IMPROVEMENTS AND APPLICABLE TO LATHES AND MACHINES FOR TURNING AND FOR CUTTING SCREWS
Year: 1862

page_text: LETTERS PATENT to William Ford Smith and Arthur Coventry, of
Gresley Iron Works," Ordsal Lane, Salford, in the County of Lancaster,
Engineers and Machinists, for the Invention of "IMPROVEMENTS
AND APPLICABLE TO LATHES AND MACHINES FOR TURNING AND FOR CUTTING
SCREWS."
Sealed the 12th September 1862, and dated the 27th March 1862.
PROVISIONAL SPECIFICATION left by the said William Ford Smith
and Arthur Coventry at the Office of the Commissioners of Patents,
with their Petition, on the 27th March 1862.
We, WILLIAM FORD SMITH and ARTHUR COVENTRY, of "Gresley Iron
Works; Ordsal Lane, Salford, in the County of Lancaster, Engineers
and Machinists, do hereby declare the nature of the said Invention for "Im-
PROVEMENTS IN AND APPLICABLE TO LATHES AND MACHINES FOR TURNING AND FOR
CUTTING 'SCREWS," to be as follows:-
Our Invention consists firstly, in combining an arrangement. of three or
more peculiar dies or cutters with the slide lathe, the ordinary screw cutting
lathe, or the screwing machine for the purpose of cutting screws, but which
when modified as to the cutters may be also used in the slide lathe for turning
shafts and similar articles. The arrangement of dies or cutters which we
prefer to use consists of three dies or cutters placed-in radial-slots formed at

page_text: equal distances apart in a circular disc, having a hole through its centre. A
projection from the disc forms a part on which it stands, a ring fits upon the
disc so as to turn upon it, and on this ring, screw, or cam inclines are formed,
which enter notches in the dies, so that by turning the ring the dies are
simultaneously drawn to or from the centre. A plate is secured to the face
of the disc, which keeps the dies in their places. The ring is provided with a
handle to turn it by, and a weight or spring is applied to keep it from moving
when at work. The disc has a stop which is adjustable in a concentric slot
or groove, and an index is also formed for convenience of adjustment. In
using this arrangement in the slide or screw cutting lathe, the stand part of
the disc is secured to the slide carriage of the lathe, or it may be cast in one
piece with it, and in using it in the screwing machine, the stand part may be
dispensed with, and projections from the disc may be formed so as to pass
upon suitable guides, or the stand part may be attached to a carriage made
to slide upon the bed same as in the lathe. The dies used are cut in the
same manner as those for ordinary screwing stocks, and then the tops of the
threads on one side of the dies are operated upon. by a "tapering rimer," so
that each of those threads acted upon by the rimer will make an independent
cut, one cut in advance of the other. For common screwing in the lathe we
leave the slide carriage free to be moved by the "drag" of the dies, which
will give the pitch of the thread, but when we require very accurate pitched
threads we employ the ordinary screw cutting lathe, in which case instead of
the slide being free to the action of the dies, the dies are moved, or are only
permitted to move by the regulating screw, which is geered to give the
required motion to the slide carriage according to the required pitch of the
screw intended to be cut. In using our arrangement of dies in combination
with the slide lathe, screw cutting lathe, or screwing machine, the dies are
withdrawn after making a cut, so that the article does not require to be
screwed back, and thus a reversing motion is rendered unnecessary. For
screws of short lengths, the slide carriage may be brought back by a weight:
By substituting turning cutters for the screw cutting dies, the mechanism
described is adapted for turning shafts and other similar articles.
Our Invention consists, secondly, in a new combination and arrangement of
a chuck applicable to lathes for turning and screw cutting, and to similar
machines, which combination and arrangement we find particularly useful and
necessary for producing good work. When cutting screws in a screw cutting
lathe arranged according to the first part of our Invention, our object being to
arrange the mechanism of the chuck so as to grip the article, and at the same
time provide for any excentricity in it, and to cause the mechanism to act as a

