Abstrict An adjustable bed having a frame in which a movable board and a
stationary board are arranged in a planar relationship and the movable
board is movable out of the plane of the stationary board by a motor
wherein a switch included in a circuit for controlling the motor
is turned off by a detector when a portion of a human body is caught
between the frame and the movable board during lowering thereof,
thereby preventing injury to the body.
Claims What is claimed as new and desired to be secured by Letters Patent
of the United States is:
1. An adjustable bed comprising:
a frame;
a stationary board fixedly mounted on said frame;
a movable board mounted on said frame and positioned in a horizontal
position with said stationary board in a plane parallel with said
frame;
driving means for moving said movable board out of the horizontal
plane formed by said stationary board, said driving means comprising
a motor, a circuit for controlling said motor, and a drive transmitting
mechanism disposed between said motor and said movable board; and
safety means for stopping operation of said motor when a portion
of the human body is caught between said frame and said movable
board during lowering thereof so as to prevent injury to the body,
said safety means comprising switch means included in said circuit
for stopping said motor and detecting means for disconnecting said
switch means.
2. An adjustable bed in accordance with claim 1 wherein said movable
board and said stationary board are located respectively at a head
board side and a foot board side of said frame.
3. An adjustable bed in accordance with claims 1 or 2 further comprising
arm means extending downwardly from a lower side of said movable
board in an outwardly direction and having a slot provided therein,
said detecting means comprising a pin connected with said drive
transmitting mechanism and in sliding engagement with said slot
provided in said arm means, said switch means further comprising
a lever fixed to said arm means and engaged with said pin such that
said switch means is disconnected after a predetermined retractive
stroke of said pin when a portion of the human body is caught between
said movable board and said frame.
4. An adjustable bed in accordance with claims 1 or 2 further comprising
pin means mounted on said movable board, said switch means also
being mounted on said movable board at a lower side thereof, said
detecting means comprising a panel fixed at a first end portion
thereof to one end portion of a lower side of said movable board
such that a second end portion of said panel is disposed a predetermined
distance from an upper end portion of said movable board and is
guided by said pin means such that said switch means is by the first
end portion of said panel when a portion of the human body is caught
between said panel and said frame.
5. An adjustable bed in accordance with claim 1 wherein said movable
board is divided into a first section and a second section, said
second section being mounted so as to be movable out of the horizontal
plane in conjunction with said first section.
6. An adjustable bed in accordance with claim 5 wherein said detecting
means comprises first and second pairs of lever means, rotatably
mounted respectively to lateral opposite sides of said first and
second sections and further comprising switch members connected
to said first and second pairs of levers.
7. An adjustable bed in accordance with claim 6 wherein said movable
board and said stationary board are located respectively at a foot
board side and a head board side of said frame.
8. An adjustable bed comprising:
a frame;
a stationary board fixedly mounted on said frame;
a first movable board mounted on said frame and located at a foot
board side of said frame, said first movable board being in a horizontal
position with said stationary board in a plane parallel with said
frame; at a head board side of said frame, said second movable board
being in a horizontal position with said stationary board in a plane
parallel with said frame;
first driving means for moving said first movable board out of
the horizontal plane formed by said stationary board, said first
driving means comprising a first motor, a first circuit for controlling
said first motor, and a first drive transmitting mechanism disposed
between said first motor and said first movable board;
second driving means for moving said second movable board out of
the horizontal plane formed by said stationary board, said second
driving means comprising a second motor, a second circuit for controlling
said second motor and a second drive transmitting mechanism disposed
between said second motor and said second movable board; and
safety means for stopping operation of said first motor of said
first circuit when a portion of the human body is caught between
said frame and said first movable board during lowering thereof
so as to prevent injury to the body, said safety means comprising
switch means included in said first circuit for stopping said first
motor and detecting means for disconnecting said switch means.
9. An adjustable bed in accordance with claim 8 said first movable
board comprising a first section and a second section, the second
section being mounted so as to be movable out of the horizontal
plane in conjunction with said first section.
10. An adjustable bed in accordance with claim 9 wherein said detecting
means comprises first and second pairs of lever means, rotatably
mounted respectively to lateral opposite sides of said first and
second sections and further comprising switch members connected
to said first and second pairs of levers.
Description BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to an adjustable bed, and more particularly
to an electrically operated adjustable bed.
2. Description of the Prior Art
There has been provided an adjustable bed wherein a head end portion
(or a foot end portion) of a bedboard may be raised so as to elevate
the head (or the feet) of the user. In an electrically operated
adjustable bed, the head end portion (or the foot end portion) is
raised by a motor through a mechanism. However, the conventional
electrically operated adjustable bed has a drawback in that a portion
of the human body (especially, a foot or a hand) can sometimes be
caught between the frame and the movable portion of the bedboard
during lowering thereof resulting in injury to that portion of human
body.
