Abstrict A height adjustable bed on a floor provides a two stage continuous
adjustment system and method of operation thereof. An upper frame
is raised from a lowermost position to a maximum intermediate position
with a first set of legs resting on the floor. The upper frame is
further raised from the maximum intermediate position to an uppermost
position with a second set of legs resting on the floor. The transition
from the first set of legs to the second set of legs and vice-versa
is smooth and continuous. The system is powered by a reversible
electric motor. A much greater range of distance is achieved over
previous height adjustable beds. The ratio of uppermost distance
of the upper frame off the floor to the lowermost distance can be
greater than 2.5. A third set of wheeled legs can be added for mobility
when it is desired to move the bed.
Claims I claim:
1. A height adjustable bed on a supporting surface, said bed comprising
an upper frame with a first set of legs, said first set of legs
being indirectly connected to a second set of legs and being moveable
relative thereto, said first set of legs and said second set of
legs each being moveable relative to said frame, control means being
indirectly connected to said first set of legs to control movement
of said first and second set of legs and of said upper frame, said
first set of legs resting on said supporting surface when said upper
frame is in a first stage position ranging from a lowermost position
to a maximum intermediate position, said second set of legs resting
on said supporting surface when said upper frame is in a second
stage position ranging from said maximum intermediate position to
an uppermost position.
2. A bed as claimed in claim 1 wherein said second set of legs
is connected to pivot relative to said first set of legs.
3. A bed as claimed in claim 2 wherein said first set of legs is
connected to said upper frame by butterfly connectors, said butterfly
connectors being connected to said control means to expand and contract
through a range of movement.
4. A bed as claimed in claim 3 wherein said first set of legs is
pivotally connected to said second set of legs by connecting arms,
said first set of legs having first legs and said second set of
legs having second legs.
5. A bed as claimed in claim 4 wherein there are two connecting
arms extending between each first leg and corresponding second leg,
one of said connecting arms being rigidly connected to an end of
the butterfly connector at each first leg.
6. A bed as claimed in claim 5 wherein the first set of legs is
connected to a lower frame so that all of the first legs move in
unison.
7. A bed as claimed in claim 6 wherein the second set of legs has
second legs that are connected to corresponding first legs so that
all of the second legs move relative to the first legs in unison.
8. A bed as claimed in claim 7 wherein said second set of legs
pivots in one direction relative to said first set of legs as the
upper frame is raised and the control means controls the butterfly
connectors to expand said second set of legs then pivoting in an
opposite direction relative to said first set of legs as said upper
frame is lowered as the control means causes the butterfly connectors
to contract.
9. A bed as claimed in claim 8 wherein the control means is powered
by a reversible electric motor.
10. A bed as claimed in claim 9 wherein there are wheels on at
least one of said first set of legs and said second set of legs.
11. A bed as claimed in any one of claims 1 2 or 3 wherein there
are four legs in each set of legs.
12. A bed as claimed in any one of claims 1 2 or 3 wherein in
the lowermost position of the upper frame, the upper frame is less
than eight inches above the supporting surface and in the uppermost
position of the upper frame, the upper frame is greater than twenty-one
inches above the supporting surface.
13. A bed as claimed in any one of claims 1 2 or 3 wherein a ratio
of a distance of the supporting surface of the uppermost position
to the lowermost position is greater than substantially 2.5.
14. A bed as claimed in any one of claims 1 2 or 3 wherein a ratio
of a distance of the supporting surface of the uppermost position
to the lowermost position is at least 2.73.
15. A bed as claimed in any one of claims 1 2 or 3 wherein there
is a third set of legs with wheels thereon connected to optionally
rest on said supporting surface in place of said first set of legs
when said bed is substantially in a lowermost position.
