U.S. patent application number 10/085966 was filed with the patent office on 2002-09-19 for hydraulic control apparatus for a hospital bed.
This patent application is currently assigned to Hill-Rom, Inc.. Invention is credited to Eckstein, Gerald D., Hornbach, David W., Moster, Jeffrey A..
Application Number | 20020130286 10/085966 |
Document ID | / |
Family ID | 23206994 |
Filed Date | 2002-09-19 |
United States Patent
Application |
20020130286 |
Kind Code |
A1 |
Eckstein, Gerald D. ; et
al. |
September 19, 2002 |
Hydraulic control apparatus for a hospital bed
Abstract
A hydraulic control apparatus for a hospital bed includes a
manifold having a manifold block with an inlet, an outlet, and a
conduit in fluid communication with the inlet and the outlet, and a
valve assembly having a valve with a portion moveable within the
conduit between a first position blocking fluid communication
between the inlet and the outlet and a second position in which the
inlet is in fluid communication with the outlet. The control
apparatus further includes a solenoid operable to move the valve
from the first position to the second position in response to an
electrical input applied to the solenoid, and a lever operable to
move the valve from the first position to the second position in
response to a manual input applied to the lever.
Inventors: |
Eckstein, Gerald D.;
(Batesville, IN) ; Hornbach, David W.;
(Brookville, IN) ; Moster, Jeffrey A.;
(Cincinnati, OH) |
Correspondence
Address: |
Bose McKinney & Evans LLP
Intellectual Property Group
2700 First Indiana Plaza
135 North Pennsylvania Street
Indianapolis
IN
46204
US
|
Assignee: |
Hill-Rom, Inc.
|
Family ID: |
23206994 |
Appl. No.: |
10/085966 |
Filed: |
February 28, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10085966 |
Feb 28, 2002 |
|
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09311466 |
May 13, 1999 |
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6352240 |
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Current U.S.
Class: |
251/129.03 ;
137/636.1; 251/114; 5/615 |
Current CPC
Class: |
F15B 13/10 20130101;
A61G 7/018 20130101; F15B 2211/78 20130101; F15B 2211/3116
20130101; F15B 2211/327 20130101; Y10T 137/87064 20150401; F15B
2211/7142 20130101; A61G 7/012 20130101; A61G 7/015 20130101; F15B
2211/20576 20130101; F15B 2211/30565 20130101; F15B 11/17
20130101 |
Class at
Publication: |
251/129.03 ;
251/114; 5/615; 137/636.1 |
International
Class: |
A47B 007/02; F16K
031/11 |
Claims
What is claimed is:
1. A manifold and valve assembly comprising a manifold block having
an inlet, an outlet, and a conduit in fluid communication with the
inlet and with the outlet, a valve having a portion movable within
the conduit between a first position blocking fluid communication
between the inlet and the outlet and a second position in which the
inlet is in fluid communication with the outlet, a solenoid
operable to move the valve from the first position to the second
position in response to an electrical input applied to the
solenoid, and a lever operable to move the valve from the first
position to the second position in response to a manual input
applied to the lever.
2. The manifold and valve assembly of claim 1, further comprising a
lock engaging the lever to lock the lever in a position having the
valve in the second position.
3. The manifold and valve assembly of claim 2, wherein the lock
includes a lock solenoid and a lock bar coupled to the lock
solenoid, the lock bar engages the lever, and the lock solenoid is
operable to move the lock bar in response to an electrical input to
the lock solenoid.
4. The manifold and valve assembly of claim 2, wherein the lock
includes a lock bar movable into and out of engagement with the
lever and a lock solenoid coupled to the lock bar, the solenoid is
operable to move the lock bar relative to the lever.
5. The manifold and valve assembly of claim 1, wherein the lever is
pivotally coupled to the manifold block.
6. The manifold and valve assembly of claim 1, wherein the solenoid
is positioned to lie between the manifold block and the lever.
7. The manifold and valve assembly of claim 1, wherein the valve
includes a stem, the lever includes an opening, and a part of the
stem is received in the opening.
8. A controller for a hospital bed having a bed frame and a support
section arranged to receive a portion of a patient's body and being
vertically movable with respect to the frame, comprising: a fluid
actuated cylinder having a housing and a piston, the piston being
attached to one of the support section and the bed frame and the
housing being attached to the other of the support section and the
bed frame, a supply of fluid, a fluid supply path providing fluid
communication between the fluid supply and the fluid actuated
cylinder, a manually operated pump in the fluid supply path, an
electrically operated pump in the fluid supply path, a valve block
including a solenoid operated supply valve with manual override in
the fluid supply path and designed to selectively interrupt the
fluid supply path, an electrical supply actuator connected to the
solenoid of the supply valve and to the electrically operated pump
to electrically control the interruption of fluid communication
between the fluid actuated cylinder and the fluid supply, and a
manual actuator connected to the manual override of the supply
valve to manually control the interruption of fluid communication
between the fluid actuated cylinder and the fluid supply, the
manual actuator having a manual setting in which the fluid supply
path is uninterrupted, and another manual setting in which the
fluid supply path is interrupted.
9. The apparatus of claim 8 and further comprising an electrically
actuated manual setting remover coupled to the electrical actuator
so that the manual setting is removed upon electrical actuation of
the solenoid of the valve.
10. The apparatus of claim 8 and further comprising a fluid return
path providing fluid communication between the fluid supply and the
fluid actuated cylinder, a solenoid operated return valve with
manual override to selectively interrupt fluid communication
between the fluid actuated cylinder and the fluid return path, an
electrical control including the electrical supply actuator and an
electrical return actuator connected to the solenoid of the return
valve to electrically control the interruption of fluid return
path, and wherein the manual supply actuator is also connected to
the manual override of the return valve to manually control the
interruption of fluid return path, the manual actuator having a
manual setting in which the fluid supply path is uninterrupted, and
another manual setting in which the fluid supply path is
interrupted.
11. A valve block comprising: a fluid supply path, a fluid return
path, a valve assembly including a supply member positionable
between a supply interruption position in which the supply member
interrupts the fluid supply path and a supply position in which the
supply member does not interrupt the fluid supply path and a return
member positionable between a return interruption position in which
the return member interrupts the fluid return path and a return
position in which the return member does not interrupt the fluid
return path, a multi-state manual actuator operably connected to
the supply member and the return member, the manually operated
valve actuator being designed and arranged to assume a supply state
in which the supply member is in the supply position and the return
member is in the return interruption position, a return state in
which the return member is in the return position and the supply
member is in the supply interruption position, and a neutral state
wherein the supply member and the return member are free to assume
any position, an electrical actuator operably connected to the
supply member to selectively position the supply member between the
supply interruption position and the supply position and operably
connected to the return member to selectively position the return
member between the return interruption position and the return
position, a controller for generating an override signal, and a
manual actuator override designed and arranged to place the
multi-state manual actuator in the neutral state when an override
signal is generated, wherein the controller generates the override
signal when the electrically operated actuator is actuated.
12. The valve block of claim 11 wherein the valve assembly includes
a supply valve and a spaced apart return valve.
