Abstract:
An improved metal detector characterized by enclosing the detector&#39;s circuitry in a foldable enclosure whereby the improved detector may be transported easily and quickly and securely erected for use.

Description:
BACKGROUND OF INVENTION 
     1. Field of the Invention 
     The present invention relates to an improvement of metal detectors such as those typically found in office buildings and airports. Such metal detectors are the type where persons and objects pass through a magnetic field created by circuitry in the detector whereby the presence of metal may be determined. Most such metal detectors are based on pulse induction technology, and while the improvement of this invention may be used with virtually any type of walkthrough metal detector, it is believed that the improvement will be utilized primarily in combination with pulse induction detectors. 
     2. Description of the Prior Art 
     As indicated above, walkthrough metal detectors are quite old and well known in the art. Obviously, at this point in our country&#39;s history, the importance of metal detectors has perhaps never been greater. While such metal detectors have been known and used for many years in facilities such as airports and government buildings, use of walkthrough metal detectors has recently been expanded to a wide variety of public facilities, including, for example, office buildings and public schools. 
     With regard to current state-of-the-art walkthrough metal detectors, they are typically a relatively permanent installation. That is to say, the device comprises an inverted U-shaped configuration that is erected and installed in a substantially permanent manner at the entry point where persons and objects are to be screened. 
     It is therefore apparent that there is a need in the art for an improved metal detector capable of relatively easy disassembly, transportation, and re-assembly for use at a different location. Such an improved metal detector must be of relatively light weight, preferably capable of being carried by one person. Of course, such an improved metal detector must also provide for ease of re-assembly without damage to the detector&#39;s circuitry, so that the reliability of its use is not compromised. 
     It was with these and other goals in mind that the present invention was developed. 
     SUMMARY OF THE INVENTION 
     The present invention comprises an improvement in metal detectors of the type where persons and objects pass through a magnetic field created by circuitry in the detector whereby the presence of metal may be determined. The improvement comprises a foldable enclosure for the detector&#39;s circuitry, that foldable enclosure comprising a plurality of detector panels and means for connecting each one of the panels to at least one other of the panels, whereby the foldable enclosure may be erected to define a substantially inverted U-shaped configuration having a closed top, opposing legs extending downwardly from the top, and an open bottom defined by the space between the legs. The improvement further comprises a base dimensioned and configured to receive the erected enclosure, whereby the metal detector may be erected and secured in an operative position. 
     It is to be understood that the scope of this invention is not intended to be limited to any particular circuitry or control devices for the metal detector, though in preferred embodiments described hereinafter, some of these elements will be discussed for purposes of providing a full and complete disclosure of the improvement of this invention. 
     The invention accordingly comprises an article of manufacture possessing the features, properties and the relation of elements which will be exemplified in the articles hereinafter described, and the scope of the invention will be indicated in the claims. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description taken in connection with the accompanying drawings, in which: 
     FIG. 1 is a perspective view of a first preferred embodiment for the foldable closure comprising the improved metal detector of this invention. 
     FIG. 2 is a perspective view of the embodiment of FIG. 1, folded and placed inside a carrying case. 
     FIG. 3 is rear elevation of the first preferred embodiment shown in the view of FIG.  1 . 
     FIG. 4 is a side elevation of the embodiment of FIG.  1 . 
     FIG. 5 is a simplified perspective view of the embodiment of FIG. 1, illustrating the folding planes. 
     FIG. 6 is a partially folded view of the embodiment as shown in FIG.  5 . 
     FIG. 7 is a view similar to that of FIG. 6, showing further folding of this embodiment. 
     FIG. 8 is a further view of the embodiment of FIG. 5, showing still further folding. 
     FIG. 9 is a folded view of the embodiment shown in FIG.  5 . 
     FIG. 10 is an elevational view of a pair of enclosure reinforcing strips. 
     FIG. 11 is a front elevation of a second embodiment of the foldable enclosure. 
     FIG. 12 is a partially folded view of the second embodiment shown in FIG.  11 . 
     FIG. 13 is a further folded view of the embodiment of FIG.  11 . 
     FIG. 14 is a completely folded view of the embodiment of FIG.  11 . 
     FIG. 15A is a third embodiment of the improvement of this invention. 
     FIG. 16A is a partially folded view of the embodiment shown in FIG.  15 A. 
     FIG. 15B is a fourth embodiment of the improvement of this invention. 
     FIG. 16B is a partially folded view of the embodiment of FIG.  15 B. 
     FIG. 17 is a further folded view of the embodiment of FIG.  15 A. 
     FIG. 18 is a completely folded view of the embodiment of FIG.  15 A. 
     FIG. 19 is an elevational view of a second embodiment for the enclosure reinforcing strips. 
     FIG. 20 is an exploded elevational view of a fifth embodiment of the improvement of this invention. 
     FIG. 21 is a detail view of the connecting means for the embodiment shown in the view of FIG.  20 . 
