Control for spraying foam into hollow body cavities

Abstract

A control for dispensing foam into hollow body cavities includes an index hole positioned adjacent to a dispense hole to receive the foam. The index hole carries information that is read by a sensor associated with a foam spray gun, wherein the information is selected to correspond to the desired amount of foam for the particular body cavity. With the inventive foam spray gun and method, an operator merely inserts the dispense nozzle into a dispense hole, and the sensor reads the information from the index hole. The sensor signal then allows control of the amount of foam dispensed into the dispense hole. This eliminates problems that have been experienced in the past wherein operators were forced to remember the amount of 'shots' of fixed volumes of foam for each hole. In the past, operators may sometimes have dispensed too little foam or too great an amount of foam for a particular hole. Further, in the past, operators may sometimes have dispensed foam into a hole that should not have received any foam. The foam spray gun is preferably of the type having a reciprocating plunger controlling flow of the foam components to the dispense nozzle. The plunger is controlled by a trigger, which in the prior art was actuated for each of the fixed volume 'shots.' With the inventive method, the use of repeated 'shots' to supply a particular volume may be eliminated. Thus, the plunger may be actuated a single time for the entire volume needed for the particular body cavity. This increases the life of the foam spray gun, as lifetime is frequently limited by the number of reciprocations of the plunger.