13. The valve block of claim 11 wherein the supply member includes
a supply-opened engagement point and the return member includes a
return-opened engagement point and the multi-state manual actuator
includes an arm wherein the arm engages the supply-opened
engagement point and does not engage the return-opened engagement
point when the multi-state manual actuator is in the supply state,
the arm engages the return-opened engagement point and does not
engage the supply-opened engagement point when the multi-state
manual actuator is in the return state, and the arm does not engage
either the supply-opened or return-opened engagement points when in
the neutral position.
14. The valve block of claim 13 wherein the multi-state manual
actuator includes a spring element to bias the multi-state manual
actuator in the neutral state, a supply state catch to lock the
multi-state manual actuator in the supply state, and a return state
catch to lock the multi-state manual actuator in the return
state.
15. The valve block of claim 13 wherein the override includes a
catch engager and a catch engager actuator to position the catch
engager between a catch-engaged state and a catch-disengaged state,
the catch engager being designed and arranged to engage one of the
supply catch and the return catch when the catch engager actuator
is in the catch-engaged state.
16. The valve block of claim 13 wherein the catch engager actuator
includes an arm the arm being biased to engage one of the supply
catch and the return catch and a solenoid electromagnetically
coupled to the arm to disengage the arm from one of the supply
catch and the return catch when the solenoid is energized.
17. The valve block of claim 16 wherein the interrupt signal causes
the solenoid to be energized.
18. The valve block of claim 17 wherein the valve assembly includes
a supply valve and a spaced apart return valve.
19. The valve block of claim 18 and further comprising a housing
having a mounting surface, a fulcrum having a first side and a
second side mounted to the mounting surface, wherein the arm is
pivotally mounted to the fulcrum and the supply valve is mounted to
the mounting surface on the first side of the fulcrum and the
return valve is mounted to the mounting surface on the second side
of the fulcrum.
20. A control for a hospital bed having a bed frame, a first
support section arranged to receive a first portion of a patient's
body and being vertically movable with respect to the frame, and a
second support section arranged to support a second portion of a
patient's body comprising: a first fluid actuated cylinder having a
housing and a piston, the piston being attached to one of the first
support section and the bed frame and the housing being attached to
the other of the first support section and the bed frame, a second
fluid actuated cylinder having a housing and a piston, the piston
being attached to one of the second support section and the bed
frame and the housing being attached to the other of the second
support section and the bed frame, a supply of fluid, a fluid
return path providing fluid communication between the fluid supply
and the cylinders, a fluid supply path providing fluid
communication between the fluid supply and the cylinders, a
manually operated pump in fluid communication with the fluid supply
path, an electrically operated pump in fluid communication with the
fluid supply path, a valve block including a first valve assembly
in fluid communication with the first fluid actuated cylinder, the
fluid supply path, and the fluid return path and designed to
selectively interrupt fluid communication between the first fluid
actuated cylinder and the fluid supply path and to selectively
interrupt fluid communication between the first fluid actuated
cylinder and the fluid return path, and a second valve assembly in
fluid communication with the second fluid actuated cylinder, the
fluid supply path, and the fluid return path and designed to
selectively interrupt fluid communication between the second fluid
actuated cylinder and the fluid supply path and to selectively
interrupt fluid communication between the second fluid actuated
cylinder and the fluid return path, a valve controller connected to
the first valve assembly and the second valve assembly to control
the interruption of fluid communication between the first fluid
actuated cylinder and the fluid supply path, the first fluid
actuated cylinder and the fluid return path, the second fluid
actuated cylinder and the fluid supply path and the second fluid
actuated cylinder and the fluid return path, wherein the valve
controller is designed to prohibit the first valve assembly from
assuming a state in which fluid communication is simultaneously not
interrupted between the first fluid actuated cylinder and the fluid
return path and the first actuated cylinder and the fluid supply
path and to prohibit the second valve assembly from assuming a
state in which fluid communication is simultaneously not
interrupted between the second fluid actuated cylinder and the
fluid return path and the second actuated cylinder and the fluid
supply path.
Description
BACKGROUND AND SUMMARY OF THE INVENTION
[0001] This invention relates to hydraulic controls for
articulating and raising hospital beds and more particularly to a
hydraulic control apparatus which uses solenoid valves and an
electric pump which can be overridden by manual controls and a
manual pump.
[0002] It is well known for patient support devices such as
hospital beds and stretchers to be provided with hydraulic systems
which allow the caregiver to raise the height of the bed and
articulate a deck underlying the patient support surface to modify
the configuration of the patient support surface. When such beds
were originally conceived, the control valves and pumps associated
with hydraulic cylinders were all manually operated. Manual
operation of pumps and control valves can become fatiguing,
therefore, articulatable and height adjustable beds were provided
with electric motors and electrically controlled valves associated
with the hydraulic cylinders. Combinations of electrically
controlled pumps and valves and manually operated pumps and valves
are also known. One problem with electrically controlled hydraulic
cylinders is that during power outages the cylinder cannot be
operated and the bed cannot be adjusted. Height adjustment and bed
articulation facilitate appropriate treatment of patient injuries,
and therefore, loss of the articulation and height adjustment is
undesirable in a hospital environment.
[0003] Hospital beds with adjustable patient support surfaces moved
by hydraulic cylinders which can be controlled either manually or
electrically have been provided to address the need for bed
adjustment in the event of a power outage. Smith et al., U.S. Pat.
No. 5,063,624, discloses a manual/electric twin jack bed which
provides for manual or electric control of valves and pumps for
providing fluids to hydraulic cylinders which will adjust the
height of the bed and allow the bed to be configured in
Trendelenburg and Reverse Trendelenburg positions.
[0004] Bailey et al., U.S. Pat. No. 4,751,754, discloses a dual
hydraulic hospital bed with emergency bypass circuit which provides
manually actuated valves and electrically actuated valves for
controlling hydraulic cylinders which raise, lower, and articulate
a patient support platform. Both of these dually controlled
hydraulic systems appear to use a different set of valves for
manual operation and electrical operation of the hydraulic systems.
Thus, the hydraulic controls could not easily be retrofitted to a
bed previously having only a manual or only an electrically
controlled hydraulic system.
[0005] Caregivers would appreciate a hydraulic control apparatus
for a hospital bed that includes a hilow function and an
articulating deck which can be operated manually, electrically, or
through a combination of manual and electric operation using a
single set of valves. Caregivers and healthcare facilities would
appreciate a hydraulic control system allowing manual and
electrical operation which could replace the controller on a bed
which was operated with only manual controls or only with
electrical controls.
[0006] According to the present invention a manifold and valve
assembly includes a manifold block having an inlet, an outlet, and
a conduit in fluid communication with the inlet and with the
outlet, a valve having a portion movable within the conduit between
a first position blocking fluid communication between the inlet and
the outlet and a second position in which the inlet is in fluid
communication with the outlet, a solenoid operable to move the
valve from the first position to the second position in response to
an electrical input applied to the solenoid, and a lever operable
to move the valve from the first position to the second position in
response to a manual input applied to the lever. The manifold and
valve assembly may also include a lock engaging the lever to lock
the lever in a position having the valve in the second position.
The lock may include a lock solenoid and a lock bar coupled to the
lock solenoid, wherein the lock bar engages the lever, and the lock
solenoid is operable to move the lock bar in response to an
electrical input to the lock solenoid. Often the lever is pivotally
coupled to the manifold block and the solenoid is positioned to lie
between the manifold block and the lever. The valve may include a
stem a part of which is received in an opening in the lever.
