Abstrict A height adjustable bed includes a sliding hinge mechanism for
attaching each of two articulated supports to wheeled bases. A linear
actuator is connected between an actuating frame that is attached
to each of the articulated supports and a horizontal linkage member
that is attached to each of the articulated supports. Extension
of the linear actuator raises the bed from a low position with assistance
of a mechanical advantage provided by a fulcrum between the articulated
support and the actuating frame that results from displacement of
downward forces from the sliding hinge to the actuating frame.
Claims What is claimed is:
1. A height adjustable bed comprising: a bed frame including a
head portion and a foot portion; a first articulated support pivotably
connected to the head portion of the bed frame, and a second articulated
support pivotably connected to the foot portion of the bed frame,
the first and second articulated supports each comprising an upper
support joined articulatedly to a lower support; a first sliding
hinge and a second sliding hinge each comprising at least one arcuate
slot and at least one pin retained in the slot, the at least one
pin of each of the first sliding hinge and the second sliding hinge
being connected to the lower supports of the first articulated support
and the second articulated support, respectively, such that the
at least one pin is capable of translating and pivoting; a first
wheeled base connected to the lower support of the first articulated
support by the first sliding hinge; a second wheeled base connected
to the lower support of the second articulated support by the second
sliding hinge; a linkage member pivotably connected on one end to
the first articulated support and on the other end to the second
articulated support; a linear actuator having a first end and a
second end, pivotably connected on the first end to the linkage
member, the linear actuator being capable of extension and retraction;
and an actuating frame pivotably connected to the second end of
the linear actuator and pivotably connected to the first articulated
support at a first fulcrum point and the second articulated support
at a second fulcrum point, wherein extension and retraction of the
linear actuator raises and lowers the bed frame and during raising
and lowering the at least one pin of each of the first sliding hinge
and the second sliding hinge in one range of intermediate positions,
is translating and in another range of intermediate positions, is
not translating.
2. The height adjustable bed of claim 1 wherein the first articulated
support and the second articulated support are identical.
3. The height adjustable bed of claim 1 wherein the linear actuator
is removably connected.
4. The height adjustable bed of claim 1 further comprising at
least one linear arm pivotably connected at one end to the actuating
frame and at an opposite end to the upper support, wherein the upper
support is pivoted in relation to the actuating frame as the linear
actuator extends or retracts.
5. The height adjustable bed of claim 1 wherein each sliding hinge
further comprises a first plate and a second plate, each of the
first plate and the second plate having a first arcuate slot for
retaining a first pin connecting each sliding hinge to a respective
lower support of one of the first articulated support and the second
articulated support, the second plate having a second arcuate slot
for retaining a second pin, the second arcuate slot comprising an
open end and a closed end opposite of the open end, the first plate,
the second plate, the first pin and the second pin being configured
such that the first pin in the first arcuate slot translates in
one range of intermediate positions, and the second pin in the second
arcuate slot translates in a circular arc around the first pin in
another range of intermediate positions, when the first pin is stationary.
6. A height and angle adjustable bed comprising: a bed frame including
at least one longitudinal framing member, a first transverse framing
member at a head portion of the bed frame and a second transverse
framing member at a foot portion of the bed frame; a first articulated
support pivotably connected to the head portion of the bed frame,
and a second articulated support pivotably connected to the foot
portion of the bed frame, the first and second articulated supports
each comprising an upper support joined articulatedly to a lower
support; a first sliding hinge and a second sliding hinge each comprising
an arcuate slot and at least one pin retained in the slot, the at
least one pin of each of the first sliding hinge and the second
sliding hinge being connected to the lower supports of the first
articulated support and the second articulated support, respectively,
such that the at least one pin is capable of translating and pivoting;
a first wheeled base connected to the first articulated support
by the first sliding hinge; a second wheeled base connected to the
second articulated support by the second sliding hinge; a linkage
member pivotably connected on one end to the first articulated support
and on the other end to the second articulated support; a linear
actuator having a first end and a second end, pivotably connected
on the first end to the linkage member, the linear actuator being
capable of extension and retraction; an actuating frame pivotably
connected to the second end of the linear actuator and pivotably
connected to the first articulated support at a first fulcrum point
and the second articulated support at a second fulcrum point, such
that extension and retraction of the linear actuator raises and
lowers the bed frame and such that during raising and lowering of
bed frame the at least one pin of each of the first sliding hinge
and the second sliding hinge, in one range of intermediate positions,
is translating and, in another range of intermediate positions,
is not translating; and an articulated mattress frame supported
by the bed frame, the articulated mattress frame including a head
assembly, a foot assembly and a central assembly, the central assembly
attaching the head assembly to the foot assembly articulatedly,
wherein the articulated mattress frame is supported by the bed frame.
