Arm support

Abstract

To provide an arm support which can be used safely without releasing locking unexpectedly.SOLUTION: An arm support is constituted of an arm support body attached in a manner to slide in a bracket vertically and a first elastic body and a second elastic body by pivotally attaching a lock member and a lever rotatably in a side part of the bracket and arranging to appropriately switching a moment of the lock member and the lever by an operation method. In elevating the arm support, the arm support can be elevated by making a first locking part of the locking member escape from a locking hole penetrated on a side part only by an action to pull the arm support body upward. In lowering the arm support, the arm support can be lowered only when a locking state of the locking hole of the arm support body and the first locking part of the lock member is cancelled by operating the lever while pulling up the arm support body once.SELECTED DRAWING: Figure 8

Description

Technical Field

[0001] The present invention relates to an arm support attached to a chair or a wheelchair for a user to place their arms on.

Background Art

[0002] Conventionally, arm supports for placing a user's arms have been attached to the sides of chairs and wheelchairs. And various arm supports have been proposed that can be fixed at an arbitrary height so that the user can place their arms in a comfortable position according to their physical condition, or so that they do not get in the way when the user transfers between a bed and the like. Various locking mechanisms for fixing have also been proposed.

[0003] For example, as described in claim 2 of the armrest of the wheelchair described in Patent Document 1, a locking pin is inserted into any of a plurality of holes drilled in the leg portion by the biasing force of a spring, and an adjustment mechanism for inserting and removing this locking pin with a lever has been proposed. This armrest of the wheelchair is a lever-type plunger mechanism, and since the insertion and removal of the locking pin with respect to the hole can be easily performed by a lever operation, it has the advantages of good workability and a simple component configuration.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

[0005] However, when adopting various proposed lever-type plunger mechanisms, including the armrest of the wheelchair described in Patent Document 1, for an arm support, the following problems are a concern. Since it is possible for a user sitting in a wheelchair to easily touch the lever with their hand, for example, a user with dementia or a child user may accidentally touch the locking mechanism and inadvertently operate the lever to release the lock, which may cause the arm support to drop and the user whose balance is disrupted to fall. That is, when a lever-type locking mechanism is provided, it is necessary to provide a safety device so that the arm support does not easily drop even if the lever is accidentally operated.

Problems to be Solved by the Invention

[0006] Therefore, the problem to be solved by the present invention is to provide an arm support that can be used safely without being accidentally unlocked.

Means for Solving the Problems

[0007] An arm support attached to both sides of a seat portion of a wheelchair, a bracket fixed to a side portion of a vehicle body frame that supports the seat portion, an arm support body slidably attached in the vertical direction within the bracket, a lock member pivotally attached to a side portion of the bracket, a lever pivotally attached in the vicinity of the lock member and having one end arranged to be able to contact one end of the lock member, and a first elastic body arranged to urge the lock member clockwise in a side view to constitute the arm support. When the arm support is raised, when the arm support body is pulled up, a first locking portion of the lock member that is locked in a locking hole formed in a side surface of the arm support body is urged clockwise in a side view from the lower surface of the locking hole and escapes. Then, the lock member is urged counterclockwise in a side view by one end of the lever so as to resist the elastic force of the first elastic body, and the first locking portion rises while contacting the side surface of the arm support body. When reaching an arbitrary locking hole, the lock member rotates counterclockwise in a side view and the first locking portion locks again in the locking hole of the arm support body to support the arm support body. When the arm support is lowered, the arm support body is pulled up to make the first locking portion of the lock member escape from the locking hole of the arm support body, and at the same time, the lever is rotated counterclockwise in a side view to separate one end of the lock member and the lever, and the lever is held in a state where only the elastic force of the first elastic body acts on the lock member to enable the arm support body to be pulled down. When reaching an arbitrary locking hole, the lever is returned to its original position to make one end of the lock member and the lever contact each other. Then, the lock member is urged counterclockwise in a side view by one end of the lever so as to resist the elastic force of the first elastic body, and the first locking portion locks in the locking hole to enable the arm support body to be supported. And, a lock member locking portion capable of contacting the lever and the lock member A stopper portion arranged at a position spaced apart from the lock member locking portion by a certain distance, a groove portion is formed between the lock member locking portion and the stopper portion, and the lock memberBy providing the second locking portion, it is possible to lower the arm support regardless of whether the lifting operation of the arm support main body or the rotation operation of the lever is performed first. And a second elastic body is provided so as to bias the lever clockwise in a side view. And a torsion coil spring is used for the first elastic body and the second elastic body. The first elastic body pivotally attaches the coil portion to the boss portion of the lever, and one end said locking member is inserted and locked into the locking holes formed in the lever and the other end is inserted into the locking hole formed in the lever, respectively. The second elastic body pivotally attaches the coil portion to the boss portion, and one end abuts against the side surface of the bracket and the other end abuts against the stopper portion of the lever. Also, the lever is arranged on the head support side in a side view. Furthermore, by tilting the bracket forward from the vertical direction in a side view, a safe lever operation space is formed between the rear wheel of the wheelchair and the lever.

