IMPROVEMENTS IN APPARATUS FOR CUTTING TOOTHED GEARING.”
Year: 1875

page_text: LETTERS PATENT to Alfred David Turner, of Dalston, in the County
of Middlesex, Engineer, for the Invention of "IMPROVEMENTS IN
APPARATUS FOR CUTTING TOOTHED GEARING.”
PROVISIONAL SPECIFICATION left by the said Alfred David Turner
at the Office of the Commissioners of Patents, with his Petition,
on the 26th May 1875.
I, ALFRED DAVID TURNER, of Dalston, in the County of Middlesex,
Engineer, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN APPARATUS FOR CUTTING TOOTHED GEARING," to be as
follows:-
The ordinary manner of cutting the teeth of toothed wheels or of
other toothed gearing is to employ a rotary cutter and a dividing plate,
the dividing plate being marked out according to the size of the teeth to

page_text: be out, so that the wheel after each successive tooth has been cut by the
rotary cutter is advanced to the proper position for the cutter to cut the
next following tooth. This mode of cutting in addition to being slow is
defective, because by it the teeth are not always out of the same size or
of the same distance apart, a matter of much importance in toothed
gearing. The apparatus besides is expensive.
Now according to my Invention all the teeth are cut at one con-
tinuous operation and with perfect truth and accuracy; the time
occupied is only about one-eighth of that required by the old apparatus,
and my apparatus is of an inexpensive character.
For the purpose of my Invention I employ a cutter of spiral form
fixed on a rotary spindle or shaft, and I mount the wheel to be cut
between centres, and so that its periphery or the portion to be cut
shall be in contact with the cutter, and I provide it with a alow feed
motion so that the cutter may be enabled to cut gradually across it.
The cutter gradually increases in thickness from one end until its
thickness is equal to the space to be cut between the teeth, while the
distance between the turns of the spiral or cutter is equal to the thickness
of the teeth.
It will be readily understood that upon the cutter being caused to
rotate in contact with the wheel to be cut the wheel will also rotate on
its axis, and as it does so the same portions or more correctly speaking
portions on the same radii are acted upon by the outter at each
. revolution, the operation being continued until the teeth have been
entirely cut. As the wheel rotates in a uniform manner and is acted :
upon by the spiral cutter it follows that all the teeth are cut of exactly
the same thickness and depth. The angle at which the wheel is placed
to the cutter will depend upon whether the wheel is to be a spur wheel,
a bevil wheel, or otherwise.
For cutting the teeth of racks the operation will be the same, except {
that when the rack has been acted upon from end to end the motion of
the cutter should be reversed, or any other suitable mode of continuing
the action of the spiral cutter upon the rack may be adopted.

page_text: Patent, and of an Order of the Lord Chancellor, by the said Alfred
David Turner in the Great Seal Patent Office on the 8th December
1875.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ALFRED
DAVID TURNER, of Dalston, in the County of Middlesex, Engineer,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-sixth day of May, in the year
of our Lord One thousand eight hundred and seventy-five, in the
thirty-eighth year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto me, the said Alfred David Turner, Her
special licence that I, the said Alfred David Turner, my executors,
administrators, and assigns, or such others as I, the said Alfred
David Turner, my executors, administrators, and assigns, should at
any time agree with, and no others, from time to time, and at all
times thereafter during the term therein expressed, should and law-
fully might make, use, exercise, and vend, within the United Kingdom
of Great Britain and Ireland, the Channel Islands, and Isle of Man,
an Invention for "IMPROVEMENTS IN APPARATUS FOR CUTTING TOOTHED
GEARING," upon the condition (amongst others) that I, the said Alfred
David Turner, my executors or administrators, by an instrument in
writing under my, or their, or one of their hands and seals, should
particularly describe and ascertain the nature of the said Invention,
and in what manner the same was to be performed, and cause the
same to be filed in the Great Seal Patent Office on or before the
Eighth day of December, One thousand eight hundred and seventy-five.
NOW KNOW YE, that I, the said Alfred David Turner, do hereby
declare the nature of my said Invention, and in what manner the
same is to be performed, to be particularly described and ascertained
in and by the following statement thereof, reference being had to the
accompanying Drawings, that is to say :-
The ordinary manner of cutting the teeth of toothed wheels or of
other toothed gearing is to employ a rotary cutter and a dividing plate,
the dividing plate being marked out according to the size of the teeth to

