Abstract:
A jewellery retention device for fastening a jewellery item which comprises a retention post, said retention device comprising a body and having an opening configured to receive a post, said retention device comprising a friction member having a first end associated with the body and a second end which is configured to be contacted by the post upon insertion of the post, said body additionally providing an abutment to support the post and provide a reaction to the force imposed on the post by said second end of the friction member, said opening comprising at least in part a receiving region through which the post may move substantially freely and into which the post may be laterally displaced and received from between the first friction member and abutment in a direction substantially perpendicular to the length of the post.

Description:
BACKGROUND 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to a retention device for securing an object in position. Specifically, but not exclusively, it relates to the securing of jewellery such as piercings in, for example, ears. 
         [0003]    2. Description of the Prior Art 
         [0004]    Typically, jewellery such as piercings and especially pierced earrings have either a straight post or hook that is inserted through a piercing in the ear lobe or the pinnae. The earring is held in place by means of an earring back or clutch in the case of a straight earring post or gravity in the case of a hook. 
         [0005]    Generally, the current principal of how earrings are retained on the wearer fall into three categories. 
         [0006]    A first method is where the earring has a straight post, sometimes with an indented shoulder, which is retained in place by an earring retention device or “back” which grips the earring post by friction only. Since the level of friction cannot be so high as to make it difficult to insert the post, the level of friction is often not high enough to retain the post effectively and the back may become dislodged by jolts and knocks. Additionally, this type of retention device has a tendency to both wear the post and become worn itself and therefore loosens over time; potentially allowing the earring to become more easily detached from the wearer. Attempts have been made to improve on this method by making the indent deeper on the post or by increasing the friction applied by the retention device. However, both of these improvements have a detrimental effect for the user as more effort is required to push the retention device onto the post and subsequently remove it. 
         [0007]    A second method is where the earring is hooked through the ear and has no further means of retention, relying on gravity to secure the earring on the user. 
         [0008]    A third method is where the earring has a straight post which is threaded. An appropriately screwed earring back is then provided which is screwed onto the post once the earring is inserted through the ear. This type of retention device has a tendency to unscrew due the movement of the wearer and eventually becomes detached allowing the earring to fall from the wearer. It takes considerably more time to attach this type of retention device, and the threads can act as traps for bacteria which is unhygienic. 
         [0009]    There are other types of earring “backs” available other than described above, however they normally require the specific modification of the piercing post and therefore can only be employed as part of the manufacture of a new earring or piercing. 
         [0010]    In the case of the first method described above examples are to be found in WO 2007043179, FR 454161 and CH 295468. More recently there has been described in WO 2008065380 a retention device which addresses at least some of the difficulties referred to in the above discussion of the first method, and the present invention seeks to provide a device which is a further improvement. 
         [0011]    The method of retention currently used for both necklaces and bracelets fall mainly into two categories. 
         [0012]    A first and common method is whereby one end of the necklace or bracelet has a ring attached and the other end has a spring-loaded catch. Although once connected this method is secure, the action required to join and release the ring and the clasp can often be difficult due to the need to achieve a non axial alignment between the components to be joined. 
         [0013]    The second method employed is where one end of the necklace or bracelet has a slotted tongue and the other end has a hinged box clasp. Joining the two ends together requires the hinged box clasp to be closed about the slotted tongue. Not only can this action be awkward, but also successful retention relies on the clasp being fully closed. The clasp can also become worn over time, allowing it to unintentionally disengage such that the necklace or bracelet becomes detached from the wearer. 
         [0014]    It is apparent that many currently available retention devices used for earrings, pierced jewellery, necklaces, bracelets, and other such items, can become unintentionally detached from the wearer. The result at best being inconvenience and at worst meaning the loss of the item, along with the, associated potentially emotional and financial loss. 
       SUMMARY OF THE INVENTION 
       [0015]    It is an object of the inventor to improve on these designs. 
         [0016]    In accordance with one of its aspects the present invention provides a jewellery retention device for fastening a jewellery item which comprises a retention post, said retention device comprising a body and having an opening configured to receive a post, said retention device comprising a friction member having a first end associated with the body and a second end which is configured to be contacted by the post upon insertion of the post, said body additionally providing an abutment to support the post and provide a reaction to the force imposed on the post by said second end of the friction member, said opening comprising at least in part a receiving region through which the post may move substantially freely and into which the post may be laterally displaced and received from between the first friction member and abutment in a direction substantially perpendicular to the length of the post. 