Advantages of the Invention

[0008] In the arm support of the present invention, when lowering the height of the arm support, if the arm support main body is not lifted first and the lever is not operated, one end of the lock member connected to the lever cannot escape from the locking hole formed in the arm support main body. That is, when lowering the height of the arm support main body, even if the user accidentally operates the lever only by operating the lever, the arm support cannot be lowered, so it can be used safely. In addition, when raising the height of the arm support where there is no possibility of the user falling, it can be operated only by lifting the arm support main body, so it has a configuration that combines operability and safety. And, by forming a groove portion in the lever, even if the first locking portion of the lock member is locked in or has escaped from the locking hole of the arm support body, the lever can be operated. Therefore, the caregiver can lower the arm support regardless of whether the caregiver first performs the lifting operation of the arm support body or the operation of the lever, which makes it easy to use. And, by biasing the lever with the second elastic body, the components can be automatically returned to the original state (the state before operating the lever). Therefore, the load on the first elastic body in the compression direction can be reduced, and the durability can be improved. Further, even if the first elastic body is damaged, the lever is biased by the second elastic body, and the first locking portion of the lock member is biased in the direction of the locking hole of the arm support body by the lever. Therefore, there is no need to worry about the lock being released and the arm support descending, and it can be used safely. And, by adopting torsion coil springs for the first elastic body and the second elastic body, the rotation axis of the lever and the coil portion of the torsion coil spring can be made coaxial. There is no need to prepare members and shapes for supporting the first elastic body and the second elastic body, the component configuration can be further simplified, the assembly is simple, and it can be provided at low cost. And, by disposing the lever position on the side portion of the head support side instead of the side portion in front of the bracket, it is made difficult for the seated user to easily operate the lever. That is, it is difficult for the user to accidentally operate the lever, such as accidentally releasing the lock of the arm support, and it can be used safely. And, by tilting forward with respect to the ground a bracket for slidably supporting the arm support body in the vertical direction and providing a space between the lever disposed on the rear wheel side and the rear wheel, contact between the rear wheel and the caregiver's hand can be avoided when operating the lever, and it can be operated safely.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Mode for Carrying Out the Invention

Example

[0010] Hereinafter, the arm supports 1, 1 of the present invention will be described with reference to the drawings. First, the wheelchair W will be described. As shown in FIG. 1, this wheelchair W is capable of traveling on the floor surface with front wheels 3, 3 disposed in front of the vehicle body frame 2 and rear wheels 4, 4 disposed at the rear, and includes a seat portion 5 supported by the vehicle body frame 2, a back support 6 supported behind this seat portion 5, a foot support 7 supported in front of the seat portion 5, and a head support 8 supported on the upper portion of the back support 6. Although the description is omitted, the wheelchair W can change its posture steplessly from the sitting posture to the reclining posture. The arm supports 1, 1 of the present invention are arranged on both sides of the right and left sides of the seat portion 5 of the wheelchair W, and the arm support bodies 17, 17 are slidably attached in the vertical direction with brackets 11, 11 connected and fixed to the bases 21, 21 fixed to the vehicle body frame 2 as guides.

