Bend detector for a pipeline pig

A bend detector for use on a pipeline pig assembly comprising a front pig element and a rear pig element pivotally connected to the front pig element by the bend detector; the front pig element having a longitudinally disposed housing with a forward drive cup for driving the assembly by the flow of a fluid through a pipeline system, the rear pig element having a longitudinally disposed housing axially supported in the pipeline, a plurality of odometer wheels radially affixed to the housing of the rear pig element for determining the distance traversed by the assembly through the pipeline system; the bend detector comprising a universal joint having a pair of yoke members pivotally connected to a central member about a pair of mutually perpendicular axes, each of the yoke members having a yoke and a collar, mounting plates for attaching the collars to the front pig element and the rear pig element, respectively, the central member being bored out for receiving a longitudinal hollow sleeve and a central opening in each of the collars thereby forming an axially aligned passageway with the hollow sleeve, a cable received in the passageway and having its rear end anchored to the rear mounting plate, the forward end of the cable being connected to an actuator shaft, the actuator shaft being connected to a stylus for recording a bend along the pipeline system, whereby traversing a bend causes the front pig element to pivot with respect to the rear pig element thereby exerting a pull on the cable causing the actuator shaft to move longitudinally rearward.