Abstract: A screen assembly for separating solid materials of differing sizes in a material stream, having a support, and a screen arrangement placed upon the support, wherein the support has at least one seal placed on the support, the seal configured to interface with a mounting surface of a shaking apparatus.

Abstract: A method of manufacturing two screens in a jig by laying a length of woven wire cloth across two rectangular frames laid side by side in the jig with longer edges abutting, and orientating the cloth so that the warp wires extend continuously across the two screens. The cloth is tensioned and bonded to the frames after which it is severed along the join and surplus cloth is trimmed away from the edges of the frame. If the cloth has a square mesh and the warp wires are of greater cross-section than the weft wires, the warp wires will extend across the width of the frame, and if the cloth has a rectangular mesh, the greater number of warp wires per unit length also extends across the width of the frame. In each case warp wires will resist the stresses across the width of the central region of each opening.

Abstract: A magnetic clamping system for a shale shaker including at least one screen having at least two side ends extending between a first side and a second side and at least one attachment surface. The system further includes at least one mating surface of the shale shaker configured to receive the at least one screen, and at least one magnet disposed between the at least one screen and the shale shaker, wherein the at least one magnet is configured to magnetically couple the at least one screen directly to the shale shaker. Additionally, the system includes at least one decoupling apparatus, the decoupling apparatus having a handle disposed proximate a perimeter of a shale shaker, and at least one shaft that extends horizontally between the handle and one of the at least one magnet, wherein the handle is rotatable to reverse the polarity of the magnet.

Abstract: A mesh panel of the type having a plurality of spaced apart apertures includes an internal frame member substantially in the form of a perforated sheet, and having a plurality of openings therein larger than the apertures. The frame member has substantial internal rigidity. An elastomeric coating encapsulates at least a portion of said frame member. In a preferred embodiment, a bonding coating between the elastomeric coating and the frame member securely bonds to both the elastomeric coating and the frame member. The bonding coating is of the type that is liquid before application to the frame member and is curable by heat or time to a hard plastic. Preferably, the bonding coating is partially cured before the elastomeric coating is applied, after which both coatings are cured by heat. The panel is particularly well suited for use as a sorting screen.

Abstract: Attachment apparatus by which a sifting screen is mounted to a tension rail of a shaker machine. The apparatus includes a portion of the sifting screen wherein a hem at the periphery thereof has a thickness smaller than that of an interior portion of the sifting screen. The hem portion further includes a wire cloth array which is cast in the hem portion. A shroud includes upper and lower segments which are folded back on each other. A hinge edge is thereby defined. Facing surfaces of the upper and lower segments of the shroud sandwich the hem portion of the sifting screen therebetween. Means are provided to inhibit movement of the facing surfaces across engaged surfaces of the hem portion.

Abstract: A screen for a gyratory sifter including a frame having a plurality of cross-members and a rigid external extension. Additionally, the screen including a filtering element securably attached to the frame. Also, a method for installing a pre-tensioned screen in a gyratory sifter including inserting the pre-tensioned screen into the gyratory sifter. The pre-tensioned screen including a frame having a plurality of cross-members and a rigid external extension and a filtering element securably attached to the frame. Additionally, the method including mating the pre-tensioned screen to a ball box, wherein the mating includes placing the pre-tensioned screen against a contoured section of the ball box, and securing the pre-tensioned screen with a screen plate.

Abstract: A screen is described for use in a vibrating machine for separating solids from liquid material, comprising woven wire cloth of orthogonal warp and weft wires, tensioned and bonded to a support structure defining at least one rectangular opening across which the cloth extends. The orientation of the cloth is chosen so that the warp wires extend across the width (i.e. shorter dimension) of the opening(s). If the cloth has a square mesh and the warp wires are of greater cross section than the weft wires, the warp wires will extend across the width of the frame, and if the cloth has a rectangular mesh, the greater number of warp wires per unit length will also extend across the width of the frame, so that in each case warp wires will resist in use the stresses across the width of the central region of the or each opening.

