Abstract:
Some designs of combination padlock allow users of the padlocks to set the combinations that unlock the padlocks. However, the operations which a user must perform to set the combination of a padlock typically involve manipulating the shank of the padlock by pulling the shank away from the housing of the padlock or pushing part of the shank further into the housing of the padlock, rotating the shank through a certain angle, and holding or fixing the shank in this position while rotating dials of the padlock to change the combination. Such operations are fiddly, and it can be difficult to remember what steps are required to change the combination. Thus there is provided a combination padlock which goes some way towards overcoming or at least ameliorating one or more of the above problems.

Description:
[0001]    This invention relates to a combination padlock. In particular, it relates to features of a combination padlock which are involved in setting the combination for the padlock. 
       BACKGROUND OF THE INVENTION 
       [0002]    Combination padlocks typically include a housing part and a padlock shank or shackle. The shank is usually approximately ‘U’-shaped, and the housing part is arranged such that it can receive and retain the ends of the shank in recesses of the housing part. 
         [0003]    The housing part houses a combination locking assembly which is operable between a locked configuration and an unlocked configuration. The combination locking assembly includes several dials which are provided with numbers, letters or other characters. The dials can be rotated and aligned with one another and with a feature of the housing part. When an incorrect combination of characters is aligned with the feature of the housing part, the combination locking assembly will be in the locked combination. When the correct combination of characters is aligned with the feature of the housing part, the combination locking assembly will be in the unlocked configuration. 
         [0004]    When the combination locking assembly is in the locked configuration, the ends of the shank are held in the recesses of the housing part, such that neither end of the shank can be withdrawn from the corresponding recess. When the combination locking assembly is in the unlocked configuration, the shank can be moved a first distance away from the housing part, such that a first end of the shank is withdrawn from its corresponding recess in the housing part. When the first end of the shank has been withdrawn from its corresponding recess, the shank can be rotated relative to the housing part about the shank&#39;s second end, the second end of the shank still being held within its corresponding recess in the housing part. 
         [0005]    If a user of the combination padlock wishes to change the combination of characters which unlocks the combination locking assembly (i.e. the ‘correct’ combination of characters for causing the combination locking assembly to be in the unlocked configuration), the user aligns the dials into the current correct combination of characters, so that the shank can be moved away from the housing part. With the dials aligned in the current correct combination, the user moves the shank the first distance away from the housing part, such that the first end of the shank is withdrawn from the housing part. The user then rotates the shank about its second end through a given angle (commonly 90° or 180°). 
         [0006]    With the shank rotated to the given angle, the user either moves the shank further away from the housing part (i.e. to a second distance greater than the first distance but such that the second end of the shank is still held within its corresponding recess), or causes the shank to move back towards the housing part (i.e. so that the second end of the shank is pushed deeper into its corresponding recess in the housing part but the first end is not within the first end&#39;s corresponding recess). 
         [0007]    This action causes the combination locking assembly to enter a combination setting mode. The user may need to apply a force to the shank and/or housing part (e.g. by pulling or pushing) to overcome a bias which attempts to return the shank to a given displacement relative to the housing part (e.g. the first distance). Furthermore, the user may need to continue applying the force so that the shank remains at the required displacement relative to the housing part while the user sets the combination. Alternatively, the user may be able to rotate the shank to an angle at which the shank is held by the housing part at the right displacement (i.e. the shank is held at the second distance or the second end of the shank is held deeper within its corresponding recess). 
         [0008]    When the shank is held in the correct position, the combination locking assembly is in the combination setting mode. With the combination locking assembly in the combination setting mode, the user moves the dials to align a new combination of characters with the feature of the housing part. 
         [0009]    When the user has aligned the dials in the desired new combination, the user takes the combination locking assembly out of combination setting mode by moving the shank to the position in which it is the first distance away from the housing part, rotating the shank relative to the housing part back through the predetermined angle, and moving the shank towards the housing part so that the first end of the shank is received in the corresponding recess in the housing part. The user can then move the dials away from the new combination so that the combination locking assembly moves from the unlocked configuration to the locked configuration. 
         [0010]    Causing the combination locking assembly to enter the combination setting mode as described above can be difficult because the steps that the user must take to cause entry into the combination setting mode are not intuitive and are easily forgotten if the user does not perform resetting of the combination frequently. 
         [0011]    Furthermore, users are often unsure whether or not the combination locking assembly has successfully entered the combination setting mode, i.e. it is not clear whether the shank has been rotated sufficiently relative to the housing part, and/or it is not clear whether the shank has been displaced sufficiently relative to the housing part, and/or it is not clear whether the user needs to keep the shank and the housing part a certain distance apart from one another or to push the shank and the housing part together in order to cause the combination locking assembly to enter or remain in the combination setting mode. 
         [0012]    Additionally, particularly for smaller padlocks, manipulating a padlock through the steps that are required to enter and leave the combination setting mode can be fiddly. This may make it difficult for people—particularly those with limited motor control or low hand strength—to operate a combination padlock. 
         [0013]    The invention aims to go some way towards overcoming or at least ameliorating one or more of the above problems. 
       SUMMARY OF THE INVENTION 
       [0014]    Accordingly there is provided a combination padlock comprising: a combination locking assembly operable between a locked configuration and an unlocked configuration; a first housing part; and a second housing part connected to the first housing part, the second housing part being movable relative to the first housing part when the locking assembly is in the unlocked configuration, wherein the second housing part is configured to cause the combination locking assembly to enter a combination setting mode when the second housing part is moved relative to the first housing part. 
         [0015]    Preferably the second housing part is configured to cause the combination locking assembly to enter the combination setting mode when the second housing part is moved away from the first housing part, more preferably when the second housing part is moved axially away from the first housing part. Preferably the second housing part is configured to cause the combination locking assembly to enter the combination setting mode when the second housing part is rotated relative to the first housing part. Combination setting mode may be entered via movement of the second housing part away from the first housing part, preferably axially, then subsequent rotation of the second housing part relative to the first housing part. 
         [0016]    Accordingly there is provided a combination padlock comprising: a combination locking assembly operable between a locked configuration and an unlocked configuration; a first housing part which is an upper housing part; and a second housing part connected to the first housing part, the second housing part being a lower housing part, the second housing part being movable relative to the first housing part when the locking assembly is in the unlocked configuration, the second housing part having an upper surface facing towards the first housing part, wherein the padlock is configured such that the combination locking assembly is caused to enter a combination setting mode by movement of the second housing part axially away from the first housing part and the padlock is configured such that rotation of the second housing part relative to the first housing part exposes at least part of the upper surface of the second housing part and maintains the second housing part at its axial displacement from the first housing part, whereby the combination locking assembly is maintained in combination setting mode. 
         [0017]    Preferably the padlock includes at least one stop configured to prevent the second housing part from rotating beyond a predetermined angle relative to the first housing part. 
         [0018]    Preferably the padlock comprises biasing means configured to bias the second housing part towards the first housing part. Preferably the biasing means includes at least one spring. 
