New or Improved Apparatus applicable to Screw-cutting or other kinds of Turning Lathes for Regulating the Depth of Cut.
Year: 1890

page_text: Date of Application, 6th June, 1890
Complete Specification Left, 27th Sept., 1890-Accepted, 1st Nov., 1890
PROVISIONAL SPECIFICATION.
New or Improved Apparatus applicable to Screw-cutting or other
kinds of Turning Lathes for Regulating the Depth of Cut.
I EDWARD RICHARDSON of Airton near Bell Busk in the West Riding of the
County of York Mechanic do hereby declare the nature of this invention to be as
follows:-
This invention relates to certain improved apparatus applicable to screw cutting
or other kinds of turning lathes for regulating the depth of cut of the tool.
The apparatus is constructed of iron or other suitable metal and is capable of easy
adjustment, and is applicable to screw cutting or other kinds of turning lathes. The
application of this apparatus to such lathes enables the tool to be brought into contact
with the material operated upon, to any depth required with perfect accuracy more
expeditiously and with less difficulty than hitherto has been possible. In carrying
out this invention the lever (with handle) upon the front end of the screw whereby
the tool slide is moved forward or backward across the saddle of the lathe, is controlled
so that the depth of any cut may with perfect accuracy be determined upon before
bringing the tool into contact with the material.
In the following description of construction particulars are given as for a 9 inch
centre lathe. I make a wheel about six and a quarter inches in diameter straight upon
the front side and about half an inch thick with a boss in the centre at the back one and
three quarters of an inch long and two inches and a half in diameter. This wheel
now under description has a hole bored through the centre one and three quarter
inches in diameter and which is consequently two inches and a quarter in depth, on
the front side of this wheel is fixed a round stood three quarters of an inch in diameter
and one inch and three quarters in length the centre of which is about two inches and
a half from the centre of the wheel. This wheel is provided with sixty four suitable
teeth on the outer edge or rim which may be numbered on the front side opposite
each tooth. I then construct a worm wheel two and a half inches in diameter and
one inch in length with a single right hand thread cut to the proper pitch and size so
as to gear into the teeth of the wheel above described. I next construct a bracket
adapted so as to bolt on to the saddle of the lathe by means of the slot nearest the
front at the left side. The bracket is made with a bearing three inches deep so as to
hold an upright shaft (three quarters of an inch in diameter at a distance of one inch
and three quarters from the front of the saddle to the centre of the shaft, and is made
so that the centre of the upright shaft is about four inches from the centre of the
screw for the cross slide of saddle, and the underside of the bearing is half an inch
above level with the centre of the above screw, the upright shaft five inches long is now
made to fit the hole in the bearing so that it can be moved round in it. The worm
wheel is now made fast upon the lower end of the shaft close under the bearing, and a
disc three inches and a half in diameter and three quarters of an inch thick (hollowed
at the underside) is made fast upon the top end close above the bearing, this disc
is marked out and numbered on the top side (or the face of it) into eight equal parts
and slightly notched on the edge opposite each mark to receive a spring catch fixed
to the bracket behind the disc for keeping it in any position required. It has also a
small handle projecting on the top side wherewith to move it around. An adjustable
pointer is suitably fixed by a thumb screw to the front of the bracket a little above
the worm wheel, which can be set to point at the numbers marked on the front of the
first wheel when that wheel is fitted and placed upon the screw for the cross slide of
the saddle, this pointer also answers for keeping the wheel in its place upon the screw
by projecting ever the teeth a little at the front.

page_text: The invention is applied and used as follows:-
The wheel with stood attached is accurately made to fit so as to move round upon
the screw for the cross slide of the saddle, and when in its position is situated close in
front of the saddle, behind the lever (with handle) upon the front end of the screw.
The bracket may now be fixed to the saddle so that the worm wheel is in proper gear
with the other wheel For external screw cutting the blank to be cut being ready
in the lathe centres and the tool rest put to a suitable distance from it, the first
notch in the disc and the first tooth in the wheel may now be set opposite the
spring catch and the adjustable pointer by turning the disc round. The lever and
handle which has been withdrawn a little to let it pass the end of the stud may now
be pushed close up and be moved forward up to the stud. The tool is now made
fast in the tool rest with the cutting edge close up to the blank to be cut, any depth
of cut may now be allowed by turning the disc round as required, to suit the class
of work or the kind of material operated upon. The lever (with handle) is simply
turned round up to the stud before commencing the cut and withdrawn from the
stud when the end of the thread is reached, the stud can whilst one cut is being
taken be easily regulated for the next cut, until the proper depth is reached, the
numbers on the wheel and the disc will now shew the depth or distance that the
tool has been put forward, so that any number of screws can be cut of the same
size. For ordinary turning supposing the screw for the cross slide to be half an inch
piich, once round of the disc is equal to a sixty fourth part of an inch more less in
diameter as may be required, and so on in proportion, or in coming at a collar or
projecting part of the piece of metal being operated upon, the tool can be brought
back sufficiently until it has passed it and then be put exactly the same depth as before
by bringing the lever up to the stud.
