IMPROVEMENTS IN. MACHINERY AND APPARATUS FOR SCREW-CUTTING, TAPPING, TURNING, AND FINISHING SCREW-BOLTS, NUTS, AND OTHER ARTICLES
Year: 1881

page_text: LETTERS PATENT to Alexander Melville Clark, of 53, Chancery Lane, in the
County of Middlesex, Patent Agent, for an Invention of "IMPROVEMENTS IN.
MACHINERY AND APPARATUS FOR SCREW-CUTTING, TAPPING, TURNING, AND
FINISHING SCREW-BOLTS, NUTS, AND OTHER ARTICLES." A communication -
from abroad by Messieurs Baville and Monlebout, of Paris, France.
PROVISIONAL SPECIFICATION left by the said Alexander Melville Clark at
the Office of the Commissioners of Patents on the 24th June 1881.
ALEXANDER MELVILLE CLARK, of 53, Chancery Lane, in the County of
Middlesex, Patent Agent. "IMPROVEMENTS IN MACHINERY AND APPARATUS FOR
SCREW-CUTTING, TAPPING, TURNING, AND FINISHING SCREW-BOLTS, NUTS, AND
OTHER ARTICLES." [A communication from abroad by Messieurs Baville and.
Monlebout, of Paris, France.]
This Invention relates to machines and tools for screw cutting, tapping, and
turning, and also to special arrangements for centering and dismounting the work.
The improvements have for their object to obtain in threading screw bolts and
turning shafts a rapidity of execution and perfection of work hitherto unattainable,
and to enable the work to be rapidly centered in the machine tools or removed
therefrom. The tool holders are specially arranged to hold cutters of suitable
dimensions grooved longitudinally, and made either of oval, square, or flat section,
as desired.
In cutting the screwthread with a fixed die, the latter after a time becomes
enlarged, and the tap which has been a certain time in use becomes reduced in
diameter so that the nuts will not then fit the bolts.
The loss of time in using fixed dies is serious, as after the bolt has been threaded
it is necessary to run the machine backwards in order to unscrew and remove it,
so that in 20 hours work only 10 hours are occupied in screw cutting, the remainder
of the time being taken in running back the dies.

page_text: The improvements of this Invention, which are designed to remedy all the above
objections, will be clearly understood by referring to the accompanying Drawings.
Sheets 1ª, 1, 10, 1d, Figures 1, 2, 3, and 4, show respectively a front elevation,
side elevation, rear elevation, and plan of a machine for screw cutting, tapping,
turning, and finishing bolts and nuts simultaneously. Figures 5 and 6 show a face
view and plan of the die box for screw cutting. Figure 7 is a face view of the
index plate. Figure 8 is a horizontal section of the slide and chuck for holding
the bolts.
A is a clutch lever, and B is a clutch engaging with wheel C upon shaft F
gearing with intermediate wheel D, which gears with a wheel E keyed on the
shaft G. This shaft is made hollow to receive the iron or steel rods for turning
small screws and bolts. For this purpose a universal chuck, shown in Sheet 4, is
screwed on the threaded end G₁ in such manner that the rod will be firmly held
and centered by a single turn of the screw.
At the rear of the machine is mounted a slide rest H carrying the various tools
for facing up and polishing the sides of the nuts, the tools J, J', being mounted
upon discs I, I¹, united by a sleeve 12. The bearings K, K¹, support the mandrel
which carries the nuts K² to be faced up. One end of this mandrel is made
hexagonal as well as the bearings K, K', so that it is only necessary to shift the
position of the nuts. A bracket. L fixed at the upper part of framing Y¹ carries a
clamp M in which is fixed an arm N carrying a pulley O round which passes a
chain P for operating a pawl lever Q by which the slide rest H is traversed in the
desired direction. A second slide rest R is mounted on slides S, S¹, moving in
guides T, T¹, upon framing Y¹. The motion of this slide rest is regulated by
screw U, Figure 4, which traverses it from end to end, and has a handle V at one
end by which it may be turned as required. Beneath the slide rest H is a third
slide rest X with an elevating screw Z and hand wheel Y for raising or lowering H.
