Abstract: Outer plates have a doughnut-like disk shape and are attached to the inner circumferential surface of a case member. On the other hand, inner plates have a substantially arc shape and are swingably supported about a position at a distance from the center of rotation of a shaft. The inner plates are held at a first position, at which the interlocking area between the outer plates and the inner plates is small, by a tension coil spring when the relative rotational speed between the case member and the shaft is small, and, when the relative rotational speed between the case member and the shaft exceeds a predetermined value are pivotally moved toward the outer plates by the shearing force of a viscous fluid and held at a second position at which the interlocking area between the movable plates and the first plates is large.

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 101a. A brake shoe 23 rotates around a rotary shaft 20 of the wheel 101c, and reduces the rotation speed of the wheel 101c 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 101c 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 101c 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.

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 101a. A brake shoe 23 rotates around a rotary shaft 20 of the wheel 101c, and reduces the rotation speed of the wheel 101c 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 101c 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 101c 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.