Patents by Inventor Derrick J. Silver

Derrick J. Silver has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 4343559
    Abstract: A retractable mechanism for a writing element especially the expendable refill of a ball-point writing pen, is disclosed. A manually depressible plunger (4) advances a latch member (7) biased to retract the plunger (4). The latch member (7) has a pair of latch arms (11,12) one of which in an advanced or retracted position thereof engage a latch means (5,6). Depression of the plunger (4) releases the engaged latch arm (11 or 12) from its latch means (5,6). The resultant of the force on the plunger (4) and bias on the writing element (1) then laterally aligns the other latch arm (12 or 11) with its latch means (6 or 5). On release of the plunger (4), the bias on the writing element (1) brings a co-operating notch (16) and pivot edge (15) of the aligned latch arm (11,12) and latch means (5,6) into register for pivot action therebetween.
    Type: Grant
    Filed: June 25, 1980
    Date of Patent: August 10, 1982
    Assignee: Platignum Limited
    Inventor: Derrick J. Silver