U.S. patent number 3,686,696 [Application Number 05/001,222] was granted by the patent office on 1972-08-29 for hospital beds.
This patent grant is currently assigned to American Hospital Supply Corporation. Invention is credited to Richard W. Lanigan.
United States Patent |
3,686,696 |
Lanigan |
August 29, 1972 |
HOSPITAL BEDS
Abstract
A hospital bed has a rectangular base frame and an intermediate
frame assembly mounted for vertical movement with respect to the
base frame by means of side scissors linkages extending
therebetween. The intermediate frame assembly includes a perimetric
retract frame having telescoping portions, one being a fixed
portion and the other being a movable portion. The movable portion
is received by the fixed portion for extension and retraction of
the foot end of the retract frame which extends beyond the foot end
of the base frame in the extended position. An articulated mattress
frame which includes a head panel, seat panel and upper and lower
leg panels is mounted on the retract frame. Adjacent panels are
pivotally interconnected for rotation about transverse axes for
achieving the desired patient positions. A linkage assembly is
provided for lowering and inclining the seat panel as the head
panel is raised. A lift mechanism selectively tilts the retract
frame about either the head end or foot end of the intermediate
frame to achieve the Trendelenberg and reverse Trendelenberg
positions at all elevations of the intermediate frame. A selective
latch mechanism is also provided for raising the lower leg panel
parallel to the retract frame when the upper leg panel is raised or
alternatively to permit the foot end of the lower leg panel to
remain lowered while the upper leg panel is raised and thus achieve
a bent knee position. The raising and lowering of the intermediate
frame, the raising and lowering of the head panel while retracting
the telescoping frame and tilting the seat panel, and the raising
and lowering of the leg panels are all independent of each other to
achieve any desired patient position.
Inventors: |
Lanigan; Richard W. (Arlington
Heights, IL) |
Assignee: |
American Hospital Supply
Corporation (Evanston, IL)
|
Family
ID: |
21694976 |
Appl.
No.: |
05/001,222 |
Filed: |
January 7, 1970 |
Current U.S.
Class: |
5/611; 5/616;
5/618 |
Current CPC
Class: |
A61G
7/002 (20130101) |
Current International
Class: |
A61G
7/002 (20060101); A61g 007/00 () |
Field of
Search: |
;5/63-65,66-69
;108/143,147 ;248/421 ;297/347 ;254/8,9,122 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Gay; Bobby R.
Assistant Examiner: Marquette; Darrell
Claims
I claim:
1. A hospital bed comprising: a generally rectangular base frame
having a head end and a foot end and including floor-engaging
support means; an intermediate frame assembly above said base
frame; a scissors link mechanism interconnecting said base frame
with said intermediate frame assembly, said scissors link mechanism
including first and second pairs of scissors links on opposite
sides of said bed and extending longitudinally thereof, said links
of each pair being adapted to move said intermediate frame assembly
between a raised position and a lowered position wherein said
intermediate frame assembly rests on said base frame, thereby to
prevent a complete closing of said scissors links; elevation
adjustment mechanism for said scissors links comprising a subframe
pivotally connected to said bed for rotation about an axis
transverse of the direction of elongation of said bed, said axis of
rotation being below the connection of said scissors links to said
base frame and said subframe being inclined when said intermediate
frame is in a lowered position, the upper ends of said subframe
engaging corresponding links of said pairs of scissors links when
said subframe is rotated to open said scissors links and thereby
raise said intermediate frame; and power-operated means pivotally
connected to said subframe at a location above its axis of rotation
for selectively rotating said subframe to raise and lower said
intermediate frame assembly to a selected elevation.
2. The structure of claim 1 wherein said power-operated means
comprises an electric motor carried by one of said frames, an
elongated threaded screw rotatably mounted to corresponding ones of
said pairs of scissors links, means interconnecting said screw with
said electric motor, a yoke threadedly received on said screw for
moving therealong when said screw is turned by said motor, and link
means interconnecting said yoke with said subframe at said location
above its axis of rotation, whereby as said screw is turned by said
motor, said yoke is moved therealong in determining the angle of
inclination of said subframe and the upper edge of said subframe
rollably engages the lower surfaces of corresponding ones of said
pairs of scissors links to selectively raise and lower the same in
determining the elevation of said intermediate frame.
3. The structure of claim 2 wherein said subframe is pivotally
connected at its lower end to corresponding ones of said pairs of
scissors links and wherein said means interconnecting said yoke
with said subframe includes a link pivotally connected to said
subframe and adapted to fold with said subframe as said bed is
lowered, said subframe being located between said side pairs of
scissors links, whereby said bed may be lowered while maintaining
leverage for raising the same.
4. The structure of claim 1 further comprising a mattress support
frame mounted on said intermediate frame assembly and comprising a
plurality of articulated panels including a seat panel pivotally
mounted at its foot end to said intermediate frame and a head panel
pivotally mounted adjacent its foot end to said intermediate frame
and including a foot-end extension beyond said pivotal connection
to said intermediate frame, the head end of said seat panel being
pivotally connected to said extension; and power-actuated means for
raising said head panel about its pivotal connection with said
intermediate frame thereby to lower the head end of said seat panel
relative to its pivotal connection with said intermediate
frame.
5. The structure of claim 4 wherein said mattress support panel
further comprises an upper leg panel pivotally connected to said
intermediate frame at the location at which said foot end of said
seat panel is connected thereto; and a lower leg panel having its
head end pivotally connected to the foot end of said upper leg
panel.
6. The structure of claim 5 further comprising drive means
including lever means for raising the foot end of said upper leg
panel, support means mounted on said mattress frame and supporting
said lower leg panel; and selective latch mechanism movable between
the first position and the second position, said latch mechanism,
when in said first position selectively engaging said support means
for said lower leg panel to maintain said lower leg panel in a
generally horizontal disposition when said upper leg panel is
raised and when in said second position, permitting the foot end of
said lower leg panel to remain lowered as the head end of said
lower leg panel is raised, thereby to cause a bend in the knees of
a patient resting on said bed.
