JP2015006265A - Carrier - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a carrier (stretcher and bed) that can be miniaturized and facilitates insertion of a C arm of an X-ray imaging apparatus, and also is effective for lowering a bed.SOLUTION: When a caster of a stretcher becomes a locked state, a guided part 25 moves to a first position in a guide part 40, and is turned to a position where an arm 30 of a center wheel 31 becomes the highest. When the caster is in a free state, the guided part 25 moves to an intermediate second position of the guide part 40 and the wheel arm 30 descends, but the center wheel 31 does not come into contact with a floor surface. Furthermore, when a pedal is operated and the guided part 25 moves to a third position of a guide part 40, the center wheel 31 rolls in the floor surface.

Description

  The present invention relates to a transport body such as a bed and a stretcher that can be transported in a hospital, and more particularly to a transport body that can be selectively provided with straightness.

  In hospitals, etc., casters are installed at the four corners of the bed so that the bed can be easily moved, and casters are installed at the four corners to transport the patient lying down. A stretcher is used. Transporters such as these beds and stretchers can be moved by casters. These casters are installed at the four corners of the base frame of the carrier, and the wheels of the casters rotate around a horizontal axis and are attached to the base frame so that the rotation axis rotates around the vertical direction. ing. Thereby, the operator can move conveyance bodies, such as a bed and a stretcher, to arbitrary directions.

  By the way, in the case of these transport bodies, it is necessary to be able to bend in an arbitrary direction, but it may be necessary to have high straightness. In particular, in the case of a stretcher used for emergency transportation, a nurse may push and move the stretcher at a fairly high speed in the hospital. In such a case, the stretcher may meander, If it is staggered, the transfer operation will be hindered. Therefore, there has been proposed a stretcher in which a center wheel that rotates around a horizontal axis at the center of the stretcher, but does not rotate such as a caster (Patent Documents 1 to 3). This center wheel rotates around a horizontal axis that extends in the width direction of the stretcher, but this horizontal rotation axis does not rotate, and when the stretcher moves in its longitudinal direction, it rolls to the floor and is smooth. However, if the stretcher tries to bend, the direction of rotation of the center wheel will be different from the direction of movement of the stretcher, and the circumference of the center wheel will frictionally slide on the floor and the stretcher will bend. Resistance is generated. As a result, the straightness of the stretcher is increased by the center wheel.

  FIG. 12 is a perspective view showing a base frame of a conventional stretcher with a center wheel, and FIG. 13 is a perspective view showing the vicinity of the center wheel. 14 to 16 are diagrams showing the operation of the center wheel. The base frame 100 includes a horizontal frame 101 to which two front wheels are attached, a horizontal frame 102 to which two rear wheels are attached, and a pair of vertical frames 103 that connect the two horizontal frames 101 and 102. The horizontal frame 101 is provided with casters 104 for front wheels at both ends thereof, and the horizontal frame 102 is provided with casters 105 for rear wheels at both ends thereof. These casters 104 and 105 are attached to the horizontal frames 101 and 102 of the base frame 100 so that the wheels rolling on the floor surface rotate around the horizontal axis and the rotation shaft rotates around the vertical direction. It has been. Accordingly, the base frame can travel while changing its direction in an arbitrary direction.

  In addition, a caster lock / free control rod 108 is rotatably supported by the front and rear horizontal frames 101 and 102 in the vicinity of one vertical frame 103 in parallel with the vertical frame 103. The pedal 107 can be rotated around the central axis of the rod 108 in the forward direction or the reverse direction. The rod 108 is rotatably connected to the rods installed on the horizontal frames 101 and 102, and is installed on the horizontal frames 101 and 102 by rotating the rod 108 in one direction by a pedal 107. The casters 104 and 105 can be locked through the rods so as not to rotate. When the rod 108 is rotated in the reverse direction by the pedal 107, the locked state of the casters 104 and 105 is released, and the base frame can be moved.

  A gate-mounting center wheel mounting frame 109 is fixed to both vertical frames 103 so as to span a portion in the vicinity of a substantially central portion of the pair of vertical frames 103. An arm 113 is rotatably installed on the frame 109, and a spring spring 114 is further attached. A rotating shaft 110 is fixed to the rod 108, and an arm 111 is rotatably connected to the rotating shaft 110. The other ends of the arm 113 and the arm 111 are rotatably connected to a common shaft, and the arm 112 is rotatably connected to the common shaft.