         [0017]    The body may be substantially planar and the first friction member may be co-planar with said body. Alternatively the first friction member may be oriented at an oblique angle relative to the body and/or post. 
         [0018]    The first friction member and body may be integral or may be separate components which, optionally, may be non-releasably secured relative to one another. 
         [0019]    At least one of the body and first friction member, or inter-connection therebetween may be deformable whereby the spacing between the second end of the friction member and the abutment may be increased by deformation of one or more of the body, first friction member and any inter-connection therebetween upon insertion of a post, and may return substantially to the original configuration upon removal of the post. One or more of said components may be capable of elastic type deformation in order to provide a resiliency feature for allowing said deformation. 
         [0020]    The retention device may comprise a second friction member having a second, distal end which serves as said abutment. The second friction member may extend from the body in a direction substantially opposite to the direction in which the first friction member extends from the body. Both friction members may lie at the same side of the body 
         [0021]    The second friction member in general may have a construction and configuration substantially corresponding to that of the first friction member. Thus it may lie inclined relative to the body and/or, when a post is in situ between the two friction members the two friction members, may be symmetrically disposed relative to the length of the post. 
         [0022]    The second end of the first friction member and the abutment (such as that defined by either the body or a distal end of a second friction member) may lie close to one another, and optionally be in contact, prior to insertion of a post or preferably, lie slightly spaced by a distance less than the minimum cross-sectional dimension of the post thereby to assist with ease of insertion of the post. If spaced, the opening defined by said spacing may be contiguous with said post receiving region from which the post may be freely withdrawn. 
         [0023]    One or each of the second end of the first friction member and abutment may be profiled to form a notch-like formation for providing a position of preferential location of the post in a lateral direction substantially perpendicular to the length of the post and the direction in which the second end of the first friction member and the abutment are movable relative to one another upon insertion of the post. 
         [0024]    The opening defined by the retention device may comprise more than one post receiving region into which the post may be laterally displaced for subsequent removal of the retention device. The retention device may comprise two receiving regions symmetrically positioned at respective ends of the confronting surfaces of the second end of the first friction member and the abutment. 
         [0025]    The body from which the first friction member extends may be substantially rigid or may be deformable in which case preferably it is elastically deformable whereby application of a force in a direction substantially parallel with the direction in which the second end of the first friction member and the abutment move relative to one another may act to reduce the frictional force imposed on the post by the friction member and abutment. 
         [0026]    The body may be provided with at least one arm which projects therefrom and is movable in order to urge the friction member in a direction away from the post in the manner described in our International patent publication WO 2008/065380. The body may comprise other features described in that patent publication in respect of a deformable body, including, for example, the feature of an actuation arm which is curved. 
         [0027]    The body may comprise an auxiliary formation which lies spaced from the abutment and second end of the first friction member as considered in a direction of post insertion to act as an alignment guide through which the end of a post may be introduced and thereby guided to align with a position between the friction member and abutment. 
         [0028]    The body may provide support for a guide component which defines a guide orifice. Said guide component may be supported by said auxiliary formation. In the case of a retention device comprising a body and a guide, the body and guide may be slidable relative to one another in said lateral direction whereby a retained post may be released by sliding the body and guide relative to one another. Return of the guide and body to an orientation in which the guide will guide an inserted post to lie between the confronting surfaces of the friction member and abutment may be manual or the retention device may comprise means, such as spring biasing means which automatically urges the body and guide to revert to their original configuration. 
         [0029]    Although it is referred to above that the body may be substantially planar and that the or each friction member may be inclined relative to the body, such that the friction member extends obliquely relative to the direction of insertion of the post, the base may be, for example, of a V shape as viewed in a sideways direction such that the base may comprise two portions each angled relative to the direction of post insertion and which may be angled to lie co-planar with one or each of a pair of friction members. 
         [0030]    According to another aspect of the present invention there is provided a retention device for fastening an item comprising a body defining an opening configured to receive a post of the item, and a first friction member having a first end attached to the fastener body and a second end which at least partially defines the opening and is configured to contact the post upon insertion, the first friction member oriented such that movement of the second end of the first friction member relative to the first end in a first direction causes the opening to become larger, and movement of the second end of the first friction member relative to the first end in a second direction causes the opening to become smaller wherein a first force applied to the post in an insertion direction urges the first end of the first friction member in the first direction and a second force applied to the post in a removal direction urges the first end of the first friction member in the second direction such that a first frictional force between the retention device and the post opposing the first force is less than a second frictional force between the retention device and the post opposing the second force, and the post being removable in a lateral direction relative to the length of the post and direction of said frictional force from an engaged to a disengaged position. 
