A NEW OR IMPROVED MACHINE FOR FILING BELT OR OTHER SAW BLADES
Year: 1882

page_text: LETTERS PATENT to Lorentz Albert Groth, K.G.V Civil Engineer and
Managing Director of the Universal Inventors and Patentees Financial
Company Limited 30 Finsbury Pavement London E.C. for an Invention
of "A NEW OR IMPROVED MACHINE FOR FILING BELT OR OTHER SAW
BLADES Communicated to him from abroad by Jens Peter Hansen
"
PROVISIONAL SPECIFICATION left by the said Lorentz Albert Groth at
the Office of the Commissioners of Patents on the 17th July 1882.
LORENTZ ALBERT GROTH K.G.V. Civil Engineer and Managing Director of the
Universal Inventors and Patentees Financial Company Limited 30 Finsbury
Pavement London E.C. "A NEW OR IMPROVED MACHINE FOR FILING BELT OR
OTHER SAW BLADES." A communication to me from abroad by Jens Peter Hansen
residing at "Soro" in the Kingdom of Denmark.
This Invention relates to a new or improved machine for the filing of belt or
other saw blades which machine is constructed as follows.
A Bed plate of wood or other suitable material is first prepared and in some cases
the top of a table or bench will serve the purpose of a Bed plate.
On the said Bed plate is fixed a driving shaft and on one end of which driving
shaft is placed a driving pulley and on the other end a crank pulley.
From the said crank pulley a connecting rod leads to a slide bar in which the
file is to be placed, the said file to move backwards and forwards alternately by
means of a slide working in the slide bar.
When the driving shaft is rotated from the driving pulley the slide bar with the.
file will be given a motion alternately backwards and forwards.
The saw blade is set into the machine below the file in a tail-vice said saw
standing on its back edge and not being too firmly gripped at its sides in order to
allow of its motion tooth by tooth under the file.
If the saw is that of a belt saw it is placed in the tail-vice in a similar
manner and the rest of the blade placed in a suitable position for the proper
working of the file.

page_text: When in this position, the blade receives a stroke of the file every time the slide
bar moves from left to right.
At the same moment when the file has reached the end of its stroke the saw
blade by suitable mechanism is pressed down a little so that the file does not touch
it whilst returning for a second stroke and during this returning of the file the
saw blade is moved a tooth forwards consequently the file when next advancing
files the next tooth, and this continues untill all teeth of the blade have passed the
file and if necessary the process can be repeated several times.
The mechanism which moves the saw blade is composed of a hook the broad
end of which falls by its own weight into the teeth of the saw, the other end of
the said hook is fixed to a disk on the end of the shaft the bearings of which are
fixed in the base plate.
The motion of the shaft is effected by conical wheels The hook aforesaid is
adjusted so that at the right inoment it moves the saw blade a tooth forwards.
The apparatus arranged for pressing down the saw during the returning
movement of the file is composed of a board one end of which is fixed to the
tail-vice and the other hinged to the underside of the bed plate. A flat spring
likewise fixed to the underside of the bed plate constantly presses the said board
and with it the tail vice upwards.
A disc the periphery of which is not circular but eccentric presses down at the
right moment a pin, which pin. goes through the bed plate and with its lower end
is fixed to the aforementioned board.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Lorentz Albert Groth in the Great Seal Patent Office on the
17th January 1883. .
LORENTZ ALBERT GROTH K.G.V: Civil Engineer and Managing Director of the
Universal Inventors and Patentees Financial Company Limited, 30 Finsbury
Pavement London E.C. "A NEW OR IMPROVED MACHINE FOR FILING BELT OR
OTHER SAW-BLADES A communication to me from abroad by Jens Peter Hansen
residing at Soro in the Kingdom of Denmark
"
This Invention relates to a new or improved machine for sharpening belt or
other saw blades, the construction of which, and its manner of working will be
readily understood on reference to the accompanying drawing.
Fig 1 is a plan view and Fig: 2 a perspective view shewing the principal
parts of this machine. Fig: 3 is a sectional view of the machine to be described
hereafter.
A is the bed plate which may be a leaf of a table or a similar surface, on which
plate the driving shaft B has its bearings C and D. To this shaft is keyed the
driving pulley F, and on the other end a disc E fitted with a crank G. From this

