US1877758A

US1877758A - Method of making razor blades

Info

Publication number: US1877758A
Application number: US311697A
Authority: US
Inventors: Kylberg Folke
Original assignee: TONSOR AB
Current assignee: TONSOR AB
Priority date: 1928-02-10
Filing date: 1928-10-10
Publication date: 1932-09-20
Anticipated expiration: 1949-09-20

Description

Sept. 20, 1932. l F KYLBERG 1,877,758

METHOD OF' MAKING RAZOR BLADES Filed Oct. lO, 1928 2 Sheets-Sheet l Fiyi.

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Sept. 20, 1932. F KYLBERG 1,877,758

METHOD OF MAKING RAZOR BLADES Filed Ooi. l0, 1928 2 Sheets-Sheet 2 Patented Sept. 20, 1932 UNITED STATES PATENT OFFICE FOLKE KYLBERG, OF GOTTENBORG, SWEDEN, ASSIGNOR T0 AKTIEBOLAGET TONSOR, OF GOTTENBORG, SWEDEN, A JOINT-STOCK COMPANY OF SWEDEN METHOD 0F MAKING- RAZOR BLADES Application filed October 10, 1928, Serial No. 311,697, and in Sweden February 10, 1928.

In producing razor blades it has been the practice hitherto to give the razor blade the desired form by punching it out of an unhardened steel band, whereupon the blades thus formed would be subjected to hardening and ,3. manufacture of the razor blades, that is to say, with the aid of automatic machines and apparatus for carrying out the various operations.

y The present invention relates to a method for manufacturing razor blades which, in distinction from the previously known methods, permits production of the blades under the said conditions, and the invention consists substantially in that the blades are produced by suitable operations out of a blank consisting of a steel band provided with holes, recesses, perforations, elevations, ridges, channels or the like, said steel band being preferably thin and of uniform width.

The blank consisting of such a steel band, preferably of the same or approximately of the same width as the razor blades produced from the blank, may then, if provided with ridges, channels or the like, have one or more of such ridges, channels Vor the like provided on the one side and extending in the longitudinal direction of the blank, the opposite side of which is then provided with grooves or the like corresponding to the said ridges, besides which the holes or the like provided in the blank may in the first place be so arranged as to form guidingl means for the razor blades when securing` the Same in shaving apparatus, and may further be arranged along the separating` lines between the razor blades so as to facilitate separation of the blades from the blank.

The band-shaped blanks thus produced may preferably be subjected to hardening and tempering before subjected to further working for the purpose of manufacturing razor blades, Which Working may take place either after the separation of the blades from the hardened or unhardened blank, or only after the hardenedblank has been subjected to one or more of the subsequent operations required to finish the blades, such as grinding, trimming, polishing, etching and drying.

The said operations may beiconceived as combined in such manner that the steel band is Caused during its continuous or intermittent feed to pass successively through all the stages of manufacture, commencing from the unhardened, preferably coiled state and proceeding to the finished razor blades. The operations may, however, be divided prior to the grinding and the other working operations, forl instance in such manner that the requisite working of the unhardened steel band takes place independently of the hardening and the grinding operations which may be effected either each per se or be carried out in connection with other operations for finishing the `razor blades.

The accompanying drawings illustrate by way of example a suitable machine for carrying the method according to the invention into effect, said machine being arranged to continuously feed a band supplied to the machine in a coiled and unhardened state and prepared in the manner set forth, and where the razor blades, on having been separated from the band, leave the machine while thrust one adjacent to the other on guiding members. Means for working the unhardened band and for grinding the end portions of the blades have not been shown in the drawings, inasmuch as these operations may be carried out in accordance with common practice.

lin the drawings, Fig. l shows a machine arranged according to the invention and viewed in elevation. Fig. 2 is an elevation of a grinding device for the steel band arranged in the said machine. Fig. 3 is a plan view of the same device, and Fig. 4 shows the device in cross-section on line A-B in Fig. 2. Figs. 5 and 6 illustrate the working of the two edges of the steel band by the grinding disks, these views being diagrammatic representations on an enlarged scale. Fig. 7

is an enlarged view of a guiding device for the steel band as used injthe machine and viewed in a plane at right angles to the longitudinal direction of the band. Fig. 8 shows an elevation of the razor blades separated from the band and arranged on the respective guide member for the purpose of round-grinding the end portions of the blades. Fig. 9 shows a plan View of the same arrangement. Figs. l0, 11 and 12 show different embodiments of cross-sections of the steel band suitable for the manufacture of razor blades. Fig. 13 shows a portion of a blank consisting of a steel band provided with the holes and recesses with which it has preferably been provided prior to being introduced into the machine shown in Fig. 1. Fig. 14 is a section taken on line 14-14 in Fig. 13.