7. The height and angle adjustable bed of claim 6 further comprising
a colinear actuator having a central portion, a first end and a
second end opposite of the first end of the colinear actuator, wherein
the central portion of the colinear actuator is attached to the
bed frame, the first end is pivotably attached to the head assembly
and the opposite end is pivotably attached to the foot assembly.
8. The height and angle adjustable bed of claim 6 further comprising
a first adjunct linear actuator and a second adjunct linear actuator,
each having a first end and an opposite end, wherein the first end
of each adjunct linear actuator is connected to the bed frame and
the second end of the first adjunct linear actuator is pivotably
attached to the head assembly and the second end of the second adjunct
linear actuator is pivotably attached to the central assembly.
9. The height and angle adjustable bed of claim 8 further comprising
a first bracket fixedly attached to the head assembly and a second
bracket fixedly attached to the foot assembly, wherein the first
bracket functions as an attachment point for the first adjunct linear
actuator for adjusting the angle of the head assembly in relation
to the central assembly, and the second bracket functions as an
attachment point for the second adjunct linear actuator.
10. The height and angle adjustable bed of claim 9 wherein the
foot assembly comprises a lower mattress support articulatedly joined
to a middle mattress support that is pivotably attached to the central
assembly and the second bracket is fixed to the middle mattress
support such that the second adjunct linear actuator is capable
of adjusting the angle of the middle mattress support in relation
to both the central assembly and the lower mattress support.
11. A height adjustable bed comprising: a bed frame including a
head portion and a foot portion; a first articulated support pivotably
connected to the head portion of the bed frame, and a second articulated
support pivotably connected to the foot portion of the bed frame,
the first and second articulated supports each comprising an upper
support joined articulatedly to a lower support; a first sliding
hinge and a second sliding hinge; a first wheeled base connected
to the lower support of the first articulated support by the first
sliding hinge; a second wheeled base connected to the lower support
of the second articulated support by the second sliding hinge; a
linkage member pivotably connected on one end to the first articulated
support and on the other end to the second articulated support;
a linear actuator having a first end and a second end, pivotably
connected on the first end to the horizontal linkage member, the
linear actuator being capable of extension and retraction; and an
actuating frame pivotably connected to the second end of the linear
actuator and pivotably connected to the first articulated support
and the second articulated support; wherein extension and retraction
of the linear actuator raises and lowers the bed frame and during
raising of the bed frame from a low position to a high position
the bed reaches a transition point and forces acting downward on
the first articulated support and the second articulated support
are applied to the first sliding hinge and the second sliding hinge,
when the bed is raised above the transition point, and as the bed
is lowered from the high position, the actuating frame contacts
the first wheeled base and the second wheeled base when the bed
reaches the transition point and the forces acting downward are
shifted away from the first sliding hinge and the second sliding
hinge to the actuating frame when the bed is below the transition
point.
12. The bed of claim 11 wherein the forces acting downward are
shifted from the first sliding hinge to the first fulcrum point
and from the second sliding hinge to the second fulcrum point, when
the bed is lowered below the transition point, whereby a mechanical
advantage is obtained.
13. The bed of claim 11 further comprising a third sliding hinge
attached at an opposite side of the first wheeled base from the
first sliding hinge and a fourth sliding hinge attached at an opposite
side of the second wheeled base from the second sliding hinge.
14. The bed of claim 11 further comprising a stabilizing device,
wherein the stabilizing device connects the actuating frame to one
of the first wheeled base and the second wheeled base such that
the bed is stabilized above the transition point.
