Abstrict An adjustable bed allowing the knee portion to automatically rise
upon the elevating of the head portion. Alternately, when desired,
the knee may remain flat while the head of the bed elevates. The
mechanism elevating the knee connects to the structure which effecuates
the raising of the head. This mechanism occupies one position when
the knee accompanies the head portion in rising and a second position
when the knee remains flat. Conveniently, this mechanism consists
of a cam connected to the member elevating the head portion. The
cam occupies a position where it contacts a cam follower on the
knee portion of the bed when the knee rises and a second position
where it does not contact the cam follower for the instance where
the knee remains flat. These two positions of the cam may have rotational
or translational separation from each other.
Claims What is claimed is:
1. In an adjustable bed of the type having a movable head portion,
head adjusting means coupled to said head portion for moving said
head portion, and a movable knee portion, the improvement comprising
knee adjusting means connected to said head adjusting means, having
an active configuration and an inactive configuration and movable
between said active and inactive configurations for, when in said
active configuration, raising said knee portion above the flat position
during at least a part of the time said head adjusting means moves
said heat portion, said knee adjusting means not moving said knee
portion when in said inactive configuration, and shifting means
for moving said knee adjusting means between said active and inactive
configurations, wherein said knee adjusting means includes a cam
and a follower and said cam, when said knee adjusting means is in
said active position and moving said knee portion, presses against
said follower, said cam being connected to said head adjusting means
and said cam follower is connected to said knee portion, said head
adjusting means includes an elongated member moving translationally
when said head adjusting means moves said head portion, and said
cam connects to said elongated member, said cam, when said knee
adjusting means occupies said active configuration, has rotational
separation from said follower when said knee adjusting means occupies
said inactive configuration, and said shifting means rotationally
moves said cam, retaining means for holding said knee adjusting
means in said active configuration until said shifting means moves
said knee adjusting means out of said active configuration when
said shifting means moves said knee adjusting means in said active
configuration, said head adjusting means includes hand crank means
manually rotatable for moving said elongated member translationally,
and wherein said cam, when said knee adjusting means is in said
inactive configuration, does not touch said cam follower, said knee
portion, or said head portion.
2. In an adjustable bed of the type having a movable head portion,
head adjusting means coupled to said head portion for moving said
head portion, and a movable knee portion, the improvement comprising
knee adjusting means connected to said head adjusting means, having
an active configuration and an inactive configuration and movable
between said active and inactive configurations for, when in said
active configuration, raising said knee portion above the flat position
during at least a part of the time said head adjusting means moves
said head portion, said knee adjusting means not moving said knee
portion when in said inactive configuration, and shifting means
for moving said knee adjusting means between said active and inactive
configurations, wherein said knee adjusting means includes a cam
and a follower and said cam, when said knee adjusting means is in
said active position and moving said knee portion, presses against
said follower, said cam being connected to said head adjusting means
and said cam follower is connected to said knee portion, said head
adjusting means includes an elongated member moving translationally
when said head adjusting means moves said head portion, said cam
connects to said elongated member, said cam, when said knee adjusting
means occupies said active configuration, has translational separation
from said cam when said knee adjusting means occupies said inactive
configuration, and said shifting means translationally moves said
cam, said cam when said knee adjusting means occupies said active
configuration, has translational separation from said cam when said
knee adjusting means occupies said inactive configuration, and said
shifting means translationally moves said cam and retaining means
for, when said shifting means moves said knee adjusting means to
said active configuration, holding said knee adjusting means in
said active configuration until said shifting means moves said knee
adjusting means out of said active configuration.
3. The improvement of claim 2 wherein said head adjusting means
includes hand crank means manually rotatable for, when rotated,
moving said elongated member translationally.
4. The improvement of claim 3 wherein said cam, when said knee
adjusting means is in said inactive configuration, does not touch
said cam follower, said knee portion, or said head portion.
5. In an adjustable bed of the type having a movable head portion,
adjusting means coupled to said head portion, and a movable knee
portion, the improvement comprising cam-and-follower means for connecting
the head and knee portions to move the knee portion when the head
portion is moved, and manually operable means for disassociating
the cam from the follower to move the head portion independently
of the knee portion.
6. The improvement as described in claim 5 said cam being a plate
cam, and said follower being a roller adapted to roll on said plate
cam.
