Note: Descriptions are shown in the official language in which they were submitted.
~513S5
DRIVING DEVICE FOR LIFTING AND LOWERING THE PLATFORM OF
A BED OR ANY OTHER THING FOR SLEEPING OR RESTING ON
BACKGROUND OF TEIE INVENTION
The presen-t invention relates to a new driving device
for lifting and lowering the platform of a bed or any other
thing for a patient, etc. to sleep on, be examined, be treated,
or be carried on.
We have now various structures for lifting and lowering
the platform of a bed for a patient, etc. to sleep or rest on,
for example, a structure in which the platform is divided into
plural portions, to lift desired portions of the platform pivot-
ally in desired directions, making the platform undulate as a
whole; a structure in which the bedstead supporting the platform
is lifted, to lift said platform as a whole; and a sturcture in
which said bedstead is lifted at either side of the head or feet
of the patient or is lifted on one side and lowered on the other
side, to lift said platform only on one side, making said platform
incline as a whole. With such a bed, a lifting mechanism is
installed at a proper position below said platform, and it com-
prises a iifting member to convert the displacement applied to
it for lifting said platform or bedstead, and a drivlng device
for applying such displacement to said lifting member.
A conventional typical driving device for applying
displacement to said lifting member is shown, for example in USP.
Nos. 3,015,113 and 3,174,161. In this device, the internal
thread provided at one end of a hollow working rod is engaged
with the external thread of a rotatable shaft, and the external
thread shaft is rotated by a crank handle, or geared motor, etc.,
to displace the working rod linearly~ Although such a device is
widely used, it has a disadvantage that the friction between the
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internal thread and the external thread requires a considerable
burden on manpower operation, and that if the frictional force
is going to be decreased to reduce the burden, the cost must be
raised. Also when said external thread shaft is rotated by a
geared motor, the cost will be raised needless to say. In addi-
tion to such a device, there is a pneumatic or hydraulic cylinder
device used as said driving device. However, the device requires
an air compressor or hydraulic pump as the pressure source, and
furthermore various valves such as a pressure reducing valve,
pressure regulating valve and control valve. The device as a
whole with l:hese and piping included reauires a large space, and
makes the cost high, further being involved in the problems of
noise generation and maintenance very disadvantageously.
SUMMARY OF THE INVENTION
The driving device of the present invention does not
use such an expensive drive source as said geared motor, air
compressor or hydraulic pump, but allows manpower driving,
thereby allowing the required space to be reduced for effective
utilization of the space below the bed, etc. and low cost to be
attained. F~rthermore, the driving device of the present inven-
tion keeps the influence of frictional force very small compared
with said device using internal thread and an external thread
shaft, to decrease the burden of manpower driving. For driving,
since a lever, etc. is reciprocated, the operation can be made
not only by a hand, but also by a foot. Therefore, the operation
mechanism allows optimum design, depending on various conditions
such as the structure of the bed, etc.
The present invention is described in detail below, in
reference to preferable embodiments.
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BRIEF DESCRIPTION OF T~E DRAWINGS
Figs. lA and lB show the driving device of -the present
invention schematically, and lA is an illustrative front view
partially cut away to show the inside as a section, while lB is
a plan view.
Fig. 2 is an enlarged illustrative longitudinal section
to show the structure and action of an important portion as a
first embodiment of the driving device of the present invention.
Figs. 3A and 3B are enlarged illustrative longitudinal
sections to show the structure and action of an important portion
as a second embodiment of the driving device of the present
invention.
Figs. 4A and 4B are enlarged illustrative longitudinal
sections to show the structure and action of an important portion
as a third embodiment of the driving device of the present
invention.
Figs. 5A and 5B are respectively an enlarged illustra-
tive plan view and an enlarged illustrative longitudinal section
of an important portion, to show the action of the leaf spring
in the third embodiment of the driving device of the present
invention shown in Figs. 4A and 4B.
Figs. 6A and 6B and Fig. 7 are illustrative front
views to show embodiments with the driving device of the present
invention applied to a bed.
Figs. 8A and 8B are respectively an illustrative per-
spective view and an illustrative longitudinal section to show
the structure and action of an embodiment of the lever means
used in the driving device of the present invention.
Fig. 9 is an illustrative front view to show the state
of using the lever means shown in Figs. 8A and 8B, with the
driving device of the present invention applied to a bed.