[0011] Next, each component of the arm support 1, 1 will be described. In this embodiment, the arm supports 1, 1 are arranged on both sides of the seat portion 5 as described above. Since they are symmetrically configured, the arm support 1 arranged on the left side of the user will be described as shown in FIG. 2 etc. without special explanation. (Regarding the arm support 1 on the right side, each component operates and rotates in the opposite direction with respect to the arm support 1 on the right side.) First, the bracket 11 will be described. As shown in FIG. 4, the opening of the bracket body 11a formed in a substantially U - shaped plate in plan view is fixed to the side portion of the base 21 of the vehicle body frame 2, forming a rectangular hollow space in plan view. Note that the base 21 is also substantially U - shaped, and a part of the side board 17e described later can be inserted into its inner surface. And a lock hole 11b is formed in the side portion of the bracket body 11a on the side of the rear wheel 4, and the first locking portion 12a of the lock member 12 described later can be inserted and removed. And screw holes 11c, 11c are screwed on the side portion of the bracket body 11a on the side of the front wheel 3 and the side portion facing the seat portion 5 of the base 21. And one end of a support shaft 11d for rotatably axially mounting the lock member 12 is fixed in the axle direction of the rear wheel 4 on the side portion of the base 21 on the side of the rear wheel 4 so as to be connected to the bracket body 11a. Also, a pin hole 11e is formed at a position parallel to the side surface of the bracket body 11a and at a certain interval from the support shaft 11d, and one end of a stepped pin 11f whose both ends are cut to have a small diameter is rotatably supported by the pin hole 11e. In this embodiment, a rectangular hollow space is formed by the bracket main body 11a and the base 21. However, this is because the arm support main body 17 described later has a rectangular shape, and it is not necessary to limit this embodiment thereto. For example, when the arm support main body 17 has a cylindrical shape, a cylindrical space may be formed. Therefore, it is only necessary to form a hollow space having the same shape as the shape of the arm support main body 17.

[0012] Next, the lock member 12 will be described. As shown in FIG. 4, the lock member 12 is rotatably mounted on the support shaft 11d. One end has a first locking portion 12a that can be inserted into and removed from the lock hole 11b of the bracket main body 11a, and the other end has a second locking portion 12b that is disposed in a groove portion 131 of a lever 13 described later. In this embodiment, as shown in FIG. 5 and the like, the first locking portion 12a and the second locking portion 12b are disposed in a substantially L-shaped positional relationship. The lock member 12 is also provided with a locking hole 12c that can lock a second elastic body 15 described later.

[0013] Next, the lever 13 will be described. As shown in FIG. 5 and the like, the lever 13 is formed in a substantially katakana "ユ" shape in a side view. A boss portion 13a formed at substantially the center of the lever 13 is inserted through the stepped pin 11f and rotatably mounted thereon. Note that both ends of the boss portion 13a protrude, and a first elastic body 14 and a second elastic body 15 described later can be respectively mounted thereon. One end is an operation portion 13b that is operated by hand by an assistant, and the other end has a lock member locking portion 13c, a stopper portion 13d, and a groove portion 131 that is formed in a substantially U shape between the lock member locking portion 13c and the stopper portion 13d. The second locking portion 12b of the lock member 12 is disposed in the groove portion 131. As shown in FIG. 5, the lever 13 can be rotated from a state where the second locking portion 12b abuts against the lock member locking portion 13c of the lever 13 to a state where it abuts against the stopper portion 13d as shown in FIG. 9. Note that, as shown in FIG. 5 and the like, the width of the groove portion 131 is formed to be larger than the width of the second locking portion 12b, so that there is a so-called play state. And, a locking hole 13e capable of locking a second elastic body 15 described later is formed in the lever 13.

[0014] Next, the first elastic body 14 will be described. As shown in FIG. 4, a torsion coil spring is used as the first elastic body 14 in this embodiment. The first elastic body 14 has a coil portion externally inserted at one end on the base 21 side of the boss portion 13a of the lever 13 and is pivotally attached so as to be rotatable. One end is inserted through and locked in the locking hole 12c of the locking member 12, while the other end is inserted through and locked in the locking hole 13e of the lever 13. Due to the elastic force of the first elastic body 14 configured in this way, as shown in FIG. 5 and the like, the locking member 12 is biased to rotate clockwise in a side view with the support shaft 11d as the rotation center, and the lever 13 is also biased to rotate clockwise in a side view with the stepped pin 11f as the rotation center.

