Abstract:
An apparatus for dreadlocking hair comprising a motor and a means for holding or engaging a strand of hair. The holding means is rotated by the motor, so that the strand of hair is twisted into a dreadlock, that is, a twisted bundle of hair where hair on the surface of the bundle describes a purely helical path, at least in a newly dreadlocked part of the strand.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the benefit under 35 U.S.C. §119 of Great Britain Patent Application Serial No. 1106950.7, filed in Great Britain on Apr. 21, 2011, entitled “Hair Care Apparatus.” 
     COPYRIGHT 
     A portion of the disclosure of this patent document contains material which is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent disclosure, as it appears in the Patent and Trademark Office patent files or records, but otherwise reserves all copyright rights whatsoever. 
     FIELD OF THE INVENTION 
     Embodiments relates to apparatus for dreadlocking hair. 
     BACKGROUND 
     Hair can be arranged in dreadlocks (hereinafter referred to as locking) manually by holding a strand of hair with one hand close to the scalp and by twisting a distal part of the strand of hair with another hand. When referring to a strand of hair reference is being made to more than one hair in a bundle. In doing so the part of the strand of hair that is to be locked is arranged in a tight twist. Hair wax may be applied to the part of the strand of hair that is to be (dread-) locked, so that the twist of the hair is retained after the manually applied twisted tension is removed. 
     From the above it will be appreciated that dreadlocking hair involves a considerable amount of effort. Moreover, newly grown parts of the strand of hair will need to be locked on a regular basis, so that the hair not only needs to be locked at an initial stage but also regularly thereafter, potentially as often as weekly. This is labour as well as cost intensive. It is moreover difficult for individuals to dreadlock their own hair. 
     SUMMARY OF INVENTION 
     According to an aspect of the present invention there is provided an apparatus for locking hair. The apparatus comprises a holder for engaging a single strand of hair. The holder is driveably connected with an electric motor so that operation of the electric motor causes a rotation of the holder applying a twisting locking motion to an unlocked part of a strand of hair in the holder. The holder of the above described apparatus is arranged to engage the strand of hair so that a distal free end of the strand of hair can rotate or spin freely. Allowing the free end of a strand of hair to spin freely (with the rotating motion imparted upon the proximal parts of the strand of hair by the apparatus) avoids the need to grab the strand of hair at its free end. In cases where hair is to be re-locked, that is where parts of the hair is already locked and only a region of new hair growth needs to be locked, the strand of hair can be engaged/grabbed close to the scalp, so that only the part of the strand of hair that needs to be re-locked is rotated and tightened by the apparatus. The part of the strand of hair distal from the clamp can then freely rotate with the rotation of the holder so that this part of the strand of hair is not unnecessarily re-tensioned. 
     Locking a strand of hair includes twisting the strand of hair about the stand&#39;s longitudinal axis creating a matted lock of entangled hair. This twisting action twists the hair into a yarn like configuration, that is, into a bundle of hair in which the individual hairs at the surface describe a substantially purely helical path. With increasing rotation of the strand of hair the tightness and density of the locked strand can increase. Gel or wax may be used to keep the hair in dreadlocks. It should be noted that the part of the strand of hair that is held by the holder does not itself have to be twisted exclusively about its longitudinal axis. Instead, the strand of hair that is being held by the holder may be twisted about its longitudinal axis while, at the same time, being rotated about another axis. The part of the strand of hair that is required to be twisted exclusively about its longitudinal axis is the part of the strand of hair closest to the scalp. Due to the natural growth of the hair this part of the strand of hair is the part that is likely to be unlocked (that is not arranged in a dreadlock), even if a more distal part of the strand of hair has been locked before. 
     Locking of hair is not to be confused with the twisting of hair or with braiding it. Twisting of hair involves the rotation of two or more strands of hair about a common longitudinal axis, much like several yarns are twisted about a common longitudinal axis when forming a thicker yarn or a rope, whereas the above described locking involves the twisting of a single strand of hair about its longitudinal axis. Braiding involves the interleaved arrangement of several strands of hair in an ordered fashion and does not have to involve a twisting motion at all. Braiding therefore does not involve creating matted locks as locking does or involve the deliberate entanglement of hair. 
