Year: 1889

page_text: I, JOHANN EDUARD PARMENTIER of Elberfeld Rhenish Prussia Germany Chemist
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:-
The sharpening of a scythe to be good must run equally along the edge of the same
and it must be made narrower or broader according to the hardness of the crops to
be cut.
.
This can only be performed by expert men with the means used hitherto, namely a
more or less pointed or flat anvil of hardened steel, by holding the body in a painful
and fatigating position, because the scythe has to be carefully held in proper position,
as by a wrong blow of the hammer the edge of the scythe will become full of notches
and the blade gets deformed.
The object of the present invention is to avoid these defects and to enable unexpert
men to sharpen a scythe according to the best method upon a comparatively narrow
faced anvil and with a broad hammer, with certainty, correctly and quickly.
The material used must be of best quality throughout to prevent wear and tear, as
is the case when a pointed hammer strikes upon a flat anvil or when a broad
hammer face strikes upon a sharp anvil face, where the broad part is hollowed out and
gets useless for the purpose, especially so when it acts always upon one and the same
spot.
The parts most exposed to wear and tear are made interchangeable so that they can
be conveniently and cheaply replaced by new ones without loss of time which is of
importance in harvest time."
My new sharpening apparatus is shown on the accompanying drawing..
Fig. 1 is a side view
"
""
2 plan
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"
"
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full size without the stand.
3 front view, half size with stand.
"
4 (a, b, c) are respectively 2 vertical elevations and a plan of an ordinary
anvil.
5 (a, b, c) are respectively ? vertical elevations and a plan of my special
anvil.
One of the main features of my apparatus is that within a large anvil or bloc a is
placed a small one a¹ (figs. 4 & 5), the face of which has the shape of the cutting edge
to be desired and which is exchangeable.

page_text: At the sides of the bloc a are fixed plates 9 g which are adjustable vertically; their
principal object is to give a larger bearing surface for the scythe.
These plates are made of angle form or flanged so as to be well guided on the
bloc a (fig. 2) and they are provided with adjustable set screws 6 b, fixed in place by
a check nut and serving for setting the width of the sharpening edge; they project a
little above the face of the anvil and beyond the upper surface of the plates g g so that
the cutting edge of the scythe can bear against their ends.
In order to obtain a good and exact bearing of the scythe upon the face of the
anvil I use springs ff which may be fixed in an adjustable manner at the back of
the bloc a or on the plates g, as is the case in the drawing. These springs give the
required pressure upon the scythe.
In using the apparatus the plates gg and the springs ff are so adjusted, that their
upper faces and the pressure faces of the springs respectively are in a line with the
face of the anvil a¹.
The scythe is then pushed between the springs and the bearing surface of the
plates g, with its concave side downwards until it meets the set screws bb and by
means of them the width of the sharpening edge is regulated.
Now the workman can do the sharpening by striking with a suitable hammer direct
upon the scythe on the anvil and by gradually shifting it forwards; the cutting edge
always bearing firmly against the but ends of the adjusting screws bb.
An uniform sharpening edge must be obtained, the form of it being given
beforehand by the shape of the anvil face and the unalterable width of the cutting
edge.
Now it very easily happens that in sharpening a scythe, especially so when the
sharpening is done by mechanical means, that the scythe is deformed and when the
man performing the work does not guide the scythe properly, so that the blows of
the scythe hammer will neutralize this deforming action the cutting edge becomes full
of fissures.
In order to avoid this defect, I have designed a scythe-anvil of special construction
for my apparatus (fig. 5).
This anvil has a face of special shape, its circumference being curved, circular or
elliptical as shown by figs. 5 a, b & c, and its edges are broken obliquely.
It will be easily understood that with an anvil or hammer, having a face with
straight edges, the blow of the hammer will act upon the whole length of the face
equally and a deformation of the blade of the scythe must take place because the
metal of the scythe is not only driven outwards to form the cutting edge, but it is also
driven sideways right and left in the direction of the edge of the scythe and therefore
the blade will be deformed.
If however an anvil or a hammer with a sharp face of a curved shape, circular
or elliptical acts upon the scythe, the metal of the latter will be displaced also in a
curved form, the displacement diminishing gradually towards right and left, and the
curves so formed will be bent in the opposite direction to the main curvature of the
cutting edge of the scythe and therefore no deformation will take place.
Now if the blows are driven one immediately after the other in continuous
succession these little curves will form a continuous line making the cutting edge of
the scythe.
There is another advantage gained by shaping the face of the anvil as described ;
the displaced metal being allowed to go out in different free directions and no
upsetting in any direction taking place, it will be easily understood, that the blows
need not be as heavy as with anvils of rectangular faces. Practical experiments have
confirmed this.
In order to perfect the apparatus in such a manner, that also unexpert men can
produce an exact and good sharpening, I fix to the back of the bloc a a forked
bracket e,
which carries the scythe hammer c and to which it serves as a vertical
guide.
This scythe hammer has a flat or slightly convex face and is driven down by an
ordinary hammer and so the sharpening is done indirectly.

page_text: The bracket e is forked or made double in order that the operator can look through
between the two arms and can always control the effect of the blows upon the
scythe.
In order to prevent indentations being made in the face of the scythe hammer as
would be unavoidable by the continued action of a sharp hammer on the flat anvil
and at the same place and vice versa and they consequently would become useless, the
hammer is therefore made so that it can be turned in the boss of the bracket e.
This can be obtained by different means of mounting it in the bracket.
The hammer c may for example be mounted in the bracket so that a spring d is
wound round the same, the uppermost winding being held in a groove at the top of
the hammer bolt, whereas the lower end which is also wound round a groove, made
by a ring and the head of the boss of the bracket e, and which is then fixed by
some means to the bracket e.
The turning and the to and fro motion of the haminer may also be obtained by
providing the same with a recess d' as shown in dotted lines in fig. 1 and limitting
the stroke of the hammer by a set screw d² in the boss of the bracket e.
The same object, allowing the bolt to be turned round its vertical axis and limiting
its stroke may also be obtained by fixing a pin d³ into the hammer below the boss of
the bracket.
By means of the described sharpening device the workman can give the blows
according to the required hardness of the scythe, whether he works direct or by using
the intermediate scythe hammer c.
In order to make the instrument complete and independent of any other support
for fixing it, I provide it further with a foot or socle m which has two arms & fixed
to it (fig. 3). The arms serve as supports for the legs of the workman and thereby
he presses the apparatus down upon the ground so that it can not be shifted either
way but giving it a firm hold when he sits on any convenient rise of the ground. No
other fixing block is then required and the apparatus is ready for use in any place and
at any moment.
.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :
1) A scythe sharpening apparatus consisting of the exchangeable scythe anvil a'
placed in the main bloc a and having a face of such shape as to correspond to the
form of the cutting edge of the scythe, the supporting plates g g fixed at the sides of
the bloc so that they are adjustable vertically and provided with the screws bb or
pins in their place for horizontal adjustment, and of the pressure springs ƒƒ, fixed to
the bloc so that they can be adjusted vertically, or fixed to the plates g g as set forth
and for the purpose described.
2) An exchangeable anvil a, having a curved-circular or elliptical-face as
described and shown.
->
3) In combination with the apparatus described in claim one, the bracket e having
a boss for guiding the scythe hammer c so that it can be turned round its vertical axis
and being held upwards by a spring..
4) In combination with the apparatus described in claims one and three a standard
or socle m being provided with the angle bars serving as supports for the legs of
the operator and for holding the apparatus firmly in place and pressing it to the
ground.
Dalth 0. 1
1000