Abstract:
A lock apparatus includes a lock body which is slidably mountable over the legs of the shackle. At least one push nut is mounted within a recess carried in the lock body to allow easy insertion of the legs of the shackle through the bores in the lock sections and the at least one push nut, but exerts a substantial force resisting separation of the lock body from the shackle in an opposite direction. The lock body is formed of a unitary one-piece body, or a pair of identical lock sections which are reoriented with respect to each other and inter-engaged to form bores at one edge which receive the legs of the shackle. A method of installing the lock apparatus includes mounting at least one push nut in a lock body and then inserting the legs of the shackle through bores in the lock body and the at least one push nut.

Description:
CROSS REFERENCE TO CO-PENDING APPLICATION 
       [0001]    This application claims priority benefit to the filing date of co-pending U.S. Provisional Patent Application Ser. No. 61/298,764 filed on Jan. 27, 2010, the entire contents of which are incorporated herein in its entirety. 
     
    
     BACKGROUND 
       [0002]    Locks, such as padlocks, come in various styles and shapes; but are all used to removably lock one article to another. 
         [0003]    In the electrical utility industry, lock devices, which function as security seals, are used to lock a transformer or meter socket enclosure. Such utility locks or seals provide a locking function for a utility enclosure; but are easily broken or cut apart. The intent of such lock-like seals is to provide a visual indication of tampering with the utility power enclosure. 
         [0004]    A typical utility lock or seal has a U-shaped shackle with two spaced, parallel legs interconnected at one end by a central end section. The legs of the shackle are inserted into two bores in a lock body. A set screw is threaded through at least side of the body into tight engagement with one of the shackle legs to lock the shackle and lock body together. 
         [0005]    The set screw requires the use of a tool, such as a screw driver, wrench, pliers or channel locks, to thread the screw into tight engagement with the shackle and, with sufficient force, to break the head of the set screw off of the shank at a frangible portion of the shank. Bolt cutters are thereby required to remove the lock by cutting the shackle. Alternately, the lock body has to be destroyed to separate the lock body from the shackle. 
         [0006]    It will be desirable to provide a lock and, in particular, a utility enclosure lock which has a low manufacturing cost and which can be engaged in a locked position without the use of a tool. 
       SUMMARY 
       [0007]    In one aspect, a lock apparatus includes a shackle having a pair of spaced legs. A lock body includes a pair of spaced bores for receiving the legs of the shackle. At least one push nut is carried within the lock body for receiving the legs of the shackle in a unidirectional insertion direction. The lock body may carry two push nuts, one for engaging each shackle leg. 
         [0008]    In one aspect, the lock body is an integral one-piece unitary body. At least one or two cavities are formed internally within the one piece body and open to slots extending from one surface of the lock body. A push nut is inserted through each slot into the cavity. 
         [0009]    In another aspect, the lock body includes first and second inter-engageable sections. Each of the first and second sections has first and second spaced ends. Apertures are formed in at least one of the first and second ends of each section. The apertures are coaxially aligned when the first and second sections are inter-engaged to form bores opening to the inter-engaged sections of the lock body. 
         [0010]    In one aspect, pairs of bores are formed on opposite side edges of the lock sections to enable the legs of the shackle to pass freely through the entire lock body. In another aspect, the lock body forms a closed interior chamber which completely encompasses the ends of the legs of the shackle when the shackle is interconnected with the lock body. 
         [0011]    Each of the first and second sections includes a first a pair of sidewalls at a first end and second pair of sidewalls at a spaced second end. The first and second sidewalls of each of the first and second sections are connected to a unitary member. Coaxially aligned apertures are formed in each of the first and second pairs of sidewalls. 
         [0012]    First and second recesses are formed in the first and second sections between the first and second pairs of sidewalls. The first and second recesses are coaxially aligned with the apertures in the sidewalls. One push nut is mounted into each of the first and second recesses. 
         [0013]    Each recess in the first and second sections cooperates with a like recess in the opposing first and second section when the first and second sections are inter-engaged to substantially encompass one push nut. 
