Wheelchair

Abstract

To provide a wheelchair capable of suppressing a seat part from rising by incorrect operation.SOLUTION: A seat part 30 is converted into a rising posture or a desired inclined posture from a seating posture by driving an actuator 40 while a lock operation lever 57 is set at an operation position, and on the other hand, a seat frame part 3 constituting the seat part 30 is locked by a lock piece part 61 when the actuator 40 is driven while keeping the lock operation lever 57 set at a non-operation position, and the seat part 30 is kept in the seating posture. According to such a configuration, the seat part 30 is prevented from rising up when the actuator 40 is driven by the incorrect operation, and thereby time and labor required for work to return the seat part 30 raised by the incorrect operation can be reduced.SELECTED DRAWING: Figure 9

Description

Technical Field

[0001] The present invention relates to a wheelchair that can be converted between a sitting posture and a standing posture of a user.

Background Art

[0002] For example, Patent Document 1 proposes a wheelchair that can put a user with a lower limb disability in a standing posture. Such a configuration includes a spring for converting a seating part (seat part) and a backrest part from a seated state to a standing state, a fixing device for fixing the seating part and the backrest part at a predetermined position between the seated state and the standing state, and an operation lever for operating the fixing device. When converting from a seated state to a standing state, the seated user operates the operation lever to release the fixing of the seating part, and then the seating part rises by the biasing force of the spring. And during the conversion from the seated state to the standing state, by repeating the operation and non-operation of the operation lever, the seating part can be gradually raised. Thus, the user can be put in a standing posture. On the other hand, when returning to the seated state, the user applies weight backward so as to lower the waist while operating the operation lever, thereby lowering the seating part.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the conventional configuration described above (Patent Document 1), the seat is fixed in a seated position by a fixing device, so it remains in that seated position unless the user operates the operating lever. As a result, under normal conditions, the user can sit stably on the seat in the seated position. However, if the operating lever is accidentally operated when the user is not seated, the seat rises up, making it impossible for the user to sit. Therefore, the raised seat must be returned to the seated position, but applying force is difficult, similar to the aforementioned action of lowering one's hips, and it sometimes required a lot of effort and time to return the seat to its original position.

[0005] This invention proposes a wheelchair that can prevent the seat from being raised due to erroneous operation, and can reduce the effort required to return the seat to its upright position if it has been raised due to such erroneous operation. [Means for solving the problem]

[0006] The present invention comprises a base frame portion provided with a pair of left and right main wheels; a seat frame portion rotatably connected to the front of the base frame portion in the vertical direction and constituting a seat portion that supports the user's buttocks; an actuator that raises the rear portion of the seat frame portion to change the seat portion from a seated position in which the user is seated to a standing position in which the user is standing; and an operation control means that drives and controls the actuator by the user's operation and can change the seat portion to a desired inclined position between the seated position and the standing position; further comprising a component provided on the base frame portion that locks to the rear portion of the seat frame portion in the seated position and prevents the rear portion from being raised; The wheelchair is characterized by having a locking piece that can be converted between a locked position and an unlocked position where it is not locked to the rear of the seat frame, and a lock release operation means that allows the user to convert the locking piece to the locked or unlocked position, and having a malfunction prevention means which, when the actuator is driven while the seat is in a seated position and the locking piece is in the locked position, the locking piece is locked to the rear of the seat frame to maintain the seated position, and when the actuator is driven while the seat is in a seated position and the locking piece is converted to the unlocked position, the rear of the seat frame is raised.

[0007] In this configuration, the seat will not rise from the seated position even if the actuator is driven by the operation control means unless the locking piece is converted to the unlocked position by operating the unlocking operation means. In other words, in order to raise the seat from the seated position, it is essential to operate the unlocking operation means to convert the locking piece to the unlocked position before operating the operation control means. As a result, even if the operation control means is accidentally operated when the user is not seated, the seat will not rise. Therefore, according to the configuration of the present invention, it is possible to suppress the seat from rising due to accidental operation when the user is not seated, and to suppress situations in which the unused seat must be returned to the seated position.