X', X², are screws for fixing the slide rest in position. The upper part of the
framing Y¹ is made of such form as to admit of change wheels being used.
The threading of bolts is effected by means of the expanding die box a.
Figures 5, 6, 7, represent this die box on a larger scale. It consists of a disc a,
screws and pinions b, 61, 62, cutters c, c¹, c², set screws d, d¹, d², for holding the dies
or cutters, bushes e, e¹, e², for the screws b, b¹, 62, and cutter holders f, ff. The
improvement consists in the means for expanding and contracting the cutter
holders, f²; g, g¹, g², are racks attached to a collar h and gearing with the
pinions of the screws b, 61, 62. The collar h is operated by the forked lever i
connected to the rod j (Figure 2) upon which is a spring / confined between
frame Y and a hand wheel screwing on rod j. The rod jis locked by a bolt m
engaging in the grooved boss n' of a hand wheel n also screwing on the rod j. To
automatically bolt m, the rod o is placed in position to act on a lever pand through
it on a connecting rod q and lever of a pinion which gears with a rack on
bolt m and raises it. The spring k thereupon slides rod j end wise and oscillates
lever, and draws back collar h and with it the racks g, g', g, attached thereto, so
as to screw back the screws b, 61, 62, and thus expand the cutter holders f, ƒ³, ƒ³,
and release the bolt. A pressure of the foot upon the treadle of lever i moves
the collar h in the opposite direction, thus causing the cutters c, c', c², to converge
again, at same time pushing in the rod j, whereupon the bolt m is forced by its
spring & into the groove n¹ and relocks the rod j.
Figure 7 shows the index plate for regulating the adjustment of the cutters
according to the diameter of the screw. For different sizes it is simply necessary
to screw the wheel n along rod j, so as to move the lever i and with it the collar /
and racks g, g, g², to adjust the cutters accordingly.
Figure 8 shows a section of the slide rest and chuck or holder for the bolts to
be threaded. This holder is attached to a tubular stem t, secured by nuts t², t³,
Figure 4, and passing loosely through a bridge piece is bolted at u¹, u, to the
carriage y. A spring is confined by a cap x, screwed on y while its other end
presses against the conical head of a sleeve upon the tubular stem t, so that if the

page_text: bolt be not truly centered this conical head could recede and move laterally so as
to centre the bolt truly in the die box. For tapping nuts the tap o' is fixed in the
socket o² upon shaft o³, the nuts 0%, 0, being fixed in a holder o upon a slide rest,
similar to that shown in Figure 8.
Sheet 2. Figures 1, 2, 3, and 4 show different sections and views of a hand stock
with expanding dies. A, A1, A2, are three holders for the three dies or cutters
B, B1, B. The latter are adjusted simultaneously for threading screws of different
diameters by turning the screws C, C', C. Each screw is provided with a conical
pinion, and the several pinions gear with a toothed ring D, the adjustment being
effected by turning the screw C which has a squared end, the motion of this screw
being transmitted by the ring D to the two other screws C1, C2, whereby the
holders A, A1, A2, and their dies or cutters B, B', B³, are simultaneously adjusted to
suit the diameter of the screw required. The screws C, C1, C2, have necks and
shoulders E, E1, E2, which turn in collars or bearings and hold the screws in place
while permitting of their turning; F, F1, F2, are screws for advancing the dies or
cutters B, B1, B2, as they wear. A longitudinal groove is made in the backs of the
cutters to receive small screws G, G1, G2, which guide and hold the cutters laterally,
so that they may be ground endwise and will be held securely until used up.
cutters B, B1, B2, are ground to a slight bevel according to the pitch of the thread,
so that by screwing up the screws F, F'. F2, the cutters will be inclined accordingly.