     The holder may comprise a tubular structure for receiving the strand of hair in the middle/in a bore. The tubular structure may comprise an engagement means for engaging the strand of hair. This engagement means may be provided at an end of the tubular structure. The engagement means may comprise one or more cuts or slits in the wall of the tubular structure. One or more of these cuts or slits may narrow over their length. 
     The holder may comprise more than one engagement means for engaging the strand of hair. Different ones of the said engagement means may have different sizes for engaging strands of hair with differing diameters. If the engagement means are the above mentioned narrowing cuts/slits, then different cuts/slits may, for example, narrow to different final width. One or more of the slits may have an individual receptacle at the end/narrowest portion, wherein different receptacles may have different sizes to hold different diameter strands of hair. 
     The apparatus may further comprise a fixator for engaging the strand of hair and for inhibiting twisting of the strand of hair about its longitudinal axis. Any such fixator may be spaced apart from the holder and be arranged to prevent rotation or reduce the amount of rotation of the strand of hair on a side of the fixator opposite from the holder. 
     The fixator may comprise an adjustable opening that engages a strand of hair in one opening position (of reduced diameter) and that allows insertion or removal of the strand of hair from the fixator in another opening position (with increased diameter). The fixator may, for example, comprise an iris-type closure, a biasing means suitable for and arranged to bias a strand of hair against a non-rotating part of the apparatus and/or one or more resilient members arranged to contact the strand of hair. 
     The holder may comprise a surface for engaging the strand of hair and means for biasing the strand of hair against the surface. The motor may be arranged to move the surface so that the surface moves tangentially to a surface of the strand of hair biased against the surface. The surface may be provided inside of an opening of the holder. The surface may have a geometry and/or materials that aid the engagement of the surface with the strand of hair. The surface may, for example, comprise teeth, as may be found on cogs, serrations or forms of undulations or unevenness that increase friction between the strand of hair and the surface. The biasing means may be arranged to be moveable relative to the opening, so that in one position of the biasing means relative to the opening a large opening for insertion of the strand of hair is provided and in another position the biasing means biases the strand of hair against the surface. 
     The biasing means may comprise an opening with a surface and may also be rotationally connected with the electric motor in a manner so that the rotation of the biasing means and rotation of the holder together induce a rotation of the strand of hair, in use. 
     The width of an opening on one end of the tubular structure may be larger than the width at the other end of the tubular structure. The tubular structure may have a tapering internal surface. 
     According to another aspect of the present invention there is provided a method of forming a dreadlock on a person from a strand of hair or from a part of the strand, preferably the part of the strand closest to the scalp of the person. The method comprises separating a strand of hair from surrounding hair, using a holder of a dreadlocking apparatus to engage with the strand of hair so that a distal portion of the strand of hair can move freely, activating a motor of the apparatus and disengaging the strand of hair from the holder after deactivation of the motor. The motor is arranged to rotate the holder, and with it the strand of hair by virtue of the engagement between the holder and the strand of hair, thereby twisting a portion of the strand of hair between the holder and the scalp of the person. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Embodiments will be described in the following by way of example only and with reference to the accompanying drawings, in which: 
         FIG. 1  shows an apparatus according to an embodiment; 
         FIG. 2  shows an explosion diagram of the apparatus illustrated in  FIG. 1 ; 
         FIG. 3  shows details of the holder of the  FIG. 1  apparatus; 
         FIGS. 4 to 9  show further apparatus according to an embodiment; 
         FIG. 10  shows yet another apparatus according to an embodiment; 
         FIGS. 11 to 18  show further embodiments of the invention. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  shows a first apparatus  100  according to an embodiment. Details of the apparatus  100  are shown in the explosion diagram of  FIG. 2 . At the centre of the apparatus is a unit  110  that comprises both the motor  120  and the holder  130  for the strand of hair. As can be seen from  FIG. 2  in this embodiment the motor forms part of a handle portion of the apparatus  100 . Connected to the motor  120  is a first bevel gear  140 . The motor  120  causes the first bevel gear  140  to rotate about its axis (which in  FIG. 2  is the vertical axis). The bevel gear  140  in turn drives a second bevel gear  150 . The second bevel gear  150  is fixedly attached to the holder  130  and rotates, together with the holder  130 , about the longitudinal axis of the holder  130 . Transmission of motion from the motor  120  to the holder  130  in this fashion provides the advantage that the spaces on either side of the holder  130  is not occupied by the motor, so that the strand of hair that is to be locked can be freely inserted through the opening in the holder and can freely exit from the holder. 