Abstract: A screening module (10) for a screening assembly includes a panel member (12) defining a plurality of screening apertures; and a support arrangement (16) with which the panel member (12) is fast. The support arrangement (16) includes a plurality of strengthening arrays (22) arranged, in use, beneath the panel member (12), each strengthening array (22) comprising a skirt portion (24) bounding an area on a bottom surface of the panel member (12).

Abstract: A screening panel 10 comprises a peripheral frame 12 consisting of a pair of mutually laterally spaced side members 14, 16, which are integral with a pair of mutually axially spaced end members 18, 20. The side members 14, 16 and end members 18, 20 define corners of the panel 22.1, 22.2, 22.3 and 22.4 and the peripheral frame 12 where they meet. A plurality of mutually spaced ribs 15 extend across the periphery of the panel 10 to define a screening surface. The side members and end members are rectangular in cross-section, thereby defining substantially flat upper peripheral surfaces 12.1, outer peripheral surface 12.2 and lower peripheral surface 12.3 of the peripheral frame 12 and thus also the panel 10. The panel 10 includes locating recesses 24 provided at or near to the corners 22.1, 22.2, 22.3 and 22.4 of the panel 10. The panel 10 also has separate securing recesses in the form of semi-circular grooves 30 formed in the lower surface 12.

Abstract: This invention relates to a method for easy installation and removal of a screen assembly for vibratory machinery and more particularly to shake table screening. The screen assembly comprises a screen frame, a screen cloth and a screen bed, whereby no clamping components are visible on top of the screen. Each assembly section can be controlled independently and clamping force is controlled by a pneumatic regulator located near an air line connection on the side of a shaker.

Abstract: The present invention relates to an apparatus and method for the easy installation or removal of screen elements from a shaker table without the use of tools. Pneumatic cylinders are used to move hold down bars up and down to either allow for screen elements to be installed or removed from the screen bed section assembly, or to clamp them into the screen bed section assembly of a shaker so that the screen elements will not move during shaker operations.

Abstract: A hookstrip screen assembly for use in a shaker is disclosed. The hookstrip screen assembly includes a filtering element and a composite frame further including a top surface, a bottom surface, and a plurality of filtering element attachment points. Also, the filtering element is attached to the plurality of filtering element attachment points. In another aspect, a method of forming a hookstrip screen assembly for use in a shaker. The method of forming a hookstrip screen assembly includes forming a wire structure, molding a composite frame incorporating the wire structure and forming a plurality of filtering element attachment points on the composite frame. The method also includes attaching a filtering element to the plurality of filtering element attachment points on the composite frame.

Abstract: A vibratory plate screen having a first end for quickly mounting in a vibrator housing, an intermediate region with openings therein and a securement end that allows one to quickly secure a vibratory plate screen in a vibratory housing. In addition, the screen is sufficiently flexible to enable one to mount the vibrator screen in a curved condition or stressed condition so that the inherent tensile strength of the material assists in holding the vibratory plate screen in position. A further feature of the invention is the quick removal and securement of the vibratory plate screen.

Abstract: A screen panel center retainer system utilizes a center retainer that is provided with a retainer base which is adapted to be secured to screen stringer rails of a vibrating separatory machine. A pair of retainer channel legs form an upper portion of the center retainer and have screen panel edge receiving slots. A locking strip, having a wedging tongue, is used in conjunction with the center retainer. The wedging tongue is insertable into the channel on the center retainer which is defined by the two retainer channel legs. Flow control dams and cross dam retainers are used in conjunction with, and in addition to the center retainers and locking strips, to provide the complete installation of screen panels on the vibrating separating machine.

Abstract: A screen assembly is disclosed for use with vibratory separators. The screen assembly includes a structural frame mounted to a vibratory separator into which a plurality of lightweight and flexible screen elements are inserted into multiple rows of perforated troughs which have geometric shapes. The perforated troughs are bonded to each other and to the structural frame. The perforated troughs are aligned parallel to the direction in which solids are conveyed by a vibratory motion.