         [0031]    The invention further provides a retention device actuable by movement in a second direction, substantially perpendicular to the first and second directions, to move a retained post to a release position at which it is disengaged from the friction members. 
         [0032]    The invention provides also the combination of a jewellery retention device and an item of jewellery having a post. Although the post may be of a type having a retention notch, it may be devoid of any such notch and may have a smooth or only lightly textured surface for contact by the friction member and abutment of the retention device. 
         [0033]    Embodiments of the present invention will now be described in detail with reference to the following figures in which: 
     
    
     
       DESCRIPTION OF THE FIGURES 
         [0034]      FIG. 1  is a front view of a retention device in accordance with a first embodiment of the invention; 
           [0035]      FIG. 2  is a front view of the retention device of  FIG. 1  with post inserted; 
           [0036]      FIG. 3  is a side view of the retention device of  FIG. 2  with post inserted; 
           [0037]      FIG. 4  is a front view of the retention device of  FIG. 1  with post disengaged; 
           [0038]      FIG. 5  is a side view of the retention device of  FIG. 1  with post disengaged; 
           [0039]      FIG. 6  is a front view of a retention device in accordance with a second embodiment of the invention; 
           [0040]      FIG. 7  is a front view of the retention device of  FIG. 6  with post inserted; 
           [0041]      FIG. 8  is a side view of the retention device of  FIG. 7  with post inserted; 
           [0042]      FIG. 9  is a front view of the retention device of  FIG. 6  with post disengaged; 
           [0043]      FIG. 10  is a side view of the retention device of  FIG. 6  with post disengaged; 
           [0044]      FIG. 11  is a perspective view of a retention device in accordance with a third embodiment of the invention; 
           [0045]      FIG. 12  is a front view of the retention device of  FIG. 11  with post inserted; 
           [0046]      FIG. 13  is a front view of the retention device of  FIG. 11  with post disengaged; 
           [0047]      FIG. 14  is a side view of the retention device of  FIG. 11 ; 
           [0048]      FIG. 15  is a section view of the retention device of  FIG. 12  along line XX-XX; 
           [0049]      FIGS. 16 and 17  show a fourth embodiment with a post respectively in an engaged and a disengaged position; 
           [0050]      FIGS. 18 and 19  show a fifth embodiment with a post respectively in an engaged and a disengaged position; 
           [0051]      FIGS. 20 and 21  show a sixth embodiment with a post respectively in an engaged and a disengaged position; 
           [0052]      FIG. 22  is a perspective view of a retention device in accordance with a seventh embodiment; 
           [0053]      FIG. 23  is a perspective view of a retention device, part cut away for clarity, in accordance with an eighth embodiment; 
           [0054]      FIG. 24  is a perspective view of a retention device of a ninth embodiment; 
           [0055]      FIGS. 25 and 26  show the device of  FIG. 24  respectively in an orientation for post insertion and an orientation for post removal, and 
           [0056]      FIGS. 27 and 29  are sections in a plane containing the longitudinal axis of the post  307  and the lines V V-V V of  FIG. 24 , and 
           [0057]      FIGS. 28 and 30  are sections in a plane perpendicular to the longitudinal axis of the post and containing the lines W W-W W of  FIG. 24 . 
       
    
    
     DETAILED DESCRIPTION 
       [0058]    In a first embodiment of the present invention, referring to  FIGS. 1 ,  2 ,  3 ,  4 , and  5 , there is shown a retention device  10  comprising a body  12 , first friction member  14  and second friction member  16 . Body  12 , friction member  14  and second friction member  16  are integral and formed from a single piece of sheet metal; e.g. stainless steel as appropriate. The friction members  14 ,  16  are formed by creating two parallel spaced vertical slots  26 , and a single horizontal slot  28  in the body  12  forming an “H” shape. 
         [0059]    The friction members  14 ,  16  are therefore joined to the body  12  at first ends  18 ,  20  respectively, which first ends span the distance between the vertical slots  26 . The friction members  14 ,  16  are free at second ends  22 ,  24  respectively, formed by the horizontal slot  28 . Slot  28  leads to a post receiving and removal area  38  that is larger than the cross-sectional area of post  36 . 