[0015] Next, the second elastic body 15 will be described. In this embodiment, the second elastic body 15 uses the same shape and configuration as the first elastic body 14, and is used by changing the mounting position. As shown in FIG. 4 and the like, the second elastic body 15 has a coil portion externally inserted at the boss portion 13a on the opposite side of the first elastic body 14 of the lever 13 and is pivotally attached so as to be rotatable. One end is assembled so as to abut against the side surface of the bracket main body 11a, and the other end is assembled so as to abut against the stopper portion 13d of the lever 13. Due to the elastic force of the second elastic body 15 configured in this way, as shown in FIG. 5 and the like, the stopper portion 13d is biased so that the lever 13 rotates clockwise with the stepped pin 11f as the rotation center with one end on the bracket main body 11a side as the base point.

[0016] The locking member 12 and the lever 13 biased by the first elastic body 14 and the second elastic body 15 configured as described above have the locking hole 12c of the locking member 12 and the locking hole 13e of the lever 13 arranged such that the moment of the lever 13 is greater than the moment of the locking member 12. More specifically, as shown in FIG. 5 and the like, the distance from the support shaft 11d, which is the rotation center of the locking member 12, to the locking hole 12c of the locking member 12 where one end of the first elastic body 14 is locked is smaller than the distance from the stepped pin 11f, which is the rotation center of the lever 13, to the stopper portion 13d of the lever 13 where the other end of the first elastic body 14 is locked. In addition, the second elastic body 15 forms a hinge mechanism with the arm support body 17, the second elastic body 15, and the lever 13, and only a moment for rotating the lever 13 clockwise in a side view is applied as shown in FIG. 5 and the like. That is, in the present embodiment, by setting the locking hole 13e of the lever 13 at a position farther from the rotation center than the locking hole 12c of the locking member 12, the moment of the lever 13 is made larger than the moment of the locking member 12. In addition, the second elastic body 15 is configured to apply a moment to the lever 13 in the same direction as the rotation direction of the lever 13 by the first elastic body 14.

[0017] Although the first elastic body 14 and the second elastic body 15 have been described in combination so far, as shown in FIG. 10, only the first elastic body 14 can also be implemented. In this case, as shown in FIG. 10, the locking member 12 is biased by the first elastic body 14 and is configured to rotate clockwise in a side view, and if the distance from the rotation center of the locking member 12 to the rotation center of the lever 13 is made longer for the lever 13, the same procedure can be performed based on the moment relationship described in the previous section. As described above, in the present embodiment, the second elastic body 15 serves to support the movement of each component including the first elastic body 14, and although the specifications required by the present invention can be satisfied without using the second elastic body 15, there are the following advantages when using the second elastic body 15. First, the second elastic body 15 constantly biases the stopper portion 13d of the lever 13 and acts so that the lever 13 rotates clockwise in a side view. This enables the lever 13 to always return to its original position after the operation of the lever 13, and at the same time, by biasing the second locking portion 12b of the locking member 12 counterclockwise in a side view by the locking member locking portion 13c of the lever 13, the first locking portion 12a is biased to lock with the locking hole 17a of the arm support body 17 described later. Therefore, since the locking member 12 is biased in the direction of locking with the arm support 17, it can be surely locked. In addition, the load in the compression direction of the first elastic body 14 can be reduced, and the durability can be improved.

[0018] Next, the cover 16 will be described. As shown in FIGS. 3 and 4, this cover 16 is used to cover the above-described respective components so that only the operation portion 13b of the lever 13 is exposed. The male screw 16c is screwed onto the female screw 111d screwed onto one end of the support shaft 11d of the bracket 11 through the holes 16a and 16b formed in the cover 16 formed in this way, and one end of the stepped pin 11f is inserted and rotatably supported.

[0019] Next, the arm support body 17 will be described. As shown in FIG. 4 and the like, this arm support body 17 is a rectangular pipe formed to be slidable within a rectangular hollow space formed within the bracket 11, and locking holes 17a, 17a,... are formed vertically at a certain interval on the side surface of the bracket main body 11a on the side of the locking hole 11b. And stopper members 17b, 17b are attached near the upper and lower ends of the arm support body 17. These stopper members 17b, 17b are configured by inserting male screws through the arm support body 17 and attaching nut members, but any configuration may be used as long as they do not fall off the bracket 11 when the arm support body 17 is slid up and down. Then, an armrest 17c is attached to the upper part of the arm support body 17, and a side board 17e is attached via a support plate 17d connected to the armrest 17c. Although detailed description is omitted, a cushioning material for supporting the user's elbow is disposed on the upper part of a structural material such as a pipe disposed below the armrest 17c. Then, the first locking portion 12a of the lock member 12 is locked to any one of the locking holes 17a of the arm support body 17 through the lock hole 11b formed in the bracket body 11a, and the sliding operation of the arm support body 17 is restricted, so that the arm support body 17 can be supported at an arbitrary height.

