Abstract:
A hair dryer is provided having a handle that may both be pivoted toward the dryer housing, and rotated with respect to the dryer housing so that the dryer may easily be operated in either a handle-held or nozzle-held mode. The hair dryer includes a dual axis joint assembly connecting the handle to the dryer housing that allows the handle to be rotated around its longitudinal axis before or during the time it is pivoted toward the dryer housing so that the control switch remains exposed and operable by a user when the handle is pivotally folded against the dryer body in preparation for nozzle-held operation. The dual axis joint assembly may include an eccentric mechanism that converts pivoting movement of the handle toward and away from said housing into rotational movement of said handle so that the handle turns 90° when pivotally folded against the dryer housing. Additionally, the electrical cord connection for supplying power to the blower assembly within the dryer housing is mounted on the blower assembly portion of the housing opposite the nozzle instead of on the handle so that the electrical cord does not interfere with the nozzle held operation of the dryer.

Description:
FIELD 
       [0001]    This invention generally relates to hair dryers, and is specifically concerned with a hair dryer having a handle that is both pivotable toward the dryer housing and rotatable with respect to the dryer housing. 
       BACKGROUND 
       [0002]    Portable hair dryers are well known in the prior art. Many such hair dryers are pistol-shaped, comprising a dryer housing containing a blower assembly and having a nozzle at one end, and a handle that extends orthogonally from the underside of the dryer housing. Often, several control switches are mounted on the front face of the handle for controlling blower assembly actuation and the flow rate and the amount of heating applied to the air stream. In use, the user typically grips the handle, actuates and adjusts the blower assembly with the control switches, and scans the nozzle over his or her hair. 
         [0003]    Despite the provision of a handle, some users prefer to hold such pistol-shaped dryers by their nozzle during operation. For example, if the user is unable to see the dryer because it is behind their head, or hair is blocking their view, they may be better able to feel where the dryer is pointing when holding the dryer by the nozzle. Also, a person drying someone else&#39;s hair, such as a hair stylist, may find a nozzle-holding grip to be more comfortable when standing over a seated person, or when using the dryer for long periods of time. Such a nozzle-holding grip also allows the stylist to achieve a maximum range of dryer movement while maintaining a same standing position relative to the seated person whose hair is being dried. 
       SUMMARY 
       [0004]    While it is possible to operate many pistol-shaped portable hair dryers from a nozzle held position, the applicants have observed a number of problems associated with such operation. For example, since the actuation and control switches are typically mounted on the handle, it is not possible to adjust these control switches from the same fingers gripping the nozzle. To solve this problem, some prior art dryers are provided with a second set of control switches mounted on the dryer housing that can be operated by the same fingers gripping the nozzle. But, while the provision of a second set of control switches on the nozzle of the dryer offers a solution to this problem, it also increases the expense and complexity of the hair dryer. 
         [0005]    Additionally, the handle that extends at an approximately 90° angle from the dryer housing interferes with the maneuverability of the dryer when the dryer is used in a nozzle-held mode. While pistol-shaped hair dryers are known that have handles which can be pivotally folded toward the dryer housing, the purpose of such folding handles has been to reduce the size of the hair dryer so that it may be more easily packed and traveled with. Consequently, no concern is given to the operability of the actuation switches that are mounted over the front face of the handle, which are sandwiched into an inaccessible position between the dryer housing and the back portion of the handle when the handle is pivoted into a folded position. Additionally, the electrical cord that powers the blower assembly typically extends out of the bottom of the handle. Consequently, when the handle is pivotally folded into a position parallel with the dryer housing, Such a design causes the electrical cord to project toward the front of the dryer when the handle is pivotally folded into a position parallel with the dryer housing, where it can interfere with both the maneuverability and balance of the dryer. 
