Block and Tackle: Difference between revisions

Latest revision as of 16:09, 3 September 2016

Description

A Block and Tackle comprises a number of pulleys grouped together in blocks or ‘sheaves’ such that one block is fixed and the other is made moveable by means of a single continuous rope, or similar, threaded around them. In this configuration, the load is shared between the number of ropes threaded between the two blocks.

Features and Applications

In the Block and Tackle shown there appears to be 3 ropes on each side joining the two blocks together and so its Mechanical Advantage would be 6 - i.e. pulling down on the rope with a force of 100kg would enable a load of 600kg to be lifted (assuming there are no losses due to friction).

Animations

Examples from Nguyen Duc Thang's YouTube Channel 2100 Animated Mechanical Mechanisms

Lifting Tackle - Mechanical Advantage = 4 (number of the cable branches that suspend the weight or twice number of movable pulleys)

Using a series of pulleys - Mechanical Advantage = 8 (each pulley halves the load).

DT Online Buyers' Guide


Panel Gripper	Door and Board Lifter	Sack Trolley	Lifting Tongs	Drywall Board Hoist	Engine Hoist	Block and Tackle	Chain Block Hoist	Hand Wire Winch

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 | [https://youtu.be/MLWs-9-HqqU '''Lifting Tackle'''] - '''[[Mechanical Advantage]]''' = 4 ''(number of the cable branches that suspend the weight or twice number of movable pulleys)''
-| {{#ev:youtube|MLWs-9-HqqU|200x200|right||frame|loop=1&autoplay=1&playlist=MLWs-9-HqqU}}
+| {{#ev:youtube|MLWs-9-HqqU|150x150|right||frame|loop=1&autoplay=0&playlist=MLWs-9-HqqU}}
 | [https://youtu.be/Zgg0qqGG7NU '''Using a series of pulleys'''] - '''[[Mechanical Advantage]]''' = 8 ''(each pulley halves the load)''.
-| {{#ev:youtube|Zgg0qqGG7NU|200x200|right||frame|loop=1&autoplay=1&playlist=Zgg0qqGG7NU}}
+| {{#ev:youtube|Zgg0qqGG7NU|150x150|right||frame|loop=1&autoplay=0&playlist=Zgg0qqGG7NU}}
 |}