Pressure foot of printed circuit board drilling apparatus
AssigneeHitachi Seiko Ltd.
InventorsKunio Arai, Yasuhiko Kanaya
Life of this patent
Estimating the term…
Abstract
In a pressure foot used in an apparatus for drilling printed circuit boards, which includes a bearing for holding a spindle, and formed at the end portion thereof with an inner void space having a bottom hole for passing the drill bit, the end portion of the pressure foot is provided with an annular end surface possibly contacting with the printed circuit board and air injection ports for injecting compressed air into the inner space. The air injection ports are so directed that the air flow from each injection port is tangently contacts with the circumferential surface of the drill.
Claims11
A pressure foot used in a printed circuit board drilling apparatus, said pressure foot being supported by a bearing holding a spindle in such a manner as to be slidable in the axial direction of the bearing, being connected with a dust collector through a vacuum port, and being adapted to press a printed circuit board in a drilling process and to exhaust the chips coming out in the drilling process through the vacuum port towards the dust collector, comprising:
- an annular end surface adapted to contact with the printed circuit board in such a manner that an interior volume of the pressure foot is isolated from the exterior of the pressure foot when the pressure foot and the printed circuit board are brought into contact with each other during the drilling process,
- a plurality of injection ports inwardly opened to the inner surface of the pressure foot, and
- compressed air feed passage means having one end thereof connected with said plurality of injection ports and at another end with a compressed air supply source, wherein said plurality of injection ports are arranged to provide rotational air flow therefrom, in a region surrounded by an inner surface of the pressure foot, to the vacuum port in such a manner that the direction of the rotational air flow is opposite to the rotational direction of the drill.
A printed circuit board drilling machine, comprising a bearing rotatably supporting a bearing therein, a spindle supporting a chuck which can be opened and closed to hold a drill, and a pressure foot supported by the bearing and defining an interior volume and has an annular portion for contacting a printed circuit board such that the drill can pass therethrough to drill the board, wherein
- a plurality of injection ports open into the interior volume of the pressure foot to inject compressed gas at a tangent to a side surface of the drill and in a direction opposite to the rotational direction of the drill, with adiabatic expansion of the gas to cool the drill during a drilling process, and
- means is provided for exhausting chips produced during the drilling process.
Dependencies are inferred from the claim text.