|Publication number||US4252837 A|
|Application number||US 05/911,026|
|Publication date||Feb 24, 1981|
|Filing date||May 31, 1978|
|Priority date||Mar 23, 1976|
|Also published as||CA1053454A, CA1053454A1, DE2712790A1|
|Publication number||05911026, 911026, US 4252837 A, US 4252837A, US-A-4252837, US4252837 A, US4252837A|
|Inventors||John P. Auton|
|Original Assignee||Warner-Lambert Company|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (1), Referenced by (96), Classifications (13)|
|External Links: USPTO, USPTO Assignment, Espacenet|
This is a continuation of application Ser. No. 778,755 filed Mar. 17, 1977 and now abandoned.
This invention relates to improvements to blade shields for shaving. For as long as man has attempted the removal of hair from the body, energies have been directed to ameliorating the effects of the sharpened cutting edge on the skin of the user. Despite all efforts, occasional skin irritation and bloodletting still occur during the shaving process.
This invention relates to particular, but not exclusively so, to the deposition preferably under vacuum conditions, of structural elements on the body of the blade and more particularly to the providing of a guard over the blade edge so as to protect the user from nicking or cutting of the skin.
Hitherto numerous methods have been devised to minimize this aspect of shaving, a large portion directed to improved forms of edge guard. A patent to Dickinson, U.S. Pat. No. 1,035,548, issued Aug. 13, 1912, discloses a straight razor having a long blade on which is spirally wound a wire or thread to form a guard. Another form of guard is disclosed by Ferraro in U.S. Pat. No. 3,263,330 issued Aug. 2, 1966, wherein the razor blade cutting edge is encapsulated in a folded sheet of metal having a row of holes through which the hairs but not the skin pass for cutting.
A more recent development is disclosed in U.S. Pat. No. 3,505,734 issued to Iten on Apr. 14, 1970, for a cutting blade with self-contained guard. In this patent a razor blade with a self-contained guard in the form of a wire is described. The wire or thread of selected diameter is wound about the body of the blade encompassing its ultimate edge. The spacing or pitch between successive turns of the wire is controlled relative to its diameter to provide protection to the skin of the user and diminished probability of cutting or nicking. With the selected critical thread diameter and spacing between successive thread portions at the cutting edge the blade may be drawn across the skin without coming in contact therewith.
While the self-contained guard of Iten has proven relatively successful in insulating the skin from the ultimate cutting edge of the razor blade, it does introduce numerous and severe problems into the manufacturing of razor blades incorporating its principal features. The thread must be of flexible material having precise dimensional conformity. It must also be sufficiently flexible for winding about the body of the blade and yet strong enough to withstand severing as it passes over and comes in contact with the blade edge. Moreover, once the wire is placed on the blade it must be adhesively or otherwise locked into position to prevent interference with shaving and to maintain its advantageous characteristics. With regard to this latter fact, it must be kept in mind that as the wire comes into contact with the ultimate edge of the blade, the edge being 300 to 500 Angstroms in radius, it necessarily seriously damages the blade edge making such contact portion substantially incapable of providing comfortable shaving characteristics. Such winding process also inherently increases blade damage resulting in a less efficient manufacturing operation.
It is an object of the preferred form of the invention to provide an improved method for applying structural elements to a cutting or razor blade. It is another object of the present invention to provide a razor blade product having structural elements thereon. Another object of the present invention is to provide a razor blade having a vacuum deposited guard formed thereon. Yet another object of the present invention is to provide for the placement of a guard over the ultimate edge of a razor blade in a more efficient and economical manner.
In overcoming the problems of the prior art and in achieving the objects as heretofore set out, the present invention contemplates a razor blade having vacuum deposited structural elements formed thereon. In one embodiment these elements extend beyond the ultimate edge of the blade thereby providing a guard for preventing nicking and cutting of the user's skin.
According to one preferred aspect of the present invention, the razor blade has deposited structural elements extending beyond the ultimate cutting edge of the blade, thereby providing a guard for preventing nicking and cutting of the user's skin.
According to another preferred aspect the present invention provides a method for depositing the necessary structural elements under vacuum conditions. In this method, a blade or blades have the areas, on which a deposit is required, defined by a suitable masking arrangement. The masked blade is placed in a vacuum chamber in such a way that material vaporized in another part of the chamber will be deposited on it, thus building up the guard structure previously described.