     The unit  110  is provided in a housing comprised of two housing halves  160  and  170  respectively. The holder  130  is rotatably held within the housing parts  160  and  170  by collars  180  and  190 . 
     Also provided as part of the apparatus  100  are springs  200  and  210 . As can be seen from  FIGS. 1 and 2  the springs form, where they overlap, an opening. As can be seen from  FIG. 2 , both of the springs  200  and  210  are fixed to the housing part  160  at one end. While it is shown that both springs are fixed to the housing at the same end, this is not essential and the springs may be fixed to the housing at opposing ends). Housing half  160  and lid  215  enclose most of the springs  200  and  210 . As can be seen from  FIG. 2 , the housing parts  160  and  170  as well as the lid  215  comprise recesses  220  and  230 .  FIG. 1  shows that these recesses expose parts  240  of the springs  200  and  210  when the apparatus is in the assembled state. These parts  240  can pushed inwardly by the user, thereby causing the bent portions  250  of the springs  200  and  210  in the area where the springs overlap to move away from a centre of the opening they define, thereby increasing the size of the opening to enable the insertion of a strand of hair through the opening. Removal of force from the springs will cause the opening to close again under the resilient force of the springs to engage the strand of hair and to prevent or reduce rotation of the parts of the strand of hair that lie outside of the apparatus  100 , to the left of the springs  200  and  210  in  FIGS. 1 and 2 . 
       FIG. 3  shows the holder  130  in more detail. The holder  130  comprises a tubular structure  300  terminating in end portion  310 . The tubular structure is provided to carry the second bevel gear  150  shown in  FIG. 2  as well as the collars  180  and  190 . The end portion  310  comprises narrowing slits  320 . Each narrowing slit  320  has a circular recess  330  at its end. The recesses  330  are intended to receive a strand of hair protruding from the bore of the tubular structure  300  and engage the strand of hair (the strand of hair may be considered as being clipped into the recess or hooked over the side wall of the tubular structure  300 , extending through a recess  330 ). When so engaged, the strand of hair has a free end that protrudes radialy beyond the outer perimeter of the tubular structure  300 . This free end can freely move with the rotating tubular structure  300 , while the rotation of the tubular structure  300 , aided by the engagement of the strand of hair provided by the recesses  330 , imparts a twisting motion upon the part of the strand of hair extending through the bore of the tubular structure  300 . 
     In one embodiment different recesses  330  have different sizes so that they can accommodate strands of hair with different diameters. The narrowing slits  320  may also differ in size to correspond to the different size recesses  330 . The sections adjacent (for example between) the narrowing slits  330  may comprise a tactile marking, so that a person trying to lock his or her own hair can locate a desired recess  330  on the end portion  310  even when he or she is no longer able to see the end portion  310 . 
     Turning now to the operation of the apparatus  100 , a person locking hair presses the exposed portions  240  of the springs  200  and  210  so as to widen the opening defined by the springs. The strand of hair that is to be locked is then inserted into the holder through the opening defined by the springs  200  and  210  until the strand of hair protrudes from the holder  130  by a desired amount. This desired amount may depend on the locking state of the strand of hair. A strand of hair that is already locked and that only requires a re-locking of new growth may, for example, require that the strand of hair is inserted through the springs  200  and  210  and through the holder  130  until the springs are located close to the scalp. This may also be desirable in a situation where a fresh strand of hair is newly locked. In the latter situation it may, however, be necessary that the apparatus be repeatedly moved distally after an initial locking of a proximal part of the strand of hair. 
     Once the strand of hair has been inserted through the opening defined by the springs  200  and  210  the user disengages the spring portions  240 , so that the springs  200  and  210  hold the strand of hair and inserts the strand of hair into an appropriate one of the recesses  330  at the end of a narrowing slit  320 . 
