Year: 1886

page_text: Date of Application, 21st June, 1885
Complete Left, 19th Mar., 1887.
Complete Accepted, 19th Apr., 1887.
1, MURRAY HINCKLEY SPEAR, of 21 Barnsbury Street, Islington, in the County of
Middlesex, Mechanical Engineer do hereby declare the nature of this invention
to be as follows:-
This invention relates to that class of chucks (designated "eccentric chucks") which
are provided with means for shifting the object on the chuck so as to bring any point
on the said object into the axial line of the lathe ; and comprises the improvements
hereinafter described.
The jaws of the improved chuck which are of any suitable construction, slide in
radial grooves in a face-plate, and may be adjusted either independently or simul-
taneously by any suitable means. I prefer to employ for this purpose a second plate,
hereinafter termed the scroll-plate, arranged to rotate behind the face-plate and having
a spiral rib or scroll engaging with teeth or projections on the backs of the jaws.
A third plate, hereinafter termed the back-plate, is fixed on the hub of the face-plate,
and bears on the back of the scroll-plate so as to maintain the latter in position. By
revolving said scroll-plate, the jaws are caused to move simultaneously toward and
from the centre of the chuck.
The said back-plate is recessed or hollowed out at the centre, and is provided with
an inwardly projecting annular flange. Upon the said back-plate I arrange a fourth
plate, hereinafter termed the guide-plate.
This guide-plate has a projecting portion adapted to fit the annular recess in the
back-plate, so that it is concentric therewith.
The guide-plate and back-plate are held in contact by means of bolts passing
through the guide-plate, and the heads of which engage beneath the annular flange of
the back-plate. The said bolts are preferably held in place by set-screws.
.
Upon the rear side the guide-plate is arranged a plate, hereinafter termed the
slide-plate. This slide-plate at one side is provided with means for attaching it to the
spindle or mandrel of the lathe, and upon its other side with a diametric rib having
bevelled or under cut sides. This rib is adapted to fit into a corresponding groove in
the back-plate, so that the latter can slide upon the slide-plate.

page_text: In the said groove, at or near the ends thereof, are formed journal bearings, and in
said bearings is journalled a screw, the ends of which are squared or otherwise adapted
for the application of either a wrench or screw-driver by which to turn said screw.
In the said slide-plate, adjacent to the groove, is fitted a half-nut, with which the
said screw engages, so that by rotating the said screw the guide-plate and the parts
connected therewith will be caused to slide radially on the slide-plate.
By the use of a chuck provided with the improvements hereinbefore described,
various kinds of ornamental work can be produced on the face of an article held by
the jaws of the chuck; or a series of holes can be drilled in said object at various
points equidistant or variously distant from the centre thereof. This is effected by
turning the slide-screw until the face-plate is carried radially out of the axial line of
the lathe a distance equal to that between the centre of the object held on the chuck
and the centre of the hole to be drilled, or scroll to be described outside the centre of
said object. The clamping bolts are then loosened, and the back plate is turned upon
the guide-plate of the chuck so as to bring the centre of the hole or scroll to be cut in
the object held on the chuck, in line with the dead spindle or axis of the. lathe.
The chuck is retained in this position by tightening the set screws.
To facilitate the aforesaid adjustment, the slide-plate and the back of the guide-plate,
and also the adjacent outer edges of the back-plate and guide-plate may be provided
with graduated scales by which to gauge the movements of said parts.
Dated this 21st day of June 1886.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London,
Agents for the Applicant.
I, MURRAY HINCKLEY SPEAR, of 21 Pärnsbury Street, Islington, in the County of
Middlesex, 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:-
My invention relates to chucks of the kind or class known as excentric chucks and
.comprises the improvements hereinafter described.
My said invention is designed to provide for altering the position of the work
relatively to the cutting tool by the rotation cr adjustment of the face-plate or other
part which holds the work, upon or about its axis as well as by its adjustment in a
direction at right angles to the axis of the mandrel. I am thus enabled to bring any
part of the work into alignment with the axis of the mandrel without readjustinent of
the jaws or clamping devices.

