JP7836084B2 - Brake mechanism - Google Patents

Description

This invention relates to a brake mechanism installed in wheelchairs, walkers, and walking aids.

Generally, wheelchairs, walkers, and mobility aids are equipped with a handle that is operated by the user or caregiver, and a braking device with a brake lever is mounted on this handle. In such wheelchairs and walkers, the user or caregiver can apply the brakes to the wheels by operating the brake lever while gripping the handle.

For example, Patent Document 1 proposes a brake device having a brake lever. This brake device allows the brake lever to be displaced between a standby position, a brake position tilted upward (towards the handlebars) from the standby position, and a lock position tilted downward (away from the handlebars). When the brake lever is in the standby position, the wheel is not braked, and when the brake lever is tilted to the brake position, the wheel is braked. Furthermore, when the brake lever is tilted to the lock position, the rotation of the wheel is prohibited. In this configuration, a pivot shaft provided on the brake lever is rotatably supported in the shaft hole of a cover member, and a protrusion provided on the brake lever is provided to be movable along a guide passage formed in the cover member. The brake lever can be displaced between the standby position, brake position, and lock position as described above by tilting around the pivot shaft and the protrusion moving along the guide passage. Here, the guide passage consists of a roughly L-shaped upper passage section and a lower passage section that is bent forward from the lower end of the upper passage section. The brake lever is displaced between the standby position and the brake position by moving the protruding portion up and down along the upper passage section, and displaced to the locked position by moving the protruding portion to the lower passage section.

Japanese Patent Publication No. 2019-180615

In the conventional brake system described above, the guide passage for the brake lever was bent into an upper and lower section. This bend hindered the movement of the protruding part, making it difficult to smoothly tilt the brake lever. Furthermore, as the brake lever moved between the upper and lower sections, the protruding part of the brake lever struck the bend between the two sections, leading to wear on both. This wear could reduce the stability of the movement when displacing the brake lever to the locked position. Thus, there was room for improvement in the conventional brake system.

This invention proposes a brake mechanism that allows the brake lever to tilt smoothly and maintain a stable displacement to a predetermined position over a long period of time.

The present invention relates to a brake mechanism comprising a brake unit that applies brakes to the wheels that drive the vehicle body, and a brake operating unit attached to a handle unit that controls the movement of the vehicle body, which operates the brake unit via a wire connected to the brake unit, wherein the brake operating unit comprises an operating base unit fixed to the handle unit and an operating lever unit tiltably mounted on the operating base unit, and the operating lever unit is held in a non-operating position where the brake unit does not apply the brakes, while being tilted from the non-operating position toward the handle unit to change its position to an operating position where the brake unit applies the brakes, wherein the brake operating unit comprises a link mechanism unit composed of the operating lever unit, a first link member, a second link member, and a third link member, wherein one end of the first link member is tiltably attached to a tilting shaft provided on the operating base unit and the other end is attached to the wire, and the position is changed by tilting to a braking position where the brake unit applies the brakes and a non-braking position where the brakes do not apply via the wire, the second link member is tiltably attached to the tilting shaft and the third link The link member is tiltably connected to the second link member and has a braking holding portion that abuts against the first link member in the braking position, and the operating lever portion comprises a first pivot portion tiltably connected to the first link member and a second pivot portion provided at a different location from the first pivot portion and tiltably connected to the third link member, and the link mechanism is normally kept in a non-braking state with the operating lever portion in the non-operating position and the first link member in the non-braking position, and when the operating lever portion is tilted from the non-operating position to the operating position, The brake mechanism is characterized in that, while the first link member is repositioned from the non-braking position to the braking position, and the braking holding portion of the third link member is converted to a normal braking mode in which it does not contact the first link member, the operating lever portion is tilted from the non-braking position to the locked position opposite the handle portion, thereby repositioning the first link member from the non-braking position to the braking position, and the braking holding portion of the third link member comes into contact with the first link member, thereby converting the first link member to a braking holding mode in which it is held in the braking position.

