Field of the Invention
-
The invention relates to chairs, and more
particularly to power actuated reclining chairs having a
wall-hugger function.
Background of the Invention
-
Manual "wall-hugger" style chairs are popular,
because they do not require any more clearance between the
backrest and a nearby wall in a normal seated position
than in a fully reclined position. As a result, they
conserve space in a room.
-
Power actuated lifting and reclining chairs are
well known. See, for example, Gaffney U.S. Patent No.
4,007,960. These chairs have, in the past, allowed elderly
or infirm persons to enjoy all the comforts and benefits
of then conventional reclining chairs. The elderly or
infirm should also have the opportunity to enjoy all the
comfort and benefits of wall-hugger style chairs.
-
Unfortunately, the special mechanisms that make
conventional, manual wall-hugger style chairs possible do
not readily lend themselves to straightforward, reliable,
and inexpensive connection to conventional power actuated
lift and recline mechanisms.
Summary of the Invention
-
One aspect of the invention provides a mechanized
base for a reclining chair, which provides a reliable,
straightforward, power-driven reclining function
with a wall-hugging feature. The reclining chair has a
backrest and a seat, which includes a front seat portion
and a rear seat portion. The base carries an actuator,
which is coupled to a reclining linkage assembly.
-
In one embodiment, the reclining linkage assembly
includes a forward thrust bar on the base adapted to
be coupled to the front portion of the seat. In this
embodiment, the reclining linkage assembly is operable,
in response to operation of the actuator, for applying a
pushing force to the forward thrust bar to advance the
seat and backrest forward while tilting the backrest
rearward from a generally upright position to a generally
reclined position. Pushing the seat and backrest forward
while the backrest reclines, keeps the distance between
the backrest and an adjacent wall generally constant when
the backrest is in the generally upright position and in
the generally reclined position.
-
In a preferred embodiment, the actuator on the
base is operable in first and second modes. In this
embodiment, a lifting linkage assembly coupled to the
actuator is also adapted to be coupled to the seat. In
use, the lifting linkage is operable, when the actuator
operates in the first mode, for lifting the seat and
tilting the seat forward to assist exit from the chair.
In this embodiment, the reclining linkage assembly is
operable, when the actuator operates in the second mode,
for applying force to move the seat and backrest forward
while tilting the backrest rearward for recline.
-
The mechanized base provided by the invention
readily accommodates a reclining chair construction in
which the backrest and seat are secured together at a
fixed angle. The mechanized base just as readily accommodates
a reclining chair construction in which the backrest
pivots relative to the seat.
-
The mechanized base also accommodates a reclining
chair having an extendable footrest. In this embodiment,
the reclining linkage assembly is linked to the
footrest to extend the footrest as the seat and backrest
are pulled forward for recline.
-
Another aspect of the invention provides a chair
comprising a seat, a footrest linkage associated with the
seat to operable between a retracted position and an
extended position, and a base. An actuator on the base
is coupled to a lifting linkage assembly, which is coupled
to the base and the seat. The lifting linkage assembly
is operable, in response to operation of the actuator, for
lifting the seat and tilting the seat forward to assist
exit from the chair. According to this aspect of the
invention, the chair includes a mechanism to resist
movement of the footrest linkage out of the retracted
position when the seat is lifted and tilted forward.
-
Other features and advantages of the inventions
are set forth in the following Description and Drawings,
as well as in the appended claims.
Brief Description of the Drawings
-
- Fig. 1 is a perspective front side view of a
reclining chair carried on a mechanized base, which
embodies features of the invention, the chair being shown
in a normal seated position on the base;
- Fig. 2 is a perspective front side view of the
reclining chair shown Fig. 1, except that the chair is
shown in an elevated position, lifted above the mechanized
base;
- Fig. 3 is a perspective front side view of the
reclining chair shown Fig. 1, except that the chair is
shown in a reclined position on the base;
- Figs. 4A, 4B, and 4C are exploded rear side
perspective views of one embodiment of the mechanized base
which the chair shown in Fig. 1 incorporates, with Fig.
4A showing the chair frame support unit, Fig. 4B showing
the bottom base unit, and Fig. 4C showing the assembly of
the chair frame support unit on the bottom base unit,
forming the mechanized base;
- Fig. 5 is a rear side perspective view of the
bottom base unit of the mechanized base with the components
oriented when the chair is in the normal seated
position shown in Fig. 1;
- Figs. 6 and 7 are rear side perspective views
of the bottom base unit of the mechanized base with the
components oriented when the chair is being elevated, with
Fig. 6 showing a partially elevated position and Fig. 7
showing a fully elevated position, generally corresponding
to the attitude of the chair shown in Fig. 2;
- Figs. 8 and 9 are rear side perspective views
of the bottom base unit of the mechanized base, with
portions of the chair frame support unit also shown, with
components oriented when the chair is being reclined, with
Fig. 8 showing a partially reclined position and Fig. 9
showing a fully reclined position, generally corresponding
to the attitude of the chair shown in Fig. 3;
- Fig. 10 is a side elevation view of the mechanized
base, with portions broken away and presented in
phantom lines to enable clear viewing, showing the orientation
of components when the chair is in a normal seated
position, generally corresponding to Fig. 1;
- Fig. 11 is a side elevation view of the mechanized
base, with portions broken away and presented in
phantom lines to enable clear viewing, showing the orientation
of components when the chair is in an elevated
position, generally corresponding to Fig. 2;
- Fig. 12 and 13 are a side elevation views of the
mechanized base, with portions broken away and presented
in phantom lines to enable clear viewing, showing the
orientation of components when the chair is in a partially
reclined position (Fig. 12) and a fully recline position
(Fig. 13), generally corresponding to Fig. 3;
- Fig. 14 is a side elevation view of another
embodiment of a mechanized base, which embodies features
of the invention, with portions broken away and presented
in phantom lines to enable clear viewing, showing the
orientation of components when the chair is in a normal
seated position;
- Fig. 15 is a side elevation view of the mechanized
base shown in Fig. 14, with portions broken away and
presented in phantom lines to enable clear viewing,
showing the orientation of components when the chair is
in a partially reclined position;
- Fig. 16 is a side elevation view of the mechanized
base shown in Fig. 14, with portions broken away and
presented in phantom lines to enable clear viewing,
showing the orientation of components when the chair is
in a fully reclined position;
- Fig. 17 is a rear side perspective view of the
mechanized base shown in Figs. 14 to 16;
- Fig. 18 is a rear perspective view of another
embodiment of a mechanized base which the chair shown in
Fig. 1 can incorporate, showing the assembly of a chair
frame support unit on the bottom base unit, forming the
mechanized base, which is shown in a normal seated condition;
- Fig. 19 is a rear perspective view of the
mechanized base shown in Fig. 18, with the base in a
partially reclined condition;
- Fig. 20 is a rear perspective view of the
mechanized base shown in Fig. 18, with the base in a fully
reclined condition, generally corresponding to claim 3;
- Fig. 21 is a side elevation view of the mechanized
base shown in Fig. 18 taken generally along line 21-21
in Fig. 18, showing the orientation of components when
the chair is in a normal seated position, generally
corresponding to Fig. 1;
- Fig. 22 is a side elevation view of the mechanized
base shown in Fig. 21, showing the orientation of
components when the chair is in an partially elevated
position;
- Fig. 23 is a side elevation view of the mechanized
base shown in Fig. 21, showing the orientation of
components when the chair is in a fully partially elevated
position, generally corresponding to Fig. 2;
- Figs. 24 and 25 are enlarged perspective views
showing a mechanism for locking a lazy tongs linkage when
the chair shown in Fig. 21 elevated, Fig. 24 showing the
orientation of the locking mechanism when the chair is
partially elevated (as also shown in Fig. 22), and Fig.
24 showing the orientation of the locking mechanism when
the chair is fully elevated (as also shown in Fig. 23);
- Fig. 26 is a rear perspective view of a mechanized
base having the features of the base shown in Fig.
18, but adapted to accept a preassembled reclining chair;
- Fig. 27 is a front perspective view of a mechanized
base, shown in an elevated position, which is
adapted to accept a preassembled reclining chair and which
includes a swinging link that applies a dynamic counter
force to the reclining mechanism of the chair when the
chair is being elevated, to thereby lock the footrest in
a retracted condition;
- Fig. 28 is a side elevation view of the base
shown in Fig. 27, with the swinging link shown in a
transfer position to place the chair in a normal seated
position; and
- Fig. 29 is a side elevation view of the base
shown in Fig. 28, with the swinging link shown in a fully
rotated position to recline the chair.
-
-
The invention may be embodied in several forms
without departing from its spirit or essential characteristics.
The scope of the invention is defined in the
appended claims, rather than in the specific description
preceding them. All embodiments that fall within the
meaning and range of equivalency of the claims are therefore
intended to be embraced by the claims.
