Improvements in Bascule Lift Bridges.
Year: 1899

page_text: Date of Application (in United Kingdom), 21st Nov., 1899
Complete Specification Left, 12th Sept., 1900-Accepted, 17th Nov., 1900
Improvements in Bascule Lift Bridges.
I, JOHN PHILO COWING, of 275, Prospect Street, Cleveland, in the County of
Cuyahoga and State of Ohio, United States of America, Bridge Builder, do
hereby declare the nature of this invention to be as follows:-
The object of the invention is to provide a new and improved bascule lift-
bridge, arranged to uniformly load the bridge piers or abutments and to permit
of opening and closing the bridge with comparatively little power, the bridge
being in equilibrium at all angles of its throw and during the opening and
closing of the bridge.
According to my invention each span of the bridge has at its pier or fulcrum
end a segmental bearing surface mounted on a rolling surface constituted by
rollers journalled in bearings in a base block and attached to the pier. The shaft
of one of the rollers is provided with pinions which mesh with segmental racks
secured to the segmental bearing surface on the pier end of the span so that when
the pinions are rotated the span is caused to swing either into the open or closed
position according to the direction in which the pinions are rotated. The pinions
would generally be driven by a motor located within the pier through any
suitable gearing. The construction of the mechanism for imparting a swinging
motion to the span may be varied. For instance the outermost of the set of
rollers may be connected by a chain running over sprocket wheels attached to the
shaft of the rollers, one of the shafts being also provided with a gear wheel
driven by the motor so that rotary motion may be transmitted to the end rollers
to impart rotary motion by frictional contact to the bearing surface on the span.
The bearing surface is in contact with the peripheral surfaces of the rollers,
and when the span is actuated the intermediate rollers are also rotated by the
bearing surface. In order to hold the bearing surface in proper position on the
rollers, I provide said surface at one or both sides with flanges extending over
the end faces of the rollers to prevent lateral displacement of the bearing surface
on the rollers to keep the span at all times in proper alignment across the
077
1

page_text: stream. The fulcrum end of each span is provided with a counterweight and
on the bearing surface is arranged a curved stop adapted to engage the peripheral
surface of one of the end rollers at the time the span is in a nearly vertical or
open position to prevent the span from opening too far.
The bottom chord of the span is adapted to rest at its shore end on a skew-
back, attached to the pier adjacent to or forming part of the base-block. The
fulcrum end of the span is preferably provided with an axle or trunnions turning
in bearings and located at the centre of the segmental bearing surface, and which
centre is also the centre of gravity of the span. The bearings are on frames or
standards attached to the pier or the base plate.
The counterweight for the span is equally disposed above and below the line
of the centre of gravity, and the centre of gravity of the counterweighted mass
is equidistant from any point on the periphery of the segmental bearing surface.
By the construction described the span when unrestrained by a load will rest
in equilibrium at any point of its throw and the centre of gravity does not
change position at any time during the opening or closing of the bridge, and
consequently it requires but little power to open or close the bridge. For very
long spans the counterweight is extended beyond the segmental bearing surface;
but for short spans the counterweight is confined within the segmental portion
of the fulcrumed end of the span. In order to extend the counterweight beyond
the segmental bearing surface, it is necessary to properly extend some of the
beams of the spans to carry the said weight between the trusses and the segmental
bearing surface, so that the counterweight clears the roller bearing, sufficient
space being provided on the pier or abutment for the free passage of the weight
when it is swung into an open position or back into a closing position. This
space may be provided by a well or recess in the pier or by using two spaced
piers, two roller bearings on the said piers and two correspondingly located
segmental bearing surfaces on the span.
For single span bridges used on canals and other narrow waterways the span
when closed becomes substantially fixed, that is, its two ends have a firm bearing
on rigid metal shoes or pedestals on the foundations, it being understood that in
this case the fulcrum end of the span rests upon a pedestal adjacent to the roller
bearing, to carry the weight of the span when closed, thus relieving the bearing
surface and the rolling surface of all strain.
It is to be expressly understood that in all cases the static or dead weight of
the span is carried by the rolling surface when the bridge is open; but when
the bridge is closed the rolling surface carries only a small portion of the live
load, as the principal strain incident to the live or moving load of the bridge is
taken up by the skewbacks, pedestals, or other supports and transmitted to the
abutments or piers, and the bridge is converted into a fixed bridge of arch,
girder or other type.
The motive power for opening and closing the bridge may be located on the
piers supporting the spans, thus making the bridge self-contained and without
requiring any approach spans upon which to locate the motive power or to act
as anchorages to pull and push against when opening or closing the bridge.
The skewback further forms a stop for the span to prevent the same from
dropping below a certain level when the bridge is closed, to insure a perfect
level of both spans when the bridge is closed. By having the rolling surface
in frictional contact with the driven surfaces the friction is reduced to a
minimum, so that comparatively little power is required to open or close the
bridge.
Dated this 91at do
T