The handles H, H', are screwed to the body of the stock I, and may be removed for
fixing the die stock in a lathe or screw cutting machine. J is a covering plato
secured by means of screws K, K1, K2, so as to retain the toothed ring D without
preventing its rotation.
The
In order to limit the convergence of the cutters according to the intended
diameter of screw, an adjustable screw stop L is mounted upon the cover J, so
that on turning screw C an ear M abuts against L and prevents the further closing
of the dies.
Figures 5, 6, 7, 8, 9, 10 represent longitudinal and end views of several forms
of dies or cutters, any one of which may be used as desired, and which may be
ground end wise until entirely used up.
Sheets 3, 3, 3b. Figures 1, 2, and 3 represent a vertical section, side elevation,
part in section, and part sectional plan of an adjustable die box for screw threading
and turning in lathes. As will be seen, this die box is composed of the same parts
as those described with reference to the hand stock shown in Figures 1, 2, and 3
(Sheet 2). The difference between the two arrangements consists in cutters for
turning. In this operation the cutters A, A1, A2, must be expanded, so as not to
cut a thread but merely turn the shaft B which on leaving the cutters A, A³, A³,
passes through annular dies C, C1, C2, diminishing successively in diameter by
about 20 of a millimeter, whereby the shaft is turned and polished. A shaft of
60 millimeters diameter may in this manner be turned and polished by feeding it
12 millimeters per turn. The adjustable die box D is fixed upon a slide rest E by
the two key bolts F, F¹. The rest E is adjustable vertically to regulate the
position of the die box D according to the height of the centres of the lathe, for
which purpose it is simply necessary to slacken screws G, G¹, and turn screw H,
thereby raising or lowering E in its grooves, and afterwards to tighten up the
screws G, G¹, in order to fix it; 1 is a tray to catch the turnings.
Figures 4, 5, and 6 show front and side elevations and plan of a cutter holder
for screw threading taps and steel screws at one operation in a lathe. The cutter J
may be ground endwise until entirely used up. Each time its length is reduced
by grinding, K must be raised by screwing up nut L and slacking back the nut M
upon screws o, o¹, respectively. The hooked form N' of the cutter holder N gives
it a spring action, which is especially useful in cutting large threads, as it enables
it to yield and avoid seizing..
Sheets 4, 4, 4b. Figures 1, 2, and 3 show sections and face view of a universal
chuck for centering bolts in screwthreading machines and for holding work in the
lathe Figure 4 is a side view of one of the holding dogs fixed in the jaws

page_text: A, A1, A2, moved towards the centre of the chuck B by means of screws C, C¹, Cº,
turning in bearings E, E, E, and actuated by the toothed ring G gearing with
their pinions. A collar F is screwed to the back of the chuck to hold the ring D
in place. The jaws A, A1, A2, have each two dovetailed grooves, in either of which
the dogs G may be fixed by means of the taper pin H and screw J, according to
the diameter of the work. The jaws are provided with centering notches I, I, I³.
Two of the teeth K of ring D are removable, as shown in Figure 1, so as to enable
the one screw and pinion C to be turned alone when it is desired to mount the
work eccentrically. The jaw A is then adjusted alone, the extent of motion being
indicated on a scale L alongside (see Figure 2). This done, the two movable teeth K
are replaced, so as to again operate the jaws simultaneously.
Figures 5, 6, and 7 show views of a chuck or holder M for round headed bolts.
The taper key o being withdrawn, the bolt N is inserted in the jaw P at the front
end of M, and the key o then replaced behind the bolt head N'. Figures 8 and 9
show longitudinal and cross sections of a holder for long rods while being
screwed. The tubular holder Q is split at the end S and encircled by a collar R,
and is furnished with removable jaws T, T'. The collar is also split and has a split
taper threaded shank R¹ upon which is screwed a correspondingly tapered wing
nut U. The holder is tubular to admit rods of any length. The jaws T, T', are
changed for rods of different diameters,

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Alexander Melville Clark in the Great Seal Patent Office on the
24th December 1881.
