JP2013226191A - Parking brake structure for wheelchair, and wheelchair - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a parking brake structure for a wheelchair with enhanced safety and convenience, and a wheelchair equipped with the parking brake structure.SOLUTION: A parking brake structure 100 for a wheelchair includes: a control lever 120 capable of controlling regulation and deregulation on a main wheel 11; a brake shoe 130 having an abutting surface 131 capable of the face-contact with a tread surface 12a of the main wheel 11, wherein the abutting surface 131 is moved to the main wheel 11 side of the wheelchair 10 to be pressed in contact with the tread surface 12a by the regulatory operation of the control lever 120; and a position adjusting mechanism. The position adjusting mechanism has a rotating shaft 112 for rotatably journaling the brake shoe 130 and locking means (113 and 133) for fixing the brake shoe 130 to the rotating shaft 112 in such a state as incapable of rotating. The position adjusting mechanism can adjust a projection width 2 of the abutting surface 131 of the brake shoe 130 to the main wheel 11 side by rotating the brake shoe 130 around the rotating shaft 112.

Description

  The present invention relates to a wheelchair parking brake mechanism for an assistant to operate the wheelchair and a wheelchair equipped with the parking brake mechanism.

  Conventionally, various parking brake mechanisms that restrict the rotation of the main wheel of a wheelchair have been used so that the wheelchair does not move while the wheelchair is parked or stopped. As the brake mechanism, a tackle brake having a side lever installed on a side portion of a seat that can be operated by a wheelchair occupant is most common.

  For example, Patent Document 1 discloses a wheelchair brake device (100). The wheelchair brake device (100) includes a brake body (10) attached to a frame (14) on both sides of the wheelchair (1), a brake lever (11) operable by a wheelchair occupant, and a wheelchair. A blade-like brake shoe (stopper 12) that contacts the main wheel (7) of (1). When the occupant operates the brake lever (11), the tip of the brake shoe (12) strongly bites into the outer peripheral surface of the main wheel (7), and the rotation of the main wheel (7) is restricted. Further, in this wheelchair brake device (100), the tube (14) of the brake lever (11) is slidably fitted into the lever support (17) of the brake body (10), and the ball (15) or the claw portion By the fixing means (18), the brake lever (11) is supported in an extended state when operated. On the other hand, when the brake lever (11) is not operated, the brake lever (11) can be shortened downward by releasing the engagement by the ball (15) or the claw portion (18). That is, in the wheelchair brake device (100) of Patent Document 1, two forms of an extended state at the time of operation and a shortened state at the time of non-operation can be selected.

JP 2003-159284 A

  However, in the wheelchair parking brake of the prior art as disclosed in Patent Document 1, since the rotation of the main wheel is regulated by causing the blade-like brake shoe to bite into the outer peripheral surface of the main wheel, the tread surface of the tire There was a risk of hurting. Further, when the air pressure of the tire of the main wheel decreases, there is a problem that the distance between the contact portion of the brake shoe and the tread surface of the tire becomes long, so that the thickness contact force is weakened and the brake performance is lowered. Alternatively, when the tire diameter increases due to tire replacement or increased air pressure, the distance between the contact portion of the brake shoe and the tread surface of the tire is shortened, resulting in a problem that the thickness contact force becomes too strong and the tire is damaged. It was. In order to cope with this problem, it is necessary to adjust the mounting position of the brake shoe so as to optimize the distance between the tread surface of the tire and the contact portion of the brake shoe. Furthermore, in order to optimize the position of the brake shoe in this adjustment work, remove the brake shoe from the brake body using a tool, align it, and then fix the brake shoe to the brake body again with bolts. It is necessary to make fine adjustments repeatedly. That is, it can be considered that the work of adjusting to the optimum position takes much labor and time. Accordingly, there is a need for a parking brake mechanism that can adjust the position of the brake shoe, and to make the adjustment work quicker and easier.

  The present invention has been made to remedy the above-described drawbacks, and has an object of having a brake shoe that presses against a tread surface of a wheelchair without damaging the wheelchair tire, and further adjusting the position of the brake shoe. An object of the present invention is to provide a wheelchair parking brake structure that can be performed quickly and easily and that has higher safety and convenience, and a wheelchair equipped with the parking brake structure.

