Plastic water meter main case

A water meter comprised of a main case enclosing an inlet chamber and a generally circular measuring chamber compartment, inlet and outlet passages in said main case communicating respectively with said inlet chamber and said compartment, a continuous compartment seating surface circumscribing said compartment including a first portion which is circular and concentric with the axis of said compartment and a second portion at a radial distance from said axis greater than the radius of said first portion, said portions of said seating surface being co-planar, a generally circular measuring chamber having a continuous downwardly facing seating surface circumscribing said measuring chamber and seated on said compartment seating surface and comprised of a first measuring chamber seating surface portion which is circular and coextensive and co-axial with said first portion of said compartment seating surface, and a second measuring chamber seating surface portion which projects beyond the radius of said first measuring chamber seating surface portion and is seated on the second portion of said compartment seating surface.

The invention defined in which said compartment is circumscribed by a vertical wall free of undercuts.

The invention defined in which the circular portion of said vertical wall is spaced from and co-axial with a circular wall formed on the interior of said main case and said inlet chamber is defined between said two vertical walls, a bottom wall and an inclined wall extending from said bottom wall the plane of said compartment seating surface.
A Plastic water meter comprised of a main case enclosing an inlet chamber and a generally circular measuring chamber compartment, inlet and outlet passages in said main case communicating respectively with said inlet chamber and said compartment, a continuous wall circumscribing said compartment including a circular first wall portion, and a second wall portion formed at a radial distance from the axis of said circular wall portion greater than the radius of said circular wall portion, a continuous seating surface on said wall comprised of a first seating portion formed on said first wall portion and a second seating surface formed on said second wall portion, said portions of said seating surface being co-planar, a generally circular measuring chamber having a continuous seating surface circumscribing said measuring chamber and seated on said compartment seating surface and comprised of a first measuring chamber seating surface portion which is circular and coextensive and co-axial with said first portion of said compartment seating surface, and a second measuring chamber seating surface portion which projects beyond the radius of said of first measuring chamber seating surface portion and is seated on the second portion of said compartment seating surface.

Conventional water meters typically are comprised of a main case which encloses a compartment into which a measuring chamber is received through a suitable opening in the case. A closure member is provided to close the opening in the main case and retain the measuring chamber in the compartment. Normally, the measuring chamber which is generally circular shaped in plan, has a downwardly facing seating surface which is received on a corresponding upwardly facing seating surface in the main case so that when the measuring chamber is seated on the upwardly facing seating surface in the main case, the inlet chamber is thereby isolated from the outlet chamber. As will be explained in more detail hereinafter, the prior art utilizes an upwardly facing seating surface within the main case which is a complete circle which corresponds and mates with the downwardly seating surface on the measuring chamber which likewise is a complete circle. However, in order to form the complete seating surface in a complete circle as will be explained in more detail below, it is necessary to provide an undercut in the main case which requires the use of a core with the main case mold thereby increasing the cost of the mold and the cost of the molding procedure. Alternatively, the undercut may be avoided in such cases by simply filling the undercut space with plastic material from which the main case is formed. This however adds significant cost to the main case.