There are various known different types of files for containing documents. One type of known file for containing documents is a file which is usually known as a lever arch file. A lever arch file comprises a cover side and a document storage side. The cover side comprises a first cover. The document storage side comprises a second cover and a document-receiving device which is secured to the second cover and which comprises first and second prongs which are moved between an open position and a closed position by a lever.

Problems sometimes arise with the known lever arch files in that documents are removed from the files when they should not be. Missing documents cause annoyance until they are replaced. If the missing documents are not replaced, for example because they have been stolen or simply lost, then appreciable cost is involved in terms of the time required for somebody to make a duplicate copy of the missing documents and insert them in the file. If the lever arch file is in a place where it may be examined by the public, then the problem of missing documents becomes acute. Thus, for example, lever arch files in libraries, exhibitions, schools, colleges and hotel lobbies are very likely to be opened and have one or more of the documents removed. There are also instances where security of the documents in the file are of importance, for example in cases where the file may contain accounts documents, or legal papers for use by solicitors or as evidence in court.

PCT WO 00/32415 discloses a file which obviates or reduces the above mentioned problem. The file comprises a cover side and a document storage side: the cover side comprising a first cover; the document storage side comprising a second cover, and a document-receiving device which is secured to the second cover and which comprises first and second prongs which are moved between an open position and a closed position by a lever; characterised in that the file has locking means for locking the lever in a position in which the first and the second prongs are in the closed position, and the locking means comprises anchor means which is secured in use to the document storage side of the file, and a locking device which locks the lever and the anchor means together.

It is an aim of the present invention to provide an alternative design to that disclosed in PCT WO 00/32415.

Accordingly, in one non-limiting embodiment of the present invention there is provided a file comprising a cover side and a document storage side: the cover side comprising a first cover; the document storage side comprising a second cover, and a document-receiving device which is secured to the second cover and which comprises first and second prongs which are moved relative to each other between an open position and a closed position by a lever; the file being such that it has locking means which is secured to the document storage side of the file, and characterised in that the locking means locks the first prong in the closed position of the first and second prongs and prevents the relative movement of the first and second prongs to the open position.

The file of the present invention is such that documents can easily be retained in the file simply by use of the locking means. The locking means locks the first prong in a position in which the first and the second prongs are in the closed position. The first and the second prongs thus cannot be moved to the open position and thus security of the documents in the file is maintained until such time as the locking means is unlocked.

The file is preferably one in which the locking means is secured in use to the document-receiving device. If desired however, the locking means may be secured in use to the second cover.

Where the locking means is secured in use to the document-receiving device, then the locking means may be secured to a plate part of the document-receiving device.

The locking means may be secured by fixing means to the plate part of the document-receiving device. The fixing means may be a rivet, nut and bolt or any other suitable and appropriate type of fixing means.

The file may be one in which the locking means comprises an abutment which abuts against the first prong in the closed position of the first and second prongs and prevents the relative movement of the first and second prongs to the open position. Preferably, the file is one in which the abutment is a bar which slides over the top of the first prong in the closed position of the first and second prongs and prevents the relative movement of the first and second prongs to the open position. Other types of abutment and other types of locking means may be employed if desired.

Preferably, the locking means is a key operated locking means. The locking means may alternatively be a combination-operated locking means, a magnet locking means, an electronic locking means, or an electro-magnetic locking means.

The file may include sleeve means for receiving adjacent ends of the first and the second prongs when the first and the second prongs are in the closed position, thereby preventing attempts to remove documents from the file by trying to flex the first and the second prongs apart when the first and the second prongs are in the locked position.

The sleeve means is preferably made of a plastics material. If desired however the sleeve means may be made of a metal. When the sleeve means is made of a metal, then it may be in the form of a tube which is a closed tube, or a tube which has a longitudinally extending slot along its length.

Usually, the file will have two of the first prongs, and two of the second prongs. The file may however be such that it has only one of the first prongs and one of the second prongs, or the file may be such that it has more than two, for example three, of the first prongs and the second prongs. Generally, the file can be of any known construction except that it will include the locking means.

If desired, the file may include tamper evident means for indicating if the locking device has been tampered with. Any suitable and appropriate type of tamper-evident means may be employed. The tamper-evident means may form part of the locking device as for example in the case of a seal which has to be broken for opening purposes and is thus able to provide evidence of the locking device being tampered with and opened in an unauthorised manner.

