IMPROVEMENTS IN FILES to be as follows
Year: 1884

page_text: I, LUDWIG MÜLLER of Dresden kingdom of Saxony, do hereby declare the
nature of said invention for "IMPROVEMENTS IN FILES to be as follows:-
"
My invention relates to files which are composed of a plurality of sections on
each of which is formed a cutting edge, the whole series of edges thus constituting
a surface similar to that of a file.
According to my invention the plates forming the individual sections and which
are provided with bevels at two opposite edges and a rectangular hole in the
middle, are strung on a mandril also rectangular in section. The said mandril fits
the holes laterally, whereas its thickness is less than the vertical height of the
holes, so that the plates may be brought into an oblique position on the mandril,
and with their bevel surfaces on one side all in a plane. When the sections are to
be put into working position, i. e. to be adjusted square to the mandril, a flat strip
of iron having a thickness equal to the space left between the horizontal sides of
the holes and the mandril, is pushed into this space, whereupon the plates are
screwed together against suitable shoulders by means of a nut working on a
screw-threaded part of the mandril.
In case the file is to have teeth instead of plain cutting edges, the front face of
each plate or section is provided with parallel grooves intersecting the bevelled
faces.
When the file is to be sharpened, the aforesaid nut is slackened and the filling-
piece withdrawn. The plates are then all adjusted with their bevelled surfaces on
one side flush with each other, whereupon they are clamped together in this
position. The said surfaces may then be ground on a grindstone and the edges
resharpened thereby. For the purpose of securing the plates in oblique position
I employ a device consisting of two bars having each a rib adapted to enter into
notches cut laterally into the plates, and which bars are pressed against the plates
by screw-clamps. Another bar may be pressed upon the plates from the top.
Dated this nineteenth day of Mov 1884

page_text: I, LUDWIG MÜLLER, of Dresden, kingdom of Saxony, Civil Engineer, do hereby
declare the nature of my Invention for "IMPROVEMENTS IN FILES," and the manner
in which it is to be performed in practice, to be particularly described and ascer-
tained in and by the following statement:—
My invention relates to files which are composed of a plurality of sections or
plates secured to a suitable holder, and on each of which is formed a cutting edge,
the whole series of edges thus constituting a surface similar to that of a file. The
improvements consist in the means employed for allowing the said sections or
plates to be adjusted in respect to the holder, and for securing them. thereto at
different angles, according as they are to be in working position or in the position
for being sharpened.
On the annexed two sheets of drawings my invention is represented in two
different arrangements. Fig. 1 shows a file of the first arrangement in longitudinal
section; Fig. 2 is a side-view and Fig 3 a plan thereof. Fig. 4 shows in side-view
and Fig. 5 in a transverse sectional-view a file with clamping device for holding
the plates a in oblique position. Fig. 6 is a front-view of a plate a with section of
central bar of the file, drawn to a larger scale. Fig. 7 is a horizontal section and
Fig. 8 a side view of a plate a. A file of the second arrangement is represented by
Fig. 9 in longitudinal section, and by Fig. 10 in plan. Fig. 11 is a transverse
section together with an end view of a plate a, and Fig. 12 a longitudinal section
of a portion of the file with the plates a in oblique position.
According to Figs. 1, 2, 3, 5 and 6, the plates a forming the individual sections,
and which are provided with bevels at two opposite sides and a hole in the middle,
are strung on a bar or mandril 6 forming the holder of the plates. The said hole
in the plates and the sectional form of the bar bare rectangular, and the width of
the latter is such as that it fits into the holes; but its thickness is inferior to the
height of the holes, so that the plates may be brought into an oblique position on
the bar b, and with their bevelled faces on one side all in a plane, as shown by
Fig. 4.
When the plates are to be put into operative position, i.e. to be adjusted
and secured square to the bar b, a flat strip of iron c, or filling-strip," having a
thickness equal to the space left between the horizontal sides of the holes and the
bar b, is pushed into this space, whereupon the plates are screwed together by
means of a nut g working on a screw-threaded part of the said bar, and pressing
the plates against shoulders formed on the other end of the bar b by an abutment-
piece fixed thereon by screws. Between the nut g and the plates a a sleeve is
placed, adapted to slide on the bar and the filling-piece. The handle & may be
screwed on the fang of the file and moreover secured by a screw h.
"
In case the file is to have teeth instead of plain cutting edges, the front face of
each plate a is provided with parallel grooves intersecting the bevelled faces, as
shown by Figs 6 to 8.
When the file is to be sharpened, the handle and the nut g are slackened, the
piece detached and the filling-piece c withdrawn. The plates a then having play
on the bar b, are brought into oblique position and adjusted, preferably on a face-
plate, with their bevelled surfaces on one side flush with each other, whereupon

page_text: they are clamped together in this position. The said surfaces may then be ground
on a grindstone, and the edges resharpened thereby.
For the purpose of securing the plates a in oblique position, a clamping-device,
shown by Figs. 4 and 5, is employed in combination with notches & Fig. 6 cut into
the sides of the plates. This device consists of two bars i, having each a rib o
adapted to enter into the said notches, and which are pressed against the plates a
by screw-clamps l. Another bar n may be pressed upon the plates from the top by
screws P.
The elements of the said clamping device may also be employed in the con-
struction of a holder adapted to hold the plates in operative position. Supposing
the two bars i i to be connected at the top, they will form a channelled bar or
holder b1, Figs. 9 to 12, having the ribs o. When the plates a provided, as in the
first case, with notches k, whose width is greater than that of the ribs o, are
inserted from the end into the said holder b₁, and pushed in vertical position with
the lower shoulders of their notches against the holder, as in Figs 9 and 11, spaces
will present themselves between the top of the ribs o and the upper shoulders of
the notches, into which filling-strips c, alike to the strip c, Figs. 1 and 6, may be
introduced. The ribs o of the holder 1 may, in this case, be considered the
equivalents of the bar b, and the notches & those of the central hole of the plates a
of the first arrangement. The means for pressing the plates together consist in a
screw working in a fixed portion of the holder, the sliding piece e¹ and the
abutment piece f, as will be readily understood from the drawing.
For sharpening the file, the screw is slackened, the piece f removed, and the
strips c withdrawn. The plates are then brought into the oblique position shown
by Fig. 12, while a filling piece c¹ is inserted into the space between the top of the
plates a and the inside top surface of the holder, the said space being either
increased in width or formed by the displacement of the plates a. By means of
the piece the plates are locked in their oblique position, and may then be
sharpened on a grindstone, in like manner as is the case with the file of the first
arrangement when placed into the clamping-device.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is
1. A file consisting of a series of bevelled plates a, either perforated or notched,
and strung respectively on a solid bar b, or a channelled bar b¹ having ribs o, the
perforation or notches of the plates exceeding in height the vertical thickness of
the bar bor of the ribs o, the space thus produced between one side of the hole or
notches and the bar b or ribs o being filled out by a filling-strip or strips c,
substantially as and for the purpose described.
2. The combination with a file comprising the plates a, solid bar b, and filling
piece c, of the clamping device consisting of the bars with ribs o adapted to
engage with notches in the said plates a, the bar n, and screw-clamps L, sub-
stantially as and for the purpose described.