US2692457A - Automatic razor blade grinding and honing machine - Google Patents

Description

Oct. 26, 1954 W, BlNDszUS I 2,692,457

AUTOMATIC RAZOR BLADE GRINDING AND HONING MACHINE Filed oct. :51, 195o 2 sheets-sheel Eig. 4 A so,

. mlllll'l'gl'llu INVENTOR.

'33 32 B .M7/hm indszds W. BIN DSZUS Oct. 26, 1954 AUTOMATIC RAZOR BLADE GRINDING AND HONING MACHINE 2 Sheets-Sheet 2 Filed Oct. 5l, 1950 A INVEN TOR. BY M'l//am /bdszus f2. Af, any.

Patented Oct. 26, 1954 UNITED STATES PATENT GFFICE AUTOMATIC RAZGR BLADE GRINDING AND HONING MACHINE 4 Claims.

This invention relates to improvements in method and means for producing a durable cutting edge on razor blades and other cutlery and particularly it refers to a method of step by step automatic grinding, honing, and burnishing of the edge to make the same unusually sharp and durable.

The automatic grinding and honing of single edge or double edge razor blades in strip or individual form in automatic or semi-automatic machines has been developed to a point where mass production has been attained at extremely low prices. The quality of the cutting edge however, is not always what it should be, and it is well known that a man with a heavy beard can only get one or two good shaves out of even the best safety razor blades on the market. A man with a light beard, may get six to ten shaves, especially if he takes the trouble to do a little stropping. With the present method and utilizing a new stainless steel, it has been possible to produce safety razor blades which will give as many as one hundred good shaves for the average user.

As hereinafter shown this tremendous improve'- ment has been possible by radical improvements in the honing and a new burnishing technique, whereby the cutting edge is specially treated and the molecular structure of the edge is actually toughened and strengthened in the honing and burnishing process, which amounts to a swagfing of the metal. This swaging effect brings the molecules of. the steel closer together and strengthens the frail edge tosuch an extent, that it will stand up much longer and retain its sharpness, despite considerable use.

An important object of my invention, is to provide a newv method and means whereby the grinding of single edge and double edge safety razor blades can be done automatically and can be controlled inside of exceedingly close limits.

Another object of my invention is to provide a new grinding wheel having in one wheel three different stones of different hardness and coarseness.

Another important object of my invention is to provide a new honing wheel having spiral grooves whereby a better honing is possible.

A further object of my invention is to provide a burnishing wheel of special composition, which will give the cutting edge the iinal treatment.

Still another object of my invention is to provide an extremely sensitive indicating mechanism, which makes it possible to adjust the grinding operation manually or automatically by means of a couple of solenoids inside of extremely close tolerances.

Other objects and advantages of this invention will be apparent during the course of the following description.

In the accompanying drawings, forming a part of this speciii'cation, and in which like numerals are employed to designate like parts throughout the same,

Figure 1 represents a front. elevation of a grinding and honing.' machine, embodying my invention,

Figure 2 represents a section taken along line 2-2 in Figure 1,

Figure 3 is a sectional plan view through one of the grinding heads of the machine,

Figure 4 is' a sectional partial end view of the grinding head shown in Figure 3,

Figure 5 represents a plan view taken along the line 5`5 in Figure 4,

Figure represents a plan view of the special honing wheels of my machine,

Figure 'I represents'a'n end view ofl the honing Wheels illustrated in Figure 6,

Figure 8f shows a single spiral honing wheel in plan view,

Figures is an end view of the single spiral honing Wheel illustrated in Figure 8,

Figure 10 represents a greatly enlarged section of a cutting edge, which is ground, honed and burnished in accordance with my method,

And Figure 11 represents a schematic view of the indicating mechanism used to indicate the amount ground voff the edge in the grinding operation.

In the drawings, wherein for the purpose of illustration, is shown a preferred embodiment of my invention, the number I2 designates the legs upon which the grind-ing and honing machine is supported upon the table I3. In the machine illustrated, there are four grinding heads Ill, two rough honing heads l5, two medium honing heads I6, two ne honing heads il; and two burnishing heads i8. The steel strip I-S, passes through the machine from righ-t to 1eit,as illustrated in Figure Land goes successively through the grinding heads, rough honing heads, medium honing heads, iine honing heads, burnishing heads and are nally cut off in the cutting `oir mechanism 20. The various heads are belt driven from pulleys 2l on the shaft 22, preferably located under the machine.

