A NEW OR IMPROVED FILE CUTTING MACHINE
Year: 1883

page_text: LETTERS PATENT to Lorentz Albert Groth. K.G.V. Civil Engineer and
Managing Director of The Universal Inventors and Patentecs Financial
Company Limited, 30 Finsbury Pavement London E.C for an Invention
of "A NEW OR IMPROVED FILE CUTTING MACHINE communicated to him
from abroad by F. Bathe, a person resident at Berlin, in the German
Empire
PROVISIONAL SPECIFICATION left by the said Lorentz Albert Groth at
the Office of the Commissioners of Patents on the 20th July 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 FILE CUTTING MACHINE a
communication to me from abroad by F. Bathe a person resident at Berlin in
the German Empire
The machine forming the subject of this invention consists of the following
arrangements.
On a four footed frame or standard are erected side by side two vertical guides
similar to those of a planing machine, in these guides are arranged two cross pieces
connected together and adapted to move vertically therein."
The movement of these cross pieces is effected by means of two screw spindles,
bevil gearing and a hand wheel. The lower of the two cross pieces carries a
horizontal shaft, on which is fixed a tilt hammer. The movement of the tilt
hammer is effected by means of a shaft furnished with cams, this shaft is carried
in bearings behind the beforementioned guides and is set in motion by a strap from
a countershaft.
The lift of the tilt hammer is regulated by the up and down movement of the
two crosspieces, by two screw springs fixed to the upper cross piece: these screw
springs act on special levers fixed on the tilt hammer shaft. These springs are
also intended to bring the hammer quickly into the position of rest and to hold
the same suspended over the work. The shaft which carries the tilt hammer is
furnished with a special apparatus which is connected with the striking or
disconnecting gear in order to bring the hammer to rest directly the machine is
put out of gear.
The anvil is caused to traverse lengthwise below the tilt hammer.
The movement is transmitted from the driving shaft which carries the cam for
moving the hammer, by means of bevil gearing, through a vertical shaft, to a

page_text: horizontal shaft laying alongside the anvil. From this latter shaft the suspending
screw spindle placed under the anvil is moved by means of star wheels.
A nut fixed to the anvil surrounds the screw spindle, this nut can be opened and
closed by means of levers and slots, and is held closed by a counterweight. The
backward movement of the anvil can be effected by self acting means, by means of
a strap or by the workman by the aid of a crank handle. In either case a toothed
wheel turning in bearings by the side of the anvil is moved and gears with a
toothed rack fixed to the anvil.
The file which rests on a thick leaden support, is pressed tightly upon the anvil
by two shafts, which carry at both ends two vertical weighted rods. The pressure
exerted on the file by the shafts can be taken off by the foot of the workman
acting on a pedal connected with a combination of levers..
For curved file surfaces, a special apparatus. is provided which keeps the file
always at the same angle under the chisel.
In cutting the point of the file, the latter is so pressed on the anvil by means of
levers, through a treadle that the part struck is always supported.
A further contrivance is adapted to the anvil, and allows two files to be cut on
the flat sides at the same time.
The tilt hammer acts on the chisel below it, and produces the proper cuts on the
file, which is laid on and fixed to the anvil.
The chisel itself is secured in the chisel holder which is carried by two arms of
a shaft. This shaft is carried in bearings in front of the first mentioned guides,
and is adjustable horizontally in the direction of its axis, and also vertically.
The first named adjustment is effected simply by screws and nuts; the latter by
means of bevil gear which acts upon two screw spindles fixed to the guides.
These screw spindles move the bearings of the shaft carrying the chisel holder to
and fro between parallel guides
By these movements the chisel can be adjusted exactly and placed at various
inclinations to the file.
The turning of the chisel holder round a fixed point allows of a variety of
inclinations of the cut in a horizontal plane.
While the anvil moves forward with the file the chisel which is underneath the
hammer receives a quadruple movement, namely, a forward and simultaneous
lifting movement, and a backward and simultaneous lowering movement.
These movements of the chisel holder are effected by three discs fixed on the
driving shaft. Against these discs press three tongues which are keyed fast on
two shafts placed below the driving shaft. These two shafts are oscillated by the
tongues, by means of the discs, and they transmit this motion to the chisel holder
by means of levers and connecting rods whereby the aforesaid quadruple motion is
produced. The chisel holder itself consists essentially of a support which is
adjustable on a prismatic lever
The movement of the chisel is of such a nature that the chisel is always pushed
by spring pressure against the arris or burr of the preceding cut. At the same
time the shaft carrying the chisel holder so operates a spiral spring on the said
chisel holder, that the chisel is always pressed against the file.
