Abstrict A control arrangement and method for a motor driven adjustable
bed which has mattress supporting portions, a frame for supporting
the mattress supporting portions, and a position controlling mechanism
operatively interconnecting the mattress supporting portions and
the frame and including a plurality of motors. In accordance with
the present invention, an operator of the bed may generate command
signals indicative of selected bed positions and a processor responsive
to command signals and to control signals stored in a programmable
memory actuates at least one of the motors for moving the frame
toward an allowed, selected bed position. In accordance with the
present invention, the motors may be actuated in selected combinations
and sequences so as to achieve particular bed positions as described
more fully in the accompanying description.
Claims That which is claimed is:
1. In a motor driven adjustable bed having mattress supporting
portions for supporting a mattress for an occupant in a variety
of positions and including a head portion at a head end of the bed,
a foot portion at a foot end of the bed, and a thigh portion between
the head and foot portions,
frame means for supporting the mattress supporting portions, and
position controlling mechanism operatively interconnecting the
mattress supporting portions and the frame means and including a
plurality of motors operatively connected with the frame means for
moving the frame means and thereby for positioning the mattress
supporting portions in desired positions,
an improvement in said position controlling mechanism which facilitates
control over movement of the bed into a variety of positions and
comprising:
command means actuable by an operator of said bed for generating
command signals indicative of selected bed positions, and
means for storing control signals indicative of allowed and disallowed
movements and operatively communicating with said command means
and with said motors and responsive to said command signals and
to said control signals for actuating at least one of said motors
for moving said frame means toward an allowed, selected bed position.
2. In a motor driven adjustable bed having mattress supporting
portions for supporting a mattress for an occupant in a variety
of positions and including a head portion at a head end of the bed,
a foot portion at a foot end of the bed, and a thigh portion between
the head and foot portions,
frame means for supporting the mattress supporting portions, and
position controlling mechanism operatively interconnecting the
mattress supporting portions and the frame means and including a
plurality of motors operatively connected with the frame means for
moving the frame means and thereby for positioning the mattress
supporting portions in desired positions,
an improvement in said position controlling mechanism which facilitates
control over movement of the bed into a variety of positions and
comprising:
command means actuable by an operator of said bed for generating
command signals indicative of selected bed positions,
programmable memory means for receiving and storing control signals
indicative of allowed and disallowed movements, and
processor means operatively communicating with said command means
and with said programmable memory means and with said motors and
responsive to said command signals and to said control signals for
actuating at least one of said motors for moving said frame means
toward an allowed, selected bed position.
3. An adjustable bed according to claim 2 wherein said command
means comprises first signal means actuable by an occupant of the
bed and second signal means actuable by an attendant and further
wherein said processor means distinguishes between command signals
originating from said first and second signal means, said second
signal means and said processor means cooperating for selectively
precluding actuation of any of said motors in response to command
signals generated by said first signal means.
4. An adjustable bed according to one of claim 2 or claim 3 wherein
said position controlling mechanism further comprises position signal
means actuable by elements of said bed for generating position signals
indicative of movement of elements of the bed to predetermined positions,
and further wherein said processor means operatively communicates
with said position signal means and is responsive to said position
signals for actuating at least one of said motors for moving said
frame means toward an allowed, selected bed position.
5. An adjustable bed according to one of claim 2 or claim 3 wherein
said processor means and said programmable memory means cooperate
for distinguishing among command signals generated by said command
means and for actuating motors for moving said frame means toward
at least one allowed, selected bed position in response to momentary
generation of a corresponding command signal.
6. An adjustable bed according to one of claim 2 or claim 3 wherein
said processor means and said programmable memory means cooperate
for distinguishing among command signals generated by said command
means and for actuating motors for moving said frame means toward
at least one allowed, selected bed position only during continuance
of generation of a corresponding command signal.
