This application relates to the field of shaving razors, and geometry of razor blades in shaving razor cartridges.
Previously, shaving razors and razor cartridges suffered from inherent drawbacks based on razor geometry. Blade components of the cartridge were built to have the same geometry across cartridges which may have hindered close yet comfortable shaving. Designs are needed that address these drawbacks.
Systems and methods here include improved razor blade cartridges and manufacture of same. In some examples, a shaving razor system is described including a cartridge housing having a length and width, a topside and an underside, the cartridge housing includes a cap generally across the length of a first side of the topside and a guard generally across the length of a second side of the topside. In some examples alone or in combination the cartridge housing includes at least three blades mounted into the cartridge housing generally across the length of the housing between the cap and the guard. In some examples alone or in combination, each blade including a blade edge, exposure is measured comparing each blade edge against an imaginary exposure reference line drawn across the width from the cap to the guard, the exposure of each of the blade edges is different when measured at different locations along the length of the cartridge. In some examples alone or in combination, wherein exposure is measured comparing each blade edge against an imaginary exposure reference line drawn across the width between the nearest blade, cap, or guard, immediately toward the front of and immediately toward the back one of each of the at least three blades.
For a better understanding of the embodiments described in this application, reference should be made to the Detailed Description below, in conjunction with the following drawings in which like reference numerals refer to corresponding parts throughout the figures.
Reference will now be made in detail to embodiments, examples of which are illustrated in the accompanying drawings. In the following detailed description, numerous specific details are set forth in order to provide a sufficient understanding of the subject matter presented herein. But it will be apparent to one of ordinary skill in the art that the subject matter may be practiced without these specific details. Moreover, the particular embodiments described herein are provided by way of example and should not be used to limit the scope of the invention to these particular embodiments.
Razor blades and razor cartridges are made with a range of geometry that includes blade spacing, angle, and exposure. Typically, a trade-off between closeness and comfort is discussed when designing a razor cartridge with specific geometries. But although there may be advantages to uniform geometry settings on a particular cartridge arrangement, it may be useful to include variances that would allow for nuances to shaving experience and averages of arrangements may provide positive but subtle effects in geometry arrangements, from blade to blade, from cartridge to cartridge, and for a single blade across a cartridge.
Such variations may aid in an improved shaving experience, especially if multiple strokes are taken over the same area of skin in a shaving operation. As skin is different for each user, and skin flexes and moves during a shaving operation, as well as considering that different areas of the body shaped differently, the variations in exposure or geometry in general, may aid in achieving the best of both worlds, close and comfortable for a broader spectrum of users. By providing different exposures and/or geometries in one cartridge, more users may be satisfied with the geometry provided. The systems and methods described here may be used to produce razor cartridges that include specific geometries, varying geometries, and/or multiple geometries for razor cartridges to take advantage of these variables and provide both close and comfortable shaving experiences.
Razor cartridges come in all shapes, arrangements, and sizes, but usually have the same main component parts.
In some examples, either or both of the guard 106 and the cap 108 may have lubrication features built in or included on them. The cartridge 100 in the example shows a frame 110 mounted in the cartridge housing 102, but described in
As mentioned, there are razor cartridges that do not use an overall frame system as shown in
The number of blades in a cartridge could be any number including but not limited to one blade, two blades, three blades, four blades, five blades and six or more blades. The non-limiting examples throughout this description is four blades, but could be any number.
The geometry of the blades 112 in relation to the frame 110 and the guards 114 may include any of various arrangements as described here in order to affect the shaving experience of a user of the razor cartridge 100 as discussed below. A first general discussion of the frame 110 and blade 112 geometry is given below including an exposure of the blades in reference to an imaginary reference line. There are two general ways of describing such an imaginary reference line, the first known as the total or overall reference line 109 is shown in
Three example geometry variables will be discussed that can be altered in a razor cartridge to affect a shave for a user. The three main example geometry variables include gap, blade angle, and blade exposure. The interplay of these variables among each other leads to trade-offs in the shaving experience. A less irritating arrangement may not be effective enough for users with tough beards. A very aggressive arrangement may be too harsh for users with sensitive skin. By arranging multiple geometries on a single cartridge, the various advantages may be grouped into one system. The embodiments described here include iterations of these three variables in multiple arrangements to achieve different shaving goals and delivering different shaving experiences to different users.