page_text: "Clement's driver" in both directions, without "back lash," in other words
to make the chuck act so as to grip the article as if it were rigidly coupled
with the lathe spindle so far as its rotation is concerned, but so as to allow
of lateral excentricity in the article. The arrangement and combination which
we prefer for carrying out the object of this part of our Invention consists of
a face plate made to screw upon the lathe spindle same as any ordinary chuck,
to this face plate a disc is connected by means of two pins and two slots, so
that the disc will be carried round with the face plate, but the slots will permit
the disc to move in one direction, namely, diametrically, a second disc is
applied against the first, and connected to the first disc in the same manner
and by the same means as the first disc is connected with the face plate,
except that its diametrical play is at right angles to that of the first disc.
The second disc carries a pair of jaws arranged in suitable slides, which
jaws are opened and closed so as to release or grip the article by one or more
screws.
One disc will only be necessary if the jaws are made so as to be carried
round with the first disc, such jaws having diametrical play at right angles to
the diametrical play allowed to the first dise.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed.
by the said William Ford Smith and Arthur Coventry in the Great
Seal Patent Office on the 27th September 1862.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, WILLIAM
FORD SMITH and ARTHUR COVENTRY, of "Gresley Iron Works," Ordsal Lane,
Salford, in the County of Lancaster, Engineers and Machinists, . send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-seventh day of March, in the year of our Lord
One thousand eight hundred and sixty-two, in the twenty-fifth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto us,
the said William Ford Smith and Arthur Coventry, Her special license
that we, the said William Ford Smith and Arthur Coventry, our exe-
cutors, administrators, and assigns, or such others as we, the said William
Ford Smith and Arthur Coventry, 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

page_text: of Great Britain and Ireland, the Channel Islands, and Isle of Man, an
Invention for "IMPROVEMENTS IN AND APPLICABLE TO LATHES AND MACHINES FOR
TURNING AND POR CUTTING SCREWS," upon the condition (amongst others) that
we, the said William Ford Smith, and Arthur Coventry, by an instrument in
writing under our 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 William Ford Smith and Arthur
Coventry, 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, and accompanying Drawings,
that is to say:-
Our Invention consists firstly, in combining an arrangement of three or more
peculiar dies or cutters with the slide lathe, the ordinary screw cutting lathe,
or the screwing machine for the purpose of cutting screws. The arrangement
of dies or cutters which we prefer to use is shown in the accompanying
Drawings by Figs. 1 to 5, Fig. 1 being a sectional elevation with the front
plate removed; Fig. 2 a longitudinal section; Fig. 3, a back elevation;
Fig. 4 a front, and Fig. 5 an edge view of a front plate which is used when
operating upon long screws. The arrangement consists of three dies or
cutters (a) placed in radial slots formed at equal distances apart in a circular
disc (6) having a hole through its centre. A projection (c) from the disc
forms a part upon which it stands. A ring (d) fits upon the disc (6) so as to
turn upon it, and to this ring, screw, or cam inclines are attached, which
actuate the dies in such manner that by turning the ring (d), the dies (a)
are simultaneously drawn to or from the centre. The ring (d) is formed in
two parts, namely, an annular or flat ring which fits upon the boss of the disc
part 6, and an outside hoop which is shrunk upon the edge of the flat ring.
This hoop also binds in their places the three cam inclines (d'), which are
in separate pieces, and act upon the inside end of the dies to push them
inwards. The dies are drawn back by separate cam or screw inclines (d2)
secured to the annular part of the ring d, and each of these screw inclines
enters a notch formed in the die which it actuates. The central or boss
part in which the slots are formed for the dies may be made of case-hardened
wrought iron, and attached by screws to the other part of the disc b. The
disc (6) and ring (d) are kept in their places by a plate e, secured by set
screws to the boss part of the disc 6. The ring (d) is turned by a handle (d),

page_text: or other suitable arraagement. To keep the ring (d) from moving when at
work, a weight (e') is applied, which is attached to one end of a chain, the
other end being secured to the ring d. The chain passes over a pulley f, carried
by a bracket from the stand part c, this keeps the chain from coming in contact
with the bed of the lathe or screwing apparatus. At the back of the disc
part b, a concentric slot b' is formed, which gives hold for the head of a bolt.
by which an adjustable stop 62 can be secured in any required. position, which
by coming in contact with a projection from the ring d limits the movement
of the ring in that direction, and thus prevents the dies from being forced
beyond the required depth. An index is formed upon the edge of the disc (b).
as shewn in Fig. 3, for convenience of adjustment. Instead of the plate
shewn in Figs. 2 and 3, one similar to that shewn in Figs. 4 and 5 may be
used, which is provided with three adjustable slides (9) acted upon by set
screws, these slides forming a stay, when operating upon a long screw to
keep it central. The dies used are cut in the same manner as those for
ordinary screwing stocks, and then the top of the threads are operated upon
by a "tapering rimer," so that each of those threads acted upon by the rimer
will make an independent cut, one cut in advance of the other. In using
the arrangement above described in the slide or screw cutting lathe, the
stand part (c) of the disc is secured.to.the slide carriage of the lathe, or it
may be cast in one piece with it, and in using it in the screwing machine
the stand part may be dispensed with, and projections from the disc may be
formed so as to pass upon suitable guides; or the stand part may be attached
to a carriage made to slide upon the bed same as in the lathe. For common
screwing or chasing in the lathe, we leave the slide carriage free to be
moved by the "drag" of the dies, which will give the pitch of the thread, but
when we require very accurately pitched threads, we employ the ordinary
screw cutting lathe, in which case instead of the slide being free to the action
of the dies, the dies are moved, or are only permitted to move by the regu-
lating screw, which is geered to give the required motion to the slide carriage
In using
according to the required pitch of the screw intended to be cut.
our arrangement of dies in combination with the slide lathe, screw cutting
lathe, or screwing machine, the dies are withdrawn after making a cut, so
that the article does not require to be screwed back, and thus a reversing
motion is rendered unnecessary. For screws of short lengths, the slide carriage
may be brought back by a weight. Fig. 6 is a front elevation of an ordinary
screw cutting lathe, shewing our improved screw cutting apparatus & applied
for cutting very accurately pitched screws; Fig. 7 is a front elevation and
Fig. 8 a cross sectional elevation of a lathe for chasing screws, and having our

