U.S. patent number 3,877,088 [Application Number 05/370,774] was granted by the patent office on 1975-04-15 for hospital bed.
This patent grant is currently assigned to Metal Craft (1970) Limited. Invention is credited to Wim John Michael Bouman.
United States Patent |
3,877,088 |
Bouman |
April 15, 1975 |
Hospital bed
Abstract
A hospital bed having an adjustable head section which is
preferably combined with an adjustable seat section. A head gatch
mechanism couples the head section to the bed frame and can be
operated to move the head and seat sections from a horizontal
position into a position in which the seat section is inclined
downwardly towards the head section which is inclined upwardly. The
mechanism is adjustable for patient weight so that the head section
can be made to follow patient movement between supine and sitting
positions.
Inventors: |
Bouman; Wim John Michael
(Toronto, Ontario, CA) |
Assignee: |
Metal Craft (1970) Limited
(Beamsville, Ontario, CA)
|
Family
ID: |
23461114 |
Appl.
No.: |
05/370,774 |
Filed: |
June 18, 1973 |
Current U.S.
Class: |
5/618 |
Current CPC
Class: |
A61G
7/015 (20130101) |
Current International
Class: |
A61G
7/015 (20060101); A61G 7/002 (20060101); A61g
007/06 () |
Field of
Search: |
;5/60,66,67,68,69 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Gilliam; Paul R.
Assistant Examiner: Dorner; Kenneth J.
Attorney, Agent or Firm: Rogers, Bereskin & Parr
Claims
I claim:
1. A hospital bed comprising:
a bed frame;
a mattress support coupled to the bed frame and including a head
section rotatable about a horizontal axis between a horizontal
position and a raised position in which the head section is
inclined upwardly from said axis;
a head gatch mechanism comprising: first and second elements
coupled together for axial telescopic movement relative to one
another; a bracket attached to the head section and pivotally
connected at a distal end thereof to an end of the second element
remote from the first element; spring means coupled at its ends to
said first and second element and adapted to bias the first element
axially away from the second element; a double-acting locking
mechanism coupled to the first and second elements and adapted to
prevent relative movement between the first and second elements
when a substantial force is applied to move one of said elements
axially with respect to the other of the elements; control means
coupled to the locking mechanism and operable to unlock the
mechanism when said substantial force is removed; and actuactor
means coupling the first element to the bed frame and adapted to
move the first element axially relative to the bed frame, whereby
when the bed is in use, the head gatch mechanism can be adjusted to
the weight of a patient on the bed by first operating the control
means to release the locking mechanism to permit relative movement
between the first and second elements, and then moving the said
first element axially using the actuactor means, so as to vary the
biassing effect to the spring means until the said effect is
balanced by the weight of the patient.
2. A hospital bed as claimed in claim 1 in which the second element
includes a shaft and the first element includes means locating the
shaft for longitudinal movement as the elements telescope relative
to one another, and in which the locking mechanism comprises a pair
of locking elements engaged about the shaft and movable between a
released position in which the locking elements are generally
perpendicular to the shaft and a locked position in which the
locking elements are inclined with respect to the shaft for
frictionally engaging the shaft; location means coupled to the
first element and adapted to locate the locking elements relative
to the first element such that the locking elements can pivot about
said location means between said released and locked positions; and
means biassing the locking elements towards said locked positions;
the said control means being adapted to permit the locking elements
to be moved from the locking positions into the released positions
upon removal of said substantial force.
