PATENT ABSTRACT
Padlocks adapted for one-handed operation are disclosed. Typically having a laterally asymmetric shackle, the lock includes an arm connected thereto so as to pivot when the locking mechanism is disengaged. A spring or other component facilitates latching of the device by biasing the arm toward an exposed end of the shackle.

PATENT DESCRIPTION
FIELD OF THE INVENTION  
         [0001]    This invention relates to locks for securing objects and more particularly to padlocks typically having an elongated, laterally asymmetric shackle and adapted for one-handed use.  
         BACKGROUND OF THE INVENTION  
         [0002]    U.S. Pat. No. 1,542,016 to Stull, incorporated herein in its entirety by this reference, discloses a “permutation” lock with an essentially symmetric, “substantially C-shaped” shackle. Also included as part of the permutation lock are a sleeve surrounded by an “operating barrel,” manipulation of which will move the sleeve. Properly turning the barrel, therefore, allows both it and the sleeve to “be bodily moved back upon the shackle” and open the locking mechanism.  
           [0003]    U.S. Pat. No. 5,433,092 to Kuo likewise discloses a keyed lock with a symmetric shackling system. Formed of two rods (rather than the one of the device of the Stull patent), the lock of the Kuo patent contemplates connecting the rods with a pin or bolt remote from the housing containing the locking mechanism. Normal use of the lock almost certainly requires two hands, one to use the key to manipulate the mechanism and the other to grasp and move at least one of the two rods.  
         SUMMARY OF THE INVENTION  
         [0004]    The present invention, by contrast, provides a padlock having, in many embodiments, a laterally asymmetric shackle. Adapted for one-handed operation, the lock additionally includes an arm connected adjacent one end of the shackle by a pin or equivalent component. In use, the arm is capable of pivoting about the pin following exposure of the opposite end of the shackle.  
           [0005]    Surrounding a portion of the arm is a cylindrical (or other) shaped sleeve. Although conceivably useful in connection with a keyed (or other) mechanism, the sleeve preferably circumscribes and includes one or more tumblers of a combination locking mechanism. When appropriately rotated, as with a thumb or finger of one hand, the one or more tumblers allow the sleeve to slide along the arm toward the pivot pin, thereby exposing the opposite end of the shackle and permitting the arm to pivot away therefrom. A spring or other component facilitates latching of the device by biasing the arm toward the exposed shackle end.  
           [0006]    The shackle of the present padlock defines at least two curved (generally but not necessarily U-shaped) sections, one having a greater radius than the other. By designing the shackle asymmetrically, the padlock is especially useful in certain locations, inclining the cylindrical sleeve in a manner facilitating its movement. In other locations the limited width of the smaller curved section requires the object to be protected to circumscribe a portion of the larger curved section of the shackle, ensuring that the arm will pivot away from the object when the lock is opened. The shackle additionally is aesthetically attractive, as the precise shapes and relative placement of its curved and straight segments, for example, are not necessarily critical to its operation.  
           [0007]    Indeed, some embodiments of the padlock of the invention resemble in appearance either a human ear or carabiners used in alpine sports activities such as mountain climbing. U.S. Pat. No. 5,4653,798 to Wurzer discusses, in a section entitled “Description of the Related Art,” aspects of conventional carabiners. As detailed at column 1, lines 52-60 of the Wurzer patent, these carabiners require, among other things, two-handed actuation and obviously are not intended to be opened using a key or tumblers. Both their function and operation, therefore, differ from those of the padlocks of the present invention.  
           [0008]    It is thus an object of the present invention to provide a padlock adapted for one-handed operation.  
           [0009]    It is also an object of the present invention to provide a padlock having a laterally asymmetric shackle.  
           [0010]    It is another object of the present invention to provide a lock in which the shackle defines at least two curved sections, one of which is wider, or has a greater radius of curvature, than the other.  
           [0011]    It is a further object of the present invention to provide a lock in which an arm is attached to the shackle proximate the narrower curved section.  
