Machine or Apparatus for Boring Taper or Parallel Holes in Metal or other Substances.
Year: 1891

page_text: Date of Application, 26th Nov., 1891
Complete Specification Left, 24th Aug., 1892-Accepted, 8th Oct., 1892
PROVISIONAL SPECIFICATION.
A Machine or Apparatus for Boring Taper or Parallel Holes in
Metal or other Substances.
WILLIAM WILLIAMS, Foreman Fitter 2 Pemberton Street Llanelly in the
County of Carmarthenshire S. Wales and CUTHBERT FREDERICK THOMPSON,
Engineer of Brynyrodin, Llanelly in the County of Carmarthenshire S. Wales,
do hereby declare the nature of this invention to be as follows
The machine or apparatus consists of a hollow bar which is constructed with a
cam or eccentric motion carrying two cutter heads one of which A has a nut geared
into the screw feed bar & the other B screwed or fastened on to the head A. This
head B being adjustable circumferentially with A either of which said travelling
heads being capable of carrying the cutters or cutting tools. The bar has one or
more bearings being in the true centre of the bar upon which the bar revolves &
the body or main portion of the bar upon which the cutter heads travel is thrown
out of centre with an eccentric or cam motion to the true centre line of the
bearings. The machine can be worked with worm or other gear from the engine or
other motive power driving same & the feed or travel of the cutter heads is given
to the tools or cutters by a screw working into a nut fixed into the cutter heads,
motion and feed being derived by means of tooth or other gearing in a convenient
manner. The adjustable head B. can be so arranged in connection with A that
a taper hole can be bored in either direction without moving the position of the
bar & by adjusting B. a parallel hole can be bored motion being given either one
way or the other, longitudinally or vertically according to position of the bar.
Dated this 20th day of November 1891.
WILLIAMS.
WM.
C. F. THOMPSON.
COMPLETE SPECIFICATION.
A Machine or Apparatus for Boring Taper or Parallel Holes in
Metal or other Substances.
We, WILLIAM WILLIAMS of 2 Pemberton Street, Llanelly in the County of
Carmarthen, Foreman Fitter, and CUTHBERT FREDERICK THOMPSON of
Brynyrodin, Llanelly in the County of Carmarthen, 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 :-
Our invention consists of a machine or apparatus for boring taper or parallel
holes in metal or other substances and the characteristic feature of the said
machine or apparatus is a hollow bar carrying two travelling cutter heads as
hereinafter described and having one or more bearings in the true centre line of
the bar upon which the bar revolves while its main portion or body upon which
the cutter heads travel is thrown out of centre so that it has an excentric or cam
motion to the true centre line. One of the cutter heads has a nut which gears
into a screw feed bar and the second head is screwed or fastened to the first and
is adjustable circumferentially therewith so as to regulate the direction and degree
of taper to be cut or to arrange for cutting a parallel hole. Both heads are
preferably made capable of carrying the cutters or cutting tools but it is not
essential that the non-adjustable head should be so.
The machine can be worked with worm or other gear from an engine or other
source of power and the feed or travel is given to the cutter heads and to the tools