         [0019]    Preferably the padlock includes a helical screw thread mechanism. Preferably one of the first housing part and the second housing part includes a male screw thread part and the other of the first housing part and the second housing part includes a female screw thread part. Preferably the male screw thread part and the female screw thread part are configured to engage one another. Preferably the second housing part is arranged to move away from the first housing part when the second housing part rotates in one direction along the screw thread parts and to move towards the first housing part when the second housing part rotates in the opposite direction along the screw thread parts. Preferably the first housing part includes the male screw thread part and the second housing part includes the female screw thread part. 
         [0020]    Preferably the padlock is configured such that the combination locking assembly is caused to enter combination setting mode when the second housing part is moved axially away from the first housing part and the padlock is configured such that rotation of the second housing part relative to the first housing part maintains the second housing part at its axial displacement from the first housing part, whereby the combination locking assembly is maintained in combination setting mode. The second housing part preferably includes an extension extending therefrom which is integral with or rigidly coupled to the second housing part and which extends into the interior cavity of the first housing part and is axially moveable and rotatable with respect to the first housing part, the extension having at least one formation and the first housing part having a corresponding formation on its interior that is engageable with said at least one formation on the extension, the padlock being configured to cause the combination locking assembly to enter combination setting mode when the second housing part is moved axially away from the first housing part, subsequent rotation of the second housing part relative to the first housing part causing said corresponding formations to engage with one another, preventing the combination locking assembly from moving out of combination setting mode whilst the corresponding formations are engaging with one another. The extension of the second housing part may be a spindle. 
         [0021]    Preferably the padlock includes at least one recess in at least one of the first and second housing parts and includes at least one corresponding protrusion on at least the other of the first and second housing parts, said at least one recess and said at least one corresponding protrusion being engageable with one another. Preferably the combination locking assembly is operable between the combination setting mode and a normal mode, wherein said at least one protrusion engages with said at least one corresponding recess in the other of the housing parts when the padlock is in normal mode. Preferably said at least one recess and said at least one corresponding protrusion are complementary in shape. Preferably the protrusion protrudes from an edge of the first housing part or the second housing part. Preferably the protrusion and the exterior surface form a substantially continuous surface. Preferably the protrusion creates a stepped profile to the edge of the first housing part or the second housing part. Preferably the protrusion protrudes from a surface of the first housing part or the second housing part. Preferably the protrusion protrudes in a direction substantially orthogonal to the plane of the surface. 
         [0022]    Preferably the first housing part has an exterior surface and the second housing part has an exterior surface, and wherein the first and second housing parts are sized and shaped such that when the combination locking assembly is not in the combination setting mode the exterior surfaces of the first and second housing parts form a substantially continuous surface. 
         [0023]    Preferably the first housing part has a lower surface facing towards the second housing part and the second housing part has a corresponding upper surface facing towards the first housing part, the padlock having an equilibrium configuration in which the upper surface of the second housing part is flush with the lower surface of the first housing part, the second housing part being rotatably connected to the first housing part, and wherein, when the combination locking assembly is in the combination setting mode, the second housing part having been rotated relative to the first housing part, at least part of the upper surface of the second housing part is exposed. 
         [0024]    Preferably the combination padlock further includes a key-operated locking assembly. At least the second housing part may be provided with an at least partially textured surface. Preferably the first housing part and the second housing part are moulded housing parts. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0025]    Specific embodiments of the invention will now be described by way of non-limiting examples, in which: 
           [0026]      FIG. 1  schematically illustrates an embodiment of a combination padlock with a combination locking assembly in an unlocked configuration; 
           [0027]      FIG. 2  schematically illustrates in side view an embodiment of a combination padlock with a combination locking assembly in an unlocked configuration and in a combination setting mode; 
           [0028]      FIG. 3 a    schematically illustrates in top perspective view an embodiment of a combination padlock with a combination locking assembly in an unlocked configuration and in a combination setting mode; 
           [0029]      FIG. 3 b    schematically illustrates in bottom perspective view the combination padlock of  FIG. 3   a.    
           [0030]      FIGS. 4 a -4 c    schematically illustrate an embodiment of a combination padlock with a combination locking assembly moving into and out of a combination setting mode; 
           [0031]      FIG. 5  schematically illustrates an interior of an embodiment of a combination padlock; 
           [0032]      FIG. 6  schematically illustrates a spindle of one embodiment of a combination padlock; 
           [0033]      FIG. 7  schematically illustrates an interior of an embodiment of a combination padlock; 
           [0034]      FIGS. 8 a -8 c    illustrate an alternative embodiment of a combination padlock with a combination locking assembly moving into and out of a combination setting mode; 
           [0035]      FIG. 9  illustrates in front view the embodiment of  FIGS. 8 a   - 8   c;  and 
           [0036]      FIG. 10  illustrates in side view the embodiment of  FIGS. 8 a -8 c    and  FIG. 9 . 
       
    
    
     DETAILED DESCRIPTION 
       [0037]    The present embodiments represent the best ways currently known to the applicant of putting the invention into practice, but they are not the only ways in which this can be achieved. They are illustrated, and they will now be described, by way of example only. 
         [0038]      FIG. 1  illustrates a combination padlock  11 . The padlock  11  includes a first housing part  12  and a second housing part  13  which are connected to one another in such a way that the housing parts  12 ,  13  can be moved relative to each other when a combination locking assembly of the padlock  11  is in an unlocked configuration. In particular, the housing parts  12 ,  13  can be moved axially away from one another (as illustrated in  FIG. 4 a    and discussed in more detail below) up to a certain distance, and can be rotated relative to each other (as illustrated in  FIG. 4 b    and discussed in more detail below) up to a certain angle. The first housing part is an upper housing part and the second housing part is a lower housing part, the terms upper housing part and lower housing part being used as relative terms to denote the first and second housing parts respectively when the padlock is in the orientation shown in  FIG. 1 . 
         [0039]    As illustrated in  FIG. 1 , the padlock  11  has at least one axis  19 . The padlock  11  also includes: a padlock shank  14  which is approximately U-shaped and arranged such that its ends can be received and retained in recesses of the first housing part  12 ; a plurality of dials  15  provided with numbers, letters and/or other characters, the dials  15  being rotatable so that characters on the dials  15  can be aligned with a feature or features (not illustrated) of the first housing part  12  and/or a feature or features of the second housing part  13 ; protrusions  16 ; and corresponding recesses  17 . For example, the front of the first housing part  12  can have an elongate ink filled trench (not shown in the figures) extending parallel with the axis  19  of the padlock as a feature that the dials can be aligned with, but of course the padlock may have any other suitable feature or features that the dials may align with. 
         [0040]    The padlock  11  further includes a combination locking assembly (not illustrated) which is operable between a locked configuration and an unlocked configuration. The combination locking assembly controls whether or not shank  14  can be moved relative to first housing part  12  and second housing part  13 . The combination locking assembly may be housed by the first housing part  12 , the second housing part  13 , or both of the first and second housing parts  12 ,  13 . 
