Improvements in Lathe Chucks.
Year: 1898

page_text: Date of Application, 28th July, 1898
Complete Specification Left, 1st May, 1899-Accepted, 2nd June, 1899
Improvements in Lathe Chucks.
I, CHARLES WILLIAM CARTER, of 1, Buckingham Street, Liverpool, in the
County of Lancaster, Engineer, do hereby declare the nature of this invention
to be as follows:-
This invention relates to lathe chucks of the ordinary as well as the self-
centring type, and to chucks intended primarily for use in brass-finishers' lathes,
the object being to provide a cheap and easily manipulated chuck adapted to
effectually grip the work without injuring the surface thereof.
I will first describe a simple form of my invention in which the chuck has
two dogs, is self-centring and is intended chiefly for light work:-
I provide a face plate across which is cut diametrally a dove-tail groove, such
na is provided in, say, the tool holder of a slide rest; in the centre of the groove,
that is to say of the face plate, an abutment is formed by securing a wedge like
cross piece in position by means of a set screw. The abutment is provided with
a slot and it is adapted to locate a double ended screw, opposite ends of the
screw having threads of opposite hands; at the centre the screw is provided
with two fixed collars (one of which may be adjustable) and when the screw is
in position the collars bear against opposite faces of the abutment.
The dogs of the chuck consist of malleable castings adapted to traverse the
radial slide and to be operated, in opposite directions by the retation of the
double-ended screw, which latter is provided with squared ends adapted to receive
a key or box spanner.
"
The inside faces of the dogs have a dove-tail groove in which lead or other
suitable clamping pieces fit; the latter are cast to suit the grooves and when in
position are turned up to the approximate diameter of the article to be chucked,
the latter is then inserted in the chuck and is secured in position by rotating
the screw.
In order to spread the grip, since there are but two dogs, the clamping pieces
may be made fairly wide, and before being turned to the approximate diameter
to be gripped, their central portions may be turned to a smaller radius; this
practically gives four well spread points of grip.
In gripping internally the dogs may be reversed, or they may have grooves
for clamping pieces on both faces.
In a chuck for heavier work I prefer to provide two double ended opposite
threaded screws arranged on opposite sides of a diameter of the chuck, and
operated by a pinion which gears with two pinions, one on each screw; the
screws lie in parallel slots and each dog is carried by a pair of sliding studs;
the studs are tapped at right angles to their axes and so form nuts for the tra-
versing screws, and as the studs carry the the dogs the latter are traversed
across the face of the chuck in opposite directions by rotating the pinion referred
to. The traversing screws are simply placed in the slots and are held in position
laterally by the studs and axial movement is prevented, and adjustment effected!

page_text: by end set screws; the slots may be bridged over at the centre of the chuck to
strengthen the construction, and the dogs are preferably made as described in
connection with the form first referred to, both faces being usually provided
with grooves for the clamping pieces.
In some cases I fit four traversing screws carried in slots rectangularly dis-
posed; each screw has a pintle on its inner end fitting in a recess in the boss of
the chuck, and near the outer squared end I pin a circular nut which acts as a
thrust collar against the periphery of the chuck. There are four dogs, one for
cach screw, and each dog is provided with grooves, as previously described, on
each face, for the clamping pieces of lead or other similar metal. Each dog is
also provided with a screwed end, a nut and washer, for clamping it in position.
1
1000
SLOAN & LLOYD BARNES,
34, Castle Street, Liverpool, Agents for the Applicant.
Improvements in Lathe Chucks,
I, CILARLES WILLIAM CARTER, of 1, Buckingham Street, Liverpool, in the
County of Lancaster, Engineer, 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 lathe chucks of the ordinary as well as the self-
centring type, and to chucks intended primarily for use in brass finishers' lathes,
the object being to provide a cheap and easily manipulated chuck adapted to
effectually grip the work without injuring the surface thereof.
I have illustrated my invention in the accompanying drawings, in which Fig. I
is an elevation of a form of chuck suitable for light work, Fig. II being an end
elevation, and Figs. III, IV, V, and VI detail views of the same. Fig. VII is
an elevation of a chuck suitable for heavier work, an end view of which is
shown in Fig. VIII and the details of which are illustrated in Figs. IX (which
is a section on the line A A of Fig. VII), X, XI, XII, XIII, XIV and XV.
Fig. XVI is an elevation of a four-jaw chuck, and Figs. XVII is an end view of
this chuck one half being in section on the line B B of Fig. XVI.
Similar parts are throughout the drawings indicated by the same figure of
reference.
I will first describe a simple form of my invention in which the chuck has
two dogs, is self-centring and is intended chiefly for light work:-
I provide a face plate, 1 across which is cut diametrally a dove-tail groove,
such as is provided in, say, the tool holder of a slide rest; in the centre of the
groove an abutinent is formed by securing a wedge like cross piece 2 in position
by means of set screws. The abutment is provided with a slot and it is adapted
to locate a double ended screw 3, opposite ends of the screw having threads of
opposite "handa" at the centre the screw is provided with two fixed collars 4
and 5 (one of which, 6, may be adjustable) and when the screw is in position the
collars bear against opposite faces of the abutment.
The dogs 6 of the chuck consists of malleable castings adapted to traverse the
radial slide and to he operated, in opposite directions, by the rotation of the
double-ended screw, which latter is provided with squared ends adapted to receive
a key or box spanner,

