JP4783624B2 - wheelchair - Google Patents

Description

  The present invention relates to a wheelchair having a fall prevention function.

A typical wheelchair has the possibility of falling backwards. Japanese Patent Laid-Open No. 2001-314450 discloses a wheelchair provided with a fall prevention mechanism. This overturn prevention mechanism can be provided in a normal wheelchair and is highly versatile.
JP 2001-314450 A

  As described above, it is preferable that the wheelchair is prevented from falling backward. On the other hand, when going over a level difference, the caregiver may tilt the wheelchair backward to lift the front wheel. Therefore, since the wheelchair in which the fall prevention mechanism can be stored is easily tilted backward, it is easy to get over the step.

  An operation is required to store the fall prevention mechanism in the used state or to shift from the stored state to the used state. This operation is usually performed by an assistant. When the overturning prevention mechanism is operated by hand, the assistant must operate the overturning spinning mechanism by removing the hand from the grip. If the fall prevention mechanism can be operated with only the foot, the assistant can operate the fall prevention mechanism without releasing his / her hand from the grip. If the fall prevention mechanism can be operated only with feet, the safety of the wheelchair will increase.

  An object of the present invention is to provide a wheelchair and a fall-preventing mechanism in which an operation for shifting to a use state and an operation for shifting to a storage state are both possible only with feet.

  The present invention relating to a wheelchair includes a rear extending portion extending rearward from the rear portion of the vehicle body, and a lower portion of the rear extending portion, and extends rearward from the rear portion of the vehicle body and rotates in the vertical direction. Provided in a movable state, and provided in a fall prevention member that can take a fall prevention position and a storage position that is above the fall prevention position, and is provided rotatably in the rearward extension part or the fall prevention member, A bridging member capable of supporting the tipping prevention member at the tipping prevention position while restricting the upward rotation of the tipping prevention member by being bridged between the rearward extension portion and the tipping prevention member; An engagement portion that is provided on the rearward extension portion or the fall prevention member and engages with the bridging member to restrict the rotation of the bridging member, and biases the fall prevention member toward the storage position. And an urging member. The wheelchair is configured such that the bridging member can be engaged with the engaging portion at the same time that the overturning preventing member is moved from the storage position to the overturning preventing position by rotating the bridging member. Has been. The wheelchair is configured to release the engagement between the bridging member and the engagement portion by rotating the fall prevention member in the fall prevention position downward.

  Preferably, the bridging member is provided at the rearward extending portion and is configured to be able to rotate by its own weight. Preferably, the engagement portion is provided on the fall prevention member. Preferably, in a state where the bridging member is engaged with the engaging portion, the center of gravity of the bridging member is located out of the vertical plane including the rotation axis of the bridging member. Preferably, the bridging member is rotated by its own weight by rotating the fall preventing member at the fall preventing position downward, and the engagement between the bridging member and the engaging portion is released by this rotation. sell.

  Preferably, in a state where the bridging member is engaged with the engaging portion, the center of gravity of the bridging member is located closer to the rotation center of the fall prevention member than the vertical plane including the rotation axis of the bridging member. Preferably, the bridging member is rotated by its own weight by rotating the fall preventing member at the fall preventing position downward, and the engagement between the bridging member and the engaging portion is released by this rotation. In addition, due to the urging force of the urging member, the overturn prevention member is brought into the housed state while the engaging portion rotates in the free end direction of the overturn prevention member.

  Preferably, a stepping portion that protrudes inward in the left-right direction of the wheelchair is provided at the free end side of the bridging member.

  Preferably, the engaging portion has a recess.

  The present invention relating to a wheelchair overturn prevention mechanism is provided with a rearward extension portion fixed to the wheelchair and a lower portion of the rearward extension portion, and the one end portion of the wheelchair is rotatable in the vertical direction. When provided, the fall prevention member capable of taking the fall prevention position and the storage position above the fall prevention position, and the rear extension part or the fall prevention member are provided rotatably and the rear extension A bridging member capable of supporting the fall-preventing member at the fall-preventing position while restricting the upward rotation of the fall-preventing member by being bridged between a protruding portion and the fall-preventing member; An engaging portion that is provided on the protruding portion or the fall prevention member and can engage with the bridging member to restrict the rotation of the bridging member, and a biasing member that biases the fall prevention member toward the storage position With. The fall prevention mechanism rotates the bridging member so that the fall preventing member is moved from the storage position to the fall preventing position, and at the same time, the bridging member can be engaged with the engaging portion. It is configured. The fall prevention mechanism is configured to release the engagement between the bridging member and the engagement portion by rotating the fall prevention member, which is in the fall prevention position, downward.

