JP2007236703A - Wheelchair - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wheelchair capable of stably traveling even on an unpaved area, an uneven ground, and the like and self-broadening a living range of a person in a wheelchair. <P>SOLUTION: This wheelchair 1 which has large-diameter rear wheels 11 and small-diameter front wheels 12 in the right/left of a body frame 8 and travels by manually rotating the right/left rear wheels 11, is further provided with accelerating transmission mechanisms 20 transmitting the rotation of the rear wheels 11 so as to accelerate the circumferential velocity of the front wheels 12 to the same to the circumferential velocity of the rear wheels, between the right/left rear wheels 11 and the front wheels 12. The accelerating transmission mechanisms 20 are interposed with one-way clutches for transmitting the advancing-directional rotation from the rear shaft to the front wheels. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a wheelchair that includes a large-diameter rear wheel and a small-diameter rear wheel on the left and right sides of the airframe, and travels by manually rotating the rear wheel.

  In general, a wheelchair that has a large-diameter rear wheel and a small-diameter rear wheel on both the left and right sides of the body and manually rotates the rear wheel is a lower end portion of a support shaft in which the front wheel is disposed substantially vertically. There is known one that is rotatably supported by a front wheel shaft that is horizontally supported by the caster arm via a caster arm that is rotatably supported by the caster arm (for example, see Patent Document 1).

  In addition, the left and right sides of the fuselage have a large-diameter rear wheel, a small-diameter front wheel, and a drive wheel that contacts the outer periphery of the rear wheel and the front wheel at the same time. There has also been proposed a wheelchair in which the rear wheel and the front wheel are simultaneously rotated in the same direction by the frictional force of the front wheel (see, for example, Patent Document 2).

Japanese Patent No. 3060403 (2nd page, FIG. 2) Japanese Patent Laying-Open No. 2005-308198 (page 2-3, FIG. 2)

  In the former prior art, since the caster arm and the front wheel are only supported rotatably with respect to the support shaft, not only the direction of the front wheel swings to the left and right during running, but also the front wheel is small and small. When hitting a step, the front wheel may be caught and the stability of the wheelchair traveling may be impaired.

  In the latter prior art, since a part of the weight of the wheelchair occupant is used for the contact pressure between the rear wheel and the front wheel and the driving wheel, the spring pressure or the like must be adjusted for each occupant. Work becomes complicated. In addition, since the vehicle travels using friction between the driving wheel, the rear wheel, and the front wheel, the transmission load of the driving force increases, and the range of living by the wheelchair passenger's own power is narrowed.

  In view of the above circumstances, an object of the present invention is to provide a wheelchair that enables stable traveling even on non-paved terrain, rough terrain, and the like, so that the range of life of the wheelchair occupant can be expanded. .

In order to achieve the object, the present invention according to claim 1 includes a large-diameter rear wheel (11) and a small-diameter front wheel (12) on the left and right sides of the fuselage (8), and the left and right rear wheels (11). In a wheelchair (1) that runs by manually rotating the
Between the left and right rear wheels (11) and the left and right front wheels (12), the rotation of the rear wheel (11) is substantially the same as the peripheral speed of the rear wheels (11). Provided with a speed increasing transmission mechanism (20) that increases the speed so as to be the same speed,
The wheelchair is characterized by that.

According to a second aspect of the present invention, the one-way rotation clutch (47) for transmitting the forward rotation from the rear wheel (11) to the front wheel (12) is provided in each speed increasing transmission mechanism (20). Provided,
It exists in the wheelchair of Claim 1 characterized by the above-mentioned.

According to the third aspect of the present invention, between the front wheels (12) and the axle (46) supporting the front wheels (12), rotation in the forward direction from the rear wheels (11) is performed in the front wheels (12). ) Provided with a one-way rotation clutch (47) for transmission to
The wheelchair according to claim 2.

  The reference numerals in the parentheses are for reference to the drawings and do not limit the present invention.

  According to the first aspect of the present invention, the rear wheel and the front wheel can be driven while being rotated at substantially the same peripheral speed, so that stable running is possible even on unpaved or rough terrain. Can expand the range of their lives.

  According to the second aspect of the present invention, the one-way rotation clutch that transmits the rotation in the forward direction to the front wheel is arranged in the speed increasing transmission mechanism, thereby turning the wheelchair and moving backward, and the wheelchair by the assistance vehicle. Can be easily performed, and the running stability can be improved without reducing the operability of the wheelchair.

