Universally oriented and magnetically attracted lighting fixture
BACKGROUND OF THE INVENTION 
     A conventional lighting fixture as shown in FIG. 11 includes: a lamp such as a fluorescent lamp F pivotally secured to plural links L by pivotal joints J, each link L and each pivotal joint J being resiliently linked by a tension spring S and a lower vertical link rotatably mounted on a clamp C for clamping the lighting fixture on a table by a vertically rotatable joint J1. However, when adjusting the lamp F to any desired orientation and position, a knob K should be rotated to fixedly fasten each joint J to prevent its loosening to thereby cause inconvenience for the lamp user. 
     SUMMARY OF THE INVENTION 
     The object of the present invention is to provide a lighting fixture including a lamp pivotally secured to a neck portion by an axial pivoting device having a magnet secured on the lamp end and a ferromagnetic disk fixed on the end of the neck portion for a mutual magnetic attraction with each other between the magnet and the ferromagnetic disk, at least a supporting arm pivotally secured with the neck portion by a transverse pivoting device having a magnet secured to a neck portion and a ferromagnetic plate secured to the arm for their mutual magnetic attraction, and a base rotatably secured with the supporting arm by a bottom pivoting means having a magnet secured on a lower portion of the supporting arm and a ferromagnetic disk secured on the base for their mutual magnetic attraction, whereby upon a pivotal movement or relative rotation between each magnet and each corresponding ferromagnetic disk or plate of the coupling parts, such as: the lamp and the neck portion, the neck portion with the supporting arm, and the arm with the base, the lamp can be optionally adjusted to any desired orientation and position as &#34;locked&#34; by magnetic attraction between the relevant coupling parts. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is an illustration showing a complete set of the present invention. 
     FIG. 2 shows a first coupling structure by pivotally connecting the lamp with the neck portion of the present invention. 
     FIG. 3 is an enlarged sectional drawing showing the pivotal connection between the lamp and the neck portion. 
     FIG. 4 is a perspective view showing a pivotal connection between the neck portion and a first supporting arm of the present invention. 
     FIG. 5 is a sectional drawing showing the pivotal connection between the neck portion and the first supporting arm. 
     FIG. 6 is a perspective view showing a pivotal connection between a first and a second supporting arm. 
     FIG. 7 is a sectional drawing showing a pivotal connection between the first and second supporting arm. 
     FIG. 8 is a rear view as viewed from 8--8 direction of FIG. 7. 
     FIG. 9 is a partial perspective view showing a pivotal connection between the second supporting arm and a base. 
     FIG. 10 is a sectional drawing showing the pivotal connection between the second supporting arm and the base. 
     FIG. 11 shows a conventional lighting fixture. 
    
    
     DETAILED DESCRIPTION 
     As shown in FIGS. 1-10, the present invention comprises: a lamp means 1, a neck portion 2, an axial pivoting means 3, a first supporting arm 4 pivotally connected with the neck portion 2 by a first horizontal pivoting means 5, and pivotally connected with a second supporting arm 6 pivotally connected with the first supporting arm 4 by a second horizontal pivoting means 7, and a base portion 8 pivotally connected with the second supporting arm 6 by a bottom pivoting means 9. The first and second supporting arms 4, 6 may be cooperatively designated as a &#34;supporting arm means&#34;. 
     The first and second supporting arms 4, 6 may be simplified to a single supporting arm (not shown) or multiple linking arms (not shown), which are not limited in this invention. Other shapes, pivoting mechanisms or linking structures may be modified by those skilled in the art. 
     The lamp means 1 includes: a lamp 11 which may be a fluorescent lamp or a bulb having a shade or reflector 14 disposed around the lamp 11, a coupling tube 12 secured to an end portion of the lamp 11, and a lamp retainer plate 13 formed on an end portion of the coupling tube 12 opposite to the lamp 11 for securing a magnet 32 of the axial pivoting means 3 on an outer surface of the lamp retainer plate 13 with the magnet 32 facing the neck portion 2. 