     Once the strand of hair has been put in place in the above described manner the motor  120  can be activated (using a switch that is not shown in the figures). This causes the holder  130  to rotate about its longitudinal axis and twists the hair. It will be appreciated that, while at the location of the recess  330  the rotation of the strand of hair about the longitudinal axis of the holder  130  does not correspond to a pure rotation of the strand of hair about its own longitudinal axis. However, the rotation of the strand of hair is purely about its own longitudinal axis at the position of the springs  200  and  210  and beyond. 
     Turning now to  FIGS. 4 to 8 , the apparatus shown in these figures substantially correspond to the apparatus described above with reference to  FIGS. 1 and 2  but have different fixators than the apparatus shown in  FIGS. 1 and 2 . As can be seen from  FIGS. 4 to 8 , none of the apparatus shown in these figures comprises the springs  200  and  210  shown in  FIGS. 1 and 2 . The apparatus  350  shown in  FIG. 4  instead comprises an adjustable opening  360  formed by the iris type closure shown in  FIG. 5 . 
     The apparatus  400  shown in  FIG. 6  comprises a jaw  410  that is downwardly biased to the position shown to the left of  FIG. 6 . In this position the opening through the apparatus is accessible for the insertion of a strand of hair. When the handle  420  is pressed towards the motor unit  400  the jaw  410  moves upwardly and the overlap between the recess  440  in the jaw  410  and the opening in the holder decreases until the recess  440  in the jaw  410  engages the strand of hair and presses the strand of hair against an upper surface of the holder. This engagement again prevents or reduces rotation of the strand of hair outside of the apparatus  400 . 
     The apparatus  450  shown in  FIG. 7  operates based on a similar principle as that shown in  FIG. 6  but comprises two moveable jaws  460  and  470 . The jaws  460  and  470  are biased towards the open position shown at the left of  FIG. 7 . Pressing of the handle  480  towards the motor unit moves the jaws  460  and  470  towards each other to engage and clamp the strand of hair inserted between the jaws  460  and  470 . 
     The apparatus  500  shown in  FIG. 8  comprises a slider  510  with an opening  520 . The slider  510  can be positioned in one position so that the opening  520  overlaps the opening in the holder  130  in a manner that allows insertion of a strand of hair  530 . In another position the slider  510  is slid to a position where overlap between the opening  520  and the opening of the holder is reduced, so that a strand of hair is engaged/clamped, as shown in the right part of  FIG. 8 . The slider  510  is located in a guide groove  540  and can be moved along the guide groove using protruding ridge  550 . 
       FIG. 9  shows another locking apparatus  600 . The apparatus  600  comprises a motor  610  and a means  620  for engaging and twisting a strand of hair. The means  620  is tubular, as in the previously described embodiments, and comprises an opening  630  from which the strand of hair that is to be locked protrudes in use. It will be appreciated that, as is the case in the previously described embodiments, the motor  610  is driveably connected to the holder  620  so that the motor  610  in use rotates the holder  620  about its longitudinal axis, that is, about the axis extending centrally through the bore of the holder  620 . A gear arrangement  640  driveably connects the motor  610  to the holder  630  and provides a desired speed conversion. 
     As can be seen from  FIG. 9 , the part of the holder  620  differs from the holder  130  discussed above with reference to the embodiments of  FIGS. 1 to 8  in that it does not comprise the narrowing slits  320  and recesses  330  for firmly holding a strand of hair while the holder rotates. Instead, the holder  620  comprises an engagement hook  650 . A portion  670  of the hook  650  is in contact with the end face  660  of the holder  620  and extends from this end face  660  in the longitudinal direction of the holder  620 . A more distal part  680  of the hook  650  extends in a direction that is substantially tangential to the outer surface of the cylindrical tubular holder. The part  680  of the hook  650  has a curvature with a radius that is larger than the radius of the holder  620 . It will, however, be appreciated that the hook may have a surface with a radius that corresponds to the radius of the holder  620 . 