In this configuration, the tilting of the operating lever causes the link mechanism to switch between three modes: a non-braking mode (where the brake is not applied), a normal braking mode (where the brake is applied), and a brake-hold mode (where the brake is held in the applied state). Because this configuration operates the brake through a linkage between the operating lever and the first to third link members, it allows for smoother tilting (position change) of the operating lever compared to the conventional configuration (where the guide passage is used for guidance), and suppresses the wear that is prone to occurring in the conventional configuration. Therefore, the operation of changing the position of the operating lever (in other words, the linkage operation that converts the link mechanism to each mode) can be performed stably over a long period of time.

Furthermore, in this configuration, the link mechanism is configured to hold the first link member in the braking position by bringing the braking holding portion of the third link member into contact with the first link member in the braking-holding configuration. The configuration can be changed from the braking-holding configuration by releasing the contact between the braking holding portion of the third link member and the first link member. Specifically, by tilting the operating lever from the locked position to the non-operating position, the contact can be released relatively easily, and the configuration can be changed back to the normal non-braking configuration. Thus, the user can release the contact between the braking holding portion of the third link member and the first link member in the braking-holding configuration by using the force of tilting the operating lever.

In the brake mechanism of the present invention described above, a configuration is proposed in which the second link member of the link mechanism is provided so as not to come into contact with the operating lever.

In this configuration, the second link member, which is not directly connected to the operating lever, is positioned so as not to come into contact with the operating lever. This allows the link mechanism as a whole to operate more smoothly, and the operating lever to tilt more smoothly. As a result, wear in the link mechanism can be further suppressed.

The brake mechanism of the present invention allows for stable operation of the brake section through the linkage mechanism, and enables smooth and stable tilting of the operating lever between the non-operating position, the operating position, and the locked position over a long period of time.

This is an external view showing the brake operating unit 2 attached to the handle unit 101. This is an explanatory diagram showing the link mechanism 4 located inside the operating base 5. (A) An explanatory diagram showing a portion of the link mechanism 4 cut out, and (B) A cross-sectional view of the link mechanism 4. This is an explanatory diagram showing the conversion of the link mechanism 4 from a non-braking mode to a normal braking mode. This is an explanatory diagram showing the conversion of the link mechanism 4 from a non-braking state to a braking and holding state. This is an explanatory diagram showing the transformation of the link mechanism 4, continuing from Figure 5.

An embodiment of the brake mechanism according to the present invention will be described in detail below.
The brake mechanism 1 of this embodiment is mainly installed in wheelchairs, walkers, and walking aids, and as shown in Figure 1, it includes a brake operating unit 2 fixed to the handle portion 101 of the wheelchair or the like. Some wheelchairs, walkers, and walking aids are equipped with a pair of left and right handle portions 101 that are operated by the user or caregiver, and the brake operating unit 2 of this embodiment is installed on the left and right handle portions 101, respectively. In the following, only the brake operating unit 2 fixed to one of the left or right handle portions 101 will be described, but of course the same brake operating unit 2 can be installed on the other handle portion 101 as well.

The aforementioned wheelchair, walker, and walking aid have a frame that forms the body (not shown), and at least one pair of left and right wheels (not shown) are mounted on the frame. The frame is made of metal pipes or the like, and is provided with a handle frame portion 102 that constitutes the handle portion 101. As shown in Figure 1, a grip portion 103 is attached to the handle frame portion 102 to form the handle portion 101. In addition, the left and right wheels are each provided with a brake portion (not shown) that applies a brake to the wheel. One end of a wire 9 (see Figure 1) is connected to this brake portion, and when the wire 9 is pulled, the wheel is braked (in other words, a braking force is applied). In addition, the brake portion is provided with a biasing means (for example, a coil spring) that biases the wire 9 toward the one end side (the brake portion side). As a result, the wire 9 is normally biased toward the brake portion side, so the brake by the brake portion is not applied to the wheel. Since these braking systems can be constructed using drum brakes, rim brakes, or disc brakes, which are commonly used in wheelchairs and walkers, a detailed explanation will be omitted.

