Patents by Inventor Merrill Block

Merrill Block 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).

  • Two-phase transformer and welding circuit therefor
    Patent number: 4169975
    Abstract: An apparatus for converting three-phase electrical energy into direct current includes Scott-connected transformers with oppositely biased SCRs connected in parallel to two of three input terminals. The SCRs are controlled so that they fire in alternate and rotating sequence between the two input terminals. The secondary output voltages of four terminals are rectified so that the common rectified output voltage is a substantially DC voltage with a minimum ripple. The secondary output terminals are aligned in a common plane and are connected to deformable, tapered leads. The rectifiers are connected between the deformable leads and to a common slotted, conductive plate which is connected to a welding electrode. A center tap from each of the secondary windings is connected to another welding electrode. The deformable tapered leads and the slotted conductive plate provide an equal resistive path for pairs of rectifiers for each secondary output to equalize the current flow through the two sets of diodes.
    Type: Grant
    Filed: July 8, 1977
    Date of Patent: October 2, 1979
    Inventor: Merrill Block
  • Two-phase transformer and welding circuit therefor
    Patent number: RE31444
    Abstract: An apparatus for converting three-phase electrical energy into direct current includes Scott-connected transformers with oppositely biased SCRs connected in parallel to two of three input terminals. The SCRs are controlled so that they fire in alternate and rotating sequence between the two input terminals. The secondary output voltages of four terminals are rectified so that the common rectified output voltage is a substantially DC voltage with a minimum ripple. The secondary output terminals are aligned in a common plane and are connected to deformable, tapered leads. The rectifiers are connected between the deformable leads and to a common slotted, conductive plate which is connected to a welding electrode. A center tap from each of the secondary windings is connected to another welding electrode. The deformable tapered leads and the slotted conductive plate provide an equal resistive path for pairs of rectifiers for each secondary output to equalize the current flow through the two sets of diodes.
    Type: Grant
    Filed: October 31, 1980
    Date of Patent: November 15, 1983
    Inventor: Merrill Block