page_text: The inside faces of the dogs have a dove-tail groove 7 in which lead or other
suitable clamping pieces 8 fit; the latter are cast to suit the grooves and when in
position are turned up to the approximate diameter of the article to be chucked,
the latter is then inserted in the chuck and is secured in position by rotating the
5 screw.
In order to spread the grip, since there are but two doga, the clamping
pieces 8 may be made fairly wide, and before being turned to the approximate
diameter to be gripped, their central portions may be turned to a smaller radius
as shown, this practically gives four well spread points of grip.
In gripping internally the dogs may be reversed, or they may have grooves for
clamping pieces on both faces.
In a chuck for heavier work shown in Figs. VII to XV, I prefer to provide
two double-ended opposite-threaded screws 3 arranged on opposite sides of a
diameter of the chuck, and operated by a pinion 9 which gears with two pinions 10,
one on each screw the screws lie in parallel slots and each dog 6' is carried by a
pair of sliding studs 11, the studs are tapped at right angles to their axes and so
form nuts for the traversing screws, and as the studs carry the dogs the latter
are traversed across the face of the chuck in opposite directions by rotating the
pinion 9. The traversing screws are simply placed in the slots and are held in
position laterally by the studs 11 and axial movement is prevented, and adjustment
effected by end set screws or by nuts 12 which encircle the ends of the screws and
which are prevented from backing by the washers 13 whose projecting wings fit
in recesses as shown in the detail views: the slots may be bridged over at the
centre of the chuck as shown to strengthen the construction, and the dogs are pre-
ferably made as described in connection with the form first referred to, both faces
being usually provided with grooves for the clamping pieces.
The spindle 14 of the pinion 9 is maintained in position axially by a screw 15
as shown in Figs. XIV and XV, and the other pinions are secured as shown in
Figs. XIII, and the screws are so arranged that the adjacent threads of each
pair are of the same
65
hand."
In some cases I fit four traversing screws 311, (as shown in Figs. XVI and
XVII) carried in slots rectangularly disposed; each screw has a pintle on its
inner end fitting in a recess in the boss of the chuck and near the outer squared
end I pin a circular nut 5 which acts as a thrust collar against the periphery of
the chuck. There are four dogs 6", one for each screw, and each dog is provided
with grooves, as previously described, on each face, for the clamping pieces of lead
or other similar metal. Each dog is also provided with a screwed end 16, and a
nut and washer, for clamping it in position, as shown in the sectional half of
Fig. XVII.
Having now particularly described and ascertained the nature of my said in-
vention, and in what manner the same is to be performed, I declare that what I
claim is:-
1. The improved lathe chuck, consisting of a face plate; a pair of dogs each
provided with a dove-tail groove to take a soft metal clamping piece, and adapted
to slide in a dove-tail diametral groove in the face plate; and a double-ended
reversely threaded screw located in the said groove by a central abutment and
provided with collars which bear against the said abutment and prevent axial
movement of the screw, so that when the latter is rotated the dogs are traversed
radially equal distances in opposite directions; substantially as described and
illustrated.
2. The improvement in lathe chucks which consists in providing two dogs with
dove-tail grooves to take soft metal clamping pieces, and guiding them by two
pairs of parallel slots in the face plate along which they may be traversed,
radially, equal distances in opposite directions by a pair of double ended screws
geared together so as to have equal angular velocities and connected to the dogs
by sliding studs; substantially as described and illustrated.

page_text: 3. The improved lathe chuck substantially as described and illustrated in
Figs. I to VI.
4. The improved lathe chuck substantially as described and illustrated in
Figs. VII to XV.
6. The improved lathe chuck substantially as described and illustrated in
Figs. XVI and XVII.
Dated this 29th day of April 1899.
SLOAN & LLOYD BARNES,
Chartered Patent Agents, 34, Castle Street, Liverpool.