[0007] According to the present invention a controller for a
hospital bed having a bed frame and a support section arranged to
receive a portion of a patient's body which is vertically movable
with respect to the frame includes a fluid actuated cylinder
attached between the support section and the bed frame, a supply of
fluid, a fluid supply path providing fluid communication between
the fluid supply and the fluid actuated cylinder, a manually
operated pump in the fluid supply path, an electrically operated
pump in the fluid supply path, a valve block having a solenoid
operated supply valve with manual override in the fluid supply path
and designed to selectively interrupt the fluid supply path, an
electrical supply actuator connected to the solenoid of the supply
valve and to the electrically operated pump to electrically control
the interruption of fluid communication between the fluid actuated
cylinder and the fluid supply, and a manual actuator connected to
the manual override of the supply valve to manually control the
interruption of fluid communication between the fluid actuated
cylinder and the fluid supply. The controller may also include an
electrically actuated manual setting remover coupled to the
electrical actuator so that the manual setting is removed upon
electrical actuation of the solenoid of the valve. The controller
may include a fluid return path providing fluid communication
between the fluid supply and the fluid actuated cylinder, a
solenoid operated return valve with manual override to selectively
interrupt fluid communication between the fluid actuated cylinder
and the fluid return path, and an electrical control including the
electrical supply actuator and an electrical return actuator
connected to the solenoid of the return valve to electrically
control the interruption of fluid return path arranged so that the
manual supply actuator is also connected to the manual override of
the return valve to manually control the interruption of fluid
return path.
[0008] A valve block in accordance with the present invention
includes a fluid supply path, a fluid return path, a valve assembly
having a supply member and a return member, a multi-state manual
actuator operably connected to the supply member and the return
member, an electrical actuator operably connected to the supply
member and to the return member, a controller for generating an
override signal when the electrically operated actuator is
actuated, and a manual actuator override. The supply member of the
valve assembly is positionable between a supply interruption
position in which the supply member interrupts the fluid supply
path and a supply position in which the supply member does not
interrupt the fluid supply path while the return member is
positionable between a return interruption position in which the
return member interrupts the fluid return path and a return
position in which the return member does not interrupt the fluid
return path. The multi-state manual actuator is designed and
arranged to assume a supply state in which the supply member is in
the supply position and the return member is in the return
interruption position, a return state in which the return member is
in the return position and the supply member is in the supply
interruption position, and a neutral state wherein the supply
member and the return member are free to assume any position. The
electrical actuator selectively positions the supply member between
the supply interruption position and the supply position and also
selectively positions the return member between the return
interruption position and the return position. The manual actuator
override is designed and arranged to place the multi-state manual
actuator in the neutral state when an override signal is
generated.
[0009] The valve assembly may include a supply valve and a spaced
apart return valve. The supply member may include a supply-opened
engagement point and the return member may include a return-opened
engagement point and the multi-state manual actuator may include an
arm which engages the supply-opened engagement point and does not
engage the return-opened engagement point when the multi-state
manual actuator is in the supply state, engages the return-opened
engagement point and does not engage the supply-opened engagement
point when the multi-state manual actuator is in the return state,
and does not engage either the supply-opened or return-opened
engagement points when in the neutral position. The multi-state
manual actuator may include a spring element biasing it in the
neutral state, a supply state catch to lock it in the supply state,
and a return state catch to lock it in the return state. The
override may include a catch engager and a catch engager actuator
to position the catch engager between a catch-engaged state in
which it engages either the supply catch or the return catch and a
catch-disengaged state. The catch engager actuator may include an
arm biased to engage either the supply catch or the return catch
and a solenoid electromagnetically coupled to the arm to disengage
the arm from the supply catch or the return catch when the solenoid
is energized. The interrupt signal may cause the solenoid to be
energized. The valve assembly may include a supply valve and a
spaced apart return valve. The valve block may also include a
housing having a mounting surface, and a fulcrum having a first
side and a second side mounted to the mounting surface, wherein the
arm is pivotally mounted to the fulcrum and the supply valve is
mounted to the mounting surface on the first side of the fulcrum
and the return valve is mounted to the mounting surface on the
second side of the fulcrum.
[0010] A control for a hospital bed having a bed frame, a first
support section arranged to receive a first portion of a patient's
body and being vertically movable with respect to the frame, and a
second support section arranged to support a second portion of a
patient's body in accordance with the present invention includes a
first fluid actuated cylinder attached between the first support
section and the bed frame, a second fluid actuated cylinder
attached between the second support section and the bed frame, a
supply of fluid, a fluid return path, fluid supply path, a manually
operated pump, an electrically operated pump, a valve block
including a first valve assembly and a second valve assembly, and a
valve controller connected to the first valve assembly and the
second valve assembly. The return fluid path provides fluid
communication between the fluid supply and the cylinders while the
fluid supply path provides fluid communication between the fluid
supply and the cylinders. Both the manually operated pump and the
electrically operated pump are in fluid communication with the
fluid supply path. The first valve assembly is in fluid
communication with the first fluid actuated cylinder, the fluid
supply path, and the fluid return path. The first valve assembly is
designed to selectively interrupt fluid communication between the
first fluid actuated cylinder and the fluid supply path and to
selectively interrupt fluid communication between the first fluid
actuated cylinder and the fluid return path. The second valve
assembly is in fluid communication with the second fluid actuated
cylinder, the fluid supply path, and the fluid return path. The
second valve assembly is designed to selectively interrupt fluid
communication between the second fluid actuated cylinder and the
fluid supply path and to selectively interrupt fluid communication
between the second fluid actuated cylinder and the fluid return
path. The valve controller controls the interruption of fluid
communication between the first fluid actuated cylinder and the
fluid supply path, the first fluid actuated cylinder and the fluid
return path, the second fluid actuated cylinder and the fluid
supply path, and the second fluid actuated cylinder and the fluid
return path. The valve controller is designed to prohibit the first
valve assembly from assuming a state in which fluid communication
is simultaneously not interrupted between the first fluid actuated
cylinder and the fluid return path and the first actuated cylinder
and the fluid supply path and to prohibit the second valve assembly
from assuming a state in which fluid communication is
simultaneously not interrupted between the second fluid actuated
cylinder and the fluid return path and the second actuated cylinder
and the fluid supply path.