  The parking brake mechanism for a wheelchair according to claim 1 is a wheelchair parking brake mechanism capable of regulating the rotation of the main wheel of the wheelchair, and includes an operation lever capable of controlling regulation and release of the main wheel, A brake shoe and a brake shoe having a contact surface that can come into surface contact with the tread surface, and the contact surface is moved to the main wheel side of the wheelchair and pressed against the tread surface of the main wheel by the restriction operation of the operation lever. A rotating shaft that is rotatably supported, and a lock means that locks the brake shoe in a non-rotatable state with respect to the rotating shaft. The brake shoe abuts by rotating the brake shoe around the rotating shaft. A position adjusting mechanism capable of adjusting a protrusion width of the surface toward the main wheel.

  The wheelchair parking brake mechanism according to claim 2 is the wheelchair parking brake mechanism according to claim 1, wherein the fitting portion formed on the outer periphery of the rotating shaft and the opening inner periphery of the brake shoe are formed. When the mating portion is fitted, the brake shoe is locked to the rotation shaft so as not to rotate.

  The wheelchair parking brake mechanism according to claim 3 is the wheelchair parking brake mechanism according to claim 2, further comprising a spring for biasing so as to maintain the fitted state between the fitting portion and the fitted portion. It is characterized by providing.

  The parking brake mechanism for wheelchair according to claim 4 is the parking brake mechanism for wheelchair according to claim 2 or 3, wherein the fitting portion is formed in an external gear shape and the fitted portion is in an internal gear shape. The protrusion width of the contact surface of the brake shoe can be adjusted stepwise according to the pitch of the gear.

  A wheelchair parking brake mechanism according to a fifth aspect is the wheelchair parking brake mechanism according to any one of the first to fourth aspects, wherein a support portion for slidably inserting a shaft portion of the operation lever is provided, A clamp mechanism for fixing the shaft portion at a predetermined position; and a release means for releasing the fixation by the clamp mechanism; and by sliding the shaft portion of the operation lever with respect to the support portion in a state where the clamp is released, The position of the grip portion of the operation lever can be arbitrarily adjusted by fixing the shaft portion at a predetermined position with the clamping means.

  The assisting wheelchair according to claim 6 is characterized in that the wheelchair parking brake according to any one of claims 1 to 5 is installed.

  According to the first aspect of the present invention, the wheelchair can be braked more reliably by bringing the contact surface of the brake shoe into pressure contact with the tread surface of the main wheel in an optimal state. That is, in the parking brake mechanism of the present invention, since the rotation of the main wheel is regulated by the surface friction between the contact surface and the tread surface, the sharp portion does not bite into the tire and the brake is applied without damaging the tire. Can do. Furthermore, the wheelchair user can effectively adjust the distance between the contact surface of the brake shoe and the tread surface of the main wheel by a simple operation of rotating the brake shoe. In other words, by operating the position adjusting mechanism, the brake shoe is rotated around the rotating shaft in accordance with changes in the tire diameter over time to adjust the protruding width of the abutment surface toward the main wheel, thereby improving the braking effect. The predetermined brake performance can be easily maintained by adjusting. Therefore, the present invention speeds up and simplifies the position adjustment of the brake shoe for maintaining the brake performance, and improves the safety and convenience of the wheelchair.

  According to the second aspect of the invention, in addition to the effect of the first aspect of the invention, the meshing portion is formed on the outer periphery of the rotating shaft and the meshed portion is formed on the inner periphery of the opening of the brake shoe through which the rotating shaft is inserted. Thus, after the brake shoe is rotated around the rotation shaft to adjust the protruding width of the contact surface, the brake shoe is locked and fixed to the rotation shaft. That is, in the present invention, the protrusion width of the brake shoe can be adjusted and fixed with a simple structure.

  According to the invention of claim 3, in addition to the effect of the invention of claim 2, the locked state of the brake shoe and the rotating shaft is maintained by the biasing force of the spring, so that the biasing force is resisted. By operating the brake shoe, the non-rotatable fitted state can be released. That is, since it is not necessary to use a tool such as a screwdriver, the protruding width of the contact surface of the brake shoe can be adjusted easily and quickly.

  According to the invention of claim 4, in addition to the effect of the invention of claim 2 or 3, the protrusion width of the contact surface of the brake shoe can be adjusted stepwise according to the pitch of the gear. The amount of change in width can be quantified according to the number of pitches, and the position can be adjusted more easily and quickly.

