this invention relates to an improved dental cuspidor and has for an object thereof the provision of a new and improved dental cuspidor . another object of the invention is to provide a dental cuspidor having a novel vacuum drain . a further object of the invention is to provide a drain having a diaphragm forming one side of a trap and actuating a valve to open a piston driven valve to connect the trap to a drainline . fig1 is a perspective view of an improved dental cuspidor forming one embodiment of the invention ; fig2 and 4 are enlarged , fragmentary , horizontal sectional views of the cuspidor of fig1 ; fig5 is a fragmentary , vertical , sectional view of the drain of fig1 ; fig6 is an enlarged vertical sectional view of the cuspidor of fig1 ; and fig7 is an enlarged fragmentary to plan view of the cuspidor of fig1 . an improved dental cuspidor forming a specific embodiment of the invention includes a bowl 10 mounted by arms 12 and 14 for pivotal movement from a retracted position away from a patient in a dental chair 12 to any desired position over or adjacent the patient . the arm 14 is movable through ninety degrees and the arm 12 is movable through one hundred eighty degrees . the arms are tubular and form a drain line housing for a flexible hose 21 from the bowl to a vacuum drain 16 connected by a flexible hose 18 to a drain ( not shown ) via a vacuum unit ( not shown ). if desired , the hose 21 may be omitted and the arms 12 and 14 may house metal tubes coupled by a sealed rotary coupling . the arms also slope downwardly from the bowl . small , flexible water lines 19 from a source ( not shown ) extend along the arms 14 and 12 to a dispensing fountain 20 controlled by a toggle switch type valve 22 , the fountain being mounted on the arm 12 . one line 19 supplies water to a nozzle 24 through a manually controlled shut - off valve ( not shown ). the nozzle supplies water to the bowl . spokes 30 extending radially of the bowl 10 and supported by the arm 12 carry an arcuate guard 28 , which is substantially concentric to the bowl and is positioned radially outwardly from the outer perimeter of the bowl to act as a guard for the bowl . the guard also is a convenience handle for moving the bowl to any desired position . vent and drain hoses 33 and 34 lead from a cup support 36 to a t - coupling 35 connecting two sections of the hose 21 . the arm 12 is in the form of a heavy downwardly facing channel and is secured by a screw 37 to tubular elbow 74 . a screw 38 secures a trap member 39 to the arm 12 . a pan 41 fixed to the trap 39 and screws 43 secure the spokes 30 to the pan . a bushing 45 connects the hose 18 to the trap portion of the member 39 . the vacuum drain 16 has a cylindrical housing 60 ( fig5 ) secured rigidly at any desired height or angle by a split clamp 41 to a post 42 , and the arm 14 is pivotal on mounting block 64 . a split clamp 44 , secured to a boss portion 72 of the arm 14 , carries arms 48 , 49 and 50 , carrying a rack 52 for instruments 54 for use by a dental assistant . the housing encloses a drain body 60 , and a cylindrical elbow tube 62 of the arm 14 mounted in and keyed to the block 64 , is rotatable in the upper end of a bore 66 in the block 64 for ninety degree rotation as limited by a screw 68 extending into a slot 70 in the tube 62 . similarly , a pin 71 ( fig4 ) extending through the boss portion 77 of elbow 74 of the arm 12 and carried by the clamp 44 is movable in a slot 76 in lower portion 78 of the elbow 74 of the arm 12 . a control box 82 for the instruments 54 is mounted on the housing . the valve body 60 has a cylindrical chamber 90 and a bottom tube 92 , which can be connected by a flexible hose ( not shown ) to a drain pipe ( not shown ) for gravity draining , or , as is shown , can be closed by a plug 94 to form a trap . a diaphragm 96 , clamped between a cup 98 and the valve body 60 , forms one side of the chamber 90 and carries a rigid disc 100 . an air valve body 102 is adjustably positioned in bore 104 in boss 106 of the cup by a tapered screw 108 . a spring 110 presses a plunger 112 in the valve body 102 into contact with the disc 100 and urges the plunger normally to a position in which a poppet valve 143 including an o - rings 114 and 116 close off an inlet port 118 from an outlet port 120 . when water in the chamber 90 reaches a predetermined height , it moves the diaphragm 96 to the left sufficiently to move the plunger 112 to a position opening the port 118 to the port 120 . air under pressure supplied to the port 118 through a line 130 then flows through lines 132 and 134 to a port 136 in a vacuum drain valve body 138 of a drain valve 139 and moves a piston 140 to the right to move , against the action of spring 141 , o - ring 142 away from valve seat 144 surrounding drain port 146 to connect the chamber 90 to a vacuum drain tube 148 connected to the flexible hose 18 . the hose 18 is connected through a vacuum unit ( not shown ) to the drain of the building . a knob 152 is provided for manually opening the valve . a bleeder line 154 leads from the line 134 through a needle valve 156 to a line 158 leading to a port 160 in tube 162 , which as shown in fig6 is connected by a hose to control box 82 . an adapter plate 164 is secured by screws ( not shown ) to the valve body 138 with a gasket 168 therebetween and the valve body 138 is secured by screws ( not shown ) to the body 60 , with a gasket 166 therebetween . as will be apparent , because the vacuum line 148 is cut off by the poppet valve 143 and the water in the chamber 90 , the cuspidor will be silent , even for those brief periods when the poppet valve is open , thus , not distracting the dentist or the patient . when the water level in the chamber 90 drops sufficiently , which will obviously be to a point above the lower edge of the bore 104 , the spring 110 moves the plunger 112 to a closing position , the lines 134 , 154 and 158 bleed off the air in counterbore 170 and the spring 141 closes the valve 139 .
the specification discloses an improved dental cuspidor having a vacuum drain means . the specification also discloses a drain having a drain chamber of which one side is formed by a diaphragm so that when water reaches a given height in the chamber , the diaphragm actuates an air valve to drive a piston to open a drain valve to a vacuum drain .