Tray assembly

Claim 1

A TRAY ARM ASSEMBLY COMPRISING A MOUNTING PANEL ADAPTED TO BE SECURED TO A DENTAL CONSOLE; A VERTICAL POST HAVING FLAT SIDES AND BEING OF UNIFORM HORIZONTAL CROSS SECTION THROUGHOUT SUBSTANTIALLY ITS ENTIRE VERTICAL EXTENT; A PLURALITY OF ROLLERS SECURED TO SAID PANEL AND ENGAGING SAID POST FOR GUIDING MOVEMENT OF SAID POST BETWEEN RAISED AND LOWERED POSITIONS; SAID ROLLERS BEING ARRANGED IN VERTICALLY-SPACED PAIRS; EACH OF SAID PAIRS ENGAGING ONE OF THE FLAT SIDES OF SAID POST; A LOCKING PLATE HAVING AN OPENING THROUGH WHICH SAID POST EXTENDS; SAID OPENING BEING SLIGHTLY LARGER THAN THE OUTSIDE CROSSSECTIONAL DIMENSIONS OF SAID POST TO PERMIT UNRESTRAINED VERTICAL MOVEMENT OF THE POST THERETHROUGH WHEN SAID LOCKING PLATE IS GENERALLY HORIZONTALLY DISPOSED; SAID LOCKING PLATE BEING MOUNTED UPON SAID PANEL FOR LIMITED PIVOTAL MOVEMENT BETWEEN A GENERALLY HORIZONTAL POSITION AND A NORMAL DOWNWARDLY INCLINED POSITION IN WHICH EDGE PORTIONS OF SAID LOCKING PLATE ENGAGE THE OUTER SURFACE OF SAID POST TO PREVENT DOWNWARD MOVEMENT OF THE POST RELATIVE TO SAID LOCKING PLATE; A HORIZONTALLY-ELONGATED TRAY ARM HAVING ONE END THEREOF AFFIXED TO THE UPPER PORTION OF SAID POST AND HAVING A TRAY MOUNTED ADJACENT THE OPPOSITE FREE END OF SAID ARM; GRIPPING MEANS PROVIDED ADJACENT SAID FREE END OF SAID ARM FOR THE MANUAL SHIFTING OF SAID TRAY, TRAY ARM, AND POST UPWARDLY AND DOWNWARDLY AS A UNIT; POWER-OPERATED RELEASING MEANS MOUNTED UPON SAID PANEL FOR MOVING SAID LOCKING PLATE INTO ITS GENERALLY HORIZONTAL POSITION; AND CONTROL MEANS ADJACENT SAID GRIPPING MEANS FOR ACTUATING SAID POWER RELEASING MEANS TO PIVOT SAID LOCKING PLATE INTO ITS GENERALLY HORIZONTAL POSITION WHEN DOWNWARD MOVEMENT OF SAID TRAY, TRAY ARM, AND POST IS DESIRED.