  According to the present invention, the fall prevention member can be stored. Furthermore, according to the present invention, the overturn prevention mechanism can be operated with only the foot.

  Hereinafter, the present invention will be described in detail based on preferred embodiments with appropriate reference to the drawings. In the following description, the left-right direction of the wheelchair is also simply referred to as the left-right direction.

  FIG. 1 is a left side view showing a wheelchair 1 according to a first embodiment of the present invention. The wheelchair 11 includes a hand grip 3, a main frame 5, a front wheel 7, a rear wheel 9, a footrest 11 and an armrest 13 in the same manner as a known wheelchair. In FIG. 1, the rear wheel 9 is simply indicated by a two-dot chain line. The front wheel 7 is a free wheel, and the rear wheel 9 is a fixed wheel. The main frame 5 includes a back pipe 15, an arm pipe 17, a front pipe 19, a back pipe 21, a base pipe 23 and a seat side pipe 25. Although not shown, the wheelchair 1 includes a back seat, a seat seat, a leg rest, a skirt guard, a safety belt, an assist brake, a hand rim, and the like. A seat seat (not shown) is provided on the seat frame 27. The seat frame 27 is a separate body from the main frame 5. The seat frame 27 is provided as a pair of left and right. Each of the seat frames 27 provided on the left and right is a substantially rod-shaped member. The main frame 5 and the like constitute a part of the vehicle body of the wheelchair 1.

  Although not shown, the wheelchair 1 has a folding mechanism. The pair of left and right main frames 5 and the pair of left and right seat frames 27 are connected by a cross member (not shown). The cross member connects the left base pipe 23 and the right seat frame 27, and connects the right base pipe 23 and the left seat frame 27. When the wheelchair 1 is folded, the seat frame 27 moves away from the seat side pipe 25 of the main frame 5. When the wheelchair 1 is unfolded, the seat frame 27 is supported in contact with a receiving tool 29 fixed on the seat side pipe 25. A back seat, a seat seat, and a leg rest are sheet-like members, and can be folded up. These structures are similar to existing wheelchairs.

  A rear extension 31 is fixed to the main frame 5. The rear extension 31 is fixed to each of the pair of left and right main frames 5. This fixing may be fixing by welding, screwing or the like. The rear extension part 31 extends rearward from the rear part of the main frame 5. The rear extension 31 is a substantially straight rod-shaped member. One end of the rear extension 31 is fixed to the main frame 5. The shape and arrangement of the rear extension 31 is similar to a tipping lever provided in a normal wheelchair. A normal tipping lever may be used as the rear extension 31. In order to secure an installation space for a toppling prevention member 33 to be described later, it is preferable that the rear extension 31 is disposed above the tipping lever of a normal wheelchair. Or in order to ensure the installation space of the fall prevention member 33, it is preferable that the back extension part 31 is inclined and provided upwards toward back.

  The main frame 5 is provided with a fall prevention member 33. The fall prevention member 33 is provided below the rear extension 31. The fall prevention member 33 is provided in a pair of left and right. The fall prevention member 33 extends rearward from the rear portion of the main frame 5. The fall prevention member 33 is provided on the main frame 5 so as to be rotatable in the vertical direction. A rotation axis (not shown) of the fall prevention member 33 is oriented in a direction substantially along the left-right direction of the wheelchair 1. The rotation surface of the fall prevention member 33 is oriented in a substantially vertical direction. The rear extension 31 is located in the rotation surface of the fall prevention member 33. The rotation center C <b> 1 of the fall prevention member 33 is located in the vicinity of the connection portion between the rear extension 31 and the main frame 5.

  The overturn prevention member 33 is a substantially straight rod-like member as a whole. A wheel 35 is rotatably provided at the end of the free fall side of the fall prevention member 33. The rotation axis of the wheel 35 is substantially parallel to the left-right direction of the wheelchair 1. The wheel 35 alleviates the grounding resistance when the end of the tipping prevention member 33 is grounded, and contributes to the smooth operation of the wheelchair 1.

