As the sizes of planing machines increase, they are given increased tool-carrying heads; thus, [Fig. 1562] represents a class in which two sliding heads are used, so that two cutting tools may operate simultaneously. Each head, however, is capable of independent operation; hence, one tool may be actuated automatically along the cross slide to plane the surfaces of the work, while the other may be used to carry a cut down the sides of the work, or one tool may take the roughing and the other follow with the finishing cut, thus doubling the capacity of the machine.
In other large planers the uprights are provided with separate heads as shown in the planer in [Fig. 1563], in which each upright is provided with a head shown below the cross slide. Either or both these heads may be employed to operate upon the vertical side faces of work, while the upper surface of the work is being planed.
The automatic feed motion for these side heads is obtained in the Sellers machine from a rod actuated from the disk or plate in figure, this rod passing through the bed and operating each feed by a pawl and feed wheel, the latter being clearly seen in the figure.
To enable the amount of feed to be varied the feed rod is driven by a stud capable of adjustment in a slot in the disk.
[Fig. 1563] represents a planing machine designed by Francis Berry & Sons, of Lowerby Bridge, England. The bed of the machine is, it will be seen, L-shaped, the extension being to provide a slide to carry the right-hand standard, and permit of its adjustment at distances varying from the left-hand standard to suit the width of the work. This obviously increases the capacity of the machine, and is a desirable feature in the large planers used upon the large parts of marine engines.
Fig. 1564.
Rotary Planing Machine.—[Fig. 1564] is a rotary planing machine. The tools are here carried on a revolving disk or cutter head, whose spindle bearing is in an upper slide with 2 inches of motion to move the bearing endways, and thereby adjust the depth of cut by means of a screw. The carriage on which the spindle bearing is mounted is traversed back and forth (by a worm and worm-wheel at the back of the machine) along a horizontal slide, which, having a circular base, may be set either parallel to the fixed work table or at any required angle thereto.
By traversing the cutter head instead of the work, less floor space is occupied, because the head requires to travel the length of the work only, whereas when the work moves to the cut it is all on one side of the cutter at the beginning of the cut, and all on the other at the end, hence the amount of floor space required is equal to twice the length of the work.