GB2393177A

GB2393177A - Sheet feeder with bias rollers

Info

Publication number: GB2393177A
Application number: GB0216168A
Authority: GB
Inventors: Steven Ward
Original assignee: JUNGLE ELECTRONICS Ltd
Current assignee: JUNGLE ELECTRONICS Ltd
Priority date: 2002-07-12
Filing date: 2002-07-12
Publication date: 2004-03-24
Also published as: GB0216168D0

Abstract

Apparatus for feeding elements in sheet form comprises a support (2) having a series of overlapping plates and rollers (6), (7), (38) and (39) for transporting sheets over the support. The rollers are arranged in pairs of driver and driving rollers and the driver rollers are resiliently mounted to accommodate sheets of varying thickness. The overlapping plates of the support (2) ensure that sheets pass progressively without snagging. The rollers are urged towards the plates by a resilient means, preferably a spring (13, 19). The apparatus may be used in a photocopier or a fuser.

Description

SHEET FEEDER

The present invention relates to apparatus for feeding elements in sheet form. The apparatus is intended particularly, but not exclusively, for use in feeding sheets of paper through a manual fuser.

5 Feeding sheets of paper sequentially to a machine can lead to paper jams particularly where the sheets are not all of the same type and/or vary in weight and/or thickness. An object of the invention is to mitigate this disadvantage.

According to the present invention, there is provided apparatus for 10 feeding elements in sheet form comprising a support for feeding elements being fed, and roller means for feeding the elements along the support mounted for displacement relative to the support means, drive means for driving the roller means and resilient means for urging the roller means towards the support means.

15 In a preferred embodiment of the invention, the support means comprise a series of plates. Adjacent plates preferably overlap one another in the direction in which the elements are fed in operation.

Advantageously, there is a fall in the plates in the feed direction. The roller means comprise two or more rollers.

20 Preferably, the roller means comprise one or more leading rollers and one or more trailing rollers. Advantageously, there are two or more leading rollers and two or more trailing rollers. Preferably the leading rollers are mounted on a first common mounting and the trailing rollers are

mounted on second common mounting. The first and second mountings may be ganged together. Guides are associated with one or more leading rollers. Advantageously, the guides are wire guides. Each roller may be mounted on the associated mounting and secured in position by means of 5 collars disposed on opposite sides thereof. The guides may extend through the collars. Preferably, the resilient means comprises springs advantageously constrained to act being the relevant mounting and the support means. The drive means may comprise a drive motor driving a series of sprockets through a drive chain and, via one or more of those 10 sprockets, the roller means.

In order that the invention m ay be more fully understood, one embodiment thereof will now be described by way of example, with reference to the accompanying drawings, in which: Figure 1 shows a front elevational view of a manual fuser according 15 to the invention, Figure 2 shows an end elevational view of the ieft-hand end of the fuser of Figure 1, Figure 3 shows an end elevational view of the right-hand end of the fuser of Figure 2, and 20 Figure 4 is a cross-sectional view of the fuser of Figure 1, taken along the line A-A of Figure 1.

Referring to the drawings, the manual fuser comprises a housing 1 incorporating a support 2, a heater 3 for heating sheet elements fed

through the fuser, and roller means for feeding elements. The roller means comprise two mountings in the form of shafts 4 and 5 disposed respectively at the front and rear of the fuser. Two rollers 6 and 7 are disposed on shaft 4 and two rollers 8 and 9 are disposed on shaft 5. Each 5 roller 6, 7, 8 and 9 is disposed between a pair of collars 10, 11 mounted on the corresponding shaft 4, 5 which maintains the roller in position.

Wire guides 12 are mounted on each pair of collars 10, 11. Each wire guide extends through an aperture 13 in the corresponding collar 10, 11.

Each shaft 4, 5 is resiliently mounted. For this purpose each end of 10 shaft 4 is mounted for movement at right angles to the axis of the shaft 4 on corresponding guides 13 and 14 against the action of corresponding helical springs 15 and 16. Similarly each end of shaft 5 is mounted for movement at right angles to the axis of the shaft 5 on corresponding guides 17 and 18 against the action of corresponding helical springs 19 15 and 20. The support 2 comprises a series of overlapping plates 21 over which in operation, the sheets travel. Each plate 21 has at its leading edge a downwardly dependent section 22 which (apart from the leading plate) extends under the trailing edge of the next adjacent plate to ensure, in operation a smooth transition of the sheets from plate to plate during 20 travel through the fuser.