  The fall prevention member 33 can take the fall prevention position X and the storage position Y above the fall prevention position X by being rotated in the vertical direction. In FIG. 1, the fall prevention member 33 at the fall prevention position X is indicated by a solid line, and the fall prevention member 33 at the storage position Y is indicated by a broken line. The fall prevention member 33 rotates between the fall prevention position X and the storage position Y by turning in the vertical direction. When the fall prevention member 33 is in the fall prevention position X, the fall prevention member 33 exhibits a fall prevention function. When the fall-preventing member 33 is in the storage position Y, it is easy to tilt the wheelchair 1 rearward to lift the front wheel.

  FIG. 2 is a perspective view of the vicinity of the fall prevention member 33. This perspective view is a view of the right-side fall prevention mechanism 50 of the pair of left and right fall prevention mechanisms 50 as viewed from the inner side in the left-right direction of the wheelchair 1. Therefore, in FIG. 2, the right rear wheel 9 is located behind the rear extension 31, the fall prevention member 33, and the like. FIG. 2 is a diagram of the state in which the fall prevention member 33 is in the fall prevention position X. FIG. FIG. 3 is an enlarged side view of the state in which the fall prevention member 33 is in the fall prevention position X. FIG. 4 is an enlarged side view of the state in which the fall prevention member 33 is in the storage position Y. 2-4 is the figure which looked at the right side fall prevention mechanism from the inner side (the left-right direction inner side of the wheelchair 1) among the fall prevention mechanisms provided in the left-right pair. FIG. 1 is a view of a left-side fall prevention mechanism among the fall-prevention mechanisms provided in a pair of left and right sides as viewed from the outside (the outside in the left-right direction of the wheelchair 1).

  A bridging member 37 is rotatably provided on the rear extension 31. The rotation axis of the bridging member 37 is substantially parallel to the left-right direction of the wheelchair 1. The rotation plane of the fall prevention member 33 and the rotation plane of the bridging member 37 are substantially overlapped. As will be described later, the bridging member 37 may be rotatably provided on the fall prevention member 33.

  As shown in FIG. 2, the bridging member 37 includes an inner member 39 and an outer member 41. One end (upper end) of the inner member 39 is disposed on the inner side in the left-right direction of the rear extension 31. On the other hand, one end portion (upper end portion) of the outer member 41 is disposed on the outer side in the left-right direction of the rear extension portion 31.

  The bridging member 37 is rotatably provided on the rear extension 31. The bridging member 37 is pivotally fixed to the rear extension 31 by a rotation shaft 43. The rotation shaft 43 of the bridging member 37 passes through the inner member 39, the rear extension 31, and the outer member 41. Note that the bridging member 37 may be rotatably provided on the fall prevention member 33.

  The bridging member 37 has a shaft body 45. As shown in FIG. 2, the other end (lower end) of the inner member 39 and the other end (lower end) of the outer member 41 are connected by a shaft body 45. The shaft body 45 is a columnar member. The shaft body 45 passes through the other end (lower end) of the inner member 39 and the other end (lower end) of the outer member 41.

  The bridging member 37 has a preliminary hole 46 through which the shaft body 45 can be inserted. By replacing the shaft body 45 with the preliminary hole 46, the floating height h1 (see FIG. 1) at the fall prevention position X can be adjusted. The main frame 5 has a plurality of axle insertion holes 48 so that the height of the axle of the rear wheel 9 can be adjusted. The preliminary hole 46 allows the floating height h1 to be adjusted according to the height of the axle of the rear wheel 9, the outer diameter of the rear wheel 9, and the like.

  From the viewpoint of enhancing the fall prevention function, the floating height h1 (see FIG. 1) at the fall prevention position X is preferably 60 mm or less. From the viewpoint of improving the operability of the wheelchair 1, the floating height h1 is preferably 5 mm or more. From the viewpoint of facilitating floating of the front wheel and overcoming the step, the floating height h2 (see FIG. 1) at the storage position Y is preferably 100 mm or more. From the viewpoint of lowering the floating height h1, the floating height h2 is preferably 140 mm or less.

  As shown in FIG. 2, the bridging member 37 has a stepping portion 47. The stepping portion 47 is provided at the inner end of the shaft body 45 in the left-right direction. The stepping portion 47 is provided at the end portion on the free end side of the bridging member 37. The wheelchair 1 protrudes inward in the left-right direction. Due to this protrusion, the stepping portion 47 is configured to be easily stepped on by an assistant or the like. From the viewpoint of difficulty in sliding, the stepping portion 47 may be made of rubber or resin.