'
ALEXANDER MELVILLE CLARK, of 53, Chancery Lane, in the County of
Middlesex, Patent Agent. "IMPROVEMENTS IN MACHINERY AND APPARATUS FOR
SCREW-CUTTING, TAPPING, TURNING, AND FINISHING SCREW BOLTS, NUTS, AND
OTHER ARTICLES." A communication from abroad by Messieurs Baville and
Monlebout, of Paris, France.
This Invention relates to machines and tools for screw-cutting, tapping, turning,
and finishing, and also to special arrangements for holding the work.
In
The improvements have for their object to enable the cutting of screw threads
and the turning of shafts to be performed in a more rapid and perfect manner than
has hitherto been possible, and to facilitate the mounting of the work in the
machine and its removal therefrom. The tool holders are specially arranged to
hold cutters.of suitable dimensions grooved longitudinally and made either of
oval, square,.or flat section.as desired, which replace with great advantage hollow
dies and other screw. cutting apparatus in which a single cutter is used.
cutting the screw thread at a single operation by means of a solid die, the latter
after a time becomes enlarged, and the tap which has been a certain time in use
becomes reduced so that the nuts will not then fit the bolts. An ordinary solid
die is worn out after threading about 1,000 bolts, whereas the cutters of the
expanding or adjustable die box of this Invention being ground end wise can be
used completely up and will make about 200,000 bolts. The loss of time in using
solid or unadjustable dies is serious, inasmuch as after the bolt has been threaded
it is necessary to run the machine backwards in order to unscrew and remove it,
so that in 20 hours work only 10 hours are occupied in screw cutting, the
remainder of the time being taken up in running back the dies, which involves a
corresponding waste of steam power and wear and tear of machinery.
The improvements of this Invention which are designed to remedy all the above
objections, will be clearly understood by reference to the accompanying Drawings
(Sheet 1), Figures 1, 2, 3, and 4, show respectively front, side, and rear elevations
and plan of a machine for shaping, screw cutting, tapping, turning, and finishing
bolts and nuts simultaneously; Figures 5 and 6 show a face view and plan of
the expanding or adjustable die box for screw cutting; Figure 7 is a face view of
the index plate; Figure 8 is a horizontal section of the slide and chuck for holding
the bolts.
A is a clutch lever, and B is a clutch engaging with wheel C upon shaft F,
gearing with intermediate wheel D which gears with a wheel E keyed on the
shaft G. This shaft G is made hollow to receive the iron or steel rods for turning
down small screws and bolts from the solid. For this purpose the tools used are
the same as usually employed, but a universal chuck, shown in Sheet 4, is screwed
on the threaded end G¹ in such manner that the rod will be firmly held true or
central by a single turn of the screw.
At the one end of the machine is a slide rest H, upon which are mounted the various
tools, or in the example shown, the mandrel to hold the nuts while being shaped
and polished by the tools J, J', mounted in rotary discs I, I¹, united by a sleeve I'
and mounted on shaft G. By this means the ordinary disc cutters are dispensed
with and great economy effected. The bearings K, K', support the mandrels
which carry the nuts K³ to be shaped. One end of these mandrels is made
hexagonal as well as the bearing which receives that end, so that it is only

page_text: A
necessary to turn the mandrel in order to shift the position of the nuts.
bracket L fixed at the upper part of the machine framing Y' carries a clamp M in
which is fixed an arm N carrying a pulley O round which passes a chain P for
operating a pawl lever Q by which the slide rest H is traversed in the desired direction
for feeding the nuts between the cutter discs. The rest H is moved up and down
in a slide X by means of an elevating screw Z and hand wheel Y. The slide X is
carried upon a horizontal transverse slide R carried by bars S, S¹, sliding in
guides T, T, upon framing Y', and operated by a screw, as shown in Figures 2
and 4, the traversing motion of this slide X.and slide rest H upon the slide R being
given by screw U which extends from end to end of R, and also has a handle V at
one end by which it may be turned as required; ✗¹, X², are screws for fixing the
slide rest at the proper height.
