GB2192254A

GB2192254A - Metal roller

Info

Publication number: GB2192254A
Application number: GB8616159A
Authority: GB
Inventors: Tatsushige Mayama
Original assignee: Nippon Tenshashi KK
Current assignee: Nippon Tenshashi KK
Priority date: 1986-07-02
Filing date: 1986-07-02
Publication date: 1988-01-06
Anticipated expiration: 2006-07-02
Also published as: DE3622792C3; DE3622792C2; GB8616159D0; GB2192254B; DE3622792A1

Abstract

The invention relates to a metal roller, and in particular to a metal roller for feeding paper or the like. A sheet matrix (3) has applied thereto a layer of corrosion resistant photoresin which is exposed through a pattern so that the exposed areas when developed are removed. The areas removed are then corroded by a corrosive solvent so that eventually mushroom shaped protrusions are formed. The protrusion top (5) can be flat or coarse and an acute angle (7) is formed between the top (5) and each protrusion side (6). The sheet matrix with protrusions so formed is then wound around a roller base body (2) to form a roller suitable for feeding paper or the like. <IMAGE>

Description

SPECIFICATION Metal roller This invention reiates to a metal roller for use in a feed device.

Generally, various items of OA (office automation) equipment, such as a printer, plotter, and copier, have a feed device such as drive and driven rollers for feeding paper. Rollers of this type are normally made of metal, synthetic resin, rubber, or the like. Rubber rollers are more often used, since they have greater frictional grip. However, rubber rollers are less favourable in respect of durability generally and of the frictional grip; hence, they have a drawback that their service life is very short.

In order ta overcome this difficulty, therefore, it has been general practice to employ a metal roller which has a multiplicity of protrusions formed on its surface by knurling (rolling), or one which has a multiplicity of protrusions formed on its surface by cutting.

Although, metal rollers of the former type are easy and inexpensive to manufacture since protrusions are formed by knurling, the protrusions are essentially of a ridge configuration and are not strictly uniform in height so that their contact with paper is not uniform, which means less frictional grip. Metal rollers of the latter type, having protrusions formed thereon by cutting, are more favourable than those of the former type in respect of the sharpness of the projection and provide better contact with paper and greater frictional grip. However, they have a difficulty that their manufacture involves more labour and time, which naturally means higher costs.

This invention is intended to eliminate the aforesaid difficulties, and accordingly, the invention has as its primary object the provision of a metal roller which has much greater frictional grip than conventional metal rollers and yet is inexpensive to manufacture.

According to a first aspect of the invention there is provided a method of producing a metal roller comprising the steps of: forming a pattern of corrosion resistant material on a metal sheet, applying corrosive to said pattern to remove metal in the interspace of the pattern, removing said corrosion resistant pattern, wrapping and affixing at least a portion of said sheet around and to a roller core.

A metal roller in accordance with this invention comprises a base body having a circular cross-section, a metal sheet matrix fixed to the outer surface of a base body, and a multiplicity of uniform and fine protrusions formed integrally on the outer surface of the base body, the protrusions each having a top and sides, the internal angle between the top and the sides being an acute angle.

In short, a sheet matrix so formed to have a multiplicity of protrusions thereon is mounted on the outer periphery of the base body, and each projection has a top and sides, the cross axes angle between the top and sides being an acute angle. The fact that the top and sides of each projection makes an acute anyle with each other permits very satisfactory contact with paper, which means high frictional grip. Therefore, the metal roller of the invention, when used as a feed roller for feeding paper, for example, assures positive and accurate paper feed.

Various embodiments of the invention will now be described by way of example only with reference to the accompanying drawings.

