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The programme examines some basic linkage mechanisms, the four bar linkage and the slider crank, and how these can be combined to produce more complex mechanisms.
Metadata describing this Open University video programme
Module code and title: T232, Engineering mechanics: solids
Item code: T232; 01
First transmission date: 02-03-1980
Published: 1980
Rights Statement:
Restrictions on use:
Duration: 00:24:00
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Producer: Martin Wright
Contributors: Tony Bright; Dudley Thompson
Publisher: BBC Open University
Keyword(s): Linkage mechanisms; Nodding donkey; Oil pumping rig; Slider crank mechanisms
Footage description: Film shots, in Dorset, of a 'nodding donkey', a pump which pumps oil from under the ground to the surface. Tony Bright, standing next to the pump introduces the programme. He looks at its component parts and explains their function, looking in detail at the individual links of the mechanism. Dudley Thompson looks at some simple examples of linkage mechanisms; two sponge mops, one of which is squeezed by slider crank mechanism and the other by four bar linkage. Animated diagrams and simple models of the linkages are used as aids. Tony Bright looks at a common application of a slider crank mechanism, the reciprocating internal combustion engine. An animation of the slider crank mechanism (Piston, connecting rod and crankshaft) is superimposed over an actual engine in operation. Bright goes on, with the aid of a working linkage model, to look at another application of linkages in a car, the windscreen wiper mechanism. He points out that this is a four bar linkage. Using animated line diagrams, Tony Bright looks at some of the other possible configurations of a four bar linkage. The behaviour of any four bar assembly, he explains, depends on which links are chosen as the fixed links. He goes on to do the same for the slider crank linkage. Bright and Dudley Thompson examine a typewriter in order to show how complex linkage mechanisms can be obtained from a combination of simple four bar and slider crank linkages. A simplified working model of the typewriter letter arm movement is used to illustrate the points made in the commentary. Dudley Thompson dons a similar analysis for the "nodding donkey" linkages. An animation showing the various simple linkage components is superimposed over film of the 'nodding donkey' at work. Tony Bright sums up the programme. Film of various linkage configurations in operation.
Master spool number: HOU3370
Production number: FOUT062D
Videofinder number: 1963
Available to public: no