15. The bed of claim 14 wherein the first sliding hinge and the
second sliding hinge each comprises: a first plate and a second
plate, each plate having a first arcuate slot for retaining a first
pin, each first pin connecting the first sliding hinge and the second
sliding hinge to the lower support of the first articulated support
and the second articulated support, respectively; and the second
plate including a second arcuate slot for retaining a second pin,
each second pin connecting the first sliding hinge and the second
sliding hinge to the lower support of the first articulated support
and the second articulated support, respectively, the first plate
and the second plate of each sliding hinge being configured such
that the first pin translates in the first arcuate slot during raising
and lowering of the bed below the transition point, and the second
pin translates in the second arcuate slot in a circular arc around
the first pin during raising and lowering of the bed above the transition
point, whereby the second plate acts as the stabilizing device.
16. The bed of claim 14 wherein the stabilizing device comprises
a guiding link connecting a first pivot point connected to the actuating
frame and a second pivot point connected to the first wheeled base.
17. The bed of claim 16 wherein each of the first sliding hinge
comprises at least one plate and the at least one plate retains
a pin, the pin connecting the first sliding hinge to the lower support
of the first articulated support, the first pivot point and the
second pivot point of the guiding link being positioned such that,
above the transition point, an imaginary line drawn from a center
of rotation of the first pivot point to a center of rotation of
the second pivot point is parallel to a second imaginary line drawn
from a center of rotation of the pin and a center of rotation of
the first fulcrum point.
18. A height adjustable bed comprising: a bed frame including at
least one longitudinal framing member, a first transverse framing
member at a head portion of the bed frame and a second transverse
member at a foot portion of the bed frame; a first articulated support
pivotably connected to the head portion of the bed frame and including
a first upper support articulatedly joined to a first lower support,
the first lower support comprising a first support leg and a second
support leg, the second support leg of the first lower support being
attached to the first support leg of the first lower support by
a first cross member; a second articulated support pivotably connected
to the foot portion of the bed frame and including a second upper
support articulatedly joined to a second lower support, the second
lower support comprising a first support leg and a second support
leg, the second support leg of the second lower support being attached
to the first support leg of the second lower support by a second
cross member; a first castor base connected to the first support
leg of the first lower support by a first sliding hinge and to the
second support leg of the first lower support by a second sliding
hinge, the first castor base comprising at least two castor wheels
connected by a caster base frame; a second castor base connected
to the first support leg of the second lower support by a third
sliding hinge and to the second support leg of the second lower
support by a fourth sliding hinge, the second castor base comprising
at least two castor wheels connected by a castor base frame; an
actuating frame comprising a left longitudinal member and a right
longitudinal member connected to the left longitudinal member by
at least one transverse member, the left longitudinal member being
pivotably connected to the first support leg of the first lower
support and to the first support leg of the second lower support,
the right longitudinal member being pivotably connected to the second
support leg of the first lower support and the second support leg
of the second lower support; a linear actuator having a first end
and a second end, being pivotably connected at the first end to
a linkage member that is pivotably connected on one end to the first
articulated support and on another end to the second articulated
support, and the linear actuator being pivotably connected at the
second end to one of the at least one transverse member of the actuating
frame such that extension and retraction of the linear actuator
raises and lowers the bed; and wherein during raising of the bed
frame from a low position to a high position the bed reaches a transition
point and forces acting downward on the first articulated support
and the second articulated support are applied to the first sliding
hinge, the second sliding hinge, the third sliding hinge and the
fourth sliding hinge, when the bed is raised above the transition
point, and as the bed is lowered from the high position, the actuating
frame contacts the first castor base and the second castor base
when the bed reaches the transition point and the forces acting
downward are shifted away from the first sliding hinge, the second
sliding hinge, the third sliding hinge and the fourth sliding hinge
to the actuating frame when the bed is below the transition point.
Description FIELD OF THE INVENTION
The field of the invention is height and angle adjustable hospital
beds.
BACKGROUND OF THE INVENTION
Typically, height and angle adjustable beds are used by medical
institutions, such as hospitals and nursing homes, and usually include
a bed frame and an articulating mechanism for lowering the bed frame
to a low position so that it may be lifted and carried like a stretcher,
and a high position so that it may be used as a gurney.
However, there is a longstanding and unresolved need for a height
and angle adjustable bed having a robust and responsive articulated
mechanism that can rapidly raise and lower a bed between a fully
depressed and a fully raised position.
SUMMARY OF THE INVENTION
A height and angle adjustable bed comprises a frame and an articulated
mechanism for raising and lowering the bed frame between a lower
position resting on at least one wheeled base and a raised position.
