IMPROVEMENTS IN APPARATUS FOR SHAPING CLAY OR SIMILAR MATERIALS
Year: 1874

page_text: LETTERS PATENT to Alexander Willison Buchan, of the Portobello
Pottery, Portobello, in the County of Mid Lothian, North Britain,
for the Invention of "IMPROVEMENTS IN APPARATUS FOR SHAPING CLAY
OR SIMILAR MATERIALS."
Scaled the 18th December 1874, and dated the 23rd June 1874.
PROVISIONAL SPECIFICATION left by the said Alexander Willison
Buchan at the Office of the Commissioners of Patents, with his
Petition, on the 23rd June 1874.
I, ALEXANDER WILLISON BUCHAN, of the Portobello Pottery, Porto-
bello, in the County of Mid Lothian, North Britain, do hereby declaro
the nature of the said Invention for "IMPROVEMENTS IN APPARATUS FOR
SHAPING CLAY OR SIMILAR MATERIALS," to be as follows, that is to say :-
This Invention relates to the addition of apparatus to a potter's wheel
to gives facilities for applying longitudinal combined with rotating move-
ments when shaping articles of clay or similar materials on the wheel.
And in carrying out the Invention according to one modification,

page_text: °
specially adapted for forming a screw-thread on the outside of an
earthenware bottle, a screw thread is formed on the spindle or shaft of
the wheel, and a comb or concavely screwed segment is carried by an
arm on a rod parallel to the wheel shaft. This rod is carried in guides
so that it can move longitudinally, and when it is turned so that its arm
causes the comb to engage with the screw the rotation of the wheel shaft
makes it move in the guides. On the other end of the rod there is fixed
or adjusted a second arm with a comb in a position corresponding to the
neck of the bottle which is being formed on the wheel, and when the
rod is turned to put the lower comb in gear the upper comb is simul-
taneously turned inwards and forms the screw on the bottle neck.
For the upper comb shapers of various forms may be substituted so as
to develop various forms on the articles operated on, and the screw for
giving the longitudinal movement may be on a shaft or spindle geared
to the wheel shaft instead of being on that shaft itself.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Alexander Willison Buchan in the Great Seal
Patent Office on the 22nd December 1874.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ALEXANDER
WILLISON BUCHAN, of the Portobello Pottery, Portobello, in the County
of Mid Lothian, North Britain, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-third day of June, in the year of
our Lord One thousand eight hundred and seventy-four, in the thirty-
eighth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Alexander Willison Buchan, Her
special licence, that I, the said Alexander Willison Buchan, my
executors, administrators, and assigns, or such others as I, the said
Alexander Willison Buchan, my executors, administrators, 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 "IMPROVEMENTS IN APPARATUS FOR SHAPING

page_text: CLAY OR SIMILAR MATERIALS," upon the condition (amongst others) that I,
the said Alexander Willison Buchan, 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
cause 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.
NOW KNOW YE, that I, the said Alexander Willison Buchan, do
hereby declare the nature of my said Invention, and in what manner
the same is to be performed, to be particularly described and ascer-
tained in and by the following statement in writing, reference being had
to the accompanying Drawings, that is to say:-
My said Invention relates to the addition of apparatus to a potter's to
wheel to give facilities for applying longitudinal combined with rotating
movements when shaping articles of clay or similar materials on the
wheel. And in order that my said Invention and the manner of per-
forming the same may be properly understood, I hereunto append a
Sheet of explanatory Drawings, to be herein-after referred to, and repre-
senting modifications of my improved apparatus as adapted for forming
screw threads on the necks of bottles or jars, the employing of my
Invention in this way being one of its most important applications. In
these Drawings the same reference numerals are used to mark the same
or like parts wherever they are repeated.
Figure 1 of the Drawings is a side elevation of a potter's wheel and
parts in connection therewith, as now commonly constructed, but with
my improved apparatus added to it, and with the wooden trough 1,
shown in vertical section. The potter takes his place at the right-hand
of the machine, as represented, and would be seen in side view if shown
in the Drawing. The vertical shaft 2 of the potter's wheel 3 has on it
a friction pulley 4, which receives motion from a disc 5 on a horizontal
shaft 6 driven by a steam engine or other suitable prime mover. The
pulley 4 is shown at the centre where the disc 5 is slightly recessed so
as not to impart any motion to it then, but it can be moved down by
means of a lever 7 (centered at a little distance towards the left-hand),
and the nearer the pulley 4 is moved to the outer edge of the disc 5 the
greater is the velocity imparted through it to the potter's wheel 3. The

