Improvements in and relating to Watertight Joints for Canal-lifts.
Year: 1894

page_text: Date of Application, 3rd Oct., 1894-Accepted, 24th Nov., 1894
COMPLETE SPECIFICATION
[Communicated from abroad by the Firm of FRIED. KRUPP GRUSONWERK, of
Magdeburg-Buckau, in the Empire of Germany, Manufacturers.]
Improvements in and relating to Watertight Joints for Canal-lifts.
1, HENRY HARRIS LAKE, of the Firm of Haseltine, Lake & Co., Patent
Agents, 45 Southampton Buildings, in the County of Middlesex, 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 relates to canal-lifts, and has for its object to provide reliable,
and simple automatic water-tight joints between the trough or caisson and the
upper and lower branches of the canal. According to the said invention use is
made, for this purpose, of the hydrostatic pressure which the contents of the trough
exert upon the stop-gates of the said trough. This pressure acts equally upon the
inner sides of the two gates, and forces the latter against the flanges of the trough
so long as the gates are closed and not subject to pressure on the outside. If
however one end of the trough is joined to a branch of the canal, and if the space
between the gate at such end and that of the canal is filled with water, the trough-
gate will be subject to pressure on the outside as well as on the inside, and will
therefore be in equilibrium of pressure, and the pressure acting upon the inner side
of the gate at the free or unconnected end of the trough will then tend to move the
trough in its longitudinal direction away from the aforesaid canal-branch. This
tendency, which exists when the gate is opened at the joined end of the trough, has
been, in canal-lifts heretofore known and constructed, opposed, by forcing the
trough against the canal-branch to ensure the maintenance of the joint between the
trongh and the canal.
In the lift forming the subject of the present invention the hydrostatic pressure
upon the gate at the free or unconnected end of the trough is not balanced by a
counter-pressure, but is utilized for automatically effecting the formation of a
watertight joint between the trough and the canal, by pressing the bearing surfaces
of the joint against each other.
The manner of obtaining this watertight joint will be seen from the constructional
example represented in the accompanying drawings, provision being shewn in this
example for the automatic formation of a watertight joint when changes in the
level of the water in the canal require the adjustment of the trough to different
heights.
Figures 1 to 3 represent the arrangements for the upper branch of the canal,
and the trough-end joined to the latter, in longitudinal section and in two horizontal
sections, the latter being taken on the lines, aud y, y respectively of Figure 1;
Figures 4 and 5 illustrate the arrangements for the lower branch and the
corresponding joined end of the trough in longitudinal section, and in horizontal
Bection, the latter taken on the line, of Figure 4;
Figures 1 and 44, represent the canal-branches and trough-ends separately and
with closed gates, and
Figure 6, is a general view of the arrangement, with the trough at a level
intermediate of its highest and lowest positions
As shown in Figures 1 and 2, a is the rebate for the gate 6 of the trough A, with
which rebate the trough 18 ordinarily flush, c is a second rebate which is joined to
the rebate a and extended below the trough to form a deep chamber d, and which
embraces both the rebate e for the gate f of the upper branch B, and flanges g

page_text: projecting behind the rebate e from the side walls and the bottom of the upper
branch. These flanges are extended laterally at the bottom of the upper branch to
form a wall the lower part of which is bent round to a U shape. The outer
wall of the chamber d passes behind the wall h, and the continuations of the said
wall on both sides of the upper branch, tiz. the narrow flanges 1, pass behind the
flanges g.
The flanges and the upper edge of the wall A are each provided on
the inner side with an india ubber jointing strip m.
During the last part of the upward movement of the trough, the latter is 50
guided that the indiarubber strip is maintained at a short distance from the
outer side of the wall and the flanges g, in order that it may not slide thereupon,
and only just before its stoppage is the trough displaced by its guide in the
dnection of the arrow to such an extent that the packing strip m is slightly
pressed against the flanges o.
According as the level of the water in the upper branch of the canal varies,
so will the height at which the trough is brought to rest vary, and the horizontal
part of the strip m will bear against the middle of the wall has shown, or above
or below the middle
After the trough is stopped, the slide n in the trough gate is opened and water
is admitted to the space o between the gates f and b, and to the rebate c, and its
chamber d The slide n may be situated in the gate f. By this means the gates b
and hitherto loaded only by a water pressure on one side and pressed against
their joint-faces, are placed in equilibrium of pressure so that only their own
weight has to be overcome when they are raised in order to allow the passage
of a boat. The pressure upon the inner side of the other gate of the trough
at the free ond of the same, however, continues to operate (in the constructional
example represented in the drawing it is even aided by a pressure corresponding
to the difference in the surfaces between the muer wall and outer wall of the
chamber d) and tends to move the trough in the direction of the arrow. By
this means it presses the wall and the flanges furnished with the packing
strips m, against the wall and the flanges g, so that an automatic tightoning of
the joint between the trough and the upper branch of the canal is obtained. As
the trough is always filled to about the same level, the aforesaid pressure which
has a tightening effect on the joint, will always be approximately the same, and
by suitably choosing the breadth of the indiarubber strip m, it is possible that
exactly such pressure will be brought to beat upon the unit of surface of the strip
as is most favourable for producing a tight joint
Prior to the downward movement of the trough, it is needful to lower the gates b
and, to close the slide n, and to run off the water contained in the space o between
the gates, in the rebate e, and in the chamber d, in the first place for the gates b
and to ngain receive water pressure on one side only to make a tight joint before
the trough is set in motion, and in the second place in order that, after breaking
the joint at m the water may not flow away and cause inconvenience.
The water
contained in the chamber d need only be drawn-off down to the level of the upper
edge of the wall X, the remainder being then moved down and up again with the
trough. As, however, the upper edge of the wall is sometimes higher and
sometimes lower than the position shown, according as the trough is raised more or
less to accommodate it to the varying level of the water in the canal, it is advisable
to effect the running-off of the water to a lower level than the top of the wall k.
This is done by syphon tubes p Each of the tubes p is provided with a cock 7 or
other closing device in its longer branch that terminates in a common discharge
piper for all the tubes
The lower trough-shaped edge of the wall & forms a channel in which the water
cannot sink below the lower edge of the open branch of each syphon tube p, so that
this branch is always closed by water, which does not flow out into the chamber d
when the trough moves down
When the water is to be run off from the space o and rebate c, the cocks q which
are preferably connected with each other are opened; the water then flows through