An embodiment of the invention will now be described by way of examples with reference to the accompanying drawings.
FIG. 1 is a perspective representation of a blade having the necessary structure deposited on it;
FIG. 2 is a diagrammatic representation of the apparatus needed to carry out the deposition process; and
FIG. 3 is a perspective diagrammatic presentation of a stack of blades together with a masking arrangement such as is needed to define the area to be built up by deposition.
Referring to FIG. 1, razor blade 10 is shown having at least two intersecting facets 11 forming an ultimate shaving edge 12. Arranged transversely to the ultimate edge are deposited structural elements 13 passing over edge 12 and extending down the face of facets 11 towards the body of the blade 10. Deposited elements 13 are respectively spaced along and throughout the longitudinal axis of blade 10. Not shown in FIG. 1 is an organic polymer coating placed over the entire edge structure in order to facilitate hair cutting and shaving comfort.
FIG. 2 shows, in schematic form, the equipment necessary to carry out a vacuum deposition. The pumping system 14 typically would consist of a combination of rotary and diffusion pumps but any apparatus capable of evacuation of the chamber 15 to a pressure of 10-5 Torr, in a time compatible with the total blade production process, could be used. In addition to the pumps, the system would include gauges for monitoring pressure, valves and other components well known to those practiced in the art.
Inside the chamber 15 is held the blade or stack of blades 16 together with their masking arrangement 17. Also in the chamber 15 is a means to vaporize material in such a way that it deposits on the blades 16. A number of methods of achieving this are known and these include thermal deposition, sputtering and ion plating. The equipment described here is that needed for ion plating, but other methods could be used to achieve the structural elements 13.
The essential elements of the ion plating system include a cathode 18, usually water cooled, which can be held at a voltage with respect to the filament 19. The assembly to be coated, in this case the stack of blades 16, is fixed to the cathode 18 in such a way that the blades and mask 17 assume cathode potential and are also cooled via the cathode 18. The material to be deposited is placed on the filament 19 which can be heated by passage of an electric current. Also needed in the system is a controlled leak valve 20 which can be used to let a suitable gas, for the purpose of this description argon, into the vacuum chamber 15.
In a typical ion plating operation, the pressure in the vacuum chamber 15 is reduced to about 10-5 Torr by using the pumping system 14. The chamber 15 is then backfilled with argon to a pressure of 10-2 to 5×10-2 Torr via the leak valve 20. This pressure is maintained by combined use of the leak valve 20 and the baffle valve 21. The bias voltage to the cathode 18, typically 3-5 KV negative with respect to the filament 19 is switched on. This causes a glow discharge and the stack of blades 16 with masking arrangement 17 is bombarded by high energy argon ions from the resulting plasma. The bombardment removes surface material and hence cleans the blades and mask. Typically this cleaning process will last 15 minutes but sometimes rather longer is necessary.
The next stage in the process is the heating of the filament 19 by passage of an electric current. The filament 19 is heated until the material to be deposited, which is on the filament, is vaporized into the discharge. This material which would typically, but not necessarily, be a metal such as gold, aluminum or copper receives energy from collisions with argon ions in the discharge and is finally deposited on the walls of the chamber 15 and on the stack of blades 16. Because of the energy received from the discharge, the material reaches its destination at high velocity and this helps in the formation of a good bond to the surface being coated and also to a good cohesive layer of the coating materials.
The areas of the stack of blades 16 which are built up by the coating are defined by the mask 17 as is later described. The thickness of the coating depends on the geometry of the deposition system, the discharge conditions, the amount of material on the filament 19 and the time during which deposition is carried out. A typical stack of blades 16 could be 10" long and the distance from the stack of blades 16 to the filament 19 could then also be about 10". Under these conditions a typical deposition rate, for metals in a commercially available ion plating system, would be 5 um per minute. The thickness required for the structural elements 13 on the blade is between about 12 um and 100 um and this means a deposition would take between 2 minutes and 20 minutes.
At the end of the deposition, all electrical voltages are switched off, the baffle voltage 21 is closed as is the leak valve 20. The stack of blades 16 can then be removed from the chamber 15, after the pressure has been raised to atmospheric.