[0020] In addition, in order to minimize the gap generated when the arm support body 17 is disposed in the bracket 11 as shown in FIG. 4, bush members 11g, 11g are fitted to the upper and lower ends of the bracket body 11a. In addition, slash members 11h, 11h are disposed between the bush members 11g, 11g, and the slash members 11h, 11h are biased by adjusting the tightening and loosening of set screws 11i, 11i through the screw holes 11c, 11c screwed into the bracket body 11a and the base 21, thereby suppressing rattling when the arm support body 17 slides in the bracket 11.

[0021] Next, the states of the respective components in the locked state and the sliding state of the arm support 1 will be described. First, the locked state of the arm support 1 will be described. FIG. 5 shows the locked state of the arm support 1 in which the arm support body 17 is fixed at an arbitrary position. This locked state is such that the first locking portion 12a of the locking member 12 passes through the locking hole 11b of the bracket main body 11a and is inserted into any one of the locking holes 17a formed in the arm support main body 17, and the upper surface 121a of the first locking portion 12a locks the locking hole 17a of the arm support main body 17, so that the arm support main body 17 is held without descending. At this time, as shown in FIG. 5, the locking member 12 is biased to rotate counterclockwise in a side view by the weight of the arm support main body 17, and the tapered surface 122a of the locking member 12 is locked to the lower surface of the locking hole 17a and the locking hole 11b of the bracket main body 11a and stops. Then, as described above, due to the combination of the moments by the elastic forces of the first elastic body 14 and the second elastic body 15, the lever 13 is biased to rotate clockwise in a side view, and the locking member locking portion 13c of the lever 13 and the second locking portion 12b of the locking member 12 are in contact and the lever 13 stops.

[0022] Next, the case of increasing the height of the arm support 1 (raising the armrest 17c) from the locked state will be described. When the caregiver grips the armrest 17c or the arm support main body 17 and pulls it upward from the locked state shown in FIG. 5, as shown in FIG. 6, the upper surface 121a of the first locking portion 12a of the locking member 12 and the locking hole 17a of the arm support main body 17 are separated and the locking relationship is released. At the same time, the tapered surface 122a of the locking member 12 is biased upward by the lower surface of the locking hole 17a. At this time, the locking member 12 rotates clockwise in a side view with the support shaft 11d as the rotation center by the force biased by the lower surface of the locking hole 17a. Note that, as described above, the moment of the first elastic body 14 that rotates the locking member 12 is also the same as the rotation direction biased by the lower surface of the locking hole 17a. Further, as the locking member 12 rotates clockwise in a side view, the second locking portion 12b of the locking member 12 biases the locking member engaging portion 13c of the lever 13 with a force greater than the moments of the first elastic body 14 and the second elastic body 15. Therefore, the lever 13 rotates counterclockwise in a side view. When the tapered surface 122a of the locking member 12 is continuously biased upward by the lower surface of the locking hole 17a, as shown in FIG. 7, the first locking portion 12a of the locking member 12 escapes from the locking hole 17a of the arm support body 17 and abuts against the side surface of the arm support body 17. At this time, the locking member 12 receives a moment due to the elastic force of the first elastic body 14 and tries to rotate clockwise in a side view. At the same time, since the lever 13 receives a moment due to the elastic forces of the first elastic body 14 and the second elastic body 15 and tries to rotate clockwise in a side view, the second locking portion 12b is biased by the locking member engaging portion 13c of the lever 13, and the locking member 12 rotates counterclockwise in a side view, and the first locking portion 12a comes into contact with the side surface of the arm support body 17. When the arm support body 17 is continuously pulled up from the state shown in FIG. 7, the first locking portion 12a reaches the next locking hole 17a while sliding on the side surface of the arm support body 17. Then, the first locking portion 12a of the locking member 12, whose rotation was restricted by the side surface of the arm support body 17, rotates and is inserted into the locking hole 17a of the arm support body 17 as shown in FIG. 6. When the assistant holds the arm support body 17 or the armrest 17c by hand and pulls down the arm support body 17, as shown in FIG. 5, the upper surface of the locking hole 17 of the arm support body 17 abuts against the first locking portion 12a of the locking member 12, and the arm support 1 enters a locked state. With such a configuration, when raising the height of the arm support 1, the assistant can simply hold the arm support body 17 or the armrest 17c and pull it upward to fix it at an arbitrary position.

