Gang Edging Machines

For dressing the edges of planks parallel and to width what are called gang edgers or gang edging machines are employed.

A gang edger consists of an arbor driving two or more circular saws, through which the boards to be edged are fed. Means are provided whereby the distance apart of the saws may be rapidly adjusted while the saws are in motion, so that if a board will not true up to a given width, the saws may be set to cut it to a less one without delay.

Fig. 3109 represents a self-feeding gang edger, constructed by J. A. Fay & Company, and in which the left-hand saw may be fixed at any required position on the left-hand half of the saw arbor, while the two right-hand ones may be adjusted independently along the arbor, while the machine is running.

At the back of the saw is a feed roll, and above it a pressure roll, whose pressure may be regulated by means of the weight and bar shown at the back of the machine. The object of placing the feed and pressure rolls at the back of the saws, is, that if a board is found to be too narrow for the adjustment of the saws, it may be withdrawn without stopping or reversing the machine, and the saws may be drawn together sufficiently to suit the case.

Fig. 3110 is a plan and Fig. 3111 an edge view of the work table, and show the means of adjusting the saws. a is the saw arbor, and 1, 2, 3, the circular saws. Saw 1 is carried by the sleeve b, which is secured in its adjusted position by the set screw c.

The mechanism for traversing saws 2 and 3 corresponds in design, and may be described as follows:

The arbor a has a spline s to drive the sleeves d, d′, which hold the saws and are carried by arms e, e′, which operate in slideways and have racks f, f′, into which gear pinions whose shafts g, g′, are operated by the hand wheels h, j.

It is obvious that by means of the hand wheels h, j, saws 2 and 3 may be regulated both in their distances apart or in their distances from saw 1, while the machine is in full motion, the bushes or sleeves d and d′ being carried by and revolving in the slide pieces or sliding bearings e and e′ respectively. Now suppose that e′ be moved to the left by hand wheel j, until it abuts against the end of d, at the slide end, and a further movement of d′ will also move d, causing it to operate its pinion and revolve the hand wheel h, hence d and d′ may be simultaneously moved without disturbing their distances apart by operating hand wheel j. On the yoke above the saws is a coarse-figured register plate to enable the setting of the saws to accurate widths apart.