Patent Document

FIELD OF THE INVENTION  
       [0001]     The invention relates generally to hair clippers and to arrangements for selectively releasing blade assemblies of such hair clippers.  
       BACKGROUND OF THE INVENTION  
       [0002]     A blade assembly of a hair clipper typically includes a blade set having a fixed blade in face-to-face relation with a movable blade. An electric motor is drivingly connected to the movable blade to effect reciprocation thereof in response to actuation of the motor. A number of suitable motors and driving arrangements are known.  
         [0003]     Hair clipper performance can generally be improved by cleaning cut hairs from around the blade set and the driving arrangement and by lubricating the blade set and the driving arrangement. To allow for this, the blade assembly is often configured to be movable from an operating position to an open position such that the blade set and the driving arrangement are exposed. Such movement also allows for the performance of other maintenance on the blade set and the driving arrangement.  
         [0004]     In the past, blade assemblies had to be released and moved away from the housing through a direct manual force on the blade assembly, or by directly disengaging a hook from a corresponding recess in the lower front end of the housing.  
       SUMMARY OF THE INVENTION  
       [0005]     A first embodiment of the present invention is directed to a hair clipper including a housing, and a blade assembly coupled to the housing. The blade assembly is movable between an operating position and an open position. The hair clipper also comprises a motor supported by the housing and drivingly connected to the blade assembly when the blade assembly is in the operating position, and a release assembly including a release mechanism, the release assembly switchable between a hold state and a release state, wherein in the hold state the release assembly holds the blade assembly in the operating position, and in the release state, upon application of a force exerted by an operator on the release mechanism, the release assembly releases the blade assembly to permit the blade assembly to move to the open position in the absence of an additional force from the operator.  
         [0006]     Another embodiment of the present invention is directed to a hair clipper including a housing having a cutting end. The hair clipper also comprises a blade assembly coupled to the housing at the cutting end, the blade assembly movable between an operating position and an open position. An attachment assembly is at least partially disposed in the housing for coupling the blade assembly to the housing and biasing the blade assembly to the open position. A motor is supported by the housing and is drivingly connected to the blade assembly when the blade assembly is in the operating position. The hair clipper also comprises a release assembly having a release mechanism, the release assembly switchable between a hold state and a release state, wherein in the hold state the release assembly holds the blade assembly in the operating position, and in the release state, upon application of a force on the release mechanism, the release assembly releases the blade assembly such that the blade assembly moves to the open position.  
         [0007]     The present invention is also directed to a method of removing a blade assembly from engagement with a housing of a hair clipper. The method comprises providing the hair clipper with an attachment assembly supporting the blade assembly for movement relative to the housing between an operating position and an open position and biasing the blade assembly to the open position. A release assembly has a release mechanism, the release assembly being switchable from a hold state to a release state wherein in the hold state the release assembly holds the blade assembly in the operating position and wherein in the release state the release assembly releases the blade assembly to permit the attachment assembly to bias the blade assembly to the open position. A force is applied to the release mechanism while the blade assembly is in the operating position to switch the release assembly from the hold state to the release state, whereby the release permits the attachment assembly to move the blade assembly to the open position. The method also comprises removing the blade assembly from the housing while the blade assembly is in the open position.  
         [0008]     The invention also provides a hair clipper comprising a housing, a blade assembly including a frame and first and second blades supported by the frame, with at least one of the blades being movable relative to the other, the housing having thereon one of a projection and a recess, and the frame including the other of the projection and the recess, the projection being insertable in the recess, the one of the projection and the recess being mounted on the housing for movement such that, when the projection is inserted in the recess, the blade assembly is movable between an operating position and an open position, and the one of the projection and the recess being biased such that a biasing force biases the blade assembly toward the open position, a motor supported by the housing and drivingly connected to the blade assembly when the blade assembly is in the operating position, and a release mechanism supported by the housing for movement between hold and release positions, the release mechanism being biased to the hold position, and being movable by an operator to the release position, the release mechanism holding the blade assembly in the operating position when the release mechanism is in the hold position, and the release mechanism allowing the blade assembly to move to the open position under the influence of the biasing force when the release mechanism is in the release position, the blade assembly being removable from the housing by removing the projection from the recess when the blade assembly is in the open position.  