  The bridging member 37 is configured to be rotatable by its own weight. The bridging member 37 can be freely rotated indefinitely with respect to the rearward extending portion 31. The rotating shaft 43 of the bridging member 37 hardly tightens the bridging member 37. When the bridging member 37 rotates, the resistance force acting between the bridging member 37 and the rear extension 31 is small. The bridging member 37 is hung on the rear extension 31 via the rotation shaft 43.

  In a state where the bridging member 37 is not in contact with the toppling prevention member 33 (hereinafter also referred to as a free state), the bridging member 37 has a center of gravity substantially equal to the rotation axis Z1 of the bridging member 37 (the axis of the rotation shaft 43). ) In a vertical plane (hereinafter also referred to as a vertical posture). That is, with regard to the bridging member 37 of the present embodiment, in a free state, the bridging member 37 is in a posture such that its longitudinal direction N (see FIG. 3) is directed in the vertical direction. Therefore, in the free state, when the center of gravity of the bridging member 37 is not in the plane of the vertical plane including the rotation axis Z1 of the bridging member 37, the bridging member 37 is under its own weight (by gravity acting on the bridging member 37). Rotates and takes a vertical posture. That is, in the free state, when the longitudinal direction of the bridging member 37 is inclined, the bridging member 37 is rotated by its own weight, and the longitudinal direction N is oriented in the vertical direction.

  The rear extension 31 and the bridging member 37 are connected by a biasing member 49. The biasing member 49 is a coil spring. The length of the urging member 49 in the longitudinal direction is the shortest when the fall prevention member 33 is in the storage position Y. The biasing member 49 that is longer than the shortest length tends to shrink. The urging member 49 constantly urges the fall prevention member 33 toward the storage position Y. The urging member 49 constantly urges the toppling prevention member 33 toward the rear extension 31.

  The fall prevention member 33 is provided with an engaging portion 51. As shown in FIG. 4, the engaging portion 51 has a recess 53. The engaging part 51 is welded to the body part of the fall prevention member 33 made of a round pipe. The engaging portion 51 is formed between the first convex portion 55 located on the rotation center side of the fall prevention member 33 and the second convex portion 57 located on the free end side of the fall prevention member 33. Yes. When the fall prevention member 33 is in the fall prevention position X, the end portion on the free end side of the bridging member 37 is engaged with the engagement portion 51. Specifically, the shaft body 45 of the bridging member 37 is engaged with the recess 53. The shape of the recess 53 substantially corresponds to the shape of the shaft body 45. When the shaft body 45 falls into the recess 53, the engagement between the bridging member 37 and the engaging portion 51 is not released even by the urging force of the urging member 49. As will be described later, the engaging portion 51 may be provided in the rearward extending portion 31.

  When the bridging member 37 is engaged with the engaging portion 51, the rotation of the bridging member 37 is restricted. The engaged state between the bridging member 37 and the engaging portion 51 is configured not to be released even by the urging force of the urging member 49. By restricting the rotation of the bridging member 37, the upward rotation of the fall prevention member 33 is restricted. Due to the upward rotation restriction and the upward biasing of the biasing member 49, the state where the fall prevention member 33 is in the fall prevention position X can be maintained. The fall prevention member 33 in the fall prevention position X is grounded when the wheelchair 1 falls backward, and prevents the wheelchair 1 from falling backward. The fall prevention mechanism 50 according to the present embodiment includes a fall prevention member 33, a rearward extension portion 31, a bridging member 37, a biasing member 49, and an engagement portion 51.

  The state in which the bridging member 37 is engaged with the engaging portion 51 is also referred to as a use state below. This use state is a state in which the fall prevention member 33 is in the fall prevention position X. In the state of use, the center of gravity (not shown) of the bridging member 37 is not on the vertical plane P1 (see FIG. 3) including the rotation axis Z1 of the bridging member 37. In the use state, the center of gravity of the bridging member 37 is located closer to the rotation center C1 than the vertical plane P1. The rotation center C <b> 1 is the rotation center of the fall prevention member 33.

