the metal carriage bar 33 it comprises spaced parallel branches 57 with one such branch extending directly above and along each row of the feeler pin extensions 41 hence whenever one or more of the pins 38 in any row of pins rises due to contact with a foreign object 50 fig8 the extension 41 or extensions will engage one of the strands or branches 57 of grounding stop motion wire 54 as shown schematically in fig9 the wire 54 is connected with a suitable circuit interrupter 58 forming a component of a conventional stop motion circuit 59 whenever contact between the wire 54 and one or more of the pin extensions 51 occurs the stop motion circuit will be broken and the operation of the card feed roll 21 and doffer 24 will be stopped when stopped the operator can observe through the transparent plate 49 which feeler pin or pins are elevated due to contact with an object 50 and the operator will then manually handle the lap 26 and remove the foreign object before restarting the card by utilizing a preferably key operated reset switch in the stop motion circuit the exact configuration of the circuitry can vary considerably within the state of the art and the details of circuitry are believed to be unimportant and unnecessary to disclose for a proper understanding of.