TECHNICAL FIELD
[0001] The present invention relates to a foldable side rail for a bed or the like, particularly
a foldable side rail in which multiple strut members are pivotally rotatably connected
between an upper crosspiece member and a lower crosspiece member, to form a parallel
link mechanism.
BACKGROUND ART
[0002] Various side rails for beds have been proposed hitherto. Among them, widely used
are foldable side rails, each comprising multiple strut members pivotally rotatably
connected between an upper crosspiece member and a lower crosspiece member, to form
a parallel link mechanism, in such a manner that the side rail can assume a deployed
state for use where the abovementioned strut members are held in an upright position
and a stowed state of disuse where the multiple strut members are laid down by pivotal
rotation to lower the upper crosspiece member in parallel. In such a foldable side
rail, it is desired that the upper crosspiece member is kept low in height in the
stowed state of disuse.
[0003] There are many conventional foldable side rails as described, for example, in Patent
Document 1. and Patent Document 2. Figs. 9 through 11 typically show such a conventional
foldable side rail. In this foldable side rail, multiple strut members c are pivotally
rotatably connected between an upper crosspiece member a and a lower crosspiece member
b, to form a parallel link mechanism, and a holding mechanism d for holding the abovementioned
strut members c in an upright position is provided. In this case, the multiple strut
members c are basically square or circular in cross sectional form as shown in Fig.
11, and they are often chamfered or partially curved. Meanwhile, the operation of
such a foldable side rail will not be explained here, since the operation is obvious
from Fig. 9 showing the deployed state for use and Fig. 10 showing the stowed state
of disuse.
[0004] In the meantime, in preparation for cases where such foldable side rails are used
for medical beds, the dimensions of respective portions of side rails are specified
in such standards as IEC standard, especially to ensure safe use.
[0005] In the IEC standard, for example in the case where a side rail has closed spaces
like a lattice, the dimension of each space, namely, the dimension A in the drawings
is specified to be 120 mm or less to prevent that the head of the user can be inserted
into the space. Further, in the case where there is a space due to a clearance such
as the clearance between the end of the upper crosspiece member a and the head board,
it is specified that the dimension B of the clearance should be 60 mm or less to ensure
that the neck of the user cannot be inserted into the space or should be 235 mm or
more to ensure that the head cannot be caught.
[0006] In the case where the dimension A does not conform to the abovementioned specification
in the side rail of Fig. 9, it can be considered to increase the number of strut members
c per unit length of the side rail as shown in Fig. 12 as a method for changing to
satisfy the specification. That is, in the side rail of Fig. 12, the number of the
strut members c in the side rail as a whole is increased to double compared with the
number of strut members of Fig. 9.
Patent Document 1: Japanese Patent 2697765
Patent Document 2: Japanese Patent 3029026
DISCLOSURE OF THE INVENTION
PROBLEM TO BE SOLVED BY THE INVENTION
[0007] However, if the number of strut members c per unit length of a side rail is increased
as shown in Fig. 12, the height C of the upper crosspiece member a in the stowed state
becomes higher than that of the side rail of Fig. 9 as shown in Fig. 13, and the stored
state looks intrusive.
This invention has been created in view of the above. The object of this invention
is to satisfy the abovementioned dimension A specified for side rails while preventing
that the height of the upper crosspiece member of a side rail in the stowed state
becomes too high.
MEANS FOR SOLVING THE PROBLEM
[0008] To solve the abovementioned problem, this invention proposes a foldable side rail
in which multiple strut members are pivotally rotatably connected between an upper
crosspiece member and a lower crosspiece member, to form a parallel link mechanism,
while a holding mechanism is provided for holding the abovementioned strut members
in an upright position, wherein at least some of the strut members are flat strut
members disposed in such a manner that the flat surfaces thereof may face the adjacent
strut members, while the number of the strut members per unit length of the side rail
is increased.
[0009] Further, this invention proposes the abovementioned constitution, wherein the strut
members are flat strut members disposed in such a manner that the flat surfaces thereof
may face the adjacent strut members except the strut member positioned at the end
in the folding direction of the side rail.
[0010] Furthermore, this invention proposes the abovementioned constitution, wherein one
out of every predetermined number of strut members is a non-flat strut member.
