Module 7 : Bigger & Smaller
  Lecture 25 : Scissors- Fulcrum & Lever, Handed Scissors, Mechanism of cutting, the cross blade scissors-three parts

 

 

Squeezers (plate 42A) are a breakthrough in cutting technology. Although "cutting" is the wrong term. The early scissors were called as sears, which correctly describes how they work.

http://t3.gstatic.com/images?q=tbn:ANd9GcR5iUnHLiTb-bwq3MoAi4tvTmfr5nFn7Fo9wRSrs9658-PjpoRi9A
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Plate 42A Squeezer Scissors
42B Children’s Scissors 
42C Pivoted Squeezer Scissors

(Source:http://www.google.co.in/search?hl=en&q=scissors+mechanism&bav=on.2,or.r_gc.r_pw
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GBonqrQf6oCICw#um=1&hl=en&biw=1332&bih=581&tbm=isch&sa=X&ei=St1KULGVHoHIrQfEu
oDQBA&ved=0CEMQvwUoAQ&q=Squeeze+Scissors&spell=1&bav=on.2,or.r_gc.r_pw.r_qf.&fp=
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; Sept. 8, 2012)

Squeezers work in the same way as ordinary scissors - but with some important improvements in design - as we will see. Two separate blades, set at a slight angle to each other (plate 42A), are moved against one another simultaneously under pressure. As one blade moves over the other, the pressure of the sharpened metal is pressed against metal shears the material that comes between the blades. The pressure that forces the two blades together is transmitted through a rivet or screw (plate 42C) that bolts the blades together back at the pivot. Commonly the pivoted scissors are used for the children for the safety reasons.