     In the embodiment the hook  650  as well as the tubular holder may be formed from a single tubular member, for example by milling. The motor  610  drives the holder  630  so that the free end of the hook  650  precedes the remainder of the hook  650  during rotation, so that the hook  650  can sweep up a strand of hair protruding from the opening  630 . As seen in the right hand illustration provided in  FIG. 9  this means that the hook rotates clockwise. It will be appreciated that a so engaged strand of hair may fold over the part  670  of the hook  650  as a result of the continuing rotation of the holder  620 , thereby increasing frictional engagement between the hook  650  and the strand of hair and imparting a twisting motion onto the strand of hair in this fashion. 
     In the  FIG. 9  embodiment the slot between the part  670  of the hook  650  and the end face  660  of the holder  620  is not a narrowing slot. It will, however, be appreciated that the width of this slot could be narrowing with increasing distance from the tip of the part  680  of the hook, so that engagement between the hook  650  and the strand of hair increases as the strand of hair is swept up by the hook  650 . 
       FIGS. 10  A to F show another apparatus  700  for locking hair. The apparatus  700  comprises a motor  710  and two gearwheels  720  and  730 . As can be seen from  FIGS. 10  A to F, the two gearwheels  720  and  730  comprise teeth extending around an outer circumference thereof. Also provided are supports  740  and  750 . Support  740  supports and is arranged concentrically with gearwheel  720 . Gearwheel  720  can rotate relative to support  740 , while remaining concentric with support  740 . Support  750  supports and is arranged concentrically with gearwheel  730 . Gearwheel  730  can rotate relative to support  750 , while remaining concentric with support  750 . 
     The two supports  740  and  750  comprise respective extensions  760  and  770 . The extensions  760  and  770  can move relative to each other by pivoting about pivot axis  780 .  FIGS. 10D and 10E  show two different pivotal positions that the supports  740  and  750  can adopt relative to each other. Pivot axis  780  lies on the longitudinal axis of the motor  710 . For this reason any pivoting movement of the gearwheels  720  and  730  with the supports  740  and  750  will not change a spacing between the teeth of the gearwheels  720  and  730  and the axis of the motor  710 . This in turn means that engagement between the teeth of the gearwheels  720  and  730  and the gearwheel  790  driven by the motor  710  is maintained irrespective of the relative rotational position between the gearwheels  720  and  730 . 
     As is shown in  FIG. 10D , in one position the openings  800  and  810  in the gearwheels  720  and  730  respectively are aligned with each other, so that a strand of hair can be passed through the so created opening. In the relative rotational position of the gearwheels  720  and  730  shown in  FIG. 10E , the overlap between the openings  800  and  810  is reduced, so that the inside surface of the openings  800  and  810  can engage the strand of hair  820  from two (in this embodiment substantially opposite) sides. 
     It will be appreciated that rotation of the gearwheel  790  by the motor  710  causes a rotation of the two gearwheels  720  and  730 . This rotation is in the same direction for both gearwheels  720  and  730 , either clockwise or counter-clockwise, depending on the direction of rotation of the gear wheel  790 . Given that the two gearwheels  720  and  730  engage the strand of hair  820  with substantially diametrically opposed parts of their respective inner surfaces  800  and  810 , contact between the inner surfaces  800  and  810  causes a rotation of the strand of hair  820 . A clockwise rotation of the two gearwheels  720  and  730 , for example causes the gearwheel  720  to impart a downwardly (in  FIGS. 10A  to F) directed force onto the part of the strand of hair  820  that it contacts, while the gearwheel  730  imposes an opposing/upwardly directed force onto the (diametrically opposite) part of the strand of hair  820  that it contacts. The two gearwheels  720  and  730 , acting in concert, therefore cause a clockwise rotation of the strand of hair  820  in this example. As can be seen from  FIGS. 10A to 10D , the inner surfaces  800  and  810  of the gearwheels  720  and  730  are not smooth to aid engagement between these surfaces and the strand of hair  820 . While  FIGS. 10A  to F show these surfaces as comprising gear teeth, this is not essential as any other surface irregularities or undulations that aid engagement without damaging the strand of hair  820  may be equally suitable. 
