A computer lock with a locking plate and protruding hook joined to a cylindrical assembly wherein the hook is inserted into a computer chassis security slot. The locking plate interacts with grooves within the cylindrical assembly to position and hold the protruding hook longitudinally within the security slot. A lockable cable engages the cylindrical assembly. The cable is secured to a fixed object to prevent the computer from being stolen or removed from a fixed location.

BACKGROUND OF THE INVENTION 
     This invention relates to security apparatus, and more particularly to apparatus for securing notebook computer equipment. 
     In recent years there has been a marked increase in the amount of computer equipment used in business and at home. Not only have the number of computers increased, but their size has become steadily smaller. Computer owners carry with them and use in areas with public access smaller computers such as laptop and notebook computers. Notebook computers only weigh several pounds or less and are easily concealed on the person or in a carry bag. Equipment items in this category generally have values from one to several thousands of dollars, and are easily marketed. Equipment such as this and their component parts are, therefore, attractive, lucrative and easy targets for thieves. 
     Many personal computers have a security slot in an external wall. Attempts to provide securing devices centered on this slot have been complicated. An example of this may be found in U.S. Pat. No. 5,502,989 (Reexamination Certificate B1 5,502,989), issued to W. R. Murray, Jr., et al. The Murray device, inter alia, provides a security device comprised of a housing with a slot engagement portion, said portion being rotatable between an unlocked position and a locked position, and a pin coupled through the housing and extending into the security slot member after said slot engagement member is in said locked position. The Murray device is specifically designed to engage a rectangular security slot. Another approach has been used in U.S. Pat. No. 5,983,679 issued to G. Reyes. The Reyes device uses a cam assembly with a single hook arm in conjunction with two prongs to engage with the predefined rectangular security slot. 
     A further problem with prior art locks, is the poor fit the locks make with the security slot. Many computer manufacturers have a different thickness in the wall with the security slot. Prior art locks have a set gripping width, i.e., the distance between the lock engagement end on one side of the security slot and the lock assembly itself on the other side of the security slot. Ideally, the gripping width should be as close to the width of the computer side wall as possible to prevent easy insertion of a prying device. The user must measure the wall thickness and shop for a lock with a gripping width as close to the wall thickness as possible. 
     SUMMARY OF THE INVENTION 
     The present invention provides a relatively simple locking mechanism for preventing the theft of a small computer, such as a notebook computer. The locking mechanism of the present invention is adapted to fit all computers made by all manufacturers, which contain a security slot in their chassis, regardless of the configuration of the security slot. 
     To attain this, the present invention provides a lock with a locking plate and protruding hook joined to a cylindrical assembly wherein the hook is adapted to being inserted into a computer chassis security slot. The locking plate interacts with grooves within the cylindrical assembly to position and hold the protruding hook longitudinally. The present invention replaces the complications inherent with the removable coupling pin of the Murray invention and eliminates the need for rotating the entire assembly in order to be positioned with a locked position. The present invention provides a sturdier and simpler locking configuration than the Reyes device. The unique design of the present invention makes the present invention an ideal choice for the individual or organization that has a variety of computer brands to secure. A lockable cable engages the cylindrical assembly. The cable is secured to a fixed object to prevent the computer from being stolen or removed from a fixed location. In the present invention a variety of different type locking cables may be used. 
     The present invention provides a means for adjusting, both manually and automatically, the gripping width of the present invention lock assembly. Regardless of the thickness of the computer wall having the security slot, the present invention can be adjusted to provide a perfect gripping width. To the best of applicant's knowledge, the present invention is the only lock which has this feature. 
     Accordingly, it is an object of the present invention to provide a computer security locking apparatus for securing small computers, such as notebook computers, which have security slots in their chassis. It is additionally an object of the present invention to provide such an apparatus which is simple, economical, easy to use and quickly installed. 
     Another object of the invention is to provide such a security apparatus which is installed to said computer without modifying the computer chassis thereby removing the risk of contacting various components and circuitry therewithin. 
