摘要 |
A portable lightweight drill assembly has a cutter mounted against a sheet of flat glass through which a hole is to be drilled; in an alternate embodiment, the drill shaft extends through a hole in the glass and has cutters mounted on both sides of the glass; in each case, the cutters are biased against the glass by a fluid pressure actuated bellows type servo constructed to exert a constant cutting force against the glass surface by means of a self-regulating action of the fluid pressure force.
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