IMPROVEMENTS IN MACHINE HAMMERS AND APPARATUS FOR ACTUATING THE SAME
Year: 1883

page_text: PROVISIONAL SPECIFICATION left by Friedrich Carl Glaser at the Office
of the Commissioners of Patents on the 5th April 1883. Communicated
to him by Julius Frölich residing at Düsseldorf in the German Empire.
FRIEDRICH CARL GLASER of Berlin in the Kingdom of Prussia and Empire of
Germany, Engineer and Patent Agent "IMPROVEMENTS IN MACHINE HAMMERS
AND APPARATUS FOR ACTUATING THE SAME [communicated to him by Julius
Frölich residing at Düsseldorf in the German Empire]
"
This invention has for its object so to construct machine hammers that the power
required to drive the same shall be usefully expended to the greatest possible
advantage, and that, with a wide range of regulation for the number and force of
the blows in a given time, the loss of power shall be constant and as small as
possible.
For this purpose, there is connected with the motor engine, whether this be a
steam engine, dynamo machine, or other motor, an intermediate motor, shewn at
fig 1 of the accompanying drawings, which may be arranged either upright or
horizontal. It consists of a cylinder with piston, arranged either single or double
acting. When single acting as in the drawing, the cylinder is connected by a pipe a
with the machine hammers to be driven, so that the air contained in the cylinder
and pipe will, on the movement of the piston, be expanded and compressed. The
cylinder of the intermediate motor, or "air-spring engine" is provided with safety
valves b and c in order to prevent excessive compression or expansion of the air.
The construction of the machine hammer will vary according to the purpose to
which it is to be applied. In figs. 2 to 6 are shewn several such constructions.
Each machine consists essentially of a fixed cylinder & with pistone working
therein, as at figs 2 to 5, or, as at fig. 6, of a fixed piston e, on which the moveable
cylinder & slides. Either the fixed or the moveable part is provided with a stem ƒ
that fits airtight into a corresponding passage g of the other part. The latter is
connected, by means of the conduit pipe, with the intermediate or "air-spring
engine." At the expansion stroke of the latter, the striking part of the machine
hammer is raised until the stem ƒ closes the passage g. If it be raised higher by
the momentum, the imprisoned air above it acts as a spring buffer, preventing
impact of the two parts. In the following compression stroke of the intermediate

page_text: motor, the gradually increasing pressure at first only acts on the surface of the
stem g, and this pressure, plus the weight of the striking part, will be counter-
balanced by the excess of upward atmospheric pressure beyond that of the rarefied
air in the annular space, until the increasing pressure on g overcomes the
atmospheric pressure and forces downwards out of the passage, whereupon the
compressed air will act upon the whole of the upper surface of the striker, which
is thus made to exert its blow. The following expansion stroke of the intermediate
motor now causes the striker to be raised again.
In the arrangement at Fig. 4, the intermediate motor is combined directly with
the hammer; at fig. 7, the stem fis formed as a pipe through which the air pressure
or suction is admitted and it can be shifted up and down through a stuffing box,
by means of the lever Z, whereby the extent of stroke of the hammer can be
varied In order to enable the machines to work with variable air pressure, the
stroke of the piston of the intermediate motor can be made variable, as shewn at
fig. 1; or this may be effected by arranging on the conduit pipe, between such
motor and the machine hammer, a cylindrical chamber containing a plunger which
can be made to project more or less into the same, so as to increase or decrease the
capacity thereof, whereby the volume of air which is subject to compression and
expansion can be varied."
The stroke of the machine hammer can also be varied by constructing the cylinder
cover as a piston or plunger, which can be adjusted so as to project more or less
into the cylinder. The intermediate motor may be made of sufficient capacity
to drive several hammers. The intermediate motor may also be made double acting
a be provided with a rotary valve or other known device, whereby the two ends of
the cylinder are alternately put in communication with the working engines which are
thus made to perforın twice as many strokes as the engine shaft makes revolutions.
The intermediate motor may also be used as a blowing engine when not required
to drive the said machines; for this purpose, a slide valve is provided, whereby the
communication with the said machines can be cut off, and each end of the cylinder
is provided with a slide containing admission and delivery valves, which are so
connected with the blast pipe that the engine can either be used as a blowing
engine or as an exhauster. In the machine hammers, in order to work with variable
pressure, the forcing of the stem ƒ out of the passage g, and the consequent
commencement of the working stroke, must take place without altering the
dimensions; this is effected by establishing a second air passage between the
passage g and the cylinder of the machine, in which is arranged a valve in such
manner as to close automatically under the air pressure from the cylinder and
consequently not to interfere with the buffer action of the air in the annular
space.