# Patent

## Title
Table for wheelchair and wheelchair comprising same

## Abstract

A wheelchair table includes: an attachment part configured to be attached to a side part of a wheelchair; an arm supported by the attachment part; and a table body provided at a tip part of the arm. The arm is supported so as to be movable upward and downward relative to the attachment part such that the table body can be lowered from an in-use position located above a user's knees to a not in-use position located in front of and below the knees while the user sits in the wheelchair. With this wheelchair table, operability and safety during wheelchair travel can be enhanced while favorably maintaining the function as a table.

## Background
TECHNICAL FIELD
The present invention relates to a wheelchair table and a wheelchair provided therewith.
BACKGROUND ART
As for conventional wheelchair tables, for example, configurations disclosed in Patent Literatures 1 and 2 are known. The wheelchair table of Patent Literature 1 is placed on both arm rests of the wheelchair and fixed by a fixing belt. According to this configuration, the wheelchair table needs to be removed from the wheelchair when the table is not used, and thus there is a problem in that storage of the wheelchair table is likely to be troublesome. On the other hand, if the wheelchair is moved around with the wheelchair table in place, the wheelchair table is likely to get in the way during moving, and furthermore, a view around the feet is blocked by the wheelchair table, and thus there is also a safety problem.
In contrast, with the wheelchair table of Patent Literature 2, a table body supported by a table support rod is rotated and lowered when the table body is not used so that the table body is retracted together with the table support rod, and thereby the table body can be stowed away without being removed.
CITATION LIST
Patent Literature
[PTL 1] JP-A H11-76311
[PTL 2] JP-A 2003-126164
SUMMARY OF INVENTION
Technical Problem
However, according to the configuration of Patent Literature 2, the table body when not in use is positioned below the armrest, and thus there is a problem in that the table body is likely to impede wheelchair operation. Moreover, formation of storage space for portable items results in an increased table body size and thus an increased wheelchair width, and is problematic in that, in addition to further deteriorating operability, moving through a narrow passage or the like is likely to be troublesome.
Accordingly, an object of the present invention is to provide a wheelchair table that can enhance operability and safety during wheelchair travel while favorably maintaining the function as a table, and a wheelchair provided therewith.
Solution to Problem
The aforementioned object of the present invention is achieved by a wheelchair table comprising an attachment part to be attached to a side part of a wheelchair, an arm supported by the attachment part, and a table body provided at a tip part of the arm, wherein the arm is supported so as to be movable upward and downward relative to the attachment part such that the table body can be lowered from an in-use position located above a user's knees to a not in-use position located in front of and below the knees while the user sits in the wheelchair.
It is preferable that in this wheelchair table the arm is supported so as to be rotatable in upward and downward directions relative to the attachment part. Furthermore, the arm can comprise a latch part capable of engagement with an engagement part of the attachment part, a spring for biasing the latch part so as to engage with the engagement part, and a lever for detaching the latch part against a biasing force of the spring, and the arm can be rotatable relative to the attachment part when the user pushes the lever while sitting in the wheelchair to cancel the engagement of the engagement part and the latch part.
The direction in which the lever is pushed for cancelling the engagement of the engagement part and the latch part can be configured to match the rotational direction of the arm.
It is preferable that the arm comprises a framework for rotatably supporting the lever, and it is preferable that the lever comprises a handle placed within the framework.
It is preferable that the wheelchair table further comprises a cushioning mechanism that eases a rapid rotational movement of the arm relative to the attachment part.
It is preferable that the in-use position of the table body comprises a first in-use position in which an upper surface of the first table body is level and a second in-use position in which the upper surface of the first table body is tilted toward the user's side.
It is preferable that the table body is rotatably attached to the arm, and it is preferable that the table body can be retracted to a side from above the knees or from in front of and below the knees of the user.
It is preferable that the table body comprises a base part supported by the arm and a receptacle that is attachable to and detachable from the base part, and it is preferable that the receptacle, once removed from the base part, is capable of being carried.
The aforementioned object of the present invention is achieved by a wheelchair in which the above-described wheelchair table is attached to a side part.
Advantageous Effects of Invention
The present invention can provide a wheelchair table that can enhance operability and safety during wheelchair travel while favorably maintaining the function as a table, and a wheelchair provided therewith.



BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a perspective view of a wheelchair table according to a first embodiment of the present invention.
FIG. 2 is a perspective view showing a state in which the wheelchair table shown in FIG. 1 is attached to a wheelchair.
FIG. 3 is a perspective view showing a state during use of the wheelchair table shown in FIG. 2.
FIG. 4 is a perspective view showing another state during use of the wheelchair table shown in FIG. 2.
FIG. 5 is a perspective view showing yet another state during use of the wheelchair table shown in FIG. 2.
FIG. 6 is a side view showing a positional relationship of the table body and the user.
FIG. 7 is a perspective view showing yet another state during use of the wheelchair table shown in FIG. 2.
FIG. 8 is a perspective view showing yet another state during use of the wheelchair table shown in FIG. 2.
FIG. 9 is a perspective view of a wheelchair table according to the second embodiment of the present invention.
FIG. 10 is an outline perspective view showing relevant parts of the wheelchair table shown in FIG. 9.
FIG. 11 is a perspective view showing a state in which the wheelchair table shown in FIG. 9 is attached to a wheelchair.
FIG. 12 is a perspective view showing a state during use of the wheelchair table shown in FIG. 11.
FIG. 13 is a perspective view showing another state during use of the wheelchair table shown in FIG. 11.
FIG. 14 is an enlarged view of relevant parts showing an example of the attachment structure for attaching the arm to the attachment part.
FIGS. 15(a) to 15(c) are drawings for explaining the operation of the attachment structure shown in FIG. 14.
FIG. 16 is an enlarged view of relevant parts showing another example of the attachment structure shown in FIG. 14.
FIGS. 17(a) and 17(b) are enlarged views of relevant parts showing yet another example of the attachment structure shown in FIG. 14.
FIG. 18 is an enlarged view of relevant parts showing yet another example of the attachment structure shown in FIG. 14.
FIG. 19 is an enlarged view of relevant parts showing yet another example of the attachment structure shown in FIG. 14.
FIGS. 20(a) to 20(c) are drawings for explaining the operation of the attachment structure shown in FIG. 19.
FIG. 21 is an enlarged view of relevant parts showing a modification of the attachment structure shown in FIG. 19.
FIG. 22 is an enlarged view of relevant parts for explaining an example of the attachment structure for attaching the table body to an arm 20.
FIG. 23 includes drawings showing relevant parts of the attachment structure shown in FIG. 22, and FIG. 23(a) is a cross-sectional view taken along the line D-D, FIG. 23(b) is cross-sectional view taken along the line E-E, and FIG. 23(c) is cross-sectional view taken along the line F-F.
FIG. 24 is a side view showing an example of the attachment part.
FIG. 25(a) is a side view, and FIG. 25(b) is a plan view, of the attachment part shown in FIG. 24.
FIG. 26 is a plan view showing another example of the attachment part.
FIG. 27 is a plan view showing yet another example of the attachment part.
FIG. 28 is a perspective view showing an example of the table body.
FIG. 29 is a perspective view for explaining a state during use of the table body shown in FIG. 28.



