IMPROVEMENTS IN MACHINERY FOR FORGING AND CUTTING FILES
Year: 1858

page_text: LETTERS PATENT to Francis Preston, of the City of Manchester,
Mechanical Engineer, and William McGregor, of the same Place,
Mechanic, for the Invention of "IMPROVEMENTS IN MACHINERY FOR
FORGING AND CUTTING FILES."
Sealed the 30th September 1858, and dated the 15th April 1858.
PROVISIONAL SPECIFICATION left, by the said Francis Preston and
William M°Gregor at the Office of the Commissioners of Patents, with
their Petition, on the 15th April 1858.
We, FRANCIS PRESTON, of the City of Manchester, Mechanical Engineer,
and WILLIAM MCGREGOR, of the same Place, Mechanic, do hereby declare the
nature of the said Invention for "IMPROVEMENTS IN MACHINERY FOR FORGING
AND CUTTING FILES," to be as follows:-
The nature of our Invention consists, first, in constructing the anvil block
and swages of the tilt hammer for forging files, so that the slides for the top
swage are kept perfectly parallel with the bottom swage, and the application
of levers and conical cams or other equivalent arrangement of machinery to
alter the weight of the hammer or tilt head as required:
Secondly, the application of a ball joint for the chisel holder used in
machinery for cutting files, and also in an improved mode of applying a spring
to keep the chisel holder in its place.
Thirdly, the spring used as an arm to affix the chisel holder to.

page_text: Fourthly, the compensating guard for working the chisel on the second cut,
the same being attached to the chisel holder or to the chisel.
Fifthly, the construction of an improved chisel, which is made with a boss
either on the face or back, or a hole through it, so as to swivel in the chisel
holder to adapt itself to the face of the file. Also, in an improved mode of
applying a spring to act either at the back or face of the chisel.
Sixthly, the application of a varying expanding cam which lifts the hammer,
so as to give different force of blows upon taper files, which cam is caused to
vary its position by levers and links, or other suitable apparatus attached to
the table.
Seventhly, recessing the bed to suit the curve or form of the pile, one side
of which is left open to facilitate the removal of the file.
Eighthly, the application of a compensating loose tail to the end of the
hammer, which is acted upon by a cam; the object of this is to cause the
hammer to strike the centre of the chisel, notwithstanding the reduction in its
length caused by wearing and grinding.
Ninthly, the application of a compensating screw to act upon the end of the
chisel holder arm, and to regulate the position of the chisel as it wears.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Francis Preston and William McGregor in the Great Seal
Patent Office on the 15th October 1858.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, FRANCIS
PRESTON, of the City of Manchester, Mechanical Engineer, and WILLIAM
MCGREGOR, of the same Place, Mechanic, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fifteenth day of April, in the year of our Lord. One
thousand eight hundred and fifty-eight, in the twenty-first year of Her reign,
did, for Herself, Her heirs and successors, give, and grant unto us, the said
Francis Preston and William McGregor, Her special licence that we, the
said Francis Preston and William McGregor, our executors, administrators,
and assigns, or such others as we, the said Francis Preston and William
McGregor, our executors,, administrators, and assigns, should at any time
agree with, and no. others, from time to time and at all times, thereafter
during the term therein expressed, should and lawfully might make, use,
exercise, and vend, within the United Kingdom of Great Britain and Ireland,