The band 1 is supplied to the machine in the form of rolls and prepared in the manner set forth. These rolls are mounted on a frame or the like 2 in such manner that the band 1 may be unwound from the roll when driven by any suitable driving means. The band is moved by means of a guide roller or the like, to begin with ythrough or over a gasfired or electrically heated furnace 3 or the like for the `purpose of being heated vto hardening temperature, and, immediately thereafter, through or over a hardening apparatus 4; which may consist of a vessel containing a liquid heated to suitable temperature, liquid metal or the like, whereupon the band is conducted to the tempering apparat-us 5 which may comprise an electrically heated plate, inutile or the like, the temperature of which may be electrically controlled with respect to the'rate of feed of the band in such manner that the desired hardness is obtained in the band. The band is then caused to pass a trimming apparatus 5 where oxide layers or the like formed on the flat sides of the band in the hardening and tempering processes are removed before the band is introduced into the grinding apparatus 6 for the grinding of the longitudinal edges of the band. v

Rotatably mounted in the frames 7 are a plurality of driving members, preferably in the form of rollers or the like 8, over which the steel band is moved, preferably in the manner disclosed in Fig. 1. It is then of importance also to provide rollers 9 to stretch the steel band. The four rollers 8 situated on the outer sides of the frames 7 may thus be driving rollers, whereas the four other rollers 9 are preferably arranged as tension rollers which for the purpose of controlling the tension of theband should be journalled in separate, Weight- .or spring-actuated members displaceably arranged relatively to the frames 7.

Along the zigzag-shaped` path through which the steel bandmoves, there-are provided a plurality of grinding disks of different machine shown in the drawings is adapted for grinding both edges of the steel band, and for this purpose the grinding disks are arranged in pairs to grind the diagonally opposed corners of the cross-section of the band. When the band thus passes the grinding place 10,

the two diagonally opposed corners of the cross-section of the band are subjected to rough grinding; in the same manner the two other corners of the section are subjected to rough grinding at 10. Intermediate grinding is effected at 11 and 11 as before and alternately at the opposite section corners; fine grinding of different grades is effected at 12 and 12 and at 13 and 13 and, finally, polishing of the edges takes place at 14 and 14.

After the band has been ground, the flat sides of the same are subjected to final polishing in an apparatus 15 devised for this purpose, whereupon the band is caused in the course of its further movement successively to pass

apparatus

16 and 16 for the marking of the two sides of the steel band, apparatus 17 for drying and apparatus 18 for trimming the band, until the band is ultimately introduced into a press 19Where the blades are separated from the band. The press is provided with an intermittently acting feeding device for the band connected with the driving mechanism of the press, said feeding device being also suitably adjusted and caused to be dependent on the peripheral speed of the driving rollers 8.

It is of importance that these driving rollers 8 be suitably distributed along the band, in order that the strains imposed upon the material of the band shall not be too great during the feeding thereof. It is of importance, moreover, that the rate of feeding the band at the press 19 be somewhat less than the peripheral speed of the rollers 8 in n0- load running. In order that'the band shall always be stretched between the rollers, the driving rollers 8 should furthermore be soarranged as to exert the requisite ulling effect on the band, in order. among ot er things to overcome the grinding or frictional resistance Offered by the adjacent grinding disks and guide members during the grinding operations. This maybe obtained either by the tension of the band being so adjusted by means of the tension rollers 9 that sliding will normally take place between the driving rollers and the band, or by the connection between eaeh driving roller andthe source of power consisting of a springor Weight-actuated frietion coupling. By suitably tensioning the spring or by displacement of the Weight, the desired driving power may be obtained at each point of the band. The latter alternative offers the advantage that the 'steel band is not injured by scratching or the like caused by the sliding action.

