Improvements in Rotary Sifting or Grading Apparatus, more especially intended for use in Sifting or Grading Tea.
Year: 1893

page_text: Date of Application, 3rd Nov., 1893
Complete Specification Left, 19th Dec., 1893-Accepted, 20th Jan., 1894
PROVISIONAL SPECIFICATION.
Improvements in Rotary Sifting or Grading Apparatus, more
especially intended for use in Sifting or Grading Tea.
I WILLIAM JACKSON of Thorn Grove, Mannofield, Aberdeen, North Britain,
Engineer do hereby declare the nature of this invention to be as follows:-
My invention relates to sifting or grading apparatus wherein rotary screens or
sieves are used and is more especially intended for use with such apparatus when
employed for sorting tea into different grades or classes.
The
Tea is liable in such apparatus as hitherto made to cling to the screen or sieve
and it is the object of my invention to overcome this objection. According to my
invention I impart a jerking, or jarring movement to the screen, or sieve, as it
rotates so as to produce sufficient vibration, or concussion thereof to prevent the
said clinging of the tea to the screen or sieve thus keeping the meshes of the screen
or sieve clear; and this effect I obtain without interfering with the steady running
of the pulleys and gear by which the screen, or sieve is rotated. This can be
effected according to my invention by mounting the driving pulleys upon a fixed
centre and causing them to drive a pinion upon the same centre the said pinion
gearing with a wheel by which the screen or sieve is rotated, the said screen or
sieve being also provided with a projection, or cam, or projections or cams which
during rotation act upon a fixed piece so as to cause the sieve or screen to vibrate,
or have the desired concussion or jarring imparted to it the screen or sieve being so
mounted that the wheel, by which it is rotated, will remain in gear with the driving
device without causing that device to be similarly vibrated or jarred.
following is an arrangement according to my invention but I do not limit myself.
to the precise details of this arrangement. I pass the ends of the shaft upon which
the screen or sieve is mounted through the ends of links, or arms, the other ends of
which are mounted upon pins which constitute centres upon which the links or
arms carrying the shaft can vibrate. The said pins are secured to the framing, or
standards, of the machine and one of the said pins carries the driving pulley, and a
pinion driven thereby which pinion engages with a toothed wheel secured to the
shaft so as thereby to transmit rotatory motion to the screen or sieve. A cam,
cams, is, or are, secured to the shaft which cam or cams as the shaft and screen or sieve
rotate bears or bear upon a block so that the shaft and screen or sieve are lifted
(the links or arms carrying the shaft turning upon their pins) and then when the
cam has, or cams have, passed the block the shaft and screen or sieve drop
suddenly and the screen is jerked or jarred, at each such drop. The aforesaid
block may be arranged so that it can be brought into position to effect the jarring
movement or be moved out of such position as desired. By mounting the block
upon an inclined plane it can be moved in one direction so as to be entirely clear
of the cam or cams, when no jarring movement is desired, or it can be moved in the
other direction to a variable extent in accordance with the amount of concussion or
jarring desired to be produced.
Dated this 3rd day of November 1893
or
J. H. JOHNSON & Co.,
47, Lincoln's Inn Fields, London, W.C., Agents.

