Title: Security lock and key

Abstract: Attempts to pick the plunger-type (barrel) lock disclosed are frustrated by the necessity of holding one axially movable part in place against the force of a spring while retracting another axially movable member to open the lock. The key that opens the lock has a central pin stationary in use for holding back a position while radially spreading fingers frictionally engage and thereby permit withdrawal of an axially movable cylinder coaxial with the piston. A frangible member is provided for installing the lock without using the special key so that the number of keys can be strictly controlled. The key will open not only the lock of this invention, but also other kinds of plunger-type locks in common use by gas and electric utility companies.

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Inventors: Signorelli, John A. (Brooklyn, NY, US)
Haus, Jr., Paul Z. (Teaneck, NJ, US)

Application Number: 728943
Filing Date: 1976-10-04
Publication_date: 1977-08-09
Assignee:
Primary Class(es): 70/34 70/395, 70/417, 70/422
Other Classes:
US Patent Ref:

3478548	Nov, 1969	Finck	70/397.
3714802	Feb, 1973	Morse	70/34.
3835674	Sep, 1974	Hoyt	70/34.

Other Refs:
Primary Examiner: Wolfe, Robert L.
Assistant Examiner:
Attorney: Brooks, Haidt, Haffner & Delahunty