Automatic Feed Motion for Drilling Machines or other Machines.
Year: 1890

page_text: Date of Application, 9th Aug., 1890
Complete Specification Left, 27th Dec., 1890-Accepted, 31st Jan., 1891
PRATICATION.
Automatic Feed Motion for Drilling Machines or other Machines.
JOHN JOSEPH WEATHERBURN Draughtsman 117 Marian Street Gateshead
Co. Durham do hereby declare the nature of this invention to be as follows:-
An apparatus for advancing or giving any required feed motion to a drill or other
suitable tool.
While drilling boring or tapping holes in iron, metal brass stone or other
material.
My invention has for its object the automatic feed motion of drilling machines
or other machines.
It may be applied to hand drilling machines to do the work which is now generally
done by a ratchet brace.
Or it may be applied by rotary rock drills, for drilling hard rocks in coal mines
or other mines and quarries.
Or it may be applied to drilling machines or other machines which are generally
used in engineering shops.
Supposing my invention to be used to give feed motion to a hand drill.
Figure 1 shows a side view, Fig. 2 a section and Figure 3 an end view of the
apparatus.
It consists of a friction clutch A which is adjusted by a set bolt B and spiral
spring C. A spindle D which rotates in the hollow screw E, which has a conical
end as shown in the drawing, and a drill box Fattached to the spindle as shown in
the drawing or by other suitable means.
When hole has to be drilled the spindle D is rotated by a hand wheel or other-
wise and carries round with it the clutch A. which rotates the screw E and advances
the drill or other tool as required.
The amount of rotation of the screw E per revolution of the spindle and drill is
regulated by the set bolt B and the spiral spring C.
The screw E works in a nut attached to an ordinary drill stand.
Datod this the 8th day of Avust 1900
JOHN J. WEATHERBURN.
COMPLETE SPECIFICATION.
Automatic Feed Motion for Drilling Machines or other Machines.
1, Joux JOSEPH WEATHERBURN, Draughtsman of 117 Marian Street, Gates-
head in the County of Durham 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:-
My invention relates to an improved automatic feed motion for drilling or
analogous purposes and consists in a novel arrangement or combination of parts
whereof a friction clutch, a set bolt, a spring and a hollow screw or nut adapted to
take a spindle or screw form the essential elements.
The principle underlying this invention is that by the compression of a spring to
an extent proportionate to the pressure or resistance or thrust of the tool, the feed
of the tool may be automatically performed by means of the spring when the
resistance to be overcome exceeds the initial pressure put upon the spring.
I will explain my invention with reference to the accompanying drawings in which
Fig. 1 shows an elevational view of one form of my improved apparatus,
Fig. 2 being a sectional elevation of the same at right angles to the view shown
in Fig. 1.

page_text: Figs. 3 and 4 show a vertical section and plan of a modified form of my
invention.
Referring to Figs. 1 and 2 a is a friction clutch into which the tapered or coned
end of the hollow screw a is designed to fit. a² is a spindle the lower end of which
is secured to the drill or tool box and between the said box and the hollow
screw a is a spring a of suitable power, are washers separating the spring at
from the screw and drill box. The upper end of the spindle in which is the slot a
is square so that the friction clutch revolves with the spindle, a' is a set bolt and
a³ a key arranged as shown so that by tightening up the set bolt the friction clutch
can engage with the coned end of screw a' and also compress the spring a
The
screw a works in a nut a' arranged in any suitable position as on the end of the
arm of an ordinary drill stand a
The action is this as follows:-The set bolt a being set so as to give the estimated
required amount of pressure to the spring the spindle and with it screw a' is
rotated by a handwheel or other power. The tool running light under these con-
ditions advances a distance equal to the pitch of the screw a per revolution.
Suppose the screw has 10 threads per inch, revolves 100 revolutions per minute and
the tool box advances inch per revolution to its work then the difference in
advance of the tool and screw per revolution tends to equal inch minus inch
which difference takes effect in relieving the pressure of the set bolt a on the
key which in turn relieves the pressure between coned end of screw a and
friction clutch and the instant this pressure is thus relieved spring a with lower
end of screw as an abutment continues the forward motion of the tool box and
tool thus effecting the automatic feed required and causing the clutch and screw to
again engage when the above operations are repeated.
Referring now to Figs. 3 and 4 which show a modified design of the same
device, is a nut with Hange thereon, is a loose washer between which and
Hange is shown a live ring of balls b³. is the spring, the friction clutch
prevented from rotating by stud m, the coned end of mut, the set nut, 68 the
screw spindle on the lower end of which is the tool box and 6ª à metal box with
projection keyed into end of arm of machine or tool stand.
The operation of this device is as follows:-Firstly the spring is compressed
by screwing up the set nut until the pressure put upon the spring is as nearly equal
as possible to the estimated resistance to be encountered by the tool. The screw
spindle is then caused to revolve by hand or machine power in any suitable
manner. Suppose the screw has 10 threads per inch, revolves 100 revolutions per
minute and advances in its work inch per revolution then the nut b will tend to
rise in the box 1 inch minus inch at each revolution and thus disengage itself
from the friction clutch; while thus disengaged the screw can no longer advance
due to its own pitch. because the screw and nut revolve together and the moment
disengagement takes place the spring forces forward both nut and screw thus
effecting the automatic feed required and causing the clutch and nut to again
engage when the above operations are repeated.
It will be observed that the nut normally acts as the fixed medium through
which the screw obtains its pitch but while the nut is disengaged from the clutch
as above described the screw loses its normal forward motion and together with the
ut is fed forward by the spring alone. While the nut is thus disengaged it
revolves with the screw against the ball bearings thus reducing friction as much
as possible. In practice the motions above described with reference to the engage-
ments and disengagements of the nut or screw and friction clutch take place as
will be understood in very rapid succession so that the moment the coned end
is disengaged from the clutch the spring causes re-engagement thus constantly
feeding forward the tool at a uniform rate.
For purposes of countersinking or knifing holes on the side of the plate opposite
to that on which the drilling machine is fixed the screw 8 can be simply taken out
of the nut and replaced therein with the drill box end uppermost or reversed.
box may be then turned upside down or reversed when the action is of course
The

page_text: changed from a pushing to a pulling force with respect to the machine, the screw
being now revolved in a direction opposite to that when working in the ordinary
way.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is -
1. An automatic feed motion device wherein a compressed spring is used to feed
forward the drill or equivalent tool when the resistance to be overcome by the
cutting edge of the tool exceeds the initial pressure put upon the spring substantially
as and for the purpose herein set forth with reference to Figs. 1 and 2 of the accom-
panying drawings.
2. An automatic feed motion device consisting of a friction clutch a, set bolt a',
spring a, spindle a² and hollow screw a' all arranged and acting substantially as
herein set forth with reference to Figs. 1 and 2 of accompanying drawings.
3. An automatic feed motion device consisting of a friction clutch 6, set bolt 17,
coned nut, spring, screw 68 and box all arranged and acting substantially as
herein set forth with reference to Figs. 3 and 4 of accompanying drawings.
4. The general arrangement and combination of parts constituting the improved
feed motion device substantially as herein set forth.
Dated this 24th day of December 1890.
A. CRAWHALL CHAPMAN,
3. St. Nicholas Buildings, Newcastle-on-Tyne,
Patent Agent for Applicant.