         [0006]    Clearly, there is a need for a pistol-shaped hair dryer that is capable of being operated in a nozzle-held position without the aforementioned drawbacks. To this end, the hair dryer of the invention comprises a housing containing a blower assembly and including a nozzle having an open end that directs air blown by the blower assembly along an axis, and an electrical cord connection mounted on the blower assembly portion of the housing that supplies power to the blower assembly; an elongated handle having a control switch that controls the blower assembly, the control switch facing a same direction as the nozzle end of the housing and being operable in pistol-grip fashion when the handle is in a position substantially orthogonal to the housing axis, and a dual axis joint assembly connecting the handle to the housing that allows the handle to be rotated around its longitudinal axis, and pivoted from said orthogonal position to a position substantially parallel to said housing axis such that the control switch is exposed and operable by a user when the handle is pivoted into said position substantially parallel to said housing axis. 
         [0007]    The dual axis joint assembly allows the handle to be rotated at least 90° such that the control switch faces away from the housing when the handle is pivoted from said orthogonal position to said position substantially parallel to said housing axis. In one embodiment of the inventive hair dryer, the dual axis joint assembly includes an eccentric mechanism that converts pivoting movement of the handle toward and away from said housing into rotational movement of said handle such that the control switch turns away from the housing into a finger-accessible position when the handle is pivoted into said position substantially parallel to said housing axis. In a second embodiment, the dual axis joint assembly allows the handle to be freely rotated between 90° and 180° prior to pivoting the handle toward the dryer housing. Such a freely rotatable handle allows the user to redirect the air stream generated by the blower assembly while gripping the handle in its normal position without turning his or her wrist at an uncomfortable angle. This is a particularly useful feature for a hairdresser standing over a seated customer during a hairdressing procedure, in that it allows the hairdresser to constantly redirect a flow of drying air to the hair of the seated customer at a large number of directions without the need for either continuously walking from one side of the customer to the other or frequently rotating the swivel chair that the customer typically sits in. 
         [0008]    In both embodiments, the dual axis joint assembly may include a lock movable into a locking and an unlocking position that prevents the handle from rotating and pivoting relative to the housing when in said locking position, as well as a hand strap connected to the exterior of the housing that receives the fingers of a user to facilitate the grip of a user around the housing. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]      FIG. 1  is a perspective view of a first embodiment of the inventive hair dryer with the handle oriented orthogonally with respect to the dryer housing; 
           [0010]      FIG. 2  is a side view of the hair dryer illustrated in  FIG. 1 ; 
           [0011]      FIG. 3  is a front view of the hair dryer illustrated in  FIG. 1 ; 
           [0012]      FIG. 4  is a partial exploded view of the hair dryer of  FIG. 1  illustrating in particular the dual axis joint assembly that connects the handle to the blower assembly portion of the housing; 
           [0013]      FIG. 5  is a cross-sectional side view of the of the hair dryer taken along the line  5 - 5  of  FIG. 3  illustrating in particular the blower assembly and the electrical cord connection mounted on the blower assembly portion of the housing; 
           [0014]      FIG. 6  is a side view of the hair dryer of  FIG. 1 , illustrating how the control switches on the handle remain accessible when the handle is pivotally folded toward the housing in preparation for a nozzle-held mode of operation; 
           [0015]      FIG. 7  is a perspective view of a second embodiment of the inventive hair dryer with the handle oriented orthogonally with respect to the dryer housing; 
           [0016]      FIG. 8  is a side view of the hair dryer illustrated in  FIG. 7 ; 
           [0017]      FIG. 9  is an exploded view of the hair dryer of  FIG. 7  illustrating in particular the dual axis joint assembly that connects the handle to the blower assembly portion of the housing; 
           [0018]      FIG. 10  is a side cross-sectional view of the of the hair dryer of  FIG. 7  illustrating in particular the blower assembly and the electrical cord connection mounted on the blower assembly portion of the housing; 
           [0019]      FIGS. 11A and 11B  are side views of the hair dryer illustrated in  FIG. 7  with the handle rotated 90° and 180°, respectively, and 
           [0020]      FIG. 12  is a side view of the hair dryer with the handle rotated 180° and pivotally folded toward the housing illustrating how the control switches on the handle remain accessible in preparation for a nozzle-held mode of operation. 
