CHAIN SAW Russian patent published in 2013 - IPC B27B17/14 

FIELD: process engineering.

SUBSTANCE: linear drive is arranged at chain saw case. Bus reciprocating relative to saw case is secured to chain saw case. Chain is stretched between chain saw case and bus. Linear drive comprises rotary shaft with section including external thread. Linear drive comprises linear driving element engaged with the bus and opening for rotary shaft threaded shaft to pass through. Said opening is shaped so that said linear driving element displaces between first and second positions in radial direction of said shaft. Internal thread is formed on hole inner surface to engage with rotary shaft external thread when linear driving element gets into first position. When said elements gets into second position internal and external threads are disengaged. Linear driving element comprises retaining unit to retain element in first position. Said retaining element comprises flexible element to displace linear driving element to first position. Flexible element retains linear driving element in first position by shifting linear driving element from rotary shaft to chain saw case outer side. Linear driving element displaces to second position by pressing to rotary shaft on chain saw case outer side.

EFFECT: higher accuracy of saw tension, simplified replacement.

3 cl, 10 dwg