[0008] In the wheelchair of the present invention described above, the malfunction prevention means is provided with a lock return means that returns the lock piece, which has been converted to the unlocked position, to the locked position, and the lock return means is provided with a function that returns the lock piece to the locked position when the seating portion is converted from an inclined position to a seated position.

[0009] In this configuration, when the seat is raised and then returned to a seated position, the locking piece automatically returns to its locked position. Therefore, each time the seat is returned to a seated position, the locking piece must be converted to the unlocked position for the seat's posture to change. This allows the aforementioned effects of the present invention, such as preventing the seat from standing up due to erroneous operation of the control means, to be exhibited even more stably.

[0010] Furthermore, in this configuration, the proposed lock return means comprises a biasing means for biasing the lock piece to the locked position, and a lock piece operating mechanism that has the function of holding the lock piece, which has been converted to the unlocked position by the operation of the unlocking operation means, in the unlocked position until the seat frame is raised, and returning the lock piece to the locked position when the seating position changes from an inclined position to a seated position.

[0011] In this configuration, the locking piece is mechanically returned to the locked position by the biasing means and the locking piece operating mechanism, and this return operation can be performed more stably and reliably. [Effects of the Invention]

[0012] According to the wheelchair of the present invention, it is possible to prevent the seat from rising due to accidental operation, and to prevent situations where the unused seat must be returned to the seated position. Therefore, it is possible to reduce the effort and time required to return the seat that has risen due to accidental operation back to the seated position. [Brief explanation of the drawing]

[0013] [Figure 1]This is a side view of the main frame 1 that constitutes the wheelchair in this embodiment. [Figure 2] This is a longitudinal cross-sectional view showing the main frame 1 with a portion omitted. [Figure 3] This is an explanatory diagram showing the process of changing the seating position 30 from a seated position to a standing position. [Figure 4] This is an explanatory diagram showing the process that follows from Figure 3. [Figure 5] This is an explanatory diagram showing the process that follows from Figure 4. [Figure 6] This is an explanatory diagram showing the standing posture. [Figure 7] This is an explanatory diagram showing the process of returning the seating portion 30 to a seated position. [Figure 8] This is an explanatory diagram showing the process that follows from Figure 7. [Figure 9] This is an explanatory diagram showing the operation of the malfunction prevention mechanism 51. [Figure 10] This is an explanatory diagram illustrating the position of the operating frame 5 in an upright position. [Modes for carrying out the invention]

[0014] An embodiment of the wheelchair according to the present invention will be described in detail below. Figure 1 shows the main frame 1 that constitutes the wheelchair of this embodiment. The main frame 1 comprises a base frame section 2 that supports the left and right main wheels 6, a seat frame section 3 that is rotatably connected to the base frame section 2 in the vertical direction, and a backrest frame section 4 connected to the seat frame section 3. Each of these frame sections 2 to 4 is mainly formed of metal pipes or FRP pipes. Note that an operating handle operated by a caregiver is connected to the backrest frame section 4, but this operating handle is omitted in each drawing.

[0015] As shown in FIGS. 1 and 2, the base frame portion 2 includes a pair of left and right base side frame portions 11 and a plurality of base connecting rod portions 12 to 14 spanned between the left and right base side frame portions 11. The left and right base side frame portions 11 are opposed to each other at a predetermined interval in the left-right direction by the base connecting rod portions 12 to 14. Main wheels 6 are provided on the left and right base side frame portions 11 via bearing portions (not shown). The base side frame portion 11 is formed by integrally fixing an upper frame portion 15, a lower frame portion 16, and a front frame portion 17. A front wheel 7 is rotatably connected to the lower frame portion 16. A footrest portion 9 is provided on the front frame portion 17. The base connecting rod portion 12 is spanned between the left and right upper frame portions 15, and the base connecting rod portion 13 is spanned between the left and right lower frame portions 16.

