Patents by Inventor John Sparshott

John Sparshott 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: 4828409
    Abstract: A print head for a dot matrix printer comprises a housing (1) containing a number of actuators (2) driving a corresponding number of print wires (6). Each actuator (2) includes an actuating coil (11) wound around a yoke (10) fixed to the housing (1) and a pivotable armature (13) adjacent the yoke (10). The armature has one end pivotally connected to the housing by a hinge of rubber or rubber-like elastomeric material (26) and has its other end engaging the head of a print wire (6) so that, upon application of current to the actuating coil the pivotable armature (13) is attracted towards the yoke (10) and pivots about its one end causing its other end to drive the printwire (6) forwards. Preferably the pivoting armature (13) is formed by two separate parts, a soft iron pole piece (20) and an actuating finger (21). Preferably they are connected together by both a spot weld (22) and an adhesive. Preferably each actuator (2 ) also includes an adjusting screw (16) which bears against a damper (15).
    Type: Grant
    Filed: June 8, 1987
    Date of Patent: May 9, 1989
    Assignee: Russet Instruments PLC
    Inventors: John Sparshott, Stephen Butler, Richard Bowsher