IMPROVEMENTS IN MULTIPLE DRILLING MACHINES
Year: 1866

page_text: PROVISIONAL SPECIFICATION left by William Clapperton at the Office of
the Commissioners of Patents, with his Petition, on the 14th November
.1866.
I, WILLIAM CLAPPERTON, Manager to Messrs. John M Dowall and Sons,
Walkinshaw Foundry, of Johnstone, in the County of Renfrew, North Britain,
do hereby declare the nature of the said Invention for "IMPROVEMENTS IN
MULTIPLE DRILLING MACHINES," to be as follows, that is to say :-
This Invention relates to improvements designed principally to render
multiple drilling machines more convenient in use than hitherto, and more
easily adjustable to different pieces of work..
The details of the machine may be varied, but in one useful modification
there is a horizontal girder or frame piece formed with V guides for a saddle
adapted to the front side to slide upon horizontally. The girder is fixed upon.
two or more standards disposed so that the saddle overhangs the article
(a keel bar, for example) to be operated upon and offering no obstruction to
the movement of the article longitudinally under the saddle. In the outer or
front vertical face of the saddle there are a number of T grooves for the
attachment separately and individually of the sockets for the drill spindles at
whatever distance from each other may be required, the minimum distance
depending of course on the sizes of the parts. The saddle can be moved along
horizontally by means of a screw spindle in the girder, and when one set of
holes has been drilled the saddle is adjusted by means of the screw spindle to
drill another set in continuation of or intermediately to the set already drilled.

page_text: The drill spindles are driven from a horizontal longitudinal driving shaft
carried above the girder, and having a number of bevil wheels which gear
with bevil wheels on short transverse spindles having bevil wheels on their
front ends in gear with bevil wheels on the drill spindles; the short trans-
verse spindles are carried each by a bracket formed on or attached to its
respective drill spindle socket, and extensions of these brackets shift the bevil
wheels on the longitudinal driving shaft and keep them in gear. An automatic
feed motion is provided, but with arrangements permitting of any one or more
of the spindles being thrown out of gear as regards the feed, so as to be fed
by hand if required. The feed details are carried by a light framing fixed by
pillars upon and above the saddle, and comprise a worm, spindle deriving its
motion by a belt from the longitudinal driving shaft, and acting on worm
wheels; each worm wheel is on an internally screwed tube which acts on
the screw feed spindle above, and in the line of the drill spindle; the tube
has a hand wheel' fixed on it, and it is held in a bush which is square exter-
nally, and which is set, in a slot in the framing; a washer is keyed on-the
tube above the bush, and- this washer is formed with an annular dovetailed
groove to receive the dovetailed end of a screw bolt which passes up through
the worm wheel, and has a nut on its upper end; when this nut is tightened
the worm wheel becomes fixed to the washer and carries round the screwed
tube, but on unscrewing. the nut the parts become loose, and the worm wheel
turns without feeding.
In another modification the girder or horizontal frame piece is arranged so
that it can be adjusted vertically upon its standards, such adjustment being
effected by means of vertical screw spindles in connection with the standards,
which screw spindles may be actuated simultaneously by means of a horizontal
shaft geared to them by bevil wheels.