PATENT SPECIFICATION

Application Date: Sept. 14, 1928. No, 18,386/29. (Divided out of No. 323003) Complete Accepted: Dec. 16, 1929.

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COMPLETE SPECIFICATION. Improvements in or relating to Blanks for the Manufacture of Razor Blades.

323,007

I, Folke Kylberg, of 3 Skyttegatan, Gothenburg, Sweden, a Swedish subject, do hereby declare the nature of this invention and in what manner the same is to be performed, to be particularly described and ascertained in and by the following statement:—

The present invention refers to a method of producing blanks for razor blades, facilitating the manufacture of such blades of perfect keenness and of a high and uniform quality out of the blanks at a low price, depending substantially on the feature that the manufacture may be rendered more rational by the novel method than has been possible hitherto. The invention consists substantially in that a steel band, which is preferably thin and unburdened and of rectangular cross-section, is provided by aid of suitable working, such as a pressing, rolling or equivalent operation, with one or more elevations, ridges, grooves, channels or the like in such a way that after such operations the blank is of substantially the same thickness throughout.

On having been subjected to the working processes the blanks thus produced may preferably be subjected to hardening and tempering, before the blanks are subsequently subjected to further working for the manufacture of razor blades as is described for example in my co-pending application No. 26410/28 (Serial No. 323003).

Four embodiments of a blank produced in the manner set forth are illustrated in the accompanying drawing where, Fig. 1 is fragmentary plan view of a blank according to one embodiment, while Fig. 2 shows the same to an enlarged scale in cross-section on line A—B in Fig. 1. Figs. 3 and 4 are corresponding views of the second embodiment. Figs. 5 and 6 show cross-sections of the third and fourth embodiments.

According to the embodiments illustrated, a thin steel band 1 of uniform thickness is provided on its one side with a ridge 2 extending in the longitudinal direction of the band, and on its other side with a groove 3 corresponding to the said ridge, this groove 3 being preferably produced by subjecting the steel band of uniform thickness to a rolling operation. The blank is substantially of the same width as the blades to be manufactured therefrom, for which reason the razor blades are obtained by cutting the band substantially on lines 6 drawn at right angles to the longitudinal direction of the band. Moreover, the blank is shown as being provided with a plurality of apertures 4 arranged along the centre thereof at a suitable distance from each other, said apertures being intended to form guiding means for securing the finished razor blades in razor devices. Furthermore, the blank is provided with a number of openings 5 along the severing lines 6. The apertures 4 and the openings 5 are preferably made by conveying the unhardened steel band through a punching machine, which may be arranged for the working of the blanks either before or after the rolling thereof.

The openings 5 may assume various forms, but preferably they should be so arranged as to be situated entirely inside the borders so as not to break through the same at any point, it being of great importance, particularly in forming the cutting edges, that the grinding disks or the like arranged for this purpose are caused to work upon entirely uniform edges, as otherwise the grinding disks would be brought into vibration by any irregularities, with an inferior result of work consequent thereto. According to Figs. 1 and 2, the openings extend transversely through the whole ridge 2, whereas according to Figs. 3 and 4 they are situated entirely inside the central portion of the ridge. The latter embodiment is preferred, the ridges and grooves respectively having, amongst other things, for their purpose during the working process to form members for the guidance of the blanks in the transversal direction, it being not then feasible to have the openings breaking through the lateral walls of the ridges and grooves respectively. If found suitable, two further openings 7 may be arranged along; each severing line 6 on both sides of the opening 5.

The manufacture of razor blades out of the blank may be effected either so that the units are first cut off the hardened or unhardened blank and are then subjected to further working, or, the separation of the units may take place only after the band has been subjected to one or more operations required to finish the blades, such as grinding, trimming, polishing, etching and drying.

