Patent Publication Number: US-10334352-B2

Title: Headphone pivot joint

Description:
BACKGROUND 
     This disclosure relates to an earcup to headband joint for headphones. 
     Many headphones have one or two earcups that are designed to sit on or over the ears. The earcups are coupled to a headband. In some cases, the earcups can move vertically, up and down the headband, so that they can fit different heads. The earcups may also be able to pivot or rotate from side-to-side about the axis of vertical motion, again to accommodate different heads. 
     SUMMARY 
     All examples and features mentioned below can be combined in any technically possible way. 
     In one aspect, an earcup to headband joint for headphones, wherein the headphones comprise an electrical cable that extends from the headband into the earcup, includes a joint structure that couples the earcup to the headband and that is constructed and arranged to provide for earcup translation along a vertical axis and rotation about the vertical axis, and at least one friction element in the earcup and in contact with at least one of the joint structure and the cable, wherein the friction element is constructed and arranged to provide forces that resist rotational motion of the earcup about the vertical axis. 
     Embodiments may include one of the following features, or any combination thereof. The earcup to headband joint may include at least two friction elements. The electrical cable may have two opposed sides, and one friction element may be in contact with one side of the cable and another friction element may be in contact with the other side of the cable. A horizontal portion of the cable may run generally along a horizontal axis that is perpendicular to the vertical axis. One friction element may be above the horizontal portion of the cable and another friction element may be below the horizontal portion of the cable. The friction elements may each comprise a strip of pliable material. The friction elements may comprise an elastomer. The friction elements may be made from silicone rubber. The earcup may comprise a generally horizontal slot that the joint structure and cable pass through, and the strips may be alongside both sides of the slot. 
     Embodiments may include one of the following features, or any combination thereof. The at least one friction element may be spaced from the vertical axis. There may be at least two friction elements that each comprise pliable material. The earcup may comprise a slot that the joint structure and cable pass through, and the friction elements may be adjacent to both sides of the slot. The cable may pass through the joint structure. The friction element may be in contact with the joint structure at a location where the cable passes through the joint structure. The joint structure at the location where the cable passes through the joint structure may comprise a tube in which the cable is located. 
     In another aspect, an earcup to headband joint for headphones, wherein the headphones comprise an electrical cable that extends from the headband into the earcup, includes a joint structure that couples the earcup to the headband and that is constructed and arranged to provide for earcup translation along a vertical axis and rotation about the vertical axis, wherein the earcup comprises a slot that the joint structure and cable pass through, and at least two friction elements in the earcup, one alongside each side of the slot and in contact with at least one of the joint structure and the cable, wherein the friction elements are constructed and arranged to provide forces that resist rotational motion of the earcup about the vertical axis, wherein the friction elements comprise strips of an elastomer. 
     Embodiments may include one of the above and/or below features, or any combination thereof. The friction elements may be spaced from the vertical axis. The friction elements may overlap both sides of the slot. The electrical cable may have two opposed sides, and one friction element may be in contact with one side of the cable and another friction element may be in contact with the other side of the cable. The friction element may be in contact with the joint structure at a location where the cable passes through the joint structure, and the joint structure at the location where the cable passes through the joint structure may comprise a tube in which the cable is located. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is front view of a headphone. 
         FIG. 2  is an exploded view of an earcup, and a joint that movably couples the earcup to the headband. 
         FIG. 3  shows parts of the assembled joint. 
         FIG. 4  shows the pivot member of  FIG. 3 . 
         FIGS. 5A-5D  are cross-sectional views taken along line  5 - 5  of  FIG. 2  (but with the joint assembled) showing several rotational positions of the earcup relative to the slider. 
         FIG. 6  is an exploded view of a pivot member and a bearing member of an alternative headphone joint. 
         FIG. 7  is an exploded view of an earcup, a slider, and the joint of  FIG. 6  that movably couples the earcup to the headband. 
         FIG. 8  shows the assembled pivot member of  FIGS. 6 and 7 . 
         FIG. 9  is an enlarged, partial, cut-away view of an earcup/slider/pivot member assembly. 
         FIG. 10A  is a partial cross-sectional view taken along line  10 - 10  of  FIG. 9 . 
         FIG. 10B  is a cross-sectional view taken along line  10 - 10  of  FIG. 9 . 
         FIG. 11  is a cross-sectional view similar to the view of  FIG. 10A , illustrating an electrical cable and friction members. 
