Mechanisms are means of power transmission as well as motion transformers. A fourbar mechanism consists mainly of four planar links connected with four revolute joints. The input is usually given as rotary motion of a link and output can be obtained from the motion of another link or a coupler point. Straight line motion from a four bar linkages has been used in several ways as in a dwell mechanism and as a linkage to vehicle suspension. This paper studies the straight line motion obtained from planar four-bar mechanisms and optimizes the design to produce the maximized straight line portion of the coupler point curve. The equations of motion for four different four-bar mechanisms will be derived and dimensional requirements for these mechanisms will be obtained in order to produce the straight line motion. A numerical procedure will be studied and computer codes that generate the coupler curves will be presented. Following the numerical results study, a synthesis procedure will be given to help a designer in selecting the optimized straight line motion based on design criteria.

Library of Congress Subject Headings

Machinery, Kinematics of; Mechanical movements--Design

Publication Date


Document Type


Department, Program, or Center

Mechanical Engineering (KGCOE)


Berak, Nir

Advisor/Committee Member

Torok, Joseph

Advisor/Committee Member

Walter, Wayne


Note: imported from RIT’s Digital Media Library running on DSpace to RIT Scholar Works. Physical copy available through RIT's The Wallace Library at: TJ175.N38 1994


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