Description of the Preferred Embodiments
-
Figs. 1 to 3 show a power actuated lifting and
reclining chair 10, which embodies features of the invention.
The chair 10 comprises an upholstered chair body 12
carried on a mechanized base 14(see Fig. 2). As shown in
Figs. 1 to 3, the chair 10 which is supported on a floor
16 in proximity to a wall 18.
I. The Chair Body
-
The chair body 12 is typical of most chairs in
residential use. The chair body 12 includes a seat 20, a
backrest 22, and side arms 24. In the illustrated embodiment,
the chair body 12 also includes an extendable
footrest or ottoman 26. Still, the presence of the
footrest 26 is not essential to the features of the
invention.
-
Fig. 1 shows the chair body 12 in a typical, normal
seated position. In this position, the backrest 22 is in
a generally upright, or perhaps somewhat tilted back,
condition. This position provides comfort to an occupant
for normal seating in the chair body 12.
-
The mechanized base 14 is coupled to a hand-held
controller 28. The controller has one or more control
buttons 30. The occupant presses the control buttons 30,
which drives the mechanized base 14 and alters the position
of the chair body 12.
-
The mechanized base 14 operates in two modes, which
will be called the lift mode and the reclined mode.
-
In the lift mode (exemplified in Fig. 2), the mechanized
base 14 elevates the seat 20 of the chair body 12
from the normal seated position. Preferably, in the lift
mode, the mechanized base 14 also tilts the seat slightly
downward, toward the floor 16.
-
As shown in Fig. 2, the backrest 22 and side arms 24
are all elevated in common with the seat 20. Still, it
should be recognized that the chair body 12 could be
constructed to enable elevating the seat 20 during the
lift mode without raising the backrest 22 or the side arms
24.
-
The lift mode is designed to aid persons who lack the
physical strength or dexterity to push themselves comfortably
from the chair seat 20 into a standing position. The
lift mode brings the occupant in the seat 20 up to or near
a full standing position, to thereby facilitate exit from
the chair body 12. In reverse, the lift mode lowers a
person from a standing position to the normal seated
position.
-
In the recline mode (exemplified in Fig. 3), the
mechanized base 14 tilts or swings the backrest 22 of the
chair body 12 rearward, from the upright position (Fig.
1) through a range of reclined positions to a preset fully
reclined position (Fig. 3). Using the controller 28, the
occupant can stop the backrest 22 at any position between
the upright position and the fully reclined position.
-
The recline mode is designed to give a range of
comfortable positions to the occupant while seated for
various activities, such as reading, watching television,
resting, or sleeping.
-
As shown in Fig. 3, during the recline mode, the
mechanized base 14 also causes the footrest 26 to extend
out from the front of the seat 20. The footrest 26 provides
added support for the occupant's legs, lifting the
legs to enhance blood circulation while enjoying a reclined
position.
-
The details of the reclining action of the backrest
22 in relation to the seat 20 during the recline mode can
vary, according to the construction of the chair body 12.
For example, the backrest 22 can, during all or a portion
of the recline, move relative to the seat 20. This is
known in the industry as a "three-way" chair construction,
in which the seat 20 and backrest 22 are pivotally hinged
together.
-
For an other example, the seat 20 and backrest 22 can
be secured together in a fixed relationship, so that,
during recline, they move as a unit, maintaining a fixed
angle between them. This is known in the industry as a
"two-way" chair construction.
-
The selection of a particular chair construction
depends upon individual preference. The mechanized base
14 can readily accommodate both types of chair constructions,
as will be demonstrated.
-
As Figs. 1 to 3 show, during the recline mode, the
mechanized base 14 provides a wall-hugger function. More
particularly, the distance DWALL, measured between the top
of the backrest 22 and the adjacent wall 18, remains
generally the same, whether the backrest 22 is in the
normal seated position or in the fully reclined position.
II. The Mechanized Base
(Three-Way, Base-Assembled, Rear Thrust Embodiment)
-
Details of one preferred embodiment of the mechanized
base 14 will now be discussed, with reference first
primarily to Figs. 4A, 4B, and 4C.
-
The mechanized base 14 includes a bottom base unit
32 (shown in Fig. 4B) and a chair frame support unit 34
(shown in Fig. 4A). In this particular embodiment, the
bottom base unit 32 and the chair frame support unit 34
are conveniently joined by five bolts B1, B2, B3, B4, and
B5 to create the mechanized base 14 (shown in Fig. 4C).
A. The Bottom Base Unit
-
Referring principally to Fig. 4B, the bottom base unit
32 includes a base frame 36. A back brace 38 is welded or
otherwise fastened across the rear of the base frame 36
to provide strength and stability.
-
The back brace 38 carries a single actuator 40. In
the illustrated embodiment, the actuator 40 comprises a
single electric motor 42 driving a single extendable ram
44. The controller 28 (previously described) is coupled
by a cable 46 to the motor 42. A power cable 48 couples
the motor 42 to a conventional electrical power outlet
(not shown).
-
In the illustrated embodiment, the extendable ram 44
includes a driver 50 driven by a conventional, rotating
lead screw 52. The lead screw 22 is coupled to the motor
42 by a right angle speed reducer 54. The driver 50
includes a drive nut 60, which threadably engages the lead
screw 52. The ram 44 is pivotally connected on a pintle
56 to an actuator mount 58, which is welded or otherwise
fastened to the back brace 38. As used in this Specification,
a "pintle" identifies a pin or bolt or other equivalent
fastening element about which the attached part can
pivot.
-
Operation of the control buttons 30 on the controller
28 command the motor to cause clockwise or counterclockwise
rotation of the lead screw. When the motor 42
rotates the lead screw 52 in a first direction (e.g.,
clockwise), the nut 60 advances the driver 50 in a first
direction (designed by arrow 1 in Fig. 4B), which in the
illustrated embodiment is away from the motor 42. For
point of reference, this direction will be called the
forward or fore direction.
-
Conversely, when the motor 42 rotates the lead screw
in a second direction (e.g., counterclockwise), the nut
60 advances the driver 50 in a second direction (designated
by arrow 2 in Fig. 4B), which in the illustrated
embodiment is toward the motor 42. For point of reference,
this direction will be called the rearward or aft direction.
-
Although the actuator 40 is shown in the illustrated
embodiment to be a motor-driven ram, other power-actuated
mechanisms can be used. For example, a hydraulic or a
pneumatic ram can be used instead of the motor-driven ram.
-
As also shown in Fig. 4B, the bottom base unit 32
carries a forward pair of lift arms 62. The forward lift
arms 62 are pivotally connected on pintles 66 to the
bottom base unit 32 by a front brace 64. The front brace
64 is welded or otherwise fastened across the base frame
36, to provide additional strength and stability.
-
The bottom base unit 32 also includes a pair of rear
lift arm mounts 68. The rear lift arm mounts 68 are
welded or otherwise secured to the back portion of the
base frame 36, adjacent the back brace 38.
B. The Chair Frame Support Unit
-
Referring now principally to Fig. 4A, the chair frame
support unit 34 includes a pair of upper and lower side
plates, respectively 70 and 72. The upper side plates 70
are coupled to the lower side plates 72 by spaced apart
front and rear seat links, respectively 74 and 76. The
seat links 74 and 76 are pivotally connected on pintles
78 at their opposite ends to the upper and lower side
plates 70 and 72. The upper support plates 70 swing on the
lower support plates 72 in fore and aft directions on the
front and rear seat links 74 and 76, as will be shown in
greater detail later.
-
A front brace 80 is coupled by fasteners 82 or welding
across the upper support plates 70 to provide structural
strength and stability. A rearward thrust bar 88, which
is also coupled by fasteners 84 or welding to brackets 86
carried by the rear seat links 76, provides a similar
function at the rear of the upper support plates 70. The
rearward thrust bar 88 and seat links 74 and 76 also serve
an important force transfer function during the recline
mode, as will be described in greater detail later.
-
Flanges 92 on the upper support plates 70 are secured
by suitable fasteners 90 to the seat 20 of the chair frame
12 (as Fig. 10 best shows). The side arms 24 are secured
by suitable fasteners 96 to flanges 94 to the lower
support plates 72 (as Fig. 10 also best shows).
-
In the embodiment shown in Figs. 4A to 4C, it is
contemplated that, the seat 20, side arms 24, and backrest
22 will be assembled on the chair frame support unit 34
as individual component parts, and are not preassembled
into a chair body 12 before their attachment to the
support unit 34.
-
If a two-way chair construction is desired, the
backrest 22 is secured directly to the chair seat 20 on
the upper support plates 70 by a conventional bracket (not
shown). Alternatively, or in combination with a direct
seat-to-backrest connection, a pair of fixed (i.e., not
pivotable) back mounts carried on rear of the upper
support plates 70 can be provided (like those identified
by reference numeral 98 in Fig. 4A, only secured in a not
pivoting fashion). The backrest 22 can be attached by
suitable fasteners (not shown) to the fixed back mounts.
