An aircraft engine thrust reverser lock system comprising: a pin-capturing member comprising a body that is rotatable about a rotational axis, the rotational axis being defined by a pivot that extends through the body, the body including: an interior surface that defines a slot, the interior surface defining first and second fixed, opposing slot sides (152, 154) between an open end of the slot and a closed end of the slot, an opening between the first and second slot sides (152, 154) at the open end of the slot being sized to receive a pin into the slot; the first slot side including: an end wall surface that extends from the open end of the slot and faces the rotational axis; a first sidewall surface that extends from the end wall surface toward the closed end of the slot; and the second slot side including a protruded sidewall surface that protrudes into the slot toward the first sidewall surface and defines an apex between the open and closed ends of the slot, the protruded sidewall surface facing the end wall between the apex and the open end of the slot, the protruded sidewall surface facing the rotational axis between the apex and the closed end of the slot, characterized in that the protruded sidewall surface includes a first sloped side that faces the rotational axis and a second sloped side that faces away from the rotational axis, and the first and second sloped sides of the protruded sidewall (211, 205) define an acute angle with respect to the apex. a pin-capturing member comprising a body that is rotatable about a rotational axis, the rotational axis being defined by a pivot that extends through the body, the body including: an interior surface that defines a slot, the interior surface defining first and second fixed, opposing slot sides (152, 154) between an open end of the slot and a closed end of the slot, an opening between the first and second slot sides (152, 154) at the open end of the slot being sized to receive a pin into the slot; the first slot side including: an end wall surface that extends from the open end of the slot and faces the rotational axis; a first sidewall surface that extends from the end wall surface toward the closed end of the slot; and the second slot side including a protruded sidewall surface that protrudes into the slot toward the first sidewall surface and defines an apex between the open and closed ends of the slot, the protruded sidewall surface facing the end wall between the apex and the open end of the slot, the protruded sidewall surface facing the rotational axis between the apex and the closed end of the slot, an interior surface that defines a slot, the interior surface defining first and second fixed, opposing slot sides (152, 154) between an open end of the slot and a closed end of the slot, an opening between the first and second slot sides (152, 154) at the open end of the slot being sized to receive a pin into the slot; the first slot side including: an end wall surface that extends from the open end of the slot and faces the rotational axis; a first sidewall surface that extends from the end wall surface toward the closed end of the slot; and an end wall surface that extends from the open end of the slot and faces the rotational axis; a first sidewall surface that extends from the end wall surface toward the closed end of the slot; and the second slot side including a protruded sidewall surface that protrudes into the slot toward the first sidewall surface and defines an apex between the open and closed ends of the slot, the protruded sidewall surface facing the end wall between the apex and the open end of the slot, the protruded sidewall surface facing the rotational axis between the apex and the closed end of the slot, characterized in that the protruded sidewall surface includes a first sloped side that faces the rotational axis and a second sloped side that faces away from the rotational axis, and the first and second sloped sides of the protruded sidewall (211, 205) define an acute angle with respect to the apex.