[0011] Additional objects, features, and advantages of the
invention will become apparent to those skilled in the art upon
consideration of the following detailed description of the
illustrated embodiment exemplifying the best mode of carrying out
the invention as presently perceived.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a perspective view of a hospital bed of the
present invention with most of its cover plates removed showing the
hydraulic control apparatus extending from the base at the foot of
the bed on the right side of the drawing;
[0013] FIG. 2 is a perspective view of the hospital bed of the
present invention showing a patient in an elevated position;
[0014] FIG. 3 is a view similar to FIG. 2 showing the patient
returned to a supine position;
[0015] FIG. 4 is a perspective view of a hospital bed including the
hydraulic control apparatus of the present invention with cosmetic
moldings and enclosures attached to the bed showing a control panel
attached to the foot board, three pedal ends of manual selector
levers of a hydraulic controller extending from a cover at the foot
of the bed, and a pump bar for actuating a manual pump extending
from the same cover;
[0016] FIG. 5 is a schematic circuit diagram for the hydraulic
system of the present invention;
[0017] FIG. 6 is a perspective view of a valve housing of the
hydraulic controller of the present invention showing solenoid
operated valves with manual overrides which are actuated either
electrically or manually, and showing manual selector lever arms
pivotally mounted to the valve housing with two shafts of the
manual overrides extending through slots in each arm;
[0018] FIG. 7 is a side elevation view of the hydraulic controller
of FIG. 6 showing a solenoid controlling a lock bar which can lock
the lever arms in a depressed state and which when retracted by
solenoid operation will allow the lever arms to return to a neutral
position;
[0019] FIG. 8 is a sectional view of the hydraulic controller along
line 8-8 of FIG. 7;
[0020] FIG. 9 is a sectional view of the hydraulic controller taken
along line 9-9 of FIG. 8 showing the manual overrides of the
solenoid operated valves received in slots in the lever arms so
that rotation of the lever arm about pivot bar will actuate the
manual overrides and showing plungers of the valves in their
normally closed position engaging valve seats to interrupt fluid
flow between the distribution manifold and a pressure manifold to
the left and a return manifold to the right;
[0021] FIG. 10 is a sectional view of the hydraulic controller
taken along line 10-10 of FIG. 8 showing a mount for a pivot bar to
which the lever arms are pivotally mounted and two internal
portions of a distribution manifold formed in the valve
housing;
[0022] FIG. 11 is a sectional view taken along line 11-11 of FIG. 8
showing the pressure manifold, release manifold and distribution
manifolds of the valve housing;
[0023] FIG. 12 is a flow chart of the operation of the hydraulic
control apparatus in electrical mode;
[0024] FIG. 13 is a view of one of the manual selector lever arms
with an angled pedal end, its associated extender valve, its
associated retraction valve and the lock bar of the present
invention in a neutral position wherein both the extender valve and
retraction valve are in their normally closed state and the lock
bar abuts a cam formed on an arcuate surface extending from the
arcuate surface;
[0025] FIG. 14 is a view similar to FIG. 13 showing the lever arm
raised to manually open the retraction valve and the lock bar
abutting the second end stop in a configuration called the down
position;
[0026] FIG. 15 is a view similar to FIG. 14 showing the pedal end
of the lever arm partially depressed so that the lock bar has
ridden to the apex of the cam on the arcuate surface; and
[0027] FIG. 16 is a view similar to FIG. 15 with the pedal end of
the lever arm fully depressed so that the lock bar has ridden over
the cam and fallen into an extension notch defined by the cam,
arcuate surface, and first end stop locking the lever arm in an
extension position in which the extender solenoid is urged open by
manual override and retraction valve is in its normally closed
state.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION
[0028] FIG. 1 illustrates a hospital bed, generally designated by
the numeral 10, of the type which is sold by the Hill-Rom Company,
Inc. under the designation of Century CC hospital bed modified to
include the hydraulic control apparatus 20 of the present
invention. Bed 10 illustrated in FIG. 1 is shown with most of the
cosmetic moldings and enclosures which normally surround it
removed. This is done in order to better see the hydraulic system
30 controlled by the present invention.
[0029] Bed 10 includes a base frame 12 which is made up of
longitudinal members 14 and 16 which are tied together by a pair of
transverse members only one of which, 18, is visible in FIG. 1.
Attached to base frame 12 are four large casters designated as 19.
Only two of these casters 19 are visible in FIG. 1, but it may be
appreciated that the two opposing casters are on the opposite side
and serve to support base frame 12 in a mobile fashion.
[0030] A valve housing 134 of the hydraulic controller 20 in
accordance with the present invention is attached to foot end 11 of
base frame 12 of bed 10 as shown, for example, in FIGS. 1-4.
Hereinafter the term foot end 11 will be applied to various
components of bed 10 and of bed 10 itself to designate the end of
the component or bed toward which a patient's feet are normally
directed. The term head end 13 will be used in a similar fashion.
FIGS. 2-4 also show a control panel 158 attached to the footboard
84 of bed 10. While in illustrated embodiment hydraulic controller
20 is attached to foot end 11 of bed 10 for operation of the valve
housing 134 by the foot of a caregiver, it is to be understood that
hydraulic controller 20 may be attached in any convenient location
to bed, and may even remain disconnected from bed 10. Valve housing
134 of hydraulic controller 20 also may be configured for operation
by the hand or a combination of the hand and foot of the caregiver
within the scope of the present invention. Hydraulic controller 20
is only one component of the hydraulic system 30 of bed 10. The
remaining lines, valves, cylinders and other components of
hydraulic system 30 will be described hereafter.
[0031] Returning to FIG. 1, there is shown two generally
triangular, vertically extending bosses 22 and 24 attached to the
foot end 11 of bed 10. Bosses 22 and 24 serve as a pivot mounting
for a cantilevered support arm 26. Cantilevered support arm 26 is
hingedly attached to bosses 22 and 24 through a pivot pin 28.
Cantilevered arm 26 is attached at its end remote from pivot pin 28
to two brackets 29, only one of which is visible in FIG. 1. Bracket
29 and its corresponding bracket on the opposite side, which is not
visible in this view, are attached to two longitudinal frame
members 32 and 34. Frame members 32 and 34 are then tied together
by transverse members 36 and 38 to form a rigid intermediate frame
37 that will move with brackets 29.
[0032] Also attached to bracket 29 is a stabilizing arm 40 which is
pivoted to boss 22. Stabilizing arm 40 moves with cantilevered arm
26 to provide a stabilizing function as cantilevered arm 26 moves.
Cantilevered arm 26 is driven by a hydraulic cylinder 42 which has
an extensible piston or rod 44 that is attached to a clevis mount
46 on cantilever arm 26. Clevis mount 46 has a pin 48 which
connects clevis mount 46 to rod 44. The base of cylinder 42 is
attached to members 14 and 16.
[0033] It may be appreciated that as rod 44 is extended and
retracted its movement will in turn be transferred through clevis
mount 46 and pin 48 to cantilevered arm 26. Extension and
retraction of rod 44 will move cantilevered arm 26 up and down. The
position shown in FIG. 1 is an essentially fully extended, or up,
position for cantilevered arm 26. It may be appreciated that
retraction of rod 44 will then cause cantilevered arm 26 to
retract, bringing with it intermediate frame 37 attached to
brackets 29. Since cylinder 42 controls the raising and lowering of
the support surface of bed 10, commonly called the hilow function,
cylinder 42 will be herein after referred to as hilow cylinder
42.
[0034] As is the case with many hospital beds, bed 10 includes an
articulating deck 39 to achieve various configurations of the
patient support surface. Articulating deck 39 is carried by
longitudinal frame members 32 and 34. Articulating deck 39 is made
up of several elements. There is a fixed seat element 50 which does
not move. Adjacent to the head end 13 of bed 10 there is a head
portion 52 on which a patient's upper body portion would normally
rest and which may be articulated from a fully down position
resting on frame numbers 32 and 34 as shown, for example, in FIGS.
3 and 4 to the fully up position, as shown, for example, in FIGS. 1
and 2. Head portion 52 is raised and lowered through a crank
mechanism 54 that is actuated by a hydraulic head cylinder 56
having an extensible piston or rod 58 which is attached to and
drives crank mechanism 54. Since cylinder 56 controls the
articulation of head portion 52, it will hereinafter be referred to
as head cylinder 56.