Both springs now act together on the chisel in such manner that the latter is
always pushed against the arris or burr of the preceding cut on the file at an
angle of 45° the consequence of which is that an absolutely equal distance between
each cut is attained.
Further, there is an apparatus applied to the chisel holder, by which a resistance
is produced when making the first cut which produces the same action on the
movement of the chisel as the arris or burr does in the following cuts.
The last named apparatus is thrown out of gear by self acting means after the
first cut is made.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Lorentz Albert Groth in the Patent Office on the 18th January
1884.
LORENTZ ALBERT GROTH, K.G.V. Civil Engineer and Managing Director of
the Universal Inventors and Patentecs, Financial Company Limited, 30, Finsbury
Pavement, London, E.C. "A NEW OR IMPROVED FILE CUTTING MACHINE," a
communication to me from abroad by F. Bathe, a person resident at Berlin in
the German Empire.
The machine forming the subject of this invention consists of the following
arrangements.
On a frame or standard are erected side by side two vertical guides similar to
those of a planing machine, in these guides are arranged two cross pieces connected
together and adapted to move vertically therein.
The movement of these cross pieces is effected by means of two screw spindles,
bevil gearing and a band wheel. The lower of the two cross pieces carries a
horizontal shaft, on which is fixed a tilt-hammer. The movement of the tilt-
hammer is effected by means of a shaft furnished with cams, this shaft is carried
in bearings behind the beforementioned guides and is set in motion by a strap
from a countershaft. The lift of the tilt-hammer is regulated by the up and down
movement of the two crosspieces by two spiral springs fixed to the upper cross-
piece; these spiral springs act on special levers fixed on the tilt-hammer shaft.
These springs are also intended to bring the hammer quickly into the position of
rest and to hold the same suspended over the work. The shaft which carries the
tilt hammer is furnished with a special apparatus which is connected with the
striking or disconnecting gear in order to bring the hammer to rest directly the
machine is put out of gear.
The anvil is caused to traverse lengthwise below the tilt-hammer. The move-
ment is transmitted from the driving shaft which carries the cam for moving the
hammer, by means of bevil gearing, through a vertical shaft, to a horizontal shaft
laying alongside the anvil. From this latter shaft the traversing screw spindle
placed under the anvil is moved by means of:
spur wheels.
A nut fixed to the anvil surrounds the screw spindle, this nut can be opened
and closed by means of levers &.slots and is held closed by a counterweight. The
backward movement of the anvil can be effected by self-acting means, by means of
a strap, or by the workman by the aid of a crank handle. In either case a toothed
wheel turning in bearings by the side of the anvil is moved and gears with a
toothed rack fixed to the anvil.
The file which rests on a thick leaden support, is pressed tightly upon the auvil
by two shafts, which carry at both ends two vertical weighted rods. The pressure
exerted on the file by the shafts can be taken off by the foot of the workman
acting on a pedal connected with a combination of levers.
For curved file surfaces a special apparatus is provided, which keeps the file
always at the same angle under the chisel. In cutting the point of the file, the
latter is so pressed on the anvil by means of levers through a pedal that the part
struck is always supported..
A further contrivance is adaped to the anvil and allows two files to be cut on
the flat sides at the same time.
The tilt-hammer acts on the chisel below it, and produces the proper cuts on the
file which is laid on and fixed to the anvil. The chisel itself is secured in the

page_text: chisel-holder which is carried by two arms of a shaft. This shaft is carried in
bearings in front of the first mentioned guides and is adjustable horizontally in
the direction of its axis, and also vertically. The first named adjustment is
effected simply by screws and nuts; the latter by means of bevil gear which acts
upon two screw spindles fixed to the guides. These screw spindles move the
bearings of the shaft carrying the chisel holder up and down between parallel
guides.
.
By these movements the chisel. can be adjusted exactly, and placed at various
inclinations to the file. The turning of the chisel holder round a fixed point
allows of a variety of inclinations of the cut in a horizontal plane.
i
While the anvil moves forward with the file the chisel which is underneath the
hammer receives a quadruple movement namely a forward and simultaneous
lifting movement and a backward and simultaneous lowering movement.
These movements of the chisel-holder are effected by three. irregular shaped
discs or tappets fixed on the driving shaft. Against these discs press three tongues
-which are keyed fast on two shafts placed below the driving shaft.
