Method of making a metal bellows assembly having an intermediate plate

Abstract

The formation of a bellows made up of a stack of a predetermined number of ring-convolutions and having an intermediate plate supported within said stack is achieved by supplying several thin metal rings, each having inner and outer edges. A pair of these metal rings are positioned in contiguous relationship and their adjacent inside edges are welded together to form a ring-convolution. This process is repeated until a sufficient number of ring-convolutions are made to eventually make the desired bellows. Before these separate ring-convolutions are fused to each other, an intermediate plate and a support ring are made. The intermediate plate is a disc of metal that is sized smaller than the inside diameter of the rings and is secured to the support ring. The support ring is then positioned between two formed ring-convolutions in contiguous relationship and the three abutting outside edges are welded to each other to form a support plate convolution. The already made ring-convolutions and the support plate convolution are then stacked in the desired order and in contiguous relationship. All not-yet welded adjacent outside edges of said ring-convolutions and said support plate convolution are then welded to form the bellows. A bottom plate is formed and welded to the outside edge of the bottommost ring-convolution and a top ring is finally welded to the uppermost convolution to complete the bellows. The top ring is meant to be welded to a base plate of an infusion pump.