In one embodiment, a single linear actuator is responsible for raising
and lowering the height and angle adjustable bed. One or more additional
linear actuators, which do not raise and lower the bed, may be added
to adjust the angle of a mattress that is supported by the bed frame.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 is a perspective view of an articulating bed according to
an embodiment of the present invention.
FIG. 2 is a side plan view of the articulating bed according to
an embodiment of the present invention in its highest position.
FIG. 3 is a perspective view of the articulating bed according
to the present invention in its lowest position.
FIG. 4 shows an enlarged side plan view of the foot of the articulating
bed in its lowest position.
FIG. 5 shows an enlarged side plan view of the foot of the articulating
bed in an intermediate position between the lowest position and
the highest position.
FIG. 6 shows an enlarged perspective view of the foot of the articulating
bed in another intermediate position between the lowest position
and the highest position.
FIG. 7 shows an enlarged side plan view of the foot of the articulating
bed in the position shown in FIG. 6 showing some hidden details.
FIG. 8 shows an enlarged side plan view of the foot of an articulating
bed in its highest position.
FIG. 9 shows an enlarged view of the mechanism for adjusting the
height and angle of the articulating bed.
FIG. 10 shows an enlarged perspective view of an articulated support.
FIG. 11A shows an enlarged side plan view of a sliding hinge in
accordance with another embodiment of the invention.
FIGS. 13A-13C illustrate an alternative embodiment.
FIG. 14 shows a detailed perspective view of one embodiment of
a castor base frame.
DETAILED DESCRIPTION OF THE FIGURES
FIG. 1 shows a height and angle adjustable bed 10 according to
an embodiment of the present invention. The height and angle adjustable
bed 10 includes a bed frame 70 wheels 14 mounted on respective
bases 16 and a mechanism that raises bed frame 70 from any lower
position to a higher position and lowers bed frame 70 from any higher
position to any lower position.
FIG. 2 shows a side plan view of the bed 10. The mechanism for
lowering and raising the bed frame 70 includes a system of levers
and joints, such as the two identical articulated supports 18 18'
as shown on the left and right side of line A--A in FIG. 2 respectively.
According to one embodiment, these two articulated supports 18
18' are identical, reducing the total part count of the bed 10.
Each of the articulated supports 18 18' comprise an upper support
60 articulatedly joined to a lower support 62 for example. The
articulated supports are adjusted by a single motor 20 that drives
a linear actuator 21 to raise and lower the bed frame 70. The arrangement
of elements used in each system of levers and joints enables a single
motor 20 such as an electric motor, to lower or raise bed frame
70 without assistance of a spring, sealed piston or other energy
storing system.
FIG. 3 shows the bed 10 of FIG. 2 in its lowest position. The articulated
supports 18 18' and four sliding hinges 110 that join the articulated
supports 18 18' to the wheeled bases 16 allow the bed 10 to be
lowered to a position that is fully depressed, such that the bed
frame 70 rests directly atop the wheeled bases 16 as shown in FIG.
3. An articulated mattress support 116 comprises a head assembly
122 a central assembly 123 and a foot assembly 117. The central
assembly 123 is attached to the bed frame 70 for example. The foot
assembly 117 is articulated, having a lower mattress support 125
and a middle mattress support 124 that are joined articulatedly
to the central assembly 123.
FIG. 4 shows the foot portion of bed 10 in its lowest position.
The lower supports 62 are positioned below the top of the wheels
14 in the fully depressed position. This allows bed frame 70 to
be lowered below the position that could be reached by conventional
articulating beds.
Referring to FIGS. 4-8 the following occurs when the bed frame
70 is raised from its lowest position. The lower supports 62 pivot
about respective fulcrum points 24. As can be seen in FIG. 4 each
lower support 62 includes a guide pin 106 at its distal end. The
guide pin 106 is fitted in an arcuate slot 108 which is formed in
each sliding hinge 110. When the lower support 62 is pivoted about
the fulcrum point 24 in its lowered position, the guide pin 106
slides within the arcuate slot 108 from one terminal end of the
arcuate slot 108 toward another opposing terminal end. As shown
in FIG. 5 this raises the bed frame 70. Once the guide pin 106
reaches the opposing terminal end of the arcuate slot 108 lower
support 62 and bed frame 70 have been lifted to an intermediate
position as shown by FIGS. 6 and 7 which is referred to herein
as the transition point. In FIG. 7 the dashed lines show features
of the slot 106 and lower support 62 that are hidden from view.