     The neck portion 2 includes: a first coupling portion 21 having a neck retainer plate 22 secured on an outer portion of the first coupling portion 21 for fixing a coupling shaft 31 of the axial pivoting means 3 on the neck retainer plate 22 for rotatably coupling the lamp means 1 by inserting the coupling shaft 31 through the lamp retainer plate 13 of the lamp means 1, an outermost neck end portion 23 of the first coupling portion 21 secured with a ferromagnetic disk 33 on the outermost neck end portion 23 to allow the ferromagnetic disk 33 to be rotatably slidably contacted with the magnet 32 of the axial pivoting means 3 for magnetically attracting the magnet 32 with the ferromagnetic disk 33 for magnetically attracting the lamp means 1 with the neck portion 2 for positioning the lamp means 1 on the neck portion 2, with the coupling shaft 31 of the axial pivoting means 3 defining a longitudinal axis 311 in a longitudinal center of the coupling shaft 31 longitudinally inserted in a center of the lamp retainer plate 13, a center of the ferromagnetic disk 33 and a center of the neck retainer plate 22 for rotating the lamp means 1 about the longitudinal axis 311 of the coupling shaft 31, and a second coupling portion 26 for pivotally connecting the neck portion 2 with the supporting arm means 4, 6. 
     The supporting arm means 4, 6 includes: a first supporting arm 4 pivotally connected with the neck portion 2 by a first horizontal pivoting means 5, and a second supporting arm 6 pivotally connected with the first supporting arm 4 by a second horizontal pivoting means 7, with the second supporting arm 6 pivotally mounted on a base portion 8 by a bottom pivoting means 9. 
     The first supporting arm 4 includes: a first arm portion 41 formed on an upper portion of the first supporting arm 4, having a lower hinge flap 411 protruding upwardly from the first arm portion 41 to be pivotally coupled, by a first transverse coupling shaft 50 of the first horizontal pivoting means 5, with an upper hinge flap 261 protruding sidewardly from a second coupling portion 26 of the neck portion 2 opposite to a first coupling portion 21 for pivotally connecting the lamp means 1; a second arm portion 42 formed on a lower portion of the first supporting arm 4, having an inner hinge flap 421 protruding downwardly from the second arm portion 42 to be pivotally coupled, by a second transverse coupling shaft 71 of a second horizontal pivoting means 7, with an outer hinge flap 611 protruding upwardly from an upper arm portion 61 of the second supporting arm 6 for pivotally connecting the first and the second supporting arms 4, 6; and a flexible cover 43 for shielding the two horizontal pivoting means 5, 7. 
     The first horizontal pivoting means 5 includes: the first transverse coupling shaft 50 defining a first transverse axis 501 projectively perpendicular to a longitudinal axis 311 defined by a coupling shaft 31 of an axial pivoting means 3 pivotally connecting the neck portion 2 and the lamp means 1, a pair of upper arcuate plates 51 with an upper fixing plate 52 secured on the neck portion 2, a pair of magnets 53 respectively secured on the pair of upper arcuate plates 51, a pair of lower arcuate ferromagnetic plates 54 each ferromagnetic plate 54 having a lower fixing plate 55 secured on the first arm portion 41 of the first supporting arm 4, and an upper tension spring 56 auxiliary resiliently linking and fastening the pair of upper arcuate plates 51 with the pair of lower arcuate ferromagnetic plates 54, each upper arcuate plate 51 and each lower arcuate ferromagnetic plate 54 having a radius about the first transverse axis 501 slightly larger than a radius of the magnet 53 about the first transverse axis 501 for a cooperative rotatable slidable contacting between each magnet 53 and each lower arcuate ferromagnetic plate 54 for magnetically attracting each magnet 53 with each lower arcuate ferromagnetic plate 54 for magnetically attracting the neck portion 2 and the first supporting arm 4 at an adjusted position. 
     The upper tension spring 56 includes: a spring rod 57 retained on the pair of upper arcuate plates 51, a pair of spring-ring members 58, each spring-ring member having a plurality of spring rings, disposed on two opposite side portions of the spring rod 57 for fastening the pair of upper arcuate plates 51, the two magnets 53, and the pair of lower arcuate ferromagnetic plates 54 with a spring end 581 of each spring-ring member 58 retained on each lower arcuate ferromagnetic plate 54, thereby resiliently fastening and linking the pair of upper arcuate plates 51 with the pair of the lower arcuate ferromagnetic plates 54 for preventing loosening or separation of the neck portion 2 and the first supporting arm 4. 