page_text: the Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN
MACHINERY FOR FORGING AND CUTTING FILES," upon the condition (amongst
others) that we, the said Francis Preston and William McGregor, our
executors or administrators, by an instrument in writing under our, or their,
or one of our or their hands and seals, should particularly describe and
ascertain the nature of the said Invention, and in what manner the same was
to be performed, and cause the same to be filed in the Great Seal Patent
Office within six calendar months next and immediately after the date of the
said Letters Patent.
NOW KNOW YE, that we, the said Francis Preston and William McGregor,
do hereby declare the nature of our said Invention, and in what manner the
same is to be performed, to be particularly described and ascertained in and
by the following statement (that is to say) :-
The nature of our Invention of improvements in machinery for forging files
consists, first, in so constructing the anvil block and swages of the tilt hammers
used in forging files, that the top swage is kept parallel with the bottom
swage.
Secondly, in the application of conical cams or other equivalent combinations
of machinery for altering the force of the blow given by the hammer or tilt
head.
Our Invention of improvements in machinery for cutting files consist, firstly,
in the application of a ball joint to the chisel holder.
Secondly, in an improved mode of applying a spring for holding the chisel
bolder, and for causing it to return to its place.
Thirdly, in the application of a compensating loose tail to the end of the
hammer lever, to regulate the force of the blow of the hammer.
Fourthly, in recessing the bed or table to the correct shape of the file to
be cut, and leaving one side of the recess open to facilitate the removal of
the file.
Fifthly, connecting the chisel holder to a spring instead of to a rigid arm
or bracket, as heretofore.
Sixthly, in the application of a compensating guard for working the chisel
on the second cut.
7
And, lastly, in the application of a varying expanding cam, or other positive
agents, to lift the hammer when cutting taper or other files that are not
parallel or nearly parallel throughout their length, so as to give blows of
different degrees of force corresponding to the breadth of the file.
And in order that our Invention may be fully understood and readily
carried into effect, we will proceed to describe the means pursued by us,

page_text: reference being had to the accompanying two Sheets of Drawings, and to the
Figures and letters marked thereon.
On Sheet 1, Fig. 1 is a front elevation, and Fig. 2 a side, elevation, partly
in section, of a tilt hammer to which our improvements are applied; Fig. 3 is
a plan of part of the same.. In these views the hammer head a and spindle b
are raised by the conical cams c fixed on the shaft d, which is turned round by
a strap driven by steam or other power in the usual manner; e is the anvil.
block, to which are cast or fixed the guides e'; the bottom swage f fits between
the guides e¹, and the top swage marked g fits in the lower end of the
spindle b, which is also guided between the slides e¹; by this means the top
swage is kept parallel with the bottom swage f. The conical cams c can be
set nearer together or further apart, so as to increase or reduce the lift of the
hammer, and thereby to vary the force of the blow given by the hammer.
Our improvements in tilt hammers are particularly useful in setting down the
end of the file to form the shank, as shewn in Fig. 2.
On Sheet 2, Fig. 4 is an elevation, and Fig. 5 a plan, of a machine for
cutting files, to which parts of our improvements are applied; Fig. 6 is a
section of part of the same. a is a cast-iron bed, to which is cast or bolted
the projection 6 supporting the standards c, c. The shafts d and e revolve in
bearings in the standards c, c, the former being provided with a fast and loose
pulley, and with a pinion d¹ gearing into the wheel e¹ fixed on the shaft e; to
the face of the wheel e¹ are fixed the two cams e² for raising the hammer f
as will be explained hereafter. The table g moves on the bed a, the requisite
motion being imparted to the table by the screw a¹, which passes through a
.
nut fixed to the table, as shewn in Fig. 6. The screw a¹ works in bearings in
the ends of the bed a; at one end of the screw is fixed a ratchet wheel a²,
which is moved a tooth at every half revolution of the shaft e, by the double
cam es acting on the lever et, which is connected to the click lever h by the
link h'; the click h² jointed to the lever h takes into the ratchet wheel a², and
gives the requisite motion to the table during the cutting of a file; the
pinion as at the other end of the screw a¹ is driven by the wheel a', and is
used for moving the table back to the starting point; the parts above referred
to are made in the usual manner. To the bed a is fixed an upright j
supporting the bracket j, to which is bolted the slide k of the chisel holder k¹;
the end of the shank of the chisel holder is hemispherical, as shewn best in
Fig. 7, and a corresponding recess is made in the slide k, by which arrange-
ment the chisel adapts itself to the face of the file to be cut; the chisel
holder is acted upon by the spring k fixed to the slide k; the chisel or cutting
tool is connected to the chisel holder by a pin, shewn in Fig. 4; to the end