To help describe the geometry of the configuration, x, y and z axis coordinates are shown in relation to the frame 310 as indicated. The frame 310 example in
In a non-limiting order, one geometry variable is a gap. A gap 370 refers to the gap between a blade edge 312 and the adjacent guard 312, whether that be the front guard or an intermediate guard in the frame, or between blade edges 312 or supports in examples without intermediate guards. The larger the gap 370, the more hair is able to fit in the gap 370 and interact with the blade edge 312. The smaller the gap 370, the less hair is able to fit in the gap, but comfort may be improved. The gap may allow wash through of water and shaving material as well.
Another geometry variable is blade angle. The blade angle refers to the angle at which the blades 312 are positioned in the cartridge and interact with the user's skin in a shaving stroke against an imaginary horizontal line. Referring to the angle of the blades 312 to the skin of a shaving user, between 0 (parallel to skin—and about the neutral exposure line 380) to about 17 degrees 313 may be considered less aggressive. Between about 17 degrees 313 up to about 45 degrees 311 may be considered more aggressive. A more aggressive blade angle may lead to a closer cut of hair from the skin in a shaving stroke but it may be more irritating than a less aggressive blade angle. Different users with different beards and skin may prefer different blade angles. Different areas of the body may require different blade angles.
Another geometry variable mentioned above, is blade exposure. Generally, exposure is how far the blade edges stick up from the cartridge and thereby how much they may interact with a shaving surface. In the example of
One way to measure exposure in a cartridge is that shown in
The example shows the overall method of measuring exposure, and the reference line 401 is assumed to be touching the top most parts of a cap and guard (not shown in
Although
Using the Welsh method, the two nearest points of the blade in question may be the cap, guard, or another blade in front of or behind the blade in question. In some examples, the first blade 910 may be measured with a line 980 extending form the guard 902 to the second blade 912. The second blade 912 may be measured with a reference line 981 between the first blade 910 and third blade 914. The third blade 914 may be measured using a reference line 982 between the second blade 912 and fourth blade 916. The fourth blade 916 may be measured using a reference like 983 between the third blade 914 and cap 904. In examples with fewer or more blades, a similar measurement system may be used, measuring between the nearest blade, cap or guard for each blade in a cartridge.
And as can be seen from the example, the results of exposure analysis and measurement may be different using the Welsh method than the total method, as in
Some example exposure arrangements that may be used include, but are not limited to those shown in the figures above, as well as, but not limited to a progressively more positive exposure arrangement, a progressively more negative exposure arrangement, a neutral arrangement, a first blade positive exposure, a first blade negative exposure, a last blade negative exposure, two middle blades neutral exposure, two consecutive blades with the second more positive exposure, three consecutive blades, with each successive blade more positive exposure, alternating positive/negative exposure on successive blades, descending exposure on successive blades, first blade neutral, and/or any and all combinations of the above, those in the figures, or any other example of exposure, these not intended to be limiting.
The descriptions above discuss exposure of a cartridge by examining a cut away side view of the cap, guard, and blades between the two, using two methods of reference lines. But it should be pointed out that by examining the exposure in such a way, only examines exposure at one place, drawn across the cartridge from top to bottom. There are examples of a single cartridge displaying different exposures for the blades, if measured at different points or lines on the cartridge.
In some examples, it may be advantageous to have all of the exposures across the body of a cartridge be the same or nearly the same. Singular exposures across a single cartridge may be beneficial for some designs. However, it may be beneficial to vary the exposure across a single cartridge, even if those variances are relatively small. Such a variance in exposure may more closely match geometry of a surface being shaved, such as skin of a user. In some examples, it may be beneficial to allow for blades to bend, move, and/or otherwise flex in order to alter or change exposure setting during use. More examples and details are given herein discussing the variables and nuances of these exposures.
In some examples, it may be advantageous to have all or some of the exposures across the body of a cartridge be different at different places. In other words, it may be advantageous to include a razor cartridge with a single blade that exhibits different exposures on different parts of the cartridge. It may be advantageous to include multiple blades on a cartridge that exhibit different exposures on different parts of the cartridge. In such examples, exposures measured at 1012 may be different than those measured at 1014 and/or 1016, and/or any other place measured on the cartridge. These exposures may be different no matter which method of exposure analysis is utilized, as described above.
The example of
One example item to note is scope or scale of the measurements, and their effect on where an exposure reference line is drawn between (cap and guard or between two closes points near blades, etc.), because the imaginary reference line may be drawn and compared to the blade edges, exposure examples described above may be affected by the scope or granularity used in measuring exposure. In some examples, measurements may be made to the smallest degree technologically possible with electron microscopes and computer graphics analysis. In such examples, measurements to the micron scale may be used to determine exposure.
