DESC:The following specification particularly describes the invention and the manner in which it is to be performed

FIELD OF INVENTION
The invention relates to hydraulic gates installed on spillways of dams, barrages and weirs, to regulate or control outflow of water. The gates are classified based on their shape & type of movement in various categories like vertical lift type, radial / sector type and tilting type gates. Sometimes they are also classified based on primary source of power required for their operation into electrically operated gates and water pressure operated automatic gates. Present invention relates to a water pressure operated automatic radial gate.

BACKGROUND OF INVENTION AND PRIOR ART
Water pressure operated automatic radial and sector type gates have been in use for several years now. Few of these gates include automatic gate for Irrigation canals (US Patent 1,130,097) granted to R V Meikle, automatically controlled hydraulic gate and gate control (US Patent No 2,984,986) granted to R A Hill, automatic water gate construction (US Patent No 3,739,585) granted to Jacques Dobouchet and gate for controlling upstream water level (US Patent 5,516,230) granted to Bargeron et al. While the gates by Meikle, Hill & Bargeron respond to upstream water levels, the one by Dobouchet responds to downstream water level. While gates by Meikle, Hill & Dobouchet employ floats/floatation chambers, the gate by Bargeron employs a huge overhead counterweight (above upstream water level) spanning across the width of gate.
The automatic radial & sector gates described above work on principle of balance of i) opening moment caused by water load acting on the gate leaf, ii) closing moment caused by self weight of gate & overhead counterweights iii) opening / closing moments caused by floats/floatation chambers (iv) intrinsic frictional moment of gate, that opposes movement of the gate towards both opening or closing.
When the opening moment acting on gate (due to water load and/or floats or floatation chambers) becomes more than sum of closing moment acting on gate (due to self weight and/or floats) and intrinsic frictional moment, the gate moves towards opening. Conversely, when closing moment acting on gate (due to self weight) becomes more than sum of opening moment (due to water load and/or floats) and intrinsic frictional moment, the gate moves towards closing.
The automatic gate by Meikle consists of a float that moves vertically upward & downward in a well filled with water, and is connected to gate through a system of wire rope & pulleys. With rise & fall of upstream water level, the float moves up & down developing reducing and increasing ‘closing’ moments respectively, and makes the gate leaf that is connected to it through wire ropes and pulleys/drums open and close accordingly.
The automatic gate by Hill consists of a floatation chamber constructed in the gate body behind the upstream skin plate. This floatation chamber is connected to water reservoir on upstream side and has an outlet pipe terminating at a specific elevation on downstream side, so that the chamber can hold water only upto the said specific elevation at any given position of gate. When the reservoir water level rises beyond the said specific elevation, the difference in upstream water level in reservoir and controlled water level in the floatation chamber creates necessary ‘opening’ moment to open the gate. When incoming discharge reduces and u/s water level falls below the said specified elevation, the said ‘opening’ moment becomes zero and closing moment due to self weight closes the gate.
The automatic gate by Dobouchet responds to rise and fall of downstream water levels. It consists of a upstream side sector shaped gate apron (gate leaf) located on upstream side of pivotal axis and a sector shaped float mounted on downstream side of said pivotal axis. The sector shaped float is submerged in a tank which is connected to downstream pool of water. When the water level in d/s pool and the tank reduces, the d/s side sector shaped float goes down, which creates ‘opening’ moment for the gate. This makes the sector shaped u/s side container (gate leaf) go up or open out. This movement allows the water from u/s side to flow to the d/s side from below the said apron (gate leaf). After some time, when the water level in d/s pool goes up, the d/s side float moves up creating ‘closing’ moment, that moves the u/s apron (gate leaf) downwards or towards closure.

The automatic gate by Bargeron does not have floats, but consists of a radial gate leaf with a bulky non-submersible overhead counterweight spanning across the width of gate. When the upstream water level rises above the self actuating level, the opening moment due to water load or hydraulic thrust acting on the upstream face of gate becomes more than sum of closing moment due to self weight & intrinsic frictional moment of the gate. As the gate opens up, the opening moment due to water load reduces and soon becomes equal to sum of closing moment due to self weight and intrinsic frictional moment. At this moment, the gate settles into a partially open position. If the discharge reduces, the closing moment due to self weight becomes more than sum of opening moment due to water load and intrinsic friction, and the gate starts to close.