-
If a three-way chair construction is desired, a pair
of pivoting back mounts 98 can be pivotally connected on
pintles 102 at the rear of the upper support plates 70 and
connected by back links 142 to cause pivoting of the
backrest 22 relative to the seat 20. Further details
concerning the pivoting back mounts 98 will be described
later.
-
A lift bar 104 is welded or otherwise fastened across
the front of the lower support plates 72. Fig. 5 shows
an unobstructed view of the lift bar, with certain adjacent
components removed for the purpose of illustration.
-
As shown in Fig. 4A, a pair of rearward lift arms 110
are pivotally connected on pintles 174 to mounts 106,
which welded or otherwise fastened to the lift bar 104.
A lift arm brace 108 is welded or otherwise fastened
across the rearward lift arms 110 to provide added structural
strength and stability.
-
As Fig. 4C shows, the pair of rearward lift arms 110
are pivotally coupled at their other ends by the two bolts
B1 and B2 to the rear pair of lift arm mounts 68 on the
bottom base unit 32. In like manner, the free ends of the
forward pair of lift arms 62 (on the bottom base unit 32)
are pivotally coupled by the two bolts B3 and B4 to the
front of the lower support plates 72 (see Fig. 4C). These
four bolts B1, B2, B3, and B4 conveniently couple the
chair frame support unit 34 to the bottom base unit 32.
-
Referred back to Fig. 4A. the lift bar 104 also
carries a pair of thrust brackets 112, which are also
shown in an unobstructed view in Fig. 5. The thrust
brackets 112 are welded or otherwise secured at equally
spaced distances from the middle of the lift bar 104.
-
A pair of thrust rocker arms 114 are pivotally
connected by pintles 116 to the thrust brackets 112. The
thrust rocker arms 114 can rotate clockwise and counterclockwise
about the pintles 116, unless otherwise restrained,
as will be described in greater detail later.
-
A forward thrust bar 118 is coupled by welding or
suitable fastening to the front of the thrust rocker arms
114, for movement on the rocker arms about the pintles
116. The forward thrust bar 118 carries a front actuator
mount 120, which is welded or otherwise secured to it.
-
As Fig. 4C shows, the free end of the driver 50 of
the actuator 40 is pivotally connected by the bolt B5 to
the front actuator mount 120. The bolt B5 operatively
couples the chair frame support unit 34 to the single
actuator 40.
-
As Fig. 4A shows, the rearward thrust bar 88 (previously
described) is pivotally connected on pintles 122 to
the ends of a pair of rear thrust links 124. The opposite
ends of the rear thrust links 124 are connected on pintles
126 to the lower portion of the thrust rocker arms 114.
-
As Fig. 4C shows, the rear thrust links 124 operatively
couple the rearward thrust bar 88 (through the
pivotally connected thrust rocker arms 114, the forward
thrust bar 118, and the mount 120) to the single actuator
40. The thrust rocker arms 114 (and, with it, the forward
thrust bar 118) are coupled to the upper and lower support
plates 70 and 72 by the rear thrust links 124, the rear
thrust bar 88, and the rear seat links 76.
C. Operation of the Mechanized Base
-
The foregoing connections between the components of
the bottom base unit 32 and the chair frame support unit
34 make possible the realization of both lift and recline
modes using the single actuator 40, while also providing
the wall-hugger feature.
1. Normal Seating Position
-
Figs. 5 and 10 show the orientation of principal
operating components of the bottom base unit 32 and the
chair frame support unit 34 when the chair body 12 is in
its normal seated position (which also generally corresponds
with the orientation of the chair body in Fig. 1).
-
In this condition, the lift bar 104 rests on the base
frame 36. The rearward lift arms 110 rest generally
parallel to and on the base frame 36.
-
Also, in this position, the actuator 40 has an
effective neutral length L1, as measured between the rear
mount 58 and the forward mount 120. The position of the
actuator 40 when in this length L1 will be called the
transfer position, because it constitutes the transition
between the lift mode and the recline mode.
ii. Lift Mode
-
Figs. 6, 7, and 11 show operation of the mechanized
base 14 in the lift mode. The lift mode begins with the
actuator 40 in the transfer position shown in Figs. 5 and
10.
-
Referring first to Fig. 6, the motor 42 is commanded
to turn the lead screw 52 in a first direction (e.g.,
clockwise, as the arrow 128 in Fig. 6 shows). The driver
50 advances in the first (forward) direction along the
lead screw 52, as the arrow 130 in Fig. 6 shows. The
length of the actuator 20 increases beyond L1, applying
a force FLIFT to the mount 120. The lift mode commences.
-
The forward force FLIFT is applied directly to the
forward thrust bar 118. In the transfer position shown in
Fig. 5, pivotal motion of the thrust rocker arms 114 in
a counterclockwise direction is restrained, because the
thrust rocker arms 114 are effectively locked to the upper
and lower support plates 70 and 72 by the intermediate
rear thrust links 124, the rear thrust bar 88, and rear
seat links 76. As a consequence, the force FLIFT created
by the extending actuator 40 pivots the actuator 40 in a
clockwise direction about its mount 58 (as shown by arrows
180 in Figs. 6 and 7). The clockwise pivot is transferred
by the forward thrust bar 118 to the lift bar 104, which
also pivots on the rearward lift arms in a clockwise
direction about the mounts 68 in synchrony with the
actuator 40.
-
As Fig. 11 shows, as the actuator 40 progressively
increases in length and pivots clockwise on the base frame
36, the lower support plate 72, and, with it, the upper
support plate 70, are lifted in tandem by the lift bar
104. The upper and lower support plates 70 and 72 pivot
on the forward and rearward lift arms 62 and 110. As Fig.
11 shows, the entire chair body 12 support unit, and with
it, the chair body 12 itself, is elevated above the base
frame unit.
-
As Fig. 11 also shows, the forward lift arms 62, which
are coupled to the front of the elevated lower support
plates 72, are shorter than the rearward lift arms 110,
which are coupled to the elevating lift bar. The assemblage
of the shorter forward lift arms 62 and longer
rearward lift arms 100 to the base frame 36 and the lower
support plates 72 creates a non-parallelogram linkage 132.
The non-parallelogram linkage 132 causes the upper and
lower support plates 72 and 74 to tilt forward toward the
floor 16 as they are elevated. As a result, the chair seat
20, carried by the upper support plate 70, tilts forward
to the same extent. The relative differences in lengths
and the spacing between the forward lift arms 62 and the
rearward lift arms 110 govern the angle of the forward
tilt.
-
When a preset fully elevated position is achieved
(which is shown in Figs. 7 and 11), a limit switch on the
motor 42 stops further clockwise rotation of the lead
screw 52.
-
In this fully lifted position (see Figs. 7 and 11),
the actuator has an new effective length L2, as measured
between the mounts 68 and 120. The new length L2 is
longer than neutral length L1 of the actuator 40 when in
the transfer position.
-
Subsequent operation of the motor 42 to turn the lead
screw 52 counterclockwise causes the driver 50 to travel
in a second direction, which will be called a rearward
direction, along the lead screw 72. The effective length
of the actuator 40 decreases from L2 back toward L1.
-
The rearward travel of driver 50 transfers a force
FLOWER to the mount 120. The force FLOWER created by the
shortening actuator 40 pivots the actuator 40 in a counterclockwise
direction about its mount 58. The counterclockwise
pivot force is transferred by the forward thrust
bar 118 to the lift bar 104, which also pivots on the
rearward lift arms in a counterclockwise direction about
the mounts 68 in synchrony with the actuator 40.
-
As the actuator 40 shortens in length from L2 toward
L1 and pivots counterclockwise on the base frame 36, the
lower support plate 72, and, with it, the upper support
plate 70, are lowered in tandem by the lift bar 104,
pivoting on the forward and rearward lift arms 62 and 110.
The entire chair body 12 support unit, and, with it, the
chair body 12 itself, descend toward the base frame unit.
-
During the descent, the forward and rearward lift arms
62 and 110 tilt the seat 20 rearward as the chair body 12
returns to it's the normal seated position. At this
point, the actuator has resumed its original effective
length L1, and is again at its transfer position.
iii. Recline Mode
-
Figs. 8, 9, 12, and 13 show operation of the mechanized
base 14 in the recline mode.
-
The recline mode begins, with the actuator 40 in the
transfer position, and the chair body 12 in a normal
seating position (as shown in Figs. 5 and 10). Referring
to Fig. 8, the motor 42 is commanded to turn the lead
screw 72 in a second direction (i.e., a direction different
than the direction of the lift mode, which is clockwise
in the illustrated embodiment, as the arrow 134 in
Fig. 8 shows). The driver 50 travels in the second (rearward)
direction along the lead screw 52, as the arrow 136
in Fig. 8 shows. The length of the actuator 20 shortens
from L2, applying a force FRECLINE to the mount 120. The
recline mode commences.
