JP6290719B2 - Wheelchair brake mechanism - Google Patents

Description

  The present invention relates to a brake mechanism that prevents a wheel from rotating in the reverse direction when a wheelchair is used.

  Conventionally, a brake mechanism for preventing a wheelchair from moving backwards against the user's intention has been proposed.

  For example, Patent Document 1 proposes a reverse rotation prevention mechanism that includes a ratchet that is fixed to the wheel side, a detent member that is fixed to the rotating shaft side, and a detent operation member that is attached to the vehicle body side and operates the detent member. Has been.

  Patent Document 2 proposes a mechanism in which a one-way pulley that rotates only in the forward direction (forward direction) is detachably attached to a position that does not hinder the brake operation on the left and right wheels.

  According to Patent Document 3, the frictional resistance between the one-way roller and the driving wheel is reduced by bringing the one-way roller, which is increased in outer peripheral friction resistance and capable of rotating in only one direction, into contact with the driving wheel. Wheelchair driving devices that rotate only in the direction have been proposed.

  Patent Document 4 proposes a wheelchair traveling safety device provided with a reverse rotation prevention means including a rotating roller with a built-in one-way clutch.

  In Patent Document 5, an inner race fixed to one of the chair body or the wheel and a cylindrical outer race fixed to the other are provided, and a first bite is provided between the outer surface of the inner race and the inner peripheral surface of the outer race. There has been proposed a wheelchair provided with means, release means and second biting means.

  And in patent document 6, when the rotation roller which incorporated the one-way clutch was press-contacted to the wheel outer peripheral part, the driving safety device of the wheelchair which the wheel was able to rotate in the advancing direction and was not able to rotate in the reverse direction. Has been proposed.

JP-A-10-225485 JP-A-11-28231 Japanese Patent Laid-Open No. 11-226058 JP 2000-203396 A JP 2002-85468 A JP 2012-157623 A

  However, the wheelchair traveling device proposed in Patent Document 1 requires a detent member to be attached to the rotating shaft of the wheel, so that the structure becomes complicated and takes time to manufacture, resulting in high manufacturing costs. There is.

  The mechanisms proposed in Patent Documents 2 to 4 have a problem that reverse running cannot be completely prevented depending on the strength of the mechanism for preventing rotation in the reverse direction and the state of frictional resistance with the tire. is there.

  The wheelchair proposed in Patent Document 5 has a very complicated structure as compared with other conventional structures, and there is a problem that the manufacturing cost is increased and the manufacturing cost may increase.

  The traveling safety device for a wheelchair proposed in Patent Document 6 uses a rotating roller with a built-in one-way clutch, and there is a problem that the structure becomes complicated.

  In any of the above-mentioned patent documents, the parts such as the ratchet mechanism and the one-way clutch come into contact with each other when the wheel rotates in the forward direction. May occur.

  Further, in some wheelchairs, the brake shoes remain in contact with the tires even during traveling, and the brake shoes bite into the tires when rotating in the reverse direction to prevent the wheels from rotating. However, such a configuration also has a problem that excessive resistance is generated on the wheel during traveling, which makes it very difficult to operate, and abnormal noise due to friction and tire wear out quickly.

  Therefore, the present invention reliably prevents reverse running by not using a one-way clutch (one-way clutch) or the like, but a brake shoe that presses against the tire as a brake greatly bites into the tire in response to rotation in the reverse direction of the wheel. On the other hand, an object of the present invention is to provide a wheelchair brake mechanism having a simple structure in which excessive resistance is not generated during traveling.

  The present invention relates to a wheelchair brake mechanism in which the wheel is prevented from rotating in the reverse direction, and is pivotally supported by a wheelchair body so as to be freely convertible between a tire release position and a tire pressure contact position. The brake body member is provided with a brake shoe capable of suppressing the rotation of the wheel by being pressed against the outer surface of the tire of the wheel. At least a part of the surface is always in contact with the outer surface of the tire of the wheel, a roller that rotates according to the rotation of the wheel is held, and at least a part of the roller is provided on the brake body member The roller is configured such that the position of the roller relative to the brake body member can be changed between a forward allowable position and a reverse inhibition position according to the guide action of the guide, and the wheel When rotating in the direction, the roller in contact with the tire of the wheel is in a reverse restraining position, and the brake main body member is in a tire pressure contact position so that the brake shoe is on the outer surface of the tire. On the other hand, when the wheel rotates in the forward direction, the roller is pressed while rotating by the tire according to the rotation of the wheel, and the roller moves to the advance allowable position. A wheelchair brake mechanism in which the brake body member is rotated to a tire release position in accordance with the guide action of the guide portion in accordance with the pressing movement of the roller, and the brake shoe is released from the tire. is there.

