CERTAIN IMPROVEMENTS IN MACHINERY OR APPARATUS FOR CUTTING FILES
Year: 1866

page_text: LETTERS PATENT to John Henshall, of Ardwick, in the County of
Lancaster, for the Invention of "CERTAIN IMPROVEMENTS IN MACHINERY
OR APPARATUS FOR CUTTING FILES."
Sealed the 18th December 1866, and dated the 27th June 1866.
PROVISIONAL SPECIFICATION left by the said John Henshall at the
Office of the Commissioners of Patents, with his Petition, on the
27th June 1866.
I, JOHN HENSHALL, of Ardwick, in the County of Lancaster, do hereby
declare the nature of the said Invention for "CERTAIN IMPROVEMENTS IN
MACHINERY OR APPARATUS FOR CUTTING FILES," to be as follows:-
My Invention is designed for the purpose of cutting files by mechanical
means, and for turning up or raising the teeth thereof in imitation of the
teeth of files which are cut by hand.
The improvements consist in the use of a light cutter holder sliding in
grooves or channels which is lifted by means of a cam and depressed by means
of two spiral springs. The cutter holder is mounted and slides in two grooves
in which it has a slight clearance or "play," and from a rod projecting from

page_text: the top of the holder a cross head extends laterally, upon the ends of which
the two springs press; the lifting cam is secured on a driving shaft and lifts
the cutter secured on the holder by acting on a bowl on the holder, and when
the cam releases the cutter holder the springs force it down on to the file
blank secured on a moveable bed beneath, and from the peculiar combination
of the light holder and the double springs the cutter vibrates or shakes
slightly in the sliding guides after it has entered the blank, and thus turns up,
"raises," or forms a tooth on the top edge of the indentation which it has cut.
The progressive motion of the file blank is effected by means of a face cam on
the driving shaft acting upon a lever in connection with a pawl, which turns
a ratchet wheel and so moves the bed on which the file blank is secured.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John Henshall in the Great Seal Patent Office on the 27th
December 1866.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
HENSHALL, of Ardwick, in the County of Lancaster, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-seventh day of June, in the year of our Lord
One thousand eight hundred and sixty-six, in the thirtieth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
John Henshall, Her special license that I, the said John Henshall, my ex-
ecutors, administrators, and assigns, or such others as I, the said John
Henshall, my 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, the
Channel Islands, and Isle of Man, an Invention for "CERTAIN IMPROVEMENTS
IN MACHINERY OR APPARATUS FOR CUTTING FILES," upon the condition (amongst
others) that I, the said John Henshall, my executors or administrators, by
an instrument in writing under my, or their, or one of 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 uext and
immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said John Henshall, do hereby declare the
nature of the said Invention, and in what manner the same is to be performed,

page_text: to be particularly described and ascertained in and by the following statement
and accompanying Drawings (that is to say) :-
My Invention is designed for the purpose of cutting files by mechanical
means, and for turning up or raising the teeth thereof in imitation of the
teeth of files which are cut by hand.
The improvements consist in the use of a light cutter holder sliding in
grooves or channels, which is lifted by means of a cam and depressed by means
of two spiral springs. The cutter holder is mounted and slides in two grooves
in which it has a slight clearance or "play," and from a rod projecting from
the top of the holder a cross head extends laterally, upon the ends of which
the two springs press; the lifting cam is secured on a driving shaft and lifts
the cutter secured in the holder by acting on a bowl on the holder, and when
the cam releases the cutter holder the springs force, it down on to the file
blank secured on a moveable bed beneath, and from the peculiar combination
of the light holder and the double springs the cutter vibrates or shakes slightly
in the sliding guides after it has entered the blank, and thus turns up," raises,"
or forms a tooth on the top edge of the indentation which it has cut. The
progressive motion of the file blank is effected by means of a face cam on the
driving shaft acting upon a lever in connection with a pawl, which turns a
ratchet wheel and so moves the bed in which the file blank is secured.
In order that the Invention may be better understood and explained in
detail, I have hereunto attached a Sheet of Drawings made upon a scale of
about three inches to the foot, similar letters of reference being marked
thereupon.
Fig. 1 represents a side elevation of the file cutting apparatus, and Fig. 2
represents a front elevation of the same. In Figs. 1 and 2 a, a, is the
foundation bed or plate, to which are secured the uprights b, b, these uprights
are provided with the parallel frames c, c, between which the sliding tool
holder d is caused to rise and fall, the former being effected by means of the
cam e on the driving shaft h, and the latter by the spiral springs f, f, through
the medium of the cross head g. The file under operation is adjusted so as
to rest firmly on the feed or sliding bed i by means of the yielding spring
presser k, the amount of pressure exerted for retaining or holding the file
being governed by the handle screw and blocks 2. A regular and intermittent
feed is given to the sliding bed i, upon which the file is secured by the
ratchet wheel in and pawi n, actuated by the eccentric o through the medium
of the bell-crank lever p and adjustable connecting rod 7. The action of the
machine being as follows:-The cutter holder d mounted and sliding in the
grooves or parallel levers c is provided with the opening or slot r and a

page_text: projecting rod s, upon which is keyed or otherwise secured the moveable cross
head g, a pressure being exerted upon the same by the spiral springs f, the
upper portion of which being caused to bed against the fixed cross head t.
The came on the driving shaft h when revolving enters the slot r so as to
press upon and lift the tool holder d and moveable cross head g, the action of
which compresses the spiral springs f until the tool holder has reached its
highest point, at which time the peculiar formation of the came gives an
instantaneous release to the tool holder, the tool of which is thus caused by the
expansion of the springsf to descend and strike the file blank, and the vibratory
nature of the blow after the tool has entered the blank turns up, "raises," or
forms a tooth on the top edge of the indentation which it has cut. The
progressive motion given to the file blank and its supporting bed through the
arrangement of apparatus herein-before described is capable of being regulated
so as to give a greater or less movement to the table in order that the file
under the action of the cutting tool may receive a fine or coarse pitch as
required.
Having now described the nature of the said Invention, together with the
method of carrying the same into practical effect, I wish it to be distinctly
understood that I claim the novel and peculiar arrangement and adaptation
to the file cutting machine of the spring marked f on the Drawing, and
came for the purpose of effecting actuating the tool holder in conjunction
with such cam in the manner and for the purpose herein-before described, set
fortb, and fully illustrated in the Drawings attached.
In witness whereof, I, the said John Henshall, bave hereunto set my
hand and seal, this Twenty-fourth day of December, in the year of
our Lord One thousand eight hundred and sixty-six.
JOHN HENSHALL. (L.S.)