Abstract:
A method for measuring the cutting force on a fiber. The method includes the steps of: providing a blade having an edge; providing a fiber mount for holding the fiber; providing at least one sensor connected to the fiber mount; moving the blade toward the fiber and cutting the fiber; and measuring the cutting force on the fiber with the at least one sensor.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application No. 61/309,913, filed Mar. 3, 2010. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to a method for measuring the cutting force on a fiber, and more particularly, to a method for measuring the cutting force exerted by a blade on a fiber such as a hair. 
     BACKGROUND OF THE INVENTION 
     In general, many techniques have been used over the years to measure the cutting forces of a blade cutting different materials. For example, the wool felt cutter test measures the force on a blade as the blade cuts through wool felt. This method has worked satisfactorily over the previous years for measuring the force on the blade as the blade cuts through the wool felt. However, the wool felt cutter test is only able to differentiate between blades when the differences in the cutting force exerted on the blades have relatively high measurable differences. 
     Another drawback with the wool felt cutter test is that it measures the force on the blade. The blade is held in a stationary position with a sensor attached to the blade. The wool felt is then moved across the blade edge to be cut. The sensor detects the force exerted on the blade as the blade edge cuts the wool felt. 
     In the wool felt cutter test, it is not known how many fibers are actually present in the wool felt. Furthermore, when the test is conducted it is not known how many fibers are actually cut by the blade and how far from the base the fibers have been cut. 
     Furthermore, in the wool fell cutter, blades have to remain static and dynamic cutting action like a sawing motion cannot be studied. 
     There is a need to provide a method for measuring the cutting force experienced by the fiber itself as the fiber is cut by a blade. 
     There is a need to provide a method for measuring the cutting force experienced by a hair as the hair is cut by a blade. Such a method would provide a more accurate measurement of the actual cutting force that is exerted on the hair by the blade during shaving. 
     There is a need to provide a method for measuring the cutting forces with a relatively high degree of sensitivity in order to determine the differences in the cutting forces between different blades. 
     There is a need to provide a method for measuring the cutting forces on different types of fibers. 
     There is a need to provide a method for measuring the cutting forces on hairs having different physiology and/or different chemical or mechanical treatment prior to cutting. 
     There is a need to provide a method for measuring the cutting force on hairs when the blades oscillate in specific direction, e.g. create a sawing, chopping or scraping movement, or with blades that are heated or electrically charged. 
     SUMMARY OF THE INVENTION 
     The present invention provides a method for measuring the cutting force on a fiber. A blade having an edge is provided. A fiber mount for holding the fiber is provided. At least one sensor connected to the fiber mount is provided. The blade is moved toward the fiber and cuts the fiber. The cutting force on the fiber is measured with the sensor. 
     The fiber mount may comprise a fiber outlet. The fiber outlet may have a shape selected from the group of circular, square, triangular, oval, and rectangular. The fiber may extend from the outlet by a distance from about 0.01 mm to about 2.0 mm prior to being cut. 
     The fiber mount may comprise a trough which is able to hold a fluid. The fluid may alter or modify the chemical or mechanical properties of the fiber prior to cutting. The fluid may be water. 
     A blade mount to hold the blade may be provided. The blade mount can be moved to cut the fiber with different portions of the edge. The blade mount may be dimensioned to hold at least two blades. The blade mount can hold the blade at different angles with respect to the fiber mount. 
     The apparatus may comprise multiple sensors. The multiple sensors measure cutting forces in multiple directions. 
     The apparatus may contain actuators on the blade mount to create additional blade motion or may contain electrically connections to heat or electrically charge the blade. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       While the specification concludes with claims particularly pointing out and distinctly claiming the subject matter that is regarded as the present invention, it is believed that the invention will be more fully understood from the following description taken in conjunction with the accompanying drawings. 
         FIG. 1  is a top plan view of a fiber cutting apparatus of the present invention. 
         FIG. 2  is a side view of another fiber cutting apparatus of the present invention. 
         FIG. 3  is a side view of a blade mount of the present invention holding two blades. 
         FIG. 4  is a front view of a fiber mount of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     A cutting apparatus  10  for measuring the cutting force on a fiber is shown in  FIG. 1 . The cutting apparatus  10  includes a blade  12  having an edge  14 . The blade  12  may be supported or held by a blade mount  16 . The cutting apparatus  10  includes a fiber mount  20  for holding said fiber  22 . A sensor  24  is connected to the fiber mount  20 . The sensor  24  is shown mounted to a fixture  26 . During operation of apparatus  10 , blade mount  16  moves linearly in direction  30  towards fiber  22  moving blade  12  towards fiber  22  until blade  12  cuts fiber  22 . As blade  12  cuts fiber  22  sensors  24  measures the cutting force exerted by blade  12  on fiber  22 . 
     The fiber mount  20  may include a trough  38 . Trough  38  may be configured to hold water or other fluids and/or liquids. For example, trough  38  may hold shave creams and shave preps or any other chemistry to modify the hair properties prior to cutting. Water may be added to trough  38  to hydrate the fiber  22  prior to being cut by blade  12 . The trough may also contain another fluid including detergents, dye, salt solution, wax, a micro- or nano-particle suspension or others that modify and/or alter the chemical or mechanical properties of the fiber prior to cutting. 