  With the above configuration, the forward rotation of the wheel can be allowed and the backward rotation can be suppressed. Accordingly, it is possible to provide a brake mechanism that appropriately regulates the rotational direction. Here, when the wheel rotates in the forward direction, a roller (rotating body) that rotates according to the rotation of the tire moves relative to the brake body member, and guides the guide member with which the roller engages. Due to the action, the brake body member is interlocked and rotated in a predetermined direction, and the brake shoe is separated from the outer surface of the tire, so that no excessive resistance is generated on the wheel during rotation in the forward direction of the wheel. The person can operate the wheelchair easily and stably. Moreover, since this structure is a simple structure compared with the structure which applied the conventionally proposed one-way clutch etc., the manufacturing cost of a wheelchair can be kept low as a whole.

  Further, the guide portion is constituted by a guide long hole in which at least a part of the roller is inserted as a guide shaft, and the guide shaft of the roller is guided and moved along the longitudinal direction of the guide long hole. The roller can be converted into a forward allowable position and a reverse inhibition position, and when the wheel rotates in the forward direction, the wheel rotates while the roller rotates according to the rotation of the wheel. The roller is pressed by the guide, and the roller moves to the advance allowable position defined at one end of the guide slot, according to the guide action of the guide slot, and the brake body according to the guide action of the guide slot When the member rotates to the tire release position, and when the wheel tries to rotate backward from the stopped state, the roller is pressed while rotating based on the rotation of the wheel, and the guide oblong hole of According to the internal action, the roller moves from the forward allowance position to the reverse inhibition position side, and the brake body member rotates to the tire pressure contact position according to the guide action of the guide slot, so that the brake shoe becomes the tire. A configuration that is in pressure contact with the outer surface of the is desirable.

  In such a configuration, the roller can be rotatably held by the guide long hole, and the roller can be reversibly moved by the guide action of the guide long hole, depending on the rotation direction of the wheel. Thus, the brake body member can be appropriately rotated in a required direction. Moreover, since the brake structure is very simplified in the above configuration, the manufacturing cost can be drastically reduced.

  And a biasing means for biasing the brake main body member toward the tire pressure contact position, and when the wheel rotates in the forward direction, the brake main body member is tired against the biasing force of the biasing means. When the wheel is turned to the separation position and the wheel is in a stopped state, the roller moves to the reverse movement inhibiting position side with the stop of the wheel, and the brake body member is pressed against the tire according to the urging force of the urging means. A configuration that rotates to the position side is desirable.

  With such a configuration, the brake body member can be always returned to the tire pressure contact position while appropriately rotating the brake body member, and the brake shoe of the brake body member is more strongly tightened while the wheel is stopped. It can be made to contact.

  Furthermore, it is desirable that the wheelchair main body is provided with a position restricting portion that contacts the brake main body member and restricts the position of the brake main body member when the brake main body member rotates to the tire pressure contact position.

  By adopting such a configuration, it is possible to prevent the brake body member from rotating excessively and causing a malfunction in the wheel braking mechanism.

  The wheelchair brake mechanism according to the present invention has an excellent effect that it can reliably prevent rotation in the backward direction of the wheel with a simple structure, and does not cause excessive resistance even when the wheel rotates in the forward direction. is there.

It is a side view of the wheelchair which has the brake mechanism for wheelchairs concerning an example. It is a side view showing a brake mechanism in the state where a wheel is stationary. It is a front view which shows the brake mechanism in the state where the wheel is stationary. It is explanatory drawing which shows a guide long hole. It is a side view which shows the brake mechanism of the state in which the wheel is rotating in the advancing direction. It is a side view showing a brake mechanism in the state where rotation to the reverse direction of a wheel is controlled. It is explanatory drawing which shows the state which has a brake main body member in a tire press-contact position.

  Hereinafter, embodiments of the wheelchair brake mechanism of the present invention will be described in detail. In addition, this invention is not limited to the Example shown below, A design change is possible suitably.