7. In a motor driven adjustable bed having mattress supporting
portions for supporting a mattress for an occupant in a variety
of positions and including a head portion at a head end of the bed,
a foot portion at a foot end of the bed, and a thigh portion between
the head and foot portions,
frame means for supporting the mattress supporting portions, and
position controlling mechanism operatively interconnecting the
mattress supporting portions and the frame means and including a
plurality of motors operatively connected with the frame means for
moving the frame means and thereby for positioning the mattress
supporting portions in desired positions,
an improvement in said position controlling mechanism which facilitates
control over movement of the bed into a variety of positions and
comprising:
first command signal means actuable by an occupant of the bed for
generating command signals indicative of selected bed positions,
second command signal means actuable by an attendant for generating
command signals indicative of selected bed positions,
position signal means actuable by elements of the bed for generating
position signals indicative of movement of elements of the bed to
predetermined positions,
programmable memory means for storing control signals indicative
of allowed and disallowed movements of the bed, and
processor means operatively communicating with said signal means
and with said memory means and with said motors and responsive to
said signals for actuating at least one of said motors for moving
said frame means toward an allowed, selected bed position, said
processor means distinguishing among command signals generated by
said first and second command signal means for actuating motors
for moving said frame means toward a horizontal, lowered position
in response to momentary generation of a corresponding command signal
by said second command signal means.
8. In a motor driven adjustable bed having
mattress supporting portions for supporting a mattress for an occupant
in a variety of positions and including a head portion at a head
end of the bed, a foot portion at a foot end of the bed, and a thigh
portion between the head and foot portions,
frame means for supporting the mattress supporting portions, and
position controlling mechanism operatively interconnecting the
mattress supporting portions and the frame means and including a
plurality of motors operatively connected with the frame means for
moving the frame means and thereby for positioning the mattress
supporting portions in desired positions,
an improvement in said position controlling mechanism which facilitates
control over movement of the bed into a variety of positions and
comprising:
first command signal means actuable by an occupant of the bed for
generating command signals indicative of selected bed positions,
second command signal means actuable by an attendant for generating
command signals indicative of selected bed positions,
position signal means actuable by elements of the bed for generating
position signals indicative of movement of elements of the bed to
predetermined positions,
programmable memory means for storing control signals indicative
of allowed and disallowed movements of the bed, and
processor means operatively communicating with said signal means
and with said memory means and with said motors and responsive to
said signals for actuating at least one of said motors for moving
said frame means toward an allowed, selected bed position, said
processor means distinguishing among command signals generated by
said first and second command signal means for actuating motors
for moving said frame means toward at least one allowed selected
bed position only during continuance of generation of a corresponding
command signal by said command signal means.
9. An adjustable bed according to one of claim 7 or claim 8 wherein
said first command signal means is normally actuable for generating
signals for lifting and lowering the head end position and for lifting
and lowering the foot end position, and further wherein said second
command signal means is manually actuable for generating signals
for lifting and lowering the head end portion and for lifting and
lowering the foot end portion and for raising and lowering the mattress
portion while in horizontal array and for tilting the mattress portion
from horizontal array toward drain and toward shock positions and
for coordinated movement into and out of a sitting array, and further
wherein said processor means and said second command signal means
cooperate for selectively precluding actuating of any of said motors
in response to command signals generated by said first command signal
means.
10. A method of controlling the operation of a motor driven adjustable
bed which has a plurality of motors operatively connected with a
frame for moving the frame and thereby for positioning a head portion,
a foot portion, and a thigh portion in desired positions, the method
comprising the steps of storing in a programmable memory, control
signals indicative of allowed and disallowed movements for the bed,
generating command signals indicative of selected bed positions,
and responding to the command signals and to the control signals
by actuating at least one of the motors for removing the frame toward
an allowed, selected bed position.
11. A method according to claim 10 wherein the step of responding
to command signals and to control signals comprises communicating
generated command signals to a processor, retrieving with the processor
control signals stored in the programmable memory, and distinguishing
from the command and control signals the selection of an allowed
bed position.
12. A method according to one of claims 10 and 11 wherein the step
of generating command signals comprises generating a first set of
command signals in response to actuation of command signal switches
by an occupant of the bed, and generating a second set of command
signals in response to actuation of switches by an attendant and
further wherein the step of responding to command signals and to
control signals comprises distinguishing between command signals
of the first set and command signals of the second set while directing
by certain command signals of the second set that actuation of any
of the motors in response to command signals of the first set be
selectively precluded.
13. A method according to one of claims 10 and 11 further comprising
generating position signals indicative of movement of elements of
the bed to predetermined positions, and further wherein the step
of responding to command signals and to control signals includes
responding to position signals for actuating at least one of the
motors for moving the frame toward an allowed, selected bed position.
