Abstract:
A mobile terminal, such as a mobile telephone, has a hinge with a helical spring and which provides both snap opening or automatic opening upon activation of a release means as well as a freely selectable angular position between the rotating parts of the terminal. Also, a new type of spring hinges or clutches are described for use in, for example, this type of terminal.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a hinge for a mobile terminal, such as a mobile telephone, and to a novel type of hinge, which may be used for mobile terminals. 
     2. Description of Prior Art 
     Presently, mobile terminals may be made as two-part terminals where the two parts are able to rotate in relation to each other from an inactive position to an active position. Some of these terminals have a snap opening function whereby the rotation to the active position is automatic upon activation of a button. However, due to the biasing, the active position and the inactive positions are the only positions maintainable. Thus, this brings about a problem when, for example, trying to position the terminal in a manner so that a display or the like may be visible. 
     It has been found that it is desirable to have, in a mobile terminal, a more freely selectable angle or rotation between such two parts. 
     SUMMARY OF THE INVENTION 
     Thus, in a first aspect, the invention relates to a mobile terminal having two parts connected to each other by a hinge, the hinge comprising:
         a helical spring having a longitudinal axis, the spring comprising one or more wound strands of material, each strand having two ends,   a first hinge part extending into the helical spring, contacting an inner part of the helical spring at a first position or area along the longitudinal axis, and being connected to or attached to a first part of the two parts, and   a second hinge part contacting the one or more strands of the helical spring and being connected to or attached to a second part of the two parts,
 
the spring facilitating that:
   rotation of the first hinge part in a first direction around the longitudinal axis and in relation to the second hinge part will provide a first, lower friction between the first hinge part and the helical spring, and   rotation of the first hinge part in a second direction, being opposite to the first direction, around the longitudinal axis and in relation to the second hinge part will provide a second, higher friction between the first hinge part and the helical spring
 
the terminal further comprising:
   release means for increasing a diameter of the helical spring at the first position or area in order to reduce the second, higher friction between the first hinge part and the helical spring during rotation of the first hinge part in the second direction, the second, higher friction being reduced to a third friction, and   biasing means for providing a rotation of the first hinge part in the second direction when the release means are operated, the biasing means providing a force exceeding a force required to overcome the third friction but being lower than a force required to overcome the second friction.       

     In this context, it should be noted that the hinge may have other, more standard, hinge means, whereby the present helical spring assembly may mostly be used as a rotatable clutch of the hinge. 
     A standard helical spring is normally made of only a single strand or elongated piece of the material (typically a metal or another stiff material). However, springs are contemplated being formed by a number of strands, the windings of which are positioned, one after the other, along the longitudinal axis of the spring. 
     Also, the helical spring needs only be formed by part of the strand(s). The ends of the strand(s) need not be part of the helical spring. These ends may be used for different purposes, such as immobilization or actual movement. 
     The normal manner of providing a wrap spring clutch is to have the two hinged or clutched elements extend into the spring and thereby engage the inner part of the spring. However, it should be noted that the same effect may be obtained by reversing the operation and engaging the spring at an outer side thereof. Thus, in order to loosen the engagement, the spring is then not loosened (diameter increased) but tightened (diameter reduced). 
     In this context, the first hinge part would normally extend into the spring from one end thereof and engage the inner side of the spring (at least in the clutched operation) along a position and area from that end and a predetermined distance into the spring along the axis. However, the part needs not contact the spring at the end but may do so at any position thereof. 
     The first hinge part preferably has, at the part extending into the spring, an at least substantially circular cross section corresponding to an inner cross section of the spring. In that manner, contact inside the spring may be a contact along the inner circumference of the spring. 
     The contact of the second hinge part and the spring may be an attachment or a biasing, depending on which type of movement of the spring the second hinge part is to prevent or brake. 
