Whitworth quick return mechanism

The Whitworth quick return mechanism converts rotary motion into reciprocating motion, but unlike the crank and slider, the forward reciprocating motion is at a different rate than the backward stroke. At the bottom of the drive arm, the peg only has to move through a few degrees to sweep the arm from left to right, but it takes the remainder of the revolution to bring the arm back. This mechanism is most commonly seen as the drive for a shaping machine.

Four-bar mechanism

A four bar linkage or simply a 4-bar or four-bar is the simplest movable linkage. It consist of 4 rigid bodies (called bars or links), each attached to two others by single joints or pivots to form a closed loop.
If each joint is with with one rotational degree of freedom (i.e., it is a pivot), then the mechanism is usually planar, and the 4-bar is determinate if the positions of any two bodies are known (although there may be two solutions).

Simple lever mechanism

The lever magnifies force or velocity. It is often used to move heavy loads with less effort. In this notebook a simple lever actuated by a hydraulic cylinder is considered. The basic model of the lever is modified, to touch the workpiece modelled with changing radius of circle The mechanism is modelled with parameterized dimensions, that helps to evaluate different design alternatives easily.

Crank-Slider mechanism

Singularity Analysis

In this notebook the singularity analysis of the crank slider mechanism is considered. The mathematical model of this one looped mechanism is built in LinkageDesigner using the slider link as the driving part. It is well known, that if the slider is moved back and forth between its two extremity, the crank rotates continuously. This continuous rotation is attributed partly to the inertia of the crank, which is not taken into account in the kinematic model of the mechanism. In case of the "virtual crank-slider mechanism", therefore one has to substitute the physic with some methodology.

Simple Modell of the Hip Join

The hip joint is a simple spherical joint kinematic pair. Its a simplified model of the kinematics of the hip joint. The morphological data of bone geometries were collected with CT Scan. From this data the 3D polygon representation is builded. I have imported the models of the bone geometry from the VRML file (http://www.ulb.ac.be/project/vakhum/vrml/vrml.htm).
The center of the spherical joint is parametrized. By changing the parameter values one can reposition the "ThighBone" link w.r.t "HipSocket" link. LinkageDesigner can be used to "synthetise" linkages defined to describe the kinematic of the bones, to find for example the best placemet of the joint center, to match the movement of the bones to the measured values.