IMPROVEMENTS IN APPARATUS FOR GUIDING IN A STRAIGHT OR PLANE PATH TRACING, CUTTING, OR GRINDING TOOLS, OR WORK OPERATED ON BY SUCH TOOLS
Year: 1873

page_text: PROVISIONAL SPECIFICATION left by James Joseph Sylvester at the
Office of the Commissioners of Patents, with his Petition, on the
25th November 1873.
I, JAMES JOSEPH SYLVESTER, of No. 60, Maddox Street, Regent
Street, in the County of Middlesex, do hereby declare the nature of
the said Invention for "IMPROVEMENTS IN APPARATUS FOR GUIDING IN A
STRAIGHT OR PLANE PATH TRACING, CUTTING, OR GRINDING TOOLS, OR WORK
OPERATED ON BY SUCH TOOLS," to be as follows:―
This Invention relates to apparatus for guiding either the tools
employed for tracing, cutting, or grinding, or the work on which such
tools operate, in a straight or plane path without the aid of slides or
straight guiding surfaces. For this purpose I employ a system of
jointed rods acting according to known mathematical principles, whereby
one point in the system is guided so as to move in a straight line, at
which point I fix the tool or work on which the tool is intended to
operate.

page_text: The system of rods is arranged in the following manner :-Four equal
rods are jointed together so as to form a square or diamond; two of the
joints of this figure, namely, the joints at two of the opposite angles are
connected by equal radius rods to a pivot in a fixed position, another
joint of the four-sided figure is connected by a radius rod to another
pivot, also fixed in such a position that its distance from the first-named
pivot is equal to the length of the radius rod last mentioned. When
this system of rods is made to move about the two pivots, the fourth
joint or angle of the four-sided figure moves in a straight line and a
tool secured in this joint in such a manner that its point coincides
with the axis of the joint will effect a straight trace or cut on material
exposed to its action.
By arranging on one plane surface two systems of jointed rods such
as I have described above, and connecting their rectilineally moving
joints together by a bar, table, or frame, this bar, table or frame will
be guided in a straight path and tools fixed thereon will effect straight
traces or cuts on materials exposed to their action; or work fixed on
such bar, table, or frame when moved in contact with a fixed tool will
have a straight trace or cut effected upon it.
And in this manner
materials may be cut, faced, or ground to a straight edge, or, by giving
the tool or work a lateral movement, to a plane surface. Such lateral
movement may be given to the tool or to the work in the ordinary way
by means of a table or rest working on straight guides and advanced by
a screw; or instead of employing straight guides one or more of the
systems of jointed rods above described may be employed, such system
or systems being mounted in the plane of the lateral movement.
Furthermore, by connecting the radius rods to the pivots and to the
three angles of the four-sided figure by joints of spherical or gimbal
form, the system can be moved about the pivots, not in the one plane
only but also in various planes inclined thereto, and the fourth angle of
the four-sided figure will always be found situated in a plane surface.
A tool or piece of work will be guided by this angle in the manner
above described so that a straight cut or trace can be effected both
longitudinally and transversely in any direction of the motion.
In order therefore to trace, cut, or grind a plane surface, I mount
two or more of the systems of jointed rods with the spherical or gimbal
joints above referred to and connect their rectilineally guided angles by

page_text: a bar, table, or frame, on which I fix the tool or the work to be operated
on by a fixed tool, and by moving the whole system about its pivots I
am enabled to effect upon the work a plane cut, trace, or grind, straight
in every direction.