  When a downward external force is applied to the fall prevention member 33 in the use state, the fall prevention member 33 can rotate downward against the biasing force of the biasing member 49. By stepping on the fall-preventing member 33 with the foot, this downward rotation is easily performed. The part stepped on by the foot is, for example, the wheel 35 of the fall prevention member 33. When the fall prevention member 33 is turned downward from the fall prevention position X, the bridging member 37 can be in a free state. As described above, the bridging member 37 in the free state rotates due to its own weight. Specifically, in FIG. 3, the bridging member 37 rotates until the longitudinal direction thereof becomes the vertical direction. By the rotation of the bridging member 37 based on its own weight, the bridging member 37 assumes a posture (vertical posture) in which the center of gravity is located in the plane of the vertical plane P1. By this rotation, the engagement between the bridging member 37 and the engaging portion 51 is released. Specifically, the engagement between the shaft body 45 of the bridging member 37 and the recess 53 is released.

  In the state where the bridging member 37 is in the vertical posture, the application of the downward external force to the fall prevention member 33 is stopped. Specifically, the foot is separated from the fall prevention member 33. Then, the fall prevention member 33 is rotated upward by the biasing force of the biasing member 49. By this upward rotation, the fall prevention member 33 comes into contact with the bridging member 37 in a vertical posture. This contact state is also referred to as an initial contact state below. In the initial contact state, the longitudinal direction of the fall-preventing member 33 is inclined so as to be lowered toward the rear of the wheelchair 1. In the initial contact state, the surface of the fall-preventing member 33 that contacts the bridging member 37 is inclined so as to be lowered toward the rear of the wheelchair 1. In other words, in the initial contact state, the surface of the overturn preventing member 33 that contacts the bridging member 37 is farther from the rotation center C2 (the rotation center C2 of the bridging member 37) as the distance from the engaging portion 51 increases. Inclined. Due to this inclination, the force that the urging force of the urging member 49 applies from the overturning preventing member 33 to the bridging member 37 is the direction in which the bridging member 37 is moved away from the engaging portion 51 (the concave portion 53 thereof) ( Rotate around). Due to this inclination, the contact portion (specifically, the shaft body 45) of the bridging member 37 with the fall prevention member 33 moves in the direction away from the engagement portion 51 (the free end side of the fall prevention member 33). The fall prevention member 33 rotates further upward than the initial contact state. Thus, the inconvenience that the bridging member 37 in the initial contact state returns to the engaging portion 51 due to the urging force of the urging member 49 is suppressed.

  The fall prevention member 33 has an inclined surface 60. The inclined surface 60 is provided on the second convex portion 57 of the engaging portion 51. The inclined surface 60 is provided at a position where it contacts the bridging member 37 in the initial contact state described above. The inclined surface 60 increases the inclination angle of the above-described inclination (inclination that becomes farther from the rotation center C2 as the distance from the engaging portion 51 increases). The inclined surface 60 is useful for suppressing the inconvenience (the inconvenience that the bridging member 37 in the initial contact state returns to the engaging portion 51 due to the urging force of the urging member 49).

  The bridging member 37 rotated in the direction away from the engaging portion 51 from the initial contact state is further rotated by the urging force of the urging member 49. This rotation is performed in conjunction with the upward rotation of the overturn prevention member 33. The overturn prevention member 33 is rotated upward by the biasing force of the biasing member 49. By means of the urging member 49, the fall prevention member 33 rotates to the storage position Y. The shaft body 45 of the bridging member 37 moves in the direction of the free end of the fall prevention member 33 while sliding on the fall prevention member 33. Eventually, the fall prevention member 33 is in the storage position Y. The state where the fall prevention member 33 is in the storage position Y is also referred to as a storage state. As described above, the transition from the use state to the storage state can be easily performed by the operation of only the foot.

  Transition from the storage state to the use state is performed as follows. By turning the bridging member 37 in this stored state (the state shown in FIG. 4), it is possible to shift from the stored state to the use state. The direction of rotation of the bridging member 37 is a direction toward the front of the wheelchair 1. This rotation can be easily performed by stepping on the free end side of the bridging member 37 in the housed state. The stepping portion 47 facilitates the rotation of the bridging member 37 by the foot. An external force is continuously applied to the bridging member 37 until it is in use. Due to this external force, the bridging member 37 rotates against the urging force of the urging member 49, and the overturn preventing member 33 rotates downward in conjunction with this rotation. An end of the bridging member 37 on the free end side (shaft body 45 in this embodiment) slides on the overturn prevention member 33 in conjunction with the rotation of the bridging member 37 and passes over the inclined surface 60 to engage. Engage with the mating part 51. When the bridging member 37 is engaged with the engaging portion 51, application of external force to the bridging member 37 is stopped. Thus, in the wheelchair 1, by rotating the bridging member 37, the fall prevention member 33 is shifted from the storage position Y to the fall prevention position X, and at the same time, the bridging member 37 is engaged with the engaging portion 51. It is configured to be able to. Therefore, the transition from the storage state to the use state can be easily performed by the operation of only the feet.

