Improvements in Machines for Engraving and Cutting Sunk Surfaces by Means of Revolving Drills or Cutters.
Year: 1887

page_text: Improvements in Machines for Engraving and Cutting Sunk
Surfaces by Means of Revolving Drills or Cutters.
We WILLIAM TAYLOR, THOMAS SMITHIES TAYLOR and HERBERT WILLIAM
HOBSON all of Slate Street, Leicester, in the County of Leicester, Engineers and
Scientific Instrument makers do hereby declare the nature of this invention to be as
follows:-
:-
This Invention relating to machines for engraving and cutting sunk surfaces by
means of revolving drills or cutters, has reference to the means of regulating the feed
of the drill or cutter so as to ensure a uniform depth of cut.
In machines of the ordinary description, the drill or cutter is fixed in a mandrel
carried in suitable bearings which are capable of being moved by a screw or lever or
other suitable means to feed the drill or cutter to the work; and the depth of cut is
regulated, either by the judgment or skill of the operator, or by the aid of a stop,
which governs or limits the travel of the mandrel and its bearings in their guides.
Now according to this Invention, a duplex feed motion is employed, viz: a primary
feed motion by which the drill or cutter is brought to the surface of the work, and a
secondary feed motion by which the drill or cutter is advanced a definite amount
which may be regulated beforehand.
The primary feed motion may consist for example of a screw working through a
fixed part of the machine and operated by a milled wheel or other suitable device so as
to move the mandrel with its drill or cutter relatively to the frame as in the ordinary
manner. The secondary feed motion may consist of another screw carried by the
body of the milled wheel or other suitable device and which passes through a projec-
tion from the bearings of the mandrel and carries a movable collar or nut revolving
in the said projection and a fixed collar and adjustable nut below the projection so that
by regulating beforehand the position of the said adjustable nut on the said screw,
the mandrel with its drill or cutter may be moved relatively to the primary screw by
the act of turning the movable collar or nut on its screw, until the motion is
arrested by the contact of the fixed collar with the adjustable nut when the desired
depth of penetration will have been obtained.

page_text: In lieu of employing screws for advancing the drill or cutter, levers, cams, links or
other equivalent devices may be used, either alone or in combination with each other
or with screws. For example, the primary feed motion may consist of the ordinary
screw operated by the milled wheel or its equivalent as hereinbefore described, and the
secondary feed motion may consist of a clutch which may be made to grip the primary
feed screw or its wheel, the arrangement being such that the clutch is retained
stationary and out of action while the primary feed is being imparted but that it may
then be moved by hand the distance between two stops (one of which is adjustable)
and acting on the milled wheel or its equivalent will move it round the distance corre-
sponding to the desired depth of cut.
The arrangement herein before described may also be otherwise modified in its
details without departing from the principle of this Invention.
Dated this 21st day of November 1887.
THOS. J. HANDFORD,
50, Bedford Row, London, W.C.,
Agent.

page_text: Surfaces by Means of Revolving Drills or Cutters.
We WILLIAM TAYLOR, THOMAS SMITHIES TAYLOR and HERBERT WILLIAM
HOBSON all of Slate Street, Leicester in the County of Leicester Engineers and
Scientific Instrument makers, 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 :-
This Invention relating to machines for engraving, and cutting sunk surfaces by
means of revolving drills or cutters, has reference to the means of regulating the
feed of the drill or cutter so as ensure a uniform depth, or the required depths of cut.
In machines of the ordinary description, the drill or cutter is usually fixed in a
spindle or mandrel, carried in suitable bearings, which are moved in a guide or guides,
by a screw or lever or other convenient means, to feed the drill or cutter to the work
and the depth of cut is regulated, either by the judgment or skill of the operator, or by
the aid of a stop which governs or limits the travel of the mandrel and its bearings
in their guide or guides, without any positive or definite relation to the position of the
surface of the work. Now according to this Invention, a duplex or compound feed
motion is employed, viz. a primary feed motion by which the drill or cutter is brought to
or near the surface of the work; and a secondary feed motion by which the drill or
cutter is advanced a definite amount, which may be regulated beforehand. As, there-
fore, the action of the secondary feed motion depends on the arrival of the drill or
cutter at or near the surface of the work, under the action of the primary feed motion,
it is evident that the requisite depth or depths of cut may be completely ensured.
And in order that the said Invention may be perfectly understood, we shall now
proceed more particularly to describe the same, and for that purpose shall refer to the
several figures on the accompanying sheet of drawings, the same letters of reference
indicating corresponding parts in all the figures.
Figures 1 and 2 of the accompanying drawings are sectiona elevations and Figure 3
is an elevation, illustrating three several modifications of this Invention.
Referring to Figure 1 of the drawings, A is the spindle to which the drill or cutter
(not shewn) is secured at a. This spindle, in the example illustrated, is supported in
bearings B, from which an arm or projection b extends for connection with the
feeding device. The drill or cutter receives its rotary motion, in the present example,
from a prime mover, by means of a cord passing over a pulley C fixed to the spindle A,
and as the drill or cutter is advanced and retracted by the feeding device, the
bearings B with their appurtenances are moved down and up or to and fro in the
stationary guide D, all as in the ordinary manner.
Now, the present invention relates to the feeding device, and consists in the employ-
ment of a duplex or compound feed motion viz. a primary feed motion such as P by
which the drill or cutter is brought to or near the surface of the work; and a
secondary feed motion such as S by which the drill or cutter may be advanced a
definite and predetermined amount.

