Abstract: An outer body has an axially extending through hole with a frusto-conical section thereof. An inner body is coaxially disposed in the outer body hole. The inner body has a frusto-conical end portion which is spacedly received in and spaced from the frusto-conical hole section of the outer body to define therebetween a frusto-conical space which acts as an air jet opening. The inner body has therein an axially extending through hole. A weft guiding body having therein an axially extending through hole for receiving therein a weft yarn is coaxially disposed in the inner body hole. The weft guiding body has an extension which projects from the apex of the frusto-conical end portion of the inner body and terminates at a position between the apex and the exit of outer body hole. The inner body is axially movable relative to the outer body, and the weft guiding body is axially movable relative to the inner body.

Abstract: Catch yarns are drawn between a pair of rotatable members which are mounted to be movable toward and away from another and yieldably urged to come together. Detecting means detects the relative movement between the pair of rotatable members and produce an alarm-signal when the relative movement of one rotatable member away from another reaches a predetermined increased value.The catch yarns in tensioned state are further utilized to hold the detecting means at a rest position thereof. The detecting means also produces an alarm-signal upon the breakage of the catch yarns.