IMPROVED MEANS OF AND APPARATUS FOR TRAPPING 'MICAS' OR MICA PITS " IN THE WASHING OR REFINING OF CHINA CLAY
Year: 1882

page_text: LETTERS PATENT to John Lovering and Robert Martin both of Saint Austell
in the County of Cornwall China Clay Merchants for an Invention of
IMPROVED MEANS OF AND APPARATUS FOR TRAPPING 'MICAS' OR MICA PITS
"
IN THE WASHING OR REFINING OF CHINA CLAY
PROVISIONAL SPECIFICATION left by the said John Lovering and Robert
Martin at the Office of the Commissioners of Patents on the 30th. June
1882.
JOHN LOVERING and ROBERT MARTIN both of St. Austell in the County of
Cornwall, China Clay Merchants "IMPROVED MEANS OF AND APPARATUS FOR
TRAPPING MICAS' OR MICA PITS IN THE WASHING OR REFINING OF CHINA CLAY"
In washing and preparing for the market china clay it is necessary to free it
from (amongst other refuse) a substance commonly called mica.
The stream of clay containing the mica has, for this purpose been caused to pass
through narrow channels, the latter having arranged in them at suitable intervala
narrow boards which are lifted as the mica settles in the channels so as to always
keep the clay stream pooled and prevent the mica running on with the clay.
These narrow boards constitute the traps which keep back the mica in the
channels or mica pits and which it has hitherto been the custom to raise from
time to time by means of a flat iron bar or its equivalent attached to the traps
and provided with holes by which it can be hung to a pin or rod fixed on a cross
shaft above the traps.
This bar is raised by hand and hung a hole higher as required to raise the
traps.
Now, according to our invention, we dispense with the flat iron bar, and also
with manual labour, and this we effect by the following means.
A long bar or rod passes longitudinally from one end of the mica channels to
the other, and is connected by means of levers to an additional cross shaft placed
above each set of mica traps. The mica traps are connected to these cross shafts
Price 6d1

page_text: by a rod and chain, or in any other suitable way, so that by partially revolving
the cross shafts in one direction the traps are raised.
This partial revolution of the cross shafts is effected, through the intermediation
of the levers connecting the said cross shafts with the main long bar, by causing
the said main long bar to move in a longitudinal direction. This movement may
be imparted to it by various mechanical means. The method we have hitherto
found advisable is to connect the end of the longitudinal bar to a float which is
in a well or cistern and then by means of a stream of water, (the flow of which
can be regulated) to fill the cistern at the rate required and thus cause the float
gradually to rise and lift the traps automatically, and (if desired) simultaneously.
If it should be desired to lift only some of the traps it is simply necessary to
disconnect the others from the cross shaft above them. If it should be desired
that some traps should rise faster than others this can be effected by shortening
the levers connecting the main long bar with the cross.shafts
I
When the traps are fully up it is time to clean out the micas after which the
cistern can be emptied when the trap, will fall. The gradual filling of the cistern
can then commence again, and the whole operation be repeated as before.
Among the advantages of this invention are
1° An improvement in the quality of the china clay as by this gradual rising
of the traps the mica can be better and more effectually separated from the clay
than heretofore
2° A saving in manual labour none being required as before for raising the
traps from time to time and the channels not requiring to be cleaned out so
often.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said John Lovering and Robert Martin in the Great Seal Patent
Office on the 30th December 1882.
JOHN LOVERING and ROBERT MARTIN both of St. Austell in the County of
Cornwall China Clay Merchants IMPROVED MEANS OF AND APPARATUS FOR
TRAPPING MICAS OR MICA PITS IN THE WASHING OR REFINING OF CHINA CLAY
"
In trapping "micas" hitherto the method adopted has been as follows
In washing and preparing for the market China Clay it is necessary to free it
from (amongst other refuse) a substance commonly called mica
The stream of clay containing the mica is for this purpose passed through narrow
channels in which are arranged at suitable intervals transverse boards which are
lifted as the mica settles in the channels so as to always keep the clay stream
pooled and prevent the mica running on with the clay
These transverse boards constitute the traps which keep back the mica in the
channels or mica pits and which it has hitherto been the custom to lift from time
to time by means of a flat iron bar or its equivalent attached to the traps and
provided with holes by which it is hung to a pin or rod fixed on a cross shaft above
the traps. This bar is lifted by hand and hung a hole or more higher as
required
Now according to our Invention we dispense with the flat iron bar and also
with manual labour and this we effect as will be clearly seen by the following
description in connection with the accompanying drawings by the following
means Fig 1 is a perspective view Fig 2 a part longitudinal section and Fig 3
a method of regulating the trap by worm and wheel.
A long bar or rod A passes longitudinally from one end of the mica
channels B B B to the other and it is connected by means of lever C to an
additional cross shaft D placed above each set of mica traps E E E and connected
therewith by means of the lever D₁ and rod or chain E¹ The mica traps Ę E E
are connected to the cross shafts D D by a rod E¹ and chain or rod F or in any other
suitable way so that by partially revolving the cross shaft D D in one direction
the traps are raised
This partial revolution of the cross shafts DD is effected through the inter-
mediation of the levers CC connecting the said Cross shafts with the main long
bar A by causing the said long bar A to move in a longitudinal direction The
method we have hitherto found advisable to impart this movement is to connect
the end of the longitudinal bar A to a float Ft (which is in a well or cistern) and
then by means of a stream of water the flow of which can be and is regulated to
feed the cistern at the rate required and thus cause the float F to gradually
rise and lift the traps E E E automatically and (if desired) simultaneously If
it should be desired to lift only some of the traps it is simply necessary to
disconnect the others from the cross shafts above them
If it should be desired that some traps should rise faster than others this can
be effected by shortening the rod or chain which connects the cross shaft D D by
means of its lever with the trap or traps
When the traps are fully up it is time to clean out the micas which is effected
by raising the plugs or stoppers H H H after which the cistern can be emptied
when the traps will fall
The gradual filling of the cistern can then commence again and the whole
operation continue as before.
Among the advantages of this Invention are
1st An improvement in the quantity and quality of the china clay as by this

page_text: gradual rising of the traps the clay can be better and more effectually separated
and freed from the mica than heretofore
2nd A saving in manual labour none being required for raising the traps from
time to time, and the channels not requiring to be cleaned out so often
And having now described the nature of our said Invention and in what manner
the same is to be performed we declare that we claim
•
1st The improved means of and apparatus for trapping "micas" or mica pits in
the washing or refining of China Clay as hereinbefore described and substantially
as shown in the annexed drawings
2nd The combination of the longitudinal bar or rod A with the levers CC the
cross bar or shaft D the lever D¹ and rod or chain E¹ for the purpose of actuating
simultaneously (or otherwise) and uniformly the traps E È È in the manner
described and for the purpose set forth
In Witness whereof we the said John Lovering and Robert Martin have
hereunto set our hands and seals this twenty eighth day of December
3000