초록 ▼

A draw back valve for fluid applicators for controlling the dripping or deposit of fluid at the nozzle orifice. The invention features a poppet within a stem which serves as a "piston". In the open position, the poppet is disposed within a chamber that has sufficient clearance to permit unrestricted

A draw back valve for fluid applicators for controlling the dripping or deposit of fluid at the nozzle orifice. The invention features a poppet within a stem which serves as a "piston". In the open position, the poppet is disposed within a chamber that has sufficient clearance to permit unrestricted fluid flow. Once it is desired to shut off fluid flow, the poppet slides in the reverse direction and is disposed within a cylinder bore such that the poppet now functions as a "piston" causing the flow to reverse. The reverse flow creates a partial vacuum at the valve "nozzle" thus causing the fluid that was being dispensed to be drawn back into the nozzle, thus, eliminating drips or dried fluid at the tip. The invention is particularly well suited for use in hand-held hot melt glue guns, however, has application to other fields as well such as paint spraying.

대표청구항 ▼

[ What is claimed is:] [1.] A valve for use with a fluid applicator apparatus that applies a fluid under pressure comprising:a stem with an opening therethrough, said stem having an inlet end, exit end, with a cylinder bore at the inlet end, a draw counter bore immediately adjacent to said cylinder

[ What is claimed is:] [1.] A valve for use with a fluid applicator apparatus that applies a fluid under pressure comprising:a stem with an opening therethrough, said stem having an inlet end, exit end, with a cylinder bore at the inlet end, a draw counter bore immediately adjacent to said cylinder bore, and said stem having a seat at said exit end;a poppet having a piston-like end and a seat end, wherein said poppet is slidably positioned within the opening of said stem;such that pressure from said apparatus provides an open position in said valve with said piston-like end of said poppet disposed within said draw counter bore of said stem and with said seat end of said poppet disposed away from said seat of said stem, wherein the fluid enters said stem at said inlet end and flows through, exiting said exit end of said stem, andsuch that release of pressure from said apparatus provides a closed position with said piston-like end of said poppet first moving from within said draw counter bore of said stem into said cylinder bore of said stem with said seat end of said poppet moving toward said seat of said stem, wherein at least a portion of the fluid within said stem flows from the exit end of said stem towards said inlet end thereby creating a partial vacuum at the exit end of said stem, then said piston-like end of said poppet further moving within said cylinder bore of said stem with said seat end of said poppet seating against said seat of said stem, wherein the fluid flow stops.