Claims:1. A device for slitting of wedges used in gate valves in thermal power plants comprising:
a clamping fixture (07) for clamping a wedge (4) to be slitted, wherein the fixture (07) is mounted on the horizontal bed (8) with a fixture hand wheel (11);
a guide rod (09) is mounted on said lower horizontal bed (08);
upper horizontal bed (05) is provided in connection with the guide rod (09) in which the horizontal bed (05) is mounted with a vertical lead screw (17) and chop saw motor (19).
2. The device for slitting of wedges used in gate valves in thermal power plants as claimed in claim 1, wherein the lower horizontal bed (08) is supported by support leg (6).
3. The device for slitting of wedges used in gate valves in thermal power plants as claimed in claim 1 or 2, wherein the guide rod (9) is provided with an extra support (18) for sturdiness during slitting.
4. The device for slitting of wedges used in gate valves in thermal power plants as claimed in the claims 1-3, wherein the vertical lead screw (17) is connected with the upper horizontal bed (05) at one end and the other end of screw (17) is connected with a gear box (10), in which the gear box (10) is linked with a second hand wheel (21) for the upward and downward motion.
5. The device for slitting of wedges used in gate valves in thermal power plants as claimed in the claims 1-4, wherein the chop saw motor (19) is coupled with one end of a belt drive (02), other end of which is connected to a chop saw/cutting wheel (03).
6. The device for slitting of wedges used in gate valves in thermal power plants as claimed in the claims 1-5, wherein the chop saw/cutting wheel (03) is connected with an operating handle (20) and chop saw (01).
7. The device for slitting of wedges used in gate valves in thermal power plants as claimed in the claims 1-6, wherein the clamping fixture (07) comprising of a right hand clamping plate (15) fixed on the top plate, a left hand clamping plate (16) attached with a lead screw (13) by an adapter (12), in which the lead screw (13) is connected with the fixture hand wheel (11) and the fixture hand wheel (11) is locked with help of a lock nut (14) after positioning a wedge (04).
8. The device for slitting of wedges used in gate valves in thermal power plants as claimed in the claims 1-7, wherein the horizontal fixture hand wheel (11) is rotated by hand to move the left hand clamping plate (16) to and fro to fix various sizes of wedge ranging from 3 inch to 32 inches gate valves for slitting purpose.
9. A method of operating a wedge slitting device (100), comprising the steps of:
positioning a wedge (04) between a left hand clamping plate (16) and a right hand clamping plate (15);
rotating a fixture hand wheel (11) and providing linear motion to a horizontal lead screw (13);
lowering an upper horizontal bed (05) through a gear box (10) and rotating a second hand wheel (21) such that a chop saw wheel (03) perform an operation on the wedge (04);
switching on a chop saw motor (19) and transmitting the power through a belt drive (02); and
releasing the left hand clamping plate (16) by reverse rotation of the fixture hand wheel (11) to remove the wedge (04) and placing another wedge (04) with various sizes to perform the slitting operation.
10. The method of operating a wedge slitting device (100) as claimed in claim 9, wherein the wedge (04) is a work piece made of metallic material and gradual pressure is applied for operating the fixture hand wheel (11) and uniform slitting (22) is accomplished in the wedge (04). , Description:FIELD OF INVENTION
[001] The present disclosure generally relates to manufacturing of valves used in thermal power plants. More particularly this invention relates to manufacturing of gate valves. More particularly the present disclosure describes a device for slitting of wedges used in the gate valves.
BACKGROUND/PRIOR ART OF THE INVENTION
[002] Background description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.
[003] During manufacturing of gate valves, first welding is done between machined valve body and seat rings. Parallelly, hard facing of wedge is done through welding. After wedge welding, there is a requirement of slitting of the wedge. The purpose of the slitting operation is to ensure the flexibility of the wedge during final working of the valve.
[004] According to the existing method, to do the slitting operation, initially, gas (oxy-acetylene) cutting was done but it was not an efficient process as it resulted into lots of spatters and slag, which remained intact with the component. These spatters/slag, thereafter, contributed to hydro-leakage and hence increase in rework. Moreover, the gas cut wedges are aesthetically not acceptable.
[005] Another alternative method to overcome the limitation of gas cutting was to adopt wedge slitting. The wedge slitting was carried out in milling / lathe machines. But this is not successful because of abnormal increase in cycle time and material handling time.