         [0041]    The combination locking assembly of the padlock  11  in  FIG. 1  is in an unlocked configuration. With the combination locking assembly in the unlocked configuration, the shank  14  can be moved away from the housing parts  12 ,  13 . In particular, the shank  14  can be moved axially away from the housing parts  12 ,  13 , i.e. in a direction substantially parallel to the axis  19  of the padlock  11 . 
         [0042]    When the shank  14  is moved axially away from the housing parts  12 ,  13 , a first end of the shank  14  is withdrawn from a corresponding recess in the first housing part  12 . A second end of the shank  14  remains within its corresponding recess in the first housing part  12 . The shank  14  is able to pivot about the second end of the shank  14  (i.e. the end which remains within its recess). In this configuration, the padlock  11  may be referred to as ‘open’. The open padlock  11  can be applied to, for example, a hasp, a chain, a clasp or another apparatus which can receive the shank  14  of the padlock  11 . 
         [0043]    The combination locking assembly of padlock  11  can also be in a locked configuration. With the combination locking assembly in the locked configuration, the shank  14  cannot be moved away from the housing parts  12 ,  13 . When the combination locking assembly is in the locked configuration, both ends of the shank  14  are held within recesses of the housing part  12  such that the ends of the shank cannot be removed from the recesses. 
         [0044]    Whether the combination locking assembly of the padlock  11  is in the unlocked configuration or the locked configuration depends on whether the correct characters of the dials  15  are aligned with the feature of the housing part. If the correct combination of characters is aligned with the feature, the combination locking assembly will be in the unlocked configuration. If an incorrect combination of characters is aligned with the feature, the combination locking assembly will be in the locked configuration. 
         [0045]    In the example of  FIG. 1 , first housing part  12  and second housing part  13  are moulded housing parts. Each housing part  12 ,  13  is approximately cuboid in shape but with some tapering and with some curved corners and edges. Each housing part  12 ,  13  may house one or more parts or components of the padlock  11 , such as the combination locking assembly. A part or component of the padlock  11  need not necessarily be housed by one of the housing parts only. A portion of a part or component may be housed by the first housing part  12 , and another portion of the same part or component may be housed by the second housing part  13 . 
         [0046]    Each housing part  12 ,  13  is provided with exterior surfaces, which may have surface texture and/or surface decoration. The surface texture or surface decoration may cover one or more areas of the housing parts  12 ,  13 , and may provide greater friction for a user gripping the padlock  11  than an equivalent untextured surface. This may help the user manipulate the first and second housing parts  12 ,  13 . The second housing part  13  may, for example, be provided with an at least partially textured surface. This may make it easier for a user of the padlock  11  to pull the second housing part  13  axially away from the first housing part  12 . 
         [0047]    The housing parts  12 ,  13  are sized and shaped such that, when the padlock  11  is in the configuration illustrated in  FIG. 1 , the exterior surfaces of the housing parts  12 ,  13  form a substantially continuous surface. More generally, at least one exterior surface of a first housing part  12  lies in approximately the same plane as an adjacent exterior surface of the second housing part  13 , and/or is similar in curvature to an adjacent exterior surface of the second housing part  13 , and/or meets an adjacent exterior surface of the second housing part  13  at a point or along a line where the two exterior surfaces have approximately the same tangent plane(s), and/or is otherwise complementarily shaped to form a substantially continuous surface with an adjacent exterior surface of the second housing part  13 . 
         [0048]    In the configuration illustrated in  FIG. 1 , exterior surface  20  of first housing part  12  is positioned adjacent to exterior surface  21  of second housing part  13 . Exterior surfaces  20 ,  21  meet along a line, as illustrated in the figures. Exterior surface  20  is roughly similar in curvature to exterior surface  21  along the line where the exterior surfaces  20 ,  21  meet. Exterior surfaces  20 ,  21  have approximately the same respective tangent planes along the line along which they meet. For instance, the tangent plane of exterior surface  20  at a point X on exterior surface  20  immediately adjacent to the line along which exterior surfaces  20 ,  21  meet is approximately the same as the tangent plane of exterior surface  21  at a corresponding point Y on exterior surface  21  immediately adjacent to the line along which the exterior surfaces  20 ,  21  meet (the two points may, in this example, be on a same or similar axial line through the padlock  11 , for instance). The exterior surfaces  20 ,  21 , when positioned adjacent to one another as illustrated in  FIG. 1 , together present one substantially continuous front surface of the padlock  11 . 
         [0049]    Similarly, the side exterior surfaces of housing parts  12 ,  13  are similar in curvature to one another and meet along lines along which they have approximately the same respective tangent planes. The rear exterior surfaces of housing parts  12 ,  13  are also similar in curvature to one another and meet along a line along which they have approximately the same respective tangent planes. 
         [0050]    The configuration of padlock  11  illustrated in  FIG. 1  may be thought of as a ‘normal’ mode of the padlock  11 . In the normal mode, the combination locking assembly can be locked and unlocked, but the combination locking assembly is not in the combination setting mode. 
         [0051]      FIG. 2  illustrates in side view a combination padlock  11  with its combination locking assembly in an unlocked configuration and in a combination setting mode. As illustrated in  FIG. 2 , first housing part  12  and second housing part  13  have been rotated relative to one another, so that they are at approximately 90° to one another. In this configuration, a user of the padlock  11  can rotate the dials  15  to set a new combination of characters for putting the combination locking assembly in its unlocked mode. 
         [0052]    In  FIG. 2 , it can be seen that first housing part  12  is provided with protrusions  16 , and second housing part  13  is provided with protrusions  18 . In the illustrated example, the padlock  11  has first and second protrusions  16 , and first and second protrusions  18 . However, in other examples, first housing part  12  and second housing part  13  may have different numbers of protrusions, including no protrusions, one protrusion from only one of the housing parts  12 ,  13 , or any other arrangement of protrusions. Second housing part  13  is provided with recesses  17  corresponding and complementary in shape to protrusions  16 . First housing part  12  is provided with recesses  40  (see  FIG. 3 b   ) corresponding and complementary in shape to protrusions  18 . The numbers of recesses corresponds to the numbers of protrusions. In examples where there are no protrusions, there may also be no recesses. 
         [0053]    The protrusions  16  protrude from first housing part  12  as extensions of the front and rear exterior surfaces of first housing part  12 . In the illustrated example, the exterior surfaces of the first housing part  12  are slightly curved. The protrusions  16  are similarly curved so as to form a continuous extension in the axial direction of the curved exterior surfaces. If instead the exterior surfaces of the first housing part  12  were planar (i.e. flat), each protrusion  16  could be substantially coplanar with the planar exterior surface. The protrusions  16  may be formed as parts of the exterior surfaces so that the protrusions  16  are integral parts of the first housing part  12 , or may be affixed to the exterior surfaces, e.g. using an adhesive or a moulding technique such as two-shot moulding. 