         FIG. 12  is a partial, interior, perspective view, illustrating the friction members and electrical cable of  FIG. 12 . 
         FIG. 13  shows the electrical cable running through the pivot member of  FIG. 11 . 
         FIG. 14  illustrates an alternative pivot member and friction members. 
     
    
    
     DETAILED DESCRIPTION 
     A headphone refers to a device that fits around, on, or in an ear, and that radiates acoustic energy into the ear canal. Headphones are sometimes referred to as earphones, earpieces, headsets, earbuds, or sport headphones, and can be wired or wireless. A headphone includes an acoustic driver to transduce audio signals to acoustic energy. The acoustic driver may be housed in an earcup. While some of the figures and descriptions following show a single headphone, a headphone may be a single stand-alone unit or one of a pair of headphones (each including a respective acoustic driver and earcup), one for each ear. A headphone may be connected mechanically to another headphone, for example by a headband and/or by leads that conduct audio signals to an acoustic driver in the headphone. A headphone may include components for wirelessly receiving audio signals. A headphone may include components of an active noise reduction (ANR) system. Headphones may also include other functionality, such as a microphone so that they can function as a headset. 
     In an around or on the ear headphone, the headphone may include a headband and at least one earcup that is arranged to sit on or over an ear of the user. In order to accommodate heads of different sizes and shapes, the earcups need to be able to pivot about at least the vertical axis, and they need to translate for some distance along the vertical axis. The headband can be collapsible or foldable, and can be made of multiple parts. Some headbands include sliders, which may be positioned internal to the headband, that provide for the necessary translation of the earcups. Some headphones include a yoke pivotally mounted to the headband, with the earcups pivotally mounted to the yoke, to provide for the necessary rotation of the earcups. 
     Some headphones have earcups that are able to move vertically, up and down the headband, and also pivot or rotate from side-to-side about the axis of vertical motion. The user experience can be improved if the side-to side pivoting motion is damped sufficiently to maintain the earcup position on the head as the headphones are used; if there is no damping the earcups may not stay in place as the wearer&#39;s head moves. 
     The headphones of the present disclosure have a joint that couples the earcup(s) to the headband. The joint is structured to allow constrained, damped rotation of the earcups relative to the headband about at least the vertical axis. In some cases, the joint may also provide for rotation about a perpendicular horizontal axis. The joint is also structured to provide for constrained translation along the vertical axis. Rotation about a vertical axis can extend to 90 degrees in one rotational direction, so that the earcups can be folded flat against the headband, anywhere along their translational motion. In this example of the joint, the joint allows the headphones to be folded flat, which allows a headphone storage case to be flatter than could otherwise be achieved without the joint. 
     An earcup to headband joint for headphones of this disclosure can include a joint structure that couples the earcup to the headband. The joint structure provides for earcup translation along the vertical axis (up and down along the headband), and earcup rotation about the vertical axis. There are one or more friction elements in each earcup. The friction elements are in contact with at least one of the joint structure and the electrical cable that extends from the headband into the earcup. The friction elements are constructed and arranged to provide forces that resist rotational motion of the earcup about the vertical axis. In one example, the friction elements are spaced from the vertical axis. The friction elements maybe located inside the earcups. 
     In one non-limiting example, each earcup includes two friction elements. One friction element may be in contact with one side of the cable and the other friction element may be in contact with another side of the cable. The friction elements may each comprise a strip of pliable material. The material may be an elastomer, such as a silicone rubber. 
     In one non-limiting example, the earcup has a generally horizontal slot that the joint structure and cable pass through, and the friction elements (e.g., the strips) are alongside both sides of the slot. In another example, the cable passes through the joint structure and the friction elements are in contact with the joint structure at the location where the cable passes through the joint structure. The joint structure at the location where the cable passes through the joint structure may comprise a tube in which the cable is located. 
