Patent Publication Number: US-2023146556-A1

Title: Knife

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. application Ser. No. 17/367,865, filed Jul. 6, 2021, which is a continuation of U.S. application Ser. No. 15/373,071, now U.S. Pat. No. 11,052,549, filed Dec. 8, 2016, which claims the benefit of and priority to U.S. Provisional Patent Application No. 62/265,487, filed Dec. 10, 2015, the entire contents of each of which are incorporated by reference. 
    
    
     BACKGROUND 
     The present invention relates to knives and more particularly to folding knives. 
     SUMMARY 
     In one embodiment, the invention provides a folding knife including a handle, a pivot axis, and a blade having a cutting edge. The blade is pivotably coupled to the handle such that the blade is pivotable relative to the handle about the pivot axis between a retracted position and an extended position. The cutting edge is exposed in the extended position and a portion of the blade is received within the handle in the retracted position. The folding knife further includes a bearing assembly for facilitating movement of the blade between the retracted position and the extended position. The bearing assembly includes a first bearing recessed within the blade and a second bearing recessed within the handle. 
     In another embodiment, the invention provides a folding knife including a first handle portion, a second handle portion coupled to the first handle portion, a pivot axis, and a blade having a cutting edge. The blade is pivotably coupled to the handle between the first handle portion and the second handle portion. The blade is pivotable about the pivot axis between a retracted position and an extended position. The cutting edge is exposed in the extended position and a portion of the blade is received within the handle in the retracted position. The folding knife further includes a bearing coupled to the second handle portion for facilitating movement of the blade between the retracted position and the extended position. The bearing includes a bearing cage and a plurality of balls partially supported by the bearing cage. The blade and the second handle portion act as a bearing race to partially support the plurality of balls of the bearing. 
     In another embodiment, the invention provides a folding knife including a first handle portion, a second handle portion coupled to the first handle portion, a pivot axis, and a blade having a cutting edge. The blade is pivotably coupled to the handle between the first handle portion and the second handle portion. The blade is pivotable about the pivot axis between a retracted position and an extended position. The cutting edge is exposed in the extended position and a portion of the blade is received within the handle in the retracted position. The folding knife further includes a bearing coupled to the blade for facilitating movement of the blade between the retracted position and the extended position. The bearing includes a bearing cage that is recessed within the blade. The bearing further includes a plurality of balls that extend beyond the blade to form a gap between the blade and the first handle portion. 
     Other aspects of the invention will become apparent by consideration of the detailed description and accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a perspective view of a knife according to an embodiment of the invention. 
         FIG.  2    is an exploded perspective view of a back side of the knife of  FIG.  1   . 
         FIG.  3    is an exploded perspective view of a front side of the knife of  FIG.  1   , illustrating a portion of a bearing assembly disposed about a rotational axis of the knife. 
         FIG.  4    is a perspective view of the bearing assembly. 
         FIG.  5    is a cross-sectional view of the knife along line  5 - 5  of  FIG.  2   . 
     
    
    
     Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. 
     DETAILED DESCRIPTION 
       FIGS.  1  and  2    illustrate a knife, and more specifically, a folding knife  10 . The knife  10  includes a first handle portion  14 , a second handle portion  18 , and a blade  22  pivotally coupled to the handle portions  14 ,  18 . The handle portions  14 ,  18  each generally define half of a handle  30  of the knife  10 . The blade  22  is pivotally coupled to the handle  30  so that the blade  22  can pivot about a pivot axis  34  between an extended position ( FIG.  1   ) and retracted or closed position ( FIG.  2   ). In the retracted position, a portion of the blade  22  is received and stored within the handle  30  between the portions  14 ,  18 . The handle  30  includes a blade cavity  38  adjacent a front side  39  of the handle  30  that receives at least a portion of blade  22  in the retracted position. The blade cavity  38  is disposed between the handle portions  14 ,  18 . 
     With continued reference to  FIGS.  1  and  2   , the blade  22  includes a tang  42  proximate the pivot axis  34  and a distal end  46  located opposite the tang  42 . The blade  22  further includes a cutting edge  50  formed by opposing faces  54 ,  58  of the blade  22  converging toward each other to a common apex. The cutting edge  50  of the blade  22  is configured to be used by an operator to perform a cutting operation. Although the cutting edge  50  of the illustrated embodiment is partially serrated, in other embodiments, the cutting edge  50  may be formed differently (i.e., a continuous edge). 
     The blade  22  further includes a protruding portion (i.e., an actuator  62 ) proximate the tang  42 . The actuator  62  is formed as an integral member of the blade  22  and protrudes outwardly from the tang  42 . Specifically, the actuator  62  extends beyond an outer periphery  63  of the handle  30  in the extended and retracted position of the blade  22 . As a result, an operator has access to the actuator  62  when the blade  22  is in the retracted position. Although the actuator  62  of the illustrated embodiment is integrally formed with the blade  22 , the actuator  62  may alternatively be a separate component from the blade  22  such that the blade  22  pivots in response to the actuator  62  acting on a portion of the blade  22 , e.g. a kicker that is rotatable separate from the blade  22  and is configured to act on the blade  22  to open the blade  22 . 
     With reference to  FIGS.  1 - 3   , the knife  10  of the illustrated embodiment further includes a spacer  82  interposed between the handle portion  18  and a liner  114 . The liner  114  is, in turn, interposed between the handle  14  and the blade  22 . A plurality of fasteners  78  connects the spacer  82 , the liner  114 , and the handle portions  14 ,  18 . The spacer  82  is disposed proximate the rear end of the knife  10  and defines a width of the blade cavity  38 . The spacer  82  includes a stop surface  86  that abuts the blade  22  in the retracted position of the blade  22  to inhibit further rotation of the blade  22  beyond the retracted position. 
     In the illustrated embodiment of  FIG.  2   , the knife  10  further includes a locking arm  90  formed as an integral component of the handle portion  18 . The locking arm  90  maintains the blade  22  in the extended position. The locking arm  90  is cantilevered from a portion of the handle portion  18 . The locking arm  90  also has a free end  98  extending away from a connecting end  102 . The locking arm  90  is curved such that the free end  98  is biased toward the blade cavity  38 . The locking arm  90  is movable between a locked configuration and an unlocked configuration. In the locked configuration, the locking arm  90  inhibits movement of the blade  22 . In the unlocked configuration, movement of the blade  22  is allowed. The locking arm  90  is biased toward the locked configuration, in which the free end  98  of the locking arm  90  engages a shoulder  106  at the tang  42  of the blade  22  to resist movement of the blade  22  away from the extended position. The free end  98  of the locking arm  90  includes a tab  110  that is partially disposed outside of the handle  30  to enable an operator to easily access the tab  110 . The tab  110  facilitates moving the locking arm  90 . A retaining member (i.e., a washer  118  and a fastener  122 ) is secured to the handle portion  18  and selectively engages the locking arm  90 . Specifically, the washer  118  engages the locking arm  90  when the locking arm  90  is actuated toward the unlocked configuration in order to inhibit the locking arm  90  from extending beyond the unlocked configuration. Also, the washer  118  avoids inadvertent or excessive bending of the locking arm  90 , which could cause the knife  10  to malfunction. 
     With reference to  FIGS.  2 - 4   , the knife  10  further includes a bearing assembly  126  disposed about the pivot axis  34  to facilitate rotational movement of the blade  22  relative to the handle portions  14 , 18 . Specifically, the handle portions  14 ,  18 , the liner  114 , and the blade  22  each include an aperture  128  co-axial with the pivot axis  34  for receiving at least a portion of the bearing assembly  126 . The bearing assembly  126  includes a first or male fastener  130  (i.e., screw, bolt, etc.) and a second or female fastener  134  (i.e., screw, bolt, etc.) that couple together in order to pivotally couple the handle portions  14 ,  18  and the blade  22 . The male fastener  130  includes a head  138 , a tool receiving portion  142  on the head  138 , and an externally threaded stem  146  protruding away from the head  138 . Similarly, the female fastener  134  includes a head  150 , a tool receiving portion  154  ( FIG.  5   ) on the head  150 , and an internally threaded stem  158  protruding away from the head  138 . The internally threaded stem  158  has the inverse thread pattern to that of the externally threaded stem  146 , such that the stem  146  is threadable and thereby receivable with stem  150 . As shown in the illustrated construction of  FIG.  4   , the outer periphery of the stem  150  is cylindrical in shape, which engages the inner periphery of the apertures  128 . 