As described above, all the automatic radial / sector gates of prior art consist of either floats which require arrangements for filling & emptying water or overhead / non-submersible counterweights which essentially make them bulky & difficult for fabrication and installation. Also, these gates cannot allow flow of water ‘above’ them as this would disturb the buoyant moments due to floats and closing moments due to counterweights, are hence unsuitable for installation where the gates are likely to be submerged.
Further, these gates get self actuated only when the upstream or downstream water level reaches a specified elevation. They do not have any arrangement for their mechanical operation, when upstream or downstream water levels are lower than self actuating levels. Such mechanical operations are routinely required for letting water on downstream side and also for maintenance purposes.

OBJECT OF THE INVENTION
The object of this invention is to have an automatic radial gate that, unlike present state of the art automatic radial / sector gates,
a) opens out automatically in response to rise in upstream water level and closes back in response to fall of upstream water level, without need for floats / floatation chambers or bulky non-submersible / overhead counterweights,
b) allows flow of water ‘over’ or ‘above’ it, making its installation possible under submersible conditions &
c) is provided with a mechanical arrangement that does not interfere with normal automatic operation, making it possible to perform opening & closing operations of gate when upstream water level is below the specified self opening or first predetermined level.

STATEMENT OF THE INVENTION
In accordance with the present invention, there is provided an automatic submersible radial gate with mechanical operating arrangement for dams, weirs & barrages, that
i) opens out automatically under action of hydraulic thrusts & gravity forces when upstream water level rises beyond a predetermined level, achieves fully open position with further rise in upstream water level above a second predetermined level and closes back in response to fall of upstream water level below a third pre-determined level due to specific profile of its upstream skin plate and without need for floats or bulky overhead counterweights,
ii) remains submerged in fully open position when upstream level rises beyond the said second pre-determined level due to its compact submersible type counterweights, &
iii) can be opened and closed when upstream water level is below said self actuating or first predetermined level with help of its unique mechanical operating arrangement.

SUMMARY OF INVENTION
An automatic submersible radial gate with mechanical operating arrangement is meant for controlling outflow from dams, weirs & barrages, is disclosed in accordance with an embodiment of the present disclosure.

The said gate system comprises
i) a set of anchor components
ii) a movable gate leaf
iii) a sealing system
iv) a trunnion assembly
v) a pair of stoppers for gate leaf
vi) a friction damping arrangement
vii) a mechanical operating arrangement