[0035] Head cylinder 56 is attached to longitudinal frame member 32
by a bracket 60. In FIG. 1, only one head cylinder 56 is visible to
drive head portion 52. However, it is preferred that two head
cylinders 56, 56' be used, one carried by frame member 32 and the
other on the opposite side carried by frame member 34. Second head
cylinder 56' is not visible in FIG. 1, but it is shown
schematically in FIG. 5. The head elevation function would work
with only one head cylinder 56, but two cylinders 56, 56' provide a
smoother motion and less chance of binding of crank mechanism
54.
[0036] Two additional portions of articulating deck 39 are a thigh
portion 62 and a leg portion 64. Thigh portion 62 and leg portion
64 are pinned together so that they move as a unit. Thigh portion
62 and leg portion 64 are also pinned to fixed seat portion 50 so
that they may be elevated as shown in FIG. 1. Actuation of thigh
portion 62 will cause corresponding raising of leg portion 64.
Thigh portion 62 is raised and lowered by a hydraulic cylinder 66
having an extensible piston or rod 68 that is attached to thigh
portion 62. Since cylinder 66 controls the articulation of leg
portion 64, it will hereinafter be referred to as leg cylinder 66.
Extension and retraction of rod 68 will cause corresponding
movement of thigh portion 62 and leg portion 64.
[0037] None of the hydraulic piping or valves necessary for
operation of this system 30 are shown in FIG. 1 to avoid
unnecessary complication. FIG. 1 does show in phantom lines that a
reservoir 70 for hydraulic fluid is carried between vertical bosses
22 and 24. Also carried between bosses 22 and 24 is a power pack 72
including an electric motor 76 and a pump 78 (see FIG. 5) for
providing electrical pumping power for hydraulic system 30 and a
manual pump 102.
[0038] As shown, for example, in FIGS. 5 and 11, hydraulic
controller 20 includes a valve housing 134 having a pressure
manifold 136, a return manifold 138, a distribution manifold 140, a
pressure inlet 142, a return outlet 144, a hilow port 146, a head
port 148, and a leg port 150. Hydraulic controller 20 also includes
three solenoid controlled extension valves with manual overrides
92, 94, 96 extending through valve housing 134 to interrupt fluid
flow between pressure manifold 136 and distribution manifold 140
and three solenoid controlled retraction valves with manual
overrides 110, 128, and 118 extending through valve housing 134 to
interrupt fluid flow between return manifold 138 and distribution
manifold 140. Thus extension valve 92 and retraction valve 110 are
associated with hilow cylinder 42, extension valve 96 and
retraction valve 128 are associated with head cylinders 56, 56',
and extension valve 94 and retraction valve 118 are associated with
leg cylinder 66.
[0039] Each solenoid operated valve with manual override 92, 94,
96, 110, 118, 128 includes an inlet 178, an outlet 180 in fluid
communication with inlet 178, a valve seat 182 disposed in the
fluid communication path between the inlet 178 and outlet 180, a
solenoid 184, and a magnetic shaft 186 as shown, for example, in
FIG. 9. Magnetic shaft 186 extends through, and is mounted for
movement with respect to, solenoid 184 and is responsive to
energization of solenoid 184. Each magnetic shaft 186 includes a
manual override portion 188 extending externally from solenoid 184
and a plunger end 190 designed to engage valve seat 182 to
interrupt fluid communication between inlet 178 and outlet 180.
Shaft 186 is biased by a spring 192 (See FIG. 5) in the normally
closed position in which plunger end 190 engages valve seat 182 and
interrupts the fluid communication between inlet 178 and outlet
180. Manual override portion 188 of shaft 186 includes an upper end
198 having a diameter 200, and a slender shaft 202 extending
between plunger end 190 and upper end 198 and having a diameter 204
less than diameter 200 of upper end 198, as shown, for example, in
FIG. 9.
[0040] Valve housing 134 of hydraulic controller 20 also includes a
pivot bar 206 attached to and displaced from valve housing 134,
three lever arms 208, 210, 212 pivotally mounted to pivot bar 206,
two override solenoids 214 mounted to opposite ends of valve
housing 134, and a u-shaped lock bar 216. Lock bar 216 includes two
magnetic portions 218 extending through, and moveable with respect
to, solenoid 214 between an extended position and a retracted
position in response to solenoid 214 energization. Lock bar 216 is
biased in the extended position by springs 220. Each lever arm 208,
210, 212 is substantially identical and includes an extension
control section 222 extending between pivot point 224 and extension
end 226, a retraction control section 228 extending between pivot
point 224 and pedal end 230 having a portion substantially parallel
to extension control section 222, a pedal 231 attached to pedal end
230, and a lock bar-engaging section 232 extending substantially
perpendicular to extension and retraction control sections 222,
228. Lock bar-engaging section includes an arcuate lock
bar-engaging surface 234 displaced from and focused about pivot
point 224. Extending radially from arcuate surface 234 are first
end stop 236, second end stop 238, and extension lock cam 240.
Extension lock cam 240 is displaced from center 242 of arcuate
surface 234 toward first end stop 236 by a distance 244
substantially equal to radius 246 of lock bar 216, as shown, for
example, in FIG. 9.
[0041] Lever arm 210, as well as lever arms 208, 212, includes a
longitudinally extending extension shaft-receiving slot 248 formed
in extension control section 222 and a longitudinally extending
retraction shaft-receiving slot 250 formed in retraction control
section 228. Each shaft-receiving slot 248, 250 has a width greater
than diameter 204 of slender shaft 202 but less than diameter 200
of upper end 198. Each lever arm 208, 210, 212 is biased by spring
254 extending between valve housing 134 and extension control
section 222 and spring 256 extending between valve housing 134 and
retraction control section 228 to be urged into a neutral position
in which extension control section 222 and retraction control
section 228 are substantially parallel to top of valve housing
134.
[0042] Each lever arm 208, 210, 212 is associated with a particular
cylinder 42, 66, 56 and controls the extension and retraction
valves associated with that particular cylinder. Lever arm 208 is
associated with hilow cylinder 42 so slender shaft 202 of extension
valve 92 is received in extension shaft-receiving slot 248 and
slender shaft 202 of retraction valve 110 is received in retraction
shaft-receiving slot 250 of lever arm 208. Lever arm 210 is
associated with head cylinders 56, 56' so slender shaft 202 of
extension valve 96 is received in extension shaft-receiving slot
248 and slender shaft 202 of retraction valve 128 is received in
retraction shaft-receiving slot 250 of lever arm 210. Lever arm 212
is associated with leg cylinder 66 so slender shaft 202 of
extension valve 94 is received in extension shaft-receiving slot
248 and slender shaft 202 of retraction valve 118 is received in
retraction shaft-receiving slot 250 of lever arm 212.
