IMPROVEMENTS IN THE MANUFACTURE OF THRASHING MACHINE DRUMS
Year: 1876

page_text: LETTERS PATENT to Jolin Dunnell Garrett, of Buckau, near Magdeburg,
Prussia, but at present residing at Delahay Street, in the City of Westminster
Agricultural Implement Maker, for the Invention of "IMPROVEMENTS IN
THE MANUFACTURE OF THRASHING MACHINE DRUMS."
Scaled the 21st November 1876, and dated the 31st May 1876.
PROVISIONAL SPECIFICATION left by the said John Dunnell Garrett at the
Office of the Commissioners of Patents on the 31st May 1876.
'
JOHN DUNNELL GARRETT, of Buckau, near Magdeburg, Prussia, but at present
residing at Delahay Street, in the City of Westminster, Agricultural Implement
Maker. "IMPROVEMENTS IN THE MANUFACTURE OF TURASHING MACHINE DRUMS."
This Invention relates to a mode of constructing the drums of thrashing machines
that will facilitate the balancing of the same and ensure an efficient momentum
without using heavy beaters for the purpose. The beaters are carried by a set of
flanged metal discs, which are fixed to the drum axle and are weighted at or near
their periphery. The disc I subject to the pressure of dies to form an annular
flange of any desired depth thercon, and within this annular flange I insert by
pressure a ring of lead or other metal. The discs I true up in a lathe to give
them an uniform diameter, and in order that the beaters may bed upon the discs
I turn their inner or contact faces to correspond to the discs. The beaters may
then be secured in place by means of screw bolts passed inwards (through the
flanges of the discs and through the rings of lead) and receiving nuts on their
inner ends. The discs are pierced at their centre to receive the drum axle, and they
are fitted with bosses of malleable cast iron, which are secured to the discs by rivets.
An important advantage of this mode of constructing the drums of thrashing
machines is that a much more uniform speed may be maintained than heretofore,
and that at a saving of the expenditure of power in the driving of the machine.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Dunnell Garrett in the Great Seal Patent Office on the 29th
November 1876.
JOHN DUNNELL GARRETT, of Buckau, near Magdeburg, Prussia, but at present
residing at Delahay Street, in the City of Westminster, Agricultural Implement
Maker. "IMPROVEMENTS IN THE MANUFACTURE OF THRASHING MACHINE DRUMS.'
This Invention relates to a node of constructing the drums of thrashing machines
that will facilitate the balancing of the same and ensure an efficient momentum
[Price 6d.]

page_text: without using heavy beaters for the purpose. The beaters are carried by a set of
flanged metal discs, which are fixed to the drum axle and are weighted at or near
their periphery.
The mode of preparing these discs and of fitting them with beaters is illustrated
in the accompanying Drawings.
Fig. 1 shows in side elevation a flanged disc fitted with one of a series of beaters,
and Fig. 2 is a cross section of the same.
In constructing a drum according to my Invention, three, four, or more of such
discs will be used to carry the beaters.
In order to manufacture the flanged discs with facility and with great exactness,
I form them out of flat discs of metal by means of pressure in dies while the metal
is at a welding heat.
Fig. 3 shews in plan view, and Fig. 4 in cross section, the dies employed for this
purpose, the same being drawn to half the scale of Figures 1 and 2.
A is a hollow circular die tapering slightly downwards from its upper end.
This die rests on the bed of a hydraulic press, and is carried upward with the metal
to be shaped to the fixed die B; C is a disc of metal pierced at its centre and
placed while in a welding heat upon the die A. An upward movement being given
to this die A. by a powerful hydraulic press it will enter the die B, as shown at
Fig. 4, bending over the edges of the disc which is first centred by a pin b of the
die B entering the hole in the disc. The inner edge of the die B is rounded off, as
shown, to allow of the metal being gradually turned over to form the flange. By
the gradual action of these dies the fibres of the metal under treatment will have
time to re-arrange themselves while the metal is taking the new form, and thus the
cracking of the fibres will be avoided.
To provide for the release of the flanged disc from the tapering die A, I form
that die as shewn in plan and side view at Figures 5 and 6, that is to say, I split
the cylinder from end to end, and insert in the opening thus made a wedge-shaped
piece a, making the lips of the opened cylinder to correspond thereto. This piece a
extends from the top to the bottom of the cylinder, and through it is passed a screw
bolt a¹, which projects through a clamping piece a, and receives a nut on its
outer end.
The wedge a forms a portion of the periphery of the die when the die is in use,
but when the shaping of the flanged disc has been effected, and it is desired to
move the same from the die, the bolt a¹ is slackened and the cylinder A will then
contract leaving the flanged disc free.
The clamping piece a extends upwards only so far as will leave the die A. free
to enter the fixed die B to a required length. The discs thus prepared in dies will
be of uniformn size and will be strong and light as compared with the wheels
hitherto used in the manufacture of thrashing machine drums.
Within the rebated annular flange of these discs I insert by pressure a ring D of
lead or other metal (see Figures 1 and 2) which will serve to weight the drum and
give it the requisite momentum when in action. The discs and rings I truc up in
a lathe to bring them to an uniform diameter, and in order that the beaters may
bed upon the discs I hollow their inner or contact faces to correspond with the
periphery of the discs, as shewn at E, Fig. 1. The beaters 1 secure in place by
means of screw bolts passed inwards (through the flanges of the discs and through
the rings of lead) and which receive nuts e on their inner ends. The discs are fitted
at the centres with bosses of malleable cast iron F to receive the drum axle, and
these bosses are secured to their discs by rivets.
I would remark that an important advantage of the above described mode of
constructing the drums of thrashing machines is that a much more uniform speed
may be maintained than when the drum is weighted by heavy beaters, and that at
a saving of the expenditure of power in the driving of the machine.
Having now set forth the nature of my Invention of "Improvements in the
Manufacture of Thrashing Machine Drums," and explained the manner of carrying
the same into effect, I wish it to be understood that under the above in part recited

page_text: Letters Patent I claim, constructing thrashing machine drums with weighted
flanged discs for receiving the beaters, such discs being flanged by pressure in dies,
as above described.
In witness whereof, I, the said John Dunnell Garrett, have hereunto set my
hand and seal, the 25th day of November, in the your of our Lord One
thousand eight hundred and seventy-six.
In the presence of
ARTHUR GEORGE MUMFORD.
JNO. D. GARRETT. (LS.)