         [0014]    In one aspect, the first and second sections are substantially identical. This enables the first and second sections to be reoriented with respect to each other such that the first pair of sidewalls on each of the first and second sections are laterally opposed from the second pair of sidewalls of the opposed first and second section. 
         [0015]    The second pair of sidewalls of each of the first and second sections may be laterally spaced closer together than the lateral spacing of the first pair of sidewalls such that the first pair of sidewalls encompasses the second pair of sidewalls when the first and second sections are inter-engaged. 
         [0016]    Engagement members may be carried on the first and second sections for cooperating with like engagement members on the opposing first and second sections when the first and second sections are inter-engaged to resist separation of the first and second sections. The engagement members may be a plurality of spaced, uni-directional angled teeth. 
         [0017]    In another aspect, a method of installing a lock including a shackle having spaced legs engageable with a lock body. The method comprises the steps of providing a lock body having a pair of spaced bores for receiving the legs of the shackle; mounting at least one push nut within the lock body for receiving the legs of the shackle in a unidirectional insertion direction; and inserting the legs of the shackle in one direction through the bores in the lock body such that the push nut forcibly engages one leg of the shackle to resist separation of the legs of the shackle from the lock body in a direction opposite from the insertion direction. 
         [0018]    In one aspect, the method includes the step of providing a one piece, unitary lock body having at least one internal cavity for receiving a push nut. A slot extends from an outer surface of the lock body into the cavity to allow insertion of a push nut through the slot into the cavity. 
         [0019]    In another aspect, the shackle and the lock body are formed of a castable metal. The end of at least one leg of the shackle is frangibly connected to the lock body during casting of the shackle and the lock body. 
         [0020]    In another aspect, the method comprises the step of providing a lock body formed of first and second inter-engageable sections. 
         [0021]    The method also includes the steps of forming a pair of recesses in each section; mounting a push nut in each of the recesses and inter-engaging the sections to form a unitary lock body with the recesses in each of the sections cooperating to substantially encompass one push nut therebetween. 
         [0022]    The method also includes the step of forming the lock body to define a closed interior chamber which completely encompasses the ends of the shackle legs when the shackle is interconnected with the lock body for added security. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
         [0023]    The various features, advantages and other uses of the present invention will become more apparent by referring to the following detailed description and drawing in which: 
           [0024]      FIG. 1  is a perspective view of a lock body; 
           [0025]      FIG. 2  is an exploded, perspective view of the lock body shown in  FIG. 1 ; 
           [0026]      FIG. 3  is a side perspective view of one of the two lock body sections; 
           [0027]      FIG. 4  is a side elevational view of the one lock body section shown in  FIG. 3  with the insertion of one push nut therein; 
           [0028]      FIG. 5  is a partially transparent, perspective view showing the internal push nuts in the assembled lock sections; 
           [0029]      FIG. 6  is a cross-sectional view generally taken along line  6 - 6  in  FIG. 5 ; 
           [0030]      FIG. 7  is a front elevational view, partially in cross section, of the lock body shackle engaged with two hasp; 
           [0031]      FIG. 8  as a perspective view of another aspect of a lock body, shown with the shackle integrally attached to the lock body after a die casting operation; 
           [0032]      FIG. 9  is a front elevational view of the lock body shown in  FIG. 8   
           [0033]      FIG. 10  is a bottom elevational view of the lock body shown in  FIG. 8 ; 
           [0034]      FIG. 11  is a cross-sectional view through the lock body showing the mounting of one push nut in the lock body and the engagement of the push nut with the shackle; 
           [0035]      FIG. 12  is a perspective view of another lock with a two section lock body; 
           [0036]      FIG. 13  is an exploded perspective view showing the two section lock body, with the push nuts mounted in one of the lock body sections; and 
           [0037]      FIG. 14  is an enlarged, perspective view of the entire lock depicted in  FIGS. 12 and 13  with one of the lock body sections shown in phantom. 
