Patents by Inventor Humphrey Roachsmith

Humphrey Roachsmith 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: 4641803
    Abstract: A railway track circuit arrangement particularly suitable for the short track circuit, down to approximately 40 metres, required in metro transit systems. Based on conventional A.C. track signalling principles for continuous track rails, the boundaries between adjacent track sections are defined by electric separation zones. An electrical short is connected between the running rails and an A.C. signal tuning unit is connected approximately 6 metres away to tune the end loop thus formed to resonance at the selected track signal frequency. The tuning units comprise a capacitor, the value of which is selected for resonance tuning, and a transformer a winding of which is connected in series with the capacitor, and a track circuit signal transmitter or receiver is connected through a second winding of the transformer. In order to reduce mutual coupling between track circuits by longitudinal leakage, in each joint, two electrical short may be connected between the rails spaced apart approximately 0.75 metre.
    Type: Grant
    Filed: January 23, 1985
    Date of Patent: February 10, 1987
    Assignee: Westinghouse Brake and Signal Company Limited
    Inventors: Christopher R. Brown, Humphrey Roachsmith
  • Patent number: 4021723
    Abstract: A vital type of transformer circuit including a saturable core transducer having an input and an output winding. A source of d.c control voltage is coupled to the input winding via a four-terminal capacitor to control the impedance of the secondary winding. The output winding is coupled to a transformer having a primary, a secondary and at least one closed tertiary winding. A source of a.c. voltage is coupled through the output winding to the primary winding for inducing a.c. voltage signals in the secondary winding when d.c. control voltage is applied to the input winding and for causing the closed tertiary winding to load the transformer so that little, if any, a.c voltage is induced into the secondary winding in the absence of d.c. control voltage on the input winding.
    Type: Grant
    Filed: April 15, 1976
    Date of Patent: May 3, 1977
    Assignee: Westinghouse Brake & Signal Company Limited
    Inventor: Humphrey Roachsmith