     Headphone  10  is shown in  FIG. 1 . Headphone  10  includes earcup  14  that is carried by headband  12 , which is adapted to be fitted on and over the user&#39;s head. Cushion  13  is depicted, to schematically represent cushioning that may be present in some headphones. Cushions may increase user comfort. Earcup  14  is movably coupled to headband  12  by joint  20 . Joint  20  is constructed and arranged to allow translation of earcup  14  up and down along vertical or translational axis X. Joint  20  is further constructed and arranged to allow rotation of earcup  14  from the neutral position shown in  FIG. 1 , in both directions about translational axis X. In one of these rotational directions the rotation extends for approximately 90 degrees, such that the open face of ear cushion  15  of earcup  14  faces either forward or backward, rather than facing inward (i.e., toward the location of the user&#39;s head (not shown)). This rotation folds the headphone “flat,” wherein the height of the headphone (i.e., its extent along the Z axis) equals the height of the earcup plus headband. In one example, this fold-flat height is approximately 54 mm. This fold-flat height is less than the height that the headphones have when the earcup is not rotated about the X axis, which would equal the diameter of the earcup; in the example of this same headphone this height would be approximately 79 mm. Since the fold-flat configuration decreases the height of the headphones, the headphone carrying case can be thinner. The fold-flat aspect of the headphones thus decreases the bulkiness of the carrying case, which makes the headphones easier to store, pack and carry. 
       FIGS. 2-5  provide pertinent details of one non-limiting example of an implementation of the joint structure that is constructed and arranged to allow translation of the earcup up and down along vertical or translational axis X, as well as damped rotation of the earcup in both directions about translational axis X. Damping of this rotation is discussed below. Joint structure  30  includes pivot member  60  that has first end  62 . End  62  is received by slider  50 , which is part of joint structure  30  and is located within the headband (not shown). Slider  50  comprises U-shaped, partially tubular body  52 . Pivot member  60  also has second end  64 . In this example, the distal surface of end  64  defines an arc-shaped surface  77 . Integral connecting portion  66  connects pivot member first end  62  and second end  64 . 
     Slider  50  fits into slider receptacle groove  42  on the outside of shell body  41  of earcup shell  40 . Horizontal slot  44  in groove  42 , which is bounded by raised ridges  45  and  46 , is sized and shaped to allow pivot member  60  to be nested into shell body  41 , such that end  62  fits through enlarged opening  56  of slider slot  54 . Slot  54  is narrower that the diameter of (generally spherical) end  62 . This construction retains end  62  in slider  50 . As shown in  FIG. 3  (which leaves out the earcup shell for the sake of clarity), when the pivot member and slider are assembled, end  62  sits against the interior of slider body  52 . Surface  77  of second end  64  projects from slider  50 . As best shown in conjunction with  FIG. 4 , connecting portion  66  of pivot member  60  has ends  67  and  68  that sit against edges  55  and  57  of slider slot  54  ( FIG. 3 ); this inhibits pivot member  60  from pivoting within slider  50  about axis  59  (which is the translational axis that corresponds to axis X,  FIG. 1 ). 
     As shown in  FIG. 4 , first end  62  includes generally disc-shaped retaining end member  61 , which has a slightly greater diameter than O-ring  63 . As shown in  FIG. 3 , O-ring  63  is fitted against the inside of slider body  52 , and thus creates some friction that allows the slider to slide along axis  59 , with some resistance. Slider slot  54  can be at least about 40 mm long, to allow for sliding of the earcup along the X axis of at least about 20 mm up and down from a neutral (centered) position. End  62  can pivot in both directions about the Z (horizontal) axis, until disc  61  contacts the interior of slider body  52 . In one non-limiting example, the rotation about the Z axis extends for up to approximately 10 degrees from a centered (neutral) position, although smaller or greater rotations can be provided for by proper construction of the joint. The rotation about the Z axis allows the earcup to adjust relative to the headband, to accommodate different sized and shaped heads. 
     The rotations of the earcup about the X axis are accommodated by arc-shaped surface  77  of pivot member  60  and the arc-shaped interior bearing surface  72  of bearing member  70 . See  FIG. 2 . Bearing member horizontal slot  71  accommodates the electrical cable that routes power and audio signals to the earcup, as described in more detail below relative to  FIG. 11 . As described above, pivot member  60  is held in slider  50  such that pivot member  60  cannot rotate about the X axis relative to slider  50 . Bearing member  70  is coupled to earcup shell body  41  such that surface  77  sits on surface  72 . This allows the earcup to be pivoted about the X axis. 
     In the non-limiting example depicted in  FIGS. 2-5 , joint structure  30  is constructed and arranged to allow for rotation in a first direction about the X axis (in  FIGS. 5A-5D  the translational (X) axis is into and out of the page), the rotation extending for about 10 degrees from a “neutral” position, and rotation of about 90 degrees in the other (a second) direction about the X axis. These rotations are illustrated in  FIGS. 5A-5D , with  FIG. 5A  showing the “neutral” position (designated as zero degrees&#39; rotation),  FIG. 5B  showing a −10 degree rotation (where the earcup is fully rotated in the first direction),  FIG. 5C  showing a +10 degree rotation (10 degrees from neutral in the second direction), and  FIG. 5D  showing a +90 degree rotation (where the earcup is fully rotated in the second direction). 