16. A method of operating a height adjustable bed with a two stage
continuous adjustment system, said bed having an upper frame connected
indirectly to a first set of legs and to a second set of legs, with
control means to control movement of said upper frame, said first
set of legs and said second set of legs relative to one another,
said first set of legs and said second set of legs each being movable
relative to said frame, said method comprising commencing with the
upper frame in a lowermost position with the first set of legs resting
on the supporting surface, activating the control means to move
the upper frame to a maximum intermediate position with the first
set of legs and the second set of legs resting on the supporting
surface, continuing to activate the control means to move the upper
frame to the uppermost position with the second set of legs resting
on the supporting surface.
Description BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a height adjustable bed that has two
moveable sets of legs to raise or lower the bed in two continuous
stages.
2. Description of the Prior Art
Height adjustable beds are known, but previous beds do not achieve
the minimum height that can be achieved with the bed of the present
invention. Previous beds often do not lower the bed sufficiently
to enable patients to get into or out of the beds more easily and
safely. In some jurisdictions, it is not permissible to have side
guards locked in position on either side of the bed. It is therefore
important to have the beds as close to the floor as possible so
that if a patient does fall out of the bed, serious injury is very
unlikely. The difficulty encountered with designing height adjustable
beds is that when the minimum height is very low, the mechanism
to raise and lower the bed will not fit under the bed.
Further, previous beds often do not achieve a ratio of the uppermost
distance to the lowermost distance from the floor of greater than
2.5. Still further, previous beds that have a low minimum height
often cannot be raised high enough to enable the use of under bed
tables and patient lifting devices with the beds. Some previous
height adjustable beds are too complex, too unstable or expensive
to achieve widespread market acceptance.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a height adjustable
bed that has a ratio of uppermost distance over lowermost distance
from the floor much greater than 2.5. It is a further object of
the present invention to provide a height adjustable bed that has
an upper frame that can be lowered to less than eight inches and
raised to a level of nearly twenty-two inches above a supporting
surface by way of a two stage continuous movement.
It is still a further object of the present invention to provide
a height adjustable bed that has two sets of legs, one set resting
on the supporting surface during a first stage of movement and another
set of legs resting on the supporting surface during a second stage
of movement.
A height adjustable bed on a supporting surface has an upper frame
with a first set of legs and a second set of legs indirectly connected
thereto. The first set of legs is indirectly connected to said second
set of legs and is moveable relative thereto. Control means is connected
to control movement of the first and second set of legs and of the
upper frame. The first set of legs rests on the supporting surface
when the upper frame is in a first stage position ranging from a
lowermost position to a maximum intermediate position. The second
set of legs rests on the supporting surface when the upper frame
is in a second stage position ranging from the maximum intermediate
position to an uppermost position.
A method of operating a height adjustable bed with a two stage
continuous adjustment system, said bed having an upper frame connected
indirectly to a first set of legs and to a second set of legs with
control means to control movement of the upper frame, first set
of legs and second set of legs relative to one another. The method
comprises commencing with the upper frame in a lowermost position
with the first set of legs resting on the supporting surface, activating
the control means to move the upper frame to a maximum intermediate
position with the first set of legs and the second set of legs resting
on the supporting surface, continuing to activate the control means
to move the upper frame to the uppermost position with the second
set of legs resting on the supporting surface.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a prospective view of the bed in a partially raised position;
FIG. 2 is a side view of the bed in an uppermost position;
FIG. 3 is a side view of the bed in a lowermost position;
FIG. 4 is an enlarged prospective view of part of the control means;
FIG. 5 is a schematic side view of the control means;
FIG. 6A is a partial side view of a first and second leg in the
lowermost position;
FIG. 6B is a partial side view of the first and second leg in a
maximum intermediate position;
FIG. 6C is a partial side view of the first and second leg in an
uppermost position;
FIG. 7 is a schematic side view of the upper frame in the uppermost
position with the upper frame shown in the lowermost position as
well;
FIG. 8 is a side view of the upper frame, hinged panels and mechanism
for raising a head and foot of the bed;
FIG. 9 is an exploded prospective view of the upper and lower frames
and control means; and
FIG. 10 is a side view of the bed in the lowermost position with
wheels added.