     It is another object of the present invention to provide a security apparatus which may use different types of anchoring cables. 
     It is an object of the invention to provide a security apparatus which does not require rotation between locked and unlocked positions. 
     These together with other objects of the invention, along with various features of novelty which characterize the invention, are pointed out with particularity in the claims annexed hereto and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and the specific objects attained by its uses, reference should be had to the accompanying drawings and descriptive matter in which there is illustrated a preferred embodiment of the invention. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of the invention, with a travel anchor cable, installed on a notebook computer, thereby securing the notebook computer to a table; 
     FIG. 2 is a perspective view of the invention, with an office anchor cable, installed on a notebook computer, thereby securing the notebook computer to a work surface; 
     FIG. 3 is a close up perspective view of a computer open security slot. 
     FIG. 4 is a side view of the invention installed in a computer security slot. 
     FIG. 5 is a side view, partly exploded, of the lock cylinder. 
     FIG. 6 is a perspective view of the upper half of a lock body. 
     FIG. 7 is a perspective view of a ring used on the lock body. 
     FIG. 8 is a side cross section view of the lock body. 
     FIG. 9 is a side cross section view of a disengaged lock body with lock cylinder. 
     FIG. 10 is a side cross section view of an engaged for installation lock body with lock cylinder. 
     FIG. 11 is a side view of one end of the holding end of an anchor cable. 
     FIG. 12 is a rear view of the lock housing. 
     FIG. 13 is a front view of the lock housing. 
     FIG. 14 is a cross section view of the lock housing. 
     FIG. 15 is a sectional side view of the invention. 
     FIG. 16 is a diagramatic side view of the lock housing. 
     FIG. 17 is a diagramatic side view of the lock body. 
     FIG. 18 is a front view of the adjustment spacer. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to the drawings in detail wherein like elements are indicated by like numerals, there is shown an embodiment of a notebook computer security hook lock assembly  1  constructed according to the principles of the present invention. The invention  1  provides lock body  40  containing a lock cylinder  20  with an attached protruding hook element  25 . The lock body  40 , itself, is housed within a cable lock housing  80 . An anchored locking cable  5  is removably attached to the cable lock housing  80 . In the examples shown, the computer  10  is a notebook computer. The computer  10  secured could be a smaller or a larger personal computer. 
     The computer  10  has a generally rectangular configuration, with a front outer wall  11 , rear outer wall  12 , two outer side walls  13 , a top  14 , and a bottom  15 . One of the computer sides  13 ′ has an open, generally rectangular, security slot  16  formed therein. The security slot has two long edges  17  defining a security slot longitudinal axis, and two short edges  18 . In this embodiment, the security slot short edges  18  are parallel to the computer chassis top  14  and bottom  15 . The invention protruding hook element  25  is insertable into the open security slot  16 . Manipulation of the lock cylinder  20  locks the lock cylinder  20  and lock body  40  to the computer  10 . The cable lock housing  80  encloses the lock body  40 . The locking cable  5  is joined to the cable lock housing  80  and is fastened to an appropriate secure object such as a table leg  3 . 
     The lock cylinder  20  is a conventional key  2  operated lock with internal indents (not shown) to hold a key rotational turn at either a radial  0  degrees or a radial  90  degrees. The lock cylinder  20  has a rear portion  21  adapted to receive a key  2 , an opposite and parallel forward portion  22  and a cylindrical body  23  extending from said rear portion  21  and terminating in said forward portion  22 , said rear  21  and forward  22  portions defining a lock cylinder longitudinal axis. The lock cylinder body  23  has an elongated channel  37  formed therein, beginning at the lock cylinder rear portion  21  and extending forwardly a desired distance, said channel  37  having a longitudinal axis coincident with the lock cylinder longitudinal axis. The lock cylinder forward portion  22  has a central, threaded aperture  24  formed therein. 
