JP3222576U - Bicycle for children - Google Patents

Abstract

There is provided a children's bicycle that can be braked by a good operation feeling that is not too heavy for young children and the like. A lever member has a first arm portion and a second arm portion that is bent with respect to the first arm portion, and an end side of the first arm portion is connected to a band. The acting point portion P1 is set, the end portion side of the second arm portion 23b is set as a force point portion P2 connected to the brake cable 40, and the intersection portion of the first arm portion 23a and the second arm portion 23b is pivotally supported by the support member 24. The ratio of the length L2 from the fulcrum part P3 to the force point part P2 to the length L1 from the action point part P1 to the fulcrum part P3 is 1: 1.6 to 1: 1.8. Within the range. [Selection] Figure 2

Description

  The present invention relates to a child bicycle in which a band brake is operated by operating a brake lever provided on a handle.

  Conventionally, as shown in Patent Document 1, for example, a general bicycle has a body frame that supports a handle and a front fork on the front end side and a rear wheel shaft on the rear end side, and is substantially concentric with the rear wheel shaft. A band brake provided; a brake lever provided on an end side of the handle; and a brake cable extending between the band brake and the brake lever, wherein a traction force by the brake lever is applied to the brake cable. Is transmitted to the band brake.

JP 2011-37311 A

By the way, the conventional general children's bicycle basically adopts the structure of the bicycle.
However, especially when young children, etc. brake the bicycle with the above structure, the grip strength is weak, so the brake lever feels too heavy or cannot be operated until the brake is applied sufficiently. There is a risk of accidents.

In view of such problems, the present invention has the following configuration.
A vehicle body frame that supports a handle and a front fork on the front end side and a rear wheel shaft on the rear end side, a band brake provided substantially concentrically with the rear wheel shaft, and a brake provided on one end side of the handle A child bicycle comprising a lever, a brake cable extending between the band brake and the brake lever, wherein the traction force by the brake lever is transmitted to the band brake by the brake cable. Includes a drum connected to a rear hub around a rear wheel shaft, a band provided around the drum, a lever member connected to the band, and a support member that rotatably supports the lever member. The band pulled by the lever member is in sliding contact with the drum, and the lever The member has a first arm portion and a second arm portion bent with respect to the first arm portion, and an end portion side of the first arm portion is an action point portion connected to the band portion, An end portion side of the second arm portion is a force point portion connected to the brake cable, and an intersection portion of the first arm portion and the second arm portion is a fulcrum portion pivotally supported by the support member, and the action point The ratio of the length from the fulcrum part to the force point part with respect to the length from the fulcrum part to the fulcrum part is in the range of 1: 1.6 to 1: 1.8. For bicycles.

  Since the present invention is configured as described above, the brake can be applied with a good feeling of operation that is not too heavy even when a young child or the like performs a brake operation.

It is a perspective view which shows an example of the bicycle for children concerning this invention. It is a side view which shows the band brake in the bicycle for children. It is a disassembled perspective view of a band brake. It is a perspective view which shows the rear-wheel side bottom part of the child bicycle.

In the present embodiment, the following features are disclosed.
A first feature is that a vehicle body frame that supports a handle and a front fork on the front end side and a rear wheel shaft on the rear end side, a band brake provided substantially concentrically with the rear wheel shaft, and one end of the handle A brake lever provided on the side, and a brake cable extending between the band brake and the brake lever, wherein a traction force by the brake lever is transmitted to the band brake by the brake cable In a bicycle, the band brake includes a drum connected to a rear hub around a rear wheel shaft, a band provided around the drum, a lever member connected to the band, and the lever member being rotatable. And a support member for supporting, wherein the band pulled by the lever member is in sliding contact with the drum The lever member has a first arm portion and a second arm portion bent with respect to the first arm portion, and an end side of the first arm portion is connected to the band portion. A point portion, an end portion side of the second arm portion is a force point portion connected to the brake cable, and an intersection portion of the first arm portion and the second arm portion is a fulcrum portion pivotally supported by the support member. The ratio of the length from the fulcrum part to the force point part to the length from the action point part to the fulcrum part is in the range of 1: 1.6 to 1: 1.8 (see FIG. 1 to FIG. 4).

  A second feature is that the vehicle body frame includes a chain stay extending forward from a support portion of the rear wheel shaft, a down tube extending forward and obliquely upward from a front end side of the chain stay, and the chain stay. The brake cable is led to the down tube side through the footrest (see FIGS. 1 and 4).