  According to the invention described in claim 5, in addition to the effect of any one of the inventions of claims 1 to 4, the shaft portion of the operation lever is slid with respect to the support portion in a state where the clamp is released by the release means. By fixing the shaft portion at a predetermined position by the clamping means, the grip portion of the operation lever can be easily and quickly adjusted to the predetermined position. For this reason, when the user (assistant or seated person) of the wheelchair uses the parking brake, the operation lever gripping portion can be arranged at a position where each user can use it most easily. Furthermore, when the user of the wheelchair does not use the parking brake, the operation lever gripping portion can be moved to the lowest position so as not to disturb the occupant of the wheelchair. That is, since the user of the wheelchair can freely adjust the position of the grip portion of the operation lever according to the intention, the convenience of the wheelchair is improved.

  According to the invention described in claim 6, by providing the wheelchair parking brake mechanism of any one of claims 1 to 5, the above-described effects can be exhibited as a wheelchair. In other words, the wheelchair of the present invention improves the safety and convenience of the caregiver and the care recipient who use the wheelchair.

1 is a schematic side view of a wheelchair according to an embodiment of the present invention. The partial expanded side view which shows the parking brake mechanism of the wheelchair of FIG. It is the elements on larger scale which show the parking brake mechanism of the wheelchair of FIG. 1, Comprising: (a) is the restriction | limiting cancellation | release state (non-brake position) of a main wheel, (b) shows a restriction | limiting state (brake position). The (a) side view and (b) top view of the main-body part of FIG. FIG. 5 is an exploded view showing a clamp mechanism and a release operation part of the main body part of FIG. 4. The side view which shows the operation lever of FIG. The (a) side view and (b) top view which show the brake shoe of FIG. The disassembled schematic of the main-body part and brake shoe of the parking brake mechanism of one Embodiment. In the parking brake mechanism of one Embodiment, it is the schematic which shows the operation | movement for adjusting the protrusion width | variety of the contact part of a brake shoe, (a) is an initial state, (b) is the tip of a rotating shaft. The state pulled in the direction, (c) shows the state after adjustment. The side view which shows the aspect of adjustment of the protrusion width of the contact part of a brake shoe, and the fixed position adjustment of an operation lever in the parking brake mechanism of one Embodiment. The side view of the parking brake mechanism of the modification of this invention. The (a) side view and (b) top view of the brake shoe of FIG. 11A is an exploded schematic view of the main body portion and the brake shoe of FIG. 11, and FIG. 12B is an exploded schematic view of the main body portion and the brake shoe of another modified example.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In addition, the shape of each figure referred in the following description is a conceptual diagram or a schematic diagram for explaining a suitable shape dimension, and a dimension ratio etc. do not necessarily correspond with an actual dimension ratio. That is, the present invention is not limited to the dimensional ratio in the drawings.

  Hereinafter, the parking brake mechanism 100 according to an embodiment and the wheelchair 10 on which the parking brake mechanism 100 is attached will be described in detail. In the following description, as a general rule, terms indicating directions such as up and down and forward and backward are defined to correspond to the forward and backward traveling direction of the wheelchair and the vertical direction of the wheelchair.

  As shown in FIG. 1, a wheelchair 10 according to an embodiment includes a pair of left and right main wheels 11, a tire 12 that forms the outer periphery of the main wheel 11, a side frame 14 that pivotally supports the main wheel 11, and the side. A parking brake mechanism 100 attached to the part frame 14. The parking brake mechanism 100 is positioned in front of the main wheel 11 of the wheelchair 10 so that a occupant of the wheelchair 10 can operate, and the distance d, so that it can contact the tread surface 12a of the tire 12 during operation. The tire 12 is separated from the tread surface 12a.

  FIG. 2 is a partially enlarged view of the vicinity of the parking brake mechanism 100 of FIG. 1. As shown in FIG. 2, the parking brake mechanism 100 of this embodiment is supported by the main body 110 and the support portion 117 of the main body 110. The control lever 120 and a brake shoe 130 attached to a first arm 111 extending from the main body 110 are provided. The solid lines of the operation brake 120 and the brake shoe 130 in FIG. 2 indicate a restriction release state (non-brake position) in which the rotation of the main wheel 11 of the wheelchair 10 is not restricted, while the broken line restricts the rotation of the main wheel 11 of the wheelchair 10. The regulated state (brake position) is shown.

  As shown in FIG. 3A, in the parking brake mechanism 100, the contact surface 131 of the brake shoe 130 is separated from the tread surface 12a of the tire 12 by a distance d in the restriction release state (non-brake position). . Then, when the operation lever 120 is regulated to the broken line position in FIG. 2, the contact surface 131 is brought into pressure contact with the tread surface 12a from the regulation release position in FIG. 3A (see FIG. 3B). It is displaced to. In the brake position shown in the broken line in FIG. 2 and FIG. 3B, the contact surface 131 and the tread surface 12a are pressed against each other with a strong force, so that a large frictional force is generated and the rotation of the main wheel 11 is restricted. Needless to say, the brake is more effective as the distance between the contact surface 131 and the tread surface 12a is shorter at the restriction release position.

