Improvements in Expanding Boring Bars.
Year: 1889

page_text: Date of Application, 9th Apr., 1889
Complete Specification Left, 8th Jan., 1890-Accepted, 8th Feb., 1890
PROVISIONAL SPECIFICATION.
Improvements in Expanding Boring Bars.
I BENJAMIN SAMUEL WESTON Engineer of 5 Parkholme Road Dalston in the
County of Middlesex, do hereby declare the nature of this invention to be as
follows:-
This relates to Boring Bars used between the lathe centres. In this improvement
either single or double cutters may be used one cutting edge only can be expanded
at a time.
It consists of a Bar fitted at one or both extremities with a cap turning eccentrically
upon, or plug turning within the end (by preference that of the mandril) this having
a centre drilled to coincide with the true centre of the Bar, the cap or plug is capable
of turning one half revolution, that is from the central position which forms the limit
in one direction, to the opposite point, the limit of eccentricity in the other, and of
being clamped or set at any part of its movement, thus in use the Bar cap or plug
is turned to the stop limit of its central position and the cutter set so that it will
travel through the cylinder without touching, the cap or plug may now be turned,
giving, by the divisions marked upon the head, the required eccentricity or cut to the
tool, it is then clamped and the cut taken, unclamped again, the cap or plug turned
back to the central limit and the saddle and work taken back for the next cut. When
clamped at the central position the Bar may be used with double cutters in the
ordinary way, or by setting out one cutter this will take the rough cut, any number
of cuts may then be taken with the other end of the cutter for finishing.
Dated this 8th day of Anril 1889
BENJAMIN SL. WESTON.
COMPLETE SPECIFICATION.
Improvements in Expanding Boring Bars.
I BENJAMIN SAMUEL WESTON Engineer of 5 Parkholme Road Dalston in the
County of Middlesex do hereby declare the nature of my invention for IMPROVE-
MENTS IN EXPANDING BORING BARS and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement:
To add to the utility of this expanding device it has been found in practice advan-
tageous to separate the cutter Bar from the lathe dog or carrier with which it was
combined, in order that ordinary cutter Bars may be fitted to it and thus be made to
expand by means of the improved dog or carrier. To suit the foregoing arrangement
I prefer to construct the carrier as follows:-shown in drawing Figs. 1 & 2. The boss A
is bored and the various Bars are fitted to it, being held by a set screw B, there are two
ends to the carrier, one carrying the driver pin C which enters the slot in the lathe
catch plate, this pin C also holds and forms the centre upon which the plate D turns,
its other end being provided with a quadrant slot E where the set screw F clamps it
in any position, there are in the plate D three holes for the lathe centre, that at G
being the one ordinarily used, those at H and I are used when greater eccentricity is
required for either cutter. It is used as follows:-With the plate D in its central
position, the Bar turns concentrically and may be used with single or double cutters
in the usual way, either cutter may be expanded by giving the required eccentricity
to the Bar by means of the quadrant slot E and the screw F, with a double cutter one
end may be used for the rough and the other for the finishing cut, the plate D is

page_text: brought back to the central position after cach cut, which enables the work to pass
back clear of the cutters, the handle J is used in shifting the centre plate D, which
has its edge K divided for setting the cutters by.
Having now particularly described and ascertained the nature of my said Inven-
tion and in what manner the same is to be performed I declare that what I
claim is
The expanding of the cutters of boring Bars by means of the attachment forming
the lathe dog or carrier substantially as herein described.
Dated this Eighth day of January 1890
BENJAMIN SL. WESTON.