page_text: The primary feed motion P (shewn in Figure 1) consists of a screw d, working
through a fixed part c of the frame of the machine, and operated by a milled wheel e
(or it may be operated by any other suitable device). The secondary feed motion S
(shewn in Figure 1) consists of a screw f, carried by the body of the milled wheel e
(or of its substitute) and which passes through a hole in the arm or projection 6 of the
bearings B, and carries a nut g working on the screw f and revolving in the said hole,
a collar being fixed to the nut g, so that as the nut is traversed on the screw f, the
arm or projection with the drill or cutter is carried with it. Beyond the nut g, on
an extension of the screw f, is an adjustable stop formed by a sleeve i which may be
moved by a nut n, and is set to the requisite position relatively to the extremity of the
nut g.
Assuming that the work or article to be operated upon has been placed in position,
and that the stop i has been adjusted as shewn in the drawings so as to leave between
it and the nut g a distance equal to the desired depth of cut, and that the drill or
cutter has been set in rotation, the milled wheel e is then turned by the operator so
as to unscrew the screw d for a sufficient distance out of the fixed part c of the frame,
thus carrying down the bearings B, and therewith the drill or cutter, until the point
of the latter comes near or in contact with the surface of the work. The operator then
turns the nut (in place of the milled wheel e) so as to cause such nut to rotate along
the screw away from 1, 1, the near extremity of the milled wheel e, until the said
nut comes into contact with the stop i, when the desired depth of cut will have
been attained. The retraction of the drill or cutter is obviously obtained by the
reverse movement of the nut g and the milled wheel e.
I
In the modification illustrated in Figure 2, which may he employed where most
convenient, the fixed part c of the frame, through which the screw d of the primary
feed motion works, is arranged at the opposite side of the gear, being carried by the
stationary guide D, but the arrangement is otherwise similar to that hereinbefore
described with reference to Figure 1.
Figure 3 represents a further modification, in which a lever is substituted for a serew
in the secondary feed motion S. In this case the screw d of the primary feed motion P,
works through a nut ¹ carried by a lever k, the extremity 2 of which is pivotted to
the frame D of the machine, whilst the opposite extremity 3 of such lever is capable of
moving between stops 1, m, one (m) of which is adjustable to suit the depth of cut
required, or both stops may be made adjustable if desired. The primary feed is
imparted by turning the milled wheel e (between which and a collar the arm or
projection of the bearings B is carried) while the extremity 3 of the lever is held
against the stop 7 as shewn in the drawing, until the point of the drill or cutter arrives
at or near the surface of the work. The extremity 3 of the lever is then moved to
the opposite stop m by which, if the position of this stop has been properly adjusted,
the required depth of cut will be ensured. The drill or cutter is retracted by reverse
movements of the parts as before.
This modification (whilst suited for obtaining letters and designs the lines of which
are equally thick, for which purpose the modifications illustrated in Figures 1 and 2
are chiefly intended) is particularly adapted for work such as what are known as script
letters in which thick and thin lines have to be cut by conical pointed drills or cutters,
whose depth of cut determines the width of line, the modification represented in
Figure 3 affording facilities for the frequent adjustment necessary to suit the con-
stantly varying depth corresponding to the width of line required.
The modifications hereinbefore described are given as typical examples of the
manner of carrying out this Invention, but the apparatus may be otherwise modified
whilst retaining the general principle of the duplex or compound feed motion, for
imparting a primary feed to bring the drill or cutter to or near the surface of the work,
and a secondary feed by which the drill or cutter may be advanced a definite pre-
determined amount to give the required depth of cut. For example, the primary
feed motion may consist of the ordinary screw operated by the milled wheel or its
equivalent as herein before described, and the secondary feed motion may consist
of a clutch, which may be made to grip the primary feed screw or its wheel, the

page_text: arrangement being such that the clutch is retained stationary and out of action while
the primary feed is being imparted, but that it may then be moved by hand the distance
between two stops (one of which is adjustable) and acting on the milled wheel or its
equivalent will move it round the distance corresponding to the desired depth of cut.
Or any other suitable modification may be employed embodying the same principle.
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. In machines for engraving, and cutting sunk surfaces by means of revolving drills
or cutters, the employment of a duplex or compound feed motion, that is to say a
primary feed motion by which the drill or cutter is brought to or near the
surface of the work and a secondary feed motion by which the drill or cutter is
advanced a definite amount, which may be regulated, substantially as herein before
described.
2. In machines for engraving, and cutting sunk surfaces by means of revolving
drills or cutters, the peculiar constructions, arrangements and combinations of parts,
for regulating the feed of the drill or cutter so as to ensure a uniform depth or the
required depths of cut, substantially as herein before described with reference respec-
tively to Figure 1, Figure 2 and Figure 3 of the accompanying drawings.
Dated this 16th dose of Awst 1000
THOS. J. HANDFORD,
50, Bedford Row, London, W.C.,
Agent.