3. A hospital bed comprising:
a bed frame;
a mattress support coupled to the bed frame and including a head
section, a seat section, and a leg section, the seat section being
pivotally coupled to the leg section for movement about an axis
between a horizontal position and an inclined position in which the
seat section slopes downwardly from the leg section, and the head
section being pivotally connected to the seat section for movement
about another axis parallel to said first mentioned axis between a
lowered position in planar alignment with the seat section when the
seat section is in the horizontal position and a raised position in
which the head section is inclined upwardly from said another axis
with the seat section being in the inclined position;
link means coupling the head section to the bed frame to at least
partly support the head section as this section moves between the
lowered and raised positions;
a head gatch mechanism comprising: first and second elements
coupled together for axial telescopic movement relative to one
another; a bracket attached to the head section and pivotally
connected at a distal end thereof to an end of the second element
remote from the first elements; spring means coupled at its ends to
said first and second elements and adapted to biass the first
element axially away from the second element; a double-acting
locking mechanism coupled to the first and second elements and
adapted to prevent relative movement between the first and second
elements when a substantial force is applied to move one of said
elements axially with respect to the other of the elements; control
means coupled to the locking mechanism and operable to unlock the
mechanism when said substantial force is removed; and actuactor
means coupling the first element to the bed frame and adapted to
move the first element axially relative to the bed frame, whereby
when the bed is in use, the head gatch mechanism can be adjusted to
the weight of a patient on the bed by first operating the control
means to release the locking mechanism to permit relative movement
between the first and second elements, and then moving the said
first element axially using the actuactor means, so as to vary the
biassing effect of the spring means until the said effect is
balanced by the weight of the patient.
4. In a hospital bed of the type having a bed frame, a mattress
supported above the frame and coupled to the bed frame, and a head
gatch mechanism coupled to the bed frame and to a head section of
the mattress support for moving the head section between a
horizontal position and an inclined position, the improvement in
which the head gatch mechanism comprises: first and second elements
telescopically interconnected for axial movement relative to one
another; spring means coupled at its ends to said first and second
elements, said spring means. biasing the elements away from one
another; means coupling the second element to the head section; a
double acting locking mechanism coupled to the first and second
elements and adapted to prevent movement between the first and
second elements when a substantial force is applied to move one of
said elements; and actuactor means coupled to the first element and
to the bed frame and adapted to move the first element axially
relative to the bed frame, whereby when the bed is in use, the head
gatch mechanism can be adjusted to the weight of a patient on the
bed by first releasing the locking mechanism to permit relative
movement between the first and second elements, and then by moving
the said first element axially using the actuactor means so as to
vary the biassing effect of the spring means until the said effect
is balanced by the weight of the patient.
5. Apparatus as claimed in claim 4 in which the second element
includes a shaft and the first element includes means locating the
shaft for longitudinal movement as the elements telescope relative
to one another, and in which the locking mechanism comprises a pair
of locking elements engaged about the shaft and movable between a
released position in which the locking elements are generally
perpendicular to the shaft and a locked position in which the
locking elements are inclined with respect to the shaft for
frictionally engaging the shaft; location means coupled to the
first element and adapted to locate the locking elements relative
to the first element such that the locking elements can pivot about
said location means between said released and locked positions;
means biassing the locking elements towards said locked positions;
and control means adapted permit the locking elements to be moved
from the locking positions into the released positions upon removal
of said substantial forces.
Description
This invention relates to hospital beds, and more particularly to a
hospital bed having a head section which can be moved between
lowered and raised positions by a patient moving himself between
respective supine and sitting positions.
Hospital beds are commonly provided with various adjustments which
are considered necessary both from a medical standpoint and also
from the standpoint of patient comfort. One of these adjustments
commonly permits a head section to be moved between a horizontal or
lowered position and an inclined or raised position. An improvement
on this adjustment is to also provide a seat section which is
coupled to the head section and which becomes inclined downwardly
towards the head section as the head section is inclined upwardly.
Consequently, in a sitting position, the seat section tends to
better locate the patient against sliding movement down the bed and
is therefore more comfortable for the patient.
The head section is commonly elevated by a manual actuator located
at the foot of the bed and operated by a nurse when the patient
wishes to change his position. Consequently, the patient must first
call a nurse before such a bed can be adjusted. An alternative
arrangement is to provide an electrical control which the patient
can operate himself. Although such controls are used with success,
they nevertheless suffer from the disadvantages both that they are
relatively expensive and that they must include safety controls
which are designed to make it difficult for a patient to injure
himself by accidental misuse of the electrical control.
