41 that fit snugly into corresponding recesses 43 inside the recesses
42. The
recesses 43 are configured to receive screws for creating a detachable
connection between
the mounting portions 40 and the lower housing portion 12. The mounting
portions 40
can be curved to conform more closely to the semispherical shape of the lower
housing
portion 12, providing a more stable and secure -connection.
[0032] The illustrated handle portions 38 are positioned generally on opposing
sides of the lower housing portion 12 and are substantially parallel to one
another. In the
illustrated embodiment, the handle portions 38 comprise elongated tubular
members
oriented generally perpendicular to the spindle member 22 and positioned so as
to
maintain a lower extreme of the lower housing portion 12 at least slightly
above the lower
support surface. The handie portions 38 are preferably sized and shaped to
allow a person
to grip them directly with his or her hands. Each mounting portion 40
preferably has one
end coupled to an end of one of the handle portions 38 and another end coupled
to an end
of the other of the handle portions 38. Eacli'end of the handle portions 38 is
preferably
coupled to only one of the mounting portions 40. The end portions of the
illustrated
mounting portions 40 extend downward and outward frorn a central portion that
mounts
to the recess 42 of the lower housing portion 12.
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[0033] In a preferred embodiment, the lower support structure 18 further
comprises four coupling mernbers 44, each of which couples one of the ends of
one of the
handle portions 38 to one of the ends of one of the mounting portions 40. In
the
illustrated embodirnent, the coupling members 44 contact the lower support
surface, while
the handle portions 38 and mounting portions 40 do not. The illustrated
coupling
members 44 comprise elbow-shaped tubular members.
[0034] As mentioned above, the upper support structure 19 is preferably
substantially similar to the lower support structure 18. Accordingly, the
illustrated
support structure 19 preferably includes handie=portions 38, mounting portions
40 adapted
to mount within recesses 42 of the upper housing portion 14, and coupling
mernbers 44,
substantially as described above. The handle portions 38 of either support
structure 18,
19 can advantageously be used to conveniently grip onto and move the reel 10.
Preferably, the support structures 18, 19 are configured to prevent the
housing 11 (e.g.,
housing portions 12, 14, and 16) from contacting a generally flat support
surface
regardless of the orientation of the reel 10. For example, the illustrated
support structures
18, 19 prevent the housing 11 from contacting the ground even if the reel 10
is tumed
onto its side. In this configuration, the support structures more effectively
protect the
housing 11 from damage. In other embodiments, the upper support structure 19
is
configured differently or can even be omitted from the reel 10. It will be
appreciated that
t' .
a wide variety of different types of suppprt structures 18, 19 can be used
without
depasting from the scope of the invention. ~
[0035] Figures 2, 3, and 5 show a preferred ernbodiment of the reel drum 20.
The illustrated drum 20 comprises a substantially cylindrical member 46 having
a spool
surface 47 onto which linear material can be spooled, a first end plate 48 at
one end of the
member 46, and a second end plate 50 at the other end of the mernber 46. The
cylindrical
member 46 and end plates 48 and 50 preferably rotate in unison together about
the spindle
member 22. The cylindrical member 46 and end plates 48 and 50 can be formed
integrally as a single unitary piece or can be formed separately and secured
together. The
middle housing porrion 16 encircles the drum 20 and preferably rotates about
the spindle
member 22 independently of the dreun 20.; ; The triangular aperture 15 is
preferably
positioned near the surface of a cylindrical member 46, so as to direct the
linear material
. .,:
onto the drum 20 during spooling.
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[0036] With reference to Figures:3 and 5, the lower housing portion 12 is
preferably adapted to house a motor 51 that drives the reel drum 20 through a
gear
reduction assembly. I~n the illustrated embodiment, the motor 51 is housed
within the
spindle member 22. The motor 51 is inserted into an opening 52 in the
underside of the
lower housing portion 12. A motor cover 54 can be provided to support the
motor 51
and/or close and possibiy seal the opening 52 to protect the motor and gears
from dust and
debris. For ease of illustration, the gear reduction is not shown in the
drawings.
However, skilled artisans will understand that the gear reduction rnay
comprise any
suitable number of gears assembled to convert the motor rotational output into
rotation of
the drum 20 about the drum axis 31. For example, as shown in Figures 3 and 5,
the gear
reduction can effect rotation of the drum'20 by rotating a ring gear 58
comprising an
annular wall on the bottom side of the end plate 48, with teeth facing
radially inward from
the annular wall. In the illustrated embodiment, the annular wall is part of a
ring-shaped
piece 70 that is secured to the bottom side of the end plate 48. In other
embodiments, the
piece 70 can be formed integrally with the end plate 48. Further details of a
preferred
configuration of the gear reduction are set forth in U.S. Patent Application
Publication
No. US 2006-0266605 A1.
