Vintage Garden Syringe Sprayers    

Back Self Supplying Sprayers - ‘Eclipse Type Valve’

Cup washer (C ) and cup washer mount (M) together with a nut and metal washer form a component which is capable of moving about 1 cm. along the plunger rod from securing nut (N ). When the plunger is pushed forward the pressure causes this to move away from the securing nut and block a hole in the plunger rod (H in picture below) . The contents of the barrel are expelled through the nozzle. At the same time the vacuum created behind the pump washer sucks in a fresh supply of liquid through the attached tube. There is a valve/filter on the end of the tube which allows liquid to flow up the tube and this opens during the forward stroke.  

On the pull stroke the Cup washers assembly moves towards the retaining nut. As the plunger moves back the liquid in the barrel flows through the through hole (H) and out through the centre of the plunger rod so that the liquid in the barrel moves from behind the plunger head to in front of it ready to be expelled on the next stroke. A valve/filter on the end of the tube prevents the liquid being forced back down the tube into the container. An additional valve at the front end of the barrel closes on the back stroke. This prevents air being sucked in through the nozzle. As the plunger is pulled back the space taken up inside the barrel by the plunger rod becomes available, so without this front valve, the vacuum created would suck air into the barrel through the nozzle. As it is the vacuum is filled by more liquid being sucked up from the container.

Replacing the cup washer

To access the cup washer remove the end nut (N). This allows the cup washer assembly (C and M) to be removed. There is a retaining nut and metal washer which holds the cup washer in place. If after replacing the cup washer the pump does not work then re-pack the stuffing box and make sure that the barrel end cap is on tightly.