Extensible and retractable rod
AssigneeCrain Enterprises, Inc.
InventorStephen B. Crain
Life of this patent
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AssigneeCrain Enterprises, Inc.
InventorStephen B. Crain
Estimating the term…
An extensible and retractable rod comprising an outer tubular section and an inner section of substantially constant outside diameter telescopically received in the outer section for extension and retraction relative thereto. The outer section has a first internal shoulder spaced from but relatively close to one end of the section, and a second internal shoulder spaced substantially farther away from said one end, said outer section being dimensioned to have a first inside diameter between said one end of the section and the first shoulder, a second inside diameter greater than the first between the first and second shoulders, and a third inside diameter greater than the second between the second shoulder and the other end of the section. The first inside diameter of the outer section is dimensioned for a relatively close clearance fit between the sections, and the second inside diameter of the outer section is dimensioned for a relatively loose clearance fit between the sections. The inner section has a stop at one end thereof engageable with the second shoulder of the outer section for limiting extension of the two sections relative to one another. The inner section may be releasably locked in an extended position relative to the outer section, with the relatively close clearance fit between the sections rigidly holding the sections in generally coaxial alignment.
An extensible and retractable rod comprising an outer tubular section and an inner section of substantially constant outside diameter telescopically received in the outer section for extension and retraction relative thereto, said outer section having a first internal shoulder spaced from but relatively close to one end of the section, and a second internal shoulder spaced substantially farther away from said one end, said outer section being dimensioned to have a first inside diameter between said one end of the section and the first shoulder, a second inside diameter greater than the first between said first and second shoulders, and a third inside diameter greater than the second between said second shoulder and the other end of the section, said first inside diameter of the outer section being dimensioned for a relatively close clearance fit between the sections, and said second inside diameter of the outer section being dimensioned for a relatively loose clearance fit between the sections, said inner section having stop means at one end thereof engageable with said second shoulder of the outer section for limiting extension of the two sections relative to one another, and means for releasably locking the inner section in an extended position relative to the outer section, with said relatively close clearance fit between the sections rigidly holding the sections in generally coaxial alignment.
An extensible and retractable rod comprising an outer tubular section open at one end and closed at its other end, and an inner section closed at one end and telescopically received in the outer section for movement between a retracted position in which its closed end is relatively close to the closed end of the outer section and an extended position in which its closed end is farther away from the closed end of the outer section, said inner section having a flange extending radially outwardly therefrom at its closed end, the outside diameter of the flange being sized for a relatively close fit of the flange at its periphery with the inside of the outer section, said flange having an opening therein whereby during retraction of the inner section into the outer section, air trapped between the closed ends of respective sections is vented through the flange opening into the annular space between the sections and thence to atmosphere.
Dependencies are inferred from the claim text.