  An arm 115 is supported by the vertical frame 103 so as to be rotatable about a rotation axis in the width direction of the stretcher, that is, in a direction parallel to the longitudinal direction of the horizontal frames 101 and 102. A center wheel 120 is rotatably supported around a horizontal axis extending in the width direction of the stretcher. Thereby, when the center wheel 120 is in contact with the floor, when the stretcher moves in its longitudinal direction, it rolls and rotates on the floor surface, but when it moves in a direction other than the longitudinal direction of the stretcher, The center wheel 120 slides with respect to the floor surface. The spring spring 114 is a tension spring that is connected to the arm 115 and elastically biases the arm 115 in a direction in which the arm 115 is always lifted.

  In this conventional stretcher, when the pedal 107 is operated with a foot and the rod 108 is rotated in one direction, the four casters 104 and 105 are locked, and as shown in FIG. 110 rotates in the direction of pulling the arm 111 outward in the width direction of the stretcher, the arm 111 pulls the arm 112 and the arm 113 outward in the width direction of the stretcher, and the arm 112 rotates the arm 115 upward. . As a result, as shown in FIG. 14, the center wheel 120 is greatly separated from the floor surface to be in the retracted position.

  On the other hand, when the pedal 107 is operated with the foot and the pedal 107 is returned to the intermediate position, the rod 108 rotates so that the rotating shaft portion 110 rotates toward the center of the stretcher, and the arm 111 moves to the arm 112, 113 is pushed toward the center of the stretcher, the arm 112 is rotated downward, and the arm 115 is rotated downward. By the rotation of the rod 108, the four-wheel casters 104, 105 are released from the fixed state, become free, and the stretcher can move. On the other hand, as described above, the arm 115 is rotated downward by the rotation of the rod 108, but the wheel 120 is not lowered until it contacts the floor as shown in FIG. Therefore, when the pedal 107 is in a horizontal state, the four-wheel casters 104 and 105 are in a free state, the center wheel 120 is in an off state, and the stretcher can move in any direction.

  Then, when the pedal 107 is operated with the foot and the pedal 107 is rotated in the reverse direction, the rod 108 is rotated to push the arm 111 further toward the center of the stretcher, and as shown in FIG. Pushes the connecting point between the arm 113 and the arm 112 further to the center of the stretcher, rotates the arm 113 and the arm 112 around the upper end of the arm 113, and lowers the center wheel 120 to contact the floor surface. Let In this state, the four-wheel casters 104 and 105 are free, but since the wheel 120 is in contact with the floor surface, the stretcher is difficult to bend and can move preferentially in the longitudinal direction. The arms 112 and 113 are rotated so as to be arranged substantially linearly, and this state is maintained by the arm 111. Therefore, even if the wheel 120 receives a reaction force from the floor surface, the wheel 120 does not move from the floor surface. There is no separation.

US Pat. No. 5,987,671 US Pat. No. 6,286,165B1 US Publication No. 2001 / 0039679A1

  However, in this conventional stretcher, the center wheel 120 moves up and down greatly between the off state (FIG. 14) and the on state (FIG. 16), so that a space for that is required. In addition, a space for installing the frame 109 for supporting the arm 113 so as to be rotatable and supporting the tension spring spring 114 is required. In particular, in the case of a stretcher, for X-ray imaging, a C-shaped imaging device (so-called C-arm) is sandwiched between a base frame 100 and a main frame on which a mattress is placed so as to be movable up and down. Need to be inserted and placed. In order to install this C-arm, it is necessary to provide a desired space between the main frame and the base frame. Further, a space for storing an oxygen cylinder or the like is also required on the base frame 100. For this reason, a stretcher will enlarge. Further, when the height of the base frame 100 is lowered in an attempt to increase the space between the main frame and the base frame, the casters 104 and 105 are in a free state and the center wheel 120 is in an off state, as shown in FIG. When transporting the stretcher, the wheel 120 is not in contact with the floor surface, but since it is at a relatively low position, the clearance with the floor surface is reduced, and the floor surface tilts downward when transporting the stretcher. When moving to the inclined surface, there is a risk that the center wheel 120 comes into contact with the floor surface and the handle is taken.