       
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
       [0021]    With reference now to  FIGS. 1-3  and  FIG. 5 , wherein like numerals designate like components throughout all of the several Figures, the hair dryer  1  of the invention includes a housing  3  having a blower portion  5  for housing a blower assembly  6 , and an elongated nozzle  7  that houses heating elements  8 . The blower portion  5  includes an air intake  9  at its back portion, an electrical cord connection  10  at its bottom portion (as shown in  FIG. 2 ), and a cam slot  11  in its front portion which forms part of a dual axis joint assembly described hereinafter. The nozzle  7  includes an open end  13  that directs blown air in a direction substantially parallel to the axis “A”, and a hand strap  15  mounted on its top portion as shown. Hand strap  15  is mounted on the nozzle by way of strap swivels  17   a,    17   b.  Strap length is adjustable via length adjusters  19   a,    19   b.  The hand strap  15  facilitates the of the hair dryer in the nozzle-gripped mode of operation by both securing the dryer to the hand of the operator and aligning the fingers of the operator over the switches of the handle when the handle is pivotally folded toward the housing  3 . The handle  23  of the hair dryer  1  is elongated as shown, and includes a front face  25  and a back face  26 . Control switches  27  are provided on the front face  25  so that the hair dryer  1  may be operated in “pistol grip” fashion by the fingers of an operator when the dryer is uses in a nozzle-gripped mode. Preferably, the handle  23  is slightly curved along its longitudinal axis as best seen in  FIG. 2  to facilitate the grip by an operator. 
         [0022]    With reference now to  FIG. 4 , the handle  23  is formed from handle halves  29   a  and  29   b.  A switch box  31  containing the control switches  27  is captured between the handle halves  29   a  and  29   b,  which are in turn secured together via mounting screws  33 . The handle  23  is connected to the housing  3  by a dual axis joint assembly  35  having a pivoting joint  37  that allows the handle to be pivotally folded toward the housing  3 , and a rotary joint  38  that allows the handle  23  to be rotated around its longitudinal axis relative to the housing  3 . Unless otherwise stated, all components of the housing  3  and of the joint assembly  35  are preferably formed from a moldable plastic material such as polyurethane. Each of these components of the dual axis joint assembly  35  will now be described in detail. 
         [0023]    The pivoting joint  37  of the joint assembly  35  includes a housing hub  39 , a handle fitting  41 , and an arcuate arm  43  that integrally connects the hub  39  to the fitting  41 . The fitting  41  is attached to the handle  23  in a manner that will be described in more detail hereinafter. The housing hub  39  includes a partial annular groove  45  that snap-fits into an annular rim  47  provided in a side wall of the blower assembly portion  5  of the housing  3  in order to rotatably mount the housing hub  39  in the housing  3 . A pair of lubricated bushings  49  and a wave compression spring  51  are sandwiched between the housing hub  39  and the annular rim  47  in order to provide a smooth pivoting action between the housing hub  39  and the rim  47  so that the handle  23  attached to the fitting  41  of pivoting joint  37  may be smoothly pivoted toward and away from the housing  3 . To this end, the bushings are preferably formed from nylon impregnated with a solid lubricant such as molybdenum disulfide, and the wave spring  51  is formed from carbon steel and has a compression rating of between about 20 and 40 pounds. 
         [0024]    With reference to both  FIGS. 4 and 5 , the rotary joint  38  of the joint assembly  37  includes an eccentric mechanism in the form of an eccentric shaft assembly  53 . Eccentric shaft assembly  53  includes a main shaft  57  integrally connected at one end to a disc-shaped head  59 . An off-center shaft  61  is connected to the outer surface  63  of the head  59 . Off-center shaft  61  is received within the cam slot  11  in the blower assembly portion  5  of the housing  3  when components illustrated in  FIG. 4  are assembled. The interior  64  of the main shaft  57  is hollow and the head  59  includes a slot  65  in order to accommodate wires  66  from the switchbox  31  which control electrical current to the motor of the blower assembly  6  and the electric heating elements. The end of the main shaft  57  opposite the head  59  includes a recessed portion  67  that is keyed into a complementary-shaped protrusion (not shown) within the handle half  29   a  is attached to handle half  29   b  so that the handle  23  and the main shaft  57  are affixed to one another and rotate together during operation. The rotary joint  38  further includes a bushing  71  that is received within the interior of the handle fitting  41 . Bushing  71  includes a cylindrical interior  72  that rotatably receives the main shaft  57  of the eccentric shaft assembly  53 . Bushing  71  also includes a flange  73  that is keyed into a complementarily-shaped slot (not shown) in the fitting  41  so that the bushing  71  cannot rotate relative the fitting  41 . 
