Year: 1882

page_text: PROVISIONAL SPECIFICATION left by the said John Dewrance at the
Office of the Commissioners of Patents on the 27th January 1882.
JOHN DEWRANCE of Great Dover Street in the County of Surrey
MENTS IN LATHES
"
This Invention has for its object improvements in lathes.
"IMPROVE-
It often happens that lathes are employed in repeating time after time the same
work and that for this work several tools of different forms are required to be used
in succession. To meet these cases what is known as a capstan rest is now in use;
the upper slide of the slide rest is made to carry a revolving head with a central
pivot and with radial sockets or holders into which the several tools are set. An
objection to this form of rest is that when employed on hollow work the rest has
to be run back a long distance whenever it is required to introduce the gauge into
the work and much time is lost. In place of this capstan head with its radial tools
I employ a square (or polygon) block with a central pivot and with the tools clamped
to it along the sides. I form the block with a circular foot entering a corresponding
hole in the top slide of the rest. In the centre of the foot is a socket which receives
the pivot projecting upwards from the traversing nut. Upon the socket there fits
a coned ring it is attached to the block by screws which serve to draw it up into
close contact with the corresponding surfaces on the slide but nevertheless not so
tightly as to prevent it turning readily. A spring bolt retains the turning block in
any of the positions to which it may be turned to present one or other of the tools
to the work.
I also make the upper slide and guide of the slide rest moveable around a central
pivot for the purpose of turning taper and I control the movement around this pivot
by means of a worm engaging with a curved rack.
To lessen the care required when constantly repeating similar work I provide the
slide rest with stops so that it cannot be run further than a position to which it has
been previously adjusted.
I provide a projection upon the slide and fix a rod upon its bed or guide parallel

page_text: to the direction of motion of the slide, I have also a clip upon the rod which I can
make fast in any position and which I can shift to either side of the projection on
the slide: when the projection and the clip come into contact no further movement
of the slide in that direction can take place.
For screw cutting I employ a sliding bar carried on the side of the bed of the
lathe and which receives from a pattern or guide screw a movement in a direction
parallel to the bed of the lathe. The arrangement is as follows; there is a sleeve
upon the bar which can be clipped fast upon it in any desired position and upon the
sleeve a hand lever which is also the tool holder is carried, it can be turned around
upon the sleeve. There is an arm upon the sleeve which when the screw cutting
apparatus is in use rests upon the bed of the lathe and is guided by it. Between
the arm of the sleeve and the handle there is an adjustable screw connection by
which the height or distance of the tool from the bed can be adjusted. Thus the
tool can be brought to the lathe centre or close to it as is required when the work
is small or it can be removed from the centre to any distance which the size of the
work may render necessary.
The handle can be thrown back to remove the tool out of tho way when not
required for use. The sleeve and the bar then turn with the handle and by the
same movement the arm which follows along the guide screw and imparts longitudinal
motion to the bar is lifted.
I also construct a lathe in which the bed receives a saddle having a vertical faco
with a slide thereon which works up and down in a vertical direction. This slide
carries at its upper end the transverse horizontal slide of the slide rest upon which
is the tool holder.
The self acting movements are taken from a longitudinal worm lying horizontally
beneath the bed. The saddle carries an axis on which is a worm wheel gearing
into the worm. This axis when it-is-desired. to traverse the saddle upon the bed
is clutched fast to a spur wheel upon it which wheel engages with a rack fixed
upon the bed. The same axis carries another spur wheel for imparting tho
automatic motion to the screw of the top or transverse slide. There is a pinion
on the screw and an intermediate wheel engages both with this pinion and with
the driving wheel. The intermediate wheel is adjustable to admit of the transverse
slide being worked automatically in any position of the vertical slide upon the
saddle. For the purpose of turning taper a bar is provided at the back of the
lathe which can be set to any incline desired. The bar is pivoted at the centre
so as to be able to move in an horizontal plane. This bar serves to guide a sliding
bearing containing a sleeve into which the end of the transverse screw of the top
slide of the slide rest is received and in which it is able to move end wise. But
when desired to turn taper the sleeve can be clipped fast upon the screw and the
screw is then drawn endwise by the inclined bar.