         [0054]    The protrusions  16  create ‘stepped’ profiles to the lower edges of the front and rear exterior surfaces of the first housing part  12 . This can be seen in  FIGS. 4 a  and 4 b   , for example, in which the lower edge  20   a  of exterior surface  20  is smoothly curved from the left-hand side to the point at which the protrusion  16  protrudes from the exterior surface  20 , and the lower edge  20   b  of exterior surface  20  is smoothly curved from the right-hand side to the point at which the protrusion  16  protrudes from the exterior surface  20 . The protrusion  16  has a lower edge  16   b  which is approximately parallel to the curved line defined by the lower edges  20   a  and  20   b  of the exterior surface  20 , and has two further edges  16   a  and  16   c  which, in the illustrated example, are approximately straight lines joining the edges  20   a ,  16   b  and  20   b . In some embodiments, one or more of the protrusions  16  may bear a badge, an insignia or another visual mark, such as the Transport Security Administration (TSA) lock symbol. 
         [0055]    In the illustrated example, recesses  17  are shallow depressions in the outer surface of second housing part  13 . Each recess  17  is shaped to receive a corresponding protrusion  16 . 
         [0056]    In the illustrated example, each protrusion  18  protrudes from an upper surface  34  of the second housing part  13 . The upper surface  34  of the second housing part  13  faces at least partially towards the first housing part  12 . Each protrusion  18  protrudes from the upper surface  34  in a direction substantially parallel to the axis  19  of the padlock  11 , towards the first housing part  12 . 
         [0057]    The first housing part  12  has a lower surface  32  which faces towards the second housing part  13  and which is sized and shaped (in particular, has an appropriate degree of curvature—including the possibility of no curvature) so that the lower surface  32  of the first housing part  12  and the upper surface  34  of the second housing part  13  correspond with one another and can meet flushly with one another when the first and second housing parts  12 ,  13  are aligned with each other. 
         [0058]    The lower surface  32  of the first housing part  12  includes the recesses  40  (see  FIG. 3 b   ) which correspond and are complementary in shape to protrusions  18 . Thus the exterior surface of the second housing part  13  has a stepped profile corresponding to the stepped profile of the exterior surface of first housing part  12 . Moving the housing parts  12 ,  13  away from one another and rotating the housing parts  12 ,  13  relative to one another exposes at least part of the lower surface  32  of first housing part  12  and at least part of the upper surface  34  of second housing part  13 . 
         [0059]    The recesses and protrusions are engageable with one another. Protrusions  16  can engage with recesses  17 , and protrusions  18  can engage with recesses  40 . The recesses and protrusions are sized and shaped such that they engage with one another while the housing parts  12 ,  13  are immediately adjacent to one another and are aligned with one another (i.e. the housing parts  12 ,  13  are in the configuration illustrated in  FIG. 1 ). In particular, the lengths of the protrusions and the depths of the recesses are such that the protrusions and recesses engage when the first and second housing parts  12 ,  13  are positioned immediately adjacent to one another and disengage when the first and second housing parts  12 ,  13  are moved away from one another. 
         [0060]    The configuration of the padlock  11  in which first housing part  12  and second housing part  13  are aligned with one another, the lower surface  32  of first housing part  12  being flush with the upper surface  34  of second housing part  13 , and the exterior surfaces of the housing parts  12 ,  13  are flush with one another, giving a substantially continuous surface to the padlock  11 , may be an equilibrium configuration of the padlock  11 , i.e. a configuration to which the padlock  11  may try to return and/or in which the padlock  11  may attempt to stay. The housing parts  12 ,  13  may be biased such that they attempt to return to this position, though other components of the padlock  11  (such as protrusions and/or recesses) may in some circumstances prevent the housing parts  12 ,  13  from returning to the equilibrium position. 
         [0061]      FIG. 3 a    illustrates in top perspective view the padlock  11  of  FIG. 2  with its combination locking assembly in the combination setting mode. As can be seen in  FIG. 3 a   , the protrusions  18  of second housing part  13  include, in this example, an indicator bearing the word ‘set’. The indicator informs a user of the padlock that the combination locking assembly of the padlock  11  is in combination setting mode, i.e. that the user can set a new combination of characters for putting the combination locking assembly of the padlock  11  in its unlocked configuration. 
         [0062]    The indicator of protrusion  18  is only revealed when the first housing part  12  and the second housing part  13  have been moved away from one another and rotated relative to one another, i.e. when the combination locking assembly has been put in the combination setting mode. Thus there are at least two clear visible and tangible features of the padlock  11  which inform the user of the padlock  11  that the combination locking assembly is in the combination setting mode: the housing parts  12 ,  13  are visibly and tangibly at 90° relative to one another, and the protrusions  18  (and their indicators) have been revealed for viewing and/or touching by a user. Thus a user can be certain whether he or she has successfully put the combination locking assembly into combination setting mode. 
         [0063]      FIG. 3 b    illustrates in bottom perspective view the padlock  11  of  FIG. 2  and  FIG. 3 a   , with recesses  40  in first housing part  12  visible in the lower surface  32  of first housing part  12 . In the embodiment illustrated in  FIG. 3 b   , the second housing part  13  also includes an aperture through which a key or other similar entity can be inserted to operate a key-operated locking assembly of the padlock  11 , as discussed in more detail below. Embodiments of the padlock  11  which do not include a key-operated locking assembly do not necessarily include an aperture through which a key can be inserted. 
         [0064]      FIGS. 4 a -4 c    illustrate movements of a padlock that put the combination locking assembly of the padlock into the combination setting mode. 
         [0065]      FIG. 4 a    illustrates the padlock  11  with its combination locking assembly in unlocked configuration (i.e. with the correct character or combination of characters aligned with the feature of the first housing part  12  or second housing part  13 ) and with the housing parts  12 ,  13  aligned with one another and positioned immediately adjacent to one another. 
         [0066]    As indicated by the arrows in  FIG. 4 a   , the second housing part  13  is moved, relative to the first housing part  12 , axially away from the first housing part  12 , withdrawing protrusions  16  of first housing part  12  from their corresponding recesses  17  in second housing part  13 , and withdrawing protrusions  18  of second housing part  13  from their corresponding recesses  40  in first housing part  12 . 
         [0067]    Moving the second housing part  13  away from the first housing part  12  may involve overcoming biasing means (such as a spring or other elastic component) which is configured to bias the second housing part  13  towards the first housing part  12 . The biasing means may help to prevent the combination locking assembly from being inadvertently put in the combination setting mode and the ‘correct’ combination for putting the combination locking assembly in the unlocked configuration from being inadvertently changed. 
         [0068]    In some embodiments, moving the second housing part  13  a predetermined distance away from the first housing part  12  may be sufficient to put the combination locking assembly into the combination setting mode. Moving the second housing part  13  away from the first housing part  12  may arrange internal clutches of the combination locking assembly such that the combination locking assembly is in the combination setting mode and the dials  15  can be rotated to set a new ‘correct’ combination of characters. 