  Note that the shape of the engaging portion 51 is such that the bridging member 37 can be easily engaged. There is almost no step between the inclined surface 60 and the surface of the body portion 34 on the free end side (the free end side of the toppling prevention member 33) from the inclined surface 60. Further, the inclined surface 60 is gentle. The gentle slope facilitates the engagement between the bridging member 37 and the engaging portion 51 in the transition from the stored state to the use state. The height of the first convex portion 55 located on the rotation center C1 side is higher than the height of the second convex portion 57 located on the free end side. This difference in height improves smoothness when the bridging member 37 in the housed state is engaged with the engaging portion 51, and the shaft body 45 of the bridging member 37 in the used state gets over the first convex portion 55. To suppress that.

  The above-described rotation of the bridging member 37 in the free state may be rotation by its own weight as in the above embodiment, or may be rotation other than its own weight. For example, the rotation of the bridging member 37 in the free state may be rotation by an urging member. Examples of the urging member include a torsion spring, a compression spring, and a tension spring. As a configuration using this biasing member, for example, the bridging member 37 is biased by the biasing member so as to rotate to the free end side (counterclockwise direction in FIGS. 3 and 4) of the fall prevention member 33. May be. In this case, when the storage state is shifted to the use state, an external force that overcomes the rotation urging force of the urging member is applied to the bridging member 37, and the bridging member 37 is rotated toward the engaging portion 51. Good. In the configuration in which the urging member is used for the rotation of the bridging member 37, it is not necessary to consider the position of the center of gravity of the bridging member 37 in the use state as in the above-described embodiment. On the other hand, as in the above-described embodiment, the configuration in which the bridging member 37 is rotated by its own weight eliminates the need for a member such as a biasing member that rotates the bridging member 37, thereby simplifying the structure, reducing the weight, and reducing the cost. Can contribute.

  From the standpoint of efficiently supporting the grounding load acting on the fall prevention member 33 and preventing the bridging member 37 and the engaging portion 51 from being disengaged by this grounding load, the longitudinal length of the bridging member 37 in the used state is used. The angle θ (see FIG. 3) formed by the direction and the longitudinal direction of the overturn preventing member 33 is preferably 70 degrees or greater and 110 degrees or less, and more preferably 80 degrees or greater and 100 degrees or less.

  The bridging member 37 may be rotatably provided on the fall prevention member 33, and the engaging portion may be provided on the rear extension portion 31. In this case, for example, the rotation of the bridging member 37 in the free state may be due to its own weight, or may be due to the rotational biasing force of the torsion spring or the like described above. For example, when releasing the engagement between the bridging member 37 and the engaging portion 51, the fall prevention member 33 is stepped on the foot and rotated downward to bring the bridging member 37 into a free state. A configuration in which the member 37 falls down due to its own weight can be employed. In this configuration, when the bridging member 37 and the engaging portion 51 are engaged, the bridging member 37 and the engaging portion 51 are raised while the bridging member 37 is raised by rotating the bridging member 37 upward with a foot. Can be engaged.

  The present invention can be applied to both self-propelled wheelchairs and assistive wheelchairs.

FIG. 1 is a left side view of a wheelchair according to the first embodiment of the present invention. FIG. 2 is a perspective view of the wheelchair fall prevention mechanism of FIG. 1 as viewed from the inside of the wheelchair. FIG. 3 is a side view of the fall prevention mechanism in the use state. FIG. 4 is a side view of the fall prevention mechanism in the housed state.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Wheelchair 3 ... Hand grip 5 ... Main frame 7 ... Front wheel 9 ... Rear wheel 11 ... Footrest 13 ... Armrest 15 ... Back pipe 31 ... Rear extension Protruding part 33 ... Fall prevention member 37 ... Bridging member 39 ... Inner member 41 ... Outer member 43 ... Rotating shaft 45 of the bridging member 45 ... Shaft body 47 ... Stepping part 49 ... Biasing member 50 ... Tipping prevention mechanism 51 ... engaging portion 53 ... concave portion 55 ... first convex portion 57 ... second convex portion X ... falling prevention position Y: Storage position C1: Center of rotation of the overturn prevention member C2: Center of rotation of the bridging member P1: Vertical plane including the pivot axis of the bridging member Z1: Rotation of the bridging member Axis h1 Floating height in use h2 Floating height in storage