Abstract: The present invention provides a screen system (8) suitable for use in a vibratory screen apparatus (1), and comprising: a screen element (11) and a support frame (12) therefor, as well as novel screen elements (11) and mesh panels (19) therefor, and the use thereof. The screen element (11) consists essentially of a mesh panel (19) provided with first and second elongate support members (22, 23) extending along opposite end portions of the mesh panel (19). The support frame (12) has spaced apart first and second elongate frame elements (13, 14) for engagement with the screen element support members (22, 23) and further elongate frame elements (17, 18) extending there between for supporting the mesh panel (19).

Abstract: A vibratory separator including a screen having a filter element and a center screen disk. The vibratory separator also including a magnet disposed on top of the center pedestal support, wherein the center screen disk and the magnet are configured to magnetically interact. Additionally, a method for replacing a screen for a vibratory separator including actuating a vibratory separator decoupler and breaking a first magnetic interaction between a first magnetic interaction surface and a second magnetic interaction surface. The method further including removing a first screen from the vibratory separator, installing a second screen into the vibratory separator, and establishing a second magnetic interaction.

Abstract: A magnetic claiming system for a shale shaker including at least one screen having at least two side ends extending between a first side and a second side and at least one attachment surface, at least one mating surface of a shale shaker configured to receive at least one screen, wherein the shale shaker has a first end and a second end, and at least on magnet disposed between the at least one screen and the shale shaker, wherein the at least one magnet is configured to magnetically couple the at least one screen to the shale shaker is disclosed. A method for replacing a screen in a shale shaker including activating at least one decoupling apparatus, wherein a magnetic clamping system includes the at least one decoupling apparatus, removing at least one screen from the shale shaker, deactivating the at least one coupling apparatus, and installing at least one screen into the shale shaker is also disclosed.

Abstract: A shaker screen including a screen frame and an inflatable sealing element integrally formed with the screen frame is disclosed. A screen sealing system including a plurality of shaker screens, each shaker screen having a screen frame and an inflatable sealing element integrally formed with the screen frame, wherein the inflatable sealing elements of each shaker screen are in fluid communication is also disclosed. A method of sealing a composite screen including assembling at least one shaker screen within a shale shaker and inflating at least one inflatable sealing element disposed along at least a portion of a perimeter of the screen frame, the portions selected from a group consisting of a top surface, a bottom surface, and an outer surface is disclosed.

Abstract: A system including a first screen having a first frame and a first sealing element attached to an outer perimeter of the first frame, and a second screen disposed adjacent the first screen, the second screen having a second frame and a second sealing element attached to an outer perimeter of the second frame, wherein the first sealing element and the second sealing element provide a seal between the first screen and the second screen is disclosed. Further, a method of forming a screen frame including forming a frame and attaching a sealing element to an outer perimeter of the frame is disclosed. Additionally, a shaker screen including a frame and a sealing element attached to an outer perimeter of the frame, wherein the sealing element is attached by one selected from thermal bonding and co-molding is disclosed.

Abstract: A filter screen to be used in conjunction with a shale shaker in removing solid matter from drilling fluids includes a filter plate having a plurality of perforations, a plurality of hold-down apertures, and a pair of end caps attached to the filter plate, wherein each end cap is configured to isolate the hold down apertures from the plurality of perforations.

Abstract: The present invention provides a screen system (8) suitable for use in a vibratory screen apparatus (1), and comprising: a screen element (11) and a support frame (12) therefor, as well as novel screen elements (11) and mesh panels (19) therefor, and the use thereof. The screen element (11) consists essentially of a mesh panel (19) provided with first and second elongate support members (22, 23) extending along opposite end portions of the mesh panel (19). The support frame (12) has spaced apart first and second elongate frame elements (13, 14) for engagement with the screen element support members (22, 23) and further elongate frame elements (17, 18) extending there between for supporting the mesh panel (19).