14. A method of operating a bed in accordance with one of claims
10 and 11 wherein the step of responding to command signals and
to control signals comprises distinguishing among command signals
and actuating motors for moving of the frame toward at least one
allowed, selected bed position in response to momentary generation
of a corresponding command signal.
15. A method of operating a bed in accordance with one of claims
10 and 11 wherein the step of responding to command signals and
to control signals comprises distinguishing among command signals
and actuating motors for moving of the frame toward at least one
allowed, selected bed position in response to momentary generation
of a corresponding command signal.
Description FIELD AND BACKGROUND OF INVENTION
This invention relates to control arrangements for an adjustable
bed and, more particularly, to a microprocessor control for motor
means actuating the position controlling mechanism of such a bed
which facilitates movement of the bed into a variety of positions.
Adjustable beds are widely used in hospitals and the like in order
to accommodate positioning of an occupant of a bed in a variety
of positions. Heretofore, adjustable beds have provided either for
manual adjustment of the position of elements of the bed or for
motor controlled positioning of elements of the bed. The present
invention is particularly concerned with motor controlled adjustable
beds, in which the positioning of elements of the bed is controlled
by actuation of motors such as electrical motors.
Previously known motor controlled adjustable beds have been able
to attain a variety of positions for an occupant of the bed, oftentimes
by controlling the simultaneous or sequential actuation of a plurality
of motors. However, the manner in which control over such actuation
of motors and movement of the elements of the bed occurs is somewhat
restricted with respect to the range of positions attainable and
the flexibility of control functions.
BRIEF DESCRIPTION OF INVENTION
With the foregoing discussion in mind, it is an object of the present
invention to efficiently and effectively accommodate movement of
a motor controlled adjustable bed into a variety of positions. In
realizing this object of the present invention, the use of a programmable
memory facilitates storage and retrieval of instructions concerning
the coordination and sequence of actuation of motors controlling
the movement of elements of an adjustable bed. By the use of a programmable
memory, the control is readily adaptable to any desired range of
positions of which an adjustable bed may be capable. Further, the
control is readily adaptable to beds of varying construction and
sophistication.
Yet a further object of the present invention is to control the
operation of an adjustable bed in accordance with a method by which
instructions concerning positioning of elements of the bed and sequences
of motor operation necessary to achieve such positioning are stored
in a programmable memory from which the instructions are retrieved,
by appropriate input signals, by a microprocessor. Such methods
of control are essentially digital, digitally directed, and are
compatible with conventional computer control methods. As a result,
adaptation of an adjustable bed controlled in accordance with the
methods of the present invention to varying circumstances of use
is more readily made possible.
BRIEF DESCRIPTION OF DRAWINGS
Some of the objects of the invention having been stated, other
objects will appear as the description proceeds, when taken in connection
with the accompanying drawings, in which
FIG. 1 is a perspective view of an adjustable bed embodying the
present invention;
FIG. 2 is a view similar to FIG. 1 showing components of the bed
of FIG. 1 with covers removed;
FIG. 3 is a side elevation view, partly in section, through the
bed of FIGS. 1 and 2;
FIG. 4 is an exploded view similar to FIG. 3 illustrating certain
of the components of the bed of FIGS. 1-3;
FIG. 5 is an end elevation view of the bed of FIG. 2;
FIG. 6 is an exploded view similar to FIG. 5;
FIG. 7 is a plan, sectional view of the bed of FIG. 4;
FIGS. 8-10 are schematic perspective views of elements of the bed
of FIGS. 1-7 illustrating a knee break action of the bed;
FIGS. 11-17 are side elevation views illustrating various positions
attainable by the bed of the present invention;
FIG. 18 is a somewhat schematic view of an occupant or patient
control station;
FIG. 19 is a somewhat schematic view of an attendant or nurse control
station; and
FIG. 20 is a schematic, block diagram representation of the control
arrangement of this invention.
DETAILED DESCRIPTION OF INVENTION
While the present invention will be described more fully hereinafter
with references to the accompanying drawings, in which a preferred
embodiment of the present invention is shown, it is to be understood
at the outset of the description which follows that persons of skill
in the appropriate arts may modify the invention here described
while still achieving the favorable results of this invention. Accordingly,
the description which follows is to be understood as being a broad,
teaching disclosure directed to persons of skill in the appropriate
arts, and not as limiting upon the present invention.