In order to impart the requisite precision to the further Working of the band Whenduring the feeding of the band the saine isinoved past the grinding disks 2O or the like provided for the purpose in view, and past tlreap-V.

paratus arranged for the other Workingoperations, it is necessary that thel moving band be supported by suitable members at `the places of grinding. Such supporting members are preferably made in the form of rollers 21 arranged in pairs on both sides of the grinding disks 2() or thelike, the tivo flat sides of the steel band bearing between said rollers 21.

lt is not sufficient, however. that the steel band is accurately guided in the longitudinal direction, it`being also necessary to guide the same effectively in the transversal direction, particularly in the grinding operation. This may be attained with steel bands produced in accordance With the invention. inasmuch as the guide members Q1 as Well as the.

rollers

8 and 9 may be arranged for this purpose in such a manner to engage in some vsay or another into the holes, recesses, channels or the like provided in the band. or so as to grip the abutments, ridges or the like on the band. Embodiments of such bands suitable for the purpose set forth are shown in l? itl-i3. where the one side of the band is provided with longitudinally e.\;tendin'1l ridges', and the other side thereof with channels 23 corresponding to saidridges. Fig. illustrates an embodiment of such a'guide member con-1 sisting of rollers 21 Where one or both rollers are provided with 'cireumferentially eXtending grooves 251,01. Hang of a shape corre sponding aceuratel he ridges Q2 or the channels 23 of the band. The rollers, which are preferably rotatably mounted in ball bearings, are madein such manner (see Figs.

2 and that the bearing of the one roller is rigid in the fra-me 7 and the bearing of the other rolleris displaceable in a direction toward the iirstsmentioned bearing. besides which the disj'ilaceably arranged roller isaetuated in the direction indi ated by a spring 52 or a Weight., Measures have also been taken to release the band l by the provision shown in Fig. 13 and having` a cross-section differing from the original rectangular shape, for instance as shown 1n Flgs. lO-lQ, 1s preferably produced by rolling of the'steel band which was initially of a uniform thickness. The blank Q6 is substantially of the same. Width as that of the razor blades produced out of the blank, for Which reason the razor vblades Vare obtained by cutting @if the band, substantially along lines 2T drawn at right angles to the longitudinal direction of the band. The blank is moreover shown as being provided With a number of holes 28 situated along the centre of the blank and located ata suitable distance from each other, said holes being intended to form guiding means for securing the finished razor blades in shaving apparatus, and as being provided with`a number of openings Q0 along the separating lines Q7 for the razor blades to be produced. The holes 28 and the openings 29 are preferably made by moving the unhardened steel band through a stamping machine, which may be arranged to Work the blank either before or after the blank is subjected to shaping by rolling the same.

For the purpose of guiding the one or both edges of the steel band hardened and prepared in the manner indicated, grinding apparatus of different constructions may be made use of. The grinding disks 20 may be adjusted substantially in txvo diiferent Ways, either so as to be arranged to rotate in a plane vextending angularly, prefe lably at right angles to the longitudinal direction of the bandgr-or so that the axes of rotation of the grinding disks are situated in a plane vextending angularly, preferably at right angles to the longitudinal direction of the band. lVithgrinding disks arranged in this manner, there `Will result With each grinding disk, if no special means are provided, either no successive grinding of the band edge Whatever, or at least no such grinding of said edge that would be controllable from case to case in regard to the amount ground olf. However, in order to obtain a. satisfactory grinding result by the machine described, it has been found to be an indisj'iensable condition that such varrangements be provided for the adjustment of the grinding disks that a value of successive grinding, Which is suitable with respect to the nature of the grinding disk and the hardness of the steel band, may be selected for each separate grinding disk. lt is, in other Words, of the greatest importance always to keep the unavoidable Wear or the deformations of the Working surfaces of the grinding disks under a control as severe as possible, so that suitable measures may` be taken conveniently and without delay in order to reduce the'wear of the grinding disks to a minimum value.

