초록 ▼

A variable ratio drive pulley, of the type employed in snowmobiles to transmit a drive from the snowmobile engine via a belt transmission to the snowmobile track, has a fixed flanged and an opposed movable flange which co-operate to drive the belt. The movable flange is spring loaded away from the f

A variable ratio drive pulley, of the type employed in snowmobiles to transmit a drive from the snowmobile engine via a belt transmission to the snowmobile track, has a fixed flanged and an opposed movable flange which co-operate to drive the belt. The movable flange is spring loaded away from the fixed flange and centrifugal means are included to overcome the spring force and urge the movable flange towards the fixed flange with a force that increases with the speed of rotation. The centrifugal means comprises a number of pivoted levers each having a roller cooperating with a ramp, and the pulley includes means whereby the position of the ramp can be rapidly adjusted without disassembly of the drive pulley, to vary the response of the drive pulley to different operating conditions.

대표청구항 ▼

A variable ratio drive pulley comprising: two opposed frusto-conical flanges arranged co-axially with respect to a drive shaft to rotate therewith and impart a variable ratio drive to a transmission belt arranged between the flanges; one said flange comprising a fixed flange that is fixed axially re

A variable ratio drive pulley comprising: two opposed frusto-conical flanges arranged co-axially with respect to a drive shaft to rotate therewith and impart a variable ratio drive to a transmission belt arranged between the flanges; one said flange comprising a fixed flange that is fixed axially relative to said shaft, and the other said flange being a movable flange that is movable axially of said shaft towards and away from said fixed flange; biassing means operatively arranged between said shaft and said movable flange to urge the latter axially away from said fixed flange; and centrifugal means acting between said movable flange and a part fixed relative to said shaft and responsive to rotation of said drive pulley to generate an axial thrust on said movable flange urging it towards said fixed flange, such axial thrust increasing with the speed of rotation until it reaches a value sufficient to overcome the force of said biassing means and displace said movable flange axially towards said fixed flange said centrifugal means being located within a casing defined by said movable flange and a cup enclosing the rear side of said movable flange; wherein said pulley includes adjustment means engaging said centrifugal means and selectively settable to vary the axial thrust response characteristics of the pulley, said adjustment means being accessible for adjustment from the exterior of said casing.