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DETAILED DESCRIPTION OF THE INVENTION
In the drawings, symbol 1 indicates a support cylinder
containing a working rod 2 extensibly, and said support cylinder
has, at one end, a driving section A and a locking section B of
said working rod 2. In said driving section A, said working rod
2 has a driving piece 3 loosely fitted movably, and a driving
shaft 4 is provided near to one side of said driving piece 3.
On said driving shaft 4, a driving protrusion 6 is formed, to
push said driving piece 3 at its one side a against the resilience
of a return spring 5, so that said driving piece 3 may be moved
forward by said driving protrusion 6 and backward by said return
spring 5. In said locking section B, said working rod 2 has a
locking piece 7 loosely fitted pivotally movably with one side
held, and a locking spring 8 is provided, so that when said
driving piece 3 is moved backward by the return spring 5, said
locking piece 7 may be kept inclined by the resilience of the
locking spring 8, to lock said working rod 2. The locking piece
7 can be supported by a groove 9 as shown in Fig. 2 or by a pro-
trusion 9' as shown in Fig. 3, or by a hinge though not illustrated.
In the state shown by solid lines in Fig. 2, if the
driving shaft 4 is rotated clockwise in the drawing by a proper
mechanism as described later, the driving protrusion 6 formed on
the driving shaft 4 pushes said driving piece 3 at its one side
against the resilience of the return spring 5. Since the driving
piece 3 is pushed only at one side in this way, to move leftward
in the drawing in its inclined state, it locks the working rod
2 according to the principle of so-called inclination lock, to
move said working rod 2 leftward in the drawing, extending said
working rod 2 from the suppor-t cylinder 1. In this case, the
locking piece 7 is inclined by the resilience of the locking
spring 8, being in contact with the working rod 2, but since the
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working rod 2 moves in the direction (leftward in the drawing) to
erect the inclined locking piece 7, the working rod 2 is not
locked by the locking piece 7, not causing the movement to be
prevented. After the driving piece 3 is moved forward to the
end of movement in this way, the driving shaft 4 is rotated in
the other direction, to move the driving protrusion 6 back, and
this causes the driving piece 3 to ~e moved back to the starting
point of forward movement by the resilience of the return spring
5. In this case, since the driving piece 3 is supported at one
side by the driving protrusion 6 which is being moved back, it
inclines in the same direction as in case of moving forward, by
the resilience of the return spring 5. However, since said
driving protrusion 6 is moved back in the direction to erect the
inclined driving piece 3, said driving piece 3 is not locked by
the working rod 2, not being prevented from moving backward. In
this case, though said locking piece 7 does not lock said working
rod 2 in the direction in which the working rod 2 is moved by
the forward movement of the driving piece 3 as mentioned before,
it locks the working rod 2 in the other direction according to
the principle of inclination lock, to prevent the movement in
such direction. Thus, in the forward movement of the driving
piece 3, the working rod 2 is moved forward, and in the backward
movement, the working rod 2 is prevented from returning by the
locking piece 7. Therefore, by repeating the forward and back-
ward movement of said driving piece 3, the working rod 2 can be
driven in one direction intermittently against the load, to be
gradually extended from the support cylinder 1. To shorten the
working rod 2 extended from the support cylinder 1 in this way,
the locking piece 7 can be pivotally moved against the resilience
of the locking spring 8 by a proper mechanism, to be erected,
releasing the lock between the locking piece 7 and the working
rod 2. ~hus, the working rod 2 can be moved in the load direction,
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to be shortened into the support cylinder.
Embodiments of the mechanism for pivotally moving said
locking piece 7 against the resilience of the locking spring 8
are described below.
In the first embodiment shown in Fig. 2, the locking
piece 7 is pulled at the other side, by a tension wire means W,
to be pivotally moved. This composition has a feature that said
locking piece 7 can be pivotally moved independently of said
driving shaft 6.
On the contrary, in the second embodiment shown in Figs.
3A and 3B and in the third embodiment shown in Figs. 4A and 4B,
said locking piece 7 is pivotally moved in relation with said
driving shaft 4. The structure and action are as described below.