[0023] Next, the case of lowering the height of the arm support 1 from the locked state (when lowering the elbow rest 17c) will be described. As a procedure in this case, while pulling up the arm support main body 17, the lever 13 is held in the pulled-up state, and then the arm support main body 17 is pulled down for operation. Specifically, when the arm support main body 17 is pulled up from the locked state shown in FIG. 5, as described above, the first locking portion 12a escapes from the locking hole 17a of the arm support main body 17 and abuts against the side surface of the arm support main body 17 as shown in FIG. 7. When the assistant pulls the lever 13 upward from this state, as shown in FIG. 8, the first locking portion 12a of the locking member 12 separates from the side surface of the arm support main body 17. This is because the force operating on the lever 13 acts as a force stronger than the elastic forces of the first elastic body 14 and the second elastic body 15. Therefore, the lever 13 rotates counterclockwise in a side view, and the locking member 12 rotates clockwise in a side view due to the elastic force of the first elastic body 14 acting, and the second locking portion 12b abuts against the locking member locking portion 13c of the lever 13 and stops. In this state, the arm support main body 17 can slide freely within the bracket 11 in the vertical direction. Therefore, the assistant grips the arm support main body 17 or the elbow rest 17c and pulls down the arm support main body 17 to lower the height. When the arm support main body 17 reaches an arbitrary position, the assistant releases the lever 13 so that the first locking portion 12a of the locking member 12 abuts against the side surface of the arm support main body 17 as shown in FIG. 7. Then, the arm support main body 17 is further lowered to be in the locked state as shown in FIG. 5, thereby lowering and locking the height of the arm support 1. Note that, as shown in Fig. 4 etc., since the arm support 1 in this embodiment has stopper members 17b, 17b attached near the upper and lower ends of the arm support body 17, even if the arm support body 17 is pulled up too much upward, it is locked by the stopper members 17b, 17b, eliminating the concern that the arm support body 17 may fall out of the bracket 11. When the arm support body 17 is lowered downward, the upper surface of the armrest 17c and the upper surface of the seat portion 5 of the wheelchair W stop on the same plane, facilitating transfer.

[0024] Next, the usage method of the arm support 1 attached to the wheelchair W in this embodiment will be described. First, the method of raising the height of the arm support 1 will be described. (1) The caregiver holds the armrest 17c (or the arm support body 17) and pulls it upward to raise it to the desired height. (2) When the armrest 17c (or the arm support body 17) reaches near the desired height, lower the armrest 17c so that the first locking portion 12a of the locking member 12 is locked in the locking hole 17a of the arm support body 17 to fix it in a locked state. Next, the method of lowering the height of the arm support 1 will be described. (A) The caregiver holds the armrest 17c (or the arm support body 17) with one hand and pulls it slightly upward. (B) While the caregiver holds the armrest 17c (or the arm support body 17), the caregiver pulls up the lever 13 with the other hand. (C) While the caregiver holds the lever 13 pulled up with one hand, the caregiver lowers the armrest 17c (or the arm support body 17) while holding it with the other hand. (D) When the armrest 17c (or the arm support body 17) reaches near the desired height, the caregiver releases the hand from the lever 13, lowers the armrest 17c (or the arm support body 17), and locks the first locking portion 12a of the locking member 12 in the locking hole 17a of the arm support body 17 to fix it in a locked state.

[0025] Note that, although the procedure for lowering the arm support 17 has been described as operating in the order of (A)→(B), it may also be operated in the order of (B)→(A). This is made possible because a groove portion 131 is provided in the lever 13 to ensure play when the lever 13 is operated. When operating in the order of (B)→(A), as shown in FIG. 9, the lever 13 is rotated clockwise in a side view, and an assistant holds the lever 13 in a state of pulling it up against the elastic force of the second elastic body 15. At this time, the locking member 12 receives an elastic force that causes it to rotate clockwise in a side view by the first elastic body 14, but since the first locking portion 12a is locked in the locking hole 17a formed in the arm support main body 17 and the rotation is locked by the weight of the arm support main body 17, it is impossible for the locking member 12 to escape from the locking hole 17a. Then, when the armrest 17c (or the arm support main body 17) is pulled upward, as shown in FIG. 8, the locking of the first locking portion 12a is released, and the first locking portion 12a can escape from the locking hole 17a under the elastic force of the first elastic body 14. That is, by providing the groove portion 131 in the lever 13, it is possible to lower the arm support 17 regardless of whether the operation of pulling up the arm support main body 17 or the operation of the lever 13 is performed first. Therefore, it can be operated according to the convenience of the assistant, which is user-friendly.

