Note: Descriptions are shown in the official language in which they were submitted.
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WHEELCHAIR LIFT FOR A STAGE
CROSS-REFERENCE TO RELATED APPLICATION
This application claims the benefit of LT.S. Provisional Patent Applications
Serial No. 601361,909, filed on February 28, 2002, and Serial No. 60/412,270,
filed on
September 19, 2002, priority from the filing dates of which is hereby claimed
under
35 U.S.C. ~ 119 and the disclosures of which are hereby expressly incorporated
by
reference.
FIELD OF THE INVENTION
The present invention is directed generally to wheelchair lifts, and more
particularly, to wheelchair lifts having retractable barriers to selectively
impede ingress
and egress from the wheelchair lift.
BACKGROUND OF THE INVENTION
Lifts are often used to provide a mode of transporting a wheelchair bound or
mobility impaired person between floors of different elevations, such as from
the main
floor of a theater or school multi-purpose room to an elevated stage. Existing
lift
products may include stationary designs that require dedicated rooms for
accessibility to
lift operation, or portable designs that must be maneuvered into position for
lift operation
and require closets or area for storage. Thus, there exists a need for a
retractable lift that
is stowed out-of sight within the main floor until the device is needed to
transport
mobility impaired persons from the main floor to an elevated floor
It is advisable, or required by regulations, such as those promulgated by the
ANSI/ASME A18.1-1999 Safety Standard for Platform Lifts and Stairway
Chairlifts, to
provide a retractable barrier to resist people on the , elevated floor from
falling or
contacting the lift during use. Although retractable barriers are available
for this purpose,
they are not without their problems.
For instance, many retractable barriers include a single panel that swings
from a
stowed position to a deployed position. This is disadvantageous for several
reasons.
First, a large area free of obstructions must be provided to allow the panel
to be swung
between the stowed and deployed position,. thus limiting the use of the space
in the
vicinity of the retractable barrier. Further, the panel may impact a person or
an object
during the swinging motion of the panel, causing injury or damage. Thus, there
exists a
need for a Lift assembly with a retractable barrier with a minimal swing area
that not only
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provides the desired barrier protection, but also is economical to
manufacture, has a high
degree of reliability, and satisfies the performance expectations of the end
user.
SUMMARY OF THE INVENTION
A wheelchair lift assembly is provided. The wheelchair lift assembly is
adapted
to be disposed in a cavity located below a lower surface when in a stowed
position. The
wheelchair lift assembly includes a lift platform and a lifting mechanism
coupled to the
lift platform for reciprocating the lift platform between a lowered position,
wherein the
lift platform is substantially coplanar with the lower surface, and a raised
position,
wherein the lift platform is substantially coplanar with an upper surface. The
wheelchair
lift assembly also includes a lift platform barrier coupled to one end of the
.lift platform
and a lift platform barrier actuating assembly coupled to the lift platform
barrier. The lift
platform barrier actuating assembly actuates the lift platform barrier between
a retracted
position, wherein the lift platform barrier is disposed substantially flush or
below the lift
platform to permit access to the lift platform, and an extended position,
wherein at least a
portion of the lift platform barrier extends above the lift platform to impede
access to the
lift platform.
In one embodiment formed in accordance with the' present invention, the lift
platform barrier actuating assembly includes an actuator for displacing the
lift platform
barrier between the retracted and extended positions. In certain embodiments,
the
actuator includes a cam surface and a cam follower. The cam follower engages
the cam
surface to selectively actuate the lift platform barrier between the retracted
and extended
positions.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing aspects and many of the attendant advantages of this invention
will
become better understood by reference to the following detailed description,
when taken
in conjunction with the accompanying drawings, wherein:
FIGURE 1 is a front isometric view of a lift and upper floor barrier assembly
formed in accordance with one embodiment of the present application, showing a
lift
platform raised to a height substantially coplanar with an upper floor
surface;
FIGURE 2 is a partial exploded isometric view of the lift assembly shown in
FIGURE 1, wherein a lifting mechanism of the lift assembly is shown in
exploded form;
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FIGURE 3 is an exploded isometric view of the lift platform, handrails, and
handrail actuating assembly taken from the back of the lift assembly shown in
FIGURE 1;
FIGURE 4 is a partial isometric exploded view of a portion of the handrail
actuating assembly depicted in FIGURE 3;
FIGURE 5 is a back elevation view of the lift assembly with a cover removed to
better show the installed configuration of the handrail actuating assembly
depicted in
FIGURE 3, wherein the handrails are shown in their stowed positions;
FIGURE 6 is a back elevation view of the lift assembly depicting the installed
configuration of the handrail actuating assembly depicted in FIGURE 3, wherein
the
handrails are shown in a partially deployed position;
FIGURE 7 is a back elevation view of the lift assembly depicting the installed
configuration of the handrail actuating assembly depicted in FIGURE 3, wherein
the
handrails are shown in their deployed positions;
FIGURE 8 is a front isometric exploded view of the lift platform and lift
platform
barrier actuating assembly shown in FIGURE 2, wherein the handrails have been
removed for clarity;
FIGURE 9 is a partial isometric exploded view of a portion of the lift
platform
barrier actuating assembly depicted in FIGURE 8;
FIGURE 10 is a front elevation view of the lift assembly with a cover removed
to
better show the installed .configuration of the lift platform barrier
actuating assembly
depicted in FIGURE 8, depicted with the Iift platform barrier in the stowed
position;
FIGURE 11 is a front elevation view of the lift assembly depicting the
installed
configuration of the lift platform barrier actuating assembly depicted in
FIGURE 10, the
lift assembly depicted when the lift platform barrier is in a partially
deployed position;
FIGURE 12 is a front elevation view of the lift assembly depicting the
installed
configuration of the lift platform barrier actuating assembly depicted in
FIGURE 11, the
lift assembly depicted when the lift platform barrier is in the fully deployed
position;
FIGURE 13 is an isometric view of the upper floor barrier assembly formed in
accordance with one embodiment of the present application, showing the barrier