SUMMARY OF THE INVENTION
It is, therefore, one of the objects of this invention to provide
an electrically operated adjustable bed without the aforementioned
drawback.
It is another object of this invention to provide an electrically
operated adjustable bed having a safety mechanism for preventing
injury to the human body.
BRIEF DESCRIPTION OF THE DRAWINGS
Various other objects, features and attendant advantages of the
present invention will be more fully appreciated as the same becomes
better understood from the following detailed description when considered
in connection with the accompanying drawings in which like reference
characters designate like or corresponding parts throughout the
several views, and wherein:
FIG. 1 is a side view of a first embodiment of an adjustable bed
in accordance with this invention;
FIG. 2 is an upper plane view as seen in an arrowed direction A
in FIG. 1;
FIG. 3 is a lower plane view as seen in an arrowed direction B
in FIG. 1;
FIG. 4 is a side view as seen in an arrowed direction C in FIG.
3;
FIG. 5 is a perspective view of the interior of a gear-box in a
drive transmitting mechanism;
FIG. 6 is a view showing the relationship between a switch and
a lever;
FIG. 7 is a perspective view of a lever;
FIG. 8 is a circuit diagram showing a circuit for controlling a
motor;
FIG. 9 is a side view of a second embodiment of an adjustable bed;
FIG. 10 is an enlarged view of a portion encircled by area D in
FIG. 9;
FIG. 11 is a perspective view of a movable board with an arm mechanism
of the adjustable bed in FIG. 9;
FIG. 12 is a circuit diagram showing a circuit for controlling
the motor of the adjustable bed in FIG. 9;
FIG. 13 is a side view of a third embodiment of an adjustable bed
of the present invention;
FIG. 14 is a perspective view of a movable board with an arm mechanism
and a panel of an adjustable bed in FIG. 13;
FIG. 15 is a circuit diagram showing a circuit for controlling
the motor of the adjustable bed in FIG. 13; and
FIG. 16 is a perspective view of a major portion of a fourth embodiment
of the adjustable bed of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIGS. 1 through 8 an electrically operated adjustable
bed 10 includes a frame 11. Frame 11 includes a head board 12 a
foot board 13 longitudinally spaced therefrom, a pair of laterally
spaced beams 14 and 15 for connecting boards 12 and 13 and a pipe
16 whose opposite ends are respectively affixed below beams 14 and
15.
On beam 14 are fixed a first supporting member 17 a second supporting
member 18 a third supporting member 19 and a fourth supporting
member 20. First supporting member 17 is positioned at a corner
formed between board 12 and beam 14. Fourth supporting member 20
is positioned at a corner formed between board 13 and beam 14. Similarly,
a fifth supporting member 21 laterally opposing first supporting
member 17 a sixth supporting member 22 laterally opposing second
supporting member 18 a seventh supporting member 23 laterally opposing
third supporting member 19 and an eighth supporting member laterally
opposing fourth supporting member 20 are provided 24 fixed to beam
15.
A stationary board 25 is fixed at opposite ends thereof to supporting
members 18 and 22. A movable head board 26 is pivotably connected
to a left end portion of stationary board 25. Board 26 is provided
at the lower side thereof with a pair of arms 27 extending downwardly
in an outwardly inclined direction. Arms 27 are operatively connected
to a motor 29 through a transmitting mechanism 28 so that arms 27
may be pushed or pulled in the longitudinal direction upon operation
of motor 29. Thus, board 26 may be movable out of the horizontal
plane normally formed by board 25.
A movable foot board 30 is divided into a first section 31 and
a second section 32. A right end portion of first section 31 is
pivotably connected to a left end portion of second section 32.
A left end portion of first section 31 is pivotably connected to
a right end portion of stationary board 25. A right end portion
of second section 32 is pivotably connected to right end portions
of a pair of laterally spaced arms 33 and 34. Left end portions
of arms 33 and 34 are respectively pivotably connected to supporting
members 19 and 23.
A pair of arms 35 are extended downwardly in an outwardly inclined
direction from a lower side of first section 31 and are operatively
connected to a motor 38 through a drive transmitting mechanism 37
so that first section 31 may be movable out of the horizontal plane
in conjunction with second section 32.
Drive transmitting mechanism 37 is now explained in greater detail
with reference to FIGS. 3 4 and 5. A bracket 39 is welded to pipe
16 and a gearbox 41 is held in bracket 39 by a screw member 40.