Embodiments of the invention will now be described solely by way of example and with reference to the accompanying drawings in which : Figure 1 is a perspective view of a known lever arch file with its document-receiving device being shown in a closed condition; Figure 2 is a side view of the document-receiving device part of the file shown in Figure 1, and in the closed position; Figure 3 is a side view similar to Figure 2 but shows the document-receiving device in an open condition; Figure 4 is a side view similar to Figure 2 but shows the document-receiving device with a plurality of documents in the form of sheets of paper; Figure 5 is a perspective view of part of a lever arch file of the present invention; Figure 6 is a top plan view of the part of the lever arch file shown in Figure 5, and with a modified plate part; Figure 7 shows sleeve means; and Figure 8 shows an alternative sleeve means to that shown in Figure 7.

Referring to Figures 1-4, there is shown a known file in the form of a lever arch file 2. The file 2 comprises a cover side 4 and a document storage side 6.

The cover side 4 comprises a first cover 8. The document storage side 6 comprises a second cover 10 and a document- receiving device 12. The document-receiving device 12 is secured to the second cover 10. The document-receiving device 12 comprises first prongs 14 and second prongs 16.

The first and the second prongs 14,16 are moved between an open position as shown in Figure 3, and a closed position as shown in Figures 1,2 and 4. This movement of the first and second prongs 14,16 is effected by a lever 18. As can best be seen from Figure 3, the first prongs 14 move and the second prongs 16 remain stationary. As can be seen from Figure 4, the second prongs 16 receive documents in the form of sheets of paper 20. The sheets of paper 20 are held in position by an optional clamp 21.

Figures 2,3 and 4 show only parts of the document- receiving device 12 but it can be appreciated from a consideration of Figures 1-4 that the lever 18 pivots about a pivot 22 on an upstanding member 24 which is formed as a pressing out of a plate part 26 of the document- receiving device 12. A roller 28 is mounted on the lever 18 adjacent the pivot 22 and the roller 28 rolls along the upper surface of a movable base part 30 of the first prong 14. The roller 28 thus enables the lever 18 to bring a rolling pressure on the movable base part 30 on depression of the lever 18 as shown in Figure 3 in order to bring each first prong 14 from the open position shown in Figure 3 to the closed position shown in Figure 2.

The file 2 is such that the first and the second covers 8,10 respectively are separated by a spine 32 as can best be appreciated from Figures 1 and 4. The construction and operation of the lever arch file 2 is well known and it will not be further described.

Referring now to Figure 5, there is shown part of a lever arch file 34 of the present invention. Similar parts as in Figures 1-4 have been given the same reference numerals for ease of comparison and understanding. In Figure 5, the file 34 includes locking means 36 which locks the first prong 14 in the closed position of the first and second prongs 14,16 and prevents the relative movement of the first and second prongs 14,16 to the open position.

The locking means 36 comprises an abutment 38 which abuts against the first prong 14 in the closed position of the first and second prongs 14,16 and prevents the relative movement of the first and second prongs 14,16 to the open position. The abutment 38 is a bar which slides over the top of the first prong 14 in the closed position of the first and second prongs 14,16 and prevents the relative movement of the first and second prongs 14,16 to the open position. The locking means 36 is a key operated lock which is operated by a key.

Figure 6 is a top plan view of the part of the lever arch file 34 shown in Figure 5 but with a different shape for the plate part 26. In Figure 6, the plate part 26 is provided with a cut-away portion along one edge as shown.

The plate part 26 can be of a wide variety of different designs.

Figure 7 shows one of two sleeve means in the form of a sleeve 128. There is one sleeve 128 on each one of the two second prongs. The sleeves 128 provide overlap between adjacent ends of the first and the second prongs 14,16.

The sleeves 128 prevent the adjacent ends of the first and the second prongs 14,16 being forced apart by an amount sufficient to remove some of the sheets of paper 20 even when the locking means is in its locked condition. The sleeves 128 are made as tubes of a plastics material.

In Figure 8 there is shown an alternative sleeve 130 which is made of metal and which includes a longitudinally extending slot 132.

It is to be appreciated that the embodiments of the invention described above with reference to the accompanying drawings have been given by way of example only and that modifications may be effected. Thus, for example, a different type of locking means to that shown in the drawings may be employed. The file of the present invention may include various types of tamper-evident means for providing evidence of tampering with the locking means.

The first and the second prongs 14,16 may be solid prongs or tubular prongs. The ends of the prongs may have interlocking portions for interlocking with each other.

In addition to or as an alternative to the sheets of paper 20, the documents may include cardboard documents and plastics files. The file of the present invention need not only be a file known as a lever arch file and it may be a file of another name and/or construction, providing the file has the features defined by the following claims.