US1957602A - Machine for making razor blades - Google Patents

Description

May 8, 1934. F. KYLBERG 1,957,602

MACHINE FOR MAKING RAZOR BLADES Original Filed Oct. 10, 1928 2 Sheets-Sheet l y 9 f-LEERG L957 02 LLXGHINE FOR MAKING RAZOR BLADES Original Filed Oct, 10, 1928 Sheets-Shet 2 n .1 Ali iatented May 8, 1934 UNITED STATES PATENT QFFICE Aktiebolaget Tonsor, joint-stock company Gottenborg, Sweden, a

Original application October 10, 1928, Serial No.

311,697. Divided and this application Decemher 3, 1929, Serial No. 411,364. In Sweden February 10, 1928 9 Claims.

This invention relates to machines for treating razor blade blanks preferably in the form of steel strips or bands so as to obtain razor blades, especially of the safety razor type, and the chief object of the invention is that the strip or band during operations, such as hardening, tempering, grinding, polishing, etching, cleaning or the like, to which it is subjected when fed along a certain path may be held and guided with great reliability and accuracy.

More particularly, an object of the invention is to provide a machine for treating longitudinally flexible strips or bands such as employed in the manufacture of safety razor blades, and in which the stationary platforms or guides customarily employed for supporting and guiding the moving band are replaced by idler rollers, thus reducing the frictional resistance encountered by the moving band. A further object is to provide a ma chine of the type stated above, and which includes a plurality of rol ers for feeding and tensioning the moving band, grinding disks which are so positioned as to exert a minimum effect upon the travel of the band, and supporting rollers at each side of the grinding disks for preventing lateral displacement of the moving band. These and other objects and advantages of the invention will be apparent from the following specification.

The accompanying drawings illustrate a machine according to the invention, 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.

Fig. 1 shows the machine 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 in the 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. 10, 11 and 12 show difierent 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 cross-section on the 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 through or over a gas-fired or electrically heated furnace 3 or the like for the purpose of being heated to 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 apparatus 5 which may comprise an electrically heated plate, muffle 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.

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 rollers 8 are mounted on stationary axes or shafts at the outer edge of the frame 7, while the rollers 9 are mounted near the center of the frame and are tensioned or yieldingly held from the respective cooperating pairs of rollers 8 by suitable weight or spring actuated members, as indicated by the springs 9. The longitudinally flexible band 1 is flexed about a substantial portion of the periphery of the rollers 8, 9, thereby taking a nonlinear or zigzag path through the machine, and the extended surface contact of the band with the driving rollers 8 provides sufficient friction for an effective feed of the band.

Along the zigzag-shaped path through which the steel band moves, there are provided a plurality of grinding disks 20 of different grades for the grinding of the one or both edges of the band during the feeding of the same. These grinding disks 20 are preferably located right between adjacent rollers. The machine shown in the drawings is adapted for grinding both edges of the steel band, and for this purpose the grinding disks 20 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 crosssection 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 19 where the blades are separated from the band. The press is pro vided 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 no-load running. In order that the band shall always be stretched between the rollers, the driving rollers 8 should furthermore be so arranged as to exert the requisite pulling effect on the band, in order among other things to overcome the grinding or frictional resistance offered by the a fiacent grinding disks and guide members during the grinding operation. This may be 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 each driving roller and the source of power consisting of a spring or weight-actuated friction 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 when during the feeding of the band the same is moved past the grinding disks 20 or the like provided for the purpose in view, and past the apparatus arranged for the other working operations, it is necessary that the 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 20 or the like, the two flat sides of the steel band bearing between said rollers 21.

It 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 21 as well as the rollers 8 and 9 may be arranged for this purpose in such a manner as to engage lateral shoulders provided by the holes, recesses, channels or the like in the band, or abutments, ridges or the like on the band. Embodiments of such bands suitable for the purpose set forth are shown in Figs. 10-14, where the one side of the band is provided with longitudinally extending ridges 22, and the other side thereof with channels 23 corresponding to said ridges. Fig. 7 illustrates an embodiment of such a guide member consisting of rollers 21 where one or both rollers are provided with circumferentia-lly extending grooves 24 or flanges 25 of a shape corresponding accurately to the ridges 22 or the channels 23 of the band. The rollers, which are preferably rotatably mounted in ball bearings, are made in such manner (see Figs. 2 and 3) that the bearing of the one roller is rigid in the frame 7 and the bearing of the other roller is displaceable in a direction toward the first-mentioned bearing, besides which the displaceably arranged roller is actuated in the direction indicated by a spring 52 or a weight. Measures have also been taken to release the band 1 by the provision of rotatably or displaceably arranged members, consisting for instance of rods 53 or the like provided with abutments or the like, to actuate the displaceable rollers, which members 53 are preferably united in such a manner that they may all be actuated at the same time from a manceuvring member common to all of the guide rollers 21.

