Patent ID: 7172523
Filing Date: 2007-02-06
Classification: F16H

Abstract:
1. An automatic mechanically controlled continuously-variable-ratio drive ( 1 ), comprising an input shaft ( 2 ); a flywheel ( 10 ) integral with the input shaft; a drive assembly ( 5 ) idle with respect to the input shaft ( 2 ) and having a drive pulley ( 6 ) defined by two half-pulleys ( 6 a , 6 b ) defining a groove ( 8 ) of variable size for a V belt (C); friction clutch means ( 32 ) interposed between at least one of said half-pulleys ( 6 a , 6 b ) and said flywheel ( 10 ); and a centrifugal control assembly ( 36 ) a centrifugal actuating device ( 42 ) controlling said clutch means ( 32 and a centrifugal speed adjusting device ( 43 ) for adjusting the size of the groove ( 8 ) of the drive pulley ( 6 ) in response to variations in the speed of said input shaft ( 2 ); said centrifugal actuating device ( 42 ) including a number of auxiliary centrifugal weights ( 45 ) connected in a rotationally rigid manner to said inout shaft ( 2 ), and controlling said clutch means ( 32 ) so as to set said clutch means ( 32 ) to a torque transmission condition in response to an angular speed value of said inout shaft ( 2 ) above a first threshold value and connect said drive pulley ( 6 ) angularly to said flywheel ( 10 ); said speed adjusting device ( 43 ) including a number of main centrifugal weights ( 68 ) controlling the size of the groove ( 8 ) of the drive pulley ( 6 ) and active over a second threshold value of the angular speed of the input shaft ( 2 ) higher than said first threshold value.