DESCRIPTION OF A PREFERRED EMBODIMENT
In FIG. 1 a bed 2 has a lower frame 4 an upper frame 5 a first
set of legs 6 and a second set of legs 8. The first set of legs
6 has four first legs 10 (only two of which are shown in FIG. 1)
and the second set of legs 8 has four second legs 12 (only three
of which are shown in FIG. 1). The second legs 12 are resting on
a supporting surface 14 and the first legs 10 are above the supporting
surface. The upper frame is in a partially raised position in a
second stage beyond a maximum intermediate position, but below an
uppermost position. The first set of legs 6 are rigidly and directly
connected to the lower frame 4. The lower frame 4 has a rectangular
shape.
The bed 2 has a head 16 a foot 18 and an upper surface 20 comprised
of a number of hinged panels 22 23 24 25. There are two large
panels 22 25 located at each end of the bed and two smaller panels
23 24 located between the large panels.
The first set of legs 6 is indirectly connected to the upper frame
5 by butterfly connectors 26 that extend from the lower frame 4
to the upper frame 5. The butterfly connectors 26 each have three
elongated members 28 (one upper and two lower) connected at a pivot
point 30. Control means (not shown in FIG. 1) controls the expansion/contraction
movement of the butterfly connectors 26. A support 32 is pivotally
connected to the two lower elongated members 28. The two lower elongated
members are rigidly affixed to a cylindrical cross member 33 of
the lower frame 4.
Higher and lower connecting arms 34 35 respectively indirectly
connect each of the first legs 10 to one of the corresponding second
legs 12. The lower connecting arm 35 is rigidly affixed to one end
36 of a lower elongated member 28. An opposite end of the lower
connecting arm 35 is pivotally connected to the second leg 12. The
higher connecting arm 34 is pivotally connected between each of
the first legs 10 and one of the corresponding second legs 12 to
keep the legs 10 12 vertically oriented as one set of legs pivots
relative to the other set of legs. The legs 10 12 and the connecting
arms 34 35 have the general shape of a parallelogram at all times
as the upper frame is raised or lowered. The arms 34 35 keep the
second legs 12 vertical as they pivot relative to the first legs
10. A swing arm 38 can be used to retain a patient within the bed
2. The swing arm 38 is unrelated to the height adjustment of the
bed and is therefore not further discussed.
In FIG. 2 the bed 2 is shown in the uppermost position with the
upper frame 5 a maximum distance above the supporting surface 14.
In FIG. 2 those components that are identical to the components
of FIG. 1 are described using the same reference numerals. Control
means 40 includes a reversible electric motor 42 having an operating
arm 44 that moves in or out depending on which direction the motor
is running. The operating arm 44 has an extension 46 that is pivotally
connected to a bar 48. The control means 40 is best shown in FIG.
5. The bar 48 extends between the lower frame 4 and the upper frame
5 and has two ends 50 with elongated connectors 52 54 pivotally
connected to each end 50 and being pivotally connected to pivot
arms 55 56 (best shown in FIGS. 4 and 5).
As the operating arm 44 moves outward from the motor 42 the bar
48 moves towards the head 16 of the bed 2. This movement causes
the butterfly connectors 26 to contract, thereby lowering the upper
frame 5 relative to the supporting surface 14. When the operating
arm 44 moves inward toward the motor 42 the bar 48 is moved towards
the foot of the bed 18 causing the butterfly connectors 26 to expand
and the frame 5 to move upward. In FIG. 2 the frame 5 is shown
in the uppermost position. It should be noted that the first set
of legs 6 is in the air above the supporting surface 14 and the
second set of legs 8 is resting on the supporting surface 14.
In FIG. 3 the frame 5 is shown in the lowermost position. Those
components of FIG. 3 that are identical to the components of FIGS.