  A third feature is that the down tube is provided with a plurality of locking portions for fixing the outer cable at intervals in the front-rear direction, and the plurality of locking portions are moved forward as they move forward. The circumferential position is shifted to the opposite side of the brake lever (see FIGS. 1 and 4).

<Specific Embodiment>
Next, specific embodiments having the above characteristics will be described in detail with reference to the drawings.

  The child bicycle A includes a body frame 10 that supports a handle 1 and a front fork 2 on the front end side and a rear wheel shaft 3 on the rear end side, and a band brake provided substantially concentrically with the rear wheel shaft 3. 20, a brake lever 30 provided on one end of the handle 1, and a brake cable 40 extending between the band brake 20 and the brake lever 30, and the traction force by the brake lever 30 is applied to the band brake by the brake cable 40. 20 is configured to transmit.

  The vehicle body frame 10 includes left and right chain stays 11, 11 extending forward from support portions on both sides of the rear wheel shaft 3, and a down tube 12 extending obliquely forward from the front end side of the chain stays 11, 11. And a footrest 13 fixed to the front end side of the chain stay 11.

One end side and the other end side of the rear wheel shaft 3 are non-rotatably supported on the rear end sides of the left and right chain stays 11, 11, respectively.
A substantially cylindrical rear hub 4 is rotatably supported on the outer periphery of the rear wheel shaft 3 via a bearing (not shown). An annular rim 4b is fixed around the rear hub 4 via spokes 4a, and a tire 4c is fitted to the outer periphery of the rim 4b.

The down tube 12 is formed in the shape of an inclined pipe that extends obliquely upward and forward from the front end side of the left and right chain stays 11, 11.
The down tube 12 is provided with a plurality (two in the illustrated example) of locking portions 12a for fastening the brake cable 40 at intervals in the front-rear direction. According to the illustrated example, each locking portion 12a is a cylindrical member through which the down tube 12 can be inserted, and is fixed to the outer peripheral portion of the down tube 12 by welding or the like.
The plurality of locking portions 12a are arranged on the lower half side in the radial direction of the down tube 12 so as to be shifted in the circumferential direction toward the opposite side of the brake lever 30 as it goes forward (see FIG. 1 and FIG. 1). FIG. 4).
More specifically, of the two locking portions 12a, the rear locking portion 12a is located on the left side when viewed from the upper rear side on the lower half side in the radial direction of the down tube 12. The front locking portion 12a is located on the right side when viewed from the upper rear side on the lower half side in the radial direction of the down tube 12. According to these arrangements, it is possible to prevent the brake cable 40 from being excessively bent or bent.
In addition, as another example of the latching | locking part 12a, it is possible to set it as shapes other than the example of illustration, such as the aspect formed in the hook shape or the fork shape.

  In addition, a seat tube 8 extending substantially in the vertical direction is inserted and fixed at an intermediate position in the extending direction of the down tube 12 (the rear end side in the illustrated example), and a saddle is attached to the upper end portion of the seat tube 8. 9 is fixed.

The footrest portion 13 is formed in a plate shape that surrounds the lower end side of the down tube 12 and the seat tube 8 in a substantially U shape from the front side thereof, and a foot such as an infant is placed on the upper surface thereof.
The footrest plate 13 secures an insertion space 13a for inserting the brake cable 40 in an inner portion surrounding the seat tube 8 and the like.
The footrest portion 13 is fixed to the upper portion of the chain stay 11 by a support bracket 14.

As shown in FIG. 4, the support bracket 14 is a substantially plate-like member fixed to the lower part of the chain stay 11, the front end side thereof is bent upward, and the bent portion of the footrest 13 is The back side is fastened. The means for fixing is screwed according to the illustrated example, but as other examples, it is possible to use fitting, welding, adhesion or the like.
The support bracket 14 is provided with a through hole 14a through which the brake cable 40 is inserted.

  A pipe-shaped head tube 5 extending in the vertical direction is connected to the front end side of the body frame 10. On the head tube 5, an upper handle 1 and a lower front fork 2 are supported so as to rotate integrally.

The front fork 2 is formed in a forked shape at the lower end side, and supports one end side and the other end side of the front wheel shaft 6 in a non-rotatable manner at the lower end side portion.
A substantially cylindrical front hub 7 is rotatably supported on the outer periphery of the front wheel shaft 6 via a bearing (not shown). An annular rim 7b is fixed around the front hub 7 via a spoke 7a, and a tire 7c is fitted on the outer periphery of the rim 7b.

