FIELDOFTHEINVENTION

The present invention relates to a gate valve of the type used to control media flow through an aperture. The invention finds applications in a variety of hydraulic installations, such as those for waste water treatment.

BACKGROUNDOFTHEINVENTION

Gate valves are well known. Such devices are used in many different applications. Typically, gate valves are found in public works, such as irrigation installations or waste water treatment facilities where water flow at a relatively low pressure needs to be controlled.

Gate valves currently available on the market suffer from a number of different drawbacks related to their ease of installation, cost and reliability. Therefore, there is a need in the industry to provide improved gate valves that alleviate to at_ least some degree the drawbacks of current products.

SUMMARYOFTHEINVENTION

In one broad aspect, the invention provides a gate valve having a structure defining media flow aperture and guide rails on either side of the media flow aperture. A valve body engages the guide rails that direct the movement of the valve body between an opened position to allow media flow through the aperture and a closed position to prevent media to flow through the aperture. An elongated channel member defines a sealing surface adjacent the media flow aperture. The valve body has a sealing assembly for engaging the sealing surface and

guide rail engaging members for allowing the valve body to move on the guide rails between the opened and closed positions. The guide rail engaging members are offset with relation to the sealing assembly in a direction of media flow through the aperture. At least one bracket secures the channel member to the structure defining the media flow aperture.

In a second broad aspect the invention provides a gate valve having a media flow aperture and guide rails on either side of the media flow aperture. A valve body is mounted on the guide rails that direct the movement of the valve body between an opened position to allow media flow

- through the -ape-rt-ure -and.. a__clαsed position to prevent media to flow through the aperture. The valve body has guide rail engaging members for allowing the valve body to move on the guide rails between the opened and closed positions. Each guide rail has at least two elongated segments positioned end-to-end one with respect to the other and a link member connecting the two elongated segments in an end-to-end relationship. The two elongated segments define a valve body engaging surface on which at least one of the guide rail engaging members travels during movement of the valve body between the opened and closed positions. The link member is located remote from the valve body engaging surface to prevent interference with the guide rail engaging member during movement of the valve body between the opened and closed positions.

In a third broad aspect, the invention provides a gate valve having a valve body for selectively opening or closing a media flow aperture and a valve head supporting

a valve body actuator mechanism. An elongated rod is mounted to the valve body and to the valve head, the valve body actuator mechanism being in driving engagement with the elongated rod for imparting motion to the elongated rod in order to selectively open or close the media flow aperture. A movable connection is provided between the valve head and the valve body actuator mechanism, the movable connection allowing the valve body actuator mechanism to move with relation to said valve head to accommodate displacements of the elongated rod occurring in a generally transverse direction to the motion of the elongated rod imparted by the valve body actuator mechanism.

In a fourth broad aspect the invention provides a valve body for a gate valve having a media flow aperture, the valve body being movable between an opened position to allow media flow through the aperture and a closed position to prevent media to flow through the aperture. The valve body has an edge portion having a top part, a bottom part and a pair of opposite sides. A main panel is provided within the edge portion to prevent media flow through the aperture when the valve body is in the closed position. The main panel has a bowed surface produced by a generatrix that extends in a direction from the top part to the bottom part of the edge portion.

In a fifth broad aspect the invention provides a sealing assembly for a gate valve. The sealing assembly has an elongated outer shell defining an internal space and a sealing body in the internal space, the sealing body being more compliant than the outer shell. The outer shell

has an opening exposing a portion of the sealing body to allow the sealing body to contact a sealing surface through the opening.

BRIEFDESCRIPTIONOFTHEDRAWINGS A detailed description of examples of implementation of the present invention is provided hereinbelow with reference to the following drawings, in which:

Figure 1 is a front elevational view of a valve gate constructed according to a non-limiting example of implementation of the invention;

Figure 2 is a cross-sectional view taken along lines A-A in Figure 1;

Figure 3 is an enlarged cross-sectional view takerT along lines B-B in Figure 1;

Figure 4 is an enlarged cross-sectional view taken along lines C-C in Figure 1;

Figure 5 is an enlarged cross-sectional view taken along lines D-D in Figure 1 (the valve body being omitted for clarity) ;

Figure 6 is an exploded perspective view of a gave valve according to a variant, some elements of the gate valve being omitted for clarity;

Figure 7 is a perspective view of the valve head of the gate valve according to another variant of the invention;

Figure 8 is a perspective view of the valve body ,of the gate valve according to yet another variant of the invention; Figure 9 is a perspective view of a gate valve using the valve head and the valve body shown in Figures 7 and

8 ; and

Figure 10 is a perspective view of the gate valve shown in Figure 9, but installed on a different concrete support structure.

