AN IMPROVED LATHE FOR BRASS FINISHING, OR OTHER PURPOSES
Year: 1884

page_text: WILLIAM DEVOLL, Engineer, 3 Boldmere Road, Erdington, Near Birmingham, in
the County of Warwick, and OLIVER HOWL, Engineer, Tipton, in the County of
Stafford. We do hereby declare the nature of our invention for AN IMPROVED
LATHE FOR BRASS FINISHING, OR OTHER PURPOSES, and in what manner the same
is to be performed, to be particularly described and ascertained in and by the
following statement :-
The object of our Invention, is to provide a Brass Finishing Lathe, with a
quicker, and more convenient means of chasing fine threads, having an odd pitch,
of the kind generally used on Brass Work, and without the use of change wheels,
and also with an Improved Capstan, or Turret Rest, to be used in connection with
the said Improved Chasing Apparatus.
For this purpose we form a Lathe Bed, with two Brackets A. A', which form the
bearings for a Spindle B, and also a Steel Socket, or Bush C, which is connected to
the Spindle B by a male and female joint, and secured by a Cotter, in the manner
shewn at D, on the accompanying Drawings, this Socket or Bush C, is screwed
internally the whole depth, to any pitch, or number of threads per inch which is
intended to be cut on the work finished by the Lathe.
On the same end of the Lathe Bed, we place an ordinary Headstock E having a
Wheel. F on the end of its Spindle, this Wheel F is connected, or geared to
another Wheel G, on the end of the Spindle B by means of a third Wheel, or
Carrier Wheel H, which revolves on a stud I fixed in the Headstock.
The three Wheels are equal in diameter and pitch and do not require to be
changed.
The remaining portion of the Lathe Bed is fitted with a Saddle J, and a Compound
Slide Rest K, K, having a Capstan, or Turret Rest L, with six Tool Holders M
equally divided.
The Saddle is moved along the Bed by means of a Rack N, and Pinion O.
A Bracket P is bolted to the underside of the Saddle, as shewn in Elevation, for
the purpose of receiving a Male Screw Q, this Male Screw is equal in diameter,
and pitch to the Screw in the Female Socket, or Bush C, and is turned to fit into
the Bracket P in the same centre line as the Bush C, and is then secured by a
Set Screw.
The parts Q, and C, are changed for cutting different pitches.
We also form, or cast a projection R on the end of the Saddle, having a recess, in
which is fitted a piece of Gun Metal S the face of which slides on the surface of

page_text: the Bed, when the Saddle is moved, but when the Saddle is not required for chasing
it can be instantly secured to the Bed for ordinary turning (after disengaging the
Male and Female Screws) by means of the Screw Handle T which gives brake
power sufficient to hold it rigid, this brake Screw can be instantly released by a
touch of the hand, when the Saddle is required to travel for Chasing Screws.
The Action is as follows:-
When any Brass Work has been bored, or turned, by means of Tools which may
be fixed in the Tool Holders M, such work may then be also chased, or screwed by
a chasing Tool fixed in one of the Tool Holders M, By Sliding the Saddle carrying
the Turret Rest, and Tool Holders forward, until the nose of the Male Screw Q
enters the Female Screw C, which is revolving in equal number of revolutions to
the Lathe Spindle (such motion being transmitted by means of the three equal
Wheels) When the Saddle, and chasing Tools will continue to travel on the work
the requisite distance, when the cutting Tool may be withdrawn from the work, and
the Lathe reversed in the ordinary manner, by means of two bands on the over-
head motion, one straight and the other crossed, when the Male Screw will be run
out of the Socket or Female Screw, only as much as is required to take another
cut on the work, when the former operation will be repeated until the work is
screwed sufficiently deep.
By this arrangement of equal Wheels and Male and Female Screws, the Screw
always revolves in equal number of revolutions to the Lathe Spindle, therefore
Screws of odd and fine pitches, can be cut more quickly, and more true than with
the ordinary leading Screw, and change Wheels, which when cutting odd pitches
requires to be worked round, until the leading Screw coincides with the Lathe
Spindle.
Having now particularly described and ascertained the nature of our said
Invention, and in what manner the same is to be performed, we declare that what
we claim is —
CLAIM.
I The Combination of a Lathe having a Headstock E, fitted with three equal
Wheels F. G. H. geared to and driving a Female Screw, or Socket C, having a
counterpart, or Male Screw Q, connected to a sliding Saddle J, fitted with a
Brake R. S. T. and also fitted with a Capstan Rest, having a Compound Slide, the
whole having the action as herein before described and as shewn in Elevation, End
Elevation and Plan on the accompanying Drawings having the action substantially
as herein before described.
Dated this 17th day of October 1884.
WILLIAM DEVOLL.
OLIVER HOWL.