Abstrict A vertically adjustable bed includes a bed frame attached to movable
legs powered by a motor. Operation of the motor causes the legs
to move longitudinally along a guide rod, collapsing the legs beneath
the bed and moving the bed frame vertically. Collapsing the bed
to its substantially lowermost position compresses a spring. The
energy stored by the compression of the spring is used to raise
the bed from its substantially lowermost position. Pivotally attached
to the legs is a caster and foot arrangement. During normal operation,
the foot engages the floor. When the bed frame moves to its substantially
uppermost position, a pin extending from the leg engages one end
of a slot, causing the caster to pivot and engage the floor, rendering
the bed horizontally mobile.
Claims Having described the invention, what is claimed is:
1. A bed that can be supported on a floor, having a bed frame and
a pair of motor powered leg mechanisms operable to vertically raise
and lower the bed frame between a lowermost and an uppermost position,
each one of the pair of leg mechanisms including rolling means,
the rolling means comprising a fixed leg member, the fixed leg member
engaging the floor when the bed frame is in the lowermost position
and disengaging the floor when the bed flame is raised to thereby
render the bed horizontally mobile on the rolling means only at
substantially the uppermost position; wherein said bed frame comprises
a pair of spaced apart transverse frame elements inward of each
end of the bed frame, having a pair of rod guide means there between
rigidly connected at each end to said transverse frame elements,
said guide means having a bearing element and a spring element circumferentially
mounted thereon, said bearing element movable along the length of
the guide means to engage as well as to compress the spring element
at one end thereof against said transverse frame element and wherein
said motor power consists of a linear actuator operatively attached
to the bearing element.
2. A bed that can be supported on a floor, having a bed frame and
a pair of motor powered leg mechanisms operable to vertically raise
and lower the bed frame between a lowermost and an uppermost position,
each one of the pair of leg mechanisms including rolling means,
the rolling means comprising a fixed leg member, the fixed leg member
engaging the floor when the bed frame is in the lowermost position
and disengaging the floor when the bed frame is raised to thereby
render the bed horizontally mobile on the rolling means only at
substantially the uppermost position; wherein each of said leg mechanisms
comprises a substantially inverted U shaped leg frame member having
a pair of downwardly extending legs, collapsibly attached to the
underside of said bed frame by means of a first pinned connection
at the top thereof between the leg frame member and the bearing
element and a second pinned linkage connection between one end of
the bed frame and substantially the midpoint of the leg frame member.
3. The bed as claimed in claim 2 wherein said fixed leg member
is a foot and said rolling means further comprises a castor member.
4. The bed as claimed in claim 2 wherein said rolling means comprises
a flange having a slot therethrough and opposite ends, said flange
rotatably attached to the bottom of each said leg of the leg frame
member and constrained to rotationally pivot with respect thereto
by means of a pin member extending from the bottom of each said
leg and passing through said slot, each said opposite end having
attached thereto respectively a fixed leg member and a caster member.
5. The bed as claimed in claim 4 wherein said slot in said flange
has a convex arcuate shape with reference to the floor.
6. The bed as claimed in claim 2 wherein each of said downwardly
extending legs is rigidly connected at its bottom end by a transverse
leg frame member and said rolling means is rotationally attached
to said transverse leg frame member.
7. The bed as claimed in claim 6 wherein said rolling means comprises
a flange having a slot therethrough and opposite ends, said flange
rotatably attached to either end of the transverse leg flame member
and constrained to rotationally pivot with respect thereto by means
of a pin member extending from said transverse leg frame member
and passing through said slot, each said opposite end having attached
thereto respectively a fixed leg member and a caster member.
8. The bed as claimed in claim 7 wherein said slot in said flange
has a convex arcuate shape with reference to the floor.