These two shafts are oscillated by the tongues by means of the discs, and they
transmit this motion to the chisel-holder by means of levers & connecting rods
whereby the aforesaid quadruple motion is produced.
The movement of the chisel is of such a nature that the chisel is always pushed
by spring pressure against the arris or burr of the preceding cut.
At the same time the shaft carrying the chisel holder so operates a spiral spring
on the said chisel-holder, that the chisel is always pressed against the file. Both
springs now act together on the chisel in such manner that the latter is always pushed
against the arris or burr of the preceding cut on the file at an angle of 45° the
consequence of which is that an absolutely equal distance between each cut is
attained. Further there is an apparatus applied to the chisel holder by which a
resistance is produced when making the first cut which produces the same action
on the movement of the chisel as the arris or burr does in the following cuts. The
last named apparatus is thrown out of gear by self acting means after the first cut
is made.
.
And in order that the said machine may be fully understood I will now proceed
to describe the same with the aid of the accompanying drawings in which:
Fig. I is a back view and Fig. 2 a side view of the complete machine resting on a
wooden framework O which carries at one end two cast iron frames A connected
together at the top by a cross piece Q; the other part of the framework is occupied
by the anvil B which is moveable on two curved guides E.
The bearings L on the frames A carry the shaft W, which drives the machine
by means of the strap pulley R¹ fixed on its left hand end (see Fig. 1). On this
shaft and near the said strap pulley R¹, is a smaller pulley R2 by which the
shaft W¹ is driven and a toothed coupling or clutch Z by which the machine is put
into or out of gear by the guide bar T. The shaft W also carries a worm C and
cam piece D consisting of two cams for moving the tilt-hammer H, and three
irregular discs or tappets U₁, U², U³.
Inside the two frames A are two cross pieces Q1 Q2 connected together and
adjustable lengthwise on vertical guides by means of two screw spindles S¹ & S³
which are turned by means of the bevil wheels G. G from the band wheel K. The
lower one Q of the two moveable cross pieces carries the shaft V, in the middle of
which the tilt hammer. His fixed, and set in motion by the cam piece D above it.
Figs. 3 & 4 show two views of the tilt-hammer.
In order to hold the hammer suspended over the work there are fixed on the
shaft V two short arms a (see Figs. 1. 9. & 10) the ends of which are connected to
two spiral springs F¹ & F2 fixed to the upper cross beam Q¹. These springs which
act simultaneously are placed symmetrical in relation to the shaft V. (Fig. 2) and
in the working of the machine they effect a strengthening of the blows of the
hanımer and a rebound of the same. By the movement. of the two cross pieces the

page_text: power of altering the stroke of the hammer is obtained, because the shaft V with
the hammer H can be placed nearer to or further from the cam piece D. During
the alteration of the stroke of the hammer the tension of the springs F¹ & F² is
regulated by the wheel work at the upper part of the spring F2. This wheel
work receives its motion froin the screwed spindle S₁ which carries at its end the
wheel (Fig. 9) which gears with the wheel 2 on the spring spindle. The
wheel is furnished with a female thread and consequently moves up and down
by turning on the spring spindle, whereby the tension of the spring F² is increased
as the strokes of the hammer become greater.
By the movement of the disengaging bar T, which carries at its fixed fulcrum P,
a curved slotted arm a¹ (Figs. 1. 11. & 12). there is moved against the action of the
small spiral spring f¹ the rectilinearly guided piece band the bow-shaped piece b²
fixed thereto. This bow-shaped piece takes with it the end of the blade b³ of the
spring F3 and thereby brings blade 63 so near the shaft V that the latch k fixed
thereon takes into the catch n of the blade 63. The blade 3 forins the end of a
spiral spring F3 hung on to the upper cross beam Q₁ and which when the latch k
takes into the catch n prevents the shaft V from turning so that when the machine
is put out of gear the hammer immediately comes to rest. When the machine is
put in gear the catch is removed from the latch k by the stretched spiral spring f
connected with the arm b¹.
In Fig. 5 is shown the chisel holder M with its complete operating mechanism,
as seen in Fig. 2 but to a larger scale.
Fig. 6 shows a plan of the chisel-holder M. fig. 7 the other side-view of the
same, and fig. 8 shows the chisel-holder from below.