page_text: screw-cutting apparatus applied; and Fig. 9 is a front elevation of a
machine for ordinary screwing purposes, having our screw-cutting apparatus
applied, which in each case is secured to the slide carriage y.
Our Invention consists, secondly, in a new combination and arrangement of
chuck applicable to lathes for turning and screw cutting, and to similar
machines, which combination and arrangement we find particularly useful and
necessary for producing good work when cutting screws in a screw-cutting
lathe arranged according to the first part of our Invention, our object being to
arrange the mechanism of the chuck so as to "grip" the article, and at the
same time provide for any excentricity in it, and to cause the mechanism to
act as a "clement's driver" in both directions without "back lash." In other
words to make the chuck act so as to grip the article as if it were rigidly
coupled with the lathe spindle so far as its rotation is concerned, but so as to
allow of lateral excentricity in the article. The arrangement and combination
which we prefer for carrying out the object of this part of our Invention is
illustrated in the accompanying Drawings by Fig. 10 a longitudinal section;
Fig. 11 a front view; Fig. 12 a section of front plate detached, shewing jaws;
and Fig. 13 a front view of the middle plate detached. It consists of a face
plate h made to screw upon the lathe spindle i same as any ordinary chuck,
to this face plate a disc k is connected by means of two pins k', these pins
pass through slots formed in face plate h, and screw into the middle disc
plate (k), so that the disc will be carried round with the face plate, but the
slots will permit the disc to move in one direction, namely diametrically, a
second disc is applied against the first (k), and connected with it in the
same manner and by the same means as the first disc is connected with the
face plate (h), except that its diametrical play is at right angles to that of the
first disc (k), the pins (2) being screwed into the first disc, passing through
slots in the second disc, which is constructed to hold a pair of jaws (F), which
are moved to and from the centre by a right and left-handed screw (1), which
passes through the screwed bosses of the jaws, and on one side of the centre,
and rotates in a bearing (3) formed in the disc, the screw having a shoulder
on one side, and lock nuts on the other side of the bearing to prevent end
movement in the screw. The jaws may be actuated by separate screws if
required. m is a screw for securing the chuck upon the lathe spindle to
prevent it from becoming unscrewed when the lathe is reversed; n is the
centre of the lathe spindle. The chuck is made rigid like an ordinary chuck
when required by passing two bolts through holes in the disc plates and the
will only be required;
face plate, thus securing them all together. One disc
and secured directly to the face plate. If the jaws and screw carried by this

page_text: disc have diametrical play at right angles to the diametrical play in the disc
obtained by the pins and slots. Our improved chuck is shewn applied in
Fig. 6 and Fig. 7.
We have now particularly described the nature of our Invention, and the
manner in which the same is to be carried into effect, and claim as our Inven-
tion the peculiar arrangement and construction of the apparatus for screw
cutting berein-before described and illustrated in the accompanying Drawings
by Figs. 1 to 5, both inclusive.
We also claim the use and combination of this screw-cutting apparatus with
the ordinary screw cutting, common slide lathe, and screwing machines, as
herein-before described and shewn in Figs. 6, 7, 8, and 9.
We also claim the peculiar arrangement and construction of chuck herein-
before described and shewn in Figs. 10, 11, 12, and 13.
In witness whereof, we, the said William Ford Smith and Arthur
Coventry, have hereunto set our bands and seals, this Twenty-sixth
day of September, in the year of our Lord One thousand eight hundred
and sixty-two.
WILLIAM FORD SMITH. (L.S.)
ARTHUR COVENTRY.
(LS.)