9. A bed, having a bed frame and a pair of motor powered leg mechanisms
operable to vertically raise and lower said bed frame over a range
of heights between a lowermost and uppermost position: (a) wherein
said bed frame comprises a pair of spaced apart transverse frame
elements inward of each end of the bed frame, having a pair of rod
guide means therebetween rigidly connected at each end to said transverse
frame elements, said guide means having a bearing element and a
spring element circumferentially mounted thereon, said bearing element
movable along the length of the guide means to engage as well as
to compress the spring element at one end thereof against said transverse
frame element; (b) wherein said motor power consists of a linear
actuator operatively attached to the bearing element to thereby
move said bearing element longitudinally along said guide means;
c) wherein each of said leg mechanisms comprises a substantially
inverted U shaped leg frame member having a pair of downwardly extending
legs, collapsibly attached to the underside of said bed frame by
means of a first pinned connection at the top thereof between the
leg frame member and the bearing element and a second pinned linkage
connection between one end of the bed frame and substantially the
midpoint of the leg frame member.
10. The bed as claimed in claim 9 wherein each of said downwardly
extending legs includes rolling means attached to the bottom thereof.
11. The bed as claimed in claim 10 wherein each of said downwardly
extending legs is rigidly connected at its bottom end by a transverse
leg frame member and wherein said rolling means is attached to the
end of said transverse leg frame member.
12. The bed as claimed in claim 9 wherein said bearing element
is made of a dry lubricant plastic.
13. A bed for use on a floor, comprising: a bed frame; first and
second legs disposed at opposite ends of the bed that support the
bed frame for vertical movement relative to the floor between an
uppermost position and a lowermost position and a plurality of intermediate
positions; each one of the first and second legs having a respective
upper end portion movably connected to the bed frame and having
a respective lower end pardon that includes a wheel and a foot,
the lower end portion being movable vertically relative to the bed
frame upon movement of the leg relative to the bed frame; the wheels
of the first and second legs engaging the floor when the bed frame
is in the uppermost position and being spaced upward from the floor
when the frame is in the lowermost position; and the feet of the
first and second legs engaging the floor when the bed frame is in
the lowermost position and in the plurality of intermediate positions;
wherein the upper end portions of the first and second legs are
movable in a direction along the length of the bed frame during
vertical movement of the bed frame.
14. A bed as set forth in claim 13 wherein, in response to movement
of the upper end portions of the first and second legs in a direction
along the length of the bed frame, the lower end portions of the
first and second legs change over between a first condition in which
the wheels and not the feet are in engagement with the floor and
a second condition in which the feet and not the wheels are in engagement
with the floor.
15. A bed as set forth in claim 14 wherein the lower end portions
of the legs change over in response to movement of the bed frame
into and out of the uppermost position.
16. A bed for use on a floor, comprising: a bed frame; first and
second legs disposed at opposite ends of the bed that support the
bed frame for vertical movement relative to the floor between an
uppermost position and a lowermost position and a plurality of intermediate
positions; each one of the first and second legs having a respective
upper end portion movably connected to the bed frame and having
a respective lower end portion that includes a wheel and a foot,
the lower end portion being movable vertically relative to the bed
frame upon movement of the leg relative to the bed frame; the wheels
of the first and second legs engaging the floor when the bed frame
is in the uppermost position and being spaced upward from the floor
when the frame is in the lowermost position; and the feet of the
first and second legs engaging the floor when the bed frame is in
the lowermost position and in the plurality of intermediate positions;
wherein at least one end portion of each one of the first and second
legs moves longitudinally when the bed frame moves vertically.
17. A bed for use on a floor, comprising: a bed frame; first and
second legs disposed at opposite ends of the bed that support the
bed frame for vertical movement relative to the floor between an
uppermost position and a lowermost position and a plurality of intermediate
positions including an upper intermediate position; each one of
the first and second legs having a respective upper end portion
movably connected to the bed frame and having a respective lower
end portion that includes a wheel and a foot, the lower end portion
being movable vertically relative to the bed frame upon movement
of the leg relative to the bed frame; each one of the lower and
portions of the legs including a leg member and a support member
that is rockably connected to the leg member at an attachment point,
the foot and the wheel being supported on the support member on
opposite sides of the attachment point for rocking movement with
the support member.
18. A bed as set forth in claim 17 wherein the support member is
a flange.
19. A bed as set forth in claim 17 wherein: the feet and not the
wheels of each of the first and second legs engage the floor when
the bed is in the lowermost position; and the wheels and not the
feet of each of the first and second legs engage the floor when
the bed is in the uppermost position.