[0011] Moreover, this invention proposes the abovementioned constitution, wherein the upper
ends of the strut members are shifted in the folding direction of the side rail while
the lower ends of the strut members are shifted in the unfolding direction of the
side rail.
EFFECTS OF THE INVENTION
[0012] In the foldable side rail of this invention, the number of strut members per unit
length of the side rail is increased to narrow the clearances formed between the strut
members, hence to easily satisfy the specified dimension, and in addition, since the
strut members are flat strut members disposed in such a manner that the flat surfaces
thereof may face the adjacent strut members, the height between the top and the bottom
of the side rail as a whole can be kept small even if the strut members overlap one
after another when they are stowed. Therefore, it can be prevented that the upper
crosspiece member becomes too high.
[0013] In the case where the upper ends of the strut members are shifted in the folding
direction of the side rail while the lower ends of the strut members are shifted in
the unfolding direction of the side rail, the clearances corresponding to the shifting
distances can be formed between the upper crosspiece member and the lower crosspiece
member on one hand and the pivotally inclined strut members on the other hand in the
stowed state or in a state just before the stowed state is reached. The clearances
serve to prevent that a finger of the user can be caught. This constitution is especially
effective in the case where temporarily halting mechanisms for temporarily halting
the strut members in a state just before the stowed state is reached are provided.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] [Fig. 1] is an illustration showing a first embodiment of the foldable side rail
of this invention in a deployed state for use.
[Fig. 2] is an illustration showing the first embodiment of the foldable side rail
of this invention in a stowed state of disuse.
[Fig. 3] is an illustration showing the first embodiment of the foldable side rail
of this invention in a temporarily halted state just before the stowed state is reached.
[Fig. 4] is an illustration showing the portion corresponding to the X-X line section
of Fig. 1 with the clearances between the strut members shortened for convenience.
[Fig. 5] is an expanded partial view of Fig. 1.
[Fig. 6] is an expanded partial view of Fig. 3.
[Fig. 7] is an illustration showing the first embodiment of the foldable side rail
of this invention in the deployed state for use.
[Fig. 8] is an illustration showing the portion corresponding to the Y-Y line section
of Fig. 7 with the clearances between the strut members shortened for convenience.
[Fig. 9] is a front view showing an example of the conventional foldable side rail
in the deployed state for use.
[Fig. 10] is a front view showing an example of the conventional foldable side rail
in the stowed state of disuse.
[Fig. 11] is an illustration showing the portion corresponding to the Z-Z line section
of Fig. 9 with the clearances between the strut members shortened for convenience.
[Fig. 12] is a front view showing a state where the strut members of the conventional
foldable side rail are increased in the deployed state for use.
[Fig. 13] is a front view showing a state where the strut members of the conventional
foldable side rail are increased in the stowed state of disuse.
MEANINGS OF SYMBOLS
[0015]
- 1u
- upper crosspiece member
- 1d
- lower crosspiece member
- 2
- strut member (flat)
- 20
- strut member (ordinary)
- 2r
- strut member (right end)
- 3
- attaching rod
- 4
- bed
- 5
- holding mechanism
- 6
- temporarily halting mechanism
- 7u, 7d
- shifted portion
THE BEST MODES FOR CARRYING OUT THE INVENTION
[0016] Embodiments of the foldable side rail of this invention are explained below in reference
to the attached drawings. At first, Figs. 1 through 6 show a first embodiment of the
foldable side rail to which this invention is applied.
In the drawings, symbol 1u denotes an upper crosspiece member and 1d denotes a lower
crosspiece member. Multiple strut members 2 are pivotally rotatably connected between
the upper crosspiece member 1u and the lower crosspiece member 1d, to form a parallel
link mechanism.
[0017] In Fig. 3, symbol 3 denotes an attaching rod projecting downward from the lower crosspiece
member 1d, and the attaching rods 3 are fitted into the fitting holes formed in the
upper surface of a bed frame, to attach the side rail to a lateral side of the bed
4. Further, symbol 5 denotes a holding mechanism for holding the strut members 2 in
an upright position, namely, for holding the side rail in the deployed state for use,
and the holding mechanism is a mechanism as described, for example, in the abovementioned
Patent Document 1 or 2.