[006] Now, reference may be made to the following: -
[007] CN Publication. No: CN203413206U discloses a valve body, in particular to a novel wedge gate valve body. The novel wedge gate body mainly comprises a body and an upper flange. The two sides of the body are provided with a first flange and a second flange respectively. The upper flange, the first flange and the second flange are respectively provided with a reinforced platform and the reinforced platforms are used for improving the anti-deformation capacity of the three flanges; a reinforcing rib is arranged between the upper flange and the first flange, a reinforcing rib is arranged between the upper flange and the second flange, the reinforcing ribs are used for reducing the upper stress and the displacement of the valve body, and the body, the upper flange, the first flange, the second flange, the reinforced platforms and the reinforcing ribs are cast into an integral structure.
[008] Another prior art CN203131068U relates to high-sealing wedge gate valve wherein a gate is arranged in a central cavity of a valve body, a valve seat is welded in the valve body, and a valve rod, a middle flange pad, an upper sealing seat, packing, a pin, a packing bushing, a packing platen, a platen nut, a movable joint, a valve rod nut, a bearing gland, a hand wheel and a round nut are sequentially assembled. The gate is connected with the valve rod through a lead screw, the valve body is fixedly connected with a bonnet through studs and nuts, and the packing platen and the bonnet are connected through the movable joint and the platen nut. To achieve the high sealing performance, poly tetra fluoro ethylene (PTFE) is inlaid in a sealing surface of the valve seat, dual sealing of PTFE to metal and metal to metal is provided, dirt on the gate can be removed by the aid of the PTFE sealing surface simultaneously, the packing is flexible graphite packing, and the sealing is reliable.
[009] Still another prior art EP3392535A1 discloses a gate valve for industrial plants, especially for chemical and petrochemical plants. This slide plate includes a slide rod which is movable in the axial direction, at least one slider plate for closing the slider plate and at least one pressure element. The pressure element is connected to the slide rod and presses the slide plate against a sealing seat. Furthermore, the slide plate comprises a spring element for acting upon the pressing member with a release force, and a fixing element which is arranged on the plunger rod for transmitting force between the slide rod and spring element. The slide plate according to the invention as a fixing member comprises a fixing plate, which surrounds the slide rod and is positively connected with the slide rod.
[010] Yet another known art US5657961A discloses a wedge gate valve having a valve body defining a valve chamber and flow passages and upwardly diverging circular seat surfaces of circular, flat configuration and defining seat planes. A valve disk or wedge having downwardly converging sealing surfaces is movable within said valve chamber between open and closed positions for controlling flow through the valve. Pressure boundary plates connected by hubs to the valve disk define the sealing surfaces of the disk and have bottom corners that establish line contact with the downstream seat surface and prevent any portion of said sealing surfaces of said valve disk from crossing the sealing plane of the downstream seat in the event of flow responsive downstream movement of the valve disk during its opening and closing movement. Guide ears of the disk are provided with flexible upper and lower extremities and rounded or chamfered inner end surfaces to minimize localized peak contact stress with disk guide rails of the valve body. The center section of the disk is rendered flexible by the provision of an internal transverse cavity that extends completely through the center section or is located centrally of the center section to define flexible walls between the hubs to thus provide for disk flexibility for overcoming the tendency for disk binding. A valve actuator for opening and closing the valve disk is provided with an adjustable downstop to prevent over travel of the disk during seating.
[011] However, none of the above can fulfill the requirements of the present invention for which it is designed.

[012] Thus, there remains a need for a method and an apparatus for slitting of wedges which are used in the manufacturing of gate valves, that can address issues of the known technologies and serve the purpose efficiently.
OBJECTS OF THE INVENTION
[013] It is an object of the present disclosure to propose a method and an apparatus for performing slitting process used in the manufacturing of gate valves in thermal power plants.
[014] An object of the invention is to propose a device for slitting of wedges used in the gate valves which overcomes disadvantages of prior art.
[015] Another object of the invention is to propose a device for slitting of wedges used in the gate valves which is to reduce the time required to do the operation comparing to the existing method.
[016] Still another object of the present invention is to provide a device for slitting of wedges used in the gate valves which is simple and easy to operate in a safe manner.
