AN IMPROVED SLIDE-REST TOOL to be as follows:
Year: 1885

page_text: I, JOHANN MARTIGNONI of Bockenheim near Frankfort-on-the-Maine, Germany,
Mechanician, do hereby declare the nature of the said Invention for "AN IMPROVED
SLIDE-REST TOOL to be as follows:-
"
The want of a general practical slide rest or turning tool is proved by the fact
that every machine shop has its own manner of preparing such tools.
It is also the case that the first work a turner docs on entering another shop is
to form the turning tools to suit himself or to change the shape of the existing
ones.
Every workman also has his own way of letting the turning tool cut into the
metal the one applying it flat, the other half round and the third pointed; and in
turning articles of large diameter, the one applies the tool above, the other on, and
the third below the centre line. The workmen are encouraged in these habits on
account of the slide rests not being always in proportion to the lathes; there are
for example many heavy lathes with too high slide rests, and in order to make
proper turning tools for these the tool is bent so as to bring it to act in the right
cutting line.
Should the slide rest be too low, then a different form must be given to the tool.
The evil of this method is that owing to the wear of the tool, the cutting line
does not long remain the same. The usual remedy is to artificially raise the tool
by washers.
To overcome these defects is the object of this Invention under which the
cutting line is constant and extends the whole length of the tool. On this line
a cutting edge is made at both ends of the tool in order to enable the tool to
work on both the left and right side of the slide rest.
The bar from which the tool is made is flat on its front, back, and under sides
the upper side being concave so as to constitute a channel running from end to end.
The cutting edges are produced by grinding, at both ends of this bar, inclined
planes extending from the back and front sides to a point at which they meet at or
near the longitudinal centre line of the tool and by grinding an incline from the
bottom or under side to meet these side inclines. The chief advantage of the

page_text: improved tool consists in this peculiar construction of the cutting edges, conjointly
with the constant height of the cutting line extending from end to end of the tool,
which enables the whole length of the tool to be utilized and in re-grinding it to be
always brought back to its original form and cutting line, the result being that a
saving of time and material is effected and more correct work is produced.
The tool is held in the slide rest by a clutch or jaw and in order to work on
the right side of the rest it is only necessary to turn the tool and the clutch to
that side.
In turning shafting, to get a smooth cut, it is customary to run on water which
at present only partially reaches the cutting tool. With the improved too! a
branch pipe is led from the water supply to an opening in the clutch, from
whence the water runs directly into the groove in the upper side of the tool and
thereby keeps it cool.
To prevent the water from running out at the free back end of the groove the
said end is blocked with wax or other suitable material.

page_text: I, JOHAN MARTIGNONI of Bockenheim near Frankfort-on-the-Maine, Germany,
Mechanician do hereby declare the nature of this invention and in what manner
the same is to be performed, to be particularly described and ascertained in and
by the following statement :-
To get a suitable cutting edge on slide rest or turning tools the tools have
hitherto been constructed in many different forms. The point in the majority of
cases has a greater or less curve and the tools when requiring to be re-sharpened
have also to be re-forged and tempered.
Under this invention these defects are obviated by so constructing the tool that
its cutting line is permanent from the first, the tool only requiring re-sharpening
from time to time without further treatment whatever, that is to say, as an effect
of the construction the improved tool differs from all others in respect of the fact
that after its cutting line is once formed no re-forming or re-tempering is required.
On the accompanying drawings figure 3, is a perspective view of the turning
tool constructed in accordance with my invention whilst figure 1, is an end view
and figure 2 a plan showing the tool in position in the rest. As seen by these
figures the cutting line a, extends from end to end of the tool in the form of a
plane inclined upwards at any suitable angle for turning. At each end x, y, the
tool has the cutting edge shaped as shown on the drawings, that is to say, it is
ground on three surfaces namely the surface g, the surface g', and the surface a³,
the said surfaces only requiring re-sharpening from time to time. The tool is held
in the slide rest by a clutch or jaw B, and it is capable of working at either the
right or left side of the rest the clutch and tool being held in the adjusted position
by the screws and nuts m, n, the latter when the position of the tool is reversed
being at the opposite side of the screw m, to that shown.
For the conduct of water to keep that point of the tool which is in operation
cool a groove or channel b, is made throughout the length of the
side as
upper
shown to which groove water is led from the source of supply by a pipe passing
into the opening of the clutch B. To prevent the water running out at the end
of the tool not in operation the channel b, is at that end stopped with wax or its
equivalent.
When the tool requires to be re-sharpened it is obvious that as the angular
cutting line a, runs from end to end of the tool the cutting point always maintains
or is brought back to its original cutting line or level and the tool may be used up
as far as the clutch B and rest permit.
Further it is clear that when adjusted to the proper height the cutting line
always remains at that height and obviates any necessity of moving raising or
adjusting the tool during work, a more mathematically correct cut and a con-
siderable saving of time being the result.
.

page_text: 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
A turning tool capable of cutting at either end and having the upwardly inclined
surface a, extending throughout the length of the tool whereby its cutting line is.
rendered permanent and the necessity of re-tempering after each sharpening is
obviated substantially as described.