20. A bed as set forth in claim 17 wherein the leg member includes
a portion that engages the support member to cause rocking movement
of the support member in response to movement of the bed frame into
and out of the uppermost position.
21. A bed as set forth in claim 20 wherein the leg member portion
is a pin that engages in a slot in the support member to cause rocking
movement of the support member.
22. A bed for use on a floor, comprising: a bed frame; first and
second legs disposed at opposite ends of the bed that are connected
to the bed frame for movement relative to the bed frame through
a range of motion and that support the bed frame for vertical movement
relative to the floor between an uppermost position and a lowermost
position and a plurality of intermediate positions including an
upper intermediate position; each one of the first and second legs
having a respective upper end portion connected to the bed frame
and having a respective lower end portion that is for engaging the
floor and that includes a wheel and a foot, on each leg the foot
and the wheel being alternatively engageable with the floor in response
to movement of the leg through its range of motion relative to the
bed frame; wherein the lower end portion of each leg includes a
leg member and a rockable support member that is connected with
the leg member and that supports the foot and the wheel.
23. A bed as set forth in claim 22 wherein the leg member includes
a portion that engages the support member to cause rocking movement
of the support member relative to the leg member in response to
movement of the bed frame into and out of the uppermost position.
24. A bed as set forth in claim 22 wherein on each one of the first
and second legs the wheel and the foot are connected to the support
member on opposite sides of the point of attachment of the support
member to the leg member.
25. A bed for use on a floor, comprising: a bed frame; first and
second legs disposed at opposite ends of the bed that are connected
to the bed frame for movement relative to the bed frame through
a range of motion and that support the bed frame for vertical movement
relative to the floor between an uppermost position and a lowermost
position and a plurality of intermediate positions including an
upper intermediate position; each one of the first and second legs
having a respective upper end portion connected to the bed frame
and having a respective lower end portion that is for engaging the
floor and that includes a wheel and a foot, on each leg the foot
and the wheel being alternatively engageable with the floor in response
to movement of the leg through its range of motion relative to the
bed frame; wherein the legs are connected to the frame for pivotal
movement relative to the frame and wherein the upper end portions
of the leg are also movable along the length of the bed frame.
26. A bed for use on a floor, comprising: a bed frame; first and
second legs disposed at opposite ends of the bed that are connected
to the bed frame for movement relative to the bed frame through
a range of motion and that support the bed frame for vertical movement
relative to the floor between an uppermost position and a lowermost
position and a plurality of intermediate positions including an
upper intermediate position; each one of the first and second legs
having a respective upper end portion connected to the bed frame
and having a respective lower end portion that is for engaging the
floor and that includes a wheel and a foot, on each leg the foot
and the wheel being alternatively engageable with the floor in response
to movement of the leg through its range of motion relative to the
bed frame; wherein, in response to movement of the upper end portions
of the first and second legs in a direction along the length of
the bed frame the lower end portions of the first and second legs
change over between a first condition in which the wheels and not
the feet are in engagement with the floor and a second condition
in which the feet and not the wheels are in engagement with the
floor.
27. A bed as set forth in claim 26 wherein the lower end portions
of the legs change over in response to movement of the bed frame
into and out of the uppermost position.
28. A bed for use on a floor, comprising: a bed frame; and first
and second leg mechanisms disposed at opposite ends of the bed for
supporting the bed frame for vertical movement relative to the floor
between an uppermost position and a lowermost position and a plurality
of intermediate positions including an upper intermediate position,
said first and second leg mechanisms being connected to the bed
frame for movement relative to the bed frame through a range of
motion; each one of the first and second legs mechanisms having
a respective upper end portion connected to the bed frame and having
a respective lower end portion that is for engaging the floor and
that includes a wheel and a foot, on each leg the foot and the wheel
being alternatively engageable with the floor in response to movement
of the leg through its range of motion relative to the bed frame;
wherein the leg mechanisms are connected to the frame for pivotal
movement relative to the frame and wherein the upper end portions
of the leg mechanisms are also movable along the length of the bed
frame.