Referring now more particularly to the accompanying drawings, an
adjustable bed embodying the control arrangements and methods of
the present invention is there shown and generally indicated at
10. In order to provide a more readily understandable background
for the specific description of the control arrangements and methods
of the present invention which will follow hereinafter, it is first
appropriate to consider the construction and arrangement of the
elements of the adjustable bed 10. However, it is to be recognized
that the control arrangement and method to be described is adaptable
to adjustable beds of other types not here illustrated or described.
Persons of ordinary skill in the arts of designing adjustable beds
may identify previously granted patents including disclosures of
such beds.
The bed 10 which has been illustrated includes mattress supporting
portions, which may be referred to as a mattress platform or as
mattress pans, and which include a head portion 11 at a head end
of the bed, a foot portion 12 at a foot end of the bed, and a thigh
portion 14 between the head and the foot portions. Adjacent the
foot end of the bed 10 is a foot board support 15 and a foot board
16 on which a control console 101 (FIGS. 1 and 19) is mounted. An
occupant control console 100 (FIG. 18) is mounted in a suitable
position adjacent the side of the bed, such as a side rail not shown,
and within easy reach of the occupant of the bed.
A base frame means, generally indicated at 20 is provided for
supporting the mattress supporting portions 11 12 14. The base
frame means 20 includes main longitudinal fore and aft or head-to-foot
frame members 21 22 having at respective head and foot ends thereof
casters 24 for engaging the floor. Cross tubes 25 extend between
the lengthwise members of the base frame means 20 in order to provide
structural integrity.
As will become more clear from the discussion which follows, the
mattress supporting portions 11 12 14 are operatively interconnected
with the base frame means 20 by position controlling mechanism.
Stated broadly, the position controlling mechanism comprises upper
frame means having a head end and a foot end and operatively connected
with the mattress supporting portions for moving the mattress supporting
portions relative to one another, lifting arm means operatively
connecting the upper frame means with the base frame means 20 for
moving the head and foot ends of the upper frame means vertically
relative to the base frame means 20 and motor means operatively
connected with the upper frame means and with the lifting arm means
for moving the upper frame means and the lifting arm means and thereby
for positioning the mattress supporting portions 11 12 14 in a
desired position. Preferably, and as described more fully hereinafter,
the motor means takes the form of electrical motors controlled by
operation of the control arrangement of this invention.
The upper frame means includes a lifting frame structure and a
sliding frame structure which is suspended from, and movable relative
to, the lifting frame as brought out more fully hereinafter. The
upper frame means is operatively connected with the base frame means
20 by a pair of head end lift arms 32 33 and a pair of foot end
lift arms 36 37. Each lift arm is pivotally connected with the
lifting frame at the upper end thereof by a suitable pivot pin.
Pivotally connected to each lift arm 32 33 36 37 intermediate
the length thereof, is corresponding stabilizing arm 38 39 40
41. The lower end of each stabilizing arm is pivotally connected
to the base frame means 20.
The lower end of each lifting arm 32 33 36 37 is pivotally connected
to a corresponding one of a head end subframe 44 and a foot end
subframe 45. The head end subframe and foot end subframe are mounted
on the base frame means 20 for movement therealong. Movement of
the lifting arms 32 33 36 37 is under the control of a lifting
drive motor means 46 which, through a suitable reduction gearing,
drives a lifting ball screw which is divided between a foot end
portion 48a and a head end portion 48b. The ball screw portions
48a, 48b are joined by means of a clutch mechanism generally indicated
at 49 and which is operative as described more fully hereinafter
to control operation of the bed 10. Each of the ball screws is engaged
by a corresponding ball nut 50a, 50b fixed to a corresponding subframe
45 44. Upon rotation of the ball screws 48a, 48b as driven by the
lifting motor means 46 one or both of the subframes 44 45 is moved
so as to move the corresponding lifting arms.
The ball screws 48a, 48b are of opposite hand. As a consequence,
where the clutch 49 is actuated so as to couple the ball screws
together for rotation at the same time and in a common rotational
direction, the ball nuts 50a, 50b are moved toward one another or
away from one another with a coordinated movement. That is, with
rotation of the ball screws 48a, 48b in a first direction, while
the clutch couples the two together, the ball nuts 50a, 50b are
drawn toward one another. As a consequence, the upper frame means
of the bed 10 is lowered while being maintained in a predetermined
orientation, such as being horizontal. With rotation of both ball
screws 48a, 48b in the opposite direction, the ball nuts 50a, 50b
are moved apart.