         [0069]    To prevent the user from needing to hold the first housing part  12  and the second housing part  13  away from one another to keep the combination locking assembly in combination setting mode, the padlock  11  may be provided with features which can restrict the movement of the second housing parts  13  axially towards the first housing part  12 . For example, in some embodiments, a user may rotate the housing parts  12 ,  13  so that at least part of the lower surface  32  of the first housing part  12  rests against at least part of the upper surface  34  of the second housing part  13 , keeping the housing parts  12 ,  13  the predetermined distance away from each other. In the illustrated example, a spindle  27  of the padlock  11  (see  FIGS. 6 and 7 ) is configured such that it can keep the housing parts  12 ,  13  the predetermined distance away from each other, as will be described in more detail below. 
         [0070]      FIG. 4 b    illustrates the padlock  11  after the first housing part  12  and the second housing part  13  have been rotated through a predetermined angle (in this case 90°) relative to one another (as indicated by the arrow beneath padlock  11  in  FIG. 4 b   ). When the housing parts  12 ,  13  have been rotated through the predetermined angle, the protrusions  18  are exposed for the user to view and feel, confirming that the combination locking assembly is in the combination setting mode. 
         [0071]    In embodiments which include biasing means, the biasing means may, after the first and second housing parts  12 ,  13  have been rotated relative to one another through the predetermined angle, cause the second housing part  13  to return a small distance towards the first housing part  12  if the user stops applying a force to move or keep the second housing part  13  away from the first housing part  12 . The padlock  11  is however configured such that, when the housing parts  12 ,  13  have been rotated relative to one another, the housing parts  12 ,  13  are kept a sufficient distance apart for the combination locking assembly to be kept in the combination setting mode (even if the housing parts  12 ,  13  do return a short distance towards each other). This may be achieved by a spindle  27  of the padlock  11  (as explained below in the context of  FIGS. 5 to 7 ), by virtue of the housing parts  12 ,  13  resting against one another under the action of the biasing means, or by other suitable means. 
         [0072]    The upper surface  34  of the second housing part  13  and the lower surface  32  of the first housing part  12  may for example be arranged such that, when the housing parts  12 ,  13  are rotated relative to one another and the biasing means returns the second housing part  13  a small distance towards the first housing part  12 , the lower and upper surfaces  32 ,  34  rest against one another in such a way as to keep the housing parts  12 ,  13  sufficiently far apart that the combination locking assembly remains in the combination setting mode. The edges of one or both of the housing parts  12 ,  13  may for example be raised edges which rest against the opposing housing part to keep the housing parts  12 ,  13  sufficiently far apart. 
         [0073]    Alternatively or additionally, the protrusions  16  and/or  18  may be configured to rest against or in the surface of the opposite housing part to keep the first and second housing parts  12 ,  13  a sufficient distance apart when the housing parts  12 ,  13  have been rotated relative to each other. 
         [0074]    Other means for keeping the housing parts  12 ,  13  a sufficient distance apart may also be provided, such as additional protrusions or internal means for counteracting or disabling the biasing means when the housing parts  12 ,  13  have been rotated relative to one another. 
         [0075]    With the padlock  11  in the configuration shown in  FIG. 4 b   , the combination locking assembly is in the combination setting mode. The user of the padlock  11  can move the dials  15  to choose a new combination of characters for putting the combination locking assembly in its unlocked configuration, by moving the dials  15  to align the new characters with the feature(s) of the first housing part  12  and/or the second housing part  13 . 
         [0076]    Once the user has aligned the dials  15  into the desired combination, the user rotates the housing parts  12 ,  13  relative to one another back (in the opposite direction to before) through the predetermined angle (90° in the illustrated example), as indicated by the curved arrow in  FIG. 4 c   . In some embodiments, the user may need to move the housing parts  12 ,  13  slightly away from one another to be able to rotate the first and second housing parts  12 ,  13  from the configuration illustrated in  FIG. 4 b    to the configuration illustrated in  FIG. 4 a   . The protrusions  16 ,  18  might impede rotational motion of the housing parts  12 ,  13  relative to one another unless the housing parts  12 ,  13  are moved slightly away from one another so that the protrusions  16 ,  18  do not rest on or in the opposing housing parts. 
         [0077]      FIG. 5  schematically illustrates an interior of the padlock  11 , including an interior cavity in which a spindle  27  (see  FIG. 6 ) resides. The front of the first housing part  12 , the spindle  27  and some other internal elements of the padlock  11  are not shown in  FIG. 5  so that features of the housing parts  12 ,  13  which would have been obscured by the spindle  27  and other internal elements are visible. 
         [0078]      FIG. 5  illustrates recesses  22 ,  23  in the first housing part  12  which can receive and retain the first and second ends of the shank  14 .  FIG. 5  also illustrates a stop  25  which can keep the first and second housing parts  12 ,  13  a sufficient axial distance apart for the combination locking assembly to be kept in the combination setting mode, and/or which can prevent the second housing part  13  from rotating beyond the predetermined angle relative to the first housing part  12 , as described in more detail below. In some embodiments, there may be only one stop  25 . However, in other embodiments, there may be several such stops positioned at different points around the circumference of the first housing part  12 . In the illustrated example, an identical stop is provided at an opposite point on the first housing part  12  (i.e. at approximately 180° to the illustrated stop  25 ). The opposing stop is not included in the illustration of  FIG. 5  as it would obscure other features of the padlock  11 . In the illustrated example a second stop  26  to prevent the second housing part  13  from rotating beyond the predetermined angle relative to the first housing part  12  is provided on the first housing part  12 , there being a further stop (not shown) identical to stop  26  at an opposite point on the first housing part  12 . 
         [0079]    In the illustrated example, the first housing part  12  includes an internal cylinder enclosing a cylindrical interior cavity. Stop  25  is a projection from the internal cylinder of the first housing part  12 , the stop  25  having approximately the same curvature as the cylinder, though in other examples the stop  25  need not be curved. The stop  25  projects from the internal cylinder in a direction roughly parallel to the axis  19  of the padlock, and extends for a portion of the circumference of the cylinder. The stop  25  includes surfaces  25   a  and  25   c  which extend in a direction approximately parallel to the axis  19  of the padlock  11  and face in directions roughly orthogonal to the axis of the padlock  11  (i.e. which face in directions which are roughly tangential to the curved wall of the internal cylinder in the illustrated example). The stop  25  also includes a surface  25   b  which extends in a direction approximately orthogonal to the axis  19  of the padlock  11  and faces in a direction approximately parallel to the axis  19  of the padlock  11 . The second stop  26  is a surface extending parallel to the axis  19  of the padlock and forms the end of a recessed channel  31  extending partway around the internal cylinder of the first housing part. 
         [0080]      FIG. 6  illustrates a spindle  27  of the padlock  11 , with an axis  30 . Spindle  27  and second housing part  13  are attached to one another such that spindle  27  and second housing part  13  move substantially together relative to the first housing part  12 . In particular, the spindle  27  is sized and shaped such that it can move axially and rotate within the cylindrical interior cavity of the first housing part  12  illustrated in  FIG. 5 . When the spindle  27  is within the padlock  11  (i.e. during ordinary operation of the padlock  11 ), the axis  30  of the spindle  27  and the axis  19  of the padlock  11  may be roughly parallel and may coincide with one another (i.e. may be collinear). 