The essential parts of the present invention will be described below.
The brake mechanism 1 consists of the brake section and the brake operating section 2 described above. As shown in Figure 1, the brake operating section 2 includes an operating base section 5 attached to the handle frame section 102 and an operating lever section 3 tiltably attached to the operating base section 5. The operating base section 5 is integrally provided with a fixing section 11 fixed to the handle frame section 102 and a case section 12 on which the link mechanism section 4, described later, is arranged.

As shown in Figures 1 to 3, the case portion 12 of the brake operating unit 2 is composed of a pair of front and back case plate portions 13, 13 arranged opposite each other at a predetermined distance, and a wall portion 14 connecting both case plate portions 13, 13. An opening 15 is formed, opening to the right on the plane of the paper in each figure. Furthermore, an insertion hole 16 is formed in the lower part of the wall portion 14 of the case portion 12, through which the wire 9 is inserted.

A link mechanism 4 is provided in the case portion 12. The link mechanism 4 consists of the aforementioned operating lever portion 3, a first link member 21, a second link member 22, and a third link member 23, with the first to third link members 21 to 23 housed inside the case portion 12. The first link member 21 and the second link member 22 are tiltably mounted on a tilting shaft 17 provided in the case portion 12. Here, the tilting shaft 17 spans across the front and back case plate portions 13, 13.

The operating lever section 3 consists of a lever main section 31 operated by the user or caregiver, and a pair of lever base sections 32, 32 on the front and back, which are provided bifurcated from the lever main section 31. The operating lever section 3 has the lever base sections 32, 32 arranged inside the case section 12, and the lever main section 31 protrudes to the right (right in the drawing) of the case section 12 through an opening 15 in the case section 12. The front and back lever base sections 32, 32 are provided opposite each other with a predetermined gap between them, and the first link member 21 and the third link member 23 can be inserted through this gap. Furthermore, the front and back lever base sections 32, 32 are each provided with a first pivot section 33 that is tiltably connected to the first link member 21, and a second pivot section 34 that is tiltably connected to the third link member 23. The first shaft portion 36 is connected to the first pivot portions 33, 33 on the front and back sides, and the second shaft portion 37 is connected to the second pivot portions 34 on the front and back sides. These first shaft portions 36 and second shaft portions 37 are provided parallel to the tilting axis 17.

The first link member 21 is formed in the shape of a strip, with one end tiltably attached to the tilting shaft 17 and the other end to which the other end of the wire 9 is attached. This first link member 21 tilts vertically around the tilting shaft 17 within the case portion 12. An arc-shaped notch 26 is formed at the other end of the first link member 21, and a cylindrical sliding member 10, to which the other end of the wire 9 is attached, is slidably supported in this notch 26. The wire 9 attached to this sliding member 10 is arranged to reach the brake portion described above via an insertion hole 16 in the case portion 12. Furthermore, the first shaft portion 36, provided on the first pivot portions 33, 33 of the operating lever portion 3, is tiltably inserted into the portion between the one end and the other end of the first link member 21. This connects the first link member 21 and the operating lever portion 3 in a relative tiltable manner.

The first link member 21 tilts around the tilt axis 17, thereby changing its position between the non-braking position shown in Figure 2 and the braking positions shown in Figures 4(B) and 6(B). When the first link member 21 is in the non-braking position, the other end of the wire 9 (sliding member 10) is closer to the brake unit compared to the braking position, and therefore the brake unit does not apply pressure. On the other hand, when the first link member 21 is in the braking position, the wire 9 is pulled away from the brake unit compared to the braking position, and therefore the brake unit applies pressure. Furthermore, the other end of the first link member 21 (notch 26) is pulled via the wire 9 by the biasing means (coil spring) of the brake unit, and is constantly biased in a clockwise direction on the plane of Figure 2.

The second link member 22 is formed in a curved plate shape, with one end tiltably attached to the tilting shaft 17, and the third link member 23 tiltably connected to the other end. In this embodiment, as shown in Figure 3(B), two second link members 22, 22 are arranged on both the front and back sides of the first link member 21 (and the third link member 23) at a predetermined interval, and are each attached to the tilting shaft 17. These two second link members 22, 22 and the first link member 21 can each tilt about the tilting shaft 17. As shown in Figure 4, although these second link members 22 can tilt left and right (left and right directions on the paper) inside the case portion 12, there is a limit to the position where they can tilt to the left due to contact with the wall portion 14 of the case portion 12.