         [0025]    Finally, the dual axis joint assembly  35  includes a brake mechanism  74  for selectively increasing the frictional engagement between the outer surface  63  of the head  59  of the eccentric shaft assembly  53  and an engagement surface  75  on the blower assembly portion  5  of the housing  3 . Brake mechanism  74  is formed from the combination of a threaded sleeve  76  that forms an integral part of the handle fitting  41 , and a compression collar  80 . The compression collar  80  has a threaded interior  81  engageable with the threads of the sleeve  76 , and a thumb wing  82  extending from one side to facilitate rotation of the collar  80  by the operator. The brake mechanism  74  also includes a ring-shaped collar limiter  84  that limits the rotation of the collar  80  to an arc of about 112°. The collar limiter  84  includes a protrusion  86  on its inner diameter that keys this component to a slot  88  in the threaded sleeve  76  of the handle fitting  41  so that this component remains stationary relative to the compression collar  80 . The collar limiter  84  further includes stop surfaces  90   a,    90   b  which engage opposite surfaces of a flange (not shown) located at the lower portion of the inner diameter of the compression collar. The pitch of the threads on the threaded sleeve  76  and collar interior  81  is chosen such that the rotation of the compression collar  80  around an arc of 112° pushes the outer surface  63  of the head  59  of the eccentric shaft assembly  53  against the engagement surface  75  of the housing  3  with enough force to frictionally “lock” the handle  23  in any desired angle between the orthogonal position illustrated in  FIG. 2  and the completely folded position illustrated in  FIG. 6 . 
         [0026]    The operation of the first embodiment  1  of the inventive hair dryer will now be explained with reference to  FIGS. 2 ,  3 ,  5  and  6 .  FIG. 2  illustrates the hair dryer  1  in a handle-held mode of operation, wherein the longitudinal axis of the handle  23  is “locked” into an orthogonal orientation with respect to the housing  3  via the brake mechanism  74 . When the hair dryer  1  is to be used in a nozzle-held mode, the compression collar  80  of the brake mechanism is rotated via thumb wing  82  to retract the outer surface  63  of the head  59  of the eccentric shaft assembly  53  from the engagement surface  75 . This action substantially reduces the frictional force between the surfaces  63  and  75 , thereby allowing the head surface  63  to slide over the engagement surface  75  of the housing  3 . The handle  23  is then pivoted 90° toward the housing  3 , via the pivoting joint  37  of the dual axis joint assembly  35 . At the same time, the rotary joint  38  rotates the handle  23  90° around the main shaft  57  of the shaft assembly as a result of the slidable engagement between the off-center shaft  61  of the eccentric shaft assembly  53  and the curve of the cam slot  11  best seen in  FIG. 3 . Accordingly, when the handle  23  is pivoted 90° into a position substantially parallel to the longitudinal axis A of the nozzle  7 , the handle  23  is simultaneously rotated 90° such that the front face  25  of the handle  23  is turned to the left as illustrated in  FIG. 6 , advantageously exposing the switches  27  located on the front face  25  of the handle and rendering them easy to use. The placement of the electrical cord connection  10  at the lower back of the blower assembly portion  5  of the housing  3  advantageously positions the electrical cord out of the way of the operator during such a nozzle-held mode of operation. 