Fig. 1 is a schematic view in perspective showing the general appearance of a metal roller embodying the invention; Fig. 2 is a fraymentary enlarged view in longitudinai section; Fig. 3 is a fragmentary enlarged view in perspective showing projections; Figs 4 to 11, inclusive, are explanatory views showing a method of manufacturing a metal sheet matrix having protrusions formed thereon; Fig, 12 is a perspective view showing a metal sheet matrix having protrusions as it appears when it is being wrapped round a base body to form a metal roller; Figs. 13 and 14 are explanatory views showing another method of manufacturing a sheet matrix having protrusions; Fig. 15 is a schematic perspective view showing a sheet matrix having protrusions wrapped spirally round a base body; Fig; 16 is a schematic perspective view showing a metal roller having a tapered configuration; Fig. 1 7 is a schematic perspective view showing a metal sheet matrix having protrusions formed thereon as it appears when it is being mounted by engagement means on a base body; Fig. 18 is a fragmentary enlarged view in longitudinal section showing key portions of a metal roller in which projection tops have a rough surface; Fig. 1 9 is a fragmentary enlarged view in longitudinal section showing a metal sheet stock having a rough surface.

Referring to the drawings, a metal roller 1 consists mainly of a base body 2, a sheet matrix 3, and protrusions 4. The base body 2 has a circular cross-section and in this case it is made of steel. The sheet matrix 3, is made of metal and is mounted on the outer periphery of the base body 2. In the present embodiment, the matrix is made of steel and has a flat sheet configuration. The protrusions 4 are fine and uniform and are conveniently of the same material as the sheet matrix 3 and are present in a multiplicity on the outer surface thereof, being integrally formed therewith.

Each protrusion has a top 5 and sides 6, the internal angle a between them being an acute angle.

In the present embodiment, each protrusion is generally of a mushroom shape with an acute angle edge 7 formed between the top 5 and each side 6. The top 5 is flat and each side 6 is arcuate. The individual protrusions 4 uniformly project upwardly according to a pre determined pattern of arrangement. The metal roller 1 has an outer diameter of 15.0mm (in cluding protrusions 4), an inner diameter of 10.0mm, and a length of 30.0mm; and each protrusion has a maximum diameter D of 0.1 mum and a height H of about 0.1 mum, with the angle a of the edge 7 set a approximately 70".

Such a metal roller 1 may be used as a drive roller for a feed device by inserting a shaft 8 into the hollow centre thereof and fix ing same, or it may be used as a driven roll for a feed device by loosely fitting a shaft 8 thereinto.

Since the sheet matrix 3 mounted on the outer periphery of the base body 2 has a multiplicity of protrusions 4 formed on the outer surface thereof, and since the angle a between the top 5 and sides 6 of each protrusion is an acute angle, the metal roller 1, when used as a feed roller for a paper feed device, provides very satisfactory contact with paper through the protrusions 4, thus exhibit ing remarkably greater frictional grip than any conventional metal roller. Therefore, the possibility of roller slippage relative to paper is substantially eliminated and this assures positive and accurate paper feed.

Such a sheet matrix 3 having protrusions 4 for such a metal roller 1 may be fabricated by a method utilizing photoetching techniques.

Figs. 4 through 11, inclusive, are views illustrating the method schematically.

In this method, various kinds of metallic materials, such as steel and the like, which can be etched through application of an etchant, may be employed as starting materials. In the present example, as Figs. 4 and 5 show, a piece of steel sheet 10 having specified dimensions, ie., 46.5mm long, 30.0mm wide, and 0.2mm thick, is used as a starting material, A corrosion resistant photoresin or a photoresist film 11 is deposited on the surface of the sheet stock 10, after it is degreased, as Fig. 6 shows. Next, a baking treatment or a so-called prebaking treatment is applied to the photoresist film.

Independently, a pattern of protrusions to be formed in the sheet stock is made with a device such as a micro-plotter or the like, which is employed to produce a precision photo-plate or photomask 12. Then, as Fig. 7 shows, the photomask 12 is laid over the photoresist film 11 for exposure. Thereafter, the sheet stock 10 which has been exposed is subjected to a development process, and further the photoresist film 11 which has remained on the sheet stock 10 through the development process is subjected to baking or a so-called post-baking treatment, whereby openings, 13 which positionally correspond with the pattern depicted on the photomask 12 are made on the photoresist film 11 as illustrated in Fig. 8 to form exposed metallic parts 14.