Abstract: A screening module retaining member 10 includes a body member 12 defining a passage 16. A retaining element 14 is displaceably arranged in the passage 16. The retaining element 14 is displaceable between a first, non-retaining position in which the retaining member is accessible from a first end of the body member 12 and a second, retaining position in which the retaining element 14 is received within the passage 16 and acts on at least a part 20 of the body member 12 for retaining the body member 12 in position relative to a component of a screen deck. A locating arrangement 22 is associated with the first end of the body member 12 for locating a screening module relative to the screen deck and for inhibiting lateral movement of the screening module relative to the body member 12.

Abstract: A shaker apparatus including a basket having an upstream side, a downstream side, and two side walls, at least one wedge guide and one support rail disposed on each side wall, and at least one screen assembly. The support rails and the wedge guides may be configured to engage the screen assembly. The screen assembly may have one or more layers of screen mesh mounted on a screen frame. The screen frame may include a first and a second side rail, each having an upstream end, a downstream end, a top surface, and a bottom surface. A slope of the top surfaces intermediate the upstream end and the downstream end may be different than a slope of the bottom surfaces intermediate the upstream end and the downstream end.

Abstract: A frame over which woven wire mesh is to be stretched and secured to form a sieving screen and which can be used to screen solids from drilling mud recovered from down-hole when drilling for oil or gas. The frame comprises a rectilinear molded plastics frame having edge regions by which it is secured in place in a shaker. Within the frame is a plurality of rectilinear windows formed by an orthogonal array of intersecting ribs also of molded plastics material. Some of the ribs are internally reinforced by a structure comprising two spaced apart layers of orthogonal intersecting spaced apart wires, running parallel to the length and breadth of the rectilinear shape of the frame within the ribs to increase their rigidity. The edge regions of the frame are reinforced internally by metal box-section members joined at their four corners and defining perimeter reinforcement, and the ends of the wires are secured to the box-section members.

Abstract: A screen includes three or four layers of woven metal screen cloth. The coarsest of these layers is a structural layer includes threads which are woven into the cloth with surfaces which are fusible below a temperature at which the other layers of screen cloth are heat affected. These woven threads include each of the threads in the coarse screen cloth with the coated threads being wire with fusible polypropylene or polyethylene coatings. The cloth could alternatively be coated or a fusible grid used between screens instead. A support layer above the structural layer may include a woven metal screen with woven elements which are either coated with fusible material or are solidly of fusible material woven periodically therethrough in at least one direction. A fusible grid could alternatively be employed. Screens are laminated with one or two fine mesh screens heated on the support woven screen cloth with fusible surfaces to locate the fusible material in the finer cloths.

Abstract: Screen separators and a screen tensioning system for separators that facilitates rapid measurement of screen tension. Each separator subframe screen is suspended between opposed subframe walls. Suitable linkages distribute vibration during the aggregate sifting process. Screen edge flanges are secured by tensioners that control a screen suspension bracket. A carriage bolt fitted through bracket orifices and the walls coaxially receive a resilient grommet captivated by an adjustable sleeve nut. As the nut is tightened, screen tension increases and the grommet diameter increases. A portable gauge with an internal U-shaped measurement sleeve is fitted over the deformed grommet to measure screen tension. A plurality of gauge calibration points bordering the deformed grommet determine applied screen tension.

Abstract: A conversion kit for interconnecting particulate screening panels to a support frame includes a plurality of panels, an interface and a connecting pin. A method of using the conversion kit includes the steps of providing at least two of the screening panels each defining at least one locating recess; providing an interface having at least one skirt depending therefrom and a bore therethrough; providing at least one pin defining a head and an opposing extension; attaching the head in the locating recesses to connect the screening panels together; inserting the skirt in an aperture of a support frame; and inserting the opposing extension in the bore of the skirt to attach the screening panels to the support frame for screening particulates.