page_text: the tubes p into the pipe
until its level in the chamber d has sunk to the level of
the open end of the tubes p. The pressure upon the trough, in the direction of the
arrow, then no longer exists, and, at the commencement of the downward movement,
the trough is moved by its guide a short distance in the opposite direction to the
arrow, and the Joint thereby broken. In the continued downward movement, the
jointing-strip m cannot then slide upon the wall h.
The cocks q are closed agam prior to the downward movement of the trough so
that the open branches of the syphon tubes p remain filled with water.
In the next upward movement of the trough the chamber d again raises the
water which it had taken down with it. The cocks are not opened again until
the gates b and fand the slide n are closed, ready for the next downward
movement.
The heights of the walls hand k depend on the difference between the highest
and lowest water level m the upper branch of the canal in which boats are
to pass. If the arrangement is such that the level of the water remains always
the same, the walls h and A need only be of such a height that the syphon tubes p
find room below the bottom of the upper branch of the canal, and the chamber d
then shrinks to a rebate.
The joint between the trough and the lower brauch of the canal, as shown in
Figures 4 and 5 is obtained by a somewhat different arrangement.
Here the trough-end does not embrace the canal-branch, but the reverse is the
case, because the trough passes in from above. The vertical wall h' with the
flanges g projecting from the sides here belongs to the trough, while the lower
branch of the canal is provided with the rebate c' and the chamber d'. Otherwise
the arrangement and mode of operation are the same as above described, only
the drawing-off of the water from the intermediate spaces causes less trouble,
because the chamber d being secured to the lower branch, the water can flow
off from it downwards. As hereinabove set forth, the watertight joint is mado
automatically at the upper branch and also at the lower branch, by the hydrostatic
pressure.
Having now particularly described and ascertained the nature of the said inveu-
tion, and in what manner the same is to be performed, as communicated to me by
my foreign correspondents, I declare that what I claim is :-
First. For making a watertight joint between the trough or caisson A of a
canal-lift and the upper branch B of the canal, flanges projecting inwards from
the walls or prolongations of the walls of the trough, which flanges, in the upward
movement of the trough embrace the upper branch and pass behind flanges
projecting from its walls, so that after the filling of the space between the
gates band and after the lifting of these gates, the water pressure acting upon
the gate at the free end of the trough presses the aforesaid Hanges of the trough
against those of the canal.
Second The modified form of the joint for the lower branch of the canal,
wherein flanges project inward from the walls or prolongation of the walls of the
lower branch and in the downward movement of the trough pass in front of
flanges which project outwards from the wall of the trough.
Third. In a canal-lift the combination of the joints for the upper and lower
branches of the canal, substantially as, and for the purpose, set forth
Fourth. The canal-lift in which the end of the trough A on the side of the
upper canal branch and the end of the lower canal branch are deepened to form
chambers d and d', and the parts situated below the bottom of the flanges & and h¹
of the trough, and hand of the branches are so expanded or widened that
without preventing the formation of a proper joint the trough may be adjusted
to various heights.
Fifth. The combination, with a canal-lift such as that referred to in the
preceding claims, of syphon tubes for the discharge of the water contained in
the spaces between the gates, prior to the downward movement of the trough.

page_text: Sixth. A canal-lift having the ends of the trough and of the canal branches
constructed substantially as described with reference to the drawings, for the
purpose specified.
Dated this 3rd day of October 1894.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.