The second link member 22 is positioned so as not to come into contact with the operating lever portion 3. In particular, the second link member 22 has a curved recess 27 in the portion facing the lever base 32 of the operating lever portion 3. This configuration prevents contact between the second pivot portion 34 of the operating lever portion 3 and the curved recess 27 of the second link member 22 when the operating lever portion 3 is tilted downward, as will be described later.

The third link member 23 is formed in the shape of a strip plate, and one end is tiltably connected to the other end of the second link member 22. Here, one end of the third link member 23 is inserted through a third shaft portion 38 that spans across the front and back of the second link members 22, 22, thereby tiltably connecting the second link members 22, 22 and the third link member 23. Furthermore, a braking holding portion 41 and a tilting limiting portion 42 are coupled to the other end of the third link member 23, which abut against the first link member 21. The third link member 23 tilts about the third shaft portion 38, and is held in the non-braking position when the tilting limiting portion 42 abuts against the first link member 21 in the non-braking position, while it can be held in the braking position when the braking holding portion 41 abuts against the first link member 21 in the braking position. The third shaft portion 38 is provided parallel to the tilting axis 17 described above.

Furthermore, the portion of the third link member 23 closest to the braking and holding portion 41 and the tilt limiting portion 42 is tiltably inserted into the second shaft portion 37 provided on the second pivot portions 34, 34 on the front and back of the operating lever portion 3. This connects the third link member 23 and the operating lever portion 3 in a way that allows for relative tilting.

The link mechanism 4 can be converted between a non-braking mode, a normal braking mode, and a braked-holding mode by the coordinated movement of the operating lever 3 and the first to third link members 21 to 23. In the non-braking mode, as shown in Figures 2 and 3, the first link member 21 is in the non-braking position, the second link member 22 is in contact with the wall 14 of the case 12, and the tilt limiting portion 42 of the third link member 23 is in contact with the first link member 21. That is, in the non-braking mode, the first link member 21, which is always biased clockwise, is held in the non-braking position by the second link member 22 in contact with the wall 14 and the third link member 23, whose tilt limiting portion 42 is in contact with the first link member 21. In this non-braking mode, the position of the operating lever 3 is the non-operational position, and the link mechanism 4 is normally maintained in a non-braking state.

As shown in Figure 4, the normal braking mode is achieved by tilting the operating lever 3 upward from the non-operating position (towards the grip portion 103 of the handle portion 101), thereby converting from the non-braking mode. In this embodiment, the operating lever 3 and the first to third link members 21 to 23 tilt integrally around the tilt axis 17, converting from the non-braking mode to the normal braking mode. In the normal braking mode, as shown in Figure 4(B), the first link member 21 is in the braking position, and the second link member 22 is separated from the wall portion 14 of the case portion 12. Therefore, the normal braking mode is not maintained, and when the force tilting the operating lever 3 upward is released, the biasing force pulling the wire 9 towards the brake portion causes the first link member 21 to tilt clockwise, and consequently, the link mechanism 4 returns from the normal braking mode to the non-braking mode. The position of the operating lever 3 in this normal braking mode is the operating position.

As shown in Figures 5 and 6, the braking and holding configuration is achieved by tilting the operating lever portion 3 downward (to the opposite side of the grip portion 103) from the non-operating position. In this conversion to the braking and holding configuration, the second link member 22 is in contact with the wall portion 14 of the case portion 12 and cannot tilt to the left (to the left on the page). Therefore, the first link member 21 and the third link member 23 move in conjunction with the tilting of the operating lever portion 3. More specifically, as shown in Figures 5(A) to (B), the first link member 21 tilts upward from the non-braking position, and the tilt limiting portion 42 of the third link member 23 moves away from the first link member 21. Furthermore, as the operating lever portion 3 tilts, as shown in Figure 6(A), the second pivot portion 34 of the operating lever portion 3 moves toward the curved recess 27 of the second link member 22, and the third link member 23 tilts to the left (left side of the paper). After this, as shown in Figure 6(B), when the first link member 21 reaches the braking position, the second pivot portion 34 of the operating lever portion 3 is positioned opposite the curved recess 27 of the second link member 22, and the braking and holding portion 41 of the third link member 23 comes into contact with the first link member 21. In this way, the link mechanism 4 is transformed into the braking and holding configuration.