         [0081]    The spindle  27  includes at least one spindle edge  28  and at least one spindle tip  29 . The spindle edge  28  includes a surface  28   a  which extends in a direction approximately parallel to the axis  30  of the spindle and which faces in a direction approximately orthogonal to the axis  30  of the spindle  27 . The spindle tip  29  includes a surface  29   a  which extends in a direction roughly orthogonal to the axis  30  of the spindle  27  and which faces in a direction roughly parallel to the axis  30  of the spindle  27 . Protruding outwardly from the side of the spindle edge  28  is a spindle protrusion  33  having a surface  33   a  which extends in a direction approximately parallel to the axis  30  of the spindle and which faces in a direction approximately orthogonal to the axis  30  of the spindle  27 . In the illustrated example, there are two spindle edges  28 , two spindle tips  29  and two spindle protrusions  33 , the spindle edges  28  positioned on opposite sides of the spindle  27  from one another (i.e. separated by approximately 180° around the spindle  27 ), the spindle tips  29  positioned on opposite sides of the spindle  27  from one another (i.e. separated by approximately 180° around the spindle  27 ) and the spindle protrusions  33  positioned on opposite sides of the spindle  27  from one another (i.e. separated by approximately 180° around the spindle  27 ). In other examples, there may be other numbers of spindle tips  29 , spindle edges  28  and spindle protrusions  33 , such as only one of each, or more than two of each. 
         [0082]    When the spindle  27  is within the interior cavity of the padlock  11  for ordinary operation of the padlock  11  and the padlock  11  is in ‘normal’ mode (not configuration setting mode), stop  25  is positioned in a recess  36  of the spindle  27 . The second, not-illustrated stop discussed above may be positioned in a not-illustrated recess of the spindle  27 , and the following description may apply equally to the second, not-illustrated stop. 
         [0083]    When the stop  25  is in recess  36 , the stop  25  prevents the spindle  27  from rotating within the internal cylinder. The surfaces  25   a ,  25   c  of the stop  25  are arranged such that they can abut corresponding surfaces of the spindle edge  28  and/or spindle tip  29  to prevent the spindle  27  from rotating (or to limit the spindle  27  to rotating through only a small angle). The stop  25  extends axially into the recess  36  from the internal cylinder of the first housing part  12 . In this configuration, a lower surface of the internal cylinder may contact an upper surface of the spindle edge  28 , which prevents the spindle  27  (and attached second housing part  13 ) from moving axially further towards the first housing part  12 . Alternatively, the lower surface of the internal cylinder and the upper surface of the spindle edge  28  may not contact each other, and instead different parts of the padlock  11  (such as lower surface  32  of first housing part  12  and upper surface  34  of lower housing part  13 ) may prevent the spindle  27  (and attached second housing part  13 ) from moving axially further towards the first housing part  12 . 
         [0084]    When the combination locking assembly of padlock  11  is to be put into its combination setting mode, the user of the padlock  11  first applies a force to the second housing part  13  to move the second housing part  13  (and attached spindle  27 ) axially away from the first housing part  12 . Moving the second housing part  13  (and spindle  27 ) a certain distance away from the first housing part  12  removes the stop  25  from the recess  36 , allowing the second housing part  13  and spindle  27  to rotate relative to the first housing part  12 . 
         [0085]    The user of the padlock  11  then rotates the second housing part  13  through a sufficiently large angle that at least part of surface  25   b  of the stop  25  overlaps with and can contact at least part of surface  29   a  of spindle tip  29  to prevent the spindle  27  and second housing part  13  from moving axially towards the first housing part  12 . The user may then stop applying the force to move the second housing part  13  and spindle  27  away from the first housing part  12 . The second housing part  13  and spindle  27  may move slightly towards the first housing part  12 , until the surfaces  25   b  and  29   a  contact and engage with each other. Surfaces  25   b  and  29   a  contacting each other prevents the second housing part  13  from moving further towards the first housing part  12 . The relative axial movement of the first and second housing parts  12 ,  13  is restricted by the stop  25  and the spindle tip  29  contacting each other. 
         [0086]    In this configuration (in which surface  25   b  of stop  25  contacts surface  29   a  of spindle tip  29 ), the stop  25  occupies part of a cavity which is defined by the spindle edge  28  and the spindle tip  29  and which extends part of the way round the circumference of the spindle  27  (for the circumferential length of the surface  29   a  of spindle tip  29 ). 
         [0087]    While the stop  25  occupies part of the cavity defined by the spindle edge  28  and the spindle tip  29  (i.e. while the surface  25   b  contacts and engages or almost contacts and engages with surface  29   a ), the spindle  27  is able to rotate about its axis  30  until one of the surfaces of spindle edge  28  which extends in a direction approximately parallel to axis  30  (e.g. surface  28   a ) contacts a corresponding surface of the stop  25  (e.g. surface  25   c ). Contact of surface  25   c  with surface  28   a  defines a predetermined angle that the spindle can rotate through. When the spindle has been rotated by the predetermined angle, surface  33   a  of spindle protrusion  33  contacts second stop  26  on the first housing part  12 , therefore acting as a second stop means to prevent further rotation. In some embodiments, there may of course be no spindle protrusion  33  and no corresponding second stop  26  acting as a second stop means. The surfaces  25   b ,  29   a  may in some embodiments be low-friction surfaces which provide only a small resistance to the relative rotation of the first and second housing parts  12 ,  13  while the surfaces  25   b ,  29   a  are in contact. 
         [0088]    The sizing, shaping and positioning of the stop  25 , the spindle edge  28  and the spindle tip  29  define the predetermined angle through which the spindle  27  can rotate before the stop  25  makes contact with the spindle edge  28 . The longer the circumferential extension of the stop  25  and/or the shorter the circumferential extension of the cavity defined by the spindle edge  28  and the spindle tip  29 , the smaller the angle through which the spindle  27  can rotate. However, while the stop  25  occupies the cavity and the surface  25   b  contacts the surface  29   a , the second housing part  13  cannot move towards the first housing part  12 . The user is prevented from rotating the first and second housing parts  12 ,  13  relative to each other beyond the predetermined angle by the abutment of one of the surfaces  25   a ,  25   c  of the stop  25  of the first housing part  12  with one of the surfaces (e.g.  28   a ) of a spindle edge  28 . 
         [0089]    In some examples, the action of moving the second housing part  13  axially away from the first housing part  12  (e.g. such that the stop  25  is withdrawn from the recess  36 ) may be sufficient to cause the combination locking assembly to enter the combination setting mode. It may not be necessary to rotate the second housing part  13  relative to the first housing part  12  to cause the combination locking assembly to enter the combination setting mode. In such examples, the action of rotating the second housing part  13  relative to the first housing part  12  so that surfaces  25   b  and  29   a  at least partially overlap may simply provide additional convenience, in that the user of the padlock  11  does not need to hold the second housing part  13  axially away from the first housing part  12  while setting a new combination, because the surfaces  25   b  and  29   a  can contact each other and keep the housing parts  12 ,  13  apart. 
