Patent Publication Number: US-11639007-B2

Title: Apparatus for releasably locking a stationary blade to a hair clipper

Description:
RELATED APPLICATION 
     The present application claims the benefit under 35 U.S.C. § 119(e) of U.S. patent application Ser. No. 62/887,222 filed on Aug. 15, 2019, the entire contents of which are incorporated by reference herein. 
    
    
     BACKGROUND 
     The present invention relates generally to hair clippers and hair trimmers, and more specifically to devices designed for enhancing the maintenance, cleaning and/or adjustment of clipper and trimmer bladesets. 
     Electric hair clippers and trimmers, collectively referred to here as clippers, conventionally use a removable bladeset including a stationary blade and a moving blade, which reciprocates laterally relative to the stationary blade. Hair which is caught between respective teeth of the moving and stationary blades is clipped as the moving blade teeth move past the stationary blade teeth under the power of an internal electric motor. For barbers and other professional hair stylists, collectively referred to as hair stylists, who use electric clippers, changes in the orientation of the tips of the moving blade relative to the fixed blade are known to provide different hair styling effects. Typically, the main effect of the blade position is to alter the cut length of the subject&#39;s hair. Another such effect is providing a sharp outline of the subject&#39;s hair relative to their neck, and also to provide geometric designs cut into the subject&#39;s hair. As such, hair stylists often have designated hair clippers which are intended to provide specific styling effects and have bladesets that are pre-adjusted. 
     Many types of conventional hair clippers are provided with blade mounting brackets having locating bushings which are adjustable by the hair stylist to achieve the desired stationary/moving blade tip spacing. Such locating bushings are conventionally held in place by threaded fasteners. 
     Other types of hair clippers are provided with an adjustment lever used to move the stationary blade relative to the moving blade as an alternate mechanism for providing the above-listed styling effects. Such adjustment levers allow the stylist to adjust the clipper as needed to achieve desired effects at the time of the styling operation. More specifically, one desired styling effect is to “taper” or “blend” the length of hair to effect the quality of the resulting hair style. 
     Another design criterion of hair clippers is that the bladesets need to be periodically removed from the hair clipper body for cleaning and/or maintenance. In most conventional clipper bladesets, this operation is accomplished by loosening and removing a threaded fastener that secures the bladeset to a bracket on the hair clipper. Depending on the hair clipper design, this removal of the bladeset may or may not require readjustment of the relative spacing of the blades during operation. Regardless, the bladeset removal operation is considered laborious by many hair stylists. 
     Thus, there is a need for an improved mechanism for removing hair clipper bladesets for cleaning and/or maintenance. There is also a need for an improved mechanism for removing hair clipper bladesets that preserves the pre-adjusted relationship of the moving blade to the stationary blade. 
     SUMMARY 
     The above-listed needs are met or exceeded by the present apparatus for releasably locking a stationary blade to a hair clipper. A feature of the present apparatus is that the user can remove the stationary blade from the hair clipper without the use of tools. In addition, the fine adjustment of the stationary blade that has been set by the user prior to blade replacement is retained using the present apparatus. Thus, the operator easily removes the stationary blade for cleaning while retaining the pre-adjusted blade setting or the alignment between corresponding teeth of the stationary and the moving blade. 
     In the present apparatus, the removal of the stationary blade is achieved using a lever associated with a bracket used to retain the stationary blade to the clipper housing. At a pivot end, the lever is provided with a barrel and cam formation that preferably projects generally perpendicular to a longitudinal axis of an arm of the lever. The barrel and cam formation pass through a blade opening in the stationary blade, and also through a bracket opening in the bracket. 
     Preferably, the cam formation is constructed and arranged to engage the blade opening, and the cam has a lobe configured for passing through the bracket opening. The cam lobe has an oblong, irregular or non-circular shape, so that rotation of the arm causes the cam lobe to move between an unlocked position, in which the stationary blade is released from the clipper, and a locked position, in which the stationary blade is operatively retained on the clipper through engagement of the lobe with the bracket opening. It is also preferable that the bracket opening is non-circular, irregular and is generally complementary to the shape of the cam lobe. 
     To remove a locked stationary blade from the hair clipper, the user moves the lever from a first position to a second position, which rotates the position of the cam lobe relative to the bracket opening. Another feature of the present apparatus is that the lever arm is provided on a free end of the lever arm with a generally perpendicular stop. In use, a first side of the stop engages the bracket in the first or locked position, and a second, opposite side of the stop engages the bracket in the unlocked position. In other words, an entire operational stroke of the lever from one position to the other, opposite position, results in either locking or unlocking the cam lobe from the bracket opening, depending on the direction of movement of the lever. 