[0026] As described above, in the arm support 1 of the present embodiment, when increasing the height of the arm support 1 as described above, the assistant can simply pull up the arm support main body 17 to adjust it to an arbitrary height. When decreasing the height of the arm support 1, the assistant can pull up the arm support main body 17 upward once with one hand, then pull the lever 13 with the other hand, and then lower the arm support main body 17 downward to adjust it to an arbitrary height. That is, even if the user accidentally pulls the lever 13 by hand while sitting on the wheelchair W, the height of the arm support 17 cannot be lowered unless the arm support main body 17 is pulled upward. Therefore, the arm support 17 will not suddenly drop and cause the user to lose balance and fall, so it can be used safely. Also, as shown in FIG. 3 etc., the cover 16 is configured such that the locking member 12, the lever 13, etc. are not visually visible. However, when it is in the locked state, when the first locking portion 12a of the locking member 12 abuts against the lower surface of the locking hole 17a by the elastic force of the first elastic body 14 from the side surface of the arm support main body 17, a contact sound (a sound like "click") is generated. Therefore, the caregiver can grasp the locked state aurally. And, although the arm support 1 in the present embodiment has a symmetric configuration, parts other than the covers 16, 16 can use the same parts for both the right and left arm supports 1, 1. Therefore, the types of parts can be reduced, and the manufacturer has the merit of cost reduction.

[0027] And, as shown in FIG. 11 etc., the lever 13 of the arm support 1 in the present embodiment is located on the rear wheel 4 side rather than the front wheel 3 side in a side view, making it a position where it is more difficult for the user's hand to reach compared to the front wheel 3 side. Also, as shown in FIG. 11 etc., by tilting the bracket 11 forward with respect to the ground and supporting it with the base 21, the arm support main body 17 is attached to the bracket 11 in a state of being tilted forward at a certain angle. At this time, the armrest 17c is fixed to the arm support main body 17 such that its upper surface is parallel to the ground. By configuring it in this way, compared to the arm support 1 disposed in the vertical direction with respect to the ground, when operating the lever 13 disposed on the rear wheel 4 side, a sufficient space S for inserting the caregiver's hand is created between the rear wheel 4 and the lever 13, and the operability and safety can be improved. It might be considered to secure space by setting the mounting position of the bracket 11 closer to the front wheel 3 and farther from the rear wheel 4. However, this method may cause durability problems with the arm support 1. Although illustration is omitted, when the mounting position of the bracket 11 is brought closer to the front wheel 3 side, the side on the rear wheel 4 side of the armrest 17c becomes longer than the side on the front wheel 3 side with the arm support body 17 as the boundary. Then, since the elbow of the user sitting on the wheelchair W is supported by the side on the rear wheel 4 side, it becomes a cantilever state and a clockwise load is applied in a side view. That is, the closer the mounting position of the bracket 11 is to the front wheel 3 side, the wider the space S becomes, but the moment becomes larger, the rattling and wear of the components become severe, and the durability decreases. Along with this, there are demerits such as the trouble when replacing parts, the increased adjustment frequency of the slush members 11h, 11h to suppress rattling even if the parts are not damaged, and the discomfort due to rattling when the user uses the armrest 17c. Therefore, if the arm support body 17 and the armrest 17c are arranged so that the sides on the front wheel 3 side and the rear wheel 4 side are as much as possible the target, that is, approaching the shape of the letter "T" in the alphabet, it is possible to balance the moment when using the armrest 17c. Taking this into account, as shown in this embodiment and as shown in FIG. 11 etc., while arranging the mounting position of the bracket 11 as close as possible to the middle between the front wheel 3 and the rear wheel 4, tilting the bracket 11 forward with respect to the ground to secure a space S between the rear wheel 4 and the lever 13, the durability can be improved.

