Arrangement for raising and lowering a vertically suspended unit

An arrangement for vertically raising and lowering a unit suspended from a support, the arrangement comprising:

• a retractable member having at least two ends and at least three interconnected lazy tongs linkages having each interconnected rodlike elements, said lazy tongs linkages forming angles at said interconections, said elements having apertures, two outer apertures being spaced a predetermined distance from each other and at least one intermediate aperture being symmetrically disposed between said outer apertures, and pivot means in said outer and intermediate apertures for connecting said lazy tongs linkages to each other at said pivot means,
• an attachment connected to one of said retractable member ends and to the support,
• another attachment connected to the other end of said retractable member and to the unit,
• connectors pivotally secured at said angles formed between each two interconnected lazy tongs linkages, thereby interconnecting at least three lazy tongs linkages to form said retractable member,
• means for retracting and extending the unit, said retraction and extension means being provided at each of said retractable member ends and in both of said respective attachments, blocks having bores formed therein, and shafts received in said respective bore members,
• whereby said shafts extend towards the center of said respective attachments.