The transverse screw at its other end passes through a similar sleeve on which
is the pinion to impart the automatic movement; but when the taper turning
mechanism is in gear the screw is left free to move longitudinally in the front
sleeve.
To facilitate the adjustment of work in the lathe I employ adjustable face
plates and angle plates consisting of two plates one capable of sliding on the
other. One plate is formed with a socket and is screwed on to the mandril of the
lathe in the usual manner.
This plate carries a pair of screws set radially and at right angles the one to the
other. They lie in grooves or slots in the plate and when turned by handles at
their ends they give motion to nuts which are contained in the grooves. The nuts
carry rollers or studs which project from the face of the main plate and enter
straight grooves in the back of the second or sliding plate. These grooves are at
right angles to each other and to the screws which control the nuts and projections
entering the grooves. Thus by means of the screws the one plate can be made
to slide on the other plate in any direction. When set the parts can be clamped
by means of clamping bolts and nuts.

page_text: The moveable plate is either cast with a right angle flange to carry the work
(if it be of a description requiring to be mounted upon an angle plate) or the
moveable plate receives the work directly upon its face.
In either case the work is fixed to the moveable plate by means of the usual
clamping bolts entering slots in the face or angle plate.
I also construct a hand rest which can be set with great facility to any position
upon the lathe bed and which can be readily removed when not required for use.
The base of the rest which stands upon the bed of the lathe has an horizontal
axis passing through it. A part of this axis is turned down and forms an eccentric.
The eccentric is contained within a loose collar or ring from which a stem descends.
The stem is screwed at its lower end and passes down through the longitudinal
opening of the lathe bed; beneath the bed it receives a cross bar and nut.
To clamp the rest of the bed the nut is screwed up when the eccentric is near
its highest position and when the parts are thus set the rest can be freed simply
by turning the axis. It can be similarly refixed when required either in the same
position or after it has been moved to another part of the bed.
Also when it happens that the rest is in the way it can be removed altogether
off the bed of the lathe; this is effected by sliding the base of the rest off tho axis
endwise and the axis and collar then alone are left upon the lathe bed.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said John Dewrance in the Great Seal Patent Office on the 27th July
1882.
JOHN DEWRANCE of Great Dover Street in the County of Surrey. "IжPROVE-
MENTS IN LATHES."
This Invention has for its object improvements in lathes.
An
It often happens that lathes are employed in repeating time after time the same
work and that for this work several tools of different forins are required to be used
in succession. To meet these cases what is known as a capstan rest is now in use;
the upper slide of the slide rest is made to carry a revolving head with a central
pivot and with radial sockets or holders into which the several tools are set.
objection to this form of rest is that when employed on hollow work the rest has
to be run back a long distance whenever it is required to introduce the gauge into
the work and much time is lost. In place of this capstan head with its radial
tools I employ a square (or polygon) block with a central pivot and with the tools
clamped to it along the sides. I form the block with a circular foot entering a
corresponding hole in the top slide of the rest. In the centre of the foot is a
socket which receives the pivot projecting upwards from the traversing nut. Upon
the socket there fits a coned ring it is attached to the block by screws which serve
to draw it up into close contact with the corresponding surfaces on the slide but
nevertheless not so tightly as to-prevent-it. turning readily. A spring bolt retains
the turning block in any of the positions to which it may be turned to present one.
or other of the tools to the work,
I also make the upper slide and guide of the slide rest moveable around a
central pivot for the purpose of turning taper and I control the movement around
this pivot by means of a worm engaging with a curved rack.
To lessen the care required when constantly repeating similar work I provide
the slide rest with stops so that it cannot be run further than a position to which
it has been previously adjusted.
