Improvements in Tunnelling Shields and Devices connected therewith.
Year: 1899

page_text: Date of Application, 30th May, 1899-Accepted, 22nd July, 1899
COMPLETE SPECIFICATION.
Improvements in Tunnelling Shields and Devices connected
therewith.
We, CORNELIUS GERRALD HASTINGS and THOMAS HENRY MURPHY, both
residing at 1401, Monadnock Building, Chicago, Illinois, Manufacturers, 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:-
My invention relates to improvements in tunneling shields and devices con-
nected therewith which are employed for excavating tunnels,, subways and
conduits and especially to shields which are used to best advantage in sand,
gravel, silt, and similar loose, soft or crumbling soils, the said shields being
pushed forward to displace or aid in the displacement of the material in front of
the shields by means of pneumatic or hydraulic pressure or both, the intervals
between each forward movement of the shield being employed in constructing
within a near projection of the shield a suitable tunnel lining.
The object of my invention is primarily to provide a very strong, light and
inexpensive shield which will resist any and all strains which will come within
its various members, and the invention consists essentially in forming the entire
length of the shields of two cylinders, suitably connected together, one with the
other from the cutting face to the rear bulk-head thereof and it also consists in
certain means for connecting, staging and dividing the space between said
cylinders for various purposes and for providing access thereto, as will herein-
after appear.
A further object of my invention is to divide the said tunneling shield by
means of one or more transverse bulkheads each of which is braced in a novel
manner to resist the force of concussion from blasting or extreme pneumatic
pressure and to present a smooth concave face upon the forward side thereof
to prevent the lodgment of material within the shield.
To provide a plurality of bulk-heads within the shields each of which may be
closed air-tight by suitable doors to provide an intermediate chamber within
which the workmen may escape from either the front working section or from
rearward of the shield when desired, and may be supplied with air under any
safe and convenient degree of pressure, while the pressure of the air may be
materially increased to a degree dangerous to life-both at the head and at the
hood of the rear of the shield within the tunnel, as will hereinafter appear.
A further object of my invention is to provide suitable means in conjunction
with my double-walled shield for directing the movement of the shield for
essening the friction upon the outer surface thereof, for changing the grade of
he tunnel and for allowing the curvature of deflection from a straight line
thereof if desired.

page_text: A further object of my invention is to provide certain improvements in the
construction of the revolving crane and in certain other details of construction
hereinafter particularly described with reference to the accompanying drawings
in which:
Figure 1 is a longitudinal vertical section through a tunneling shield com-
plete Figure 2, an elevation of the forward end or cutting face of the shield;
Figure 3, a transverse section in line, of Figure 1 looking to the rear;
Figure 4a similar section in line y, y of Figure 1; Figure 5 a plan view of the
rear end and of the shield showing the flexible hood; Figure 6 a rear elevation
of the shield showing the double-armed crane; Figure 7 an enlarged side eleva-
tion, and Figure 8 a similar elevation of the crane, partly broken away; Figure 9
an enlarged face view of the scroll disc for operating the segment holders on the
ends of the crane; Figure 10 a perspective view of one of the cast-iron segments,
and Figure 11 a similar view of the wooden segment to be used as an outer lining
when a brick lining only is to be employed.
The shell of the tunnel shield comprises two cylinders 1 and 2 made of boiler
plates connected together, the cylinder being placed one within the other and
connected at one end to the rear bulk head 12 at its junction with the hood D
and at the opposite end to the peripheral dished rim plate 5 which is provided
with radial cutter blades 6, projecting inwardly therefrom and thus provide
together with the dished rim plate a suitable cutting face for the shield which
will effectively direct the excavated material from the outer cutting edge to the
interior of the forward cylindrical compartment, the latter being provided with
a bulk head 8 consisting of a rear flat-plate 9 secured at its periphery to the
inner cylinder 2 of the shell, and a forward concave or dished plate 10 projecting
forwardly at the top and dished or curved inwardly and downwardly at the top
and sides until it meets the flat plate 9, which forms the inner wall of the bulk-
head. The plate 9 is preferably stayed upon its inner face by the angle iron 9
secured vertically thereto which also may serve as supports or guides for the
doors, the latter being made to either hinge, or slide therein and are adapted to
be closed tight to form an air-tight partition at the forward end of the middle
compartment 11, the rear end of said compartment being provided with a similar
air-tight bulk-head 12 formed of double plates of flat sheet metal placed parallel
to each other and stayed by a dished plate 12", similar to the plate 10 at the
front side of the bulk-head 8, the dished plates 10 and 12" serving to resist not
only the excessive pneumatic pressure when caused to act upon the rear-bulk-
head to push forward the shield, but will effectively resist the concussive force
of the blasts used at the heading for breaking up solid obstruction of any kind.
The outer and inner cylinders are connected at the forward shell section A by
longitudinal flat stay plates 13 placed radially between said inner and outer
cylinders and secured thereto in a suitable manner and said cylinders are con-
nected at the rear shell section B by longitudinal cradle plates 14 of U-shaped
cross-sections which are connected at their inner open ends to the inner cylinder
and are riveted at the centre line of the bow by a single row of rivets, the bow-
shaped outer portion giving great strength and allowing but one row of rivets
to be employed for each longitudinal plate, which forms the sides 14ª, 14b, of the
cradles 14 the said sides being located in the same plane with the stay plates 13
and the cradle 14 providing suitable compartments to receive the hydraulic
rams 15 which are placed at equal distances from each other around the shield.
The stay plates 13 and cradle 14 will thus be in direct line of pressure of the
rams, thus serving also as stays for connecting the inner and outer cylinders
and will give great strength to the shield, both to resist longitudinal thrust
and direct radial pressure. Diametric ring stay segments 3 connect the inner
and outer shell between the bulk-heads and diametric ring stays 4 in the same
plane with the bulk-heads giving additional strength to the shield.
Air pipes 18 extend through the lower portions of sections and above these