Among the tivo alternative adjustments of the grinding disks suggested, the last-men Vtioned adjustment must be regarded as eX- tremely unsuitable for the reason that the grinding disks Will in the grinding operation aetuate the steel band in a direction substantially coinciding with the direction of feed of the band, or in the opposite direction, which will cause the feed of the` band to be disadvantageously influenced by the grinding disks during the rotation thereof.; For the control of a successive grinding for a grinding disk arranged in the manner indi cated, there is no possibility left but to alter the diameter of the disk. The first-men,-

tioned alternative method is therefore to'be preferred, inasmuch as the grinding d isks cannot in'sueh case have any effect whatever on the feed of the band. In order to be able at all to obtain successive grinding with a grinding disk disposed in the saidmanner, the working surface of the disk must be so arranged, however, as to form an angle with the edge ofthe band. The successive grind# ing can then be controlled only by altering the Value of this angle, which alteration kisvin such case generally effected by grinding the working surface of the grinding disks by means of a diamond.

Vith the embodiments of a grinding apparatus shown in Figs. 2-4 and provided with grinding disks 2O disposed substantially in the manner set forth, it is rendered possible to adjust the grinding disks individually in such manner that the amount of the successive grinding of the band edge may be controlled as desired by the aXes of rotation of the grinding disks 20 being situated in or adjacent to planes extending through the band edge worked upon, and by the shafts 30 being adj ustably arranged in this plane, partly in a direction toward the edge of the band and partly in such a manner that they may form arbitrary angles with the said edge of the band.

The adjustment of the shafts in the manner set forth is effected in the embodiment shown by the bearings carrying the ends of the shaft 30 being so arranged that the one bearing 31 is pivotally mounted about a shaft extending substantially at right angles to said plane, while the other bearing 32 is displaceable, substantially in a direction toward the edge of the band. ll`$oth bearings 3l and 32, which in Fig. 4 are shown as consisting of spherical ball bearings, are carried by an arm 34 pivotally1 secured in the frame 7, preferably by means of a pin 33, said arm being adjustable vertically, and the bearing 32 being adapted to be displaced relatively to the arm 34 by means of a hand wheel 35. For the simultaneous adjustment of the arm 34 and thus of the grinding disks 2O in the vertical direction, a hand wheel 36 is arranged to turn two screws 38 by means of a toothed gearing 37, said screws 38 being threaded in the arm 34 and having their ends bearing against abutments 40 carried by the frame and preferably secured on a rotatable shaft 39. The grinding disks 2O are arranged to be driven by means of a belt from an electric motor 41 carried by the arm, for which purpose the shaft 30 is provided with a belt pulley 42. For grinding of the diagonally opposed edges of the band-cross-section, the grinding disks are mounted in pairs each on a separate arm ,34,'which arms are carried by the frame 7, by means of the pin 33 common to both arms and by means of the shaft 39. By arranging driving pulleys 43 on the two free ends of the motor shaft, one and the same motor 4l may be used to operate both shafts 30. The'arms are furthermore actuated in a direction toward each other by means of the spring 44, and may also be actuated by the rotary shaft 39 by means of abutments 45 secured thereon. v

lWith the aid of the arrangement described each of the grinding disks 20 may be adjusted and fixed at a suitable elevation by means of the hand-wheels 3Gagainst the action of the spring 44, and may also be adjusted by means of thehand-wheels 35 for suitable successive grinding of the edges of the steel baud running between the rollers 21 and guided by these rollers in the transversal direction. T he rotary shafts 30 of the grinding disks may thus be adjusted so that they, while forming a certain angle V with the edge of the band, impart to the working surfaces of thc grinding disks, which surfaces may be of a cylindrical as well as of a conical shape, a. suitable inclination to the edge of the band. The Figures 5 and 6 disclose more fully how the grinding disks should be adjusted relatively to the steel band and to the direction of feed 0f the band as indicated by an arrow. From this it will be obvious that the angle between the working surface of each grinding disk and the edge of the band, which constitutes a measure of the successiveness that can be obtained with a certain grinding disk, is substantially dependent on the width of this grinding disk and on the adjusted operating depth. For the maintenance of the grinding disk, both in regard to its shape and with respect to its wear, it will thus be found to be of im portance that the disk be mad-e sufficiently wide, and that the operating depth does not become too great. It 'is obvious, likewise, that if a grinding disk would be so adjusted that the working surface is rendered'parallel to the edge of the band at the place of grinding, or coincides with the edge of the band, this circumstance must result in that the corner of the grinding disk directed against the direction of feed of theband will wear olf quickly, the grinding disk havingfor this reason to be subjected to frequent adjustments. A machine as that described, which comprises a comparatively great number of grinding disks, is entirely dependent on the grinding disks maintaining their shape as long as possible. Too frequent adjustments of the working surfaces of the grinding disks or too frequent replacements of Ygrinding disks would cause an uneven grinding result and frequently occurring interruptions in operation, which would interfere too much with the working capacity of the machine.

