Lighting device

Claim 1

A LIGHTING DEVICE COMPRISING A STACK OF SEPARABLE UNITS INCLUDING, IN ORDER FROM BOTTOM-TO-TOP, A BASE, AT LEAST ONE MODULAR LIGHT FIXTURE UNIT AND A COVER, FASTENING MEANS EXTENDING THROUGH THE STACK AND FASTENED TO THE BASE AND TO THE COVER FOR HOLDING THEM TOGETHER IN STACKED RELATIONSHIP, SAID BASE BEING IN THE SHAPE OF A PAN HAVING AN UPPER CYLINDRICAL MARGINAL EDGE OF A PRESCRIBED OUTSIDE DIAMETER, SAID PAN HAVING AN OPEN AXIAL SLEEVE EXTENDING UPWARDLY FROM THE BOTTOM THEREOF FOR RECEIVING THE UPPER END OF A SUPPORT POST, EACH MODULAR LIGHT FIXTURE UNIT COMPRISING A CIRCULAR CYLINDRICAL TUBE HAVING A GREATER DIAMETER THAN LENGTH AND TERMINATING IN UPPER AND LOWER EDGES LOCATED IN PLANES NORMAL TO THE AXIS OF THE TUBE, SAID TUBE HAVING AN OUTSIDE DIAMETER CORRESPONDING TO THE PRESCRIBED OUTSIDE DIAMETER OF THE BASE, SAID TUBE OUTSIDE DIAMETER BEING UNIFORM EXCEPT THAT THROUGHOUT A NARROW MARGIN AROUND THE TUBE AT THE LOWER EDGE THEREOF THE TUBE DIAMETER IS INCREASED SUFFICIENTLY SO THAT THE INSIDE SURFACE OF THE TUBE AS SAID MARGIN WILL BE CAPABLE OF A SLIP FIT ONTO THE END OF ANOTHER SURFACE HAVING SAID PRESCRIBED OUTSIDE DIAMETER FOR ASSEMBLYING A PLURALITY OF SAID TUBES END-TO-END AND ASSEMBLYING A TUBE ON SAID