-
The force FRECLINE is applied directly to the forward
thrust bar 118. In the transfer position shown in Fig. 5,
pivotal motion of the thrust rocker arms 114 in a clockwise
direction is not restrained. Thus, rearward travel
of the driver 50 past the transfer position pulls rearward
on the forward thrust bar 118, causing the thrust rocker
arms 114 to rotate about the pintles 116 in a clockwise
direction (as shown by the arrow 182 in Fig. 8).
-
As Figs. 8 and 9 show, as the actuator 40 progressively
shortens, the clockwise pivot of the thrust rocker
arms 114 about the pintles 116 , pulls the rear thrust
links 124 forward. This force, in turn, pulls the rearward
thrust bar 88 forward. The forward pulling force is
transferred by the rear seat links 124 to the upper
support plates 70, which are advanced forward on the front
and rear links 74, accordingly. Figs. 12 and 13 also show
the forward travel of the upper support links 70 created
by the pulling force on the rearward thrust bar 88, as the
lower side plates 72 remain stationary. As Figs. 12 and
13 show, the seat 20 (coupled to the upper support plates
70) thereby moves forward, while the side arms (coupled
to the lower support plates 72) remain stationary.
-
As Figs. 12 and 13 also show, the front seat links
74 are longer than the rear seat links 76. The assemblage
of the front and rear seat links 74 and 76 to the upper
and lower support plates 70 and 72 thereby forms another
non-parallelogram linkage 138. As the upper side plates
70 move forward, the seat links 74 and 76 will lift the
front of the chair seat 20 higher than the back of the
seat 20. As a result, the seat 20 tilts back, or reclines.
The relative differences in lengths and the
distances between the front and rear seat links 74 and 76
govern the angle that the seat 20 reclines.
-
The motion of the backrest 22 as the seat 20 moves
forward and reclines depends upon the construction of the
chair body 12. If the backrest 22 and seat 20 are secured
together at a fixed angle, typical of a two-way chair
construction, as previously described, forward movement
and recline of the seat 20 in the manner just described
will likewise cause forward movement and recline of the
backrest 22 to generally the same degree. In this construction,
the back mounts 98 (if used) are restrained
from pivoting by a suitable fastener (not shown) to fix
the position of the back mounts 98 on the upper support
plates 70. In this construction, the back mounts 98 (if
used) are not linked to other components operative during
the recline mode.
-
In the illustrated embodiment (see Figs. 12 and 13),
a three way chair construction is shown. In this construction,
the backrest 22 is secured independent of the seat
20 to the back mounts 98 by screws or suitable fasteners
140. In this arrangement, the back mounts 98 are allowed
to pivot on pintles 178 on the rear of the upper support
plates 70. A pair of backrest links 142 are pivotally
coupled by pintles 144 between the back mounts 98 and the
rear of the lower support plates 72.
-
As Fig. 10 shows, the backrest links 142 and rear seat
links 76 are approximately parallel when the upper support
plate 70 places the chair seat 20 in the normal seated
position. Forward movement of the upper support plates 70
about the links 74 and 76 (carrying the seat 20 forward
while also reclining it) (see Figs. 12 and 13) also pivots
the back links 142 forward. The back links 142 exert a
pulling force on the back mounts 98, rotating them in a
clockwise direction about the pintles 144(as shown by
arrow 148 in Fig. 13). The clockwise rotation of the back
mounts 98 tilts the backrest 22 rearward relative to the
seat 22. This movement of the backrest 22 is independent
of the movement of the seat 20 caused by the non-parallelogram
linkage 132. Adjusting the relatively lengths of and
distances between the back links 142 and the rear seat
links 74 governs the degree to which the backrest 22
reclines relative to the seat 20 during the recline mode.
If desired, close to a full, bed-like repose can be
achieved using a three-way chair construction.
-
Governed by the occupant's use of the controller 28,
the actuator 40 continues to shorten in the recline mode
until a preset fully reclined position is achieved, which
is shown in Figs. 9 and 13. At this time, a limit switch
on the motor 42 stops further rotation of the lead screw
52. Of course, the occupant can, using the controller 28,
stop the motor 42 at any time during the recline mode, and
thereby achieve an intermediate degree of recline, such
as shown in Fig. 12.
-
In the fully reclined position (see Fig. 13), the
actuator 40 has shortened to an effective length L3
shorter than effective length L1, as measured between the
mounts 58 and 120.
-
The above described operation of the mechanized base
14 in the recline mode provides a wall hugger function.
In the recline mode (see Figs. 12 and 13), the mechanized
base 14 causes the chair seat 20 and backrest 22 to move
forward, away from the adjacent wall 18. This assures
that, during the recline mode, the top of the backrest 22
stays at essentially the same distance from the adjacent
wall 18 in both the normal seated position and the fully
reclined position.
-
In the illustrated and preferred embodiment (see Figs.
8, 9, 12, and 13), the forward movement of the upper
support plates 70 during the recline mode also extends the
footrest 26. As shown in Figs. 8 and 9, the footrest 26
is coupled to a conventional lazy tongs linkage 150. The
lazy tongs linkage 150 comprises individual links (designated
LT1 to LT4) of unequal lengths joined together by
pintles 162 in an asymmetrical fashion, according to
conventional practice. The most forward links L3 and L4
are pivotally connected by pintles 160 to the upholstered
footrest 26. The most rearward links L1 and L2 are pivotally
connected by pintles 164 to the upper support plates
70 of the mechanized base 14.
-
The top of the innermost link L1 of the lazy tongs
linkage 150 is coupled by a pintles 152 to intermediate
links 154. The intermediate links 154 are, in turn,
coupled by pintles 156 to the middle of the front seat
link 74.
-
As the upper support plate 70 moves forward during
the recline mode (see Figs. 12 and 13, too), the front
seat link 74 pivots in a counterclockwise direction (as
shown by arrow 158 in Fig. 12). The counterclockwise pivot
of the front seat link 74 pulls on the lazy tongs linkage
150, causing it to extend. The lazy tongs linkage 150
also causes the footrest 26 to rotate clockwise (as
indicated by the arrow in Figs. 12 and 13), so that the
footrest 26 faces upward when the lazy tongs linkage 150
reaches its fully extended position (see Fig. 13). The
lazy tongs linkage 150 reaches its fully extended position
at the time the actuator reaches its shortest effective
length L3, which marks the end of the recline mode.
-
As Figs. 9, 12 and 13 show, the lazy tongs linkage
150 includes intermediate brackets 166 secured by pins or
suitable fastener 168 to the link L4. An upholstered
cross brace 170 is secured across the intermediate brackets
166. As the lazy tongs linkage 150 extends (see Figs.
8 and 12), it lifts the upholstered cross brace 170 into
a mutually aligned orientation with the footrest 26. When
the footrest 26 is fully extended (see Figs. 9 and 13),
the upholstered cross brace 170 provides intermediate
support to the occupant's legs.
-
With the seat 20 and backrest 22 in the reclined
position (or any intermediate reclined position), subsequent
operation of the motor 42 to turn the lead screw 52
in a clockwise direction causes the driver 50 to advance
forward. The effective length of the actuator 40 increases
beyond L3 back toward the length L1 of the transfer
position.
-
The forward advancing driver 50 transfers a forward
pushing force upon the forward thrust bar 118, causing it
to rotate in a counterclockwise direction on the thrust
rocker arms 114. The pivot of the thrust rocker arms 114
pushes the rear thrust links 124 in a rearward direction,
thereby pushing the rearward thrust bar 88 in a rearward
direction as well. The rearward pushing force is transferred
by the rearward thrust bar 88 to the upper side
plates 70. The upper side plates 70 move in a rearward
direction. The non-parallelogram linkage lowers the front
of the seat 20 as the seat 20 moves rearward. For a three-way
chair construction, the back brackets pivot forward
(counterclockwise), returning the backrest 22 toward an
upright position.
-
The rearward movement of the upper side plates 70 also
transfers, via the clockwise swinging front seat link 74,
a rearward pulling force upon the lazy tongs linkage 150.
The lazy tongs linkage 150 retracts, pulling the footrest
26 and upholstered cross brace 170 back toward a retracted
position.
-
As the lengthening actuator 40 reaches its length L1
(at the transfer point), the footrest 26 and cross brace
170 are fully retracted, and the backrest 22 and the seat
20 are again in the normal seated position.