It is an object of the present invention to provide a head section
which will move between a lowered or horizontal position and a
raised or inclined position as a patient moves himself between the
supine and sitting positions.
It is a further object of the invention to provide a combination
head section and seat section which move to support a patient as
the patient moves between a supine position and a sitting
position.
Accordingly, in one of its aspects, the present invention provides
a hospital bed having an adjustable head section on a bed frame. A
head gatch mechanism couples the head section to the bed frame and
can be operated to raise and lower the head section. The mechanism
is adjustable for patient weight so that the head section can be
made to follow patient movement between supine and sitting
positions.
In another of its aspects the present invention provides a hospital
bed having adjustable head and seat sections pivotally connected to
one another and coupled to a bed frame. A head gatch mechanism
couples the head section to the bed frame and can be operated to
move the head and seat sections from a horizontal position into a
position in which the seat section is inclined downwardly towards
the head section which is inclined upwardly. The mechanism is
adjustable for patient weight so that the head section can be made
to follow patient movement between supine and sitting
positions.
These and other aspects of the invention will be better understood
with reference to the drawings, in which:
FIG. 1 is a perspective view of a bed incorporating the
invention;
FIG. 2 is a side view of the bed with parts in section to
illustrate hidden detail and including a double-acting locking
mechanism in a locked position;
FIG. 3 is a sectional view on line 3--3 of FIG. 2;
FIG. 4 is a sectional view on line 4--4 of FIG. 2;
FIG. 5 is a sectional side view of the double-acting locking
mechanism in a released position; and
FIG. 6 is a view similar to FIG. 2 showing the bed in another
position.
Reference is first made to FIG. 1 which shows an exemplary bed
frame 10 to which is attached a head gatch mechanism 12 for use in
adjusting the head section 14 and seat section 16 of a mattress
support 18. This support is adapted to carry a conventional
mattress such as that indicated at 19 in FIG. 2.
The bed frame 10 is typical of any suitable frame and includes
longitudinal members 20, 22 connected at their ends to respective
transverse members 24, 26. The longitudinal and transverse members
define a rectangular frame and four legs 28 extended downwardly
from corners of this frame. As is conventional, the legs are
supported at their lower ends on respective castors 30.
Three support members 32, 34, and 36 extend transversely between
the longitudinal members 20, 22. Each of the support members is in
the form of a shallow inverted U and these members are positioned
so that the members 32, 34 support a leg section 38 of the mattress
support 18 and the member 36 supports an outer end of the head
section 14.
The leg section 38 is attached to the members 32, 34 and is
connected by a pair of pivots 40 (one of which is shown) to the
seat section 16. Pivots 42 at the other end of the seat section 16
connect this section to the head section 14. The respective pivots
40, 42 lie on parallel transverse axes. Head section 14 is also
supported by a pair of links 44, 46 which are connected at their
respective lower inner sides of the longitudinal members 20, 22 by
pivots 48, 50 and to the head section 14 by pivots 52, 54. The
links 44, 46 combine with the head gatch mechanism 12 to control
the movement of the seat section 16 and head section 14 as these
sections move between the positions shown in FIGS. 1 and 6. These
movements will be described after completing description of the
structural components of the head gatch mechanism 12.
Reference is now made to FIGS. 1 and 2 with particular reference to
FIG. 2 to described the head gatch mechanism 12. This mechanism is
operated manually by a crank 56 on an outer end of a shaft 58 which
is carried in a swivel bearing 60 on the transverse member 24 of
the frame 10. The shaft 58 is threaded at its inner end for
engagement in threaded end piece 62 of a first element 64. This
element is telescoped at its forward end in a second element 66 for
relative axial movement of one element relative to the other
element. The element 66 is connected by a pivot 68 to a distal end
of a heavy bracket 70 attached to the underside of the head section
14 adjacent the pivots 42.
