Abstract:
The present invention relates to a snap-type locking device for releasable and principally external keeping together of two parts ( 1, 2 ) and comprising at least one grip pat ( 11, 11   a   , 18, 20, 21, 22 ), at least one movable arm ( 12, 12   a,    12   b ) and at least one spring ( 14, 14   a   , 14   b   , 14   c ), said at least one movable arm ( 12, 12   a   , 12   b ) being turnably attached to said at least one grip part ( 11, 11   a   , 18, 20, 21, 22 ) as well as, directly or indirectly, to a first part ( 1 )of said two parts ( 1, 2 ). Said at least one spring ( 14, 14   a   , 14   b   , 14   c ) abuts against said at least one grip part ( 11, 11   a   ; 18, 20, 21, 22 ) in order to urge the same in a direction away from said two parts ( 1, 2 ).

Description:
[0001]    The present invention relates to a snap-type locking device for releasable and principally external keeping together of two parts and comprising at least one grip part, at least one movable arm and at least one spring, said at least one movable arm being turnably attached to said at least one grip part as well as, directly or indirectly, to a first part of said two parts. 
       PRIOR ART 
       [0002]    U.S. Pat. No. 2,829,912 discloses draw bolts for luggage. Each draw bolt or locking device has a grip part, a movable arm and springs. The springs are not arranged to urge the grip part in a direction away from the luggage, and therefore unintentional locking or sticking may occur in the unlocked position. 
       SUMMARY OF THE INVENTION 
       [0003]    A first object of the invention is to provide a snap-type locking device that is convenient to lock and unlock and convenient to use also in the unlocked state in such a way that the lock not unintentionally gets stuck in the locked or semi-locked position. A second object of the invention is to provide a snap-type locking device having fewer components included than in locks of known types. A third object of the invention is to provide a snap-type locking device that is simple and therefore cost-effective to produce. 
         [0004]    Hence, the invention embodies a snap-type locking device for releasable and principally external keeping together of two parts and comprising at least one grip part, at least one movable arm and at least one spring, said at least one movable arm being turnably attached to said at least one grip part as well as, directly or indirectly, to a first part of said two parts. Said at least one spring abuts against said at least one grip part in order to urge the same in a direction away from said two parts. 
         [0005]    Said at least one spring may abut against a first side, facing said two parts, of said at least one grip part. 
         [0006]    Said at least one movable arm may be turnable around a first axis of rotation in relation to said at least one grip part and turnable around a second axis of rotation in relation to said first part. Said at least one movable arm may be turnably or fixedly attached to at least one fixed arm, which in turn is turnably or fixedly attached to said first part. Said at least one fixed arm may be a part of the locking device. Said at least one fixed arm may be a part of said first part. Said at least one fixed arm may be integral with said first part. 
         [0007]    Said at least one spring may comprise at least one anchoring spring leg, which extends from a second axis of rotation, around which said at least one movable arm may be arranged to turn in relation to said first part, and into a recess, slot or the like in said first part, and/or in an additional part attached to said first part, in order to, in this way, prevent said at least one spring in its entirety from being turned around said second axis of rotation. 
         [0008]    Said at least one spring may be equipped with at least two urging spring legs, which extend at an angle in relation to each other from said second axis of rotation into abutment against a first side, facing said two parts, of said at least one grip part in such a way that at least a first urging spring leg of said at least two urging spring legs can bring said at least one grip part to turn in a first direction around said second axis of rotation and at least a second urging spring leg of said at least two urging spring legs can bring said at least one grip part to turn in a second direction around said second axis of rotation, said second direction being counter-directed to said first direction and a state of equilibrium occurring when the locking device is in the unlocked position. In said state of equilibrium, said at least one grip part may be positioned in a free position at a distance from said two parts. A main extension plane of said at least one grip part may, in the unlocked position, extend principally parallel to a main extension plane of said at least one grip part in the locked position. 