[0043] When any lever arm 208, 210, 212 is in neutral position, as
shown, for example, in FIGS. 6-10 and 13, normally closed extension
valves 92, 96, 94 and retraction valves 110, 128, 118 associated
with lever arms 208, 210, 212 return to, or remain in, their
normally closed positions. Upper end 198 of manual override portion
188 of shaft 186 of extension valve 92, 96, 94 is slightly above
top surface 258 of lever arm 208, 210, 212 adjacent to extension
shaft-receiving slot 248. Likewise, upper end 198 of manual
override portion 188 of shaft 186 of retraction valve 110, 128, 118
is slightly above top surface 258 of lever arm 208, 210, 212
adjacent to retraction shaft-receiving slot 250. Thus when a lever
arm 208, 210, 212 is in neutral position each of its associated
valves is closed. Also, lock bar 216 engages center 242 of arcuate
surface 234 and abuts cam 240, as shown, for example, in FIGS. 6,
7, 10, 12. The portion of arcuate surface 234 immediately adjacent
to cam 240 on the side closer to second end stop 238 to both sides
of center 242 is the neutral surface 243.
[0044] When a pedal 231 of a lever arm 208, 210, 212 is depressed,
lever arm 208, 210, 212 pivots about pivot bar 206, lock bar 216
rides over cam 240 compressing springs 220 while passing over cam
240 as shown, for example, in FIG. 15, until lock bar 216 reaches
extension portion 260, i.e. between cam 240 and first end stop 236,
of arcuate surface 234 allowing springs 220 to again expand as
shown, for example, in FIG. 16. Top surface 258 of lever arm 208,
210, 212 adjacent extension shaft-engaging slot 248 pivots upwardly
to engage upper end 198 of manual override portion 188 of shaft 186
of extension solenoid 92, 96, 94 to urge shaft 186 upward causing
plunger 190 to disengage valve seat 182. Retraction control section
228 pivots downwardly allowing retraction valves 110, 128, 118 to
remain in their normally closed states. Springs 220 have greater
spring constants than springs 254, 256 so springs 254, 256 cannot
force lock bar 216 to again ride over cam 240 and return to neutral
position 243, i.e. near center 242 of arcuate surface 234, so lever
arm 208, 210, 212 is locked in its depressed state even if
caregiver removes pressure from the pedal 231. While lock bar 216
rides over cam 240 of a lever arm 208, 210, 212 which is having its
pedal 231 depressed, any previously depressed lever arm 208, 210,
212 which is not also being depressed will return to the neutral
position because springs 254, 256 will urge cam 240 to ride over
the depressed lock bar 216.
[0045] When a pedal 231 of a lever arm 208, 210, 212 is lifted,
extension control section 222 pivots downwardly allowing extension
valve 92, 96, 94 to return to, or remain in, its normally closed
position, retraction control section 228 pivots upwardly causing
top surface 258 of lever arm 208, 210, 212 adjacent to retraction
shaft-receiving slot 250 to engage upper end 198 of manual override
portion 188 of shaft 186 inducing plunger 190 to disengage from
valve seat 182 opening retraction valve 110, 128, 118 as shown, for
example, in FIG. 14. Since there is no cam between neutral portion
243 of arcuate surface 234 and second end stop 238, lock bar 216
remains in its extended position and rides along arcuate surface
234 between neutral portion 243 and retraction portion 262. When
caregiver ceases lifting pedal 231, springs 254, 256 return lever
arm 208, 210, 212 to the neutral position. While the invention is
described as having two springs 254, 256 urging each lever arm 208,
210, 212 to the neutral position, this same biasing function could
be performed by a single spring extending between housing and lever
arm, a torsion bar, or some other position restoring mechanism
within the teachings of this invention.
[0046] As shown, for example, in FIGS. 1, 2, 3, and 4, lever arms
208, 210, 212 and a pump bar 74 for operation of the hydraulic
system 30 of the present invention in a manual mode extend from a
cover 71. Pump bar 74 is an actuator for manual pump 102. By
pumping on pump bar 74 a caregiver will provide hydraulic pressure
to the system 30 generated by manual pump 102. The hydraulic
pressure thus provided may be directed by operation of lever arms
208, 210, 212 connected to the slender shaft 202 of manual override
portion 188 of magnetic shaft 186 of solenoid operated valves 92,
94, and 96 to the appropriate cylinder 42, 56, 66 as previously
stated. Lever arms 208, 210, 212 are used in a manual operation
mode as will be shown with respect to the discussion of the
hydraulic circuit 30 of the present invention.
[0047] Manual overrides of solenoid operated valves 92, 96, and 94
are operated by lever arms 208, 210, 212 which may be actuated by
depressing pedal 231 attached to pedal end 230 of lever arms 208,
210, 212 pivotally mounted to valve housing 134 as previously
described. Likewise manual overrides 188 of solenoid operated
valves 110, 118, 128 are also actuated by lever arms 208, 210, 212.
Override portion 188 of shaft 186 of valve 92 which controls
extension of hilow cylinder 42 is attached on the opposite side of
pivot point 224 of lever arm 208 from override portion 188 of shaft
186 of valve 110 which controls retraction of hilow cylinder 42 as
shown, for example, in FIGS. 6, 7. Override portion 188 of shaft
186 of valve 94 which controls extension of leg cylinder 66 is
attached on the opposite side of pivot point 224 of lever arm 212
from override portion 188 of shaft 186 of valve 118 which controls
retraction of leg cylinder 66 as shown, for example, in FIGS. 6, 7.
Override portion 188 of shaft 186 of valve 96 which controls
extension of head cylinders 56, 56' is attached on the opposite
side of pivot point 224 of lever arm 210 from override portion 188
of shaft 186 of valve 128 which controls retraction of head
cylinder 56, 56' as shown, for example, in FIGS. 6, 10.
[0048] To manually raise a component of bed 10, a caregiver
depresses pedal 231 of lever arm 208, 210, 212 associated with the
desired component until it locks in its depressed position which
opens extension valve 92, 96, 94 associated with the component and
closes retraction valve 110, 128, 118 associated with the
component, respectively. The caregiver then repeatedly depresses
pump bar 74 allowing pump bar 74 to return to its normal location
between depressions to operate manual pump 102. When the desired
component reaches the desired level of extension, caregiver ceases
depressing pump bar 74. Caregiver may then unlock the lever arm
208, 210, 212 by lifting and releasing pedal 231, or may leave
lever arm 208, 210, 212 in its locked state.
[0049] To manually lower a component by releasing pressure provided
to the system 30, the component's associated lever arm 208, 210,
212 is lifted allowing its associated extension valve 92, 96, and
94 to close or remained closed while forcing its associated
retraction valve 110, 128, and 118 open allowing hydraulic pressure
to be released from hydraulic system 30 so that the components of
bed 10 may be lowered. Releasing lever arm 208, 210, 212 prior to
full retraction of the desired component will cause its associated
retraction valve 110, 128, 118 to return to its normally closed
state causing the desired component to be maintained at its degree
of extension at the time of release of lever arm 208, 210, 212.
Lever arms 208, 210, 212 control lowering of the hilow function,
the head portion, and the foot portion, respectively, by holding
open valves 110, 128, 118 respectively only while lever arms 208,
210, 212 are held in the raised position. If lever arms 208, 210,
212 are released, they will spring to a neutral position allowing
normally closed valves 110, 128, and 118 respectively to close.
[0050] Referring to FIG. 2, bed 10 is shown with a patient 80
occupying the sleep surface which has been raised to the position
generally shown in FIG. 1. A headboard 82 and a footboard 84 have
been added to bed 10 as would normally be the case in use. Attached
to footboard 84 is a control panel 158 used to operate the
hydraulic control apparatus in electrical mode. FIG. 3 shows
patient 80 having reached the fully flat position from the position
shown in FIG. 2.
