IMPROVEMENTS IN STEAM HAMMERS
Year: 1861

page_text: LETTERS PATENT to William Hobson, of Ellesmere Road, Sheffield, in
the County of York, Engineer, for the Invention of "IMPROVEMENTS IN
STEAM HAMMERS."
Sealed the 17th December 1861, and dated the 21st June 1861.
PROVISIONAL SPECIFICATION left by the said William Hobson at the
Office of the Commissioners of Patents, with his Petition, on the 21st
June 1861.
I, WILLIAM HOBSON, of Ellesmere Road, Sheffield, in the County of York,
5 Engineer, do hereby declare the nature of the said Invention for "IMPROVE-
MENTS IN STEAM HAMMERS," to be as follows:-
This Invention contemplates the substitution of a simple self-acting motion
and peculiar cylindrical valve for the complicated gearing generally in use..
To the guide handle is attached a slotted or morticed tabbett, which moves
upon an elbow tabbett connected with the rod which actuates the steam valve;
the trip or hammer in moving strikes against the elbow tabbett, & therefore
influences the sliding tabbett, rendering the combination self-acting. The
valve is cylindrical, and acts vertically, it is formed with flanges so as to admit
of a concentric space for steam. When the valve is raised so that the top
5 flange passes above the steam port or orifice in the top of the cylinder, this
port becomes the inlet, and depresses the piston and hammer; the length of
the valve is so regulated that the lower steam port is then below the lower
flange, and becomes an exhaust port, the steam passing off through the centre

page_text: of the valve to the exhaust pipe at the top; when, on the contrary, the valve
is depressed, the lower flange passes below the port in the bottom of the
cylinder, which then becomes the inlet, the exhaust steam passing off by the
top port to the outlet.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Hobson in the Great Seal Patent Office on the
21st December 1861.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
HOBSON, of Ellesmere Road, Sheffield, in the County of York, Engineer, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-first day of June, One thousand eight
hundred and sixty-one, in the twenty-fifth year of Her reign, did, for Her-
self, Her heirs and successors, give and grant unto me, the said William
Hobson, Her special license that I, the said William Hobson, my executors,
administrators, and assigns, or such others as I, the said William Hobson,
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 STEAM HAMMERS,"
upon the condition (amongst others) that I, the said William Hobson, 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.
NOW KNOW YE, that I, the said William Hobson, do hereby declare the
nature of my said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement, reference being had to the accompanying Drawings, and to the
letters and figures marked thereon, that is to say:-
This Invention contemplates the substitution of a simple self-acting motion,
and peculiar cylindrical valve for the complicated gearing generally in use.
To the guide handle is attached a slotted or morticed tabbett, which moves
upon an elbow tabbett connected with the rod which actuates the steam valve;

page_text: the trip or hammer in moving strikes against the elbow tabbett, and therefore
influences the sliding tabbett, rendering the combination self-acting. The
valve is cylindrical, and acts vertically, it is formed with flanges so as to admit
of a concentric space for steam. When the valve is raised so that the top
flange passes over the steam port or orifice in the top of the cylinder, this port
becomes the inlet, and depresses the piston and hammer; the length of the
valve is so regulated, that the lower steam port is then below the lower flange,
and becomes an exhaust port, the steam passing off through the centre of the
valve to the exhaust pipe at the top. When on the contrary, the valve is
depressed, the lower flange passes below the port in the bottom of the cylinder
which then becomes the inlet, the exhaust steam passing off by the top port
to the outlet.
In order that my said Invention may be fully understood, I will now
proceed to describe the accompanying Drawings, which exhibit the arrange-
ment contemplated; the same letters of reference indicate corresponding parts
throughout all the figures.
Figure 1 represents an elevation of a steam hammer constructed with my
improvements; Figure 2 is a sectional elevation of the same; Figure 3 is a
horizontal section taken through the cylinder and. valve on the line A, B,
Figure 2; Figure 4 is a horizontal section taken through the lower steam ports
on the line C, D, Figure 2; and Figure 5 is a view shewing the connection of
the shaft F (Figures 1 and 2), with the rod G, which actuates the working
valve.
The steam when turned on from the boiler into the pipe H, is admitted or
shut off from the steam chamber I by means of the hand lever K, which com-
municates by a rod with an ordinary stop or mushroom valve in L. When the
steam is admitted into the concentric steam chamber I, around the valve at m,
with the piston M depressed as shewn, the hand lever N is raised and the
slotted tabbett O, lowered upon the elbow tabbett P, this turns the shaft F
and lever L, which moves the rod G and valve R, so as to admit the steam
through the ports n, n, n, beneath the piston. The piston rod and hammer
being thus raised, the friction roller S is brought into contact with the elbow
tabbett P, and turns the shaft F so as to raise the rod G and valve R to such
an extent that the pressure of steam is adapted to the position of the hammer.
When the flange O is raised above the lower steam ports n, n, n, and the
flange P above the top steam ports q, q, q, the steam passes from the chamber I
to the top ports above the piston, and depresses the hammer, the waste steam
passing through the centre of the valve R into the exhaust pipe T. The fric-
tion roller G in falling forces the slotted tabbett to the lower part of the

page_text: tabbett P, and modulates the pressure of the steam. When the piston is again
raised the waste steam passes above the valve R to the exhaust pipe T.
Having now described and particularly ascertained the nature of my said
Invention, and the manner in which the same is or may be made and carried
into effect, I would observe, that I do not claim the various parts or elements
of the machinery herein-before described, but what I consider novel and
original, and therefore claim as the Invention to be secured to me by the
above in part recited Letters Patent, is,-
First, the construction and combination of the tabbets as herein-before
described.
Second, the peculiar construction and arrangement of valve herein set
forth and delineated..
In witness whereof, I, the said William Hobson, have hereunto set my
hand and seal, this Twentieth day of December, in the year of our
Lord One thousand eight hundred and sixty-one.
Witness,
T. F. CASHIN.
W. HOBSON. (L.S.)