  On the other hand, when the distance between the main frame and the base frame cannot be increased, the shape of the C-arm of the X-ray imaging apparatus is restricted, and the imaging performance is affected. Also, oxygen cylinders and the like cannot be stored.

  The present invention has been made in view of such a problem, and provides a transport body that can be reduced in size, can be easily inserted into a C-arm of an X-ray imaging apparatus, and is effective for lowering a bed. For the purpose.

The carrier according to the present invention is
In the carrier installed on the base frame, the main frame that supports the bed part,
Casters disposed at four corners of the base frame;
A lock mechanism for fixing the rotation of these casters and releasing the fixation;
A pedal that switches between fixing and releasing the caster by the lock mechanism according to a change in angle;
A wheel drive member installed on the base frame so as to be rotatable about a direction perpendicular to its longitudinal direction as a rotation axis;
A connecting member that connects the pedal and the wheel driving member, and rotates the wheel driving member in accordance with a change in the angle of the pedal;
A wheel arm for a rectilinear wheel installed on the base frame so as to be rotatable about a direction perpendicular to the longitudinal direction thereof as a rotation axis;
A rectilinear wheel installed at the tip of this arm so as to be rotatable about a direction perpendicular to the longitudinal direction of the base frame as a rotation axis;
A tension spring having one end locked to the wheel drive member and the other end locked to the wheel arm;
Have
The wheel arm has a groove-shaped or hole-shaped guide portion provided between the rotating shaft and the straight traveling wheel,
The wheel driving member has a guided portion that engages with the guide and is guided along the guide,
When the pedal is rotated to a first angle that puts the caster in a fixed locked state, the wheel driving member is rotated via the connecting member to move the guided portion to the first position in the guide portion. In this first position, the wheel is located at the highest position farthest from the floor surface,
When the pedal is rotated to a second angle that brings the caster into the unlocked free state, the wheel driving member is rotated via the connecting member to bring the guided portion into the second position in the guide portion. Moved, and in this second position, the wheel is located in a middle position away from the floor without contacting the floor,
When the pedal further rotates to the third angle, the wheel driving member rotates through the connecting member to move the guided portion to the third position in the guide portion, and at this third position, The wheel is located at a low position in contact with the floor surface.

The wheel driving member is
A first arm that is rotatably supported by the base frame at a middle portion of the base frame with a direction perpendicular to the longitudinal direction thereof as a rotation axis, and the connecting member is rotatably connected at one end; ,
A second arm provided with the guided portion at the tip;
A connecting portion for connecting the first arm and the second arm in a fixed state at the other end thereof;
Have
When the connecting member rotates the first arm, the second arm rotates, and the guided portion is guided by the guide portion to move relatively so that the wheel arm rotates. And
One end of the tension spring is locked at a position on the other end side of the second arm, and the other end is locked on the wheel arm,
When the line segment connecting the locking points of the tension spring is on the opposite side of the wheel from the rotation axis of the first arm, the line segment is urged in the direction of raising the wheel, and the line segment is When the wheel is located on the wheel side with respect to the rotation shaft of the first arm, the wheel can be configured to be biased in a downward direction.

Also,
The guide portion of the wheel arm may be configured to be in a straight line shape or a wave shape in which the guided portion is easy to move along the guide portion.

Furthermore,
The pedal is arranged for each caster,
A front wheel lateral interlocking member provided on the base frame for connecting two front wheels;
A rear wheel lateral interlocking member provided on the base frame and connecting two rear wheels;
A longitudinal interlocking member that connects the front wheel lateral interlocking member and the rear wheel lateral interlocking member;
Have
When any one of the four pedals is rotated to the first angle, the second angle, or the third angle, the front wheel lateral interlocking member, the rear wheel lateral interlocking member, and the vertical interlocking member are interposed. And all casters can be locked or switched,
The connecting member may be configured such that the longitudinal interlocking member is also used.