DESCRIPTION OF EMBODIMENTS
Below, an embodiment of the present invention will now be described with reference to the attached drawings. FIG. 1 is a perspective view of a wheelchair table according to the first embodiment of the present invention. A wheelchair table 1 comprises an attachment part 10 to be attached to a wheelchair, an arm 20 supported by the attachment part 10, and a table body 30 provided on the arm 20.
The attachment part 10 comprises an main body 12 having a holding part (not shown) on the back surface side for holding onto, for example, the frame of a wheelchair in a clamping manner, and a retaining part 14 extending upward from the main body 12. The proximal end part of the arm 20 is rotatably attached by a rotating shaft 22 to the tip part of the retaining part 14. It is preferable that the attachment part 10 can be detachably fixed to a wheelchair such that the arm 20 can be erected in the vertical direction, and a suitable means other than the holding part can be used, such as attachment by a belt, screwing, and interlocking. Note that the attachment part 10 can also be integrated into a wheelchair so as to be undetachable therefrom by welding or the like. The rotating shaft 22 is fixed stepwise by a ratchet mechanism (not shown) and can retain the arm 20 at the desired rotational position.
The table body 30 comprises a mounting part 34 on the side wall of a casing 32 that has storage space inside, and the mounting part 34 is rotatably attached by a rotating shaft 36 to the tip part of the arm 20. The rotating shaft 36 is fixed stepwise by a ratchet mechanism (not shown) and can retain the table body 30 at the desired rotational position. The upper opening of the casing 32 is closed by a lid 38 that can be opened and closed in a slidable manner. It is preferable that the rotational direction of the arm 20 relative to the attachment part 10 (the direction indicated by arrow A) and the rotational direction of the table body 30 relative to the arm 20 (the direction indicated by arrow B) are different from each other, and in this embodiment, imaginary planes including the respective rotational directions are configured to be perpendicular to each other. The material of the table body 30 is not particularly limited as long as necessary strength can be secured, and examples include iron, stainless steel, aluminum, plastics, carbon, ceramics, wood, and the like. If the storage space in the table body 30 is not needed, the table body 30 can be configured to correspond only to the lid 38 to save weight.
FIG. 2 is a perspective view showing a state in which the wheelchair table 1 shown in FIG. 1 is attached to a wheelchair 100. The wheelchair 100 comprises frames 112 and 112 on both right and left sides of a seat 110 on which a user sits, and driving wheels 120 and 120 and small wheels 122 and 122 on the outer sides of the frames 112 and 112. Footrests 130 and 130 are provided in front of the seat 110. With respect to the wheelchair 100 having such a configuration, the attachment part 10 of the wheelchair table 1 is attached to the lower part of one frame 112, and erecting the arm 20 places the table body 30 into an in-use position above the user's knees. The position of the table body 30 shown in FIG. 1 is the first in-use position in which, with the wheelchair 100 being placed on a level surface, the upper surface of the lid 38 is level. The wheelchair 100 is not particularly limited as long as it is configured such that a user can move around while sitting therein, and may be manually powered or electrically powered. Furthermore, the wheelchair 100 may be, for example, a chair on casters. Also, other than the frame, the place of attachment of the wheelchair table 1 to the wheelchair 100 can be the hanger bracket, arm rest, or the like of the wheelchair.
The lid 38 in the upper part of the table body 30, when slid forward, can open the mouth of the casing 32 as shown in FIG. 3, and user's personal effects (such as tablet information terminals, cell phones, wallets, and keys) can be accommodated in the casing 32. The upper surface of the lid 38, regardless of whether the lid is in an open or closed state, can be used as, for example, a work bench for a user or a surface on which personal effects of the user are placed.
Thus, attaching the wheelchair table 1 of this embodiment to the wheelchair 100 to form a storage compartment eliminates a need for a user to carry a bag. Therefore, there is no possibility that a bag placed on, for example, the lap gets in the way or falls when operating the wheelchair 100, thus making it easy for the user to concentrate on operation. Also, when work is performed using the table body 30, small items can be immediately stored in the casing 32 after the work is finished, and workability can be enhanced. A specific configuration of the casing 32 will be described in detail below.
As shown in FIG. 4, the table body 30 can also be used in an in-use position in which the arm 20 is rotated further rearward (toward the user) on the rotating shaft 22 than the first in-use position shown in FIG. 1. The position of the table body 30 shown in FIG. 4 is the second in-use position in which, with the wheelchair 100 being placed on a level surface, the upper surface of the lid 38 is tilted toward the user. In this position, a user can use the table body 30 while leaning against the backrest of the seat 110, and workability can be enhanced. When not using the table body 30, the arm 20 is rotated forward on the rotating shaft 22 to move the table body 30 to a not in-use position that is in front of and below the user's knees, as shown in FIG. 5.