7. In a hospital bed, the combination comprising rectangular base
frame supported on a floor, an intermediate frame mounted to said
base frame for adjustable elevation relative thereto, articulated
mattress frame means supported on said intermediate frame including
an upper leg panel adapted for rotation about a first horizontal
axis transverse of said bed, said horizontal axis being at the head
end of said upper leg panel, and a lower leg panel having its head
end pivotally connected to the foot end of said upper leg panel;
drive means for rotating the upper leg panel about said first
transverse axis to raise the same; support means pivotally mounted
to said mattress frame for supporting said lower leg panel; a shaft
defining a second transverse axis and driven by said drive means
when said upper leg panel is raised and lowered, said second
transverse axis being located adjacent the pivotal connection of
said support means to said mattress frame and including a cam
movable therewith; a key member on said support means including a
bearing surface, said key member being movable between a first
position wherein its bearing surface engages said cam, whereby said
support means is rotated when said shaft is driven to raise said
lower leg panel in a horizontal disposition, said key means being
selectively movable to a second position of disengagement from said
cam, whereby said support means is not rotated when said shaft is
driven and the foot end of said lower leg panel remains in a
lowered position.
8. The structure of claim 7 further comprising a crank mounted to
said bed and movable between a first and a second position, said
crank including a dog adapted to engage said key member of said
support means for said lower leg panel to move the same selectively
between said first and second positions.
9. In a hospital bed, the combination of a base frame including
floor-engaging support means, an intermediate frame above said base
frame, power-driven link means interconnecting said base frame with
said intermediate frame for selectively elevating said intermediate
frame above said base frame; a telescoping mattress support frame
having a fixed member carried by said intermediate frame and
located to the side thereof and a movable member telescopically
received on said fixed member; crank mechanism for lifting said
fixed member of said telescoping mattress support frame above said
intermediate frame along a transverse line intermediate the head
and foot ends of said bed; and latching means for selectively
locking one end of the fixed member of said telescoping frame to a
corresponding end of said intermediate frame, whereby as said crank
mechanism is extended, said telescoping frame will tilt about the
locked end thereof relative to said intermediate frame.
10. In a hospital bed having an articulated mattress frame and
support means therefor, said mattress frame including a head panel,
a seat panel, and upper and lower leg panels, the improvement
comprising: means for pivotally mounting said head panel adjacent
its foot end to said support means for pivotal movement between a
generally horizontal lowered position and an upwardly inclined
raised position, said head panel defining a footward extension
beyond said pivotal connection to said support means to provide a
pivotal connection for the head of said seat panel, said support
means being an integral portion of the frame of said bed; means for
pivotally mounting the foot end of said seat panel to said support
means while preventing relative vertical motion between the foot
end of said seat panel and said support means, whereby as said head
panel is raised, the footward extension thereof will lower the head
end of said seat panel to cause the same to be inclined relative to
the horizontal and thereby provide a seat depression in the zone of
connection between said head and said panels; said upper leg panel
being pivotally connected at its head end to said support means for
rotation about a horizontal transverse axis; and a lower leg panel
having a head end pivotally connected to the foot end of said upper
leg panel, said system further including drive means for rotating
said upper leg panel about its transverse horizontal axis of
connection with said support means; a lever mechanism mounted on
said support means and operatively associated with the foot end of
said lower leg panel and including selective latch means movable
between a first position of disengagement with said lever thereby
permitting the foot end of said lower leg panel to remain in a
lowered position as the head end thereof is raised, said selective
latch means being movable to a second position of engagement with
said lever mechanism for maintaining the foot end of said lower leg
panel at substantially the same elevation as the head end thereof.
Description
BACKGROUND AND SUMMARY
The present invention relates to power-assisted beds of the type
used in hospitals and nursing homes; and more particularly, it
relates to an electrically driven hospital bed capable of
independently achieving a wide range of patient positions for all
elevations of the mattress frame.
Power-driven hospital beds are well known which are capable of
elevating a mattress frame to raise and lower a patient and which
have articulated or sectioned mattress frames for raising and
lowering the head panel and the leg panels relative to a fixed seat
panel. Further, there are commercially available hospital beds
which are capable of raising the head panel while foreshortening
the length of the bed to move a patient to a sitting position while
simultaneously translating the leg panels towards the head of the
bed so that the head and shoulders of the patient remain stationary
relative to a night stand, for example, while achieving a sitting
position.
In typical commercial constructions, however, the elevation of the
patient is achieved by raising bed posts supporting the mattress
frame on supporting legs provided with casters by drawing the posts
with a cable and pulley arrangement. It will be realized that while
elevating the patient, the mattress support frame should remain
parallel with his initial position -- that is, it must not tilt
during elevation.
Link mechanisms have also been suggested for elevating the mattress
frame; however, those which elevate the mattress frame by means of
a tee linkage also translate the mattress frame relative to the
base frame during elevation. Cross bar links have been used for
elevating the mattress frame wherein the cross bars are located at
the head and foot ends of the bed; but such arrangement is not
practicable when it is desired to achieve a retractable or
foreshortenable mattress frame.
The present invention provides a hospital bed which has a
rectangular base frame, supported at its corners by casters and
shorter in length than the overall length of the mattress
supporting a patient. An intermediate frame assembly is disposed
above the base frame and consists essentially of an intermediate
frame which is connected to the base frame by lateral scissors
linkages, and a retract frame which extends about the intermediate
frame. The power-operated scissors linkage arrangement has been
found to provide a relatively high degree of stability at all
elevations of the intermediate frame assembly and to result in
improved control over the elevating mechanism.