         [0090]    In other examples, the action of moving the second housing part  13  axially away from the first housing part  12  (e.g. such that the stop  25  is withdrawn from the recess  36 ) may not be sufficient to cause the combination locking assembly to enter the combination setting mode. In such examples, the action of rotating the second housing part  13  relative to the first housing part  12  may be required to cause the combination locking assembly to enter combination setting mode. In such examples, the spindle tip  29  may be arranged such that its surface  29   a  forms a roughly helical line around the spindle  27 . This may be achieved by a variable thickness of the spindle tip  29  around the circumference of the spindle  27 , or by mounting the spindle tip  29  in a plane which is not orthogonal to the axis of the spindle  27 , such that the spindle tip  29  traces a helical path around the spindle  27 . As a consequence, rotating the second housing part  13  relative to the first housing part  12  while the surface  25   b  of the stop  25  and the surface  29   a  of the spindle tip  29  are in contact may cause the first and second housing parts  12 ,  13  to move further apart by virtue of the contact between the stop  25  and the spindle tip  29 . 
         [0091]    The spindle  27  is affixed to the second housing part  13  so that the spindle  27  and the second housing part  13  rotate substantially together relative to the first housing part  12 , i.e. so that the spindle  27  rotates within the interior cavity of the first housing part  12  when the second housing part  13  is rotated by a user of the padlock  11 . The spindle  27  may for instance be formed as an integral part of the second housing part  13 , or may be fixed to the second housing part  13  by means of an adhesive, a moulding process, a snap- or push-fit mechanism, or another suitable fixing means or method. In the illustrated example, the spindle  27  and the second housing part  13  are fixed together by means of protrusions  38  which protrude from spindle  27  and which, during normal operation of the padlock  11 , are positioned within corresponding recesses  39  in second housing part  13  (see  FIGS. 5 to 7 ). 
         [0092]    The protrusions  38  and recesses  39  correspond in circumferential size and shape such that the protrusions  38  fill the recesses  39  in a circumferential direction and force can be transferred between the spindle  27  and the second housing part  13  by means of the contact surfaces of the protrusions  38  and corresponding recesses  39 . In particular, the protrusions  38  and recesses  39  are arranged such that rotational movement of the second housing part  13  relative to the first housing part  12  effects rotational movement of the spindle  27 , by virtue of forces transferred between the contact surfaces of the protrusions  38  and the recesses  39 . 
         [0093]    Additionally, an upper surface of a protrusion  38  is arranged such that it can abut a lip/shoulder of a recess  39  (as viewed in  FIG. 7 ) to allow force to be transferred from the second housing part  13  to the spindle  27  to pull the spindle  27  axially away from the first housing part  12 . In this way, a user applying a force to the second housing part  13  to move the second housing part  13  axially away from the first housing part  12  causes the spindle  27  to move axially away from the first housing part  12  within the first housing part  12 . 
         [0094]    A biasing force may be applied (e.g. by a spring or other biasing component of the padlock  11 ) to the spindle  27  to try to move the spindle  27  axially towards the first housing part  12 . The biasing force may attempt to cause surface  29   a  of the spindle tip  29  to directly abut surface  25   b  of stop  25 , or may try to cause the stop  25  to enter the recess  36 , depending on the relative angular position of the first and second housing parts  12 ,  13  (and therefore the relative angular position of the first housing part  12  and the spindle  27 ). However, a user of the padlock  11  applying a sufficient force to the second housing part  13  to overcome the biasing force can move the spindle  27  axially away from the surface  25   b  of the stop  25 . 
         [0095]    Features of the first housing part  12  and the spindle  27  may prevent the user from moving the spindle  27  (and thus the second housing part  13 ) beyond a certain distance axially away from the first housing part  12 . First housing part  12  may for instance include a protrusion (e.g. a lip or a shoulder) against which part of the spindle  27  can abut to prevent the spindle  27  (and thus the second housing part  13 ) from moving too far away from the first housing part  12 . In the illustrated example, an underside  41  of spindle tip  29  (as viewed in  FIG. 6 ) is arranged such that it can abut a lip/shoulder  42  of first housing part  12  if second housing part  13  is moved a certain distance axially away from first housing part  12 . The underside  41  of spindle tip  29  may abut the lip/shoulder  42  of first housing part  12  directly, or may abut an intervening component or intervening components to abut the lip/shoulder  42  indirectly. 
         [0096]    The stop  25  and the spindle edge  28  each extend in a direction approximately parallel to the axes  19 ,  30  sufficiently far that the stop  25  and the spindle edge  28  at least partially overlap in the direction approximately parallel to the axes  19 ,  30 . In other words, irrespective of the axial separation between surfaces  25   b  and  29   a  (within the limits defined by the underside  41  of the spindle tip  29  and the lip/shoulder  42 , for example), portions of the surfaces of the stop  25  and spindle edge  28  which extend in a direction approximately parallel to the axes  19 ,  30  ( 25   c  and  28   a , for example) will overlap in the direction approximately parallel to the axes  19 ,  30 . As a consequence, the spindle edge  28  will contact the stop  25  if the first and second housing parts  12 ,  13  are rotated sufficiently far relative to one another, no matter how far the user of the padlock  11  has pulled the second housing part  13  away from the first housing part  12  within the range allowed by the features  41 ,  42 . 
         [0097]      FIG. 7  illustrates an interior of the padlock  11  including some of the interior features of the padlock  11  that were not illustrated in  FIG. 5 . These include, for example, the spindle  27  and biasing means (in this example a spring  43 ) for applying a force to the second housing part  13  to try to move the second housing part  13  towards the first housing part  12 . 
         [0098]      FIGS. 8 a -8 c    illustrate an alternative combination padlock  81  moving into and out of a combination setting mode. The padlock  81  includes a first housing part  82  and a second housing part  83  which are similar in form to the first and second housing parts  12 ,  13  of the padlock  11  of  FIGS. 1-7 . 
         [0099]    Padlock  81  also includes a helical screw thread mechanism. In the illustrated example, a cylindrical shaft  91  protrudes from the first housing part  82 . The cylindrical shaft  91  of the first housing part includes a male screw thread part  92 . The second housing part  83  includes a female screw thread part on an interior part (not shown) of the second housing part  83 . The male screw thread part and the female screw thread part are configured to engage one another. The male and female screw thread parts may, for example, have corresponding pitches, corresponding major and minor diameters, and corresponding pitch diameters. The screw threads may also have other corresponding properties, such as corresponding thread tapers. In other examples, the cylindrical shaft  91  of the first housing part  82  may include a female screw thread part, and the second housing part  83  may include a male screw thread part. 
         [0100]    As illustrated in  FIG. 8 a   , a user of the padlock  81  moves the second housing part  83  away from the first housing part  82 , e.g. by applying a pulling force to the second housing part  83 . Moving the second housing part  83  away from the first housing part  82  reveals the cylindrical shaft  91  including the male screw thread part  92 . As can be seen in  FIG. 8 b    and  FIG. 10 , the cylindrical shaft  91  also has an unthreaded section at the end nearest the first housing part  82 . 
