Improvements in Chaff Cutters.
Year: 1896

page_text: Improvements in Chaff Cutters.
I EDMUND ERNEST BENTALL of Heybridge, near Maldon in the County of
Essex, Agricultural Engineer, do hereby declare the nature of this invention to be
as follows:-
This invention relates to an improved construction of chaff cutter, the object
being to provide against material injury to the machine, when it is choked by the
passage, into the mouth of the chaff cutter, of a stone or any other unyielding
substance. It is well known that the parts liable to breakage are the frame, the
mouth piece, and the fly wheel (sometimes one only, or it may be all three).
Moreover the gearing can be broken, or the spindles twisted, or both, by over-
feeding the machine.
The plan hitherto adopted to remedy the defect has been to so strengthen those
parts that they should resist the sudden strain caused by a hard foreign substance
in the mouth, but this plan is anything but satisfactory.
I now propose, instead of adding weight to the parts liable to injury from the
cause above stated, to adopt the following contrivances. I propose that the bottom
comb, or bottom edge of the mouthpiece, which has to resist the pressure of the
knives, instead of forming part of the frame, or being firmly attached thereto, or cast
with the main part of the mouth piece, should be supported by bolts or otherwise in
such a manner that the attachment will give way, if any sudden undue strain is
thrown upon the bottom comb, and allow the comb to fall away, thus releasing the
hard foreign substance before a breaking strain on the other parts of the machine
arises.
An obvious modification would be to make the bottom comb unequal to resisting
an undue strain, and therefore to break up, when such a strain is applied thereto.
In the first case, the comb would require re-attachment, and in the second,
replacement by a new one, a trivial expense in either case.
I further propose to drive one of the gear wheels through a spring clutch, which
will yield to any excessive strain, and thus avoid torsion of the spindles and
breakage of the gearing.
For this purpose, I cast the boss of the pinion to be so driven, with a ring of
internal teeth or projections, so shaped that a driving pawle will ride over them,
when the choking of the machine occurs.
The pawle is carried by a disc keyed on to the driving shaft, and it is by means
of a strong spring that the pawle is held in its driving position. On the spring
yielding to an undue strain, the pawle will ride over the teeth with which it comes
in contact, and the risk of damage to the machine will be avoided.
On the attendant reversing the motion of the driving shaft, the pawle will catch
onto the front of one of the teeth within the boss, and reverse the direction of
rotation of the gearing, thereby withdrawing the feed from the mouthpiece, and
allowing the extraneous matter to be removed.
Dated this 10th day of March 1896
NEWTON & SON,
Agents for the Applicant.

page_text: Improvements in Chaff Cutters.
I EDMUND ERNEST BENTALL of Heybridge near Maldon in the County of
Essex, Agricultural Engineer, do hereby declare the nature of this invention
and in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement:-
This invention relates to an improved construction of chaff-cutter, the object
being to provide against material injury to the machine, when it is choked by the
passage into the mouth of the chaff cutter, of a stone or any other unyielding
substance.
It is well known that the parts liable to breakage are the frame, the mouthpiece,
and the fly wheel, (sometimes one only, or it may be all three). Moreover, the
gearing can be broken, or the spindles twisted, or both, by over-feeding the
machine.
The plan hitherto adopted to remedy the first-named defect, has been to so
strengthen those parts that they should resist the sudden strain caused by a hard
foreign substance in the mouth, but this plan is anything but satisfactory.
I now propose, instead of adding weight to the parts liable to injury from the
cause above stated, to adopt one or other of the means illustrated in the
accompanying drawings at Figs. 1, 2, 3, 4, 5, and 6, and, to prevent the torsion of
the shafting, or the breaking of the gearing, I provide the means for driving the
same shown in Figs. 7, 8, and 9.
Fig. 1 shows in front view the mouth piece of a chaff-cutter constructed
according to my invention, and Fig. 2 is a section of the same, taken in the line of
the feed.
In these figures, AA is a casting forming the sides of the trough, and
constituting the main portion of the framing.
Bis a casting forming the bottom of the trough in front of the lower feed roller C,
which roller is grooved annularly to receive the comb teeth of the casting B.
This casting B, commonly termed the comb, carries the shearing edge of the
mouthpiece as usual, and it is held in place by incans of vertical bolts and nuts b,
which secure it to the framing A.
The ends of this comb are cored out to receive the heads of the bolts b, in such
a way that the metal intended to resist the strain put on the mouthpiece, will give
way when any sudden undue strain is thrown thereon, and allow the comb to fall
away, thus releasing the hard foreign substance, before a breaking strain on the
other parts of the machine arises.
In place of relying upon the breaking up of the casting to release the hard
foreign substance, I may attach the comb to the framing in such a manner as to
provide for its being forced out of place without injury to any part of the machine.
This plan is shown in front view at Fig. 3 and in side view at Fig. 4.
The framing is cast with two vertical slots a, through which project screw
bolts bb, which are passed through the comb, and receive binding nuts on their
forward ends.
When, therefore, undue pressure is put upon the mouthpiece, the screw bolts
will be forced down out of the slots a, and thus the comb will be released and fall
to the ground.
To restore the chaff cutter to its working state, it will only be necessary to
replace the comb, and tighten up the binding nuts on the bolts, which, being
inserted in the slots in the framing, will hold the comb in place with the
firmness sufficient to resist the normal pressure put upon the feed by the cutting
knives.

