 Leading the world in
energy absorption

# Industrial

### Vertical Impact Design mass for buffer Ep = Mg(H+S) Maximum impact force Design mass for buffer or Initial Plunger Velocity Multiple Mass Case: Potential energy to be absorbed Maximum impact force Ep = M1g (H+S) + M2gS Maximum impact force Initial Plunger Velocity Buffer design Mass #### Summary of notation

To avoid confusing conventions within calculations always use SI units in formulae then convert to more appropriate units if required.

 Notation Quantity SI Unit M Mass of body kg M Mass of body kg M Mass of body kg Me Buffer design mass kg Me Freefall height m S Buffer stroke m Ep Potential energy J v Velocity m/s F Maximum Impact force N m/s2 Acceleration due to gravity g n Number of buffers in parallel - ξ Efficiency -

#### Worked example

Eg. Consider a body of mass (M1) = 22000kg (22 tonnes) / free falling onto another body of mass (M2) 3000kg (3 tonnes) supported by a buffer.The free fall height (H) being 0.15m. A typical example of this being in catch gear buffers for mine cages where 4 Type 4-114mm stroke buffers are used; this is a multiple mass case.

To find the equivalent energy absorbed:
Ep = M1 g (H+S) + M2 g S = (22000).(0.15+0.114) x 9.81 + 3000 x 9.81 x 0.114 = 60331.5J = 60.3315kJ

To find the maximum impact end force:

F = 661529.6N = 661.5296 kN

To find the equivalent mass for metering pin selection:
Initial plunger velocity

By selecting a Type 4 buffer with a dynamic capacity of 1000 kN these requirements are met.Therefore select metering pin code 05 for masses up to 20000kg (20 tonnes).