Improvements in Potters' Lathes.
Year: 1886

page_text: Date of Application, 30th June, 1886.
Complete Left, 8th Feb., 1887.
Complete Accepted, 15th Mar., 1887.
Improvements in Potters' Lathes.
JAMES RICHARD PRATT, Earthenware Manufacturer, Fenton Potteries Fenton,
Staffordshire, do hereby declare the nature of my invention for IMPROVEMENTS IN
POTTERS LATHES to be as follows:-
My invention has for its object; improvements in Potters lathes. Hitherto screw-
cutting upon Earthenware, China, and similar substances has been slow and unsatis-
factory, the thread sometimes being so much deformed, that the article upon which it
was cut or moulded often had to be thrown away as useless. By means of my inven-
tion I overcome these difficulties by a very simple and reliable contrivance, which can
easily be attached to exhisting Potter's lathes, by means of which threads may be easily
and accurately formed. I will describe my invention as applied to an ordinary Potters
lathe, although I would have it clearly understood that I do not tie myself to the
details herein enumerated, so long as I adhere to the principle.
An ordinary Potters lathe consisting, of a base having an upright at each end,
to support the spindle, by means of a screw at one end and a taper collar at the other,
the said screw being to compensate the wear of the spindle by keeping the taper
surfaces in proper contact this spindle which for clearness I call the driving spindle is
made to receive cones or pullies to revolve it :-Upon the said driving spindle I form
a thread or screw corresponding to the one required upon the article, and also a nut
to work upon said screw. To one side of this nut I form a handle for the operator to
put the nut in gear with the screw, and the other side of said nut is connected to
a spindle placed parallel to the driving spindle, but which does not revolve except when
acting as a hinge when the nut is put in or out of gear, but simply travels longi-
tudinally with the nut upon the said driving spindle, this spindle I call the sliding
spindle, as it simply slides in apertures bored out to fit it and attach to, or formed
in, the uprights of the lathe.

page_text: The said sliding spindle is made sufficiently long to project past the front of
the lathe headstock to the article to be operated upon and is provided with a profile
or profiles, there being generally two employed-one for inside screwing and the other
for outside screwing.
The said profiles being made to the shape of the required thread or screw, and
provided with a stop to make the articles a given diameter.
The mode of operating is as follows:-When the article is of the required size, the
lathe spindle is caused to revolve, when the operater puts the before named nut
in gear with the screw, causing it to travel longitudinally and also the sliding spindle
attached to it, and, at the same time holds the profile upon the outer end of said sliding
spindle, in position, when it will cut the required screw, the same process being
repeated each time.

page_text: JAMES RICHARD PRATT, Earthenware Manufacturer, Fenton Potteries, Fenton,
Staffordshire, do hereby declare the nature of this invention and in what manner the
same is to be performed, to be particularly described and ascertained in and by
the following statement:-
Hitherto screw-
My invention has for its object improvements in potters lathes.
cutting upon Earhenware, China and similar substances, has been slow and unsatis-
factory; the thread sometimes being so much deformed, that the articles upon which it
was cut or moulded, often had to be thrown away as useless. By means of my
invention I overcome these difficulties by a very simple and reliable contrivance which
may easily be attached to existing potters lathes, and by which means, threads may be
easily and accurately formed.
An ordinary potters lathe, consisting of a base having an upright at each end,
to support the spindle by means of a screw at one end, and a taper collar at the other;
the said screw being to compensate the wear of the spindle, by keeping the taper
surfaces in proper contact; this spindle which, for clearness I call the driving spindle,
is made to receive cones or pullies to revolve it.
Upon the said driving spindle I form a thread or screw; and also a nut to work upon,
or gear with said screw. To one side of this nut I form a handle, for the operator to
put the nut in gear with the screw; and the other side of said nut is connected
to a spindle placed parallel to the driving spindle, but which does not revolve, except
when acting as a hinge when the nut is put in or out of gear; but simply travels
longitudinally with the nut when geared with the screw upon the said driving spindle,
this spindle I call the sliding spindle as it slides in apertures bored out to fit it
and attached to or formed in the uprights of the lathe. The said sliding spindle
is made sufficiently long to project past the front of the lathe headstock, to the article
to be operated upon, and is provided with a profile or profiles, there being generally
two employed -one for inside screwing and the other for obtside screwing. The said
profiles being made to the shape of the required thread or screw.
Reference may now be had to accompanying drawings, in which the same letters
refer to the corresponding parts in each figure.
Fig. 1. is a side view. Fig. 2. a plan.
The headstock A represents an ordinary type of potters lathe to which are added
bearings B, B, which support and guide sliding spindle C. At one part of driving
spindle D, I form screw E, corresponding as regards the pitch of the thread, to the one
required upon the article. Upon said sliding spindle C, I secure an arm or lever F
which is recessed to form a half nut, fitting upon the screwed part E of driving
spindle D; said arm or lever F I provide with a handle G for putting the nut in or
out of gear.
I construct the before named sliding spindle ( sufficiently long to carry
a rest H, upon which are fixed the profiles I. I.

page_text: My mode of operating is as follows:—
When the article, which is placed upon the head J, is of the required size, I pull
down the arm or lever F which puts the nut in gear with the screw, and when driving
spindle D is revolved, sliding spindle C travels longitudinally, I then cause one
or both of the profiles I, I, as the case may be to press.against the article, and upon
which it forms a screw thread. The said profiles I provide with catches or stops, to
insure the profile being at the same angle each time. I would also have it understood,
that I do not confine myself to the exact details herein before described, as the same
admit of modification, without departing from the essential features of my invention.
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 :-
The mode of cutting screws upon Earthenware, China and like substances by means
of apparatus combined with an ordinary potters lathe, as herein described and
illustrated by accompanying drawings.
BILLINGTON & NEWTON,
Agents for Applicant.