In the drawings, embodiments of the invention are illustrated by way of example. It is to be expressly understood that the description and drawings are only for purposes of illustration and as an aid to understanding, and are not intended to be a definition of the limits of the invention.

DETAILEDDESCRIPTION

With reference to Figures 1 and 2, the gate valve 10 ^" is mounted to a concrete support structure 12 to control the flow of water through the concrete support structure 12. The concrete support structure may be part of an irrigation system, a waste water treatment system or any other hydraulic installation where water flow at a relatively low pressure needs to be controlled. The gate valve 10 has a valve body 14 in the general form of a panel that closes or opens the aperture formed in the concrete support structure 12 through which water flows. The valve body 14 is caused to slide up and down in order to open or close the aperture. The sliding movement is imparted to the valve body 14 via an elongated rod 16. An actuator mechanism 18 mounted on a valve head 20 raises or lowers the rod for, in turn, raising or lowering the valve body 14.

Figure 3 is an enlarged cross-sectional view of the

^,

-6- valve body 14. A sealing assembly is mounted on the periphery of the valve body 14 to prevent water seepage. The sealing assembly includes three generally rectilinear sealing sections. The first rectilinear sealing section is mounted along the top edge of the valve body 14 and the two others are placed along the side edges of the valve body 14. All the rectilinear sealing sections extend the full length the respective edges of the valve body 14 and meet at the adjacent corners of the valve body. Figure 3 shows one of the rectilinear sealing sections 22 mounted on the side of the valve body 14. As the drawing shows this section runs generally vertically. The rectilinear sealing section 22 on the opposite side of the valve body

—1-4 is- ^~ ±dentical-. Each -rectili-near sealing -section 22 Jaas an outer shell 24 in the form of a channel made of ultra¬ high molecular weight synthetic material. The outer shell 24 has a pair of main walls 25 to which are mounted respective flaps 28. The flaps 28 are hinged to the respective main walls 25 thus allowing the flaps 28 to flex with respect to the main walls 25. The flaps 28 do not connect with one another leaving an opening 29 between them. A sealing body 30 made of softer and more compliant synthetic material than the material of the outer shell 24 is placed in the void formed by the outer shell 24 and it is exposed through the opening 29. The sealing body 30 thus can contact an external sealing surface to form a seal.

The main walls 25 are somewhat shorter than the sealing body 30, leaving a gap from a backing plate 32 on which the rectilinear sealing section 22 is mounted. This gap allows the sealing body 30 to compress when the outer

shell 24 is urged toward the backing plate 32. Thus, as the entire valve body 14 is urged toward the sealing surface, the resulting displacement will cause the outer shell 24 to slightly move back toward the backing plate 32 and further compress the sealing body 30. The thus compressed sealing body 30 will create an augmented contact pressure with the sealing surface resulting into a better overall seal.

The purpose of the flaps 28 is mainly to protect the softer sealing body 30 exposing it only where it contacts the sealing surface. The flexibility of the flaps 28 with relation to the main walls 25 allows the outer shell 24 to move back toward the -backing plate -32, as described earlier.

The rectilinear sealing section 22 is secured laterally on the backing plate 32 between an inverted L- shape shoe 34 that fits on the backing plate 32 and a projecting lip 36 which is an extension of the panel forming the valve body 14. ' Both the lip 36 and the inverted L-shape shoe 34 allow the outer shell 24 to move toward and away from the backing plate 32.

The rectilinear sealing section 22 is received in a channel structure 38 that is secured to the concrete structure 12. The channel structure 38 is generally S- shaped in cross-section and defines a cavity 39 in which the rectilinear sealing section 22 is received. The cavity 39 is formed by three walls, namely wall 41, wall 43 and wall 45. The wall 45 constitutes the sealing surface that is engaged by the sealing body 30 as the valve body 14

moves up and down.

A flat elastomeric gasket 51 is mounted between the channel structure 38 and the concrete support structure 12.

