Scissors represent a hand-operated shearing tool used for cutting various thin materials like paper, metal, foil, plastic, or rope. They also are employed by barbers, beauticians, and pet groomers to cut hair.
Scissors consist of a pair of metal blades pivoted so that their sharpening edges slide against each other when the respective handles opposite to the pivot point are closed by the user's hand. The two blades having sharpened edges that cooperate when the scissor blades are closed to produce a precise cut along a material that needs to be cut.
But, over time, these sharpened edges of the scissors blades will become dull. Moreover, tougher or abrasive materials will cause the blades to become dull more quickly. Dull blades do not cut as easily or precisely, and can create a danger to the end user by requiring greater hand force to make a cut. Moreover, dulled blades can include rolled edges, burrs, or ragged edges with regions along the cutting surface that are out of alignment with each other. Such misaligned blades can damage the material being cut.
Therefore, such dulled scissors blades must be periodically sharpened. Typically, grinding wheels or whetstones have been used to restore the cutting edges along the blades of scissors. But, this constitutes a precise operation in which the angle of the cutting edge of the blade must match the angle of the whetstone or grinding wheel surface. It is easy to damage the cutting edge of the scissors blade further if the sharpening exercise is performed poorly. Thus, most scissors users need to send out their dulled scissors to a professional sharpening service, or to replace the scissors with a new pair of scissors. This can be time-consuming and expensive.
Other scissors users have been known to employ more humble methods for sharpening dulled scissors blades. For example, taking a pair of scissors and cutting three strips of sand paper allegedly will restore some degree of sharpness to the cutting edges due to the movement of the cutting edges against the abrasive particles on the sand paper. Other “home-grown” methods for sharpening scissors blades include cutting a pin while sliding it forward along the scissors blades, cutting a couple of strips of aluminum foil that are folded multiple times to produce a thick stack, or pushing the scissors blades against the exterior surface of a glass cylinder like a drinking glass or soda bottle while closing the scissors. However, while these methods do not require expensive equipment or technical skill, they are believed to do a better job of polishing an already-sharpened scissors blade than sharpening the blade itself.
U.S. Pat. No. 3,942,394 issued to Juranitch is directed to a finishing sharpener device specially designed for sharpening a knife blade. It includes a handle having a pair of wings extending therefrom. Each of the wings constitutes a flat bar defining a sharpening edge that is arcuate in cross section and smooth. By drawing a dulled knife blade cutting edge across the sharpening edge of one of the wings at the proper angle, the knife blade cutting edge may be restored to its sharpened configuration. The handle of the finishing sharpener serves as a guide for properly drawing the knife blade along the wing's sharpening edge. But, this process still requires some skill by the person sharpening the knife blade to ensure a proper match of the knife blade cutting edge angle with the angled surface of the sharpening edge of the wing. Moreover, the arcuate cross-section surface of relatively small radial extent having a highly smooth configuration is insufficient for removing material from the cutting edge of the knife blade. This finishing sharpener may only be used after the knife blade is sharpened first on a hone or grinding wheel.
Razor Edge Systems of Ely, Minnesota has commercialized a SCISSORSAVER device useful for sharpening, steeling, or maintaining the cutting edges of scissors blades, particularly for use in the meat processing industry. It constitutes a sharpening steel that is engaged by the dulled blades of a scissors closed against the sharpening steel. It also has a vertical post for aligning the scissors blades and providing some sharpening functionality to the interior edge of the blades. The sharpening steel is positioned above the vertical post, so that when the sharpened scissors is removed from the SCISSORSAVER device, the upper sharpening steel falls by means of gravity to return to its standby position against the vertical post. But, this SCISSORSAVER device represents a relatively large, stationary-mounted apparatus that can be positioned in front of or next to a meat processing or factory assembly line worker. It is not particularly useful for barbers, beauticians, pet groomers, crafters, florists, or home users of scissors who would benefit from a small, portable sharpening device. Furthermore, this device must be carefully installed in such a position as to ensure that the upper sharpening steel will, in fact, fall back upon the lower vertical post when the scissors is removed from the device. Otherwise, the upper sharpening steel will not be available to sharpen again a pair of scissors.
Therefore, it would be very advantageous to provide a sharpening apparatus that may be used by a relatively unskilled person to simultaneously sharpen the interior and exterior surfaces of the cutting edge of both blades of a scissors by hand and with minimal effort and training. Such an apparatus should be small and portable so that the person may take it out to sharpen the cutting edge of the scissors blades when needed, as opposed to mounting the sharpening apparatus in a stationary location. Moreover, the device should enable the sharpening of the blades of the scissors due to a simple closing of the scissors blades around the sharpening steels of the apparatus. Furthermore, the sharpening apparatus should automatically return itself from its sharpening position to its standby position without regard to the orientation of the device in three-dimensional space. Such a sharpening apparatus can be used to maintain an extremely sharp scissor edge for precise cutting of a material like hair without crushing or other damage with significantly reduced physical force and strain upon the user.
USPTO Backgrounds
USPTO Backgrounds