Selective actuation of the clutch means 49 will permit movement
of the upper frame means into other orientations. For example, assuming
that the mattress supporting portions 11 12 14 are arranged in
co-planar generally horizontal array, movement of the foot end ball
nut 50a may accomplish positioning of the adjustable bed 10 in a
selected one of the positions known as Trendelenburg and reverse
Trendelenburg. In Trendelenburg or shock position, the foot of the
bed is elevated over the head. In reverse Trendelenburg or drain
position, the head of the bed is elevated over the foot. In order
to reach the Trendelenburg position, the bed may be lowered to the
lowermost position and, upon actuating the lifting drive motor 46
the clutch 49 may be operated to disengage the ball screws 48a,
48b. As a consequence, only the foot end ball screw 48a would be
driven in rotation, permitting movement of the foot end lifting
arms 36 37 so as to raise the foot end of the bed. Should it be
desired to attain a reverse Trendelenburg position, the bed may
be moved to its maximum elevated position thereafter, upon actuation
of the lifting drive motor 46 with the clutch 49 disengaged, the
foot end ball screw 48a may be driven in such a manner as to lower
the foot end of the bed and achieve the reverse Trendelenburg position.
As will be clear, actuation of the lifting motor 46 with the clutch
49 engaged will lower and raise the bed while maintaining the particular
angular attitude to which the upper frame means and the mattress
supporting portions have been moved.
The mattress supporting portions 11 12 14 are constructed of
peripheral frames having cross members and are operatively supported
on and by, and connected with, a number of components of the upper
frame means 30. The upper frame means 30 includes a component which
essentially maintains a single head-to-foot orientation and position
with respect to the base frame and is thus referred to as a stationary
upper frame element 51. The stationary upper frame element 51 provides
a connection point for the lift arms 32 33 36 37. Additionally,
the stationary upper frame 51 provides support for an upper sliding
frame 52 a lower sliding frame or intermediate frame 54 and certain
other components as will be described more fully hereinafter.
Mounted on the lower moving frame or intermediate frame 54 is a
foot drop drive motor 55 which drives a foot drop screw 56. By means
of a foot drop yoke assembly 58 engaging the foot drop screw 56
and a foot drop arm 59 coupled to the yoke assembly 58 a swing
frame 60 which forms a portion of the upper moving frame 52 may
be pivoted about a pivot location defined by a pivot pin 61. The
swing frame 60 underlies the foot wing or foot portion 12 of the
mattress supporting portions of the bed 10 and, on being moved by
operation of the foot drop motor 55 positions the foot end portion
12 at a desired position. As will be pointed out more fully hereinafter,
the cooperation of these elements of the bed of the present invention
with other elements yet to be described permits achieving bed positions
approximating those of a chair, in order that a patient may essentially
be seated upright.
Mounted on the stationary upper frame is a head lift drive motor
62 which drives a head lift screw 64. The head lift screw 64 is
engaged by a drive nut mounted in a support member 65 which engages
a number of components of the bed 10 of the present invention. First,
the support member 65 is coupled, through a pivot pin 66 to a joint
between the head end mattress supporting portion 11 and the thigh
portion 14. Further, at its lower end, the support member 65 engages
the moving intermediate frame 54. Finally, the support member 65
is coupled to the moving upper frame 52. As a consequence, when
the head lift motor 62 is operated to rotate the head lift drive
screw 64 in one particular direction, the support member 65 moves
(to the left in FIGS. 4 and 5) in such a direction as to move the
mattress supporting portions 11 12 14 the upper moving frame
52 and the intermediate moving frame 54 all in a common direction.
As such movement occurs, a head wing lift arm 68 which extends between
the head portion 11 and the stationary upper frame 51 causes the
head wing portion 11 to be pivoted upwardly about the pivot point
66 mentioned earlier.
