IMPROVEMENTS IN STEAM HAMMERS
Year: 1859

page_text: LETTERS PATENT to Thomas Robinson, of St. Helens, Lancashire, Iron-
founder, for the Invention of "IMPROVEMENTS IN STEAM HAMMERS."
Sealed the 2nd March 1860, and dated the 24th September 1859.
PROVISIONAL SPECIFICATION left by the said Thomas Robinson at
the Office of the Commissioners of Patents, with his Petition, on the
24th September 1859.
I, THOMAS ROBINSON, of St. Helens, Lancashire, Ironfounder, do hereby
declare the nature of the Invention for "IMPROVEMENTS IN STEAM HAMMERS,"
to be as follows:-
This Invention has for its object improvements in steam hammers.
Heretofore steam hammers have commonly been made what is called
single acting, that is to say, when the hammer has been lifted by the pressure
of steam admitted under the piston it is allowed to fall again by its own
weight. They are also made what is called double-acting, that is to say,
when the hammer has been lifted by the pressure of steam admitted under
the piston, it is forced down again also by the pressure of steam admitted over
the piston and acting in conjunction with the weight of the hammer. This
arrangement, however, requires complicated gearing, and is in other respects
objectionable.
Now this Invention consists in applying the pressure of steam or com-

page_text: pressed air or other fluid constantly to the upper surface of the piston, so as
at all times to tend to force the hammer downwards, and the hammer is then
lifted either by employing steam of higher pressure under the piston, or by
allowing steam of the same pressure to act on a larger area of piston surface.
This arrangement allows of gearing being employed as simple in construction
as that used in single-action hammers, and it also allows of the hammers
being readily rendered single-acting by cutting off the steam or compressed
air or other fluid from the top of the piston.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Thomas Robinson in the Great Seal Patent Office on the
24th March 1860.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
ROBINSON, of St. Helens, Lancashire, Ironfounder, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-fourth day of September, in the year of our
Lord One thousand eight hundred and fifty-nine, in the twenty-third year
of Her reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said Thomas Robinson, Her special licence that I, the said Thomas
Robinson, my executors, administrators, and assigns, or such others as I,
the said Thomas Robinson, 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 Thomas Robinson, 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
immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Thomas Robinson, 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, that is to say:-
This Invention has for its object improvements in steam hammers.

page_text: Heretofore, steam hammers have commonly been made what is called
single-acting, that is to say, when the hammer has been lifted by the pressure
of steam admitted under the piston, it is allowed to fall again by its own
weight. They are also made what is called double-acting, that is to say,
when the hammer has been lifted by the pressure of steam admitted under
the piston, it is forced down again also by the pressure of steam admitted over
the piston and acting in conjunction with the weight of the hammer. This
arrangement, however, requires complicated gearing, and is in other respects
objectionable.
Now, this Invention consists in applying the pressure of steam or com-
pressed air or other fluid constantly to the upper surface of the piston, so as
at all times to tend to force the hammer downwards, and the hammer is then
lifted either by employing steam of higher pressure under the piston, or by
allowing steam of the same pressure to act on a larger area of piston surface.
This arrangement allows of gearing being employed as simple in construction
as that used in single-action hammers, and it also allows of the hammers being
readily rendered single acting by cutting off the steam or compressed air or
other fluid from the top of the piston.
Having thus stated the nature of my Invention, I will proceed more fully
to describe the manner of performing the same.
DESCRIPTION OF THE DRAWING.
Figure 1 is a side elevation, partly in section, of a steam hammer con-
structed and combined according to my Invention. Figure 2 shews a front
view thereof; and Figure 3 a plan. In each Figure, the same letters of
reference are used to indicate the same parts.
A, A, is the framing, the nature of which is clearly shewn in the Drawing;
B is an outer vessel or cylinder, within which the steam cylinder C is fixed.
The cylinder or vessel B receives a constant supply of steam from the steam
boiler, and there is a free communication from the vessel or cylinder B for
the steam to pass into the cylinder C above the piston therein. D is a safety
valve on the upper part of the cylinder or vessel B, which, as before stated, is
constantly supplied with steam; E is the steam valve box; F is the steam
pipe; G is the steam valve, the lower part of which is fitted with elastic
metal rings, and is larger in diameter than the stalk or upper part which
works through a stuffing box, by which stuffing box the steam is prevented
escaping into the outer atmosphere. The extra size or diameter is to allow
of the steam when such enlarged part is pressed down beyond the passage &
to flow in under the piston so as to lift it and the hammer, the steam being

page_text: at a greater pressure than what it is within the external cylinder or vessel B;
this it is evident may be accomplished either by using separate boilers or by
allowing the steam admitted from the one boiler into the vessel B to expand
to the extent of difference of pressure desired. H is the exhaust pipe, com-
municating with the steam cylinder C below the piston; I is the lever for
working the valve G, which is connected with hand lever M, as is shewn
in the Drawing; K is the reducing valve for admitting steam into the outer
vessel or cylinder B, when only one steam boiler is used. When the lever M
is not pressed down, the steam from the boiler depresses the valve G and
raises the piston in the steam cylinder C. The cranked lever N is by the
rod P connected with the steam valve. O is the tup which carries the hammer,
and is guided as is shewn between the uprights of the framing; Q is an
inclined plate, which is attached by several bolts to the tup. All the upper
holes through this plate are slotted, as shewn, and a spring R constantly
presses it forward; as the tup rises the incline on the plate acts on the roller
at the cranked end of the lever N, and closes the steam valve, and thus
prevents the tup rising too high. I would remark, that in place of using
higher pressure steam on the under side of the piston, it will be evident that
arrangements may be made for the steam acting on a lesser area or surface on
upper side of the piston than on the under side thereof. I would state,
that although I have only described steam as being used, other elastic fluid
may be employed in place thereof, but steam is preferred.
the
Having thus described the nature of my Invention and the manner of
performing the same, I would have it understood that I make no claim to
any of the mechanical parts separately, nor do I confine myself to the details
shewn and described; but what I claim is, the combination or arrangement of
the parts of a hammer worked by steam or other elastic fluid, in such manner
that the steam or elastic fluid may constantly press on the upper surface of
the piston.
In witness whereof, I, the said Thomas Robinson, have hereunto set
my hand and seal, this Twenty-first day of March, in the year of our
Lord One thousand eight hundred and sixty.