In Figs. 3A and 3B, Figs 4A and 4B and Figs. 5A and 5B,
symbol 10 indicates a releasing bar provided in the rear of said
driving protrusion 6 and in front of said locking piece 7. Said
releasing bar 10 is moved toward said locking piece 7, by moving
said driving protrusion 6 backward beyond the position correspond-
ing to the start point of the forward movement of said driving
piece 3.
In this composition, if the working rod 2 is driven by
the action mentioned before, the driving protrusion 6 is stopped
at a position before it pushes the releasing bar 10 when the
driving piece 3 iS moved backward, in order that the locking
piece 7 may not be pivotally rotated to be erect by said releas-
ing bar 10.
If said driving shaft 4 is rotated to move the driving
protrusion 6 further backward beyond said stop position reached
during driving, said driving protrusion 6 contacts, at its rear
side, the releasing bar 10, to move it. Therefore, the locking
piece 7 is pivotally moved to be erect by said releasing bar 10
against the resilience of the locking spring 8, to unlock the
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working rod 2. Thus, in this state, t~le working rod 2 can be
moved in the direction reverse to the driving drirection, and moves
in the load direction as illustrated, being shortened illtO the
support cylinder 1.
As described above, when the working rod 2 is driven,
the drivlng protrusion 6 is s-topped at a position bcfore it pushes
the releasing bar 10, and when the working rod 2 is moved backward,
it is moved further backward beyond said stop position. For such
operation, for example, a proper stopper can be provided in cor-
respondence to the stop position, so that during driving, said
stopper is actuated, to prevent the backward movement, and for
returning of the working rod 2, said stopper is released, to
allow the backward movement. As another composition, d load by
the resilience of a spring can be applied for the backward move-
ment beyond said stop position, so that the driving protrusion
6 may be stopped at said stop position by said load during driv-
ing, and may be moved further backward by a force larger than
said load, during returning. Any other composition can be easily
adopted for such operation.
A preferable embodiment of the latter composition in
which said operation can be made by the resilience of a spring
is shown in Figs. 4A and 4B and Figs. 5A and 5B. In the drawings,
symbol 11 indicates an arcuately curved leaf spring provided
between the tip of said releasing bar 10 and said locking piece
7, with its convex side turned toward said releasing bar 10.
The leaf spring ll is set as described above, for example, being
fitted into fitting grooves 12 formed on the side wall of the
casing of the locking section B as illustrated.
In this composition, as mentioned before, for driving
the working rod 2, when the driving piece 3 is moved backward,
the driving protrusion 6 pushes said releasing bar 10, and must
be stopped before the position where the locking piece 7 is
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actuated, so that the locking piece 7 may not be pivotally rotated
to be erected by said releasing bar 10. In this embodiment, since
the arcuately curved leaf spring 11 is provided between the tip
of the releasing bar 10 and the locking piece 7, with the convex
side turned toward the releasing bar 10, said leaf spring 11
generates a large repulsive force when the releasing bar 10 is
moved toward the locking piece 7, and the repulsive force can
easily and reliably stop the driving protrusion 6, preventing
false operation.
When the driving shaft 4 is rotated, the driving pro-
trusion 6 can be moved backward beyond the stop position reached
during driving, to move the releasing bar 10 toward the locking
piece 7 against the repulsive force of the leaf spring 11. If
the releasing bar 10 pushes the locking piece 7 through the leaf
spring 11, to pivotally rotate the locking piece 7 against the
resilience of the locking spring 8, the inclined locking piece
7 is erected, unlocking the working rod 2. Therefore as mentioned
above, in this state, the working rod 2 can move in the direction
reverse to the driving direction, to be shortened into the support
cylinder 1. In this case, since the leaf spring 11 is curved
arcuately as illustrated, to be convex toward the tip of the
releasing bar, said repulsive force is very large at the beginning,
but when the convex portion in contact with the tip of the re-
leasing bar 10 becomes flat with the movement of the releasing
bar 10 as illustrated, the repulsive force becomes very small,
allowing sudden bending by said releasing bar 10. Such sudden
change of status is transmitted to the hand or foot of the
operator through a lever 13 described later. Therefore, if such
sudden change of status is made to correspond to the completed
erect action of the locking piece 7, the operator can confirm
whether the locking by the locking piece 7 is released, by a
reaction to him during operation. Thus, the unlocking can be
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effected definitely, and t~le working rod 2 can be moved backward
smoothly.