In this braking and holding configuration, the first link member 21, which is always biased clockwise, is held in the non-braking position by the second link member 22, which abuts against the wall portion 14, and the third link member 23, whose braking and holding portion 41 abuts against the first link member 21. As a result, the link mechanism 4 is held in the braking and holding configuration unless an external force (force from the user or caregiver) acts on the operating lever portion 3. That is, it is kept in a state where the brake is applied by the brake portion. The position of the operating lever portion 3 in this braking and holding configuration is the locked position. By setting the operating lever portion 3 to the locked position, the first link member 21 is held in the non-braking position against the biasing force pulling the wire 9 towards the brake portion (in other words, held in the braking and holding configuration).

The braking and holding state described above is released when the user or caregiver tilts the operating lever 3 upward (towards the grip 103), thereby converting from the braking and holding state to the non-braking state. In this conversion, the upward tilting of the operating lever 3 causes the first link member 21 and the third link member 23 to move in the opposite direction to the movement that led to the braking and holding state, returning to the non-braking state (see Figures 5 and 6). Thus, the braking and holding state can be released relatively easily by the user or caregiver gripping the operating lever 3.

As described above, the brake mechanism 1 of this embodiment is installed on a wheelchair or walker and operated by the user of the wheelchair or walker or their caregiver. When moving the wheelchair or walker, the user or caregiver holding the handle 101 keeps the operating lever 3 in the non-operation position without operating it. As a result, the link mechanism 4 is kept in the non-braking state, and the wheels are not braked, allowing for easy movement. When stopping the wheelchair or reducing the speed, the user or caregiver grips the operating lever 3 and tilts it to the braking position. As a result, the link mechanism 4 changes from the non-braking state to the normal braking state (see Figure 4), and the wheels are braked. When the wheelchair stops or the desired speed is reached, the user releases the operation of the operating lever 3, and the link mechanism 4 returns to the non-braking state. On the other hand, when parking a wheelchair or similar vehicle, the user tilts the operating lever 3 from the non-operated position to the locked position. This converts the link mechanism 4 from the non-braking state to the braked-holding state (see Figures 5 and 6), and as it is held in this braked-holding state, the wheels remain braked (parked). After this, when moving the wheelchair or similar vehicle, the user grips the operating lever 3 and tilts it from the locked position to the non-operated position. This converts the link mechanism 4 from the braked-holding state to the non-braking state, releasing the brakes.

Thus, the brake mechanism 1 of this embodiment is configured to apply the brakes to the wheels by switching the link mechanism 4 between a non-braking mode, a normal braking mode, and a brake-holding mode as needed. Since the link mechanism 4 is switched between these modes by coordinating the operation lever 3, operated by the user, with the first to third link mechanisms 21 to 23, the switching between modes can be performed easily and smoothly.

The link mechanism 4 is designed so that, aside from actively pressing the first link member 21 and the third link member 23 together when converting to each mode, the operating lever 3 does not come into contact with the link members 21-23. More specifically, the first link member 21 and the third link member 23 are configured to remain in contact with each other during conversion to each mode without relative sliding, thereby suppressing wear between them. Furthermore, the operating lever 3 and the second link member 22 are configured not to come into contact. Here, as mentioned above, the second link member 22 becomes immobile due to the wall portion 14 of the case portion 12 in the non-braking mode and the braking-holding mode. By preventing contact between the operating lever 3, operated by the user, and the second link member 22 in this immobile state, wear is prevented during conversion to these modes. Thus, the link mechanism 4 of this embodiment can suppress wear during conversion to each mode, allowing for stable and easy conversion to each mode even after repeated conversions over a long period.