     If both the first and second hinge parts extend into the spring, the first and second hinge parts engage or contact the spring at different positions or areas along the longitudinal axis of the spring. The first hinge part extends into the spring, but the second one may engage an outer surface thereof, an inner surface thereof, or actually a part of the strand(s) not being part of the actual helical shape of the spring. This will become clearer below. 
     It is clear that friction is a manner of keeping two elements in a predetermined position until a force is experienced large enough to overcome the friction, where after rotation is obtained. 
     The operation and direction of the biasing force results in that the biasing means is not able to actually rotate the parts until the release means of the hinge is operated, whereby the second friction is reduced to the third friction. It is seen that the release thus provides a snap/automatic movement of the pertaining parts of the terminal. However, the hinge provides, at the same time, a freely selected rotational position of the two parts in that the biasing or snap action is only provided when the release means is operated. 
     In one embodiment, the spring comprises a non-helical part at an end of each of the one or more strands, and the second hinge part contacts only the non-helical part. Thus, the second hinge part does not actually extend into the spring and/or engage the inner part thereof. In this embodiment, the contact between the second hinge part and the non-helical part of the spring may be an attachment. Preferably, the first hinge member contacts at least substantially a full inner surface of the spring and/or extends a full length of the helical part of the spring (in the direction of the axis). 
     In another embodiment, one end of each of the strand(s) of the spring is fixed in relation to the second hinge part and the release means is adapted to displace the other end(s) of the strand(s) from a first position to a second position. In this embodiment, the release means are preferably adapted to not be rotated in relation to the second hinge part in order to facilitate the design of the release mechanism. 
     It may be desired to actually ensure that an accidental operation of the release means does not bring about rotation. Thus, the terminal could further comprise locking means for maintaining the parts in a predetermined rotational angle even when the release means are operated. 
     One manner of obtaining this displacement is one wherein the release means comprises, for each hinge, a wedge-shaped element adapted to be translated and thereby displace the end(s). 
     Another manner is one wherein the release means comprises, for each hinge, a flexible element engaging the end(s), the end(s) being adapted to bias the flexible element into a first, deformed state when in the first position, and the release means comprising means for bringing the flexible element into a first, regular state and thereby bringing the end(s) into the second position. This may be obtained when the flexible element is hollow and wherein the means for bringing comprise a means adapted to be translated into the hollowness of the flexible element. These bringing means may be translatable into and out of the flexible element and may be biased in a direction out of the hollowness so as to ensure that the end returns to the first position and that engagement is obtained between the first hinge part and the spring. 
     A second aspect of the invention relates to a hinge or a clutch for facilitating rotational movement of a first hinge part in relation to a second hinge part and around a rotational axis of the hinge, the hinge comprising:
         a helical spring having a longitudinal axis along the rotational axis, the spring comprising one or more wound strands of material, each strand having two ends and a part extending outside the helical spring,   the first hinge part extending into the helical spring, contacting an inner part of the helical spring at a first position or area along the longitudinal axis, and   a second hinge part being attached only to the extending parts of each of the one or more strands of the helical spring,
 
the spring facilitating that:
   rotation of the first hinge part in a first direction around the longitudinal axis and in relation to the second hinge part will provide a first, lower friction between the first hinge part and the helical spring, and   rotation of the first hinge part in a second direction, being opposite to the first direction, around the longitudinal axis and in relation to the second hinge part will provide a second, higher friction between the first hinge part and the helical spring.       

     Thus, the second hinge part does not contact the spring inside the helical part thereof—or at least does not contact the spring in the helical part. Contacting the spring at an end of the strands, such as ends not forming part of the helical spring but extend away there from, may render the mass production of this hinge or clutch more controllable. 
     Naturally, this hinge preferably comprises release means for increasing a diameter of the helical spring at the first position or area in order to reduce the second, higher friction between the first hinge part and the helical spring during rotation of the first hinge part in the second direction, the second, higher friction being reduced to a third friction 
     Also, the hinge preferably further comprises biasing means for providing a rotation of the first hinge part in the second direction when the release means are operated, the biasing means providing a force exceeding a force required to overcome the third friction but being lower than a force required to overcome the second friction. In this situation, both the automatic rotation and the freely selectable position are possible. 
