Year: 1886

page_text: bridge to be bun
The apparatus may moreover be applied to a bridge of large size, which requires
to be operated by a steam-engine, even if there be no plant for hydraulic power
on the spot.
The operation may be effected by hand or any other power, such as hydraulic :
power.
Referring to the accompanying 4 sheets of drawings. Fig. 1 is a plan of.
hydraulic mechanism according to this invention for opening, closing and locking
a swing bridge. Fig. 2 is an elevation of the same. Fig. 3 is a transverse section.
Fig. 4 (Sheet 2) is a plan of a part of swing bridge with its hydraulic mechanism,
part of the roadway being removed to shew the under part. Fig. 5 is an elevation
of the same. Figs. 6, 7 and 8 (Sheet 3) shew the locking gear in three positions.
Figs. 9 and 10 (Sheet 4) are respectively a plan and elevation shewing a modified
apparatus according to this invention, for locking a bridge by hand power.
The operating mechanism is situated at a point X in the masonry of the bridge
indicated on Fig. 4 Sheet 2 which shows the bridge in its closed, and its locked
position.
In order to open the bridge, it must be first unlocked.
The locking mechanism comprises two cylinders A and B, shown on Figs. 2
and 5, provided with a common plunger C, in the middle of this plunger is a cross-
head D, which, by means of a connecting rod E, operates a shaft F provided at
one end with a lever G (Fig. 5), which transmits its motion through links to the
shafts H and I on which are fixed the locking cams K and L.

page_text: In order to unlock the bridge the lever O.is moved; this actuates the slide of
the distributor 1 (Figs. 2 and 4).
Water from the hydraulic main enters the cylinder A, forces the plunger C and
the crosshead D towards the cylinder B, and transmits the motion to the cams K
and L, by means of the connecting rods and links.
Sheet III shows the three different positions of the bridge during the operations
of locking and unlocking.
The supports and R shown in those drawings represent the rollers on which
the bridge rests, when it is completely unlocked.
In the first position (Fig. 6) the bridge is shown locked, and the rollers raised
clear of the roller path.
When the cams have made one-eighth of a revolution, the rear end M of the
bridge has sunk, and the rollers Q rest on their rails, since the radius of each of
the cams R is the same up to that point. The bridge is then at the same level,
but the gib or extreme end N of the bridge is raised from the supports S on which
it is locked.
The third position (Fig. 8) shows the completion of the unlocking operation.
When the cams have completed a fourth of a revolution, the rollers R bear also on
their rails; the gib N of the bridge descends through one half of the distance to
which it had been raised by the second position, and the bridge is completely
unlocked.
During this movement, the link P, shown in Fig. 2, being moved by the pivot
of the crosshead D, pushes the lever O into its first position, and thus stops the
admission of the water into the cylinder A, by means of the distributing valve I.
The movement is thus stopped automatically without help from the attendant.
The bridge is now unlocked and ready to be opened."
In order to lock the bridge it is sufficient to again operate the lever 0 (there is
no need of saying in which direction, as the lever is prevented from moving in the
wrong direction by the adjustable stop screw P). The slide of the distributing
valve I is thus operated so as to cause the water to enter the cylinder B, and the
remainder of the movement is effected automatically without help from the
attendant in the same way as for unlocking.
The preceding description relates to locking and unlocking by hydraulic power.
In order to effect the same movement by hand power, it is sufficient to operate the
lever O in the direction indicated in the sectional view (Fig. 3), and thus to
disconnect the connecting rod, and to put the clutch 2 in gear with the toothed
wheel 3, which is turned in the one or the other direction, according as it is
desired to lock or unlock the bridge, by means of the worm shown in Figs. 4
and 5. There is no essential difference between the operation of locking by hand
power and that by hydraulic power, other than that both the plunger and the
connecting rod remain immoveable during the former operation.
The transmission of the hydraulic force acts on the plungers which actuate the
levers, and this movement is transmitted by links which are always kept in tension
and are therefore not liable to get out of order.
The method and means for locking the bridge are properly speaking quite
different from those now in use; at present, wedges or eccentrics are used for
locking the bridge, but are very inconvenient, and are liable to become unlocked
by accident, when the pressure diminishes, or their links lose their hold.
According to this invention there are employed cams of various radii, and a
plane portion so that the bridge cannot become unlocked when the pressure no
longer acts on the plungers, or when these become detached from their links.
The operation of unlocking having been performed, the means for opening and
closing the bridge by hydraulic power will be described.
The rotating or turning mechanism of the bridge comprises two cylinders a
and b shown on Sheet 1, each provided with a plunger on which is mounted a cap
provided with pulleys..
The plungers are rendered-water-tight by means of leathers or other packing..