The grinding heads I4, are villustrated in detail in Figures 2 5 inclusive. Each of the grinding heads I4, have a grinding wheel 2-3, which is illustrated in detail in Figures 3 and 4. The wheels 2,3 are made up out of three separate discs of abrasive material of different hardness,

grain size, or fineness and different thickness as indicated in Figure 3. If the strip to be ground designated by numeral i9, is moving in the direction of the arrow, Figure 3, then it will strike rst the grinding wheel 23A which is coarse, and will travel next to grinding wheel 23B, which is medium and nally will be finished by grinding wheel 23C, which is of finer grain. The grinding wheels 23 are mounted upon shaft 24, with pulley 25 and which is journalled in bearings 26. The bearings 26 are clamped onto frame 21, which is pivoted at 28. The frame 21 has an arm 29, by means of which the wheel 23 may be rotated around pivot 28. The arm 29 rests upon the adjusting screw 30, which may be moved up and down by means of the rotatable hub 3l of the ratchet wheel 32. The ratchet wheel 32 is rotatable by means of two solenoids 33 and 34, arranged as illustrated in Figure 3 and Figure 5. The solenoids 33 and 34 work by means of the actuating fingers 35 and 36, the solenoid 34, as illustrated in Figure 5, will operate the ratchet wheel 32, in a clockwise direction, while the solenoid 33 will operate the ratchet wheel in the opposite direction.

The arm 29 is furthermore spring loaded, by means of a yoke 3'1, which extends on both sides of the arm 29, see Figure 4, said yoke 3'! has a spiral tension spring fastened at each end (not illustrated). The tension of these springs and thereby the spring loading on arm 29 is adjustable by means of the hand wheel 38, which turns screw 39, which again pushes yoke 3'! out through slotl 40. The length of the arm 29 and the radius of the distance between pvot 28 and shaft 24 are so dimensioned that when ratchet wheel 32 is turned one notch the grinding wheel 23 will take two ten thousandth of an inch more or less oi the edge.

The guide block 4! through which the strip I9 is pulled is made from extremely hard steel, such as tungsten carbide and is mounted upon support 42. A coolant pump pumps a refrigerated and ltered cooling medium through pipe 43 and nozzle 44, directly onto the cutting edge being ground. Each grinding head works on one side of the blade only and the next following grinding head works on the opposite side. The following two heads illustrated work on the opposite edge inasmuch as the Amachine shown is designed for producing a double edged razor blade.

The honing heads are similar to the grinding head mechanically, except that each honing head has two opposing honing wheels. They are hand adjusted. The honing wheels have spiral cut grooves 45, which are relatively wide at one end of the wheel, but which gradually narrow down until they are only about half the original width at the other end of the wheel. The face or land 2B, accordingly is wide at one end of the honing wheel and narrows down to less than half its original width at the other end of the wheel. These wheels are finished so that the land 45, nts into the grooves 25, when the wheels are in their operating position. Actually the land 46, goes from 20 to 30 thousandths of an inch into the groove l5 as illustrated exaggeratedly in Figure '7. This is one point where the present invention diiTers importantly from the previously known art. It was well known before, to use honing wheels with a simple helical groove as for instance was disclosed in Patent Number 2,290,964. I have found however, that by using a land of differing width, I can get a much more satisfactory result of the honing. This is due to the fact that the wear of the wheel would be much more pronounced at the beginning where the blade rst hits the wheel. An ordinary honing wheel of the older type, therefore, wears oiI gradually from one end to the other, so that iinally only a very small part of the surface is active in the honing operation. With my spiral groove, on the other hand, the width of the land varies approximately in relation to the wear of the same, so that the wear becomes even from one end of the wheel to the other, thereby providing a much more even honing and a more satisfactory and uniform nal result. Due to the improved honing wheels it is only necessary to adjust them twice a day. The honing wheels are made from carborundum or similar materials now standard in the industry.

The indicating mechanism illustrated in Figure ll, serves to indicate and automatically control the grinding carried out by the grinding heads. The lever 4l is pivoted at i8 and thus has a long arm a and a short armb and is mounted adjacent to grinding wheel 23, a spring 31a holds the lower end against the edge. The arm b is supplied with a precious stone 49, which is in sliding contact with the cutting edge being ground upon strip I9. The outer end of lever a has a double contact making mechanism 53, which when moved to the left as illustrated, makes contact and energizes solenoid number I and if moved to the right makes contact and energizes solenoid number 2. The operation of this indicating mechanism is simple and is adjusted so that if the grinding wheels wear off slightly and take off a little less of the cutting edge, then the arm b as illustrated in Figure ll will move to the right and the arm a will move to the left thereby energizing solenoid number I, which will turn the ratchet wheel 32, one tooth, thereby moving arm 29 and grinding wheel 23 sufliciently to take off one ten thousandth of an inch more. This adjustment can also be made manually, by the use of a simple double throw switch. An electrical delay action is provided to compensate for the distance from stone to ieeler gauge.