A fixed portion of the retract frame rests on studs projecting from
the sides of the intermediate frame and a movable portion of the
retract frame is telescopically received on the foot end of the
fixed portion and extends beyond the foot end of the base frame. As
the telescoping retract frame is foreshortened, a link mechanism
interconnecting the head panel of a mattress supporting frame with
the fixed portion of the retract frame raises the head panel. This
mechanism, in turn, lowers the head of the seat panel so that it
tilts downwardly and forwardly -- thus providing a seat depression
or recess which more comfortably accommodates the patient in a
sitting position and which also serves to restrain sliding movement
of the mattress relative to the mattress supporting frame.
The perimetric arrangement of the retract frame about the
intermediate frame results in a relatively low silhouette when the
bed is completely lowered, thereby permitting a patient to easily
touch the floor with his feet for support when getting out of
bed.
The articulated mattress frame includes a head panel, a seat panel
and upper and lower leg panels. Adjacent panels are pivotally
interconnected for rotation about a transverse axis to achieve any
desired patient position.
A selective catch mechanism is also provided for raising the lower
leg panel parallel to the retract frame when the upper leg panel is
raised, or alternatively, to permit the foot end of the lower leg
panel to remain lowered while the upper leg panel is raised, and
thus achieve a bent knee position.
A lift mechanism selectively tilts the telescoping retract frame
about either the head end or the foot end of the intermediate frame
to achieve either the Trendelenberg or the reverse Trendelenberg
position; and these positions may be achieved at all elevation
settings of the bed.
Other features and advantages of the present invention will be
apparent to persons skilled in the art from the following detailed
description of an illustrative embodiment accompanied by the
attached drawing wherein identical reference numerals will refer to
like parts in the various views.
THE DRAWING
FIG. 1 is a perspective view from the head side of a hospital bed
according to the present invention;
FIG. 2 is a perspective view of the bed of FIG. 1 showing it in its
retracted position with the head panel raised and the seat panel
tilted;
FIG. 3 is a fragmentary elevation view of the foot board of the bed
of FIG. 1 showing the control panel;
FIG. 4 is a side elevation view of the bed of FIG. 1 without the
side guard rail and cover panel;
FIG. 5 is a side elevation view of the bed of FIG. 1 illustrating
the raised and lowered positions of the intermediate frame relative
to the base frame;
FIG. 6 is a plan view of the bed of FIG. 1;
FIG. 7 is a vertical cross section view, on a reduced scale, taken
through the sight line 7--7 of FIG. 6 showing the Trendelberg lift
mechanism;
FIG. 8 is a plan view of the intermediate frame and scissors
linkages for elevating the intermediate frame;
FIG. 9 is a head end view of the bed of FIG. 1;
FIG. 10 is a close-up side elevation view of the latching mechanism
for raising the lower leg panel parallel to the intermediate
frame;
FIG. 11 is a fragmentary plan view of the latching mechanism shown
in FIG. 10; and
FIGS. 12-14 are perspective views showing the latching mechanism of
FIGS. 10-11 in different operating conditions.
DETAILED DESCRIPTION
Referring to FIG. 1, there is seen a generally rectangular base
frame designated in general by reference number 10. An intermediate
frame assembly, which in the illustrated embodiment comprises an
intermediate frame 12 and a telescoping or retract frame 13, is
operatively connected to the base frame by scissors linkages
designated generally by numeral 11. The retract frame, which
includes a fixed portion 14 and a movable portion 15, rests on the
intermediate frame 12. The fixed portion 14 of the telescoping
frame 13 seats on studs extending from the sides of the
intermediate frame 12, as will be explained in greater detail
hereafter, and the upper surfaces of these two frames lie in the
same plane. In other words, the sides of the retract frame 13 are
located respectively alongside the sides of the intermediate frame
12.
Supported on the retract frame 13 is an articulated mattress
support frame generally designated by reference numeral 16. The
mattress frame 16 can be seen to include a head panel 17, a seat
panel 18, an upper leg panel 19, and a lower leg panel 20. Although
the panels 17-20 in the illustrated embodiment are made of sheet
metal for supporting an inner spring mattress, it will be
appreciated that each of these panels could itself be a spring
frame.
The bed is provided with a headboard 22 which is removable and a
foot board 23 on which is mounted a control panel (FIG. 3) as well
as control circuitry housed within a cabinet 24. First and second
side rails 25 and 26, and first and second side panels (only panel
27 being seen in FIGS. 1 and 3) are also incorporated into the
bed.
Turning now to FIGS. 5, 8 and 9, the scissors mechanism for
elevating the intermediate frame 12 will be explained. As can be
seen there, the base frame 10 and the intermediate (or high/low)
frame 12 have the same dimensions in length and width; and the
intermediate frame 12 is located directly above the base frame 10.
The base frame 10 is supported at its corners by means of
conventional casters 28 and includes a pair of U-shaped side
channel members 29 and 30, each having upper and lower inwardly
turned flanges. The scissors mechanism 11 includes inner and outer
link units 31 and 32 (FIG. 1). The outer link unit 32 of the
scissors mechanism is composed of rigid first and second elongated
and parallel tubular members 33 and 34 which extend substantially
the entire length of the base frame 10 and intermediate frame 12
and which are rigidly secured together at the foot end of the base
frame by means of a transverse end bar or member 35. The transverse
end member 35 of the outer link unit of the scissors mechanism is
secured at the foot end of the base frame 10 by means of center
locating pins 37.
The intermediate frame 12 is similar to the base frame 10 in that
it includes U-shaped side channel members 38 and 39 with the open
portions of the U turned inwardly so that they are facing each
other. A transverse bar or member 36, similar to the previously
described transverse member 35 is welded to the head ends of the
elongated members 33 and 34 of the outer scissors link 32 to form a
rigid assembly. Transverse bar 36 is movably received within the
channel members 38 and 39 of the intermediate frame 12 by means of
rollers 41 and 42 secured to it.