III. Mechanized Base
(Three-Way, Preassembled, Rear Thrust Embodiment)
-
Figs. 14 to 16 show another embodiment of a mechanized
base 200, which embodies features of the invention. The
mechanized base 200 is, in substantial part, identical to
the mechanized base 14 shown in Figs. 4A to 4C. Therefore,
common reference numerals will be used, and only
significant differences will be discussed.
-
As previously described, the chair body 12 carried
by the mechanized base 14 was not preassembled. Rather,
the seat 20, backrest 22, and side arms 24 comprised
component parts, which were assembled as such on the chair
frame support unit 34. In Figs. 14 to 16, the chair body
202 comprises a preassembled, conventional reclining
chair. The chair body 202 is capable of use without
attachment to the mechanized base 200. The chair body 202
can provide a manual reclining action independent of any
attachment to the mechanized base 200. Of course, without
attachment to the mechanized base 200, the chair body 202
can not provide a lifting function.
-
The preassembled chair body 202 is shown in Fig. 14
in a normal seated position. The chair body 202 includes
a chair base 224, a seat frame 204, and a backrest frame
206. Side arms 208 are also coupled to the chair base 224
and shown in phantom lines in Fig. 14.
-
Fig. 14 shows these components without upholstery for
the purpose of illustration. It should be appreciated
that the chair body 202 would be fully upholstered in
conventional fashion, and would look substantially like
the chair body 12 shown in Fig. 1.
-
As shown in Fig. 14, the chair body 202 comprises a
three-way chair construction. The backrest frame 206 is
connected on a pintle 210 for pivoting relative to the
seat frame 204. A back link 212 is coupled on a pintle 214
to the backrest frame 206 to recline the backrest frame
206 independent of the seat frame 204, as will be described
in greater detail later.
-
It should be appreciated that the chair body 202 could
comprise a two-way chair construction. In this arrangement,
the backrest frame 206 and seat frame 204 would be
coupled together at a fixed angle for reclining as a unit.
-
As shown in Fig. 14, the chair body 202 also includes
an extendable footrest 216. The footrest 216 is coupled
to a conventional lazy tongs linkage 218.
-
The chair body 202 also includes conventional front
and rear seat links 226 and 228 (which are best seen in
Fig. 16 and 17). The seat links 226 and 228 pivotally
couple the seat frame 204 to the chair base 224. The seat
links 226 and 228 are also coupled to the lazy tongs
linkage 218 in conventional fashion, to extend the footrest
216 when during recline. A traveling link 220 coupled
to the lazy tongs linkage 218 is also coupled to the back
link 212.
-
The assemblage of seat frame 204, chair base 225, the
lazy tongs linkage 218, seat links 226 and 228, backrest
frame 206 and associated back link 212 shown in Fig. 14,
can be purchased preassembled, e.g., from Leggett and
Platt Incorporated., which incorporates the assemblage as
part of its WALLHUGGER ® IMPERIAL™ line of recliners.
-
The entire preassembled chair body 202 -- comprising
the seat 204, backrest 206, footrest 216, and associated
linkage 212, 218, and 220 -- is mounted as a unit on the
mechanized base 200. Fig. 17 shows the base 200 before
mounting of the chair body 202. The base 200 shown in Fig.
17 differs from the base 14 shown in Fig. 4C, in that the
chair frame support unit 34 does not include an upper
support plate 70 and the associated front and rear seat
links 74 and 76, lazy tongs linkage 150, back mounts 98,
and back links 142. This is because the preassembled
chair body 202 already carries equivalent components;
namely, the seat frame 204, seat links 226 and 228, lazy
tongs linkage 218, backrest frame 206, and back link 212,
respectively.
-
The chair base 224 is bolted or otherwise secured with
fasteners 230 to the flange 94 to the lower support plates
72, as Fig. 14 best shows. As Fig. 14 also shows, the
rear thrust bar 88 is secured by a bracket 234 and fasteners
232 to the seat frame 204.
-
The mechanized base 200 operates in the lift and
recline modes in the same manner as previously described.
The actuator 40 has an initial transfer length L1 when the
chair body 202 is in the normal seated position, shown in
Fig. 14. In the lift mode, lengthening of the actuator
40 beyond the transfer length L1 to fully extended length
L2 lifts the tilts the seat frame 204 forward on the lift
arms 62 and 110, in exactly the same manner previously
described in connection with Figs. 6, 7, and 11. In the
recline mode, shortening of the actuator 40 from the
transfer length L1 to a fully retracted length L2 (see
Fig. 16) tilts the seat frame 202 rearward, while also
tilting the backrest frame 206 rearward.
-
Figs. 15 and 16 provide further details of the
operation of the mechanized base 200 in the recline mode.
As Fig. 15 shows, shortening of the actuator 40 from its
transfer length L1 pulls rearward on the forward thrust
bar 118, causing the thrust rocker arms 114 to rotate
about the pinties 116 in a clockwise direction (as shown
by the arrow 182 in Fig. 15). The clockwise pivot of the
thrust rocker arms 114 about the pintles 116, pulls the
rear thrust links 124 forward. This force, in turn, pulls
the rearward thrust bar 88 forward. The forward pulling
force is transferred to the seat frame 204. The seat frame
204 and backrest frame 206 move forward. The side arms
208 (coupled with chair base 224 to the flange 94 of the
lower support plates 72) remain stationary.
-
As Figs. 15 and 16 also show, the front seat links
226 are longer than the rear seat links 228 and, with the
seat frame 204 and chair base 224, form a non-parallelogram
linkage 138. As the seat frame 204 moves forward,
the seat links 226 and 228 lift the front of the seat
frame 204 higher than the back of the seat frame 204. As
a result, the seat frame 204 tilts back, or reclines. The
relative differences in lengths and the distances between
the front and rear seat links 226 and 228 govern the angle
that the seat 20 reclines.
-
As the seat frame 204 moves forward during the recline
mode, the counterclockwise pivot of the front seat link
226 pulls on the lazy tongs linkage 218 (via intermediate
links 236), causing it to extend. The extending lazy
tongs linkage 218 rotates the footrest frame 216 clockwise
to face upward when the lazy tongs linkage 218 reaches its
fully extended position (see Fig. 16). The lazy tongs
linkage 218 reaches its fully extended position at the
time the actuator reaches its shortest effective length
L3, which marks the end of the recline mode.
-
As Figs. 14 to 16 show, the lazy tongs linkage 218
carries a cross brace 238, which provides intermediate
support to the occupant's legs in the manner previously
described.
-
If the backrest frame 206 and seat frame 204 are
secured together at a fixed angle (i.e., a typical two-way
chair construction), forward movement and recline of the
seat frame 204 will likewise cause forward movement and
recline of the backrest frame 206 to generally the same
degree.
-
In the three way chair construction shown, the
traveling link 220 (coupled to the lazy tongs linkage 218)
pulls on the back link 212 as the lazy tongs linkage 218
fully extends (see Fig. 16). In response, the back link
212 pivots clockwise in response, tilting the backrest
frame 206 rearward.
-
The above described operation of the mechanized base
200 in the recline mode provides a wall hugger function.
In the recline mode (see Figs. 15 and 16), the mechanized
base 200 causes the seat frame 204 and backrest frame 206
to move forward, away from the adjacent wall 18. This
assures that, during the recline mode, the top of the
backrest frame 206 stays at essentially the same distance
from the adjacent wall 18 in both the normal seated
position (Fig. 14) and the fully reclined position (Fig.
16).
IV. The Mechanized Base
(Three-Way, Base-Assembled, Forward Thrust
Embodiment)
-
Details of another embodiment of a mechanized base
314 (see Fig. 18) that provides a wall hugger function
will now be discussed.
-
In many respects, the mechanized base 314 shares many
structural components that are the same as the mechanized
base 14 shown in Figs. 4A, 4B, and 4C. To begin with, the
mechanized base 314 includes a bottom base unit 332 and
a chair frame support unit 334 joined by the five bolts
B1, B2, B3, B4, and B5 (in generally the same manner
earlier shown in Fig. 4C).
-
In the embodiment shown in Fig. 18, it is contemplated
that, the components of the chair itself (i.e., the seat
320, side arms 324, and backrest 322, as shown in phantom
lines in Fig. 21, but which are not shown in Fig. 18 to
simplify the illustration) will be assembled on the chair
frame base unit 334 as individual component parts, and are
not preassembled into a chair body before their attachment
to the support unit 334.
-
However, a chair frame base unit of the type shown
in Fig. 18 can readily accept the mounting of a preassembled
chair body, as will be described later with reference
to Fig. 26.
A. The Bottom Base Unit
-
Referring to Figs. 18 to 20, the bottom base unit 332
includes a base frame 336. A back brace 338 is welded or
otherwise fastened across the rear of the base frame 336
to provide strength and stability.
