IMPROVED PNEUMATIC METHOD OF CONSTRUCTING FUNDAMENTS OR FOUNDATIONS FOR THE PIERS OF BRIDGES AND OTHER STRUCTURES AND APPARATUS EMPLOYED THEREWITH
Year: 1881

page_text: PROVISIONAL SPECIFICATION left by Edwin Ambrose Brydges at the Office
of the Commissioners of Patents on the 1st October 1881. A communi-
cation from abroad by G. Gregersen, of Budapest, in the Kingdom of
Hungary.
EDWIN AMBROSE BRYDGES, of the Firm of Brydges & Co., Engineers and
Patent Solicitors, of 73, Koeniggraetzer Str., in the City of Berlin, in the
Kingdom of Prussia and German Empire. "IMPROVED PNEUMATIC METHOD OF
CONSTRUCTING FUNDAMENTS OR FOUNDATIONS FOR THE PIERS OF BRIDGES AND
OTHER STRUCTURES AND APPARATUS EMPLOYED THEREWITH." (A communication
by G. Gregersen, of Budapest, in the Kingdom of Hungary.)
This Invention relates to an improved pneumatic method of constructing funda-
ments or foundations for the piers of bridges and other similar constructions,
whereby double buckets are employed and the raising and workinen's compartments
are attached to the caisson, and differ from all other systems; that these snid
raising and workmen's compartments are entirely separate from each other,
which necessitates a novel construction of the same and a peculiar mode of
manipulation.
The caisson, which consists of the chief supports and the cross beams, contains
two raising or bucket compartments and one compartment for the workmen, which
said compartments are entirely separated from each other.
Each of the raising compartments consists of four tubular sheet metal walls,
which are attached at the upper part to the lid and at the lower part to the bottom
of the compartment or compartiments by means of angle iron and rivets. The
pressure (about three atmospheres) on these sheet metal walls is transmitted to the
bottom plate and the lid by means of suitable supports. Above the before
mentioned cross beains of the caisson is rivetted a plate which acts as cover, and
above this said plate is attached iron, which fits on to the main and cross beams
or girders of the framework.
The pressure of three atmospheres caused by the compressed air in the caisson.
presses on the upper covering plate and its strengthening pieces or ribs, which said
pressure is transmitted to the main girders or beams by means of suitable bolts.
The joints between the top plate and the iron are rendered air and watertight
by means of india-rubber or other suitable rings.

page_text: In order to prevent the bending of the upper flange of the ☐ iron by the strain
on the bolts this flange is connected to the lower flange or the main girders. For
safety-sake, a second strengthening device is employed so as to transfer the vertical
pressure to the main girders. Cast iron supports or supporting pieces are placed
between the uprights or vertical supports and the walls of the bucket-compartment
and attached by means of suitable bolts. These said bolts are freed from pressure
by suitable plates, which must be unrivetted before the bucket compartment can
be drawn out of the shaft.
The complete bucket compartment can be withdrawn after the pit or shaft for
the foundation or fundament is completed and provided with concrete. In the 1
lower part of the bucket compartment are two circular openings of sufficient size
to admit the passage of the bucket.
Each of the excavation or raising buckets is placed within a bucket receiver,
which is rendered air tight by suitable india-rubber or other rings. The bottom of
the bucket compartment is provided with two openings, which are closed by means 1
of a suitable cover, and are provided with a suitable bridge or bow. A wrought
iron cross is rivetted to the cover in order to equalise the strain, the one end of
which said cross is so bent upwards that a loop or eye is formed, so that cover and
bow, span or bridge can be attached to each other by means of a wrought iron
handle. The chief-parts-of-this-device-which-have-to-be-frequently-removed-aro-2
-balanced-by-counterweights.
The bucket receiver is held by arms which are keyed to a shaft or axle, and
which said arms can be raised or lowered by means of a screw spindle with double
threads and a cross lever for operating the said screw. A suitable lever serves not
only as handle for turning the bucket-receiver and bucket which is to be filled out 2
of the compartment, but catches on a suitable stop or projection on the frame and
arrests the bucket at its central position under the opening in the plate.
In order to facilitate the turning out of the bucket and its receiver the walls are
suitably flattened.
The bucket receivers are provided with doors which are employed when the pit 3
or shaft is to be filled up with concrete or other materials or matter.
The axis of the bucket receiver works on a bolt or screw and the revolving
motion of the same is arrested by a suitable stop pin or pivot in the hinge, so that
the bucket receiver can bo roughly adjusted before the screw adjustment is brought
into operation.
The nuts employed are supported by angle iron, which in its turn is supported
by strong cross beams or girders to which the upper bearing for the axis of the
bucket receivers is attached. The side nearest the axle of the buckets is supported
direct on the high edge system, and a fishbellied girder is employed to transfer
the strain to the vertical support.
A pin, which is square at the lower end, is inserted in the upper part of the axle
to prevent the cover being prematurely opened, the same passes through the lower
plate and revolves with the axle. The upper end of this pin terminates in a broad
head.
A wrought iron arm turns on a pin and carries at the one end a washer or boss,
at the opposite end a cap.
The parts are so arranged that a slit or slot in the washer or disc employed only
then permits the arm to turn open when the bucket is in its proper position
when the cap is removed from the nut of the screw to the bridge span or bow on
the cover.
During the loosening or releasing of the parts the disc and also the axle are
prevented from turning. After the cover is closed the parts are returned to their
original position.
The workmen's compartment is hermetically closed and is attached to the frame-
work in the middle of the caisson, the main girders being at this part covered by
an airtight strong plate which forms the bottom of the descending shaft.
The workmen enter and leave the compartment by means of a suitable door in

page_text: the side of the same, through which the necessary tools are also passed. The
workmen's compartment contains two doors for descending the shaft or pit, beneath
which a sufficient number of ladders and horizontal bars are introduced to enable
the workmen to reach the doors of the said compartment, in which they can remain
a considerable time in case of danger. This compartment is divided in two parts
by a suitable plate, and under ordinary conditions the workmen pass only through
the lower portion, so that waste of compressed air is prevented.
If danger appears imminent, the first workman entering the lower division of
the compartment at once opens the communication door, so that the united space
can be occupied by the workmen. The doors opening downwards are balanced by
counterweights. In and outlet cocks or valves are provided for admitting and
letting off compressed air in each chamber.
Two winding engines, driven by a locomobile or other suitable engine, are
situated on the scaffolding or framework over the pit for raising and lowering the
buckets.
The pullies of the winding engines are so arranged that when one bucket is
raised the other is lowered. Suitable arrangements of levers permit the ready
transfer of the driving bands from the fixed to the loose drum, and vice versa, and
also applier releases the brake mechanism.
When the shaft or pit has been sunk sufficiently deep the sides are built up with
concrete and the apparatus withdrawn.