Improvements relating to Milling Outters and other Tools.
Year: 1898

page_text: Date of Application, 17th Nov.,
1898
Complete Specification Left, 16th Aug., 1899-Accepted, 14th Oct., 1888
PROVISIONAL SPECIFICATION.
Improvements relating to Milling Outters and other Tools.
We, CHARLES GEORGE GARRARD, and CHARLES RILEY GARRARD, both of 6,
Oliver Road, Edgbaston, in the City of Birmingham, Engineers, do hereby declare
the nature of this invention to be as follows:-
This invention consists of improvements relating to milling cutters and other
tools such as screw taps, boring reamers, and screwing dies, our object being to
make the cutting blades or like parts of such tools separately from their stock or
holder, but to so arrange and connect them with such stock or holder as to permit
of relative adjustment for the purposes hereinafter described.
In the application of our invention to the construction of a circular milling
cutter we employ a number of separate and independent cutting blades_or_teeth
formed from steel of a rectangular or other suitable section, the inner end of each
blade being rounded to rest upon a corresponding seating at the base of each of
the blade apertures formed around the tool stock or holder. We also provide a
circular and conical lug or projection from both sides of each blade or tooth to
enter corresponding recesses in the caps or retaining pieces which are detachably
connected to the tool stock or centre.
The cutting blades or teeth when the caps or retaining pieces are slackened can
be turned upon their pivot like inner ends through a small are in either direction
to the extent of the difference between the width of the blades and the width of
the grooves or apertures in which they are seated. When all the blades have
been thus turned against one side of the grooves and secured thereat by the caps
or retaining pieces their outer or cutting ends can be turned to the desired shape
in a lathe or other machine, and after being thus turned they are removed and
suitably hardened and tempered. On replacing them in the tool stock or holder
we roll or rock them over to the opposite side of their grooves or apertures and
secure them at such position. The tools are then at the required angle for
effective cutting; the precise angle or rake of the blades (which is fixed by the
dimensions of the blade apertures relatively to the blades themselves) is deter-
mined by the particular work for which the milling cutter is required.
When the blades or cutters require sharpening the caps or retaining pieces are
slackened to permit of the blades being pushed over to the opposite side of their
slots; they can then be readily sharpened by rotating them in a grinding machine
against an emery wheel or other sharpening device. In the case of formed cutters
it is preferable to grind them on the face from the front of the teeth as usual,
instead of rotating and grinding them on the back of the teeth.
We sometimes make our blades, dies, or other cutting tools so that they will
cut by being revolved, or by revolving the work, against or around them in either
direction.
In such a case we can hold the tool in the middle of the slot or thereabouts
while it is being turned, machined, or ground, and after hardening and when
ready for use it can lie against the side that is the more remote from the cutting
edge. Thus if the cutter is turning to the right the blades or tools will lie to the