     A mechanical limiter may be provided to limit the pivoting of the supports  740  and  750  relative to each other, so that no undue force can be applied onto the strand of hair by the gearwheels  720  and  730 . 
     Turning now to  FIGS. 11A to 11C , a further embodiment of the invention is disclosed in these figures. In  FIG. 11A  a view is provided showing the lock clamping mechanism  900  as it would be seen from the outside by a user (but omitting the motor unit shown in other embodiments described above). As can be seen, the clamping mechanism  900  comprises a cover  910  and a means  920  for attaching it to a remainder of the apparatus. Also visible in  FIG. 11A  are three clamping arms  930  and an activation ring  940 . As can be seen from a comparison of  FIGS. 11B and 11C , the clamping arms  930  can move from a position in which they are inwardly biased by the actuation ring  940  to engage a lock of hair (shown in  FIG. 11B ) to a position in which their clamping tips are moved away from the centre of the clamp, so that a lock of hair can be inserted through the opening of the clamping mechanism in the previously described manner. 
     As can be seen from  FIGS. 11B and 11C , the clamping arms  930  are located within a housing  950 . This housing comprises one shoulder  960  for each clamping arm  930 . The clamping arms  930  are biased outwardly so that they contact the shoulders  960  at all times. The housing  950  can be rotated together with the actuation ring  940  relative to the clamping arms  930 , so that the arms  930  move along the shoulders and are displaced inwardly against the spring bias to clamp a lock of hair located between the clamping arms  930 . While the embodiment shown in  FIG. 11  relates to a clamp that inhibits the twisting of a clamped strand of hair (much like the wires  240  shown in  FIG. 1 , it will be appreciated that, if the clamping mechanism  900  were rotated about its own longitudinal axis/the clamped strand of hair, then it could also impart a twisting motion onto the strand of hair. 
       FIGS. 12A and 12B  show a further embodiment of the invention. In this embodiment a lock of hair is again to be inserted through the upper part of the locking apparatus  1000 . The locking apparatus comprises to pivotable jaws  1010  with a protrusion  1020  each on the inside. In the open formation shown in  FIG. 12B , the jaws are moved away from each other, thereby permitting insertion of a strand of hair though the head  1030  of the locking apparatus. When the jaws  1010  are moved towards each other the protrusions  1020  engage the lock of hair. The lock of hair may extend through the head  1030  of the locking apparatus and extend out of the head  1030  on the right hand side shown in  FIGS. 12A and 12B . In the embodiment shown the two jaws  1010  are jointly rotatable about the longitudinal axis of the head for locking of the hair. In an alternative embodiment the two jaws  1010  are not rotatable in this manner and instead simply hold the stand of hair to prevent or reduce twisting in analogy with the wires  240  shown in  FIG. 1 . 
     Turning now to  FIGS. 13A to 13F , in the embodiment shown in these figures the apparatus  1100  is provided with a handle portion  1110  that comprises a motor and a battery and that is connected to a lock engagement portion  1120 . The motor can be activated and deactivated via button  1130 . The lock engagement portion  1120  comprises two jaws  1140  that are pivotably arranged relative to each other. Opposing recesses  1150  are provided on insides of the respective housings of the jaws  1140 . These recesses allow a lock of hair to extend through the lock engagement portion  1120  in a direction perpendicular to the longitudinal direction of the apparatus  1100 . Opposing belts  1160  are provided inside the jaws  1140 . The operation of these belts  1160  will be discussed in detail below. A lever  1170  is fixedly connected to one of the jaws  1140  and may be spring biased towards the position shown in  FIG. 13A . A user can press the lever  1170  towards the handle  1110 , thereby pivoting the jaw  1140  it is connected to toward the jaw  1140  that is fixed to the handle  1110  and thus closing the gap between the jaws  1140 , as shown in  FIG. 13B . 
       FIG. 13C  shows the belts  1160  within the jaws  1140  in more detail. As can be seen from this figure, the belts  1160  can run over rollers  1180 .  FIGS. 13C and 13D  show the belts  1160  in the closed position of the jaws  1140  also shown in  FIG. 13B . In  FIG. 13C  the belts  1160  engage a thick lock of hair, while in  FIG. 13D  a thinner lock of hair is being engaged. This flexibility in engaging locks of hair of differing diameters is achieved by mounting the rollers  180  on a common base plate (not shown), which in turn can pivot in the illustrated manner. 