  As shown in FIG. 3, the band brake 20 includes a drum 21, a band 22 provided around the drum 21, a lever member 23 pivotally connected to one end of the band 22, and a lever member 23. And a support member 24 that is rotatably supported. The band 22 pulled by the lever member 23 is brought into sliding contact with the drum 21.

The drum 21 is formed in an annular shape or a disk shape, and is fixed to the rear hub 4 in a concentric manner so as to rotate integrally with the rear hub 4.
In order to increase the braking force when the drum 21 is tightened by the band 22, a surface treatment (for example, chrome plating treatment) having a relatively high frictional force with the band 22 is performed.

The band 22 is a substantially C-shaped member provided around the drum 21, a lever member 23 is connected to one end side thereof, and the other end side is supported by a support member 24.
When the one end side of the band 22 is pulled by the lever member 23, the diameter of the band 22 is reduced, the inner side shoe is brought into sliding contact with the outer peripheral surface of the drum 21, and the drum 21 is braked.

The lever member 23 is formed in a substantially L shape having a first arm portion 23a and a second arm portion 23b bent with respect to the first arm portion 23a, and the end portion side of the first arm portion 23a is banded. 22, the end point side of the second arm portion 23 b is a force point portion P 2 connected to the rear end side of the inner wire of the brake cable 40, and the first arm portion 23 a and the second arm portion 23 b are connected. Is a fulcrum P3 pivotally supported by the support member 24 (see FIG. 3).
The lever member 23 has a ratio of the length L2 from the fulcrum part P3 to the force point part P2 to the length L1 from the action point part P1 to the fulcrum part P3, from 1: 1.6 to 1: 1. In the preferred example of this embodiment, it is set to 1: 1.71 (see FIG. 2).

  The tensile force when the force point P2 of the lever member 23 is pulled by the brake cable 40 until the band 22 is slidably contacted with the outer peripheral portion of the drum 21 is appropriately set in consideration of the brake operability by an infant or the like.

  The support member 24 is formed in a circular case shape that covers the drum 21 and the band 22 in an annular shape, a through hole 24b through which the rear wheel shaft 3 is inserted, a support shaft 24a that pivotally supports the lever member 23, and the like. Have

  In FIG. 3, reference numeral 23 c is a nut that is screwed into the support shaft 24 a that is inserted through the fulcrum part P <b> 3 of the lever member 23. Reference numerals 23 d and 23 e are bolts and nuts for fastening the inner wire of the brake cable 40.

  In FIG. 3, reference numeral 25 denotes a torsion spring that urges the lever member 23 in the return direction. Reference numerals 26a and 26b are adjustment bolts and lock nuts that adjust and fix the tension of the brake cable 40, and reference numeral 27 is a bracket 27 that supports the adjustment bolts 26a and lock nuts 26b. The bracket 27 is fixed to and supported by a support piece 24 of the band brake 20 and a support piece 11a (see FIG. 4) integral with the chain stay 11 by bolts, nuts, and the like.

The adjustment bolt 26a has a length L3 in the front-rear direction that is about 5 mm longer than usual, and is set within a range of 8 to 12 mm. In particular, in the preferred example of this embodiment, the length is about 10 mm.
Further, the distance L4 from the fixing hole 27a of the bracket 27 to the center of the adjustment bolt 26a is set to be within a range of 18 to 22 mm, which is shorter by about 5 mm than usual, and in the preferred example of this embodiment, it is about 20 mm. Yes.
According to these configurations, on the front side of the adjusting bolt 26a, the brake cable 40 can be curved forward and upward with a relatively large bending radius after being linearly guided forward (see FIGS. 1 and 4). As a result, the outer wire of the brake cable 40 can be prevented from being broken.

A compression coil spring 28 is mounted between the lever member 23 and the bracket 27 to urge the lever member 23 toward the initial position. As the compression coil spring 28, one having a relatively small elasticity is used, and in the preferred example of the present embodiment, one having a wire diameter of about 0.8 mm is used.
As another example, the operation force of the brake lever 30 can be further reduced by omitting the compression coil spring 28.

  The brake lever 30 is attached to one end side in the left-right direction of the handle 1 (left end side in the illustrated example). The brake lever 30 is swung by a grip operation brought closer to the handle 1 and pulls the inner wire of the brake cable 40.

The brake cable 40 includes a long flexible cylindrical outer wire and a long flexible inner wire inserted into the outer wire. For these outer wire and inner wire, those having a relatively low frictional resistance are used.
The rear end side of the outer wire of the brake cable 40 is supported by the bracket 27 via the adjusting bolt 26a and the lock nut 26b described above.
Further, the rear end side of the inner wire is inserted through the adjusting bolt 26 a and the lock nut 26 b and connected to the power point P <b> 2 of the lever member 23. The front end side of the inner wire is connected to the base end side of the brake lever 30 (the side opposite to the swing end side).

