IMPROVEMENTS IN LATHES OR MACHINE TOOLS FOR Turning OR FINISHING IRREGULAR OR SPECIAL FORMS
Year: 1874

page_text: LETTERS PATENT to James Reid and James Webster, of Glasgow, in
the County of Lanark, North Britain, both Engineers, for the
Invention of "IMPROVEMENTS IN LATHES OR MACHINE TOOLS FOR Turning
OR FINISHING IRREGULAR OR SPECIAL FORMS."
Sealed the 13th May 1875, and dated the 21st Novembor 1874.
PROVISIONAL SPECIFICATION left by the said James Reid and James
Webster at the Office of the Commissioners of Patents, with their
Petition, on the 21st November 1874.
WC, JAMES REID and JAMES WEBSTER, of Glasgow, in the County
of Lanark, North Britain, both Engineers, do hereby declare the nature
of the said Invention for "IMPROVEMENTS IN LATHES OR MACHINE TOOLS FOR
TURNING OR FINISHING IRREGULAR OR SPECIAL FORMS," to be as follows, that is
to say:
1
-

page_text: The Invention consists in combining the gearing which moves or
traverses the cutting or finishing tool with a curved pattern guide, slot,
groove, or rib in a plate, such plate being changed for different forms.
Such pattern slot exhibits no resemblance in shape to the intended form
to be given to the article to be operated on, but is easily deduced in
particular case by means of diagrams or what may be termed graphical
calculations.
any
One modification of the improved machine tools is advantageously
applicable for finishing crank bosses for locomotive wheels.
The machine is constructed like a gap lathe with a large chuck plate:
for holding and slowly turning the crank boss or other article. The
finishing tool is a revolving cutter on a horizontal spindle carried by a
pair of bearings on a transversely movable slide rost, and driven by
means of a belt from an overhead shaft. A connecting rod jointed to
the slide rest is also jointed to a pin or block working in the slot of the
pattern guide plate, and a transverse movement is imparted to the slide
rest by moving the pin or block along the slot. The pin or block is
moved along its slot by a rod jointed to it and to a nut, which last is on
a screw spindle driven in concert with the chuck plate.
When the shape to be produced comprises two similar symmetrical:
halves the pattern groove may be made to correspond to only one half,
the screw movement shifting the block being reversed for the second
half by means of a tappet on the chuck plate or otherwise.
? Another modification is adapted for cutting a screw on a barrel shaped
spindle such as is used in a certain kind of locomotive reversing gear.
The cutting tool is held by a compound slide rest fitted on a plate, which
is mounted so as to move horizontally about a centro pin corresponding
in position to the centre of curvature of the barrelled outline of the
spindle. The longitudinal movement of the tool is derived from a
longitudinal screwed shaft as in an ordinary screw cutting lathe, but
instead of this being done in the ordinary direct manner the block or
nut on which the screwed shaft acts is formed with a transverse groove,
and a pin projecting down into this groove passes up through a curved
pattern guide slot in a plate 'above. A rod connects the pin to the frame
carrying the slide rost, and the pattern guide slot modifies the action of
the screwed shaft to properly suit the barrelled form of the spindlo
operated upon.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said James Reid and James Webster in the Great
Seal Patent Office on the 20th May 1875.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, JAMES
REID and JAMES WEBSTER, of Glasgow, in the County of Lanark,
North Britain, both Engineers, send grecting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-first day of November, in the
year of our Lord One thousand eight hundred and seventy-four, in
the thirty-eighth year of Her reign, did, for Herself, Her heirs and
successors, give and grant unto us, the said James Reid and James
Webster, Her special licence that we, the said James Reid and
James Webster, our executors, administrators, and assigns, or such
others as we, the said James Reid and James Webster, our 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 lawfully 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 LATHES OR MACHINE TOOLS FOR TURNING OR FINISHING IRREGULAR OR
SPECIAL FORMS," upon the condition (amongst others) that we, the
said James Reid and James Webster, our executors or administrators,
by an instrument in writing under our, 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 within
six calendar months next and immediately after the date of the said
Letters Patent.
NOW KNOW YE, that we, the said James Reid and James Webster,
do hereby declare the nature of our said Invention, and in what manner
the same is to be performed, to be particularly described and ascertained
in and. by the following statement in writing, reference being had to the
accompanying Drawings, that is to say :—
Our said Invention has for its object the modifying of lathes or
machine tools so as in simple, convenient, and automatic ways to turn
or finish irregular or special forms.