As can be seen in broken lines in FIG. 5, as the intermediate frame
12 is elevated, the transverse bar 36 will be translated toward the
foot end of the bed to position 36' as the rollers 41 and 42 move
within the side channel members 39 and 38 respectively of the
intermediate frame 12.
The inner link unit 31 of the scissors mechanism 11 is a rigid,
unitary structure similar to the outer link unit 32. The inner link
unit 31 comprises first and second elongated tubular members 43 and
44, similar to the elongated members 33 and 34 of the outer
scissors link unit. The elongated members 43 and 44 are welded to a
first transverse bar or member 45 which is rotatably mounted to the
foot end of the intermediate frame 12 by means of center guide pins
46. The ends of the tubular members 43 and 44 located at the head
of the base frame 10 are welded to a transverse bar 47 which is
mounted on rollers and received within the U-shaped channel members
29 and 30 of the base frame 10 in a similar fashion to the mounting
of the head end of the outer scissors link unit. Thus, when the
intermediate frame 12 is elevated, the transverse bar 47 moves to
position 47' in FIG. 5.
The link members 33 and 43 are secured together at their midpoints
by means of a roll pin 48 which permits relative rotation in
parallel vertical planes. Similarly, a roll pin 49 secures the link
members 34 and 44 together while permitting relative scissors-like
rotation between the two. Each of the roll pins 48 and 49 is
suitably journaled within their associated tubular members 43 and
44 by means of bushings 48a and 49a respectively.
As seen best in FIGS. 5 and 8, an electric drive motor 50 is
mounted on a plate 51 which is secured to the sides of the
intermediate frame 12. Also mounted on the mounting plate 51 and
driven by the shaft of motor 50 is a gear box 52 housing a
conventional miter gear mechanism for coupling the output of motor
50 to a shaft 53 which extends perpendicular to the shaft of the
motor 50. A connecting rod 53a couples the shaft 53 to a worm 54.
The worm 54 is journaled at its ends in two vertical mounting
plates identified by reference numerals 55 and 56 respectively in
FIG. 5. The vertical mounting plates 55 and 56 which support the
worm 54 depend from transverse bars 57 and 58 (best seen in FIG.
8), which are secured to the top of the intermediate frame 12.
A yoke 59 defining a central, threaded aperture is received on the
worm 54 so that as the worm 54 is driven by the motor 50 as
previously described, the yoke 59 traverses the worm 54
longitudinally of the bed. The yoke 59 includes two ears 59a and
59b which are located to either side of the worm 54 and which
extend downwardly. An axle pin 60 is journaled in the two ears of
the yoke 59 beneath the worm 54; and a connecting rod 61 extends
toward the foot of the bed; and it is received in a bracket 62. A
locating pin 63 secures the foot end of the rod 61 to the bracket
62 (see FIG. 9). The bracket 62 is mounted on a transverse bar 64
having a width slightly less than the separation between the two
inner tubular members 43 and 44 of the inner scissors link. The bar
64 is journaled within two side links 65 and 66 which extend toward
the foot end of the bed and slightly upwardly as seen in FIG.
5.
Rotatably secured to the foot end of the links 65 and 66 are second
links 67 and 68 (journaled thereto by means of pins 69 and 70
respectively). The links 67 and 68 extend downwardly and slightly
toward the foot of the bed (see bar 68 in FIG. 5); and they are
welded respectively to tubular members 71 and 72 which extend
slightly downwardly and toward the head of the bed in generally
parallel relation to the previously described links 65 and 66.
Welded to the bottom of each of the rods 71 and 72 is a transverse
bar 73 which is rotatably supported at its ends by means of links
74 and 75 which are mounted respectively to the lower surfaces of
the tubular members 33 and 34.
At the upper ends of the tubular members 71 and 72 there are
mounted yokes 76 and 77 which receive roller members 78 and 79
respectively. The rollers 78 and 79 bear against the lower surfaces
of the tubular members 44 and 43 respectively of the inner scissors
link to provide an upward lift force when the rods 71 and 72 are
rotated counterclockwise in FIG. 5. A second transverse brace 80 is
welded between the tubular members 71 and 72 to add rigidity to the
lifting structure.
In operation, as the worm 54 is driven in the proper rotational
direction to force the yoke 59 to the left in FIG. 5, forces are
exerted in rod 61 connected to the axle 60 to pull it toward the
head of the bed which, in turn, pulls the bracket 62. This action
pulls the links 65 and 66 toward the head of the bed thus exerting
a counterclockwise coupling moment on the links 67 and 68. Since
their lower ends are welded to the tubular members 71 and 72, this,
in turn, forces the tubular members 71 and 72 in counterclockwise
rotation (as viewed in FIG. 5) about the transverse bar 73 secured
beneath the outer scissors link. Thus, the tubular members 71 and
72 will be rotated counterclockwise to the positions shown at 72'
in chain line in FIG. 5, and thereby raise their associated rollers
78 and 79 to the position shown at 79'. Since the rollers 78 and 79
bear against the lower surfaces of the inner scissors link, it will
be raised and as already mentioned, the lower transverse tube 47
thereof will be moved toward the foot of the bed to the position
47'. At the same time, the foot end of the rod 61 will become
downwardly inclined due to clockwise rotation about the axle 60, as
seen at 61' and 60' respectively in FIG. 5.
The bed is raised, as mentioned, by rotating a rigid structure
including tubular member 71, 72 and 80, as well as the rigid links
connected thereto (namely, the links 67 and 68 which are best seen
in FIG. 9) about the transverse shaft 73. This shaft is pivotally
connected to the side tubular scissors frame members 33 and 34 by
means of the dogs 74 and 75. This structure just described is
referred to in the claims as the "subframe."