[0016] The seat frame portion 3 includes a pair of left and right seat side frame portions 21 and a plurality of seat connecting rod portions 22 and 23 spanned between the left and right seat side frame portions 21. The left and right seat side frame portions 21 are opposed to each other at a predetermined interval in the left-right direction by the seat connecting rod portions 22 and 23. The seat side frame portion 21 includes a support frame portion 25 in the front-rear direction, a seating frame portion 26 disposed above the support frame portion 25, and a horizontal frame portion 27 fixed to the seating frame portion 26. The front end portion of the horizontal frame portion 27 is rotatably connected to the upper end portion of the front frame portion 17 of the base side frame portion 11. The support frame portion 25 is rotatably connected to the front end portion of the upper frame portion 15 of the base side frame portion 11 at its front portion. The seat connecting rod portion 22 is spanned between the rear end portions of the left and right support frame portions 25. The seat connecting rod portion 23 is spanned between the rear end portions of the left and right seating frame portions 26, and a seat sheet 29 is spanned between the left and right seating frame portions 26. A seating portion 30 for supporting the user's buttocks is formed by the seat sheet 29.

[0017] The backrest frame portion 4 includes a pair of left and right back frames 31 and a connecting plate portion 32 that connects the back frames 31 to be tiltable relative to the seat side frame portion 21. The connecting plate portion 32 is fixed to the lower end portion of the back frame portion 31 and is rotatably connected to the seat connecting rods 22 and 23 of the seat frame portion 3, respectively. An armrest portion 34 is rotatably connected to the upper portion of the back frame portion 31. Further, a backrest sheet (not shown) is inserted between the left and right back frames 31, and a backrest portion (not shown) that supports the user's back is formed by the backrest sheet.

[0018] In such a wheelchair of this embodiment, since the front end portions of the support frame portion 25 and the horizontal frame portion 27 that constitute the seat frame portion 3 are rotatably connected to the base frame portion 2, the seat frame portion 3 can be rotated vertically with respect to the base frame portion 2 by raising and lowering the rear portion of the seat frame portion 3 (see FIGS. 3 to 8). And the backrest frame portion 4 is rotated integrally with the seat frame portion 3 while maintaining a predetermined tilt angle.

[0019] An actuator 40 for raising and lowering the rear portion of the seat frame portion 3 is disposed on the main body frame 1. In this embodiment, the actuator 40 is constituted by a gas spring, one end of which is rotatably connected to a base connecting rod portion 13 extended to the left and right lower frame portions 16, and the other end of which is rotatably connected to a seat connecting rod portion 22 extended to the left and right support frame portions 25. In the wheelchair of this embodiment, two actuators 40 are arranged side by side at a predetermined interval in the left - right direction.

[0020] The gas spring constituting the actuator 40 extends in the longitudinal direction and has a locking function that allows it to be stopped and held (locked) at any position within the stroke range. A gas spring with such a locking function can be of a generally known configuration, and in this embodiment, the locking function can be operated by the lifting operation lever 41, which will be described later. That is, when the lifting operation lever 41 is operated, the gas pressure in the cylinder of the gas spring increases and the gas spring extends. When the operation of the lifting operation lever 41 is released, the increase or decrease in the gas pressure in the cylinder stops and the gas spring stops operating. In this released state, the inflow and outflow of gas into the cylinder is blocked, so the gas spring is held in place without being able to extend or retract. Also, when the lifting operation lever 41 is operated, if a force greater than the gas pressure is applied, the gas spring can be retracted. As mentioned above, a known gas spring can be used, so a detailed explanation of it will be omitted.

[0021] The extension and retraction of the actuator (gas spring) 40 allows the seating portion 30 to be converted between the seated position shown in Figures 1 and 2 and the upright position shown in Figure 6, and also allows it to be stopped and held in a desired tilted position between the seated and upright positions. More specifically, when the lifting lever 41 is operated in the seated position, the rear of the seat frame 3 is raised by the extension of the actuator 40, causing the seating portion 30 to tilt forward from the seated position. Then, when the operation of the lifting lever 41 continues and the seating portion 30 reaches the upright position, the lifting of the seat frame 3 stops. In this state, when the operation of the lifting lever 41 is released, the seating portion 30 is held in the upright position. On the other hand, when the operation of the lifting lever is released between the seated and upright positions, the seat frame 3 stops, and the seating portion 30 is maintained in the tilted position. Furthermore, when the height adjustment lever 41 is operated, pressing the rear of the seat frame 3 downwards causes the seat 30 to tilt downwards. This allows the seat 30 to return to a seated position. By appropriately operating the height adjustment lever 41 and pressing the seat frame 3 in this way, the seat 30 can be converted between a seated and standing position and stopped at a desired tilted position.