7. The improvement as described in claim 5 said means for disassociating
the cam from the follower comprising a rotatable support for the
cam, and means for rotating the cam into and out of alignment with
the roller.
8. The improvement as described in claim 7 and including means
for locking the rotatable support for the cam against rotation.
9. The improvement as described in claim 5 said means for disassociating
the cam from the follower comprising a slidable support for the
cam and means for sliding the cam into and out of contact with the
roller.
10. The improvement as described in claim 8 said locking means
comprising a spring-pressed interlock between the rotatable cam
support and the adjusting means coupled to said head portion.
11. The improvement as described in claim 9 and means for locking
the slidable support for the cam against sliding movement relative
to the roller.
12. The improvement as described in claim 11 said locking means
comprising a pivoted control device, and a pin-and-slot connection
between the pivot control device and the cam, said connection having
a dead-center position corresponding to the locked condition of
said locking means.
Description BACKGROUND
Adjustable beds, such as those in hospitals and nursing homes,
generally include some mechanism for elevating the head portion
of the bed. Raising this segment serves a number of different purposes.
Commonly, elevating the head allows the use of the bed for such
normal daily activities as eating, reading, watching televsion,
and others. However, frequently the bed's occupant, with his toro
elevated, tends to slide towards the foot of the bed due to gravitation.
Elevating the knee portion of the bed helps to preclude this sliding.
Other situations may require an elevation of the head but with
the knee remaining flat. One example includes a patient having undergone
recent surgery of the lower abdominal area. Elevating the knee portion
of this patient may place an undesirable strain upon the tissues
in the incisional area.
Furthermore, the knee should remain flat for patients with circulatory
problems in order to prevent or minimize clotting in their lower
extremities. Also, a slight elevation of the head with no knee elevation
improves the drainage removal of congestion for patients with respiratory
ailments.
Orthopedic patients having a straight cast on a broken leg cannot
have their knees elevated although they may wish to sit up by raising
the head portion of the bed. Moreover, elevating the head but not
the knee allows more facile entrance into and exit from the bed
of a patient who has difficulty maneuvering.
Consequently, a number of beds have afforded a choice between the
knee section remaining flat as the head section raises or the knee
following the head section in coordinated motion. Nonetheless, they
have suffered from such drawbacks as complicated and expensive mechanisms
interconnecting the head and knee portions of the bed. Some have
required an unacceptable exertion when manipulating the appropriate
mechanisms to achieve the desired results.
With regards to the latter, E. C. Ortmeier, in his U.S. Pat. No.
1658736 shows a bed in which the knee must raise with the head
to some extent before it can disengage and return to the flat position.
Specifically, once elevated slightly, the operator must physically
lift up the foot of the bed and remove it from the mechanism which
flexes the knee. Aside from the physical burden of lifting the actual
portion of the bed, this procedure also presents the danger of entrapping
and injuring fingers. Moreover, after the head reaches its lowest
position, the bed requires a repetition of the foregoing procedure
to again disengage the knee-raising mechanism.
U.S. Pat. No. 3398411 to J. Douglass, shows a bed in which the
knee-adjusting mechanism connects to the actual head portion of
the bed itself. This structure, which thus must support the load
of the knee portion, entails an appreciable added expense to the
construction of the bed.
C. W. Pratt, in his U.S. Pat. No. 474690 shows a bed which he
attempts to convert into a chair by allowing the feet to lower as
the head rises. By not allowing the knee portion of the bed to raise,
the altered configuration aggravates the gravitation of the patient
as well as the mattress to the foot of the bed, rather than precluding
it. The modern efforts have rejected this early concept when providing
a bed-ridden patient with a configuration in which to conduct daily
activities.
In F. J. Burst et al.'s bed, disclosed in their U.S. Pat. No. 3821821
the entire mattress moves towards the head of the bed as the head
portion raises. This, of course, allows the patient to remain near
to the usual accessory equipment found at this end of the bed. The
relative motion between two bed frames accomplishes this movement
of the mattress. The knee adjusting mechanism utilizes this relative
motion between the frames in order to, when desired, elevate the
knee when the head rises. This device represents a significant accomplishment
in the field of adjustable beds, but only has pertinence to those
beds with the moving frames.