In the above description, material was vaporized into the discharge by the resistance heating of a filament 19. This is only one method of vaporization and this disclosure covers the others. Specifically, the use of a high energy electron beam, incident on the material to be deposited, as a means of vaporizing the material is included. Other variants such as the use of crucibles and boats instead of a spiral filament are also included as is the use of an RF heated crucible.
FIG. 3 shows diagrammatically a stack of blades 16 together with a masking arrangement 17. In the diagram, the mask 17 is shown as a foil in which slots 22 have been cut by suitable means such as chemical milling. These slots 22 define the area of the blade edge 12 which receives coating material. Their width determines the width of the structural elements 13. These are typically of width 12 um to 100 um and hence the slots 22 in the mask 17 will be in this range. The distance between slots 22 will normally be between 350 um and 750 um.
As an alternative to slots in foil, it is possible to arrange parallel strips or wires so that the gaps between them define the width through which material can pass before deposition on the blade.
In most deposition processes, the material deposited moves in a straight line between source and destination. However, in ion plating, collisions in the plasma change the direction of molecules of evaporant. With the masking arrangement indicated in FIG. 3, only the width of the structural element 13 on the blade edge 12 will be that of the slot 22 in the mask. The width will be greater the further one goes down the face of the facets 11. This effect will be particularly noticeable when the deposition process used is ion plating because of the scattering collisions in the discharge but the tapered profile of the structural elements 13 will not affect the shaving performance of the finished blade. The length to which the structural element 13 extends down the facet 11 is not critical but will normally be in the range 50 um to 150 um. The thickness of the elements 13 will gradually taper off with distance down the facet 11 from the edge 12.
Razor blades with elements 13 deposited by a vacuum process will have a blade shield possessing a high degree of uniformity from blade to blade and may be made in high volume production at a low unit manufacturing cost. It may be said that razor blades with edge shields formed by vacuum deposition provide an opportunity to maximize safety from nicks and cuts without sacrificing closeness of the shave to be achieved and without introducing undue difficulties and inefficiencies into the shaving process.
Thus, the disclosed invention has provided a method for producing a razor blade having inherently safer cutting characteristics without sacrificing the efficiency of the cutting operation itself or the efficiency of the manufacturing process. The novel application of vacuum deposition to the formation of a guard member about the ultimate edge of the razor blade introduces unique advantages in the blade industry and an improved product. Disclosure and drawings contained herein are intended as illustrative of the invention and not delimiting of its scope; therefore, all those modifications and extensions of the invention which are obvious to one of ordinary skill in the art are considered to come within the scope and ambit of the patent application.
|Cited Patent||Filing date||Publication date||Applicant||Title|
|US1846622 *||Nov 15, 1930||Feb 23, 1932||Gillette Safety Razor Co||Safety blade|
|Citing Patent||Filing date||Publication date||Applicant||Title|
|US4418473 *||Mar 26, 1982||Dec 6, 1983||International Business Machines Corp.||Method of making edge protected ferrite core|
|US4451344 *||Jun 23, 1983||May 29, 1984||International Business Machines Corp.||Method of making edge protected ferrite core|
|US4670293 *||Aug 22, 1986||Jun 2, 1987||Sanyo Electric Co., Ltd.||Method of making semiconductor film|