I provide a projection upon the slide and fix a rod upon its bed or guide
parallel to the direction of inotion of the slide. I have also a clip upon the rod
which I can make fast in any position and which I can shift to either side of the
projection on the slide. When the projection and the clip come into contact no
further movement of the slide in that direction can take place.
Figure 1 is a plan, Figure 2 is an elevation partly in section and Figures 3 and 4
are end views of a lathe to which my improvements are applied. In respect to
the slide rest and tool holder; a is the lower guide of the slide rest, it is clamped
down to the bed b of the lathe by any convenient clamping apparatus, that which
I employ is clearly represented in Figure 2. c is the slide upon the guide a, it
can be traversed in the usual way by the hand screw d. e is the upper guide, it is
connected with the slide c by the pivot e¹ and the holding down bolts e* e² which
pass through slots in e as is seen in Figure 1. When the bolts e² are slackened the
guide e can be rotated and set to any desired inclination to the lathe bed by
Imeans of the handle fand worm f' the latter gearing into worm teeth upon the
piece e. Bearings c¹ c' for the worm spindle are formed upon the end of the
slide c. g is the upper slide working in the guide e and this carries the tool
holder h. This tool holder is a square metal block with grooves h' h' on all sides
to receive the tools which are held in place by the pinching screws h³ h². The
block h has a circular foot h³ which is received into a corresponding hole in the
slide g. h is a socket in the foot receiving the stem of the traversing nut upon

page_text: the hand screwe of the upper guide. h³ is a coned ring, it surrounds the socket h
and is attached by tap screws to the block. Thus the block h with the tools
which it carries can be turned round upon the upper slide to bring either of the
tools to a working position. Thero is a pin or bolt connecting g and h to lock the
tool holder when it has been set. a¹ is a rod fixed to the side of the guide a,
and a is a clip which can be set to any position on this rod, it acts as a stop to a
projection upon one of the bearings c¹ so that, as the stop is now placed, the slido
cannot be withdrawn beyond a certain distance; or the stop can be shifted to the
other side of the slide and then it serves to limit the distance the slide can be
run in, say to prevent the possibility of turning below a certain diameter.
For screw cutting I employ a sliding bar carried on the side of the bed of the
lathe and which receives from a pattern or guide screw a movement in a direction
parallel to the bed of the lathe. The arrangement is as follows:-There is a sleeve
upon the bar which can be clipped fast upon it in any desired position and upon
the sleeve a hand lever which is also the tool holder is carried, it can be turned
around upon the sleeve. There is an arm upon the sleeve which when the screw
cutting apparatus is in use rests upon the bed of the lathe and is guided by it.
Between the arm of the sleeve and the handle there is an adjustable screw con-
nection by which the height or distance of the tool from the bed can be adjusted.
Thus the tool can be brought to the lathe centre or close to it as is required when
the work is small or it can be removed from the centre to any distance which the
sizo of the work may render necessary.
The handle can be thrown back to remove the tool out of the way when not
required for use. The sleeve and the bar then turn with the handle and by the
same movement the arm which follows along the guide screw and imparts longi-
tudinal motion to the bar is lifted.
In Figures 1, 2, 3 and 4, is a bar which is capable of sliding longitudinally and
also of turning in bearings b' b¹ fixed upon the side of the lathe bed. is a sleeve
which can be clipped fast upon the bark in any desired position. m is a hand
lever carried upon the sleeve on which it is free to turn but it is connected with
the rigid arm of the sleeve by means of the adjusting screw n. The adjusting
screw works through a trunnion nut m' carried upon the hand lever m and its
lower end is connected by a trunnion collar with the rigid arm of the sleeve.
m² is a socket upon the hand lever to receive the tool; it is secured in the socket
by a pinching screw. The position of the socket is such that the point of the tool
can be brought to coincide with the lathe centre.