[0022] As shown in FIGS. 1 and 10, the above-described lifting operation lever 41 is disposed on an operation frame portion 5 provided on the left and right base frame portions 2 so as to be tiltable in the vertical direction. The operation frame portion 5 is connected to the upper frame portion 15 of the base frame portion 2 via a tilt positioning mechanism 42. The tilt positioning mechanism 42 includes a mechanism base portion 43 fixed to the upper frame portion 15, a mechanism movable portion 44 attached to the base end portion of the operation frame portion 5, and a position conversion lever 45 disposed on the operation frame portion 5. The mechanism base portion 43 is provided with a plurality of engagement groove portions 47 on a substantially arc-shaped outer peripheral edge at predetermined intervals in the arc direction of the outer peripheral edge. Further, the mechanism movable portion 44 is provided with an engagement protrusion 48 that can enter and exit the engagement groove portion 47 so as to be movable between an engagement position where it is inserted into and engaged with the engagement groove portion 47 and a non-engagement position where it escapes from the engagement groove portion 47. The engagement protrusion 48 is biased to the engagement position by a biasing means such as a spring (not shown), and can be moved from the engagement position to the non-engagement position by the operation of the position conversion lever 45, and is held in the engagement position by the release of the operation.

[0023] The operation frame portion 5 can be tilted in the vertical direction by the operation of the position conversion lever 45, and the tilt position can be changed stepwise by releasing the operation of the position conversion lever 45 and changing the engagement groove portion 47 that engages the engagement protrusion 48. Thereby, by changing the tilt position of the operation frame portion 5 according to the posture of the seating portion 30 described above, it becomes easier for the user to operate the lifting operation lever 41 and the position conversion lever 45, and it becomes easier to place a hand on the operation frame portion 5 to support the weight or to apply the weight to the seating portion 30 and press it backward and downward.

[0024] Furthermore, in this embodiment, as shown in Figure 2, a footrest lifting mechanism 81 is provided to raise and lower the footrest portion 9 in accordance with the change in posture of the seat portion 30 from a seated position to a standing position. The footrest lifting mechanism 81 comprises a cylindrical lifting cylinder portion 82 provided on the front frame portion 17 of the base side frame portion 11, and a movable rod portion 83 fitted inside the lifting cylinder portion 82 so as to be able to move up and down, with the footrest portion 9 attached to the lower end of the movable rod portion 83. The lifting cylinder portion 82 has a guide elongated hole portion 85 formed along its longitudinal direction, and one end of a movable connecting portion 84 is rotatably connected to the movable rod portion 83 via the guide elongated hole portion 85. The other end of this movable connecting portion 84 is rotatably connected to the front end of the support frame portion 25 of the seat frame portion 3. As shown in Figures 3 to 6, when the rear of the seat frame portion 3 rises, the movable rod portion 83 descends along the lifting cylinder portion 82 via the movable connecting portion 84. Conversely, as shown in Figures 6 to 8, when the rear of the seat frame portion 3 descends, the movable rod portion 83 rises in accordance with the lifting cylinder portion 82. In this way, the footrest portion 9 descends in conjunction with the raising of the rear of the seat frame portion 3, and the footrest portion 9 rises in conjunction with the descending of the rear of the seat frame portion 3.

[0025] Furthermore, as shown in Figure 2, the wheelchair of this embodiment is provided with a malfunction prevention mechanism 51 that prevents the seat frame 3 from being raised due to erroneous operation of the lifting lever 41 while the seat 30 is in a seated position. The malfunction prevention mechanism 51 comprises a lock release operation part 52 and a lock operation part 53. The lock release operation part 52 is provided on a base connecting rod 12 that spans the left and right upper frame parts 15, and the lock operation part 53 is provided on a base connecting rod 14 that spans the left and right base side frame parts 11. In addition, the malfunction prevention mechanism 51 includes a connecting rod 54 that operates the lock release operation part 52 and the lock operation part 53 in conjunction.