In this example, a so-called posi-type method is employed wherein a photoresist film which, after exposure, is subjected to the development process for removal of the exposed portions thereof is used in conjunction with a photomask which coacts with the former. As is well known, it is equally possible to employ a nega-type method wherein a photoresist film which, after exposure, is subjected to a development process for removal of portions thereof other than exposed areas is used in conjunction with a photomask which coacts with the former. In short, it is essential that the photoresist film must remain on those portions which correspond to the protrusions to be formed in the sheet stock.

Thereafter, the sheet stock 10 having exposed metal portions 14 thus obtained is subjected to an etchant A and physically subjected to relative movement so that the exposed metal portions are chemically corroded with the etchant A during such relative movement. Since the sheet stock 10 and the etchant are physically subjected to relative movement, the effect of etching spreads transversely as the depth of etching increases.

In other words, etching progresses in the same manner as the natural act of erosion, and accordingly recesses 15 are formed on the surface of the sheet stock 10 so that after the etching process the recesses are gulf-shaped in section as Fig. 10 shows.

For the purpose of the aforesaid physical relative movement, for example, a stationary nozzle B can be kept spraying an etchant A as Fig. 9 shows, and a sheet stock 10 having exposed metal portions 14 is moved in a given direction so that it may travel under a jet of etchant. In this way, a spray of etchant strikes the surface of the sheet stock 10 in a uniform manner and gulf-shaped recesses 15 may be etched in a short period of time.

Upon completion of the etching step, the photoresist film 11 which remains on the sheet stock is removed.

Thus, as Fig. 11 shows, protrusions 4 are formed between adjacent recesses 15. A metal sheet matrix 3 having a multiplicity of protrusions 4 formed on the surface thereof can be prepared in the above described manner.

Thereafter the sheet matrix 3 having such protrusions 4 is mounted on the outer periphery of the steel-made base body 2 by wrapping the former round the latter, with an adhesive layer interposed therebetween, as Fig. 12 illustrates.

Through the above steps, a metal roller 1 as shown in Figs. 1 to 3 is obtained. The top 5 of each protrusion 4 on the metal roller 1 retains its flat (not curved) surface even after the sheet matrix is wrapped round the base body 2 for mounting in position thereon.

As described above, the formation of protrusions 4 on the sheet matrix 3 of the metal roller 1 is performed by a photo-etching method such that a photoresist film 11 remains on the surface portions of the sheet stock 10 which correspond to the protrusions to be formed. Alternatively, a printing method may be employed. That is to say, a corrosion resistant ink and a printing block are used instead of the photoresist film 11 and photomask 12 used in the photoetching method, and by employing a known precision printing machine, such corrosion resistant ink is deposited on portions of the surface of the sheet stock 10 which correspond to the protrusions to be formed thereon.

Fig. 13 illustrates one example of a precision printing machine. Numeral 20 designates an original printing block (a silk original block in the present example), 21 designates a fine mesh formed on the printing block 20 in conventional manner, 22 designates an acid-resistant ink, and 23 designates a brush. The brush 23 is movable unidirectionally parallel, and the sheet stock 10 is in contact with the printing block 20.

Accordingly, the corrosion resistant ink 22, as it passes through meshes 21 of the printing block 20 while being smoothed by the brush 23, is applied and deposited on the surface of the sheet stock 10 as Fig. 14 illustrates, so that exposed metal areas 14 are formed on portions of the sheet stock other than those corresponding to the protrusions to be formed.

Subsequently, the exposed metal areas 14 are subjected to etching with an etching solution A according to aforesaid etching technique, and upon completion of the etching, any residual ink 22 present is removed. A sheet matrix 3 having protrusions 4 as shown in Fig, 11 is thus obtained.