     With reference to  FIG.  5   , when assembling the knife  10 , the apertures  128  of the handle portions  14 ,  18 , the liner  114 , and the blade  22  are aligned in order to pass the female fastener  134  through the apertures  128  until the head  150  engages the handle portion  14 . Subsequently, the male fastener  130  passes through the handle portion  18  to mate with the female fastener  134 . At this point, at least one of the fasteners  130 ,  134  is rotated to cause the threaded portions  146 ,  158  to engage causing axial movement of the fasteners  130 ,  134  along the rotational axis  34  until each head  138 ,  150  engages the handle portions  18 ,  14 , respectively, thereby capturing the handle portions  14 ,  18 , the liner  114 , and the blade  22  between the heads  138 ,  150 . The heads  138 ,  150  are low-profile in order to minimize the amount at which the fasteners  130 ,  134  protrude beyond a width W of the knife  10 . 
     With reference to  FIGS.  2 - 4   , the bearing assembly  126  further includes a set of thrust bearings  162 ,  166  disposed co-axially with the axis  34  and about the female fastener  134  to minimize friction during relative movement between the handle portions  14 ,  18  and the blade  22 . Like conventional rotary rolling-element bearings, the thrust bearings  162 ,  166  permit rotation between parts (e.g., the blade  22  and the liner  114 ). However, the thrust bearings  162 ,  166  also provide support to a load in a predominately axial direction (e.g., pivot axis  34 ). The thrust bearings  162 ,  166  are disposed on opposing sides of the blade  22  creating a gap  170  ( FIG.  5   ) on either side of the blade  22  to inhibit contact between the opposing face  54  of the blade  22  and the liner  114 , and the other opposing face  58  and the handle portion  18 . Each thrust bearing  162 ,  166  includes a plurality of engagement members (e.g., balls  174 ) and a disc-shaped cage  178  having a plurality of apertures  182 . Each thrust bearing  162 ,  166  further includes inner and outer circumferential flanges  186  that extend away from the disc-shaped cage  178 . The balls  174  are radially constrained by the inner and outer circumferential flange  186 . Also, the balls  174  are axially constrained at least partially by the apertures  182  of the disc-shaped cage  178 . The balls  174  are further constrained in the axial direction by the blade  22  and the liner  114 . Specifically, the liner  114  and the blade  22  substantially act as a race for the thrust bearing  162  to further constrain the balls  174  in the axial direction of axis  34 . Also, the blade  22  and the handle portion  18  substantially act a race of the thrust bearing  166  to further constrain the balls  174  in the axial direction of axis  34  Eliminating the race as being an integral member of the thrust bearings  162 ,  166  advantageously decreases the width W of the knife  10  for ease of storage in the user&#39;s pocket, tool belt, knife holster, or the like. Although the bearing  166  of the illustrated embodiment is disposed within the handle  18 , in other embodiments, the bearing  166  may alternatively be disposed within the blade  22  such that both bearings  162 ,  166  are disposed within the blade  22 . 
     With reference to  FIG.  5   , when the knife  10  is assembled, the thrust bearing  162  is recessed within an annular inwardly-extending groove  190  (i.e., a pocket) formed on the blade  22 , whereas the thrust bearing  166  is recessed within an annular inwardly-extending groove  194  (i.e., a pocket) formed on the handle portion  18 . As such, the disc-shaped cage  178  of each bearing  162 ,  166  is encased within each groove  190 ,  194 , respectively. That is, the thrust bearing  162  is coupled to the blade  22  and the thrust bearing  166  is coupled to the handle portion  18 . The balls  174  of the thrust bearing  162  extend beyond the opposing face  54  of the blade  22  to form the gap  170  between the blade  22  and the liner  114 . Similarly, the balls  174  of the thrust bearing  166  extend beyond the handle portion  18  to form the gap  170  between the blade  22  and the handle portion  18 . 
     In operation, to pivot the blade  22  from the retracted position to the extended position, an operator applies a force to the actuator  62 . Once the blade  22  is in the extended position, the locking arm  90  engages the shoulder  106  of the blade  22 . To pivot the blade  22  from the extended position to the retracted position, an operator applies a force to a portion of the blade  22 , while simultaneously moving the locking arm  90  from the locked configuration to the unlocked configuration. While the blade  22  pivots between the retracted and extended positions, the plurality of balls  174  of the thrust bearing  162  engage with and roll against the groove  190  of the blade  22  and the liner  114 . Also, the plurality of balls  174  of the thrust bearing  166  engage with and roll against the groove  194  of the handle portion  18  and the opposing face  58  of the blade. 
     Although the invention has been described in detail with reference to certain preferred embodiments, variations and modifications exist within the scope and spirit of one of more independent aspects of the invention as described.