this being one of the screws which secures the latch body to the edge of the door in this position the plate 58 is pushed against the spring 52 and the spring 52 pushes the plate 40 against the door pillar 14 so that the tool body cannot fall off the striker plate or become misaligned during the time when the vacuum chamber 46 is at atmospheric pressure if there is no screw head 64 at the appropriate place then the plate 58 would act against the sheet metal of the door shut face 62 fig1 shows how the flexible tube 18 will extend through the gap between the edge of the door 10 and the door pillar 14 there will usually be a gap here which is sufficient for a tube of about 5 mm outside diameter to pass through in an installation for use on a car assembly line there may be a set of tool bodies 22 to provide dedicated bodies for the left and right hand doors of both 2 door and 4 door vehicle bodystyles the pneumatic circuit shown in fig7 controls the supply of vacuum to the appropriate tool body by directing compressed air to the appropriate tool air is supplied from a pressure line 70 via a push button valve 72 pushing the button allows a switching air pulse to pass via a binary counter 74 to two and gates 76 and 78 the gate 76 feeds the tools for the 2 door body the gate 78 feeds the tools for the 4 door body operation of a twin valve 80 directs a second stream.