The anchor components supporting the trunnion assembly and one part of sealing system are partially embedded in RCC piers, weir body wall & bridge at one end, and partially project out at another end in the opening between RCC piers.
The movable gate leaf on which second part of sealing system is disposed is supported by a pair of trunnion assemblies. In an operative configuration, under action of hydraulic & gravity forces acting on it, the said movable gate leaf rotates about a horizontal axis to attain :
? a fully closed position when upstream water level is below the first pre-determined level
? a partially open position when upstream water level exceeds the first pre-determined level
? a fully open position when upstream water level rises beyond the second pre-determined level and
? a fully closed position when upstream water level falls below third pre-determined level
The pair of stoppers disposed on projected portion of anchor components prevent further opening of movable gate leaf beyond its fully open position
The friction damping arrangement prevents flow induced oscillations of said movable gate leaf during its opening and closing operations. One part of friction damping arrangement is disposed on movable gate leaf while other part is disposed on projected portion of anchor components.
The mechanical operating arrangement facilitates manual opening and closing operations of the said movable gate leaf when upstream water level is below the first pre-determined level.
The said movable gate leaf opens out automatically in response to rise in upstream water level beyond first predetermined level, retains its fully open position even after getting fully submerged during heavy floods beyond second predetermined level, and closes back completely when upstream water level recedes below third predetermined level.
BRIEF DESCRIPTION OF ACCOMPANYING DRAWINGS
The invention is now described herein with the help of
Figure 1 & Figure 2 (on sheet Nos.1 & 2) show automatic submersible radial gate with mechanical operating arrangement in closed position, in upstream & downstream isometric views respectively.
Figure 3A (on sheet No.3) & Figure 3B (on sheet no. 4) show the parts of anchor components (20) in upstream and downstream side isometric views respectively.
Figure 4A (on sheet No.5) & figure 4B (on sheet no.6) show the movable gate leaf (30) in upstream and downstream side isometric views respectively.
Figures 5A & 5B (on sheet No.7) show upstream and downstream side isometric views of one part of sealing system (50) that is disposed on gate leaf while figure 5C (on sheet no. 8) shows other part of the said sealing system that is disposed on anchor components.
Figures 6A & 6B (on sheet no. 9) show upstream and downstream side isometric views of left side part of trunnion assembly (60).
Figure 7A & 7B (on sheet No. 10) show upstream and downstream side isometric views of left side stopper for gate leaf (65a).
Figures 8A, 8B, 8C, 8D & 8E (on sheet no.11) show isometric views of the friction damping arrangement (70).
Figures 9A, 9B, 9C, 9D & 9E (on sheet No.12) show isometric views of mechanical operating arrangement (80).
Figures 10A, 10B & 10C (on sheet No.13) & figures 10D & 10E (on sheet no. 14) , show diagrammatic representations of the automatic submersible radial gate with mechanical operating arrangement in sectional side elevation. Figures 10A, 10B & 10C show the gate in closed, partially open and fully open position respectively, while figures 10D & 10E show the gate in fully open and fully closed position respectively.
Figures 11A shows the automatic submersible radial gate with mechanical operating arrangement in sectional side elevation in closed position . Figures 11B & 11C show the gate in sectional side elevation, operated and held in partially open & fully open position respectively by hydraulic/mechanical jacks.

DETAILED DESCRIPTION OF INVENTION WITH REFERENCE TO DRAWINGS
As shown in figures 1 & 2, the present disclosure comprises
i) a set of anchor components (20) that are partially embedded in RCC piers (11a & 11b), weir body wall (12) & Steel/RCC bridge (14) at one end and partially project out at another end in the opening (13) between RCC piers
ii) a movable gate leaf (30) disposed in opening (13)
iii) a sealing system (50)
iv) a trunnion assembly (60)
v) a pair of stoppers for gate leaf (65a & 65b)
vi) a friction damping arrangement (70)
vii) a mechanical operating arrangement (80)

As shown in figures 3A & 3B, anchor components (20) comprise a pair of trunnion girders (21a & 21b) for supporting trunnion brackets, a pair of first anchor girders (22a & 22b) for supporting brackets of angular levers, a pair of anchor frames for curved side seal seats (23a & 23b), a pair of second anchor girders (24a & 24b) for supporting brackets of actuating levers, a sill beam assembly (25) for supporting bottom seal seat , a pair of third anchor girders (26a & 26b) for supporting stoppers of gate & a pair of anchor plate assemblies (27a & 27b) for support posts of adjusting bolts of friction damper assemblies.