29. A bed for use on a floor, comprising: a bed frame; and first
and second leg mechanisms disposed at opposite ends of the bed for
supporting the bed frame for vertical movement relative to the floor
between an uppermost position and a lowermost position and a plurality
of intermediate positions including an upper intermediate position,
said first and second leg mechanisms being connected to the bed
frame for movement relative to the bed frame through a range of
motion; each one of the first and second legs mechanisms having
a respective upper end portion connected to the bed frame and having
a respective lower end portion that is for engaging the floor and
that includes a wheel and a foot, on each leg the foot and the wheel
being alternatively engageable with the floor in response to movement
of the leg through its range of motion relative to the bed frame;
wherein, in response to movement of the upper end portions of the
first and second leg mechanisms in a direction along the length
of the bed frame, the lower end portions of the first and second
leg mechanisms change over between a first condition in which the
wheels and not the feet are in engagement with the floor and a second
condition in which the feet and not the wheels are in engagement
with the floor.
30. A bed as set forth in claim 29 wherein the tower and portions
of the leg mechanisms change over in response to movement of the
bed frame into and out of the uppermost position.
Description BACKGROUND OF THE INVENTION
Field of the Invention
The present invention relates to improvements in a vertically adjustable
mechanical bed. Such a bed may be lowered or raised as required
by an operator by means of motor activation. The bed is used in
its "lower most positions" to minimize the risk of injury
to persons who may through inattention or infirmity fall out of
the bed. The lower the height, the less risk of injury. The bed
is used in its "upper most" positions to enable personnel
to perform their functions with respect to the bed or its occupant
without bending down or having to work in an awkward physical position.
SUMMARY OF THE INVENTION
One aspect of the present invention is to provide the bed with
a foot/caster leg arrangement which enables the bed to remain in
a stable or non mobile condition on the floor surface resting on
the foot portion of the leg over almost the entire range of vertical
travel. As the bed frame reaches its upper most point, the novel
foot/caster leg arrangement of the present invention will automatically
pivot onto the caster portion of the leg which permits mobility.
The bed according to the present invention is almost always in the
stable position resting on the foot portion through almost the entire
range of vertical travel. At about prior to the highest position,
the bed becomes mobile as the weight of the bed is transferred onto
the casters that have automatically come into contact with the floor
or ground as hereinafter described.
According to another aspect of the invention, the bed frame may
be elevated or lowered using the described linkage mechanisms and
arrangements such that the bed frame moves vertically over the same
"footprint". In other words, the bed frame moves upwardly
or downwardly without any longitudinal or horizontal component of
travel. One of the advantages associated with this type of "straight
up and down" feature is that the end of the bed frame immediately
adjacent, for example, a wall, will not move away from the wall
or into the wall with the consequent possibility of property damage
or personal injury.
The present invention in one embodiment provides a bed having a
bed frame and a pair of motor powered leg means operable to vertically
raise and lower the bed frame over a range of heights between a
lowermost and uppermost position. The leg means include rolling
means which automatically operate to engage a floor surface in response
to the operation of said leg means to raise said bed frame to substantially
its uppermost position and render said bed horizontally mobile on
the rolling means only at said substantially uppermost position.
The present invention in yet another embodiment provides a bed
frame comprising a pair of spaced apart transverse frame elements
inward of each end of the bed frame, having a pair of rod guide
means therebetween rigidly connected at each end to said transverse
frame elements. The guide means have a bearing element and a spring
element circumferentially mounted thereon. The bearing element is
movable along the length of the guide means to engage as well as
to compress the spring element at one end thereof against said transverse
frame element and wherein the motor power consists of a linear actuator
operatively attached to the bearing element.
The present invention in yet another embodiment provides leg means
comprising a substantially inverted U shaped leg frame member having
a pair of downwardly extending legs, collapsibly attached to the
underside of said bed frame by means of a first pinned connection
at the top thereof between the leg frame and the bearing element
and a second pinned linkage connection between one end of the bed
frame and substantially the midpoint of the leg frame member.