[017] Yet another object of the present invention is to provide a device for slitting of wedges used in the gate valves which is to cover the different sizes of wedge slitting.
[018] These and other objects and advantages of the present invention will be apparent to those skilled in the art after a consideration of the following detailed description taken in conjunction with the accompanying drawings in which a preferred form of the present invention is illustrated.
SUMMARY OF THE INVENTION
[019] One or more drawbacks of conventional systems and process are overcome, and additional advantages are provided through the apparatus and a method as claimed in the present disclosure. Additional features and advantages are realized through the technicalities of the present disclosure. Other embodiments and aspects of the disclosure are described in detail herein and are considered to be part of the claimed disclosure.
[020] Accordingly, referring to the figure 2, the sub assembly of the clamping fixture consisting of right hand clamping plate which is fixed on the top plate by means of welding. The left hand clamping plate is attached with a lead screw by means of an adapter. The horizontal lead screw is connected with a fixture hand wheel. The fixture hand wheel is locked with help of a lock nut. The whole sub assembly of clamping fixture is assembled in the wedge slitting device bed by means by fasteners. The fixture hand wheel can be rotated by hand to move the left hand clamping plate to and fro to fix various sizes of wedge ranging from 4 inch to 32 inches for slitting purpose.
[021] According to the present invention, in the wedge slitting device, the guide pillar is mounted on the bed where the bed is supported by support legs. The guide pillar is provided with extra support for sturdy during slitting operation. A vertical lead screw is mounted on the bed. The vertical lead screw is connected with an upper horizontal bed on one side and the other end is connected with a gear box. The gear box is linked with a second hand wheel for the upward and downward motion. The upper horizontal bed is connected with the guide bar and the vertical lead screw. The upper horizontal bed is mounted with a chop saw motor and coupled with one end of a belt drive. The other end of the belt drive is connected to a chop cutting wheel. The chop saw cutting wheel is linked with an operating handle.
[022] Thus, according to this invention there is provided a device for slitting of wedges used in gate valves in thermal power plants comprising:
a clamping fixture for clamping a wedge to be slitted, wherein the fixture is mounted on the horizontal bed (8) with a fixture hand wheel;
a guide rod is mounted on said lower horizontal bed;
upper horizontal bed is provided in connection with the guide rod in which the horizontal bed is mounted with a vertical lead screw and chop saw motor.
[023] The lower horizontal bed is supported by support leg.
[024] The guide rod is provided with an extra support for sturdiness during slitting.
[025] The vertical lead screw is connected with the upper horizontal bed at one end and the other end of screw is connected with a gear box, in which the gear box is linked with a second hand wheel for the upward and downward motion.
[026] The chop saw motor is coupled with one end of a belt drive, other end of which is connected to a chop saw/cutting wheel.
[027] The chop saw/cutting wheel is connected with an operating handle and chop saw.
[028] The clamping fixture comprising of a right hand clamping plate fixed on the top plate, a left hand clamping plate attached with a lead screw by an adapter, in which the lead screw is connected with the fixture hand wheel and the fixture hand wheel is locked with help of a lock nut after positioning a wedge.
[029] The horizontal fixture hand wheel is rotated by hand to move the left hand clamping plate to and fro to fix various sizes of wedge ranging from 3 inch to 32 inches gate valves for slitting purpose.
[030] A method of operating a wedge slitting device, comprising the steps of:
positioning a wedge between a left hand clamping plate and a right hand clamping plate;
rotating a fixture hand wheel and providing linear motion to a horizontal lead screw;
lowering an upper horizontal bed through a gear box and rotating a second hand wheel such that a chop saw wheel perform an operation on the wedge;
switching on a chop saw motor and transmitting the power through a belt drive; and
releasing the left hand clamping plate by reverse rotation of the fixture hand wheel to remove the wedge and placing another wedge with various sizes to perform the slitting operation.
[031] The wedge is a work piece made of metallic material and gradual pressure is applied for operating the fixture hand wheel and uniform slitting is accomplished in the wedge.
[032] Various objects, features, aspects, and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which like numerals represent like components.
[033] It is to be understood that the aspects and embodiments of the disclosure described above may be used in any combination with each other. Several of the aspects and embodiments may be combined to form a further embodiment of the disclosure.