As shown in figures 4A & 4B, the movable gate leaf (30) comprises a curved upstream skin plate (31) in shape of an arc of a circle, a downstream skin plate (32) that could be straight or curved, a plurality of vertical stiffeners (33), a plurality of horizontal stiffeners (34), a pair of end girders (35a & 35b), a pair of curved track bases (36a & 36b) disposed on upstream faces of end girders, a plurality of base plates (37) for end arms, a plurality of end arms (38), a pair of trunnion hubs (39a & 39b), a pair of bush bearings (40a & 40b) for trunnion hubs, a pair of counterweight boxes (41a & 41b) and a pair of ballast counterweights (42a & 42b) placed inside the counterweight boxes. Unlike in case of prior art, the position of centre of curvature of said curved upstream skin plate (31) is uniquely kept eccentric or away with respect to the trunnion axis (4).
As shown in figures 5A & 5B, one part of sealing system (50) is disposed on gate leaf while other part of the said sealing system that is disposed on anchor components as shown figure 5C. The said first part of sealing system comprises a pair of side seal assemblies (51a & 51b) & bottom seal assembly (53) disposed on sides & bottom edge of movable gate leaf (30) respectively. In gate closed position, the flexible seals of left and right side seal assemblies abut the pair of curved side seal seats (52a & 52b) of the other part. The side seal seats are disposed on anchor frames (23a & 23b). Similarly, the flexible seal of bottom seal assembly abuts the bottom seal seat (54) that disposed on sill beam assembly (25). The flexible seals abut the seal seats when gate is in gate closed position, and create a barrier for water on upstream side to effect storage against the gate.
As shown in figures 6A & 6B, left side part of trunnion assembly (60), comprises left side trunnion support bracket (61a) and left side trunnion axle assembly (62a). The left trunnion support bracket (61a) is disposed on left side trunnion girder (21b). The respective components of right side part of trunnion assembly are disposed similarly on right side. The left & right side trunnion hubs (39a & 39b) of movable gate leaf are pivotally connected to the left and right side trunnion support brackets (61a & 61b) respectively.
As shown in figures 7A & 7B the left side stopper (65a) for gate leaf is disposed on third anchor girder (26a). The right side stopper is disposed similarly on right side. The left & right side stoppers restrict further upward movement of gate leaf beyond its fully open position by abutting with left & right side end arms respectively.
As shown in figures 8A, 8B, 8C, 8D & 8E, the friction damping arrangement (70) comprises a pair of curved friction tracks (71a & 71b) disposed on curved track bases (36a & 36b) of end girders , a pair of friction shoe assemblies (72a & 72b) disposed on lower legs of pair of angular levers (74a & 74b), the said pair of levers being pivotally connected to pair of support brackets (78a & 78b) by means of axle assemblies (79a & 79b). The support brackets are in turn are disposed on pair of first anchor girders (22a & 22b). A pair of thrust bolts (73a & 73b) is provided to friction shoe assemblies to control the compressive force exerted by them on curved friction tracks on which the latter tightly abut. Adjusting bolts (77a & 77b) are provided for angular levers to control extent of their angular displacement. The said pair of adjusting bolts is disposed on pair of adjusting nuts (76a & 76b) that are in turn welded to pair of support posts (75a & 75b). The pair of support posts is in turn disposed on anchor plate assemblies (27a & 27b).
As shown in figures 9A, 9B, 9C, 9D & 9E, the mechanical operating arrangement (80) comprises a pair of gate hoisting brackets (81a & 81b) disposed on pair of counterweight boxes, a pair of vertical lever links (82a & 82b) provided with a plurality of bush bearings (83), the said pair of lever links being pivotally connected at lower end to pair of gate hoisting brackets by means of plurality of axle assemblies (84) and pivotally connected at upper end to a pair of actuating levers (86a & 86b). The said pair of actuating levers provided with bush bearings (87a & 87b) is pivotally connected to a pair of support brackets (85a & 85b) through a pair of axle assemblies (88a & 88b) at centre and has extensions on other side to act as pair of operating handles (89a & 89b). The pair of said support brackets is disposed on pair of second anchor girders and the said pair of operating handles can be lifted upwards to ‘open’ the gate and pushed downwards to ‘close’ the gate manually or through a pair of portable hydraulic or mechanical jacks (90a & 90b);

TABLE 1 below provides a list of all components described above with their reference numerals :