         [0009]     Further objects of the present invention, together with the organization and manner of operation thereof, will become apparent from the following detailed description of the invention when taken in conjunction with the accompanying drawings wherein like elements have like numerals throughout the drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]      FIG. 1  is a perspective view of a hair clipper embodying various features of the invention, including a blade assembly in contact with a housing.  
         [0011]      FIG. 2  is another perspective view of a portion of the hair clipper shown in  FIG. 1 , including the blade assembly pivoted away from the housing.  
         [0012]      FIG. 3  is another perspective view of a portion of the hair clipper shown in  FIG. 1  with the blade assembly removed from the housing.  
         [0013]      FIG. 4  is an exploded view of the hair clipper shown in  FIG. 1 .  
         [0014]      FIG. 5  is a cross-sectional view of the hair clipper taken along line  5 - 5  of  FIG. 1 .  
         [0015]      FIG. 6  is another cross-sectional view of the hair clipper taken along line  6 - 6  of  FIG. 2 .  
     
    
       [0016]     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. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless specified or limited otherwise, the terms “mounted,” “connected,” “supported,” and “coupled” and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings. Further, “connected” and “coupled” are not restricted to physical or mechanical connections or couplings.  
       DETAILED DESCRIPTION  
       [0017]     A hair trimmer or clipper  10  according to the present invention is illustrated in  FIGS. 1-6 . The clipper  10  includes a housing  12  comprising an upper housing  22  and a lower housing  26 . The housing  12  is preferably made of injection-molded plastic, but can be made of any suitable material as in known in the art. The housing includes a cutting end  46  (shown in  FIGS. 2-6 ) and an opening  70  (shown in  FIG. 4 ). As illustrated in  FIG. 4 , the lower housing  26  includes two seats  144  and two seats  154 . The upper housing  22  and the lower housing  26  enclose an electric motor  30 . An eccentric  38  is mounted on the output shaft of the motor  30 . A cord  34  provides electricity to the electric motor  30  via a switch  44  mounted in the lower housing  26 . An on/off switch actuator  36  is positioned for sliding movement along the side of the housing  12 . The switch  36  actuator is coupled to the switch  44  for activating and deactivating the motor  30  to turn the clipper  10  on and off, respectively. Many alternative devices and mechanisms can be used to turn the clipper  10  on and off, as well known in the art, and can be used as a substitute to the mechanism illustrated in  FIGS. 1-6 .  
         [0018]     As shown in  FIGS. 4-6 , a support bracket  42  is coupled to the lower housing  26  with fasteners (not shown). The support bracket  42  supports the motor  30  and is fastened to the motor  30  by screws  68 . Any conventional fastener can be employed to secure the support member  42  to the motor  30  as just described, such as nails, rivets, pins, posts, clips, clamps, inter-engaging elements, and any combination of such fasteners. The support bracket  42  includes two extension portions  50 , each having a recess  52 . The purpose of the recesses  52  is explained below. In the illustrated embodiment, the recesses  52  are generally cylindrical. An aperture  48  is located between the extension portions for receiving a portion of the motor  30 . The support bracket  42  shown in the illustrated embodiment is molded from plastic. In other embodiments, the support bracket  42  can be formed of a different material or combination of materials.  
         [0019]     As illustrated in  FIG. 4 , a blade assembly  14  is located proximate the cutting end  46  of the upper housing  22 . The blade assembly  14  includes a blade frame  40  to support the components of the blade assembly  14 . The blade frame  40  includes a ridge  94  having a cam surface  146  (shown in  FIG. 6 ), the reasons for which are explained below.  