Consequently, the search continues for a mechanism that permits
the knee section, when desired, to elevate with the head section
while obviating the drawbacks of the previous devices.
SUMMARY
In order to provide the desired coordinated movement, an adjustable
bed must first have a movable head portion. A head-adjusting means
effects the desired movement of this head portion.
This type of bed, moreover, should also permit movement of its
knee portion. To achieve the desired structure, the included knee-adjusting
means must display a number of characteristics. First, it must possess
an active configuration. In this active configuration, it serves
to raise the knee portion of the bed above the normal flat position
during at least a portion of the time that the head adjuster moves
the head portion.
The knee-adjusting mechanism need not elevate the knee during all
of the time that the head section rises. Where the head section,
for example has only minimal elevation, the gravitation of the occupant
does not represent an appreciable problem. Consequently, the knee
may remain flat at this point. On the other hand, the knee, after
reaching a certain elevation, for example 15.degree. of knee flexing,
will suffice to prevent gravitation even though the head section
may elevate further. Consequently, the knee need not accompany the
rising head section after reaching this elevation.
The knee-adjusting means must also have an inactive configuration.
When occupying this latter configuration, it will not move the knee
portion notwithstanding any elevation of the head portion.
Movable between the active and inactive configurations, the knee-adjusting
means requires some mechanism for accomplishing this important motion.
A shifting means performs this role.
Frequently, an adjustable bed includes an elongated member such
as a long tube which rungs longitudinally under the mattress and
spring. The tube moves translationally to change the elevation of
the head section. Moved in one direction, it forces the head section
to raise while the other direction results in the lowering of the
head section. A hand crank, a motor, or both, produce the translational
motion of the tube. When manually activated, the hand crank appears
at the foot of the bed for the convenience of the attending personnel.
Conveniently, the knee-adjusting means may then connect to this
translationally moving tube. More specifically, it may assume the
form of a cam which moves translationally with the tube and urges
against a cam follower on the knee section to effect its raising.
The cam then, of course, has two positions which it may occupy.
In the active position, the longitudinal motion of the tube as it
elevates the head section will force the cam against the cam follower
on the knee portion to elevate it. In the inactive position, it
will not contact the cam follower in a fashion to raise it.
Generally, the active cam surface projects upwards from the longitudinal
tube to contact the cam follower when raising the knee section.
Rotating it about the tube represents one method of placing it in
its inactive configuration. A second method results from moving
the cam longitudinally along the elongated member to a place where
it cannot contact the cam follower over the entire range of motion
of the longitudinal member. The cam also includes a retainer to
insure that when in its active configuration, the force of the knee
section transmitted through the cam follower does not displace it.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a top view of a manually adjustable bed which possesses
a knee cam to elevate the knee section with the head section.
FIG. 2 gives a side view of the same bed of FIG. 1. The knee cam
in both FIGS. 1 and 2 occupies an elevated position where it will
induce the raising of the knee portion.
FIG. 3 displays a view of the same bed as the prior FIGURES except
that the cam has raised the knee portion of the bed as the head
portion elevated.
FIG. 4 shows the same bed of FIGS. 1 2 and 3 and with the head
section raised. Here, the knee cam occupies a lateral position in
which it does not raise the knee portion of the bed.
FIG. 5 gives a top view of the knee cam mechanism in the lateral
position which it occupies in FIG. 4.
FIG. 6 has a perspective view of the head and knee raising mechanism
of the bed of the prior FIGURES with the knee cam occupying a vertical
position.
FIG. 7 shows a side view of a bed having an alternate form of knee
cam mechanism. The cam moves translationally out of and into its
position where it will raise the knee as the head elevates.
FIG. 8 gives a perspective view of the alternate mechanism of FIG.
7.
DETAILED DESCRIPTION
The adjustable bed of FIGS. 1 and 2 displays many features typical
of modern beds for nursing homes, hospitals and other such institutions.
A lower frame, indicated generally at 5 supports the remainder
of the mattress frame as well as the moving mechanical portions
of the bed. The frame 5 includes a lower frame angle bracket 6 which
runs the length of the bed on both of its sides. A head cross brace
7 a middle cross brace 8 and a foot cross brace 9 connect together
the two lower angle brackets 6 to form a rectangular structure.
