Improvements in Machines for Drilling and Boring Metals.
Year: 1890

page_text: Date of Application, 30th June, 1890
Complete Specification Left. 31st Mar, 1891-Accepted, 2nd May, 1891
PROVISIONAL SPECIFICATION.
Improvements in Machines for Drilling and Boring Metals.
I JOHN HENRY HAMILTON of Stapleford in the County of Nottingham
Engineer do hereby declare the nature of this invention to be as follows:-
The first part of this invention relates to a combined vertical and horizontal
radial drilling machine so arranged that while the vertical spindle drills vertical
holes in any article clamped to or laid on the bed plate or table of the machine
the horizontal spindle may drill horizontal holes in the same article or the drills
may operate on different articles at the same time.
For this purpose I form a bearing or bearings in the bed or base plate of the
machine in which a gudgeon or trunnion is carried. This gudgeon or trunnion
has attached to or cast with it a radial arm upon which the drill spindle carriage
may be traversed by means of a screw or rack as usual in radial drilling
machines.
The power may be communicated to the drill spindle from a shaft concentric
with the gudgeon or trunnion by means of bevel gearing or belts in the usual
manner, the said shaft receiving its motion from cone pulleys secured to it, or
running loose upon it but connected with it through back gearing.
In some cases I may carry the gudgeon or trunnion the whole length of the bed
plate and secure to the other end of it another radial arm having a sliding carriage
containing a bearing adapted to steady one end of a boring bar which is supported
at the other end by the horizontal drill spindle. The traversing mechanism of
this carriage may be connected with that of the drill carriage in such a way that
their movements correspond and the steadying bearing remains in line with the
drill spindle.
The second part of this invention consists of an improved method of balancing
the weight of the horizontal radial arm and drill spindle and carriage and is
applicable to all horizontal radial drilling machines.
For this purpose I cast with the radial arm and. gudgeon or trunnion another
shorter arm in line with the former arm but on the opposite side of the centre of
oscillation, and on this shorter arm I fix a sliding block to which is pivotted a
weight or weights.
The screw which traverses the drill spindle carriage is also prolonged alongside
the shorter arm and screws through the sliding block or through a nut attached to
the latter.
This screw is however of the opposite hand to that which engages the nut on
the drill spindle carriage and less in pitch so that the carriage and sliding block
either both move towards the centre of the gudgeon or trunnion, or both move
away from this centre simultaneously.
By properly adjusting the weight pivotted to the sliding block, the relative
pitches of the screws and the relative positions of the drill spindle carriage and
sliding block, the radial arm is suitably balanced irrespective of the position of the
drill spindle carriage on that arm.
Datad this 20th dor of Tuna 1890
'
AYRTON & THOMAS,
Agents for the Applicant.

page_text: COMPLETE SPECIFICATION.
Improvements in Machines for Drilling and Boring Metals.
I, JOHN HENRY HAMILTON of Stapleford in the County of Nottingham,
Engineer, do hereby declare the nature of this invention and in what manner
the same is to be performed, to be particularly described and ascertained in and
by the following statement :-
The first part of this invention relates to a combined vertical and horizontal
radial drilling machine so arranged that while the vertical spindle drills or bores
vertical holes in any article clamped to or laid upon the bedplate or table of the
machine, the horizontal spindle may drill or bore horizontal holes in the same
article, or the spindles may operate on different articles at the same time.
I shall now proceed to describe one form of machine embodying my improve-
ments, referring to the accompanying drawings in which
Fig. 1 represents an end elevation, Fig. 2 a side elevation and Fig. 3 a plan of
the machine.
The mechanism for drilling vertical holes may be of any known construction
mounted as usual on the bedplate or table B. In this table 1 form bearings a,
and b, to receive a horizontal gudgeon or trunnion C cast on or secured to a radial
arm upon which slides the carriage E carrying the horizontal drill spindle which
may be driven by means of bevel wheels or otherwise in a manner similar to that
in which the vertical spindle is driven. I prefer to have all the driving gear at
the opposite end of the machine to that at which the horizontal drilling apparatus
is placed and one convenient arrangement is shewn in Figs. 2 and 3. In this the
stepped cone G and back gearing drive a spindle passing from end to end of the
machine and operating the horizontal drill spindle while the stepped cone F and
back gearing drive a short sleeve through which the former spindle passes and
which has secured to it inside the bedplate a bevel wheel for driving the vertical
spindle.
It is obvious that both drill spindles might be driven by one set of driving gear
if the nature of the work were such that the same speed would answer for both
and in this case a clutch may or may not be provided for stopping one drill spindle
independently of the other. But for general work in which the speeds of the
drill spindles will usually require to be different I prefer to drive them by means
of independent driving gear.
I prefer also to have an additional baseplate H (Figs. 1 and 3) to which larger
work may be secured and operated upon by both drills.
The second part of this invention consists of an improved method of balancing
the weight of the radial arm and horizontal drill spindle carriage, and is applicable
to all horizontal radial drilling machines.
-or
For this purpose I cast with the radial arm R another arm S on the opposite
side of the centre of oscillation and on this arm I place the sliding weight W-
by an alternative arrangement-a sliding block to which a hanging weight is
pivotted.
The weight W (or block in the alternative arrangement) is provided with a
nut N (Fig. 3) screwed to receive the end of the screw T by which the carriage E
is traversed along the arm R. The screw threads at opposite ends of this screw
are of opposite hand so that the carriage E and weight W, either both move
towards the centre, or both away from the centre simultaneously, and in order to
obtain a true balance for every position of the carriage E and arm R it is
necessary that the relative pitches of the screws should be determined in the
manner which I now proceed to describe with reference to Fig. 4.
In this O represents the centre about which the arm oscillates, M. the centre of
gravity of the arm R and L that of the arm S; P and Q any two positions of the
centre of gravity of carriage E as it is traversed along the arm R. If M. P
and M. Q be divided at J and K in the inverse ratio of the weights of the arm R