         [0060]    The friction members  14 ,  16  are plastically deformed at first ends  18 ,  20  such that their second ends  22 ,  24  have been moved in a first direction (denoted by arrow  32  in  FIG. 3 ) and they form an angle with the body  12 . Referring to  FIGS. 2 and 3  an enlarged opening  28  is formed by this action, defined partially by the second ends  22 ,  24  of the friction members  14 ,  16 . Any movement of the second ends  22 ,  24  in the first direction  32  causes the opening  28  to become larger. Similarly any movement of the second ends  22 ,  24  in a second direction  34  (opposite to the first direction  32 ), for example under the action of attempting to pull the post back through the opening  28 , causes the opening  28  to become smaller and for a firmer grip to be exerted on the post. 
         [0061]    In use, the retention device  10  is positioned such that a post  36  of a piece of jewellery is inserted in the first direction into the opening  28  as shown in  FIGS. 2 ,  3 ,  4  and  5 . In the embodiments described the post  36  is circular in cross-section but may take any substantially prismatic or cylindrical shape. 
         [0062]    The position of the friction members  14 ,  16  is such that the height of the opening  28  as viewed in  FIG. 1  (i.e. the distance between the second ends  22 ,  24 ) is smaller than the diameter of the post  36 . Therefore the friction members  14 ,  16  act as built-in cantilevers and are elastically deformed at their first ends  14 , 16  and along their lengths in order to widen the opening  28  to accommodate the post  36 . 
         [0063]    Applying force to the post  36  in the first direction  32  creates a friction force between the post  36  and the friction members  14 ,  16  resulting in the second ends  22 ,  24  being urged in the first direction and urging the opening  28  to open. The retention device can therefore be easily assembled onto the post  36  such that the piece of jewellery can be secured, as the frictional force caused by the mere elastic resilience of the friction members  14 ,  16  is relatively small. 
         [0064]    Applying force to the post  36  in the second direction  32  also creates friction between the post  36  and the friction members  14 ,  16  resulting in the second ends  22 ,  24  being urged in the second direction and urging the opening  28  to close on the post  36 . This closing action increases the clamping force exerted by the friction members  14 ,  16  which in turn increases the frictional force on the post  36 . The more force that is applied to the post  36 , the higher the clamping force will be and consequently movement of the retention device  10  in the second direction is made either difficult or prevented completely. 
         [0065]    Therefore the retention device  10  is easily placed onto the post  36  in order to secure the piece of jewellery (not shown) in place, but accidental removal is made difficult. 
         [0066]      FIGS. 4 and 5  show the disengagement of frictional clamping force of members  14  and  16  from the post  36 . With post  36  inserted between members  14  and  16  as shown in  FIGS. 2 and 3 , applying lateral force to the main body  12  in the direction  42  whilst retaining the lateral position of post  36  urges the disengagement of the post from the friction members  14  and  16 . The eventual relocation of the post  36  to a position within the free area  38  shown in  FIGS. 4 and 5  enables the unobstructed removal of post  36  from body  12 . 
         [0067]    The retention device  100  shown in  FIGS. 6 , to  10  is similar to retention device  10  of the first embodiment, with the difference that the retention device  100  comprises only a single friction member  14 . The device  100  operates in the same way as device  10 , except that a clamping force is only provided on a single side of the post  36 , and is reacted by an abutment in the form of a reaction surface  50  of the opening  28 .  FIGS. 9 and 10  show the manner of removal of the retention device from the post  36 . With post  36  inserted between members  14  and reaction surface  50  as shown in  FIGS. 7 and 8 , applying lateral force to the main body  12  in the direction  42  whilst retaining the lateral position of post  36  creates a sliding movement between the post and surfaces  22  and  50 . The eventual relocation of the post  36  to a position within the free area  38  as shown in  FIGS. 9 and 10  enables the unobstructed removal of post  36  from body  12 . This embodiment is simpler and less expensive and time consuming to produce. 
         [0068]    In a third embodiment,  FIGS. 11 to 15  show a retention device  200  substantially similar to retention device  10 , except that retention device  200  comprises a main body  12  in combination with a post guide component in the form of a guide body  201 . Guide body  201  is a unitary body comprising a circular plate portion  202  and a semi oval section  203 . A circular orifice  204  extends through the body  201  and is co-axial with the slot  28  and direction of post insertion. The end of the orifice  205  (see  FIG. 15 ) proximate the main body is convergent in the insertion direction, as formed by chamfer  206 , and as such insertion of the post is made easier. 
         [0069]    In use, the main body  12  partially wraps around the semi oval section of the guide body  203 . Upon insertion of the post  36  into the body  201 , the post is guided by cylindrical section  204  towards the slot  28 , preventing misalignment of the post  36  which could impede the function of the retention device  200 . 