In this composition, when used for a becl 14 or any
other thing for sleeping or resting on, the driving device of the
present invention is connected to a ~ifting ~ember for lifting
and lowering the platform 15 or bedstead ',6 of t-he ~ed, to make a
lifting mechanism of the platform ]5. Embodimcrl~ are described
below. Fig. 6 shows an example, in which the roc)t of the support
cylinder 1 is fitted to a bedstead 16, and the tip of the working
rod 2 is connected to a lifting member 18 provided be]ow a movable
platform portion 17, whereby said driving piece 3 is reciprocated,
to extend the working rod 2 from the support cylinder 1, raising
the movable platform portion 17 pivotally by the lifting member
18 against gravity. In this example, the driving shaft 4 reci-
procating the driving piece 3 can be driven by a lever 13 directly
fitted to the driving shaft 6 as shown in 6A, or the lever 13 can
be connected to the driving shaft 4 through a proper motion
transmitting mechanism M such as a link work, with said lever 13
set at a proper position below the ~ed 14 as shown in 6B. Fig. 7
shows another example, in which the bedstead 16 and a base 19
are connected by parallel links 20, to allow said bedstead 16 to
be lifted and lowered in parallel, and a crank arm 21 like a bell
crank is connected to one of said parallel links 20, with the tip
of the working rod 2 connected to said crank arm 21, and the root
of the support cylinder 1 connected to the base 19. In this
example, the lever 13 provided at a proper position as described
in the previous example is locked, to extend the working rod 2
from the support cylinder 1 to raise the bedstead 16 in parallel
against gravity. The style and mechanism for lifting the plat-
form 15 can be composed by any other way. If the platform 15 is
lifted in this way, the load is applied through the ]ifting
mechanism to the working rod 2, acting to shorten said working
~15~35~
rod 2 into the support cylind~r 1. EIowever, the workincJ rod 2 is
locked by the locking piece 7 acc5rdil-~ to the principle of in-
clination lock, to prevent the working rod 2 from being shortened,
thereby supporting said load. And by rotating the lever 13, as
mentioned above, the locking piece 7 is pivota]ly rotated to be
erected against the resilience of the locking sprincl 8, alLowing
the working rod 2 to be shortened into the support cylinder 1,
and in this state, the platform 15 can be lowered.
When the driving device of the present invention is
used to make a lifting mechanism of the platform 15 as mentioned
above, a buffer spring means D for energizing said platform 15
in the direction reverse to the action of gravity is installed to
prevent the sudden drop of the platform 15 by the load. ~s far
as buffer spring means D provides a force of energizing the
platform 15 in the direction reverse ~o the action of gravity,
the structure and place of installation can be freely selected.
A preferable embodiment of the buffer spring means D is illus-
strated.
In this embodiment, the buffer spring means D is con-
nected in the support cylinder 1 between the support cylinder 1
and the working rod 2, to energize the working rod 2 in the
direction for the working rod 2 to be moved by the driving of
said driving piece 3. If the buffer spring means D is contained
in the driving device in this way, the lifting mechanism as a
whole can be simplified.
The buffer spring means D described above can be a
general spring means such as coil spring, but if a spring means
using the compressive elasticity of a gas, viz. a spring means
known as gas spring is used as illustrated, said energizing force
can be adjusted easily, and a desired energizing force can be
given by a small-sized means as a feature of the gas spring.
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5 15:3L35S
A.-; c~escribed above, since the driving device of the
present inverltion reasonably use~ the princip]e of inclination
lock, the drivin(l shaft 4 can be rot~lted in a]ternate directions
to repeat the reciprocation of -the driving piece 3, movin~l the
working rod 2 in olle direction graclually agdinst the load.
Therefore, it has a large feature that said driving shaft 4 can
be rotated n~ only by a lever operated by a l~land, but .llso by
a foot lever.