  Next, each component of the parking brake mechanism 100 according to the embodiment will be described.

  FIG. 4A is a side view of the main body 110 of the parking brake mechanism 100. The main body 110 includes a first arm 111 extending from the rear side of the main body 110 downward to the wheelchair, and a second arm 115 extending from the front side of the main body 110 to the front of the wheelchair. The base end of the first arm 111 is pivotally supported inside the main body 110, and the distal end of the first arm 111 is the front and rear of the wheelchair 10 by rotating backward (in the direction of the main wheel 11 of the wheelchair 10) from the illustrated non-brake position. Can be displaced. On the other hand, the second arm 115 is configured to be able to support the operation lever 120, and is pivotally supported by the main body 110 so as to rotate around the rotation shaft 116 when the operation lever 120 is operated.

  The first arm 111 and the second arm 115 are connected to each other inside the main body 110 so as to be interlocked with each other. In the parking brake mechanism 100 of the present embodiment, the second arm 115 rotates clockwise by rotating the operation lever 120 from the restriction release position (solid line in FIG. 2) to the restriction position (broken line in FIG. 2). In conjunction with the rotation of the second arm 115, the first arm 111 rotates counterclockwise, and the tip of the first arm 111 is displaced forward. On the other hand, by rotating the operation lever 120 in the reverse direction from the forwardly displaced state, the first arm 111 is rotated clockwise, and the tip of the first arm 111 is displaced rearward. Further, in the coupling mechanism between the first arm 111 and the second arm 115, the first arm 111 is urged in either the restriction position or the restriction release position, and is locked so as not to rotate at each position. Then, the lock is released by the rotation of the second arm 115 (that is, the operation of the operation lever 120), and the position of the tip of the first arm 111 is changed from the restriction position to the restriction release position, or the restriction release position. To the restricted position. In addition, about the connection structure inside this main-body part 110, it is the same as that of the tackle brake (or parking side brake) of the conventional wheelchair, and it abbreviate | omits to explain in detail. Moreover, this invention is not limited to the said embodiment, It is good also considering the rotation direction of a 2nd arm (operation brake) as an opposite direction.

  As shown in FIGS. 4A and 4B, a rotating shaft 112 that supports the brake shoe 130 rotatably through the opening 131 is projected from the tip of the first arm 111. A fitting portion 113 that fits into a fitting portion 133 of a brake shoe 130 described later is formed on the outer periphery of the rotation shaft 112 on the proximal end side. The fitting portion 113 is fixed to the first arm 111 with a screw and has a fixing hole 113a for fixing the rotating shaft 112 so as not to rotate. Moreover, the outer periphery of the fitting part 113 is processed into the external gear shape which has several teeth, and the said external gear shape respond | corresponds to the internal gear shape of the to-be-fitted part 133 of the brake shoe 130 mentioned later. Further, a spring 114 is disposed around the distal end side of the rotating shaft 112. As will be described later, one end of the spring 114 engages with the protruding portion 112a (the head of the collar or bolt) at the tip of the rotating shaft 112, and the other end engages with the spring engaging portion 134 of the brake shoe 130. Are arranged as follows. The spring 114 is compressed when the brake shoe 130 is moved in the distal direction of the rotating shaft 112 and acts to urge the brake shoe 130 toward the first arm 111.

  In this embodiment, the rotating shaft 112 is a bolt that is fixed to the fixing hole 113a in order to support the brake shoe 130 on the first arm 111. However, the rotating shaft and the bolt may be configured separately. Good. Moreover, the outer periphery (and inner periphery) shape of a fitting part (and to-be-fitted part) is not limited to the said embodiment. For example, the outer peripheral shape of the fitting portion can be a polygon that can be fitted to the fitted portion.

  The second arm 115 is configured to move the operation lever 120 up and down and to be supported and fixed at a predetermined position. The second arm 115 includes an insertion hole 117 (support portion), a clamp mechanism 118, and a release operation portion 119 (release means). With. Hereinafter, a more specific description will be given with reference to FIG. 5 which is an exploded view of these members.