page_text: The rear part of each cylinder is also provided with a cap upon which there are
mounted sheaves, the whole forming, two sets of pulleys one of which is moveable,
around which the chain is wound with three bights as shown in Figs. 4 and 5.
The
A chain consisting in part of a pitch chain, is fastened by one of its ends to a
stretcher fixed on the cylinder a at the point 1, is led round the pulleys forming
the tackle of that cylinder, passes over the guiding sheaves b, c, d, e, f, g and ke, and
passes round the toothed wheel V when the bridge is moved by the motor.
toothed wheel being held stationary by a worm w, the chain exerts a tractive force
on the sheaves and m, passes over the return sheaves n, o, h, passes round the
sheaves forming the tackle of the cylinder b, and is fastened by its other end to
the stretcher fixed on that cylinder at the point 2.
This
The portion of the chain consisting of pitch links has-the length of q to r.
portion of the chain is useless, when the apparatus is to be applied to an n existing
bridge already provided with hand power mechanism.
Then instead of employing a chain to pass round the guide sheaves and passing.
from one cylinder to the other, a chain is employed for each cylinder.
These chains pass through the point of traction m, k; these chains are not
fastened to that point, but continue to s and t, where they end in means for
adjusting their length; the stretcher of the cylinder becoming useless in this case.
The object of the length of the chains between m-k and t t is thus solely to render
the point of attachment easily accessible, and to permit of the easy regulation of
the chains:
In order to open the bridge, the attendant has only to move the lever A¹ (to the
side shown in Fig. 2) and thus to operate the slide of the distributor 2. The
water enters the cylinder a, pushes out its plunger, and the two sets of sheaves of'
this cylinder become separated. After having passed over the guiding sheaves;
the chain finds its point of traction in the sheaves and m, and being held by the
toothed wheel I, draws this point up to the sheave f.
When it has arrived at this point, the bridge is quite open.
During this movement the other plunger is forced by the other end of the chain
back into its cylinder b. On the cap of the plunger of this cylinder, is fixed a
pivot B', and when the plunger has arrived at the end of its stroke, the pivot
strikes a tappet C¹ which actuates the fork D¹ by means of the return links E¹ F¹,
and G and having replaced the lever in its first position, stops the admission of
the water to the cylinder by the distributor 2. The whole movement of the bridge'
is thus stopped automatically. In order to close the bridge, the lever is moved in-
the opposite direction, the water enters the other cylinder, and when the bridge
is quite closed, it stops, automatically, as in the opening operation.*
The operation may be effected either by employing the special hydraulic
mechanism described above, or capstans, or any other suitable moving power.
One of the chief objects in view, in making the point of application of the
tractive force at m l is not to strain the pivot. If the power had been applied by
means of a chain pulling on a wheel fixed to the pivot of the bridge the object
would also have been partly attained whilst employing the same moving apparatus;
but the strain on the pivot would have required a special and expensive construction
of the latter, and in this case, the operating cylinders would have been of a greater
diameter, the consumption of water would have been larger, and in the case of an
accident happening to the chains or to the step of the pivot, repairs would cause
great difficulty.
A method of locking a bridge by hand power according to this invention is
represented on Sheet IV.
At a point A, a worm is fixed, provided with a hand wheel for operating it in
one or the other direction according as the bridge is to be locked or unlocked.
A shaft B furnished with cams with plane portions C, and placed as near as
possible to the extremity of the rear end of the bridge, supports the beams of the
latter, when it is locked.

page_text: Another shaft E also furnished with cams E with plane portions, is placed
beyond the pivot, as near as possible to the jib of the bridge. The sole object
of the cams is to support the beams of the bridge, and thus render the latter morǝ
secure than would be the case if these beams were supported only by their
extremities.
Each end of the shafts B and E is provided with a lever G. These ends are
connected to each other by links H and I, which are always in a state of tension ;
a favorable condition for the transmission of power through them.
The first of these shafts is also provided with a toothed wheel J, gearing with
the thread of the worm K, so that on turning the wheel of the worm, both shafts
and the fixing cams C and F are also put in motion.
When the cams C have completed one-eighth of a revolution, the rear end of the
bridge has descended, and, rests with its wheels L on the circular path; since the
cams F are of the same. radius up to that point. In this position and up to this
point, the bridge has remained at the same level, but the gib or end M of the
bridge is raised from its supports N which are arranged as inclined planes, so that
when once the bridge is closed, it can never shift.
This is a great advantage, the system being simple and practical, especially for
bridges designed for the passage of railway trains. When the cams F together
with the others have completed one-fourth of a revolution, the wheels O will also
bave a bearing. The end or gib of the bridge will descend through half the height
resulting from the first eighth of a revolution of the cams F and G, and the bridge
will be completely unlocked.
In order to lock the bridge, it is only necessary to turn the wheel of the worm in
the opposite direction. However great the weight of the bridge, this system can be
so worked out and applied that one man can perform the operation.
Some of the principal advantages of this apparatus are as follows:
Comparatively low cost less than that of other apparatus now in use.
Considerable reduction in the consumption of water, and therefore economy in
fuel for the pumping engines.
Economy of maintenance.
Great ease and rapidity in the working of the apparatus, and great security.
Ease of application to existing swing bridges.
:
Ease of application to new bridges, the chain of the special motor being capable
of being operated by manual power.
Ease of access.