in a
deployed position;
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FIGURE 14 is an isometric view of a lift assembly having an upper floor
barrier
assembly formed in accordance with one embodiment of the present invention,
showing
the lift assembly and upper floor barrier assembly in a stowed position;
FIGURE 15 is an isometric view of the lift and upper floor barrier assembly
shown in FIGURE 14, showing the upper floor barrier assembly in a deployed
position;
FIGURE 16 is an isometric view of the lift assembly shown in FIGURE 14, the
lift assembly depicted with the upper floor barrier assembly and cover panels
depicted in
deployed positions;
FIGURE 17 is an isometric view of the lift assembly shown in FIGURE 14, the
lift assembly depicted with the upper floor barrier assembly, cover panels,
and handrails
depicted in deployed positions, and wherein the lift platform has risen from a
stowed
level to a lower floor level such that the Lift platform is coplanar with the
Lower floor;
FIGURE 18 is an isometric view of the Lift assembly shown in FIGURE 17, the
lift assembly depicted with an upper floor barrier deployed to impede ingress
and egress
from the lift platform;
FIGURE 19 is an isometric view of lift assembly shown in FIGURE l, wherein
the upper floor barrier assembly has been retracted to permit ingress and
egress from the
lift platform;
FIGURE 20 is an isometric view of a lift assembly in combination with a
retractable ~ barrier formed in accordance with another embodiment of the
present
invention, wherein the retractable barrier is shown mounted to a wall of an
upper floor
located adjacent and above the Lift assembly, wherein the retractable barrier
and the lift
assembly are both shown in a stowed position;
FIGURE 21 is an isometric view of the retractable barrier depicted in
FIGURE 20, the retractable barrier depicted in the stowed position;
FIGURE 22 is an isometric view of the retractable barrier depicted in
FIGURE 20, showing the retractable barrier in a 75% deployed position;
FIGURE 23 is a cross-sectional view of the retractable barrier of FIGURE 22,
taken substantially through Section 23-23 of FIGURE 22, showing the actuating
assembly in a 75% deployed position;
FIGURE 24 is an isometric view of the retractable barrier shown in FIGURE 20,
showing the retractable barrier in a 25% deployed position, wherein an outex
panel and an
inner panel are shown in phantom to better illustrate the components of a
drive assembly;
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FIGURE 25 is a cross-sectional view of the retractable barrier depicted in
FIGURE 24, the cross sectional cut taken substantially through Section 25-25
of
FIGURE 24, showing the actuating assembly in a 25% deployed position;
FIGURE 26 is an isometric view of the retractable barrier shown in FIGURE 20,
the retractable barrier depicted in a fully deployed configuration; and
FIGURE 27 is a cross-sectional view of the retractable barrier depicted in
FIGURE 26, the cross sectional cut taken substantially through Section 27-27
of
FIGURE 26, showing the barrier actuating assembly in the fully deployed
position.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIGURE 1 illustrates a lift assembly 100 formed in accordance with one
embodiment of the present invention. The lift assembly 100 permits a mobility
impaired
person (not shown) to be conveyed from a~lower floor I02 to an upper floor
104, such as
a stage. Referring to FIGURE 1, the lift assembly 100 includes a frame 106, a
lift
platform 108, a lift platform barrier 110, an upper floor barrier 112, a pair
of side
curbs 114a and 114b, a pair of cover panels 116a and 116b, a protective apron
118, and a
pair of handrails 124a and 124b.
As may be best seen by referring to FIGURES 2-19, the subsystems and
components of an actuation system that controls the operation of the lift
assembly 100
will now be described. The actuation system includes a lifting assembly 132, a
handrail
. actuating assembly 134, a lift platform barrier actuating assembly 136; an
upper floor '
actuating barrier assembly 138, and a cover panel actuating assembly 139.
As best seen by referring to FIGURE 2, the lifting assembly 132 includes a
scissors jack 140. The scissors jack 140 is formed from a first pair of spaced
struts 142a
and 142b pivotally coupled to a second pair of spaced struts 144a and 144b.
The lower
ends of struts 142a and 142b are coupled to one another by a first support
tube 146a to
increase the rigidity of the struts 142a and 142b. Likewise, the lower ends of
struts 144a
and 144b are coupled to one another by a second support tube 146b. The pairs
of
struts 142 and 144 are pivotally coupled to one another by well known pivot
pins 148
(one shown) at about the middle of each strut 142 and 144.
The upper ends of struts 142a and 142b are pivotally coupled to the lift
platform 108 by a pair of pivot pins 150 (one shown). A pair of rollers 154A
and 154B
are coupled to the lower distal ends of struts 142a and 142b. The rollers 154
engage a
pair of horizontally oriented guide tracks 152a and 152b coupled to the frame
106.
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Similarly, a pair of rollers 156B (one shown) are coupled to the upper distal
ends of
struts 144a and 144b. The rollers 156.engage a pair of horizontally oriented
guide tracks
(not shown, but which are similar to guide tracks 152) coupled to the lift
platform 108.
The lower ends of struts 144a and 144b are pivotally coupled to frame 106 by a
pair of
stub shafts 161 extending from each end of the second support tube 146b and
engage a
pair of retainer plates 159 that are rigidly attached to frame 106.
The lower ends of a pair of actuators 158a and 158b are pivotally coupled to
the
lower ends of the second pair of struts 144 by pivot pins 160. The upper ends
of the
actuators 158 are coupled to the first pair of struts 142 at a location
between the upper
ends of the struts I42 and the location wherein the struts 142 and 144 are
pivotally
coupled to one another. The location of the attachment of the actuators 158a
and 158b to
the struts 142 and I44 is preferably selected such that actuation of the
actuators I58a and
158b is optimized. The upper ends of the actuators 158a and 158b are coupled
to the
struts 142 by pivot pins 162 (one shown).
The actuators 158 are adjustable in length. Increasing the length of the
actuators 158 causes a resultant decrease in a separation angle 164 defined by
the angle
between opposing pairs of struts 142 and 144. By decreasing the separation
angle 164,
the scissors jack 140 causes the lift platform 108 to raise in elevation. By
increasing the
separation angle 164, the scissors jack 140 causes the lift platform 108 to
lower, as should
be apparent to those skilled in the art and others. In the illustrated
embodiment, the
actuators 158 are formed from well known hydraulic pistons, however it should
be
apparent to those skilled in the art that other type of actuators are suitable
for use and
within the spirit and scope of the present invention, such as electrical
solenoid actuators,
mechanical actuators, etc.