  According to the third aspect of the present invention, since the one-way rotation clutch that transmits the forward rotation to the front wheel is provided between the front wheel and the axle that supports the front wheel, the wheelchair can be easily manufactured. In addition, the turning operation and the reverse operation can be easily performed, and the running stability can be improved without reducing the operability of the wheelchair.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  1 to 7 show an embodiment of the present invention. FIG. 1 is a side sectional view of a wheelchair according to the present invention, FIG. 2 is a plan partial sectional view of FIG. 1, and FIG. 4 is an enlarged sectional view of the front wheel drive unit of FIG. 1, FIG. 5 is an enlarged front view of the front wheel drive unit of FIG. 1, and FIG. 6 shows a power transmission state when the wheelchair moves forward. FIG. 7 is a side view showing a power transmission state when the wheelchair moves backward.

  As shown in FIGS. 1 to 3, the wheelchair 1 has a main body frame 8 on which a seat seat 2, a back seat 3, a leg rest 5, a footrest 6, a hand grip 7, and the like are arranged. On both sides, a large-diameter rear wheel 11 provided with a hand rim 10 for traveling operation and a small-diameter front wheel 12 as a caster are arranged.

  Between the left and right rear wheels 11 and the front wheels 12, the rotation of the rear wheels 11 is increased so that the peripheral speed of the front wheels 12 is substantially the same as the peripheral speed of the rear wheels 11. A speed increasing transmission mechanism 20 for transmission is provided. The front wheel 12 is supported by the main body frame 8 via the speed increasing transmission mechanism 20.

  The speed increasing transmission mechanism 20 includes a speed increasing portion 21 and a transmission portion 30, and the speed increasing portion 21 includes a large-diameter gear 23 that is integrally fixed to the rear wheel 11 via a bracket 22, and a bracket 25. A small-diameter gear 27 fixed to mesh with the gear 23 at one end of a sprocket shaft 26 that is rotatably supported by the main body frame 8.

  As shown in FIGS. 1 to 5, the transmission 30 is fixed to a sprocket 31 fixed to the sprocket shaft 26 and a sprocket shaft 33 rotatably supported by a plate 32 fixed to the main body frame 8. Sprocket 35 and a chain 36 spanned between each sprocket 31 and sprocket 35. A bevel gear 37 is fixed to the sprocket shaft 33.

  The transmission unit 30 includes an upper power transmission shaft 40 rotatably supported by a frame pipe 38 that is fixed to the plate 32 with its axis oriented in the vertical direction, and one end of the upper power transmission shaft 40. The bevel gear 41 that meshes with the bevel gear 37 is fixed.

  A gear 42 is attached to the lower portion of the upper power transmission shaft 40. Further, an inverted U-shaped caster arm 45 that opens downward through a bearing 43 is rotatably supported at the lower end of the upper power transmission shaft 40. The front wheel 12 is supported on an axle 46 rotatably supported by the lower end portion of the caster arm 45 via a one-way rotation clutch 47 that transmits the forward rotation from the rear wheel 11 to the front wheel 12. Yes. A bevel gear 48 is fixed to the axle 46.

  A lower power transmission shaft 52 is rotatably supported by a frame pipe 51 that is integrally fixed to the caster arm 45 via a bracket 50. A gear 53 that meshes with the gear 42 is fixed to the upper end of the lower power transmission shaft 52, and a bevel gear 55 that meshes with the bevel gear 48 is fixed to the lower end.

  In the above configuration, as shown in FIG. 6, when the passenger of the wheelchair 1 turns the hand rim 10 or is pushed by an assistant to rotate the rear wheel 11 in the direction of arrow A, the wheelchair 1 moves forward ( Travel in the direction of arrow B). At this time, the gear 23 fixed integrally with the rear wheel 11 also rotates in the direction of arrow A simultaneously with the rear wheel 11. The rotation of the gear 23 is increased by the gear ratio with the gear 27 and transmitted to the sprocket shaft 26, and is transmitted to the sprocket shaft 33 disposed above the front wheel 12 via the sprocket 31, the chain 36 and the sprocket 35, The sprocket shaft 33 is rotated.