[0037] Thus, the motor 51 produces rotation of the drum 20 about the spindle
member 22. As seen in Figure 3, in the preferred embodiment the motor 51 is
upside
down (i.e., its output faces downward). However, it will be appreciated that
the motor 51
can be oriented other than as shown. Skilled artisans wili also understand
that a variety of
different types of rnotors and gear reduction assemblies can be employed
without
departing from the scope of the invention.
[0038] In use, a user can unwind the linear material 2 from the druxn 20 by
pulling the material out through the triangula.r aperhue 15 of the middle
housing portion
16. In doing so, the drum 20 begins to rotate with respect to the upper and
lower housing
portions 12, 14 and the spindle member 22. The middle housing portion 16 is
also freely
rotatable, and its rotational position may vary because the aperture 15 will
tend to follow
the radial direction in which the user pulls the linear material 2. As the
user moves
around the reel 10 holding a portion of the linear material that is withdrawn
from the
housing 11, the middle housing portion 16 freely rotates to allow the aperture
15 to follow
the radial direction of the withdrawn linear material. In this manner, the
freely rotatable
middle housing portion 16 facilitates using the linear material within a
larger area. For
-10=
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example, the reel 10 can be placed centrally within a room or outdoor area
(e.g., on the
ground or mounted to a ceiling) and the linear material can be relatively
easily withdrawn
=,. .
toward any direction or portion of the roomS or area. When the user wishes to
spool the
: ,.
linear material onto the'drum 20, the user can switch on the motor 51
accordingly. The
resultant rotation of the drum 20 causes the -linear material to be pulled
back into the
housing 11 through the aperture 15 of the middle housing portion 16.
j00391 During spooling, the middle housing portion 16 rnay tend to rotate
along with the drum 20, due to friction therebetween. This can cause the
linear rnaterial
to swing around the reel 10, which can result in harm to surrounding persons
or objects.
Preferably, the reel 10 includes a mechanical and/or electrical mechanism to
rotationally
lock the middle housing portion 16 with respect to the upper and lower housing
portions
12, 14 during spooling. With reference to Figure 3, the illustrated embodiment
includes a
solenoid device 62 secured to the lower liousing portion 12. The solenoid
device 62 is
electrically operable, as well known in the art;= to cause a piston stem 64 to
extend in and
out of an outer opening of its housing. The stem 64 is sized and shaped to
slide into any
one of a ring of indentations 66 provided on the inner surface of the middle
housing
portion 16. The indentations 66 can have any of wide variety of shapes and
sizes, keeping
in mind the goal of permitting the solenoid stem 64 to stop the middle housing
portion 16
from rotating by entering one of the indentations 66. When the stem 64 enters
one of the
indentations 66, it "locks" the middle housing portion 16. In other words, the
extended
stem 64 prevents the middle housing portion 16 from rotating with respect to
the upper
and lower housing portions 12, 14. An electronic control system can be
provided to
actuate the solenoid device 62 (i.e., cause the stem 64 to extend) when the
motor 51 is
= :..; .=:
switched to a spooling operation, and to retract the solenoid device 62 (i.e.,
cause the stem
64 to retract into its housing) when the .motor 51 is switched off or to a
powered
unspooling operation.
[0040] In a preferred embodiment, the illustrated electrical cord reel 10 is
adapted to provide electrical power to an electrical cord 2 wound on the druun
20, the cord
2 being operable to deliver power to an external device. Accordingly, the reel
10 can
include suitable means for enabling a power connection between the cord 13
(Figure 1)
and the wound cord 2, as known in the art. For example, the bottom of the end
plate 48 of
the drurn 20 can include electrically conductive rings 78 (Figure 5), also
referred to as
"slip rings," adapted to contact electrical brushes (not shown) that are in
tum in electrical
-1.1-
. ~;.
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commumcation with the cord 13. Further, the drum 20 can be configured to
provide an
electrical connection between the slip rings 78 and a power connector (not
shown) on the
drum 20, to which the wound cord 2 is connected. Further details of a
preferred
configuration for providing electrical power.. to the wound cord 2 are
provided in U.S.
Patent Application Publication No. US 2006-0266605 Al.
.;;
Trian ug_ lar Aperhzre
[0041] Figure 6 shows the triangular apertare 15, in accordance with a
preferred embodiment of the invention. As mentioned above, the middle housing
portion
16 includes a generally triangular aperture 15 sized to receive a linear
material (in the
illustrated embodiment, the electrical cord 2) wound onto the drum 20. The
aperture 15
has a first side 92, a second side 94, and a third side 96. The first side 92
is preferably
oriented generally parallel to the drum axis 31 (Figure 2). The first side 92
and second
side 94 meet at a vertex 97. The first side 92 and third side 96 meet at a
vertex 95. The
second side 94 and the third side 96 meet at. a= vertex 93.
[00421 The vertex 93 is preferably positioned generally midway between
opposing ends of the spool surface 47 of the drum 20. For example, in the
illustrated
embodiment, the vertex 93 is preferably positioned generally midway between
inner
surfaces of the end plates 48 and 50. The aperture 15 is advantageously sized
and
oriented so that, during winding, the linear material 2 tends to translate
against the vertex
93. Preferably, a locking apparatus or mechanism (such as the solenoid device
62
described above) is provided to positionally lock the rniddle housing portion
16 while the
linear material 2 is being wound onto the.drurn 20, so that the vertex 93
remains fixed
with respect to the rotating drum.