1 and 2 are described using the same reference numerals as those
used in FIGS. 1 and 2. In FIG. 3 the bar 48 has moved toward the
head 16 causing the butterfly connectors 26 to collapse completely
so that the first set of legs 6 rests on the supporting surface
or floor 14 and the second set of legs 8 are located in the air
above the floor 14. The upper frame 5 is located just above the
first set of legs 6.
The positions shown in FIGS. 2 and 3 are the extreme uppermost
and lowermost positions respectively. In moving from the position
shown in FIG. 2 to the position shown in FIG. 3 and vice-versa,
there is an instant, when the upper frame 5 is located at the maximum
intermediate position, where both the first set of legs 6 and the
second set of legs 8 are in contact with the supporting surface
(not shown). From this maximum intermediate position, if the motor
remains activated to move the bar 48 further toward the foot 18
the second set of legs 8 will remain on the supporting surface 14
and the first set of legs 6 will lift off the supporting surface
and ultimately the upper frame will reach the uppermost position
shown in FIG. 2.
In FIGS. 2 and 3 there are, of course, four first legs 10 and four
second legs 12 even though there are only two first legs and two
second legs shown in these two drawings.
In FIG. 4 the linkage for the elongated connectors 52 54 and
the pivot arms 5556 is shown. There is one of these linkages located
at each end of the bed 2 as shown in FIGS. 2 3 and 5. The bar 48
is pivotally connected to a rod 58. Elongated connectors 52 are
pivotally connected between the rod 58 and a lower end of the pivot
arms 55 that are rigidly affixed to a rotatable cross member 57
of the upper frame 5. The elongated connectors 54 are pivotally
connected between the rod 58 and the upper end of the pivot arms
56 that are in turn rigidly affixed to a rotable cross member 59
of the lower frame 4. The movement of the bar 48 towards the pivot
arms 55 56 causes the pivot arms 55 to rotate clockwise and the
cross member 57 of the upper frame 5 to rotate clockwise. Similarly,
the same movement of the bar 48 causes the pivot arms 56 to rotate
counterclockwise and to cause the cross member 59 of the lower frame
4 to rotate counterclockwise. The rotation of the cross member 57
clockwise and the cross member 59 counterclockwise from the view
as shown in FIGS. 4 2 and 3 causes the butterfly connectors 26
to collapse, thereby lowering the upper frame 5. When the bar 48
moves further away from the pivot arms 55 56 the opposite occurs
and the butterfly connectors 26 expand, thereby raising the upper
frame 5.
In FIG. 6A, the first leg 10 rests on the supporting surface 14
and the second leg 12 is located above the supporting surface. The
lower elongated member 28 of the butterfly connector 26 is rigidly
connected to the rotable cross member 59 of the lower frame 4. The
lower connecting arm 35 is rigidly connected to the same cross member
59 and pivotally connected to the second leg 12. The connecting
arm 34 is pivotally connected at each end thereof to the first leg
10 and the second leg 12. As the cross member 59 rotates clockwise
from the view shown in FIG. 6A, the arm 28 moves upward and the
arm 35 moves downward, thereby causing the second leg 12 to move
downward. The upper frame 5 (not shown in FIG. 6A) is at the lowermost
position with the first leg 10 on the supporting surface 14 and
the second leg 12 in the air (see also FIG. 3).
Ultimately, as shown in FIG. 6B, as the rotation of the cross member
59 continues in a clockwise manner, the second leg 12 rests on the
supporting surface 14. The remaining components of FIG. 6B are identical
to the components of FIG. 6A and the same reference numerals are
used to describe these components. In the position shown in FIG.
6B, the upper frame (not shown in FIG. 6B) is at the maximum intermediate
position as both the first leg 10 and second leg 12 are resting
on the supporting surface 14.
Further clockwise rotation of the cross member 59 causes the first
leg 10 to lift off the supporting surface 14 leaving the bed supported
by the second leg 12 which rests on the supporting surface 14. In
the position shown in FIG. 6C, the upper frame (not shown in FIG.
