Patent Publication Number: US-2023150093-A1

Title: Sharpening device

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application is a divisional of U.S. patent application Ser. No. 17/126,242, filed Dec. 18, 2020, now U.S. Pat. No. 11,565,375, which claims priority to U.S. Provisional Patent App. No. 62/949,725, filed Dec. 18, 2019, the entireties of which are hereby incorporated by reference. 
    
    
     FIELD 
     The present disclosure generally relates to sharpeners and more particularly to blade sharpeners such as used for sharpening knife blades, scissor blades, and the like. 
     BACKGROUND 
     After a knife has been used for some time, a cutting edge of the knife usually becomes dull. The cutting edge can be sharpened using a sharpener. 
     SUMMARY 
     In one aspect, a blade sharpening device comprises a first support including a first arm, a second arm, and a first pivot hub. The first and second arms extend away from the first pivot hub in different directions. The first and second arms include respective first and second abrasive sharpening surfaces for sharpening the blade. The blade sharpening device includes a second support including a third arm, a fourth arm, and a second pivot hub. The third and fourth arms extend away from the second pivot hub in different directions. The third and fourth arms include respective third and fourth abrasive sharpening surfaces for sharpening the blade. A pivot connection connects the first and second pivot hubs. The first and second supports are pivotable about the pivot connection to pivot the first and second arms away from each other and pivot the third and fourth arms away from each other to configure the first and second supports in an operational configuration for use in sharpening the blade. 
     In another aspect, a blade sharpening device for sharpening a blade comprises a housing defining an interior. The housing includes an opening permitting access to the interior. The housing includes at least one receiver different from the opening. The blade sharpening device includes a blade sharpening assembly. The blade sharpening assembly includes first and second arms connected by a pivot connection about which the first arm is pivotable with respect to the second arm. The first and second arms include respective first and second abrasive sharpening surfaces for sharpening the blade. The blade sharpening assembly is configurable in a stowed configuration in which the arms extend alongside each other. The blade sharpening assembly is configurable in an operational configuration in which the arms are pivoted away from each other to present the abrasive sharpening surfaces for use in sharpening the blade. The blade sharpening assembly in the stowed configuration is receivable in the interior of the housing from the opening to arrange the housing and blade sharpening assembly in a stowed arrangement. The blade sharpening assembly in the operational configuration is receivable in the at least one receiver to arrange the housing and blade sharpening assembly in an operational arrangement in which the housing serves as a base to support the blade sharpening assembly extending upward from the housing for use of the first and second abrasive sharpening surfaces to sharpen the blade. 
     Other objects and features of the present disclosure will be in part apparent and in part pointed out herein. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a perspective of a blade sharpening device of the present disclosure in a stowed arrangement; 
         FIG.  2    is a perspective of the blade sharpening device of the present disclosure in an operational arrangement; 
         FIG.  3    is a section of the blade sharpening device taken in a plane including line  3 - 3  of  FIG.  2   ; and 
         FIG.  4    is a fragmentary section of the blade sharpening device taken in a plane including line  4 - 4  of  FIG.  3   . 
     
    
    
     Corresponding reference numbers indicate corresponding parts throughout the drawings. 
     DETAILED DESCRIPTION 
     Referring to  FIGS.  1  and  2   , a blade sharpening device of the present disclosure is indicated by  10 . The blade sharpening device can be used to sharpen various types of blades, such as knife blades and scissor blades, or to sharpen other objects. The blade sharpening device  10  includes a housing  12 , which may also be referred to as a base. The blade sharpening device  10  also includes a blade sharpener assembly  14 . In a stowed arrangement (e.g.,  FIG.  1   ), the blade sharpener assembly  14  is stored in the housing  12 , and in an operational configuration (e.g.,  FIG.  2   ) the blade sharpener assembly is supported by the housing as a base for use of the blade sharpener in sharpening a blade. The housing  12  defines an interior in which the blade sharpening assembly  14  is receivable via an end opening  16  in the housing to form the stowed arrangement, and the housing includes receivers  18 A- 18 C for receiving and supporting the blade sharpening assembly in the operational arrangement. 