  As shown in FIG. 1, the wheelchair 1 includes a main body frame 10 made of a metal pipe. The main body frame 10 includes a pair of left and right side frames 10A, 10A. The side frame 10A includes a base frame portion 11 formed in the front-rear direction and a rear leg frame portion 12 rising from the base frame portion 11. The back frame portion 13 extends further upward from the rear leg frame portion 12 and the seat frame portion 15 extends forward and horizontally from the upper end portion of the rear leg frame portion 12. .

  Further, the rear leg frame 12 is provided with a rotating shaft portion 3 of a main wheel on which a tire 2 is mounted. In addition, since what has been conventionally used for this main wheel can be employ | adopted suitably, detailed description is abbreviate | omitted.

  Further, a front frame portion 25 is extended in the vertical direction at the front end portions of the base frame portion 11 and the seat frame portion 15, and a caster 26 is attached to the lower end of the front frame portion 25. A foot frame 27 is attached from the front frame portion 25 toward the front side, and a footrest 28 is attached to the foot frame 27.

  Hereinafter, the wheelchair brake mechanism 30 for suppressing the rotation of the main wheel in the reverse direction will be described in detail.

  As shown in FIG. 1, the wheelchair brake mechanism 30 includes a flat base plate 40 suspended from the base frame portion 11 of the main body frame 10.

  Further, the wheelchair brake mechanism 30 includes a swing-type brake body member 50 pivotally supported on the base plate 40, and the brake body member 50 rotates at a position facing the front side of the tire 2 in the main wheel. It is free.

  Specifically, as shown in FIGS. 2 and 3, the brake body member 50 is provided with a rotating shaft 51 that is extended toward the base plate 40. The brake body member 50 is inserted into a through hole 41 provided in the base plate 40, and is held rotatably with respect to the base plate 40. The main body frame 10 including the base plate 40 to which the swing-type brake main body member 50 is attached constitutes a wheelchair main body according to the present invention.

  As shown in FIGS. 2 and 3, the brake body member 50 includes a brake base portion 52 made of a U-shaped member and a plate-like cam portion 53, and the brake base portion 52 and the cam portion 53 are connected to each other. The rotation shaft 51 is connected. As shown in FIG. 3, when the brake body member 50 is pivotally supported by the base plate 40, the brake base 52 is disposed on the tire 2 side with respect to the base plate 40. On the other hand, the cam portion 53 is disposed on the center side of the wheelchair 1 with respect to the base plate 40. The brake base member 52 and the cam portion 53 are integrally rotated by rotating the brake body member 50 about the rotation shaft 51.

  The brake base 52 includes a substantially horizontal bottom plate portion 523 and a pair of left and right roller holding plate portions 521 and 521 rising from both the left and right sides of the bottom plate portion 523. The tire 2 is interposed between the pair of left and right roller holding plate portions 521 and 521, and a brake that can press-contact a front end portion of the bottom plate portion 523 facing the tire 2 to the outer surface of the tire 2. The shoe 56 is used. The outer surface of the tire 2 is a surface that contacts the ground according to the rotation of the tire 2.

  Further, as shown in FIG. 2, guide long holes 521a and 521a as guide portions are respectively provided in the roller holding plate portions 521 and 521 in a penetrating manner. The guide elongated holes 521a and 521a are respectively inserted into both end portions of a roller 60 as a rotating body, whereby the roller 60 is rotatably held between the roller holding plate portions 521 and 521. .

  Specifically, the roller 60 is made of a round bar, and the outer diameter thereof is set to be approximately equal to the short diameter of the guide long hole 521a. Both end portions of the roller 60 are guide shafts 601a and 601a supported by the hole edges of the guide long holes 521a and 521a. A large-diameter retaining ring 602 is attached to the tip of each guide shaft 601a so that the guide shaft 601a and the guide long hole 521a are engaged with each other. This prevents the holes 521a and 521a from falling off. With this configuration, the roller 60 is slidable along the longitudinal direction (major diameter direction) of the guide long holes 521a and 521a.

  Further, the position of the roller 60 is set such that the outer peripheral surface 601 of the roller 60 is always in contact with the outer surface of the tire 2. Thereby, the roller 60 can rotate according to the rotation of the tire 2.