[0028] Next, another embodiment of the present invention will be described with reference to FIG. 12. What is shown in FIG. 12 is that the first elastic body 14 and the second elastic body 15 are changed from the torsion coil springs described above to compression springs to form the arm support 11. Although detailed description is omitted, even in this case, the arm support can be used in the same operation method as described above. That is, the present embodiment is not limited as long as the rotation directions of the lock member 12 and the lever 13 can be adjusted by a combination of moments of the first elastic body 14 and the second elastic body 15.

[0029] Although the wheelchair W has been used as an example of the embodiment of the present invention, it can also be used for chairs that can have armrests, such as commonly used seats (non-movable chairs without wheels) or electric wheelchairs. In addition, when used for the wheelchair W, the arm supports 1, 1 are arranged on both sides for explanation. However, when used for a general seat, only one of them may be arranged. That is, the use is not limited to the wheelchair W, and the arm supports 1, 1 of the present invention may be used according to the application.

Explanation of Reference Numerals

[0030] 1 Arm support 11 Bracket 12 Lock member 12a First locking portion 12b Second locking portion 13 Lever 131 Groove portion 13c Lock member locking portion 13d Stopper portion 14 First elastic body 15 Second elastic body 16 Cover 17 Arm support body 17a Locking hole 2 Vehicle body frame 3 Front wheel 4 Rear wheel 5 Seat portion 6 Back support 7 Foot support 8 Head support W Wheelchair

Claims

Claim 1 An arm support attached to both sides of the seat portion of a wheelchair, comprising a bracket fixed to a side portion of a vehicle body frame that supports the seat portion, an arm support body slidably attached in the vertical direction within the bracket, a lock member pivotally attached to a side portion of the bracket, a lever pivotally attached in the vicinity of the lock member and having one end arranged to be able to abut against one end of the lock member, and a first elastic body arranged to urge the lock member clockwise in a side view to constitute the arm support. When the arm support is raised, when the arm support body is pulled up, the first locking portion of the lock member that is locked in a locking hole formed in the side surface of the arm support body is urged clockwise from the lower surface of the locking hole in a side view and escapes, and then the lock member is urged counterclockwise in a side view by one end of the lever so as to resist the elastic force of the first elastic body, and the first locking portion rises while abutting against the side surface of the arm support body. When reaching any of the locking holes, the lock member rotates counterclockwise in a side view and the first locking portion locks again in the locking hole of the arm support body to support the arm support body. When the arm support is lowered, the arm support body is pulled up to release the first locking portion of the lock member from the locking hole of the arm support body, and at the same time, the lever is rotated counterclockwise in a side view to separate one end of the lock member and the lever, and the lever is held in a state where only the elastic force of the first elastic body acts on the lock member, enabling the arm support body to be pulled down. When reaching any of the locking holes, the lever is returned to its original position to bring the one end of the lock member and the lever into contact, and the lock member is urged counterclockwise in a side view by one end of the lever so as to resist the elastic force of the first elastic body, and the first locking portion locks in the locking hole to enable the arm support body to be supported. An arm support characterized by this. Claim 2 The lever is provided with a locking member engaging portion capable of contacting the locking member, a stopper portion disposed at a position spaced apart from the locking member engaging portion by a certain distance, and a groove portion is formed between the locking member engaging portion and the stopper portion, and the second locking portion of the locking member is disposed in the groove portion, so that the arm support can be lowered regardless of whether the lifting operation of the arm support body or the rotation operation of the lever is performed first. The arm support according to claim 1, characterized in that.

3. The arm support according to claim 2, characterized in that a second elastic body is disposed so as to bias the lever clockwise in a side view.

4. The first elastic body and the second elastic body use torsion coil springs. The first elastic body rotatably axially attaches the coil portion to the boss portion of the lever, and inserts one end into the locking hole formed in the locking member and the other end into the locking hole formed in the lever, respectively, for locking. The second elastic body rotatably axially attaches the coil portion to the boss portion, and is configured such that one end abuts against the side surface of the bracket and the other end abuts against the stopper portion of the lever. The arm support according to claim 3, characterized in that.

5. The arm support according to any one of claims 2 to 4, characterized in that the lever is disposed on the head support side in a side view.

6. The arm support according to any one of claims 2 to 5, characterized in that by tilting the bracket forward from the vertical direction in a side view, a space where the lever can be safely operated is formed between the rear wheel of the wheelchair and the lever.

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