     Different fibers may be cut with apparatus  10 . Examples of such fibers include but are not limited to head hair, beard hair, leg hair, nylon, thread, yarn, wool, synthetic fibers, natural fibers, monofilament fibers, bi-component or multi-component fibers, etc. Fibers of different diameters or cross sections may also be cut with apparatus  10 . 
     The blade mount  16  can be adjusted to hold blade  12  at different angles  40  with respect to fiber mount  20 . For example, blade mount  16  may include a blade support  42 . Blade supports  42  having different shapes may be used to position blade  12  at different angles  40  with respect to fiber mount  20 . 
     The blade mount  16  may be connected to a power source via power supply cable  60  to provide power to blade mount  16 . With the available power the blade mount  16  may be equipped to heat the blade  12 . The blade mount  16  may be equipped to electrically charge blade  12 . The blade mount  16  may oscillate in a specific direction to create a sawing, chopping or scraping movement by blade  12  with respect to fiber  22 . 
     The fiber  22  may extend from the fiber mount  20  by a distance  23  of from about 0.01 mm, 0.05 mm, 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm and 0.5 mm to about 1.0 mm, 2.0 mm, 3.0 mm, 4.0 mm and 5.0 mm Preferably the fiber  22  extends from the fiber mount  20  by a distance  23  of from about 0.5 mm to about 2.0 mm. 
     The blade  12  may be positioned relative to the fiber mount to cut the fiber  22  at a distance of from about 0.01 mm, 0.5 mm, 0.1 mm to about 0.2 mm, 0.3 mm, 0.4 mm and 0.5 mm. 
     Another cutting apparatus  10  for measuring the cutting force on a fiber is shown in  FIG. 2 . The cutting apparatus  10  includes a blade  12  having an edge  14 . The blade  12  may be supported or held by a blade mount  16 . The cutting apparatus  10  includes a fiber mount  20  for holding said fiber  22 . Pluralities of sensors  24  are connected to the fiber mount  20 . The sensors  24  are shown mounted to a fixture  26 . Apparatus  10  is shown with four sensors  24 . Apparatus may have any number of sensors. For example, apparatus  10  may have one, two, three, four, or more sensors  24 . Sensors  24  measure cutting forces in multiple directions different from one another. During operation of apparatus  10 , blade mount  16  moves linearly towards fiber  22  moving blade  12  towards fiber  22  until blade  12  cuts fiber  22 . As blade  12  cuts fiber  22  sensors  24  measure the cutting force exerted by blade  12  on fibers  22 . 
     The fiber mount  20  may include a trough such as trough  38  shown in  FIG. 1 . The blade mount  16  can be adjusted to hold blade  12  at different angles with respect to fiber mount  20  as discussed with respect to  FIG. 1 . 
     The blade mount  16  can be moved in a direction indicated by arrow  44  to cut the fiber  22  with different portions of the blade  14 . Referring now to  FIG. 3 , blade mount  16  is shown holding two blades  12 . Blade mount  16  may hold more than two blades  12 . For example blade mount  16  may hold three, four, or more blades  12 . Blade mount  16  can be moved in a direction indicated by arrow  44  to first cut a fiber with one blade and then cut a fiber with the other blade. 
     Referring now to  FIGS. 1 ,  2  and  4 , fiber mount  20  has a front face  21  from which fiber  22  extends. Front face  21  has a fiber outlet  50  through which fiber  22  are fed. In  FIG. 4 , fiber outlet  50  is shown to have a circular shape. Other shapes such as square, triangular, oval, and rectangular may be used for fiber outlet  50 . 
     The fiber  22  may be fed through fiber outlet  50  either manually or automatically. Preferably, the fiber  22  is held by clamps, rollers, or other devices while the fiber  22  is cut by blade  12 . The fiber may be clamped rigidly. Alternatively the fiber may be held between two deformable pads, such as rubber or elastic pads, to simulate the way a hair is embedded in skin tissue. 
     The fiber  22  is shown to extend from fiber mount  20  substantially perpendicular to front face  21 . Fiber  22  may be positioned to extend from fiber mount  20  at various angles with respect to front face  21 . 
     The dimensions and values disclosed herein are not to be understood as being strictly limited to the exact numerical values recited. Instead, unless otherwise specified, each such dimension is intended to mean both the recited value and a functionally equivalent range surrounding that value. For example, a dimension disclosed as “40 mm” is intended to mean “about 40 mm. ” 
     Every document cited herein, including any cross referenced or related patent or application is hereby incorporated herein by reference in its entirety unless expressly excluded or otherwise limited. The citation of any document is not an admission that it is prior art with respect to any invention disclosed or claimed herein or that it alone, or in any combination with any other reference or references, teaches, suggests or discloses any such invention. Further, to the extent that any meaning or definition of a term in this document conflicts with any meaning or definition of the same term in a document incorporated by reference, the meaning or definition assigned to that term in this document shall govern. 
     While particular embodiments of the present invention have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this invention.