         [0009]    Each one of two movable arms may be turnably attached to said at least one grip part as well as, directly or indirectly, to said first part, wherein the arms may constitute a unit together with a first spindle, coinciding with a first axis of rotation, and a second spindle, coinciding with said second axis of rotation, in order to move together, wherein each one of the spindles may extend between and unite the arms, wherein said first spindle, in the unlocked position, may abut against at least one of said at least a first and a second urging spring legs. 
         [0010]    Said at least one spring may abut against a first side, facing said two parts, of said at least one grip part of a spring side of a plane that intersects a main extension plane of said at least one grip part under a principally right angle and that simultaneously passes through, and principally parallel to, a second axis of rotation, around which said at least one movable arm may be arranged to turn in said first part and vice versa, wherein at least a first arm leg of said at least one movable arm, in the unlocked position, may abut against at least one fold on said first side of an arm side of said plane, wherein said spring side and said arm side may be different sides of said plane. 
         [0011]    At least a second arm leg of said at least one movable arm may, in the unlocked position, abut against said at least one spring, wherein said at least one grip part may be positioned in a free position at a distance from said two parts. Said main extension plane of said at least one grip part may, in the unlocked position, extend principally parallel to said main extension plane of said at least one grip part in the locked position. 
         [0012]    Said at least one movable arm may be turnable around a first axis of rotation in relation to said at least one grip part and may be formed in such a way that it simultaneously constitutes a first spindle, at least partly coinciding with said first axis of rotation, and a second spindle, at least partly coinciding with said second axis of rotation, wherein a first end of said at least one movable arm may be mounted in a bearing in a recess suitable therefor in a first flange of said at least one grip part, a second end of said at least one movable arm may be mounted in a bearing in a recess suitable therefor in a second flange of said at least one grip part and a portion of said at least one movable arm occurring therebetween may be mounted in a bearing in a recess suitable therefor in said first part, and/or in an additional part attached to said first part. 
     
    
     
       LIST OF DRAWINGS 
         [0013]      FIG. 1  shows, in a side view from the left, a first embodiment of a locking device according to the invention and in the locked state. 
           [0014]      FIG. 2  shows, in a front view, the locking device of  FIG. 1 . 
           [0015]      FIG. 3  shows, in a partly sectioned side view from the left, the locking device of  FIG. 1  in the unlocked state. 
           [0016]      FIG. 4  shows, in a partly sectioned side view from the left, the locking device of  FIG. 1  in a semi-locked state. 
           [0017]      FIG. 5  shows, in a partly sectioned side view from the left, the locking device of  FIG. 1  in the locked state. 
           [0018]      FIG. 6  shows, in a sectioned perspective view from the right, a second embodiment of a locking device according to the invention and in the locked state. 
           [0019]      FIG. 7  shows, in a sectioned side view from the right, the locking device of  FIG. 6  in the locked state. 
           [0020]      FIGS. 8 and 9  show, in sectioned perspective views from the right, the locking device of  FIG. 6  in the locked state. 
           [0021]      FIGS. 10 and 11  show, in sectioned perspective views from the right, the locking device of  FIG. 6  in the unlocked state. 
           [0022]      FIG. 12  shows, in a perspective view from the left, the locking device of  FIG. 6  in the unlocked state. 
           [0023]      FIG. 13  shows, in a sectioned perspective view from the left, the locking device of  FIG. 6  in the unlocked state. 
           [0024]      FIG. 14  shows, in a perspective view from the left, the locking device of  FIG. 6  in the locked state. 
           [0025]      FIG. 15  shows, in a perspective view from the right and from above, a part of the locking device of  FIG. 6 . 
           [0026]      FIG. 16  shows, in a perspective view from the right and from below, the part according to  FIG. 15 . 
           [0027]      FIG. 17  shows, in a perspective view from the right, parts of the locking device of  FIG. 6 . 
