Improvements in Movable Weirs.
Year: 1891

page_text: Date of Application, 31st July, 1891
Complete Specification Left, 24th Aug., 1891—Accepted, 3rd Oct., 1891
PROVISIONAL SPECIFICATION.
Improvements in Movable Weirs.
I, LOUIS DEBARLE of 15 Rue des Halles, Paris, France, Engineer, do hereby
declare the nature of this invention to be as follows :-
This invention has for object the easy regulation by damming of a river or water
course by means of a movable weir capable of being easily raised and lowered to its
full extent.
A weir according to this invention comprises a door or shutter (hereinafter
called a door) and a float connected together and jointed to a common horizontal
axis.
The door A. situated between piers or abutments at the sides of the river is
capable of turning about journals B arranged in an extension of the sole plate C,
and is connected by arms D of sector-shape to a cylindrical or prismatic float F.
This float may be provided with inlet and outlet to render it capable of serving as
a tunnel or passage from one bank of the river to the other. When the difference
of levels above and below the dam is sufficiently great, the float F is surmounted
by auxiliary reservoirs G H which aid in working the weir.
The float F is coupled by means of a cable I to a windlass J, (a portion only of
which is shewn in the drawings) and it is furnished at each end with a shaft or
well K in each of which is located a ladder or a staircase to allow of the passage
from one bank to the other. This is, of course, only practicable when the float is
of large diameter.
Below the sole plate, and along the whole length of the door, or of each of the
doors, if there be more than one, is provided a chamber L with a curved bottom;
in this chamber the float F is capable of entering and moving. In the angle a of this
chamber are fixed the pulleys b₁bl around which and around the pulleys bb...
attached to the float, is passed the cable I, which, passing up a well formed in one
pier or abutment (Fig. 1), is wound on the windlass J. A diver is able to descend
through the well through which the cable I passes, into the chamber L and to
ascertain whether all is in order therein.
These
Strong female caps c are fixed on the sole plate C, at the angle formed by the
sole plate with the chamber L, and on the right of each of the sector-arms; they
engage with other (male) caps c¹..., fixed to the corresponding sector arms.
caps serve as hinges to the journals B..., which abut against their outer cheeks or
faces. Between each pair of journals B.. there is fixed on the sole plate metallic
sheets f..., the edge of which is very near the lower edge of the door, exactly in
the extension of the theoretical axis of the journals B. Thus along this theoretical
axis and between the journals, there exists only a very narrow passage to which
there may be fitted, if desired, a small metallic tube or any other packing.
The weir formed as above described has the following characteristic property,
viz. if the door makes on the right of the vertical line passing through the axis of
the journals, an angle a equal to the angle ẞ which is made below the horizontal
line by the plane passing through the axis of the journals and the centre of pressure
of the float; and if on the other hand deduction is made for the depth of the over-
flow water, and of the weight of the parts, the weir under consideration is in
equilibrium in all positions. Hence it follows that it is possible, even in the case
of great falls, to balance the weir very nearly even without forming a right angle
between the two planes under consideration, and to operate it easily by means of a
relatively slight upward reaction. Control can then be exerted either by means of
windlass or by means of said windlass and reservoirs G H, whose action is herein-
after set forth.