6C) is at the uppermost position relative to the supporting surface
14 (see also FIG. 2).
In FIG. 7 there is shown a schematic side view which shows the
general outline of the first legs 10 and the second legs 12 when
the upper frame 5 is in the uppermost position relative to the supporting
surface 14. Those components that are identical to the components
of the other drawings are described in FIG. 7 using the same reference
numerals. It can be seen the that upper frame 5 is partially shown
in its lowermost position as well so that the relative distance
of movement of the upper frame 5 between the lowermost position
and uppermost position can readily be observed.
In FIG. 8 it can be seen that the upper frame 5 has panels 22
23 24 25 located thereon, the panels being connected together
by hinges 64. The same reference numerals are used to describe those
components that are identical to the components described in the
previous drawings. There are two conventional mechanisms 66 68
that are used to raise or lower the panel 22 at the head 16 and
the panels 24 25 at the foot 18 respectively. The two mechanisms
66 68 operate independently of one another.
The mechanism 66 is powered by a reversible electric motor 70 that
has an operating arm 72 that moves inward or outward depending on
which direction the motor is operating. The operating arm 72 has
an extension 74 thereon that is pivotally connected to bracket 76
at pivot point 78. The bracket 76 is rigidly affixed to rotatable
tubular member 80 that can be rotated clockwise and counterclockwise
depending on the direction that the motor 70 is operating. A long
arm 82 is rigidly connected to the tubular member 80. A free end
of the long arm 82 has a roller 84 rotatably mounted thereon. As
the operating arm 72 moves inward toward the motor 70 the extension
74 also moves inward pulling the bracket 76 toward the motor 70
and causing the tubular member 80 to rotate in a clockwise direction
from the view shown in FIG. 8. The clockwise rotation of the tubular
member 80 causes the long arm 82 to rotate upward, thus raising
the panel 22. When the motor rotates in the opposite direction,
the operating arm 72 and extension 74 cause the tubular member 80
to rotate in a counterclockwise direction, thus lowering the arm
82 and panel 22 to the point where the panel 22 lies flat on the
upper frame 5.
The mechanism 68 is very similar to the mechanism 66 and has essentially
the same components that will be described using different reference
numerals so that the two mechanisms can be differentiated from one
another. The mechanism 68 has a reversible electric motor 86 with
an operating arm 88 and extension 90 pivotally connected to a bracket
92 at pivot point 94. The bracket 92 is rigidly affixed to tubular
member 96 that is mounted so that it can rotate clockwise and counterclockwise
depending on the direction that the motor 86 is operated. A long
arm 98 is also rigidly affixed to the tubular member 96. The long
arm 98 has a roller 100 rotatably supported at a free end thereof.
Related to the movement of the mechanism 68 there is a short support
102 that is pivotally mounted at either end in brackets 104 106.
The bracket 104 is rigidly affixed to the upper frame 5 and the
bracket 106 is rigidly affixed to a lower surface of the panel 25.
In operation of the mechanism 68 when the motor 86 is operated
to extend the operating arm 88 the extension 90 also extends away
from the motor 86. This causes the bracket 92 to rotate the tubular
member 96 clockwise from the view shown in FIG. 8. As the tubular
member 96 rotates clockwise, the long arm 98 is also rotated clockwise
causing the arm 98 to move closer to the upper frame 5 thus lowering
the panel 24. As the panel 24 lowers, the panel 25 also lowers as
does the short support 102. If the motor continues to extend the
operating arm 88 and extension 90 the long arm 98 will ultimately
lower the panels 24 25 to the point where they lie flat on the
upper frame 5. When the motor is rotated in the opposite direction
to retract the operating arm 88 and extension 90 toward the motor
86 the tubular member 96 will rotate in a counterclockwise direction
and the arm 98 and roller 100 will raise the panel 24. This is turn
will cause the panel 25 to be raised and will pull the pivot arm
102 upward away from the upper frame 5.
