Pressure gauge spring

Abstract

The pressure gauge spring is a responsive and easy to manufacture gauge for connection to a pressure source. The spring assembly comprises a coiled hollow tube having a first end and a second end with a body portion therebetween, the hollow tube adapted to produce a displacement of the second end in response to a change in said pressure source to which said first end is connected. The second end of the body portion is sealed. The body portion of the spring assembly has a first longitudinal portion and a second longitudinal portion extending from proximate to said first longitudinal portion to said second end and substantially uniformly compressed along the second longitudinal portion to reduce volume thereby. A transition area is disposed between said first end and said first longitudinal portion of said hollow tube, and is compressed so as to form a continuous longitudinally extending ridge along said transition area.

What is claimed is:  
     
         1 - 10  (Canceled)  
     
     
         11 . A spring assembly for a pressure gauge for connection to a pressure source, the spring assembly comprising: 
 a coiled hollow tube having a first end and a second end with a body portion therebetween, the hollow tube adapted to produce a displacement of the second end in response to a change in the pressure source to which the first end is connected;    the body portion having a substantially cylindrical portion extending from proximate the first end, a first longitudinal portion, and a second longitudinal portion extending from proximate the first longitudinal portion to the second end, the second longitudinal portion substantially uniformly compressed to reduce volume thereby;    a transition area defined by the region between the substantially cylindrical portion and the second longitudinal portion of the hollow tube, the transition area being compressed so as to form a continuous longitudinally extending ridge along the transition area; and    wherein the second end of the body portion is sealed.