Aspirator probe for sand blasting apparatus

Claim 1

An aspirator probe for insertion into a reservoir of flowable material for delivering a mixture of (1) the flowable material, and (2) air into a vacuum line connected between the said probe and a discharge device, as a sandblast nozzle, comprising: a first upstanding inside structure defining an elongated upwardly extending generally tubular delivery passage, said passage having an opening at its lower end to receive therein the flowable material from a reservoir when the said probe is inserted into the reservoir, said upstanding structure having means at the upper end thereof for facilitating connection of a vacuum line thereto, said passage in said structure having an opening at its upper end for delivering a mixture of flowable material and air therefrom and into a vacuum line connected to said structure, a second upstanding outside structure substantially surrounding said first structure in non-coaxial relation thereto and attached thereto at one side thereof, with said second structure of lesser height than said first structure, confronting walls of said non-coaxial first and second structures defining an elongated upwardly extending tubular air supply passage which is open at its upper end to receive ambient air, and air communicating means located within said second structure and in proximity to the lower end of said first inside structure for communicating said first tubular structure delivery passage with said second tubular structure air supply passage for permitting a restricted flow of air to pass from the air supply passage to the delivery passage under the influence of an aspiration effect created as material from the reservoir flows in a direction established by the delivery passage past the air communicating means.