At the head end H of the bed, the fasteners 13 rigidly attach the
head corner lock bracket 14 to the lower frame bracket 6. The rivets
15 protrude from the inside of the corner brackets 14 where they
slide into the slots 16 of the head bed hook 17. The head bed hook
17 in turn, securely attaches to the head leg assemblies 18 which
the head angle brackets 19 hold together.
Similarly, at the foot end F, the foot cross bracket 25 holds together
the two foot leg assemblies 26. The foot hooks 27 rigidly attach
to the leg assemblies 26 and have the slots 28 to entrap the rivets
29 of the foot corner lock brackets 30. The brackets 30 in turn
fasten by means of the fasteners 31 to the lower angle brackets
6 to support them at the foot end F of the bed.
The head-end and foot-end slots 16 and 28 of course, allow the
rivets 15 and 29 to raise out of them. This permits disassembling
the lead leg assemblies 18 and the foot leg assemblies 26 from the
lower frame 5 and the remaining mechanism of the bed.
Supported on the lower frame 5 the bed includes a head portion
35 a middle section 45 a thigh section 55 and a foot section
65. The head section 35 includes first a U-shaped head angle bracket
36. To provide additional support, the head section may include
a support tube 37 welded to the bracket 36.
To permit its raising, the head section 35 also incorporates a
head elevating tube 38 which has the eyelets 39 welded to it. The
U-shaped head angle bracket 36 the head elevating tube 38 and
the eyelets 39 possess a rigid spacial configuration with respect
to each other. They rotate as a unit about the head pivot point
at 40 when the head section elevates.
The screws at 40 attach the head section 35 to the middle section
45. When the head section 35 rotates about the point 40 to its lowest
position, the levelizer 41 which attaches to the head angle bracket
36 rests upon the lower bracket 6 and supports the U-shaped angle
bracket 36 in a parallel relationship with the lower angle bracket
6.
The middle section 45 includes the two plates 46 and 47 which,
at their top, form angle brackets to help support a mattress. The
thumb screws 48 retain extensions of the plates 46 in a fixed relationship
to the plates 47. Removing the screws allows the plates to separate
from each other as well as the lower angle bracket 6 along the midline
49. When this occurs, the entire structure divides along this midline
49 for more facile storage.
The knee portion of the bed actually includes both the thigh section
55 and the foot section 65. The thigh section includes first the
angle brackets 56. The fasteners at 57 pivotally connect these brackets
56 to the middle section plate 47 at the thigh pivot point 57. To
provide rigidity, the thigh section 55 includes the support tube
58 and the thigh elevating tube 59 both welded to the angle brackets
56. As its name implies, the thigh elevating tube 59 also functions
in the rising of the knee portion of the bed.
The thigh section 55 further includes the thigh leveler 60 welded
to the thigh angle brackets 56. As with the head leveler 40 the
thigh leveler 60 rests upon the lower angle bracket 6 when the thigh
section has reached its lowest position. This insures that the thigh
section rests parallel to the lower angle brackets 6 to form a flat
bed.
The foot section, which forms part of the knee portion, includes
the U-shaped angle bracket 66. At its ends, the U-shaped angle bracket
66 attaches to the knee pivot point 67 where fasteners pivotally
hold it. The support tube 68 lends rigidity to the foot section
65 although not all beds require it.
Lastly, the foot levelizer 69 forms part of the foot section 65.
As shown in FIGS. 3 5 and 7 the head levelizer 40 and the thigh
levelizer 60 raise from the lower angle bracket 6 upon the raising,
respectively, of the head section 35 and the thigh section 55. As
shown in FIG. 5 the knee portion raises by the elevation of the
knee pivotal point 67. The foot levelizer 69 accordingly remains
in contact with the lower angle bracket 6 supporting the lower
end of the foot section 65. As the thigh and foot sections 55 and
66 elevate to raise the knee, the foot levelizer 69 moves along
the lower angle bracket 6. To facilitate this movement of the foot
levelizer 69 it includes a roller 70 which makes the actual contact
with the lower angle bracket 6.
