IMPROVEMENTS IN DRUM GUARDS FOR THRASHING MACHINES
Year: 1879

page_text: PROVISIONAL SPECIFICATION left by John Lampitt and Henry Bloxam at
the Office of the Commissioners of Patents on the 6th October 1879.
JOHN LAMPITT, Engineer, and HENRY BLOXAM, Engineer, both of Banbury, in
the County of Oxford. "IMPROVEMENTS IN DRUM GUARDS FOR THRASHING
MACHINES."
This Invention relates to a peculiar method of suspending the feed-board of a
thrashing machine by means of four stud pins or runners fixed in the end pieces or
cheeks of the feed-board, two studs in each, usually, but not always, in a line above
but parallel to the face of the feed board.
These studs are arranged to rest and, when required to do so, to glide on inclined
planes consisting of narrow strips or guide-rails of metal screwed, bolted, or other-
wise secured to the interior walls of the thrashing machine just above the drum.
The guide-rails are so constructed that when the feed board is in its normal
position for work the upper suspending studs at either end rest against the sharply
inclined surfaces of the upper portion of the guide-rails in readiness to slide down
them when allowed to do so, the lower studs resting in hollows formed at the
bottom of the sharp inclines, through the guide rails being bent at that point to an
angle not varying greatly from the horizontal, but sloping very slightly downwards
from the upper rims of the before mentioned hollows.
The lower extremities of the guide rails are turned up to stop the further travel
of the lower studs when the feed board has fallen into its defensive position across
the drum aperture.
When the feed board is in position for work the upper edge of it stands at a
suitable distance above the top of the thrashing machine; downward pressure
applied to the top of it causes the feed board to pivot on the upper stud; as the top
is depressed the lower stud is lifted out of the hollow in which it rests till, clearing
the little upward slope leading from the hollow, it is free to traverse the lower limb
of the guide rail; the feed-board then instantly descends by its own gravity, guided
in its course by the studs on the guide-rails, till it comes to rest in a nearly hori-
zontal position right across the feed aperture, effectually blocking the way, its
lower surface being well clear of the lips of the drum beaters.
By inserting a finger into a hole bored near the top of the middle of the feed-
board it can be immediately drawn up into working position again.
For the purpose of depressing the top of the feed-board so as to discharge it in
case of danger, a light framework of timber or other material, consisting of two
parallel levers connected by a cross rail, surrounds the feed aperture on three sides.

page_text: The cross-rail is placed above and in a line with the projecting top of the feed-
board, which cross-rail when pressed down comes in contact with the top of the
feed-board, which it also depresses.
The levers pass by each end of the feed aperture, clearing it by an inch or so, and
are carried back to any convenient distance, and these work upon hinges fixed to
the top of the thrashing machine behind the feed aperture.
Under each lever, near their connecting cross-rail, a flat spring is attached, which
springs rest on the top of the thrashing machine, and bear the weight of the lover
frame, sustaining it just above the projecting end of the feed-board.
Any person stepping, stumbling, or kneeling on the lever frame surrounding the
three before-mentioned sides of the feed-aperture causes the lever-frame to depress
the top of the feed-board, which immediately slips down and blocks the way to
the drum.
At the back of the feed aperture a curved "hood" is arranged to pivot on metal
studs secured to each end of it and near the bottom of it.
One of these studs points inwards and the other outwards, and they are thrust
simultaneously into holes in suitable brackets fixed on each side of the feed-
aperture.
One of these brackets is placed just inside one of the levers, and the other just
outside the other lever, so that by merely removing a split cotter in one or other of
the studs the hood can be unshipped by drawing it off end ways.
At the lower part of each end of the hood, and a few inches on each side of the
pivotting studs, projecting pieces are secured, which, when the hood is rocked in
either direction by any one leaning on or falling against it, press upon the before
mentioned lever frame, and cause the feed-board to instantly slide down into the
defensive position.
To prevent the possibility of the foot of the feed-board being lifted out of place
or carried forward by wheat or other grain being carried round with the drum, and
by such means a premature discharge of the feed-board taking place, pieces of
metal or other material may be arranged to act as check-plates on each side of the
machine.
Each check plate hangs over the lower limb of each guide rail, and when at rest
the lower edge of the check-plato touches the tip of the central hollow of the
guide-rail.
The upper part of the check-plate is attached to the lower limb of a lever centred
to slope upwards so that its upper limb can be depressed by a piece of metal or
wood projecting inwards from each side of the lever frame.
The travel of the check plate is also guided by a stud fixed in the well of the
thrashing machine and working through a vertical slot in the check-plate.
It is to be observed therefore that the lower stud of the feed-board is not at
liberty to escape and descend till the check-plate is lifted by the depression of the
lever frame, an operation which takes place (according to the setting of the check
plate lever) either previously to or simultaneously with the depression of the top of
the feed-board.