The upper part of the machine framing Y' is made of such form as to admit of
change wheels being used.
The threading of bolts is effected by means of the expanding die box a.
Figures 5, 6, 7, represent this die box on a larger scale. It consists of a disc a,
screws and pinions b, b', 62, cutters c, c', c², set screws d, d', d, for holding the
dies or cutters, bushes e, e¹, e², for the screws b, 61, 62, and cutter-holders' ƒ‚ ƒ³‚ ƒ³.
The improvement consists in the means for expanding and contracting the cutter.
holders f, f, f²; g, g², g², are racks (of which only one is shown attached to a
collar hand gearing with the pinions of the screws b, b¹, b². The collar h is
operated by the forked lever i connected to the rod j, Figure 2, upon which is a
spring confined between frame Y and a hand wheel 7 screwing on rod j. The
rod jis locked by a bolt m engaging in the grooved boss n' of a hand wheel n
also screwing on the rod j and forming a stop. To automatically disengage bolt m
the rod o is placed in such position that its end will come in contact with a lever p
and through it act on a connecting link q and lever ² fixed to a pinion which
gears with a rack on the bolt m and raises it. The spring thereupon slides rod j
endwise and oscillates lever i and draws back the collar h and with it the
racks g, g, g², attached thereto so as to screw back the screws b, 61, 62, and thus
expand the cutter holders f, f¹, 2, and release the bolt. The bolt being removed
and with it the rod o a pressure of the foot upon the treadle of lever i moves.
the collar h in the opposite direction, thus causing the cutters c, c', c², to converge
again, at same time pushing in the rod j, whereupon the bolt m is forced by its
springs into the groove n' and relocks the rod j. Figure 7 shows the index plate
for regulating the adjustment of the cutters according to the diameter of the screw.
For different sizes it is simply necessary to screw the stop n along rod j so as to
move the lever i and with it the collar h and racks g, g¹, g³, to adjust the cutters
accordingly.
Figure 8 shows a section of the carriage or slide and chuck or holder for the
bolts to be threaded. This holder is attached to a tubular stem t secured by nuts
t2, 3, Figure 4, and passing loosely through a conical socket u which is bolted at
u, u², to the carriage y. A spring v is confined by a cap x screwed on y, while
its other end presses against the shoulder at back of the conical head z of a sleeve
upon the tubular stem t, so that if the bolt be not truly central this conical head
could recede laterally so as to bring the bolt truly central in the die box without
straining any part of the machine.
For tapping nuts the tap o¹ is fixed in the socket o² upon shaft o³, the nuts o¹, 05,
being held in a corresponding socket in a holder 0 upon a slide or carriage
similar to y.
Sheet 2, Figures 1, 2, 3, and 4, show different sections and views of a hand
stock with expanding dies. A, A1, A2, are three holders for the three dies or
cutters B, B1, B2. The latter are adjusted simultaneously for threading screws of
different diameters by turning the screws C, C1, C2. Each screw is provided with
a conical pinion, and the several pinions gear with a toothed ring D, the adjust-
ment being effected by turning the screw C which has a squared end, the motion
of this screw being transmitted by the ring D to the two other screws C¹, C³,

page_text: whereby the holders A, A', A², and their dies or cutters B, B1, B2, are simul-
taneously adjusted to suit the diameter of the screw required. The screws
C, C¹, C, have necks and shoulders E, E¹, E², which turn in collars or bushes and
hold the screws in place while permitting of their turning. F, F1, F2, are screws
for advancing the dies or cutters B, B1, B2, as they wear. A longitudinal groove
is made in the backs of the cutters to receive small screws G, G', G3, which guide
and hold the cutters laterally so that they may be ground endwise and will be
held securely until used up. The cutters B, B', B2, are ground to a bevel
according to the right line of the thread, which gives the obliquity corresponding
to the pitch, so that by screwing up the screws F, F1, F the cutters will be inclined
according to the obliquity of the thread. The handles H, H', are screwed to the
body of the stock I, and may be removed for fixing the die stock in a lathe or
screw cutting machine. J is a covering plate secured by means of screws
K, K', K2, so as to retain the toothed ring D without preventing its rotation.
