IMPROVEMENTS IN APPARATUS FOR GUIDING, TRACING, CUTTING, OR GRINDING TOOLS, OR WORK OPERATED ON BY SUCH Tools, and for eFFECTING PARALLEL MOTIONS.
Year: 1873

page_text: LETTERS PATENT to James Joseph Sylvester, of No. 60, Maddox
Street, Regent Street, in the County of Middlesex, for the In-
vention of "IMPROVEMENTS IN APPARATUS FOR GUIDING, TRACING, CUTTING,
OR GRINDING TOOLS, OR WORK OPERATED ON BY SUCH Tools, and for eFFECTING
PARALLEL MOTIONS.'
"
Sealed the 16th June 1874, and dated the 18th December 1873.
PROVISIONAL SPECIFICATION left by the said James Joseph Sylvester
at the Office of the Commissioners of Patents, with his Petition,
on the 18th December 1873.
I, JAMES JOSEPH SYLVESTER, of No. 60, Maddox Street, Régent
3Street, in the County of Middlesex, do hereby declare the nature of
the said Invention for "IMPROVEMENTS IN APPARATUS FOR GUIDING, TRACING,
CUTTING, OR GRINDING TOOLS, OR WORK OPERATED ON BY SUCH TOOLS, AND FOR
EFFECTING PARALLEL MOTIONS," to be as follows:
:
This Invention relates to apparatus for guiding either the tools
0 employed for tracing, cutting, grinding, and like operations or the work

page_text: on which such tools operate in straight or curved paths without the aid
of slides or guiding surfaces, and to modifications in such apparatus
whereby parallel motions can be effected. For this purpose I employ a
system of jointed rods arranged according to known mathematical prin-
ciples, whereby one or more points in the system are guided to move in
straight or circular paths. At the point or points so guided I fix the
tools or the work to be operated on, or I connect to such guided points
the parts desired to have parallel motions.
The system of rods is arranged in the following manner :-Four equal
rods are jointed together so as to form a four-sided figure of square or
diamond form, the angles of which can be freely varied. Two of the
joints of this figure at opposite angles thereof are connected by equal
radius rods, which for the purpose of distinction I will hereafter call
beams, to a pivot in a fixed position. Another joint of the four-sided
figure is connected by a rod, which I will call the radius, to another
pivot which may be termed the centre.
.
When the radius is of a length equal to the distance between the
centre and the pivot, on the system being moved about the centre and
pivot, it will be found that the fourth angle of the four-sided figure
moves in a straight path, but by making the length of the radius unequal.
to the distance between the pivot and the centre the said fourth angle of
the four-sided figure will move in a circular path having a radius and
direction of curvature dependent on the proportions of the parts of the
system. A tool secured in the fourth joint of the four-sided figure in
such a manner that its point coincides with the axis of that joint can
thus be guided to move in a straight or curved path so as to effect a
trace or cut of corresponding form on material exposed to its action.
By arranging on one plane two or more systems of jointed rods such
as I have above described, and connecting their guided joints by a bar,
table, or frame, tools fixed thereon can be guided in like manner, or work
fixed thereon can be guided, and in either case the work or the tools can
be moved in any known manner, as in a planing machine or lathe, or by
another system of jointed rods such as I have described, so that surfaces
can be cut, planed, ground, or polished, either plane or curved,
according to the nature of the movements thus imparted to the tools
and to the work respectively. Furthermore by connecting the beams