Referring to FIGURE 3, the detailed description will now focus upon the
handrail
actuating assembly 134. Inasmuch as the components of the handrail actuating
assembly 134 are substantially similar for each handrail 124a and 124b,~ this
detailed
description, for the sake of brevity, will describe the components of the
handrail actuating
assembly 134 associated with handrail 124b only. Where the context permits,
reference
in the following description to an element of the handrail actuating assembly
134
associated with handrail 124b shall be understood as also referring to the
corresponding
element in the portion of the handrail actuating' assembly 134 associated with
handrail I24a.
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The handrail actuating assembly 134 includes a torsion rod 166. A first end
168
of the torsion rod 166 is rigidly coupled to the lift platform 108 by a well
known
fastener 172. The torsion rod 166 passes through a guide tube 170 formed with
the
handrail 124b. A second end 174 of the torsion rod 166 is keyed to a first end
180 of the
guide tube 170. The guide tube 170 is supported at opposite ends 180 and 181
by
bearings 176 and bearing holders 178 coupled to the lift platform 108 in a
well known
manner. Thus, rotation of the handrail 124b causes a build up or release of
torsional
tension within the torsion rod 166.
In the illustrated embodiment, the torsion rod 166 is suitably preloaded with
a
torsional force upon the handrail 124b to bias the handrail 124b toward the
deployed
position. As such, the preload counteracts the forces of gravity acting upon
the
handrail 124b tending to pull the handrail 124b toward the stowed position.
Thus,
substantially no force other than that supplied by torsion rod 166 is required
to actuate the
handrail 124b between the stowed and the deployed positions.
The handrail actuating assembly 134 includes an actuation control assembly
182.
The actuation control assembly 182 operates to selectively control the
deployment of
handrai1124b from its respective stowed position to its deployed position. As
best seen by
referring to FIGURE 4, the actuation control assembly 182 includes first and
second
levers 184 and 186, a connecting rod 188, a torsion spring 190, and a spindle
192. The
first lever 184 is rigidly coupled to end 180 of guide tube 170, such that
rotation of guide
tube 170 causes a corresponding rotation of the first lever 184. The first
lever 184
includes a shaft 194 extending perpendicularly outward from one end of the
first
lever 184. The shaft 194 is sized to be rotatingly received within a bushing
196 disposed
in a first end 198 of the connecting rod 188 and secured with a well known
fastener, such
as a retaining clip 200.
A second end 202 of the connecting rod 188 is coupled to a first end 204 of
the
second lever 186 by a shaft 206. The shaft 206 is sized to pass through
bushings 212 and
214 disposed in the second end 202 of the connecting rod 188 and the first end
204 of the
second lever 186 respectively, and is secured in place by well known
fasteners, such as
retaining clips 200. Also secured on the shaft 206 is a roller 208 which is
rotatingly
received by a bushing 210.
A second end 216 of the second lever 186 is pivotally coupled to a mounting
bracket 218 rigidly coupled to the lift platform 108. The second end 216 of
the second
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lever 186 is coupled to the mounting bracket 218 by passing a shaft 220 of the
spindle 192 through a pair of opposing apertures 222 in the mounting bracket
218. The
shaft 220 passes through the center of the torsion spring 190, a first bushing
224, a
collar 226 (collar 226 is rigidly attached to second lever 186 and adapted to
rotatingly
receive the torsion spring 190), and a second bushing 230. The spindle 192 is
coupled to
the mounting bracket 218 by passing a well known fastener (not shown), such as
a
threaded fastener, through aperhtre 252 in the spindle 192 and coupling the
fastener to a
corresponding aperture 234 in the mounting bracket 218.
As noted above, the torsion spring 190 is rotatingly received by the collar
226. A
first end 236 of the torsion spring 190 is received by a first retainment
structure 238
disposed on the mounting bracket 2I8. A second end 240 of the torsion spring
190 is
retained upon a second retainment lever 187 (not shown in its entirety)
rigidly attached to
collar 226. The torsion spring 190 acts upon the second retainment lever 187
to bias
rotation of the second lever 186 in a counterclockwise direction.
Referring now to FIGURES 4-7, the operation of the actuation control.
assembly 182 during deployment of the handrail124b will be described. The
rotation of
the second lever 186 is controlled by interaction with a cam surface 244
formed on a cam
plate 242 coupled to the frame 106. The roller 208 (i.e., cam follower)
coupled to the
second end 202 of the connecting rod 188 and the first end 204 of the second
lever 186
rides upon the cam surface 244 to selectively control the rotation of the
handrail 124b.
Referring to FIGURE 6, as the lift platform 108 is raised, the roller 208
passes
over a ridge 248. As the roller 208 passes onto the cam surface 244, the
second lever 186
begins to rotate in the counterclockwise direction about shaft 220. This
enables
connecting rod 188 to move, thus allowing frst lever 184 to rotate in a
counterclockwise
direction.
The roller 208 is.biased to engage the stop surface 246 and the cam surface
244 by
the torsion spring 190 (see FIGURE 4) and torsion rod 166 acting through first
lever 184.
As the roller 208 passes along the cam surface 244 and is rotated and due to
the increase
in separation distance between the actuation control assembly 182 from the cam
plate 242, the first lever 184 is further rotated counterclockwise. Rotation
of the first
lever 184 causes a corresponding rotation of the handrail 124b from its stowed
position to
its deployed position. As the lift platform 108 is raised further, the roller
208 disengages
from the cam plate 242.
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Referring to FIGURES 4 and 7, the handrail I24b is locked in the fully
deployed
position by restricting the movement of the connecting rod 188. More
specifically,
surface 228 engages the connecting rod 188 to impede the movement of the
connecting
rod 188. Moreover, when the handrail 124b is in the fully deployed position,
the
surface 228 engages a bend or notch 250 in the connecting rod 188. The
engagement of
the surface 228 within the notch 250 of the connecting rod 188 prevents the
second
lever 186 from any further rotation in the counterclockwise direction, thereby
preventing
the over rotation of the handrail 124b past the deployed position shown in
FIGURE 7.