And for example,
The rotation axis of the wheel arm is fitted and supported in a long hole provided in the base frame, and the rotation axis of the wheel arm can move in the long hole.

  According to the present invention, the straight wheel can be moved up and down by a small mechanism, a large space can be generated between the base frame and the main frame, and the shape of the C-arm for X-ray photography is restricted. It can be inserted without receiving, and a sufficient space for storing the oxygen cylinder can be secured.

It is a perspective view which shows the base frame 1 of the stretcher of embodiment of this invention. 3 is a perspective view of a wheel driving member 20. FIG. 3 is a perspective view showing a wheel arm 30. FIG. 4 is a perspective view showing components of the wheel driving member 20. FIG. The component which supports the wheel arm 30 so that rotation is possible is shown. (A) thru | or (d) is a side view which shows the vertical movement operation | movement of a center wheel. It is a perspective view which shows other embodiment of this invention. (A), (b) is a figure which similarly shows the operation | movement of the wheel drive member. (A) thru | or (d) is a figure which similarly shows the operation | movement of the wheel drive member. It is a figure which shows other embodiment of this invention. It is a figure which shows other embodiment of this invention. It is a perspective view which shows the base frame of the conventional stretcher with a center wheel. It is a perspective view which shows the vicinity of the center wheel. It is a figure which shows operation | movement of a center wheel. It is a figure which shows operation | movement of a center wheel. It is a figure which shows operation | movement of a center wheel.

  Hereinafter, embodiments of the present invention will be specifically described with reference to the accompanying drawings. 1 is a perspective view showing a base frame 1 of a stretcher according to an embodiment of the present invention, FIG. 2 is a perspective view of a wheel driving member 20, FIG. 3 is a perspective view showing a wheel arm 30, and FIG. FIG. 5 is a perspective view showing parts, FIG. 5 is a part for rotatably supporting the wheel arm 30, and FIGS. 6A to 6D are side views showing the vertical movement operation of the center wheel.

  The base frame 1 includes a front-wheel-side horizontal frame 2, a rear-wheel-side horizontal frame 4, and a pair of vertical frames 3 that connect the horizontal frame 2 and the horizontal frame 4. Further, support columns 5 and 6 are erected on the vertical frame 3, and a main frame (not shown) is installed on the support columns 5 and 6. A bed (not shown) is installed on the main frame. The casters 7 and 9 are arranged at the four corners of the base frame 1. The casters 7 and 9 are rotatably installed around the vertical rotation shafts 8 and 10 provided on the base frame 1. The casters 7 and 9 roll around the floor surface by rotating around a horizontal rotation axis perpendicular to the rotation axes 8 and 10. Thus, since the casters 7 and 9 rotate about the horizontal axis and roll on the floor surface, the base frame 1 can be transported on the floor surface. The rotation direction rotates around the vertical rotation shafts 8 and 10 and can be directed in any direction, and the base frame 1 can be bent in any direction.

  Pedals 11 are arranged in the vicinity of casters 7 and 9 at the four corners of the base frame 1. When the pedal 11 is at the first angle, the casters 7 and 9 and the rotation shafts 8 and 10 cannot be rotated and are fixed. Further, when the pedal 11 is at the second angle and the third angle, the casters 7 and 9 are fixed, and the casters 7 and 9 and the rotation shafts 8 and 10 can be rotated. In the vicinity of the horizontal frames 2, 4, left and right interlocking rods 12 are installed in parallel with the horizontal frames 2, 4, and in the vicinity of the pair of vertical frames 3, the front and rear are parallel to the vertical frame 3. An interlocking rod 13 is installed. The left and right interlocking rods 12 installed in the vicinity of the front wheel lateral frame 2 are connected to a pair of left and right pedals 11 and rotate when the pedals 11 are rotated. Is also designed to rotate in conjunction. Similarly, the left / right interlocking rod 12 installed in the vicinity of the rear wheel lateral frame 4 also rotates in conjunction with the other pedal 11 as one pedal 11 rotates. The front wheel left / right interlocking rod 12 and the rear wheel left / right interlocking rod 12 are connected to a front / rear interlocking rod 13, and the front / rear interlocking rod 13 is moved in the longitudinal direction of the base frame 1 (front / rear) by rotating the pedal 11. Direction). Since the front wheel left / right interlocking rod 12 and the rear wheel left / right interlocking rod 12 are connected by the front / rear interlocking rod 13, any one of the four pedals 11 can be stepped on to change its angle. Then, all casters 7 and 9 are interlocked and simultaneously fixed or released.

