FR2588632A1 - Device for the mechanical transmission and control of a rotating shaft - Google Patents

Abstract

The invention relates to a device making it possible to transmit and automatically to vary a rotary drive power by mechanical control. It consists at least of two pulleys 1 and 2 driven by a cable 3 making, at least, a round turn round the two pulleys and whose returning thread is gripped to a small extent by a disengageable tensioner 4. The device according to the invention is particularly intended for engine transmissions.

Description

 The object of the present invention is the production of gear ratios or multiplications (fixed or variable) of a rotary movement.

 The achievements in this area are known: pinions, flat, trapezoidal, or notched belts.

 The device according to the invention is distinguished from these embodiments by the fact that instead of having only a punctual mechanical contact (pinions) or sectoral (belts) the transmission force is applied over the entire perimeter of the component pulleys the transmission.

 In effect, the connection between the pulleys is carried out by a cable of circular section making at least one dead turn around the driving and receiving pulleys. The direction of winding of the cable is such that the traction and return strands are parallel. cable tensioning device, such as a bicycle chain derailleur, for example, allows, with reduced effort, to engage the two pulleys together by garrot effect. To amplify this effect, the peripheral surface of the pulleys will be dug, either in diabolo , or in a hollow of curved shape; this according to the number of dead turns made by the cable around the pulleys.

The cable retention device also serves, in principle, to disengage the system. According to one form of the invention, the driving pulley can have a certain elasticity in the radial direction, allowing it, depending on the engine torque applied, to uniformly reduce its diameter under
tourniquet of the soue cable; voltage.

 Figure; l shows a device according to the invention, with rotation of the axes of the pulleys of the leading direction, or, of opposite direction.

 Figure 2 shows the winding of the transmission cable with a dead turn.

 FIG. 3 represents a device for continuously varying the torque-speed ratio, in accordance with the invention, automatic and manual.

The device shown in Figure 1 comprises a receiving pulley (l), a driving pulley (2), connected by a cable (3) of circular section making at least one dead turn tight at the bottom of the groove of each pulley, while keeping its strands parallel round trip.

The transmission cable (3) is held in slight tension on the return strand by a device (4) comprising, for example, an arm pivoting about an axis, and, carrying at its other end a caster pressing on the cable return strand. The tension of the cable tensioner can be given by an elastic device, by an electromagnet, hydraulically, etc. In accordance with the invention, the devices mentioned above can be used to remove the retention on the cable.

 Figure (3) shows an exemplary embodiment according to the invention of a drive pulley for continuously varying the torque-speed ratio, automatically, and manually. On a shaft (5) is firmly a flange (6 ); a flange (7), free around a sleeve (l0) sliding on the shaft (5) is linked to the flange (6) by free rods (8) (ball joints for example) at their ends, therefore permitting the assembly (6, 7,8) to take the form of a cylinder or a diabolo, therefore to vary greatly its useful diameter of the driving pulley.

The sliding sleeve (10) has a flange (ll) supporting the thrust of a spring (9), and, a flange (12) by or is exerted thanks to a thrust ball bearing (for example) manual adjustment by near the spring (9); at the resistance near the spring (8), the tension of the cable (3) tends to cause the whole (6,7,8) to take the shape of the diabolo.

 By placing on the same motor axes, and, receiving the two devices of FIG. (L), a system of reversal of direction of rotation is produced: extremely rapid, controlled by the tensioners (4); a pressure measuring device (piezoelectric for example) will allow knowing the exact moment of the release of the tension of the tensioner (4) to save more time; this sensor will be placed at the level of the tensioner roller (4).

 The devices according to the invention are particularly tinesltoutes rotary transmissions in particular the propulsion automobile, bicycle-motorist, nautical (catching up of the recoil of the propeller of a boat in progress), with the machine tools (back and forth with fast pass ), and, quick control of the control surface.

Claims (5)

 l (Device carrying out a reduction or inverting between a rotary motor shaft and a rotary receiving shaft ca acted in that it comprises, at least, a driving pulley (2) with hollow groove, a receiving pulley (l) also hollow groove, a transmission cable (3) of circular section making at least one dead turn around the two pulleys and whose pulling and turning strands are offset but parallel. A tensioner (4), controllable, acting on the turning strand of the cable allows the device to be engaged and disengaged.  2) Device according to claim 1 characterized in that the drive pulley (2) may have a certain elasticity in the radial direction;  3) Device according to claim 1 characterized in that the drive pulley (2) consists of a shaft (5) carrying a fixed flange (6), a free flange (7) on (5), (6) and (7) being linked by rods (8) with free movement at their ends, and, kept apart by an elastic device (and) or controllable. The rods serve as a variable groove for the cable (3).  4) Device according to one of the preceding claims characterized in that the tensioner (4) can be controlled by the drive motor according to one of its characteristics (speed, consumption, etc.)  5) Device according to claims 1,3, and, 4 characterized in that the variabe pulley (5,6,7,8 ...) is with variations in diameter auto mastic and controllable at the same time, which allows to control the motor output no longer by the power supply, but mechanically.