Abstract: A screen assembly for a shale shaker comprising a panel (500) and a support structure (600), the panel (500) having an area provided with a multiplicity of apertures and at least one layer of screening material arranged over the multiplicity of apertures, wherein said panel (500) is removable from said support structure (600).

Abstract: A screen system 8 suitable for use in a vibratory screen apparatus 1, comprising: a screen element 11 consisting essentially of a mesh panel 19 provided with first and second elongate support members 22, 23 extending along opposite end portions 20, 21; and a support frame 12 therefore. The support frame 12 has spaced apart first and second elongate frame elements 13, 14 for engagement with said screen element support members 22, 23 and further elongate frame elements 17, 18 extending between the first and second frame elements 13, 14 for supporting the mesh panel 19. The support frame 12 is provided with at least one mesh panel support 27 provided with an elevating support surface, which tensions the screen element 11 across the support surface 27 and between the screen element support members 22, 23. The latter 22, 23 and the first and second frame elements 13, 14 are being formed and arranged for secure interengagement.

Abstract: A vibratory plate screen having a first end for quickly mounting in a vibrator housing, an intermediate region with openings therein and a securement end that allows one to quickly secure a vibratory plate screen in a vibratory housing. In addition, the screen is sufficiently flexible to enable one to mount the vibrator screen in a curved condition or stressed condition so that the inherent tensile strength of the material assists in holding the vibratory plate screen in position. A further feature of the invention is the quick removal and securement of the vibratory plate screen.

Abstract: A screening assembly support frame includes a body member defining a longitudinal axis. The body member has a pair of parallel, spaced elongate support members with a spacer arrangement extending between the support members. An engaging formation, for engaging a screen panel of the screening assembly to be supported by the body member, is carried on each support member with the body member and the engaging formations being symmetrical about the longitudinal axis.

Abstract: A screen assembly for a conventional vibratory screening machine includes a series of screens bonded to a rigid rectangular metal frame having rectangular tubular frame members and at least two and no more than ten intermediate frame members. This leaves a series of permeable areas through the screen assembly that are in the range of 2-32% of the overall area of the screen assembly. The screens include an upper fine mesh screen which passes particles below a predetermined size and rejects particles above this size. A second or blinding screen, below the first screen, acts to dislodge particles caught in the mesh of the first screen. A load bearing assembly supports the first and second screens and includes a first support screen coarser than the screens above it, a bonding layer and a second support screen coarser than the first support screen.

Abstract: A screening machine includes wall members, a screen assembly, and a compression assembly. The screen assembly includes a frame with a plurality of side members and a screen supported by the frame. The compression assembly is attached to at least one wall member and forms the screen assembly into a concave shape.

Abstract: A screen deck runner assembly (20) suitable for use in a vibratory screening machine characterized by the assembly including a saddle member (5), being configured and 420 dimensioned to removably straddle a screen deck runner (1) and to engage a screen panel (3).

Abstract: A wedging apparatus including an outer polygonal surface configured to secure a screen to a shaker, the outer polygonal surface having a bottom surface, a top surface opposite the bottom surface, and at least one end surface joining the top surface and the bottom surface, and an inner core defined by the outer polygonal surface, wherein the inner core defines a cavity is disclosed. A method of forming an apparatus for securing a screen to a shaker is disclosed, the method including forming a mold of a wedging apparatus configured to secure a screen to a shaker, wherein a shape of the mod is an inverse of an outer polygonal surface having a bottom surface, a top surface opposite the bottom surface, and at least one end surface joining the top surface and the bottom surface, and an inner core defined by the outer polygonal surface, wherein the inner core defines a cavity, injecting a liquid resin into the mold, allowing the liquid resin to solidify, and removing the wedging apparatus from the mold.