     The blade sharpening assembly  14  includes a first support  20  and a second support  20 . The first and second supports  20  include respective pivot hubs  20 A connected to each other by a pivot connection defining a pivot axis PA. The first support  20  includes first and second arms  26 ,  28  extending in opposing directions away from the pivot connection. Likewise, the second support  20  includes first and second arms  26 ,  28  extending in opposing directions away from the pivot connection. The arrangement is such that the first arms  26  of the first and second supports  20  form a first pair of arms and the second arms  28  of the first and second supports form a second pair of arms. The pairs of arms  26 ,  28  are movable toward and away from each other in a scissors fashion by pivoting one or both of the supports  20  about the pivot connection. The blade sharpening assembly  14  is configurable in a stowed configuration by pivoting one or both of the supports  20  about the pivot connection to arrange the respective arms  26 ,  28  of each pair of arms alongside each other. The blade sharpening assembly  14  is configurable in the operational configuration by pivoting the supports  20  to move the respective arms  26 ,  28  of each pair of arms away from each other. In the operational configurations, the supports  20  form a generally X shape. 
     Blade sharpeners  40 A,  40 B are provided on the arms  26 ,  28  for sharpening opposite sides of a blade. In the illustrated embodiment, the sharpeners  40 A,  40 B comprise rectangular sharpening stones that have generally planar abrasive sharpening surfaces. Other types of sharpeners can be used without departing from the scope of the present disclosure. The abrasive sharpening surfaces of the sharpeners  40 A on the first pair of arms  26  have a first grit (e.g., coarse grit, such as 400 grit), and the abrasive sharpening surfaces of the sharpeners  40 B on the second pair of arms  28  have a second grit (e.g., fine grit, such as 800 grit). For example, the sharpeners  40 A on the first set of arms  26  may be used in a first stage of sharpening, and the sharpeners  40 B on the second pair of arms  28  may be used in a second stage of sharpening. When in the stowed configuration, the abrasive sharpening surfaces of the respective pairs sharpeners  40 A,  40 B are immediately adjacent or abutting each other (e.g., in generally flatwise engagement with each other). 
     It will be appreciated that the supports  20  are configured to permit a compact stowed configuration in which the arms  26 ,  28  of each pair of arms extend alongside each other, with the abrasive sharpening surfaces opposing each other and being close to each other. In one aspect, arms  26 ,  28  of one support  20  are located on opposite sides of a reference plane that includes the pivot axis PA and that extends parallel to a length of an abrasive sharpening surface of one of the arms  26 ,  28 . This arrangement results from the arms  26 ,  28  of a support  20  extending in an offset manner with respect to each other from the pivot hub to which the arms are connected. The construction permits the abrasive sharpening surfaces to be essentially in flatwise face-to-face engagement when the assembly  14  is in the stowed configuration. It will be appreciated as well that the pivot hub  20 A of one support  20  is located in a gap of the other support between proximal ends of the other support&#39;s arms  26 ,  28 . The pivot hubs  20 A are narrower than the arms  26 ,  28 , and the pivot hubs have a combined width about the same as the width of the arms  26 ,  28 . 