         [0101]    When the user of the padlock  81  has moved the housing parts  82 ,  83  a sufficient distance apart, the male screw thread part  92  of the first housing part  82  will be in contact with the female screw thread part on the interior collar of the second housing part  83 . 
         [0102]    Once the female screw thread part and the male screw thread part are in contact with one another, the user may rotate the second housing part  83  relative to the first housing part  82  in a first direction, as indicated by the curved arrow in  FIG. 8 b   . This rotation causes the male and female screw thread parts to engage one another. 
         [0103]    As the user continues to rotate the first and second housing parts  82 ,  83  relative to each other and the second housing part  83  rotates along the screw thread parts (i.e. along the helical path defined by the screw thread parts), the second housing part  83  moves further away from the first housing part  82 , as indicated by the downward arrows in  FIG. 8 b   , as well as rotating relative to the first housing part  82 . The additional separation distance between the housing parts  82 ,  83  causes a combination locking assembly of the padlock  81  to enter its combination setting mode. The user of the padlock  81  is then able to align dials of the padlock  81  with a feature or features of one or both of the housing parts  82 ,  83  to set a new ‘correct’ combination of characters to put the padlock  81  in its unlocked configuration. 
         [0104]    When the user has aligned the dials of the padlock  81  into the desired combination of characters, the user rotates the second housing part  83  relative to the first housing part  82 , in the opposite direction to the previous direction of rotation (as indicated by the curved arrow in  FIG. 8 c   ). This causes the second housing part  83  to move towards the first housing part  82 , as indicated by the upward arrows in  FIG. 8 c   . When the second housing part  83  has reached the end of the helical curve defined by the screw thread parts, the screw thread parts disengage one another, and the second housing part  83  can be moved towards the first housing part  82  so that the housing parts  82 ,  83  abut one another, as illustrated in  FIG. 9 . 
         [0105]      FIG. 9  illustrates a front view of the padlock  81  with its combination locking assembly in a ‘normal mode’, i.e. not in a combination setting mode. The padlock  81  may, in the illustrated configuration (i.e. with its first and second housing parts  82 ,  83  immediately adjacent to one another and aligned with one another), be visually indistinguishable from the padlock  11  of  FIGS. 1-7 . 
         [0106]      FIG. 10  illustrates in side view the padlock  81  with its combination locking assembly in an unlocked configuration and in a combination setting mode. The male screw thread  92  is visible on the cylindrical shaft  91  between the first housing part  82  and the second housing part  83 . Being able to see the male screw thread part  92  may help a user of the padlock  81  remember or determine which direction second housing part  83  must be rotated in relative to first housing part  82  to take the combination locking assembly out of combination setting mode. 
         [0107]    Padlock  81 , like padlock  11 , may be provided with one or more internal stops which prevent the first and second housing parts  82 ,  83  rotating beyond a predetermined angle relative to one another. Additionally or alternatively, a feature of the male and/or female screw thread parts may prevent the screw thread parts from disengaging one another at one end of the helical path defined by the screw thread parts, i.e. it may prevent the housing parts  82 ,  83  from rotating beyond the end of the helical path defined by the screw thread parts. Alternatively or additionally, the padlock  81  might be provided with means for preventing the housing parts  82 ,  83  from moving too far apart if the housing parts  82 ,  83  do rotate beyond the end of the helical path. 
         [0108]    Padlock  81  may be provided with any of the other features of padlock  11 , such as protrusions, recesses and/or set indicators, for example. The padlock  81  might for instance feature biasing means to try to cause the second housing part  83  to return towards the first housing part  82 . However, at least in some examples, the biasing means may not apply sufficient force to cause the second housing part  83  to rotate along the helical path back towards the first housing part  82 . The frictional resistance provided by the parts of the screw thread mechanism may be sufficient to prevent the first and second housing parts  82 ,  83  from rotating relative to each other. 
         [0109]    In padlock  11  and padlock  81 , each dial  15  comprises a plurality of slots (not visible in the figures) formed on the dial&#39;s inside surface, each slot for receiving and engaging a radially extending fin (not visible in the figures) of a corresponding clutch. Each clutch is received around the spindle  27 , and its corresponding dial is received around the clutch, the clutches being able to freely rotate around the spindle  27 . The internal cavity of the first housing part  12 , in which the clutches reside, is configured such that axial movement of each clutch is prevented (and therefore axial movement of the spindle  27  is also prevented) unless the fin of each clutch is aligned with a corresponding slot (not visible in the figures) within the internal cavity of the first housing part  12 . 
         [0110]    When the fins are aligned with their corresponding slots in the internal cavity of the first housing part  12 , the clutches are able to be moved axially downwards relative to the first housing part  12 , and therefore the spindle  27  is also able to be moved axially in a direction away from the first housing part  12 . 
         [0111]    The padlock  11 ,  81  is configured such that the fins are aligned with their corresponding slots when the dials  15  are aligned with the correct combination of characters to put the padlock  11 ,  81  into the unlocked configuration. When the dials  15  are aligned in this way, the user is able to move the second housing part  13  away from the first housing part  12 , moving the spindle  27  in a direction away from the first housing part  12 , thus moving the clutch fins out of engagement with their corresponding dials  15 , allowing the user to change the combination of characters which unlocks the combination locking assembly. 
         [0112]    Some (though not necessarily all) padlocks as previously described may be provided with a key-operated locking assembly. The key-operated locking assembly may enable a user of the padlock equipped with an appropriate key to open the padlock without knowing the combination for the padlock and without setting a new combination for the padlock. The key-operated locking assembly may operate independently of the combination locking assembly, and/or may override the combination locking assembly so that the combination locking assembly unlocks when the key-operated locking assembly is actuated with an appropriate key. The key may be inserted into the key-operated locking assembly through an aperture in second housing part  13 ,  83 , for example (such as the aperture illustrated in  FIG. 3 b   ). 
         [0113]    Although the padlocks illustrated in the Figures include first and second housing parts which are approximately cuboid in shape, other shapes of padlock housing parts are possible. The housing parts may, for instance, be prisms of any shape, such as approximately circular, triangular, pentagonal, hexagonal, etc. The housing parts may be tapered and/or may change shape along one of their lengths. 
         [0114]    Although the illustrated first and second housing parts correspond with one another in shape and sizing and have corresponding exterior surfaces, in other embodiments the first housing part may be different in size, shape and exterior surface from the second housing part. In some embodiments the housing parts may not correspond to one another or be similar. 
         [0115]    Although in some examples movement of a second housing part has been described as towards or away from a first housing part, a skilled person appreciates that this is equivalent to the first housing part moving towards or away from the second housing part in a different reference frame, and to the two housing parts moving towards each other or away from each other in a third reference frame. Thus movement of the first and second housing parts should be considered to be relative movement of the parts away from or towards each other. 
         [0116]    A padlock as described above may be said to be in combination setting mode when the combination locking assembly of that padlock is in combination setting mode. A combination locking assembly may also be referred to as a combination setting assembly.