       
    
    
     DETAILED DESCRIPTION 
       [0038]    Referring now to  FIGS. 1-7  there is depicted one aspect of a lock assembly or lock  10  formed of a lock body  12  and a shackle  14 . 
         [0039]    As shown in detail in  FIG. 7 , the shackle  14  is typically formed of metal and has two spaced parallel legs  15  and  16  which are unitarily connected at one end by a central bight section  17 . 
         [0040]    Referring back to  FIGS. 1-6 , the lock body  12  includes a first lock section  18  and a second lock section  19  which are interconnectably engaged to form the complete lock body  12 . One of the features of the lock body  12  which contributes to its low manufacturing cost is that the first and second sections  18  and  19  are identically constructed. Thus, the following description of the construction of the first and second lock sections  18  and  19  will be provided in detail only for the first lock section  18 , it being understood that the second lock section  19  is identically constructed. 
         [0041]    The first lock section  18  is formed of a unitary body, such as a die cast metal, plastic, etc. The first lock section  18  includes a wall  20  extending from a first end  22  in the form of a curved outer endwall  24 . A first sidewall  26  projects angularly, such as perpendicularly, from the wall  20  adjacent to the first endwall  24 . An aperture  28  is formed in the first sidewall  26 . 
         [0042]    A second sidewall  30  project from the opposed edge of the wall  20  adjacent to the first end  22  generally parallel to the first sidewall  26 . A through aperture  32  is formed in the second sidewall  30 . 
         [0043]    An interior wall  34  projects from the outer wall  20  between the first and second sidewalls  26  and  30  and is spaced from the first endwall  24 . A first conical recess  36  is formed in the wall  20  between the first endwall  24  and the interior wall  34 . A larger arcuate recess  38  is also formed between the first endwall  24  and the interior wall  34  co-axial with the conical recess and the apertures  28  and  32 . 
         [0044]    An intermediate strengthening wall  40  is provided on the outer wall  20  spaced from the interior wall  34 . 
         [0045]    A second end  44  is formed on the wall  20  in the form of an arcuate outer end wall  46 . An inner wall  58  also extends from the wall  20  spaced from the second endwall  46 . 
         [0046]    A third sidewall  48  extends angularly, such as perpendicularly, from the outer wall  20  between the second endwall  46  and the second interior wall  47 . A first aperture  50  is formed in the third sidewall  48 . A similar fourth sidewall  52  is spaced generally parallel from the third sidewall  48  and extends angularly from the outer wall  20  between the second endwall  46  and the second interior wall  47 . An aperture  54  is formed in the fourth sidewall  52 . 
         [0047]    A conical recess  62  is formed between the second endwall  46  and the second interior wall  58 . Similarly, an arcuate recess  60  is positioned co-axially to the conical recess  62  between the second endwall  46  and the second interior wall  50 . The recesses  60  and  62  are coaxial with the apertures  50  and  54  in the pair of parallel third and fourth sidewalls  48  and  52 . 
         [0048]    As shown in  FIGS. 2 and 4 , two lock or push nuts  74  and  75 , which can be PAL push nuts, for example each have an annular disc  76  with a plurality of spring fingers  78  extending angularly away from one side of the disc  76 . The inner ends of the spring finger  78  define a central aperture  80  through the push nut  74  or  75 . 
         [0049]    As shown in  FIGS. 4-7 , the disc portion  76  of one push nut  74  is inserted into the conical recess  36  between the pair of first and second sidewalls  26  and  30 . It will also be understood that the push nuts  74  and  75  can be inserted into the die cast mold for insert casting with the molding with one of the first and sections  18  or  19 . 
         [0050]    The disc  76  of the other push nut  75  is inserted into the conical recess  62  between the third and fourth sidewalls  48  and  52 . In this orientation, shown in  FIG. 4 , the spring fingers  78  extend into the annular recesses  38  and  60  at opposite ends of the first lock section  18 . 