     The belts  1160  are further driveably engaged by the driving roller  1200 . The driving roller is rotated by the motor in the handle portion  1110  shown in  FIGS. 13A and 13B  and causes the belts  1160  to run over rollers  1180 . The belts  1160  in turn engage the locks of hair  1190  and rotate them, as indicated. It will be appreciated that best adjustability of the jaws  1140  is achieved, if the base plates upon which the rollers  1180  are mounted can pivot about the rotational axis of the driving roller  1200 . 
       FIG. 13F  shows different possible types of belt  1160  surfaces. As can be seen, the belt surfaces can be structured, in this example using trapezoidal protrusions. These protrusions help to engage and rotate the lock of hair. Belts  1160  with different protrusion types/sizes may be provided for different type/thickness of hair. 
       FIGS. 14A and 14B  show another embodiment of the invention. The apparatus  1300  again comprises a handle portion  1310  (with motor and batteries) and a hair engagement portion  1320 . The hair engagement portion  1320  can be slid relative to the handle portion  1310 , as can be seen from a comparison of  FIGS. 14A and 14B . Rollers  1340  are rotatably connected to the handle portion  1310  and rollers  1350  are rotatably connected to the hair engagement portion  1320 . In one embodiment only the rollers  1340  are rotated by the motor in the handle portion  1310 , in another embodiment both the rollers  1340  and the rollers  1350  are rotated by the motor in the handle portion  1310 . When the rollers  1340  and  1350  are in the position shown in  FIG. 14B  they can engage a lock of hair and, through their rotation by the motor, rotate the lock of hair. 
       FIGS. 15 and 16  show to further ways of engaging locks of hair. Both of these further embodiments are for use in an apparatus in which a lock of hair is fed through the apparatus.  FIG. 15A  shows an arrangement  1400  that comprises two rings  1410  through which a strand of hair  1430  is fed. Connected between the rings are spring wires  1420 . As can be seen from  FIG. 15A , for one relative rotational position of the rings  1410  the wires  1420  extend substantially parallel to the lock of hair  1430 . In this configuration an opening is formed between the wires  1420 , allowing feeding of a lock of hair through the assembly  1400 . When the rings  1410  are rotated relative to each other so that or until the wires  1420  extend tangentially to the strand of hair  1430 , then the wires  1420  engage the strand of hair  1430 . The two rings can then be rotated by the motor in this configuration and in unison about the axis of the strand of hair. 
       FIG. 16A  shows another embodiment with an arrangement  1500  similar to that shown in  FIGS. 15A and 15B . The arrangement  1500  comprises two rings  1510  spaced apart along their axis of rotational symmetry. This axis coincides with the axis of the strand of hair  1520  that is to be locked and, for this purpose, to be inserted through the openings in the rings  1510 . The rings  1510  are connected via resilient curved wireforms  1530  and can be displaced along their axis of symmetry relative to each other. In the configuration shown in  FIG. 16A  the rings  1510  are space further apart from each other than in the configuration shown in  FIG. 16B , and therefore stretch the wireforms  1530  more than in  FIG. 16B . For this reason more space is provided at the centre of the embodiment as shown in  FIG. 16A  than in the centre of the embodiment when it is in the configuration shown in  FIG. 16B . In the latter configuration the strand of hair  1520  is engaged and can be locked by rotating the ring  1510  and wireform  1530  arrangement about its axis of rotational symmetry. 
       FIGS. 17A and 17B  show a further embodiment of the invention that is similar to that shown in  FIGS. 16A and 16B  but in which the two rings  1510  and the wireforms  1530  are replaced by an elastically deformable member  1540  that comprises an open bore that is adapted to narrow upon longitudinal compression of the elastically deformable member  1540 . Such compression leads to a releasable engagement of the strand of hair  1520 . 