     Another feature of the present apparatus is that the lever includes a lobe axis which extends through opposed ends of the lobe, and an arm axis which extends through the free end and the pivot end of said arm. The lobe axis is inclined by an angle α relative to the arm axis. In an embodiment, the angle α is oblique. In another embodiment, the angle α is 45 degrees. In an embodiment, the barrel has a wave washer circumscribing an exterior of the barrel. 
     Another feature of the present apparatus is a securing mechanism extending through the lever proximate the pivot end for attaching the barrel and the cam to the arm. 
     Yet another feature of the present apparatus is that the lobe further includes a first opposed surface and a second opposed surface. The first opposed surface is closer to the arm than the second opposed surface. Opposing rounded corners are provided on the first surface, such that when the lever is rotated from the second, unlocked position to the first, locked position, the rounded corners slide along chamfered edges of the bracket opening. 
     In an embodiment, the barrel engages the arm at the pivot end, and the barrel and the pivot end are configured to be attached to each other using a keyed structure so that an axis of the lobe extends at a predetermined angle to an axis of the arm. 
     More specifically, an apparatus is provided for releasably locking a stationary blade to a hair clipper, and includes a stationary blade with a blade opening, and a bracket configured for fixing the stationary blade to the hair clipper. Also, the bracket has a bracket opening. An actuator in the apparatus has a locking formation engageable in the openings and is operable between a first, locked position locking the stationary blade to the bracket, and a second, unlocked position releasing the stationary blade from the bracket. 
     In another embodiment, an apparatus is provided for releasably locking a stationary blade to a hair clipper. The apparatus includes a stationary blade with a blade opening, a bracket configured for fixing the stationary blade to hair clipper, the bracket having a bracket opening, and an actuator having a locking formation engageable in the openings and operable between a first, locked position locking the stationary blade to the bracket, and a second, unlocked position releasing the stationary blade from the bracket. 
     The actuator is a lever including an arm with a free end and a pivot end, a barrel proximate the pivot end extending from the arm, having an outer periphery, and a stop having opposed sides, proximate the free end and extending from the arm. One of the opposed sides of the stop is in contact with the bracket when the lever is in either the first, locked position or the second, unlocked position, and another of the opposed sides is in contact with the bracket when the lever is in the other of the first, locked position or the second, unlocked position. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a fragmentary bottom view of a hair clipper equipped with the present apparatus for releasably locking the stationary blade to the hair clipper; 
         FIG.  2 A  is a top plan view of the stationary blade with the present apparatus in the unlocked position; 
         FIG.  2 B  is a bottom plan view of the stationary blade of  FIG.  2 A ; 
         FIG.  2 C  is a top plan view of the stationary blade with the present apparatus in the locked position; 
         FIG.  2 D  is a bottom plan view of the stationary blade of  FIG.  2 C ; 
         FIG.  3    is an exploded perspective view of the present apparatus; 
         FIG.  4    is a bottom plan view of the stationary blade equipped with the present apparatus in the unlocked position; 
         FIG.  5    is a section taken along the line  5 - 5  of  FIG.  4    and in the direction indicated generally; 
         FIG.  6    is a bottom plan view of the stationary blade equipped with the present apparatus in the locked position; 
         FIG.  7    is a section taken along the line  7 - 7  of  FIG.  6    and in the direction indicated generally; 
         FIG.  8    is a bottom perspective view of the present lever; 
         FIG.  9    is a bottom plan view of the lever of  FIG.  8   ; 
         FIG.  10    is an exploded bottom perspective view of the lever of  FIG.  8   ; 
         FIG.  11    is a fragmentary bottom view of a hair clipper equipped with a second embodiment of the present apparatus for releasably locking the stationary blade to the hair clipper; 
         FIG.  12 A  is a top plan view of the stationary blade with the embodiment of  FIG.  11    in the unlocked position; 
         FIG.  12 B  is a bottom plan view of the stationary blade of  FIG.  12 A ; 
         FIG.  12 C  is a top plan view of the stationary blade with the embodiment of  FIG.  11    in the locked position; 
         FIG.  12 D  is a bottom plan view of the stationary blade of  FIG.  12 C ; 
         FIG.  13    is a fragmentary top plan view of the stationary blade with another alternate embodiment of the present apparatus; 
         FIG.  14    is a fragmentary bottom view of the apparatus of  FIG.  13    in the locked position; 
         FIG.  15    is a fragmentary horizontal cross-section of the apparatus of  FIGS.  13 - 14    showing locking stops on the locking formation engaging the bracket; and 
         FIG.  16    is a fragmentary top plan view of the stationary bade with still another alternate embodiment of the present apparatus. 
     
    
    
     DETAILED DESCRIPTION 
     Referring now to  FIGS.  1 - 3   , the present apparatus for locking a stationary blade to a hair clipper is generally designated  10 , and is shown mounted on a conventional hair clipper  12 , more specifically on a hair clipper housing  14 . As is well known in the art, the hair clipper  12  is equipped with a bladeset  16  featuring a stationary blade  18  and a laterally reciprocating moving blade  20  ( FIG.  1    shown hidden). 