The channel structure 38 is mounted to the concrete support structure 12 via brackets 49. In Figure 3 only

^' one bracket 49 is shown, it being understood that for a typical installation a plurality of such brackets 49 will located in spaced apart relationship along the channel structure 38.

. The. bracket....43 can _be__.s.een ...in gx.ea£ex_. detaU in. Figure 6. The bracket 49 is shaped to mate with the channel structure 38 and thus keep it in place during the operation of the valve body 14. The bracket 49 is attached to the surface of the concrete support structure 12 by any suitable manner. Examples include embedding the bracket 49 in the concrete or using fasteners to mount the bracket 49 to the concrete surface, among many other possibilities. It should be expressly mentioned that the structure of the bracket 49 is not an essential element of the invention and many different bracket designs can be considered here without departing from the inventive concept.

Referring back to Figure 3, the channel structure 38 is mounted to the bracket 49 by bolts 47.

The guide rails 15 that assist the movement of the valve body 14 during the opening or closing of the valve

gate 10 are mounted along the sides of the valve body 14. Each guide rail 15 is in the form of a hollow tube having a circular cross-sectional shape and providing a curved valve body engaging surface. Guide rail engaging members 40 made of ultra-high molecular weight synthetic material ride on the guide rails 15. In the example shown in Figure 3, four such guide rail engaging members 40 are provided, one near each corner of the valve body, but it will be plain to the person skilled in the art that more or less, guide rail engaging members 40 can be used without departing from the spirit of the invention. Each guide rail engaging member 40 has a surface that is complementary to the valve body engaging surface of the

—respective- -guide- r-a-il- -15- _* -- -I-n the- example _ illiαstnated _in_ the drawings the valve body engaging surface is arcuate and the guide rail engaging members 40 have arcuate recesses that fit on the arcuate surface of the guide rail 15.

The guide rails 15 are attached to the brackets 49 with bolts 47.

The guide rail 15 is separate and spaced from rectilinear sealing section 22 along the direction of water flow through the valve gate 10. The guide rails 15 will support the valve body 14 when the valve body 14 is raised and the seal assembly 22 is no longer engaged in the channel structure 38.

Figure 4 illustrates the rectilinear sealing section of the seal assembly mounted on the upper edge of the valve body 14. The rectilinear sealing section is very

similar to the rectilinear sealing section 22 with the exception that the outer shell uses a single side wall and a single flap to hold the elastomeric sealing body. The person skilled in the art will recognize that the same seal design as the one on the sides of valve body 14 can be used without departing from the spirit of, the invention.

Figure 5 illustrates a seal member for the bottom edge of the valve body 14. Specifically, the valve body

14 includes an elongated resilient member 42 made of soft and compliant material. When the valve body 14 is in the closed position, it engages a sealing surface 44 that is formed ^" on ^~ a—channel-like struct-ure --attached,, to the. concrete structure 12 and facing the lower edge of the valve body 14.

Figure 6 is an exploded perspective view of the gate valve 10 where the valve body 14 has been omitted for clarity. The gate valve 10 includes a framework 44 that is attached to the concrete structure 12 (not shown) surrounding the aperture through which water flows. The framework 44, which includes the channel structure 38 and a resilient gasket 51, is secured to the concrete structure 12 by using brackets, such as the brackets 49 previously discussed. In Figure β a variety of such brackets are shown. It will be understood that other types of brackets can be used without departing from the spirit of the invention. By providing a selection of different brackets, the installation of the gate valve 10 is simplified significantly since no custom fastening system needs to be made for every different installation.

-li¬ lt suffices for the designer or installer to pick the appropriate bracket in the set of available brackets.

The modularity of the gate valve 10 can also be extended to the guide rails 15 which may be made into different sections that can be assembled on site instead of requiring a custom fabrication for each installation. Specifically, each guide rail 15 (only one being shown in Figure 6) includes two or more different segments 46 that are positioned end to end and secured to one another by links 48. The links 48 are positioned remotely from the surface of the guide rails on which the guide rail engaging members 40 ride to prevent interference. The assembly of the gudde--rails -1-5 from two -or more. segments is facilitated by pre-drilling all the components such as to facilitate fastener placement.