  A wheel driving member 20 for vertically driving the straight traveling wheel is installed at a substantially central portion of the base frame 1. As shown in FIG. 4, the wheel driving member 20 includes a pair of short flat plate-like first arms 21 and a pair of long flat plate-like second arms 22 in a pipe-like connecting portion 23. The first arm 21 is disposed at both ends of the connecting portion 23 and the second arm 22 is disposed at the central portion of the connecting portion 23. The first arm 21 and the second arm 22 are fixed to the connecting portion 23 so as to be parallel to each other, but the arm extending direction with respect to the connecting portion 23 is slightly different. The first arm 21 has a hole 21a formed in the middle thereof, and a hole 21b formed in the tip thereof. Further, the second arm 22 has a hole 22a formed at the base end portion thereof, and a hole 22b formed at the tip end portion thereof. A guided portion 25 (see FIG. 6) is attached and fixed to the second arm 22 through a hole 22 b at the tip of the second arm 22. Further, a rod-shaped locking portion 24 (see FIG. 6) is fixed to the second arm 22 through a hole 22 a at the base end portion of the second arm 22.

  As shown in FIG. 2, a pair of left and right vertical frames 3 of the base frame 1 is fixed with a U-shaped shaft member 14 in plan view, and the first arm 21 of the wheel drive member 20 has a hole in the first arm 21. 21 a is rotatably attached to the shaft member 14 by a bolt 15. Further, the hole 21 b of the first arm is rotatably connected to the front / rear interlocking rod 13 by a pin 17. As a result, when the front / rear interlocking rod 13 reciprocates in the longitudinal direction of the base frame 1, the wheel driving member 20 can rotate forward and backward with the bolt 15 as a rotation axis.

  As shown in FIG. 3, the wheel arm 30 has a structure in which a pair of flat plate-like parallel members 32 are connected by a connecting portion 33, and a center wheel 31 is rotatably supported at the tip of the parallel member 32. Has been. A hole 34 is formed in the base end portion of the parallel member 32, and a groove-shaped guide portion 40 that extends in the longitudinal direction of the parallel member 32 but is slightly waved is formed in the intermediate portion of the parallel member 32. Is formed. The guided portion 25 of the second arm 22 is inserted into the groove guide portion 40, and the guided portion 25 is guided by the groove guide portion 40 and relatively moves. A rotation shaft member 42 (see FIG. 6) is inserted into the pair of holes 34 of the parallel member 32, and the parallel member 32 is connected by the rotation shaft member 42.

  As shown in FIG. 2, shaft members 16 are fixed to the opposing surfaces inside the pair of vertical frames 3, respectively. As shown in FIG. Symmetrically shaped flat holes 16a and 16b that are inclined upward and downward are formed, and the rotation shaft member 42 of the wheel arm 30 is inserted into the hole 16b so that the wheel arm 30 can rotate on the shaft member 16. It is supported. The rotation shaft member 42 which becomes the rotation shaft of the wheel arm 30 can move slightly within the flat hole 16b. The shaft member 16 is formed with two vertically symmetrical flat holes 16a and 16b, because it is necessary to install the two shaft members 16 symmetrically in the width direction of the stretcher. is there. On the side surface of the stretcher shown in FIGS. 5 and 6, the shaft member 16 is attached to the vertical frame 3 so that the rotating shaft member 42 of the wheel arm 30 is inserted into the flat hole 16b inclined up and down. On the opposite side surface of the letcher, the shaft member 16 in FIG. 5 is turned upside down and attached upside down to the vertical frame 3 on the opposite side. Then, the rotating shaft member 42 of the wheel arm 30 is inserted into the flat hole 16a positioned below. Thereby, only one part (shaft member 16) is manufactured and prepared, and one part can be used in common as the shaft member 16 installed on the left and right in the width direction of the stretcher.