[034] The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWING
[035] The illustrated embodiments of the subject matter will be best understood by reference to the drawings, wherein like parts are designated by like numerals throughout. The following description is intended only by way of example, and simply illustrates certain selected embodiments of devices, systems, and processes that are consistent with the subject matter as claimed herein, wherein: -
Fig. 1 shows: A device for slitting of wedges used in the gate valves of the present invention.
Fig. 2 shows: A sub assembly of a clamping fixture used in the wedge slitting device in accordance with the present invention; and
Fig. 3 shows: A wedge (work piece) to be silted by securing in the clamping fixture in the present invention.
[036] The figures depict embodiments of the disclosure for purposes of illustration only. One skilled in the art will readily recognize from the following description that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the disclosure described herein.
DETAIL DESCRIPTION OF THE PRESENT INVENTION WITH REFERENCE TO THE ACCOMPANYING DRAWINGS OF PREFERRED EMBODIMENTS
[037] While the embodiments of the disclosure are subject to various modifications and alternative forms, specific embodiment thereof have been shown by way of example in the figures and will be described below. It should be understood, however, that it is not intended to limit the disclosure to the particular forms disclosed, but on the contrary, the disclosure is to cover all modifications, equivalents, and alternative falling within the scope of the disclosure.
[038] Embodiments explained herein pertain to a method and an apparatus for performing slitting of wedges used in the manufacturing of gate valves in thermal power plants. Now, reference may be made to FIG. 1 showing an assembly of a wedge slitting device (100) with its components in an assembled condition in an embodiment of the present invention.
[039] The apparatus (100) for performing slitting process comprises a clamping fixture (07) to clamp a wedge (04). Here, a guide rod (09) is mounted on a lower horizontal bed (08) and the lower horizontal bed (08) is supported by support leg (06). The guide rod (09) is provided with an extra support (18) for sturdiness during slitting operation. The vertical lead screw (17) is connected with an upper horizontal bed (05) on one side and the other end of the screw (17) is connected with a gear box (10). The gear box (10) is linked with a second hand wheel (21) for the upward and downward motion. The upper horizontal bed (05) is connected with the guide rod (09) and the vertical lead screw (17). A fixture hand wheel (11) is fixed in a suitable position. The upper horizontal bed (5) is mounted with a chop saw motor (19) which is a motor drive and coupled with one end of a belt drive (02). The other end of the belt drive (02) is connected to a chop saw/cutting wheel (03). The chop saw /cutting wheel (03) is linked with an operating handle (20). Further, guard of chop saw (01) is provided for the safety.
[040] In one embodiment the wedge (04) is a work piece made up of metallic material. In a preferred embodiment the wedge (04) is manufactured from a material such as steel. The material is given as example. Thus, other materials readily apparent to a person skilled in the art are understood to be within purview of invention.
[041] The wedges (04) undergo machining and are bolted together to form a non-cast, non-forged and welded gate valve particularly well suited for thermal power plants.
[042] Referring to FIG. 2 illustrating a sub assembly of a clamping fixture (07) implemented in the wedge slitting device (100) in an embodiment of the present invention. As shown in FIG. 2, a sub assembly of the clamping fixture (07) comprising of a right hand clamping plate (15) which is fixed on the top plate by means of welding. A left hand clamping plate (16) is attached with a lead screw (13) by means of an adapter (12). The lead screw (13) is connected with the fixture hand wheel (11). The fixture hand wheel (11) is locked with help of a lock nut (14) after positioning a wedge (04). The whole sub assembly of the clamping fixture (07) is assembled in the wedge slitting device (100) using the lower horizontal bed (08) by means by fasteners such as bolt, screws, hook, snap, pins, or nails etc. The horizontal fixture hand wheel (11) is rotated by hand to move the left hand clamping plate (16) to and fro to fix various sizes of wedge ranging from 3 inch to 32 inches gate valves for slitting purpose.