[0026] The unlocking operation unit 52 comprises a flat rotating plate portion 56 rotatably connected to the base connecting rod portion 12, and a locking operation lever 57 fixed to the rotating plate portion 56. One end of the connecting rod portion 54 is rotatably connected to an elongated hole portion 58 formed in the rotating plate portion 56, so as to be movable in the longitudinal direction of the elongated hole portion 58. The locking operation lever 57 has a substantially L-shape (not shown) consisting of a left-right shaft portion fixed to the rotating plate portion 56 and an operation portion bent from the tip of the shaft portion. The operation portion is positioned directly above one of the left or right base side frame portions 11 and is operable by the user.

[0027] The locking mechanism 53 includes a locking piece 61 rotatably connected to the base connecting rod 14, and a spring member 62 that biases the upper part of the locking piece 61 forward. The other end of the connecting rod 54 is rotatably connected to the lower end of the locking piece 61. The upper part of the locking piece 61 includes an inclined contact edge 64 against which the seat connecting rod 22 of the seat frame 3 abuts when the seating portion 30 is in a seated position, an arc-shaped seat locking portion 65 that locks the seat connecting rod 22 so that it cannot move upward, a first pressed portion 66 that protrudes forward from the seat locking portion 65, and a second pressed portion 67 formed at the upper end of the locking piece 61. Here, the inclined contact edge 64 is provided in a form that is inclined upward toward the rear and is connected to the arc-shaped seat locking portion 65. The second pressed portion 67 is provided in a form that is inclined downward toward the front and is connected to the first pressed portion 66.

[0028] This malfunction prevention mechanism 51 consists of a lock release operation unit 52 and a lock operation unit 53 connected by a connecting rod 54, and the lock operation lever 57 can be switched between a non-operational position (see Figures 2, 3(A)) and an operation position (see Figure 3(B)). The malfunction prevention mechanism 51 is activated by the operation of the lock operation lever 57 of the lock release operation unit 52, the force acting from the seat connecting rod 22 of the seat frame 3 to the lock operation unit 53, and the biasing force of the spring member 62.

[0029] The malfunction prevention mechanism 51 allows the rear of the seat frame 3 to be raised or lowered by operating the aforementioned lifting operation lever 41 when the locking operation lever 57 is operated to the operating position, thereby allowing the seat 30 to be raised from a seated position or returned to a seated position (see Figures 3-8). On the other hand, when the lifting operation lever 41 is operated while the locking operation lever 57 is in the operated position, the seat connecting rod 22 of the seat frame 3 is locked to the seat locking portion 65 of the locking piece 61, making it impossible for the seat 30 to be raised from a seated position (see Figure 9). The operation of this malfunction prevention mechanism 51 will be explained below according to the change in the posture of the seat 30.

[0030] In the seated position of the seating section 30, as shown in Figures 2 and 3(A), when the locking operation lever 57 is in the operated position, the seat connecting rod 22 of the seat frame section 3 comes into contact with the inclined contact edge 64 of the locking piece 61. The locking piece 61 is prevented from rotating by the biasing force of the spring member 62 by the seat connecting rod 22 and is held in the position where the inclined contact edge 64 comes into contact with the seat connecting rod 22. Furthermore, one end of the connecting rod 54 is located at the upper end of the elongated hole 58 of the rotating plate section 56. This state in which the locking operation lever 57 (and the rotating plate section 56), the locking piece 61, and the connecting rod 54 are positioned is called the standard operating state of the malfunction prevention mechanism 51. In this seated position of the seating section 30, the footrest section 9 is maintained at a predetermined height position (hereinafter referred to as the standard height position).