Further, due to the neax or actual linear alignment of the connecting rod 188
relative to the second lever 186, the handrail 124b is further locked in the
deployed
position. The surface 228 restricts the connecting rod 188 from rotating in a
clockwise
direction. The restriction of the connecting rod I88 from rotating in the
clockwise
direction is accomplished by the near or actual linear alignment of the
connecting rod 188
and the second lever 186. This alignment of the connecting rod 188 and second
leverl86
effectively locks the handrail 124b from rotating by a force applied to the
handrail 124b.
The bias of spring 190 acting against the second retainment lever 187 causes
notch 250 of
connecting rod 188 to bear against surface 228 resulting in a toggle-lock.
If a force is applied to the handrail 124b in the direction of the arrow
indicated by
reference numeral 249, the force would first have to overcome the preload
applied by the
torsion rod 166. Any remaining force would then tend rotate the first lever
184 in a
counterclockwise direction. Rotation of the first lever 184 causes a
corresponding force
upon the connecting rod 188 longitudinally along its length. This force is
transferred to
the second lever 186. However, rotation of any of the levers 184 and 186, and
the
connecting rod 188 is impeded because the second lever 186 is substantially
linearly
aligned with the connecting rod 188, thus any force applied to the connecting
rod 188 is
transferred to the second lever 186.
A force creating a counterclockwise moment upon the connecting rod 188 is
required to free the connecting rod 188 and handrail 124b from the locked
position. To
release the handrail 124b and connecting rod I88 from the locked position, a
clockwise
moment is applied to the connecting rod 188 by interaction of the roller 208
with the cam
plate 242. This clockwise moment must first overcome the bias of spring 190
thereby
causing the handrail 124b to rotate back to the stowed position.
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Referring to FIGURES S and 6, handrails 124a and 124b in conjunction with
respective actuating control assemblies 182 and cam plate 242, are co~gured
such that
handrail 124b is operatively located above handrail 124a to deploy handrail
124b slightly
ahead of handrail 124a, thus timing the handrail deployment to avoid
interference
between handrails 124a and 124b. Although the illustrated embodiment of the
present
invention is depicted with the handrails, lift platform barrier, and lift
platform moving
simultaneously, it should be apparent to one skilled in the art that the
actuation of the
handrails, lift platform barrier, and lift platform could be performed
sequentially.
Referring now to FIGURES 8 and 9, the detailed description will now focus upon
the lift platform barrier actuating assembly 136. Inasmuch as the components
of the lift
platform barrier actuating assembly 136 are substantially similar for each
side of the lift
platform barrier 110, this detailed description, for the sake of brevity, will
describe the
components of the lift platform barrier actuating assembly 136 associated with
one side
of the lift platform barrier only. Where the context permits, reference in the
following
description to an element of one side of the lift platform barrier actuating
assembly 136
shall be understood as also referring to the corresponding element of the
opposite side of
the lift platform barrier actuating assembly 136..
Each side of the lift platform barrier actuating assembly 136 includes a first
lever 254 and a second lever 256. The upper end of the first lever 254 is
pivotally
coupled to a stub shaft 260 coupled to the lift platform barrier 110,
including a well
known bushing 262 and washer 264. The lower end of the first lever 254 is
coupled to a
pivot pin 266 extending perpendicularly outward from the upper end of the
second
lever 256. A well known bushing 268 and. a washer 270 are used to reduce
rotational
friction and wear between the first and second levers 254 and 256. The second
lever 256
is rotatingly coupled to the lift platform 108 by a pivot shaft 272 of the
second lever 256
and a bearing holder 274 coupled to the lift platform 108. A washer 276 and a
bearing 278 axe used to reduce rotational friction and wear between the pivot
shaft 272
and the bearing holder 274.
Pivotally coupled to the lower end of the second lever 256 is a cam follower
280.
The cam follower 280 is mounted upon a pivot shaft 282 extending
perpendicularly
outward from the lower end of the second lever 256. The cam follower 280 is
rotatingly
received upon the pivot shaft 282 by a bushing 284 and a washer 286, and is
removably
retained upon the pivot shaft 282 by a well known retaining clip 288. A spring
290
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extends between a Iip 292 disposed on the second lever 256 and a post 294
extending
perpendicularly outward from the lift platform 108. The spring 290 biases the
second
lever 256 in a clockwise rotation about the pivot shaft 272.
As may be seen by referring to FIGURES 10-12, angular rotation of the second
lever 256 is controlled by a pair of cam plates 296 coupled to the frame 106.
Inasmuch as
the cam plates 296 are mirror images of each other, only one cam plate 296
will be
described in greater detail. Each cam plate 296 includes a cam surface 298 and
a stop
surface 300. The cam follower 280 coupled to the lower end of the second lever
256
rides upon the cam surface 298 and the stop surface 300 to selectively control
the
deployment of the lift platform barrier 110.
More specifically, as . the lift platform 108 is raised, the lift platform
barrier
actuating assembly 136 is also elevated since it is coupled to the lift
platform 108. As the
lift platform 108 rises, the separation distance between the lift platform
barrier actuating
assembly 136 and the cam plate 296, which is coupled to a stationary portion
of the
frame 106, is increased. This causes the cam follower 280 to ride vertically
along the
stop surface 300. As the cam follower 280 rides vertically along the stop
surface 300, the
second lever 256 does not rotate and the lift platform baxrier 110 remains
stationary in the
stowed (retracted) position.
As the lift platform 108 is raised further, the cam follower 280 eventually
passes
over a ridge 302 marking the transition of the stop surface 300 to the cam
surface 298.
As the cam follower 280 passes onto the cam surface 298, the second lever 256
begins to
rotate about the pivot shaft 272. The cam follower 280 is biased by a spring
290 to
engage the stop surface 300 and the cam surface 298. As the cam follower 280
passes
along the cam surface 298 and is rotated, the first lever 254 rotates and is
driven along its
length as the cam follower 280 rides along the cam surface 298, thereby
actuating the lift
platform barrier 110 from its stowed position to its partially deployed
position shown in
FIGURE 11.
Referring to FIGURES 11 and 12, as the lift platform 108 is raised above the
elevation depicted in FIGURE 11, the cam follower 280 disengages from the cam
surface 298 of the cam plate 296. When the cam follower 280 disengages from
the cam
surface 298, the second lever 256 biased by spring 290 is free to rotate about
the pivot
shaft 272, causing the lift platform barrier 110 to be actuated from the
partially deployed
position shown in FIGURE 11 to the fully deployed position shown in FIGURE 12.