page_text: or cutters by the screw feed bar which gears with the nut in one of the cutter
heads as already described the feed, bar itself being driven by toothed or other
gearing. The screw feed bar and boring bar can be arranged vertically or
horizontally as circumstances may require.
Figure 1 of the accompanying drawings is an elevation partly in section and
Figure 2 a plan of a machine or apparatus constructed according to our
invention.
Figures 3 and 4 are elevations taken at right angles to each other and
Figure 5 an end view of the boring bar detached and on a larger scale.
Figure 6 is an elevation of the two cutter heads attached to each other.
Figure 7 is a view of the under side of the adjustable head and
Figure 8 a view of the upper side of the non-adjustable head.
Figure 9 is a view of a plate by which the nut is retained in this head.
a is the boring bar having at the upper part a bearing in the collar and at the
lower part a bearing to turn in any suitable socket or centre, these bearings
being both in the true centre line of the bar. The body of the bar a is thrown
out of centre as clearly seen in the drawings so that when it revolves it has an
excentric or cam motion to the true centre line. The bar a is hollow and receives
the screw feed bar d. It also carries two cutter heads e and the head ƒ being
adjustable circumferentially with respect to the head e by means of the grooves g
and screw bolts h h. The head e receives in its recess ; an arm of a nut i
through which the screw feed bar d passes so that as this bar revolves it causes
the head e and with it the head to travel along the boring bar which has a
longitudinal slot as seen in Figure 4 for the arm of the nut to move in. The
nut is secured within the head e by means of a sliding plate Figure 9 fixed by
screws. The boring bar a is shown as driven by means of a worm m which is
keyed on a rotating shaft n and gears with a worm wheel p on the boring bar; and
the screw feed bar d is shown as driven from the boring bar by means of cog
wheels q¹³ but any other suitable arrangements for imparting the required
rotary motions to the boring bar and to the screw feed bar can be adopted. The
wheel is keyed on the boring bar a; the wheels 2 and 3 are keyed together
and are loose on their spindle and the wheel is keyed on feed bar d. The
number of teeth in these wheels should be respectively such as to give a slow feed
motion to the bar d as is well understood:-say for example, the wheels q¹
and g 40 teeth each, the wheel 23 42 teeth, and the wheel 38 teeth.
The cutter heads and for the head only are or is provided with apertures
and fixing screwss for securing the cutters or cutting tools.
If starting with the cutter heads at the lower part of the boring bar a, the
head is so adjusted as to bring the tool fixed therein opposite the point of the
boring bar, that is to say where the throw of the excentric movement is greatest,
the diameter of the base of the hole it will bore will be the largest of which the
machine is capable, and the hole bored will gradually diminish in diameter as the
tool travels with the cutter head up the boring bar, because owing to
the inclination or cant of the body of the bar the excentric throw of the tool will
gradually diminish. A taper hole will thus be bored.
If on the other hand the head be so adjusted that the tool is at starting
opposite the point 2 of the boring bar, that is to say where the throw of the
excentric movement is least, the diameter of the base of the hole it will bore will
be the smallest of which the machine is capable, and the hole bored will gradually
increase in diameter as the tool travels with the cutter head up the boring bar
because owing to the inclination of the body of the bar the excentric throw of the
tool will gradually increase. A taper hole the reverse of that bored with the
cutter starting opposite the point I will thus be bored.
Again if the head be so adjusted that the tool is at starting opposite a point in
the circumference of the head half way between the points 1 and 2 the throw
will be equal during the whole of the travel of the cutter head and tool and
therefore a parallel hole will be bored. Or if the tool is at starting opposite

page_text: any intermediate point the taper will be greater or less according as the tool is
further from or nearer to the half way points. This will be clearly understood
from the diagram shown in Figure 10. The circle 5 represents the circumference
of the cutter head f and 6 the true centre on which it revolves. 6-1 will be
the greatest throw and 6--2 the shortest throw of the excentric movement and 3
and 4 are the half way points. If the cutter is started at say 3 or at 4 it will bore
a parallel hole; at any intermediate point between 1 and 3 or between 1 and 4 it
will bore a taper hole the taper being greater or less according as the cutter is
nearer to or further from 1; with the cutter at the point 1 the extreme limit or
greatest taper will be obtained; at any point between 2 and 3 or between 2 and 4
the cutter will bore a taper hole the taper being greater or less according as the
cutter is nearer to or further from 2 but the taper will be the reverse of that
obtained with the cutter at 1 or between 1 and 3 or between 1 and 4.
cutter started at 2 the extreme limit of the reverse taper will be obtained.
It will thus be understood that by adjusting the head fa hole with any desired
amount of taper (within the limits) and in either direction or a parallel hole can
be bored. The same result would be obtained if the tool were placed in one or
other of several holes in the head e but the tool could not be placed in any position
between the holes which is essential if the apparatus has to be capable of boring
all possible intermediate tapers. The adjustable head which enables this to be
effected is therefore very important, but is not essential if the apparatus is not
required to bore a greater number of variations of taper (including the parallel
hole) than can be provided for by a corresponding number of holes for the tool in
the head e.
With the
Having now particularly described and ascertained the nature of our said inven-
tion, and in what manner the same is to be performed, we declare that what we
claim is :-
1. A boring machine or apparatus having a revolving boring bar the body or
main portion of which, along which a cutter head or heads travel, is out of
centre with the true centre line on which the said bar revolves, so that the bar and
the cutter head or heads have an excentric movement and cause the cutter or tool
to bore a hole which is more or less taper or is parallel according to the position
in which the tool is placed relatively to the excentricity of the bar, substantially as
set forth.
2. A boring machine or apparatus having a revolving boring bar the body or
main portion of which along which two cutter heads travel is out of centre with the
true centre line on which the said bar revolves so that the bar and the cutter heads
have an excentric movement and cause the cutter or tool to bore a hole which is
more or less taper or is parallel according to the position in which the tool is placed
relatively to the excentricity of the bar, one of the cutter heads being adjustable
circumferentially so as to bring the tool held therein to any desired point, sub-
stantially as set forth.
3. The machine or apparatus constructed and working substantially as herein-
before described and represented in the accompanying drawings for boring taper or
parallel holes in metal or other substances.
Dated this 23rd day of Aurust 1802
J. C. MEWBURN,
55 & 56, Chancery Lane, London, Chartered Patent Agent.