page_text: lever 7 is part of a kind of lever frame which at the further side has
attached to it a tread-plate (not shown) for the potter to put his right
foot on, and it is by depressing his foot on this treadle more or less that
he causes the speed of his wheel 3 to be greater or less, as is well under-
stood. A counterweight applied to the lever frame 7 causes it to move
the pulley 4 towards the centre whenever the potter lifts his foot.
In carrying out my Invention a screw thread 8 is formed on a boss on
the spindle or shaft 2, or such screw thread might be formed' on tlic
-shaft itself, and a comb or concavely screwed segment 9 is formed on or
attached to an arm 10 fixed on a rod 11 parallel to the wheel shaft 2.
This rod 11 is placed in guides 12, in which it can turn and also move
vertically, the guides being formed in brackets, which may be fixed to a
side wall or to any convenient fixture; and when the rod 11 is turned
so that its arm 10 causes the comb 9 to engage with the screw 8 of the
spindle 2 the rotation of the spindle makes it move vertically in the
guides 12. On the upper part of the rod 11 there is fixed or adjusted a
second arm 13 with a comb 14 in a position corresponding to the neck
of the bottle 15 which is being formed on the wheel 3, and when the
rod 11 is turned to put the lower comb 9 in gear with the screw 8 the
upper comb 14 is simultaneously turned inwards and forms the screw on
the bottle neck. The combs 9 and 14 should in strictness not be seen
in the Drawing, as they would in reality be hid, the one 9 by the
- screwed part 8, and the other 14 by the neck of the bottle 15, but the
arms 10, 13, are shortened so as to show them. They are at the right-
hand side of the potter.
When the potter has so far completed the shaping of the bottle 15, as
is done in the ordinary way, he takes his foot quite off the lever frame 7,
and through the action of the counterweight the pulley 4 returns to the
centre, and the potter's wheel 3 consequently ceases to be driven by the
shaft 6. The potter then with his right-hand turns inward the upper
arm 13 so that its comb or shaper 14 comes in contact with the soft
bottle neck. The arm 13 being fixed to the rod 11 turns the latter, and
the rod turns the lower arm 10 so as to put its comb 9 into contact with
the screwed part 8 of the shaft 2. The parts are of course adjusted so
that when the lower comb 9 is in contact with the screw 8 the upper
comb or shaper 14 is in the precise position for shaping the screw-thread
of the desired diameter on the bottle neck. Having thus turned inwards
the upper arm 13 the potter takes hold of the wheel 3 with his left-hand