The element 64 includes a cover 72 having a generally U-shaped
section and attached at its end to the end piece 62. A fillet 74 is
also attached to the cover 72 and is adapted to slidably receive an
elongated hardened shaft 76 forming part of the second element 66.
As seen in FIG. 3, this shaft is also located between a pair of
transverse pins 78, 80 which are engaged in the cover 72. A washer
82 is held against these pins by a compression spring 84 contained
in the second element 66.
The cover 72 also has a pair of pins 86, 88 attached to it above
the shaft 76 between the fillet 74 and the pins 78, 80. The pins
86, 88 form parts of a double-acting locking mechanism 90 which is
adapted to limit relative movement between the elements 64, 66 as
will be described. The mechanism 90 includes a pair of similar
locking elements 92, 94 which are biased away from one another by
respective tension springs 96, 98 anchored in opposition in the
cover 72. These elements are of a material which complements the
shaft 76 to permit the elements to lock the shaft frictionally
without substantial damage either to the elements or to the shaft.
Locking element 94 is typical of both locking elements and is
better seen in FIG. 4. The element 94 fits relatively snugly inside
the cover 72 to locate the element 94 transversely and the shaft 76
passes through the element 94 loosely. The spring 98 biases the
element into frictional engagement with the shaft 76 and this
frictional engagement will become sufficient to lock the element to
the shaft under certain conditions which will be described.
Returning to FIG. 2, the frictional engagement of the locking
elements 92, 94 on the shaft 76 can be relieved by actuating a hand
control 100 which is connected by a sheathed cable 102 to the
locking mechanism 90. On operating the hand control the sheath
bears against the locking element 92 and the cable pulls the
locking element 94 so that the elements are moved toward one
another into a position such as that shown in FIG. 5. In this
position there is a minimal frictional engagement between the
locking elements 92, 94 and the shaft 76 so that the elements 64,
66 are no longer locked to one another.
The element 66 includes a cover 104 to which an anchor 106 is
attached for connecting an end of the shaft 76 to the cover 104.
The compression spring 84 is retained in compression between the
washer 82 (FIG. 3) and the anchor 106 to bias the elements 64, 66
apart when the locking mechanism 90 is in the position shown in
FIG. 5. The significance of this arrangement will become apparent
upon describing the operation of the bed as follows.
In use, the head gatch mechanism 12 can be used conventionally with
the handle control 100 in the normal or locked position
corresponding to the position of the locking mechanism 90 shown in
FIG. 2. In effect the elements 64 and 66 are then locked to one
another and form the equivalent of a single link connecting the
heavy bracket 70 on the underside of the head section 14 to the
threaded shaft 58 which is attached to the crank 56. Consequently,
upon rotating the crank in a direction corresponding to raising the
head section, the bracket 70 is made to rotate in a generally
anti-clockwise direction as drawn in FIG. 2. Consequently, the head
section 14 also rotates guided by its connection with the seat
section 16 and the respective links 44, 46 (FIG. 1). Further
rotation of the crank 56 will ultimately result in the sections 14
and 16 taking the positions shown in FIG. 6 in which the head
section 14 is at an angle of about 60 degrees to the horizontal.
The seat section 16 is then inclined downwardly from the leg
section 38 to better locate the patient in a sitting position.
Returning to FIG. 2, it will be evident that use of the head gatch
mechanism as just described requires that a nurse is available.
However, the combination of the first and second elements 64, 66 is
also intended to permit the patient to raise and lower himself as
will now be described.
Imagine the situation in which the compression spring 84 is
compressed sufficiently that it tends to force the second element
66 away from the first element 64 to raise the head section 14.