page_text: a nut 22, which last is on a screw spindle 23 driven in concert with the
chuck plate 9.
When the shape to be produced comprises two similar symmetrical
halves the pattern groove 19 may be made to correspond to only one-half
the screw movement which shifts the pin or block 18, being reversed for
the second half by means of a tappet on the chuck plate or otherwise.
In the modification shown in Figures 1, 2, 3 the shaft 24, which by
means of a pinion 25 drives the chuck plate 9, is extended to the further
end of the bed, and there by a pair of bevil wheels 26 drives a short
vertical shaft having fast on its upper end a bevil wheel 27, which is in
gear with two bevil wheels 28. These bevil wheels 28 are loose on a
shaft forming an extension of the screw spindle 23, and a clutch 29 is
arranged between them to put either in gear with the shaft as required,
whilst a lever for shifting this tch may be connected to a lever placed
so as to be acted on by a tapet on the chuck plate 9.
In Figure 4 the desired shape of crank boss is shown in the right-
hand diagram by a black line, the similar red line 30 showing the corre-
sponding path of the centre of the rotating cutter 11. A series of
equidistant radial lines are drawn through a centre corresponding to the
centre of the chuck plate 9, and by cutting the red line 30 measure the
successive distances from the centre line that the slide rest 15, 13, has
to assume. The vertical lines 31 in the left-hand diagram mark successive
equal distances in the progressive movement of the screw spindle 23,
and arcs being drawn at these distances all of one radius equal to the
links 21 are cut by arcs of a radius equal to the connecting rod 17, and
centered successively at a series of points on the transverse line 32, and
which points have spaces between them respectively equal to the
differences in the radial lengths shown in the right-hand diagram. The
intersections of the two sets of arcs give points of the required curve,
and these points may be made more or less numerous by taking more or
fewer radial and corresponding divisions. The black line in the left-hand
diagram being traced through the intersections of the arcs constitutes
the centre line for the pattern groove 19. The diagrams in Figures 4,
5, 6 are all constructed in the same way, but the second set of arcs are
not shown to avoid confusion.

page_text: The modification of our improved machine tools, shown on Sheet 2 of
the Drawings, is adapted for cutting a screw on a barrel-shaped spindle,
such as is used in a certain kind of locomotive reversing gear, and is
shown in plan in Figure 7 and in side elevation in Figure 8. The cutting
tool is held by a compound slide rest or tool box 33 fitted on a plate 34,
which is mounted so as to move horizontally about a centre pin 35 fixed
to a bracket projecting from the back of the lathe bed 36. This centre
pin 35 corresponds in position to the centre of curvature of the barrelled
outline of the spindle 37, so that the angular movement of the plate 34
gives the outline form. This movement however requires to be regulated
as regards its rate so that the pitch of the screw thread may be kept
uniform throughout the length of the spindle 37; and with this view,
whilst the movement is derived from a longitudinal screwed shaft 23, as
in an ordinary screw cutting lathe, it is not done in the ordinary direct
manner, but the block or nut 22 on which the screwed shaft 23 acts is
formed with a transverse groove, and a pin 18 projecting down into this
groove passes up through a curved pattern guide slot 19 in a plate 20
above. A. rod 17 connects the pin 18 to the frame 34, carrying the slide
rest or tool box 33, and the pattern guide slot 19 modifies the action of
the screwed shaft 23 so as to make it properly suit the barrelled form of
the spindle 37 operated upon.
In both machines, herein-before described, the plato 20 having the
pattern guide slot is a separate piece fixed in position when working, but
which can be changed for a plate having a different form of guide slot.
In some cases it may be more convenient to move the slotted pattern
plate 20 by means of the screwed shaft 23 instead of moving a pin or
block along a fixed slotted plate; or instead of arranging the pattern
plate to move rectilineally it may be fixed on a worm wheel and be
turned round by the screwed shaft 23.
Having thus particularly described our said Invention and the manner
of performing the same, we have to state that we do not restrict our-
selves to the precise details herein described or delineated, but that what
wo believe to be novel and original, and claim as the Invention secured
to us by the heroin-before in part recited Letters Patent is, the adapting
of lathes or machine tools for turning or finishing irregular or special
forms by combining screw movements for moving or traversing the
cutting or finishing tools thereof, with pattern plates, formed with curved