A shaft 42 is provided in gearbox 41 with a worm gear 43 at one
end and another end portion 42a of shaft 42 is projected from box
41. End portion 42a of shaft 42 is connected to an axle 38a of motor
38 by means of a drive shaft 44. A sleeve 45 is rotatably mounted
to box 41 while a gear 46 is fixedly mounted on sleeve 45 and is
in mesh engagement with gear 43. A threaded shaft 47 is passed through
a tapped hole in sleeve 45 and is connected to arms 35. Thus, shaft
47 may be projected or retracted in accordance with rotation of
axle 38a of motor 38 upon operation thereof, and board 30 may be
raised or lowered relative to frame 11.
Four identical levers 48 are provided on lower opposite sides of
the first and second sections 31 and 32. Lever 48 may be obtained
by bending a single wire and has a central portion 48a, opposite
end portions 48b and 48c unevenly parallelly spaced to central portion
48a, a first bent portion 48d formed into an inverted L-shape for
connecting end portion 48b to central portion 48a, and a second
bent portion 48e similar to first bent portion 48d for connecting
end portion 48c to the central portion. Opposite end portions 48a
48b and 48c are respectively rotatably supported to a pair of longitudinally
spaced side walls 31a (only one shown). A horizontal portion of
bent portion 48d is supported by a pin 49 driven into side wall
31a. A limit switch 50 with an extension 51 is fixed to the side
wall 31a so that extension 51 is pushed by the horizontal portion
of the bent portion 48d upon counterclockwise rotation of the horizontal
portion about end portion 48b, thereby stopping motor 38.
An electric circuit 55 for driving the motor 38 is explained hereinafter
with reference to FIG. 8 wherein a power supply 56 a fuse 57 a
transformer 58 a rectifier 59 a condensor 60 a change-over switch
61 a first relay 62 a second relay 63 a neutral point 64 a contact
65 of the first relay 62 a contact 66 of the second relay 63 a
condensor 67 a main-coil 68 of the motor 38 and an auxiliary coil
69 of the motor 38 are illustrated. A lever 61a of change-over switch
61 may be connected to a terminal 62a of first relay 62 a terminal
63a of second relay 63 or the neutral point 64. Four limit switches
50 are connected in series and are held respectively in an "on"
condition.
In operation, when lever 61a of change-over switch 61 is connected
to terminal 62a, motor 38 is driven and axle 38a thereof is rotated
in a first direction. This rotation is transmitted to drive transmitting
mechanism 37. That is to say, when this rotation is transmitted
to shaft 42 by drive shaft 44 gear 43 is rotated together with
shaft 42 with the result that gear 46 and sleeve 45 are rotated
in the first direction. Thus, shaft 47 is advanced or projected
so as to move arm 35 thereby raising movable board 30 i.e. moving
first section 31 out of the horizontal plane in conjunction with
second section 32. Under this condition, when lever 61a is brought
into connection with neutral terminal 64 rotation of axle 38a ceases.
On the contrary, when lever 61a is connected to terminal 63a, axle
38a of motor 38 is rotated in a second direction opposite that of
the first direction. Thus, movable board 30 is lowered, i.e. first
section 31 and second section 32 are so rotated that both sections
31 and 32 may be brought into horizontal position with one another.
During lowering of the movable board 30 when a portion of the human
body such as a foot or a hand is caught between central portion
48a of lever 48 and beam 14 or 15 of frame 11 the horizontal portion
of bent portion 48d of lever 48 is raised, thereby contacting extension
51 of limit switch 50. Thus, limit switch 50 is brought into an
"off" condition with the result that motor 38 is stopped.
Consequently, injury of that portion of the human body is avoided.
Next, referring to the FIGS. 9 through 12 wherein an electrically
operated adjustable bed 110 is illustrated. In bed 110 a movable
board 126 is disposed at a left end portion thereof and is pivotably
connected at its right end portion to a left end portion of a stationary
board 125. Movable board 126 is connected to stationary board 125
and a pair of laterally spaced arms 127 and 127' extend downwardly
in an outwardly inclined direction from a lower side of movable
board 126.
Arm 127 is provided with a slot 127a and arm 127' is provided with
a slot 127'a identical and corresponding to slot 127a. A drive transmitting
mechanism 137 identical to the aforementioned mechanism 37 of the
first embodiment (see FIG. 3) is provided below frame 111. A shaft
147 of transmitting mechanism 137 may be advanced or retracted in
accordance with rotation of an axle (not shown) of a motor 138 (not
shown) in a first or second opposite direction as described hereinbelow.
A cap 170 with a tongue portion 171 is provided at a left end portion
of shaft 147. A pin 172 is fixed to tongue portion 171 of cap 170
and opposite end portions 172a (only one of which is shown) of tongue
portion 171 are in sliding engagement with slots 127a and 127'a
respectively. Movable board 126 and the pair of arms 127 and 127'
are rotatable downward onto frame 111. A limit switch 150 with a
lever 151 is provided on arm 127.