The improvements and advantages claimed for this my invention are these that by
using my apparatus the tool can at once be put with perfect accuracy either externally
or internally into its proper depth of contact for each successive cut in screw-
cutting, or to produce a certain diameter without loss of time or danger of breakage
to the cutting edge of the tool.
1 do not confine myself to the exact dimensions given above as the same and also
the number of teeth in the wheel or threads in the worm wheel may be varied to suit
the size or construction of the lathe to which it is applied also to adapt it for either the
vulgar fraction or decimal style of calculation or lathes may be specially constructed
for and in conjunction or combination with my said invention.
Dated this 4th day of June 1890.
EDWARD RICHARDSON.
COMPLETE SPECIFICATION.
New or Improved Apparatus applicable to Screw-cutting or other
kinds of Turning Lathes for Regulating the Depth of Cut.
I, EDWARD RICHARDSON, of Airton, near Bell Busk, in the West Riding of the
County of York, Mechanic, 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 relates to certain improved apparatus applicable to screw cutting
. or other kinds of turning lathes for regulating the depth of cut made by the tool.
The apparatus is capable of adjustment on the slide-rest of existing lathes and by
means thereof, the depth of cut to be made by the cutting tool may be gauged to the
greatest nicety and in the most expeditious manner, at the same time its simplicity of
construction allows of its being readily manipulated by the most inexperienced.
The invention will be more readily understood upon reference to the accompanying
drawings in which Fig. 1 is a front elevation of a portion of a lathe having my improved
apparatus adapted thereto. Fig. 2 is a plan and Fig. 3 a side elevation, both drawn
to a larger scale, showing my invention detached from the lathe; Fig. 2 also showing
part of the saddle of the lathe slide. Figs. 4 and 5 are enlarged detail views of parts

page_text: of the apparatus, and Fig. 6 shows a stud or arbor referred to in describing the
working of the invention.
In carrying out my invention I construct a wheel A having a suitable number of
teeth on its periphery, say sixty-four as shown on the drawings, or it may be provided
with say fifty teeth to suit the decimal system. This wheel A has a boss A' at its
centre on the back, and the wheel and boss are bored through to form the said boss
into a sleeve, the hole therein being made accorately of a size to allow the said wheel
to revolve independently when adjusted on the front end a of the threaded spindle
which moves the slide-rest transversely, on removal of the lever or handle a'. The
face of this wheel A is divided off and provided on its outer circumference with
numbers (say from 1 to 64, in a wheel having sixty-four teeth) corresponding with
and opposite to each tooth.
The inner circumference on the face of this wheel may also be divided into eighths
or other proportionate divisions as desired. A² is a stud or stop on the said wheel
for purpose to be hereinafter described.
A single threaded right hand worm-wheel B
of suitable dimensions is made to gear with the wheel A, being mounted on an arbour
or shaft C capable of revolving in a bracket or bearing D, bolted to the left front side
of the saddle of the rest by the bolt E. To the upper end of the shaft C is fixed a
dise F which is also divided circumferentially on its face, in this instance preferably
into eighths or fourths. The right top front of the bracket D is provided with a
projecting part d having a curved slot therein into which a pointer H (shown more
clearly in the enlarged detail view Fig. 4) is arranged and a pointer G is also fixed,
near the said pointer H as shown. The pointer H is movable in the slot but may be
made fast therein by means of the thumb-screw 7, see Figs. 2 and 3. A portion of
the bracket D is made to overlap the front of the teeth in wheel A which thus keeps
the said wheel in its position upon the screw a. The disc F has a groove f cut
around its periphery and at every fourth (or other) part within this groove findenta-
tions or notches are cut out, exactly coinciding with the numbers on the face of
the disc. A spring-catch or pawl J, shown better in enlarged detail view Fig. 5,
which is a plan of the underside of same, of peculiar construction, is arranged on
the bracket D and its point takes into the indentations on the disc F. By pressing
a finger on the knob of this catch the resistance of its spring 2, see Fig. 3, is over-
come and it is disengaged from the disc F, and the disc may now be freely revolved
by means of the loose handle 2. There is no necessity to hold the finger against the
knob to keep the catch J out of the indentations f¹, as the pressure applied by the
finger turning the catch on its centre causes the point j³ Fig. 5, to pass to the other
side of the centre line of the centre j', which thus causes the pressure of the spring
to be applied in keeping the catch clear of the disc F and the part being made
flat at such an angle as shown prevents the catch J from leaving the dise F too far, a
slight pressure of the finger on the opposite side of the knob j immediately returns the
catch J into its former position. In rotating the disc F the catch J bears on the
surface of the groove f. The worm-wheel B may be so arranged as to be capable of
being put out of gear with the tooth wheel ; this may be done, for example, by
adjusting an eccentric bearing within the bracket D for the arbour C to revolve in,
the said eccentric bearing being provided with a projecting part to which a handle is
attached for turning the bearing and so bringing the arbour C and with it the worm-
wheel B either away from or in gear with the tooth-wheel A.