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As may be best seen by referring to FIGURE 13, the upper floor barrier
assembly 138 includes a barrier 112 and an actuator 123. The barrier 112
includes a
plate 800 and first and second slide plates 802 .and 804. The plate 800 is
suitably
rectangular in configuration and form from a well known material, such as
aluminum.
The first and second slide plates 802 and 804 are suitably attached to
opposite ends of the
plate 800 by well known fasteners (not shown), such as rivets or bolts. The
first and
second slide plates 802 and 804 are positioned for sliding engagement with
first and
second slides 806 and 808 of an anchor plate 810.
The first and second slides 806 and 808 are fastened to opposite ends of the
anchor plate 810, such that edge portions of the first and second slide plates
802 and 804
are slidably positioned between opposing ends of the first and second slides
806 and 808
and corresponding sides of the anchor plate 810. The actuator 123 is anchored
to a
portion of the anchor plate 810 and is operatively coupled to the barrier 112,
such that
actuation of the actuator 123 selectively displaces the barrier 112 into and
out of the
deployed position.
Referring back to FIGURES, the cover panel actuating assembly 139 will now be
described in greater detail. The cover panel actuating assembly 139 includes a
pair of
actuators 304a and 304b. Each actuator 304. is coupled to one end of each
cover
panel 116a and 116b. The upper end of each actuator 304 is coupled to lever
arms 306
that are, in turn, pivotally coupled to a series of fulcrums 308 coupled to
the frame 106.
The lever arms 306 are rigidly coupled to respective cover panels 116a or
116b.. A lower
end of each actuator 304 is pivotally coupled to the frame 106.
The actuators 304 are selectively adjustable in length. Shortening the length
of
the actuators 304 relative to the length depicted in FIGURE 5 causes the cover
panels 116a and 116b to move from their stowed position to their deployed
position.
Likewise, lengthening the actuators 304 causes the cover panels 116a and 116b
to move
from the deployed position to the stowed position. In the illustrated
embodiment, the
actuators are formed from hydraulic pistons, however, it should be apparent to
those
skilled in the art that other actuators axe suitable for use with and within
the spirit and
scope of the present invention, such as electrical solenoid actuators,
mechanical actuators,
etc. Further, although in the illustrated embodiment, the cover panels 116a
and 116b are
depicted as coupled to the frame 106 of the lift assembly 100, it should be
appaxent to
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those skilled in the art that the cover panels 116 may alternately be coupled
to a structure
other than the lift assembly 100, such as the lower floor 102.
Operation of the lift assembly 100 may be best understood by referring to
FIGURES 14-19. In FIGURE 14; the lift assembly 100 is shown in a stowed
position. In
the stowed position, a majority of the lift assembly 100, such as the lift
platform 108, lift
platform barrier 110, side curbs 114, and protective apron 118, are disposed
in a
cavity 120 located below the lower floor 102. The cover panels 116a and 116b
are shown
in a stowed position, wherein the cover panels 116a and 116b are preferably
oriented
substantially coplanar (i.e. flush) with the lower floor 102 and extend over
and cover the
IO cavity 120.
Configured in this manner, a person may walk over the cavity 120, supported by
the cover panels I 16a and I 16b, without encountering tripping hazards or
falling into the
cavity 120. Preferably, for aesthetics, the cover panels 116a and 116b are
covered with a
material that corresponds with the material of the adjacent flooring, such as
wood, carpet,
I S or tile. Alternately, the outer surface of the cover panels 116a and 116b
may be textured
to provide a slip resistant surface.
Referring now to FIGURE 1 S, the lift assembly 100 is shown as the deployment
of the lift assembly 100 is initiated. In a first stage of deployment of the
lift
assembly 100, the upper floor barrier 112 is actuated by a well known linear
actuator 123,
20 such as a hydraulic piston, from the stowed (retracted) position to the
deployed
(extended) position. In the deployed position, the upper floor barrier 112
extends above
the upper floor 104 and is oriented substantially perpendicular to the upper
floor 104. In
the deployed position, the upper floor barrier 112 impedes a person from
attempting to
ingress the lift platform 108 prematurely, i.e. prior to arrival of the lift
platform 108 to the
25 upper floor 104. Further, the upper floor barrier 112 impedes objects from
falling from
the upper floor 104 and striking a person using the lift assembly 100. Further
still, the
upper floor barrier 112 also functions as a warning that the lift assembly 100
is in
operation or is about to operate. Although the upper floor barrier 112 is
described and
depicted as being actuated from the stowed to the deployed position, it should
be apparent
30 to those skilled in the art that the upper floor barrier 112 may be
deployed in alternate
manners, such as by rotating the upper floor barrier 112 from the stowed to
the deployed
position.
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Referring now to FIGURE 16, the lift assembly 100 is shown as the deployment
of the lift assembly 100 enters a second stage of the deployment. In the
second stage of
deployment, the cover panels 116a and 116b are rotated from the stowed
position
depicted in FIGURES 14 and 15 to the deployed position shown in FIGURE 16. In
the
deployed position, the cover panels 116a and 116b extend above the lower floor
102 and
are oriented substantially perpendicular to the lower floor 102. Although the
cover
panels 116a and 116b are described and depicted as being rotated from the
stowed to the
deployed position, it should be apparent to those skilled in the art that the
cover
panels 116a and 116b may be deployed in alternate manners.
Referring now to FIGURE 17, the lift assembly 100 is shown as the deployment
of the lift assembly 100 enters a third stage of deployment. In the third
stage of
deployment, the handrails 124a and 124b are rotated from a stowed position to
a
deployed position. Referring to FIGURE 16, in the stowed position, the
handrails 124a
and 124b are configured to be substantially parallel with the lift platform
108 and in an
overlapping relationship, such that handrail 124a is located below handrail
124b. As the
lift platform 108 is raised, the deployment of the handrails 124a and 124b
commences,
due to the overlapped relationship of the handrails 124a and 124b, the
deployment of
upper handrail 124b is initiated. before the deployment of lower handrail
124a. The
deployment of the handrails 124a and 124b is accomplished by rotating the
handrails 124a and 124b to the deployed position shown in FIGURE 17.