The portion of a band-shaped blank 26 shown in Fig. 13 and having a cross-section differing from the original rectangular shape, for instance as shown in Figs. 10-12, is preferably produced by rolling of the steel band which was initially of a uniform thickness. The blank 26 is substantially of the same width as that of the razor blades produced out of the blank, for which rea son the razor blades are obtained by cutting off the band, substantially along lines 2'7 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 at a 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 29 along the separating lines 27 for the razor blades to be produced. The holes 23 and the openings 29 are preferably made by moving the unhardened steel hand 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 grinding 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 are so arranged, as shown in Figs.

2, 3 and 4, that the reaction of the grinding disks upon the moving band has substantially no tendency either to accelerate or to retard the band. This is particularly important as the flexible band is fed by friction rollers and not by a positive drive which engages perforations in the band.

W ith the embodiments of a grinding apparatus shown in Figs. 2-4 and provided with grinding disks 20 disposed substantially in the manner set forth, it is rendered possible to adjust the grind ing disks individually in such a maner that the amount of the successive grinding of the band edge may be controlled as desired by the axes of rotation 30 of the grinding disks 20 being situated in or adjacent to planes extending through the band edge worked upon, and by the shafts 39 being adjustably 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. Both bearings 31 and 32, which in Fig. 4 are shown as consisting spherical ball bearings, are carried by an arm 34 pivotally 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 thusof the grinding disks 20 in the vertical direction, a hand wheel 36 is arranged to turn two screws 33 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 20 are arranged to be driven by means of a belt from an electric motor 41 carried by the rm, for which purpose the shaft 30 is provided with a belt pulley 42. For grinding of the diagonally opposed edges of the band-crosssection, 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 il 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 abutment-s 45 secured thereon.

With 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 handwheels 36 against the action of the spring 44, and may also be adjusted by means of the handwheels 35 for suitable successive grinding of the edges of the steel band running between the rollers 21 and guided by these rollers in the transversal direction. The rotary shafts 30 of the grinding disks may thus be adjusted so that they, while forming a certain angle V, see Fig. 4, with the edge of the band, impart to the working surfaces of the 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. 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 of 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 cut 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 importance that the disk be made sufficiently wide, and that the operating depth does not become too great. Both to avoid high tensile stresses in the moving steel band and to prevent frequent dressing of grinding disks or frequent replacements, it is an important feature of the invention that the radial surfaces of the grinding disks do not contact the band, i. e. the line of contact between the band and the peripheral working surface of each disk must not be parallel to the edge of the band and the angle V must be so related to the width of the peripheral working surfaces that the radial face towards which the band moves does not conlact the moving band. The angle V between the active grinding surface and the edge of the band will be termed the angle of attack since it is this angular arrangement which permits a progressive grinding action by different portions of the peripheral surface of the disks.

if the working surfaces of the grinding disks are made accurately cylindrical and entirely concentric with the shaf s 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 touching each other grind off the working 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 45 mounted on shaft 39 in the frame 7. If the abutments of all grinding apparatus are in mechanical connection with one another, it will thus be possible to bring all grind ing disks out of working position with a single manipulation, from one and the same manceuvring place. The manteuvring means for releasing the ban from the grinding disks 20 may then be connected with a corresponding means for releasing the band from the supporting members or rollers 21, in such manner that a single manipulation 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 of the shafts in question, if desired. Each cutting edge is acted upon alternately by the successive groups of grinding disks which groups, in the illustrated embodiment of the invention, include the four disks 20 on the associated pair of shafts 30.

When the steel band has reached the press 19 after the grinding of the band has been finished 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 difficulty by reason ofthe 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 to complete shearing.

The razor blades separated from the band are moved automatically down onto a piling cushion, see Figs. 8 and 9, comprising a member 46 provided with suitable guiding means for the razor blades and a cover or the like 48 attached to the member 46 by means of a screw 47. The guiding means consist of pins 49 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. When 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 48 has been put in place with the guidance of the pins 49, the screw 47 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 of the roughness remaining at 50 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 46 and the head of the screw 4'7 may be provided with suitable centre holes 51.

The blanks 26 may vary as desired in regard to the distribution and the number of the holes 28; the openings 29 may, likewise, assume some other shape than that shown in Fig. 13, the same being, for instance, in the form of two slots, perforations 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 respectively may also be 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, in which case the units may preferably be separated on the lines forming the longitudinal sides of the razor blades. It is also evident that the invention 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.