As the movements described immediately above occur and the head
end portion 11 of the mattress supporting portions of the bed is
moved to and from a raised or elevated position, it is possible
to also change the angulation of the thigh portion 14 of the bed
10. Because it is not always comfortable to coordinate or combine
head lift and thigh lift or knee break movements, change in angulation
of the thigh portion 14 is optional. More particularly, a knee break
arm 70 is provided and is mounted from the stationary upper frame
51. The knee break arm may be selectively biased by a spring toward
an elevated position (see solid lines in FIG. 14) or may be withdrawn
(FIG. 15). Particularly, and referring to FIGS. 14 and 15 a knee
break control handle 71 is provided and which may, through a connecting
rod 72 and link 73 move the arm 70 downward against the biasing
force of a spring 75 which normally urges the arm 70 toward a raised
position. The upper end of the knee break arm 70 adjacent the thigh
portion 14 is connected to a coupling bar 76. The coupling bar
76 may be moved into and out of the path of movement of an actuating
hook 78. More particularly, where the knee break arm 70 is moved
toward the raised position by the biasing force of the spring 75
the bar 76 is positioned in the path of the hook 78 as translational
movement of the thigh portion 14 occurs in response to actuation
of the head lift motor 62. With such translational movement (indicated
by an arrow in FIG. 14), the hook 78 engages the rod 76 and the
knee break arm 70 functions as a pivoting link to elevate the foot
end of the thigh portion 14 (FIGS. 5 and 14). Should it be desired
that the knee break not occur, then the actuating handle 71 may
be latched with a catch member 79 (FIG. 15) so as to lower the knee
break arm 70 against the biasing force of the spring 75 and position
the actuating rod 76 below the path of travel of the hook 78. As
a consequence, with translating movement of the thigh portion 14
the hook 78 passes over and does not engage the rod 76. Absent the
action of the pivoting knee break arm 70 the thigh portion 14 is
maintained essentially horizontal by the moving upper frame 52.
As will be appreciated, the translation of the mattress supporting
portions 11 12 14 and the lifting of one or both of the head portion
11 and the thigh portion 14 as described above may be combined with
movement of the swing frame 60 which will control the position of
the foot end portion 12. Thus, a wide range of positions are available
for selection. Indeed, the interconnection of the elements described
hereinabove is such that the swing frame 60 may be pivoted downwardly
to an extreme position in which the foot end portion 12 of the bed
10 approaches the vertical, thereby approximating a chair position.
With the above discussion of a particular adjustable bed in mind,
it can be appreciated that the improvement of the present invention
is in the position controlling mechanism which operatively interconnects
the mattress supporting portions and the frame and which includes
the plurality of motors described above. The improved position controlling
mechanism of the present invention facilitates control over movement
of the bed into a variety of positions and comprises command means
actuable by an operator of the bed for generating command signals
indicative of selected bed positions, and means for storing control
signals indicative of allowed and disallowed movements and operatively
communicating with the command means and with the motors and responsive
to command signals and control signals for actuating at least one
of the motors for moving the frame toward an allowed, selected bed
position. Specific forms of and connection among the command means
and the means for storing and responding to signals will be pointed
out more fully hereinafter.
In particular, the command means preferably includes, as shown,
a first command signal means actuable by an occupant of the bed
and heretofore referred to as the occupant control console 100
also referred to as a patient station. The command means includes
a second command signal means actuable by an attendant and heretofore
referred to as a nurse station control console 101. The patient
station 100 may be supported on one side of the bed or may be contained
within a pendant control so as to be freely accessible to an occupant
of the bed 10. The patient station controls include a head portion
up actuator 104 a head portion down actuator 105 a foot portion
up actuator 106 and a foot portion down actuator 107. The head portion
or backrest up and down actuators 104 105 are manually actuable
by a patient for generating signals for lifting and lowering the
head end portion 11 through actuation of the head lift motor 62.
The foot portion or foot drop up and down actuators 106 107 are
manually actuable by a patient for generating signals for lifting
and lowering the foot end portion 14 by actuating the foot drop
drive motor 55. As pointed out more fully hereinafter, the patient
station 100 is operable only when such operation has been enabled
at the nurse station 101. When the patient station 100 is operable,
the head portion 11 and foot portion 14 positions may be infinitely
adjustable and will be movable to any position within the range
spanned. Adjustment of the head portion 11 may be accomplished in
all positions of the bed except the privileged Trendelenburg and
reverse Trendelenburg positions as pointed out more fully hereinafter.
The position of the foot portion 14 is infinitely adjustable only
when the bed 10 is in the lowered position, as pointed out more
fully hereinafter.
