An interesting patent application from Apple surfaced today in the United States Patent & Trademark Office’s database. Entitled “Aparathus and Method for Intricate Cuts”, it describes a cutting apparatus of sorts and includes a drawing that suggests Apple’s been using this tool to cut out the Apple logo in casings of its products. Apple writes:
The cutting apparatus includes a base member and an elongate member extending from the base member. The elongate member includes a tapered region having an abrasive surface. The tapered region defines at least one vertex defining an angle of a desired cutout shape. Additionally, the tapered region is toothless.
Multiple tools like this can be sequentially inserted through an aperture in a fiber-in-matrix material to “incrementally increase the size of the aperture to form the radial shape having at least one sharp feature of the tapered elongate members”, the company explains. But why go to great lengths and devise your own tool for a simple task like punching shapes in metal?
Apple notes that traditional techniques such as machining are not suitable for forming intricate cuts with sharp or acutely angled features because they’re pricey in manufacturing. Other techniques involving CNC milling, water jet cutting or laser cutting “may not provide adequately sharp features at a reasonable cost”. In addition, stamping, punching or fine-blanking processes produce “rough edges with exposed fibers and a generally unacceptable appearance”. Thus, the technique Apple describes can be used on its own or in combination with other manufacturing processes. The aperture may take a general shape of a desired intricate cut. For example, Apple explains, “when the ultimately desired shape is an apple, the general shape created by CNC milling may be a circle or oval. Often, the aperture may be a circle, a square or other geometric shape”. Apple describes a manufacturing process in intricate detail. “A tapered shaft having an abrasive surface is inserted into the aperture. The cross-section of the shaft is the shape of the desired intricate cut. The shaft gradually expands radially (i.e., gets bigger) along the length of the shaft. As the shaft increases in size, the cross-section shape stays the same. That is, the shape of the shaft remains the same along the length of the shaft as the cross-sectional size of the shaft increases due to the taper. The tapered shaft is toothless. That is, the tapered region does not include teeth, in contrast to conventional broach tools, for cutting through material”.The document credits Apple engineer Kevin M. Kenney as the sole inventor. The patent application can be retrieved by entering the ID number 20110183580 into the USPTO search engine.