In the deployed position, the handrails 124a and 124b extend above the lift
platform 108 and are oriented substantially perpendicular to the lift platform
108.
Although the handrails 124a and 124b are described and depicted as being
rotated from
the stowed to the deployed position, it should be apparent to those skilled in
the art that
the handrails 124a and 124b may be deployed in alternate manners, such as
linearly
actuating each of the handrails 124a and 124b from the stowed to the deployed
position.
Still referring to FIGURE 17, as the lift platform 108 is raised, the
handrails 124a
and 124b are simultaneously actuated to the fully deployed position, to
coincide when the
lift platform 108 is located substantially coplanar .with the lower floor 102.
In this
configuration, the lift assembly 100 is now ready to permit a wheelchair bound
user to
roll from the lower floor 102, across an entrance threshold 126, to the lift
platform 108.
Referring now to FIGURE 18, after the mobility impaired user is secured upon
the
lift platform 108, deployment of the lift assembly 100 enters a fourth stage.
In the fourth
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stage of deployment, the Lift platform barrier 110 is actuated from a stowed
position
depicted in FIGURE 17 to the deployed position shown in FIGURE 18. In the
deployed
position, the lift platform barrier 110 extends above the lift platform 108
and is oriented
substantially perpendicular to the lift platform 108: In the deployed
position, the lift
platform barrier 110 impedes a person from attempting to egress from the lift
platform 108 prematurely. Although the lift platform barrier 110 is described
and
depicted as being actuated from the stowed to the deployed position, it should
be apparent
to those skilled in the art that the lift platform barrier 110 may be deployed
in alternate
manners, such as by rotating the lift platform barner 110 from the stowed to
the partially
deployed position. As the lift platform 108 is raised, the lift platform
barrier is deployed
simultaneously.
Referring now to FIGURE 19, the lift platform 108 is raised until the lift
platform 108 is substantially coplanar with the upper floor 104. As the lift
platform 108
is raised, a protective apron 118 is formed below the lift platform 108. The
protective
apron 118 impedes a person or object from accessing portions of the lift
assembly 100
during operation. This reduces the potential of injury to those in proximity
to the lift
assembly 100 and impedes the entrance of foreign objects within the lift
assembly 100
that may cause damage or hamper operation of the lift assembly 100. In the
illustrated
embodiment of the present invention, the protective apron 118 is formed from a
series of
telescoping ~ panels 128a, 128b and 128c. The panels 128 are coupled to the
lift
platform 108 and frame 106 such that the panels 128 slide relative to one
another to form
a protective barrier of adjustable height suspended from the lift platform
108. Although
the protective apron 118 is described and depicted as a series of telescoping
panels 128, it
should be apparent to those skilled in the art that the protective apron 118
may take many
other suitable forms, such as a panel linearly actuated upward at the same
rate as the lift
platform 108.
Referring now to FIGURE 19, the lift assembly 100 is shown as the wheelchair
bound person is permitted to egress from the lift platform 108. The lift
platform 108 is
substantially coplanar with the upper floor 104. To permit egress, the upper
floor
barrier 112 is linearly actuated from the deployed position shown in FIGURE 18
to the
stowed position shown in FIGURE 19. In the stowed position, the upper floor
barrier 112
is flush or slightly below the upper floor 104 so as to permit the wheelchair
bound person
to roll from the Lift platform 108 and on to the upper floor 104.
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FIGURES 20-27 illustrate an alternate embodiment of the upper floor
barrier assembly 138 of the previously described embodiment. The
alternate.embodiment
of the upper floor barrier assembly 138 has been renamed for clarity as a
retractable
barrier assembly 400 to difFerentiate the alternate embodiment from the
previous
embodiment.
The retractable barrier assembly 400 is adapted for use in conjunction with a
lift
assembly 350. The lift assembly 350 identical in materials and operation as.
the lift
assembly of the embodiment described above.
Although the illustrated embodiment of the retractable barrier 'assembly 400
is
described as implemented in relation to a lift assembly 350, one skilled in
the relevant art
will appreciate that the disclosed retractable barrier assembly 400 is
illustrative in nature
and should not be construed as limited to application in relation to a lift
assembly. It
should therefore be apparent that the retractable barrier assembly 400 of the
present
embodiment has wide application, and may be used in any situation where a
retractable
barrier is desirable, such as use as a door, a fall prevention barrier, a roll
stop, a protective
cover, and so forth. It should be noted that for purposes of this disclosure,
terminology
such as upper, lower, side, horizontal, vertical, left, and, right, aft should
be construed as
descriptive and not limiting.
Referring to FIGURES 20 and 21, one embodiment of a retractable barrier
assembly 400 formed in accordance with the present invention is depicted. The
retractable barrier assembly 400 is attached to a wall 358 located adjacent
and above a lift
assembly 350. The retractable barrier assembly 400 includes a barrier 401. The
barrier 401 is actuatable between a stowed position and a deployed position.
Preferably, the actuation of the barrier 401 is tied to the operation of the
lift
assembly 350. More specifically, as the lift assembly 350 is actuated from a
stowed
position to a fully raised position, the barrier 401 is deployed and stowed in
accordance
with the operation of the lift assembly 350. Moreover, the retractable barrier
assembly 400 selectively deploys the barrier 401 to deter a person or object
present on the
upper floor 356 from inadvertently falling into or contacting the lift
assembly 350 during
actuation of the lift assembly 350. Further still, the actuation of the
retractable barrier
assembly 400 also functions as a warning that the lift assembly 350 is in
operation or is
about to operate.
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Referring to FIGURE 21, the structural components of the retractable barrier
assembly 400 will now be discussed in further detail. The retractable barrier
assembly 400 includes a barrier 401 formed from ~an outer panel 402 pivotally
coupled to
an inner panel 404. The barrier 401 is in turn coupled to a frame 406. The
frame 406 is
rectangular in shape and includes axi upper frame member 408 oriented
horizontally
above the barrier 401. Oriented parallel with the upper frame member 408 and
below the
barrier 401 is a lower frame member 410. On one side of the barrier 401 is a
vertically
oriented first side frame member 412. On an opposite side of the barrier 401
is a
vertically oriented second side frame member 414. The frame 406 may in. turn
be
coupled to a structure such as a wall 358.