page_text: left of the grooves, whilst on reversing the same cutter to make it cut whilst
running left handed the blades will lie over to the right hand sides of the grooves.
Our invention also admits of a staggered or uneven distribution of the cutters
for various purposes. Thus if we require to cut an article in such a manner as to
leave a ridge on it with two straight sides, we stagger the blades and so place
them alternately to the right and left as to preserve a uniform width of the ridge
notwithstanding the wear of the cutting edge.
Dated this 16th day of Novamban 1000
MARKS & CLERK,
18, Southampton Buildings, London, W.C., &
13, Temple Street, Birmingham, Agents for the Applicants.
Improvements relating to Milling Outters and other Tools.
We, CHARLES GEORGE GARRARD and CHARLES RILEY GARRARD, both of 6,
Oliver Road, Edgbaston, in the City of Birmingham, Engineers, 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 consists of improvements relating to milling cutters and other
tools such as screw taps, boring reamers, and screwing dies, our object being to
nake the cutting blades or like parts of such tools separately from their stock or
holder, but to so arrange and connect them with such stock or holder as to permit
of relative adjustment for the purposes hereinafter described.
to.
In the accompanying sheet of explanatory drawings to be hereinafter referred
Figure 1 is an end elevation (with half in section), and Figure 2 a side elevation
(with one retaining cap removed), of a circular milling cutter constructed in
accordance with our invention.
Figure 3 is a sectional end elevation and Figure 4 a side elevation of the
stock or holder forming a part of the complete milling cutter.
Figure 5 is a sectional end elevation and Figure 6 a side elevation of one of
the caps or retaining pieces.
Figure 7 is a side elevation and Figure 8 an end elevation showing one of the
separate and independent cutting blades or teeth.
The same reference letters in the different views indicate the same parts.
In the application of our invention to the construction of a circular milling
cutter such as shown at Figures 1 and 2, we employ a number of separate and
independent outting blades or teeth as A formed from steel of a rectangular or
other suitable section, the inner end of each blade being rounded to rest upon a
corresponding seating at the base of each of the blade apertures b formed around
the tool stock or holder B. We also provide a circular and conical lug or pro-
iection a from both sides of each blade or tooth A to enter corresponding recesses c
in the caps or retaining pieces C which are detachably connected to the tool
stock or centre, preferably by means of clamping nuts screwed on to the mandrel
by which the complete tool is rotated. The outer side of the recess in the cap
or retaining pieces is of a tapered form as shown, and thus when the caps are
tightened a wedge like action is set up between them and the conical lugs a of
the blades A, which effectually clamps the said blades to the seats of the aper-
tures in the stock or holder B.
The cutting blades or teeth A when the caps or retaining pieces C are slackened,
can be turned upon their pivot like inner ends through a small arc in either
direction to the extent of the difference between the width of the blades and the

page_text: width of the grooves or apertures 6 in which they are seated. When all the
blades have been thus turned against one side of the grooves and secured thereat
by tightening the caps or retaining pieces, their outer or cutting ends can be
turned to the desired shape in a lathe or other machine, and after being thus
turned they are removed and suitably hardened and tempered. On replacing
them in the tool stock or holder we roll or rock them over to the opposite sides of
their grooves or apertures and secure them at such position. The tools are then at
the required angle for effective cutting; the precise angle or rake of the blades
(which is fixed by the dimensions of the blade apertures relatively to the blades
themselves) is determined by the particular work for which the milling cutter is
required.
When the blades or cutters require sharpening the caps or retaining pieces C
are slackened to permit of the blades being pushed over to the opposite side of
their slots; they can then be readily sharpened by rotating them in a grinding
machine against an emery wheel or other sharpening device. In the case of
formed cutters (such as shown in the illustration) it is preferable to grind them
on the face from the front of the teeth as usual, instead of rotating and grinding
them on the back of the teeth.
We sometimes make our blades, dies, or other cutting tools so that they will
ent by being revolved, or by revolving the work, against or around them in either
direction. In such a case we can hold the tool in the middle of the slot or there-
abouts while it is being turned, machined, or ground, and after hardening and
when ready for use it can lie against the side that is the more remote from the
cutting edge. Thus if the cutter is turning to the right the blades or tools will
lie to the left of the grooves, whilst on reversing the same cutter to make it cut
whilst running left handed the blades will lie over to the right hand side of the
grooves.
Our invention also admits of a staggered or uneven distribution of the cutters
for various purposes.
We make our independent cutters in varying shapes and employ them with
stocks or holders of such form as may be best adapted to the particular service
for which they are required.
Having now particularly described and ascertained the nature of our said
invention and in what the same is to be performed, we declare that what we
claim is:-
1. In milling cutters and other tools such as screw taps, boring reamers, and
screwing dies, the arrangement of separate and independent cutting blades or
teeth with a stock or holder permitting of a turning or rocking movement of the
said blades or teeth relatively to the said stock or holder, substantially as and for
the purposes described.
2. In milling cutters and other tools such as screw taps, boring reamers, and
screwing dies, having separate and independent blades or teeth as A, means for
clamping the said blades in the required position within the apertures 6 of the
stock or holder B, substantially as described and as illustrated.
3. An improved milling cutter or like tool having separate and independent
blades or teeth adjustable within their stock or holder, substantially as described
and as illustrated.
DJ him th
1000
Dated this 15th day of August
1000
4035
MARKS & CLERK,
18, Southampton Buildings, London, W.C..
13, Temple Street, Birmingham, & 25, Cross Street, Manchester,
Agents for the Applicants.