  Further, as shown in FIG. 6A, the tension spring 41 is locked to the locking portion 24 of the second arm 22 and the rotating shaft member 42 of the wheel arm 30. The wheel drive member 20 is urged in the direction in which the center wheel 31 rises.

  Next, operation | movement of the stretcher of this embodiment comprised in this way is demonstrated. 6A shows the locked state (fixed state) of the casters 7 and 9, and FIG. 6B shows the free state (fixed released state) of the casters 7 and 9. In the locked state of the casters 7 and 9, as shown in FIG. 1, the pedal 11 is inclined with one of the lifted up. The angle of the pedal 11 in this locked state is defined as a first angle. When the pedal 11 is at the first angle, the front / rear interlocking rod 13 is engaged with the front / rear interlocking rod 13 (not shown in FIG. 6) via the pin 17 (hole 21b) as shown in FIG. 6 (a). The combined first arm 21 is in a position to tilt around the rotation shaft (bolt 15 and hole 21a). When the first arm 21 is tilted as shown in FIG. 6A, the second arm 22 is also tilted in the same direction as the first arm 21, and as a result, the guided portion at the tip of the second arm 22 is tilted. 25 moves in the guide portion 40 to the first position in the vicinity of the end portion on the center wheel 31 side. Thereby, the wheel arm 30 rotates so that the front-end | tip raises, the center wheel 31 raises and retracts in the position most distant from the floor surface. At this time, the tension spring 41 is shortest and urges the wheel arm 30 in the upward direction. In a state where the casters 7 and 9 are locked, the stretcher keeps the stopped state and does not run by itself even if an unexpected force is applied.

  Next, when the pedal 11 is returned to the horizontal state, the casters 7 and 9 are in a free state (fixed release state). The angle of the pedal 11 in this free state is the second angle (horizontal). At this time, the pedal 11 changes from an inclined state to a horizontal state, the front / rear interlocking rod 13 moves slightly forward, and the first arm 21 connected to the front / rear interlocking rod 13 via the pin 17 is shown in FIG. As shown in (b), it rotates until it becomes a substantially vertical state. At this time, since the second arm 22 also rotates together with the first arm 21, the guided portion 25 moves to the second position in the center of the guide portion 40, and the inclination of the wheel arm 30 decreases. However, in this state, the center wheel 31 at the tip of the wheel arm 30 remains at a position separated from the floor surface. At this time, the tension spring 41 extends slightly from the state of FIG. 6A and biases the wheel arm 30 in the direction of rotating upward. When the casters 7 and 9 are in a free state, the stretcher can freely move in an arbitrary direction by being pushed or pulled by the operator.

  Next, when the pedal 11 is further tilted in the reverse direction of FIG. 1, the front / rear interlocking rod 13 further moves forward, and the first arm 21 connected to the front / rear interlocking rod 13 via the pin 17 is shown in FIG. As shown in (c), it tilts in the opposite direction of FIG. The angle of the pedal 11 is defined as a third angle. When the pedal 11 is inclined at the third angle, the casters 7 and 9 remain free.

  As shown in FIG. 6C, when the first arm 21 tilts, the second arm 22 also tilts in the opposite direction of FIG. The guided portion 25 at the distal end moves the guide portion 40 to the third position in front of the stretcher, and as a result, rotates the wheel arm 30 in the direction in which the wheel 31 at the distal end descends. Thereby, the center wheel 31 descend | falls, contacts a floor surface, and if a stretcher moves, it will roll to a floor surface. In the process of shifting from FIG. 6B to FIG. 6C, when the axial center of the tension spring 41 passes through the rotation shaft (hole 21a) of the first arm 21, the tension spring 41 extends the longest. Thereafter, as shown in FIG. 6C, the first arm 21 and the second arm 22 are further rotated, and the axis of the tension spring 41 passes through the rotation axis (hole 21a) of the first arm 21. Then, the tension spring 41 is slightly contracted. As a result, the direction in which the tension spring 41 tries to rotate the wheel driving member 20 is reversed, and the tension spring 41 pushes the first arm 21 and the second arm 22 and the center wheel 31 is pressed against the floor surface. Energize. Therefore, in the state of FIG. 6C, the center wheel 31 stably exerts a drag on the floor surface and rolls stably on the floor surface. Therefore, even if the pedal is released, the center wheel 31 is kept in contact with the floor surface. That is, the coil axis connecting the locking portion 24 and the rotation shaft member 42 is located closer to the wheel 31 than the rotation axis (hole 21a) of the first arm 21, so this axis is the rotation axis. Unlike the case of FIGS. 6A and 6B, which is closer to the rotating shaft member 42 than the hole 21 a, the tension spring 41 is attached with the wheel arm 30 facing downward via the second arm 22. Rush. Thereby, the center wheel 31 exerts a pressing force on the floor surface and receives a reaction force from the floor surface, so that the center hole 31 rolls on the floor surface with an appropriate frictional force.

