Bacon & Thomas
Compact pressure gauge
 A pressure gauge includes an air cylinder which is accommodated within the cylindrical chamber of a body, and an indicating needle which can rotate in a plane generally parallel to the cylinder. A U-shaped piston rod has a first arm extending into the cylinder, and a second arm having a rack surface generally parallel to the first arm. A pinion is secured to a rotating shaft and meshes with the rack so as to rotate the rotating shaft. The indicating needle is secured to the rotating shaft. The cylinder has an axially extending slot formed in the inner surface thereof in communication with the straight intake passage of the pressure gauge and a sealed space defined in the chamber by the piston of the cylinder. The intake passage is generally parallel to the rotating shaft so as to communicate with a horizontal tube which is to be measured. An adjustable member is externally threaded so as to engage with the internally threaded lower end of the cylinder. When an outer housing is removed from the body, the adjustable member may be rotated by a tool so as to adjust the biasing force of a spring which is applied on the piston. 
G
G01L
inventional
Tien-Tsai
Huang