         [0020]     The blade assembly  14  also includes a blade set  106  having an inner blade  110  and an outer blade  114 . The inner blade  110  is moves relative to the outer blade  114 , which is fixed. The outer blade  114  is coupled to the blade frame  40  by screws  116  ( FIG. 2 ), although any suitable fastener can be employed to secure the outer blade  114  to the blade frame  40 . The inner blade  110  is coupled to a blade box  102  by screws (not shown) and is biased toward the outer blade  114  by a biasing spring  98 . The spring  98  is fixed to the outer blade  114  by screws  117  ( FIG. 6 ). A portion  104  of the blade box  102  receives the eccentric  38 , and the inner blade  110  and the blade box  102  are supported such that the inner blade  110  moves back and forth across the outer blade  114  in response to movement of the eccentric  38 , as is known in the art. The blade frame  40  also includes a tongue receiving member  130  (shown in  FIGS. 5-6 ).  
         [0021]     As illustrated in  FIG. 4 , an attachment assembly  20  includes a tongue  126  for insertion into the tongue receiving member  130  of the blade frame  40 . The tongue  126  has thereon a sleeve  140  to help create a more snug fit between the tongue  126  and the tongue receiving member  130 , and to couple torsion springs  138  to the tongue  126  (discussed below). As shown in  FIGS. 3-4 , the tongue  126  is generally a flat, rigid piece of plastic or metal fixed to a shaft  118 . In this embodiment, the tongue  126  is molded to the shaft  118 . In other embodiments, the tongue  126  may be fastened or otherwise linked to the shaft  118  for movement with or about the shaft  118 . The shaft  118  is supported on either end by reservoir cups  122 . The reservoir cups  122  are seated in the seats  144  of the lower housing  26  and are trapped or held in the seats by downwardly extending portions of the bracket  42 , as best shown in  FIG. 3 . Preferably, the reservoir cups  122  are filled with lubricant (not shown), such as oil, binders with graphite or Teflon, ethers, silicones, or any such lubricant that dampens the rotation of the shaft  118 .  
         [0022]     Along the shaft  118 , the tongue  126  is surrounded on either side by two torsion springs  138 . A first end  152  of each spring  138  fits within a respective seat  154  of the lower housing  26 . The ends  152  of the springs  138  are trapped or held in the seats  154  by downwardly extending portions of the bracket  42 , as shown in  FIGS. 5 and 6 . The other ends  156  of the springs  138  extend into the sleeve  140 , so that the sleeve  140  is biased to pivot in the counterclockwise direction as viewed in  FIGS. 5 and 6 . When the sleeve  140  is inserted in the tongue receiving member  130  of the blade frame  40 , the entire blade assembly is biased in the counterclockwise direction as viewed in  FIGS. 5 and 6 . The attachment assembly  20  supports the blade assembly  14  for pivotal movement relative to the housing  12  between an operating position ( FIG. 5 ) and an open position ( FIG. 6 ). The springs  138  bias the blade assembly toward the open position.  
         [0023]     The clipper  10  also includes a release assembly  16 . The release assembly  16  includes a release mechanism  66 . In the embodiment illustrated in  FIGS. 1-6 , the release mechanism  66  can include a button, a switch, a detent, or any similar device used to allow the state of a device to change. The release mechanism is preferably made of injection molded plastic and includes a button that extends through aperture  70  of the upper housing  22 . The release mechanism  66  also includes two hooks  74  each including a top edge  142  and cam surfaces  150 . The purpose of the hooks  74  is explained below.  
         [0024]     The release mechanism also includes two downwardly extending projections or shafts  64 , each of which is vertically aligned with and extends into a respective recess  52  in the bracket  42 . Surrounding each 64 and extending into the associated recess  52  is a respective spring  58 . The upper end of each spring  58  contacts the underside of the release mechanism  66 , such that the springs  58  bias the release mechanism  66  upward. Upward movement of the release mechanism is limited by engagement of a shoulder on the release mechanism with the underside of the upper housing  26 . This is the upper position of the release mechanism.  