  As shown in FIG. 5, an insertion hole 117 through which the shaft portion 121 of the operation lever 120 can be inserted is formed in the second arm 115 vertically. A bush 117 a is attached to the insertion light 117. An annular clamp mechanism 118 that can hold and support the shaft 121 of the operation lever 120 is disposed in the insertion hole 117. In the present embodiment, the clamp mechanism 118 is an elastically deformable metal cylinder having an inner diameter smaller than the diameter of the shaft portion 121. That is, when the shaft portion 121 is inserted into the clamp mechanism 118, the inner diameter thereof elastically deforms and expands, and the elastic return force acts on the shaft portion 121 as an inward biasing force. To do. A release operation unit 119 configured to be able to release the clamp is connected to the lower end of the clamp mechanism 118 via a washer 117b and a cap 117c. When this release operation part 119 is operated (more specifically, when it is pushed upward), a protrusion 119a extending outward from the tip of the release operation part 119 pushes the inner diameter of the clamp mechanism 118 and attaches to the shaft part 121. The power can be countered. That is, in the state where the release operation portion 119 is pushed upward, the clamp by the clamp mechanism 118 is released, so that the shaft portion 121 of the operation lever 120 can move up and down in the insertion hole 117.

  As shown in FIG. 6, the operation lever 120 includes a longitudinal shaft portion 121 arranged to extend up and down of the wheelchair 10, and a grip portion 122 formed at the upper end of the shaft portion 121 and operated by a wheelchair user. And a stopper 123 protruding in the radial direction from the lower end of the shaft portion 121. As described above, the shaft 121 of the operation lever 120 has a diameter that can be freely inserted into the insertion hole 117 of the main body 110 and can be gripped by the clamp mechanism 118. On the other hand, the grip portion 112 and the stopper 123 are formed thicker than the inner diameter of the insertion hole 117 so as to prevent the operation lever 120 from coming out of the insertion hole 117.

  As shown in FIG. 7A, the brake shoe 130 has a substantially oval shape in a side view. The brake shoe 130 includes a contact surface 131 that contacts the tread surface 12a of the tire 12, and an opening 132 that penetrates the side of the brake shoe 130 so that the rotation shaft 112 of the main body 110 can be inserted.

  FIG. 7B shows a plan view of the brake shoe 130. As shown in FIG. 7B, the contact surface 131 is formed on the surface of the wheelchair 10 that faces the main wheel 11, and matches the shape of the tread surface 12 a so as to be in close contact with the tread surface 12 a of the tire 12. The center is curved so as to be recessed in an arc shape. Furthermore, a plurality of protrusions 135 are formed on the contact surface 131 along the width direction (the left-right direction of the wheelchair 10) so as to improve the braking performance.

  As shown in FIGS. 7A and 7B, the opening 132 is formed at a position biased to one side (not the center) of the oval-shaped side view of the brake shoe 130. When the brake shoe 130 rotates about the opening 132 (or the rotation shaft 112), the protrusion width w changes. That is, since the distance r from the center of the opening 132 of the brake shoe 130 to the outer surface (contact surface 131) is not constant at each position of the contact surface 131, the protrusion width w varies depending on the rotation angle. . As will be described later, the larger the protrusion width w with respect to the distance d, that is, the closer the abutment surface 131 is to the tread surface 12a, the greater the pressure contact force of the abutment surface 131 against the tread surface 12a increases. Demonstrate power.

  The opening 132 has an inner diameter that is sufficiently large to allow the rotary shaft 112 to be freely inserted. An inner gear-shaped fitted portion 133 having a plurality of teeth is formed on the inner peripheral surface of the opening 132. The inner diameter and the number of teeth of the internal gear shape correspond to the outer diameter and the number of teeth of the external gear shape of the fitting portion 113 and can be fitted to each other. Furthermore, the inner wall protrudes so that the inner diameter of the spring 114 is narrower than the outer diameter of the spring 114 at approximately the center in the penetrating direction of the opening 132, thereby forming a spring engaging portion 134. As will be described later, the spring 114 is disposed between the projecting portion 112 a at the tip of the rotating shaft 112 and the spring engaging portion 134.