TABLE 1

Numerals Description

1 First pre-determined water level (above which gate starts to open)
2 Second pre-determined water level (Upstream level at which gate achieves fully open position)
3 Third pre-determined water level (below which gate closes completely)
4 Trunnion axis or (axis of rotation for movable gate leaf)
10 Automatic Submersible Radial Gate with Mechanical operating arrangement
11a and 11b Pair of RCC Piers
12 Weir body wall or spillway
13 Opening between RCC piers (gate bay)
14 Steel or RCC service bridge
20 Anchor Components
21a and 21b Pair of trunnion girders for supporting trunnion brackets
22a and 22b Pair of first anchor girders ( for support brackets of angular levers)
23a and 23b Pair of anchor frames for curved side seal seats
24a and 24b Pair of second anchor girders for support brackets of actuating levers
25 Sill Beam assembly (For supporting bottom seal seat)
26a & 26b Pair of third anchor girders for stoppers of gate
27a & 27b Pair of anchor plate assemblies for support post of adjusting bolt of friction damping arrangement
30 Movable Gate leaf
31 Curved upstream skin plate
32 Downstream skin plate (curved or flat)
33 Plurality of vertical stiffeners
34 Plurality of horizontal stiffeners
35a and 35b Pair of End Girders
36a and 36b Pair of curved track bases disposed on U/S faces of end girder
37 Plurality of base plates for end arms
38 Plurality of end arms
39a and 39b Pair of trunnion hubs
40a and 40b Pair of bush bearings for trunnion hubs
41a and 41b Pair of counterweight boxes
42a and 42b Pair of Ballast counterweight
50 Sealing System
51a and 51b Pair of side seal assemblies
52a and 52b Pair of curved side seal seats
53 Bottom seal assembly
54 Bottom Seal Seat
60 Trunnion assembly
61 a & 61 b Pair of trunnion support brackets
62 a & 62 b Pair of trunnion axle assemblies
65 a & 65 b Pair of Stoppers for Gate leaf
70 Friction damping arrangement
71a and 71b Pair of Curved friction tracks
72a and 72b Pair of friction shoe assemblies
73a and 73b Pair of thrust bolts of friction shoe assemblies
74a and 74b Pair of angular levers
75a and 75b Pair of support posts for adjusting bolts
76a and 76b Pair of nuts disposed on support post
77a and 77b Pair of Adjusting Bolts for angular levers
78a and 78b Pair of Support bracket for angular levers
79a and 79b Pair of Axle assemblies for support brackets of angular lever
80 Mechanical Operating Arrangement
81a & 81b Pair of gate hoisting brackets
82a & 82b Pair of Vertical Lever Links
83 Plurality of bush bearings for lever link
84 Plurality of axle assemblies for vertical lever link
85a & 85b Pair of support brackets for actuating lever
86a & 86b Pair of actuating levers
87a & 87b Pair of bush bearing of actuating levers
88a & 88b Pair of axle assemblies for support brackets of actuating lever
89a & 89b Pair of operating handles
90a & 90b Pair of portable mechanical / hydraulic jacks

OPERATION IN AUTOMATIC MODE
The operation or working of the present invention in automatic mode is now explained with help of figures 10A, 10B, 10C, 10D & 10E. Figures 10A, 10B & 10C show the gate in closed, partially open and fully open position respectively, while figures 10D & 10E show the gate in fully open and fully closed position respectively.
When water level on upstream side of gate is below the first predetermined level (1), which normally refers to full reservoir level of a dam or barrage, the net opening moment due to water load acting on movable gate leaf about its trunnion axis (4 ) is less than the closing moment caused by self weight of gate. The gate therefore remains in closed position under this condition.
When upstream water level reaches first predetermined level (1) , the net opening moment due to water load acting on gate becomes equal to sum of closing moment caused by self weight of gate & intrinsic frictional moment in the gate mechanism, and the gate is on the verge of opening, as depicted in figure 10A.
When the upstream water level rises above the first predetermined level, the opening moment due to water load become more than sum of closing moment caused by self weight of gate & intrinsic frictional moment in the gate mechanism, and the gate opens out and achieves a partially open position , as depicted in figure 10B. With increasing flood discharge, the upstream water level tends to rise further, and in response to greater opening moment due to water load, the gate increases in extent of opening. When the upstream water level rises beyond the second predetermined level (2), the gate achieves fully open position, as shown in figure 10C. If the discharge increases further leading to further rise in upstream water level, the gate remains submerged in fully open position. As shown in figure 10D. During receding floods, as the incoming discharge and the upstream water level falls below the second predetermined level, the gate automatically reduces the extent of opening and achieves partially open position as shown in figure 10B again. When the upstream water level falls below the third predetermined level (3), the closing moment due to self weight becomes more than sum of opening moment due to water load and intrinsic frictional moment in the gate, and gate achieves fully closed position as shown in figure 10E. This kind of operation of gate is achieved because of suitable positioning of centre of curvature of upstream skin plate (31) in such a way that it is eccentric with respect to trunnion axis (4) of gate and also by suitable selection of its radius of curvature.
During entire opening & closing cycle of gate, the friction damping arrangement (70) provides additional frictional damping moment to prevent jerky movements and flow induced vibrations / oscillations of movable gate leaf.
Under normal circumstances, when the gate is in automatic mode, the portable hydraulic / mechanical hoist is not kept at site, and during entire automatic operation, the mechanical operating arrangement comprising gate bracket, vertical lever link & actuating lever with the operating handle passively undergo movements, as shown in figures 10A to 10E.
Thus, unlike the gates of prior art, the present invention (i) does not need any floats or overhead counterweights and (ii) is able perform its automatic opening & closing operations even on sites where high discharges are encountered leading to its complete submergence. This will make it possible to construct weirs and barrages with automatic radial/sector gates on sites where high discharges and submersible conditions encountered and gates of prior art can’t be installed.

