Variable diameter centrifugal pulley with means to vary the mass of centrifugal weights

Claim 2

A centrifugal weight for use in a variable diameter centrifugally operated pulley, comprising a block of elongated shape having substantially parallel flat lateral surfaces, a top surface, a bottom surface, and inclined end surfaces converging towards said top surface, said block having a cavity made therein and opening at one of said top and bottom surfaces and a closure for removably closing said cavity, said cavity adapted to receive calibrating weight elements.

Claim 3

A centrifugal weight as claimed in claim 1, wherEin said cavity is of cylindrical shape and is inwardly threaded from its open end to its bottom, said closure being an externally threaded disk like plug screwed within said cavity and adapted to tightly hold the calibrating weight elements against the bottom of said cavity.

Claim 4

A centrifugal weight as claimed in claim 1, wherein said end faces are each provided with a pair of spaced, raised elongated lands extending between said top and bottom surfaces and conforming to a frusto-conical concave surface of revolution with its axis parallel to the long axis of the block.

Claim 5

A centrifugal weight as claimed in claim 1, wherein said top surface is transversely convex and said bottom surface is transversely concave, the radius of curvature of the top surface being greater than the radius of curvature of the bottom surface.

Claim 6

A centrifugal weight as claimed in claim 2, wherein said disk like plug is provided with an elongated hole for receiving the blade of a screwdriver for screwing and unscrewing said plug. 6 A variable diameter pulley for a V-transmission belt comprising a shaft portion, a first pulley flange secured to said shaft portion, a circular member secured to said shaft portion and spaced from said first pulley flange, a second pulley flange mounted on said shaft portion for axial movement towards and away from said first pulley flange and located between the latter and said circular member, spring means urging said second pulley flange away from said first pulley flange, said circular member and second pulley flange forming opposed surfaces of revolution, at least one of said surfaces inclined relative to the longitudinal axis of said shaft portion radially outwardly towards the other of said surfaces, centrifugal blocks extending between and having their end faces in slidable contact with said opposed surfaces, radial guide means on both said surfaces guiding said blocks for radial movement under centrifugal force to move said second pulley flange towards said first pulley flange against the action of said spring means, each centrifugal block having a cavity made therein and each having a removable closure for said cavity, said cavity adapted to receive a variable number of calibrating weight elements.

Claim 7

A variable diameter pulley as claimed in claim 6, wherein said cavity is of cylindrical shape and is inwardly threaded from its opened end towards its bottom, said closure is an externally threaded disk like plug element adapted to be screwed within said cavity down to its bottom so as to hold said weight elements against movement within said cavity.

Claim 8

A variable diameter pulley as claimed in claim 7, wherein said centrifugal blocks have an elongated shape, a radially outer face, a radially inner face and end faces converging towards said radially outer face, said cavity opening at said radially inner face of said block.

Claim 9

A variable diameter pulley as claimed in claim 6, wherein both said surfaces are concave and substantially frusto-conical in shape and are substantially equally radially outwardly converging, said blocks being movable outwardly between a radially innermost and a radially outermost position, being of elongated shape with transversely curved inclined end faces conforming to said frusto-conical surfaces in the innermost position of said blocks.

Claim 10

A variable diameter pulley as claimed in claim 6, wherein said second pulley flange is rotatably as well as axially movable on said shaft portion, said blocks constituting means to drive said second pulley flange at the same rotational speed as said first pulley flange due to the interengagement of said blocks with the guide means of both said surfaces.

Claim 11

A variable diameter pulley as claimed in claim 10, wherein said cavity is of cylindrical shape and is inwardly threaded from its opened end towards its bottom, said closure is an externally threaded disk like plug element adapted to be screwed within said cavity down to its bottom so as to hold said weight elements against movemEnt within said cavity.

Claim 12

A variable diameter pulley as claimed in claim 6, wherein said second pulley flange comprises two sections secured together, one section constituting a pulley flange proper and the other section of annular shape when seen in plan view and of right angular section with its radially inner edge secured to said pulley flange proper at the radially inner edge of the latter and its radially outer edge secured to the periphery of said pulley flange proper, said other section reinforcing said pulley flange proper and providing said surface for slidably receiving one end of said centrifugal blocks.

Claim 13

A variable diameter pulley as claimed in claim 12, wherein said spring means is a compression coil spring and its resistance to shortening is a non linear function of the amount of shortening.

Claim 14

In a centrifugally operated variable diameter pulley having a fixed pulley flange, an axially movable pulley flange movable between first and second limit positions adjacent to and spaced from said first pulley flange respectively, spring means urging said movable pulley flange away from said fixed pulley flange, and centrifugally operated means acting on said movable pulley flange to urge the latter towards said fixed pulley flange against the action of said spring means, said spring means opposing the action of said centrifugally operated means with a force which increases at a greater rate when said movable pulley flange approaches said first limit position than when said movable pulley flange leaves said second limit position.

Claim 15

In a centrifugally operated variable diameter pulley having a fixed pulley flange, an axially movable pulley flange movable between first and second limit positions adjacent to and spaced from said first pulley flange respectively, spring means urging said movable pulley flange away from said fixed pulley flange, and centrifugally operated means acting on said movable pulley flange to urge the latter towards said fixed pulley flange against the action of said spring means, said spring means opposing the action of said centrifugally operated means with a force which increases at a greater rate when said movable pulley flange approaches said first limit position than when said movable pulley flange leaves said second limit position.