Vehicle speed control device and vehicle equipped with vehicle speed control device

Patent metadata

Field	Value
Publication number	US-9744949-B2
Application number	US-201214346702-A
Country	US
Kind code	B2
Filing date	Sep 13, 2012
Priority date	Sep 27, 2011
Publication date	Aug 29, 2017
Grant date	Aug 29, 2017

Abstract

Provided is a vehicle speed control device with respect to which the speed at which a centrifugal brake operates can be easily changed from the outside without disassembling the device. A brake drum 11 is fixed to a vehicle body 101 a . A brake shoe 23 rotates around a rotary shaft 20 of the wheel 101 c , and reduces the rotation speed of the wheel 101 c as a result of coming into contact with an inner circumferential side face of the brake drum 11 . A spring 24 prevents contact between the brake drum 11 and the brake shoe 23 when the rotation speed of the wheel 101 c is lower than or equal to a predetermined speed, and permits contact between the brake drum 11 and the brake shoe 23 when the rotation speed of the wheel 101 c exceeds the predetermined speed. A position change mechanism 25 is installed within the brake drum 11 , and changes the position of an end of the spring 24 on one end side. A transmission mechanism 26 transmits a force that is input by an external operation to the position change mechanism 25 and drives the position change mechanism.

First claim

The invention claimed is:

1. A vehicle speed control device for a vehicle whose vehicle body moves due to a wheel rotatably attached to the vehicle body rotating as a result of a person manually pushing the vehicle body and is capable of controlling a speed of the vehicle, comprising:
a brake drum that has a tubular portion and is configured to be fixed to the vehicle body;
a brake shoe that rotates around a rotary shaft of the wheel and reduces a rotation speed of the wheel with friction by coming into contact with an inner circumferential side face of the brake drum;
an elastic member for preventing contact between the brake drum and the brake shoe when the rotation speed of the wheel is lower than or equal to a braking speed, and permitting contact between the brake drum and the brake shoe when the rotation speed of the wheel exceeds the braking speed;
a position change mechanism that is installed within the brake drum and changes a position of an end of the elastic member on one end side, wherein the change of the position of the end of the elastic member changes the braking speed; and
a transmission mechanism for transmitting a force that is input by an external operation to the position change mechanism and driving the position change mechanism,
wherein the position change mechanism has an elastic member position holding portion that holds the end of the elastic member on the one end side, and a drive portion for driving the elastic member position holding portion so as to change the position of the elastic member position holding portion that holds the end of the elastic member, with the force that is input from an outside and transmitted by the transmission mechanism, and
the position change mechanism has at least one of a rack-and-pinion mechanism, a link mechanism which comprises a link member rotatably connected to another link member or the elastic member position holding portion at an end of the link member, and a wedge-shaped mechanism with which the elastic member position holding portion is displaced as a result of opposed tapered faces sliding relative to each other.

2. The vehicle speed control device according to claim 1 ,
wherein the transmission mechanism has any one of:
an adjustment gear that is installed such that at least a part thereof is exposable to the outside, and transmits the force that is input from the outside, to the drive portion;
a plate portion that is installed such that at least a part thereof is exposable to the outside, and is provided as a plate-like portion that is installed so as to be integrated with, fixed to or in contact with the drive portion; and
an operating portion that is installed such that at least a part thereof is exposable to the outside, and is provided so as to be integrated with or fixed to a wedge-shaped member that is provided with one of the opposed tapered faces in the wedge-shaped mechanism.

3. The vehicle speed control device according to claim 1 ,
wherein at least one of the position change mechanism and the transmission mechanism has a positioning mechanism capable of positioning the end of the elastic member on the one end side by changing the position with respect to a plurality of predetermined positions.