page_text: 5
of the shank of the chisel holder is connected one end of the spring m, the
other end being secured to a stud projecting from the slide k; this spring m
holds the chisel holder in its place, and causes it to return to its place after it
has been raised by the incline n, and after the chisel has been struck by the
hammer.
When it is necessary to regulate the angle of the chisel the level of the chisel
holder can be varied by the compensating screw k³, and the lateral position of
the chisel is regulated by the compensating screw k', which passes through the
end of the slide k, and acts against the bracket j¹.
The chisel is lifted off the face of the file after every cut by the incline n,
fixed to the bar n'; this incline is pushed under the stud by the excentric e*,
which acts on the lever n², to the lower end of which the bar n' is jointed, or.
the chisel can be lifted in any other convenient manner.
The hammer fis fixed to the horizontal arm of the elbow lever f¹, whose
fulcrum is the stud f2; to the vertical arm of the lever f¹ is fixed the adjustable
piece f³, to which is secured the compensating loose tail f*; the wheel e¹ in.
revolving causes the cams e² to act on the tail piece f* in order to elevate the
hammer f, which descends by its own gravity, and falling on the end of the
chisel, imparts to it a blow of the requisite force for cutting a tooth in the file;
the force of the blow depends on the weight of the hammer and the height to
which it is raised, and this can be regulated by moving the piece ƒ³ nearer to
or further from the stud f, and by moving the tail piece f* nearer to or
further from the centre of the shaft e; the stud f2 is also adjustable in a slot
of the bracket f³ in which it is fixed; this bracket is capable of being moved
up and down on the standard c. By these means hammers of different sizes
may be used, and the face of the hammer can be set so as to strike the centre
of the chisel, notwithstanding the reduction in its length caused by wearing and
grinding.
The table g which we prefer to make of solid wrought iron is recessed to suit
o the curve or form of the file to be cut, as shewn in Fig. 4, and one side of the
recess is left open to facilitate the removal of the file, as shewn in Fig. 6; by
thus making the recess to the correct shape of the file, it is only requisite to
place a piece of strong paper or a thin sheet of lead or other suitable material
between the file and the table, merely to protect the teeth on the under side of
5 the file, thereby obtaining the requisite solidity to resist the blow of the hammer
on the chisel.
When the machine is set to work, the end of the file marked A is brought
under the chisel, and as soon as the hammer has struck the chisel it is raised
off the file by the incline n, as above described and as shewn in Fig. 4, the ball

page_text: socket of the chisel holder
allowing it to swivel in the slide ; the table g
is then moved the requisite distance for cutting a fresh tooth in the file by the
cam ³ giving motion to the ratchet wheel a²; the spring n³, see Fig. 5, then
withdraws the incline » from under the stud ko, and the spring k², acting in the
chisel holder k¹, brings the chisel again on to the face of the file, ready to
receive the next blow of the hammer f; these operations are repeated until the
whole surface of the file has been cut, when by means of a self-acting stop
motion not shewn in the Drawing, as it forms no part of our Invention, the
driving strap is thrown from the fast to the loose pulley, thereby stopping the
machine. The attendant then turns round the wheel a to bring the table g
back to its original position, and after reversing the position of the file or
replacing it with another file blank, again sets the machine in operation.
Fig. 8 is a side elevation, Fig. 9 a plan, and Fig. 10 an end elevation of
a tool holder, illustrating the fifth and sixth of our improvements. In these
views the chisel holder p is furnished with a shank which swivels in a bush
attached to the spring q, which is fixed in a bracket similar to j¹.
In Figs. 8 and 9 the spring q is set so as to press the chisel on to the file,
and the chisel is lifted off the face of the file when a tooth has been cut, by the
incline n, see Fig. 4, acting on a stud 5, as before described.
The chisel holder p is furnished with the compensating guard r, which is 2
held at all times in contact with the face of the file in the following manner :-
The guard r fits in a groove in the chisel holder p, and to it is fixed the plate r¹
and the spring 2, the upper ends of which press against projections from the
chisel holder; when the chisel holder has been raised, to lift the chisel off the
file, the spring pressing against the said projections holds the guard r in 2
2.2
contact with the file, thereby enabling the chisel to work accurately on the
second cut.
Fig. 11 represents a plan of part of a file cutting machine, illustrating the
last of our improvements. a¹ is the screw in the bed marked a in Fig. 5; to
this screw is fixed a bevel wheel aº, gearing into the wheels fixed to the shaft 3
s', at the other end of which is the worm s², gearing into a worm wheel t, to
which is fixed the excentric t, which acts on the lever t, fixed to an upright
shaft furnished above with a forked lever t³, taking into a groove in the boss of
the wheel e¹; to this wheel are fixed the varying expanding cams e³, which act
on the tail piece f*; the end of the lever t is held up to the excentric t¹ by a 3
spring t. The excentric t¹ must be shaped according to the file that is to be
cut, and the wheels and worn by which it is driven must be so calculated that
it shall perform nearly one revolution during one traverse of the table 9; in
the present instance we have shewn a cam suitable for cutting. a file that is