page_text: GOLDIE DI MULTIATION.
Improvements in Rotary Sifting or Grading Apparatus, more
especially intended for use in Sifting or Grading Tea.
I WILLIAM JACKSON of Thorn Grove, Mannofield, Aberdeen, North Britain,
Engineer do hereby declare the nature of this invention and in what manner the
зame is to be performed to be particularly described and ascertained in and by the
following statement :-
My invention relates to sifting or grading apparatus wherein rotary screens or
sieves are used and is more especially intended for use with such apparatus when
employed for sorting tea into different grades or classes. Tea is liable in such
apparatus as hitherto made to cling to the screen or sieve and it is the object of my
invention to overcome this objection.
According to my invention I impart a jerking, or jarring, movement to the screen,
or sieve, as it rotates, so as to produce sufficient vibration, or concussion, thereof to
prevent the said clinging of the tea to the screen, or sieve, thus keeping the meshes
of the screen, or sieve, clear; and this effect I obtain without interfering with the
steady running of the pulleys and gear by which the screen or sieve, is rotated.
This can be effected according to my invention by mounting the driving pulleys
upon a fixed centre and causing them to drive a pinion upon the same centre-the
said pinion gearing with a wheel by which the screen, or sieve, is rotated the said
screen, or sieve, being also provided with a projection, or cam, or projections, or
cams, which, during rotation, act upon a piece so as to cause the sieve, or screen, to
vibrate, or have the desired concussion, or jarring, imparted to it, the screen, or
sieve, being so mounted that the wheel, by which is rotated, will remain in gear
with the driving device-without causing that device to be similarly vibrated, or
jarred.
I will now describe with reference to the accompanying drawings an arrangement
according to my invention but I do not limit myself to the precise details of this
arrangement.
Figure 1 is a side elevation and Figure 2 a plan with the mid part of the screen
broken away.
Figures 3 and 4 are views as seen from each end of the machine.
A is the screen, B the shaft upon which it is mounted and C the standards or
frame upon which the machine is supported.
The ends of the shaft B pass through the ends of links, or arms c, the other ends
of which are mounted upon pins c² which constitute centres upon which the links or
arms c can vibrate. The said pins e² are secured to the framing or standards C, of
the machine and one of the said pins carries the driving pulley E (and its
accompanying loose pulley) and a pinion D driven thereby which pinion engages
with a toothed wheel secured to the shaft B so as thereby to transmit rotatory
motion to the screen, or sieve A. A. cam, or cams, is, or are, secured to the shaft at
either one or at both ends which cam, or cams, as the shaft and screen, or sieve,
rotate bears or bear upon a block so that the shaft and screen, or sieve, are lifted
(the links, or arms, c, carrying the shaft turning upon their pins c²) and then when
the cam has, or cams have, passed the block the shaft and screen, or sieve, drop
suddenly and the screen is jerked, or jarred, at each such drop. In the drawing I
have shewn two cams fat each end of the shaft the said cams being set relatively
to each other so that the cams at one end come into action between the times at
which those at the other end come into action but they may be set in any other way
and be in any other number as desired. The aforesaid block against which the
cams bear is shewn at g. It may be arranged so that it can be brought into
position to effect the jarring movement or be moved out of such position so as to be
entirely clear of the cam, or cams, when no jarring movement is desired, or it can

page_text: be moved to a variable extent in accordance with the amount of concussion or
jarring desired to be produced. The said block g is shewn in the drawing as
being adjustable vertically by means of a pinching nut and bolt g³ passing through
the framing C and through a slot in the tail piece 2 of the block but the
adjustment may be effected in other convenient way for example the block may be
mounted on an inclined plane on which it can be elevated and lowered by means of
a screw. hare projections from the standards C constituting rests or stops to
support the outer ends of the links c and consequently the shaft B and screen A
when they descend.
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:-
1. The combination and arrangement of parts constituting the rotary sifting or
grading apparatus substantially as hereinbefore described and illustrated by the
accompanying drawings.
2. In rotary sifting or grading apparatus mounting the screen or sieve so that it
can be vibrated or raised and allowed to fall and conveying the rotary motion to the
said screen so that the driving gear has not the same vibratory or rising and falling
motion substantially as hereinbefore described.
3. In rotary sifting or grading apparatus mounting the shaft of the screen or
sieve upon arms capable of turning upon fixed centres and conveying the rotary
motion to the said shaft by gear from one or both of the said fixed centres in
combination with means for causing the shaft and screen to vibrate on the said
fixed centres substantially as hereinbefore described.
Dated the 19th day of December 1893.
J. H. JOHNSON & Co.,
47, Lincoln's Inn Fields, London, W.C., Agents.