Limit switch 150 is so designed that switch 150 is normally held
in an on condition by lever 151 in pushed-engagement with limit
switch 150. A pin 172 of end portion 172a normally holds lever 151
in pushed-engagement with limit switch 150 and pin 172 is positioned
at one end wall of slot 127a by means of shaft 147 (see FIG. 10).
When a portion of the human body is caught between frame 111 and
movable board 126 during lowering movement thereof, pin 172 is disengaged
from one end wall of slot 127a and slidably moves within slot 127a.
Movement of pin 172 causes lever 151 to rotate counterclockwise
out of electrical contact with limit switch 150 (see FIG. 10). Thus,
limit switch 150 is brought into an off condition, thereby stopping
motor 138 to prevent further rightwardly movement of shaft 147 and
thus, rotation of movable board 126 is stopped. An electric circuit
155 for driving motor 138 shown in FIG. 12 is identical to circuit
55 shown in FIG. 8 except there is only one limit switch 150 in
circuit 155 but there are four limit switches 50 in circuit 55.
In circuit 155 when lever 61a of switch 61 engages contact 62a,
motor 138 rotates to move the shaft 147 to the left (see FIG. 10)
through transmission mechanism 137. The leftwardly movement of shaft
147 rotates movable board 126 in a clockwise direction, i.e., pivotally
raising movable board 126 out of the horizontal plane of stationary
board 125 by means of arms 127 127'. When the movable board 126
is rotated to a predetermined position, lever 61a is moved to neutral
point 64 and motor 138 is disengaged. Movable board 126 will be
maintained in the predetermined position by shaft 147 engaging slots
127a, 127'a of arms 127 127' through opposite end portions 172a.
When lever 61a engages contact 63a, motor 138 reversely rotates
such that shaft 147 is moved to the right (see FIG. 10). Rightwardly
movement of shaft 147 rotates movable board 126 in a counterclockwise
direction, i.e., pivotally lowering movable board 126 into the horizontal
plane of stationary board 125 due to the weight of movable board
126.
In FIGS. 13 through 15 a movable board 226 is substantially identical
to the movable board 126 as described hereinabove and shown in FIG.
11 and movable board 226 is provided at the lower side thereof with
a pair of limit switches 250 (only one shown), a pair of pins 271
and a panel 270. A right end portion of panel 270 is fixed to a
right end portion of movable board 226 so that a left end portion
of panel 270 may be located away from a left end portion of board
226. The left end portion of panel 270 is in abutment with a pair
of levers 251 (only one of which is shown) of limit switches 250
and movement of the left end portion of panel 270 into contact with
the left end portion of movable board 226 is guided along pins 271.
Movable board 226 is rotated upwardly and downwardly in a manner
similar to movable board 126 described hereinabove (see particularly
FIG. 10) by motor 238 (not shown) and drive transmission mechanism
237. Circuit 255 for motor 238 is substantially the same in construction
and operation as circuit 155 discussed hereinabove with the exception
that the single limit switch 150 of circuit 155 is replaced by the
two limit switches 250 in circuit 255. During normal upwardly and
downwardly rotation of movable board 226 the left end portion of
panel 270 is spaced apart from the left end portion of movable board
226 and the levers 251 abutting panel 270 so as to maintain the
limit switches 250 in the "on" condition. If a portion
of the human body is caught between frame 211 and panel 270 the
left end portion of panel 270 is pushed into contact with the left
end portion of movable board 226 by guided movement along pins 271
and this contacting movement between panel 270 and board 226 moves
levers 251 such that limit switches 250 are disengaged, thus stopping
motor 238 and preventing further rotation of board 226. The other
portions of an adjustable bed 210 are similar to those of adjustable
bed 110 discussed hereinabove.
FIG. 16 shows a combination of the second (see FIGS. 9-12) and
third (see FIGS. 13-15) embodiments described hereinabove and wherein
three limit switches 350 are provided for a movable board 326. Two
of the switches 350 are so located at a lower side of movable board
326 such that these two switches 350 may be turned off by a panel
370 when a portion of the human body is caught between panel 370
and a frame (not shown) as described in the embodiment of FIGS.
13-15. The remaining limit switch 350 is positioned at an arm 327
and operates in a manner as described in the embodiment of FIG.
10 so that the third limit switch 350 may be turned off for stopping
a motor 338 (not shown) if the two switches 350 of movable board
have not been turned off by a potion of a human body interposed
between the frame and movable board 326. The other portions of the
adjustable bed are similar to those described hereinabove. An electric
circuit for this embodiment is similar in construction and operation
as circuit 255 of FIG. 15 with the exception that the two limit
switches 250 of circuit 255 are replaced by the three limit switches
350 described hereinabove.
Obviously, numerous modifications and variations of the present
invention are possible in light of the above teachings. It is therefore
to be understood that within the scope of the appended claims, the
invention may be practiced otherwise than as specifically described
herein.
|