The driving and the guiding means for the steel band may be 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 suitaable 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 into 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.

While the operation of the apparatus will be apparent from the above description, particular attention is directed to the fact that the invention eliminates the tables or platforms previously employed to support the moving band during the grinding operations. The flexible band is supported by the rollers 8, 9 and guide rollers 21 which are arranged at each side of the grinding disks. Furthermore, even though the band may be ridged to provide shoulders which are engaged by the guiding wheels to prevent lateral displacement, the band retains its flexibility since the ridges are very shallow.

This application is a division of my application Serial No. 311,697, filed October 10, 1928, Method of making razor blades, on which Letters Patent No. 1,877,758 were granted on September 20, 1932.

What I claim is:-

1. A machine for treating razor blade blanks consisting of steel strips having shoulders, comprising means for carrying and feeding a blank, an edge grinding mechanism for operating upon said blank, means for supporting the blank during grinding consisting of supporting rollers arranged in pairs on both sides of each grinding member to engage the two fiat sides of the blank, one of said means including guiding means for engaging the shoulders on the blank to support the blank against lateral movement when so fed and ground.

2. A machine for treating razor blade blanks consisting of steel strips having longitudinal ridges, comprising means for carrying and feeding a blank, an edge grinding mechanism for operating upon said blank, means for supporting the blank during grinding, consisting of supporting rollers arranged in pairs on both sides of each grinding member to engage the two fiat sides of the blank, one of said means including guiding means for engaging the longitudinal ridges on the blank to support the blank against lateral movement when so fed and ground.

3. A machine for treating razor blade blanks consisting of feeding and carrying means for the blank, rotating grinding disks disposed with their peripheral surfaces contacting with said blank for grinding the latter during the feeding thereof, means supporting the rotary shafts of said grinding disks and positioning the same at least approximately in a plane in which the blank edge worked upon lies, means for adjusting each of said shafts in said plane parallel to itself, and means for adjusting the shafts to control the angle at which the generatrix of the peripheral working surfaces of the respective disks is presented to the fiat side of the blank.

4. In a machine for forming a cutting edge upon a razor blade blank of the elongated metal band type, the combination with means for supporting a blank and moving the same longitudinally, of a shaft supported approximately in a plane passing through the edge of said blank and at an angle to the path of longitudinal movement of said blank, a pair of substantially cylindrical means for moving said shaft towards and from the edge of said blank, and adjustabl means for regulating the angle between said shaft and the direction of travel of said blank, thereby to position said disks to work said blank successively with the peripheral surfaces of said disks.

5. A machine for treating razor blade blanks consisting of feeding and carrying means for the blank, a rotating grinding disk for grinding said blank during the feeding thereof, the rotary shaft of said grinding disk being situated substantially parallel with the edge of the blank worked upon, and means mounting said shaft for adjustment in the common plane in which the shaft and the edge of the strip are located in a direction toward the blank edge and angularly with respect to said blank edge, the shaft being carried by two bearings located at the ends of the shaft, one of said bearings being pivotally mounted about a shaft extending substantially at right angles to said plane, and the other bearing being displaceable by means of adjusting members, substantially in a direction toward the edge of the blank.

6. A machine for forming at least one cutting edge upon a longitudinally flexible steel band having lateral shoulders between the edges thereof, said machine comprising a plurality of rollers each having a substantial portion of the periphery thereof contacted by the moving band, where by the band follows a non-linear path through the machine, means urging certain of said rollers away from the adjacent pair of cooperating rollers to tension the band, means for driving certain of said rollers to move said band through the machine, a plurality of grinding means for successively working at least one edge of said blade to sharpen the same, and means adjacent each grinding means for supporting said band against lateral displacement during the grinding operation; said supporting means consisting of a plurality of pairs of cooperating rollers engaging said blade, and means supporting a pair of said cooperating rollers at each side of each grinding means.

7. A machine as claimed in claim 6 for forming at least one cutting edge upon a longitudinally flexible steel band having lateral shoulders provided by a longitudinal groove of the depth of the order of the thickness of the band, wherein said pairs of cooperating rollers each comprise complementary rollers having peripheral surfaces conforming respectively to the contour of the 0pposite faces of the band.

8. A machine as claimed in claim 6 for forming at least one cutting edge upon a longitudinally flexible steel band having lateral shoulders provided by a longitudinal groove of the depth of the order of the thickness of the band, wherein said certain driving rollers have peripheral surfaces conforming to one of the faces of the grooved band.

9. A machine as claimed in claim 6, wherein each of said grinding means comprises a disk having radial surfaces and a peripheral working surface, and means supporting said disk to present said peripheral working surface at an angle of attack to the edge of the moving band.

FOLKE KYLBERG.

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