AN IMPROVED GUARD FOR THRASHING MACHINE DRUMS
Year: 1879

page_text: LETTERS PATENT to John Potterton Fison, of Teversham, in the County of
Cambridge, for the Invention of "AN IMPROVED GUARD FOR THRASHING
MACHINE DRUMS."
Sealed the 12th December 1879, and dated the 16th June 1879.
PROVISIONAL SPECIFICATION left by the said John Potterton Fison at the
Office of the Commissioners of Patents on the 16th June 1879.
JOHN POTTERTON FISON, of Teversham, in the County of Cambridge.
IMPROVED GUARD FOR THRASHING MACHINE DRUMS."
"AN
My Invention relates to improvements in drumguards for thrashing machines
of the kind for which Letters Patent were granted to me dated 5th July 1875,
No. 2431. The present improvements have for their object to simplify the construc-
tion of the guard and render it more effectual in its working, more easily fitted in
position, and more easily packed up after work.
The present Invention is designed to prevent accidents by making it impossible
for any person to fall upon or be drawn into the thrashing drum. As in the said
former Patent the drumguard consists of a guard cylinder placed over and acting
in conjunction with a balanced and pivoted feed board to prevent accidents of the
nature above mentioned, but my present Invention differs from that described in
the aforesaid Letters Patent in the mode of coupling the guard cylinder with the
feed board and in various other arrangements incidental to the construction and
working of the guard. In this case moreover the guard cylinder does not receive
power, it not being intended to act as a feeder.
The feeder board is constructed preferably of wood cased with zinc, and is
mounted to oscillate on a horizontal axis consisting of a rod with a cotter pin at
each end. The feed board is balanced by a weight fixed to its under side along
the back edge or that next the beaters, the said weight being fixed adjustably
by slots. This arrangement of the weight is far preferable to the weighted levers
described in my aforesaid Patent, as the latter are liable to be displaced when
travelling. The guard cylinder is a sheet metal or other light roller whose journals
are received in slots which are inclined extending nearly from top to bottom of two
bracket standards bolted on the beams of the machine by slot bolts and cotters with
steady pins cast on the bottom of the standards at each side of the bolt holes, so
CD431