     A generally flat and generally rectangular locking plate  30  is fixedly attached to the lock cylinder forward portion  22 . The locking plate  30  has a flat plane parallel to a radial plane of the lock cylinder cylindrical body  23 . The locking plate  30  has a forward surface  31 , a rearward surface  32 , two parallel long side edges  33 , two parallel short side edges  34 , and a central aperture  35  corresponding to the lock cylinder forward portion aperture  24 . The locking plate rearward surface  32  is attached to the lock cylinder forward portion  22 . The locking plate short side edges  34  define a locking plate longitudinal axis which is parallel to the locking plate long side edges  33  and which is transverse to the longitudinal axis of the lock cylinder  20 . The locking plate long side edges  33  exceed a lock cylinder cylindrical body radial diameter. The lock cylinder  22  is adapted so that movement of the key  2  to and from 0 degrees through 90 degrees causes a direct corresponding turn of the locking plate  30  longitudinal axis about the locking plate central aperture  35 . 
     The present invention is further comprised of a protruding hook element  25  attached to the lock cylinder forward portion  22 . The hook element  25  has a front end  26  and a rear end  27  terminating in a threaded element  28  extending rearwardly from the hook element rear end  27 . The hook element front end  26  is bent at an obtuse angle thereby forming an obtuse hook. The hook element threaded element  28  is adapted to threadingly engage the lock cylinder forward portion central threaded aperture  24  through the locking plate central aperture  35 . A compression spring  29  is fitted over the hook element  25 . 
     As stated above the invention is comprised of a lock body  40  containing the lock cylinder  20  with protruding hook element  25 . The lock body  40  has an enclosed front end  41  from which a cylindrical side wall  42  extends to an open rear end  43 , said front end  41  and rear end  43  defining a lock body longitudinal axis, said front end  41 , side wall  42  and rear end  43  defining a hollow lock body interior  44 , said lock body  40  being generally cylindrical in shape. The lock body front end  41  has a generally rectangular aperture  46  formed centrally therein. The side wall  42  has an exterior surface  45  and an interior surface  60 . For purposes of manufacturing and installation of the lock cylinder within the lock body interior  44 , the lock body side wall  42  may be split into two longitudinal halves. The two side wall longitudinal halves may be joined and held in place by a combination of pins  52  and opposing apertures  53  as shown in FIG. 6, and rings  55  (described below). 
     The side wall exterior surface  45  is divided into four circumferential radial external bands, each external band radially encircling the exterior surface  45 . The first exterior band  47  beginning at the lock body front end  41  and extending longitudinally rearwardly a selected distance has threads  48  formed thereon. The fourth exterior band  51  beginning at the lock body rear end  43  and extending longitudinally forwardly a selected distance also has threads  48  formed thereon, and has a radial outer diameter equal to a first exterior band radial outer diameter. The second exterior band  49  beginning at the first exterior band  47  and extending longitudinally rearwardly a selected distance has a smooth surface formed thereon, and has a radial outer diameter greater than the first and fourth exterior band radial outer diameters. The third exterior band  50  beginning at the second exterior band  49  and extending longitudinally to the fourth exterior band  51  has a smooth surface formed thereon, and has a radial outer diameter less than the radial outer diameter of the second external band but greater than the first and fourth exterior band radial outer diameters. 
     The lock body  40  is further comprised of two identical rings  55 , each ring having an outer surface  56  and a threaded inner surface  57 , said rings  55  adapted to threadingly engage the first and fourth exterior bands  47 ,  51 . Each ring  55  has a radial outer diameter equal to the radial outer diameter of the second exterior band  49 . The ring outer surfaces  56  are nominally smooth. However, for improved gripping purposes the outer surfaces  56  of one or both rings may be knurled or otherwise ridged or channeled for gripping purposes. 