page_text: The auxiliary reservoir G, which is water tight and distinct from the float L,
has for object in the case of damming great bodies of water, to increase the upward
reaction in proportion as the door yields under the action of a float which increases
the thrust and the depth of the water running over. Its further action allows of
diminishing to the same extent the initial reaction of the float, and consequently of
relieving the tension of the cable I. It also allows of relieving the strain on the
windlass, in the sense that at the moment of complete lowering of the weir by
reason of strong floods, water may be introduced by gravity into the reservoir G,
this water, at the moment of raising the weir, being sucked out by means of any
suitable apparatus, or forced out by means of compressed air obtained by utilizing
the fall of the weir itself.
The upper auxiliary reservoir H is also distinct from the float F and from the
reservoir G. By means of a pipe d and cock e, it may be caused to receive a
certain amount of water from the up stream water and by means of a pipe d¹ and a
towards
cock e¹, it can be caused to discharge this water, or a portion of the same,
the down-stream side.
By this means, by the simple operation of these cocks which can be effected from
within one of the shafts K, the preponderance of the reaction of the float F or of
the said float and reservoir G can be diminished or increased.
A cover plate M N, capable of motion about the axis O, bears on the float F
when the latter becomes slightly elevated above the sole plate by reason of the
existence of a certain height of water on the downstream side, which it is advan-
tageous to utilize in order to diminish to an equal extent the depth of foundation of
the chamber L. The cross beam N in touching the under side of the fixed floor T,
ensures the horizontality of the cover plate M. This cover plate in conjunction
with the overflow or weir face E effects a certain separation between the waters
that have run over, and the waters of the chamber L. The upper limiting position
of the float F is determined by the angle-iron Q which abuts against the cross
beams P.
Each of the shafts K moves about the axis of the journals B, in a recess formed
in the face of the pier or abutment, in such a manner that the outer face of the
shaft shall be in line with the face of the pier or abutment.
In order to obviate torsion along the length of the door, the crest R of the over-
flow or weir face E is cut away for a certain length at each side of the centre of the
door; so that the overflow water always begins to appear at said cut-away portions,
and flows there with greater force than at the side portions.
In Fig. 1 of the drawing, which is to a smaller scale than Fig. 2, the weir is
shewn in its highest position when damming, corresponding to the least discharge
of the river; it has also a tendency to rise further due to the buoyancy of the
float F being greater than the weight of the parts and the thrust of the water on
the upstream side.
In this position the weir can be lowered, and adjusted to the required height by
the traction exerted by the windlass J.
This traction can be aided or its power reduced by causing water to enter either
into the reservoir H, or into the reservoir G, or into both, particularly when it is
desired, through fear of strong floods, to cause the weir to disappear altogether.
Under these conditions the preponderance of the float does not completely disappear
the cable always exerting a certain amount of traction.
If when the weir is in the position shown in Fig. 1 with a tendency to rise resisted
by the cable and the door forming with the vertical, an angle a = 20 degrees approxi-
mately, a flood should happen, or ice should accumulate momentarily against the
crest of the door, and the float would yield for a moment; but equilibrium will
again be re-established by the immersion of a portion of the auxiliary air reservoir G,
whose presence is then necessary.
When the discharge diminishes or the ice has cleared away by passing over the
weir face, then the weir rises automatically.
It will be seen from the arrangements described and shown, that the apparatus

page_text: is such, and is always in such a position, that it is easy without excessive effort to
regulate its position by means of the windlass J. It will also be seen that
particularly in the case of damming large bodies of water, the reservoirs G H may
aid efficiently in operating the weir, by increasing or diminishing the upward force,
and that for actions due to temporary causes the door can operate automatically.
Dated this 31st day of July 1891.
L. DEBARLE.
By L. W., per F. B.
COMPLETE SPECIFICATION.
Improvements in Movable Weirs.
I, LOUIS DEBARLE of 15 Rue des Halles, Paris, France, Engineer, 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:-
This invention has for object the easy regulation by damming of a river or water
course by means of a movable weir capable of being easily raised and lowered to
its full extent.
A weir according to this invention comprises a door or shutter (hereinafter
called a door) and a float connected together and jointed to a common horizontal
axis.
Referring to the drawings filed with my Provisional Specification
-:
The door A, situated between piers or abutments, at the sides of the river, is
capable of turning about journals B arranged in an extension of the sole plate C,
and is connected by arms D of sector-shape to a cylindrical or prismatic float F.
This float may be provided with inlet and outlet to render it capable of serving as
a tunnel or passage from one bank of the river to the other. When the difference
of level above and below the dam is sufficiently great, the float F is surmounted by
auxiliary reservoirs G H which aid in working the weir.
The float F is coupled by means of a cable I to a windlass J, (a portion only of
which is shewn in the drawings) and it is furnished at each end with a shaft or
well K in each of which is located a ladder or a staircase to allow of the passage
from one bank to the other. This is of course, only practicable when the float is
of large diameter.
Below the sole plate, and along the whole length of the door, or of each of the
doors, if there be more than one, is provided a chamber L with a curved bottom;
in this chamber the float F is capable of entering and moving. In the angle u of
this chamber are fixed the pulleys bb... around which and around the
pulleys
attached to the float, is passed the cable I which, passing up a
well formed in one pier or abutment (Fig. 1) is wound on the windlass J. A diver
is able to descend through the well through which the cable I passes, into the
chamber L and to ascertain whether all is in order therein.
... g
Strong female caps c are fixed on the sole plate C, at the angle formed by the
sole plate with the chamber L, and on the right of each of the sector arms; they
engage with other male caps c¹ fixed to the corresponding sector arms. These
caps serve as hinges to the journals B..., which abut against their outer cheeks
or faces.
Between each pair of journals B.. there is fixed on the sole plate a
metallic sheet f..., the edge of which is very near the lower edge of the door,
exactly in the extension of the theoretical axis of the journals B. Thus along
this theoretical axis and between the journals, there exists only a very narrow
passage to which there may be fitted, if desired, a small metallic tube or any other
packing.
The weir formed as above described has the following characteristic property;
viz. if the door makes on the right of the vertical line passing through the axis