lf the working surfaces of the grinding disks are made accurately cylindrical and entirely concentric with the shafts of the disks, adjusting of the shape of the working surface of the grinding disks may be brought about in an empty machine by parallel adjustment of the two shafts and by approaching the latter until the grinding disks will during their rotation and while touchingi` each other grind ott' the working1 surfaces of one another. On occasions where the band is to be released, the grinding disks may be moved out of their working position by turning the abutment mounted on shaft 39 in the frame 7. lf the abutmcnts of all grinding apparatus are in mechanical connection with one another, it will thus be possible to bring all grinding disks out of working position with a single manipulation, from one and the same manuvring place. The manoeuvring means `for releasing the band from the grinding disks 2O may then be connected with a correspomling means for releasing` the band from the supporting members, rollers 2l, in such manner that a single n'ianipulation is sufficient for complete releasing of the band from the machine 6 in question.

In the embodiment shown, two disks are mounted on the same shaft. Such an arrangement involves the advantage that the Wear of the disks is materially reduced, inasmuch as the grinding places are thus doubled. There is of course nothing that would prevent the provision of more than two grinding disks on each one ofthe shafts in question, if desired. Each cutting edge being operated on by the grinding disks, each other time from the one side of the edge and, con-- sequently, each other timefrom the opposite side, the edge will, during the feed of the band` be subjected to a treatment which is closely allied to the grinding methods established by practical experiments.

The grinding means above described may be modified in many respects. lf the shaft is thus provided at its one end with a grinding disk and at its other end Vwith a belt pulley and is carried by a single bearing, the adjust ment of the shaft may be effected by arranging the bearing to be displaceable in a direction toward the edge of the band and also to be pivoted about. a shaft, pin or the like eX- tending substantially at right angles to the plane. lt is obvious that the grinding means may also he made use of in case the steel band is to be provided with a. cutting edge only along the one edge thereof, and where varying cross-sectional forms of the cutting edge are to be considered.

lVhen the steel band has reached the press 19 after the grinding of the band has been inished and the treatment of the band has otherwise been completed for the separation of blade units therefrom, the separation of the blades can take place even from a hardened steel band without any dilliculty by reason of the provision of the openings 29 or the like at the separating lines 27. The demands on the keenness of the stamping tool may thus be reduced, which is of importance, as the hardened steel band would not permit the use of tools adapted for complete shearing. y

The razor blades separated from the band are moved automatically down onto a piling cushion, sec Figs. 8 and 9, comprising a member 4G provided with suitable guiding means for the razor blades and a cover or the like 48 attached to the member 4G by means of a screw el?. rllhe guiding means consist of pins .i9 which by means of the holes 28 provided in the razor blades cause the latter to assume the desired position so that the razor blades may be piled. lllhen the required number of blades have been introduced into the piling cushion, replacement is preferably effected automatically in such manner that the filled piling cushion is removed and an empty cushion introduced in place of the first cushion. After the cover d8 has been put in place with the guidance of the pins 49, the screw 4T is introduced into the central hole of the pile of razor blades, and is tightened up. The filled piling cushions are then removed to a machine for round-grinding, where among other things removal ofthe roughness remaining at 5() upon the separation is effected and. adjustment of the ends of the razor blades is taking place. To facilitate centering when the piling cushions are mounted in the grinding machine, the member lf3 and the head of the screw 47 may be provided with suitable centre holes lly making the razor blades in accordance with the invention, a product of very high and uniform quality is obtaine'l. rlhis will particularly he the case if thc manufacturer, v-:ho generally is compelled to buy the blanks for the razor blades from a steel mill, leaves the finishing of the blanks as well as the hardening and tempering of the same to be done by the mill.

