GB2206501A

GB2206501A - Filtering screen assembly

Info

Publication number: GB2206501A
Application number: GB08715916A
Authority: GB
Inventors: Marshall Graham Bailey; George Lawrence Souter
Original assignee: Thule United Ltd
Current assignee: Thule United Ltd
Priority date: 1987-07-07
Filing date: 1987-07-07
Publication date: 1989-01-11
Anticipated expiration: 2007-07-07
Also published as: GB8715916D0; GB2206501B

Abstract

A frame for a filtering screen is approximately square in plan and has a tongue formed at one end (8) and a groove formed at the other end (10). When two such frames are assembled end to end in abutting relationship, a tongue and groove connection is made which forms a seal, preventing the passage of material to be filtered between the abutting ends (8 and 10). The two frames may be relatively inclined, and the frames may be held between rails. <IMAGE>

Description

Filtering Screens Field of the invention This invention relates to filtering screens, and more particularly to the frames for such screens which are placed in abutting relationship to form a larger screen assembly.

Background to the invention Filtering screens for filtering particles contained in a suspension in a slurry are often constructed from frame units which are mounted between rails in abutting relationship. An example of a filtering screen of this nature is disclosed in British Patent Speckfication No.

2162091 when such frames are mounted together in a vibratory sifting apparatus, for example apparatus as described in British Patent Specification No. 2176424, in which the frames are pneumatically clamped within the rails or mounting frame of the apparatus, a problem may arise in the sealing between one frame and the next, or the frame and the adjacent rail. As a result some of the slurry to be filtered tends to find a way through between the filter frames, without being filtered.

It is an object of the present invention to mitigate the above shortcomings, and to provide a filtering frame which will provide an improved seal with the next frame.

Summary of the invention According to one aspect of the present invention there is provided a frame for a filtering screen, the frame being of rectangular shape, wherein opposed ends of the frame are formed respectively with a tongue and a groove configuration, so that when in abutting relationship with another frame the tongue of one frame enters the groove of the next frame, forming a seal past which the material to be filtered is prevented from passing.

According to another apsect of the present invention there is provided an assembly for a filtering screen comprising at least two such abutting filtering frames mounted between rails.

At the end of the rails there may be a cross rail which likewise provides a tongue in groove connection with the respective abutting filtering frame.

Where there are two abutting frames, one may be inclined upwardly relative to the other. A suitable inclination may be about 10 between the frames. In this case it is preferred to arrange for the groove to be suitably inclined, instead of the tongue.

The frame may be made of metal, plastics material, glass fibre reinforced plastics (GRIP) or of a composite material.

Brief description of drawings An example of the invention will now be described with reference to the accompanying drawings in which: Figure 1 is a perspective view of a pair of screen frames in an interlocking relationship; Figure 2 is a scrap side view of Figure 1, taken in the direction of the arrow II; ancL Figure 3 is an end view showing the screen frames in position between rails.

Detailed description of the invention Referring first particularly to Figure 1, each of the two screen frames 2 and 4 shown is approximatelysquare in plan, thus each having a side of a length substantially equal to that of the ends 8 and 10.

Each of the sides 6 is flat, as shown best in Figure 3.

One end 8 of each frame is formed with a tongue 12, while the other end 10 is formed with a complement#ary groove 14.

Figure 2 shows the pair of frames being assembled, with the tongue 12 of the frame 4 about to enter the groove 14 of the frame 2.

The side edges 6 of the frames are firmly held in place between respective C shaped channels or rails 16, shown in Figure 3.

Joining the rails 16 at the end adjacent the frame 2 is a cross rail (not shown) which may be provided with a similar groove as the groove 14, to enable the tongue 12 Ot the frame 2 to enter into such a groove.

Mounted on each frame is a screen 20 which may consist of a mesh of screen cloth formed from woven metal wire.

In some arrangements it may be preferred to have the pair of adjacent frames disposed in slightly different planes.

For example, the frame 4 may be inclined upwardly relative to the frame 2 by an angle of about 10 . In such a construction the tongue 12 is preferably parallel with its frame 4, while the groove is formed at such an angle.

The frame itself may be constructed from any suitable material such as metal, plastics material, glass reinforced plastics (GRP), or it may even be from a composite material.

It will be appreciated that such a "slot seal" between the abutting edges of the frames 2 and 4 provides for an excellent seal to prevent the slurry to be sifted from passing in between the frames. To ensure tXat the frames are firmly held between the rails they may be clamped in position by any suitable means, for example by the pneumatic clamps in the sifting machine described in the above mentioned British Patent Specification No. 2176424.

In this way the risk of two frames separating, or of one frame moving away from the end rail, is substantially reduced. Such movement between the frames could be initiated by the strong vibration force which is imparted by the sifting machine.

Claims

1. A frame for a filtering screen, the frame being of rectangular shape, wherein opposed ends of the frame are formed respectively with a tongue and a groove configuration, so that when in abutting relationship with another frame the tongue of one frame enters the groove of the next frame, forming a seal past which the material to be filtered is prevented from passing.

2. An assembly for a filtering screen comprising at least two abutting filtering frames in accordance with claim 1, said frames being mounted between rails.

3. An assembly according to claim 2 in which at the end of the rails there is a cross rail which likewise provides a tongue and groove connection with the respective abutting filtering frame.

4. An assembly according to claim 2 or claim 3 in which one of said at least two abutting frames is inclined upwardly relative to the other.

5. An assembly according to claim 4 in which the inclination between the frames is about 100.

6. An assembly according to claim 4 or claim 5 in which the groove is thus inclined and the tongue is parallel to the frame.

7. A frame for a filtering screen or an assembly therefor according to any one of claims 1 to 6 in which the frame is made of metal, plastics material, glass fibre reinforced plastics (GRP) or of a composite material.

8. A frame for a filtering screen or an assembly therefor substantially as herein described with reference to, and as shown in, the accompanying drawings.