| CPC A61B 34/71 (2016.02) [A61B 34/70 (2016.02); B25J 1/02 (2013.01); B25J 9/10 (2013.01)] | 11 Claims |
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1. A bending mechanism comprising:
an elongated support member extending along a longitudinal axis;
a swivel that is pivotably connected to a distal end of the support member so as to be pivotable about an axis intersecting the longitudinal axis of the support member;
a handle configured to be operated to pivot the swivel with respect to the support member by a pivoting angle determined in accordance with an amount of operation on the handle;
a first link and a second link disposed opposite to the first link along the longitudinal axis of the support member, the first and second links each being coupled at a respective proximal end to the handle and being configured to transmit a driving force received from the handle to pivot the swivel with respect to the support member; and
a connector that is provided on at least one of the first and second links, and includes a groove cam that has a guide groove, an engagement part of the at least one of the first and second links being engaged with the guide groove of the groove cam in a direction of the longitudinal axis, an engagement position between the guide groove and the engagement part being configured to be moved in the direction of the longitudinal axis in accordance with the amount of operation on the handle,
wherein the connector is configured to switch one of the first and second links from a first coupled state to a second coupled state when the pivoting angle of the swivel exceeds a threshold such that a permissible stress of the one of the first and second links becomes less than a permissible stress of the other of the first and second links.
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