FIG. 6 is a side view showing the positional relationship of the table body 30 and a user U when the table body 30 is in a first in-use position P1, a second in-use position P2, and a not in-use position P3. As shown in FIG. 6, the first in-use position P1 and the second in-use position P2 are both located above knees K of the user U, and the not in-use position P3 is located in front of and below the knees K of the user U. When the table body 30 is moved to the not in-use position P3 from the first in-use position P1, the user, by leaning slightly forward, can see as far as the vicinity of the footrests 130 as indicated by the dashed arrow, and therefore the user can safely operate the wheelchair 100 while checking, for example, the unevenness of the road surface and the presence and absence of obstacles on the road surface. Moreover, since the table body 30 is not present above the user's knees, the user can concentrate on operation without having an oppressive feeling, and also the table body 30 can be prevented from getting in the way when the user sits at another table in, for example, a kitchen. The sight of the user's feet can also be secured by rotating the table body 30 from the first in-use position P1 to the second in-use position P2 when the length of the table body 30 in the longitudinal direction (fore-aft direction in the state during use) is short, and for example, when the user wishes to move a little while using the table body 30, such a rotating operation is convenient in some cases.
In consideration of the ease of securing sight during traveling as well as workability and storability, the size of the table body 30 is preferably 80 to 400 mm in the longitudinal direction (fore-aft direction) (more preferably 80 to 220 mm) and is preferably 80 to 600 mm in the transverse direction (right-left direction) (more preferably 80 to 450 mm and even more preferably 100 to 270 mm).
The table body 30 can also be moved by the rotational operation of the table body 30 relative to the arm 20 other than the rotational operation of the arm 20 relative to the attachment part 10 described above. The table body 30 shown in FIG. 7 shows a state reached from the state in which the table body 30 is in the first in-use position as shown in FIG. 1 by rotating the table body 30 downward on the rotating shaft 36 that is in the horizontal direction such that the table body 30 is first lifted up toward the side, and the table body 30 can be retreated to the side from above the user's knees. The table body 30 shown in FIG. 8 is in a state reached from the state in which the table body 30 is in the not in-use position as shown in FIG. 5 by rotating the table to the side on the rotating shaft 36 that is in the vertical direction, and the table body 30 can be retreated to the side from in front of and below the user's knees. In both states shown in FIGS. 7 and 8 as well, there is no possibility that the table body 30 gets in the way when a user gets in and out the wheelchair 100, and ease of use can be enhanced. In particular, the rotational movement of the table body 30 shown in FIG. 8 is performed along the horizontal plane with the rotating shaft 36 extending in the vertical direction, and therefore the arm 20 can support the weight of the table body 30 even when a large number of personal effects or the like are stored in the table body 30, and the user's burden can be reduced.
FIG. 9 is a perspective view of the wheelchair table 1 according to the second embodiment of the present invention. FIG. 10 is a side view of relevant parts of the wheelchair table shown in FIG. 9. As shown in FIGS. 9 and 10, the wheelchair table 1a comprises an attachment part 10a to be attached to a wheelchair, an arm 20a supported by the attachment part 10a, and a table body 30a provided on the arm 20a. 
As with the attachment part 10 shown in, for example, FIG. 1, the attachment part 10a comprises a main body 12a to be attached to, for example, the frame of a wheelchair, and a retaining part 14a extending upward from the main body 12a. In the retaining part 14a, a slit 16a is formed in the longitudinal direction.
The arm 20 comprises a support part 22a into which the retaining part 14a is inserted, an upstanding part 24a provided on the support part 22a, and a guide pin 26a. The table body 30a has the same configuration as the table body 30 shown in, for example, FIG. 1, and a mounting part 34a is rotatably attached to the tip part of the upstanding part 24a by a rotating shaft 36a. As shown in FIG. 10, the guide pin 26a is fixed to the support part 22a, and is supported by an elevating device 18a such as a gas spring or an electric cylinder that is provided inside the retaining part 14a. The elevating device 18a can raise or lower the arm 20a relative to the attachment part 10a by moving up or down the guide pin 26a. 
Attaching the wheelchair table 1a of the second embodiment to the wheelchair 100 as shown in FIG. 11 to place the table body 30a into an in-use position that is above the user's knees makes it possible to use the wheelchair table 1a in the same manner as the wheelchair table 1 shown in, for example, FIG. 2. Moreover, rotating the table body 30a relative to the arm 20a and then lowering the arm 20a relative to the attachment part 10a as shown in FIGS. 12 and 13 make it possible to move the table body 30a between the in-use position that is above the user's knees (the position shown in FIG. 11) and the not in-use position that is in front of and below the user's knees (the position shown in FIG. 13). Since the upward and downward movement of the arm 20a can be performed by the actuation of the elevating device 18a, operability can be enhanced.