page_text: and turns it. This turns both the bottle 15 and the shaft 2, and the
screwing action of the part S makes the rod 11. move longitudinally,
that is, vertically, exactly in proportion to the rotation. A vertical
motion is thus imparted to the upper comb 14, and this combining with
the rotation of the bottle 15 produces the screw thread on its neck. As
the potter is turning the wheel 3 by hand he can stop the motion exactly
and easily the instant the screw thread has extended the desired length.
The downward movement of the rod 11 is limited by means of a ring 16
adjusted on its upper part and fixed by a pinching screw, this ring coming
in contact with the upper guide bracket 12 and then supporting the
rod 11.
With the modification shown in Figure 1 the screw thread formed on
the bottle neck will be of the same pitch as that S on the spindle 2.
When however the apparatus is required for forming screws of different
pitches at different times the upper arm 13 of the rod 11 may be arranged
as shown in Figures 2 and 3. In this modification the arm 13 is jointed
to the rod 11 and oscillates on a fulcrum pin 17 fixed to a pendent
bracket 18, which last is itself fixed on the horizontal bar 19 of a bracket
fixed to the wall or supported in any convenient way. The vertical
movement of the comb 14 is in this arrangement opposite to that of the
rod 11, so that if the screw S on the spindle is right-handed, that formed
on the bottle will be left-handed, and vice versa. The extent of the
movement and consequently the pitch depends on the position of the
fulcrum pin 17, lengthways of the arm 13, which now acts as a lever,
and the arm being formed with a series of holes and the pendent bracket
18 being adjustable on the horizontal bar 19 a fulcrum pin can be put
in any one of several different positions so as to give the comb 14 a
movement less than equal to or greater than that of the rod 11, and so
vary the pitch of the screw formed on the bottle or other article as may
be required.
Figure 2 is an elevation, and Figure 3 is a horizontal section as taken
just above the arm 13.
The fulcrum pin 17 is curved concentrically with the rod 11, as shown
.in Figure 3, to allow of the arm 13 being turned away from the bottle
5 or article, and a number of pins are provided to suit the different
distances from the rod 11. When giving the arm 13 the lever motion
I prefer to form the comb 14 so as, whilst at right angles to the arm 13,

page_text: to be situated to the upper side of it; and the screw-shaping action is
commenced with the comb end of the arm, inclined upwards, and termi-
nates when the arm is moved into the horizontal position, and the
downward movement may be limited by a stop. The pendent bracket 18
is formed with a number of holes to admit of the fulcrum pin 17 being
placed at different heights to suit bottles or other articles of different
heights.
In arranging the parts shown in Figures 2 and 3 I prefer to place
them with the vertical rod 11 at or near the corner of the trough furthest
from the potter on his right-hand, so that they may not be in the way
when he is shaping the bottle or other article before putting the screw
on it.
When requiring to form an internal screw, as, for example, inside of
the neck of a jar, the modification shown in Figure 4 may be adopted.
The comb 14 is formed or fixed on a curved piece 20 jointed to a tubular
picce 21 fitted to slide on the arm 13 between stops, the outer one of
which determines a central position of the comb 14, from which it can
be turned on the joint clear out of the jar neck, whilst the other stop 22
is adjustable and determines the position of the comb so as to give the
desired diameter to the screw thread.
For the upper comb (14) shapers of various forms may be substituted
so as to develop various forms on the articles operated on, and the screw
(8) for giving the longitudinal movement may be on a shaft or spindle
geared to the wheel shaft (2) instead of being on that shaft. Thus for
example a rolling shaper held in a fork attached to the arm 13 like the a
66 runner used by potters may be used to produce helical or spiral lines
of ornament, whilst diamond shaped ornamentation may be imparted by
employing reversed screws (8) in succession.
"
Having thus particularly described my said Invention and the manner
of performing the same, I have to state that I do not restrict myself to a
the precise details herein described or delineated, but that what I believe
to be novel and original, and claim as the Invention secured to me by
the herein-before in part recited Letters Patent is,―
1. The combining with a potter's wheel of improved apparatus, sub-
stantially such as herein described and delineated, for applying s
longitudinal, combined with rotating movements, when shaping articles
of clay or similar materials-on the wheel.

page_text: 2. The forming of external or internal screw threads on articles made.
f clay or similar materials by means of improved apparatus, arranged
nd operating substantially in the improved manner herein-before
escribed in connection with the potter's wheel or apparatus on which
he article is originally shaped.
In witness whereof, I, the said Alexander Willison Buchan, have
hereunto set my hand and seal, this Nineteenth day of December,
in the year of our Lord One thousand eight hundred and
seventy-four.
Witness,
EDMUND HUNT,
Patent Agent,
Glasgow.
A. W. BUCHAN. (L.S.)