Lastly, the head angle bracket 36 the middle brackets 46 and 47
the thigh brackets 56 and the foot bracket 66 include on their upper
surface openings 71 passing through them to allow for the attachment
of a bed spring in the usual fashion. Moreover, the support tubes
37 59 and 68 bend below the level of the spring to allow the spring
to depress under the weight of a patient and not make contact with
these supports.
The crank handle 75 permits the elevation of the various bed portions.
The handle 75 connects to the head elevating screw 76 which the
FIG. 6 shows more clearly. The screw 76 in turn terminates inside
of the head adjusting tube 77. The end of the screw 76 has a threading
which engages a nut affixed to the side of the tube 77. Rotation
of the screw 76 by the handle 75 results in translational or longitudinal
motion of the tube 77. The crank guide 78 retains the tube in its
proper position as well as preventing the pinching of extraneous
items as it moves toward the foot F of the bed.
The end of the tube 77 has pins 79 which engage openings in the
eyelets 39. Turning the screw to force the tube 77 towards the head
H of the bed moves the end of the eyelets with the holes engaged
by the pin 79 towards the head H. This force on the eyelets, welded
to the tube 38 exerts a torque, or a rotational motion, on the
eyelets 39 the tube 38 and the head section 35 clockwise in FIG.
2 around the head pivot point 40 to raise the head. Similarly, turning
the screw 76 in the opposite direction pulls the eyelets 39 towards
the foot of the bed and rotates the head section 35 counterclockwise
around the point 40 in FIG. 2 to lower it. A motor, rather than
the crank handle 75 would suffice to impart the desired translational
motion to the tube 77.
The knee portion, consisting of the thigh and foot sections 55
and 65 may or may not elevate with the head portion 35 depending
upon the position of the cam 81. In the FIGS. 1 2 3 and 6 the
cam 81 occupies a vertical position. A permanent welding attaches
the cam 81 to the cam tube 82 which concentrically surrounds the
head adjusting tube 77 but with rotational freedom. The knee break
lands 83 project from the head adjusting tube 77 to which they rigidly
attach. As the tube 77 moves, under the pressure of the screw 76
towards the head of the bed, the lands 83 similarly force the cam
tube 82 and the cam 81 in that direction. As the lands 83 move the
cam 81 forward, the cam, when in its vertical position, contacts
the roller 84 of the cam follower 85 attached to the thigh elevating
tube 59. As the cam 81 continues to progress toward the head H,
it forces the roller 84 the cam follower 85 the thigh elevating
tube 59 and thus the thigh section 55 upwards. The raising of the
thigh section also elevates the foot section 65 resulting in the
elevated knee portion shown in FIG. 3.
Moving the head adjusting tube 77 in the opposite direction lowers
the head section 35 and moves the pins 90 into compression against
the spring 91 which pushes the cam 81 towards the foot of the bed.
As the cam 81 moves towards the foot, the knee section composed
of the thigh and foot sections 55 and 65 lowers until once again
reaching its flat position.
The cam 81 however, may also occupy a horizontal rather than a
vertical position. When this occurs, it cannot contact the cam follower
85 when the head adjusting tube 77 forces the cam towards the head
H of the bed. In this instance, the cam does not force the knee
portion of the bed to rise as the head section elevates.
The release handle 95 controls the attitude of the cam 81. To move
it from the vertical as shown in FIGS. 1 2 3 and 6 to the horizontal
as in FIGS. 4 and 5 requires first pushing the release handle 95
towards the head of the bed H.
Moving the handle 95 towards the head H also pushes the cam release
rod 96 in the same direction. This moves the cam 81 and the cam
tube 82 but not the tube 77 towards the head until the indentations
86 on the cam tube 82 are free of the matching lands 83 as seen
more clearly in FIG. 6. When the indentations 86 no longer engage
the lands 83 rotating the handle 95 in a counterclockwise direction,
as seen from the foot F of the bed, rotates the cam 81 also counterclockwise
until it occupies the horizontal attitude shown in FIGS. 4 and 5.
The knee break bracket 97 attached to the head elevating tube support
98 guides the handle 95 and the rod 96 during the rotational motion.
When the cam 81 occupies this horizontal attitude, rotating the
crank handle 75 will force it towards the head H as with the cam
in the vertical position. However, lying on its side, the cam 81
cannot raise the knee portion of the thigh and foot sections 55
and 65. However, since the cam 81 does not affect the head portion
35 rotating the crank handle 75 will still raise the head portion
35 to achieve the configuration shown in FIG. 4. As seen there,
the head portion 35 occupies an elevated section, with the thigh
section 55 and foot section 65 remaining at their lowest, flat position,
parallel with the lower angle bracket 6.