The present invention in yet another embodiment provides rolling
means comprising a flange having a slot therethrough and opposite
ends, said flange rotatably attached to the bottom of each said
leg of the leg frame member and constrained to rotationally pivot
with respect thereto by means of a pin member extending from the
bottom of each said leg passing through said slot, each said opposite
end having attached thereto respectively a fixed leg member and
a caster member. The slot in the flange has a convex arcuate shape
with reference to the floor surface. Each of said downwardly extending
legs may be rigidly connected at its bottom end by a transverse
leg frame member and said rolling means may be optionally rotationally
attached to said transverse leg frame member.
The present invention in yet another embodiment provides a bed,
having a bed frame and a pair of motor powered leg means operable
to vertically raise and lower said bed frame over a range of heights
between a lowermost and uppermost position. The bed frame comprises
a pair of spaced apart transverse frame elements inward of each
end of the bed frame, having a pair of rod guide means therebetween
rigidly connected at each end to said transverse frame elements,
said guide means having a bearing element and a spring element circumferentially
mounted thereon, said bearing element movable along the length of
the guide means to engage as well as to compress the spring element
at one end thereof against said transverse frame element. The motor
power consists of a linear actuator operatively attached to the
bearing element to thereby move said bearing element longitudinally
along said guide means. The leg means comprises a substantially
inverted U shaped leg frame member having a pair of downwardly extending
legs, collapsibly attached to the underside of said bed frame by
means of a first pinned connection at the top thereof between the
leg frame and the bearing element and a second pinned linkage connection
between one end of the bed frame and substantially the midpoint
of the leg frame member. Castor wheels may be attached to the bottom
of each leg.
Further features of the invention will be described or will become
apparent in the course of the following detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
In order that the invention may be more clearly understood, a preferred
embodiment thereof will now be described in detail by way of example,
with reference to the accompanying drawings, in which:
FIG. 1 is a perspective view of the mechanical bed frame and leg
arrangement shown in the highest position.
FIG. 2 is a perspective partly sectional view of the foot/caster
leg arrangement.
FIG. 3 is a side, partly sectional view, of the foot/caster leg
arrangement.
PREFERRED EMBODIMENT
Referring to FIG. 1 a vertically adjustable bed 1 is shown having
a rectangular like bed frame 2 which has cross members 3 and 9 which
gives the bed frame its rigidity.
The leg arrangement associated at each end of the bed consists
of a inverted U shaped main leg frame member 7 which is pivotally
and movably attached to the bed frame by means of bearing block
4 at pivot point A. This arrangement allows the top of the leg frame
member 7 to follow the bearing block as it travels longitudinally
along the linear guide 5 in response to the movement of a linear
actuator associated with the motor means 10. The bearing block consists
of a square like block having a circular aperture therethrough.
The operation of the motor moves the bearing block 4 by means of
the linear actuator longitudinally along the linear guide rod 5.
This action causes the main frame leg to collapse and lower or extend
and rise under the bed.
Returning to the leg arrangement, the main leg frame member 7 is
pivotally attached at its mid point B to one end of a linkage arm
8. The other end of the linkage arm 8 is fixedly attached at C to
a rotatable sleeve on cross member 9. It should be noted that the
pivot points A, B and C are equidistant from one another which permits
the vertical up and down motion of the bed in response to the movement
of the bearing block along the linear guide by means of the linear
actuator. In operation, the movement of the bearing block along
the linear guide rod 5 will either rotationally collapse or raise
the main leg.
One problem with raising a bed from its lowermost position is the
greater motor power required to initiate the raising sequence action.
This is because there is no effective angle .theta. between the
main leg frame member 7 and the bed frame 2 as shown in FIG. 1.
When collapsed, the main leg frame member 7 is tucked under the
bed frame and is virtually parallel thereto. The angle .theta. is
effectively zero. For this reason, spring members 6 are provided
at each end of the linear guide rod mounted circumferentially thereon
and optionally fixedly attached to one of the transverse cross-members
3 as shown or to the bottom of the leg. Referring to the earlier
description of the operation of the bed, when lowering the bed the
front face of the bearing block 4 will eventually come into contact
with and engage the spring 6. Further lowering action will cause
the spring 6 to longitudinally compress between the bearing block
and the transverse cross-member. Full compression occurs at the
lowermost position. When the bed is sought to be raised the energy
in the compressed spring 6 acts on the front face of the bearing
block 4 to initiate the first or initial movement along the linear
guide rod without reliance on the motor at this most critical point.