It is noted that in the earlier described embodiment, a sheet matrix 3 of a rectangular configuration having protrusions 4 formed thereon is wrapped round the base body 2 in a regular pattern; but alternatively the sheet matrix may be wrapped in a spiral pattern, for example, as illustrated in Fig15.

It is further noted that the configuration of the base body 2 is not necessarily limited to a cylindrical one as described with respect to the above embodiment. In another embodiment, the base body may be of a tapered configuration, for example, as illustrated in Fig.

16. In a further embodiment, it may be of a columnar or tapered shape integral with a shaft 8.

In the described embodiments, the sheet matrix 3 having protrusions 4 is fixed to the base body 2 through an adhesive layer 9. Alternatively, it may be fixed, for example, by welding or by engagement. Fig. 17 illustrates one example of fixing by engagement means.

On the outer periphery of the base body 2 there are provided axially extending dovetail grooves at given angle intervals. Sheet matrices 3 having protrusions 4 formed thereon, each bent at both ends, are brought into engagement at their respective ends with corresponding dovetail grooves, whereby the sheet matrices 3 and the base body 2 can be assembled together.

In the described embodiments, although the base body 2 is described as being made of metal, it can be made of synthetic resin, for example. Also in the described embodiment, the protrusions 4 are regularly oriented, but in another embodiment they may be randomly oriented.

In the described embodiment, the top 5 of each protrusion 4 is a smooth surface, but in another embodiment, as shown in Fig. 18, the top 5 may be a coarse surface, Where the top 5 is a coarse surface, the very fine irregularities present on the top surface provide improved abrasion resistance.

Such an effect may be achieved by using a coarse surfaced material as sheet stock 10.

Such a coarse surface of the sheet stock 10, which means increased surface area, assures positive deposition of the photoresist film 11 and corrosion resistant ink 22 and subsequent etching performance.

In the described embodiment, the sheet matrix 3 having protrusions 4 is made without heat treatment. In another embodiment, for example, the surface layer of the matrix on which protrusions are present, or the entirety of the matrix may be heat treated and baked.

This results in increased hardness of the protrusions 4 in particular, which means much longer service life.

Although the roller described is a feed roller for use in a feed device, the application of the metal roller according to the invention is not limited to such use; it may be employed for various other uses, such as a caster roller, sash roller, or a roller for conveyer belts.

As already described, this invention provides various advantages as enumeratad below.

(1) Remarkably increased frictional grip.

This is due to the fact that the inner angle between the top of each protrusion and the sides thereof is an acute angle. Accordingly, where the metal roller of the invention is used as a feed roller for paper feed, roller contact with paper is remarkably improved and thus positive and accurate paper feed is assured.

In the manufacture of conventional metal rollers, protrusions are formed by knurling by means of a die, or by cutting with a cutter or cutting tool, and this involves withdrawal of the tool during processing. Consequently, the inner angle between the top of each protrusion and the sides thereof is obtuse or a right angle, and cannot be made an acute angle.

(2) Lower cost of manufacture.

The manufacture of conventional metal rollers involves mechanical processing, such as knurling or cutting, and therefore it requires much time and labour. In contrast to this, the metal roller of the invention is manufactured in such a way that a sheet matrix having protrusions formed thereon is prepared by chemical processing, such as photoetching, which means less time and less labour required in the manufacture thereof, and therefore it can be manufactured on a mass production basis.

More especially, the fact that the formation of protrusions is performed through the process of chemical etching carried out while a piece of metal sheet stock and an etching solution are moved relative to each other contributes remarkably to the reduced time requirement.

(3) Protrusions not iiable to deformation or breakage.

This is due to the fact that the protrusions are formed homogeneously and integrally on the outer surface of a metal sheet matrix, and also to the fact that the protrusions are formed by chemical processing.

Conventional metal rollers, wherein protrusions are formed by mechanical processing, such as knurling or cutting, are liable to postprocessing set up of stresses therein, which may often result in deformation or breakage of the protrusions.

(4) Protrusions may be randomly oriented.