     In the neutral position shown in  FIG. 5A  the earcup is centered on the Y axis. Rotation about the X axis in the first direction can extend up to about 10 degrees as shown in  FIG. 5B . The end-point is defined when end  65  of second end  64  of pivot member  60  contacts earcup shell body  41  (at point  81 ). As the earcup is rotated in the second direction it passes through the +10 degree location ( FIG. 5C ), to the second travel endpoint at +90 degrees ( FIG. 5D ), where end  69  of second end  64  of pivot member  60  contacts earcup shell body  41  (at point  82 ). In this +90 degree position the earcup lies along the Z axis, at right angles to the longitudinal axis of slider  50  (which corresponds to the X axis). The relative locations of the X, Y and Z axes are illustrated, but offset from the actual positions. As can be seen by comparing  FIGS. 5A and 5D , this rotation to a “fold flat” position ( FIG. 5D ) substantially reduces the depth of the headphones (i.e., their extent along the Z axis), from the diameter of the earcup ( FIG. 5A ), to the depth of the earcup plus about half the diameter of the slider (distance  53 ,  FIG. 5D ). This substantially reduces the height needed in an earphone storage case, and thus reduces the size and bulk of the case. 
     An alternative pivot member/bearing member assembly  90  is depicted in  FIGS. 6-9 . Pivot member  91  in this case is made from two separate portions—first end  92  and second end  94 . The first and second ends are interconnected via attachment structure  110  and attachment structure  106  being positioned such that their holes are aligned, with pivot pin  111  passing through opening  104  in end  92  and through holes in structures  106  and  110 . This allows end  94  to pivot relative to end  92 . This pivoting is about the Z axis ( FIG. 1 ), and helps to accommodate different shapes and sizes of heads. In one non-limiting example, this pivoting extends for about 10 degrees in either rotational direction from the “neutral” position depicted in  FIG. 1 . Other degrees of rotation can be accomplished by proper construction of ends  92  and  94  in a manner that would be apparent to one skilled in the art. 
     First end  92  includes one or more rubber strips or portions (such as strips  103 ,  141  and  142 ,  FIG. 8 ) that provide the frictional fit in the slider  140 , in a similar manner to O-ring  63 . As shown in  FIG. 7 , slider  140  includes slider body  142  with slot  144 , and slot opening  146 . Second pivot member end  94  includes arc-shaped surface  112  that rides on arc-shaped interior bearing surface  122  of bearing member  100 . Earcup shell  130  includes slot  132 , which has a construction that is very similar to the embodiment shown in  FIG. 2 . Bearing member  100  is mounted inside of earcup shell  130  via four tabs (tab  162  numbered) that overlie mating pads that are part of the earcup shell (pad  164  numbered), using fasteners such as screws. See  FIG. 9 . 
     Constrained rotations about the Z axis can be accomplished in the manner illustrated in  FIGS. 10A and 10B . The Z axis is coincident with the center of pin  111 . The X and Y axes are also illustrated. Pivot member second end  94  can rotate up and down about the Z axis, relative to first end  92 , which is held in slider  50 .  FIG. 10A  illustrates the neutral position, in which the earcup is centered on the Y axis. Spring steel portion  170  of headband  12  pushes first end  92  toward bearing member  100 , which is fixed to the inside of earcup shell body  41 . This force also pushes second end  94  against bearing member  100 , such that surface  112  rides on surface  122 . The spring force thus provides for smooth rotational motion about the X axis. 
       FIG. 10B  illustrates the farthest downward extent of rotation of earcup  40  about the Z axis, which can be approximately 10 degrees in one non-limiting example. The rotation end point (in both directions) occur when earcup shell body  41  of slot  44  contacts slider body  52 . Slot  44  and slider body  52  can have the same radius of curvature to facilitate the +/−10 degree rotations, but they do not need to have the same radius of curvature. 