-
The back brace 338 carries a single actuator 340. In
the illustrated embodiment, the actuator 340 comprises a
single electric motor 342 driving a single extendable
driver 350. The controller 328 (previously described) is
coupled by a cable 346 to the motor 342. A power cable
348 couples the motor 342 to a conventional electrical
power outlet.
-
The driver 350 can be driven by a conventional,
rotating lead screw. Other power-actuated mechanisms can
be used, e.g., a hydraulic or a pneumatic ram.
-
In the illustrated embodiment, the driver 350 is
coupled to the motor 342 by a right angle speed reducer
354. The driver 350 includes a drive nut, which
threadably engages the lead screw. The actuator 340 is
pivotally connected on a pintle 356 to an actuator mount
358, which is welded or otherwise fastened to the back
brace 338.
-
As also explained before, operation of the control
buttons 330 on the controller 328 command the motor to
cause clockwise or counterclockwise rotation of the lead
screw. When the motor 342 rotates in a first direction
(e.g., clockwise), the driver 350 advances in a first
direction, which in the illustrated embodiment is away
from the motor 342. For point of reference, this direction
will be called the forward or fore direction.
-
Conversely, when the motor 342 rotates in a second
direction (e.g., counterclockwise), the driver 350 retracts
in a second direction, which in the illustrated
embodiment is toward the motor 342. For point of reference,
this direction will be called the rearward or aft
direction.
-
The bottom base unit 332 also carries a forward pair
of lift arms 362. The forward lift arms 362 are pivotally
connected on pintles to the bottom base unit 332 by a
front brace 364.
-
The bottom base unit 332 also includes a pair of rear
lift arm mounts 368. The rear lift arm mounts 368 are
welded or otherwise secured to the back brace 338.
B. The Chair Frame Support Unit
-
The chair frame support unit 334 includes a pair of
upper and lower side plates, respectively 370 and 372.
The upper side plates 370 are coupled to the lower side
plates 372 by spaced apart front and rear seat links,
respectively 374 and 376. The seat links 374 and 376 are
pivotally connected on pintles at their opposite ends to
the upper and lower side plates 370 and 372. The upper
support plates 370 swing on the lower support plates 372
in fore and aft directions on the front and rear seat
links 374 and 376.
-
A front spanning brace 380 is coupled by fasteners
or welding across the front of the upper support plates
370 to provide structural strength and stability. A rear
spanning brace 388 provides a similar function at the rear
of the upper support plates 370.
-
Flanges 392 on the upper support plates 370 are
secured by suitable fasteners 390 to the seat 320 of the
chair frame 312 (as Fig. 21 shows). The side arms 324 are
secured by suitable fasteners 396 to the lower support
plates 372 (as Fig. 21 also shows).
-
If a two-way chair construction is desired, the
backrest 322 is secured directly to the chair seat 320 on
the upper support plates 370 (see Fig. 21) by a conventional
bracket (not shown). Alternatively, or in combination
with a direct seat-to-backrest connection, a pair of
fixed (i.e., not pivotable) back mounts carried on rear
of the upper support plates 370 can be provided (like
those identified by reference numeral 398 in Fig. 21, only
secured in a not pivoting fashion). The backrest 322 can
be attached by suitable fasteners (not shown) to the fixed
back mounts.
-
If a three-way chair construction is desired (as Fig.
21 shows), a pair of pivoting back mounts 398 can be
pivotally connected on pintles at the rear of the upper
support plates 370 and connected by back links 442 to
cause pivoting of the backrest 322 relative to the seat
320.
-
A forward thrust bar 407 is welded or otherwise
fastened across a pair of thrust links 409, which are
pivotally connected by pintles or bolts to the upper
support plates 370 and the lower support plates 372. Fig.
20 shows an unobstructed view of the forward thrust bar
407 and thrust links 409.
-
A pair of rearward lift arms 410 are pivotally
connected on pintles to thrust brackets 412, which welded
or otherwise fastened to a lift bar 404. A lift arm brace
408 9 (shown in Fig. 18) can be welded or otherwise
fastened across the rearward lift arms 410 to provide
added structural strength and stability.
-
The pair of rearward lift arms 410 are pivotally
coupled at their other ends by the two bolts B1 and B2 to
the rear pair of lift arm mounts 368 on the bottom base
unit 332. In like manner, the free ends of the forward
pair of lift arms 362 are pivotally coupled by the two
bolts B3 and B4 to the front of the lower support plates
372. These four bolts B1, B2, B3, and B4 conveniently
couple the chair frame support unit 334 to the bottom base
unit 332.
-
The lift bar 404 also carries a pair of thrust
brackets 412, which are also shown in an unobstructed view
in Fig. 20. The thrust brackets 412 are welded or otherwise
secured at equally spaced distances from the middle
of the lift bar 404.
-
A pair of thrust rocker arms 414 are pivotally
connected by pintles to the thrust brackets 412. The
thrust rocker arms 414 can rotate clockwise and counterclockwise
about the pintles , unless otherwise restrained,
as will be described in greater detail later.
-
A thrust bar 418 is coupled by welding or suitable
fastening to the front of the thrust rocker arms 414, for
movement on the rocker arms 414 about the pintles. The
thrust bar 418 carries a front actuator mount 420, which
is welded or otherwise secured to it.
-
The free end of the driver 350 of the actuator 340
is pivotally connected by the bolt B5 to the front actuator
mount 420. The bolt B5 operatively couples the chair
frame support unit 334 to the single actuator 340.
-
The forward thrust bar 407 (previously described) is
pivotally connected by pintles to the ends of a pair of
forward thrust links 424. The opposite ends of the
forward thrust links 424 are connected on pintles to the
lower portion of the thrust rocker arms 414.
-
The forward thrust links 424 operatively couple the
forward thrust bar 407 (through the pivotally connected
thrust rocker arms 414, the thrust bar 418, and the mount
420) to the single actuator 340. The thrust rocker arms
414 (and, with it, the forward thrust bar 418) are coupled
to the upper and lower support plates 370 and 372 by the
forward thrust bar 407 and the forward thrust links 409.
C. Operation of the Mechanized Base
-
The foregoing connections between the components of
the bottom base unit 332 and the chair frame support unit
334 make possible the realization of both lift and recline
modes using the single actuator 340, while also providing
the wall-hugger feature.
i. Normal Seating Position
-
Figs. 18 and 21 show the orientation of principal
operating components of the bottom base unit 332 and the
chair frame support unit 334 when the chair body (shown
in phantom lines in Fig. 21) is in its normal seated
position. This position generally corresponds with the
orientation of the chair body 12 in Fig. 1.
-
In this condition (see Fig. 21), the lift bar 404
rests on the base frame 336. The forward and rearward lift
arms 362 and 410 also rest generally parallel to and on
the base frame 336.
-
Also, in this position, the actuator 340 has an
effective neutral length L1, as measured between the rear
mount 358 and the forward mount 420. The position of the
actuator 340 when in this length L1, previously called the
transfer position, constitutes the transition between the
lift mode and the recline mode.
ii. Lift Mode
-
Figs. 21 to 23 show sequential operation of the
mechanized base 314 in the lift mode. The lift mode begins
with the actuator 340 in the transfer position shown in
Fig. 21.
-
The motor 342 turns the lead screw in a first direction
(e.g., clockwise) to advance the driver 350 in the
first (forward) direction, as Fig. 22 shows. The length
of the actuator 340 increases beyond L1, applying a force
FLIFT to the mount 420. The lift mode commences.
-
The forward force FLIFT is applied directly to the
forward thrust bar 418. In the transfer position shown in
Fig. 21, pivotal motion of the thrust rocker arms 414 in
a counterclockwise direction is restrained, because the
thrust rocker arms 414 are effectively locked to the upper
and lower support plates 370 and 372 by the forward thrust
bar 407 and forward thrust links 409. As a consequence,
the force FLIFT created by the extending actuator 340 pivots
the actuator 340 in a clockwise direction about its mount
358, as Figs. 22 and 23 show. The clockwise pivot is
transferred by the thrust bar 418 to the lift bar 404,
which also pivots on the forward and rearward lift arms
362 and 410 in a clockwise direction about the mounts 368
in synchrony with the actuator 340.
-
As Figs. 22 and 23 show, as the actuator 340 progressively
increases in length and pivots clockwise on the
base frame 336, the lower support plate 372, and, with it,
the upper support plate 370, are lifted in tandem by the
lift bar 404. The upper and lower support plates 370 and
372 pivot on the forward and rearward lift arms 362 and
410. As Figs. 22 and 23 show, the entire chair body
support unit 334, and with it, the chair body itself, is
elevated above the base frame unit 332.
-
As before described, the assemblage of the shorter
forward lift arms 362 and longer rearward lift arms 410
to the base frame 336 and the lower support plates 372
creates a non-parallelogram linkage. The non-parallelogram
linkage causes the upper and lower support plates 370 and
372 to tilt forward toward the floor as they are elevated,
tilting the chair seat 320 forward to the same extent.