The tilt-hammer H acts on the chisel M below it and produces the proper cut
on the file (Fig. 2) which is laid on and fixed to the anvil B. The chisel M' is.
secured in the chisel-holder which is carried by the arms c¹ and c² fixed in the
sockets & 2 on the shaft N (Figs 6. 2. & 1) The arm c² gives a second point
of support to the shaft w which takes a bearing at r under the chisel-holder M¹ (see
Fig. 8).
The arm e¹ carries the hinder part of the chisel-holder, which has its fulcrum at b
(see Fig. 8) & thus allows of an adjustment of the chisel M
On the other hand by the movement of the shaft N in a horizontal direction
lengthwise of its axis; and in a vertical direction an adjustment of the chisel-holder
and the chisel can be effected. The first named movement is effected by turning
the hand wheel K2 on the nut m, taking on to the screwed end of the shaft N
which passes through the case J (see Figs. 1 & 14).
The movement of the shaft N vertically is effected by turning the hand wheel K³
(Figs. 1 & 2) which acts by means of bevil gearing on the spindles s¹ carrying the
bearing t of the shaft N between parallel guides. The case J on the shaft N
contains, beside the nut and spindle, a train of gearing with a coiled spring f2
(Figs. 13 & 14) which latter tends always to turn the shaft N so that the chisel is
pressed against the file. This coiled spring f2 as shown in Fig. 13, is fastened at
one end to the shaft N and connected at the other with the toothed-wheel 73 on
this shaft. The wheel is geared with the wheel the axis of which carries
outside the case J a ratchet wheel s² (Fig. 14.)
By means of this ratchet wheel 82 and the catch the tension of the spring f
is regulated and can be increased or diminished by turning the axis of the ratchet
wheel by means of a key.
.While the anvil with the file moves forward a fourfold movement is imparted to
the chisel namely a simultaneously forward and upward, and a simultaneously
backward and downward movement.
The motion of the chisel-holder M is effected by the three irregular discs or
tappets, U, U2, U³, on the shaft W which tappets cause the shafts V₁and V2 placed
side by side, to oscillate by means of the tongues Z¹ Z & Z³ (Figs. 1 & 5) fixed to
the said shafts V & V and pressing against the discs. On the shafts V₁ & V? are

page_text: sockets h³ & h (Fig. 5) which respectively inpart a to and fro motion to arms x¹ x²
both being connected to the chisel-holder. The tappet U acts through the tongue Z¹
on the shaft & through this latter on the arm and the lever g so as to turn the
small shaft w under the chisel-holder.
By this means the foot u fixed on the shaft w and bearing with its point on the
file (Fig. 2) takes part in the rotation, and occasions a rising and falling of the
chisel holder M by means of its fixed bearing point. By means of the hand wheel
(Fig. 5) secured on the end of the arm x¹ and a screw and nut the arm x¹ can be
lengthened or shortened so as to produce a variation of the stroke of the chisel-
holder.. During the beforementioned movements the tappets U2 and U³ act on the
arm and through this by the lever g¹ turning at y (Fig. 8) & the lever g²
connected with it, on the front part of the chisel-holder so that the slide 83 (Fig. 6)
carrying the chisel M moves to and fro between the guides m¹. The tappets U¹ U'
& Us are so placed in relation to one another that the chisel moves forward whilst
rising and the arris or burr of the last cut is not injured. The chisel guide then
moves backwards and allows the chisel to sink, whereby it is again put in place and
a fresh blow of the hammer can then be given. The object of the springs f³ & f*
(Fig. I) fixed on the shafts v' & v² is to press the tongues close against the discs
and to counteract any vibration.
The spiral springs f5 (Fig. 5)-fixed to the end of the arm x is put in tension by
the back ward movement of the said arm, and pushes the chisel as far as possible
up against the arris or burr of the last cut, the chisel is however prevented from
passing over the burr by the action of the coiled spring f2 in the case T (fig. 13)
but the pressure of the chisel is caused to act against the file at an angle of
about 45°.
In order to produce when making the first cut on the file the same tension of
the spring as that produced by the pushing of the arm x2 against the preceding
cut (which offers a resistance that puts the spring f³ in tension) a pin c is placed
at the side of the chisel-holder M (Figs. 5 & 6) and carries a small tappet & over
which is fixed a latch (vorreiber) v. This latch is so placed against the hook ended
blade spring.f fixed to the chisel-holder, that this said spring is pressed down by
the latch and is brought into gear by its hook-shaped part with the catch n¹ fixed
on the slide s³ of the chisel-holder. By this means the tappet d takes the position
shown in Fig. 6.