     In one embodiment, again, the release means comprises, for each hinge, a wedge-shaped element adapted to be translated and displace the end(s). 
     In another embodiment, the release means comprises, for each hinge, a flexible element engaging the end(s), the end(s) being adapted to bias the flexible element into a first, deformed state when in the first position, and the release means comprising means for bringing the flexible element into a first, regular state and thereby bringing the end(s) into the second position. This flexible element could be hollow and the means for bringing could then comprise a means adapted to be translated into the hollowness of the flexible element. Also, then the bringing means are preferably adapted to be translated into and out of the flexible element and are biased in a direction out of the hollowness. 
     A third aspect of the invention relates to a method of operating a mobile terminal according the first aspect of the invention, the method comprising:
         operating the release means so as to have the biasing means rotate the first hinge part from an initial position in the second direction in relation to the second hinge means through a first angle to a second position,   disengaging the release means,   rotating the first hinge part in the second direction and through a second angle being smaller than the first angle to a third position, and   allowing the hinge to maintain the first hinge part in the third position.       

     Thus, using this method, the automatic opening and the then freely selectable position is obtained. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
       The invention will be explained more fully below, by way of example, in connection with preferred embodiments and with reference to the drawing, in which: 
         FIG. 1  illustrates the parts of a clutch/hinge, 
         FIG. 2  illustrates the parts of  FIG. 1  assembled to the hinge, 
         FIG. 3  illustrates a different embodiment of a hinge, 
         FIG. 4  is a cut-through view of yet an embodiment of a hinge, 
         FIG. 5 , is a cut-through view of the hinge of  FIG. 4  now also having a biasing spring, 
         FIG. 6  illustrates one manner of loosening the helical spring, 
         FIG. 7  illustrates another embodiment of a manner of loosening the helical spring, 
         FIG. 8  illustrates a system having two parts, a hinge as seen in  FIG. 5  and a spring loosening means, 
         FIG. 9  illustrates three different positions or angles between a mobile telephone body and a movable part thereof, and 
         FIG. 10  illustrates an embodiment different from that of  FIG. 9 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  illustrates the basic elements of a known wrap-spring clutch/hinge. This hinge  10  comprises two rod members  12  and  14  and a helical spring  16  having an internal surface  17  and two strand ends  18  and  20 . The diameters of the rod members  12  and  14  are larger than the internal diameter of the spring  16 . 
     This hinge is assembled in  FIG. 2  where the rod members touch inside the spring  16 . It is clear that if the end  18  is kept fixed in relation to the rod member  12 , rotation of the rod member  14  in the direction of the arrow will tighten the spring  16  and thus lock the two rod members  12  and  14  to each other so as to obtain maximum torque. In that manner, torsion or rotational energy is transferred from rod member  14  to rod member  12 . On the other hand, if the rod member  14  was rotated in the other direction (opposite to the arrow), this movement will only loosen the spring  16 , whereby almost no torque is transferred. 
     Also illustrated in  FIG. 2  is a wedge  15  which may be used for moving the end  20  of the spring  16 . If the wedge is moved so as to lift (on the figure) the end  20 , the spring  16  will be “loosened” which means that the internal diameter thereof will increase so that the rod member  14  may now be moved in the direction of the fat arrow without tightening the spring  16  and transferring torque to the rod member  12 . 
     In that manner, rotation of the member  14  in the direction of the fat arrow, around the longitudinal axis A, without operating the release wedge  15 , a high friction is obtained due to the fact that the spring  16  will tighten. Rotation in the opposite direction of the member  14  will, on the other hand, incur a much lower friction due to the spring  16  loosening. Also, when operating the wedge  15 , a third, low friction is experienced when rotating the member  14  in the direction of the fat arrow. 
