Description of
parameters for extension springs with english hooks
Physical parameters
- d
(wire diameter): This parameter
describes the diameter of wire used as material for spring.
- De
(external diameter): External
diameter of a spring concerns both hooks and coils. Tolerance for this
parameter is (+-)2%(indicative).
- H
(Hole): This is minimum
diameter of hole in which spring can work. Tolerance for this parameter is
(+-)2%(indicative).
- Ln
(Maximum length): Maximum
acceptable extension length for a spring. It is also the maximum extension
for static applications. Tolerance for this parameter is
(+-)15%(indicative).
- Fn
(Maximal force): Maximal
acceptable force which can operate on a spring. It is also the maximum
force for static applications. Tolerance for this parameter is
(+-)15%(indicative).
- L0
(free length): Free length is
measured in spring's free state. Tolerance for this parameter is
(+-)2%(indicative).
- Nr
of coils: This is a total
number of coils in a spring - in the picture above it is equal to six.
- R
(Spring rate): This parameter
determines spring's resistance, while it is working. It is measured in 1
DaN/mm = 10 N/mm. Tolerance for this parameter is (+-)15%(indicative).
- L1
& F1 (length under charge F): The charge F1 at length L1 can
be calculated using the equation : F1 = Fn -
R(Ln-L1).
Equation derived from the previous for calculating L1 = Ln -
(Fn-F1)/R.
- Hooks: Extension
springs with English hooks have both hooks closed forming a ring. Both
hooks lie in the same plane.