A magniiied cross-section of the nished cutting edge is illustrated in Figure 10. The grinding is usually done at 7 to 71/2 degrees from the vertical and covers the entire width of the cutting edge. I thereupon do the coarse honing at 9 degrees, medium honing at 10 degrees and the final fine honing and burnishing at 11 degrees. Each successive time a much smaller portion of the cutting edge is honed, as illustrated in Figure 10, where c represents the distance covered by the coarse honing and d represents the dis tance covered by the medium honing. In this manner, the cutting edge, becomes somewhat rounded on and is much stronger mechanically than would otherwise be the case. As mentioned above, the successive honings and burnishings produce a swaging effect which hammers the molecules of the steel closer together, thereby making it tougher and harder. The three stages of honing shown in Figure l, is for stainless steel. Where carbon steel is used, one stage of honing may be dispensed with.

The burnishing stage adds to the swaging effect already described above, as obtained in the honing stages. It thus helps to straighten and strengthen the cutting edge and to furnish one of great sharpness. The burnishing wheels are not abrasive and can be made from any different kinds of materials. I have obtained very good results with thermoplastic resins such as acrylic and polystyrene, but undoubtedly other similar materials can be used equally as well. It is well vknown that in burnishing operations, the frictional heat developed by the burnishing wheel has a tendency to soften and draw the material being burnished. In the present case the effect seems to be to pack the molecules closer together thereby producing the equivalent of a swaging effect, which tends to strengthen and toughen the cutting edge and make same more durable.

The operation of my invention is as follows: when the steel strip i9, arrives in front of the rst grinding head, it will first hit the coarse section of the grinding wheel 23, which will do the roughest part of the grinding. As the strip travels a little further, it will successively come in contact with the medium and finer parts of the grinding wheel 23. These sections of the grinding wheel will therefore continue the grinding operation and will remove the necessary amount of metal and will nish the cutting edge on one side. The splitting up of the grinding wheel in three sections of different hardness and different grain size, represents a new `improvement in the grinding art and has proven of great importance in getting continuous operation at high speed without any costly delays for dressing of wheels, etc. By having this first section of the wheel of a very coarse grain, this part of the wheel will rough off the metal without any undue wear and the second and third sections will do the finer grinding also without eX- cessive wear. Following the rst grinding wheel and while the strip I9 is still held securely in the guide mechanism 4I, the indicating and control mechanism, illustrated in Figure l1, is brought in contact with the cutting edge. The gauge nger 49, touches the cutting edge and if the predetermined amount of metal has been removed, the contact mechanism 50, remains in the same position. If however, too much or too little metal has been removed, the contact mechanism 50, will move to one side or the other and will actuate the relays which will in turn move the grinding wheels .0002" closer or farther away, as the case may be. In this manner, the grinding may be held to an accuracy of plus or minus .0002" which is highly desirable to obtain a uniform product. The strip now enters the second grinding head which will perform the same operation on the opposite side of the strip. The other two grinding heads will do the same thing on the opposite edge, so as to produce a double edged blade. Following each grinding wheel, there is another indicating gauge which automatically gauges the overall height of the blade. From time to time as the wheels wear down, the operator will adjust the setting of these gauges manually. With the type of wheels, which have been developed by the present inventor, this setting becomes quite infrequent, mostly only twice a day. With this adequate control it has been possible to greatly improve the accuracy and quality of the product.

After the steel strip has been ground, as described in the preceding paragraph, it enters the rst honing stage. As mentioned above and as illustrated in Figure 7, the strip I9 passes in the center between two honing wheels, either above or below the wheels as the case may be, in accordance with whether the one or the other edge of a double edge blade is produced. The heads l5 as illustrated in Figure 1 therefore, are

so arranged that one head hones the upper cutting edge and the second `head hones the lower cutting edge. The same is true of the heads I6 and '[1, which do the medium and fine honing respectively. Due to the novel method described above of using a spiral groove 45 producing a face or' land of varying width from one end of the honing wheel to the other, see 45 and 46 in Figures 6 and 8, the wear of the honing wheel is even and a ne uniform honing is produced. As stated above, this honing produces a swaging effect, which greatly strengthens the cutting edge and thereby preserves its sharpness much longer.

