Improvements in Apparatus for Sharpening the Knives of Reaping and Mowing Machines.
Year: 1885

page_text: Improvements in Apparatus for Sharpening the Knives of
Reaping and Mowing Machines.
I GEORGE WILSON MURRAY of the town and county of Banff Engineer do
hereby declare the nature of my Invention for "IMPROVEMENTS IN APPARATUS
FOR SHARPENING THE KNIVES OF REAPING AND MOWING MACHINES to be as
follows:-
33
The object of my invention is to improve and render more convenient in use
that class of machines employed for grinding and sharpening the knives of reaping
and mowing machines in which the adjacent edges of a pair of the V like knives
are simultaneously ground by means of a rotating grindstone carried on a framing
on which the reaper knife bar is supported in position.
I form holes in the main frame for holding the rod which supports the end of
the knife during the grinding operation.
To make provision for wearing and consequent decreasing of diameter of
grindstone I form a broad end on the saddle frame which holds the knife when
being sharpened with room for several holes in the same for allowing the said
saddle frame or knife holder to be shifted forward as the stone decreases in
diameter.
The arm of the first moving frame is also suitably bent out laterally to clear the
knives as the saddle frame is shifted forward.
The moveable framing is jointed as usual to the main frame of the grindstone
and the oscillating commonly imparted to it is communicated by a crank or
eccentric on the grindstone driving crank to tilt the knife bar and bring the
points and heels of the knives alternately in contact with the grinding surface.

page_text: COMPLETE SPECIFICATION.
Improvements in Apparatus for Sharpening the Knives of
Reaping and Mowing Machines.
I, GEORGE WILSON MURRAY, of the town and county of Banff, Engineer, do
hereby declare the nature of my invention, and in what manner the same is to
be performed, to be particularly described and ascertained in and by the following
statement in writing, reference being had to the accompanying Sheet of Drawings,
and to the letters and figures marked thereon that is to say:
The object of my invention is to improve and render more convenient in use
that class of machines employed for grinding and sharpening the knives of reaping
and mowing machines in which the adjacent edges of a pair of the V-like knives
are simultaneously ground by means of a rotating grindstone carried on a framing
on which the reaper knife bar is supported in position.
And in order that the nature, novelty, and mode of carrying my said invention
into effect or practice may be properly understood, I have hereunto appended a
Sheet of explanatory Drawings; the same reference letters indicating the saine
parts in the several Figures where shown.
Figure 1 is a side elevation and Figure 2 a corresponding plan of the machine
illustrating my said invention or improvements. Figure 3 is an end elevation of
the same corresponding to Figure 1. Figures 4 and 5 show an elevation and a
plan respectively of the saddle C2 detached, for carrying the knife bar Ċ while the
knives on it are being sharpened. Figure 6 is an end elevation of the supporting
arin on the end of the carrying bar a¹ of the knife bar C.
Referring to these Figures 1 to 3, the general construction of this machine,
to which my improvements are applied, consists of two main side frames or
standards A, secured together by the usual stays or tie bars A¹, carrying the
grindstone A2, revolving in its water trough A, on its spindle A³, within bush
bearings at A in the upper central part of the two frames A. The grindstone A¹
is turned by the spur pinion B, keyed on its spindle A³, gearing into its actuating
wheel B¹, secured on the inner end of the short first motion spindle B2, carried and
revolving in an eye bearing in the front frame of the machine, and driven by the
crank handle B³, secured on its outer end. The sharpening edge of the grindstone A*
is of an obtuse A shape, and acts on the adjacent V edges of the pair of knives
or cutters to be sharpened at the same time. According to my improvements
connected with the adjusting of the knife carrying mechanism and fittings, I form
holes or recesses a in the upper edge of the main side frames or standards A, for
holding steady the sliding rod a¹, which carries the standard a² on its outer end
for supporting the overhanging end part of the knife bar C at the proper height
and angle to suit the grindstone during the sharpening operation. The knife bar C,
(while the grindstone is sharpening the two V edges of each pair of knives as

page_text: stated) is secured on the two resting arms C¹ by the pinching screw C" in the
centre of the bow of the improved rocking knife holding or saddle frame C³
oscillating on an adjustable centre C³, in its first carrying and oscillating frame D,
fulcrumed at its front end on the adjustable centre or bar D¹ in the upper front
end of the two side frames A. The outer end of the bar a¹,-which carries the
overhanging end or part of the knife bar C,-has secured on it by a slotted guide
and screw, an adjustable supporting bracket or standard a², with an angled joint
setting forked arm a at the top, for carrying the knife bar C, and shown
particularly in the detached end view Figure 6, all so as to be adjustable to the
same height and angle as the saddle knife holder C2; and to suit the varying
diameter of the grindstone A as hereinafter referred to.
To make provision for wearing and the consequent decrease in diameter of the
grindstones A, 1 form the saddle frame C,-which holds the knife bar C, while
the knives are being sharpened,-with broad ends or flanges c to give room for and
form the several holes c¹ in the same, (as shown particularly in the detached views
Figures 4 and 5), for allowing the said saddle frame or knife holder C² to be
shifted forwards or backwards and up or down to suit the varying diameter of the
grindstone as it decreases by wearing or is renewed.
The actuating arm D₁ of the first moving frame D is also suitably bent down
laterally at d, out of the way, to clear the knives and its bar C, as the saddle
frame C is shifted down or forward into its new fulcrum holes c¹ to suit the
diameter of the grindstone A2 for the time being.
This movable knife saddle carrying frame D is jointed as usual to the main
frames A, but with the adjustable slots d¹ for the fulcrum D'; and the oscillation
commonly imparted to it is communicated to its actuating arm D2 by the short
connecting rod e, with adjustable pin holes e¹ in it, connected at its lower end to
a crank or eccentric pin D³, on the inner end of the driving crank spindle B' or its
wheel B¹ of the grindstone, all so as to tilt the knife bar C and bring the points cl
and heels c² of the knives alternately in contact with the grinding surface of the
stone, more effectually than hitherto, by my several adjusting arrangements to suit
the different diameters of the grindstone.
Having now described and particularly ascertained the nature of my said
Invention and in what manner the same is to be carried into effect or practice,
I declare that what I claim is
First. The general arrangement and combination of the parts of the improved
apparatus or machine for sharpening the knives of reaping and mowing machines,
all substantially as herein described, in reference to and shown in the accompanying
Drawings.
Second. In machines for grinding and sharpening the knives of reaping and
mowing machines, the arrangement and combination of the improved adjustable
knife carrying mechanism indicated by italic letters, all substantially as and for
the purposes and advantages herein described, and as shown in the accompanying
Drawings.
Third. In machines for grinding and sharpening the knives of reaping and
mowing machines, the improved recesses a in the main frames for giving the
improved adjustment of the rod a¹ with its improved slotted adjusting and
supporting standard a³, a³, of the knife bar, substantially as herein described, and
shown in the accompanying Drawings.
Fourth. In machines for grinding and sharpening the knives of reaping and
mowing machines, the improved construction of knife carrying saddle C² with
broad flanges and various adjustable fulcrum holes c, c, for adjusting or setting
the knife bar to suit the varying diameter of the grindstone and sharpen the knives
equally well, substantially as herein described, and shown in the accompanying
Drawings.

page_text: Fifth. In machines for grinding and sharpening the knives of reaping and
mowing machines, the forming of the actuating arm D of the oscillating carrying
frame D, so as to clear the knives at d and that of its motive connecting rod e,
with adjusting pin holes e¹; all to suit the decreasing diameter of the grindstone as
herein described, and shown in the accompanying Drawings.