Abstract: A braking device and a system for braking thread being drawn off of a thread storage drum over its output circumference. The braking device includes a braking body having a band which is symmetric in shape around an axis and has a continuous active braking surface facing inwardly toward the axis, the surface being sufficiently hard to be resistant to wear from thread friction. An elastic member urges the band, and thus the braking surface, into engagement with an output circumference on the drum so as to brake thread passing through the braking body between the surface and the drum output curcumference.

Abstract: A modulated thread beating device for weft feeders has a first lamina and a second lamina that are arranged opposite one another and are supported by pairs of fixed and respectively movable bars that engage the ends of the respective laminae, flexing them in an arched shape; the laminae are arranged opposite each other at their convex face. The movable bars are supported by a corresponding movable element which is suspended elastically and is provided with an energization coil that is subjected to the field of a permanent magnet. The coil of the movable element is supplied with an energization current that is modulated in proportion to the advancement speed or mechanical tension of the thread.

Abstract: An electropneumatic device for the automatic threading of apparatuses for feeding weft to textile machines, and a weft feeding apparatus including the device. The device has first and second ducts for feeding pressurized pneumatic fluid. The ducts are cut off by a manually-actuated valve and end in thread inlet and outlet bushes to create a pneumatic flow and a consequent suction current which entrains the thread from one end of the feeder apparatus to the other. An intermediate open channel is arranged adjacent and parallel to the drum of the apparatus to convey the pneumatic flow and the thread entrained thereby in the free portion comprised between the radial arm outlet and a thread brake. A pneumatic pusher is fed by a third pneumatic duct and is arranged at the outlet of the intermediate channel. The pusher acts on a braking device to deform it and hinder elastic action applied to the drum, so as to guide the thread entrained by the flow through the braking device.

Abstract: The breaking device has a single truncated-cone braking body, supported by an elastic member coaxially and frontally with respect to a drum of a feed unit and is actuated by the elastic member so that it engages, with an elastic contact, against the drum along a circumference thereof which is smaller than the maximum circumference of the drum. The thread slides between the drum and the braking body and extends from a point of contact with the drum and braking body along a path which is inclined with respect to the axis of the drum, so that the tension produced by the braking body has at least one axial component which is discharged onto the braking body and is balanced by the elastic member. Increase in the tension on the thread produces, or tends to produce, by virtue of the corresponding increase in axial component, separation of the braking body from the drum with a corresponding self-adjusting braking action.

Abstract: A weft feeder for weaving looms including a fixed drum, a rotating arm winding, a plurality of thread turns on said drum, an asynchronous motor for said rotating arm, braking means for breaking thread unwinding from said fixed drum, a guiding ring for guiding unwound thread and a piezoelectric transducer rigidly associated to the side of the solid of revolution generated by the unwinding thread and adapted to emit an electric pulse upon every passage of the thread at the generatrix of the solid of revolution which is arranged in the meridian plane which contains or intersects the axis of a feeler associated with the transducer.

Abstract: A weft feeding device, for weaving looms, of the type comprising a drum for winding the thread and an array of metallic laminas for braking the thread which unwinds from the drum. The metallic laminas are arranged on the surface of a rotational paraboloid. The paraboloid is fitted on the drum and is tangent thereto, to elastically engage a thread, at its own minimum-radius circumference. The paraboloid has one end rigidly coupled to a fixed supporting ring which encircles the drum, the other free of the paraboloid end being subject to the action of a movable ring which, when moved axially with respect to the paraboloid, varies the paraboloid's curvature in order to correspondingly vary the contact pressure of the laminas on the thread.