Claims (5)

A rear extension extending rearward from the rear of the vehicle body;
Provided below the rear extension, extends rearward from the rear part of the vehicle body, and is provided so as to be pivotable in the vertical direction, and has a fall prevention position and a storage position above the fall prevention position. A fall prevention member that can be taken; and
Together provided rotatably on the rearward extending portion, the fall prevention member while restricting the upward rotation of the fall prevention member by being hung on SL fall prevention member at the fall prevention position A supportable bridging member ;
Provided in the upper Symbol fall prevention member, by engaging with the bridging member, an engaging portion capable to restrict the rotation of the bridging member is supported by the fall prevention position the safety member against overturning,
A biasing member that biases the fall prevention member toward the storage position,
In the fall prevention position, the fall prevention member is inclined so that its free end is lowered,
The rotation plane of the fall prevention member and the rotation plane of the bridging member overlap,
The engaging portion is positioned on the rotation center side of the fall-preventing member from a position vertically below the rotation center of the bridging member. With this, when the bridging member is engaged with the engaging portion, the bridging member The center of gravity is positioned on the rotation center side of the fall prevention member with respect to the vertical plane including the rotation axis of the bridging member,
By rotating toward the center of rotation of the safety member against overturning said cross member, cross member, the fall prevention member is rotated downwardly toward the anti-tip position from the storage position, the cross member the configured so as to be able to engage from above the engaging portion,
A wheelchair configured to release the engagement between the bridging member and the engagement portion by rotating the fall prevention member in the fall prevention position downward. In a state where the bridging member is engaged with the engaging portion, the center of gravity of the bridging member is located closer to the rotation center side of the fall prevention member than the vertical plane including the rotation axis of the bridging member,
By rotating the fall prevention member set as the fall prevention position downward, the bridging member is rotated by its own weight, and by this rotation, the engagement between the bridging member and the engaging portion is released, The wheelchair according to claim 1 , wherein the overturning prevention member is placed in the housed state while the engaging portion is rotated in the free end direction of the overturning prevention member by the biasing force of the biasing member.   The wheelchair according to claim 1, wherein a stepping portion that protrudes inward in the left-right direction of the wheelchair is provided at an end portion on the free end side of the bridging member.   The wheelchair according to claim 1, wherein the engaging portion has a recess. A rear extension portion whose one end is fixed to the wheelchair;
When provided below the rear extension portion, one end portion of the wheelchair is provided so as to be pivotable in the vertical direction, and a fall prevention member capable of adopting a fall prevention position and a storage position above the fall prevention position. When,
Together provided rotatably on the rearward extending portion, the fall prevention member while restricting the upward rotation of the fall prevention member by being hung on SL fall prevention member at the fall prevention position A supportable bridging member ;
Provided in the upper Symbol fall prevention member, by engaging with the bridging member, an engaging portion capable to restrict the rotation of the bridging member is supported by the fall prevention position the safety member against overturning,
A biasing member that biases the fall prevention member toward the storage position,
In the fall prevention position, the fall prevention member is inclined so that its free end is lowered,
The rotation plane of the fall prevention member and the rotation plane of the bridging member overlap,
The engaging portion is positioned on the rotation center side of the fall-preventing member from a position vertically below the rotation center of the bridging member. With this, when the bridging member is engaged with the engaging portion, the bridging member The center of gravity is positioned on the rotation center side of the fall prevention member with respect to the vertical plane including the rotation axis of the bridging member,
By rotating toward the center of rotation of the safety member against overturning said cross member, cross member, the fall prevention member is rotated downwardly toward the anti-tip position from the storage position, the cross member the configured so as to be able to engage from above the engaging portion,
A wheelchair fall prevention mechanism configured to release the engagement between the bridging member and the engagement portion by rotating the fall prevention member in the fall prevention position downward.

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