       FIG. 18  shows a further embodiment of the invention similar to that shown in  FIG. 2 . A motor  120  drives a gearbox  1610  which rotates a first bevel gear  140 . The first bevel gear  140  drives a second bevel gear  150 . A tubular structure  1620  may be located inside of, and driven by, the second bevel gear  150 . In operation, a strand of hair could be fed into the tubular structure and engaged by recesses  330  located at one end of the tubular structure  1620 . 
     The tubular structure  1620  may have a wider opening at the end of the structure into which the stand of hair is intended to be inserted than at the other end. This would allow the hair to be easily fed into the tubular structure  1620  whilst still allowing for the hair to lock properly upon rotation. To further aid this, the internal surface of the tubular structure  1620  may taper inwards from one end to the other. 
     In addition, one or more resilient members  1630  may be provided on the tubular structure  1620 . Each of the resilient members  1630  comprises a protrusion at a free end thereof. These protrusions may engage with corresponding recesses (not shown) on the inside of the second bevel gear  150  in a snap fit arrangement. This would allow the tubular structure  1620  to be removed from the device. This is beneficial as it would allow for the tubular structure  1620  to be cleaned and could facilitate maintenance. It is particularly advantageous to be able to easily clean the tubular structure  1620  as, during operation, it is likely to have extensive contact with hair which is may be coated in wax. 
     Providing the tubular structure such that it can be removed from the other parts of the apparatus also allows the use of different tubular structures. A number of tubular structures could, for example, be provided, wherein the inner diameter of the tubular structure at the end at which the strand of hair is inserted or at the opposite end may differ between different between different tubular structures in the set to allow for locking of different diameter strands of hair. 
     The tubular structure shown in  FIG. 18  also comprises a conical cut in its side wall, opening into a circular opening at its apex for receiving and holding a strand of hair. In addition to the above discussed differences in the internal diameter of the tubular structures, or alternatively thereto, different tubular structures in the set may have conical cuts that taper to different size end openings, so that different diameter strands of hair can be engaged for locking. 
     It will be appreciated that whilst  FIG. 18  and the accompanying description describe one arrangement, the invention is not confined to this one configuration. The invention may include a tubular structure  1620  with a tapered inside surface but might not have snap fits  1630 . Equally, the tubular structure  1620  may include snap fits  330  but may not have a tapered inside surface. 
     It will be appreciated that the above description has been made by way of example only. Various modifications may be implemented by the person skilled in the art, some of which are elaborated upon, albeit again by way of example only. If the strand of hair is engaged by a surface (rather than through engagement by way of a geometry that holds, grips or traps the strand of hair in a way that allows twisting of the strand of hair) the surface may have properties which prevent an undue twisting of the strand of hair. The surface may, for example be configured so that the amount of torque that can be applied to the strand of hair is limited. The surface may, for example have a roughness or unevenness that helps engage the strand of hair under the influence of a biasing of the strand of hair against the surface, while at the same time being made of, coated with or comprising a low friction material that allows slippage between the strand of hair and the surface if the amount of torque applied to the strand of hair is above a maximum value. 
     Alternatively or additionally the motor may be configured so that the maximum amount of torque that it can create is such that the amount of torque that can be applied to the strand of hair (when taking into account any torque conversion that may be achieved by the driveable connection between the motor and the holder) is such that it cannot exceed the maximum value. 
     Alternatively or additionally a clutch mechanism may be provided as part of the drivable connection between the motor and the holder, wherein the clutch causes a transmission of the motor&#39;s rotation to the holder if the torque applied to the strand of hair is below the maximum value and disconnects the drivable connection between the motor and the holder if the torque applied to the strand of hair is above the maximum value. Put in other words, the clutch can be configured to transmit movement if the resistance to such transmission that it experiences is below a desired value and to impede transmission of such movement if the resistance to the transmission of movement is above the desired value. 
     The apparatus may moreover have a speed adjustment means to allow users of varying skill to perform satisfactory and safe locking. 
     It will be appreciated that, while certain of the above embodiments comprise fixation means for impeding a twisting motion of the strand of hair (for example the wires  240  shown in  FIG. 1 , such fixation means are entirely optional and may not be used in other examples. 
     While the present invention has been described above with reference to examples, these examples are not limiting and the scope of the present invention is defined by the following claims.