page_text: My said invention will be readily understood from the following description,
reference being had to the accompanying drawings, in which
Figure 1 is a side elevation of one form of my improved chuck.
Figure 2 is a rear elevation thereof with the main portion or body of the chuck
adjusted so that it is excentric with respect to the part to be secured to the mandrel.
Figure 3 is a side elevation of the said chuck, partly in longitudinal central section.
Figure 4 is a rear elevation of the main portion or body of the chuck detached.
Figure 5 is a front elevation of a slide hereinafter referred to, and
Figure 6 is a side elevation of a bolt hereinafter described.
Like letters indicate corresponding parts throughout the drawings.
A is the part of the chuck which is to be secured to the mandrel of the lathe, or to
a face-plate attached thereto. B is a plate or disc which is fitted to slide on the part A
and which is hereinafter termed the slide. is the main portion or body of the chuck
which is fitted and secured upon the slide B as hereinafter described so that it can be
rotated or adjusted upon or about its axis while the said slide remains stationary.
The body, in the apparatus shown in the drawings, comprises a face-plate a having
radial grooves a¹ in which the jaws are fitted to slide towards and away from the
centre of the said face-plate. A plate or disc c having a milled edge is fitted on the
hub a of the face-plate a so that it can be rotated thereon. The said plate or disc c
is provided with a projecting spiral rib or scroll (not shown in the drawings) which
engages with teeth or projections on the backs of the jaws b as in scroll-chucks
heretofore constructed. A plate or disc d is fixed on the hub a² of the face-plate a
so that it hears against the back of the scroll-plate c and holds the same in position
while permitting the rotation thereof. By rotating the said scroll-plate in one or the
other direction, the jaws & may be caused to move simultaneously toward or away from
the centre of the chuck in a well-known manner.
b
To provide for the rotation or adjustment of the body C upon or about its axis, it is
connected with the slide as hereinafter described, that is to say, the plate d is made
with an internal annular flange d' and is secured to the slide B by means of bolts e the
heads e of which engage with the said flange d¹ and the shanks of which fit into
holes B in the slide B, as shown in Figure 3. Set-screws fare inserted in the slide B
for the purpose of securing the body in any position into which it may be adjusted.
These set-screws are made with conical points adapted to enter holes e² of corresponding
shape in the bolts e. These holes are so arranged relatively to the said set-screws that,
when the said screws are tightened, their conical points will press against the edges of
the said holes and thus tend to draw the bolts away from the plate d, so that the
flange d' of the said plate will be tightly clamped between the heads e¹ of the said bolts
and the slide B.
The back of the slide B is provided with a diametric groove the two walls of which
are dovetailed or undercut as shown in Figures 1 and 3, and the part A is made with
a rib or projection which fits into the said groove. At or near the ends of the said
groove are formed journal-bearings i, and in these bearings is journalled a screw j
both ends of which are grooved as at j¹, or they may be otherwise adapted for the
application of either a screw-driver, wrench or other suitable tool by which to turn
the said screw.
The part A has a half-nut k fitted in a central hole therein; this half-nut engages
with the screw, so that, by turning the said screw in one or the other direction, the
slide and body may be caused to slide upon the part A in a direction at right
angles to the axis of the mandrel, as in excentric chucks heretofore constructed.
A screw-plug is inserted in the part A to hold the half-nut in place; this screw-plug
also serves for adjusting the said half-nut to compensate for wear.
It will be seen from the foregoing description that the work can be adjusted in a
direction at right angles to the axis of the mandrel by turning the screw j in one or
the other direction, and can also be rotated cr adjusted upon er about its axis by
unscrewing the set-screws and thus loosening the clamping bolts e and then turning
the body upon the slide E. The set-screws are then to be tightened to clamp the
body C in the position to which it has been adjusted. By this combined adjustment

page_text: of the work, any point thereof can be brought into alignment with the centre or axis
of the mandrel. The position of the work relatively to the cutting tool can therefore
be altered without the necessity for slackening or re-adjusting the jaws b.
To facilitate the adjustment of the parts in the manner above set forth, the slide B
and the ends of the screw are sometimes graduated or marked with a scale by which
to gauge the movement of the said slide relatively to the part A. The adjacent outer
edges of the slide B and plate or disc are, moreover, in some instances graduated or
marked with a scale for a similar purpose.
By means of my improved chuck, various kinds of ornamental work can be
produced, or a series of holes can be drilled in an object or article held in the chuck,
at various points either equidistant from its centre or at different distances therefrom.
Although I have herein more particularly described my improvements as applied to
an excentric scroll-chuck, yet I wish it understood that they are also advantageously
applicable to other excentric chucks. It is, morcover, obvious that the details of
construction may be somewhat modified without departing from the nature of my said
invention. For instance, I can use other means than those above described for
securing the body Cupon the slide B in such a manner that it can be rotated or
adjusted upon or about its axis for the purpose above specified.
Having now particularly described and ascertained the nature of my said invention
and in what manner the same is to be performed I wish it understood that I claim :-
First A lathe-chuck wherein provision is made for altering the position of the
work relatively to the cutting tool by the adjustment of the face-plate or its equivalent
upon or about its axis, as, and for the
purposes, specified.
Second-The combination of the main portion or body C with the slide B
substantially as described so that the said body is capable of rotation while the slide is
held stationary, as, and for the purposes, specified.
Third The improved excentric chuck consisting of the parts constructed and
combined substantially as described with reference to the accompanying drawings and
operating as, and for the purposes, specified.
Datad this 18th day of Manah 1907