When the tool is in use the end of the arm l' rests upon the bed of the lathe and
the parts are so set by means of the adjusting screw n, that the point of the tool
below and in front of the centre as far as the diameter of the screw to be cut may
render necessary. No special adjustment of the tool in the socket will be necessary
for threads of different diameters for the way in which the tool is carried ensures
that when properly set for any size it will be right for all others: the only adjust-
ment necessary being that effected by means of the screw n. is an arm at the
end of the bark and it carries a finger o which bears against the pattern screw p
to the thread of which the end of the finger is shaped to conform.
The pattern screw p is carried upon the boss of a wheel q which gears with a
pinion upon the lathe spindle. The pattern screw has a left hand thread. When
the screw tool is not required for use the handle m is thrown back until it is
stopped by the projection k* on the arm k' coming against a corresponding stop
upon the adjacent bearing b¹.
Figure 5 is a front elevation of another lathe to which the improvements above
described are applied, the forms of the parts being somewhat varied.
I also construct a lathe in which the bed receives a saddle having a vertical face
with a slide thereon which works up and down in a vertical direction. This slide
carries at its upper end the transverse horizontal slide of the slide rest upon which
is the tool holder.
The self-acting movements are taken from a longitudinal worm lying horizontally

page_text: beneath the bed. The saddle carries an axis on which is a worm wheel gearing
into the worm.
This axis when it is desired to traverse the saddle upon the bed
is clutched fast to a spur wheel upon it which wheel engages with a rack fixed
upon the bed. The same axis carries another spur wheel for imparting the
automatic motion to the screw of the top or transverse slide. There is a pinion on
the screw, and an intermediate wheel engages both with this pinion and with the
driving wheel. The intermediate wheel is adjustable to adinit of the transverse
slide being worked automatically in any position of the vertical slide upon the
saddle.
For the purpose of turning taper a bar is provided at the back of the lathe
which can be set to any incline desired. The bar is pivotted at the centre so as to
be able to move in a horizontal plane. This bar serves to guide a sliding bearing
containing a sleeve into which the end of the transverse screw of the top slide of
the slide rest is received and in which it is able to move endwise. But when
desired to turn taper the sleeve can be clipped fast upon the screw and the screw is
then drawn end wise by the inclined bar.
The transverse screw at its other end passes through a similar sleeve on which
is the pinion to impart the automatic movement; but when the taper turning
mechanism is in gear the screw is left free to move longitudinally in the front
sleeve.
a is
Figure 6 is a plan of portions of a lathe to which these improvements are
applied. Figure 7 is a front elevation and Figure 8 is a transverse section.
the bed. b is the saddle bearing both on the top and the side of the bed and
sliding thereon the saddle has a vertical face against which the slide crests and on
which it is able to move a short distance vertically. Thero is a dovetail upon the
slide which is received between corresponding guides upon the saddle. c¹ is the
screw-by which-the-slide.c.is set up or down as may be required: it steps into a
socket ' fixed to the saddle and works through a nut attached to the slide c.
b² be are screws in the top of the saddle which may be screwed up to support the
slide when raised in cases where the work is such as to render this further
support necessary. d is the transverse slide upon the top of the slide c, and d¹ is
the tool holder. is the screw by which the slide d is traversed. e is an axis
running lengthwise of the lathe and driven through change wheels from the lathe
spindle. is a worm capable of sliding along the axis e but made to rotate with
it by groove and feather. The worm is embraced by a piece b³ attached to the
saddle so that the saddle in sliding along the bed carries the worm with it. The
worm drives a worm wheel g' upon an axis g passing through a hollow axis h which
can turn in a bearing in the saddle b. 9 is a nut upon the axis g by which coned
parts upon the axes g and h can be made to lock together. is a toothed wheel
upon the hollow axis h gearing with a rack a' fixed upon the bed of the lathe; by
this gear the saddle is propelled when the axes g and h are locked together. h³ is
a pinion on the axis h which gears with another pinion on the axis of the hand
wheel. The hand wheel is employed to traverse the saddle along the bed when
the self acting gear is not in operation. is a pinion upon the axis g which
whilst the saddle is stationary, may be employed to actuate the traversing screw c³
of the top slide d. The screw as the Drawings shew has a pinion upon it and an
intermediate wheel gears it with the pinion g³. The intermediate wheel is carried
upon a bracket c fixed upon the slide and is adjustable upon the bracket to
accommodate the varying positions of the slide or to admit of its being removed
out of gear when the self acting traverse is not required.