Abstract: Mechanical separators and screening machines, and methods for flexible sieve mat screening and flexible mat conveying are disclosed. In an example configuration, a flexible mat screening apparatus is provided with geometrically optimized guiding edge seals at lateral sides. One preferred configuration includes an assembly wherein a sieve mat has upwardly curved lateral sides forming a non-vertical, gradually curved shape. In another configuration, a movable support section is supported on a main frame section via a plurality of shear blocks, each arranged with its compression axis disposed horizontally. In yet another configuration, the movable support section is further connected to the main frame section via vertical stabilizers or leaf springs, the vertical stabilizers permitting longitudinal movement between the movable support section and the main frame section, but inhibiting vertical and/or lateral movement therebetween.

Abstract: A screen for use in a vibratory machine for separating particulate material from liquid material comprising a rigid rectangular support frame having flanges along all four edges to which screen cloths of the type described are bonded with the longer dimension of the rectangular openings defined by the warp and weft wires of the cloth parallel to the longer dimension of the frame. The frame includes an array orthogonal rigid interstices defining a plurality of similar sized rectangular openings or window and the cloths are also bonded to the interstices for the purpose of maintaining the length to width ratio of the openings in the cloths defined by the warp and weft wires thereof. The warp and weft wires of the cloths are tensioned before being bonded to the flanges and interstices.

Abstract: A screen assembly for a vibratory separator includes a composite screen frame that has a rigid support section formed from a polymer material and a cushioned strain relief zone. The strain relief zone is located along the inner periphery of the rigid support section and provides support at the interface between the screen frame and the screen cloth. The strain relief zone may extend along an inner peripheral wall of the rigid support section. The rigid support section may include a flange and the strain relief zone may extend around the rigid support section to encapsulate the flange in addition to providing additional support to the screen cloth. The rigid support section and the strain relief zone may be co-formed in a molding process. Alternatively the rigid support section may be a molded member and the strain relief zone may be an extrusion to be assembled to the rigid support member. The screen cloth is affixed to the peripheral frame.

Abstract: A vibratory screening machine having opposite sides with a plurality of stationary aligned tensioning members mounted on one side and a plurality of nut actuated movable tensioning members mounted on the opposite side and a vibratory screening screen mounted on the stationary and movable tensioning members. The tensioning members have upstanding fingers which are received in apertures in the plates of the vibratory screen, and the edge portions of the vibratory screen include screening material which extends all of the way to the extreme edges of the supporting plate and the fingers are below the screening material. Also, the tensioning structure is mounted on the side walls of the vibratory screening machine below the vibratory screen.

Abstract: The present invention provides a screen system (8) suitable for use in a vibratory screen apparatus (1), and comprising: a screen element (11) and a support frame (12) therefor, as well novel screen elements (11) and mesh panels (19) therefor, and the use thereof. The screen element (11) consists essentially of a mesh panel (19) provided with first and second elongate support members (22, 23) extending along opposite end portions of the mesh panel (19). The support frame (12) has spaced apart first second elongate frame elements (13, 14) for engagement with the screen element support members (22, 23) and further elongate frame elements (17, 18) extending there between for supporting the mesh panel (19).

Abstract: A screening assembly 10 includes at least one rail 14 to be secured to a support member of a screening machine. At least one locating formation 16 extends from an operatively upper surface of the rail 14. Each locating formation 16 includes a catch member 32. The assembly 10 further includes a plurality of screening modules 12, each screening module 12 having an end supported on the rail 14. A pair of modules 12 lie in end-to-end abutting relationship with the abutting ends overlying the rail 14 so that the catch member 32 of each locating formation 16 protrudes beyond an upper surface of the screening modules 12. Further, a locking member 18 engages the catch member 32 of the locating formation 16 for locking the pair of modules 12 with respect to each other and with respect to the rail 14.