  FIG. 8 is a partially exploded view of the main body 110 and the brake shoe 130. As shown in FIG. 8, a fitting portion 113, a brake shoe 130, and a spring 114 fixed to the first arm 111 are arranged from the first arm 111 side, and a bolt-shaped rotating shaft 112 is attached to this through a collar 112a. The parking brake mechanism 100 is configured by penetrating and screwing into the fixing hole 113 a of the fitting portion 113. In this configuration, the brake shoe 130 can move freely along the rotation shaft 112 that passes through the opening 132 of the brake shoe 130, and the fitting portion 113 on the proximal end side of the rotation shaft 112 is fitted to the brake shoe 130. It can be fitted to the joint 133. Further, the rotating shaft 112 passes through the spring 114, and the spring 114 is sandwiched between the projecting portion 112 a (collar or bolt head) of the rotating shaft 112 and the spring engaging portion 134 of the brake shoe 130. Arranged in a natural length or compressed state. That is, the spring 114 is compressed by the spring engaging portion 134 when the brake shoe 130 is moved in the direction of the distal end of the rotating shaft 112 of the main body 110, and the brake shoe 130 is moved to the main body 110 by the elastic return force. Energize in the direction of drawing. Further, in the fitted state of the fitting part 113 and the fitted part 133, the rotation shaft 112 of the main body part 110 is fixed to the first arm 111 so as not to rotate, so the fitting part 113 locks the brake shoe 130. To do. That is, the parking brake mechanism 100 of the present embodiment is configured to be able to maintain a locked state in which the main body 110 and the brake shoe 130 cannot rotate with each other by the elastic force of the spring 114. That is, the fitting part 113, the to-be-fitted part 133, and the spring 114 function as locking means in conjunction with each other.

  In the present embodiment, the main body 110 and the brake shoe 130 are urged to approach each other by the elastic restoring force of the compressed spring 114, but the present invention is not limited to this. For example, both ends of the spring can be fixed to the main body and the brake shoe, respectively, and the spring can be arranged so as to be biased in the direction of approaching each other by the restoring force of the extended spring.

  The above-described constituent members are mainly made of metal or hard resin, but it goes without saying that the present invention is not limited to the materials and manufacturing methods.

  9A to 9C are operation schematic diagrams when the protruding width w of the contact surface 131 of the brake shoe 130 is adjusted from the restriction release position in the parking brake mechanism 100 of the present embodiment.

  FIG. 9A shows a state where the contact surface 131 of the brake shoe 130 is disposed at the restriction release position, and the distance between the tire tread surface 12a and the contact surface 131 is d. And the protrusion width w of the contact surface 131 in this restriction release position is defined as 0. When the brake shoe 130 is pulled by hand in the direction of the distal end of the rotary shaft 112 so as to compress the spring 114 from the restriction release position in FIG. 9A, the spring 114 is compressed as shown in FIG. 9B. The brake shoe 130 is separated from the first arm 111, and the fitted portion 133 of the brake shoe 130 is detached from the fitting portion 113 of the main body 110. When the brake shoe 130 is rotated around the rotation shaft 112 in the detached state of FIG. 9B, the contact surface 113 is displaced, and the protrusion width w is changed. At this time, the protrusion width w can be adjusted stepwise by relatively rotating in accordance with the gear pitch. Then, after the brake shoe 130 is rotated to a predetermined protruding width w and then released from the brake shoe 130, the brake shoe 130 is urged to the main body 110 by the elastic return force of the compressed spring 114, and the fitting portion 113 and the fitted part 133 are re-fitted and locked.

  FIG. 9C shows the parking brake mechanism 100 after adjusting the protruding width w. Since the distance between the contact surface 131 and the tread surface 12a is dw, and the contact surface 131 and the tread surface 12a are close to each other, in the state where the brake of FIG. It can be demonstrated. The difference between the maximum protrusion width and the minimum protrusion width of the brake shoe 130 is an adjustment allowance, which is 15 mm in this embodiment. In the above description, the contact surface 131 and the tread surface 12a are adjusted so as to approach each other. However, the contact surface 131 and the tread surface 12a are adjusted to be separated from each other (that is, w <0). May be.

  Further, as shown by a solid line and a broken line in the side view of the wheelchair 10 in FIG. 10, the contact surface 131 and the tread surface are displaced by moving the contact surface 131 facing the tread surface 12a toward the main wheel 11 with the protruding width w. The distance to 12a can be adjusted from d to dw. In addition, when the user of the wheelchair 10 operates the clamp mechanism 118 and the release operation unit 119 of the main body 110 and slides the operation lever 120 in the insertion hole 117, the operation lever 120 is in a range from a solid line to a broken line. It can be fixed at the selected position.

  Hereinafter, the effect of the parking brake mechanism 100 and the wheelchair 10 of one Embodiment of this invention is demonstrated.