     In  FIG. 3 , a different embodiment is illustrated which also has the rod member  14  and the spring  16  with the ends  18  and  20 . However, the rod member  12  has been removed, and instead the element hitherto connected to the rod member  12  is attached to the end  18 . As described above, this embodiment has certain advantages to the embodiment where the rod members abut in the spring  16 . Preferably, the rod  14  now extends throughout the whole of the helical spring  16 . 
       FIG. 4  illustrates another embodiment of a hinge having the same function. This hinge also has a first rod member  12 , the second rod member  14 —now in the form of a tubular element extending over part of the rod member  12 . The spring  16  has the “unlocking end”  20  and the end  18 , which is now fixed to a fixed element. 
     In  FIG. 5 , the hinge of  FIG. 4  has added elements  30  (fixed to the rod member  12  and in which the end  18  is fixed) and  32  (fixed to rod member  14 ) as well as a locking element  42  preventing the spring  16  from moving into a space between the rods  12  and  14  and creating backlash etc. in the system. It is seen that instead of immobilizing the end  18 , the element  30  may be immobilized. Also, a biasing spring  44  is added having one end attached to the element  32  and the other (not illustrated) fixed to the rod member  12 . Thus, it is clear that the element  32  and rod member  14  may be rotated over the rod member  12 , this movement being biased by the biasing spring  44 . 
     In this respect, it is preferred that the fixed end  18  and the wedge  15  (see also  FIGS. 6 and 7 ) exist in the same system—meaning that these elements are not rotatable (but may be translatable) in relation to the rod member  12  or element  30 . This will become clear from  FIG. 8 . 
     A number of choices exist when assembling the present hinge. Either the spring  16  is slightly opened before introducing the rods  12  and  14  (when the outer diameter of the rods is larger than the inner diameter of the spring) so as to obtain an engagement or friction there between in the un-operated situation (when the outer diameter of the rods is smaller than the inner diameter of the spring), so that operation may be a loosening of the spring  16 . Alternatively, it may be desired to actually bias the end  20  in the un-operated situation, so that operation may be a tightening of the spring  16 . In either way, it may be desired to bias the end  20  in the “tightening” direction in the un-operated situation. 
       FIGS. 6 and 7  illustrate different manners of actually loosening the spring  16 . In  FIG. 6 , the wedge  15  is illustrated together with two different positions of the end  20  of the spring  16 . Depending on the distance between the wedge  15  and the helical part of the spring  16 , this movement of the end  20  will provide more or less loosening of the spring  16 . 
     In  FIG. 6 , the wedge  15  is supplemented by another element  15 ′ forming, together with the wedge  15  a track in which the end  20  travels. This track may be used for actually biasing the end  20  in the tightening direction. This operation is seen as the un-biased position of the end  20  is illustrated by a dotted end  20 ′. Thus, moving the end  20  upwards will loosen the spring, and in the un-operated position, the end  20  is that depicted at the lower position, which is lower than the unbiased position  20 ′. 
     Another manner is seen in  FIG. 7 , where the end  20  rests against a flexible element  24  inside which an elongated, stiff element  26  may slide. It is seen that the end  20 , in fact, is biased against the element  24  in such a manner that when the element  26  is retracted, the end  20  will deform the element  24  and thereby tighten the spring  16 . 
     The element  26  is biased away from and out of the element  24  by a biasing spring  27 , and the elements  26 ,  24  and  20  are controlled by holding means  22 . 
     Returning to  FIG. 2 , it is clear that loosening of the spring  16  may be performed by moving the spring end  20  in a number of ways, such as in the direction of the fat arrow or in a direction along the end  20  toward the spring  16 . 
       FIG. 8  illustrates a two-part system having a first part  30  connected via a hinge  50  to a second part  32 . The reference numerals from  FIG. 5  have been omitted in order to retain the clarity of the figure. 