The burnishing operation which is carried out by the heads i8, continues the swaging effect, which was started by the honing operation and gives the cutting edge the final set up required to reach the ultimate in sharpness. The burnishing wheels operate similarly to the honing wheels, but do not remove any material at all from the edge. The high speed wheels, however, produce a packing of the molecules, which greatly toughens the structure of the steel and produces an edge which will outlast an ordinary cutting edge many times. It is important to note, that it is the coordination of all the various processes mentioned above, with the most minute attention to details, which produces the final cutting edge of such quality that it will give one hundred smooth shaves. The various steps are all interrelated because, without the one preceding the next following would not be satisfactory. It is thus, of the greatest importance that the first grinding be done with the greatest possible precision so that the same amount of material is removed at the edge all the time. It is also important that the grinding is smooth and leaves the surface in a uniform condition. This is where the triple graded grinding wheels and automatic control comes in. If the grinding were uneven and left the surface in a rough condition. the honing wheels would have to remove more material and would accordingly wear off more or clog up, and would not produce the fine uniform results required. This is also true of the spiral face honing wheels, which will wear evenly and give uniform and perfect results under proper operating conditions. By keeping these conditions right, as described above, a greatly increased precision is possible with resulting low cost.

It is obvious to one skilled in the art that the shape and form of my invention may vary according to the ideas of the individual designer, but in general the form of my invention, herewith shown and described, is to be taken as a preferred example of the same, and it is obvious that various changes in the shape, size and arrangement of parts may be resorted to, Without departing from the spirit of my invention, or the scope of the subjoined claims.

Having thus described my invention, I claim:

1. A machine for producing a durabley cutting' edge on a continuously moving steel strip, said machine comprising a frame; a plurality of grinding wheels mounted on said frame in operational relation to said moving steel strip, on both sides of same, said wheels being arranged to have a decreasing grain size along the line of travel of said strip, and each wheel furthermore being made up of a plurality of layers of decreasing grain size along the line of travel; an individually driven shaft carrying each of said grinding wheels; a U-shaped yoke pivoted on said frame and having bearings in which said shaft is journalled, said pivoted yoke having an arm extending horizontally away romsaid wheels; a micrometer screw mountedin said frame engaging the end of said arm, whereby said wheels may be adjusted in extremely small increments; a plurality of honing Wheels rotatably mounted upon said frame along said steel strip, each of said wheels geared together to rotate in opposite direction, said wheels having a square thread of gradually decreasing pitch, thereby leaving a honing surface of gradually decreasing width along the path of travel of said steel strip, and a plurality of high speed burnishing wheels mounted on said frame following said honing wheels along said steel strip.

2. In a machine for producing a durable cutting edge on a continuously moving steel strip, such as described in claim 1, in which said arm of said U-shaped yoke carrying said grindling wheels is supplied with a manually adjustable spring return holding said yoke and said arm against said micrometer screw, and in which said micrometer screw mounted on said frame is supplied with a two-Way automatic remote control.

3. A machine for producing a durable cutting edge on a, continuously moving steel strip, as described in claim 1, in which said micrometer screw mounted in said frame has a rigidly secured concentric gear having a suitable number of teeth; la pair of solenoids each having Ya pawl engageable with said gear in opposite direction, said gear, teeth, screw and arm being of such relation that the turning of said gear by the angle corresponding to one tooth will move said grinding wheel in relation to said strip by approximately 1/ 10,000 inch.

4. A machine for producing a durable cutting edge on a continuously moving steel strip, as described in claim 1, in which said burnishing wheels having grooves similarly to said honing wheels, and said honing and burnishing wheels being manually adjustable in reference to each other and to said steel strip.

References Cited in the le of this patent UNITED STATES PATENTS Number Name Date 1,009,877 Winn Nov. 28, 1911 1,139,485 Busler May 18, 1915 1,197,619 Fullen et al Sept. 12, 1916 1,200,421 Green Oct. 3, 19.16 1,438,098 DelZell Dec. 5, 1922` 1,734,494 Kohlmiller Nov. 5, 1929 1,803,364 Stephens May 5, 1931 1,918,111 Kohlmller July 11, 1933 1,941,501 Steiner Jan. 2, 1934 2,290,964 Hill July 28, 1942

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