  In the parking brake mechanism 100 and the wheelchair 10 according to the embodiment, the wheelchair 10 can be more reliably braked by optimally pressing the contact surface 131 of the brake shoe 130 to the tire tread surface 12a. That is, in the parking brake mechanism 100, the contact surface 131 curved in accordance with the shape of the tread surface 12a is in close contact with the tread surface 12a, and the rotation of the main wheel 11 is regulated by the surface friction. The brake can be effectively applied without the sharp part biting into the tire 12 and damaging the tire 12. Further, a user (especially a seated person) of the wheelchair 10 changes the protrusion width w of the contact surface 131 of the brake shoe 130 by a simple operation of pulling and rotating the brake shoe 130 toward the distal end of the rotating shaft 112. Thus, the distance between the contact surface 131 and the tread surface 12a can be effectively adjusted. That is, the position adjusting mechanism includes a rotating shaft 112 that rotatably supports the brake shoe 130, a fitting portion 113 as a locking means, a fitted portion 133, and a spring 114. By the operation of the position adjusting mechanism, By adjusting the protrusion width w of the contact surface 131 toward the main wheel 11 according to the increase or decrease of the tire diameter, a predetermined brake strength can be easily maintained.

  Further, in the parking brake mechanism 100 according to the embodiment, the brake shoe 130 and the rotating shaft 112 are maintained in a non-rotatable fitting state by the urging force of the elastic spring 114, so that the urging force is resisted. By operating the brake shoe 130, the locked state can be released. That is, since it is not necessary to use a tool such as a screwdriver for unlocking, the protruding width w of the contact surface 131 of the brake shoe 130 can be adjusted easily and quickly.

  Furthermore, in the parking brake mechanism 100 according to the embodiment, the fitting portion 113 and the fitted portion 133 are in a correspondence relationship between the external gear and the internal gear, and therefore, the contact surface 131 with respect to the rotation angle based on the pitch of the gear. The amount of change in the protrusion width w can be quantified. In other words, the protrusion width w can be adjusted stepwise, and the effectiveness of the brake can be finely adjusted in accordance with a decrease in tires or a change in air pressure.

  In the parking brake mechanism 100 according to the embodiment, the operation lever 120 is operated in a state in which the release operation unit 119 formed on the second arm 115 of the main body 110 is operated (pushed up) and the clamp mechanism 118 releases the clamp. The shaft portion 121 is slid with respect to the insertion hole (support portion) 117 of the main body portion 110, and the shaft portion 121 is fixed at a predetermined position by the clamp mechanism 118, thereby easily and quickly adjusting the clamp position of the operation lever 120. Is possible. For this reason, when the user (assistant or seated person) of the wheelchair 10 applies the parking brake, the grip portion 122 of the operation lever 120 can be arranged at a position where each user can use it most easily. Furthermore, when the user of the wheelchair 10 travels without using the parking brake, the operation lever grip 122 can be moved to the lowest position so as not to disturb the occupant of the wheelchair 10. That is, the user of the wheelchair 10 can arbitrarily move the grip portion 122 of the operation lever 120 to a convenient position according to the will.

  Therefore, the parking brake mechanism 100 of the present embodiment speeds up and simplifies the position adjustment of the brake shoe 130 for maintaining the braking performance, and improves the safety and convenience of the wheelchair 10. By mounting the parking brake mechanism 100 on the wheelchair 10, the above-described remarkable effect can be exhibited as the wheelchair 10.

  Although the modification of this invention is demonstrated below, the description is abbreviate | omitted about the structure which is common in the parking brake mechanism 100 of one Embodiment.

(Modification 1)
FIG. 11 shows a parking brake mechanism 100A according to a modification of the present invention. The parking brake mechanism 100A includes a main body 110A, an operation lever 120A, and a brake shoe 130A, as in the embodiment. This modification has different features in the shape of the brake shoe 130A.

  As shown in FIG. 12, the brake shoe 130A includes a contact surface 131A having a minimum protrusion 131aA and a maximum protrusion 131bA, and has a substantially cylindrical shape. The distance r from the rotation center of the brake shoe 130A to the outer surface gradually changes so as to draw an arc from the minimum protrusion 131aA to the maximum protrusion 131bA. In this shape, since the amount of change in the distance r for each rotation angle of the brake shoe 130A is substantially constant, the variation value of the protrusion width w of the contact surface 131A with respect to the rotation angle is a range from the minimum protrusion width to the maximum protrusion width. (5 mm in this embodiment) can be quantified and adjusted. For example, although not shown, it is also possible to visually display the fluctuation amount of the protrusion width w by displaying a scale or the like around the brake shoe 130A.