  The rotation of the sprocket shaft 33 is transmitted to the upper power transmission shaft 40 through the bevel gear 37 and the bevel gear 41, and further transmitted from the upper power transmission shaft 40 to the lower power transmission shaft 52 through the gear 42 and the gear 53. The transmission shaft 52 is rotated. The rotation of the lower power transmission shaft 52 is transmitted to the axle 46 through the bevel gear 55 and the bevel gear 48 to rotate the axle 46. The rotation of the axle 46 is transmitted to the front wheel 12 via the one-way rotation clutch 47, and the front wheel 12 is rotationally driven in the direction of arrow a so that the peripheral speed thereof is substantially the same as the peripheral speed of the rear wheel 11.

  That is, by rotating the rear wheel 11, the front wheel 12 can be driven to rotate at the same time. Therefore, when the wheelchair 1 travels forward, even if the front wheel 12 (wheelchair 1) hits a small stone or a small step ahead, the front wheel 12 Can easily get over these obstacles without being caught by pebbles or steps.

  Further, since the frame pipe 51 is fixed integrally with the caster arm 45, even if the caster arm 45 rotates about the axis of the upper power transmission shaft 40, the gear 42 and the gear 53 are not disengaged. The power from the rear wheel 11 can be reliably transmitted to the front wheel 12.

  Since the caster arm 45 is supported rotatably about the axis of the upper power transmission shaft 40, the direction of the caster arm 45, that is, the front wheel 12, can be easily changed. Further, since the front wheel 12 is supported on the axle 46 via the one-way rotation clutch 47, the peripheral speed of the front wheel 12 can be made larger than the peripheral speed of the rear wheel 11, and the wheelchair 1 is smoothly turned. be able to.

  Therefore, stable running is possible not only in a room or paved area, but also on uneven pavement or rough terrain, and the range of living by a wheelchair passenger can be expanded. In addition, the wheelchair can be easily turned and moved backward, and the running stability can be improved without reducing the operability of the wheelchair.

  When the one-way rotation clutch 47 is provided only on the axle 46, the speed increasing transmission mechanism 20 is idled when the assistant pushes it, so that it becomes a transmission load. If a one-way rotation clutch is further provided on the upstream side of the speed increasing transmission mechanism 20, the transmission load can be reduced.

  As shown in FIG. 7, when the occupant of the wheelchair 1 pushes the hand rim 10 or is pulled by an assistant to rotate the rear wheel 11 in the direction of arrow C, the wheelchair 1 travels in the backward direction (arrow D direction). To do. At this time, the gear 23 fixed integrally with the rear wheel 11 also rotates in the direction of arrow C simultaneously with the rear wheel 11. The rotation of the gear 23 is increased by the gear ratio with the gear 27 and transmitted to the sprocket shaft 26, and is transmitted to the sprocket shaft 33 disposed above the front wheel 12 through the sprocket 31, the chain 36 and the sprocket 35. The sprocket shaft 33 is rotated, and the rotation of the rear wheel 11 is transmitted to the axle 46 in the same manner as described above.

  At this time, the rotational direction of the axle 46 is the reverse direction (the direction of the arrow c), so that the rotational force is not transmitted to the front wheel 12 by the action of the one-way rotational clutch 47. Therefore, the front wheel 12 is freely rotated in the reverse direction (arrow c direction).

1 is a side sectional view of a wheelchair according to the present invention. It is a plane fragmentary sectional view of FIG. It is a front fragmentary sectional view of FIG. It is an expanded sectional view of the front-wheel drive part of FIG. FIG. 2 is an enlarged front view of a front wheel drive unit in FIG. 1. It is a side view which shows the power transmission state at the time of the forward movement of a wheelchair. It is a side view which shows the power transmission state at the time of reverse drive of a wheelchair.

Explanation of symbols

1 Wheelchair 8 Airframe (frame)
11 Rear wheel 12 Front wheel 20 Speed increasing transmission mechanism 46 Axle 47 One-way rotation clutch

Claims (3)

In a wheelchair that has a large-diameter rear wheel and a small-diameter front wheel on the left and right sides of the aircraft, and manually rotates the left and right rear wheels to travel,
Accelerated transmission between the left and right rear wheels and the left and right front wheels by increasing the rotation of the rear wheels so that the peripheral speed of the front wheels is substantially the same as the peripheral speed of the rear wheels. Each mechanism was provided,
A wheelchair characterized by that. In each of the speed increasing transmission mechanisms, a one-way rotation clutch that transmits the forward rotation from the rear wheel to the front wheel is provided.
The wheelchair according to claim 1. A one-way rotation clutch that transmits rotation in the forward direction from the rear wheel to the front wheel is provided between each front wheel and the axle that supports the front wheel.
The wheelchair according to claim 2.

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