Figs. 8A and 8B show a preferable embodiment of the
lever means used for the driviny device of the present invention
different from that shown in Figs. 6A and 6B and Fig. 7. 'i`he
structure and action are as described below. In the drawings,
symbol 22 is a rotating shaft made of a pipe, etc, and at one
side of the rotating shaft 22, a guide cylinder 23 is provided,
with a lever 24 slidably fitted in said guide cylinder 23. Said
guide cylinder 23 has a stopper 27 which brings a stopper pin 25
into resilient contact with said lever 24 by a spring 26. Said
lever 24 is provided with dents 28 which can be engaged with the
tip of said stopper pin 25. In the drawing, there are two dents
28 above and below but only one dent can be provided below, or
more than two dents can be prGvided. In the drawing, there is
a slope 29 on one side of each dent 28, and this is provided to
enable the dent 28 to be disengaged from said tip of the stopper
pin 25, by simply moving the lever 24 at more than a predetermined
force. But the slope 29 can be of course provided on the tip of
the stopper pin 25. Symbol 9 is a properly shaped grip.
In this composition, the lever means of the embodiment
is connected, through its rotating shaft 22, with the driving
shaft 4 of the driving device of -the present invention, being
installed at a side of the platform 15 of the bed 14, etc. For
use, the lever 24 can be operated with a low force, by engaging
said stopper pin 25 resiliently with said dent 28 which makes
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the distance between the grip 30 arLd the ro~ati-ncJ shaft 22 the
longest. In this pOSition, not onl,~ a nurse, etc. but also a
patient can operate the lever means. Since the lever 24 is fixed
with the stopper pin 25 resilier~tly engaged wlth the lever 24, it
is kept fixed unless a force of more t~lan that predetermined by
the resilience of the spring 26 is applied in the axial direct;on
of the lever 24. Furthermore it is free from loosenin-~ and play,
and also in this regard, it does not adversely affect the opera-
tion at all.
When a patient on the bed 14 gets off from the platLoYm
15, or when a serious patient is moved from the bed 14 to any
other place, or when a nurse, etc. arranges the bed 14, the lever
positioned above a side of the bed 14 is disturbing. In this
case, if a force of more than that predetermined by the resilience,
etc. of said spring 26 is applied in the axial direction of the
lever 24, -the stopper pin 25 is disengaged from the dent 28 along
the slope 29, and the lever 24 can be simply shortened as illus-
trated, to put the grip 30 below the platform. Therefore, the
grip 30 is not disturbing at all even in the above mentioned case.
As described in detail above, in the present invention, for
the forward movement of the driving piece 3, the working rod 2
is moved against the load of the platform 15, and for the back-
ward movement of the driving piece 3, the locking piece 7 prevents
the return of the working rod 2 by the load. In other words, the
working rod 2 can be moved against the load intermittently and
gradually in one direction by the rotation of the driving shaft
4 in alternate directions for repeating the reciprocation of the
driving piece 3, by reasonable use of the principle of inclination
lock. In the above description, the working rod is arranged to
be moved, being driven by the driving piece 3, in the direction
of extending from the support cylinder 1, but on the contrary,
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the working rod 2 carl be of course arranged to be driven ~y the
driving piece 3 .in the direction of shorteni-ng into the suppor-t
cylinder l. The drivi.ng devic~ of tlle present inventi.nn has the
following various fe~ltures, w~ n dpp1:ied to the 1ifting mech~nism
of the platform of a bed, for exampl.e. (1) Since the stlucture
is very simple ancl is not 1.arge-scal~d, the liftilg mechanism of
the platform can be made very simple. (2) Compared with the
driving device with internal thread engaged wi.th external thL-ead,
the loss of manpower by frictional force is small, makirlg the
burden of manpower small. (3) Since the working rod 2 can be
moved in one directi.on against the load by -the rotation of the
driving shaft 4 in alternate directions, the operation of the
lever for rotating the driving shaft 4 is simple. And for example,
a foot lever can be used as the lever, and in this case, the
burden of manpower for lifting the platform can be reduced further.
(4) If the buffer spring means D in the direction for the working
rod 2 to resile against the load is connected between the working
rod 2 and the support cylinder l, to be contained in the driving
device of the present invention, the sudden return of the working
rod 2 by the load can be prevented, and therefore the sudden drop
of the platform can be prevented without installing such a buffer
spring means D or any other buffer means in any other portion of
the lifting mechanism of the platform, enabling the entire
structure of the lifting mechanism to be very simplified. (5)
Since precision working of internal thread, external thread, etc.
is not required, manufacture is easy, and the device can be
supplied at low cost. (6) Since the device allows manpower
driving without using an expensive driving source such as a
geared motor, air compressor or hydraulic pump, the space below
the bed, etc. can be used effectively, and the device can be
supplied at very low cost also in connection with the feature (5).
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