By using the blanks above described for the manufacture of razor blades, the further advantage is obtained that a greater or smaller part of the working thereof may be left to the furnisher of the blanks, so that the manufacturer, who is generally reduced to buying his blanks front a furnisher, in the first place lessens part of his risk for any manufacturing faults involved in the manufacture, and also may have a greater warranty for a superior and uniform quality in the finished product. It is believed to be of particular importance that the hardening and tempering of the blanks is also left to the furnisher, inasmuch as the latter, in possession of an intimate knowledge of his material, should have the greatest qualifications for imparting suitable properties to the material in regard to hardness and the like. In case the finished razor blades shall be provided with one or more of the apertures 4 arranged for securing the blades in the razor device, the blank should therefore be furnished with such apertures, as well as with the openings 5, inasmuch as punches or other tools with a shearing action are hardly suitable for working upon hardened material. On the other hand, the separation of the units from the steel band may take place without difficulty by aid of some other suitable tool, thanks to the openings 5 provided at the severing lines of the razor blades.

Out of a blank with ridges, grooves or corrugations extending in the longitudinal direction, razor blades are obtained which may be made thinner than would otherwise be possible, besides which the ridges and grooves form suitable guiding means for the blades during the working thereof, which is of importance, whether the working is to take place after the blades have been separated, of before. The ridges, grooves etc. may also form guiding means for the guidance of the finished blades in razor devices.

A blank produced in accordance with the invention may be varied at will in regard to the distribution and number of the holes 4, and, likewise, the openings 5 may assume some other form, the same consisting, for instance, of perforations, or being arranged in some other manner to reduce the cross-section of the band.

The ridges, grooves etc. may also be subjected to considerable variations in regard to position, shape and number, the same being, for example, disposed so as to form a suitable angle with the border of the band. The blank may also be of the same width as the length of the razor blades manufactured therefrom, in which case the units are preferably severed along the lines forming the longitudinal sides of the blades. It is obvious, also, that the invention may be applied to steel bands of widths varying within wide limits, in which case the severing lines indicating the openings 5, as well as the distributions of the holes 4 along the band, must be grouped otherwise than above described.

Having now particularly described and ascertained the nature of my said invention and in what manner the same is to be performed, I declare that what I claim is:—

1. Method of producing blanks for the manufacture of razor blades consisting in that a steel band is provided by the aid of suitable working, such as one or more pressing, rolling or equivalent operations, with one or more elevations, ridges, channels or the like in such a way that after such operations the blank is of substantially the same thickness throughout.

2. Method according to claim 1, consisting in that a steel band or rectangular cross-section, which is preferably thin and unhardened is provided by the aid of suitable working, such as one or more pressing rolling, or equivalent operations, with one or more elevations, ridges, channels or the like.

3. Method according to claim 1 or 2, consisting in that the steel band is deformed in such a way that on the one flat side of the band the deformations constitute one or more channels, the bottom of each of which gives rise to a corresponding ridge on the other flat side of the band.

4. A method according to any of the preceding claims consisting in providing a band, having a length corresponding to the length of a plurality of blades, with a channel and with holes in the bottom of said channel.

5. A method according to claim 4, characterised by the fact that the channel is very shallow and has a flat bottom.

6. A method according to any of the preceding claims, characterised in that the Steel band is provided with a single longitudinal ridge in the middle of the band.

7. A method according to any of the preceding claims, characterised by the blanks being subjected to hardening and tempering after the working thereof.

8. A blank for the manufacture of razor blades, produced according to the method set forth in any of the preceding claims.

9. A blank for the manufacture of razor blades, according to claim 8, characterised by the fact that the blank consisting of a steel band is provided on its one side with one or more ridges or the like, extending in the longitudinal direction of the band, and on the other side with grooves or the like corresponding to said ridges or the like.

10. A blank for the manufacture of razor blades according to claim 8 or 9, characterised by the fact that the blank consisting of a steel band is of the same or approximately of the same width as the razor blades to be manufactured from the blank.

11. A blank for the manufacture of razor blades according to claim 8, 9 or 10, characterised by the fact that the blank consisting of a steel band is also provided with a number of holes or the like arranged in such a manner that the holes may form guiding means for securing the finished razor blades in razor devices.

12. A blank for the manufacture of razor blades according to any of the preceding claims, characterised by the fact that the blank consisting of a steel band is provided along the severing lines for the razor blades, with openings, perforations or the like situated entirely inside the borders of the band.

13. A blank for the manufacture of razor blades according to claim 12, characterised by the openings, perforations or the like being so arranged as not to break through the lateral edges of the ridges or grooves respectively.

14. A blank for the manufacture of razor blades substantially as described with reference to the accompanying drawing.