page_text: and the radius respectively to the pivot and centre and to the three
angles of the four-sided figure by joints of spherical or gimbal kind the
system can be moved not in one plane only but also in various planes
inclined thereto, and the fourth angle of the four-sided figure will in
that case always be found either in a plane or in a spherical surface,
according as the radius and centre are adjusted to guide it in a straight
line or in a circular arc. And two or more systems provided with the
spherical or gimbal jointing above referred to may have their guided
joints connected by a bar, table, or frame, on which tools, or work can be
fixed for the purpose of surfacing or being surfaced.
For convenience of adjustment the centre joint may be made to work
in a slotted hole in the radius and in the bed or framing of the apparatus,
with means of fixing it in any desired part of such slotted holes. When
it is fixed in the middle position, where the length of the radius is equal
to the distance between the centre and the pivot, the apparatus will be set
to guide in a straight or plane path. When it is fixed at either side of the
middle position so as to make the radius greater or less than the distance
between the pivot and the centre, the fourth joint of the four-sided
figure will be guided in a circular or spherical path, concave or convex,
towards the centre.
I have above described the system of rods as arranged for guiding only
one point in the desired straight or circular path. I will now describe
a modification whereby two or more points can be guided in straight
paths parallel to one another or in corresponding circular paths, the
apparatus so modified being applicable for parallel motions, as for the
piston rods and pump rods of a beam engine.
•
This I effect in the following manner:-At any points in the two
beams, or in their extensions in either direction, such points being equi-
distant from the pivot on which the beams work, I joint the ends of two
equal rods, jointing together the other ends of those rods which are made
of such length that when so jointed they are parallel to the sides of the
four-sided figure. On the system being moved about the centre and
pivot the joint connecting those two rods is guided in a path corre-
sponding to that of the fourth joint of the four-sided figure. When the
system is adjusted for guiding the latter joint in a straight path the joint
of the two rods is likewise guided in a straight path parallel thereto.

page_text: In the apparatus described above, the guided joint of the four-sided
figure, the opposite joint of the same and the joints of any and all such
equal rods as are jointed to the beams in the manner last set forth, will
always be found in one straight line with the pivot on which the beams
work, consequently for the purpose of relieving the joints and steadying
the apparatus these joints may be made to work in slotted holes in a
beam or guide radius mounted on the pivot of the other two beams.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said James Joseph Sylvester in the Great Seal Patent
Office on the 16th June 1874.
'
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
JOSEPH SYLVESTER, of No. 60, Maddox Street, Regent Street, in the
County of Middlesex, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Eighteenth day of December, in the
year of our Lord One thousand eight hundred and seventy-three, in the
thirty-seventh year of Her reign, did, for Herself, Her heirs and
successors, give and grant unto me, the said James Joseph Sylvester,
Her special license that I, the said James Joseph Sylvester, my exe-
cutors, administrators, and assigns, or such others as I, the said James
Joseph Sylvester, 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 "IMPROVEMENTS IN APPARATUS FOR GUIDING, TRACING,
CUTTING, OR GRINDING TOOLS, OR WORK OPERATED ON BY SUCH TOOLS, AND FOR
EFFECTING PARALLEL MOTIONS," upon the condition (amongst others) that
I, the said James Joseph Sylvester, 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

page_text: calendar months next and immediately after the date of the said Letters
Patent.
NOW KNOW YE, that I, the said James Joseph Sylvester, do hereby
declare the nature of the said Invention, and in what manner the
same is to be performed, to be particularly described and ascertained
in and by the following statement thereof, reference being had to the
accompanying Sheet of Drawings, and to the figures and letters marked
thereon, that is to say :—
This Invention relates to apparatus for guiding the tools employed for
tracing, cutting, grinding, and like operations, or the work on which such
tools operate in straight or curved paths without the aid of slides or
guiding surfaces, and to modifications in such apparatus whereby
parallel motions can be effected. For this purpose I employ a system
of jointed rods arranged according to known mathematical principles,
whereby one or more points in the system are guided to move in straight
or circular paths. At the point or points so guided I fix the tools or the
work to be operated on, or I connect to such guided points the parts.
desired to have parallel motions.
The system of rods is arranged in the following manner :-Four equal
rods are jointed together so as to form a four-sided figure of square or
diamond form, the angles of which can be freely varied. Two of the
joints of this figure at opposite angles thereof are connected by equal
radius rods, which for the purpose of distinction I will hereafter
calls beams, to a pivot in a fixed position, which may be called the
fulcrum. Another joint of the four-sided figure is connected by a rod,
which I will call the radius, to another pivot which may be termed the
centre.
When the radius is of a length equal to the distance between the
centre and the fulcrum, on the system being moved about the centre and
fulcrum it will be found that the fourth angle of the four-sided figure
moves in a straight path, but by making the length of the radius unequal
to the distance between the fulcrum and the centre the said fourth angle
of the four-sided figure will move in a circular path having a radius and
direction of curvature dependent on the proportions of the parts of the
system. A tool secured in the fourth joint of the four-sided figure in
such a manner that its point coincides with the axis of that joint can