           [0012]    It is an additional object of the present invention to provide a lock having one or more tumblers circumscribing portions of the arm and adapted to rotate when manually manipulated by a thumb or finger.  
           [0013]    It is yet another object of the present invention to provide a lock in which a spring or other component biases an arm toward a locked or latched position.  
       
    
    
       [0014]    Other objects, features, and advantages of the present invention will become apparent with reference to the remainder of the text and the drawings of this application.  
       BRIEF DESCRIPTION OF THE DRAWINGS  
       [0015]    [0015]FIG. 1 is a perspective view of an exemplary padlock of the present invention.  
         [0016]    [0016]FIG. 2 is an exploded view of the padlock of FIG. 1.  
     
    
     DETAILED DESCRIPTION  
       [0017]    FIGS.  1 - 2  illustrated a version of padlock  10  of the present invention. Included as part of typically oblong-shaped padlock  10  are shackle  14  and locking mechanism  18 , some or all of which may be made or plastic, metal, or any other appropriate material. As shown principally in FIG. 2, mechanism  18  may include each of arm  22 , tumblers  26 , sleeve  30  (formed of segments  30 A and  30 B), collars  34 , stop  38 , blade  42 , and spring  46 . Also detailed in FIGS.  1 - 2  is pin  50 , which in use connects arm  22  to shackle  14 .  
         [0018]    An exemplary shackle  14  incorporates curved sections  54  and  58  separated by section  62 . The radius of curvature of section  54  typically is greater than that of section  58 , so that shackle  14  is not symmetric laterally. By contrast, section  62  usually is straight (or relatively so), so that the appearance of padlock  10  resembles a human ear or carabiner. Padlock  10  need not necessarily be oblong, however, but rather may assume other desired shapes. In some embodiments of lock  10 , furthermore, shackle  14  need not be laterally asymmetric.  
         [0019]    Formed at end  66  of section  54  is recess  70 , whose mouth  74  faces section  62 . As described later in this application, recess  70  is adapted to receive stop  38  of locking mechanism  18 . Additionally optionally incorporated into end  66  are flat regions  78 , which engage corresponding regions of sleeve halves  30 A and  30 B to orient sleeve  30  correctly and prevent it from rotating about arm  22 .  
         [0020]    Opposed end  82  is present as part of section  58  of shackle  14 . Formed at end  82  is recess  86  having mouth  90 . Unlike mouth  74 , however, mouth  90  faces end  66  rather than section  62 . In use, recess  86  receives blade  42 , which assists in the bias of arm  22  by spring  46 .  
         [0021]    Also formed at end  82  of section  58  is aperture  94 . Extending the depth (diameter) of shackle  14 , aperture  94  is designed to receive shaft  98  of pin  50 , and consequently has a diameter approximately the same as (although slightly larger than) that of shaft  98 . Expanded-diameter heads  102  of pin  50  retain the pin  50  in position once inserted through aperture  94 .  
         [0022]    As illustrated in FIGS.  1 - 2 , the radius of curvature R 1  of section  54  is greater than radius R 2  of section  58 . Accordingly, shackle  14  lacks symmetry laterally. Certain hasps, staples, or other objects to be fastened by lock  10 , furthermore, are sufficiently large compared to radius R 2  so that section  58  cannot readily slide through them. As a consequence, lock  10  frequently is oriented with section  54  upward, resting in contact with the object to be protected, and section  58  depending therefrom. This likewise permits sleeve  30  to slide downward when lock  10  is opened, in the direction of gravitational force. In other situations, the asymmetry of shackle  14  may incline sleeve  30  toward a user, facilitating manual manipulation of tumblers  26 .  