Such a substantial force from the spring 84 causes the friction in
the locking element 94 of the locking mechanism 90 to tend to move
towards the associated spring 98 about the pin 88. This attempted
movement will result in increased reaction forces between the
locking element 94 and the shaft 76 to lock the shaft 76 in
position relative to the element 74. Consequently, no movement can
take place in this condition. Also, if a patient or nurse were to
attempt to unlock the mechanism 90 by operating the hand control
100, the result would simply be that the locked element 94 would be
unmoved and the other element 92 would be free to move under the
influence of the sheathed cable 102. The mechanism would however,
remain locked. It will therefore be evident that the mechanism 90
can be unlocked by pressing downwardly on the head rest to balance
the force exerted by the spring 84 on the mechanism 90. The crank
56 can then be rotated to relax the spring until the upward force
at the head rest is removed.
Consider now the situation shown in FIG. 2 in which the spring 84
is relaxed and a patient is lying on the bed. The mechanism 12 is
adjusted by operating the hand control 100 and turning the crank 56
until the head section is about to move upwardly. The patient then
balances the spring force and if the patient moves towards a
sitting position the seat section 16 and head section 14 will
follow him as seen in FIG. 6. If he gets out of bed, then the
locking element 94 will come into play automatically to prevent
sudden movement of the head and seat sections under the influence
of the compressed spring 84. When a patient is to give up his bed
to another patient it is preferable to relax the spring 84 by
turning the crank 56. The mechanism is then adjusted to the weight
of the next patient by turning crank 56 to compress the spring as
previously described with reference to the first patient. However,
if the first patient simply leaves the bed set for him and a
lighter or heavier second patient then takes the bed, it will be
necessary to readjust the bed.
In the case of a lighter second patient his weight will not be
sufficient to unlock the locking element 94. Consequently, he can
do one of two things. Firstly he can apply more weight to the head
section by moving himself or by having a nurse help him by pushing
down on this section. This permits the hand control to release the
locking element 94 and the crank 56 is then used to relax the
spring to a condition in which the second patient is balanced.
Secondly he can have a nurse turn the crank 56 to raise the head
section until the limit of the travel is reached to balance the
spring force. Consequently the locking elements 92, 94 can then be
released using the control 100 and the crank is then used to allow
the spring to relax to the desired condition to balance the
patient.
In the case of a heavier second patient his weight will tend to
cause the locking element 92 to lock to the shaft 76. Here again
there are two possibilities. Firstly, the patient can reduce the
weight on the head section either by raising himself slightly or by
having a nurse apply an upward force to the head section to permit
the control 100 to be relaxed. The crank 56 is then turned to
re-set the spring compression to match the second patient's weight.
Secondly, he can have a nurse turn the crank 56 to lower the head
section to the limit of its travel which will cause a reaction
between the head section and the support member 36 sufficient to
permit the control 100 to release the locking element 92, 94 so
that the spring 84 can be adjusted.
It will now be evident that when the mechanism 12 is adjusted, the
head section 14 and seat section 16 move towards a sitting position
under the influence of the spring 84 and return to the lowered or
flat position under the influence of the patient's weight. Also, it
is necessary to re-set the mechanism 12 whenever a new patient uses
the bed unless this patient happens to have substantially the same
weight characteristics as the previous patient.
Although the preferred embodiment shown in the drawings includes a
pivotal seat section, the principle of a balanced head section can
also be applied to a mattress frame in which the seat section 16 is
permanently aligned with the leg section 38. In such a structure
the links 44, 46 could be eliminated and the head section would be
supported at pivots 42 during movement above the support member 36.
While a structure of this type is within the scope of the invention
the embodiment described with reference to the drawings provides
greater advantages and is therefore considered to be
preferable.
In some instances electric actuation could be preferable. The crank
56 would then be removed in favour of an electric motor and gear
box to drive the shaft 58. Generally the crank 56 and shaft 58 are
typical of any suitable actuator means adapted to cause the head
and seat sections to move as described.
* * * * *