Patent ID: 11920686
Assignee: MAKITA CORPORATION
Field: Machine tools (Mechanical engineering)
Classification: CPC F  B | IPC B  F

Claim 5:
6. A pneumatic tool, comprising:
a chamber configured to store compressed air; and
a relief valve in fluid communication with the chamber,
wherein:
the relief valve comprises:
an airflow channel that includes, in seriatim, from an inlet of the airflow channel to an outlet of the airflow channel:
an inflow channel in communication with the chamber;
a tapered section that (i) begins at an outlet of the inflow chamber and (ii) has a cross section that gradually increases from the outlet of the inflow channel to an outlet of the tapered section; and
an outflow channel that (i) begins at the outlet of the tapered section and (ii) has a cross-sectional area greater than a cross-sectional area of the inflow channel;

a valve stem (i) configured to slide along the inflow channel and the tapered section and (ii) having an annular groove in an outer circumference of a slide portion of the valve stem that is configured to slide along the inflow channel and the tapered section; and
an O-ring (i) in the annular groove and (ii) configured to seal the inflow channel when the slide portion is in the inflow channel;
the airflow channel, the O-ring and the valve stem are configured to prevent the O-ring from being displaced from the annular groove of the valve stem as the O-ring is expanded in a radial direction, when the O-ring is moving from the inflow channel to the tapered section, due to an internal pressure of the chamber.