[0051] FIG. 5 shows the hydraulic circuit 30 of the present
invention in a standard hydraulic schematic form. Power pack 72 is
seen to consist of an electric motor 76 driving a pump 78 which
when actuated provides hydraulic fluid through line 89 to line 90.
Alternatively, manual pump 102 when actuated provides pressurized
hydraulic fluid through line 100 to line 90. Line 90 is connected
to pressure inlet 142 of valve housing to be in fluid communication
with pressure manifold 136 which splits to feed the inlets 178 of
the three extension valves 92, 94 and 96. Each of these valves 92,
94, 96 serve as extension valves which when open allow pressurized
hydraulic fluid to flow into hilow cylinder 42, leg cylinder 66,
and head cylinders 56, 56' respectively. Each of these valves 92,
94, 96 are normally closed and only allow fluid flow when their
solenoid 184 is energized or when valve is actuated by manual
override portion 188.
[0052] Solenoid valve 92, when open, will allow pressurized
hydraulic fluid from pressure manifold 136 to flow through the
hilow branch 139 of distribution manifold 140, hilow port 146, and
line 147 to hilow cylinder 42 which raises bed 10. Hilow branch 139
of distribution manifold 140 includes pressure branch 98 and return
branch 112. The pressurized hydraulic fluid in pressure manifold
136 is supplied from line 90 through pressure inlet 142. The
pressurized hydraulic fluid in line 90 may be provided through line
89 extending from electric pump 78 or line 100 extending from
manual pump 102. Thus, hilow cylinder 42 is able to receive
hydraulic fluid pressurized by either electric pump 78 or manual
pump 102 through valve 92.
[0053] Line 89 extending from electric pump 78 and line 100
extending from manual pump 102 merge to form line 90 as shown
schematically, for example, in FIG. 5. Line 89 is formed to include
a check valve 88. Line 100 is also formed to include a check valve
108. When electric pump is operated the pressurized hydraulic fluid
opens check valve 88 and closes check valve 108 to prevent back
flow through manual pump 102. When manual pump 102 is operated
check valve 108 is opened and check valve 88 is forced shut to
prevent back flow through electric pump 78. If one of extension
valves 92, 94, 96 remains open after either pump 78, 102 ceases
operation (as often occurs during manual operation), check valves
108 and 88 are closed by back pressure of hydraulic fluid in line
90.
[0054] Both foot pump 102 and power pack 72 draw hydraulic fluid
from hydraulic reservoir 70. Reservoir 70 serves as a source for
the hydraulic fluid to the entire system 30. Before the hydraulic
fluid enters power pack 72 or foot pump 102, it passes from
reservoir 70 through line 103, filter 104, and line 105. There is a
separate branch line 106 which connects line 105 to foot pump
102.
[0055] Returning now to hydraulic hilow cylinder 42, hilow cylinder
42 is of the single acting type. That is its rod 44 is extended by
supplying pressurized hydraulic fluid through line 147 to hilow
cylinder 42. If solenoid valve 92 is then closed, pressure will be
trapped in line 147 and pressure branch 98 of hilow branch 139 of
distribution manifold 140 and rod 44 will remain extended. To
retract rod 44, solenoid valve 110 is actuated to allow fluid to
flow back along line 147 through hilow port 146 then through
release branch 112 of hilow branch 139 of distribution manifold 140
into solenoid valve 110, from whence the fluid exits through return
manifold 138, return outlet 144, and return line 114 to return to
reservoir 70. With pressure trapped in line 147, pressure branch 98
and release branch 112 of hilow branch 139 of distribution manifold
140, and solenoid valves 92 and 110 both closed, rod 44 will stay
in the position where it was placed. If valve 92 has been manually
actuated by lever arm 208, it will typically remain open until
closed as previously described. In the case of manual actuation of
valve 92, check valves 88, 108 prevent fluid from returning to
reservoir 70 through either electric pump 78 or manual pump
102.
[0056] When solenoid valve 110 is actuated, either manually or
electrically, rod 44 will slowly retract as a result of the weight
on it, and thus bring cantilevered arm 26 downward and retract
entire bed 10 toward the floor. When rod 44 has reached the desired
extended position releasing lever arm 208 or de-energizing solenoid
184 causes valve 110 to close leaving line 147 pressurized. In
order to relieve the pressure, lever arm 208 may be raised, or
solenoid 184 energized, to actuate valve 110 and allow hydraulic
fluid to return to reservoir 70.
[0057] The operation of all of cylinders 42, 56, and 66 are
substantially identical to the operation thus described. Solenoid
valves 92, 94 and 96 are all identical and may be electrically
operated from control panel 158 located on the bed 10, either in
the siderail or at the foot 11 of bed 10, as shown, for example in
FIG. 4. Pump outlet line 90 provides pressurized hydraulic fluid to
pressure manifold 136 which is also connected to inlet 178 of the
normally closed solenoid valve 94. Pressure portion 116 of leg
portion 141 of distribution manifold 140 is in fluid communication
with outlet 180 of normally closed solenoid valve 94. Leg portion
141 is connected through leg port 150 and line 151 to leg cylinder
66 which operates thigh and leg portions 62, 64 of articulating
deck 39. In the electrically operated mode, pressure from pump 78
will flow through line 89, line 90, pressure inlet 142, pressure
manifold 136, and, if solenoid valve 94 is actuated to its open
position, then through pressure branch 116 of leg branch 141 of
distribution manifold 140, leg port 150, and line 151 operate leg
cylinder 66 and extend rod 68. This then will move thigh portion 62
and leg portion 64 to the upright position shown in FIG. 1. When
solenoid valve 94 is closed, pressure will remain in line 151 and
rod 68 will remain in the position where it was placed.
[0058] In order to retract rod 68 and allow thigh portion 62 and
leg portion 64 to return to their flat position, a normally closed
solenoid valve 118 is opened. Inlet 178 of solenoid valve 118 is
connected to a release branch 120 of leg branch 141 of distribution
manifold 140 which is in fluid communication through leg port 150
with line 151 coupled to leg cylinders 66. Outlet 180 of solenoid
valve 118 is then connected to reservoir 70 through release
manifold 188, return outlet 144, and return line 114. Thus,
actuation of the solenoid valve 118 by energizing its solenoid 184
will allow the pressurized hydraulic fluid extending leg cylinder
66 to be released by returning the hydraulic fluid to reservoir 70
through line 151, leg port, 150, leg portion 141 of distribution
manifold 140, return manifold 138, return outlet 144, and return
line 114. This will allow rod 68 to retract.
[0059] During manual mode of operation of leg cylinder 66, lever
arm 212 and manual pump 102 are operated in a manner similar to
that previously described with respect to the hilow cylinder 42.
Lever arm 212 is depressed causing manual overrides 188 to close
valve 118 and open valve 94. Operation of foot powered pump 102 by
pump bar 74 generates pressurized hydraulic fluid which will flow
from reservoir 70 through pump lines 103, 105, and 106 to 102, then
through line 89 and 90, pressure inlet 142, pressure manifold 136,
valve 94, pressure branch 116 of leg branch 141 of distribution
manifold 140, leg port 150, and line 151 to extend rod 68 of leg
cylinder 66. Ceasing operation of foot pump 102 will cause the
pressurized fluid to remain in cylinder 66 and lines 151
maintaining rod 68 in the position which it was in at the time
operation was ceased. Raising pedal 231 of lever arm 212 will cause
manual overrides 188 to close valve 94 and open valve 118.