Abstract: An assembly for sealing a shaker screen assembly in a shaker separator includes a substantially inflexible gasket affixed to each screen support and a flexible gasket affixed to each screen support such that the screen frame rests atop the gaskets on the support around its periphery. A wedge block retainer bracket is affixed to each side wall of the shaker separator above the corresponding section of the screen frame. A wedge block is selectively drivable into the space between the wedge block retainer bracket and the corresponding section of the screen frame, providing force thereto sufficient to seat the screen frame against the inflexible gasket and to compress the flexible gasket between the screen frame and the screen support, thereby providing a substantially fluid tight seal.

Abstract: The present invention relates to a sieve device for screening at least two solid substances preferably different from each other comprising at least one sieve module (1), comprising at least two sieve devices (2), comprising at least one fitting (3) with a bottom with sieve (4), closing the respective fitting (3).

Abstract: A screening assembly 10 includes at least one rail 14 to be secured to a support member of a screening machine to lie parallel to, and intermediate, side members of the screening machine. At least one locating formation 18 stands proud of an operatively upper surface of each rail 14. The assembly includes a plurality of screening modules 12. Each screening module 12 has an end supported on the rail 14 so that a pair of modules 12 lie in end-to-end abutting relationship with the abutting ends, in use, overlying the rail 12 and defining a receiving formation through which the locating formation 18 protrudes to project beyond the receiving formation into a recessed region defined by the abutting ends of the pair of modules 12. A locking member 46 is associated with the receiving formation and is receivable in the recessed region for engaging its associated locating formation to lock the pair of modules with respect to each other and with respect to the rail 14.

Abstract: Screen assemblies for a vibratory separator, the screen assemblies in certain aspects having at least two screening members, the at least two screening members connected by sewing material, and methods for making such screen assemblies.

Abstract: Screen assemblies for a vibratory separator and methods of using them, the screen assemblies in one aspect including a first screen portion having a first end and a second end spaced apart from the first end, a second screen portion adjacent the second end of the first screen portion, the second screen portion projecting down from the second end of the first screen portion.

Abstract: A method for making a screen assembly for a vibratory separator, the method including, in at least certain aspects, gluing together with glue at least two layers of fine screening material, allowing the glue to set, preheating the glued together at least two layers of fine screening material, placing the thus-preheated at least two layers of fine screening material in a heating apparatus, placing a coarse mesh layer on the at least two layers of screening material on the heating apparatus, placing on the coarse mesh layer a support with heat activated material thereon for adhering the support to the coarse mesh layer, and heating the coarse mesh layer, at least two fine layers of fine screening material, and the support to adhere the support to the coarse mesh layer and to glue the at least two layers of fine screening material to the coarse mesh layer.

Abstract: A method of plugging an area of damaged mesh in a sifting screen. The method is applicable to screens in which woven wire mesh is stretched, tensioned and secured over a supporting frame containing a plurality of windows and in which local damage to the mesh is in an area of the mesh which overlies one of the windows. The method has the steps of inserting into the window a device which is a close fit therein, and securing the device in the window so as to completely cover the area of damaged mesh. The device may be a former having stretched thereacross and secured thereto mesh similar to that stretched across the window in question, or simply a plate or block. The device may be secured in place by a force or interference fit, mechanical means, or adhesive, or the device may be resiliently deformable to allow it to be pushed past a projection in the window, so as to snap fit the device in place.

Abstract: A fastening device (1) for fastening polyurethane screening panels (6,7) to a screen (8) is made up of a composite fastener and a disc stringer support. The composite fastener is a steel bolt (2) and nut (3) with a polyurethan holding component (4) and a polyurethane cover (9) for the bolt head. The disc and stringer support is a stringer (31) serving as a joist spanning between girders of the screen frame, the stringer (31) having no flange and being narrow and deep, with discs (35) set in the top surface of the stringer at spaced apart positions, having a hole (36) in each disc for the bolt and nut and a recess (38) in the stringer underneath each disc for the nut. The bolt and nut have a toggle (14) which allows insertion into the hole in the disc and tightening the bolt and nut entirely from above the screen.