A NEW OR IMPROVED ROTARY TOOL HOLDER FOR POTTERS' LATHES
Year: 1875

page_text: LETTERS PATENT to John Gaskell, of Burslem, in the County of
Stafford, Potter, for the Invention of "A NEW OR IMPROVED ROTARY
TOOL HOLDER FOR POTTERS' LATHES."
Sealed the 29th October 1875, and dated the 7th May 1875.
PROVISIONAL SPECIFICATION left by the said John Gaskell at the
Office of the Commissioners of Patents, with his Petition, on the
7th May 1875.
I, JOHN GASKELL, of Burslem, in the County of Stafford, Potter, do
hereby declare the nature of the said Invention for "A NEW OR IMPROVED
ROTARY TOOL HOLDER FOR POTTERS' LATHES," to be as follows:-
This Invention consists substantially of the following arrangement of
parts-The article required to be turned is attached to the mandril of
the lathe, and two cams corresponding exactly in shape to the article
desired to be produced are securely bolted or otherwise properly fastened
to the lathe bed. Attached to the headstock and joined thereto is a
bracket working on two guide bars, and the tool holder having a flat

page_text: front is held up to and against the said cams by means of two spiral or
helical springs which are coiled round the said guide bars.
A straight-edged tool is screwed securely to the tool holder, so that
when the said tool holder is caused to rotate round the said cams the
tool or cutter shapes the article attached to the mandril into exactly the 5
same form or figure as is represented by the cams.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said John Gaskell in the Great Seal Patent Office on
the 6th November 1875.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
GASKELL, of Burslem, in the County of Stafford, Potter, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Seventh day of May, in the year of
our Lord One thousand eight hundred and seventy-five, in the thirty-
eighth year of Her reign, did for Herself, Her heirs and successors,
give and grant unto me, the said John Gaskell, Her special licence
that I, the said John Gaskell, my executors, administrators, and
assigns, or such others as I, the said John Gaskell, my executors, ad-
ministrators, and assigns, should at any time agree with, and no others,
from time to time and at all times thereafter during the term therein
expressed, should and lawfully might make, use, exercise, and vend,
within the United Kingdom of Great Britain and Ireland, the Channel
Islands, and Isle of Man, an Invention for "A NEW OR IMPROVED ROTARY
TOOL HOLDER FOR POTTERS' LATHES," upon the condition (amongst others)
that I, the said John Gaskell, my executors or administrators, by an
instrument in writing under my, or their, or one of their hands and
seals, should particularly describe and ascertain the nature of the said
Invention, and in what manner the same was to be performed, and
the same to be filed in the Great Seal Patent Office within six
calendar months next and immediately after the date of the said Letters
Patent.
cause

page_text: be performed, to be particularly described and ascertained in and by
the following statement (that is to say) :-
This Invention consists substantially of the following arrangement of
parts-The article required to be turned is attached to the mandril of
5 the lathe, and two cams corresponding exactly in shape to the article
desired to be produced are securely bolted or otherwise properly fastened
to the lathe bed. Attached to the headstock is a bracket, which has
jointed to it the tool holder working on two guide bars, and this having
a flat front is held up to and against the said cams by means of two
O spiral or helical springs which are coiled round the said guide bars.
When a flat-sided bowl or other article is desired to be turned a
straight-edged tool is screwed securely to the tool holder, so that when
the said tool holder is caused to rotate round the said cams the tool or
cutter shapes the article attached to the mandril into exactly the same
form or figure as is represented by the cams.
Similarly, when a bowl or other article having an indented or uneven
surface is desired to be made, the tool holder is fitted with a tool of
suitable shape (as more particularly described in the Drawings hercin-
after referred to), so that when the bowl or other article is turned it
Opartakes partly of the shape of the cams and partly of the shape of the
tool.
That my Invention may be better understood I have annexed Drawings
thereof, which I now proceed to describe.
Fig. 1 is a plan, Fig. 2 is a side elevation, and Fig. 3 an end elevation
of a tool holder constructed according to my Invention. For the sake of
clearness the tool in Fig. 1 and the tool holder in Fig. 3 have been
omitted.
a is the headstock of the lathe, and b, b, is the centre line of the
mandril. Upon the lathe bed is bolted a bracket c having an upper and
lower projecting plate d, d, the two extremities of which e, e, form fixed
cams or patterns of the same outline as the article which it is desired to
produce. The vertical tool holder f, to the top of which is secured the
flat tool by means of the plate h and nut i, slides horizontally upon
two guide bars k, k, and is held against the cams e, e, by means of two
coiled springs 1, l. The guide bars k, k, arc fixed into a vertical bar m

page_text: which is supported upon centre pins n, n, screwed into a bracket o
which is bolted firmly to the face of the headstock a.
An article to be turned having been fixed upon a chuck in the usual
manner, and the mandril having been set revolving the handle p is
moved horizontally to the extent of about a quarter of a circle, as shown
by the dotted are 1, carrying with it the tool holder fand tool g. The
distance of the latter from the centre of the article to be turned is
controlled by the cams e, e, against which the tool holder is pressed as
aforesaid, and the result is that to the finished article is given an outline
corresponding with the outline of the said cams e, e.
In Fig. 4 is shown a castor 8, the outline of which from t to u has
been determined by the cams e, and the face of which has been formed
into the shape shown by means of a corresponding curve upon the edge
of the tool g, which curve comes into action towards the termination of
the circular movement of the tool holder f.
Should a flat face be required the edge of the tool is made straight
instead of curved.
When one face and half the edge of an article have thus been formed
the article is reversed in position upon the chuck, and the remaining
portion is similarly acted upon by the tool g. ·
Thus by the combined action of the tool holder and of the shape
of the turning tool large numbers of exactly similar articles of almost
any desired outline may be produced without the aid of skilled labor.
Having now described the nature of my said Invention, and the manner
in which the same is or may be performed, I desire it to be understood
that without limiting myself to the precise details herein-before con-
tained (as these may be varied or modified without departing from
the nature of my said Invention), what I claim as the Invention to be
protected by the herein-before in part recited Letters Patent is,―
First. The cams e, e, applied to a potter's lathe, substantially as and
for the purpose herein-before described, and as illustrated in the accom-
panying Drawings.
Second. Holding the tool holder by means of coiled springs against
the said cams in a potter's lathe, substantially as and for the purpose
herein-before described, and as illustrated in the accompanying
Drawings.

page_text: Third. The general combination of parts for the purposes set forth,
substantially as herein-before described and illustrated in the accom-
panying Drawings.
In witness whereof, I, the said John Gaskell, have hereunto set
my hand and seal, this Third day of November, in the year of
our Lord One thousand eight hundred and seventy-five.