Bando Chemical Industries, Inc.

Yutaka Furukawa

Hirofumi Miyata

Hiroshi Matsuoka

Eiichiro Ikeda

Yoshihiro Akahoshi

In a continuous speed-shifting device in which a variable speed pulley mechanism and a planetary gear mechanism are combined with each other, respective cam mechanisms are provided on respective back sides of movable sheaves of variable speed pulleys of the variable speed pulley mechanism so as to move the sheaves toward and away from fixed sheaves of the variable speed pulleys, a linkage mechanism for linking both the cam mechanisms to each other is provided so that the diameters at which the belt is wound around both the pulleys are varied in a reverse direction to each other, the variable speed pulley mechanism is shifted in speed in such a manner that an output gear for supporting a pinion of the planetary gear mechanism is switched among a normal rotation state, a neutral state and a reverse rotation states with respect to a rotary shaft, the output gear is adjustable to the neutral state by a balance between the thrusts to the belt by both the pulleys, and the variable speed pulley mechanism serves as a circulating power channel at the forward state of the vehicle at which the use frequency is higher. Thus, the frequency with which large driving power is applied to the belt of the pulley mechanism is decreased so that the belt load is reduced, thereby readily obtaining the normal and reverse rotation states without a normal and reverse rotation mechanism.

Continuous speed-shifting device

The continuous speed-shifting device of the present invention is provided with the first, second and third rotary shafts, a differential gear mechanism having the first gear element connected to the third rotary shaft, a variable speed pulley mechanism which connects the second and the third rotary shafts speed-changeably by a belt, a driving power gear mechanism which connects the first rotary shaft to the second or the third gear element of the differential gear mechanism and a circulating power gear mechanism which connects the second rotary shaft to the third or the second gear element of the differential gear mechanism. According to switching of the advancing and the retreating, the first rotary shaft and the driving power gear mechanism or the second rotary shaft and the circulating power gear mechanism are connected or disconnected by the gear clutch. Large driving power transmitted from the first rotary shaft to the differential gear mechanism is passed through the gear mechanism but small circulating power returned to the first rotary shaft from the differential gear mechanism is always passed through the pulley mechanism. When the first rotary shaft and the driving power gear mechanism or the second rotary shaft and the circulating power gear mechanism are connected with each other by a gear clutch, rotation of the third rotary shaft is made zero to obtain a neutral state.

In a pulley type speed-shifting device with a belt trained between a pair of variable speed pulleys, a movable sheave of each pulley is driven by a cam mechanism. Each cam mechanism has a cylindrical cam arranged concentrically with a rotary shaft and a cam follower which is arranged concentrically with a rotary shaft and carries a rolling body which makes contact with the cam as it is rolling on a cam face. The movable sheave is driven in axial direction by either the cylindrical cam or the cam follower rotating around the rotary shaft and rotating relatively to the other. As the cam follower makes contact with the cam face through the medium of the rolling body, resistance is small and the transmission ratio can be shifted with light handling force.

Pulley type speed-shifting device

An automatic tension maintaining power transmission belt, a method of making the same and a method for maintaining tension in a rubber belt transmission. The belt is made by embedding polyester fiber cord employing a polyester of high relative viscosity and after being subjected to a hot stretching process as a tensile member in rubber forming the belt. The thermal contraction force of the polyester cord is to be substantially maintained by avoiding shrinkage of the belt during vulcanization. The belt of the present invention is characterized by exhibiting shrinkage of said polyester fiber cords through thermal contractive forces caused by frictional heat generated by slippage of the belt upon lowering of belt tension during belt running. The minimum tension necessary for transmission of power is recovered, the slippage is eliminated for a while and proper tension is maintained. Such automatic action repeats when it becomes needed again.

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Kobe, Japan

Yutaka Furukawa