The fulcrum point 24 pivotably attaches the lower support 62 to
an actuating frame 46 as shown in FIG. 10 for example.
As shown in FIGS. 4-7 the actuating frame 46 remains at rest until
the bed frame 70 raises to the transition point. Thereafter, the
lower support 62 continues to pivot about guide pin 106 but the
guide pin 106 does not translate in the arcuate slot 108. Upon further
raising, the actuating frame 46 raises above the base 16 and the
force of lifting the bed shifts to guide pin 106 while the lower
support 62 continues to pivot about the fulcrum point 24 as shown
in FIG. 8 which shows the highest position of the bed 10. Shifting
the point of downward force from the fulcrum point 24 to the guide
pin 106 increases the throw of the lower support 62 which increases
the rate of movement of the bed frame 70 compared to the rate of
movement prior to reaching the transition point.
FIG. 9 shows a detailed view of one embodiment having a linear
actuator 21. The linear actuator 21 is attached removably at one
end 50 to a crossmember of the actuating frame 46 and at an opposite
end 40 to a horizontal linkage member 42. The horizontal linkage
member has two opposite ends that each connect to one of two brackets
44 that are fixed to the lower supports 62 that are on opposite
sides of line A--A as shown in FIG. 2. The brackets 44 act as levers
to pivot the lower supports 62 about their respective fulcrum points
24 which raises and lowers the bed 10.
FIG. 10 illustrates an articulated support comprising an upper
support 60 joined articulatedly to a lower support 62. Lever arms
65 are pivotably connected at one end to the actuating frame 46
and at the other end to the upper support 60 helping to support
upper support 60 during raising and lowering, as the lower support
62 pivots in relation to the actuating member 46. Fulcrum point
24 can be seen from the back side in FIG. 10 for example, which
shows the brackets connecting the lower support 62 to the actuating
frame 46.
FIG. 11 illustrates one embodiment of a sliding hinge 110. The
sliding hinge 110 comprises two plates, an outer plate 138 and an
inner plate 139. For example, each plate 138139 has a first arcuate
slot 108 for retaining pin 106 that is retained in a hole in the
end of the lower support 62. For example, the pin 106 may be removably
inserted through a corresponding hole in the lower support 62. Only
a portion of the lower support 62 is shown in FIG. 11. A removable
retaining pin or loop 131 is used to retain the pin 106 in the arcuate
slot 108 of the sliding hinge 110 shown in FIG. 11.
In one embodiment, a second arcuate slot 102 in the inner plate
139 has an open end, a closed end and a slope different than the
first arcuate slot 108. A second pin 104 is retained in the second
arcuate slot 102 and connects a different location of the lower
support 62 than the pin 106 retained in the first slot. The plates
138 139 slots 102 108 and pins 104 106 are configured such that
the second arcuate slot 102 and the second pin 104 act as a stabilizing
device for the articulated supports 18 18' during raising and lowering
when the bed is above the transition point. When the bed is below
the transition point, the second pin 104 may move freely outside
of the open end of the arcuate slot 102. Thus, the first pin 106
is allowed to translate in the first arcuate slot 108 during raising
and lowering only when the actuating frame 46 is resting on the
castor base 16. The second pin 104 translates within the second
slot 102 during raising and lowering only when weight is shifted
to the first pin 106 when it is stationary at the end of the first
arcuate slot 108. Then, when the bed is above the transition point,
the second pin 104 translates in the second arcuate slot in a circular
arc with the first pin 106 at the center of its circular arc, for
example. This stabilizes the bed by preventing the first pin 106
from translating in the first slot 108 when the actuating frame
is no longer resting on the castor bases 16.
In FIGS. 13A-13C, another stabilizing device is shown. The shaded
structure in FIG. 13A is normally partially hidden in a side plan
view, but is shown here for clarity. Actuating guide 500 comprises
an actuating bracket 510 attached to the actuating frame 46 at one
end and pivotably attached to a guiding link 512 at an opposite
end 524. Guiding link 512 pivotably links the opposite end 524 with
a base bracket 514 that is mounted on one of the castor bases 16.