Therefore, according to the brake mechanism 1 of this embodiment, the operating lever portion 3 can be tilted stably and smoothly to the non-operating position, operating position, and locked position, making it easy for the user or caregiver to operate over a long period of time.

The present invention is not limited to the embodiments described above, and can be modified as appropriate without departing from the spirit of the invention. For example, the dimensions and shapes of each part in the embodiments described above can be changed as appropriate.
In this embodiment, the wire is biased by a coil spring in the brake section, but the system is not limited to this configuration. For example, a biasing means (coil spring, leaf spring, air cylinder, gas cylinder, etc.) for biasing the wire can be provided in the brake operating section. Alternatively, the brake operating section can be equipped with a biasing means for biasing the operating lever to the non-operating position.
In this embodiment, the operating lever (first pivot point, second pivot point) and the second link member are not in contact. However, the configuration is not limited to this, and for example, in the braking and holding mode, the second pivot point of the operating lever can be in contact with the second link member.
In this embodiment, the first link member and the third link member are connected so as to be tiltable by the lever bases on the front and back of the operating lever and the second link members on the front and back (a so-called double-supported structure). However, the structure is not limited to this, and it may also be a structure in which the lever base of the operating lever and the second link member, which are located on one side of the operating lever, are connected so as to be tiltable (a so-called cantilevered structure).

1 Brake mechanism 2 Brake operating part 3 Operating lever part 4 Link mechanism part 5 Operating base part 9 Wire 10 Sliding member 11 Fixing part 12 Case part 13 Case plate part 14 Wall part 15 Opening 16 Through hole 17 Tilting shaft 21 First link member 22 Second link member 23 Third link member 26 Notch part 27 Curved recess 31 Main part of lever 32 Base part of lever 33 First pivot part 34 Second pivot part 36 First shaft part 37 Second shaft part 38 Third shaft part 41 Brake holding part 42 Tilting limiting part 101 Handle part 102 Handle frame part 103 Grip part

Claims (2)

The braking unit applies brakes to the wheels that move the vehicle,
It includes a brake operating unit attached to the handle portion for controlling the movement of the vehicle body, and which operates the brake portion via a wire connected to the brake portion,
The aforementioned brake operating unit
The system comprises an operating base fixed to the handle portion and an operating lever portion tiltably mounted on the operating base portion.
In a brake mechanism in which the operating lever portion is held in a non-operating position where the brake portion does not apply the brake, and is tilted toward the handle portion from the non-operating position to change its position to an operating position where the brake portion applies the brake,
The brake operating section comprises a link mechanism consisting of the operating lever section, a first link member, a second link member, and a third link member.
The first link member is tiltably attached at one end to a tilting shaft provided on the operating base and has the wire attached to the other end, and by tilting, its position is changed between a braking position in which the brake is applied by the brake unit via the wire and a non-braking position in which the brake is not applied.
The second link member is tiltably mounted on the tilting shaft,
The third link member is tiltably connected to the second link member and is provided with a braking and holding portion that contacts the first link member in the braking position.
The operating lever portion comprises a first pivot portion that is tiltably connected to the first link member, and a second pivot portion that is provided at a different location from the first pivot portion and tiltably connected to the third link member.
The aforementioned link mechanism is
Under normal conditions, the operating lever portion is kept in the non-operating position and the first link member is kept in the non-braking position, thus maintaining a non-braking dynamic state.
As the operating lever portion is tilted from the non-operating position to the operating position, the first link member is repositioned from the non-braking position to the braking position, and the braking holding portion of the third link member is converted to a normal braking mode in which it does not contact the first link member.
A brake mechanism characterized in that the operating lever portion is tilted from the non-braking position to the locked position opposite to the handle portion, thereby changing the position of the first link member from the non-braking position to the braking position, and the braking holding portion of the third link member comes into contact with the first link member, thereby changing the configuration to a braking holding configuration in which the first link member is held in the braking position. The brake mechanism according to claim 1, characterized in that the second link member of the link mechanism is provided so as not to come into contact with the operating lever.