FIG. 14 is an enlarged view of relevant parts for explaining an example of the attachment structure for attaching the arm 20 to the attachment part 10 in the wheelchair table 1 shown in FIG. 1. A disc-like part 11 is formed in the upper part of the retaining part 14 of the attachment part 10, and a plurality of depressions 13 that serve as engagement parts are formed along the outer circumference of the disc-like part 11. On the other hand, inside the arm 20 a rod 25 is provided that moves back and forth in the longitudinal direction due to the operation of a lever 21, with a pivot shaft 23 serving as a fulcrum. A latch part 27 is provided at the tip of the rod 25. The latch part 27 is biased by a spring 15 composed of a coil spring so as to be accommodated in a depression 13, and the rotational position of the arm 20 relative to the attachment part 10 is fixed by the engagement of the latch part 27 and the depression 13. The spring 15 is not particularly limited to a coil spring as long as it biases the latch part 27 to be engaged with the depression 13, and may be another elastic body.
According to the attachment structure shown in FIG. 14, as shown in FIG. 15(a), rotating the lever 21 in the direction indicated by the arrow causes the latch part 27 to move in the direction of leaving the depression 13 against the biasing force of the spring 15, and makes the arm 20 rotatable relative to the retaining part 14. In this state, rotating the arm 20 in the direction indicated by the arrow shown in FIG. 15(b) and then releasing the lever 21 cause, as shown in FIG. 15(c), the latch part 27 to be pulled back into the depression 13 due to the action of the spring 15 and the lever 21 to return in the direction indicated by the arrow, thus making the arm 20 unrotatable.
With the attachment structure shown in FIG. 14, pushing the lever 21 downward enables the arm 20 to be rotated, and therefore even in the case where a user does not have sufficient strength due to, for example, a physical disability, it is possible to initiate the rotation of the arm 20 using, for example, the weight of the upper half of the body and, without interruption, rotate and fix the arm 20 by operating only the lever 21. Moreover, providing a large number of depressions 13 with which the latch part 27 engages enables the arm 20 to rotate stepwise, thus making it possible for a user to fix the table body 30 to the desired rotational position.
In order to prevent rapid movement of the table body 30, it is preferable that the configuration shown in FIG. 14 comprises a cushioning mechanism that can ease the rapid rotation of the arm 20. For example, as shown in FIG. 16, using a spring 151 that is composed of a torsion spring or the like and providing, for example, a damper 17 or a gas spring as a cushioning mechanism make it possible to safely and reliably rotate the table body 30 to the desired position.
FIG. 17 is an enlarged view of relevant parts for explaining another example of the attachment structure for attaching the arm 20 to the attachment part 10 in the wheelchair table 1 shown in FIG. 1. In FIG. 17(a), a disc-like part 11a provided in the upper part of the retaining part 14 comprises a large number of grooves 111a (shown only partially in the figure) that are radially formed, with the rotating shaft 22 being the center. The engagement of a projecting engagement part 27a provided on the side opposite to the lever 21a and a groove 111a of the disc-like part 11a, with a pivot shaft 23a serving as a fulcrum, fixes the rotational position of the arm 20. Between the disc-like part 11a and the engagement part 27a, a spring 15a such as a coil spring for biasing both components to be tightly attached to each other is interposed, and thus the engagement of the engagement part 27a and the groove 111a is secured, thereby making it possible to fix the arm 20 to the desired rotational position. The engagement of the engagement part 27a and the groove 111a can be easily cancelled by operating the lever 21a in the direction indicated by the arrow shown in FIG. 17(b). The spring 15a can be configured to function such that the engagement part 27a and the groove 111a when not in an engaged state are biased so as to be separated in the direction of the rotating shaft 22, and the engagement part 27a is accommodated in a cover (not shown) and is tightly attached to the groove 111a when the engagement part 27a and the groove 111a engage.
It is possible that the rotation and fixation of the arm 20 relative to the attachment part 10 are attained by a motor 40 that is directly coupled to the rotating shaft 22 as shown in FIG. 18, and operability for a user can be enhanced also in this way. The motor 40 is not particularly limited as long as it has a configuration that enables positional control, and examples include a geared motor, a stepping motor, and the like.
FIG. 19 is an enlarged view of relevant parts for explaining yet another example of the attachment structure for attaching the arm 20 to the attachment part 10 in the wheelchair table 1 shown in FIG. 1. In FIG. 19, a disc-like part 11b is provided in the upper part of the retaining part 14 via a rotating part 111b. The rotating part 111b has a configuration in which a rotating shaft 112b provided at the tip of the retaining part 14 is sandwiched between a pair of blocks 113b and 114b, and the disc-like part 11b is fixed to the block 114b. While the blocks 113b and 114b are fixed to the rotating shaft 112b by tightening bolts 115b and 115b, they become rotatable relative to the rotating shaft 112b by loosening the bolts 115b and 115b, thus making it possible to adjust the position, e.g., height position or inclination, of the disc-like part 11b. 
A plurality of depressions 13b are formed along the outer circumference of the disc-like part 11b. On the other hand, in a support part 20b constituting the proximal end side of the arm 20, a rod 25b is provided that moves back and forth due to the operation of a lever 21b, with a pivot shaft 23b serving as a fulcrum. The support part 20b is provided with a guide part 201b, and the guide part 201b guides the rod 25b so as to move back and forth in the longitudinal direction of the arm 20. A latch part 27b is provided at the tip of the rod 25b. The latch part 27b is biased by a spring 15b composed of a torsion spring so as to be accommodated in a depression 13b that serves as an engagement part, and the rotational position of the arm 20 relative to the attachment part 10 is fixed by the engagement of the latch part 27b and the depression 13b. 