         [0051]    As shown in  FIG. 2 , when assembling the lock body  12 , one of the first and second sections  18  and  19 , with the second section  19  being used in this explanation by way of example only, is inverted with respect to the first lock section  18  such that the first end  22  of the second lock section  19  is spaced from the second end  44  of the first lock section  18 , and the second end  44  of the second lock section  19  is spaced from the first end  22  of the first lock section  18 . 
         [0052]    The first and second lock sections  18  and  19  are then urged together to form the unitary lock body  12 . Since the conical recesses  36  and  62  and the arcuate recesses  38  and  60  have a hemispherical form in each individual first and second lock sections  18  and  19 , the recesses  62  and  60  in the second lock section  19  will slide over the projecting portions of the push nuts  74  and  75  to capture the push nuts  74  and  75  between the interconnected first and second lock sections  18  and  19 . 
         [0053]    It should also be noted that the spacing between the pair of first and second sidewalls  26  and  30  is less than the spacing between the pair of third and fourth sidewalls  48  and  52 . This enables the pair of sidewalls  48  and  52  of each lock section  18  and  19  to slide over the first and second sidewalls  26  and  30  of the opposed lock section  18  and  19 . 
         [0054]    As shown in  FIGS. 1 and 2 , inner edges  82  and  84  of the first and second sidewalls  26  and  30 , respectively, have an engagement or locking profile. By way of example, the engagement profile can be provided as a plurality of angled teeth  86  extending along the length of each of the inner edges  82  and  84 . As shown in  FIG. 1 , the teeth  86  have a directional offset such that the inversion of one lock section, such as the second lock section  19 , with respect to the first lock section  18  during the assembly of the lock body  12  will bring the teeth  86  into mating engagement resisting sideways separation of the joined lock sections  18  and  19 . 
         [0055]    Referring now to  FIG. 7 , the installation of the entire lock  10  in a locking position will be described. A pair of hasps or flanges  90  and  92 , each having a through aperture  94  and  96 , respectively, extend outward from two movable doors or one door and a stationary portion of a utility enclosure, not shown. When the door or doors are in the locked position, the apertures  94  and  96  align thereby enabling the shackle  14  to be inserted through the apertures  94  and  96 . The lock body  12  is then forcibly urged over the legs  15  and  16  of the shackle  14  by inserting the ends of the legs  15  and  16  of the shackle  14  through the aligned apertures  28  and  32 , and  50  and  52  in the joined locked sections  18  and  19 . During this insertion, the legs  15  and  16  of the shackle  14  pass through the apertures  80  in the push nuts  74  and  75  and bend the inner ends of the spring fingers  76  slightly outward. However, the spring fingers  78  remained in an inward angled position relative to the respective discs  76  so as to bite into and prevent opposite sliding movement to separate the legs  15  and  16  of the shackle  14  from the lock body  12 . 
         [0056]    It will also be understood that the lock  10  is also completely functional when only one lock nut  74  or  75  is mounted within the joined sections of the lock body  12 . 
         [0057]    Referring now to  FIGS. 8-11 , there is depicted another aspect of a lock apparatus  100 . The lock apparatus  100  includes a shackle  14  identical to the shackle described above and shown in  FIGS. 1-8 . The lock apparatus  100  also includes a lock body  102 . 
         [0058]    In this aspect, by way of example only, the shackle  14  and the lock body  102  are integrally formed of a castable metal in a die cast operation. As shown in  FIG. 8 , the shackle  14  and the lock body  102  are integrally formed as a one piece assembly where one leg  15  of the shackle  14  is integrally coupled to the lock body  102  by a frangible portion  104 . This frangible portion  104  enables the shackle  14  to be separated from the lock body  102  for use. 
         [0059]    As shown in  FIGS. 8-11 , the lock body  102  has a general rectangular profile, cubicle shape formed of a top surface  106 , an opposed, bottom surface  108 , a front surface  110 , an opposed rear surface  112 , and opposed side surfaces  114  and  116  in the orientation shown in  FIG. 8 . A pair of through bores  120  and  122  extends through the lock body  102  between the front surface  110  and the rear surface  112 . The bores  120  and  122  intersect a pair of slots  124  and  126 , respectively, each of which extends from an open end in the bottom surface  108  into the interior of the lock body  102  as shown in detail in  FIG. 11 . 