|US4764394 *||Jan 20, 1987||Aug 16, 1988||Wisconsin Alumni Research Foundation||Method and apparatus for plasma source ion implantation|
|US5206060 *||Aug 9, 1990||Apr 27, 1993||Saint Gobain Vitrage Int'l. "Les Miroirs"||Process and device for the deposition of thin layers and product made thereby|
|US5429843 *||Nov 19, 1992||Jul 4, 1995||Nisshin Steel Co., Ltd.||Vapor deposition for formation of plating layer|
|US5456009 *||Aug 23, 1994||Oct 10, 1995||Warner-Lambert Company||Multi-blade razor head with improved performance|
|US5630275 *||Sep 1, 1995||May 20, 1997||Warner-Lambert Company||Multi-blade razor head with improved performance|
|US5985742 *||Feb 19, 1998||Nov 16, 1999||Silicon Genesis Corporation||Controlled cleavage process and device for patterned films|
|US5994207 *||Feb 19, 1998||Nov 30, 1999||Silicon Genesis Corporation||Controlled cleavage process using pressurized fluid|
|US6010579 *||Feb 19, 1998||Jan 4, 2000||Silicon Genesis Corporation||Reusable substrate for thin film separation|
|US6013563 *||Feb 19, 1998||Jan 11, 2000||Silicon Genesis Corporation||Controlled cleaning process|
|US6027988 *||Aug 20, 1997||Feb 22, 2000||The Regents Of The University Of California||Method of separating films from bulk substrates by plasma immersion ion implantation|
|US6032372 *||Jun 22, 1998||Mar 7, 2000||Dischler; Louis||Intrinsically fenced safety razor head|
|US6035535 *||Oct 1, 1998||Mar 14, 2000||Dischler; Louis||Flexible safety razor head with intrinsically fenced cantilevered cutting edges|
|US6048411 *||Feb 19, 1998||Apr 11, 2000||Silicon Genesis Corporation||Silicon-on-silicon hybrid wafer assembly|
|US6146979 *||Feb 19, 1998||Nov 14, 2000||Silicon Genesis Corporation||Pressurized microbubble thin film separation process using a reusable substrate|
|US6155909 *||Feb 19, 1998||Dec 5, 2000||Silicon Genesis Corporation||Controlled cleavage system using pressurized fluid|
|US6159824 *||Feb 19, 1998||Dec 12, 2000||Silicon Genesis Corporation||Silicon-on-silicon wafer bonding process using a thin film blister-separation method|
|US6159825 *||Feb 19, 1998||Dec 12, 2000||Silicon Genesis Corporation||Controlled cleavage thin film separation process using a reusable substrate|
|US6162705 *||Feb 19, 1998||Dec 19, 2000||Silicon Genesis Corporation||Controlled cleavage process and resulting device using beta annealing|
|US6187110||May 21, 1999||Feb 13, 2001||Silicon Genesis Corporation||Device for patterned films|
|US6221740||Aug 10, 1999||Apr 24, 2001||Silicon Genesis Corporation||Substrate cleaving tool and method|
|US6245161||Feb 19, 1998||Jun 12, 2001||Silicon Genesis Corporation||Economical silicon-on-silicon hybrid wafer assembly|
|US6263941||Aug 10, 1999||Jul 24, 2001||Silicon Genesis Corporation||Nozzle for cleaving substrates|
|US6284631||Jan 10, 2000||Sep 4, 2001||Silicon Genesis Corporation||Method and device for controlled cleaving process|
|US6291313||May 18, 1999||Sep 18, 2001||Silicon Genesis Corporation||Method and device for controlled cleaving process|
|US6291326||Jun 17, 1999||Sep 18, 2001||Silicon Genesis Corporation||Pre-semiconductor process implant and post-process film separation|
|US6294814||Aug 24, 1999||Sep 25, 2001||Silicon Genesis Corporation||Cleaved silicon thin film with rough surface|
|US6350489 *||Dec 18, 1996||Feb 26, 2002||Canon Kabushiki Kaisha||Deposited-film forming process and deposited-film forming apparatus|
|US6391740||Apr 28, 1999||May 21, 2002||Silicon Genesis Corporation||Generic layer transfer methodology by controlled cleavage process|
|US6458672||Nov 2, 2000||Oct 1, 2002||Silicon Genesis Corporation||Controlled cleavage process and resulting device using beta annealing|
|US6486041||Feb 20, 2001||Nov 26, 2002||Silicon Genesis Corporation||Method and device for controlled cleaving process|
|US6500732||Jul 27, 2000||Dec 31, 2002||Silicon Genesis Corporation||Cleaving process to fabricate multilayered substrates using low implantation doses|
|US6511899||May 6, 1999||Jan 28, 2003||Silicon Genesis Corporation||Controlled cleavage process using pressurized fluid|