The nurse station signal means 101 has a significantly greater
capability for generating command signals than does the patient
station 100 and, as pointed out more fully hereinafter, may selectively
enable or disable functions of the patient station 100. More particularly,
the nurse station controls include manually actuable actuators for
generating signals for lifting and lowering the head end portion,
indicated at 110 and 111; for enabling and disabling patient control
of head end portion lifting and lowering, as respectively indicated
at 112 and 113; for lifting and lowering the foot end portion as
indicated at 114 and 115; for enabling and disabling patient control
of foot end portion movement, as indicated at 116 and 117; for raising
the bed horizontally, indicated at 118; for lowering the bed horizontally,
indicated at 119; for coordinated movement of the portions of the
bed into a sitting arrangement or array, indicated at 120; for coordinated
movement out of the sitting array and into a horizontal, lowered
position, indicated at 121; for tilting the mattress portions from
horizontal array toward the drain position (indicated at 122) or
toward the shock position (indicated at 124); for returning the
bed from either drain or shock position to horizontal and lowered
(indicated at 123 and 125); and for turning power to the bed on
(indicated at 126) and off (indicated at 127).
Preferably, both the patient station signalling means 100 and the
nurse station signalling means 101 are constructed as matrix arrangements
of flexible conductors supported on flexible films and normally
maintained in spaced relation one relative to another by a compressible
media between the films. Electrical switch assemblies of the type
generally described are known and have been fabricated heretofore
and may, while handling relatively low voltage and current electrical
signals, provide a particularly compact manner for arranging the
manually actuable elements described above. Further, such matrix
format switches are highly compatible with the levels of electrical
voltage and current typically employed in transistor-based logic
circuits of the type to be described hereinafter and employed in
the improved position controlling mechanism of the present invention.
As will be understood by persons of appropriate skill in the applicable
arts of electronic controls, manual actuation of the indicated portions
of the patient station command means 100 and the nurse station command
means 101 will generate command signals indicative of the selected
bed positions or functions briefly described above.
As indicated by block diagram, command signals generated by the
command means are operatively communicated with a processor means
which, together with a programmable memory means as described more
fully hereinafter, defines a means for storing control signals indicative
of allowed and disallowed movements and responding to the command
signals and control signals for actuating the motors for moving
the frame of the bed toward an allowed, selected bed position.
In operating embodiments of beds in accordance with the present
invention, the programmable memory means contemplated by the present
invention takes the form of an erasable, programmable read only
memory device or EPROM. Such devices and their use in conjunction
with a processor means are well known to persons of ordinary skill
in the arts of electronic controls and, accordingly, need not be
here described at great length. The processor means incorporated
in the position controlling mechanism of the present invention,
in one operating embodiment constructed, takes the form of an 8085
microprocessor. Data sheets and information concerning such microprocessors
are readily available to persons of ordinary skill in the arts of
electronic controls and will enable such persons, when taken together
with the functional descriptions contained in the present specification,
to use such a processor means in the manner here described.
By means of appropriate conductors, the processor means, generally
indicated at 140 operatively communicates with the command means
in the form of the patient station 100 and the nurse station 101.
Additionally, the processor 140 similarly communicates with the
programmable memory means or EPROM 141 and with each of the motors
46 55 62. Communication with the motors is preferably established
through conventional semiconductor circuits of a type known as drivers
and typically including bidirectional semiconductor switches or
triacs. Additionally, the processor means 140 communicates with
a clutch control solenoid 144 which governs engagement and disengagement
of the clutch 49 described above and with limit switches which function
as position signal means actuable by elements of the bed for generating
position signals indicative of movements of elements of the bed
to predetermined positions. More specifically, a pair of drain and
shock limit switches 145 146 signal movement of the lifting arms
which achieve maximum permissible Trendelenburg and reverse Trendelenburg
tilts on the order of approximately 13 degrees from the horizontal.
Additionally, each of the motors 46 55 62 includes an internal
position signalling switch actuable in response to rotation of the
motor shaft and thus of the corresponding screw for signalling such
rotation. Persons skilled in the design of electronic controls will
be able to understand, from these brief descriptions, the manner
of using such position signalling means and will be able to contemplate
other types of movement of elements of the bed which it may, in
certain circumstances, be desirable to signal.