The
Having declared the nature of this invention [ will now proceed to show how
the same may be performed; and for this purpose I will presume that a screw
thread of a predetermined pitch is to be cut upon a blank X, (Fig. 1) ready turned
to the required diameter and already adjusted between the lathe centres.
handle a¹ is drawn back a little on the screw a sufficiently to prevent contact of the
stud A² with the handle a' in revolving the screw a. The toothed wheel A may now
be set by revolving the disc F so that the fixed pointer G is opposite No. 64 tooth
which pointer is so placed that the catch J will fall into the slight indentation
opposite No. 1 division in the disc F. The handle a' is then moved round so as to
place the tool rest at a suitable distance from the work, and the handle a' then pushed

page_text: back home on the screw a, after which it is partially revolved to the right until it
comes in contact with the stud A². The tool being inade fast in the tool rest with
its cutting edge just up to the work, any depth of cut may now be allowed by
turning the disc F in the direction of the arrow Fig. 2. Suppose the transverse
screw a has a pitch of half an inch, it follows that one revolution of the handle a¹
would force the point of the cutting tool half an inch forward into the work operated
upon. But will presume that one sixty fourth part of an inch is the depth of cut
desired. To obtain such a cut by the use of my apparatus the disc F operating the
worm-wheel B must be rotated two revolutions, thus causing the wheel A to revolve
for the space of two teeth and the stud A2 thereon to leave the handle for a pro-
portionate space; this being equivalent to a thirty-second part of a revolution and
regulating the cutting tool for producing a cut one sixty-fourth part of an inch
deep. If the screw to be cut is to have a right hand thread the tool is slided
longitudinally so as to bring it just past the end of the blank X, the handle a¹
moved round to the right until in contact with the stud A2, and the lathe is now
ready for the first cut. The lathe being set in motion, whilst the first cut is being
made the apparatus can easily be set for the next cut. When the end of the thread
now being cut is reached the handle a' is simply turned backwards from the stud A²
so as to bring the tool clear of the work; the tool is then slided back longitudinally
in the usual manner to the other end of the work and the handle a' being again brought
up to the stud A2, the lathe is ready for the next cut, this being repeated until the
required depth of thread is obtained. Suppose the depth of thread required is to be
one eighth part of an inch, then the tooil No. 16 (or the equivalent to one fourth of
a revolution of the wheel A) will require to be opposite the fixed pointer G for the
finishing cut. In the cases, already cited the fixed pointer Ġ only has been
mentioned to indicate the position of the wheel A for both the starting and intermediate
and also the finishing cuts, but should the predetermined depth of any desired screw
thread be such as to require any other of the divisions of the disc F (except No. 1)
to be opposite the spring catch or pawl J, in which case there would not be any tooth
in the wheel A directly opposite the fixed pointer G, as the said pointer would point
to some part in between a tooth, then the adjustable pointer H may be set opposite the
next tooth which will indicate the exact depth for the finishing cut.
If the
One revolution of the disc F, turning the wheel A one tooth, will thus produce a
cut one one hundred and twenty-eighth of an inch deep, and a half of a revolution,
bringing the number of the disc up to the catch J and the wheel A half a tooth
round, will procure a one two hundred and fifty-sixth part of an inch cut.
teeth of wheel A were fifty in number and the pitch of screw a unaltered, one revolu-
tion of disc would cause a cut to be made of the one hundredth part of an inch
deep, provided the worm-wheel B were altered to suit the alteration in the teeth of
the wheel A. Or other systems of calculating might be employed by adapting the
teeth of the wheel A and the worm-wheel B to suit same.