|US6513564||Mar 14, 2001||Feb 4, 2003||Silicon Genesis Corporation||Nozzle for cleaving substrates|
|US6519856||Dec 20, 1999||Feb 18, 2003||Delphi Oracle Corp||Safety razor head with intrinsic fencing and lateral skin tensioning|
|US6528391||May 21, 1999||Mar 4, 2003||Silicon Genesis, Corporation||Controlled cleavage process and device for patterned films|
|US6548382||Aug 4, 2000||Apr 15, 2003||Silicon Genesis Corporation||Gettering technique for wafers made using a controlled cleaving process|
|US6554046||Nov 27, 2000||Apr 29, 2003||Silicon Genesis Corporation||Substrate cleaving tool and method|
|US6558802||Feb 29, 2000||May 6, 2003||Silicon Genesis Corporation||Silicon-on-silicon hybrid wafer assembly|
|US6632724||Jan 13, 2000||Oct 14, 2003||Silicon Genesis Corporation||Controlled cleaving process|
|US6790747||Oct 9, 2002||Sep 14, 2004||Silicon Genesis Corporation||Method and device for controlled cleaving process|
|US6890838||Mar 26, 2003||May 10, 2005||Silicon Genesis Corporation||Gettering technique for wafers made using a controlled cleaving process|
|US7056808||Nov 20, 2002||Jun 6, 2006||Silicon Genesis Corporation||Cleaving process to fabricate multilayered substrates using low implantation doses|
|US7160790||Aug 19, 2003||Jan 9, 2007||Silicon Genesis Corporation||Controlled cleaving process|
|US7348258||Aug 6, 2004||Mar 25, 2008||Silicon Genesis Corporation||Method and device for controlled cleaving process|
|US7371660||Nov 16, 2005||May 13, 2008||Silicon Genesis Corporation||Controlled cleaving process|
|US7410887||Jan 26, 2007||Aug 12, 2008||Silicon Genesis Corporation||Controlled process and resulting device|
|US7759217||Jan 26, 2007||Jul 20, 2010||Silicon Genesis Corporation||Controlled process and resulting device|
|US7776717||Aug 17, 2010||Silicon Genesis Corporation||Controlled process and resulting device|
|US7811900||Oct 12, 2010||Silicon Genesis Corporation||Method and structure for fabricating solar cells using a thick layer transfer process|
|US7846818||Jul 10, 2008||Dec 7, 2010||Silicon Genesis Corporation||Controlled process and resulting device|
|US7883994||Feb 8, 2011||Commissariat A L'energie Atomique||Process for the transfer of a thin film|
|US7902038||Apr 11, 2002||Mar 8, 2011||Commissariat A L'energie Atomique||Detachable substrate with controlled mechanical strength and method of producing same|
|US7960248||Jun 14, 2011||Commissariat A L'energie Atomique||Method for transfer of a thin layer|
|US8048766||Jun 23, 2004||Nov 1, 2011||Commissariat A L'energie Atomique||Integrated circuit on high performance chip|
|US8101503||Dec 12, 2008||Jan 24, 2012||Commissariat A L'energie Atomique||Method of producing a thin layer of semiconductor material|
|US8142593||Aug 11, 2006||Mar 27, 2012||Commissariat A L'energie Atomique||Method of transferring a thin film onto a support|
|US8187377||May 29, 2012||Silicon Genesis Corporation||Non-contact etch annealing of strained layers|
|US8193069||Jul 15, 2004||Jun 5, 2012||Commissariat A L'energie Atomique||Stacked structure and production method thereof|
|US8252663||Aug 28, 2012||Commissariat A L'energie Atomique Et Aux Energies Alternatives||Method of transferring a thin layer onto a target substrate having a coefficient of thermal expansion different from that of the thin layer|
|US8293619||Jul 24, 2009||Oct 23, 2012||Silicon Genesis Corporation||Layer transfer of films utilizing controlled propagation|
|US8309431||Oct 28, 2004||Nov 13, 2012||Commissariat A L'energie Atomique||Method for self-supported transfer of a fine layer by pulsation after implantation or co-implantation|
|US8329557||Dec 11, 2012||Silicon Genesis Corporation||Techniques for forming thin films by implantation with reduced channeling|
|US8330126||Dec 11, 2012||Silicon Genesis Corporation||Race track configuration and method for wafering silicon solar substrates|
|US8389379||Dec 1, 2009||Mar 5, 2013||Commissariat A L'energie Atomique||Method for making a stressed structure designed to be dissociated|
|US8470712||Dec 23, 2010||Jun 25, 2013||Commissariat A L'energie Atomique||Process for the transfer of a thin film comprising an inclusion creation step|
