Abstract: A hybrid vacuum pump comprising an ejector type compressed air-operated vacuum pump. Such pump comprises a housing having an inlet for compressed air, a second inlet connectable to the enclosure to be evacuated, and a discharge outlet. The incoming compressed air being divided into at least two parallel streams by a multiple-outlet chamber, each stream of compressed air passing through at least two nozzles arranged in series, intermediate chambers between successive nozzles of each parallel stream being provided separately for each stream. Pressure-operated valves being provided to automatically prevent flow of gas being evacuated to some of said nozzles as progress is made in producing the desired vacuum, and thus to increase air flow in the remaining nozzles for the achievement of a high vacuum. The pump being characterized by the use of a single body structure being used to support multiple nozzles having different forms.

Abstract: An ejector device consists of a number of ejector units each of which includes a suction chamber. The individual units are positioned in a common housing. For making the ejector the housing is produced and the suction chambers are produced therein. These latter are four sided recesses. The holes are made in the partitions between the chambers and in the walls of the housing and nozzles are fixed in these holes. In a further step a flexible cover is placed on the open sides of the chambers. There are openings in that cover. It is covered by a rigid plate with an opening and a second flexible cover is placed on the plate. Finally a second housing is secured to the assembly. Inlet and outlet ports are provided in the second housing.

Abstract: An ejector device having large evacuation capacity comprises a cylindrical body the cylinder face of which is subdivided into ring shaped chambers which extend around and are partitioned off from an empty space at the center of the cylinder. The said chambers are interconnected in succession to one another by ejector nozzles seated co-axially to one another in the partitions between the chambers. There is also provided an inlet into the device for a pressure medium and an outlet from one of the chambers. The cylinder is inserted into a sleeve which tightly encloses it and closes the chambers.

Abstract: An ejector device which comprises a housing and a number of ejector nozzles positioned in partitions between successive suction chamber is produced by making the housing, producing suction chambers in the latter, forming communication opening between successive chambers, drilling holes through the walls of the housing and the partitions, inserting ejection nozzles into the holes in the partitions, providing flaps to cover the communication opening and closing the housing with a top cover.