     The side wall interior surface  60  is divided into two longitudinal portions, a rearward interior surface portion  61  and a forward interior surface portion  62 . The rearward interior surface portion  61  is smooth and has a radial inner diameter slightly greater than the radial diameter of the lock cylinder cylindrical body  23 . The rearward interior surface  61  has a small circular aperture  69  formed therein, said aperture containing a pin  68  projecting inwardly toward a lock body central longitudinal axis. The pin  68  is adapted to engage the lock cylinder body elongated channel  37 , thereby holding the lock cylinder body  23  in position within the lock body interior  44  and preventing the lock cylinder body  23  from moving out of the lock housing  80 . The forward interior surface portion  62  contains two radial channels, a forward first radial channel  63  and a rearward second radial channel  64 , and also two longitudinal channels, a first longitudinal channel  65  and a second opposite longitudinal channel  66 . The radial channels  63 ,  64  intersect the longitudinal channels  65 ,  66 . The inner diameters of the forward interior surface portion channels  63 ,  64 ,  65 ,  66  are equal to each other, but are greater than the radial inner diameter of the rearward interior surface portion  61 . The inner diameters of the forward interior surface portion channels  63 ,  64 ,  65 ,  66  are slightly greater than the locking plate long side edges  33 . The inner diameter of the rearward interior surface portion  61  is less than the locking plate long side edges  33 . The diameter of the forward interior surface portion  67  between the radial channels  63 ,  64  is equal to the diameter of the rearward interior surface portion  61 . The longitudinal channels  65 ,  66  extend longitudinally from the lock body front end  41  rearwardly past the radial channels  63 ,  64  to the interior surface rearward portion  61 . 
     The lock cylinder  20  is positioned within the lock body interior  44  with the front end  25  of the hook element  25  protruding through the lock body front end aperture  46 . In the unlocked position, the lock cylinder locking plate  30  is positioned so that the locking plate short side edges  34  are placed within the lock body interior surface longitudinal channels  65 ,  66 . The locking plate  30  is adapted to turn radially  90  degrees when the key  2  is turned to lock the lock cylinder  20 . The locking plate  30  is adapted then to slide into one of the forward interior surface portion radial channels  63  or  64 . The diameter of the forward interior surface portion  67  between the radial channels  63 ,  64  and the diameter of the rearward interior surface portion  61  prevents the locking plate  30  from moving rearward. The compression spring  29  about the hook element  25  maintains a rearward pressure on the lock cylinder forward portion  22  and locking plate  30 . 
     The lock body  40  containing the lock cylinder  20  is housed within a cable lock housing  80 . The lock housing  80  has an enclosed front end  81  from which a cylindrical side wall  83  extends to an open rear end  82 , said front end  81  and rear end  82  defining a lock housing longitudinal axis, said front end  81 , side wall  83  and rear end  82  defining a lock housing hollow interior  84 , said lock housing body  80  being generally cylindrical in shape. The lock housing front end  81  has a generally circular aperture  89  formed centrally therein. The side wall  83  has a smooth exterior surface  85  and a smooth interior surface  86 . 
     The side wall exterior surface  85  has a rounded, radially protruding, elongated element  90  formed thereon extending longitudinally from the housing rear end  82  to an approximate housing longitudinal midpoint  87 . The protruding element  90  has a closed forward end  91 , an open rearward end  92 , a radially rounded top  93  and a bottom  94  formed from the housing side wall  83 , said forward end  91  and rearward end  92  defining a protruding element longitudinal axis, said protruding element longitudinal axis being parallel to the lock housing longitudinal axis. The forward end  91 , rearward end  92 , top  93  and bottom  94  define a protruding element interior  97 . The protruding element  90  is divided longitudinally into a forward section  95  and a rearward section  96 . The interior  97  portion of the protruding element forward section  95  is solid. However, an inwardly protruding sprin-loaded ball  88  is embedded in the forward section protruding element bottom  94  projecting inwardly toward a lock housing central longitudinal axis. The spring-loaded ball  88  is adapted to engage the lock body third exterior band  50 . 
     The interior  97  portion of the protruding element rearward section  96  is hollow. The bottom  94  portion of the protruding element rearward section  96  is open. A radial channel  98  is formed within the protruding element rearward section interior  97  portion adjacent the protruding element forward section  95  interior  97  portion. The radial channel  98  has a diameter greater than the diameter of the open rearward end  92  and a bottom  94  opening greater than the bottom  94  opening of the open rear end  92 . 