page_text: crank the connecting rod H leads to the slide bar I in which the file L is fixed, and
which is reciprocated or moved backwards and forwards in the slide_guide K.
When the shaft of the driving pulley is rotated the slide-bar with the file will be
moved backwards and forwards in a horizontal plane.
The saw blade, M, to be sharpened, is placed in the machine in the position shewn
in the figures. That is to say it is placed below the file within a vice or guide N
so that its cutting edge is upwards and it can move freely between the cheeks of
the said vice or guide. If the blade to be sharpened is that of an endless belt saw,
it is applied in a similar manner and the rest of the blade is placed in the position
indicated by the dotted line.-In this position the blade receives a stroke of the file
every time that the slide-bar moves from left to right of fig: 1. At the moment
the file reaches the end of its stroke to the right the saw blade is lowered or
pressed down a little so that the file shall not touch it during its return or
back ward motion, and during this return motion the saw blade is fed forward one
tooth so that the file, when again advancing will sharpen the tooth next to that
which has just been sharpened. The saw blade is therefore filed every time that
the file is advancing, but is pre-sed down and fed forwards one tooth every time
that tlic file is going backwards, and thus the sharpening continues until the whole
blade has passed, it may be several times, under the action of the file.
The mechanism for feeding forward the saw blade is shewn in the plan view
figure 1, and consists of a pawl P the broad end of which falls by its own weight
into the saw teeth. This pawl P is fixed to the excentric Q, on the end of the
shaft R, the bearings S, of which shaft are fixed in the plate A. Rotary motion is
imparted to this shaft by bevil gearing m. n., as seen in fig: 1. The pawl P is so
adjusted as to feed the saw blade forward one tooth at the proper moment in the.
direction of the arrow.
:
The apparatus by which the saw blade is slightly lowered or pressed down
during the return motion of the file, is composed simply of a board W, one end of
which is fixed to the vice or guide N, and the other is hinged to the underside of
the bed plate A. This is shewn, in the sectional view, fig: III. A flat spring T
fixed to the underside of the bed plate, A, bears constantly against the board and
tends to press the vice or guide N, upwards. The pressing down is effected by the
excentric Q whose periphery is elliptical or oviform, and at the right moment, bears
downwards against a block g. which works freely through a slot in the bed plate A
and is fixed to the hinged board W.
U and U' represent standards fixed to the plate A, and serving to support the
slide guide K. The figures I and II show the slide-bar in its extreme position to
the right.
A belt saw blade can be laid into the machine by loosening the slide bar and
pulling it sufficiently to one side.
Figures IV. V and VI. shew a modified construction of machine. Instead of
giving the file a backward and forward movement in a horizontal plane, and
making the vice or guide and the saw-blade moveable in a vertical direction the
converse arrangement can also be adopted and this altered arrangement will now
be described.
Fig: IV is a longitudinal section taken on the line 1. 2. fig: 1 and shews the
slide guide K, slide bar I, file L, vice or guide N, and board or bed plate A. The
vice or guide N is here fixed to the board, while the slide guide K is pivotted at
one end to the support U, shown to the left of the drawing, its opposite end being
free and moveable in a vertical direction against the support U₁ To the board A
is fixed at a. a strong spring, the opposite end of which, by means of a screw b.
bears with an adjustable pressure on the slide guide K. This spring serves, at the
right moment, to depress the slide guide and causes the file to act upon the saw-
blade M.-When the slide-bar with the file has completed its forward stroke, it
requires to be lifted; since the saw-blade in this arrangement is fixed and cannot
be pressed down, and this lifting of the file is effected in the following manner.
On the underside of the board A, instead of the mechanism shewn in fig: III a
.

page_text: flat iron bar or lever f. moveable on a bolt l. in the bearings c. is arranged. On
one end of this iron-bar or lever is fixed the block g. which as above mentioned
works freely through the board A in a vertical direction beneath the excentric Q.
The other end of the rocking bar or lever f, which end is indicated in fig: IV, is
provided with an upright iron-bolt the upper end of which bears against the
underside of the slide guide K.-When therefore the excentric Q presses down the
block g. the opposite end of the iron-band f. will be raised, and the bolt r. be
pressed up against the slide guide K, thereby causing the said slide guide K. to be
slightly lifted at that end in which the slide-bar with the file is placed. The file
thus makes its return motion without touching the saw-blade.
Fig: V shews the slide guide K, the slide-bar I, the spring S, the spring d, the
supports U and U' and a part of the rod H as seen from above, and fig: VI the
plate A as seen in inverted plan view with the rocking bar f. in its bearings c, and
the bolt . on which the bar rocks.
K' denotes the point at which the slide guide K is pivotted. To the support U¹
is fixed a bent spring d, which with its outer end continually presses the slide
guide K against the said support, or against the screw 8. passing through this
support.
The support U. the spring d. and the screw 8, can be made removable; the slide
guide K is then free to turn around the point K'.
Having now set forth the nature of this Invention as communicated to me by
my Foreign Correspondent and having explained in what manner the same may
be carried into practical effect, I wish it to be understood that I claim :-
First The saw sharpening machine described with reference to figures I, II
and III of the Drawing
Secondly: In a saw sharpening machine, the mechanism for raising and
lowering the vice or guide N substantially as described with reference to fig: III,
of the drawing:
Thirdly: The modified construction of saw sharpening machine described with
reference to figures IV, V, and VI of the drawing.
Fourthly; In a saw sharpening machine, the mechanism for effecting the raising
and lowering of the slide-guide K substantially as described with reference to
Figures IV, V and VI of the drawing.
In witness whereof I the said Lorentz Albert Groth have hereunto set my
hand and seal the thirteenth day of January in the year of our Lord One
thousand eight hundred and eighty three.
TROM
LORENTZ ALBERT GROTH, (L.D.)