(57) A ladder capable of preventing an accident from being caused due to the weakened
combining force between beams and hinges while a user uses the ladder to perform work,
and capable of preventing the beams and the steps from being released from each other.
The ladder includes two pairs of beams (1,1' and 2,2')engaged with each other by hinge
means (H,H' ) , and a plurality of steps(S) disposed between the beams (1,1',2,2')
at the same distance interval. Both ends of the steps(S) are inserted into holes (100)
which are formed at one side surfaces of the beams (1,1',2,2')and have the same cross
sectional shape with that of the steps(S) and a predetermined size adapted to receive
the ends of the steps (1,1',2,2'). Both ends of the steps(S) are enlarged due to the
striking force applied by a punch (102) and are engaged with the beams (1,1',2,2')under
the state that rounded ends of the steps(S) are formed from the outer side surfaces
of the beams (1,1',2,2')to inner side surfaces of the beams (1,1',2,2') due to the
striking force applied by the punch (102) and the rounded ends are brought into contact
with the ends of the steps(S).
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