Operation of the processor 140 preferably proceeds in accordance
with a program or control signals stored in the programmable memory
means 141 and as timed by an oscillator or clock. The normal program
state of the processor is one of essentially waiting, subject to
an interrupt responsive to the generation of a command signal. The
command signal may be one which directly establishes a preferred
status for the adjustable bed and is referred to as a machine state.
By way of example, should a nurse manually actuate the patient disable
control 113 so as to prevent patient actuation of the head lift,
such a command signal would be received by the processor and transmitted
to the programmable memory for storage as a control signal indicative
of a disallowed movement of the bed. The disallowed movement would
be a patient-controlled head portion lifting or head portion lowering
movement. The machine state control signals may be modified, for
example, by the nurse actuating the patient enable control 112 so
as to permit an occupant of the bed to have control over the head
portion lifting and lowering functions. The drain position and shock
positions, reached by nurse actuation of the respective controls
122 124 are privileged positions in that movement of the adjustable
bed to such positions results in the processor entering into the
programmable memory control signals indicative that the only allowed
movement will be a return from the respective one of the drain or
shock positions, with all other movements being disallowed.
As will be understood, interruption of the waiting state of the
processor means by a command signal will result in the processor,
following an established program, reviewing the machine state to
determine whether or not the indicated selected bed position is
a movement allowed by the machine state. Additionally, with respect
to all functions other than lowering of the bed to down flat, as
requested by nurse actuation of the corresponding control 119 results
in a cyclical review of the continued presence of the command signal.
That is, with a command signal such as a signal for lifting the
head portion of the bed, the processor means reviews the continued
generation of the command signal on a periodic basis such as approximately
once every thirty milliseconds. For so long as the corresponding
command signal is generated, the processor means continues to signal
for actuation of the corresponding motor, until such time as either
the command signal is discontinued (due to the patient or nurse
being satisfied by the position in which the bed has been moved)
or the associated position signal means such as the limit switches
generate a position signal indicative of movement of the portion
of the bed to a predetermined limiting position. Should the moving
portion of the bed, such as the head portion 11 have available
a range of movement toward the allowed, selected bed position, then
the processor means will respond to the position signal from the
corresponding limit switch by actuating the corresponding motor
so as to permit moving the frame of the bed toward the allowed,
selected bed position. Should the corresponding limit switch indicate,
by signal state, that the limiting position has been reached, then
the processor means will interrupt such movement of the bed portion.
In order to facilitate access to a patient or occupant of the bed
in the event of an emergency situation, selected command signals
may be given a preferred status and excluded from the cyclic review
of a continuance of generation of command signal. By way of specific
example, the programmable memory means may receive and store a control
signal indicative that the nurse actuated down flat control 119
be given priority. In such an instance, the processor means will
respond to momentary generation of the corresponding command signal
by beginning movement of the bed toward the horizontal array, lowered
position and continue such movement until that position is attained,
without requiring that generation of the corresponding command signal
be continued during such time as such movement occurs. Thus, should
an attendant to the occupant of the bed require access to the occupant,
it is not necessary that the attendant remain by the footboard and
maintain manual actuation of the corresponding nurse station control
element 119.
As will be appreciated, the cooperation of the programmable memory
means and the processor means additionally provides such sequencing
features as precluding movement of the bed toward the sitting position
(as upon a nurse actuating the sitting position control 120) until
such time as some necessary preliminary movement has been made.
By way of example and referring to the sitting position, an operating
embodiment of the bed in accordance with the present invention cannot
be moved to the sitting position until such time as the bed has
first been moved to the horizontal array, fully lowered position.
When moved through such a sequence, an adjustable bed in accordance
with the present invention may assume a configuration generally
similar to that of a chair.
As will be understood by persons of appropriate skill in the electronic
control arts, the combination and cooperation of the command means
actuable by an operator of the bed and the means for storing control
signals and responding to command and control signals introduces
great flexibility into the position controlling mechanism of a bed
constructed and operated in accordance with the present invention.
A number of illustrations have here been given, in very brief form,
of the types of operations available in an adjustable bed of the
type described. Many more combinations and interactions are available
and will be accomplished by persons skilled in the applicable arts
as the invention described above is applied to varying environments
in which adjustable beds are used.
In the drawings and specification there have been set forth preferred
embodiments of this invention, and although specific terms are employed,
they are used in a generic and descriptive sense only and not for
purposes of limitation, the scope of the invention being defined
in the claims. |