This is due to the fact that the protrusions are formed by chemical processing. One advantage of such random orientation is that in the case of paper feed, for example, random contact of the protrusions with the paper prevents the paper from damage. With conventional metal rollers, wherein protrusions are formed by mechanical processing, the protrusions are necessarily regularly oriented and not otherwise.

(5) Configuration of top surface of projection may be made other than rhombic or rectangular.

This is because of the fact that the protrusions are formed by chemical processing.

With conventional metal rollers, wherein protrusions are formed by mechanical processing, the configuration of the top of the projection is necessarily rhombic or rectangular, and no other configuration, such as circular, for example, is available.

(6) The material of the base body may be made different from that of the metal sheet matrix having protrusions formed thereon, This is because of the fact that the sheet matrix having protrusions is mounted on the base body. If the base body is of a light material, such as aluminum alloy, synthetic resin, or the like, the gross weight of the metal roller is reduced. Conversely, the gross weight may be increased by selecting some other material.

The material of the base body may be changed according to the use to which the metal roller is directed.

Claims

1. A method of producing a metal roller comprising the steps of: forming a pattern of corrosion resistant material on a metal sheet, applying corrosive to said pattern to remove metal in the interspace of the pattern, removing said corrosion resistant pattern, wrapping and affixing at least a portion of said sheet around and to a roller core.

2. A method as claimed in claim 1 including the step of producing relative movement between the corrosive and the pattern in the plane of said metal sheet whereby an enlarged interspace area is corroded below the pattern surface.

3. A metal roller as produced by a method described in claim 1 or 2.

4. A metal sheet as produced by a method as claimed in claim 1 or 2.

5. A metal roller comprising a base body having a circular cross-section, a metal sheet matrix fixed to the outer surface of the base body, and a multiplicity of uniform and fine protrusions formed integrally on the outer surface of the sheet matrix, the protrusions each having a top and sides, the internal angle between the top and the sides being an acute angle.

6. A metal roller according to claim 5 wherein the base body is made of metal.

7. A metal roller according to claim 5 wherein the base body is made of synthetic resin.

8. A metal roller according to claim 5 wherein the base body is cylindrical.

9. A metal roller according to claim 5 wherein the base body is tapered.

10. A metal roller according to claim 5 wherein the base body is integral with a shaft.

11. A metal roller according to any one of claims 5 to 11 wherein the sheet matrix wraps round and is fixed onto the outer surface of the base body,

12. A metal roller according to any one of claims 5 to 11 wherein the sheet matrix wraps round and is fixed on the outer surface of the base body in a spiral pattern.

13. A metal roller according to claim 11 or 12 wherein the sheet matrix is fixed with an adhesive to the base body.

14. A metal roller according to claim 11 or 12 wherein the sheet matrix is fixed to the base body by welding.

15. A metal roller according -to claim 11 or 12 wherein the sheet matrix is fixed to the base body through engagement means.

16. A metal roller according to any one of claims 5 to 15 wherein protrusions are formed on the sheet matrix in a predetermined regular pattern.

17. A metal roller according to any one of claims 5 to 15 wherein protrusions are formed on the sheet matrix in a random pattern.

18. A metal roller according to any one of claims 5 to 17 wherein the top of each protrusion has a smooth surface.

19. A metal roller according to any one of claims 5 to 17 wherein the top of each protrusion has a coarse surface.

20. A metal roller according to any one of claims 5 to 19 wherein the sheet matrix and the protrusions thereon are without heat treatment.

21. A metal roller according to any one of claims 5 to -19 wherein the sheet matrix with the protrusions thereon is heat treated (hardened) in its entirety.

22. A metal roller according to any one of claims 5 to 19 wherein the protrusions and the outer surface portion of the sheet matrix on which the protrusions are located are heat treated (hardened).

23. A method of producing a metal roller substantially as herein described with reference to the accompanying drawings.

24. A metal roller substantially a herein described with reference to the accompanying drawings.