PETRI 7 - SPRINGS

During the disassembly, I came across a lot of springs. Some of wich are realy tiny, what makes it hard to notice them in the first place.

The first kind is the tensile spring. These are used in a system that needs to be cocked, and eventually be returned to its original setting.

tensile spring in the film winding mechanism

tensile spring in the shutter mechanism

tensile spring in the indicator mechanism

Another kind is the torsion spring. These are normally connected by small screws and are located directly on the axis of the moving parts, or nearby.

I also calculated the spring rate of the two largest tensile springs.

Calculations:

-> Spring 1

k = F / u

u-normal : 10 mm

u-streched : 18 mm

F = 0,380 x 9,81 = 3,73 N

u-difference = 0,008 m

k = F / u = 466 N/m

-> Spring 2

k = F / u

u-normal : 8,5 mm

u-streched : 11 mm

F = 0,012 x 9,81 = 0,118 N

u-difference = 0,0025 m

k = F / u = 47 N/m