The lands 83 engaged with the indentations 84 on the cam tube 82
prevent the accidental rotation of the cam 81 from the vertical
to the horizontal position. An intended pushing of the knob 95 to
free the indentations 86 must precede the rotation of the cam 81.
Without depressing the handle 95 the spring 91 forces the cam tube
82 towards the foot of the bed to engage the indentations 86 with
the lands 83.
Furthermore, when the cam 81 has actually forced the knee portion
to an elevated position, the handle 95 and rod 96 cannot effect
rotation of the cam 81 to its horizontal position. With the cam
follower 85 in actual contact with the cam 81 the sides 99 of the
follower extend below the roller 84 and prevent the rotation of
the cam 81 even when attempted by the handle 95.
The bed in FIGS. 7 and 8 employs an alternate mechanism to control
the raising of the knee when elevating the head. As with the prior
figures, a screw 76 turned by a handle has a threaded end which
engages a nut 100 rigidly attached to the head elevating channel
101. Rotating the screw 76 results in longitudinal motion of this
channel 101.
The eyelet guides 102 at the head end of the channel 101 engage
pins 103 on the eyelets 39. As the channel 101 moves towards the
head H, it exerts a rotational motion, on the eyelets 39 the head
elevating tube 38 and, thus, the head portion 35 counterclockwise,
in FIG. 7 around the head pivot point at 40. This rotational motion
elevates the head 35. Similarly, moving the guide 101 towards the
foot F results in the lowering of the head portion 35.
Again, the position of the cam 81 determines whether the knee portion
of the bed will accompany the head portion in its raisings and lowerings.
However, rather than rotating from a vertical to a horizontal position
to disengage, the cam 81 moves longitudinally backward along the
channel 101 to avoid contact with the cam follower 85. Specifically,
as shown in FIG. 8 the cam 81 rigidly attaches to the cam support
105 which fits neatly over the channel 101. The support 105 has
a guide 106 in the form of a slot at its end. The screw 107 passes
loosely through the guide 106 and attaches to the channel 101 itself.
The screw serves to hold the cam support 105 and thus, the cam
81 to the channel 101 while allowing it the necessary longitudinal
motion along the channel.
The cam 81 has a slot 110 cut from it, through which the knee break
handle 111 passes. The handle 111 in turn, pivotally connects to
the channel 101 with the spacers 112 on either side providing clearance
between the handle 111 and the channel 101. Moving the handle cover
113 forward towards the head H or backwards towards the foot F results
in the rotation of the handle 111 at its attachment to the channel
101.
Specifically, as the handle 111 moves towards the head H, it presses
against the forward edge of the slot 110 and moves the cam 81 towards
the head, as shown in FIG. 8. If the channel 101 then moves towards
the head of the bed while the cam 81 occupies this forward position,
the cam 81 will contact the roller 84 of the cam follower 85 to
raise the knee, as shown in solid in FIG. 7.
The forward slant of the bottom of the slot 110 on the cam 81 acts
as a toggle mechanism to prevent the cam 81 from sliding backward
along the channel 101 under the weight of the knee of the bed acting
through the cam follower 85. This shape of the slot 110 actually
results in the secure lodging of the cam 81 in its forward position
under the weight of the bed.
Alternatively, moving the handle cover 113 towards the foot F also
moves the handle 111 and thus the cam 81 in that direction. When
occupying its rear most position, the cam 81 will not engage the
cam follower 85 over any part of the range of motion of the channel
101. Thus, the channel 101 may move forward towards the head H and
raise the head portion 35 to its maximum elevation without the cam
81 engaging the cam follower 85 or raising the knee. FIG. 7 shows
the head portion 35 elevated, but also, in phantom, the cam 81 in
its rear most position and the thigh and foot sections 55 and 65
also in phantom, in their flat position.
The channel cover 104 covers the space left vacant when the channel
101 moves towards the head H of the bed. This precludes the entrapping
or pinching of items in that space when the channel 101 returns
towards the foot F.
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