Year: 1885

page_text: I, CHARLES DENTON ABEL, of No 28 Southampton Buildings, Chancery Lane in
the County of Middlesex, Consulting Engineer and Patent Agent, do hereby
declare the nature of this invention and in what manner the same is to be
performed to be particularly described and ascertained in and by the following
statement:
This invention relates to an improved construction of steam hammers whereby
these are rendered applicable to all descriptions of forging operations.
The improvements will be readily understood on reference to the accompanying
drawings in which Fig. 1 shews a vertical section, Fig. 2 a side view and Fig. 3 a
horizontal section of part of the valve gear.
The slide valve rod d is made of increased diameter at ƒ thus forming a piston or
plunger upon which the steam in the slide valve box acts, thus tending to move
the slide valve and its rod downwards. The slide valve can be held in a certain
position by means of a pawl g which gears with a catch or shoulder n fitted into
the plunger f; the spring m acting upon the end of the double ended lever
presses the pawl against the shoulder. This lateral pressure against the slide valve
rod is counteracted by a counter-pressure roller p. The pawl is moved out of gear
by pressing down the treadle o which is connected to the lower end of the lever
by means of a system of links and levers. Motion is imparted to the slide valve
rod in the known manner through the elbow lever a a¹ mounted eccentrically,
which is actuated either from the piston rod or from the hammer block.
The long
end a of the lever slides in a pivotted socket b on the hammer block, while the
shorter end, a¹, takes into a slot c in the slide valve rod. When the pawl g has
been moved out of gear with the slide valve rod, by the depression of the treadle,
the steam, in pressing on the plunger f, forces the slide valve downwards so that
the slide valve rod comes in contact by means of its slot c with the end a¹ of the
lever. The steam hammer then works automatically.
If the steam hammer is to work for a length of time in this manner, the treadle
is secured in its depressed position by means of a catch q. If, on the other hand,
the treadle be left free, the spring m will cause the pawl to gear with the shoulder n
D

page_text: and the slide valve e will thereby be held stationary in the corresponding position.
This position is such, that only so much steam can pass in through the lower steam
port as is requisite to raise the piston of the steam hammer. The piston hammer
block is thus raised into the highest position in which it remains, until, by the
depression of the treadle, the pawl g is again moved out of gear so as to release the
slide valve. Thus by alternate depression and letting free of the treadle, it is
possible to cause the hammer to make either single strokes or a series of strokes,
and also to maintain the hammer block in its raised position during any desired
interval of time. When worked in this manner, the steam hammer is particularly
suitable for forging in dies. The strength of the blows of steam hammers depends
upon the quantity of steam admitted above the piston, and, consequently, upon the
extent of opening of the upper steam port. Instead of regulating this quantity of
steam by adjusting the position of the admission slide each time by means of the
hand lever y, the stroke of the distributing slide e is increased or decreased at will
by means of a wedge s upon which the lower end of the slide valve rod bears.
The wedge 8 is connected to a rod t sliding in guides and is moved by means of the
lever v fixed upon the axis u. The farther the wedge is pushed forward, and
consequently, the higher its upper surface is raised, the smaller will be the motion
of the slide valve e, the smaller will also be the admission of steam to the upper
side of the piston. The wedge can also be so placed that the upper port is not
opened at all and consequently, no steam admitted above the piston.
The reverse motion of the wedge does not affect the slide valve motion required
for the rapid action of the hammer. In order to diminish the quantity of steam
admitted beneath the piston, at the same time that the admission is reduced above
the piston, the lower steam port is provided with a plunger w which is moved by
means of a lever on the axis u and is, consequently, pushed forward together with
the wedge 8 so as to reduce the area of the lower steam port and, consequently,
diminish the lower steam supply in the same proportion as the upper steam supply
is diminished by the raising of the wedge.
Having now particularly described and ascertained the nature of; my said
invention and in what manner the same is to be performed I declare that what
I claim is
1. In a steam hammer, the use of the pawl g held by the spring m in gear with
the shoulder n on the slide valve rod whereby the slide valve e is held in such a
position that only sufficient steam can enter beneath the piston as is requisite to
maintain the piston and hammer block in the raised position.
2. Constructing the slide valve rod with a plunger or piston f whereby the rod
is made to press downwards upon the lever a¹ so as to render the action automatic
so soon as the pawl is moved out of gear by means of the treadle.
3. Regulating the downward stroke of the slide valve by means of a wedge 8 so
as to increase or decrease the opening of the upper steam port as may be required.
4. The use, in combination with the regulating wedge s, of a plunger w whereby
the admission of steam below the piston is regulated simultaneously with the
regulation of the steam supply above the piston.
Dated this 1st day of December 1885