     The present headphones have earcups that are able to move vertically, up and down the headband, and also pivot or rotate from side-to-side about the axis of vertical motion. The user experience is improved by damping the side-to side pivoting motion. The damping is preferably but not necessarily sufficient to maintain the earcup position on the head as the headphones are used. The headphones have a joint that couples the earcup(s) to the headband. The joint is structured to allow constrained, damped rotation of the earcups relative to the headband about the vertical axis. 
       FIGS. 11-13  illustrate a non-limiting example of joint structure  208  of an earcup to headband joint  206  for headphones. Joint structure  208  includes pivot member  210 , which is similar to pivot member  91 , and includes first end  212  that is able to move up and down along slider  140 , as described above. Pivot member  91  also includes second end  214  that can pivot relative to first end  212  about pivot pin  215  that is received in opening  217 . Cable  220  is carried by slider  140  and is re-routed (turned 90 degrees, generally along or parallel to the Y axis) into earcup  130  by pivot member  210 , as best shown in  FIG. 13 . Second end  214  has bearing surface  320  which contacts bearing member  216  of joint structure  208 . Bearing member  216  is similar to bearing member  70 , but includes generally “U”-shaped outer portions  217  and  218 . Bearing member  216  is attached to earcup  130  in the same fashion as illustrated in  FIG. 9 , by using fasteners such as screws (not shown) to attach tabs  162  to earcup shell pads  164 . Cavity  232  is formed in pivot member second end  214  so as to accommodate and retain cable  220  such that it turns into the earcup. Cavity  232  may comprise a generally horizontal slot as shown, or the slot may be turned more vertically to better retain the cable. 
     As best shown in  FIGS. 11 and 12 , joint  206  also includes friction elements  222  and  224 . Friction elements  222  and  224  are fixed to outer portions  217  and  218 , respectively, of bearing member  216 , which are designed to accommodate (i.e., fix-in-place) strips  222  and  224 . Strips  222  and  224  can be fixed to bearing member  216  in a desired fashion, such as by an adhesive, or a mechanical faster. Alternatively, strips  222  and  224  could be overmolded onto bearing member  216 . Strips  222  and  224  overlap slot  213  so as to either fully or partially close it off. The construction is such that the friction members contact opposed sides of cable  220 . Friction members  222  and  224  are in this example thin strips of a pliable material, such as an elastomer. In one non-limiting example, the elastomer is a silicone rubber, which may be but need not be a material with a durometer of approximately Shore 50A. The friction elements are slightly deformed by cable  220  as the cable passes through them, as shown in  FIG. 12 . As the earcup pivots about the vertical (X) axis, cable  220  moves along horizontal slot  213  of bearing member  216  (which is similar to slot  71  of bearing member  70 ,  FIG. 2 ); the friction between the upper surface  220   a  of the cable jacket and friction member  224 , and between the lower surface  220   b  of the cable jacket and friction member  222  as the cable moves along the inner edges of the friction member strips, causes forces that damp (i.e., resist) the pivoting motion of the earcup. This force provides some feedback to the user as the earcup is pivoted, and also helps to maintain the final earcup rotational position and so to help keep the earcups in place as the user walks and moves. 
     Preferably, but not necessarily, the material and thickness and arrangement of the friction elements, together with the size (diameter) and jacket material of the cable, are selected to achieve a desired damping. The damping can be specified by an amount of torque created by these forces together with their offset from rotational axis X. The desired torque can be created using other arrangements of the elements of the earcup to headband joint structure, and/or the friction element or friction elements that provide forces that resist rotation about the X axis. 
     One example of such an alternative arrangement is shown in  FIG. 14 , wherein alternative pivot member second end  240  includes extension portion  205 . Portion  250  comprises tube  252  through which cable  220  runs. In this case, friction elements  222   a  and  224   a  (which are carried by bearing member  216 ) contact the outside of tube  252  rather than the outside of the cable as in the example of  FIGS. 11-13 . Other alternatives are within the scope of this disclosure and include the use of only one, or more than two, friction elements. For example, there could be one friction strip. Or, there could be a friction element (such as a sleeve) located on the cable or extension portion  205 . Also, the friction could occur directly between the inner faces of bearing member  216  that form slot  213 , and either the cable or the extension portion, thus obviating the need for separate friction elements and instead accomplishing friction elements directly in the bearing member (either by judicious choice of the bearing member material or by using a different material for the parts of the bearing member that define slot  213 ). 
     A number of implementations have been described. Nevertheless, it will be understood that additional modifications may be made without departing from the scope of the inventive concepts described herein, and, accordingly, other embodiments are within the scope of the following claims.