In order to limit the convergence of the cutters according to the intended
diameter of screw, an adjustable screw stop L is mounted upon the cover J, so
that on turning screw C an ear M abuts against L and prevents the further closing
of the dies.
Figures 5, 6, 7 represent longitudinal and end views of dies or cutters which
may be used, and which may be ground endwise until entirely used up. They
may be square, flat, or oval in section, as preferred.
.
Sheet 3, Figures 1, 2, and 3 represent a vertical section, part sectional side
elevation, and plan of an adjustable die box for screw threading and turning in
lathes. As will be seen, this die box is composed of the same parts as those
described with reference to the hand stock shown in Figures 1, 2, and 3 (Sheet 2),
The difference between the two arrangements consists in the cutters for turning.
In this operation the cutters A, A1, A2, must be expanded so as not to cut a thread
but merely turn the shaft B, which on leaving the cutters A, A1, A2, passes through
circular dies or cutters C, C1, C2, diminishing successively in diameter by about
10th of a millimeter, whereby the shaft is turned and finished. A shaft of
60 millimeters diameter may in this manner be turned and finished by feeding it
twelve millimeters per turn. The adjustable die box D is fixed upon a carriage E
by the two key bolts F, F'. The carriage E is adjustable vertically to regulate the
position of the die box D according to the height of the centres of the lathe, for
which purpose it is simply necessary to slacken screws G, G¹, and turn screw H,
thereby raising or lowering E in its grooves, and afterwards to tighten up the
screws G; G¹, in order to fix it. I is a tray to catch the turnings.
Figures 4, 5, and 6, show front and side elevations and plan of a cutter holder
for screw threading taps and steel screws at one operation in a lathe. The cutter J.
may be ground end wise until entirely used up. Each time its length is reduced by
grinding K must be raised by screwing up nut L and slacking back the nut M
upon screws o, o¹, respectively. The hooked form N' of the cutter holder N gives
it a spring action, which is especially useful in cutting large threads, as it enables
it to yield and avoid seizing.
Sheet 4, Figures 1, 2, and 3, show sections and face view of a universal chuck
for holding bolts in screw threading machines, and which may be used for holding:
work in any required position in the lathe. Figure 4 is a side view of one of the
holding dogs, fixed by means of taper pin H and screw J in its jaw. The
jaws A, A, A³, are moved towards the centre of the chuck B by means of
screws C, C1, C2, turning in bearings E, E¹, E², and actuated by the toothed ring D:
gearing with their pinions. A collar F is screwed to the back of the chuck to
hold the ring D in place. The jaws A, A1, A2, have each two dovetailed grooves,
in either of which the dogs G may be fixed according to the diameter of the work.
The jaws are provided with notches I, I, I, for holding small bars or rods. Two
of the teeth K of ring D are removable, as shown in Figure 1, so as to enable the
one screw and pinion C to be turned alone when it is desired to mount the work
eccentrically. The jaw A is then adjusted alone, the extent of motion being

page_text: indicated on a scale L alongside (see Figure 2). This done, the two movable teeth K
are replaced so as to again operate the jaws simultaneously.
Figures 5, 6, and 7, show views of a chuck or holder M for round headed bolts.
The taper key o being withdrawn, the bolt N is inserted in the fork or jaw Pat
the front end of M, and the key o then driven in behind the bolt head N³.
Figures 8 and 9 show longitudinal and cross sections of a holder for long rods
while being screwed. The tubular holder Q is split at the end S and encircled by
a collar R, and is furnished with removable serrated jaws T, T'. The collar is also
split, and has a split taper-threaded shank R¹, upon which is screwed a
correspondingly tapered wing nut U. The holder is tubular to admit rods of any
length. The jaws T, T', are changed for rods of different diameters.
