Patent ID: 8800340
Filing Date: 2014-08-12
Classification: B21D,E04B

Abstract:
1. A method of making sound attenuating micro funnels through a metal plate, comprising the steps of: (A). feeding a metal plate on a workbench forward to extend beyond a shearing edge of the workbench, such that a first surface disposed at a bottom of the metal plate is contacted with the workbench, and a part of the metal plate is protruded and extended beyond the shearing edge of the workbench; (B). locating a punching head at a first lateral position above the part of the metal plate protruded and extended beyond the shearing edge of the workbench defining a working space of sufficient distance between the punching head and the workbench in the feeding direction of the metal plate to permit a shearing force applied to said metal plate, wherein the punching head includes a plurality of unit blade portions arranged in a row parallel to the shearing edge of the workbench; (C). applying the shearing force to the metal plate by the punching head external to the working space to provide said shearing force to said metal plate; (D). bending the part of the metal plate extending beyond the shearing edge of the workbench along the direction of applying the shearing force by the punching head, and forming a plurality of spot-shaped cavities arranged in a row on a second surface of the metal plate facing the punching head, the plurality of spot-shaped cavities formed by an action of the unit blade portions disposed in the punching head; (E). bearing the shearing force on the first surface of the metal plate to form a linear groove along the shearing edge of the workbench, the groove extending in a lateral direction transverse to the feeding direction; (F). selectively engaging the punching head a predetermined stroke distance to deform the metal plate by the shearing force, thereby interconnecting the spot-shaped cavities arranged in a row on the second surface with the linear groove on the first surface to form a plurality of micro-holes at the intersection of the linear groove and the spot-shaped cavities; (G). disengaging, by the predetermined stroke distance, the punching head from the metal sheet, and then shifting the punching head a predetermined lateral distance in a direction parallel to the shearing edge to a second lateral position while maintaining the working distance between the shearing edge and the punching head; (H). feeding the metal plate in a direction towards the shearing edge of the workbench again; (I). repeating Steps C, D, E and F when the punching head is situated at the second lateral position; and (J). disengaging, by the predetermined stroke distance, the punching head from the metal sheet, and then laterally shifting the punching head in a direction parallel to the shearing edge of the workbench to return the punching head to the first lateral position to complete a processing cycle.