page_text: I, JOHN PHILO COWING, Bridge Builder, of 275, Prospect Street, Cleveland,
in the County of Cuyahoga and State of Ohio, United States of America, do hereby
declare the nature of my invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement:-
The object of the invention is to provide a new and improved bascule lift-
bridge, arranged to uniformly load the bridge piers or abutments and to permit
of opening and closing the bridge with comparatively little power, the bridge
being in equilibrium at all angles of its throw and during the opening and
closing of the bridge.
The invention consists of novel features and parts and combinations of the
same, as will be fully described hereinafter and then pointed out in the claims.
A practical embodiment of my invention is represented in the accompanying
drawings forming a part of this specification, in which similar characters of
reference indicate corresponding parts in all the views.
Figure 1 is a side elevation of the improvement arranged as an arched double-
span bridge;
Figure 2 is a plan view of the pier with the roller bearing and motor,
Figure 3 is an enlarged transverse section of the fulcrum end of the span and
bearing therefor, the section being on the line 3-3 in Figure 1;
Figure 4 is an enlarged sectional side elevation of a modified. form of the
improvement;
Figure 5 is a transverse section of the same, on the line 5-5 in Figure 4;
Figure 6 is an enlarged plan view of the roller bearing for the same; and
Figures 7 and 8 are diagrammatic side elevations of modified forms of the
improvement.
The bascule lift-bridge illustrated in Figure 1 is provided with two spans A, A',
meeting in the centre and both alike in construction, each span having its pier
or fulcrum end formed with a segmental bearing surface B, mounted on a rolling
surface formed by rollers C, C and intermediate rollers D, all journalled in
suitable bearings in a base-block E, attached to the pier F. On the shaft of one
of the rollers (as shown the roller C) are held loosely the pinions G, in mesh
with the segmental gear racks G¹, secured to the segmental bearing surface B,
so that when the pinions G are rotated a rotary motion is imparted by the
pinions to the segmental gear racks G' to cause a swinging of the span either
into an open or closed position, according to the direction in which the pinions G
are turned. The pinions G are shown in mesh with the pinions H, secured on
the driving shaft I¹ of a motor I, preferably located on the pier F and under the
control of the bridge-tender; but any suitable gearing between the pinions and
motor may be employed.
The construction of the mechanism for imparting a swinging motion to the
span may be varied.
For instance, as shown in Figures 4, 5 and 6, the outermost
rollers C, C are connected at their shafts C2 by means of sprocket wheels G², G³
and a chain G', and on the shaft C2 of the roller C is also secured a gear wheel H¹,
driven from a suitable motor, so that when the latter is set in motion a rotary
motion is transmitted by the gear wheel H₁ to the roller C and by the sprocket
wheels G2, G3 and chains G to the roller C¹ to cause the rollers C, C' to impart
a rotary motion by frictional contact to the bearing surface B, so that the span A