OPERATION WITH MECHANICAL OPERATING ARRANGEMENT
Figures 11A shows the gate in closed position, while figures 11B & 11C show the gate operated and held in partially open & fully open position by hydraulic/mechanical jacks. When the upstream water level is below first predetermined level (1), the mechanical operation of gates can be achieved by lifting /holding /lowering the pair of operating handle manually (for smaller size of gates, where very small hoisting effort is required) or by engaging the pair of portable mechanical/hydraulic jacks (90a & 90b) to pair of operating handles, and operating the said jacks either manually or through external power sources. Thus, unlike the gates of prior art, the gate of present invention can be opened, held in partially or fully open position and closed with the mechanical operating arrangement when upstream water level is below the self actuating level. This arrangement facilitates letting out required quantum of water through gates to meet water demand of industries / farms located on downstream side.

TECHNICAL ADVANCEMENTS & ECONOMICAL ADVANTAGES
The technical advancements offered by present disclosure include realization of an automatic submersible radial gate system for use on dams, weirs and barrages wherein
• the movable gate leaf does not need floats or bulky counterweights for enabling its water pressure actuated ‘opening’ and ‘closing’ actions
• the movable gate leaf remains submerged & operational in fully open position during heavy floods and need not be stored ‘above water level’ to avoid malfunction or damage
• the movable gate leaf is provided with a mechanical operating arrangement which does not interfere in normal automatic operation of gate, but can be used to open, hold in partially open position & close the said gate leaf as per need, when upstream water level is below the full reservoir level

The present disclosure also offers many economical advantages over the automatic radial gates of prior art:-

• Since there are no floats or counterweights involved, the cost of gate system is substantially reduced
• Since the entire gate system including mechanical operating arrangement can get submerged, there is no need to position RCC piers supporting RCC service bridge & steel trestles supporting hoist bridge & hoists above high flood level. This substantially reduces cost of gate supporting structure
• Since the trunnion girders are located in central portion of RCC piers, no anchor bars or anchor girders are required for transferring load to RCC piers by the gate system of present disclosure. This substantially reduces the cost of steel anchorages as well as RCC piers, as lesser thickness of same is sufficient.

Throughout this specification, the word “comprise”, or variations such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.
The foregoing description of the specific embodiment will so fully reveal the general nature of the embodiment herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiment without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiment. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiment herein has been described in terms of preferred embodiment, those skilled in the art will recognize that the embodiment herein can be practiced with modification within the spirit and scope of the embodiment as described herein.
,CLAIMS: I CLAIM:

1. A submersible automatic radial gate with mechanical operating arrangement (10) for dams & barrages, comprising :
• A set of anchor components (20) that are embedded in RCC piers (11a & 11b) and weir body wall (12 ) at one end & project out in the opening (13 ) at other end;