  Here, as shown in FIG. 4, the long axis γ along the longitudinal direction of the guide long hole 521 a is a tangent line α at the position where the roller 60 and the tire 2 are in contact with each other, and the axis of the rotating shaft 51. And an imaginary line β connecting the brake shoe 56 and an inclination angle such that the long axis γ is separated from the outer surface of the tire 2 toward the front. It is set to be.

  Further, as shown in FIGS. 2 and 3, wall portions 521 b and 521 b facing the side surface of the tire 2 extend at the tip portions of the pair of left and right roller holding plate portions 521 and 521 in the brake main body member 50. Is formed.

  Further, as shown in FIG. 2 and the like, a coil spring (attached) in an elastic state is provided between the mounting hole 531 provided at the distal end portion of the cam portion 53 and the mounting hole 401 provided in the base plate 40. 70) is suspended. With this configuration, the brake body member 50 is urged toward the direction in which the brake shoe 56 is pressed against the tire 2.

  As shown in FIGS. 2 and 3, a position restriction that restricts a rotation angle range of the brake main body member 50 at a position on the center side of the wheelchair 1 on the base plate 40 and facing the cam portion 53. A pin (position restricting portion) 80 is erected.

Next, the operation mode of the wheelchair brake mechanism 30 will be described in detail.
As shown in FIGS. 2 and 3, when the tire 2 is stationary, the roller 60 in contact with the tire 2 is in a non-rotating state. The brake body member 50 is urged in a required direction according to the urging force of the coil spring 70, and the brake shoe 56 is pressed against the outer surface of the tire 2. Here, the position of the brake main body member 50 at this time is a tire contact position A, and the position of the roller 60 in the guide long hole 521a with respect to the brake main body member 50 is an intermediate position a.

  In the above configuration, as shown in FIG. 5, when the tire 2 rotates in the forward direction, the roller 60 is supported by the guide slot 521a by friction with the outer surface of the tire 2 rotating forward. While rotating in a state, it is pressed downward by the rotational force of the tire 2 and is abutted against one end of the guide long hole 521a according to the guide action of the guide long hole 521a. Here, the position of the roller 60 in the guide elongated hole 521a with respect to the brake main body member 50 is defined as a forward allowable position b.

  Further, when the roller 60 is disposed at the advance allowance position b, the brake body member 50 moves the rotation shaft 51 around the central axis against the urging force of the coil spring 70 according to the guide action of the guide long hole 521a. As a result, the brake shoe 56 is separated from the outer surface of the tire 2. Here, the position of the brake body member 50 at this time is a tire release position B. In such a state, as long as the tire 2 continues to rotate forward, the roller 60 is held at the forward movement allowable position b and rotated while the brake body member 50 is held at the tire release position B. The wheelchair 1 can be run without the tire 2 and the brake shoe 56 contacting each other.

  On the other hand, as shown in FIG. 6, when the tire 2 is about to rotate in the reverse direction, the roller 60 moves in a direction away from the advance allowable position b as the tire 2 rotates, With the movement of 60, the brake body member 50 rotates forward (counterclockwise in FIG. 6) in accordance with the guide action of the guide elongated hole 521a and the biasing force of the coil spring 70, whereby the brake shoe 56 Is in a state of being pressed into the outer surface of the tire 2 and biting in. Thus, when the brake shoe 56 is pressed into the tire 2 and bites into the tire 2, the reverse rotation of the main wheel is suppressed. Here, the position of the brake body member 50 at this time is a tire pressure contact position C. Further, a position in the guide long hole 521a of the roller 60 where the brake main body member 50 is set to the tire pressure contact position C is set as a reverse movement inhibiting position c. When the brake body member 50 is located at the tire pressure contact position C, the cam portion 53 of the brake body member 50 abuts on the position restriction pin (position restriction portion) 80, and the position of the brake body member 50 is It is restricted and excessive rotation is prevented.

  In this configuration, the roller 60 can be rotatably held by the guide long hole 521a, and the roller 60 can be reversibly moved by the guide action of the guide long hole 521a. The brake main body member 50 can be appropriately rotated in a required direction according to the rotation direction. In addition, since the wheelchair brake mechanism 30 is greatly simplified, the manufacturing cost can be drastically reduced.

  As shown in FIG. 7, since the tire 2 is sandwiched between the pair of left and right wall portions 521b and 521b, excessive elastic deformation of the tire 2 in the width direction is prevented even if the brake shoe 56 bites in strongly. Thus, the pressure contact force with the brake shoe 56 is prevented from decreasing.