Once movement has been started by the spring and an effective angle
.theta. established, the motor is able to take over to easily raise
the bed.
The operation of the special foot/caster leg arrangement will now
be described with reference to FIGS. 2 and 3. It can be seen that
each open end of the U shaped main leg frame member 7 is connected
by a rigidly attached horizontal cross frame member 18. According
to this invention, a foot/caster leg is rotationally or pivotally
attached at each end of cross member 18 by means of a shoulder bolt
(non shown) passing through hole 16 in the flange 17 to which the
foot 14 and caster 13 are attached at either end. As such, and with
reference to FIG. 3 the center line of the caster 13 is distance
B from the center line passing through the shoulder bolt. The center
line of the foot 14 is distance A from the center line passing through
the pin 15. The caster and foot are thus separated from one another
by a ratio of B:A. Further operation of the foot/caster leg arrangement
is now described.
As the bed is lowered or raised, a dog or pin 11 which is fixedly
attached and outwardly extends from each end of the cross leg member
18 will move in an arcuate fashion by reason of its off center
location with reference to the longitudinal center line of the cross
member 18. The arcuate movement of the dog or pin 11 is achieved
as a function of rotation of the main leg frame member 7. The dog
or pin 11 is aligned and constrained within an arcuate slot 12 in
the flange. Thus, and with reference to FIG. 3 when the bed as
in the example shown is in its upper most position, the dog 11 will
have moved clockwise in the arcuate slot 12 to the position shown
in 3 thus engaging the flange at the point of contact X as shown.
Further movement of the dog as the bed is raised causes the flange
to rotate in a clockwise direction onto the caster wheel. Correspondingly,
the foot will come off the ground. The reverse action will cause
the dog 11 to rotate counter clock wise within the arcuate slot
12 ultimately into disengagement with the end of the slot X and
towards the other end of the slot Y wherein the foot will fully
engage the floor. It is the constraint of the dog within the arcuate
slot which ensures that, excepting only one intermediate position,
only the leg or caster are in contact with the floor but not both.
It can be seen that the pivot distances B and A (ratio B:A) shown
in FIG. 3 can be geometrically matched and sized to the length of
the arcuate slot 12 to ensure that the foot 14 comes off the floor
at or about the uppermost travel position of the bed. Further movement
of the bed to its highest position causes the foot/caster leg to
pivot to fully engage the caster wheels with the floor. Thus, the
bed remains fixed on the ground through most of the vertical travel
sequence.
The particular arrangement shown for the pin is not essential.
What is important is to use the rotational motion at the bottom
of the leg or horizontal base frame member by some means such as
a pin to engage one end of a slot or channel to obtain the desired
action. As such, the pin can be made to extend upwardly at right
angles to the longitudinal axis of the horizontal base frame member
and the foot/caster can be adapted with an interior channel within
which the pin can move to engage one end of the channel.
A second foot/caster leg on the other end of cross member 18 operates
in the same identical fashion but in reverse with respect to the
description of the clock wise and the counter clock wise travel
directions of the dog 11 within the arcuate slot 12. Obviously,
the other main leg frame is equipped identically and operates in
an identical and complementary fashion. All of the actions are synchronized
to achieve the objects of this invention. As well, the foot caster
may be optionally attached to the bottom of the leg and made to
function in like fashion.
From the foregoing, it will be seen that this invention is one
well adapted to attain all the ends and objects hereinabove set
forth together with other advantages which are obvious and which
are inherent to, the structure.
It will be understood that certain features and sub-combinations
are of utility and may be employed without reference to other features
and sub-combinations. This is contemplated by and is within the
scope of the claims.
Since many possible embodiments may be made of the invention without
departing from the scope thereof, it is to be understood that all
matter herein set forth or shown in the accompanying drawings is
to be interpreted as illustrative and not in a limiting sense. |