       
    
    
     DESCRIPTION OF EMBODIMENTS 
       [0028]    A first embodiment of the locking device has an appearance and a function in accordance with the  FIGS. 1-5 . The locking device is mounted on a first part  1 , for instance a bottom part  1  of a case, and comprises a grip part  11 , two movable arms  12  and two springs  14 . Said grip part  11  is turnably attached to each one of the movable arms  12  (and vice versa), each one of which in turn is turnably attached to one and the same fixed arm  13 , which is attached to the first part  1 . Said springs  14  hold, in the unlocked state, the grip part  11  at a certain distance from not only the first part  1  but also a second part  2 , such as, for instance, a lid part  2  of a case. 
         [0029]    The movable arms  12  are turnable around a first axis of rotation  16 , which coincides with a spindle  16 , in relation to the grip part  11  and turnable around a second axis of rotation  17 , which coincides with a spindle  17 , in relation to the fixed arm  13  and thereby simultaneously to the first part  1 . Two urging spring legs  14   a ,  14   b  of each spring  14 , i.e., totally four urging spring legs, extend in pairs at an angle in relation to each other from said second axis of rotation  17  into abutment against a first side  11   a  of the grip part  11 , i.e., the side of the grip part  11  that is facing the first and second parts  1 ,  2 . A first urging spring leg  14   a  of said two urging spring legs  14   a ,  14   b  of each spring  14  brings the grip part  11  to turn in a first direction around said second axis of rotation  17  and a second urging spring leg  14   b  of said two urging spring legs  14   a ,  14   b  of each spring  14  brings the grip part  11  to turn in a second direction around said second axis of rotation  17 , said second direction being counter-directed to said first direction and contributing to the fact that a state of equilibrium occurs when the locking device is in the unlocked position. 
         [0030]    The mutually principally parallel arms  12  constitute a unit together with the mutually principally parallel first and second spindles  16 ,  17  and move together with them. Each one of the spindles  16 ,  17  extends, at a distance from each other, between and unites the arms  12  and meets the arms  12  at principally right angles. In the unlocked position, the spindle  16  abuts, by the spring action described above from occurring spring legs, against a  14   b  of the urging spring legs  14   a ,  14   b  of each pair, i.e. of each spring  14 , which acts as an anchorage for the entire locking device in the unlocked state. In this anchored position, a main extension plane of the grip part  11  extends principally parallel to a main extension plane of the grip part  11  in the locked position of the locking device. 
         [0031]    Rotation of each one of the occurring springs  14  around the spindle  17 , in connection with the operation of the locking device and/or upon storage, can be avoided by the fact that each spring  14  also comprises an anchoring spring leg  14   c , which extends from the spindle  17  and into a recess in said first part  1 . 
         [0032]    Each spring  14  is ingeniously manufactured in one piece from a wire of metal or the like, which has been formed to, in a first end, show the spring leg  14   a  in abutment against the side  11   a  of the grip part  11  in order to, therefrom, extend towards the spindle  17  and around the same at least one turn in order to further extend down into the recess in the first part  1  and there form a loop included in the anchoring spring leg  14   c  and extend back to the spindle  17  and around the same at least one turn in order to further extend at an angle in relation to the spring leg  14   a  in the direction of the side  11   a  of the grip part  11  in order to be terminated in the form of the spring leg  14   b  in abutment against the side  11   a . The two springs  14  are mounted in each end of the spindle  17  and the angle between the two urging spring legs  14   a ,  14   b  of each spring  14 , as well as the anchoring spring leg  14   c  of the same spring  14 , is in one and the same plane, which is principally perpendicular to the direction of extension of each one of the spindles  16 ,  17 . 
         [0033]    A second embodiment of the locking device has a geometry and a function in accordance with the  FIGS. 6-17 ,  FIGS. 15 and 16  of which only show the grip part  11  and  FIG. 17  only shows the other parts. Here, only one movable arm  12  is present, which is formed in such a way that it alone gives the same possibilities of operation as two arms and two spindles together according to the first embodiment of the invention. Thus, the movable arm  12  is turnable around a first axis of rotation  16  in relation to the grip part  11  and is formed in such a way that it simultaneously constitutes a first spindle  16 , at least partly coinciding with said first axis of rotation  16 , and a second spindle  17 , at least partly coinciding with said second axis of rotation  17 . A first end of said movable arm  12  is mounted in a bearing in a recess suitable therefor in a first flange  20  in the grip part  11  while a second end of said movable arm  12  is mounted in a bearing in a recess suitable therefor in a second flange  21  in the grip part  11 . A portion of said movable arm  12  occurring therebetween is mounted in a bearing in a recess suitable therefor in an arm or a projection  13  attached to said first part  1 . 