The blade spring fo thus placed against n¹ holds the slide 3 of the chisel-holder
at the half stroke and the spring f5 is thus brought into tension.
At the backward movement of the slide 83 the blade spring ƒ7 (Figs. 5 & 6),
fixed to the side of the said slide, pushes against the tappet d and moves at the
same time the latch v whereby the spring fe springs upward and disengages the
connection with the catch n¹. At the next blow the tension of the spring f³ is
brought about by the resistance of the arris or burr of the first cut.
The chisel M is clamped in the chisel-holder between india-rubber plates by a
spring which can easily be released by the thumb screws (Figs. 5 & 6) and a rack
& gearing.
The spiral spring with bell crank levers seen at the right side of the chisel-
holder (Figs. 6 & 7) and which are connected with the bell apparatus g³ are for
the purpose of warning the workman when the blows occur with unequal strength
but they do not effect the principle of the machine.
The anvil which is shown in Figs. 15. 16. & 17. on the sides not visible in
Figs. 1 & 2 receives its motion from the worm C (Fig. 1). fixed on the shaft W.
This worm is in gear with a worm wheel & transmits the motion to the vertical
shaft V₁, from the latter by bevil wheels to the horizontal shaft V2 at the side of
the anvil (Figs. 15 & 17.) and through the wheels & to the screw spinde 8°
placed under the anvil and taking its bearings at 11. The spindle s can be put
into gear with the locking nut m² fixed on a narrow side of the anvil, (Fig. 15)
by the weight G¹. The weight G₁ acts on a fork-shaped lever h the fulcrum axis.c¹

page_text: of which passes through the anvil B. With the lever h are connected two pins e³
&e (Figs. 15 & 17) which take into the slots of the two parts of. the locking
nut m these latter open and close by the up and down movement of the lever h
and are maintained in the closed position by the weight G¹ under which condition
the anvil moves forward on the curved guide rails E. The opening of the locking
nut is effected simply by lifting the weight G' which is then held in that position
by the catch on the blade spring f³ (Fig. 18). By pressing back the spring f
the weight is allowed to fall and the locking nut closes round the spindle as
before.
When the machine is at work the anvil B moves from left to right in Fig. 2.
It can be brought back automatically by strap gear or by the workman by means
of a crank handle. In the former case the motion is transmitted from the shaft W
by strap gear through the pulleys R & R³ to the shaft W₁ carried in bearings
inside the wood frame O. This shaft W₁ drives the short shaft W (Figs 15. 17.
& 2) by a strap and the pulleys R* & R³. The latter shaft W2 carries a toothed
coupling or clutch Z and wheelwork 7 which gears with the rack z (Fig. 2) fixed
to the side of the anvil.
When the
By putting the coupling Z' into gear by the lever H and opening the locking
nut m² the anvil is moved back by the tooth wheel 7 and rack z.
coupling is put out of gear the anvil can be moved by the crank handle K' on
the shaft W'.
The file which rests on a thick support of lead on the anvil is pressed firmly.on
to the latter by the two shafts w¹ & w² by means of the vertical rods g³ & g
fixed at the ends of these shafts, and carrying at their lower ends the weights g¹
&g. The pressure of the two shafts w¹ & w² loaded with the weights g* & g³ is
taken off by the levers p¹, p², p³, pt, connected with the treadle t & t2 through
the rods 8 & 86 which are guided rectilinearly. The end or tang of the file is
placed in the socket x which is screwed to the forked lever e on the anvil (Figs. 1.
16. and 17).
The lever e the axis of which is designated in the aforesaid Figures by the
letter i, is moved upwards by pressing down the treadle to the object of which is
to give the point of a curved file a firm bearing on the anvil at the commencement
of cutting.
Pressing down the treadle t³ acts on the lever c³ connected with the rod a² which
is guided in a right line, in such a manner that the said lever with the rod a²
are drawn down. The upper end of the rod a² carries a pin 2 (Figs. 16 & 17)
and acts ou the lever 12, the fulcrum n² of which is fixed inside the frame A
(Fig. 1), in such manner that the said lever is pressed down. This lever l² now
presses with its point on the lever 13 (Fig. 16) at the side of the anvil, this turns
the shaft w³ fixed to the lever (Figs. 15. 16. & 17) By this turning of the
shaft the link is moved up & down and communicates the motion to the forked
lever e connected with it.