When the drive motor 50 is stopped, the bed will remain in whatever
state of elevation the drive mechanism had placed it; and this has
been found to be a very accurate and reliable mechanism for
achieving control over the elevation of the intermediate frame. In
addition, the provision of the scissors mechanism has been found to
add a great deal of stability (both lateral and longitudinal) to
the intermediate frame 12 for all positions of elevation. This is
considered to be an important feature of the present invention
particularly since the telescoping frame extends well beyond the
foot of the intermediate frame 12 when the mattress frame is in a
horizontal position as can be seen in FIG. 4.
TELESCOPING RETRACT FRAME
Mounted to the sides of the intermediate frame 12 at the head and
foot portions are four outwardly extending studs designated by
reference numeral 81. The studs 81 receive mounting brackets 82
(see FIG. 9) which are welded to the inner surfaces of the fixed
portion 14 of the retract frame 13. Each of the brackets 82 defines
a downwardly facing aperture to receive its associated stud so that
the retract frame may be lifted vertically off the intermediate
frame, but is secured against sliding relative to it in a
horizontal plane.
The fixed portion 14 of the retract frame 13 includes side members
83 and 84 which are tubular and have a generally square transverse
cross section. U-shaped channel members 85 and 86 comprise the side
sections of the moveable portion 15 of the telescoping frame; and
they are received respectively on the box-shaped tubular members 83
and 84 for sliding motion longitudinally thereof. Referring now to
FIGS. 4 and 6, the head ends of the box-shaped frame members 83 and
84 are joined together by a similarly shaped tube 87 to form a
rigid structure. Riveted to the side of the box-shaped members 83
and 84 are caped studs 88 and 89 respectively for removably
receiving the side flanges mounted on the head board 22 -- one such
flange being identified by reference numeral 90 in FIGS. 1, 2 &
4.
Referring now to FIGS. 4 and 6, guide plates 91 and 92 are welded
to the inner surfaces of the box frame members 83 and 84
respectively. Each of the guide plates defines a slot similar to
that shown for plate 92 and identified by reference numeral 93. The
slot 93 extends generally horizontally and then upwardly at the
foot end of the slot for receiving a pin 94 connected to a link 95
which is secured at its foot end to a transverse bar 96 extending
beneath and supporting the head panel 17. At the other end of the
bar 96 is a similar link 97, the lower end of which is provided
with a pin 98 received in a slot in the bracket 91 similar to the
previously described slot 93. The links 95 and 97 together with the
transverse bar 96 form a supporting and raising structure for the
head panel 17. The head panel is limited from lowering below a
predetermined height above the intermediate frame 12 by means of
rigid side links 99 and 100 interconnected at the sides of a
transverse bar 101 which engages the head panel 17 when it is
lowered to a horizontal position. The bar 101 is rotatable toward
the foot of the bed to a lowered position for lowering the head end
of the head panel.
As will be apparent presently, when the retract frame telescopes to
its shortened condition, the head panel 17 is translated slightly
to the head of the bed until pins 94 and 98, riding in their
respective slots, engage the ends thereof, at which time the side
links 95 and 97 pivot the head panel upwardly. At its foot end, the
head panel 17 is provided with a pair of bracket extensions 102 and
103 which constitute rigid portions of the head panel. The
extensions 102 and 103 are pivotally mounted by pins 106 and 107 to
upwardly extending ears 104 which are fixed to a transverse support
bar 105, the transverse line of pivotal movement being spaced
forwardly (i.e., towards the head end of the bed) a substantial
distance from the foot end of the head panel as defined by the rear
ends of extensions 102 and 103. The support bar 105 is welded to
the top of the movable portion 15 of the retract frame.
As best seen in FIG. 4 each head panel extensions 102 and 103 has a
generally horizontal slot 108 which receives a roll pin 109 which
is also received in a similar slot 110 at the forward flanges 111
of the seat panel 18 thereby pivotally connecting the rear of the
head panel to the front of the seat panel. As the movable portion
15 of the telescoping frame is translated towards the head board
(by structure described herein), and when the pins 94 and 98 reach
the ends of their respective slots, the links 95 and 97 are rotated
counterclockwise and the head panel 17 is rotated clockwise (as
viewed in FIG. 4) about the pins 106 and 107. Since the pivotal
connection between the head panel extensions and the seat panel is
behind (i.e., towards the bed's foot end) the pivotal connection of
the head panel to the retract frame, upward pivotal movement of the
head end of the head panel causes downward pivotal movement of the
head end of the seat panel. The foot end of the seat panel 18 is
pivotally mounted on a transverse bar 112 which is supported by
upstanding flanges secured to the top of the channel members 85 and
86 of the movable portion of the telescoping frame (see flange 113
in FIG. 4). Thus, as the head panel is raised, the seat panel 18
rotates counterclockwise about the rod 112 to form a seat
depression or recess, as seen in FIG. 2, which prevents gravitation
of the mattress and patient toward the foot board of the bed and
which provides a more comfortable sitting position for the patient.
Because of the drop or lowering of the head end of the seat panel
when the head panel is raised, a seated patient is supported in
much the same manner as in a backwardly inclined lounge chair.
UPPER AND LOWER LEG PANEL MOVEMENT
Rigidly secured to ends of the transverse shaft 112 are first and
second braces 115 and 116 which extend toward the foot of the bed
and which support the upper leg panel 19. A pair of links 117 and
118 are also rigidly secured to the transverse shaft 112; and they
extend downwardly and slightly toward the head of the bed (see link
117 in FIG. 4). The head end of the lower leg panel 20 is pivotally
connected to the braces 115 and 116 as at 119 and 120 respectively.
The links 117 and 118 together with the braces 115 and 116 of the
upper leg panel 19 form a bell crank with the shaft 112 serving as
the transverse pivotal axis to raise the upper leg panel 19.
At the lower end of the links 117 and 118 there is journaled a pin
121 which receives a connecting bracket 122 extending toward the
foot of the bed. At the foot end of the connecting bracket 122
there is located a transverse pin 123 similar to the pin 121 the
ends of which are journaled in a yoke 127 which holds a threaded
journal block 128.