page_text: In the first position (Fig. 6) the bridge is shown locked, and the rollers raised
clear of the roller path.
When the cams have made one-eighth of a revolution, the rear end M of the
bridge has sunk, and the rollers Q rest on their rails, since the radius of each of the
cams is the same up to that point. The bridge is then at the same level, but the
gib or extreme end N of the bridge' is raised from the supports S on which it is
locked.
The third position (Fig. 8) shows the completion of the unlocking operation.
When the cams have completed a fourth of a revolution, the rollers R bear also on
their rails; the gib N of the bridge descends through one half of the distance to
which it had been raised by the second position, and the bridge is completely
unlocked.
During this movement, the link P, shown in Fig. 2, being moved by the pivot
of the crosshead D, pushes the lever O into its first position, and thus stops the
'admission of the water into the cylinder A, by means of the distributing valve 1.
The movement is thus stopped automatically without help from the attendant.
The bridge is now unlocked and ready to be opened.
:
In order to lock the bridge it is sufficient to again operate the lever O (there is
no need of saying in which direction, as the lever is prevented from moving in the
wrong direction by the adjustable stop screw P). The slide of the distributing
valve 1 is thus operated so as to cause the water to enter the cylinder B, and the
remainder of the movement is effected automatically without help from the
attendant in the same way as for unlocking.
The preceding description relates to locking and unlocking by hydraulic power.
In order to effect the same movement by hand power, it is sufficient to operate the
lever O¹ in the direction indicated in the sectional view (Fig. 3); and thus to
disconnect the connecting rod, and to put the clutch 2 in gear with the toothed
wheel 3, which is turned in the one or the other direction, according as it is desired
to lock or unlock the bridge, by means of the worm shown in Figs. 4 and 5.
There is no essential difference between the operation of locking by hand power
and that by hydraulic power, other than that both the plunger and the connecting
rod remain immoveable during the former operation.
The transmission of the hydraulic force acts on the plungers which actuate the
levers, and this movement is transmitted by links which are always kept in tension
and are therefore not liable to get out of order.
.
The method and means for locking the bridge are properly speaking quite
different from those now in use; at present, wedges or eccentrics are used for
locking the bridge, but are very inconvenient, and are liable to become unlocked
by accident, when the pressure diminishes, or their links lose their hold.
According to this invention there are employed cams of various radii, and a
plane portion so that the bridge cannot become unlocked when the pressure no
longer acts on the plungers, or when these become detached from their links.
The operation of unlocking having been performed, the means for opening and
closing the bridge by bydraulic power will be described.
The rotating or turning mechanism of the bridge comprises two cylinders a and b,
shown on Sheet I, each provided with a plunger on which is mounted a cap
provided with pulleys.
The plungers are rendered water-tight by means of leathers or other packing.
The rear part of each cylinder is also provided with a cap upon which there are
mounted sheaves, the whole forming two sets of pulleys one of which is moveable,
around which the chain is wound with three bights as shown in Figs. 4 and 5..
A chain consisting in part of a pitch chain, is fastened by one of its ends to a
stretcher fixed on the cylinder a at the point 1, is led round the pulleys forming
the tackle of that cylinder, passes over the guiding sheaves b, c, d, e, f,.g and k, and,
passes round the toothed wheel when the bridge is moved by the motor.. The
toothed wheel being held stationary by a worm w, the chain exerts a tractive force
on the sheaves and m, passes over the return sheaves n,.o, p, passes round the