         [0060]    Each slot  124  and  126  opens to an enlarged cavity  128  within the lock body  102 . The cavity  128  is centered about the respective through bore  120  or  122 . The slots  124  and  126  shown in  FIG. 11  have a cross section approximate that of the push nut  74  by example only. 
         [0061]    Each cavity  128  is configured for receiving one push nut  74  inserted through one of the slots  124  and  126 ; with the push nut  74  being inserted into the slot  126  in the example shown in  FIG. 11 . The slots  124  and  126  have a cross section slightly smaller than the height of the push nut  74 . During the insertion and step, the spring fingers  78  on each push nut  74  or  75  are compressed slightly to fit through the narrow slot  124  and  126 . Once the push nut  74  is fully inserted within each cavity  128 , the spring fingers  78  relax and expand back to their original shape. This coaxially aligns the aperture  80  between the inner ends of the spring fingers  78  of each push nut  74  and  75  with the respective through bore  120  and  122  in the lock body  102 . 
         [0062]    It will also be understood that the slots  124  and  126  may be eliminated and the push nuts  74  and  75  integrally cast within the cavity  128  in the lock body  102  during the die casting of the lock body  102 . 
         [0063]    During installation, after the shackle  14  has been separated from the lock body  102 , the shackle  14  can be inserted through the surfaces to be locked, such as the hasps  90  and  92  shown in  FIG. 7 . The lock body  102  is then oriented with respect to the shackle  14  to place the front surface  110  facing toward the ends of the shackle legs  15  and  16 . 
         [0064]    The lock body  102  and the shackle  14  are then engaged by inserting the shackle legs  15  and  16  into the bores  120  and  122  in the lock body or by urging the bores  120  and  122  of the lock body  102  over the ends of the shackle legs  15  and  16 . 
         [0065]    During the insertion step, the shackle legs  15  and  16  pass through the one or more push nuts  74  mounted in the cavities  128  in the lock body  102  causing the inner ends of the spring finger  78  to expand outward. 
         [0066]    The insertion step continues until the installer is satisfied with the placement of the lock body  102  along the length of the shackle legs  15  and  16 . In this position, as shown in  FIG. 11 , the spring fingers  78  of the one or more push nuts  74  or  75  resist separation of the lock body  102  from the shackle  14  in a direction opposite from the insertion direction. In order to separate the lock body  102  from the shackle  14 , one or both of the shackle legs  15 ,  16  has to be cut, such as through the use of bolt cutters, or the lock body  102  has to be destroyed. 
         [0067]    It has been found that the assembly of the lock  10  can be completed without a tool and using only 15-25 pounds of insertion pressure to engage the lock body  12  or  102  with the shackle  14 . However, the push nuts  74  and  75  captured with the lock body  12  or  102  exert sufficient resistance to separation of the legs  15  and  16  of the shackle  14  from the lock body  12  that 400 pounds of pull out force are required on each leg  15  and  16  of the shackle  14  to pull each leg  15  or  16  from the lock body  12  or  102 . 
         [0068]    It should also be noted that the engagement of the shackle legs  15  and  16  with the push nuts  74  and  75  retains the first and second lock sections  18  and  19  of the lock body  12  together in non-separating engagement. 
         [0069]    Referring now to  FIGS. 12-14 , there is depicted another aspect of a lock  140  formed of a lock body  142  and a shackle  144 . In this aspect, the shackle  144  may be identical to the shackle  14  shown in  FIG. 8 . The shackle  144  may have shorter length legs  145  and  146  for secure fitting within the lock body  142  as described hereafter. 
         [0070]    As in the first aspect of the lock  10  shown in  FIGS. 1-7 , the lock body  142  is formed of substantially identical lock sections  148  and  149 . Each lock section  148  and  149  is formed of a unitary body, such as a one-piece body formed of die cast metal, plastic, etc. 