Pressurized fluid will then return from cylinder 66 through line
151, leg port 150, return branch 120 of leg branch 141 of manifold
140, valve 118, return manifold 138, return outlet 144, and line
114 to reservoir 70 allowing rod 68 to retract. If lever arm 212 is
released at any time during retraction of arm 68, valve 118 will
close and arm 68 will remain extended to the extent that it was
extended at release of lever arm 212.
[0060] FIG. 1 showed only one head cylinder 56 operating head
portion 52, the actual configuration of two cylinders is shown in
FIG. 5. These cylinders are designated as 56 and 56'. Head
cylinders 56 and 56' are both operated simultaneously through
solenoid valves 96 and 128. Inlet 178 of solenoid valve 96 is
connected through pressure manifold 136, pressure inlet 142, line
90, and line 89 to power pack 72. Solenoid valve 96 is a normally
closed valve and its actuation will allow pressurized operating
fluid to simultaneously flow to both head cylinders 56 and 56'
through pressure branch 124 of head branch 143 of manifold 140,
head port 148, line 149 and branch connectors 125 and 126.
Actuation of head cylinders 56 and 56' will cause their respective
rods 58 and 58' to be extended and raise the head portion 52 as
seen in FIG. 1. Pressurized hydraulic fluid is trapped in lines
149, 125 and 126 by closing solenoid valve 96 after the pressurized
fluid has been furnished and rods 58 and 58' have been
extended.
[0061] To release the pressure on head cylinders 56 and 56',
solenoid valve 128 which is normally closed is opened. This then
allows the operating fluid in head cylinders 56 and 56' to flow
through branch lines 125, 126, line 149, leg port 118, and return
branch 130 of head branch 143 of distribution manifold 140 to
solenoid valve 128. When solenoid valve 128 is opened, the
operating fluid will then flow through return manifold 138, return
port 144, and line 114 to reservoir 70.
[0062] Solenoid valves with manual overrides 94, 96, 118, 128, all
serve as a first hydraulic control valve means to control
functioning of head portion 52, thigh portion 62, leg portion 64
and their associated operating hydraulic cylinders. Solenoid valves
with manual overrides 98 and 110 serve as a second hydraulic
control valve means to control the hilow function of bed 10 and
hilow cylinder 42.
[0063] Solenoid valves 118 and 128 are fixed to allow a certain
flow of hydraulic fluid through them when they are actuated. This
flow is calculated to allow a relatively gradual lowering of the
portions which they control. This avoids unnecessary jarring and
uncomfortable feelings on the part of the patient.
[0064] FIG. 4 shows footboard 84 of the type usually used with the
bed 10. Footboard 84 is attached to foot end 11 of bed 10. A bed
control panel 158 is hooked to footboard 84. While illustrated
control panel 158 is shown hooked to footboard 84, it is to be
understood that it may be incorporated into a housing in footboard
84, attached to or incorporated into headboard 82 or a side rail,
or remain unattached to bed 10. Control panel 158 carries a number
of electrical switches which control various functions. The
illustrated control panel 158 includes a head up switch 160, a head
down switch 162, a leg up switch 164, a leg down switch 166, a
hilow up switch 168, and a hilow down switch 170.
[0065] Each switch is normally open and is electrically connected
to not only the valve housing 134 but also to the solenoids 214
controlling the lock bar 216. Upon actuation of any of the switches
160, 162, 164, 166, 168, 170, a circuit is closed to energize
solenoids 214 inducing retraction of lock bar 216. With lock bar
216, retracted lever arms 208, 210, 212 return to the neutral
position allowing the normally closed valves 92, 96, 94, 110, 128,
118 to close or remain closed. This removes any valve settings
which may had been manually entered previously through actuation of
lever arms 208, 210, 212. Head up switch 160 turns on power pack 72
and opens valve 96 by energizing its solenoid 184. This causes head
portion 52 to be raised by the action of cylinders 56 and 56'. Head
down switch 162 is electrically connected to solenoid 184 of head
retraction valve 128 and lock bar solenoids 214. Actuation of head
down switch 162 will open valve 128 by energizing its solenoid 184
allowing hydraulic fluid to return to reservoir 70 and head portion
52 to drop.
[0066] Leg up switch 164 will turn on power pack 72 and open valve
94 by energizing its solenoid 184. This will cause leg cylinder 66
to operate and raise thigh portion 62 and leg portion 64.
Conversely operation of a leg down switch 166 will open valve 118
by energizing its solenoid 184, causing hydraulic fluid to return
to reservoir 70 and thigh portion 62 and leg portion 64 to return
to their horizontal position.
[0067] When hilow up switch 168 is operated, power pack 72 will
operate and valve 92 will be opened by its energized solenoid 184.
This will cause hilow cylinder 42 to operate and raise bed 10. To
lower bed 10, a hilow down switch 170 is activated. This will cause
valve 110 to open in response to its energized solenoid 184 and
allow hydraulic fluid to return to reservoir 70 through valve
110.
[0068] Operation of any of the switches 160, 162, 164, 166, 168, or
170 will initially actuate solenoids 24 which will retract lock bar
216 causing all spring loaded lever arms 208, 210, 212 to return to
their neutral positions allowing all valves 92, 94, 96, 110, 118,
and 128 to return to their normally closed positions unless the
solenoid 184 of that particular valve is currently being
energized.
[0069] While hydraulic control apparatus 20 has been described as
having three lever arms 208, 210, 212 each associated with a two
port two position (2.times.2) extension valve 92, 96, 94 and a
2.times.2 port two position retraction valve 110, 128, 118, it is
within the teaching of the invention to have a single three port
three position (3.times.3) normally closed solenoid actuated valve
with manual override attached to each lever arm for controlling the
extension and retraction of its associated component. It is also
within the teaching of the invention to have less than three or
more than three hydraulic components controlled by the apparatus by
adding or subtracting the appropriate number of extension valves,
retraction valves, lever arms, up buttons and down buttons.
[0070] The hydraulic control apparatus 20 need not be an original
component supplied with a bed but may be used to upgrade beds with
hydraulic systems 30 which do not currently provide both manual and
electrical control of the hydraulic system 30.
[0071] It is also envisioned that in the event of power pack 72
failure, pump bar 74 could be manipulated while one of the up
switches 160, 164, 168 is actuated to supply pressurized hydraulic
fluid with manual pump 102 through an electrically actuated
extension valve 96, 94, 92 to a hydraulic cylinder 56, 66, 42. In
the unlikely event of failure of solenoids 184 of extension valves
96, 94, 92, lever arms 212, 210, 208 could be depressed while up
switches 160, 164, 168 are actuated so that pressurized hydraulic
fluid generated by electric pump 76 can be supplied to a hydraulic
cylinder 56, 66, 42 through a manually actuated valve 96, 94,
92.
[0072] Although the invention has been described in detail with
reference to a certain illustrated embodiment, variations and
modifications exist within the scope and spirit of the invention as
described and defined in the following claims.
* * * * *