[0043] During unwinding of the linear rnaterial2, the middle housing portion
16 is preferably unlocked with respect to tlie housing portions 12, 14,
allowing the
`+ : `
housing portion 16 to rotate in a directiori;'tlthat would ease the retraction
of the linear
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material. As a result, the linear material 2 is free to retract through a
portion of the
triangular aperture 15 other than just the vertex 93 (in Figure 6, any portion
of the
aperture 15 to the right of the vertex 93). Advantageously, a larger vertical
dimension of
the aperture 15 is available for retracting the linear materiai 2, resulting
in significant
improvements in the ease of retraction of the linear material. Also, the novel
triangular
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WO 2007/098110 PCT/US2007/004278
~
shape of the aperhu-e 15 allows for a greater amount of linear material 2 to
be spooled into
the housing 11, such as an increase of about 25%.
[0044] In a preferred embodirnent, the vertices 93, 95, and 97 are rounded,
with a radius preferably equal to or greater than that of the linear material
2. Such
rounded vertices are preferred over sharp vertices because the latter would
involve
heightened stress concentrations in the middle housing portion 16. Also, the
thickness of
the middle housing portion 16 is preferably increased along the edges or sides
92, 94, 96
of the aperture 15, to provide increased strength for withstanding loads
imposed against
such edges by the taught linear material 2 during winding or unwinding.
[0045] Skilled artisans will appr=eciate that the ease with which the linear
material 2 can be unwound from the reel 10 depends upon the length of the
first side 92 of
the triangular aperture 15 relative to the length of the drum 20. The first
side 92 extends
across preferably at least 35%, more preferably at least 50 fo, more
preferably at least
60 !0, rnore preferably at least 80%, and even more preferably at least 95% of
a length of
the spool surface 47 of the drwn 20. It will also be appreciated that the ease
with which
the linear material can be unwound depends upon the extent to which the first
side 92 of
the triangular aperhire 15 is centered with respect to the* length of the drum
20. In this
regard, a distance y between (1) a plane 102 that is parallel to the drum axis
31 (Figure 1)
a.nd that extends through a center 98 of the 'first side 92, and (2) a plane
104 that is
. ; : =
perpendicular to the drum axis 31 and that es,;.xtends through a center of a
length of the
spool surface 47 of the drurn 20, is preferably'less than 20%, more preferably
less than
10, and even more preferably less ihan 5% of the length of the spool surface.
In the
illustrated embodiment of Figure 6, the plane 104 is belovv the center 98 of
the length of
the first side 92 of the aperture 15; however, it will be appreciated that the
plane 104
could be above or directly level with the center 98.
[0046] Skilled artisans will understand that the advantages of providing the
triangular aperture 15 are achieved when the aperture "points" in the correct
direction. In
particular, the linear material 2 is preferably wound in a direction in which
the vertex. 93
points. For example, in the orientation of Figure 6, the linear material 2 is
preferably
wound in a clockwise direction (viewing the reel and aperture 15 of Figure 6
frorn above)
about the drum. In other words, the linear ma.telial2 is preferably wound in a
direction so
that, during winding of the linear material onto the drum, the linear material
tends to slide
against the vertex 93.
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[00471 Skilled arkisans will also-~appreciate that the ease of retraction of
the
linear material depends also upon the shape of the triangular aperture 15. In
a preferred
embodiment, the aperture 15 is shaped substantially like an isosceles triangle
and the
second side 94 and third side 96 are oriented with respect to one another at
an angle
preferably within 20-50 , more preferably within 25-45 , and even more
preferably within
30-40 . Other possible ranges include 25-55 , 30-50 , and 35-45 .
[0048] Skilled artisans will also appreciate that the ease of retraction of
the
linear material also depends upon the size of the aperture 15 relative to that
of the drum
20. The spool surface 47 of the drum 20 is preferably cylindrical and the
distance
between the vertex 93 and the first side 92 is preferably within 40-300%, more
preferably
within 60-200%, more preferably within 75-150%, and even more preferably
within 85-
= . ?. .:. ? 3
125% of a diameter of the spool surface 47.'In one embodiment, the distance
between the
,
vertex 93 and the first side 92 is about tlie?same. as the diameter of the
spool surface.
.. :.,~.,.
Other suitable ranges for said angle are 70-130%0, 85-115%, and 95-105% of the
diameter
of the spool surface 47.
[00491 Although the invention has been disclosed in the context of certain
embodiments and examplea, it will be understood by those skilled in the art
that the
invention extends beyond the specifically disclosed embodiments to other
alternative
embodiments and/or uses and obvious modifications and equivalents thereof.
Accordingly, the invention is not intended to be limited by the specific
disclosures of
preferred embodiments herein.
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