     The bladeset  16  is secured to the housing  14  using a bladeset bracket  22 . The bracket  22  is generally “U”-shaped when viewed from the rear as seen in  FIG.  1   . Such brackets  22  are slidably engaged on the housing  14 , with edges  24  engaged in grooves (not shown) on the housing. On the stationary blade  18  is found a plurality of blade teeth  26  at one end, and at an opposite end, a blade base  28  having two bushing apertures  30  which are each dimensioned to accommodate a generally cylindrical bushing  32 . A bushing fastener  34  is provided for securing the generally tubular bushings  32  to the blade set bracket  22 , engaging mounting bores  35  ( FIG.  3   ). Once the bushing fastener  34  is engaged through the bushing  32  and is threaded into the bracket  22 , fine adjustments to the position of the stationary blade  18  are made by the user relative to the moving blade  20 . 
     Between the bushing apertures  30  is a bracket opening  36  which is aligned with a main opening  38  in the bladeset bracket  22 . In conventional hair clippers, a threaded fastener is used to fasten the stationary blade  18  to the bracket  22  through the main opening  38  and the bracket opening  36 . An important feature of the present apparatus  10  is that the conventional fastener is replaced with an actuator  40 , in the present embodiment taking the form of a lever having a locking formation  42  engageable in the bracket opening  36  and the main opening  38  and operable between a first, locked position ( FIGS.  2 C,  2 D  locking the stationary blade  18  to the bladeset bracket  22 , and a second, unlocked position ( FIGS.  2 A,  2 B ) releasing the stationary blade from the bracket. In the preferred embodiment, the lever  40  is constructed and arranged so that a full operational stroke of the lever from the first position to the second position is also the full limit of travel of the lever relative to the bracket  22 . 
     Referring now to  FIGS.  3 ,  7  and  8 - 10   , the lever  40  includes an arm  44  having a free end  46  and an opposite pivot end  48 . A barrel  50  is proximate the pivot end  48  and is preferably coaxially attached to the pivot end, preferably using a threaded barrel fastener  52 . The locking formation  42  takes the form of a cam located proximate to the barrel  50 , and includes a lobe  54  with an outer periphery  56  having opposing ends  58 . In the preferred embodiment, the lobe  54  is non-circular, oblong, parabolic or oval in shape, and it is contemplated that the shape may vary to suit the application. 
     A relatively narrow diameter neck  60  connects the locking formation  42  to an adjacent end  62  of the barrel  50 . When viewed from a side, the locking formation  42  and the neck combine to form a “T”-shape. Compared to the barrel  50 , the neck  60  has a narrower diameter, and the neck also has a shorter outer periphery than an outer peripheral edge  56  of the lobe  54 . Also, the neck  60  axially spaces the cam lobe  54  from the barrel  50  such that the lobe accommodates a thickness of the bladeset bracket  22  as well as a thickness of the stationary blade  18  ( FIG.  5   ). 
     Referring now to  FIGS.  9  and  10   , another feature of the present lever  40  is that the cam lobe  54  has a lobe axis “L” which extends through the opposed ends of the lobe, and the arm  44  has an arm axis “A” which extends through the free end  46  to the pivot end  48  of the arm. Further, the lobe axis “L” is inclined by an angle α relative to the arm axis “A”. In the preferred embodiment, the angle α is oblique, and more preferably the angle α is 45 degrees, which may vary to suit the application ( FIGS.  9  and  10   ). The angular orientation of the cam lobe  54  to the arm is maintained through the use of a key formation  66  projecting from the pivot end  48  of the arm  44 , which matingly engages a receiving formation  68  on the barrel  50  such that when the lever  40  is assembled, the cam lobe  54  is oriented at the desired angular orientation. 
     In the preferred embodiment, the key formation  66  is a polygonal projection, and the receiving formation  68  is a complementarily-shaped socket, however the structures may be reversed depending on the application, and the key shape may also vary as needed. Also, the main opening  38  in the bracket  22  accommodates the outer periphery  56  of the cam lobe  54 . The cam lobe  54  is inserted through the opening  38  in the bladeset bracket  22  and through the bracket opening  36  in the stationary blade  18  at the second, unlocked position, and the lever  40  is rotated to the first, locked position where said lobe becomes locked, and the blade  18  is held in position on the bracket. 
     Referring now to  FIGS.  2 A,  2 B,  2 C,  2 D, and  8 - 10    another feature of the lever  40  is that at the free end  46 , a stop  69  having opposed sides  70 , having opposed sides, extends from the arm  44 . In the preferred embodiment, the stop  69  extends generally perpendicularly from the arm  44 , however other angular orientations are contemplated. In operation, one of the opposed sides  70   a  of the stop  69  is closely adjacent or in contact with the stationary blade  28  when the lever  40  is in either the first, locked position or the second, unlocked position, and another of the opposed sides  70   b  is closely adjacent or in contact with the blade when the lever is in the other of the first, locked position or the second, unlocked position. 