Referring to FIGURES 22 and 23, the barrier assembly 400 includes an upper and
a lower actuating assembly 468 and 470. The elements of the upper and lower
actuating
assemblies 468 and 470 are mirror images of one another. Therefore, for
brevity, only
the lower actuating assembly 470 will be described in detail, as it should be
apparent to
one skilled in the art that reference in the following description to an,
element of the lower
actuating assembly shall be understood as also referring to the corresponding
mirrored
element in the upper actuating assembly 468.
Each actuating assembly 468 and 470 includes a linkage assembly 419 actuated
by a driven carriage 428. The linkage assembly 419 causes the outer panel 402
to pivot
relative to the inner panel 404, and the inner panel 404 to pivot relative to
the frame 406
in a bi-fold arrangement. The driven carriage 428 is reciprocated by a drive
assembly 472. Movement of the driven carriage 428 longitudinally along the
lower frame
member 410 causes the linkage assembly 4I9 to configure the retractable
barrier 401
from a deployed position to a stowed position, or vice versa, as desired by
the user.
The driven carriage 428 includes a horizontally oriented flat plate 464.
Extending
perpendicularly downward from the flat plate 464 is a first guide 448 and a
second
guide 450. The guides 448 and 450 are sized and positioned to engage a
carriage
track 458 running longitudinally along the length of the lower frame member
410. The
guides 448 and 450 guide the movement of the driven carriage 428 along the
longitudinal
path defined by the carriage track 458.
Pivotally coupled to guide 450 is a hinge plate 442. The inner panel 404 is
coupled to the hinge plate 442 by a well known fastener 440. The hinge plate
442 also
includes a boss 444 for permitting the pivotal coupling of an inner panel
actuating
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link 424 to the boss 444 by a pivot pin 446. An outer panel connector link 422
is coupled
to the driven carriage 428 by a pivot pin 457. Likewise, an inner panel
connector
link 426 is pivotally coupled to the driven carriage 428 by another pivot pin
454. As the
driven carriage 428 is reciprocally driven along the path defined by the
carriage
track 458, the inner panel connector link 426 and the outer panel connector
link 422 are
forced to pivot about their attachment points to the driven carriage 428,
i.e., pivot pin 454
and pivot pin 457, respectively. The pivoting of the inner panel connector
link 426 and
the outer panel connector link 422 in turn causes the rotation of inner and
outer
panels 404 and 402 between the stowed and deployed positions.
The degree and rate of rotation of the inner panel connector link 426 is
controlled
by a guide 452 disposed on an end of the inner panel connector link 42f. The
guide 452
engages and reciprocates within an inner panel linkage guide track 462. . The
inner panel
linkage guide track 462 is formed in the lower frame member 410 and is arcuate
in shape
such that the distance separating the inner panel linkage guide track 462 from
the carriage
track 458 decreases as the driven carriage 428 is reciprocated in driving the
barrier 401
from the stowed position to the fully deployed position. Thus, as the driven
carriage 428
is reciprocated into the fully deployed position, the inner panel connector
link 426 pivots
in a counterclockwise rotation when viewed from above thereby acting upon the
inner
panel actuating link 424.
The inner panel actuating link 424 is pivotally coupled at guide 452 to the
inner
panel connector link 426. The inner panel actuating link 424 is also coupled
at an
opposing end to the boss 444 of the hinge plate 442 at pivot pin 446. Thereby,
when the
inner panel connector link 426 is rotated counterclockwise, the inner panel
actuating
link 424 imposes an outward force upon the boss 444 of the hinge plate 442,
thereby
rotating the hinge plate 442 and attached inner panel 404 about guide 450
of.the driven
carriage 428, rotating the inner panel 404 and attached outer panel 402 in a
counterclockwise direction. .
While the inner panel 404 is rotated by the linkage assembly 419 as described
above, the outer panel 402 is likewise rotated in a counterclockwise direction
in a similar
manner as the inner panel 404 by the linkage assembly 419. More specifically,
as the
driven carriage 428 is reciprocated in driving the barrier 401 from the stowed
to the fully
deployed position, outer panel connector link 422 is forced to rotate about
pivot pin 457.
The rotation of the outer panel connector link 422 is controlled by a guide
456 disposed
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on an end of the outer panel connector link 422. The guide 456 engages and
reciprocates
within an outer panel linkage guide track 460. The outer panel linkage guide
track 460 is
formed in the lower frame member 410 and is arcuate in shape so that the
distance
separating the outer panel linkage guide track 460 from the carriage track 458
initially
decreases as the driven carriage 428 is reciprocated longitudinally along
lower frame
member 410 and then slightly increasing as the driven carriage 428 approaches
the fully
deployed position.
Thus, as the driven carriage 428 is reciprocated towaxd a deployed position,
the
outer ~ panel connector link 422 pivots initially in a counterclockwise
rotation when
viewed from above and subsequently in a clockwise rotation. An outer panel
actuating
link 420 is pivotally coupled at guide 456 to the outer panel connector link
422. The
outer panel actuating link 420 is also coupled at an opposing end to the boss
434 of the
hinge plate 430 at pivot pin 436. Thereby, when the outer panel connector link
422 is
rotated counterclockwise, the outer panel actuating link 420 imposes an
outward force
upon the boss 434 of the hinge plate 430, thereby rotating the hinge plate 430
and
attached outer panel 402 about pivot pin 438 and inner panel 404 in a
counterclockwise
direction when viewed from above. Likewise, as the driven carriage 428
approaches the
fully deployed position, the outer panel connector link 422 is then rotated
clockwise, the
outer panel actuating link 420 imposes an inward force upon the boss 434 of
the hinge
plate 430, thereby rotating the hinge plate 430 and attached outer panel 402
about pivot
pin 438 and inner panel 404 in a clockwise direction when viewed from above.
Referring to FIGURE 24, the drive assembly 472 will now be discussed in
further
detail. The drive assembly 472 includes a motor 474 having a worm wheel (not
shown)
for .engaging a worm 476 formed from an elongate helically threaded shaft. By
selectively engaging the worm 476 with the worm gear, the drive assembly 472
may be
selectively reciprocated along the length of the worm 476. An interface plate
478 permits
the coupling of the drive assembly 472 to a driven member 416. The driven
member 416
is a vertically disposed structural member coupled to the driven carriage 428
of the upper
and lower actuating assemblies 468 and 470. Thus linear movement of the drive
assembly 472 along the length of the worm 476 thereby causes likewise linear
movement
of the driven carriages 428 of the upper and lower actuating assemblies 468
and 470,
causing the linkage assembly 419 to actuate the barrier 401 from the stowed to
the
deployed position, or vice versa.
