IMPROVEMENTS IN THE CONSTRUCTION OF FORGE HAMMERS AND OTHER MACHINES OR APPARATUS, SO THAT AIR HEATED BY GAS MAY BE USED AS A MOTIVE POWER
Year: 1878

page_text: PROVISIONAL SPECIFICATION left by William Edward Gedge at the Office
of the Commissioners of Patents on the 15th April 1878. A communication
from abroad by Pierre Schrabb and Auguste Terrien, both of Paris, France.
WILLIAM EDWARD GEDGE, of No. 11, Wellington Street, Strand, in the County
of Middlesex, Patent Agent. "IMPROVEMENTS IN THE CONSTRUCTION OF FORGE
HAMMERS AND OTHER MACHINES OR APPARATUS, SO THAT AIR HEATED BY GAS
MAY BE USED AS A MOTIVE POWER." A communication from abroad by Pierre
Schrabb and Auguste Terrien, both of Paris, France.
The object of this Invention is to furnish machines or apparatuses and tools for
forging, welding, swaging, stamping, crushing, punching, perforating, and other
purposes, working without the aid of any driving engine or generator separate from
the machine itself.
The accompanying Sheet of Drawing represents a forge hammer with variable
lift and stroke, which may serve as a type of the kind of machiné claimed as of this
Invention,―
Figure 1 representing a section at a, b, Fig. 3.
Figure 2, a section of the cylinder and view of the stock of the anvil at c, d;
Figr. 3.
Figure 3, a sectional plan view at e, f, Fig. 1.
And Figure 4, a section at g, h, Fig. 2, showing the bottom of the cylinder.
a, cylinder bored and closed at the bottom by a cover b.
c, piston fitted in a; it may be rendered air tight by thick rings, segments, or
by any of the methods of packing used in steam or other machines. This piston
slides on the rod d between the washer and the collar or shoulder at the top of
this rod.
d, piston rod; the hammer is attached to it as in ordinary steam hammers.
e, slide valve for introduction of the explosive mixture.
f, slide valve for escape of gases remaining after each explosion.
g, small pipe leading gas to the interior burner h of the chamber h of the slide
valve e.

page_text: i, exterior gas burner, lighting the inner burner h; the two pipes are attached
to a three-way cock, introducing the gas; this cock may partially close so as to
allow less gas to pass into the machine while leaving the same flame to the burners
h and i.
The machine thus combined works as follows:-Assuming that the hammer is
about to fall again as the piston c can slide on its rod d at the moment that the
hammer touches the anvil, în consequence of the speed acquired, the piston continues
its descent, falls upon the tappets j; these compress the springs, which cause them
to enter the cylinder, and the piston descends until it comes on to the bottom of
the cylinder. At the same time the piston causes the escapement slide valve ƒ to
lower by striking against the tappet f¹ fixed to this slide valve; the opening fl
of this slide valve comes into connection with the clack valve f111, and vitiated air
escapes. At this moment the springs of the tappets j expand, and cause the piston
to rise again (the hammer not rising), a vacuum is formed between the bottom of
the cylinder and the piston; the. escape slide valve rises again, and the clack
valve prevents the air re-entering on this side.
If by means of a lever k worked by hand, or by the hammer itself, according to
circumstances, the slide valve is brought to the position shown, Fig. 2, the air
uplifts the clack valve e¹, the groove e! opens at the same time, and the mixture
of air and gas is drawn or sucked in in proportions determined by the regulation of
the orifices, and fills the space between the bottom of the cylinder and the piston.
Further, this mixture is slightly compressed by reason of the rebounding which the
springs of the tappets give to the piston at each stroke.
By lifting the lever k the burner i lights the inner burner h; the slide valve
continuing to rise the inner burner sets the. mixture contained in the cylinder on
fire. The piston is driven violently against the washer screwed at the top of the
piston rod; a sheet of water filling the hollow into which this washer d"enters
with a little play serves to deaden this shock; this water is scattered and driven
forcibly against the sides of the cylinder, and serves to cool it; a slight thread or
jet of water falling upon the piston compensates the water which passes between
the cylinder, the piston, and the rod. Directly the hammer is at the top the piston
descends again by its own weight, and comes upon the collar or shoulder of the
rod d; the vacuum is immediately formed beneath, the hammer released falls with
its entire weight, plus the effort of the atmospheric pressure on the piston. When.
the hammer has touched the anvil the piston continues to lower the tappets j, the
above-described action re-commences, and so on.
The volume of the mixture is always the same to give the same stroke; this
arrangement of sliding piston permits the hammer to come down a greater or lesser
distance, according to the progressive crushing and variable thickness of the piece
to be forged.
To vary the lift of the hammer the piston must be made to rise to a less height
at the moment of the feeding, which may be done by means of a plate 7 turning
outside of the bottom of the cylinder; this plate has ribs or flanges in inclined.
plane ; the ends of the tappets bearing by their springs upon the inclined planes,
accordingly as the plate is more or less turned, the inclined planes permit more or
less rise of the tappets, and consequently of the piston. This arrangement may be.
infinitely varied to produce the same effect. The movement operated by the lever k
rests upon a plate ¹, the centre of which is that of the rod m, which, rising and
lowering with the lever k, works the inlet slide valve e. The vertical movement of
k and consequently of m, is always the same; by turning the lever / horizontally.
the rod m turns with the entire arrangement. The lever m' and the connecting
rod m cause the plate to turn without effort, and thus limit the stroke or travel'
of the tappets j, and consequently the volume of the mixture.
The lever m¹ turns in a support m¹¹, and is carried along by a cottar fixed upon
m, so as to permit the rod m to slide vertically while carrying the lever m and
plate . A rod n bearing on a spring, and entering recesses n upon the plate h¹
permits the hand to feel the point corresponding to each lift of the hammer.

page_text: To keep the hammer raised a shaft o with notches o¹ is set in one of the columns
or uprights supporting the cylinder. A catch p permits the hammer to rise, but
directly it would descend this catch forms a prop, taking into the one of the notches
o' which corresponds to the lift of the hammer.
To free the hammer it is only necessary to lower the lever k; the shaft o, by
means of the arrangement of levers and connecting rods q, makes a quarter turn,
and the catch then only finding a smooth part of the shaft o, permits the hammer
to fall.
In lifting the shaft o turns back, and the catch is again in front of the notches o¹,
into which it enters directly the hammer would descend; this catch may be covered
with leather to prevent the noise which it might make in rising.
The hammer rises when k is lifted, and falls directly this lever is lowered, which
absolutely prevents any introduction of the mixture when the piston is up.
If it is desired not to keep the hammer raised it is only necessary to throw the
lever movement q out of gear, and leave the smooth side of the shaft o always
facing the catch.
If the top of the cylinder is closed the compressed air above the piston may act
as a spring to increase the power and rapidity of the strokes. In this case the
water may be introduced by a blow valve.
All the ordinary modes of constructing forge hammers may be applied to this
kind of machine.
In the case of a horizontal hammer the weight of the piston and of the hammer
may be replaced by a spring operating upon the piston rod.