-
When a preset fully elevated position is achieved
(which is shown in Fig. 23), a limit switch on the motor
342 stops further clockwise advancement of the driver 350.
-
In this fully lifted position, the actuator 340 has
an new effective length L2, as measured between the mounts
368 and 420. The new length L2 is longer than neutral
length L1 of the actuator 40 when in the transfer position.
-
Subsequent operation of the motor 342 to turn the lead
screw counterclockwise causes the driver 350 to travel in
a second direction, which has been called a rearward
direction, along the lead screw 372. The effective length
of the actuator 40 decreases from L2 back toward L1.
-
The rearward travel of driver 350 transfers a force
FLOWER to the mount 420. The force FLOWER created by the
shortening actuator 340 pivots the actuator 340 in a
counterclockwise direction about its mount 358. The
counterclockwise pivot force is transferred by the thrust
bar 418 to the lift bar 404, which also pivots on the
rearward lift arms in a counterclockwise direction about
the mounts 368 in synchrony with the actuator 340.
-
As the actuator 340 shortens in length from L2 toward
L1 and pivots counterclockwise on the base frame 336, the
lower support plate 372, and, with it, the upper support
plate 370, are lowered in tandem by the lift bar 404,
pivoting on the forward and rearward lift arms 362 and
410. The entire chair body support unit, and, with it, the
chair body 12 itself, descend toward the base frame unit.
-
During the descent, the forward and rearward lift arms
362 and 410 tilt the seat 20 rearward as the chair body
312 returns to its normal seated position. At this point,
the actuator has resumed its original effective length L1,
and is again at its transfer position.
iii. Recline Mode
-
Figs. 18 to 20 show sequential operation of the
mechanized base 314 in the recline mode.
-
The recline mode begins, with the actuator 340 in the
transfer position, and the chair body in a normal seating
position.
-
The motor 342 is commanded to turn the lead screw in
a second direction (i.e., a direction different than the
direction of the lift mode, which is clockwise in the
illustrated embodiment). The driver 350 travels in the
second (rearward) direction. The length of the actuator
320 shortens from L2, applying a pulling force FRECLINE to
the mount 420. The recline mode commences.
-
The pulling force FRECLINE is applied directly to the
thrust bar 418. In the transfer position shown in Fig. 18,
pivotal motion of the thrust rocker arms 414 in a clockwise
direction is not restrained. Thus, rearward travel
of the driver 350 past the transfer position pulls rearward
on the thrust bar 418, causing the thrust rocker arms
414 to rotate about the pintles in a clockwise direction.
-
As Figs. 19 and 20 show, as the actuator 340 progressively
shortens, the clockwise pivot of the thrust rocker
arms 314 about the pintles pushes the forward thrust links
424 forward. This forward force, in turn, pushes the
thrust bar 407 forward. The forward pushing force is
transferred by the forward thrust links 409 to the upper
support plates 370, which are advanced forward on the
front and rear links 374 and 376, accordingly. The lower
side plates 372 remain stationary, as the forward travel
of the upper support links 370, created by the forward
pushing force on the thrust bar 407, proceeds. The chair
seat (not shown) carried by the upper support plates 370
will thereby move forward, while the side arms (not
shown)coupled to the lower support plates 372 remain
stationary.
-
As Figs. 19 and 20 also show, the front seat links
374 are longer than the rear seat links 376. The assemblage
of the front and rear seat links 374 and 376 to the
upper and lower support plates 370 and 372 thereby forms
another non-parallelogram linkage. As the upper side
plates 370 move forward, the seat links 374 and 376 will
lift the front of the chair seat higher than the back of
the seat. As a result, the seat tilts back, or reclines.
The relative differences in lengths and the distances
between the front and rear seat links 374 and 376 govern
the angle that the seat reclines.
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The motion of the backrest as the seat moves forward
and reclines depends upon the construction of the chair
body 312. If the backrest and seat are secured together
at a fixed angle, typical of a two-way chair construction,
as previously described, forward movement and recline of
the seat in the manner just described will likewise cause
forward movement and recline of the backrest to generally
the same degree. In this construction, the back mounts 398
(if used) are restrained from pivoting by a suitable
fastener (not shown) to fix the position of the back
mounts 398 on the upper support plates 370. In this
construction, the back mounts 398 (if used) are not linked
to other components operative during the recline mode.
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In the three way chair construction shown in the
illustrated embodiment, the backrest is secured independent
of the seat to the back mounts 398 by screws or
suitable fasteners. In this arrangement, the back mounts
398 are allowed to pivot on pintles on the rear of the
upper support plates 370. A pair of backrest links 442 are
pivotally coupled by pintles between the back mounts 398
and the rear of the lower support plates 372. The details
of the three way reclining action are as previously
described in connection with the embodiment shown in Figs.
10, 12, and 13.
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Governed by the occupant's use of the controller 328,
the actuator 340 continues to shorten in the recline mode
until a preset fully reclined position is achieved, which
is shown in Fig. 20. At this time, a limit switch on the
motor 342 stops further retraction of the driver 350. Of
course, the occupant can, using the controller 328, stop
the motor 342 at any time during the recline mode, and
thereby achieve an intermediate degree of recline, such
as shown in Fig. 19.
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In the fully reclined position, the actuator 340 has
shortened to an effective length L3 shorter than effective
length L1, as measured between the mounts 358 and 420.
-
The above described operation of the mechanized base
314 in the recline mode provides a wall hugger function.
In the recline mode (see Figs. 19 and 20), the mechanized
base 314 causes the chair seat and backrest to move
forward, away from the adjacent wall. This assures that,
during the recline mode, the top of the backrest stays at
essentially the same distance from the adjacent wall 18
in both the normal seated position and the fully reclined
position.
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In the illustrated and preferred embodiment, the
forward movement of the upper support plates 370 during
the recline mode also exerts, through the thrust links
409, a forward force upon the lazy tong linkage 450 of the
footrest 326. The lazy tongs linkage 450 extends.
Further details of the extension of the lazy tongs linkage
450 are as previously described in connection with the
embodiment shown in Figs. 12 and 13.
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With the seat and backrest in the reclined position
(or any intermediate reclined position), subsequent
operation of the motor 342 to turn the lead screw in a
clockwise direction causes the driver 350 to advance
forward. The effective length of the actuator 340 increases
beyond L3 back toward the length L1 of the transfer
position.
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The forward advancing driver 350 transfers a forward
pushing force upon the thrust bar 418, causing it to
rotate in a counterclockwise direction. The pivot of the
thrust rocker arms 414 resulting from a forward pushing
force on the thrust bar 418 pulls the thrust bar 407 in
a rearward direction. The rearward pulling force is
transferred to the upper side plates 370 by the thrust
links 409. The upper side plates 370 move in a rearward
direction. The non-parallelogram linkage lowers the front
of the chair seat as the seat moves rearward. For a three-way
chair construction, the back brackets pivot forward
(counterclockwise), returning the backrest toward an
upright position.
-
The rearward movement of the upper side plates 370
also transfers, via the thrust links 409, a rearward
pulling force upon the lazy tongs linkage 450. The lazy
tongs linkage 450 retracts, pulling the footrest 326 back
toward a retracted position.
iv. Lazy Tongs Linkage Lock During Lift Mode
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As the seat tilts forward at the upper end of the lift
mode (see Fig. 23), the weight of the occupant may cause
the upper side plates 370 to shift forward. The forward
shift of the side plates 370 during the lift mode may, in
turn, exert through the thrust links 409, a forward force
upon the lazy tong linkage 450 of the footrest 326. The
lazy tongs linkage 450 could unexpectedly extend during
the lift mode, causing the occupant to slide out of the
chair.
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In the illustrated embodiment, the mechanical base
314 includes a locking mechanism 500. The locking mechanism
500 interferes with the lazy tongs linkage 450 when
the base 314 is operating in the lift mode, to resist
opening of the lazy tongs linkage 450 in response to a
forward force imposed by the thrust links 409.
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The locking mechanism 500 can be variously constructed.
In the illustrated embodiment, the locking
mechanism includes an appendage 502 on each of the front
lift arms 362. As illustrated, the appendage 502 takes
the form of an L-shaped finger that projects from the end
of each front lift arm 362 outwardly of and slightly
beyond the associated lower side panel 372(see Fig. 18).
Other configurations could be used.
-
As Figs. 21 and 22 show, as each lift arm 362 pivots
during the lift mode, the associated appendage 502 also
pivots successively toward contact with the lazy tongs
linkage 450. Figs. 24 and 25 show the successive pivoting
of the appendage 502 toward the lazy tongs linkage 450 as
the lift arm 362 pivots.