The curved form of the file is imitated on the curved guide-bars E and it
follows therefrom that the file is always supported firmly during the rest of the
cutting.
A further contrivance is shown in the plan of the anvil (Fig. 17) and is for the
purpose of holding two files for the cutting of their narrow sides simultaneously.
The tangs of the two files are placed as before in the two sockets x. x. fixed on the
forked lever e, whereby the said lever e carries, simultaneously the two fulcra of
the pieces d¹ & d². On the pieces d¹ & d' are screwed the cheeks & which
press sidewise against the file."
The pieces d¹ & d2 take by two pins into the slots of the two parts o¹ & o² which
are pulled by the rods u¹. (Fig. 15) and the lever arms u² fixed on the shaft w*
by the action of the weight G2 on the lever arm acting on the shaft the cheeks
are by this means presed firmly against the files.

page_text: een the two files is pushed a wedge of soft metal which is held in position
ns of the notches on the sector y¹ and prevents the two files from touching
ther.
ng now described the nature of the said invention and the manner in
the same is to or may be performed, I would have it understood that
claim as the invention to be secured by the within in part recited Letters
is:
The new or improved file cutting machine constructed with the moveable
anvil B, the moveable chisel-holder M, the chisel M 'the adjustable tilt
hammer H, and the mechanism for effecting the requisite movements, as
herein before described and illustrated in Figs. 1 & 2 of the drawings hereto
annexed.
The peculiar arrangement of the tilt hammer fixed on the shaft V with the
springs F&F acting on the said shaft as hereinbefore described and
illustrated in the drawings hereto annexed.
The disengaging apparatus of the machine consisting of the combinations
of the disengaging bar T, the angle piece b', the spiral spring f', the
curved piece b, and the blade 3 acting in such manner that the last blow
of the hammer is intercepted by the throwing out of gear of the machine
as hereinbefore described & illustrated in Figs 11 & 12 of the drawings.
hereto annexed.
The chisel-holder M with the peculiar arrangements which enable a
variable inclination of the cut in a horizontal plane to be effected by
means of the hinge turning, on the point b at the hinder part of the chisel-
holder and which enable the chisel to be placed against the file at various
inclinations by adjusting the shaft N carrying the chisel-holder. The
movement of the chisel-holder by means of the irregular discs or
tappets UU & U³, the tongues Z' Z & Z³, the shafts v¹ & v², the
arms x & x the levers g g' & g and the foot u carried by the shaft w
acting together so as to effect a to and fro motion of the chisel with a
simultaneous rising and falling motion of the same as, illustrated in
Figure 5.
The arrangement of the spiral ƒ³ (Figure 5) on the arm x2 and of
the coil spring f³ in the case J (Figures 13 and 14) which act on the
chisel in such manner that the latter is pushed against the edge of the
preceding cut at an angle of about 45° and the apparatus place at the
side of the chisel-holder, consisting of the pin e the tappet d the latch
(vorréiber) b the blade spring f and 7 and the catch n which produces
tension of the spring f for making the first cut on the file.
The arrangements for giving motion to the anvil B by transmitting the
motion from the shaft W to the shafts V₁ and V2 and by the spur
wheels and to the screw spindle st under the anvil through the locking
nut m and the arrangements for effecting the opening and closing
motions of the said locking nut by means of the forked lever h and the
weight Gas herein before described and illustrated in Figures 1, 15 and 17
of the drawings hereto annexed.
The mechanism for holding the file firmly on the anvil, consisting of the
shafts w2 and 3 the rods and sand the levers p p² ³ and
connected therewith, the movement of the same being effected by the
treadles t¹ and 2. Also the lever mechanism (Figure 16) consisting of the
levers a 12 and 13 the shaft w and the levers and 15 connected
therewith which effects the laying of the point of the file on the anvil as
herein before described and illustrated in the drawings hereto annexed.
The apparatus for holding the files firmly when it is required to operate
upon two files at the same time with the same cut such apparatus
consisting of the pieces d' and d² furnished with the cheeks k' & l² which
t

page_text: pieces and d² are so connected by the rods u¹ and u³ that the weight G²
acting on the shaft w' presses the cheeks against the files, as herein before
described and illustrated in Figure 17 of the drawings hereto annexed.
In witness whercof I the said Lorentz Albert Groth have hereunto set my
hand and seal this Eighteenth day of January in the year of Our Lord, one
thousand eight hundred and eighty four.
LORENTZ ALBERT GROTH (L.S.)