         [0025]     The release assembly  16  generally has two states, a hold state (shown in  FIG. 5 ) and a release state (shown in  FIG. 6 ). The hold state occurs in the absence of a downward force on the button  66 . As illustrated in  FIG. 5 , in the hold state of the release assembly  16 , the release mechanism is in its upper position, and the hooks  74  are engaged with the ridge  94  of the blade frame  40  to hold the blade assembly  14  in its operating position. The ridge  94  is held within the hooks  74  until force is applied to the release mechanism  66  to move the release mechanism downward, so that the release assembly is in its release state. By pushing the button  66  downward and thereby moving the hooks  74  downward, the hooks  74  are disengaged with the ridge  94  to allow the blade assembly to pivot to its open position. When the force on the button is removed, the springs  58  bias the release mechanism  66  back to the hold state. In other embodiments, a force applied to the release mechanism  66  can be in any direction to cause the release mechanism  66  and hooks  74  to move from the hold state to the release state. Alternatively, the release mechanism  66  can be pivoted, moved in a horizontal direction, moved in a vertical direction, or the like to move from the hold state to the release state.  
         [0026]     As illustrated in  FIGS. 5 and 6 , in moving toward the open position, the blade assembly  14  pivots about the shaft  1118 . The lubricant in the reservoir cups  122  dampens the pivoting motion of the blade assembly  14 . When the shaft  1118  has rotated a specific amount, the blade assembly  14  will cease rotation when the springs  138  are in a free state (i.e., no force is applied to the blade assembly  14  by the springs  138 ).  
         [0027]     During trimming operation of the clipper  10 , the user operates the clipper  10  with the blade assembly  14  in the operating position. For cleaning and replacement purposes, the blade assembly  14  is removable from the housing  12  of the clipper  10 , as illustrated in  FIG. 3 . To remove the blade assembly  14  from the housing  12 , downward force F is first applied to the release mechanism  66 . The force F on the release mechanism  66  causes the release mechanism  66  and the hooks  74  to move downward against the force of the springs  58 . When the release mechanism  66  is lowered vertically to a point where the top edge  142  of each hook  74  is no longer in contact with the ridge  94  of the blade assembly  14 , the blade assembly  14  then begins pivoting toward the open position.  
         [0028]     In the open position, the blade assembly  14  is capable of being removed from the housing  12 . By pulling the blade assembly  14  away from the attachment assembly  20 , the tongue receiving member  130  of the blade assembly  14  is detached from the tongue  126  of the attachment assembly  20  and thereby from the housing  12 . The blade set  106  of the blade assembly  14  may then be cleaned, repaired, or replaced.  
         [0029]     The blade assembly  14  can be re-coupled to the attachment assembly  20  by inserting the tongue  126  and sleeve  140  into the tongue receiving portion  130  of the blade assembly  14 . The user can then pivot the blade assembly  14  clockwise as seen in  FIG. 6 , against the force of the springs  138 , toward the closed or operating position. As the blade assembly approaches the operating position, the cam surface  146  of the ridge  94  engages the cam surfaces  150  of the hooks  74  and thereby causes the hooks  74  to pull the release mechanism  66  downward, against the force of the springs  58 , to allow the blade assembly to move fully to the operating position. After the ridge  94  clears the hooks  74 , the springs  58  push the release mechanism upward to its upper position, in which the hooks  74  engage the ridge  94  and thereby secure the blade assembly  14  in the operating position. The release assembly  16  has then returned to the hold state.  
         [0030]     The embodiments described above and illustrated in the figures are presented by way of example only and are not intended as a limitation upon the concepts and principles of the present invention. As such, it will be appreciated by one having ordinary skill in the art that various changes in the elements and their configurations and arrangement are possible without departing from the spirit and scope of the present invention as set forth in the appended claims.

Technology Category: 7