page_text: swings either into an open or closed position, according to the direction in
which said rollers C, C are rotated.
The bearing surface B is in line contact with the peripheral surfaces of the
rollers, and when the span is actuated the intermediate rollers D, D are also
rotated by the bearing surface B. In order to hold the bearing surface B in
proper position on the rollers, I provide said surface at one or both sides with
Hanges B¹, extending over the end faces of the rollers to prevent lateral dis-
placement of the bearing surface on the rollers to keep the span at all times in
proper alignment across the stream. The fulcrum end of each span A and A¹
is provided with a counterweight J, and on the bearing surface B is arranged a
curved stop K, adapted to engage the peripheral surface of the roller C at the
time the span A is in a nearly vertical open position, thus preventing the span
from opening too far.
The bottom chord A2 of the span A or A¹ is adapted to rest at its shore end
on a skew-back L, attached to the pier F' adjacent to or forming part of the base-
block E. The fulcrum end of the span is preferably provided with an axle or
trunnions N, turning in bearings N₁ and located at the center of the segmental
bearing surface, and which centre is also the centre of gravity of the span.
(See Figure 7.) The bearings N are on frames or standards attached to the
pier For the base plate E.
The counterweight J is equally disposed above and below the line
of the centre of gravity, and the centre of gravity of the counterweighted mass
is equidistant from any point on the periphery of the segmental bearing surface.
By the construction described the span when unrestrained by a load will rest
in equilibrium at any point of its throw and the centre of gravity does not
change position at any time during the opening or closing of the bridge, and
consequently it requires but little power to open or close the bridge. For very
long spans the counterweight is extended beyond the segmental bearing surface;
but for short spans the counterweight is confined within the segmental portion
of the fulcrumed end of the span. In order to extend the counterweight beyond
the segmental bearing surface, it is necessary to properly extend some of the
beams of the spans to carry the said weight between the trusses and the segmental
bearing surface, so that the counterweight clears the roller bearing, sufficient
space being provided on the pier or abutment for the free passage of the weight
when it is swung into an open position or back into a closing position. This
space may be provided by a well or recess in the pier or by using two spaced
piers, two roller bearings on the said piers, and two correspondingly located
segmental bearing surfaces on the span.
For single span bridges used on canals and other narrow waterways the span
when closed becomes substantially fixed-that is, its two ends have a firm bearing
on rigid metal shoes or pedestals L1, L2 on the foundations F1, F2, as will be
readily understood by reference to Figure 8; it being understood that in this
case the fulcrum end of the span rests upon the pedestal L¹, adjacent to the
roller bearing, to carry the weight of the span when closed, thus relieving the
bearing surface and the rolling surface of all strain.
It is to be expressly understood that in all cases the static or dead weight of
the span is carried by the rolling surface when the bridge is open; but when
the bridge is closed the rolling surface carries only a small portion of the live
load, as the principal strain incident to the live or moving load of the bridge is
taken up by the skewbacks, pedestals, or other supports and transmitted to the
abutments or piers, and the bridge is converted into a fixed bridge of arch,
girder or other type.
The motive power for opening and closing the bridge, as shown, is located on
the piers supporting the spans, thus making the bridge self-contained and with-
out requiring any approach spans upon which to locate the motive power or to
act as anchorages to pull and push against when opening or closing the bridge.
The skewback L further forms a stop for the span to prevent the same from

page_text: dropping below a certain level when the bridge is closed, to insure a perfect
level of both spans when the bridge is closed. By having the rolling surface B
in frictional contact with the driven surfaces the friction is reduced to a minimum,
so that comparatively little power is required to open or close the bridge.
I do not limit myself to the peculiar form of driving gear, as it is evident
that a swinging motion may be given to each span by different mechanism,
such as a strut, as indicated, for instance in Figure 7, the surface B, however,
rolling on the rolling surfaces formed by the journalled rollers C, C and D.
By reference to Figures 7 and 8 it will, be seen that different types of bridges
may be provided with the improvement, and it is evident that the form of my
improvement can be greatly varied, according to the form of the bridge to be
used for spanning a river, stream, or the like, and the improvement is equally
applicable to two-span bridges as well as to single spans. (Shown in Figure 8).
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed I declare that what
I claim is:-
1. In a bascule lift bridge, operating the swinging bridge span by driving
the rollers on which it is supported, substantially as described.
2. In a bascule lift bridge, the stop secured to the swinging span and adapted
to engage one of the supporting rollers, substantially as described.
3. In a bascule lift bridge, the arrangement of skew backs to engage and
support the span when the bridge is closed, to relieve the bearing of strain by
receiving the load of the bridge as well as the weight of the span, substantially
as described.
•
4. In a bascule lift bridge, supporting the swinging span on rollers of different
diameters so that when they rest on a horizontal surface, their upper surfaces
will form a segmental bearing surface, substantially as described.
Dotal this 19th dor of Sentemhar 1900
A. M. & WM. CLARK,
Chartered Patent Agents, 53, Chancery Lane, London.