page_text: 1
be cut, so that the wheel after each successive tooth has been cut by the
rotary cutter is advanced to the proper position for the cutter to out the
next following tooth. This mode of cutting, in addition to being slow, is
defective, because by it the teeth are not always cut of the same size or
of the same distance apart, a matter of much importance in toothed
gearing. The apparatus besides is expensive.
Now according to my Invention all the teeth are cut at one con-
tinuous operation and with perfect truth and accuracy; the time
occupied is only about one-eighth of that required by the old apparatus,
and my apparatus is of an inexpensive character.
For the purpose of my Invention I employ a cutter of spiral form
'fixed on a rotary spindle or shaft, and I mount the wheel to be cut
between centres, and so that its periphery or the portion to be cut shall
'be in contact with the cutter, and I provide it with a slow feed motion
so that the cutter may be enabled to cut gradually across it. The
cutter gradually increases in thickness from one end until its thickness
is equal to the space to be cut between the teeth, while the distance
between the turns of the spiral or cutter is equal to the thickness of the
teeth.
It will be readily understood that upon the cutter being caused to
rotate in contact with the wheel to be cut the wheel will also rotate on
its axis; and as it does so the same portions, or more correctly speaking
portions on the same radii are acted upon by the cutter at each
revolution, the operation being continued until the teeth have been
entirely cut. As the wheel rotates in a uniform manner and is acted
upon by the spiral cutter it follows that all the teeth are cut of exactly
the same thickness and depth. The angle at which the wheel is placed
to the cutter will depend upon whether the wheel is to be a spur wheel,
a bevil wheel, or otherwise.
For cutting the teeth of racks the operation will be the same, except
that when the rack has been acted upon from end to end the motion of
the cutter should be reversed, or any other suitable mode of continuing
the action of the spiral cutter upon the rack may be adopted.
My Invention will be fully understood by reference to the accom.
nanving Drawings.

page_text: Figure 1 is a front view shewing a frame A which is bolted or otherwise
secured to the saddle of a lathe or milling machine; B is a fixed, and O
a travelling centre between which a spindle D is held; E, E, are the
wheels to be cut; they are placed on the spindle D, and are firmly
secured thereon by means of a lock nut F; G is the spiral cutter (seen
more clearly in the side view Figure 2) fixed to the chuck H of the lathe.
I.
As will be seen in Figure 2, the cutter gradually increases in thickness
from the first end 9 until it reaches a thickness equal to the space to be
cut between the teeth of the wheel, while the distance between the turns
of the spiral is as before mentioned equal to the thickness of the teeth.
The relative position of the wheels E and the cutter G is such that the
cutter will cut exactly to the required depth of the teeth, and in order
to properly adjust them the frame A may be raised or lowered as
required by means of set screws passed through the frame into the
saddle of the lathe; or if a milling machine be employed the adjustment
will be effected in the ordinary manner. As the cutter is caused to
rotate and one of the wheels E, owing to the feed motion given to the
saddle of the lathe, is brought into contact therewith the wheel will also
rotate turning with it the spindle D, the result of which is that portions
on the same radii of the wheel are acted upon by the cutter at each
revolution of the wheel, and as the feed motion of the wheel is con-
tinuous it follows that the cutter cuts gradually across the periphery of
the wheel until the teeth are entirely cut. The teeth will be out square
or of V shape according to the square or taper form of the teeth of the
cutter.
The first two wheels E in Figure 1 are shown as entirely cut, while
the next two are in course of being out, the remaining wheels not yet
having reached the cutter. The number of wheels E held between the
centres B and C may be varied as thought best. When the axes of
the wheels and the axis of the pitch of the spiral (that is to say, an axis
represented by the dotted line 1, 1, in Figure 2) are at right angles to
each other the wheels will be cut in the form of spur wheels. For
cutting bevil wheels the axes must be placed at a sufficient angle, while
for cutting mitre wheels the axes must be so placed that the cutter
will act upon the proper face of the wheel.
And having now described the nature of my said Invention, and in
what manner the same is to be performed, I declare that I claim, the

page_text: employment in apparatus for cutting toothed gearing of a spiral cutter,
arranged and acting substantially as berein-hefore described.
In witness whereof, I, the said Alfred David Turner, have here.
unto set my hand and seal, this Thirtieth day of November,
One thousand eight hundred and seventy-five.