page_text: Another mode of securing the comb or mouth piece in place, so as to permit of
its automatic release without injury thereto, when undue pressure is put upon it, is
shown in Figs. 5 and 6, Fig. 5 being a front view of the mouth-piece in place, and
Fig. 6 a section in the line of the feed. In this arrangement, the vertical bolts b
are used, as in Fig. 1, but instead of passing through the end of the comb, the bolts
serve to support angle pieces 6', upon which rests the comb or mouth-piece B, the
comb being cast with tenons at its ends, that fit loosely into vertical guides in the
sides of the frame. These angle pieces are cast with a strength sufficient only to
resist the ordinary pressure put upon the feed, and to break away when subjected
to an undue pressure. The comb will then fall uninjured, and it will simply
require the renewal (in place) of the broken angle piece or pieces, and the
replacing of the fallen comb thereon, to restore the efficiency of the machine.
The means provided for preventing the torsion of the shafts and the breaking of
the gearing, is shown in end elevation at Fig. 7, and in sectional elevation at Fig. 8,
the section being taken in the line 1-2 of Fig. 7.
This contrivance consists of a spring clutch D, E, carried by the cutter shaft F,
which, through a pinion E' of the clutch, imparts motion to the gearing of the
feed rollers.
D is a disc made fast to the cutter shaft, and serving to carry a pawl d, as shown
best in the detached view Fig. 9, and E is a flanged disc cast on the side of the
pinion E, and running loosely on the shaft F.
The pawl d is so shaped as to bear frictionally upon one of a ring of wedge-
shaped teeth e cast with the flanged disc E.
d is a strong spring fitted to the disc D, and bearing upon the inner side of the
pawl d, its use being to hold the pawl in close frictional contact with one or other
of the teeth e. The frictional surfaces of the pawl d and teeth e are relatively
shaped, so that as the shaft F is rotated, the pawl d will drive the disc and
pinion E E', and thereby transmit rotary motion to the feed roller C.
The length of the teeth e is such, that the driving pawl d will ride over them
when a choking of the machine occurs, the spring d yielding for that purpose, and
disengaging the clutch, thus avoiding injury to the machine.
At the same time, a tooth on the back of the pawi comes into the circuit of the
ring of teeth. The duty of the attendant is now to reverse the motion of the
driving shaft; the on the back of the pawl d will then catch onto the nearest
of the teeth e, and reverse the direction of rotation of the gearing, thereby
withdrawing the feed from the mouth-piece, and allowing the extraneous matter to
be removed.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. The combination in chaff-cutters of the duplex means above described for
removing their liability to injury from choking when in use.
2. The application to chaff cutters of the automatically detachable comb or
mouthpiece for the purpose above set forth.
3. The arrangement above described for transmitting motion through a spring
clutch to the feed rollers of chaff cutting machines.
Dated this 24th day of November 1896.
NEWTON & SON,
Agents for the Applicant.