Figure 7 illustrates a variant of the valve head 18. In this example, the valve head 50 is in the form of a cross-member 52 with receptacles 54 at each end for receiving the end portion of a guide rail 15. The receptacles 54 have a shape complementary to the shape of the guide rails 15 (not shown) to create a solid joint. Fasteners, such as bolts, received in pre-drilled holes secure the assembly. A valve body actuator mechanism 56 is mounted on the cross-member 52. The valve body actuator mechanism 56 receives the rod 16 and raises and lowers the rod 16 for, in turn, raising or lowering the valve body 14. The valve body actuator mechanism 56 can be mechanical or use a motor. The variant shown in Figure 7 is mechanical and requires a large hand wheel (not shown) that threadedly engages the rod 16 and that pulls the rod

16 up as it is rotated in one direction or lowers the rod as it is rotated in the opposite direction. Various different possibilities exist to drive the rod 16 without departing from the spirit of the invention. Another example is shown at Figure 1 where the rod 16 is in the form of a rack. A lever engaging the rod 16 via gears is rotated to lower or raise the rod 16.

The valve body actuator mechanism 56 is mounted to the cross-member 52 • via a movable connection to accommodate lateral movements of the rod 16 in • some installations where the valve body 14 may not be perfectly square with relation to the remainder of the gate valve IO. ^" -" ^' Irr ^~ "a. particular- -and - non-limiting example ...Q£__ implementation, the movable connection is in the form of a pivot that allows the valve body actuator mechanism 56 to rock on the cross member 52 about axis 58. Consider the example where cross-member 52 is not perfectly horizontal due to a slight difference in length between the guide rails 15. A fixed (non-movable) joint between the valve body actuator mechanism 56 and the cross-member 52 will force the rod 16 to bend due to the lateral motion that the rod 16 undergoes as it is raised or lowered. This bending is shown in a highly exaggerated manner in Figure 7. This creates stresses that are undesirable. In contrast a movable connection between the cross-member 52 and the valve body actuator mechanism 56, will prevent or at the very least reduce such bending of the rod 16.

Figure 8 illustrates in greater detail the structure of the valve body 14 that has in this example a bowed main panel 60. The shape of the main panel 60 is produced by a

generatrix that extends from top to bottom. In the example shown the generatrix is vertical and produces a shape that is a segment of a cylinder. A bowed main panel 60 is advantageous over a flat one because it can withstand pressure better due to its curvature. As a result, the main panel 60 can be made thinner providing weight and raw material reduction. The valve body 14 includes two secondary panels that form in conjunction with the main panel 60 a fully closed structure to prevent the flow of water when the valve body 14 is in the closed position. Particularly, the valve body has a top secondary panel 62 and a bottom secondary panel 64 shaped as segments of a circle. The top secondary panel 62 carries- a connection 66- to which attaches the rod. 16 (not__ shown) . A link member 68 extending from the top secondary panel 62 to the bottom secondary panel 64 is provided to transfer loads from the top secondary panel 62 to the bottom secondary panel 64, imparted to the top secondary panel 62 by the rod 16 during the raising or the lowering of the valve body 14. A web 70 closes the space between the link member 68 and the main panel 60. The link member 68, in the form a tube, also protects the threaded section of the rod 16 from debris when valve body 14 is in open position and rod 16 is in non-rising configuration. A rod having a non-rising configuration is a rod that engages in a nut secured to the link member 68. As the rod turns, the nut and the entire valve body 14 are pulled up on the rod as the rod progressively enters the tubular link member 68.

The web 70 rigidifies the link member 68 to the top secondary panel 62 and the bottom secondary panel 64 and

at the same time prevents flexible waste materials such as pieces of fabric carried by the water flow to become entangled around the link member 68.

Figures 9 and 10 are perspective views of different installations of the gate valve. In figure 9 the gate valve is shown installed flat against the concrete structure 12, the gate valve being retained to the concrete structure 12 via a set of brackets dimensioned specifically for such type of installation. In Figure 10 the gate valve is installed within the concrete structure, specifically it is placed in a recess. The mounting of the various components of the gate valve in this recess

^" "can ""be" done- also with -suitable- brackets .or by..JjnbedcLLng._ one or more of those components in the concrete mass.

Although various embodiments have been illustrated, this was for the purpose of describing, but not limiting, the invention. Various modifications will become apparent to those skilled in the art and are within the scope of this invention, which is defined more particularly by the attached claims.