page_text: thus be guided to move in a straight or curved path so as to effect a
trace or cut of corresponding form on material exposed to its action.
By arranging on one plane two or more systems of jointed rods such as
I have above described, and connecting their guided joints by a bar, table,
or frame, tools fixed thereon can be guided in like manner, or worked
fixed thereon can be guided, and in either case the work or the tools can
be moved in any known manner, as in a planing machine or lathe, or by
another system of jointed rods such as I have described, so that surfaces
can be cut, planed, ground, or polished, either plane or curved, according
to the nature of the movements thus imparted to the tools and to the
work respectively. Furthermore by connecting the beams and the radius
respectively to the fulcrum and centre and to the angle of the four-
sided figure by joints of spherical or gimbal kind the system can be
moved not in one plane only but also in various planes inclined thereto,
and the fourth angle of the four-sided figure will in that case always be
found either in a plane or in a spherical surface, according as the radius
and centre are adjusted to guide it in a straight line or in a circular arc.
And two or more systems provided with the spherical or gimbal jointing
above referred to may have their guided joints connected by a bar, table,
or frame on which tools or work can be fixed for the purpose of surfacing
or being surfaced.
For convenience of adjustment the centre joint may be made to work
in slotted holes in the radius and in the bed or framing of the apparatus,
with means of fixing it in any desired part of such slotted holes. When
it is fixed in the middle position where the length of the radius is equal
to the distance between the centre, and the fulcrum of the apparatus is
set to guide in a straight or plane path; when it is fixed at either side
of the middle position so as to make the radius greater or less than the
distance between the fulcrum and the centre, the fourth joint of the
four-sided figure will be guided in a circular or spherical path concave or
convex towards the centre.
I have above described the system of rods as arranged for guiding only
one point in the desired straight or circular path. I will now describe a
modification whereby two or more points can be guided in straight paths
parallel to one another, or in corresponding circular paths, the apparatus
so modified being applicable for parallel motions as for the piston rods
and pump rods of a beam engine.

page_text: This I effect in the following manner :-At any points in the two
beams or in their extensions in either direction, such points being equi-
distant from the fulcrum on which the beams work, I joint the ends of
two equal rods, jointing together the other ends of those rods, which are
made of such length that when jointed they are parallel respectively to
the sides of the four-sided figure. On the system being moved about
the centre and fulcrum the joint connecting those two rods is guided in
a path corresponding to that of the fourth joint of the four-sided figure.
When the system is adjusted for guiding the latter joint in a straight
path the joint of the two rods is likewise guided in a straight path
parallel thereto.
In the apparatus described above, the guided joint of the four-sided
figure, the opposite joint of the same, and the joints of any and all such
equal rods as are jointed to the beams in the manner last set forth will
always be found in one straight line with the fulcrum on which the
beams work, consequently for the purpose of relieving the joints and
steadying the apparatus these points may be made to work in slotted
holes in a beam or guide radius mounted on the fulcrum of the other
two beama