     Referring now to  FIGS.  3 ,  5  and  7   , to enhance the locking action of the lever  40  against the bladeset bracket  22 , at least one wave washer or spring washer  72  is provided. The washer  72  slidably engages and circumscribes a periphery of the barrel  50 , preferably adjacent a larger diameter head  74  at the pivot end  48 . Also, the locking action of the cam lobe  54  is facilitated by the lobe having a sloped shape proximate to the barrel end  62 , and the main opening  38  in the bladeset bracket has a chamfered interior edge  78  ( FIGS.  5  and  7   ). 
     Referring now to  FIGS.  11 ,  12 A,  12 B,  12 C and  12 D , an alternate embodiment of the present apparatus  10  is generally designated  80 . Components shared with the apparatus  10  are designated with identical reference numbers. A main difference between the apparatus  80  and the previously-described apparatus  10  is that in the latter, the lever  40  is external to the stationary blade  18 , while in the former, the lever  40  is held inverted between the blade bracket  22  and the clipper housing  14 . An advantage to the apparatus  80  is that the lever  40  is retained to the bladeset bracket  22  in both the locked and unlocked position, by virtue of a gap  82  between the clipper housing  14  and the bladeset bracket. This gap  82  traps the lever  40  in position until the bladeset bracket  22  is removed from the hair clipper  12 . In the apparatus  10 , when the lever  40  is in the unlocked position, the lever is removable from the bladeset bracket  22  and potentially misplaced by the user. 
     Another feature of the apparatus  80  is that the locking formation  42  engages the stationary blade  18  and holds it against the bladeset bracket  22 . More specifically, the cam lobe  54  presses against the stationary blade  18 , whereas in the apparatus  10  the lobe presses against the bladeset bracket  22 . 
     Referring now to  FIGS.  13 - 15   , another alternate embodiment of the present apparatus  10  is generally designated  90 . Components shared with the apparatus  10  and  80  are designated with identical reference numbers. An important distinguishing feature of the apparatus  90  is that the actuator  40  takes the form of a relatively smaller profile, “paddle”-shaped handle  92 . A grip  94  of the handle  92  is dimensioned so as to not extend past a bottom edge  95  of the base  28  of the stationary blade  18  when in the locked position, shown in  FIGS.  13  and  14   . In other words the grip  94 , and more generally the handle  92 , are situated within the area bounded by the outer periphery of the stationary blade  18  so as to leave the bottom edge  95  unobstructed by the handle  92 . Such a configuration advantageously allows for the use of blade combs, blade guards, and other componentry that are designed to mate with an unobstructed edge such as bottom edge  95 . 
     Referring now to  FIGS.  14  and  15   , another feature of the apparatus  90  is that the barrel fastener  52  is preferably omitted and replaced with a rivet  96 . Still another feature of the apparatus  90  is that, in view of the relatively shorter grip  94 , the stop  69  has been removed. Instead, the locking formation  42  is equipped with at least one and preferably a pair of radially outwardly projecting locking stops  98  that frictionally, tightly engage an adjacent interior surface  100  of the main bracket opening  38 . The locking stops  98  are dimensioned so that once the grip  94  is in the locked position shown in  FIGS.  13  and  14   , a tight, wedged relationship is created between the stops and the surface  100  to maintain the locking formation  42  in position during clipper operation. While in the preferred embodiment, the locking stops  98  are generally triangular in shape, and are relatively diametrically opposed on the locking formation  42 , it will be appreciated that other orientations are suitable depending on the application. 
     Referring now to  FIG.  16   , still another alternate embodiment of the present apparatus  10  is generally designated  110 . Components shared with the embodiments  10 ,  80  and  90  are designated with identical reference numbers. The embodiment  110  is most closely related to the embodiment  90 . Instead of the “paddle”-shaped handle  92 , the actuator  40  is provided in the form of a further reduced profile, or “bat-wing” formation  112 . As was the case with the grip  92  described in the embodiment of  FIGS.  13 - 15   , the formation  112  is dimensioned to not extend past the periphery of the stationary blade base  28 . It is contemplated that the formation  112  will be dimensioned to facilitate user manipulation between the locked and unlocked positions described above, without the use of tools. Also, modification of the frictional force generated by the locking stops  98  is envisioned to facilitate user manipulation of the locking member without the use of tools. 
     While a particular embodiment of the present apparatus for releasably locking a stationary blade to a hair clipper has been described herein, it will be appreciated by those skilled in the art that changes and modifications may be made thereto without departing from the invention in its broader aspects and as set forth in the following claims.