page_text: and carriage E, then J and K will be the positions of the common centre of gravity
of both arm and carriage corresponding to the positions P and Q of the latter and
this common centre of gravity will move along the line J K (parallel to PQ) as the
carriage is traversed along the arm R. To secure a true balance the common
centre of gravity of the arm S and weight W. should move along the line f. d. the
point being on the line JO produced, at a distance from O such that the sum of
the weights of the arm S and weight W multiplied by the distance O. f. shall
equal the sum of the weights of the arm R and carriage E multiplied by the
distance O. J; the distance O. d, on the line K. O. produced is determined in the
same way and the line fd will obviously be parallel to J K and hence to QP.
The path of the centre of gravity of the weight W will be the line V u parallel
to f. d, that is parallel to PQ, the point V being found by producing the line Lf
and making the distance f V. multiplied by the weight of W equal to the
distance L multiplied by the weight of arm S; and the point u may be found in
the same way; or by drawing V u parallel to PQ to intersect Ld produced.
Thus the pitches of the screws which move the carriage E and weight W should
be in the ratio of P Q to V u.
I would have it understood that I do not confine myself to the particular
arrangement of parts hereinbefore described with reference to Figs. 1, 2 and 3 as
this may be varied without affecting the principle of my invention.
Thus the horizontal drilling apparatus may be placed at the same end of the
bedplate as the vertical or a horizontal drilling apparatus may be placed at each
end, either mounted on one and the same trunnion, or on separate trunnions. In
the former case one radial arm may be free to revolve on the trunnion and be
provided with bolts for clamping it securely to the latter when it is desired that
both arms shall revolve together with the trunnion, and in this case one of the drill
carriages may carry a bearing to support one end of a boring bar driven by the
spindle in the other carriage. Or instead of the drill spindle carriage carrying a
bearing, a simple carriage having a bearing for the end of a boring bar may be
used, and in either case the screws which move the carriages on both arms may be
geared together so that the carriages shall move together in a manner which will
be well understood by those conversant with machine tool construction.
But I prefer the simpler plan of graduating the slides of each radial arm so that
the carriages may be moved independently, but can be set to corresponding
graduations when it is desired to bring the bearing in line with the spindle, driving
the boring bar; and a line on the trunnion and the radial arm loose thereon may
indicate the correct angular adjustment for the same purpose.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what
I claim is:
1. The combination in one machine of vertical and horizontal radial drilling
apparatus, substantially as described and illustrated in Figs. 1, 2, and 3 of the
accompanying drawings.
2. The combination in one machine of a vertical radial drilling apparatus and of
a horizontal drilling or boring apparatus consisting of two radial arms carrying
suitable carriages and preferably mounted on one trunnion passing from end to end
of the machine and supported by bearings in the bedplate of the same, substantially
as hereinbefore described.
3. In horizontal radial drilling apparatus or machines, the method of balancing
the weight of the radial arm and drill carriage irrespective of the position of the
latter upon the arm substantially as illustrated and described.
Dated this 28th day of March 1891
JOHN H. HAMILTON.