Abstract: A shaft device for a bellows-type gas meter. A first eccentric cam assembly and an element having a radial groove are both coupled to the shaft. A second eccentric cam assembly having an opening is placed on the shaft. A rotatable insert element is inserted in the opening in the second eccentric cam assembly. A follower is provided on the insert element for engaging the radial groove in the element coupled to the shaft. A radial protrusion is provided for axially locking the shaft by rotating the insert element. The angle between the centerline of the first eccentric cam assembly and the centerline of the second eccentric cam assembly is adjusted by rotating the insert element.

Abstract: A bellows-type gas meter comprises two compartments each having a diaphragm as well as a shaft common to said two compartments, said shaft having two eccentric cam assemblies, one of said eccentric cam assemblies being connected with the crank assemblies of said diaphragms and the other one of said eccentric cam assemblies being connected with the crank assemblies of two valves creating in a cyclic mode passages between the four chambers into which said two compartments are divided by said diaphragms and a gas inlet or a gas outlet respectively, said two eccentric cam assemblies being displaced relative to each other by an angle so that each such valve, during the chamber filling cycle, closes before the diaphragm operating in conjunction therewith moves into its final position, the eccentric cam assembly connected with said valves being provided with a disk cam assembly for each such valve, said disk cam assemblies being accommodated on said common shaft, the form of each such disk cam engaging with a substa