page_text: sheaves forming the tackle of the cylinder b, and is fastened by its other end to
the stretcher fixed on that cylinder at the point 2.
The portion of the chain consisting of pitch links has the length of q to r. This.
portion of the chain is useless, when the apparatus is to be applied to an existing
bridge already provided with hand power mechanism.
Then instead of employing a chain to pass round the guide sheaves and passing
from one cylinder to the other, a chain is employed for each cylinder.
These chains pass through the point of traction m, k; these chains are not
fastened to that point, but continue to t and t,, where they end in means for
adjusting their length; the stretcher of the cylinder becoming useless in this case.
The object of the length of the chains between m―k and tt is thus solely
to render the point of attachment easily accessible, and to permit of the easy.
regulation of the chains.
.
In order to open the bridge, the attendant has only to move the lever A¹ (to the:
side shown in Fig. 2) and thus to operate the slide of the distributor 2. The
water enters the cylinder.a, pushes out its plunger, and the two sets of sheaves of
this cylinder become separated. After having passed over the guiding sheaves, the,
chain finds its point of traction in the sheaves k and m, and being held by the
toothed wheel 7 draws this point up to the sheave f.
When it has arrived at this point, the bridge is quite open.
During this movement the other plunger is forced by the other end of the chain
back into its cylinder b. On the cap of the plunger of this cylinder, is fixed a
pivot B¹, and when the plunger has arrived at the end of its stroke, the pivot
strikes a tappet C₁ which actuates the fork D¹ by means of the return links E¹ F¹,"
and G¹ and having replaced the lever in its first position, stops the admission of
the water to the cylinder by the distributor 2. The whole movement of the bridge..
is thus stopped automatically.
In order to close the bridge, the lever is moved in the opposite direction, the
water enters the other cylinder, and when the bridge is quite closed, it stops.
automatically, as in the opening operation.
The operation may be effected either by employing the special bydraulic
mechanism described above, or capstans, or any other suitable moving power.
One of the chief objects in view, in making the point of application of the
tractive.force at m k, is not to strain the pivot. If the power had been applied by
means of a chain pulling on a wheel fixed to the pivot of the bridge the object
would also have been partly attained whilst employing the same moving apparatus;
but the strain on the pivot would have required a special and expensive construction
of the latter, and in this case, the operating cylinders would have been of a greater
diameter, the consumption of water would have been larger, and in the case of an
accident happening to the chains or to the step of the pivot, repairs would cause
great difficulty.
A method of locking a bridge by hand power according to this invention is
represented on Sheet IV.
At a point A, a worm is fixed, provided with a hand wheel for operating it in.
one or the other direction according as the bridge is to be locked or unlocked.
A shaft B furnished with cans with plane portions C, and placed as near as possible,
to the extremity of the rear end of the bridge, supports the beams of the latter,
when it is locked.
Another shaft E also furnished with cans F with plane portions, is placed
beyond the pivot, as near as possible to the jib of the bridge. The sole object of
the cams is to support the beams of the bridge, and thus render the latter more
secure than would be the case if these beams were supported only by their
extremities.
Each end of the shafts B and E is provided with a lever G. These ends are
connected to each other by links H and I, which are always in a state of tension;
a favorable condition for the transmission of power through them.

page_text: The first of these shafts is also provided with a toothed wheel J, gearing with
the thread of the worm K, so that on turning the wheel by the worm, both shafts
and the-fixing cams C and F are also put in motion.
When the cams C have completed one-eighth of a revolution, the rear end of the
bridge has descended, and rests with its wheels L on the circular path; since the
cams F are of the same radius. up to that point. In this position and up to this
point, the bridge has remained at the same level, but the gib or end M of the
bridge is raised from its supports N which are arranged as inclined planes, so that
when once the bridge is closed, it can never shift. This is a great advantage, the
system being simple and practical, especially for bridges designed for the passage
of railway trains. When the cams F together with the others have completed one-
fourth of a revolution, the wheels O will also have a bearing. The end or gib of
the bridge will descend through half the height resulting from the first eighth of a
revolution of the cams F and G, and the bridge will be completely unlocked.
In order to lock the bridge, it is only necessary to turn the wheel of the worm
in the opposite direction. However great the weight of the bridge, this system
can be so worked out and applied that one man can perform the operation.
Some of the principal advantages of this apparatus are as follows:
Comparatively low cost less than that of other apparatus now in use.
Considerable reduction in the consumption of water, and therefore economy in
fuel for the pumping engines.
Economy of maintenance.
Great ease and rapidity in the working of the apparatus, and great security.
Ease of application to existing swing bridges.
Ease of application to new bridges, the chain of the special motor being capable
of being operated by manual power.
Ease of access.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what
I. claim is :-
1) Opening or closing a swing bridge by a chain or chains having its or their
point of traction at a certain distance from the pivot, and being guided by one or
more guiding pulleys fixed to the masonry or stationary portion of the bridge
substantially as described.
2) In the locking gear of a swing bridge cams with plane portions upon
the bridge rests when locked.
which
3) In apparatus for opening closing and locking swing bridges a single motor
capable of performing the operations of opening closing and locking the bridge and
of being operated both by manual power or by water under pressure, substantially
as described with reference to the drawings.
4) In locking apparatus for bridges cams with plane portions in combination
with hydraulic cylinders acting on a common ram and with apparatus for operating
them by manual power, substantially as described.
5) The improved means for opening and closing swing bridges substantially as
described with reference to Figs. 1, to. 5 (Sheets 1 and 2) of the drawings.
Dated this 8th day of Sentember 1886.
°