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In light of the above description of the components of the retractable barrier
assembly 400, the operation of the retractable barrier assembly 400 during
deployment
will be described. Although the deployment of the barrier from the stowed to
the
deployed position will only be discussed in detail, it should be apparent to
one skilled in
the art that the reciprocation of the barrier 401 from the deployed to the
stowed position is
identical in all respects except . the motions are performed in reverse,
therefore the
description of the deployment of the barrier 401 into the stowed position has
been omitted
for brevity.
As the drive assembly 472 is activated, it is reciprocated along the length of
the
worm 476 and the attached driven member 416 is likewise reciprocated. Inasmuch
as the
driven carriage 428 is coupled to an end of the driven member 416, the driven
carriage 428 is likewise displaced horizontally , along the carriage track
458. As the
driven carriage 428 is driven, the actuating assembly 470 is actuated from the
stowed
position, as depicted in FIGURES 20 and 21, to the 25% deployed position
depicted in
FIGURES 24 and 25. As the baxrier 401 is reciprocated from the stowed to the
deployed
position, each panel 402 and 404 of the barrier 401 is selectively displaced
while
simultaneously rotated to deploy the panels 402 and 404 along an arcuate path
shown in
phantom and indicated by reference numeral 480. Of note, the arcuate path 480
is
initially tangent to the plane containing the barrier 401 in the stowed
position.
Still referring to FIGURES 24 and 25, this detailed description will now focus
on
the movement of the linkage assembly 419 as the barrier 401 is actuated from
the stowed
to the 25% deployed position. As described above, in actuating the barrier 401
from the
stowed to the 25% deployed position, the driven carriage 428 is driven to the
Left along
the carriage track 458. In doing so, the barrier 401 is reciprocated to the
left and the inner
panel connector link 426 is rotated counterclockwise (when viewed from above)
through
the interaction of guide 452 with the inner panel linkage guide track 462. The
counterclockwise rotation of the inner panel connector link 426 in turn drives
the inner
panel actuating link 424 clockwise and linearly outward along its length,
thereby pivoting
the inner panel 404 counterclockwise along the arcuate path 480 through the
interaction
of the inner panel actuating link 424 with the lunge plate 442 to the 75%
deployed
position depicted in FIGURES 22 and 23.
Likewise, as the driven carriage 428 is driven, the outer panel connector link
422
is rotated counterclockwise through the interaction of guide 456 with the
outer panel
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linkage guide track 460. The counterclockwise rotation of the outer panel
connector
link 422 in turn rotates and drives the outer panel actuating link 420
linearly to the left,
thereby pivoting the outer panel 402 counterclockwise along the arcuate path
480 through
the interaction of the outer panel actuating link 420 with the hinge plate 430
to the 75%
deployed position in FIGURES 22 and 23.
Referring to FIGURES 26 and 27, as the activation of the drive assembly 472 is
continued, the drive assembly 472 is displaced further along the length of the
worm 476.
Inasmuch as the driven carriage 428 is coupled to the end of the drive member
416, the
driven carriage 428 is likewise reciprocated to the left. As the driven
carriage 428 is
driven to the left, the actuating assembly 470 is actuated to the fully
deployed position
depicted in FIGURES 26 and 27. A's the barrier 401 is actuated to the fully
deployed
position, the inner panel connector link 426 is rotated counterclockwise (when
viewed
from above) through the interaction of guide 452 with the inner panel linkage
guide
track 462. The counterclockwise rotation of the inner panel connector link 426
in turn
drives the inner panel actuating link 424 clockwise and outward toward the
hinge
plate 442, thereby pivoting the inner panel 404 counterclockwise.
As the driven carriage 428 is driven farther to the left, the outer panel
connector
link 422 now changes direction of rotation and is now rotated clockwise
through the
interaction of guide 456 with the outer panel linkage guide track 460, which
now slightly
angles away from the guide track 458 to increase the distance separating the
two
tracks 458 and 460. The clockwise rotation of the outer.panel connector link
422 in turn
draws the outer panel actuating link 420 inward along its length away from
hinge
plate 430. This movement, in combination with the counterclockwise rotation of
the
inner panel 404, causes the distance separating pivot pin 438 from guide 456
to increase,
thereby causing the outer panel 402 to now rotate clockwise.
As such, the barrier 401 is not swung outward as is done in previously
designed
retractable barriers, but is linearly reciprocated while simultaneously
pivoted outward in a
bi-fold manner as to define an arcuate travel path 480, preferably circular in
shape. In
scribing the arcuate path 480, the area required for deployment is greatly
reduced. As the
barrier 401 does not swing outward about a single pivot axis, the barrier 401
does not
swing through the deployment area, causing damage or injury to any object or
person
located therein, or sweep any object or person located in the deployment area
off the
upper floor.
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Although the illustrated embodiment of the present invention is depicted with
a
barrier 401 formed from two panels, it should be apparent to one skilled in
the art that a
barrier 401 formed from any number of panels may be utilized, such as a
barrier formed
from one panel, or three or more, without departing from the spirit and scope
of the
present invention. Further, although the arcuate path 480 scribed by the
barrier 401
during deployment is arcuate in shape, and more specifically circular, it
should be
apparent to one skilled in the art that the path may contain linear segments
in whole or
part. Further still, although a specific actuation system was depicted in the
illustrated
embodiment, it should be apparent to one skilled in the art that any number
and types of
actuation systems are suitable for use with and are within the scope of the
present
invention, such as hydraulic, pneumatic, electrical, and magnetic actuation
systems.
Further still, although the retractable barrier assembly 400 of the present
invention is
described as being disposed upon a wall, it should be apparent to one skilled
in the art
that the retractable barrier assembly 400 may also be located upon a floor as
well.
While the preferred embodiment of the invention has been illustrated and
described, it will be appreciated that various changes can be made therein
without
departing from the spirit and scope of the invention.
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