         [0070]    It should be noted that in order to function satisfactorily, the retention devices  10 ,  100 , and  200  should be constructed such that the deformation induced by the applied compressive force  42  remains elastic; i.e. such that the retention device is capable of returning to its undeformed state upon release. In retention devices  10 ,  100 , and  200  the body  12  should be sufficiently strong in the areas adjacent the friction members  14 ,  16  for this to occur. 
         [0071]    As well as the above features, the dimensions of the retention device should be selected to provide the appropriate level of clamping force. 
         [0072]    The clamping force provided by the free arms  14  and  16  may be increased by pretensioning them; i.e. by forming body  12  such that surfaces  22  and  24  provide a clamping force on post  36  in the rest position shown in  FIG. 3 . 
         [0073]      FIGS. 16 and 17  show a retention device  300  substantially similar to that of  FIG. 1  but provided with two post receiving openings  38 . A post  36  can be moved from between two friction members to either of the post receiving openings  38  as shown in  FIG. 17  by lateral movement in either of the directions  42 R and  42 L. 
         [0074]    Substantially similarly,  FIGS. 18 and 19  show a variation of the embodiment of  FIG. 6  and in which a retention device  301  comprises two post receiving regions  38  into either of which a post may be moved from between a friction member and abutment  50  provided by the body. 
         [0075]      FIGS. 20 and 21  show a retention device  302  substantially similar to that of  FIGS. 16 and 17  but with confronting ends of the two friction members  14 ,  16  each provided with a recess region  122 ,  124 . That recess may, for example, be curved or V shaped. The recesses facilitates centralisation of the post between the friction members  14 ,  16  and also assist in providing a retention device in which the force required for lateral disengagement can be more accurately designed and predicted. 
         [0076]    In the retention device  303  of  FIG. 22  the body  12  comprises curved end regions  310  which lead to two confronting planar portions the confronting ends of which define an opening  304  which acts as a guide for insertion of a post, thereby to guide the post to between confronting ends of the friction members. In this embodiment the lateral movement required for disengagement of a post from between the friction members is achieved by a component of the rotational movement in the direction  42  such that, in effect, the post is tilted about the opening  304 . Thus the part of the post previously retained between the friction members is displaced to the post-receiving region  306 . 
         [0077]      FIG. 23  shows a variation of the retention device of  22  and in which the post guide opening  304  is elongate. Thus movement to disengage a post may be either by substantially lateral movement or a combination of lateral movement in the direction  42  of  FIG. 23  and rotational movement in the direction  42  of  FIG. 22 . 
         [0078]      FIGS. 24 to 26  show a variation of the embodiment of  FIGS. 11 to 14 . In this embodiment body  12  is of a V shape as viewed in a sideways direction and comprises two regions each co-planar with a respective one of the two friction members. The body  12  is movable laterally relative to the guide  201  in a direction  42  to lie either at the orientation of  FIG. 25  at which it is ready to receive a post  307  or the orientation of  FIG. 26  at which a post lies in the receiving region  306  from which it is freely removable. In this construction it is necessary to manually slide the body and guide relative to one another to the orientation of  FIG. 25  subsequent to removal of a post. 
         [0079]    To avoid the need for manual operation the retention device  305  may incorporate a spring bias arrangement as shown in more detail in  FIGS. 27 to 30 . For the purpose of automatic return the body  12  is made of spring steel and comprises obliquely orientated extensions  61  which bear against inclined guide surfaces  62  on the guide body  201 . The application of lateral force to the main body  12  in the direction  42  of  FIGS. 25 and 26  causes the extensions  61  to separate from one another as they climb but remain on the respective guide surfaces  62 . When a lateral force  42  is removed from the body and no post is present, the main body returns to the configuration shown in  FIG. 25  in consequence of the spring energy stored in the main body  12  and which urges the obliquely orientated extensions  61  to slide down the guide surfaces  62 . 
         [0080]    Numerous changes can be made within the scope of the present invention. For example the retention device does not have to be a single piece, and can be constructed from a multi-piece assembly with, for example, the friction members as separate components. 
         [0081]    The friction members can be biased with separate biasing means, for example springs. 
         [0082]    The retention device need not be constructed from metal, and can be constructed, for example, from a plastics material. 
         [0083]    The retention device may incorporate any more than two friction members, in different orientations; for example two pairs of transversely oriented friction members may be employed to provide additional clamping force. 
         [0084]    The retention device can be used on various types of jewellery, for example earrings wherein the post is attached to the earring, and necklaces/bracelets wherein the post is attached to a first end of the necklace/bracelet and the retention device is attached to a second end.