BALL-POINT PEN SAFETY LOCK

• US 3,679,317 A
• Filed: 09/14/1970
• Issued: 07/25/1972
• Est. Priority Date: 09/14/1970
• Status: Expired due to Term

• Current Assignee: Ivar G. Larson
• Original Assignee: Ivar G. Larson
• Inventors: Larson, Ivar G.
• Primary Examiner(s): Charles, Lawrence
• Application Number:
  US05/071,725
• Time in Patent Office: 680 Days
• Field of Search: 401/99-117,195 200/169BP,44,159
• US Class Current: 401/109
• CPC Class Codes: B43K 24/084 with saw-like or analogous cams

Abstract

Mechanism for locking an ordinary retractable writing element ball-point pen to prevent inadvertent or accidental depression of the actuating plunger is described. The locking mechanism comprises an elongated abutment member extending longitudinally of the outside of the pen actuating plunger and normally overlying, at its lower end, a solid wall portion at the upper end of the pen housing, resilient means normally rotatively constraining the plunger so that the abutment members is in such overlying position, and a recess in the upper end of the pen casing, rotatively removed from the solid wall portion at the upper end of the pen, permitting manual depression of the actuating plunger only after the plunger is first turned from its normal or locking position to a position whereat the abutment member can pass through the recess.

Claims

1. A safety lock mechanism for retractable ball-point pens of the type having a ball-point writing element selectively movable between a first position whereat the writing element is withdrawn within one end of the pen housing and a second position whereat the writing element is in the projecting position with respect to said one end of the pen housing, and wherein the actuating mechanism for said selective movement comprises an actuating plunger member projecting through an opening in the other end of the pen housing and movable, selectively, between a first outwardly projecting position and a second outwardly projecting position relatively inward of said first outwardly projecting position, with respect to said opening at the other end of the pen housing, comprising, in combination, means permitting limited rotative movement between first and second rotative positions of said actuating plunger member with respect to the pen housing, means yieldingly constraining said actuating plunger member in the first of said rotative positions, abutment means on said actuating plunger member cooperative with said pen housing and operative to prevent selective movement of said plunger from said first to said second outwardly projecting position, and means permitting movement of said actuating plunger between said first and second projecting positions when said actuating plunger is in said second rotative position, said means permitting limited rotative movement of said actuating plunger member comprising an arcuate recess provided in a marginal peripheral zone of the pen housing opening through which said actuating plunger member projects.

2. A safety lock mechanism for retractable ball-point pens as defined in claim 1, wherein said means yieldingly constraining said actuating plunger member in said first of said rotative positions comprises a torsion spring coaxially arranged with respect to said actuating plunger member, and wherein said means permitting limited rotative movement of said actuating plunger member further comprises an upwardly directed end portion of said helical spring extending from within said pen housing upwardly through said arcuate recess, and means co-acting between said actuating plunger member and said upwardly directed end of said helical torsion spring for constraining their rotative movement in unison.

3. A safety lock mechanism for retractable ball-point pens as defined in claim 1, wherein said abutment means comprises an elongated, longitudinally extending rib element the lower end of which, when said actuating plunger member is in said first rotative position, overlies a peripheral marginal zone of the pen housing opening which is arcuately removed from said arcuate recess.

4. A safety lock mechanism for retractable ball-point pens as defined in claim 2, wherein said abutment means comprises an elongated, longitudinally extending rib element the lower end of which, when said actuating plunger member is in said first rotative position, overlies a peripheral marginal zone of the pen housing opening which is arcuately removed from said arcuate recess In the direction of torsional stress of said torsion spring.

5. A safety lock mechanism for retractable ball-point pens as defined in claim 1, wherein said abutment means comprises a first elongated longitudinally extending rib element the lower end of which, when said actuating plunger member is in said first rotative position, overlies a peripheral marginal zone of the pen housing opening which is arcuately removed from said arcuate recess, and wherein said means permitting limited rotative movement of said actuating plunger member further comprises a second elongated, longitudinally extending rib element on said actuating plunger member arcuately spaced with respect to said first rib element, said second rib element being so disposed as to extend through said arcuate recess when said actuating plunger member is in said first outwardly projecting position.

6. A safety lock mechanism for retractable ball-point pens as defined in claim 5, wherein said means yieldingly constraining said actuating plunger member in said first of said rotative positions comprises a torsion spring coaxially arranged with respect to said actuating plunger member, one end of said torsion spring being interfixed with respect to the lower end of said second rib element for resiliently constraining one side of said second rib element in sliding engagement with an edge portion of said arcuate recess.

7. A safety lock mechanism for retractable ball-point pens as defined in claim 6, wherein said first and second rib elements are integrally formed with said actuating plunger member and wherein the lower end of said first rib element is substantially co-extensive with the upper end of said second rib element.