In the side surface of the disc-like part 11b, an arc-shaped guide slit 116b is formed and, furthermore, a plurality of indentations 117b for indices are formed in the circumferential direction. The guide slit 116b and an indentation 117b engage with a projection 202b composed of a pin provided on the support part 20b and a projection 203b composed of a ball plunger, respectively, and thus the range of rotation of the arm 20 relative to the attachment part 10 is regulated and the rotational position is identified.
In the attachment structure shown in FIG. 19, as shown in FIG. 20(a), rotating the lever 21b in the direction indicated by the arrow cancels the engagement of the latch part 27b and the depression 13b, and as shown in FIG. 20(b), the arm 20 can be rotated relative to the attachment part 10 in the direction indicated by the arrow to the desired rotational position. Then, releasing the lever 21b causes the lever 21b to return to the original rotational position due to the biasing force of the spring 15b such that the latch part 27b and the depression 13b engage as shown in FIG. 20(c), and the arm 20 is fixed. In this embodiment, a spring 17b such as a torsion spring is attached to the rotating shaft 22 so as to constitute a cushioning mechanism, and the engagement of the spring 17b with the projection 202b generates a biasing force that makes the rotational movement of the arm 20 subdued.
In the attachment structure shown in FIG. 19, the direction of rotation by pushing the lever 21b and the direction of rotation of the arm 20 match as indicated by the arrows in FIGS. 20(a) and 20(b), and therefore, by grasping the lever 21b, a user can easily rotate the arm 20 from an in-use position to a not in-use position. In the attachment structure shown in FIG. 19, torsion springs are used for the springs 15b and 17b, but other elastic bodies such as coil springs may be used, and the biasing force that acts may be any of compressive force and tensile force.
FIG. 21 shows a modification of the attachment structure shown in FIG. 19, and the same components as in FIG. 19 are given the same reference numbers. In FIG. 21, the support part that serves as the proximal end side of the arm 20 is composed of a framework 20c, and a handle 211c of a lever 21c is placed within the framework 20c. The function of the lever 21c is the same as that of the lever 21b shown in FIG. 19, and grasping the framework 20c and the lever 21c in an integral manner causes the lever 21c to rotate in the direction indicated by the arrow against the biasing force of the spring 15c and makes the arm 20 rotatable relative to the attachment part 10. In the configuration shown in FIG. 21, a user can easily perform rotational operation of the lever 21c in all positions P1, P2, and P3 of the table body 30 shown in FIG. 6.
FIG. 22 is an enlarged view of relevant parts for explaining an example of the attachment structure for attaching the table body 30 to the arm 20 in the wheelchair table 1 shown in FIG. 1. The rotating shaft 36 for the arm 20 and the table body 30 has one end side that is fixed to the table body 30 and the other end side that is rotatably accommodated in a casing 31 fixed to the arm 20 by bolts 37 and 37. A cover 35 is attached to the casing 31 on the table body 30 side of a main body 33, and the arm 20 is sandwiched between the main body 33 and the cover 35. The position where the arm 20 is fixed to the casing 31 is not particularly limited, and the arm 20 can also be fixed to the end face of the main body 33.
FIG. 23 shows relevant parts of the attachment structure shown in FIG. 22, FIG. 23(a) is a cross-sectional view taken along the line D-D of FIG. 22, FIG. 23(b) is a cross-sectional view taken along the line E-E of FIG. 22, and FIG. 23(c) is a cross-sectional view taken along the line F-F of FIG. 22. As shown in FIG. 23(a), the cover 35 comprises an accommodating recess 351 that has a protrusion 352 in a part of a circular depression, and an engagement projection 361 projecting from the outer circumferential surface of the rotating shaft 36 is accommodated in the accommodating recess 351. As shown in FIG. 23(b), a ball plunger 331 is provided inside the main body 33, and the ball part of the ball plunger 331 engages with any of the multiple indentations 363 formed in the circumferential direction of the rotating shaft 36. As shown in FIG. 23(c), the arm 20 has a plurality of arc-shaped elongated holes 371 and 371 into which bolts 37 and 37 are inserted on the respective sides of the part where the rotating shaft 36 penetrates, and thus the angle of attachment to the casing 31 (see FIG. 22) can be fine-tuned.
According to the attachment structure shown in FIGS. 22 and 23, the range of rotation of the rotating shaft 36 is regulated by the engagement of the engagement projection 361 and the accommodating groove 351, and the rotational position of the rotating shaft 36 is identified by the engagement of the ball plunger 331 and an indentation 363. The attachment structure for attaching the table body 30 to the arm 20 is not limited to the configuration shown in FIG. 22 and, for example, a configuration similar to the above-described attachment structure for attaching the arm 20 to the attachment part 10 is also applicable.
