IMPROVEMENTS IN APPARATUS FOR GUIDING PISTON RODS AND OTHER PARTS OF MACHINERY WHICHS TON PARTS OF MRY WHICH MOVE IN A STRAIGHT LINE SO AS TO PRESERVE THEIR PARALLELISM, COMMONLY CATTED A SPADATTEL MOTION
Year: 1874

page_text: LETTERS PATENT to William Hayden, the younger, of the City of
Chichester, Solicitor's Clerk, for the Invention of "IMPROVEMENTS IN
APPARATUS FOR GUIDING PISTON RODS AND OTHER PARTS OF MACHINERY WHICH
LETTERS PATENT to William Hayden, the younger, of the City of
Chichester, Solicitor's Clerk, for the Invention of "IMPROVEMENTS IN
APPARATUS FOR GUIDING PISTON RODS AND OTHER PARTS OF MACHINERY WHICH
MOVE IN A STRAIGHT LINE SO AS TO PRESERVE THEIR PARALLELISM, COMMONLY
CATTED A SPADATTEL MOTION" "
PROVISIONAL SPECIFICATION left by the said William Hayden at
the Office of the Commissioners of Patents, with his Petition, on
the 28th April 1874.
I, WILLIAM HAYDEN, the younger, of the City of Chichester,
Solicitor's Clerk, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN APPARATUS FOR GUIDING PISTON RODS AND OTHER PARTS OF
MACHINERY WHICH MOVE IN A STRAIGHT LINE SO AS TO PRESERVE. THEIR
PARALLELISM, COMMONLY CALLED A PARALLEL MOTION,' "to be as follows:-
$
This Invention has for its object the application and use of a simple
and effective parallel motion.

page_text: This parallel motion is constructed in the following manner:-At two
points in a line with the centre of the rod to which the parallel motion
is to be applied and on cach side of the said rod I fix centres, and on
these fixed centres I mount two arms capable of moving on them as
radii. These arms I call the first mentioned radial arms. At another
point at a distance and in the plane of these fixed centres, which plane
must be at right angles to the line of motion of the rod to which the
parallel motion is applied, I fix another centre. The distance at which
this last mentioned fixed centre must be placed from the centre of the
rod to which the parallel motion is applied is to the length of each of
the arms mounted on the first mentioned fixed centres as 5 is to 2. On
this last mentioned fixed centre I mount one end of an arm capable of
moving on it as a radius. This arm I call the secondly mentioned radial
arm, the length of which said secondly mentioned radial arm is to each
of the first mentioned radial arms as 3 to 2. At the other end of this
secondly mentioned radial arm I form a moving joint, and connect such
moving joint with the free or moving ends of the first mentioned radial
arms by an angular connecting arm, the junction of which with the free
or moving ends of the first mentioned radial arms being by a moving
joint at the elbow or angle of the angular arm, the length from which
moving joint at the elbow or angle to the first mentioned moving joint,
that is to say, the moving joint of the secondly mentioned radial arm,
being equal to the length of each of the first mentioned radial arms.
The remaining end of the angular arm is to be jointed to the centre of
the rod to which the parallel motion is applied.
:
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said William Hayden in the Great Seal Patent Office
on the 27th October 1874.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
HAYDEN, the younger, of the City of Chichester, Solicitor's Clerk, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-eighth day of April, in the year
of our Lord One thousand eight hundred and seventy-four, in the thirty-
seventh year of Her reign, did, for Herself, Her heirs and successors,

page_text: give and grant unto me, the said William Hayden, the younger, Her
special licence that I, the said William Hayden, the younger, my
executors, administrators, and assigns, or such others as I, the said
William Hayden, the younger, 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, excrcise, and vend, within the United King-
dom of Great Britain and Ireland, the Channel Islands, and Isle of
Man, an Invention for "IMPROVEMENTS IN APPARATUS FOR GUIDING PISTON
RODS AND OTHER PARTS OF MACHINERY WHICH MOVE IN A STRAIGHT LINE SO AS TO
PRESERVE THEIR PARALLELISM, COMMONLY CALLED A‘'PARALLEL MOTION,"
upon the
condition (amongst others) that I, the said William Hayden, the younger,
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 next and imme-
diately after the date of the said Letters Patent.
399
NOW KNOW YE, that I, the said William Hayden, the younger, do
hereby declare the nature of my 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
Drawings hereunto annexed and the letters and figures marked thereon
(that is to say) :-
This Invention has for its object the application to the piston rods of
steam engines and other parts of machinery which are required to move
in a straight line of a simple and effective parallel motion.
And in order that my said Invention and the mode of carrying it into
cffect may be most clearly understood I will first by the aid of the
accompanying Drawings describe an application of my said improved
parallel motion to the piston rod of a steam engine, and afterwards give
the formula and a diagram by which the proportions of the several parts
of the apparatus may be readily calculated.
Figure I. represents a method of applying my improved parallel
motion to the piston rod of a steam engine, and Figure 2 the diagram
illustrative of the formula by which the proportions of the several parts
of the apparatus may be readily calculated, the letters of reference in