  In this state, since the center wheel 31 rolls to the floor surface and the center wheel 31 rotates about only the direction perpendicular to the longitudinal direction of the base frame 1 as the rotation axis, the stretcher moves without resistance when going straight. When the stretcher tries to bend, the center wheel 31 slides on the floor surface, so that a resistance force is generated. As a result, the stretcher can be straight when transported and the transport safety is improved.

  Further, as shown in FIG. 6 (d), there may be an obstacle 45 on the floor when the stretcher is transported, but the hole 16b of the shaft member 16 is flat and engages with the hole 16b. The rotating shaft member 42 that moves can move in the hole 16b. For this reason, in the steady state of FIG. 6C, the rotation shaft member 42 that is the rotation shaft of the wheel arm 30 is located at a substantially intermediate position of the hole 16b. As shown in FIG.6 (d), it can move to the lower end of the hole 16b. Then, since the wheel arm 30 rotates slightly upward with the guided portion 25 as the center, the wheel arm 30 rotates slightly upward when the rotation shaft member 42 is positioned at the lower end of the hole 16b. As described above, even when the obstacle 45 exists on the floor surface, the wheel arm 30 rotates upward, and the center wheel 31 can get over the obstacle 45. For this reason, even if the obstacle 45 exists, the center wheel 31 is prevented from being damaged.

  In the present embodiment, the pedals 11 are arranged in the vicinity of the four casters 7 and 9, and each pedal 11 is connected by the lateral interlocking rod 12 and the front / rear interlocking rod 13. Then, the center wheel 31 can be raised and lowered. For this reason, the center hall 31 can be moved up and down immediately regardless of the position of the stretcher.

  FIG. 7 is a perspective view showing another embodiment of the present invention. In this embodiment, the groove-shaped guide part 50 formed in the parallel member 32 of the wheel arm 30 extends linearly. As shown in FIG. 3, if the groove-shaped guide portion 40 is bent so as to be slightly waved, the guided portion 25 can smoothly move the guide portion 40, but as shown in FIG. 7, The groove guide portion 50 may be formed linearly. In this case, as shown in FIG. 8, the guided portion 25 moves through the linear guide portion 50. FIG. 8A shows a locked state of the casters 7 and 9, and FIG. 8B shows a free state of the casters 7 and 9. Similarly, FIG. 9 shows the operation of the center wheel. When the pedal 11 is further rotated from the caster-free state of FIG. 9A, the center wheel is moved as shown in FIG. 9B. When the wheel 31 comes into contact with the floor surface and the shaft core of the tension spring 41 passes through the rotation shaft (hole 21a) of the first arm 21 as shown in FIG. As shown in FIG. 9D, when the second arm 22 is further rotated, the axis of the tension spring 41 passes through the rotation axis of the first arm 21, and the tension spring 41 is slightly contracted. . As a result, the direction in which the tension spring 41 tries to rotate the hall driving member 20 is reversed, and the center wheel 31 stably exerts a drag on the floor surface and rolls stably on the floor surface.

  As shown in FIG. 10, the guide part 51 provided in this wheel arm may have a bent shape. FIG. 10A shows the locked state of the casters, and the guided portion 25 is located at the end portion on the wheel 31 side. FIG. 10B shows a free state of the caster, and the guided portion 25 is located at an intermediate position of the guide portion 51.

  FIG. 11 further shows another guide portion 52. The guide portion 52 is obtained by increasing the wave shape of the guide portion 40.