  Next, the extension path of the brake cable 40 will be described in detail. As shown in FIG. 1, the brake cable 40 extends forward from the adjustment bolt 26a and the lock nut 26b, and has a large bending portion with a relatively large radius. 41 is bent obliquely forward and upward so as to pass through the through hole 14a (see FIG. 4) of the support bracket 14 and the insertion space 13a of the footrest 13 and guided to the down tube 12 side.

Further, the brake cable 40 is extended obliquely upward and forward along the lower half side of the down tube 12 in the radial direction. The plurality of locking portions 12a are locked at intervals.
As shown in FIG. 1, the brake cable 40 is bent so as to have a large curved portion 42 having a relatively large radius on the side opposite to the brake lever 30 side (the handle right-hand side). Connected to. More specifically, the end of the outer wire of the brake cable 40 is supported by a bracket or the like integrated with the handle 1, and the end of the inner wire of the brake cable 40 is fixed to the base end side of the brake lever 30. .

Next, the characteristic effect of the child bicycle A having the above configuration will be described in detail.
When a user such as a child pulls the brake lever 30 of the handle 1 toward the handle 1, the inner cable of the brake cable 40 is pulled, and the lever member 23 is rotated by the tensile force, and the band 22 is moved. It is possible to brake the drum 21 and the rear wheel shaft 3 and the like integrated with the drum 21 by elastically reducing the diameter and sliding the inner peripheral surface thereof to the drum 21.
In the above operation, the inner wire of the brake cable 40 slides with respect to the outer outer wire, but the sliding resistance is such that the upper large bent portion 42, the plurality of engaging portions 12a shifted in position, and the lower It is reduced by the large music part 41 or the like.

In addition, the child bicycle A having the above-described configuration has an appropriate ratio of the lengths L1 and L2 of the first arm portion 23a and the second arm portion 23b of the lever member 23. The pulling force when pulling the power point P2 of the lever member 23 is relatively small.
Therefore, the force (grip strength) that pulls the brake lever 30 for braking can be made relatively small, and even when a young child or the like brakes, the brakes can be sufficiently applied with a good feeling of operation that is not too heavy. You can hang it.

  In addition, this invention is not limited to the embodiment mentioned above, In the range which does not change the summary of this invention, it can change suitably.

1: Handle 3: Rear wheel shaft 4: Rear hub 6: Front wheel shaft 10: Body frame 12: Down tube 12a: Locking portion 13a: Insertion space 20: Band brake 21: Drum 22: Band 23: Lever member 23a: First Arm part 23b: second arm part 24: support member 30: brake lever 40: brake cable A: bicycle for children L1, L2: length P1: action point part P2: force point part P3: fulcrum part

Claims (3)

A vehicle body frame that supports a handle and a front fork on the front end side and a rear wheel shaft on the rear end side, a band brake provided substantially concentrically with the rear wheel shaft, and a brake provided on one end side of the handle In a children's bicycle comprising a lever, a brake cable extending between the band brake and the brake lever, and transmitting traction force by the brake lever to the band brake by the brake cable,
The band brake includes a drum connected to a rear hub around a rear wheel shaft, a band provided around the drum, a lever member connected to the band, and a support that rotatably supports the lever member. And the band pulled by the lever member is configured to be in sliding contact with the drum,
The lever member has a first arm portion and a second arm portion bent with respect to the first arm portion, and an action point portion in which an end portion side of the first arm portion is connected to the band portion. And an end portion side of the second arm portion is a power point portion connected to the brake cable, and an intersection portion of the first arm portion and the second arm portion is a fulcrum portion pivotally supported by the support member, The ratio of the length from the fulcrum part to the force point part to the length from the action point part to the fulcrum part is in the range of 1: 1.6 to 1: 1.8. Bicycle for children.   The vehicle body frame is fixed to a chain stay extending forward from a support portion of the rear wheel shaft, a down tube extending obliquely upward and forward from a front end side of the chain stay, and a front end side of the chain stay. The child bicycle according to claim 1, further comprising a footrest portion, wherein the brake cable is guided to the down tube side through the footrest portion.   The down tube is provided with a plurality of locking portions for fastening the outer cable at intervals in the front-rear direction, and the plurality of locking portions move to the opposite side of the brake lever as moving forward. The child bicycle according to claim 2, wherein the circumferential position is shifted.

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