4. The vehicle speed control device according to claim 3 ,
wherein the position change mechanism is configured as a wedge-shaped mechanism in which the elastic member position holding portion is displaced as a result of the opposed tapered faces sliding relative to each other,
the elastic member position holding portion includes an elastic member-side wedge-shaped member provided with one of the opposed tapered faces,
the drive portion includes a drive-side wedge-shaped member provided with the other of the opposed tapered faces, and
the positioning mechanism has a plurality of recessed portions provided in one of the tapered face of the elastic member-side wedge-shaped member and the tapered face of the drive-side wedge-shaped member, and a projecting portion that is provided in the other of the tapered face of the elastic member-side wedge-shaped member and the tapered face of the drive-side wedge-shaped member, and that is capable of being locked in the recessed portions.

5. The vehicle speed control device according to claim 3 ,
wherein
the transmission mechanism has a rotary plate portion that is installed such that at least a part thereof is exposable to the outside and is provided as a plate-like portion installed so as to be integrated with, fixed to or in contact with the drive portion, and the force is input to the rotary plate portion as a result of a rotating operation from the outside, and
the positioning mechanism has a through hole provided in the rotary plate portion, and a pin member that is installed in a state of passing through the through hole and is capable of being locked with respect to the through hole at a plurality of points of the through hole.

6. The vehicle speed control device according claim 1 ,
wherein the elastic member is provided as a compression spring for biasing the brake shoe with respect to the position change mechanism, in a compressed state.

7. The vehicle speed control device according to claim 1 , further comprising:
a planetary gear mechanism that is provided on a path through which rotation is transmitted from the wheel to the brake shoe, accelerates and transmits the rotation of the wheel.

8. The vehicle speed control device according to claim 7 ,
wherein the planetary gear mechanism has a sun gear, a planetary gear that rotates on an axis of the planetary gear and revolves around the sun gear while meshing with the sun gear, and a carrier that rotatably supports the planetary gear, and
the carrier is provided so as to be integrated with or fixed to a wheel structure portion of the wheel.

9. The vehicle speed control device according to claim 8 , wherein the sun gear comprises a first sun gear and a second sun gear, the planetary gear comprises a first planetary gear and a second planetary gear, and the carrier comprises a first carrier and a second carrier,
wherein the planetary gear mechanism includes:
a first-stage accelerating portion having the first sun gear, the first planetary gear, and the first carrier; and
a second-stage accelerating portion that has the second sun gear, the second planetary gear, and the second carrier, and accelerates and transmits rotation of the first-stage accelerating portion, and
the first carrier in the first-stage accelerating portion is provided so as to be integrated with or fixed to the wheel structure portion of the wheel, and the first sun gear in the first-stage accelerating portion and the second carrier in the second-stage accelerating portion are provided so as to be integrated with or fixed to each other.

10. The vehicle speed control device according to claim 1 ,
wherein a tire provided on an outer circumference of the wheel is installed concentrically with the brake drum.

11. The vehicle speed control device according to claim 1 , further comprising:
a cover that is detachably attached to the wheel on an outside in a vehicle width direction that is a width direction of the vehicle body, and covers a part of the wheel; and
an operation tool that is installed on the cover in an attachable and detachable manner on the inside in the vehicle width direction, and is used in an operation by which the force from the outside is input to the transmission mechanism.

12. The vehicle speed control device according to claim 1 ,
wherein in the position change mechanism having the wedge-shaped mechanism, the elastic member position holding portion includes an elastic member-side wedge-

Assignees

• Takezawa Yoshinori
• Matsuo Shinpei
• Taniguchi Naoya
• Katsumoto Satoshi
• Nabtesco Corp
• Acro Nainen Co Ltd

Inventors

• Takezawa Yoshinori
• Matsuo Shinpei
• Taniguchi Naoya
• Katsumoto Satoshi

Classifications

• A61H2003/046

  with braking means · CPC title

• F16D2121/14

  Mechanical · CPC title

• A61H3/04

  Wheeled walking aids for patients or disabled persons · CPC title

• F16D2125/64

  Levers · CPC title

• F16D59/00

  Self-acting brakes, e.g. coming into operation at a predetermined speed · CPC title