In some examples, a more simple and less accurate measurement may be made using physical tools such as a straight edge to observe exposure using the human eye. In such examples, a physical straight edge may be placed against the cap and guard and an observation may be made as to whether the blades touch the straight edge, do not touch the straight edge, or generally rest along the straight edge to determine exposure.
Any range of measurements from electron microscope, optical microscope, magnifying glass, to human eye, may be utilized to measure exposure in different scenarios due to the application and purpose they are meant to serve, providing a shaving experience for a user.
Yet another consideration is the imaginary reference line itself In some examples, a line may be drawn from cap to guard on the physical cartridge or an image captured by a computer, laser, camera, and/ or film. But at a close scale, it may be found that the materials that make up the cap and/or guard are not uniformly flat, and that the heights vary across the materials. In some examples, the cap and/or guard may be bumpy, include grooves, include features, or be made of material that is not uniform or flat when viewed by an electron microscope, optical microscope, laser or other device. In such examples, for each measurement, 1012, 1014, and/or 1016, the reference line may start or end on a different height than the reference line next to it or on another part of the cartridge.
The example of
This is the case no matter which method of exposure line drawing is used, Welsh or overall total method as the other end of the reference line 1180, 1181, 1182, 1183 that is not on the bumpy cap 1104 touches either another blade 1114 or guard bar (not shown for scale). Although for the Welsh method, it may only affect the measurement to the blade closest the bumpy surface, such as the last blade in the cartridge 1116. But in an overall total method, it would result in different positioning of the reference lines for each measurement for all blades.
In such examples, measurements from one part of the strip may produce exposure results that are different than a measurement just to the side or on another part of the cartridge.
Besides examples where the cap is made of a bumpy material, the material itself may change over time, thereby changing the exposure line resting on different heights of lubrication strip across the cartridge thereby affecting measurements. In such examples, the cap may be made of material, or have impregnated in it, material that degrades, washes away, dissolves, or otherwise changes during shaving operations because it includes lubrication materials. In some examples the material on or in the lubrication strip may swell when exposed to water. In such examples, the physical height of the strip may thereby change when the material dissolves or is washed away making a measurement of exposure before and after use different because the height of the material against which the reference line is drawn moves or changes.
Likewise, the guard may include ridges or bumps or be made of water soluble material, that may change the position of a reference line and thereby the exposure measured every few microns across the width of a cartridge. The caps and/or guards and/or blades may be coated with any kind of material to ease friction or aid in standing up hairs for closer cuts, such as chrome, polytetrafluoroethylene PTFE, plastics, paint, lacquer, or other coatings, changing the position of the reference line across the cartridge. Any or all of such examples in any combination may affect the drawing of a reference line against which blade exposures may be measured.
The foregoing description, for purpose of explanation, has been described with reference to specific embodiments. However, the illustrative discussions above are not intended to be exhaustive or to limit the embodiments to the precise forms disclosed. Many modifications and variations are possible in view of the above teachings. The embodiments were chosen and described in order to best explain the principles of the embodiments and its practical applications, to thereby enable others skilled in the art to best utilize the various embodiments with various modifications as are suited to the particular use contemplated.
Unless the context clearly requires otherwise, throughout the description, the words “comprise,” “comprising,” and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is to say, in a sense of “including, but not limited to.” Words using the singular or plural number also include the plural or singular number respectively. Additionally, the words “herein,” “hereunder,” “above,” “below,” and words of similar import refer to this application as a whole and not to any particular portions of this application. When the word “or” is used in reference to a list of two or more items, that word covers all of the following interpretations of the word: any of the items in the list, all of the items in the list and any combination of the items in the list.
Although certain presently preferred implementations of the embodiments have been specifically described herein, it will be apparent to those skilled in the art to which the embodiments pertains that variations and modifications of the various implementations shown and described herein may be made without departing from the spirit and scope of the embodiments. Accordingly, it is intended that the embodiments be limited only to the extent required by the applicable rules of law.
This application relates to, claims priority to, and is a Continuation application of U.S. patent application Ser. No. 17/228,627 filed on Apr. 12, 2021, which in turn claims priority from and is a Continuation application of U.S. patent application Ser. No. 17/099,681 filed on Nov. 16, 2020 (now U.S. Pat. No. 11,000,960), the entireties of which are hereby incorporated by reference.
Number | Date | Country | |
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Parent | 17228627 | Apr 2021 | US |
Child | 17574539 | US | |
Parent | 17099681 | Nov 2020 | US |
Child | 17228627 | US |