Control lever system, particularly for vehicle brakes
AssigneeStart S.p.A. Studi Apparecchiature e Ricerche Tecniche
InventorOsvaldo Fasano
Life of this patent
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Abstract
A control lever mechanism which operates to provide a different mechanical advantage at different points in the range of movement of a main operating control member and in dependence on the force applied to, and the force of resistance to the movement of, the main control member is disclosed. The main control lever is pivoted to a fixed fulcrum and linked to a force transmission member by a second pivot forming a fulcrum which is movable along an arcuate path closer to or further away from the fixed fulcrum. When both the fixed fulcrum and the movable fulcrum lie on the same side of the line of action of the force transmission member a component of the applied force tends to move the movable fulcrum towards the fixed fulcrum to increase the mechanical advantage of the control lever.
Claims5
In a control lever mechanism of the type comprising:
- a control lever having a fixed end carried on a fixed fulcrum and a free end, said lever being turnable about said fixed fulcrum upon the application of a force to said free end thereof,
- a force transmission member linking said control lever with an element to be controlled, and
- pivotal connection means connecting said force transmission member to said control lever, said pivotal connection means forming a second fulcrum on said control lever,
- the improvement wherein,
- said second fulcrum is displaceable with respect to said control lever, there are provided:
- guide means for guiding the displacement of said second fulcrum along an arcuate path which brings it closer to or further away from said first fulcrum,
- resilient biasing means urging said second fulcrum along said arcuate path away from said first fulcrum, and
- limit stop means for limiting the movement of said second fulcrum along said arcuate path, and
- said guide means are positioned such that the centre of curvature of said arcuate path defined thereby lies on one side of the line of action of said force transmission member when said control lever is at one end of its range of pivotal movement about said first fulcrum, and on the other side of said line of action when said control lever is at the other end of its said range of movement, whereby the force exerted on said second fulcrum by said force transmission member in reaction to a force applied in one direction to said free end of said control lever urges said second fulcrum towards one end of said arcuate path when
- said control lever is at said one end of said range of movement and towards the other end of said arcuate path
- when said control lever is at said other end of said range of movement.
Dependencies are inferred from the claim text.