         [0034]    Only one spring  14  is present, which abuts against said first side  11   a  of a spring side of a plane that intersects a main extension plane of the grip part  11  under a principally right angle and that simultaneously passes through, and principally parallel to, said second axis of rotation  17 . A first arm leg  1   2   a  of said movable arm  12  abuts, in the unlocked position, against at least one fold  18  on said first side  11   a  of an arm side of said plane, said spring side and said arm side being different sides of said plane. A second arm leg  12   b  of said movable arm  12  abuts, in the unlocked position, against said spring  14 , said grip part  11  being in a free position at a distance from said two parts  1 ,  2 . In this anchored position, a main extension plane of the grip part  11  extends principally parallel to a main extension plane of the grip part  11  in the locked position of the locking device. 
         [0035]    Each spring  14  is ingeniously manufactured in one piece from a wire of metal or the like, which has been formed to, in a first end, start from a dedicated groove  19  in said projection  13  attached to said first part  1  in order to, therefrom, extend out of this groove  19  and towards the spindle  17  and around the same in order to further extend in the direction of the side  11   a  of the grip part  11  into abutment against the side  11   a  in order to further extend along the side  11   a  in a direction that is principally parallel in relation to the principal direction of extension of the spindle  17  in order to, therefrom, again extend towards the spindle  17  and around the same in order to further extend in the direction of said groove  19  in said projection  13  in order to, in said groove  19 , be terminated in the form of a second end. The part of the spring  14  that is between the spindle  17  and the grip part  11  may be regarded as an urging spring leg  14   a , while the parts of the spring lo  14  that are between the spindle  17  and the groove  19  in said projection  13  may be regarded as anchoring spring legs  14   c , which accordingly prevent rotation of the entire spring  14  around the spindle  17 . 
         [0036]    Upon closure including subsequent locking, a front/upper part of the grip part  11  can be forced over a fold  15  present on the second part  2 , see  FIG. 4 , and then the locking device can be brought to lock together the second part  2  and the first part  1  by snap action by the fact that a rear/lower part of the grip part  11  is pressed against the first part  1 , see  FIG. 5 . Said front/upper part of the grip part  11  is provided with a third flange  22  particularly adapted for the purpose, the main extension plane of which forms principally the same angle with the main extension plane of the grip part  11  as does a main extension plane of a particularly adapted recess  23  in said fold  15  in the unlocked as well as the locked state of the locking device. From, for instance,  FIG. 7 , it is seen that the angle, which may vary between close to 0° and close to 90°, in the present case is approx. 45°. Upon unlocking, said rear/lower part of the grip part  11  can instead be retreated from the first part  1 , see  FIG. 4 , after which said front/upper part of the grip part  11  can be removed from the fold  15  present on the second part  2 , see  FIG. 3 . 
         [0037]    The locking device is particularly suitable for a tool case of plastic provided with two locking devices, but a number of other application areas are feasible such as, for instance, most known types of cases, boxes, drawers, fittings and various forms of building elements etc. The number of locking devices of each application object may vary and, for instance, a case is conceivable having one or more locking devices. Distances between occurring locking devices and their placement on the case or the like may also vary. 
         [0038]    The parts included in the locking device are preferably manufactured from metal but any other expedient material is feasible, for instance, various forms of plastic. Also combinations of different materials are feasible, such as, for instance, a grip part  11  of plastic and a movable arm  12  and a spring  14  of metal. Also combinations of different materials in one and the same part is feasible. 
         [0039]    The invention is not limited to the embodiments shown here but may be varied within the scope of the subsequent claims.