     The base  12  has an elongate shape and includes a lower portion configured to rest on a support surface and an upper portion including the plurality of receivers  18 A- 18 C. The receivers  18 A- 18 C are sized and shaped to receive arms  26 ,  28  of the blade sharpening assembly  14  to support the blade sharpening assembly in the operational configuration. Depending on whether the user would like to use the first or second pair of sharpeners  40 A,  40 B, the user can select which pair of arms  26 ,  28  is installed in the receivers  18 A- 18 C. In the illustrated embodiment, three receivers  18 A- 18 C are provided. Each receiver  18 A- 18 C comprises an opening permitting access into the interior of the base  12 . When the blade sharpening assembly  14  is in a receiver  18 A- 18 C in the operational arrangement, the blade sharpening assembly extends into the interior and occupies a portion of the interior that is occupied by the blade sharpening assembly in the stowed arrangement. In a first operational arrangement of the base  12  and assembly  14 , arms  26  or  28  of the blade sharpening assembly  14  are received in the first and second receivers  18 A,  18 B, and in a second operational arrangement, arms  26  or  28  of the blade sharpening assembly are received in the first and third receivers  18 A,  18 C. The first and second receivers  18 A,  18 B are arranged such that when the blade sharpening assembly is in the first operational configuration, the abrasive sharpening surfaces of the upper pair of sharpeners  40 B are oriented at a first angle (e.g., 19 degrees) with respect to vertical. The first and third receivers  18 A,  18 C are arranged such that when the blade sharpening assembly is in the second operational configuration the abrasive sharpening surfaces are oriented at a second angle (e.g., 26 degrees) with respect to vertical (greater than the first angle). For example, it may be desirable to sharpen fillet knives using the first operational configuration and to sharpen utility knives or multi-purpose knives using the second operational configuration. Other numbers of operational configurations can be used (e.g., one, three, etc.) can be used without departing from the scope of the present disclosure. 
     Optionally, the blade sharpening assembly  14  can be configured to prevent the supports  20  from freely pivoting about the pivot connection (e.g., “flopping” open or closed). For example, the supports  20  can be frictionally prevented from freely pivoting about the pivot connection except in response to manual force applied by a user. The blade sharpening assembly  14  can include a pivot damper configured to apply friction to the first and second supports  20  to dampen pivoting movement. In the illustrated embodiment, pivot hubs  20 A of the supports  20  are pivotally connected by fasteners  56  threaded to each other, and a washer  58  is provided between the pivot hubs. The pivot damper comprises two compression springs  50  captured between the supports  20  and the fasteners  56 . The pivot axis PA of the pivot connection passes through the springs  50 . The springs  50  are received over the fasteners  56 . First ends of the springs press against pivot hubs  20 A of the supports  20 , and opposing ends of the springs press against the fasteners  56 . The compression of the springs  50  causes the springs to apply a frictional force against the supports  20  at the pivot hubs  20 A to prevent gravitational pivoting of the supports and to require manually applied force to pivot the supports about the pivot connection. The compression of the springs  50  and thus the friction applied by the springs (and the force required to pivot the supports  20 ) can be adjusted by changing the amount the fasteners  56  are tightened to draw heads of the fasteners toward each other. The pivot damper may also be referred to as a retainer which retains the supports in the operational and/or stowed configuration and permits pivoting of the supports under manual pressure applied by a user. 
     It will be appreciated that the blade sharpening assembly  14  can be supported by the base  12  in the operational configuration with either the first pair of arms  26  extending upward for sharpening with the first pair of sharpeners  40 A, or the second pair of arms  28  extending upward for sharpening with the second pair of sharpening stones  40 B. The blade sharpening assembly  14  is inverted to present the first or second pair of sharpeners  40 A,  40 B for use. 
     To sharpen the blade, the blade is moved downward along the opposing abrasive sharpening surfaces of the upper sharpeners  40 B in an alternating fashion to sharpen opposite sides of the blade to form a desired cutting edge. More specifically, the blade can be sharpened by, while holding the knife with the longitudinal axis of the blade extending generally horizontally, with the cutting edge pointing downward and the blade extending vertically from the cutting edge to a back edge of the blade, moving the cutting edge downward across the abrasive sharpening surfaces, alternating between the opposite abrasive sharpening surfaces to sharpen both sides of the cutting edge. Depending on whether the first or second operational configuration is being used, the edge margins of the blade adjacent the cutting edge become beveled at an angle corresponding to the angle of the abrasive sharpening surfaces with respect to vertical. In one method, the blade sharpening assembly  14  is arranged in the selected first or second configuration with the coarse sharpeners  40 A to create a coarse bevel at the edge margin adjacent the cutting edge. Then the blade sharpening assembly  14  is flipped over and reinstalled in the base in the same first or second configuration but with the fine sharpeners  40 B on top. The fine sharpeners  40 B are used in a similar alternating downward strokes on the opposite fine abrasive sharpening surfaces to create a smoother bevel surface at generally the same bevel angle as the coarse bevel, to complete sharpening of the blade. 