page_text: that the standards may be readily affixed and removed. These brackets are flanged
on the inside and the ends of the guard cylinder work close up against them, so
that it is impossible for anything to foul the working parts and so stop the action
of the guard.
The feed board is connected with the guard cylinder by chains or other flexible
connections attached one to each end of the feed board at a convenient point in
rear of its axis, and passing up to and over a guide pulley mounted in the hollow at
the upper part of each bracket standard above mentioned, the chain then passing
down and being connected to the adjacent end of the guard cylinder spindle, so that
should any unusual weight come upon the upper or front part of the feed board,
the roar part of the feed board is raised and the guard roller is at the same time
lowered to meet one another and entirely close the feed entrance to the thrashing
drum.
The guide pulleys over which the chains pass are shielded and rotate on studs
fixed in slots in the brackets so that they can be readily shifted as required for the
relative adjustment of the feed board and guard roller, and to enable the feed board
to be set at different inclinations.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed by
the said John Potterton Fison in the Great Seal Patent Office on the 16th
December 1879.
JOHN POTTERTON FISON, of Teversham, in the County of Cambridge. "AN
IMPROVED GUARD FOR THRASHING MACHINE DRUMS."
My Invention relates to improvements in drum guards for thrashing machines
of the kind for which Letters Patent were granted to me dated 5th July 1875,
No. 2431. The drum guard is designed to prevent any person falling upon or being
drawn into the thrashing drum, and the present improvements have for their object
to simplify the construction of the guard and render it more effectual in its working,
more easily fitted in position, and more easily packed up after work. As in the
said former Patent the drum guard consists of a guard cylinder placed over and
acting in conjunction with a balanced and pivoted foed board to prevent accidents
of the nature above mentioned, but my present Invention differs from that described
in the aforesaid Letters Patent in the mode of coupling the guard cylinder with the
feed board, and in various other arrangements incidental to the construction and
working of the guard. In this case moreover the guard cylinder does not receive
power, it not being intended to act as a feeder, but it is merely free to be rotated
by the contact of the corn as it passes into the machine.
In order that the Invention may be more readily understood, I will describe it
with reference to the accompanying Drawings, in which Figure 1 is a plan of the
improved drum guard, and Figures 2 and 3 are sections on line 1-1, Figure 1,
respectively showing the guard in its normal position, and in that which it is
caused to assume by an undue weight coming on the feed board or the cylinder;
Figure 3a is a side olevation of one of the standards in which said cylinder is
mounted, showing the mode of fastening it to the thrashing machine frame which
is indicated by dotted lines; Figure 4 is a vertical section of the same standard;
Figure 5 is an underside view of the feed board showing the means of adjusting its
balance weight. The same letters of reference indicate the same parts in all the
Figures.
A is the thrashing drum and B the concave as usual; C is the guard cylinder,
and D the feed board. The guard cylinder C is a sheet metal or other light
roller whose journals c are received in slots e which are inclined and extend nearly
from top to bottom of two bracket standards E bolted on the side beams F of
the thrashing machine by slot bolts G passing through the flanged base of the
standard and through the beam F and secured by tapered pins or cotters g at
the underside of said beam, steady pins or studs f being cast on the bottom of the
standard at each side of the bolt holes and received in holes in the beam F, so that
the standards may be readily affixed and removed. These brackets are flanged on
the inner surface, and the ends of the guard cylinder C work close up against them
so that it is impossible for anything to foul the working parts and so stop the
action of the guard.
The feed board D is constructed preferably of wood cased with zinc and is
mounted to oscillate on a horizontal axis & parallel to that of the guard cylinder C
and consisting of a rod secured by a cotter pin at each end. The feed board is
balanced by a weight H fixed adjustably to its underside along the back edge or
that next the beaters. This arrangement of the weight is far preferable to the
weighted levers described in my aforesaid Patent, as the latter are liable to be
displaced when travelling. The feed board D is connected with the guard
cylinder C by two chains I or other flexible connections, each attached to one end
of the feed board at a convenient point in rear of its axis and passing up to aud
over a guide pulley i mounted in the hollow at the upper part of the nearest
standard E, the chain then passing down and being connected to the adjacent end

page_text: of the guard cylinder spindle c, as shown, so that should any unusual weight
come upon the upper or front part of the feed board D the latter will be oscillated,
its rear part being raised, and the guard roller will at the same time be lowered
until they meet and thus entirely close the feed entrance to the thrashing drum,
as shown in Figure 3.
5
The guide pulleys over which the chains pass are shielded and rotate on studs J
fixed by nuts in slots j in the brackets E, so that they can be readily shifted
as required for the relative adjustment of the feed board and guard roller, and to
enable the feed board to be set at different inclinations. The weight H is fixed
adjustably to the underside of the feed board by nuts and bolts passing through 1
slots in the weight. By loosening the nuts the weight can be readily set at
any required distance from the edge of the feed board.
Having described the nature of my said Invention, and the manner of performning
the same, I declaro that what I claim as my Invention to be protected by the
herein before in part recited Letters Patent is,-
1st. In a thrashing machine drum guard of the kind herein described the
means of coupling together the oscillating feed board and the movable guard
cylinder, substantially as shown and described, whereby when the former is raised
the latter is lowered as described.
1
2nd. Making the pulleys over which the chains connecting the feed board and 2
guard cylinder pass adjustable in slots as and for the purpose described.
3rd. Balancing the feed board by a weight attached directly to it and made
adjustable, substantially as and for the purpose shown and described.
In witness whereof, I, the said John Potterton Fison, have hereunto set my
hand and seal, this Fifteenth day of December, in the year of our Lord 2
One thousand eight hundred and seventy nine.
TATTIT TATTETTAV DINAV