     The cable lock housing  80  and lock body  40  combination is used in conjunction with an anchored locking cable  5 . The locking cable  5  has two ends, an anchored end  6  and a holding end  7 . As may be seen in FIGS. 1A,  1 B and  2 , the cable anchored end  6  may terminate in a simple slip knot and wrapped around a secure object such as a table leg  3 . The cable anchored end  6  may also be attached to a special adaptor  4  glued to a secure object such as the underside of a desk. Any number of anchor cables having different anchored ends  6  may be used with the present invention. As may be seen additionally from FIGS. 2 and 4, the holding end  7  of the cable is comprised of a cylindrical shank  8  terminating in a disk-like protrusion  9  having a diameter greater than said shank  8 . The anchor cable  5  is adapted to being connected to the lock housing  80  by sliding the anchor cable disk  9  into the protruding element radial channel  98  through the protruding element rearward section open bottom  94  and threading the cable shank  8  through the protruding element rearward end  92 . The lock body  40  is then slid into the lock housing interior  84  and the cable  5  is secured within the protruding element radial channel  98 . 
     In operation, the anchor cable  5  is installed as described above. The lock body  40  is slid into the lock housing interior  84 . The lock cylinder key  2  is held in the unlocked position and the locking plate  30  pushed completely forward wherein the key  2  is turned to turn the locking plate  30  and engage the lock body first radial channel  63 . The protruding hook  25  is now at its maximum extension and is easily inserted into the computer open security slot  16 . With the hook  25  engaged within the security slot  16 , the key  2  is turned back to unlock the lock cylinder  20 , and the compression spring  29  pushes the lock cylinder away from the lock body front end  41 , thereby drawing the protruding hook front end  26  up against the inside  113  of the computer side wall  13 ′ and pushing the cable lock housing front end  81  against the outside  114  of the computer side wall  13 ′, thereby assuring a snug fit against the security slot  16 . The locking plate  30  is pushed back even with the lock body second radial channel  64 . The key  2  is again turned to the lock position wherein the locking plate  30  engages the second radial channel  64  and the front end  81  of the cable housing  80  secured against the computer security slot  16 . The key  2  is now removed and the computer  10  is thereby secured. 
     Different computers may have different thicknesses for the wall  13 ′ containing the security slot  16 . The present invention provides a means for adjusting the gripping width of the present invention lock assembly  1 . The gripping width is defined as the distance between the underside  19  of the protruding hook front end  26  and the cable lock housing front end  81 . Ideally, the gripping width should be as close to the width of the computer side wall  13 ′ as possible. Adjustment is provided with the ring  55  in threading engagement with the lock body first exterior band  47 . By manipulating this ring  55  the overall longitudinal length of the lock body  40  may be increased or decreased changing the extension of the protruding hook  25  from the lock body front end  41  and through the lock housing front end  81  into the security slot  16 , thereby affecting the gripping width of the lock assembly  1 . 
     An adjustment spacer  75  is also provided. The adjustment spacer  75  is a round, flat piece with an elongated aperture  76  formed centrally therein. The spacer  75  has a thickness equal to the thickness of the housing front end  81 . The lock body  40  and lock cylinder  20  may be fitted to a computer  10  by removing the lock housing  80  and placing the spacer  75  over the protruding hook  25 . The spacer  75  replaces the lock housing  80 . The lock body  40  with lock cylinder  20  and spacer  75  are fitted into the security slot  16 . After a desired adjustment is made by manipulation of the ring  55  engaged with the first exterior band  47 , the spacer  75  is removed and the lock housing  80  is fitted over the lock body  40  for installation on the computer  10 . 
     It is understood that the above-described embodiment is merely illustrative of the application. Other embodiments may be readily devised by those skilled in the art which will embody the principles of the invention and fall within the spirit and scope thereof.