     Similar reference characters refer to similar parts throughout the several views of the drawings. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The present invention relates to an improvement in walkthrough metal detectors comprising a foldable enclosure for the detector&#39;s circuitry, and a first preferred embodiment for the improved foldable enclosure is generally indicated as  30  in the view of FIG.  1 . That same first embodiment  30  is shown in its folded condition inside a carrying case generally indicated  32  in the view FIG.  2 . Because the present invention relates to an improvement in the nature of a foldable enclosure for the metal detector&#39;s circuitry, it is to be understood that the circuitry and other elements of a walkthrough metal detector are not claimed as elements of this invention and that the improved foldable enclosure is intended for use in combination with and as an improvement to virtually any such metal detector. Nevertheless, certain elements of the metal detector will be identified and discussed in order to more fully set forth the nature of the present invention. 
     For example, as shown in the view of FIG.  1  and other ones of the drawings, provision is made for the location and placement of a detector control panel  34 , whereby persons responsible for actually operating and monitoring the metal detector may make necessary settings and adjustments. In similar fashion, an outlet  36 , also visible in the view of FIG. 1, is provided whereby the detector&#39;s circuitry may be operatively connected to a power source. 
     Operation of such walkthrough metal detectors, and the circuitry necessary for their proper performance, are well known in the art and basically comprise coils, orwires, which generate a magnetic field through which persons and/or objects pass. If metal passes through the field, the field is disturbed and visual and/or audible signals are created. These coils or wires are operatively disposed within foldable enclosure  30  and may be surrounded with, for example, high density polyurethane. In all embodiments shown, the actual metal detector utilizes quad coil detection fields and state-of-the-art digital microprocessors. 
     It is also to be understood that in state-of-the-art metal detectors such as those for which this invention is an improvement typically include a protective core surrounding the circuitry within the side panels. Frequently, this protective core takes the form of one or more sheets of polyurethane foam which may actually include pockets or receptacles for the circuitry. All embodiments of this invention would include such a protective core, though not shown in the drawing figures. It is further contemplated that all embodiments of the improvement of this invention would include means for accessing the circuitry within the side panels for known purposes of repair, maintenance and modification. 
     Referring now to the first preferred embodiment of FIG. 1 for the foldable enclosure  30 , one can see that foldable enclosure  30  comprises side panels  38 ,  40 ,  42  and  44 , and a top panel  46 . Side panels  38 ,  40 ,  42  and  44  include detector coils operatively mounted therein, and top panel  46  is for structural integrity of the foldable enclosure  30 . Disposed in receiving relation to the distal ends of side panels  40  and  44  is a base, generally indicated as  48 . In the preferred embodiment for base  48 , a substantially H-shaped configuration is provided and the distal ends of side panels  40  and  44  each rest on a respective one of the base sides,  50  and  52 . Crossbar  54  extends an interconnecting relation between sides  50  and  52 . Though not shown in all drawing figures, each of the further preferred embodiments shown in the drawing figures and described in greater detail below do include a corresponding base  48 . 
     Referring to the view of FIG. 4, one can see that the side of side panel  42  opposite that from which detector control panel  34  is mounted, includes a pair of display lights  56  and  58 . According to known metal detector devices, lights  56  and  58  provide a visual indication to a person preparing to pass through the detector as to whether or not the detector is “ready,” and light  56  is typically red while light  58  is typically green. 
     Referring now to the views of FIGS. 5-9, one may see in the series of drawings how the invention of first embodiment  30  is actually folded for placement inside carrying case  32 . Attention is invited to the fact that base  48  is not shown in the views FIGS. 7-9. One can clearly see the various fold lines as designated at  60 ,  62  and  64 . The effective “hinges” at fold lines  60 , 62  and  64  preferably comprise a flexible material interconnecting side panels  38  and  40 ,  44  and  42 , and  42  and  46 , respectively. With particular regard to fold lines  60  and  62 , circuitry for the detector coils operatively disposed in panels  38 ,  40 ,  42  and  44  include flexible connectors within fold line  60  and fold line  62 . 
     Owing to the construction of this first embodiment  30 , the folding connecting between side panel  38  and top panel  46  is preferably defined by a segment of flexible material  66  so that side panel  38  can be folded over top panel  46  as shown in the views of FIGS. 8 and 9. Flexible connectors for the detector coils also pass through fold line  64  and the segment of flexible material  66  in order to complete the detector&#39;s electrical circuitry. 
     The view of FIG. 10 illustrates a pair of enclosure reinforcing strips  68  and  70 . Strips  68  and  70  are preferably formed from a rigid, plastic material such as, for example, lexan, and may be covered with a fabric material. According to a preferred embodiment for the invention, two pairs of strips  68  and  70  are provided, and the strips are attached by any suitable means to respective front and back edges of first embodiment  30  to provide rigidity to the unfolded, assembled enclosure  30 . For example, hook and loop fasteners are an acceptable means for attaching the strips  68  and  70  to the respective front and back edges of panels  38 ,  40 ,  42 ,  44 , and  46 . The dotted lines in the view of FIG. 10 illustrate fold points for strips  68  and  70 . 
