Year: 1855

page_text: LONDON:
PRINTED BY GEORGE E. EYRE AND WILLIAM SPOTTISWOODE,
PRINTERS TO THE QUEEN'S MOST EXCELLENT MAJESTY:
PUBLISHED AT THE GREAT SEAL PATENT OFFICE,
25, SOUTHAMPTON BUILDINGS, HOLBORN.

page_text: LETTERS PATENT to John Ramsbottom, of Longsight, near the City
of Manchester, Engincer, for the Invention of "IMPROVEMENTS IN THE
CONSTRUCTION OF CERTAIN METALLIC PISTONS."
Sealed the 20th July 1855, and dated the 12th February 1855.
PROVISIONAL SPECIFICATION left by the said John Ramsbottom at
the Office of the Commissioners of Patents, with his Petition, on the
12th February 1855.
I, JOHN RAMSBOTTOM, of Longsight, near the City of Manchester, Engineer,
do hereby declare the nature of the said Invention for "IMPROVEMENTS IN THE
CONSTRUCTION OF CERTAIN METALLIC PISTONS" to be as follows:-
The nature of my Invention consists in an improved mode of constructing
the packing rings of the pistons, for which Letters Patent were granted to me
on the Sixteenth day of November, One thousand eight hundred and fifty-two.
In order to obtain the form of the packing ring of such pistons so as to produce
a uniform pressure against the cylinder, I bend a packing or other wire to a
circle of the size of the cylinder, the ends just touching each other. This wire
is then subjected to twelve or other convenient number of equal radial forces
(acting outwards from the centre), which in the aggregate amount to the
pressure required for making a steam-tight joint; these forces, being equally
applied upon equal portions of the circumference, expand the ring to the form
required, to which form or curve I bend or otherwise manufacture my improved
packing, rings for pistons. The mode above described for obtaining the form
of packing ring to press equally against the working surface of the cylinder is
sufficiently correct for practical purposes, but it may also be determined
mathematically so as to be theoretically correct.

page_text: In order to bend the wires to the above shape for use, I first bend (by the
ordinary bending rollers) the wires into a segment of a circle, equal in curvature
to that part of the ring which is least bent. This segment is then run half
way through the rolls, and the third roller, which determines the curvature, is
then brought in contact with the segment, and gradually pressed against it to
the degree required by a lever and cam actuated by the rollers; the wire is
then reversed, and the second half bent in the same manner. The wire may
be bent round a block of the required shape, but the mode above described
is preferred.
The improvements above described are also applicable in determining and
producing the form of spring ring which is sometimes used for the purpose of
forcing out the metallic packing of certain other descriptions of pistons.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John Ramsbottom in the Great Seal Patent Office on the
3rd August 1855.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
RAMSBOTTOM, of Longsight, near the City of Manchester, Engineer, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twelfth day of February, in the year of our
Lord One thousand eight hundred and fifty-five, in the eighteenth year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said John Ramsbottom, Her special license that I, the said John
Ramsbottom, my exccutors, administrators, and assigns, or such others as
I, the said John Ramsbottom, 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 THE CONSTRUCTION OF CERTAIN METALLIC PISTONS," upon
the condition (amongst others) that I, the said John Ramsbottom, by an
instrument in writing under my hand and seal, 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 immediately after
the date of the said Letters Patent.

page_text: NOW KNOW YE, that I, the said John Ramsbottom, do hereby declaro
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
Specification thereof, reference being had to the accompanying Drawings,
that is to say:-
My Invention consists in an improved mode of constructing the packing
rings of the pistons, for which Letters Patent were granted to me on tho
Sixteenth of November, One thousand eight hundred and fifty-two, and also
the springs used for forcing out the metallic packings of certain other pistons.
In order to obtain the form of such packing or spring rings so as to produce
a uniform pressure against the cylinder, I bend a packing or other wire
to a circle of the size of the cylinder in which the piston is to work, the
ends just touching each other. This wire is then subjected to fourteen or
other convenient number of radial forces, which in the aggregate amount
to the pressure required for making a steam-tight joint; these forces, being
equally applied upon equal portions of the circumference, expand the ring to
the form required.
Figure 1 of the said Drawings represents a plan of an apparatus suitable for
determining the form of packing rings in the manner above referred to.
a is the circular table, in which is a contre hole b; the circumference of the
table and of the hole are each furnished with fourteen grooved pulleys, marked
c and d; a greater or less number may, however, be employed. The dotted
circles e, e, represent a packing wire, which has been bent into a circle of the
size of the cylinder in which the piston is to work, and the dotted lines f, f,
represent cords attached at equal distances to the circumference of the said
ring. These cords pass over the pulleys c, and to the end of each is attached a
weight g. These weights draw the circular hoop e into the form required, as
represented by the lines h, to which form or curve I bend or otherwise manu-
facture my improved packing rings for pistons. In order to ascertain whether
the form or curve be correct, the cords f,f, may be attached to a packing wire
that has been bent to the form indicated by the lines h. These cords being
taken over the pulleys d, and the weights g then acting towards the centrec, will
draw the bent wire h into the form of the circular hoop e. As packing rings
require more outward force in proportion to the pressure of the steam for which
the pistons to which they are applied are used, it is evident that the weights g
must be increased or reduced, so that their aggregate weight may amount
to the pressure required for making a steam-tight joint. The mode above
described for obtaining the form is sufficiently correct for practical purposes,
but it may also be determined mathematically, so as to be theoretically correct.

page_text: may be
Figure 2 is a front view of a machine, by which the packing wires
bent to the form represented by the lines h, in Figure 1; Figure 3 is a side
view of the same. k is a standard, through which work the axes of the rollers
Zand m, and the shaft n. One end of this shaft is furnished with an excentric
o, on which is mounted the guide roller p. and to the other end is fixed the
disc g, to which is attached the lever r. The rollers and m are connected by
spur pinions l' and m', into the former of which gears the wheels, revolving
on a stud fixed on the standard k. To the wheels is fixed a cam or shaper
plate t, that acts when the wheel s revolves on the stud u, projecting from
the lever r.
The mode of operation is as follows:-The wire to be formed into packing
rings is first cut to the required length, and bent by the ordinary bending rollers
into a segment of a circle, equal in curvature to the part of the ring which is
least bent. This segment is then run half way through the rollers l, m, and p,
the latter of which, owing to the combined action of the shaper plate t, and
excentric o, being brought in contact with the wire segment, presses it into the
required shape, indicated by the lines h, in Fig. 1. The direction of the motion
of the rollers is then reversed, and the other half of the segment is bent in the
same manner. Instead of employing the above machine the wire may be bent
round a block of the required shape.
The improvements above described are also applicable in determining and
producing the form of spring ring which is sometimes used for the purpose of
forcing out the metallic packing of certain other descriptions of pistons.
Having thus described the nature of my Invention, and the manner of
performing the same, I declare that I claim as of my Invention, the mode
shewn and described of determining the shape of the packing and spring rings
of certain metallic pistons, and the machinery for bending the same into the
said shape.
In witness whereof, I, the said John Ramsbottom, have hereunto set my
hand and seal, this Thirty-first day of July, in the year of our Lord
One thousand eight hundred and fifty-five.
JOHN RAMSBOTTOM. (L.S.)
Witness to the signature,
H. B. BARLOW,
Manchester. 28 SE 55