[0031] When raising the seating portion 30 from a seated position, the locking lever 57 is tilted to the operating position, as shown in Figure 3(B). This causes the rotating plate portion 56 to rotate integrally with the locking lever 57, and the upper part of the locking piece 61 tilts backward. Consequently, the locking piece 61 separates from the seat connecting rod portion 22 of the seat frame portion 3. With the locking lever 57 in this operating position, when the lifting lever 41 is operated, the actuator 40 extends. As a result, as shown in Figure 4(A), the rear part of the seat frame portion 3 rises, and the seat connecting rod portion 22 of the seat frame portion 3 comes into contact with the first pressed portion 66 of the locking piece 61. As the actuator 40 continues to extend, as shown in Figure 4(B), the first pressed portion 66 of the locking piece 61 is pressed backward, and the upper part of the locking piece 61 tilts backward. As the locking piece 61 tilts, one end of the connecting rod 54 moves forward along the elongated hole 58 of the rotating plate 56.

[0032] Subsequently, as shown in Figure 5, when the rear of the seat frame 3 moves upward above the first pressed portion 66 of the locking piece 61, the force pressing the upper part of the locking piece 61 backward is released, causing the upper part of the locking piece 61 to tilt forward according to the biasing force of the spring member 62. Consequently, the rotating plate 56 rotates and the locking operation lever 57 tilts forward. Here, since one end of the connecting rod 54 is located at the lower end of the elongated hole 58 of the rotating plate 56, the locking operation lever 57 stops at a position tilted forward from the operated position (hereinafter referred to as the operating position). Also, as the seat frame 3 tilts forward, the footrest 9 descends from the reference height position via the operation of the footrest lifting mechanism 81.

[0033] Furthermore, when the seating section 30 is raised from a seated position, and the operation of the lifting lever 41 is released, the extension operation of the actuator 40 stops and is held, thus allowing the seating section 30 to be maintained in an inclined position. This inclined position of the seating section 30 can be arbitrarily changed and held between a seated position and an upright position by releasing the operation of the lifting lever 41, so it can be changed according to the user's preference or convenience.

[0034] By continuing the operation of the lifting operation lever 41, the seating part 30 can be converted to the standing posture as shown in FIG. 6. Then, by releasing the operation of the lifting operation lever 41 in this standing posture, the seating part 30 can be held in the standing posture. In the present embodiment, since the standing posture is set as the upper limit for raising the seating part 30, even if the operation of the lifting operation lever 41 is continued, it will not tilt forward any further. When converting the seating part 30 to the standing posture, the malfunction prevention mechanism 51 is maintained in the state of FIG. 5 described above (the state where the lock operation lever 57 is in the operating position).

[0035] With such a posture conversion of the seating part 30, the footrest part 9 moves downward, and in the standing posture, the footrest part 9 stops at the lowest position closest to the ground.

[0036] When returning the seating part 30 from the above-described standing posture (or inclined posture) to the sitting posture, the lock operation lever 57 is operated to apply a force to tilt the seating part 30 backward. Here, by applying a force greater than the gas pressure generated in the actuator 40 to the seating part 30, the seating part 30 can be tilted backward. For a user using the wheelchair, it can be relatively easily done by applying the body weight backward to lower the waist on the seating part 30. When the operation of the lock operation lever 57 is released, it stops in the inclined posture at the time of release. Therefore, when returning to the sitting posture, the operation of the lock operation lever 57 is maintained.

[0037] When the seating portion 30 is tilted downwards, as shown in FIGS. 7(A) to (B), the seat connecting rod portion 22 of the seat frame portion 3 contacts the second pressed portion 67 of the locking piece portion 61. Further, by tilting the seating portion 30 downwards, the upper portion of the locking piece portion 61 tilts rearward, and as shown in FIG. 8(A), the seat connecting rod portion 22 contacts the first pressed portion 66 of the locking piece portion 61. When the upper portion of the locking piece portion 61 tilts rearward in this way, the rotating plate portion 56 rotates and the lock operation lever 57 tilts rearward. After that, as shown in FIG. 8(B), the seat connecting rod portion 22 of the seat frame portion 3 moves below the first pressed portion 66 and contacts the inclined contact edge portion 64. At this time, when the upper portion of the locking piece portion 61 tilts forward by the biasing force of the spring member 62, the unlocking operation portion 52 tilts forward, and accordingly the rotating plate portion 56 rotates. Then, when one end portion of the connecting rod portion 54 moves along the long hole portion 58 and is positioned at the upper end portion, the lock operation lever 57 returns to the operated position. In this way, in the malfunction prevention mechanism 51 of this embodiment, by returning the seating portion 30 from the upright position (or inclined position) to the seated position, the lock operation lever 57 automatically returns to the operated position. Thereby, the malfunction prevention mechanism 51 returns to the reference operating state.