The journal block 128 receives a threaded shaft 129 which is
connected by means of a coupler 130 to a shaft 131 of a gear box
132. The gears in the box 132 are driven by a drive motor 133
mounted on a mounting plate 134 at the foot end of the moveable
member 15 of the telescoping frame 13. The head end of the threaded
shaft 129 is journaled in a bracket at 135 for vertical support so
that as the shaft 129 is driven in rotation, the bearing guide
block 128 is translated longitudinally of the bed. As the block 128
is pulled towards the foot of the bed, the connecting bracket 122
will be pulled in the same direction; and the bell crank formed by
the links 117 and 118 and the braces 115 and 116 will be rotated
counterclockwise (as viewed in FIG. 4) to raise the upper leg panel
19.
Links 124 and 125 are rigidly secured to a shaft 126 and extend
downwardly and slightly toward the head of the bed therefrom. The
shaft 126 is rotatably received in upstanding brackets secured to
the moveable portion of the retract frame and described in greater
detail within. The lower portion of the links 124 and 125 are
connected by means of second links (see links 124a in FIG. 4) to
the journal block 128.
As has already been mentioned, it is desirable in some instances to
raise the lower leg panel 20 in parallel relation with the
intermediate frame as the upper leg panel is raised -- and in other
situations, to leave the foot end of the lower leg panel 20 in its
lowered position as the upper leg panel 19 is raised. The mechanism
for accomplishing this function is shown in detail in FIGS.
10-14.
Turning now to FIGS. 10 and 11, as has already been disclosed, the
link 124 is pulled by the link 124a toward the foot of the bed when
the journal box 128 is translated toward the foot of the bed. This
rotates the shaft 126 counterclockwise as viewed in FIG. 10 and
clockwise and viewed in FIGS. 12-14. In FIGS. 12-14, the lower leg
panel 20 has been removed to obtain a clearer picture of the
raising structure. At the right hand side of the shaft 126 (as
viewed from the head end of the bed looking toward the foot end) is
welded a cam 137. The cam 137 lies in a generally vertical plane
which extends longitudinally of the bed; and it defines a
cam-bearing surface 138 which extends downwardly and slightly
rearwardly of the shaft 126 when the upper leg panel 19 is in a
horizontal position -- that is, before the shaft 126 has been
rotated.
The shaft 126 is concentrically mounted on an axle 135; and at the
outboard ends of the shaft 126 secured to the axle 135 are a pair
of arms 139 and 139a, the right side arm being designated 139 in
the drawing. The arms 139 and 139a extend toward the foot of the
bed and their function is to raise the foot end of the lower leg
panel when it is desired to do so.
Turning now to FIG. 10, a bracket 140 is secured to the top of the
channel member 86 of the moveable portion 15 of the telescoping
frame. A similar bracket (designated 141 in FIG. 6) is mounted to
the top of the complementary channel member 85. Each of the
brackets 140 and 141 defines a vertical finger (see the finger 142
integral with the bracket 140 in FIG. 10) for rotatably receiving
the axle 135 on which is mounted the shaft 126. The bracket 140
also defines inwardly turned stop members 143 and 144 (best seen in
FIG. 11), the function of which will be describe presently. The
inwardly turned flange 143 defines an upwardly facing aperture for
receiving a crank 145 which extends toward the rear of the bed
where it is secured to a crank shaft 146 which extends beneath the
channel member 86 to define a crank handle 147. The crank 145 is
translated longitudinally of the bed by turning the crank handle
147; and, as mentioned, it is supported at its forward end by means
of the slot at the top of the support member 143. The forward end
of the crank 145 is provided with upwardly turned foot 148 which is
translated back and forth within the vertical channel defined by
the stop members 143 and 144.
As best seen in FIGS. 12-14, there is rotatably mounted to and
extending between the arms 139 and 139a a transverse bar 150 at the
right side of which is rigidly secured a key member 151. The key
member 151 defines a bearing surface 152 which may be selectively
moved into and out of engagement with the cam surface 138 of the
cam 137 by moving the crank 145 to its forward and rear positions.
The key 151 as well as the bar 152 are biased in a counterclockwise
rotation (as viewed in FIG. 12) by means of a tension spring 153 so
that an inwardly turned foot 155 on the end of the key 150 engages
the upwardly turned corresponding foot 148 of the crank 145. Thus,
as the crank is pulled toward the foot of the bed, the foot 148
will engage the foot 155 of the key 151 to rotate the same
clockwise about the shaft 150 and thus out of engagement with the
cam surface 138 of cam 137 as the shaft 126 is driven in clockwise
rotation.
As can be seen best in FIG. 13, when the crank 145 is left in its
forward position and the shaft 126 is driven by the motor 133 and
links 124 and 124a, the cam surface 138 will engage the bearing
surface 152 of the key 151 and lift the arms 139 and 139a to raise
the lower leg panel (shown in chain line in FIGS. 12 and 13). At
the distal end of the arms 139 and 139a are nylon roller bearings
157 which engage the lower surface of the foot panel to raise the
same. The arms 139 and 139a are rotated in a clockwise direction in
FIG. 13 about the axle 135; and they are connected together
intermediate their ends by means of a connecting rod 158 to form a
rigid structure in supporting the lower leg panel.
Referring now to FIG. 14, when the crank 145 is pulled to its rear
position, the upstanding foot member 148 at its forward end rotates
the key 151 against the tension in the spring 153 in a clockwise
direction so that the bearing surface 152 cannot be engaged by the
cam surface 138 of the cam 137 as the shaft 126 is driven when the
upper leg panel is raised as previously described. Under these
circumstances, the roller bearing 157 will remain in a lowered
condition so that it will not raise the foot end of the lower leg
panel, thereby resulting in a bent knee position when the upper leg
panel is raised.
