Patent ID: 7635245

Claim:
A transporting rail unit comprising: a rail guiding movement of an object; and a pair of link mechanisms respectively having first and second arms coupled to each other through a connecting pin, the first and second arms taking first and second bending attitudes, the first bending attitude establishing a first angle between the first and second arms around the connecting pin, the second bending attitude establishing a second angle larger than the first angle between the first and second arms around the connecting pin, a first joint between the first and second arms in one of the link mechanisms being opposed to a second joint between the first and second arms in other of the link mechanisms, wherein the link mechanisms each comprises: a first elastic member exhibiting an elasticity sufficient to distance the first and second arms from each other through a swinging movement around the connecting pin from the first angle to the second angle; a shaft member coupling the first arm to the rail for relative rotation around a rotation axis set in parallel with an axis of the connecting pin at a location spaced from the connecting pin by a first distance; a contact member configured to establish a point of action for receiving a force from the object, the point of action being distanced from the connecting pin by a second distance larger than the first distance; a restricting piece holding the first arm at a specific angular position around the rotation axis when the force acts on the point of action from a first location, the first location set outside first and second imaginary planes, the first arm located inside the first imaginary plane including an axis of the connecting pin and the point of action, the first and second arms located inside the second imaginary plane including the rotation axis and the point of action; a second elastic member allowing accumulation of an elastic repulsive force based on the relative rotation of the first arm around the rotation axis from the specific angular position when the force acts on the point of action from a second location set outside the first imaginary plane and inside the second imaginary plane; and a lock member holding the first arm at the specific angular position around the rotation axis when the force acts on the point of action from a third location set outside the first imaginary plane and inside the second imaginary plane, wherein the transporting rail unit further comprises a controlling mechanism connected to the lock member, the controlling mechanism configured to allow release of the first arm from the lock member in one of the link mechanism while the lock member holds the first arm at the specific angular position in other of the link mechanism.