[0018] On the other hand, in this embodiment, the lower crosspiece member 1d is provided
with temporarily halting mechanisms 6 for supporting the strut members 2 in a state
just before the stowed state is reached, and as the temporarily halting mechanisms,
mechanisms as described, for example, in the abovementioned Patent Document 1 can
be applied.
[0019] In the above constitution of this invention, at least some of the strut members 2
are flat strut members disposed in such a manner that the flat surfaces thereof may
face the adjacent strut members, and in this embodiment, all the strut members 2 are
flat strut members except the strut member 2r positioned at the end in the folding
direction of the side rail.
[0020] Fig. 4 corresponds to the X-X line section of Fig. 1, and shows the respective strut
members 2 with the respective clearances shortened for convenience, but it can be
seen that the respective strut members 2 are flat strut members disposed in such a
manner that the flat surfaces thereof may face the adjacent strut members.
[0021] Two types of strut members 2 different in the width in the pivotal rotation direction
are used in this embodiment, and the strut members 2 supported by the abovementioned
temporarily halting mechanisms 6 are larger in width to have a higher strength, though
the strut members 2 can also be equal in width if they are strong enough. Further,
in this embodiment, the strut members 2 are solid members, but can also be hollow
members or can also be hollow members with ribs or the like formed inside.
[0022] Further in this embodiment, the upper ends of the strut members 2 are shifted in
the folding direction of the side rail, and the lower ends of the strut members 2
are shifted in the unfolding direction of the side rail. In the drawings, symbols
7u and 7d show shifted portions.
[0023] In the above constitution, in the foldable side rail of this embodiment, the number
of the strut members 2 per unit length of the side rail is increased to narrow the
clearances A formed between the strut members 2 in the deployed state for use, hence
to easily satisfy the specified dimension.
[0024] In addition, the strut members 2 are flat strut members disposed in such a manner
that the flat surfaces thereof may face the adjacent strut members. Therefore, even
if the respective strut members 2 overlap one after another in the stowed state as
shown in Fig. 2, the overall height between the top and the bottom can be kept small.
Therefore, it can be prevented that the upper crosspiece member 1u becomes too high
in the stowed state.
[0025] Furthermore in this embodiment, the upper ends of the strut members 2 are shifted
in the folding direction of the side rail, and the lower ends of the strut members
2 are shifted in the unfolding direction of the side rail. Therefore, the clearances
S corresponding to the shifting distances 7u and 7d can be formed between the upper
crosspiece member 1u and the lower crosspiece member 1d on one hand and the pivotally
inclined strut members 2 on the other hand in the stowed state or in a state just
before the stowed state is reached. The clearances S serve to prevent that a finger
of the user can be caught. This embodiment is especially effective since the temporarily
halting mechanisms 6 for temporarily halting the strut members in a state just before
the stowed state is reached are provided.
[0026] Figs. 7 and 8 show a second embodiment of the foldable side rail to which this invention
is applied. In this embodiment, two flat strut members 2 disposed in such a manner
that the flat surfaces thereof may face the adjacent strut members and an ordinary
strut member 2o are disposed alternately so that every two flat strut members 2 are
disposed between one each ordinary strut member 2o. The same components as those of
the first embodiment are denoted by the same symbols, to avoid double explanation.
[0027] This embodiment can be constituted, for example, by disposing two flat strut members
2 for every strut member of the foldable side rail shown in the abovementioned Patent
Document 1 or 2.
[0028] In this constitution, the load acting on the upper crosspiece member 1u can be received
by the strut members 2o. Therefore, the flat strut members 2 are not required to be
provided as structural components to withstand the load, and accordingly can be formed,
for example, like thin strips. In this constitution, even if the strut members 2 and
2o overlap one after another in the stowed state, the upper crosspiece member 1u cannot
be so high, since the strut members 2 are thin in thickness.
INDUSTRIAL APPLICABILITY
[0029] Since the foldable side rail of this invention is as described above, the foldable
side rail satisfies the specified dimension and can prevent that the upper crosspiece
member becomes too high in the stowed state. Therefore, the foldable side rail of
this invention is most suitable for medical beds and stretchers.
[0030] Of course, the foldable side rail of this invention can also be used not only for
medical beds but also for home care beds and general beds.