[0038] By thus returning the seating portion 30 from the upright position to the seated position, the footrest portion 9 ascends from the lowest position (see FIG. 6) and returns to the above-described reference height position (see FIG. 8(B)).

[0039] Next, the case where the lift operation lever 41 is erroneously operated will be described. With the seat portion 30 in a seated position, if the lifting operation lever 41 is accidentally operated without operating the locking operation lever 57, as shown in Figure 9(A), the actuator 40 extends. This extension of the actuator 40 causes the rear of the seat frame portion 3 to rise, and as shown in Figure 9(B), the seat connecting rod portion 22 of the seat frame portion 3 is locked to the seat locking portion 65 of the locking piece portion 61, preventing the seat frame portion 3 from rising. At this time, the force received by the locking piece portion 61 via the seat connecting rod portion 22 causes the upper part of the locking piece portion 61 to tilt forward. Consequently, one end of the connecting rod portion 54 moves within the elongated hole portion 58 of the rotating plate portion 56, causing the rotating plate portion 56 and the locking operation lever 57 to tilt forward, and the locking operation lever 57 to be in the operating position. If the lifting lever 41 is operated incorrectly in this manner, the seat 30 will rise slightly, but will remain in a nearly seated position.

[0040] To release the locking of the seat connecting rod 22 of the seat frame 3 to the seat locking portion 65 of the locking piece 61, the lock operation lever 57 is operated to push the seat portion 30 downward. This causes the rear of the seat frame 3 to descend, and the seat connecting rod 22 moves from the seat locking portion 65 to the inclined contact edge portion 64. As a result, the upper part of the locking piece 61 tilts backward, causing one end of the connecting rod 54 to move to the upper end of the elongated hole portion 58, and the lock operation lever 57 returns to the operated position. This returns the malfunction prevention mechanism 51 to its standard operating state.

[0041] Furthermore, as mentioned above, the wheelchair of this embodiment allows the tilt position of the operating frame 5 to be changed in stages (see Figure 10). Therefore, when changing the seating position 30 between a seated position and a standing position, the tilt position of the operating frame 5 is changed, allowing the user seated on the seating position 30 to easily operate the lifting lever 41.

[0042] As described above, the wheelchair of this embodiment is equipped with a malfunction prevention mechanism 51 that prevents the seat 30 from being accidentally raised. For example, if the lifting lever 41 is accidentally operated when no one is using the wheelchair, the seat 30 will not be raised, and the seat 30 will remain in a seated position. As a result, even after the lifting lever 41 has been accidentally operated, the user can easily sit on the seat 30, and by sitting on the seat 30, the malfunction prevention mechanism 51 can be returned to its normal operating state, so the wheelchair of this embodiment can be used as usual.

[0043] In this embodiment, the wheelchair allows the user to raise the seat 30 from a seated position by operating the lifting lever 41 after moving the locking lever 57 to the operating position, thereby changing the user's posture to a standing position or a desired inclined position. Then, by shifting their weight while operating the lifting lever 41, the user can tilt the seat 30 back to a seated position. Once the user returns to a seated position, the malfunction prevention mechanism 51 returns to its standard operating state as described above. In this way, the user can easily and repeatedly change the posture of the seat 30 while the wheelchair is in use.

[0044] Furthermore, in this embodiment, the footrest 9 moves up and down in conjunction with the change in posture of the seat 30, allowing the user to place their feet at a height that matches the posture of the seat 30. This allows the user to use the seat 30 in a relatively natural posture when changing posture. In addition, since the tilt position of the operating frame 5 can be changed in stages, changing the tilt position of the operating frame 5 in accordance with the change in posture of the seat 30 makes it easier for the user to operate the lifting lever 41, and also allows them to support the operating frame 5 by placing their hands on it. This has the excellent advantage of improving the ease of use for the user when changing posture of the seat 30.