     The second horizontal pivoting means 7 includes: the second transverse coupling shaft 71 defining a second transverse axis 711, parallel to a first transverse axis 501 of the first transverse coupling shaft 50, and pivotally connecting the first supporting arm 4 and the second supporting arm 6, a pair of upper arcuate ferromagnetic plates 72 each having an upper fixing plate 73 secured on a second arm portion 42 of the first supporting arm 4, a pair of lower arcuate plates 74 having a lower fixing plate 75 secured to the upper arm portion 61 of the second supporting arm 6, a pair of magnets 76 each magnet 76 secured on each lower arcuate plate 74 and rotatably slidably contacting each upper arcuate ferromagnetic plate 72 when pivotally moving the first supporting arm 4 with respect to the second supporting arm 6 about the second transverse coupling shaft 71 for magnetically attracting each magnet 76 with each upper arcuate ferromagnetic plate 72 for attracting the first and the second supporting arms 4, 6 at an adjusted position, and a lower tension spring 77 auxiliary resiliently linking and fastening the pair of upper arcuate ferromagnetic plates 72 with the pair of lower arcuate plates 74 for preventing loosening and separation of the first and the second supporting arms 4, 6. 
     The lower tension spring 77 includes: a spring rod 771 retained on the pair of upper arcuate ferromagnetic plates 72, a pair of spring-ring members 78, each spring-ring member 78 having a plurality of spring rings and disposed on two opposite side portions of the spring rod 771 for resiliently fastening the pair of lower arcuate plates 74, the two magnets 76, and the pair of the upper arcuate ferromagnetic plates 72, each spring-ring member 78 having a spring end 781 retained on each lower arcuate plate 74, thereby resiliently fastening the first and the second supporting arms 4, 6. 
     The bottom pivoting means 9 includes: a vertical coupling shaft (or bolt) 91 defining a vertical axis 911 and rotatably coupling the second supporting arms 6 and the base portion 8, a magnet 93 retained in a magnet socket 63 formed on a lower arm portion 62 of the second supporting arm 6, and a ferromagnetic disk 92 fixed in a disk recess 82 recessed in a base plate 81 of the base portion 8 as locked by a retaining protrusion 83 secured on the base portion 8, with the magnet 93 magnetically attracting the ferromagnetic disk 92 for magnetically attracting the second supporting arm 6 on the base portion 8 after rotating the second supporting arm 6 on the base portion 8 about the vertical axis 911 to thereby rotate a lamp means 1 about the vertical axis 911 to a desired position. 
     The second supporting arm 6 has an outer sleeve 64 formed on a central bottom portion of the second supporting arm 6 and rotatably engageable with an inner sleeve 84 formed on a central portion of the base plate 81 of the base portion 8, the inner sleeve 84 surrounding the vertical coupling shaft 91 having a packing 85 concentrically disposed about the vertical coupling shaft 91 and inserted in between the vertical shaft 91 and the inner sleeve 84, whereby upon rotation of the outer sleeve 64 of the second supporting arm 6 about the inner sleeve 84 of the base portion 8, the magnet 93 will be slid on the ferromagnetic disk 92 until a desired position of a rotating angle. 
     The neck portion 2 includes a bracket 24 protruding downwardly from a first coupling portion 21 of the neck portion 2 for pivotally connecting an upper disk end 251 of an auxiliary link 25 juxtapositional to the first supporting arm 4, the auxiliary link 25 having a lower link end 252 pivotally connected with an upper arm portion 61 of a second supporting arm 6 for forming a parallelogram linkage among the auxiliary link 25, the neck portion 2, the first supporting arm 4 and the second supporting arm 6 for a stable pivotal movement of the parallelogram linkage for free adjusting a height and orientation of the lamp means 1. 
     Accordingly, this application provides a lighting fixture for an instantly positioning of the lamp 11 pivotally secured on the neck portion 2, the supporting arm means 4, 6 and the base portion 8 by magnetically attracting each magnet with its corresponding ferromagnetic disk or plate without further loosening and fastening a knob on a pivotal joint as found in a conventional lighting fixture as shown in FIG. 11, thereby rendering a very convenient lighting fixture for optionally adjusting its desired orientations, rotating angles and positions.