• A movable gate leaf (30) disposed in the opening (13 ), which in an operative configuration, on account of interaction of hydraulic & gravity forces acting on it attains :
a fully closed position when upstream water level is below the first pre-determined level (1)
a partially open position when upstream water level exceeds the first pre-determined level (1)
a fully open position when upstream water level rises beyond the second pre-determined level (2) and
a fully closed position when upstream water level falls below third pre-determined level (3);
and comprises a cylindrical arc shaped upstream skin plate (31) with its centre or axis of curvature located above and on upstream side of centre line of trunnion axle assemblies (62a & 62b) ,

• a sealing system (50) for enabling the said movable gate leaf (30) to store water in closed position, having one part disposed on said movable gate leaf and other part on said anchor components

• trunnion assembly (60) for supporting and facilitating rotational movement of said movable gate leaf during opening and closing operations;

• a pair of stoppers (65a & 65b) disposed on said anchor components to prevent opening of movable gate leaf beyond its fully open position;

• A friction damping arrangement (70) to prevent flow induced oscillations of said movable gate leaf during its opening and closing operations; having one part disposed on said movable gate leaf and other part disposed on said anchor components;

• a mechanical operating arrangement (80) for facilitating manual opening and closing operations of the said movable gate leaf when upstream water level is below the first pre-determined level(1) ;

wherein the said movable gate leaf opens out automatically in response to rise in upstream water level beyond first predetermined level (1), achieves fully open position when upstream water level rises beyond second predetermined level (2), retains its fully open position when upstream water level rises further submerging the said movable gate leaf, and closes back when upstream water level recedes below third predetermined level(3)

2. A submersible automatic radial gate with mechanical operating arrangement as claimed in claim 1 above, wherein the said curved upstream skin plate (31) could be of parabolic or involute shape rather than arc of a circle
3. A submersible automatic radial gate with mechanical operating arrangement as claimed in claims 1 & 2 above, wherein the said mechanical operating arrangement is adapted to move the said gate leaf from closed to partially open position, hold it in that position and further move it to fully open position when the upstream water level is lower than the first pre-determined level manually or placing mechanical or hydraulic jacks between bridge and operating lever ; and wherein the said mechanical operating arrangement is further adapted to undergo passive movement by removing the said mechanical or hydraulic jacks, when the said gate leaf opens out & closes back automatically when upstream water level rises above the first predetermined level and falls below the third predetermined level respectively
4. A submersible automatic radial gate with mechanical operating arrangement as claimed in claims 1, 2 & 3 above, wherein the friction damping arrangement (70) can be adapted by using operating the adjusting bolts (77a & 77b) & thrust bolts (73a & 73b) to act as unidirectional locking arrangement enabling movement of said gate leaf from closed to partially open to fully open position and preventing its movement in reverse direction; the said uni-directional locking system being further adapted to allow movement of the said gate leaf in reverse direction to closed position under its own weight, by operating the said adjusting bolt
5. A submersible automatic radial gate with mechanical operating arrangement as claimed in claims 1, 2, 3 & 4 above, wherein the friction damping arrangement (70) is adapted in such a way that the pair of friction tracks (71a & 71b) are disposed on anchor components (20) and friction shoe assemblies (72a & 72b) are disposed on movable gate leaf (30)
6. A submersible automatic radial gate with mechanical operating arrangement as claimed in claims 1, 2, 3, 4 & 5 above, wherein the set of anchor components (20), and structural components of movable gate leaf (30), sealing arrangement (50), trunnion assembly (60), pair of stopper assemblies (65a & 65b), friction damping arrangement (70) & mechanical operating arrangement are made of iron, steel, stainless steel, alloy steel, aluminium, brass, bronze, fibre reinforced plastic or any other metal or alloy; side seals of side seal assemblies (51a & 51b) and bottom seal of bottom seal assembly (53) of sealing system (50) are made of natural or synthetic rubber, wood, or any other resilient polymer material and disc springs of said friction shoe assemblies (72a & 72b) are made of spring steel, stainless steel or other type of resilient metal or alloy.

Dated this 9th Day of July 2018


GODBOLE PRASHANT PRABHAKAR
APPLICANT