Having described the nature of the said Invention, and the manner of performing
the same, I declare that what I claim as the Invention to be protected by the
herein before in part recited Letters Patent is,-
1st. In machinery for screw cutting, tapping, turning, and finishing simul-
taneously screw bolts and nuts, as shown in Figures 1 to 4; a hollow main shaft G,
which receives the rods to be turned or screwed, and a chuck screwed onto the
threaded end G', as described and represented and for the purpose set forth.
2nd. The slide rest H, the discs I, I', and the sleeve 12, carrying the tools J, J₁,
for shaping and polishing the sides of, the nuts in combination with the
bearings K, K', which support the mandrel which carries the nuts K² to be shaped,
substantially as shown and described.
3rd. The arrangement of the driving mechanism of the slide rest H composed of
the bracket L, the clamp M, traversed by the shaft N, the pulley O round which
passes the chain P and the pawl lever Q, as above described and for the purpose
set forth.
4th. The slide X in combination with the slide rest H, as above described and
for the purpose set forth.
5th. In a screw threading machine, the employment of an expanding die box
constructed of a disc a, screws and pinions b, b1, b2, cutters c, c¹, c², set screws d, d', d²,
for holding the said cutters, bushes e, e¹, e², to hold in their places the screws b, b', b²,
and the cutter holders f. f¹, f, substantially as shown and described.
6th. The mode of working the cutter holders f,ff, by means of the racks g, g', g²,
attached to a collar h, and gearing with the screws b, b', b², in combination with the
lever i and the rod j, substantially as shown and described.
7th. The arrangement for taking the machine out of gear, which consists of the
shaft j, the bolt m, the grooved boss n¹, joined to the hand wheel n³, combined
with the rod o, the lever p, the link g, the pinion r, and the spring 8, as above
described and represented in Figure 2 of the annexed Drawings.
8th. The arrangement of the holder for the bolts to be threaded, consisting of the
tubular stem t, the box t', the socket u, the spring v, and the carriage y, as above
described and represented in Figure 8.
9th. In an expanding hand stock for screw cutting, the arrangement for controlling
the cutters B, B1, B2, so as to enable them to cut screws of different diameters, and
which consists of the screws C, C¹, C², combined with the toothed ring D,
substantially as shown and described.
10th. In hand stocks for screw cutting the arrangement of the screws F, F1, F2, in
combination with the small screws G, G³, G2, which are received in grooves in the
back of the cutters, and which serve to guide and hold the said cutters until they
are used up; also the arrangement of the handles H, H¹, by which they may be
removed for fixing the die stock in a lathe or screw cutting machine.
11th. In an adjustable cylindrical stock for lathes, the special arrangement of the
cutters A, A1, A2, and annular dies C, C1, C2, as above described and represented in
Figures 1, 2, 3 (Sheet 3).
12th. The arrangement of the carriage E of the stock for regulating the said stock
according to the height of the centres of each lathe, substantially as shown and
described.

page_text: 13th. The arrangement of the cutter J disposed for screw cutting, as described
and shown in Figures 4, 5, and 6 (Sheet 3) of the accompanying Drawings.
14th. In a screw cutting machine the arrangement of a universal chuck, shown
in Figures 1, 2, 3, and 4 (Sheet 4) for holding bolts, consisting of the toothed ring D,
having two removable teeth K, the jaws A, A1, A2, dogs G, taper pin H, and
notches I, I, I².
15th. The arrangement of the chuck or holder M, shown in Figures 5, 6, and 7
(Sheet 4) for round headed bolts, as described.
16th. The tubular holder Q, shown in Figures 8 and 9 (Sheet 4) for long rods, as
above described and for the purpose set forth.
In witness whereof, I, the said Alexander Melville Clark, have hereunto set
my hand and seal, this Twenty fourth day of December, A.D. 1881.
A. M. CLARK. (L.S.)