Shapers and planersA shaper is a machine that forms surfaces by successive reciprocating cuts of a tool over the work. The work is stationary with reference to the tool but moves laterally in small steps so that the successive cuts can be made. Although most of the work performed on shapers consists of plane horizontal surfaces, it is also possible to finish vertical and angular surfaces, and, with the proper tools and accessories, even curved surfaces may be machined. The size of a shaper is determined by the longest stroke of the ram. Shapers are driven by belt from a countershaft, by direct connected motor, or by hydraulic power. Planers are essentially for machining plane surfaces which are larger than can be cut or reached on the shaper. The modern planer with modern electric controls has a high output. The planer has a reciprocating table which travels beneath a cross bar on which the tool heads are mounted. Normally one or two tool heads are mounted on the cross bar, but additional tools, generally for cutting vertical faces, may be mounted on the columns supporting the cross bar. The usual design comprises two vertical columns between which the table reciprocates. The cross bar is so mounted that it can slide vertically on these columns. All motions for feed or cut take place either by dropping the cross bar, moving the tool head across the cross bar, or lowering the tool holder mounted on the tool head. The first two of these motions are generally power or hand-operated but the last is often hand-operated only. The table is normally operated by some form of rack-and-pinion or spiral drive. Modern high-speed planers are now fully electrified.
|
