IMPROVEMENTS IN ELLIPTIC TURNING MACHINERY
Year: 1877

page_text: PROVISIONAL SPECIFICATION left by William Henderson and William
Brooks at the Office of the Commissioners of Patents on the 8th November
1877.
WILLIAM HENDERSON, Engineer, and WILLIAM BROOKS, Turner, both of Glasgow,
in the County of Lanark, North Britain. "IMPROVEMENTS IN ELLIPTIC TURNING
MACHINERY."
This Invention relates to turning machinery for producing elliptic forms in wood,
metal, or other material, and comprises along with an improved elliptic chuck
special arrangements for advantageously turning comparatively long rods or bars,
such as hammer handles and the like.
In the improved chuck a cross is combined with two discs, the cross consisting,
as it were, of two bars attached to each other at their middles, but lying in different
planes. One of the bars works in a slot or groove formed in one of the discs, which
can turn in a permanently fixed guide ring, and the other bar works in a slot in the
other disc, which can turn in a guide ring fixed to the other guide ring by bolts
passing through elongated holes to admit of the adjustment of the ring for different
eccentrics. One of the discs is fixed on the lathe spindle, or is toothed or attached
to a toothed ring which is in gear with a pinion on a driving shaft. The centre
chuck or holder for the work is upon the cross, and the described combination of
parts gives the motion to the work required for producing the elliptic form.
When hammer handles or other comparatively long articles are to be turned, both
ends of the article are held and made to rotate elliptically by similar chucks, the
driving shaft being made long enough to carry pinions for driving the discs of
both headstocks.
In addition to the two stationary headstocks a travelling tool carrier and work
supporter is provided, which moves from one headstock to the other, and whilst
carrying the tools along as the turning progresses also holds the work in its proper
position, so that it cannot yield and bend from the pressure of the tool.
A tool or tools for roughing are applied at the forward side of the travelling
piece, one or more finishing tools being applied at the after side, the latter being, if
wished, also acted on by a stationary pattern guide to give a barrelled or other form
of varying diameter.

page_text: The work holder on the travelling piece consists of a pair of discs in guide rings
like the headstock chucks, and also driven by a pinion on the same driving shaft;
but these travelling. discs are formed with wider slots, and the cross is also made
with the bars wider, or of a simple square form, and with an opening at the centre
for the work to pass through. The forward tool or tools shape the work to fit, or
nearly fit, the opening in the cross, or a suitable bush placed in the opening, and the
other tools always following close to the supported part of the work effect the
finishing turning action in an accurate manner. The travelling piece is moved
along by screw or rack, and pinion gearing, worked automatically or by hand.
The various parts may be modified in such manner that the work may be held
stationary whilst the cutting tools are made to revolve elliptically.
"
A single set of the improved parts may be mounted on ordinary lathe bed or
other suitable framing; or one driving shaft, with two sets of the other parts
arranged one above the other may be mounted on fixed travelling and adjustable
brackets or slides, carried in overhanging positions by vertical standards provided
with horizontal guides. More than two sets of the parts may also be combined in
a similar way.