1: base frame 2, 4: horizontal frame 3: vertical frame 7, 9: caster 11: pedal 13: front / rear interlocking rod 20: wheel drive member 21: first arm 21a: hole (rotating shaft of the first arm)
22: second arm 24: locking portion 25: guided portion 30: wheel arm 31: center wheel 40, 50, 51, 52: guide portion 41: tension spring 42: rotating shaft member

Claims (5)

In the carrier installed on the base frame, the main frame that supports the bed part,
Casters disposed at four corners of the base frame;
A lock mechanism for fixing the rotation of these casters and releasing the fixation;
A pedal that switches between fixing and releasing the caster by the lock mechanism according to a change in angle;
A wheel drive member installed on the base frame so as to be rotatable about a direction perpendicular to its longitudinal direction as a rotation axis;
A connecting member that connects the pedal and the wheel driving member, and rotates the wheel driving member in accordance with a change in the angle of the pedal;
A wheel arm for a rectilinear wheel installed on the base frame so as to be rotatable about a direction perpendicular to the longitudinal direction thereof as a rotation axis;
A rectilinear wheel installed at the tip of this arm so as to be rotatable about a direction perpendicular to the longitudinal direction of the base frame as a rotation axis;
A tension spring having one end locked to the wheel drive member and the other end locked to the wheel arm;
Have
The wheel arm has a groove-shaped or hole-shaped guide portion provided between the rotating shaft and the straight traveling wheel,
The wheel driving member has a guided portion that engages with the guide and is guided along the guide,
When the pedal is rotated to a first angle that puts the caster in a fixed locked state, the wheel driving member is rotated via the connecting member to move the guided portion to the first position in the guide portion. In this first position, the wheel is located at the highest position farthest from the floor surface,
When the pedal is rotated to a second angle that brings the caster into the unlocked free state, the wheel driving member is rotated via the connecting member to bring the guided portion into the second position in the guide portion. Moved, and in this second position, the wheel is located in a middle position away from the floor without contacting the floor,
When the pedal further rotates to the third angle, the wheel driving member rotates through the connecting member to move the guided portion to the third position in the guide portion, and at this third position. The carrier is located at a low position where the wheel contacts the floor surface. The wheel driving member is
A first arm that is rotatably supported by the base frame at a middle portion of the base frame with a direction perpendicular to the longitudinal direction thereof as a rotation axis, and the connecting member is rotatably connected at one end; ,
A second arm provided with the guided portion at the tip;
A connecting portion for connecting the first arm and the second arm in a fixed state at the other end thereof;
Have
When the connecting member rotates the first arm, the second arm rotates, and the guided portion is guided by the guide portion to move relatively so that the wheel arm rotates. And
One end of the tension spring is locked at a position on the other end side of the second arm, and the other end is locked on the wheel arm,
When the line segment connecting the locking points of the tension spring is on the opposite side of the wheel from the rotation axis of the first arm, the line segment is urged in the direction of raising the wheel, and the line segment is 2. The carrier according to claim 1, wherein the carrier is biased in a direction in which the wheel is lowered when the wheel is closer to the wheel than the rotation axis of the first arm. 3. The carrier according to claim 1, wherein the guide portion of the wheel arm has a straight line shape or a wave shape in which the guided portion easily moves along the guide portion. The pedal is arranged for each caster,
A front wheel lateral interlocking member provided on the base frame for connecting two front wheels;
A rear wheel lateral interlocking member provided on the base frame and connecting two rear wheels;
A longitudinal interlocking member that connects the front wheel lateral interlocking member and the rear wheel lateral interlocking member;
Have
When any one of the four pedals is rotated to the first angle, the second angle, or the third angle, the front wheel lateral interlocking member, the rear wheel lateral interlocking member, and the vertical interlocking member are interposed. And all casters can be locked or switched,
The conveying member according to any one of claims 1 to 3, wherein the connecting member is also used as the longitudinal interlocking member. The rotation axis of the wheel arm is fitted and supported in a long hole provided in the base frame, and the rotation axis of the wheel arm is movable in the long hole. The carrier according to any one of 1 to 4.

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