Since the arms 139 and 139a are freely rotatable relative to the
shaft 126, the lower leg panel may be raised to maintain the feet
in an elevated condition by hand rotation of the arms 139 and 139a
about the shaft 135. Referring to FIG. 10, the head end of the arm
139 is provided with an extension 160 which projects forwardly of
the shaft 135 and defines a lower limit surface 161 which engages
the stop member 144 of the bracket 140 when the arm 139 is thus
raised. As can be seen in FIG. 12, if the arm 139 is rotated
clockwise, the stop surface 161 will extend slightly forwardly of
the axis of rotation of the shaft 126 to engage the stop member 144
to stabilize the position of the arms 139 and 139a in holding the
leg panel elevated.
RETRACTION DRIVE
Referring again to FIG. 6, the drive mechanism for forcing the
retract frame to its retracted and expanded states will now be
described in detail. A motor 162 is mounted on the mounting plate
134 and adapted to drive gears housed within a gear box 163. The
gears within the housing gear box 163 drive a shaft 164 which
rotates a coupling member 165 and a threaded screw 166 according to
the direction of rotation of the motor 162. An internally threaded
nut is received in a yoke having side flanges 168 and 169 and which
is mounted on the top of a transverse mounting plate 170.
The mounting plate 170 is secured at each side by means of flanges
171 and 172 to the top of the box-shaped longitudinal side members
83 and 84 of the fixed portion 14 of the telescoping retract frame
13. Thus, as the motor 162 is driven in one direction, the
connecting screw 160 is rotated to draw the yoke toward the foot of
the bed and thereby pull the movable member 15 of the telescoping
frame over its associated fixed member 15. By driving the motor 162
in the opposite direction, the moveable member 15 of the
telescoping frame 13 is driven away from the fixed member 14.
TRENDELENBERG LIFT MECHANISM
As seen best in FIGS. 4, 6 and 7, a transverse support bar 175 is
located about midway of the base frame 10 and intermediate frame
12; and it is rigidly mounted at each side to the box-shaped side
members 83 and 84 of the fixed portion of the telescoping frame by
means of vertical supports 176 and 177 respectively. Secured to the
lower flange of the channel member 38 of the intermediate frame 12
is a housing 178 for a first helical gear 179 which extends in a
generally vertical direction. Similarly, a housing 180 for a second
helical gear 181 is secured to the lower flange of the channel
member 39 of the intermediate frame 12 (see FIG. 7). The upper end
of the helical gear 179 is rigidly fastened to the cross bar 175 as
at 182; and the upper end of the helical gear 181 is similarly
secured to the cross bar 175 at 183.
A crank shaft 184 extends to the side of the intermediate frame 12
where it removably receives a crank handle (not shown). The crank
shaft 184 is coupled to a gear which drives the helical gear 179
directly; and it is coupled by means of a universal joint 185, a
connecting rod 186, a second universal joint 187 and a second
connecting rod 188 to a similar gear which drives the helical worm
181. The connecting rod 188 is seen to be at a lower level than the
crank shaft 184; and it is journaled within mounting plates 190 and
191 which extend from beneath the cross bar 175. The cross bar 175
is made of a continuous rigid structure by means of a portion 175a
extending beneath the pressure therein. As the crank shaft 184 is
rotated, the helical worms 179 and 181 are raised thereby raising
the cross bar 175 and the telescoping frame relative to the
intermediate frame as defined by the channel members 38 and 39.
It will be remembered from the previous discussion concerning FIG.
9, that the telescoping frame seats on the intermediate frame by
means of corner studs which extend outwardly of the sides of the
intermediate frame; and these studs have bee previously designated
by reference numerals 81 and 81a in FIG. 8, the forward studs being
denoted 81, and the studs at the foot end of the bed being 81a.
Turning now to FIG. 4, a bracket 194 defining an open channel 196
facing toward the head of the bed is mounted on the box-shaped
elongated side member 84 of the telescoping frame for selective
horizontal movement over the pin 81.
A connecting rod 195 couples the bracket 194 to a lever 196 which
depends from a pivotal connection at 197 from the box-shaped frame
member 84. The rod 195 is pivotally connected to the lever 196 by
means of a pin 198; and the lever 196 is biased by means of a
spring 199 in a rearward position. A pin 200 extending from the
side of the lever 196 is received in a slot 201 on a bracket 202
which is secured to the bottom of the side member 84 of the fixed
portion of the retract frame. The slot has a circular lower curve
to accommodate the arcuate motion of the pin 200 on the lever 196,
but at its forward end, it defines an upwardly-inclined race 201a
to lock the pin thereat and thus hold the lever 196 in a forward
position against the tension of spring 199.
Similarly, a bracket 203 defines an open channel 204 which faces
the foot of the bed for selectively fitting over the rear stud 81a
and is connected to the lever 196 by means of a connecting rod 205.
It will be appreciated that when the lever 196 is in a rearward
position, the bracket 203 locks on the rear stud 81a so that the
fixed member of the telescoping frame cannot be raised relative to
the intermediate frame 12 at this point. At the same time, the
forward bracket 194 is disengaged from the forward stud 81. Hence,
when the lever 196 is in the position shown in FIG. 4, and the
Trendelenberg lift mechanism is cranked upward, the telescoping
frame will pivot about the stud 81a to achieve the reverse
Trendelenberg position. Conversely, when the lever 96 is moved to
its forward position so that the pin 200 catches in the upwardly
turned portion 201a of the slot 201, the forward bracket 195 will
prevent a relative vertical motion between the retract frame and
the intermediate frame; and the rear bracket 2-3 will be moved to
allow the foot end of the telescoping frame to be lifted above the
intermediate frame as the Trendelenberg crank is actuated to
achieve the Trendelenberg position.
From the foregoing detailed description of the illustrated
embodiment accompanied, where appropriate, with description of the
function and operation of the disclosed structure, the details of
the operation of each element of the bed will be apparent to
persons skilled in the art. However, a summary of bed operation in
order to achieve the various patient positions will now be
given.