page_text: the diagram (Figure 2) corresponding so far as they are applicable with the
letters of reference marked on the several parts represented in Figure I.
Figure I. At two points A, A, in a line with the centre line of motion
of the piston rod Z to which the parallel motion is to be applied, and on
each side of the said rod I fix the centres A, A, and on these fixed centres
mount two arms C, C, capable of moving on the said fixed centres A, A,
as radii. These arms C, C, which I call the first mentioned radial arms,
are united by a bar Y screwed to them to keep their motion uniform.
At another point B at a distance and in the plane of the fixed centres
A, A, (which plane must be at right angles to the line of motion of the
piston rod Z) I fix another fixed centre B. The distance at which this
last mentioned fixed centre B must be placed from a point in the centre
of the piston rod (such point being where a line joining the fixed centres
A, A, cuts the centre of the piston rod) is to the length of each of the
radial arms C, C, as 5 is to 2. On this last mentioned fixed centre B I
mount an arm C' capable of moving on it as a radius. This arm C' I
call the secondly mentioned radial arm, the length of which said secondly
mentioned radial arm C' is to each of the first mentioned radial arms C, C,
as 3 is to 2. At the other end of the secondly mentioned radial arm C¹ I
form a moving joint D, and connect such moving joint D with the free
or moving ends of the first mentioned radial arms C, C, and also with
the head of the piston rod by an angular connecting arm F', F, the
junction of which angular connecting arm F, F, with the free
or moving ends of the first mentioned radial arms C, C, is by a
moving joint F at the elbow or angle of the angular arm, and the
junction of which angular connecting arm F', F', with the head of the
piston rod is by the moving joint G. The distance at which the moving
joint Fat the elbow or angle of the angular connecting arm F, FI, is
from the moving joint D must be equal to the distance at which the said
moving joint F is from the fixed centres A, A.
The position of the moving joint G', which connects the angular con-
necting arm F, F, with the head of the piston rod, is determined in the
following manner :-The first mentioned radial arms C, C, are to be
placed in such a position as that the fixed centres A, A, and the moving
joints F and D shall be in a right line, which right line is represented
by the line A, F, D, in Figure 2, and to which right line the secondly
mentioned radial arm C shall be at right angles, as represented by the
line D, B, in Figure 2, where A, D, B, is the right angle. A line (D, E,

page_text: Figure 2) is then to be considered as so drawn from the moving joint D
to a point in the centre line of motion of the piston rod, as that the said
line to be so drawn shall be at right angles with the said centre line of
motion (D, E, A, Figure 2, being such right angle), or in other words so
that the line D, E, shall be parallel to the line A, B, Figure 2. It will
be found that the line so drawn will intersect the centre line of motion
of the piston rod, as that the distance from the centre of the moving
joint F to the point E is equal to the distance from the centre of the
said moving joint F to the point where a line joining the centres of the
fixed centres A, A, cuts the centre line of motion of the piston rod
(denoted by the letter A in Figure 2); and further, the point F
(Figure 2) is equidistant from the points A, E, and D, that is to say that
the line A, F, (Figure 2) is equal to the line F, D, and to the line F, E.
The centre of the moving joint F is then to be brought into the plane,
passing through the centre of the said fixed centres A, A, and B denoted
by the letter X on Figure 2), where D', X, E', represents the then
position of the triangle D, F, E. It is found by calculation that there
is an angle A, X, E¹ (Figure 2), and therefore the point E is on that
side of A, E, towards X, that is to say, there is a distance between the
point E and the centre line of inotion of the piston rod, and referring
to Figure 2 A, E, is the centre line of motion of the piston rod. A line
(E, G, Figure 2) being supposed to be drawn from the point E' at
right angles to the line E', D', the point where such line (E', G,) cuts
the centre line of motion of the piston rod (being the point Grin
Figure 2) is the centre of the joint of the angular arm by which it is to-
be connected with the head of the piston rod; and the motion of G³ to
G", supposing E¹ to have moved back to E, will be on the line A, E,
produced.
Referring to Figure 2 the proof of the foregoing will appear as
follows: If the line G, Gr, be produced to cut A, X, in G, G¹, A, G','
is a right angled triangle, of which G, G, is the hypotenuse. Now
when E becomes E, G¹, G, coincides with E, A, by construction, and.
the triangle G', A, G vanishes.
Although I have thus described my parallel motion as applied to the
piston rod of a steam engine it is evident that it may be readily applied
to any other portion of machinery which it is desired to cause to move
in a straight line.

page_text: I will now give the formula for calculating the lengths of the various
parts of the above described parallel motion, and for this purpose will
again refer to the diagram, Figure 2.
Let each of the first mentioned radial arms C, C, (A, F, or A, X, in
Figure 2) equal unity, then the length of the secondly mentioned radial
arm C (B, D, equal to B, X, in Figure 2) will be equal to 1-5. The
length of the parallel motion (G¹ to G", Figure 2) is rather more than
1125. The distance between the points E', G', (Figure 2) is approxi-
matively equal to 0024458. The length of the line joining E and D
(Figure 2) will be 1.6. The distance A, E, in Figure 2 will be 1.2.
☐
]

page_text: Having thus described the nature of my Invention, together with the
manner in which the same may be performed or carried into effect, I
declare that what I claim and desire to have secured to me by the herein-
before in part recited Letters Patent is, the parallel motion herein-before
described and illustrated in the Drawings hereto annexed.
In witness whereof, I, the said, William Hayden, the younger, have
hereunto set my hand and seal, this Twenty-fourth day of October,
in the year of our Lord One thousand eight hundred and seventy-
four.
Signed, sealed, and delivered
in the presence of
G. ASHLEY TYACKE,
Westgate,
Chichester,
Gentleman.
W. HAYDEN. (L.S.)