Fluid operated web break detector assembly with switch actuator motion blocking means

Claim 1

In an apparatus which is to be mounted in proximity to a moving web for detecting breaks and voids in the web, and which is of the type that includes: A. an extended tube for receiving pressurized fluid, said tube having 1. a lateral orifice by which such fluid can be directed against one side of the web, and 2. an external part slidable along the tube so as either to cover the orifice or to leave it uncovered; B. a control structure to be positioned in facing relation to, but on the opposite side oF the web from said tube, said structure comprising 1. a deflectable part operable when deflected to actuate a switching element for stopping movement of the web, 2. a housing at least partially enclosing the deflectable part and having an opening directed toward the normal path of the web surfaces, 3. a cup-like member mounted on said deflectable part and movable when subjected to deflect the deflectable part, said member having a. its lateral wall portion projecting through said opening with the open face of the member directed toward the web path, and b. its open face at least partially surrounded by a peripherally extending lip which overhangs the edge of the opening; the improvement which comprises: C. a movable member supported on the surface of said housing and slidable thereon to become interposed between said lip and the housing so as to block control-actuating motion of the cup-like member; and D. means joining the said slidable part and the said movable member for sliding them concurrently so as simultaneously to cover the said orifice and block motion of the cup-like member.