Abstract: A dipstick assembly including a handle member having a passageway extending therethrough between the ends thereof, a measuring blade connected to the handle member and a cap member also having a passageway extending therethrough between the ends thereof and connected to the handle member in such a way as to allow ventilation of a sealed chamber when the dipstick assembly is disposed in an access passageway to the chamber. The cap member includes a sealing device for perfecting the seal between the dipstick assembly and the access passageway. Auxiliary venting ports allow ventilation of excess gases from the access passageway and the sealed chamber in the event that the open end of the passageway in the cap member is below the fluid level of the chamber.

Abstract: A dipstick assembly including an alignment guide comprising a fluid level indicating instrument having a rigid arcuate portion and an access passageway having a rigid arcuate portion of the same arcuate contour as the arcuate portion of the fluid level indicating instrument for preventing the rotation of the fluid level indicating instrument when it is received within the access passageway.

Abstract: A sealing plug assembly for closing and sealing a cylindrical tubular member, such as an oil fill tube for an internal combustion engine, including a frustum-shaped sealing plug, a support member supporting the sealing plug for complete insertion into the tubular member, a cap member supported by the support member for closing the end of the tubular member and for limiting the amount of travel of the sealing plug into the tubular member, the cap member being spaced apart from the sealing plug, and a device for squarely locating the sealing plug in the tubular member, the locating device including a plurality of spring arms supported by the support member for engaging the walls of the tubular member.

Abstract: A dipstick assembly including a pressure relief valve comprising a handle member having a passageway extending therethrough between the ends thereof, a measuring blade connected to the handle member, a sealing device for perfecting a seal between the dipstick assembly and an access tube adapted to receive the assembly and a valve located within the passageway of the handle member for maintaining a predetermined pressure within a vessel to which the access tube is connected.