  The present invention is not limited to the embodiments described above. For example, the brake body member 50 is not held at the tire pressure contact position C by the contact between the cam portion 53 and the pin 80, but the roller 60 is the rotation allowable position a of the guide long hole 521a. You may make it hold | maintain in this tire press-contacting position C by being located in the reverse movement suppression position c defined in the other end of the other side.

  Further, the coil spring 70 that is an urging means may not necessarily be attached, and the roller 60 may move to an intermediate position a of the guide long hole 521a as the tire 2 stops. The center of gravity of the brake body member 50 around the rotation shaft 51 may be set as appropriate.

  The shape of the roller 60 is not limited to a round bar shape, and may be a sphere or the like. Further, the roller 60 does not need to be configured by a single member, and may be configured by combining two or more members.

  Further, the wall portions 521b and 522b may not be formed. Further, the rotation angle range of the brake main body member 50 may be restricted by a suitably provided pin. The means for guiding the roller 60 is not limited to the elongated guide hole 521a, and other structures may be employed.

DESCRIPTION OF SYMBOLS 1 Wheelchair 2 Tire 30 Wheelchair brake mechanism 50 Brake body member 51 Rotating shaft 56 Brake shoe 60 Roller 70 Coil spring (biasing means)
80 Position restriction pin (position restriction part)
521a Guide long hole (guide part)
601 Outer side surface 601a Guide shaft b Advance allowed position c Reverse drive restraint position B Tire release position C Tire pressure contact position

Claims (4)

A wheelchair brake mechanism in which rotation in the reverse direction of the wheel is suppressed,
A swing-type brake body member that is pivotally supported by the wheelchair body and is capable of changing the position between the tire release position and the tire pressure contact position,
The brake body member includes
A brake shoe capable of suppressing the rotation of the wheel by being pressed against the outer surface of the tire of the wheel is provided,
At least a part of the outer peripheral surface is always in contact with the outer surface of the tire of the wheel, and a roller that rotates according to the rotation of the wheel is held,
Further, at least a part of the roller engages with a guide portion provided on the brake main body member, and the roller is positioned relative to the brake main body member according to the guide action of the guide portion. It is possible to convert the position to
When the wheel is going to rotate in the reverse direction, the roller that contacts the tire of the wheel is in the reverse inhibition position, and the brake body member is in the tire pressure contact position so that the brake shoe is in the tire. Pressed against the outer surface of
On the other hand, when the wheel rotates in the forward direction, the roller is rotated and pressed by the tire according to the rotation of the wheel, and the roller moves to the forward allowable position, and A wheelchair brake mechanism, wherein the brake body member is rotated to a tire release position in accordance with the guide action of the guide portion in accordance with the pressing movement, and the brake shoe is released from the tire. The guide portion is constituted by a guide long hole into which at least a part of the roller is inserted as a guide shaft,
When the guide shaft of the roller is guided and moved along the longitudinal direction of the guide elongated hole, the roller can be converted into a forward allowable position and a reverse inhibition position.
When the wheel rotates in the forward direction, the roller is pressed by the tire of the wheel while the roller rotates according to the rotation of the wheel, and the roller follows the guide action of the guide slot, The brake body member moves to the tire release position in accordance with the guide action of the guide long hole, while moving to the advance allowance position defined at one end of the guide long hole,
On the other hand, when the wheel tries to rotate in the reverse direction from the stopped state, the roller is pressed while rotating based on the rotation of the wheel, and the roller moves forward according to the guide action of the guide slot. The brake main body member moves to the tire pressure contact position in accordance with the guide action of the guide slot, and the brake shoe is in pressure contact with the outer surface of the tire. The wheelchair brake mechanism according to claim 1. Urging means for urging the brake body member to a tire pressure contact position;
When the wheel rotates in the forward direction, the brake body member rotates to the tire release position against the urging force of the urging means,
When the wheel is in a stopped state, the roller moves to the reverse drive inhibition position side with the stop of the wheel, and the brake body member rotates to the tire pressure contact position side according to the urging force of the urging means. The wheelchair brake mechanism according to claim 1 or 2. In the wheelchair body,
The position control part which contacts the brake main body member and controls the position of the brake main body member when the brake main body member rotates to the tire pressure contact position is provided. The wheelchair brake mechanism described in 1.

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