     Referring once again to the view of FIG. 1, this embodiment of foldable enclosure  30  further comprises at least one base strap  72  attached to the distal end of side panel  40  and side panel  44 . A corresponding base buckle  74  is attached to each of the base sides  50  and  52  in receiving relation to base strap  72 , whereby the unfolded panels  38 ,  40 ,  42 ,  44  and  46  may be secured to base  48 . Though not visible in the view of FIG. 1, corresponding straps  72  and buckle  74  would also be provided on the opposite side of first embodiment  30 . It is also to be understood that corresponding straps  72  and buckles  74  are preferably used in all embodiments of the improved foldable enclosure of this invention. 
     A second preferred embodiment, generally indicated as  30 A, is shown in the views of FIGS. 11,  12 ,  13 , and  14 . Similar structural elements have been designated in second embodiment  30 A with identical reference numerals: however, the segment of flexible material extending between side panel  38  and top panel  46  is now designated as  66 A, and the hinge between side panel  42  and top panel  46  is now indicated as  64 A. The letter A has been added to these elements because of the slight difference in their placement in this second preferred embodiment  30 A. 
     Referring now to the views of FIGS. 15A,  16 A,  17  and  18 , a third preferred embodiment is generally indicated as  30 B. As above, similar structural elements have been identified with the same reference numeral. However differences with regard to this third preferred embodiment  30 B have been indicated by the addition of a letter “B” to the reference numeral. For example, one can see that top panel  46  of first preferred embodiment  30  now comprises a pair of top panels  46 B including a top panel fold line  76  joining the two halves  46 B. 
     The view of FIG. 19 illustrates a second embodiment for the reinforcing strips particularly suitable for use in combination with third preferred embodiment  30 B. A pair of side strips  78  and  80  are provided, and a substantially U-shaped top reinforcing strip  82  is including for the purpose of spanning top panels  46 B. As above, the dotted lines shown in the view of FIG. 19 indicate where side strip  78  and  80  may be folded onto themselves. The construction and placement of strips  78 ,  80  and  82  are substantially as described above with regard to reinforcing strips  68  and  70 . 
     The views of FIG. 15B and 16B illustrate a fourth embodiment for the foldable enclosure of this invention, generally indicated as  30 C. One can see that the foldable enclosure  30 C is substantially similar to third preferred embodiment  30 B, with the sole exception being the placement of fold lines  64 C and  66 B. 
     With particular regard to the four preferred embodiments thus far described,  30 ,  30 A,  30 B and  30 C, the panels of those embodiments are preferably covered with a fabric material. Attention is now invited to the views of FIGS. 20 and 21 wherein a fourth embodiment, generally indicated as  84  is illustrated. In this embodiment, the panels are preferably covered with a hard material such that for preferred embodiment  84  is substantially rigid, but still foldable by disassembly. Though not shown in the view FIG. 20, it is to be understood that fourth embodiment  84  would be assembled in combination with a base substantially identical to base  48  described above. Furthermore, attachment of fourth embodiment  84  to its base  48  would employ corresponding base straps  72  and base buckles  74 . 
     Fourth embodiment  84  of the foldable enclosure comprises side panels  86 , 88 , 90  and  92  and a top panel  94 . Top panel  94  includes female receptacles  96  formed therein in engaging relation to corresponding male plugs provided on side panels  86  and  90 . The opposed edges of side panels  86  and  90  include female receptacles  96  formed therein in receiving relation to corresponding male plug  98  formed on side panels  88  and  92 . Electrical connections for the circuitry of the metal detector may be made through the interconnection of female receptacles  96  with male plugs  98 . Exemplary details of this structure are shown in the fragmentary view of FIG.  21 . 
     For the purpose of securing the connection between side panels  86  and  88  and  90  and  92 , fourth preferred embodiment  84  further comprises drawbolt latches, generally indicated as  100 . It is to be understood that similar drawbolt latches could also be used at the joints between side panels  86  and  90  with top panel  94 . Turning to the detailed view of FIG. 21, an exemplar construction for drawbolt latch  100  is illustrated. A female hook  102  is provided at the end of side panel  90  substantially adjacent female receptacle  96 . A male latch  104  is mounted to side panel  92  substantially male plug  98 . Male latch  104  further comprises a moveable draw member  106  having a latch  108  attached thereto in engaging relation to female hook  102 . Such drawbolt latches  100  are well known in a variety of structural configurations, and this drawbolt latch  100  is intended to be exemplar of such matches. Thus, it is to be understood that drawbolt latches  100  are provided to enhance the stability of an assembled boltable enclosure  84 . 
     It is also to be understood that this fourth embodiment  84  of the foldable enclosure, when disassemble/folded, could also be placed within a suitable carrying case  32 . It is also to be understood that while carrying case  32  is shown in the view of FIG. 2 as being formed from a fabric material, a hardshell carrying case is intended to be within the scope of the present invention. 
     It will thus be seen that the objects set forth above, among those made apparent from the preceding description, are efficiently attained, and, since certain changes may be made in the above article without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense. 
     It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall there between. 
     Now that the invention has been described,