Fig. 1878.
The simplest form in which the milling machine appears is termed the hand milling machine, and an example of this is shown in [Fig. 1878]. This machine consists of a head carrying a live spindle which drives the cutting tools, which latter are called cutters or mills. The front of the head is provided with a vertical slideway for the knee or bracket that carries an upper compound slide upon which the work-holding devices or chucks are held. The work is fed to the revolving cutter by the two levers shown, the end one of which is for the vertical and the other for the horizontal motion, which is in a direction at a right angle to the live spindle axis.
In other forms of the hand milling machine the live spindle is capable of end motion by a lever.
In [Fig. 1878a] is shown Messrs. Brown and Sharpe’s plain milling machine, or in other words a milling machine having but one feed motion, and therefore suitable for such work only as may be performed by feeding the work in a straight line under the cutter, the line of feed motion being at a right angle to the axis of the cutter spindle.
Machines of this class are capable of taking heavy cuts because the construction admits of great rigidity of the parts, there being but one slideway, and therefore but one place in the machine in which the rigidity is impaired by the necessity for a sliding surface.
Fig. 1878a.
The construction of this machine is as follows: The head a which carries the cutter spindle is pivoted at c to a stiff and solid projection on the frame f, and means are provided to solidly clamp the two together.