  FIG. 13A is a partially exploded view of the main body 110A and the brake shoe 130A. From the first arm 111A side, a fitting portion 113A fixed to the first arm 111A, a brake shoe 130A, a spring seat (optional), a spring 114A, and a stepped washer (optional) are arranged. The parking brake mechanism 100A is configured by the rotation shaft 112A penetrating. Since the mechanism for urging the brake shoe 130A toward the main body 110A is the same as that of the embodiment, the description thereof is omitted.

(Modification 2)
FIG. 13B shows the parking brake mechanism 100B. The parking brake mechanism 100A of the first modification is different from the parking brake mechanism 100A in that no spring as a locking unit is interposed. That is, in the parking brake mechanism 100B, the rotating shaft 112B also serves as a locking unit. That is, when the fastening of the bolt-shaped rotating shaft 112B is loosened, the rotating shaft 112B protrudes in the direction of the shaft tip, and the brake shoe 130B can move freely with respect to the rotating shaft 112B. In this state, by moving the brake shoe 130B toward the distal end of the rotating shaft 112B, the fitting portion 113B and the fitted portion 133B are separated from each other, and the brake shoe 130B can rotate around the rotating shaft 112B. . After adjusting the protrusion width w by rotating the brake shoe 130B by a predetermined angle, the brake shoe 130B is manually pushed again in the base end direction of the rotating shaft 112B to fit the fitting portion 113B and the fitting portion 133B. In addition, by refastening the rotating shaft 112B, the brake shoe 130B can be locked so as not to rotate with respect to the main body 110B. The advantage of this structure is that since the spring structure is not required, the overall shape can be configured more compactly in the axial direction, and the member cost can be reduced.

  The present invention is not limited to the above-described embodiments and modifications, and can be implemented in various modes as long as they belong to the technical scope of the present invention.

DESCRIPTION OF SYMBOLS 10 Wheelchair 11 Main wheel 12 Tire 12a Tread surface 13 Side frame 100 Parking brake mechanism 110 Main body part 111 First arm 112 Rotating shaft 113 Fitting part 114 Spring 115 Second arm 116 Rotating shaft 117 Insertion hole (support part)
118 Clamp mechanism 119 Release operation part (release means)
120 Operation lever 121 Shaft part 122 Grip part 123 Stopper 130 Brake shoe 131 Contact surface 132 Opening part 133 Fit part 134 Spring engagement part w Projection width

Claims (6)

A wheelchair parking brake mechanism capable of regulating the rotation of the main wheel of the wheelchair,
An operation lever capable of controlling regulation and deregulation of the main wheel;
The main wheel has a contact surface that can come into surface contact with the tread surface of the main wheel, and the contact surface moves to the main wheel side of the wheelchair and presses against the tread surface of the main wheel by the restriction operation of the operation lever , Brake shoes,
A rotating shaft that rotatably supports the brake shoe; and a lock unit that locks the brake shoe in a state in which the brake shoe cannot rotate with respect to the rotating shaft, and the brake shoe is rotated around the rotating shaft. A wheelchair parking brake mechanism comprising: a position adjusting mechanism capable of adjusting a protrusion width of the contact surface of the brake shoe toward the main wheel.   When the fitting portion formed on the outer periphery of the rotating shaft and the fitted portion formed on the inner periphery of the opening of the brake shoe are fitted, the brake shoe is non-rotatably locked to the rotating shaft. The parking brake mechanism for a wheelchair according to claim 1.   The parking brake mechanism for a wheelchair according to claim 2, further comprising a spring that biases the fitting portion and the fitted portion so as to maintain a fitting state.   The fitting portion is formed in an external gear shape and the fitted portion is formed in an internal gear shape, and the protrusion width of the contact surface of the brake shoe is stepwise according to the pitch of the gear. 4. The wheelchair parking brake mechanism according to claim 2, wherein the parking brake mechanism is adjustable. A support portion that is slidably fitted into the shaft portion of the operation lever;
A clamp mechanism for fixing the shaft portion of the operation lever at a predetermined position;
Release means for releasing fixation by the clamp mechanism,
By sliding the shaft portion of the operation lever with respect to the support portion in a state where the clamp is released, and fixing the shaft portion to a predetermined position by the clamp means, the position of the grip portion of the operation lever can be arbitrarily set. The wheelchair parking brake mechanism according to any one of claims 1 to 4, wherein the parking brake mechanism is adjustable.   A wheelchair comprising the wheelchair parking brake according to any one of claims 1 to 5.

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