MENTS IN CHAFF CUTTING MACHINES.
Year: 1880

page_text: PROVISIONAL SPECIFICATION left by Charles Thomas Burgess at the Office
of the Commissoners of Patents on the 22nd December 1880.
CHARLES THOMAS BURGESS, of Brentwood, in the County of Essex,
MENTS IN CHAFF CUTTING MACHINES.".
"
IMPROVE-
This Invention has for its object improvements in chaff cutting machines.
In chaff cutting machines as commonly made the hay, straw, or other matter to
be cut is fed forwards from the feeding trough to the mouthpiece, by means of a
pair of rollers driven from the main axis which carried the cutting knives.
For this purpose in small sized chaff cutters the main axis has had upon it a
worm gearing with a pair of toothed wheels, one upon the axis of one roller, the
other upon the axis of the other roller, and in this case the rollers have been driven
continuously.
In place of employing a worm formed of a uniform spiral I employ a worm parts
of which on opposite sides of the axis cross the axis at right angles or nearly so,
thus when the parts of the worm which cross the axis at right angles or nearly so
are gearing with the teeth of the wheels on the axes of the rollers, the rollers both
stand still and do not feed the bay or other material forwards, or might even move
it slightly backwards; but when the inclined parts of the worm thread come into
gear with the toothed wheels, the rollers turn and feed the hay or material forward,
thus the forward feed can be given to the material between the times when the
knives are cutting.
In some cases ratchet wheels have been used so as to give an intermittent feed,
and when it has been desired to vary the length of cut this has been effected by
varying the throw of the crank or eccentric by which the pawl or pawls used
drive the ratchet wheel or wheels have received their motion. In place of
depending upon altering the throw of the crank or eccentric I give motion to the
pawl or pawls by a rod that has a to and fro motion given to it by a lever, that
is caused to rock on its fulcrum by a crank or eccentric, and I vary the speed at
which the pawl or pawls drive the ratchet wheel or wheels, and consequently vary
the length of cut, by varying the relation between the distance of the fulcrum of the
lever from the point where the rod is connected to it, and the distance of the fulcrum
from the point where the connecting rod from the crank or eccentric is connected to
it. A convenient way of effecting this is to give motion to the pawl or pawls by a

page_text: vertical rod, which can move to and fro in guides, and which has a pin upon it to
enter a slot in a horizontal lever carried at one end by a moveable fulcrum, and at
the other coupled by a connecting rod to the crank or eccentric. By moving the
fulcrum towards or away from the pin on the rod the extent to which the rod is
moved to and fro, and consequently the amount of movement given to the pawls,
can be varied without stopping the machine to effect the alteration. The moveable
fulcrum of the slotted lever may be carried by one arm of a lever, which can be
turned into and retained in any desired position, so as to bring the moveable
fulcrum nearer to or further from the pin on the rod, or other means may be
adopted for moving the fulcrum to and fro.
The crank or eccentric which gives motion to the slotted lever may be on an axis
at right angles to the main axis which carries the cutting knives, and driven from
it so as to revolve at the same speed; in this case if two knives are carried by the
wheel on the main axis, as is usual, two pawls would be used, one to turn the
ratchet wheel on the upward movement of the rod, and one on its downward
movement, so as to get the feed at the times when the knives are not cutting.
The advantage of driving the crank or eccentric at the same speed as the main
axis is, that if a crank handle is placed on its axis a man can assist to drive the
machinery by turning this crank, and can work with just as good effect as the
man turning the crank handle of the cutter wheel on the main axis.
The feed rollers may be coupled as heretofore to two toothed wheels which gear
together, and the connection of the top feed roller with its toothed wheel may as
heretofore be made in such a manner as to allow this top roller to rise and fall.
The ratchet wheel for giving the feed can be on the axis of one or other of the
toothed wheels. Provision is also made for throwing the pawls out of gear with
the ratchet wheel should it be required to turn the feed rollers backwards. To
turn the feed rollers backwards a second ratchet wheel may be used, and in the
arrangement of machines just described the slotted lever may carry a pawl, which
comes into operation when the fulcrum has been brought into a position to allow it
to do so, the other pawls would then be disengaged.
If either the hand lever of the mechanism- used for varying the feed, or any
additional lever in connection with this mechanism, is placed alongside of the feed
trough, it can be made to throw the backing gear into action either by the voluntary
or involuntary action of the man feeding the material forward up to the rollers, so
that if his arm or portion of his dress gets drawn in towards the mouthpiece, the
lever will be acted upon and the feed motion reserved.