[0045] In the embodiment described above, the lifting operation lever 41 corresponds to the operation control means according to the present invention. The locking operation lever 57 corresponds to the lock release operation means according to the present invention. The position of the locking piece 61 when the locking operation lever 57 is in the operated position (see Figures 2, 3(A)) corresponds to the unlocked position according to the present invention, and the position of the locking piece 61 when the locking operation lever 57 is in the operated position (see Figure 3(B)) corresponds to the locked position according to the present invention. The locking return means according to the present invention is composed of the locking piece 61, the spring member 62, the connecting rod 54, and the elongated hole 58 of the rotating plate 56.

[0046] The present invention is not limited to the embodiments described above, and can be modified as appropriate without departing from the spirit of the invention. For example, the dimensions and shapes of each part in the embodiments described above can be changed as appropriate. The wheelchair in this embodiment has an actuator made of a gas spring, but it is not limited to this, and can also be made of, for example, an air cylinder or a leaf spring. In the embodiment, the malfunction prevention mechanism 51 is configured mechanically, with the lock release operation unit 52 and the lock operation unit 53 operating in conjunction with each other via a connecting rod 54. However, it is not limited to this configuration, and it is also possible to use an electrical configuration, for example, in which the lock piece is operated and controlled by a motor or solenoid. [Explanation of symbols]

[0047] 1. Main frame 2. Base frame section 3. Seat frame section 4. Backrest frame 5. Operating frame section 6 Main wheels 7 Front wheels 9 Footrest section 11. Base side frame section 12-14 Base connecting rod 15 Upper frame section 16 Lower frame section 17 Front frame section 21 Seat side frame section 22,23 Seat connection rod part 25 Support frame section 26. Seating frame section 27 Horizontal frame section 29 seats 30 Seating area 31 Back frame section 32 Connecting plate part 34 Armrest 40 Actuators 41 Lifting / lowering lever 42. Tilt positioning mechanism 43 Mechanism base 44 Mechanism moving parts 45 Position change lever 47 Engagement groove 48 Engagement protrusion 51 Malfunction prevention mechanism 52. Unlock operation section 53 Locking mechanism 54 Connecting rod part 56 Rotating plate section 57 Locking lever 58 Long hole part 61 Lock piece 62 Spring component 64 Slanted abutment edge 65 Seat locking part 66 First pressed portion 67 Second pressed portion 81 Footrest Height Adjustment Mechanism 82 Lifting cylinder section 83 Movable rod part 84 Movable connection part 85 Guide slot

Claims

1. A base frame section equipped with a pair of left and right main wheels, A seat frame portion is connected to the front of the base frame portion so as to be rotatable in the vertical direction and constitutes a seating portion that supports the user's buttocks, An actuator that raises the rear of the seat frame to change the seating position from a seated position in which the user is seated to a standing position in which the user is standing, The actuator is driven and controlled by the user's operation, and the seating portion is controlled by an operation control means that can convert the seating portion to a desired tilted position between a seated position and a standing position. Equipped with, Furthermore, the base frame portion is provided with a locking piece that can be switched between a locking position that engages with the rear of the seat frame portion in a seated position, preventing the rear portion from being raised, and an unlocking position that does not engage with the rear of the seat frame portion. A lock release operation means that allows the user to change the locking piece to a locked or unlocked position. The system includes a mechanism to prevent malfunctions, wherein when the actuator is driven while the seating portion is in a seated position and the locking piece is in a locked position, the locking piece is locked to the rear of the seat frame to maintain the seated position, and when the actuator is driven while the seating portion is in a seated position and the locking piece is in an unlocked position, the rear of the seat frame is raised. The malfunction prevention means includes a locking lever, which is positioned to the side of the user seated on the seat. A wheelchair characterized by the following features.

2. The malfunction prevention means includes a lock return means that returns the lock piece, which has been converted to the unlocked position, to the locked position. The lock return means is The wheelchair according to claim 1, characterized in that it has a function that returns the locking piece to the locked position when the seating portion is converted from an inclined position to a seated position.

Images