Operation of Device
[043] Reference may be made to fig. 3. The wedge (04) to be silted is secured in the clamping fixture (07). The wedge (04) which is to be silted is placed between the left hand clamping plate (16) and right hand clamping plate (15) by means of rotating the fixture hand wheel (11) to give linear motion to the lead screw (13) positioned horizontally. The upper horizontal bed (05) is lowered through a gear box (10) and rotating the second hand wheel (21) suitably so that a chop saw/cutting wheel (03) perform an operation on the wedge (04). A chop saw motor (19) is a motor drive which is switched on and the power is transmitted through a belt drive (02). The feed is given by the operator by applying gradual pressure to operate the fixture hand wheel (11) and uniform slitting (22) is completed in the wedge (04). The left hand clamping plate (16) is released by reverse rotation of the fixture hand wheel (11) to remove the wedge (04) and to place the next wedge (04) to continue the operation.
[044] In one embodiment the wedge slitting device (100) is developed with separate clamping fixture (07) to fasten the wedge (04) and the clamping fixture (07) is mounted on the lower horizontal bed (08) which is having motor to carry out the slitting operation uniformly and with less time without much cost. Using this apparatus, a semi- skilled operator or user could operate the machine for slitting operation and moreover the wedge slitting device (100) is capable of accommodating the various sizes of wedges suitable for 3 inch to 32 inches gate valves especially used in the power stations.
Advantageous Features
- An apparatus maintaining safety for performing slitting of wedges used in the manufacturing of gate valves in thermal power plants
- Elimination of manual grinding
- No slag generation
- No need of skilled worker as unskilled employee can easily perform the task with reduction in cycle time with quality improvement in the process.
[045] Listed below is set of components used in the present invention.
Reference No. Description of the components
01 Guard of chop saw
02 Belt drive
03 Chop saw/cutting wheel
04 Wedge (Work piece)
05 Upper horizontal bed
06 Support legs
07 Wedge clamping fixture (Sub assembly)
08 Lower horizontal bed
09 Guide rod
10 Gear box
11 Fixture hand wheel
12 Adapter
13 Horizontal lead screw
14 Lock nut
15 Right hand clamping plate
16 Left hand clamping plate
17 Vertical lead screw
18 Extra support
19 chop saw motor / Motor drive
20 Operating handle
21 Gear box hand wheel / second hand wheel

[046] Each of the appended claims defines a separate invention, which for infringement purposes is recognized as including equivalents to the various elements or limitations specified in the claims. Depending on the context, all references below to the "invention" may in some cases refer to certain specific embodiments only. In other cases, it will be recognized that references to the "invention" will refer to subject matter recited in one or more, but not necessarily all, of the claims.
[047] Groupings of alternative elements or embodiments of the invention disclosed herein are not to be construed as limitations. Each group member can be referred to and claimed individually or in any combination with other members of the group or other elements found herein. One or more members of a group can be included in, or deleted from, a group for reasons of convenience and/or patentability. When any such inclusion or deletion occurs, the specification is herein deemed to contain the group as modified thus fulfilling the written description of all groups used in the appended claims.
[048] It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as “open” terms (e.g., the term “including” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “includes” should be interpreted as “includes but is not limited to,” etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases “at least one” and “one or more” to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles “a” or “an” limits any particulars claim containing such introduced claim recitation to inventions containing only one such recitation, even when the same claim includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an” (e.g., “a” and/or “an” should typically be interpreted to mean “at least one” or “one or more”); the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., the bare recitation of “two recitations,” without other modifiers, typically means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogues to “at least one of A, B and C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B and C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances where a convention analogous to “at least one of A, B, or C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, or C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase “A or B” will be understood to include the possibilities of “A” or “B” or “A and B”.
[049] The above description does not provide specific details of manufacture or design of the various components. Those of skill in the art are familiar with such details, and unless departures from those techniques are set out, techniques, known, related art or later developed designs and materials should be employed. Those in the art are capable of choosing suitable manufacturing and design details.
[050] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present disclosure. It will be appreciated that several of the above-disclosed and other features and functions, or alternatives thereof, may be combined into other systems or applications. Various presently unforeseen or unanticipated alternatives, modifications, variations, or improvements therein may subsequently be made by those skilled in the art without departing from the scope of the present disclosure as encompassed by the following claims.
[051] The claims, as originally presented and as they may be amended, encompass variations, alternatives, modifications, improvements, equivalents, and substantial equivalents of the embodiments and teachings disclosed herein, including those that are presently unforeseen or unappreciated, and that, for example, may arise from applicants/patentees and others.
[052] While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims.