[CHAPTER VII]
HORIZONTAL BORING MACHINES
A boring machine of the horizontal type is shown in [Fig. 1]. The construction and operation of this machine is very different from that of a vertical boring mill and it is also used for an entirely different class of work. The horizontal machine is employed principally for boring, drilling or milling, whereas the vertical design is especially adapted to turning and boring. The horizontal type is also used for turning or facing flanges or similar surfaces when such an operation can be performed to advantage in connection with other machine work on the same part.
Fig. 1. Lucas Horizontal Boring, Drilling and Milling Machine
The type of machine illustrated in [Fig. 1] has a heavy base or bed to which is bolted the column C having vertical ways on which the spindle-head H is mounted. This head contains a sleeve or quill in which the spindle S slides longitudinally. The spindle carries cutters for boring, whereas milling cutters or the auxiliary facing arm are bolted to the end A of the spindle sleeve. The work itself is attached either directly or indirectly to the table or platen P. When the machine is in operation, the cutter or tool revolves with the spindle sleeve or spindle and either the cutter or the part being machined is given a feeding movement, depending on the character of the work. The spindle can be moved in or out by hand for adjustment, or by power for feeding the cutter, as when boring or drilling.
The entire spindle-head H can also be moved vertically on the face of the column C, by hand, for setting the spindle to the proper height, or by power for feeding a milling cutter in a vertical direction. When the vertical position of the spindle-head is changed, the outboard bearing block B also moves up or down a corresponding amount, the two parts being connected by shafts and gearing. Block B steadies the outer end of the boring-bar and the back-rest in which this block is mounted can be shifted along the bed to suit the length of the work, by turning the squared end of shaft D with a crank. The platen P has a cross-feed, and the saddle E on which it is mounted can be traversed lengthwise on the bed; both of these movements can also be effected by hand or power. There is a series of power feeding movements for the cutters and, in addition, rapid power movements in a reverse direction from the feed for returning a cutter quickly to its starting position, when this is desirable.