FIG. 24 is a side view for explaining an example of the structure of the attachment part 10b, in the wheelchair table 1 shown in FIG. 1, to be attached to the frame 112 of the wheelchair 100. FIG. 25(a) is a side view of the attachment part 10b, and FIG. 25(b) is a plan view of the attachment part 10b. The attachment part 10b comprises a retaining-part attachment part 102b provided on one end side of the main body 101b and a frame attachment part 103b provided on the other end side of the main body 101b. The retaining-part attachment part 102b is formed by bending the end part of the main body 101b, and is fastened by a brace 105b that is equipped with a lever 104b so that the retaining part 14 can be fixed inside. The frame attachment part 103b is composed of a bracket that can sandwich the frame between the attachment part 103b and the main body 101b by fasteners 107b and 107b. The fasteners 107b and 107b are movable along arc-shaped guide slits 108b and 108b that are formed in the main body 101b, and can adjust the angle of attachment of the frame attachment part 103b to the main body 101b. Accordingly, irrespective of the inclination angle of the frame 112 shown in FIG. 24, the attachment part 10b can be reliably attached to the wheelchair 100, and versatility can be enhanced.
Various modifications can be made to the structure of the attachment part that is to be attached to the frame 112 of the wheelchair 100. For example, as shown in the plan view in FIG. 26, a retaining-part attachment part 102c and a frame attachment part 103c can be placed on the front surface side and the back surface side of a main body 101c of an attachment part 10c, respectively. The retaining part 14 can be sandwiched between the retaining-part attachment part 102c and the main body 101c, and the frame 112 can be sandwiched between the frame attachment part 103c and the main body 101c, using fasteners such as bolts in both cases. According to this configuration, the retaining part 14 can be adjacently placed on the side of the frame 112, and the retaining part 14 can be reliably supported in an upright state. Retaining grooves 1011c and 1012c extending along the retaining part 14 and the frame 112 are formed in the front and rear surfaces of the main body 101c, respectively. The retaining grooves 1011c and 1012c are inclined relative to each other so as to support the retaining part 14 in the vertical direction when the attachment part 10c is attached to the inclined frame 112.
Moreover, as shown in FIG. 27, an attachment part 10d may be configured to simply sandwich the retaining part 14 and the frame 112 between two blocks 102d and 103d, and the number of components can be reduced.
The table body 30 shown in FIG. 3 is configured to allow the opening and closing of the storage space with the lid 38 that slides across the opening of the casing 32. Various modifications can be made to the attachment structure for attaching the lid 38 to the casing 32, and examples include a configuration in which the lid 38 slides across the opening of the casing 32, with a corner of the casing 32 serving as a hub, a configuration in which the lid 38 is rotated, with one side of the casing 32 serving as a pivot shaft, a configuration in which the lid 38 is formed into a tubular shape and the casing 32 is moved in and out, a configuration in which the lid 38 is opened and closed by a parallel link, and similar configurations. In the case where the casing 32 is accommodated in the lid 38 that is in a tubular shape, the casing 32 can be divided into multiple portions. It is preferable that the lid 38 can maintain the casing 32 in a closed state by a magnet, metal brace, band, zipper, or the like such that items accommodated inside the casing 32 do not scatter around due to the rotation of the arm 20 or the table body 30. In the table body 30 shown in FIG. 3, the casing 32 is attached to the arm 20, but the table body 30 may be configured such that the lid 38 that has high rigidity and strength is attached to the arm 20, and the casing 32 is moved relative to the lid 38.
FIG. 28 is a perspective view showing a preferable example of the table body 30a. The table body 30a comprises a base part 341a fixed to the mounting part 34a for attachment to the arm (not shown) and a receptacle 342a the lower surface of which is supported by the base part 341a. The receptacle 342a is composed of, for example, synthetic resin or cloth, and the upper part of the casing 32a having storage space is covered by a lid 38a. The lid 38a comprises a handle 381a, and the lid 38a can be opened and closed by holding the handle 381a. With the casing 32a in a closed state, the lid 38a can be fixed to the casing 32a by a magnet or the like.
The receptacle 342a comprises an engagement member (not shown) such as an elastic band or a belt, and is configured to be attachable to and detachable from the base part 341a by engaging and disengaging this engagement member with the base part 341. In order to reliably prevent the receptacle 342a from falling off the base part 341a when the table body 30a is rotated, a fastener such as a buckle, swivel, or magnet can be suitably used. It is preferable that the base part 341a has high rigidity and strength, and even when the receptacle 342a is composed of a flexible material such as cloth or resin sheet, widely opening the lid 38a makes it possible to do work on the base part 341a via the bottom part of the receptacle 342a. 
According to the table body 30a shown in FIG. 28, the lower surface of the receptacle 342a can be supported by the base part 341a, and therefore the receptacle 342a even when it has a large size can be reliably supported, and the storage space and the work space can be increased. Moreover, when getting off the wheelchair, the receptacle 342a can be removed from the base part 341 as shown in FIG. 29, and it can be carried like a bag by, for example, holding the handle 381a. With a conventional wheelchair, a user needs to place a bag on the lap, under the seat, or in a side part, rear part, or similar place of the wheelchair, and therefore operability and workability are impaired, but the use of the receptacle 342a of this embodiment in place of a bag can enhance the operability and workability of the wheelchair.
REFERENCE SIGNS LIST