|US8609514||May 24, 2013||Dec 17, 2013||Commissariat A L'energie Atomique||Process for the transfer of a thin film comprising an inclusion creation step|
|US8778775||Dec 18, 2007||Jul 15, 2014||Commissariat A L'energie Atomique||Method for preparing thin GaN layers by implantation and recycling of a starting substrate|
|US8993410||Sep 2, 2011||Mar 31, 2015||Silicon Genesis Corporation||Substrate cleaving under controlled stress conditions|
|US20030113983 *||Oct 9, 2002||Jun 19, 2003||Silicon Genesis Corporation||Method and device for controlled cleaving process|
|US20030124815 *||Nov 20, 2002||Jul 3, 2003||Silicon Genesis Corporation||Cleaving process to fabricate multilayered substrates using low implantation doses|
|US20040067644 *||Oct 4, 2002||Apr 8, 2004||Malik Igor J.||Non-contact etch annealing of strained layers|
|US20040097055 *||Mar 26, 2003||May 20, 2004||Silicon Genesis Corporation||Gettering technique for wafers made using a controlled cleaving process|
|US20050070071 *||Aug 6, 2004||Mar 31, 2005||Silicon Genesis Corporation||Method and device for controlled cleaving process|
|US20050186758 *||Aug 19, 2003||Aug 25, 2005||Silicon Genesis Corporation||Controlled cleaving process|
|US20060252229 *||Jun 23, 2004||Nov 9, 2006||Jean-Pierre Joly||Integrated circuit on high performance chip|
|US20070062047 *||Sep 19, 2005||Mar 22, 2007||Andrew Zhuk||Razor blades|
|US20070123013 *||Jan 26, 2007||May 31, 2007||Silicon Genesis Corporation||Controlled process and resulting device|
|US20070281445 *||Oct 28, 2004||Dec 6, 2007||Nguyet-Phuong Nguyen||Method for Self-Supported Transfer of a Fine Layer by Pulsation after Implantation or Co-Implantation|
|US20080038901 *||Aug 20, 2007||Feb 14, 2008||Silicon Genesis Corporation||Controlled Process and Resulting Device|
|US20080153220 *||Feb 15, 2008||Jun 26, 2008||Silicon Genesis Corporation||Method for fabricating semiconductor devices using strained silicon bearing material|
|US20080179547 *||Sep 7, 2007||Jul 31, 2008||Silicon Genesis Corporation||Method and structure for fabricating solar cells using a thick layer transfer process|
|US20080286945 *||Jul 10, 2008||Nov 20, 2008||Silicon Genesis Corporation||Controlled process and resulting device|
|US20090120568 *||Aug 11, 2006||May 14, 2009||Chrystel Deguet||Method of transferring a thin film onto a support|
|US20090156016 *||Dec 16, 2008||Jun 18, 2009||Lea Di Cioccio||Method for transfer of a thin layer|
|US20100025228 *||Dec 18, 2007||Feb 4, 2010||Tauzin Aurelie||Method for Preparing Thin GaN Layers by Implantation and Recycling of a Starting Substrate|
|US20100044595 *||Feb 25, 2010||Silicon Genesis Corporation||Race track configuration and method for wafering silicon solar substrates|
|US20100167499 *||Dec 1, 2009||Jul 1, 2010||Commissariat A L'energie Atomique||Method for making a stressed structure designed to be dissociated|
|US20100216294 *||Oct 10, 2008||Aug 26, 2010||Marc Rabarot||Method of fabricating a microelectronic structure involving molecular bonding|
|US20100317140 *||May 12, 2010||Dec 16, 2010||Silicon Genesis Corporation||Techniques for forming thin films by implantation with reduced channeling|
|US20100323497 *||Jun 17, 2010||Dec 23, 2010||Franck Fournel||Method of transferring a thin layer onto a target substrate having a coefficient of thermal expansion different from that of the thin layer|
|US20110092051 *||Apr 21, 2011||Commissariat A L'energie Atomique||Process for the transfer of a thin film comprising an inclusion creation step|
|USRE39484||May 30, 2003||Feb 6, 2007||Commissariat A L'energie Atomique||Process for the production of thin semiconductor material films|
|WO1987004471A1 *||Jan 20, 1987||Jul 30, 1987||The Gillette Company||Formation of hard coatings on cutting edges|
|U.S. Classification||427/576, 30/346.58, 427/295, 427/528, 204/192.16, 427/531|
|International Classification||B26B21/40, B26B21/60, B23P15/28|
|Cooperative Classification||B26B21/4006, B23P15/28|
|European Classification||B26B21/40A, B23P15/28|