         [0027]      FIGS. 7 ,  8  and  10  illustrate a second embodiment  100  of the hair dryer of the invention. Like the previously-described first embodiment  1 , the second embodiment of the invention includes a housing  3  having a blower portion  5  for housing a blower assembly  6 , and an elongated nozzle  7  that houses heating elements  8 . The blower portion  5  includes an air intake  9  at its back portion, and an electrical cord connection  10  at its bottom portion. The nozzle  7  includes an open end  13  that directs blown air in a direction substantially parallel to the axis “A”, and a hand strap  15  mounted on its side portion as shown and having all the adjustment features previously described with respect to the first embodiment  1 . The hand strap  15  facilitates the of the hair dryer  100  in the nozzle-gripped mode of operation by both securing the dryer  100  to the hand of the operator and aligning the fingers of the operator over the switches  27  of the handle  23  when the handle  23  is pivotally folded toward the housing  3 . Like the first embodiment  1 , the handle  23  of the second embodiment is slightly curved along its longitudinal axis as best seen in  FIG. 8  to facilitate the grip by an operator. However, unlike the first embodiment  1 , the housing  3  of the second embodiment  100  includes a recess  102  for receiving the back face  26  of the handle  23  when the handle is rotated 180° from the position shown in  FIG. 8  and pivoted toward the housing  3  of the hair dryer  100 . 
         [0028]    With reference now to  FIGS. 9 and 10 , the handle  23  is formed from handle halves  29   a  and  29   b  in the same manner as the first embodiment  1 . A switch box  31  containing the control switches  27  is captured between the handle halves  29   a  and  29   b,  which are in turn secured together via mounting screws  33 . The handle  23  is connected to the housing  3  by a dual axis joint assembly  105 . 
         [0029]    However, unlike the joint assembly  35  of the first embodiment, the joint assembly  105  of the second embodiment allows the handle to be rotated 180° with respect to the housing instead of only 90°. Moreover, the rotary movement of the handle  23  is independent of the pivoting movement of the handle. To these ends, the dual axis joint assembly of the second embodiment includes a dual axis shaft  107  best seen in  FIG. 9 . Dual axis shaft  107  includes opposing, partial pivot shafts  109   a,    109   b  which implement the pivoting action of the joint assembly  105 . These partial pivot shafts  109   a,    109   b  are captured within a pivot socket  112  extending from the blower assembly portion  5  of the housing  3 . Pivot socket  112  is formed from a pair of socket halves  114   a,    114   b  as shown. While not specifically shown in the drawings, the housing  3  is formed from two halves which are fastened together by screws or the like, and the two socket halves  114   a,    114   b  are present on opposite halves of the housing  3 . The partial pivot shafts  109   a,    109   b  are captured between the two socket halves  114   a,    114   b  when the housing halves of the hair dryer  100  are fastened together so that the outer, arcuate surfaces  110  of the partial pivot shafts  109   a,    109   b  frictionally engage complementary-shaped arcuate inner surfaces of the two socket halves  114   a,    114   b  to provide a smooth pivoting action. The dual axis shaft  107  further includes a rotary shaft  166  which is rotatably mounted in the handle  23  and which implements the rotary action of the joint assembly  105 . The dual axis shaft  107  further includes a midsection  117  that integrally connects the partial pivot shafts  109   a,    109   b  to the rotary shaft  166 . The midsection  117  has a non-round outer surface for “keying in” other components of the joint  105  to prevent them from rotating, as described hereinafter. The dual axis shaft  107  includes a hollow interior  118  for accommodating electrical wires  66  from the switchbox  31 , as is best seen in  FIG. 10 . Finally, midsection  117  of the dual axis shaft  107  includes an offset  119  which cooperates with a protrusion (not shown) within the handle  23  to limit the angle of rotation of the handle relative to the housing  3  to 180°. 