The base bracket 514 is pivotably attached to the guiding link 512
at a pivot point 522. The distance between the guide pin 106 and
the pivot point 522 is constant only at or above the transition
point. Below the transition point, as the guide pin 106 translates
in the arcuate slot 108 the distance between the guide pin 106
and the pivot point 522 changes. The opposite end 524 of the actuating
bracket 510 does not move relative to fulcrum point 524. Thus, imaginary
lines B-B' and C-C' drawn through the centers of the opposite end
524 of the actuating bracket and pivot point 522 and through the
guide pin 106 and the fulcrum point 524 respectively, form a pair
of parallel lines in all positions of the bed 10 from the transition
point to the highest raised position. For example, FIGS. 13B and
13C show a perspective view of the bed 10 at its highest point and
below the transition point, respectively. Below the transition point,
the guide pin 106 starts moving in the arcuate slot 106 and lines
B-B' and C-C' are no longer parallel. Instead, the imaginary lines
are convergent at the B' and C' ends and divergent at the B and
C ends of the imaginary lines.
The embodiment shown in FIGS. 13A-13C need not have a second arcuate
slot 102 that has a slope different than the first arcuate slot
108. Instead, the second plate of the sliding hinge 110 may be identical
to the first plate, reducing the part count of the bed 10. In this
case, a plurality of guiding links may be added to one or both of
the castor bases 16. Alternatively, both stabilizing devices may
be used, further improving stability of the castor base 16. FIG.
4 shows an embodiment of a castor base 16 (frame only with castors
not shown) having both a base bracket 514 for a guiding link and
a second arcuate slot 102.
In one embodiment, a mattress support assembly 116 comprises a
head assembly 122 pivotably attached to a central assembly 123
which is fixed to the bed frame 70 as shown in FIG. 2. An articulated
foot assembly 117 comprises a lower support 125 articulatedly joined
to the bed frame 70 by a mattress frame linkage member 600 and articulatedly
joined to a middle support 124 which is pivotably attached to the
central assembly 123.
As shown in FIG. 9 two adjunct linear actuators 141 142 raise
and lower the mattress support frame 116 which is comprised of
a head assembly 122 joined to a central assembly 123 and joined
to a foot assembly 117. The foot assembly 117 is articulated. The
articulated foot assembly 117 is comprised of a middle support 124
joined to a lower support 125. The middle support 124 is pivotably
connected to one of the two adjunct linear actuators 142. The head
assembly 122 is pivotably joined to the other of the two adjunct
linear actuators 141. Thus, the angle of the foot assembly 117 and
the angle of the foot assembly 117 are independently adjustable
by the two adjunct linear actuators 141 142 which are connected
to the support frame 70. For example, the two adjunct linear actuators
141 142 are removably connected in a side-by-side arrangement,
as shown in FIG. 9.
In an alternative embodiment, the angle of the mattress support
assembly 116 is adjusted by a colinear actuator 127 pivotably attached
at a first end 126 and a second end 128 which is opposite of the
first end 126 as shown in FIG. 12. The first end 126 is attached
to the middle support 124 by a bracket 120. The second end 128 is
attached to the head assembly 122 by a second bracket 121. The first
and second brackets 120 121 act as levers to adjust the angle of
the foot assembly 117 and the head assembly 122.
The colinear actuator 127 may be configured such that the first
end 126 and the second end 128 move independently. Thus, the angle
of the head assembly 122 and the middle support 124 are independently
adjustable. A colinear actuator 127 is a unitary package; however,
the unitary package may comprise either one motor or a plurality
of motors. The first and second ends 126 128 may be aligned in
a single line or may be offset, as shown in FIG. 12. In one embodiment,
the colinear actuators are aligned and operate together to adjust
the angle of the head assembly 122 in unison with the foot assembly
117 simplifying control of mattress support adjustments.
As shown in the embodiment of FIG. 12 the angle of the lower mattress
support 125 is determined by the angle imparted to the middle support
124. A mattress linkage member 600 is pivotably attached at one
end 602 to the lower mattress support 125 and at its opposite end
601 to the bed frame 70 helping to stabilize the position of the
lower mattress support 125.
Although the present invention has been described in relation to
particular embodiments thereof, many other variations and modifications
and other uses will become apparent to those skilled in the art.
It is preferred, therefore, that the present invention be limited
not by the specific disclosure herein, but only by the appended
claims. |