page_text: parallel for a part of its length and then taper towards the point, as shewn in
dotted lines. In commencing operations the smaller ends of the cams act
on the tailpiece f*, and raise the hammer f sufficiently to give the requisite
blow for cutting the point of the file, and as the excentric t gradually turns in
the direction of the arrow, it causes the wheel e¹ and cams e³ to slide along
the shaft e, thus bringing the larger parts of the cams e into operation on the
tailpiece, and thereby increasing the lift of the hammer, and consequently
increasing the strength of the blow on the chisel, in proportion to the increased
surface of the file to be cut. When the taper portion of the file has been cut
the concentric portion of the excentric t¹ comes in contact with the end of the
lever t, and the largest diameters of the cams e³ act on the tailpiece f*, and
the lateral motion of the wheel e¹ is stopped until the parallel portion of the
file is completed.
Having thus stated the nature of our Invention, and described the manner
of performing the same, we wish it to be understood that we do not limit
ourselves to the details set forth, nor do we claim any of the well-known
parts of machinery which we have shewn in order to illustrate the mode of
applying our improvements; but what we do claim is,-
First, the guides e¹ cast with or attached to the anvil block of tilt hammers
to hold the top and bottom swages parallel, as shewn and described in reference
to Sheet 1.
Secondly, the application of the conical cams marked c or other equivalent
positive mechanical agents, for altering the force of the blow of tilt hammers,
as shewn and described in reference to Sheet 1.
Thirdly, the application of a ball joint to the chisel holder of file cutting
machines, as shewn and described in reference to Figs. 4, 5, and 7 of
Sheet 2.
Fourthly, the improved mode of applying the spring m to the chisel holder,
as shewn in Fig. 4.
Fifthly, the application of the compensating loose tail f* and the piece f³ to
the hammer lever, to regulate the force of the blow of the hammer, as shewn
and described in reference to Figs. 4 and 5.
Sixthly, the recessing of the table g to suit the curve or form of the file to
be cut, and leaving one side of the recess open in the manner and for the
purposes described in reference to Figs. 4 and 6.
Seventhly, the connecting the chisel holder to a spring instead of to a
rigid arm or bracket, as shewn and described in reference to Figs. 8, 9,
and 10.

page_text: Eighthly, the application of the compensating guard r, for working tlie chisel
on the second cut, as shewn in Figs. 8, 9, and 10.
And, lastly, the application of the varying expanding cams e³, or other
positive mechanical agents, for varying the force of the blow of the hammer, as
shewn and described in reference to Fig. 11.
In witness whereof, we, the said Francis Preston and William
McGregor, have hereunto set our hands and seals, this Thirteenth day
of October, in the year of our Lord One thousand eight hundred and
fifty-eight.
Witness,
H. B. BARLOW,
Manchester.
(L.S.)
FRANCIS PRESTON.
WILLIAM MCGREGOR. (L.S.)