Warp detection system

In a loom in which warp threads are delivered to a weaving zone in a generally planar array in two interspersed groups via a leasing zone formed by a pair of lease rods with the threads in the respective groups winding over and under said rods to define a warp cross point intermediate said rods, an improved system for detecting loss of tension in individual warp threads due to breakage and the like, which comprises:

• means for creating a narrow beam of light passing across the warp array in proximity to one of its sides along a locus generally within the limits of said leasing zone, a rotatable fan blade on the other side of said warp array operable when rotated to generate a flow of air directed generally against the portion of the threads within said leasing zone to displace any relatively untensioned warp threads into the path of said light beam to instantaneously intercept said beam converging air flow-guides between said blade and said cross point for directing the air flow from said rotating blade toward said leasing zone, and light beam receiving means for detecting said instantaneous interception of said light beam due to said thread displacement and providing a control signal in response thereto.