kis the bar provided to facilitate the production of taper work. It rests upon a
table like surface at the back of the lathe bed and is pivotted thereon at k¹,
kare clamping bolts passing through slots in the parts of the bar around the
pivot. To move the bar conveniently from one position to another the handle k³
is provided, it has a pinion on its axis genring with a toothed are upon the table.
is a bearing having a projection upon its side entering the longitudinal groove of
the bark. A small roller is provided at to reduce friction. m is a sleeve held

page_text: in the bearing and free to revolve, the screw c³ passes through it. For the purpose
of turning taper the screw c³ is set fast in this sleeve. The sleeve is split longi-
tudinally and furnished with lips which can be drawn together by the hand screw
and nut m', the screw c³ at its other end passes through a similar sleeve c³, on the
slide c and when turning taper the screw is set free to slide through the sleeve co.
Then as the sleeve m follows the inclination of the bark it draws the screw c³
end wise thereby imparting the proper motion to the slide d and the tool holder.
Except when taper work is in process the screw c³ is set free in the sleevc m
and is firmly held in the sleeve c³ so that then it cannot move longitudinally.
To facilitate the adjustment of work in the lathe I employ adjustable face plates
and angle plates consisting of two plates ono capable of sliding on the other. One
plate is formed with a socket and is screwed on to the mandril of the lathe in the
usual manner.
This plate carries a pair of screws set radially and at right angles the one to the
other. They lie in grooves or slots in the plate and when turned by handles at
their ends they give motion to nuts which are, contained in the grooves. The nuts
carry rollers or studs which project from the face of the main plate and enter
straight grooves in the back of the second or sliding plate. These grooves are at
right angles to each other and to the screws which control the nuts and projections
entering the grooves. Thus by means of the screws the one plate can be made to slide
on the other plate in any direction. When set the parts can be clamped by means
of clamping bolts and nuts.
The moveable plate is either cast with a right angle flange to carry the work (if
it be of a description requiring to be mounted upon an angle plate) or the moveable
plate receives the work directly upon its faco.
In either case the work is fixed to the moveable plate by means of the usual
clamping bolts entering slots in the face or angle plate.
Figure 9 is a front elevation and Figure 10 is a vertical section showing an
adjustable angle plate arranged in accordance with my Invention. a is the plate
which screws on to the mandril of the lathe by the socket al. a³ a³ are screws
contained in radial grooves or slots in this plate. b bare nuts upon the screws a²
they fit the grooves in the plate and can be moved along them by turning the
screws. bare projections upon the nuts which are received into grooves c¹ c² at
the back of the plate c. d d are bolts and nuts for clamping the plates a and c
fast together when they have been suitably set by means of the screws a³. These
screws are passed through grooves a³ ³ in the plate a and through other
grooves c c at right angles to then in the plate c.
Figure 11 is a front elevation and Figure 12 is a vertical section of an adjustable
face plate similar in construction to the angle plate. The parts are lettered to
correspond to the description alrearly given. The plate c is grooved to receive the
clamping dogs e e by which the work is held upon the plate.
I also construct a hand rest which can be set with great facility to any position
upon the lathe bed and which can be readily removed when not required for use.
The base of the rest which stands upon the bed of the lathe has an horizontal
axis passing through it. A part of this axis is turned down and forms an eccentric.