    
    
        1. Wheelchair table
        10. Attachment part
        20. Arm
        22. Rotating shaft
        30. Table body
        36. Rotating shaft
        100. Wheelchair

## Claims

1. A wheelchair table comprising:
an attachment part configured to be attached to a side part of a wheelchair;
an arm supported by the attachment part; and
a table body provided at a tip part of the arm;
wherein the arm is supported so as to be rotatable in upward and downward directions relative to the attachment part such that the table body can be lowered from at least one in-use position located above a user's knees to a not in-use position located in front of and below the knees while the user sits in the wheelchair;
wherein the arm includes
a latch part configured to engage an engagement part of the attachment part,
a spring configured to bias the latch part to engage with the engagement part, and
a lever configured to detach the latch part against a biasing force of the spring;

wherein the arm is configured to rotate relative to the attachment part when the lever is rotated by applying a pushing force to the lever to counter the engagement between the engagement part and the latch part; and
wherein a direction of rotation of the lever matches a rotational direction of the arm.

2. The wheelchair table according to claim 1, wherein the arm further comprises:
a framework configured to rotatably support the lever, the lever including a handle within the framework.

3. The wheelchair table according to claim 1, further comprising:
a cushioning mechanism configured to ease rapid rotational movement of the arm relative to the attachment part.

4. The wheelchair table according to claim 1, wherein the at least one in-use position of the table body comprises:
a first in-use position in which an upper surface of the table body is level; and
a second in-use position in which the upper surface of the table body is tilted toward the user's side.

5. The wheelchair table according to claim 1, wherein
the table body is rotatably attached to the arm; and
the table body is configured to be retracted to a side from above the knees or from in front of and below the knees of the user.

6. The wheelchair table according to claim 1, wherein the table body comprises:
a base part supported by the arm; and
a receptacle configured to be attached to and detached from the base part, wherein
the receptacle is configured to be carried once removed from the base part.

7. A wheelchair in which the wheelchair table of claim 1 is attached to a side part.