         [0030]    With reference again to  FIGS. 9 and 10 , the dual axis joint  105  further includes a brake mechanism  120  for simultaneously locking the handle  23  into a desired pivotal and rotational position with respect to the housing  3 . To this end, the brake mechanism  120  includes a compression washer  121  having an opening  122  that slidably receives the midsection  117  of the dual axis shaft  107 . The non-circular shape of the exterior of the midsection  117  prevents the compression washer  121  from rotating relative to the dual axis shaft  107 . Preferably, compression washer  121  is made from nylon impregnated with a solid lubricant such as molybdenum disulfide. Disposed beneath the compression washer  121  is a compression collar  125  having a thumb wing  126  extending from its exterior. The annular interior of the collar  125  includes three flanges  127  (of which only one is visible) which slidably ride on arcuate ramps  129  which form part of a ramp ring  131 . As a result of the sliding engagement between the flanges  127  and ramps  129 , rotating the collar  125  counterclockwise moves the collar  125  away from the ramp ring  131  into a handle locking position, while rotating the collar  125  clockwise moves the collar  125  toward the ramp ring  131  into a handle loosening position. Located below the ramp ring  131  is a compressible spring ring  133  formed from an elastomeric material. Spring ring  133  is supported by washer  135 , which, like compression washer  121 , includes an opening  137  that slidably receives the midsection  117  of the dual axis shaft  107  such that the washer can move axially with respect to the midsection  117 , but not rotatably. A compression collet  140  is located beneath the washer  135 . Collet  140  has a cylindrical interior which rotatably receives the rotary shaft  116  of the dual axis shaft  107 , and a frusto-conically-shaped exterior which is received within a frustro-conical recess  145  defined within the handle halves  29   a  and  29   b.  Finally, the brake mechanism  120  includes an end cap  146  which is glued or otherwise secured to the distal end of the rotary shaft  116  of the dual axis shaft  107 . End cap  146  includes a circular opening  148  for receiving wires  66 . 
         [0031]    The operation of the second embodiment  100  of the inventive hair dryer will now be explained with reference to  FIGS. 9 ,  10 ,  11 A,  11 B and  12 .  FIG. 10  illustrates the hair dryer  1  in a handle-held mode of operation, wherein the longitudinal axis of the handle  23  is “locked” into an orthogonal orientation with respect to the housing  3  via the brake mechanism  120 . In such a “locked” orientation, the compression collar  125  has been rotated to its maximum extent counterclockwise such that the collar  125  has been moved apart from the ramp ring  131  a maximum extent. Such axial movement of the compression collar  125  has the effect of pulling the arcuate surfaces  110  of the partial pivot shafts  109   a,    109   b  into a locking frictional engagement with the inner surfaces of the socket halves  114   a,    114   b.  Such axial movement also has the effect of compressing the spring ring  133 , and pulling the end cap  146  at the end of the shaft  116  upwardly. The upward movement of end cap  146  forcefully wedges the conical exterior of the collet  140  against the conical walls of the recess  145 , thereby radially compressing the cylindrical interior  142  of the collet into frictional locking engagement against the shaft  116 . When the hair dryer  100  is to be used in a nozzle-held mode, the compression collar  125  of the brake mechanism  120  is rotated clockwise via thumb wing  126  to retract the compression collar  125  back toward the ramp ring  131  and release the locking friction applied by the brake mechanism  120  to the dual axis shaft  107 . The handle  23  is then rotated 180° as illustrated in  FIGS. 11A and 11B  until the front face  25  of the handle  23  faces backwards. The handle  23  is then pivoted 90° toward the housing  3  until the back face  26  of the handle is received in the recess  102  in the housing  3  as shown in  FIG. 12 , such that the switches  27  located on the front face  25  of the handle  23  are exposed and easy to use by the operator. The operator then rotates the compression ring 120° counterclockwise to re-establish the frictional lock that the brake mechanism  120  applies to both the partial pivot shafts  109   a,    109   b  and the rotary shaft  116  of the dual axis shaft  107 . As in the first embodiment  1 , the placement of the electrical cord connection  10  at the lower back of the housing  3  of the second embodiment advantageously positions the electrical cord out of the way of the operator during such a nozzle-held mode of operation. 
         [0032]    While the invention has been described in detail with particular reference to certain preferred embodiments thereof, it will be understood that variations and modifications can be effected within the spirit and scope of the invention, which is limited only by the appended claims and equivalents thereof.