
Appendix
71
GLOBAL
INDUSTRIES, INC.
Drag Conveyors
10230011
2016-06-14
D
PIN PULL OFF OR PIN BREAKAGE
Another form of failure is the link pulling off the
pin as shown in the example at right. A typical
cause of this may be a bent attachment. Normally,
when a bar bends it will twist and bend the side
bar of the chain. If the attachment is only pulled
back and not twisted, then usually (1) chain has
jumped ahead of the other. An obstruction in the
sprocket may cause (1) chain to skip a tooth or
perhaps (1) sprocket key is sheared causing (1)
side of the chain to carry the load.
Pin pull off may also be caused by a pin head
being worn down leaving little resistance to the
failure.
Another form of failure is pin breakage. This is
very rare and is caused by brittle pins. Typically
this is caused by improper heat treating in the
manufacturing process or by the effects of
hydrogen within the load.
pin pull off
E
LAMINATION
Failure may also be caused by lamination.
Lamination is shown in the example at
right and is caused by a defect in the steel
manufacturing process.
cracked lamination