     In another aspect, the housing  12  includes grips  60  to grip the blade sharpening assembly  14  when the blade sharpening assembly is received in the receivers  18 A- 18 C in an operational configuration and to grip the blade sharpening assembly when in the interior of the housing in the stowed configuration. In the illustrated embodiment, the main body  12 A of the housing or base  12  is made of plastic material that has a relatively low coefficient of friction. A layer of polymeric material  12 B is overmolded onto the main body of the housing  12 . The grips  60  are formed by portions of the polymeric material  12 B overmolded onto the main body  12 A and are exposed in and protrude into the interior of the housing  12 . The grips  60  frictionally engage opposing portions of the blade sharpening assembly  12  when the blade sharpening assembly is received in the receivers  18 A- 18 C in the operational configuration and in the housing interior in the stowed configuration. Desirably, the grips  60  provide a tolerance or friction fit with the blade sharpening assembly  14  in the operational and stowed configurations. In the illustrated embodiments, the same grips  60  are used to frictionally engage the blade sharpening assembly in operational and stowed configurations. As a user inserts the arms  26 ,  28  of the blade sharpening assembly into the receivers  18 A- 18 C or inserts the collapsed blade sharpening assembly  14  into the interior of the housing via the end opening  16 , the blade sharpening assembly becomes lodged between opposing grips  60 . The grips  60  hold the blade sharpening assembly in position with respect to the housing or base  12  in the operational and stowed configurations. The user can overcome the frictional engagement of the blade sharpening assembly  14  and grips  60  by applying sufficient pulling force to remove the blade sharpening assembly from the receivers  18 A- 18 C or housing interior. The grips  60  facilitate formation of a stable foundation for the blade sharpening assembly  14  with the base  12  when the blade sharpening assembly is received in the receivers  18 A- 18 C in the operational configuration and prevent the blade sharpening assembly from inadvertently exiting the housing when in the stowed configuration. 
     In yet another aspect, the blade sharpening assembly  14  includes pivot connection structure configured to not damage the cutting edge of the knife blade if the pivot connection structure is unintentionally struck by the cutting edge during sharpening. In particular, the first and second supports  20  include the pivot hubs  20 A at which the supports are pivotally connected by the fasteners  56 . When the blade sharpening assembly  14  is in an operational position, the hubs  20 A define a bottom of a generally V shape formed by the upper arms  28 . As the knife blade is moved downward along an abrasive sharpening surface of a sharpener  40 B, the user should stop short of the pivot connection structure to avoid contacting the cutting edge of the blade with the pivot connection structure. However, the pivot connection structure includes shields  70  of protective material configured to be contacted by the cutting edge in case of accidental contact of the cutting edge with the pivot connection structure. Desirably, the protective material  70  is configured to be contacted by the blade without substantially dulling or harming the cutting edge. Desirably, the protective material  70  is softer than the material from which the supports  20  are constructed. For example, the supports  20  may be formed of metal (e.g., aluminum), and the protective material  70  can comprise a polymeric material (e.g., synthetic rubber) overmolded onto the supports. 
     It will be apparent that modifications and variations are possible without departing from the scope of the invention defined in the appended claims. 
     As various changes could be made in the above constructions and methods without departing from the scope of the invention, it is intended that all matter contained in the above description and shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.