With both mechanisms 66 68 as an alternative, the tubular members
80 96 could be mounted so that they remain fixed and do not rotate.
Then, the bracket 76 and long arm 82 and the bracket 92 and long
arm 98 could be rigidly affixed to one another and mounted so that
they both pivot about the elongated members 80 98 to raise or lower
the panels 22 and 24 25 respectively. The short support 102 does
not have any motor but is pivoted by the force exerted from the
panel 24 on the panel 25.
In FIG. 9 there is shown an exploded view of the lower frame 4
and upper frame 5. The same reference numerals are used in FIG.
9 for those components that are identical to the components shown
in the previous figures. The purpose of the exploded view is to
show how the various components interrelate. Also, for example,
it can be seen that there are two long arms 82 and corresponding
rollers 84 rigidly affixed to the rotatable tubular member 80. Similarly,
there are two long arms 98 and corresponding rollers 100 rigidly
affixed to the rotatable tubular member 96 of the mechanism 68.
There are also two elongated members 28 on the lower frame 4 and
one elongated member 28 on the upper frame 5 making up each of the
four butterfly connectors 26 near the head 16 of the bed (not shown)
and two butterfly connectors 26 near the foot 18 of the bed (not
shown). Two supports 32 are pivotally connected between the rotatable
tubular member 59 on the lower frame 4 and corresponding brackets
108 on the upper frame 5.
In FIG. 10 there is shown an embodiment of the invention that
is virtually identical to the embodiment shown in FIG. 3 except
that the bed 2 has support wheels 110 mounted thereon. There are
four wheels 110 on legs 112 (only two of which are shown) and the
four legs with wheels comprise a third set of legs. The support
wheels 110 rest on the supporting surface as the bed is lowered
to the lowermost position and prevent the bed from reaching the
lowermost position shown in FIG. 3. As the bed approaches the lowermost
position, the first set of legs 6 lift off the supporting surface
and the bed is supported solely by the wheels 110. This makes the
bed mobile in that one position. When the bed is in any other position,
either the first set of legs 6 or the second set of legs 8 is always
on the supporting surface and the bed is immobilized. A bed with
this third set of legs cannot be lowered to the same lowermost position
as the wheels rest on the supporting surface just before the lowermost
position is reached. In other words, the minimum height of the bed
shown in FIG. 10 will be slightly greater than the minimum height
of the bed shown in FIGS. 1 2 and 3.
The bed could have an independent braking means (not shown) so
that the bed can be immobilized when desired. The independent braking
means could be applied to two or more of the wheels that are on
the supporting surface simultaneously or they could be an independent
braking means that places a "foot" on the supporting surface
to anchor the bed in one position.
A standard size hospital bed or nursing home bed constructed in
accordance with the present invention can have a height above the
supporting surface to the upper frame from 77/8" in the lowermost
position to nearly 22" (e.g. 21.5") in the uppermost position.
These distances are sometimes referred to as the mattress deck height.
The ratio of the distance of the upper frame above the supporting
surface from uppermost to lowermost is greater than 2.5. The actual
height of the upper frame above the supporting surface will vary
with the size of the bed. A bed ranging from a lowermost position
of 77/8" to an uppermost position of 21.5" has a ratio
of 2.73. Variation within the scope of the attached claims will
be readily apparent to those skilled in the art. For example, the
use of two sets of legs in two continuous stages to greatly increase
the change in height of a bed can be achieved in various ways that
are different than the manner described herein. Beds of the present
invention can be made relatively inexpensively and provide a safe,
practical bed that is low enough to the floor to allow easy ingress
and egress and to minimize injuries if a user should fall out of
the bed. Beds of the present invention can be raised high enough
to allow care givers to comfortably administer patients in the beds,
to change the sheets and to use under bed tables and patient lifting
devices. |