         [0023]    Arm  22  of mechanism  18  is multiply sectioned. Lower section  106  of arm  22  is hollow for an extended depth, so that spring  46  and blade  42  may be received therein and it may be fitted over (flat surfaces  110  of) end  82 . Incorporated additionally in lower section  106  are openings  114 . If fitted appropriately over end  82 , lower section  106  will have openings  114  aligned with and surrounding aperture  94 . Once so fitted, openings  114  and aperture  94  may receive pin  50 , with heads  102  (whose diameter exceeds that of openings  114 ) fixing the relative placement the lower section  106  and end  82 . Pin  50  thus functions not only as a retainer, but also as an axis about which arm  22  may pivot.  
         [0024]    Preferably, interior portions of lower section  102  adjacent openings  114  are flat so as to abut flat surfaces  110  of end  82 . However, those skilled in the art will recognize that such portions need not necessarily be flat, nor need be surfaces  110 . Likewise, pivot mechanisms other than pin  50  may be employed as appropriate or desired in connection with the invention. Nevertheless, FIGS.  1 - 2  illustrate a version of lock  10  suitable for many purposes.  
         [0025]    Exterior  118  of lower section  106  may include an elongated notched region  122  and flat surfaces  126 . As detailed hereafter, the existence of region  122  permits sleeve  30  to slide along arm  22  toward end  82  of shackle  14 . Surfaces  126  similarly assist this sliding, as well as inhibiting sleeve  30  from rotating about the arm  22 .  
         [0026]    Middle section  130  of arm  22  contains one or more segments  134  of reduced diameter. Each such segment  134  present in arm  22  is circumscribed by a tumbler  26 , and if the segments  134  number more than one, is spaced from an adjacent segment  134  by an island  138 . Each island  138  includes a notched region  142  which is aligned longitudinally with notched region  122  of lower section  106 .  
         [0027]    Upper section  146  of arm  22  has a generally U-shaped (or other) interior  150  designed to mate with, or engage, flat regions  78  of end  66  (or, alternatively, simply abut end  66 ). Additionally incorporated in upper section  146  are openings  154  into which stop  38  is inserted. As inserted, therefore, stop  38  spans interior  150 , and as arm  22  is pivoted toward end  66 , step  38  is received by mouth  74  into recess  70  but prevents further movement thereof.  
         [0028]    Sleeve  30  may, as noted earlier, be formed of segments  30 A and  30 B. If so, collars  34  may be fitted about the segments  30 A and  30 B to retain them as unitary sleeve  30 . Sleeve  30  additionally houses tumblers  26  positioned about arm  22 .  
         [0029]    Each tumbler  26  may have an interior protrusion  158  corresponding to a numeral or other symbol present on its face. Such protrusion  158  additionally is adapted to be received by notched regions  142  and  122 . Thus, when each tumbler  26  is manipulated so as to align protrusions  158  with notched regions  142 , sleeve  30  can slide along arm  22  toward end  82 . Doing so exposes end  66  of shackle  14 , permitting arm  22  to be pivoted by manual pressure inward toward section  62  (into interior space  162 ) and thereby “open” lock  10 .  
         [0030]    Because blade  42  is oriented as shown in FIG. 2, pivoting arm  22  inward opposes the force of spring  46 . The blade  42  and spring  46  thus bias upper section  146  of arm  22  outward toward end  66 , attempting to return stop  38  into recess  70 . This bias facilitates “closing” lock  10  when manual pressure on arm  22  is released, as the user need merely allow the arm  22  to return to its biased position and then slide sleeve  30  upward and rotate tumblers  26  so that at least one protrusion  158  no longer is aligned with a corresponding notched region  142 . One-handed operation of lock  10  is thus a viable aspect of the present invention, although two-handed operation may occur as well.  
         [0031]    The foregoing is provided for purposes of illustrating, explaining, and describing embodiments of the present invention. Further modifications and adaptations to these embodiments will be apparent to those skilled in the art and may be made without departing from the scope of spirit of the invention. Locking mechanism  18  need not necessarily be as expressly described above, for example, and may have more or fewer components. It likewise may be keyed or otherwise adapted to be opened and closed without use of tumblers  26 . As further examples, biasing devices other than blade  42  and spring  46  could alternatively be used, as could retainers other than pin  50  and stop  38 .