Where the apparatus is not made to allow of the worm-wheel B being put out of
gear with the wheel A, it may sometimes be found advantageous to lengthen the
spindle of screw a, in order to allow of the better partial withdrawal of the handle a¹
so as to clear the stop A² when required.
The apparatus may equally well be employed for cutting internal screw threads,
or for regulating the depth of cut made by a cutting tool used in turning lathes other
than for screw cutting purposes without alteration of the parts relating to this
invention; also, as by this apparatus, the regulation of the depth of cut made by a
cutting tool is accomplished by regulating the backward and forward motion of the
transverse slide, it is obvious that the apparatus may be employed for regulating the
motion of the said transverse slide of a lathe in cases other than where a cutting tool is
or may be employed.
In using the apparatus for ordinary turning,-suppose, for instance, a stud or
arbor Z Fig. 6, with a collar in the middle and having two lesser diameters at one end,
as shown on the drawings, is to be turned. The apparatus being adjusted as described
already (for screw cutting) the cutting edge of the tool may for example be set to a

page_text: standard gauge, say one inch in diameter, which is placed between the lathe centres.
and up to which the tool can be set. The tool having been set in position is made
fast in the tool rest the arbor Z is adjusted between the lathe centres and the lathe set
in motion. When the tool arrives at the collar Z' the handle a' is turned back away
from the stud A' until the tool has passed the said collar, and when right past, the tool
can be returned to exactly the same position as before, so as to turn the part at the other
side of the collar to the same diameter, by revolving the handle al until it again
strikes the stud A; the position of the disc F and the teeth on the wheel A showing
the depth of the finishing cut for this portion of the arbor or stud Z. Whilst the
finishing cut is being made the apparatus can be set for the smaller part, which is
say three-quarters of an inch in diameter, by moving the disc F round sixteen revolu-
tions which will allow the tool to be adjusted so as to cut to a diameter of one fourth of
an inch less. Whilst this cut is being made the disc F may be rotated other eight
revolutions thus allowing the tool to cut one sixteenth of an inch deeper still for the
part 21, which is say five eighths of an inch diameter. It will be seen that when any
certain diameter has been produced, any other diameter may be obtained, either
larger or smaller, by imparting to the disc F the necessary number of revolutions, or
parts of a revolution, in the proper direction.
In using the apparatus for cutting internal screw threads or other kinds of internal
work it is only necessary to revolve the handle a' in the opposite or left direction so
as to bring it up against the other side of the stud A2 and to turn the disc F in the
opposite direction to the point of the arrow Fig. 2.
It may be observed that one special advantage to be gained by the apparatus is that
while one cut is being produced the mechanism may be easily adjusted for the following
cut, thus enabling the cutting tool to be at once brought up to the work and to cut to
the proper depth without delay.
The construction of some lathes might require a different form of bearing to the
one shown at. D, without departing from the essential features of the invention; and,
if desired, lathes may be specially constructed for or in combination with the apparatus
constituting this my said invention.
Having now particularly described and ascertained the nature of this inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is
Firstly. The construction of improved apparatus for regulating or gauging the depth
of cut made by a cutting tool employed in screw cutting or other lathes, adapted for
attachment to the lathe rest, substantially as herein described and shown on the
drawings.
Secondly. The combination of a loose toothed wheel such as A having numbered
divisions thereon with the transverse lathe rest screw of a screw cutting or other turning
lathe, the said toothed wheel being provided with a stop or stud for arresting the
progress of the handle of the said transverse lathe rest screw when revolving same,
substantially as described and for the purposes specified.
Thirdly. The combination of the sleeved toothed-wheel A baving numbered divisions
and the stop or stud A² thereon, with the worm-wheel B and disc F also having
numbered divisions thereon both on the shaft or arbor C, said shaft working in the
bracket or bearing D provided with the pointers G and H and the spring-catch or
pawl J taking into the groove and indentations around the said disc, substantially
as described and shown on the drawings.
Fourthly. The adaptation of this apparatus either for the decimal or other system
of calculation by the employment of an altered form of worm-wheel B and by
altering the teeth of the wheel A to suit the changed circumstances, substantially as
herein set forth.
n
ባለ
1
A
1000
CROSSLEY & Co.,
72, New Market Street, Bradford, Yorkshire, Agents.