Drive means 30 for driving the roller means are disposed at one axial end of the fuser. These drive means comprise an electric motor 31 having a drive sprocket 32 on its output shaft. Two further sprockets 33

and 34 are drivably connected to the sprocket 32 through a drive chain 35 which provides a reliable positive drive. The driven sprockets 33 and 34 are in turn connected to drive shafts 36 and 37 respectively mounted in the housing 1. Mounted on each drive shaft are a pair of drive rollers, 5 38 and 39 on shaft 36 and 40 and 41 on shaft 37. Drive rollers 38, 39, 40 and 41 respectively contact driven rollers 6, 7, 8 and 9 to drive them in operation through friction. Contact is made through slots formed in the plates of the support 2 adjacent the drive rollers 38, 39, 40 and 41.

In operation sheets are fed individually to the manual fuser. On 10 entry to the fuser each sheet is guided into the nips between leading roller pairs 6 and 38 and 7 and 39 by the wire guides 12. Any variation in the thickness of sheet is accommodated by the movement of the rollers 6 and 7 on the shaft 4 against the resilient force applied by corresponding springs 15 and 16. The construction of the support 2 ensures that sheets 15 pass progressively over the support without snagging. Each sheet is pulled through by the pairs of driven and driving rollers 6 and 38 and 7 and 39 at the entrance to the fuser and also by the corresponding pairs of driven and driving rollers 8 and 40 and 9 and 41 at the exit from the fuser. Rollers 8 and 9 may also move against the resilient force applied 20 by corresponding springs 17 and 18 on the shaft 5 as each sheet passes under the heater 3 to heat the sheet.

It will be appreciated that the above embodiment has been described by way of example only and that many variations are possible

without departing from the scope of the invention. For example, although the fed mechanism has been described for a manual fuser, it may equally well be used for other applications.

Claims

1. Apparatus for feeding elements in sheet form comprising a support for feeding elements being fed, and roller means for feeding the 5 elements along the support mounted for displacement relative to the support means, drive means for driving the roller means and resilient means for urging the roller means towards the support means.

2. Apparatus for feeding elements as claimed in claim 1, in which the 10 support means comprise a series of plates.

3. Apparatus for feeding elements as claimed in claim 2, in which adjacent plates overlap one another in the direction in which, in operation, elements are fed.

4. Apparatus for feeding elements as claimed in claims 2 or 3, in I S which there is a fall in the plates in the direction in which, in operation, elements are fed.

5. Apparatus for feeding elements as claimed in any preceding claim, in which the roller means comprises two or more rollers.

6. Apparatus for feeding elements as claimed in claim 5, in which the 20 roller means comprise one or more leading rollers and one or more trailing rollers.

7. Apparatus for feeding elements as claimed in claim 6, in which the leading rollers are mounted on a common mounting.

8. Apparatus for feeding elements as claimed in claims 6 or 7, in which the trailing rollers are mounted on a further common mounting.

9. Apparatus for feeding elements as claimed in claim 8, in which the 5 common mountings are ganged together.

10. Apparatus for feeding elements as claimed in any of claims 7 to 9, in which guides are associated with one or more leading rollers.

11. Apparatus for feeding elements as claimed in claim 10, in which the guides are wire guides.

10

12. Apparatus for feeding elements as claimed in any of claims 7 to 11, in which each roller is mounted on the associated mounting and secured in position by means of collars disposed on opposite sides thereof.

13. Apparatus for feeding elements as claimed in claim 12 when 15 appendant to claim 10 or 11, in which the guides extend through the collars.

14. Apparatus for feeding elements as claimed in any preceding claim, in which the resilient means for urging the roller means towards the support means comprises springs.

20

15. Apparatus for feeding elements as claimed in claim 14, in which the springs are constrained to act between the relevant mounting and the support means.

16. Apparatus for feeding elements as claimed in any preceding claim, in which the drive means comprises a drive motor, drive sprockets and drive chain.

17. Apparatus for feeding elements substantially as hereinbefore 5 described with reference to the accompanying drawings.