In order to shorten the bed, the drive motor 162 (FIG. 6) drives
the screw 166 to draw the nut 167 toward the foot of the bed. The
nut 167 is, of course, rigidly secured to the fixed portion 14 of
the retract frame 13; and the motor 162 is mounted on a mounting
plate which is a unitary part of the moveable portion 15 of the
retract frame. Thus, by turning the screw 166, the U-shaped side
channel members 85 and 86 of the moveable portion of the retract
frame slide forwardly toward the head of the bed over their
corresponding box-shaped side members 83 and 84 of the fixed
portion of the retract frame.
Referring also to FIG. 4 now, the transverse bar 105 which is
secured to the moveable portion 15 of the retract frame is also
translated toward the head of the bed; and it carries with it the
head panel 17 and the seat panel 18 of the mattress supporting
frame. For a short while, the pins 94 and 98 will ride in their
associated slots 92 and 91 until they engage the head ends of the
slots. At this time, forward motion of the links 95 and 97 will be
prevented; and they will begin to rotate about their respective
lower pins to translate the head panel upwardly. This, in turn,
rotates the brackets 102 and 103 about the pins 106 and 107 and, in
turn, lowers the head end of the seat panel 18 by rotating it about
the transverse horizontal axis defined by the shaft 112 which is
also mounted to the movable portion of the retract frame. It will
be appreciated that the foreshortening of the retract frame is
independent of any elevation of the mattress support frame as well
as of the position of the upper leg panel 19 and lower leg panel
20. As indicated in FIG. 3, separate buttons are provided for
controlling the raising and the lowering of the mattress support
frame, for controlling the raising and the lowering of the upper
leg panel, and for controlling the raising and the lowering of the
head panel. Diagrammatic symbols are shown on each of six buttons
for energizing the drive motors in the required direction to
achieve these positions.
Elevation of the mattress support frame is achieved by energizing
the motor 50 (FIG. 8) to drive the screw 54 in a direction to pull
the bearing lock 59 toward the head of the bed. This, in turn,
rotates the tubular bars 71 and 72 about the transverse bar 73
which is mounted beneath the tubular members 33 and 34 of the outer
scissors link. Rotation of the tubular bars 71 and 72 exerts an
upward force on the elongated members 43 and 44 of the inner
scissors link via the rollers 78 and 79 as seen in FIG. 5. It will
be appreciated that this action is independent of either the
knee-bending operation or the head panel elevating mechanism since
both of these operations rely on the intermediate frame 12 only for
support.
In order to elevate the upper leg panel 19, drive motor 133 turns
screw 129 in a bearing block 128 to draw the bracket 122 toward the
foot of the bed. A bell crank formed about the shaft 112 (including
the rearwardly extending support arms 115 and 116) then raises the
intersection between the upper leg panel 19 and the lower leg panel
20.
If it is desired to raise the lower leg panel 20 in parallel
relation with the intermediate frame when the upper leg panel 19 is
raised, the crank handle 145 of FIG. 12 is left in its forward
position so that the cam-bearing surface 138 of cam 137 engages the
corresponding bearing surface 152 of the key 151 to rotate the side
arms 139 and 139a about the shaft 135. The roller bearings 157 will
then engage the lower surface of the lower leg panel 20 to raise it
in parallel relation with the intermediate frame.
If it is desired to achieve a bent knee position, the crank handle
145 is moved to its rear position so that the upwardly extending
finger 148 thereof pulls the key 152 to a retracted position so
that as the shaft 126 is driven in rotation by the motor 133, the
cam-bearing surface 138 does not engage its corresponding surface
on the key 151; and the foot end of the lower leg panel will then
remain lowered.
The Trendelenberg lift mechanism has an upper moveable section
including threaded shafts 179 and 181 rigidly connected to the
box-shaped members 83 and 84 of the moveable portion of the retract
frame to lift the intermediate section of the retract frame
relative to the intermediate frame 12. If the lever 196 is in a
rearward position, bracket 203 (FIG. 4) slides over and engages the
stud 181a so that when the lift mechanism is cranked, the retract
frame is tilted relative to the intermediate frame about the foot
end thereof for achieving the reverse Trendelenberg position. When
the lever 196 is moved to the forward position so that the pin 200
slides upwardly in the portion 201a of the slot 200, the bracket
194 engages the forward stud 81 and the bracket 203 is removed from
the rear stud 81a so that when the Tendelenberg lift mechanism is
cranked, the retract frame will be tilted relative to the
intermediate frame by rotating it about the stud 81. It will be
appreciated that achieving either Trendelerberg positions is
accomplished independent of the elevation of the mattress
supporting frame. Further, the mutually exclusive coupling action
of the two locking brackets 194 and 203 is advantageous in
achieving the safety feature of always having one end of the
retract frame coupled to the intermediate frame. That is to say,
the length of the rods 195 and 205 is such that, in combination
with the bistable shape of the bracket 200, there will always be
one but only one end of the retract frame which is raised when the
Trendelenberg lift mechanism is cranked.
As previously mentioned, the retract frame and the intermediate
frame are both components of an intermediate frame assembly
interposed between the base frame 10 and the mattress supporting
frame 16. If Trendelenberg and Reverse Trendelenberg operations are
not required, then it is believed apparent that the intermediate
frame assembly may be simplified, with the independently tipable
perimetric frame arrangement eliminated and the intermediate frame
12 adapted to serve as the fixed portion of the retract frame
13.
Having thus described in detail one embodiment of our inventive bed
construction, it will be appreciated by persons skilled in the art
that many structural modifications may be made to the bed to
achieve similar functions without departing from the inventive
principle; and it is, therefore, intended that all such
modifications and substitutions be covered as they are embraced
within the spirit and scope of the appended claims.
* * * * *