-
As the frame support unit 334 reaches or nears its
fully elevated position (as Figs. 23 and 25 show), the
appendage 502 is brought into contact with the lazy tongs
linkage 450, or at least in an adjacent interfering
relationship laying in the extension travel path of the
linkage 450. The lift arm 362 holds the appendage 502 in
interference with the lazy tongs linkage 40 when the frame
support unit 334 is fully elevated. The interference
prevents extension of the lazy tongs linkage 450. The
appendage 502 effectively locks the lazy tongs linkage in
its fully retracted, closed condition.
-
Movement of the frame support unit 334 back toward
the normal seated position pivots the appendage 502 out
of interference with the lazy tongs linkage 450 (see Figs.
21 and 22). The lazy tongs linkage 450 is thereby freed
to open, as desired, in response to a forward force
imposed by the thrust links 409 when the base 314 is
operated in the recline mode.
V. The Mechanized Base
(Three-Way, Pre-Assembled, Forward Thrust Embodiment,
With Lazy Tongs Linkage Lock)
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The assemblage of chair body including the seat 320,
side arms 324, chair back 322 (see Fig. 21), along with
the associated side plates 370 and 372, with the reclining
linkage (e.g., the reclining links 374 and 378), and the
lazy tongs linkage 450 can be purchased preassembled,
e.g., the ZERO-WALL™ line of recliners made by Hickory
Springs Manufacturing Company (Hickory, North Carolina)
or a similar style recliner.
-
The entire preassembled chair body can be mounted as
a unit on a mechanized base 532, as shown in Fig. 26. Fig.
26 shows the base 532 before mounting of the chair body.
The base 532 shown in Fig. 26 includes the thrust bar 418,
which is linked to the thrust bar 407 via the rocker arms
414 and thrust links 424. The base 532 also includes the
actuator 340 coupled to the mount 420 to move the thrust
bar 418, and thereby move the thrust bar 407. The base 532
also includes the front and rear lift arms 362 and 410.
-
The base 532 shown in Fig. 26 does not include upper
and lower support plates 370 and 372, and the associated
front and rear seat links 374 and 376, lazy tongs linkage
450, back mounts 398, and back links 442, because the
preassembled chair body already carries equivalent components.
-
The chair body is bolted or otherwise secured with
fasteners directly to the side flanges 534 of the base
532, to which the front lift arms 362 are pivotally
attached. The thrust bar 407 of the chair base 532 is
suitably coupled to the reclining linkage of the preassembled
chair. The preassembled chair will typically include
its own front brace, which is removed to accommodate
attachment of the thrust bar 407 of the base 532. The rear
lift arms 410 are also attached to the frame of the
preassembled chair or to its reclining linkage to provide,
together with the front arms 362, the lift function.
-
With the preassembled chair attached, the mechanized
base 534 operates in the lift and recline modes in the
same manner as previously described.
-
It should be appreciation that variations to the
described structures can be made while keeping many of the
important features of the invention.
VI. The Mechanized Base
(Three-Way, Pre-Assembled, Forward Thrust Embodiment,
with Dynamic Lazy Tongs Linkage Locking)
-
Figs. 27 to 29 show yet another embodiment of a
mechanized base 600. Figs. 27 to 29 show the base 600
before mounting of a chair body and associated reclining
and lazy tong mechanisms. To better expose the component
parts to view, Fig. 27 shows the base 600 in the position
in which the chair body is lifted. Fig. 28 shows the base
600 in the position in which the chair body is in a normal
seated condition. Fig. 29 shows the base 600 in the
position in which the chair body is in a reclined condition.
-
The base 600 includes a base frame 602. Side plates
604 and 606 are coupled to the base frame 602 by forward
and rearward lift arms 608 and 610, as previously described.
Fig. 27 shows the side plates 604 and 606 elevated
and tilted forward by the lift arms 608 and 610.
Fig. 28 shows the side plates 604 and 606 in the normal
seated condition.
-
The base 600 can be fabricated to include chair body
components, such upper and lower support plates 370 and
372, and the associated front and rear seat links 374 and
376, lazy tongs linkage 450, back mounts 398, and back
links 442 (as shown, e.g., in Fig. 18). Alternatively,
an entire preassembled chair body can be mounted as a unit
on a mechanized base frame 602. For this reason, the base
600 is shown not include reclining components of the chair
body, because the preassembled chair body already carries
equivalent components. The assemblage of an entire chair
body including the seat 320, side arms 324, chair back
322, along with the associated side plates 370 and 372,
with the reclining linkage (e.g., the reclining links 374
and 376), and the lazy tongs linkage 450 can be purchased
preassembled, e.g., the ZERO-WALL™ line of recliners made
by Hickory Springs Manufacturing Company (Hickory, North
Carolina) or a similar style recliner.
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To assemble the chair body to the base 600, the
reclining links of the chair body are attached to the side
plates 604 and 606 of the base 600, in the same manner
that the links 374 and 376 are coupled to the plates 372
in Figs. 18 and 21.
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The base 600 includes a rear thrust bar 612, which
is linked to a forward thrust bar 614 via the thrust links
616 and a swinging link 618. The swinging link 618 is
pivotally connected to a support bracket 630 by a pin 620
(shown in Figs. 28 and 29). The thrust bar 614 of the
chair base 600 is suitably coupled to the reclining
linkage of the preassembled chair, as previously described
in the context of Fig. 26.
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The base 600 also includes an actuator mount 622 which
is pivotally coupled to the motor end of the actuator 624,
which is shown in phantom lines in Figs. 28 and 29. The
extendable driver 626 of the actuator 624 is pivotally
coupled by a pin 628 to the swinging link 618. As Figs.
28 and 29, the actuator pivot pin 628 is spaced away from
the swinging link pivot pin 620, about which the swinging
link 618 rotates.
-
Fig. 28 shows the swinging link 618 in a transfer
position, in which the chair body is in a normal seated
condition. As Fig. 29 shows, retraction of the driver 626
when the swinging link 618 is in the transfer position
swings the link 618 in a clockwise direction (as indicated
by the arrow in Fig. 29). The pin 628, which pivotally
couples the actuator 624 to the swinging link 618, travels
in an arcuate path below the pin 620, about which the
swinging link 618 pivots. Clockwise rotation of the
swinging link 618 imparts forward linear movement to the
thrust bar 614, through the thrust bar 612 and links 616.
-
The application of force by the actuator driver 626
below the rotational axis of the swinging link 618 results
in a smooth, uninterrupted transfer of forward force from
the actuator driver 626 to the thrust bar 614. Forward
movement of the trust bar 614 advances the chair seat
forward. As previously described (and as shown in Figs.
19 and 20), as the chair seat moves forward, the reclining
links 374 and 376 recline the chair back in a wall-hugging
motion. This, in turn, actuates the lazy tongs linkage
450, causing the footrest 326 to extend.
-
Conversely, with the chair back reclined, subsequent
extension of the driver 626 swings the link 618 in a
counterclockwise direction, until the link 618 again
assumes the transfer position shown in Fig. 28. The thrust
bar 614 moves rearward, pulling the chair seat rearwardly
with it. As previously described (and as shown in Figs.
19 and 20), as the chair seat moves rearward, the reclining
links 374 and 376 return the chair back to its normal
seated condition. This, in turn, actuates the lazy tongs
linkage 450, causing the footrest 326 to retract.
-
The application of force by the actuator driver 626
below the rotational axis of the swinging link 618 results
in a smooth, uninterrupted transfer of rearward force from
the actuator driver 626 to the thrust bar 614.
-
When the swinging link 618 is in the transfer position
shown in Fig. 28, further rotation in a counterclockwise
direction is resisted. Further extension of the driver 626
therefore applies a lifting force to the lift bar 632,
which is coupled to the chair support bracket 630. As
previously described (and as shown in Figs. 21 to 23), the
lifting force elevates the chair body (as Fig. 27 shows).
-
The lifting force applied by the actuator driver 626
through the swinging link 618 applies a counter force to
the reclining mechanism of the chair. The counter force
locks the reclining mechanism in the normal seated condition
as the chair body is lifted. Because the actuator 624
is coupled to the swinging link 618 below the pivot point
of the swinging link 618 (i.e., below the pin 620), the
moment arm between the actuator and the swinging link
pivot point will increase as the chair body is lifted. The
magnitude of the counter force applied through the swinging
link 618 to the reclining mechanism thereby increases
as the chair body is lifted. This dynamic counter force,
which is applied to the reclining mechanism via the
swinging link 618 during lifting, resists actuation of the
lazy tongs linkage 450 during the lifting mode.
-
Subsequent retraction of the driver 626 applies a
lowering force to the lift bar 632. As previously described
(and as shown in Figs. 21 to 23), the lowering
force returns the chair body to a normal seated condition,
at which the swinging link 618 assumes its transfer
position (shown in Fig. 28).
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The features of the invention are set forth in the
following claims.