         [0071]    As both of the first and second lock sections  148  and  149  are substantially identical, the following description of the first lock section  148  will be understood to apply equally to the second lock section  149 . In the following description of the assembly of the first and second lock sections  148  and  149 , like elements of the second lock section  149  will be given the same reference number as the corresponding element of the first lock section  148 , along with an “A” suffix. 
         [0072]    As shown in detail  FIG. 13 , the first lock section  148  includes a sidewall  150  extending between a first edge  152  and an opposed second edge  154 . A first endwall formed of stepped sections  156  and  158  is formed along one side edge of the sidewall  150 . A similar second endwall formed of stepped sections  160  and  162  extends along the opposite side edge of the sidewall  150 . 
         [0073]    Each of the stepped sections  156  and  158  includes a through bore  161  and  163 , respectively. Each through bore  161  and  163  is coaxially aligned with a push nut seat  164  and  166 , respectively, formed on the sidewall  150  immediately adjacent to the stepped sections  156  and  158 . 
         [0074]    Similar to the push nut seats described above and shown in the first aspect of the lock  10  in  FIGS. 1-7 , the push nut seats  164  and  166  include a conical recess  168  and an enlarged diameter, annular recess  170 . The annular recess  170  is adapted for receiving the enlarged annular end of one push nut  74  or  75 . The annularly bent spring fingers  78  of each push nut  74  and  75  are seated within the conical recesses  168 . 
         [0075]    In this manner, the push nuts  74  and  75  may be inserted into the push nut seats  164  and  166  formed in either of the first and second lock sections  148  and  149  as shown in  FIG. 13 , prior to the interconnection of the first and second lock sections  148  and  149 . 
         [0076]    As seen in  FIG. 13 , the endwall sections  156  and  160  are spaced closer together than the adjacent endwall sections  158  and  162 . This enables the first and second lock sections  148  and  149  to be reversed in orientation with respect to each other, as shown in  FIG. 13 , and then snapped engaged into a locked position surrounding the push nuts  74  and  75   
         [0077]    Similar to the engagement or locking profile for the lock sections of the lock body  12  shown in  FIGS. 1 and 2 , the lock sections  148  and  149  have an engagement or locking profile provided by a plurality of angled teeth  176 ,  176 A along the edge of the stepped sections  156  and  158  and along the edge of the stepped sections  160  and  162 . The orientation of the first and second lock sections  148  and  149  are reversed with respect to each other and interlocked as shown in  FIGS. 12 and 14 . 
         [0078]    Until the shackle  144  is inserted into engagement with the lock body  140 , the interconnected first and second lock sections  148  and  149  may be separated from each other by disengaging the teeth  176  and  176 A while moving the first and second lock sections  148  and  149  away from each other. 
         [0079]    When the first and second lock sections  148  and  149  are interconnected as shown in  FIGS. 12 and 14 , the ends  147  and  149  of the shackle legs  145  and  146  may be inserted through the aligned bores  161  and  163 A, and  163  and  161 A in the lock sections  148  and  149 . The ends  147  and  149  of the shackle legs  145  and  146  are inserted through the push nut  74  and  75  into the interior of the lock body  142  as shown in  FIG. 14 . The angled arrangement of the spring fingers  78  of each push nut  74  and  75  prevents the shackle legs  145  and  146  from being withdrawn from the lock body  142 . 
         [0080]    The lock  140  uniquely encompasses the ends  147  and  149  of the shackle legs  145  and  146  when the shackle  144  is secured to the lock body  142  as seen in  FIGS. 12 and 14 . This increases the security of the lock  140  by preventing any contact with the ends  147  and  148  of the shackle legs  145  and  146 , such as in unauthorized attempt to remove the lock  140 . This is achieved by providing the sidewalls  150  and  150 A of the lock sections  148  and  149 , respectively, with a sufficient length to enable the ends  147  and  149  of the shackle legs  145  and  146  to be inserted to any desired position within the lock body  142  before contacting or even bottoming out on the lower most endwall sections  160  and  160 A.