page_text: and fulcrum F are placed within the diamond, the point A being in this
case also guided to travel in a straight path.
Fig. 3 represents a plan of the system of rods shewn in Fig. 1 with
the centre C made adjustable by fitting the pin on which the radius
works in a slot formed in the radius itself and in the bed or frame on t
which the system is mounted. When the pin C is shifted towards c¹
farther from F, the radius being thus shortened, the point A is guided in
a path A, a', which is a portion of a circle of large radius convex
towards C. When on the other hand the pin C is shifted towards c²,
increasing the radius, the point A is guided in a circular are A, a², 1
concave towards C. The dotted lines on the lower part of the figure
shew a position of the system when the centre is at c¹%; those in the
upper part of the figure shew a position of the system when the centre
is at c. When the centre is thus made adjustable the system is rendered
easily applicable for tracing or forming a circular are of large radius by 1
the action of a tool fixed in the centre of the joint A.
Fig. 4 represents two systems of rods, such as are shewn in Fig. 1 with
the guided joints A connected by a rod, plate, or bar P. As both the
extremities of this bar are guided in straight paths, or when the centres c
are made adjustable in circular paths, every part of the bar P in the
line of the joints A, A, is similarly guided. Tools may therefore be
fixed in any desired part of the bar P, or a piece of material to be acted
on by a fixed tool may be fixed on P, and when the system is moved
about its pivots the tool will trace or cut, or the material will have
traced or cut on it straight lines or circular arcs as determined by the
position of the centres C.
Fig. 5 represents a system of jointed rods like that shewn in Fig. 1,
but with gimbal joints at the points F, C, and E, which permit the
system to be moved not only in the one plane but also in planes inclined
thereto. In this case the centre of the joint A is guided to travel in
any direction in a plane perpendicular to the centre line or axis F, C, A.
If the centre C be shifted towards or away from the fulcrum F, the
radius C, E, being lengthened or shortened to a corresponding extent, the
joint A will be guided to travel over a spherical surface concave or
convex towards F.

page_text: It is obvious that two or more systems of rods having their gimbal
joints such as are described above might have their guided joints con-
nected, as shewn in Fig. 4, by a bar, plate, or frame P, and that work
or tools fixed thereon would be guided in a plane or in a spherical
surface according to the adjustment of the centre C and radius C, E.
Fig. 6 represents a system of the jointed rods modified so as to effect
the guiding of more than one point in a straight path. In this case the
beams F, B, and F, D, are extended beyond B and D, and at points G, H,
equidistant from the fulcrum F have a pair of rods G, K, and H, K, jointed
to them and to each other at K, these rods being of such length as to be
parallel to B, A, and D, A, respectively. The joint K will then be guided
like A in a straight path. Moreover, the points F, E, A, and K being
always in a straight line passing through the fulcrum F. a beam F, K,
may be mounted on F as a pivot having slotted holes to permit of the
to-and-fro movement of the pins of E, A, and K. In this manner the
system of rods may be applied as a parallel motion to the beam of a
steam or other engine, for example, the piston rod may be connected to
the joint K and the air-pump rod to A. And in like manner other
points may be guided by jointing to the beams F, B, F, D, at any points
) of their length equidistant from F on either side of F equal rods such as
G, K, and H, K, parallel respectively to sides of the diamond A, B, E, D.
Having thus described the nature of my Invention, and in what
manner the same is to be performed, I hereby declare that I make no
general claim to any use of a system of rods jointed in the manner
above described except as set forth in the following claims, that is to say,
I claim,―
First. The use of rods jointed in the manner described in reference
This 1 and
11

page_text: Fig. 4 for the purpose of guiding tools or work to be operated on by
them.
Fourth. The gimbal jointing as shewn in Fig. 5 for the purpose of
guiding the joint A. over a plane or spherical surface.
Fifth. The addition as shewn in Fig. 6 of jointed rods to the beams
for the purpose of guiding additional points in straight or circular paths
in combination with a slotted beam.
In witness whereof, I, the said James Joseph Sylvester, have
hereunto set my
hand and seal, this Fifteenth day of June, in
the year of our Lord One thousand eight hundred and seventy-
four.