     The actual “direction” of the hinge (that is, the high friction and low friction rotation directions and the directions of the biasing springs) will depend on the actual embodiment. Two embodiments are described in relation to  FIGS. 9 and 10 . 
     The part  30  of the system of  FIG. 8  has a spring loosening mechanism having a push button  29  connected to a loosening mechanism  36 , such as the wedge  15 , and being biased by a biasing spring  38  engaging a fixed element  40  in the part  30 . 
     The first part  30  is further rotationally attached to the second part  32  by an element  42 . This is only to stabilize the rotation of the parts. 
     In  FIG. 9 , the mobile telephone  28  has the first and second parts  30  and  32  as well as a hinge or clutch illustrated at  33 , a release mechanism  34  for the hinge  33 . 
       FIG. 9  illustrates three different angles between the first part  30  and the second part  32  and therefore a specific use of the mobile telephone  28 . 
     In normal non-operative use, the mobile telephone  28  will be stored as illustrated in the left-most drawing where the first and second parts  30  and  32  are adjacent to each other. In the present embodiment, the second part  32  has a microphone  41  protected in the position in the left-most illustration. The telephone  28  also has a speaker  39  in the first part  30 . 
     The hinge  33  is provided in the telephone  28  so that the rod member  14  is attached to the second part  32  and so that the rod member  12  and/or the end  18  is attached to the first part  30 . Also, a release mechanism as that illustrated by the wedge  15  is operatively connected to the button  34 . The spring  16  is directed so that the rotation in the direction of the fat arrow (see  FIG. 2  or  3 ) will take place when rotating the second part  32  as illustrated by the fat arrow in the middle illustration of  FIG. 9 . 
     In order to operate the telephone  28 , such as when wishing to make a telephone call, the second part  32  is rotated as illustrated by the fat arrow in the middle illustration. In this manner, the microphone becomes accessible. This activation is obtained by releasing the release mechanism  34 , which loosens the spring  16  and allows the biasing means to overcome the third friction and rotate the second part  32  to, for example, a stopping position as that illustrated in the middle illustration. This position may be pre-defined as that providing the optimal position for use when making a telephone call. This position may also be one where the second part  32  is rotated further in the direction of the fat arrow. 
     Having obtained that position of the second part  32 , the release button  34  is disengaged. 
     Having, for example, made the telephone call, it may be desired to have a different angle on the second part  32  such as in order for the telephone  28  to be able to stand up and present a display  31  thereof to the user. Thus, the second part  32  may be rotated in a direction opposite to that illustrated by the fat arrow. Due to the friction of the hinge  33 —as well as the operation of the biasing means, the second part  32  will be substantially fixed and will be able to, for example, hold the telephone at the desired angle or in the desired position. 
     The telephone  28  may also have a locking means  37  for maintaining the second part  32  in the closed position even if the release button  34  is operated. 
     Naturally, the hinge may be reversed to that a snap closing is achieved by operating the button  34 . Thus, the parts are rotated by hand (in the low friction direction of the hinge), and are maintained in that angular position until the button is operated, where after the biasing spring will close the parts again. 
     Finally, in  FIG. 10 , a further embodiment is seen at an angle from the back (above) and directly from the front (below). This embodiment  51  may also be a telephone or a palm computer having two parts  52  and  54  interconnected by a hinge (not illustrated) and having a release button  56  to be used as described above. 
     Thus, operation may be as described above: operation of the release button  56  may make the biasing means open the telephone/computer  51  for operation. Releasing the release button will make further rotation in the opening direction (the fat arrow) difficult (due to the high friction), but rotation in the opposite direction (the closing direction) will be easy. 
     Again, any desired angle between the parts may be obtained at the same time as a snap opening (the operation of the biasing means) may be obtained. 
     The present embodiments have centered on mobile telephones. However, the same functionality may be obtained in any type of element where a combination of an automatic opening of a device is desired combined with a subsequent, freely selected positioning of the elements. This may be in hand-held or palm-size electronic systems, portable computers or toys of any type.