page_text: of the journals, an angle a equal to the angle ẞ which is made below the horizontal
line by the plane passing through the axis of the journals and the centre of
pressure of the float; and if on the other hand deduction is made for the depth of
overflowwater and of the weight of the parts, the weir under consideration is in
equilibrium in all positions. Hence it follows, that it is possible, even in the case
of great falls, to balance the weir very nearly, even without forming a right angle
between the two planes under consideration, and to operate it easily by means of
a relatively slight upward reaction. Control can then be exerted either by means
of a windlass, or by means of said windlass and reservoirs G H, whose action is
hereinafter set forth.
The auxiliary reservoir G, which is water-tight and distinct from the float F,
has for object, in the case of damming great bodies of water, to increase the
upward reaction, in proportion as the door yields under the action of a flood which
increases the thrust and the depth of the water running over. It further allows
of diminishing to the same extent the initial reaction of the float, and consequently
of relieving the tension of the cable I. It also allows of relieving the strain on
the windlass, in the sense that at the moment of complete lowering of the weir by
reason of strong floods, water may be introduced by quantity into the reservoir G,
this water at the moment of raising the weir being sucked out by means of any
suitable apparatus, or forced out by means of compressed air obtained by utilizing
the fall of the weir itself.
The upper auxiliary reservoir H is also distinct from the float F and from the
reservoir G. By means of a pipe d and cock e, it may be caused to receive a
certain amount of water from the up-stream water; and by means of a pipe d' and
a cock e¹, it can be caused to discharge this water, or a portion of the same, towards
the down stream side.
By this means, by the simple operation of these cocks, which can be effected
from within one of the shafts K, the preponderance of the reaction of the float F
or of the said float and reservoir G can be diminished or increased.
A cover plate M N, capable of motion about the axis O, bears on the float F
when the latter becomes slightly elevated above the sole plate, by reason of the
existence of a certain height of water on the downstream side, which it is
advantageous to utilize in order to diminish to an equal extent the depth of founda-
tion of the chamber L. The cross beam N in touching the under side of the fixed
floor T, ensures the horizontality of the cover plate M. This cover plate in con-
junction with the overflow or weir face E, effects a certain separation between the
waters that have run over, and the waters of the chamber L. The upper limiting
position of the float F is determined by the angle-iron Q which abuts against the
cross beam P.
Each of the shafts K moves about the axis of the journals B, in a recess
formed in the face of the pier or abutment, in such a manner that the outer face of
the shaft shall be in line with the face of the pier or abutment.
In order to obviate torsion along the length of the door, the crest R of the over
flow or weir face E is cut away for a certain length at each side of the centre of
the door; so that the over-flow water always begins to appear at said cut-away
portions, and flows there with greater force than at the side portions.
In Fig. 1 of the drawing which is to a smaller scale than Fig. 2, the weir is
shewn in its highest position when damming, corresponding to the least discharge
of the river; it has also a tendency to rise further due to the buoyancy of the
float E being greater than the weight of the parts and the thrust of the water on
the upstream side.
In this position the weir can be lowered, and adjusted to the required height by
the traction exerted by the windlass J.
This traction can be aided, or its power reduced by causing water to enter either
into the reservoir H, or into the reservoir G, or into both, particularly when it is
desired, through fear of strong floods, to cause the weir to disappear altogether.

page_text: Under these conditions the preponderance of the float does not completely disappear,
the cable always exerting a certain amount of traction.
If when the weir is in the position shewn in Fig. 1, with a tendency to rise
resisted by the cable, and the door forming with the vertical, an angle a = 20 degrees
approximately, a flood should happen, or ice should accumulate momentarily against
the crest of the door, the float would yield for a moment; but equilibrium will
again be re-established by the immersion of a portion of the auxiliary air
reservoir G, whose presence is then necessary.
When the discharge diminishes or the ice has cleared away by passing over the
weir-face, then the weir rises automatically.
It will be seen from the arrangements described and shewn, that the apparatus is
such, and is always in such a position, that it is easy without excessive effort, to
regulate its position by means of the windlass J." It will also be seen that
particularly in the case of damming large bodies of water, the reservoirs G H may
aid efficiently in operating the weir, by increasing or diminishing the upward
force, and that for actions due to temporary causes the door can operate
automatically.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. A weir comprising a door A capable of rotating about an axis at B, and
joined by arms D with a float F immersed in the water on the downstream side the
said float having sufficient upward reaction or buoyancy to place the whole apparatus
in a condition bordering on equilibrium, but being under the control of a
windlass J to which the float is attached by a cable I passing over the pulleys b b
and b
2. In a weir of the kind referred to in the previous claim, the combination with
the float F, of auxiliary reservoirs G H, the said reservoirs facilitating the manipu-
lation of the weir by the windlass J, particularly in cases when large bodies of
water are retained.
Dated this 24th day of August 1891.
L. DEBARLE.
By L. W., per F. B.