AN IMPROVED OVAL LATHE
Year: 1885

page_text: We, WILLIAM HENRY BARKER and GEORGE BARKER, of 42, Queen Street,
Fenton, Tool Makers, and GODWIN EMBREY, of 1, Queen Street, Fenton, Gentleman,
all in the County of Stafford, do hereby declare the nature of our invention for
AN IMPROVED OVAL LATHE and in what manner the same is to be performed, to
be particularly described and ascertained in and by the following statement:-
The Lathe is specially designed for turning wood handles or hafts of an oval
section.
Oval handles are greatly preferred to round, for pickaxes, sledge hafts and such
purposes, and are at present usually turned round, and afterwards rendered oval
by flattening two opposite sides.
The special features of our improved lathe are 4 in number viz;
(1) Two similar chucks of novel design are placed one at each end of the lathe
centre.
These chucks impart an elliptical movement to the shaft which is being turned,
so that its outer surface describes an oval and not a circular orbit, the result being
that the shaft is automatically turned to an oval outline.
This is effected by placing behind the face plate of the chuck a fixed collar or.
ring which is firmly bolted to the headstock.
The face plate of the chuck contains a sliding plate from the centre of which
the centre-bit projects. This sliding plate has two strong pins or studs projecting
backwards through slots in the face plate and fitted close to the exterior surface of
the collar or ring in such manner that when the spindle revolves and carries round
with it the face plate, sliding plate, and the holding or centre-bit of the chuck, the
two fingers necessarily follow the circumference of the collar or ring.
When therefore this collar or ring behind the face plate is fixed slightly out of
the lathe centre, as is necessary for turning oval, it will by means of the two studs
and slide plate before described impart an elliptical or eccentric motion to the
holding or centre-bit.
It effects this by compelling the sliding plate and the wood shaft which is being
turned, to move from side to side, or in other words to travel out of the centre,
just sufficiently to impart the required oval motion to the wood shaft.

page_text: (2) Another feature of the lathe is a special feed motion causing the cutting
tool to travel along the shaft which is being turned.
This feed motion consists of a horizontal revolving screw running across the
lath, parallel with its centre, and a hinged frame with weight at end hung on a
horizontal bar placed at the back of the lathe, the said frame having underneath
a half nut fitting into the thread of the aforesaid screw, so that the said frame is
caused to travel with the motion of the screw but can be released from the screw
motion in a moment by lifting the frame.
This frame carries the tool holder described in paragraph 4.
(3) Another speciality of this lathe is a double tool holder which consists of two
vertical supports connected by a horizontal base or bottom plate.
The cutting tools are fastened to the upright supports by being passed through
the eyes or hooks of ring headed or hook headed bolts inserted through slots or
boles in the supports and screwed up tight by means of nuts on the reverse of the
support.
The tool is thus held firmly against the side of the support.
This tool-holder is attached to and travels with the frame described in the
previous paragraph.
(4) An important feature of the lathe is the template which corresponds in length
and outline with the shape of the handle to be turned.
Thus one end of the handle being required taper and the other end enlarged, the
template is accordingly lower at one end and higher at the other.
In turning oval spokes for wheels, an ornamental "swell
be obtained by a corresponding elevation in the template.
"
or enlargement could
The template is a long bar or plate of iron on which the tool holder rests while
travelling automatically with the frame along the handle which is being turned.
It is supported by two slotted stays, the lower ends of which are attached by
moveable bolts to the front of the lathe bed.
Thumb-screws or bolts with nuts pass through the slots in the stay and connect
the template to the stays in such manner that it can be raised or lowered as
required.
On the top of this template the double tool holder travels, the actual point of
contact being the end of a screw about half an inch in diameter which passes
through the base of the tool holder and is of sufficient length to allow of
considerable adjustment in the distance between the template and the tool holder.
In the accompanying drawings the same letters denote identical parts
throughout.
Figure 1-represents a front view of the lathe with the 2 chucks and the
template in position.
Figure II is a plan, and Figure III is a section of the same.
Figure IV-shews a section of the right hand headstock at the line A
- B.
Figure V-shews the eccentric chuck-C. C. are the improved chucks--D. D. the
pins or studs, and E E the collars or rings on which they work.
T is the slide plate on the face plate W.
F. is the iron template and supports. G is the feed motion. H the hinged
frame I the weight on ditto J. the horizontal bar on which H slides.
K. the tool holder.
L. the lathe centre.
M. the feed pulley for the screw.
N. the overhead motion.

page_text: Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is
1. An improved eccentric chuck with separate collar or ring by means of which
an oval motion can be obtained when required.
2. An improved adjustable fixed template for guiding the cutting tool.
3. An improved self acting feed motion with lifting frame which can be lifted
up when required.
4-A double tool holder to which two tools can be attached by bolts or screws
in the usual way.
5. The combination of the above improvements in a lathe for turning oval
handles.