page_text: pipes are larger pipes 19 through which water, running quicksand, or soft earth,
may be forced by the air pressure between the heading and the forward bulk-head.
The forward ends of air-pipes 19 may be either fitted with caps or with nozzels
upon which may be secured air-pipes leading to pneumatic or other drills, said
pipes being used as conduits or for such purposes. The forward bulk-head or
both bulkheads may be provided with pipes 21, fitted with stop cocks 21". which
admit the air from one compartment to the other on completing such com-
munication.
Horizontal partitions, platforms and division walls may be arranged in any
suitable or preferred manner within the shields as shown on Figure 4, and a
scaffold may be suspended both at the front and rear ends thereof upon which
the workmen may stand, the said scaffolds being preferably made removable.
The rear end of the shield is provided with a hood 1) which is formed in a novel
manner of a series of straight strips of plate spring steel d secured at their for-
ward ends to a rim d' of the outer cylinder 1 of the shell and placed sufficiently
near together to prevent the loose earth from falling between them and also
admit of their being slightly bent out of a straight line, as shown in Figure 5
of the drawings, when it is required to change the grade or angle of the shield
or to conduct the same in a curved line without causing the shield to bind or be
cramped cross-ways within the excavation. The crane 23 at the rear end of
the shield is supported upon the rear end of the shaft 24 carried by bearings 25
supported upon the bulk-heads 8 and 12 and projects rearwardly into the hood D),
the end of the said shaft having the hub 23 of the crane arm 23 secured thereto,
a platform 11 in the middle compartment 11 serving to support an engine or
other suitable machine 25", which is geared by pinion 24 and 24 to the said
shaft 24 by means of which the erane is operated, the arm 23 supports a movable
chuck 27 fitted thereon by means of slotted arm extensions 23° which slide between
the side plates of the arm 23 of the crane and is slotted to receive the pins 234
connecting said arm plates. The chuck 27 is fitted with two cross-heads 27b,
slotted to receive a bolt 27 and supported upon lug 27d of the chuck 27, suitable
clamp nuts being fitted upon the bolt 27 to hold the cross-plates in any position
at which they are set, studs 27 upon the ends of the plates 27b also being pro-
vided to engage with the rivet boles 29" of the segment-locks 29, which are thus
supported and secured upon the ends of the crane arm.
The chuck 27 is held
and adjusted to any required position distant from the centre of the crane shaft
by means of a rod 30 which connects the chuck with a scroll disc 31, a pin 30"
of the said rod engaging with the groove 31 of the disc, suitable guide blocks 2
on the crane arms serving to hold the rod in working position. The chuck 27
is designed to support a small key segment upon the arm extensions at one end
of the double crane arm and a chuck 27 is provided to support the large main
segments upon similar extensions and a rod 30* serving to connect the chuck 27*
with the scroll disc 31 at a point opposite the inner end of the rod 30, the
rod 30-30, and chuck 27 and 27 being thus drawn together by the rotation
of the scroll disc. When the chucks are thus placed either in or out to the
required position, they may be secured fixedly to the crane arms by means of a
pin 28 on a collar 28 of the crane hub, which engages with a hole 31 in the
hub of the scroll disc, thus causing the said scroll disc and crane to revolve
together. It will be understood that one of the segments is placed upon the
end of the crane arm when the chucks are drawn together, the crane arm then
revolves by the driving mechanism until these segments are properly opposite
its position and the chucks then forced outwardly by the scroll discs until the
segment is held in its position to be riveted in place." The cross-plates are then
drawn together by suitable means or by pushing them from opposite sides thus
releasing the segments. The segments are made perferably of cast iron as shown
in Figure 10, a rim flange having rivet holes therein providing suitable means
for securing them together.