The eccentric is contained within a loose collar or ring from which a stom descends.
The stem is screwed at its lower end and passes down through the longitudinal
opening of the lathe bed; beneath the body it receives a cross bar and nut.
To clamp the rest to the bed the nut is screwed up when the eccentric is near its
highest position and when the parts are thus set the rest can be freed simply by
turning the axis. It can be similarly refixed when required either in the same
position or after it has been moved to another part of the bed.
Also when it happens that the rest is in the way it can be removed altogether
off the bed of the lathe; this is effected by sliding the base of the rest off the axis
endwise and the axis and collar then alone are left upon the lathe bed.
Figure 13 is a front elevation and Figure 14 is a transverse section of a hand

page_text: rest made in accordance with my Invention. Figure 15 is a section on the line 1. 1
in Figure 14.
The bed of the lathe is seen in section at a a in Figure 14. bis the base of the
rest and c is an axis passing through it. The portion c' of the axis is turned to a
smaller size eccentrically to the remainder. The part c¹ is passed through a collar d
and after the collar has been put on an eccentric ring c³ is placed upon the part of
the axis behind the collar and is secured by a pin. The exterior of the ring c² is
of the same diameter as the part c of the axis, with which also when in place it is
concentric. The collar & has a stem d passing down through the opening in the
lathe bed, the lower end of this stem is cylindrical and it has a screw thread cut
upon it. This portion of the stem goes through a hole in the cross bar e which
bearing beneath the bed forms the abutment for tightening the rest upon the bed.
Under the cross bar the stem receives the nut f. The under side of the base bis
slotted in rear of the stem d¹ to allow of the base b and upper part of the rest
being removed altogether from the lathe by sliding end wise off the end of the
axis c.
Thus this arrangement gives great facility for the rest to be set and
clamped in any position and at any inclination upon the bed or of being removed
altogether when not required. The upper parts of the rest are clearly represented
in the Drawings, they are of the usual construction..
Having thus described the nature of my said Invention and the manner of
performing the same I would have it understood that I claim :-
First. My rotating tool holder consisting of a rotating block h with lateral
grooves or recesses to receive the tools substantially as described in respect to
Figures 1, 2 and 3 of the annexed Drawings.
Second. My improved slide rest substantially as described and shown in Figures
1, 2 and 3 of the annexed Drawings.
Third. My improved method substantially as described for carrying the screw
tool; upon a lever sustained by a support from the bed of the lathe and adjustable
to bring the point of the tool to that distance from the lathe centre which the
diameter of the screw to be cut requires.
Fourth. My improved screw cutting mechanism substantially as described in
respect to Figures 1, 2, 3 and 4 of the annexed Drawings.
Fifth. My improved slide rest, consisting of a saddle b, vertical slide cand
transverse slide d carrying the tool holder, substantially as described in respect to
Figures 6, 7 and 8 of the annexed Drawings.
Sixth. My improved self acting gear for moving the saddle along the bed and
for traversing the transverse slided with the tool holder substantially as described
in respect to Figures 6, 7 and 8 of the annexed Drawings.
Seventh. My improved mechanism for facilitating the production of taper work,
consisting of an inclined bar ke serving as a guide to a sleeve m which can be made
to control the screw c³ substantially as described in respect to Figures 6, 7 and 8 of
the annexed Drawings.
Eighth. My improved adjustable angle plates and face plates substantially as
described in respect to Figures 9, 10 11 and 12 of the annexed Drawings.
Ninth. The method of clamping a rest upon the bed of a lathe by means of an
axis upon which the base of the rest can be slidden or from which it can be with-
drawn at pleasure—such axis having a tightening eccentric thereon substantially as
described in respect to Figures 13, 14 and 15 of the annexed Drawings.
In witness whereof I the said John Dewrance have hereunto set my hand
and seal this Twenty fifth day of July in the year of our Lord One thousand
eight hundred and eighty twen