The blanks Q6 may vary as desired in regard to the distribution and the number of ihe holes 29: the openings E29 may, likewise, assume some other shape than that shown in Fig. lf3, the same being. for irstance` in the form of two slots, pcrforatious or the like situated at the edges of the band. The length of the openings may be made smaller than that of the ridges or the channels. The ridges or the channels respectivelyv may also bev subjected to material variations in regard to position, shape and number; they may, for instance, be disposed so as to form an angle with the edge of the band. In cross-section, the blank may be of various thickness, so that the latter is greater at the ridges, for example, and smaller at the channel than the average thickness of the blank. The blank may also be of a width equal to the length of the razor blades manufactured therefrom,

lin which case the units may preferably be separated on the `lines forming the .longitudinal sides of the rfazorblades. It is also evident that theinvention may be applied with the use of steel bands or steel plates of a width varying within wide limits, in which case the separating lines marking the openings 29 as well as the distribution of the holes 28 along the band or the plate respectively will be grouped otherwise than above described.

rl`he drivingand the guiding means for the steel band maybe modified in many respects. For instance, the intermittent movement at the press may be replaced by a continuous movement, if the pressing tools are given a form suitable for this purpose; likewise, the continuous feed of the band by means of the driving rollers 8 may be replaced by an intermittent feed. To obtain the requisite friction at the driving rollers 8, special pressure rollers loaded by springs or weights may be arranged at the driving rollers, if required, so that the band is pressed onto the same with the pressure called for. The guide members provided to guide the band in the transversal direction may also assume other forms than the rollers 21 shown.' The holes 28 punched inte the band may thus form guiding means in the direction indicated if the rollers are provided with corresponding pins or the like. The grinding disks or the like may be arranged for the grinding of the one edge of the steel band only, if the razor blades are of a type provided with a single cutting edge. The form of the cutting edge may also differ from that shown in the drawings. The means for driving the grinding disks or the like may be subjected to certain alterations, if desired, so that each disk shaft is driven per se by a separate motor. The power transmission between the motor and the grinding disk may also be varied, which is also the case with the motor in relation to the grinding disks.

Razor blades manufactured in accordance with the invention may, if provided with longitudinal ridges-or channels respectively, be readily made of a thinner material than ordinarily, inasmuch as the said ridges or channels respectively increase the rigid-ness of the blades, particularly in the longitudinal direction. Moreover, the shaving apparatus may be simplified, inasmuch as the two outer guide holes in the razor blades arranged for the lguiding of the blades and the guide pins provided in the apparatus are not then necessary, requisite guiding of the razor blades in the transversal direction being obtained by slots, rldges or the like arranged in the shaving apparatus and extending in the longitudinal direction thereof, While guiding in the longitudinal direction of the blades is obtained by a screw, guide pin or the like extending through the central hole 24.

What I claim is l. In the production of razor blades from a metal strip or ribbon, the process which comprises offsetting a portion of the strip to provide a shallow longitudinal channel having angular shoulders of a depth of the order of the thickness of said strip, feeding the strip longitudinally and guiding the same transversely by surfaces bearing against both sides of said shoulders.

2. In the production of razor blades from a metal strip or ribbon having a length corresponding to that of a plurality of blades, the process which comprises offsetting a portion of the strip to provide a shallow longitudinal channel having a depth of the order of the thickness of the strip and having continuous sidewalls, removing from the strip at intervals corresponding to a single blade length, portions of the strip spaced from said continuous side walls, feeding the strip longitudinally for engagement with grinders, and guiding the strip transversely by movable guiding surfaces engaging said continuous side Walls.

3. In the production of razor blades from an elongated steel strip, having substantially the width of a finished blade, the method which comprises offsetting a portion of the strip by an amount of the order of the thickness of the strip to form a longitudinal channel having continuous side walls, feeding the strip longitudinally for engagement with grinding wheels, and guiding the strip dur-n v ing such longitudinal feeding by passing the same between guide rolls having complementary cylindrical surfaces engaging the side walls of said channel.

4. The process as set forth in the preceding claim, wherein the strip is laterally scored after the edge-forming operations to define individual blades, separating the blades from said strip and stacking the same in superposed relation, and grinding the end-edges of the blades thus superposed.

5. The process as set forth in claim 3, in combination with the steps, of perforating the bottom of the said channel to provide a series of holes spaced from one another by a distance less than one-half the length of a finished blade, separating blades from the said strip after the formation of cutting edges thereon, stacking the blades in superposed relation, maintaining the blades thus stacked in exact superposition by guide rods entering the said holes, and grinding the end edges of a stack of blades.

In testimony whereof I affix my signaturev FOLKE KYLBERG.