page_text: The operation of the several parts herein claimed will be readily understood
from the foregoing description. A detailed description of the placing of the shield
in working position connecting it with the tunnel heading and bulk-heads, means
for connecting the various air, water and conduit pipes with a supply and delivery
apparatus and the details of the mode of operating and conducting the work
within the shield being well known by practical tunnel engineers and superin-
tendents.
The shield may employ some of the features herein claimed without embodying
all of them, and features now shown may be added when required for carrying
out well-known objects without departing from my invention.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we declare that what
we consider novel and desire to claim is:
1, A tunneling shield comprising a cutting face at the forward end and a
hood at the rear end thereof, two concentric cylindrical shells extending from
and connecting said outer face and hood connected together at both ends thereof,
and a plurality of hydraulic rams placed at the rear end of said cylindrical shells,
substantially as described.
2, A tunneling shield comprising a cutting face at the forward end, a hood at
the rear end thereof, two concentric cylindrical shells connecting the same and
a series of radial plates interposed between and connecting the said cylindrical
shells longitudinally, substantially as described.
3, A tunneling shield comprising a double-walled cylindrical shell a bulk head
at the forward end thereof and a series of trough-shaped partitions extending
longitudinally thereof and connected to both the inner and outer cylindrical
shells, substantially as described.
4, A tunneling shield comprising a double walled cylindrical shell, a bulk-
head at the forward end thereof a series of trough-shaped plates extending longi-
tudinally thereof, connecting said shells, and hydraulic rams enclosed within
said troughs, substantially as described.
5. A tunneling shield comprising a double-walled cylindrical shell a cutting
face and bulk-head at the forward end thereof a bulk-head at the rear end thereof
and a number of stays extending diametrically between and secured to the said
cylinder, providing cellular compartments between the shells, substantially as
described.
6, A tunneling shield comprising a cylindrical shell and cutting face at the
forward end thereof a working hood at the rear end thereof, a bulk-head fitted
with air-tight covered openings at the forward end of the shield and a similar
bulk-head at the rear end thereof also provided with air-tight covered openings
to provide a closed chamber between the said air-tight bulk-heads for the work-
men within the shields, substantially as described.
7, A tunneling shield comprising a cylindrical shell, a bulk-head provided with
doors therein and having a concaved face to strengthen the bulk-head and direct
the loose material towards the door opening, substantially as described.
8, A tunneling shield comprising a cutting face at the forward end a cylindrical
shell, a hood at the rear end thereof, having longitudinal strips projecting rear-
wardly from the cylinder and separated from each other to admit of independent
movement or deflection, substantially as described.
9, A tunneling shield comprising a cutting face at the forward end, a cylin-
drical shell and hood at the rear end thereof and a crane arm having each of its
ends provided with an extension piece fitted with hoods for carrying respectively
the large and smail segments of the tunnel lining, substantially as described.
10, A crane for tunneling shields comprising an arm having a central hub,
a shaft upon which said hub is supported, a scroll disc adapted to rotate upon said
shaft, a segment holding head movably secured to the end of said arm and a link
connecting said head to the scroll disc, substantially as described.

page_text: 11, In a crane for tunneling shields, the combination with the supporting shaft
of the hub, the crane arm, the segment holding block movably secured to the end
thereof, the scroll disc mounted upon the shaft, and a bolt connecting the said
hub and scroll disc, substantially as described.
Dated this 29th day of Mox 1800
H. D. FITZPATRICK,
100, Wellington Street, Glasgow, Agent.