Yielding Rail Patents (Class 246/309)
  • Mine ventilation door with wings and slidable or pocket personnel door
    Patent number: 9476301
    Abstract: A personnel access door assembly of an opposing wing of a mine ventilation door. The personnel access door includes a frame including a top portion, a bottom portion, a first post portion and a second post portion, the top frame portion and the bottom frame portion coupled to respective top and bottom ends of the first post and second post portions. The personnel access door further includes sets of trolley wheels affixed to the top or bottom of the frame to engage a top rail or bottom rail affixed on the opposing wing.
    Type: Grant
    Filed: February 22, 2013
    Date of Patent: October 25, 2016
    Assignee: American Mine Door Co.
    Inventors: Daniel S. Zenisek, Robert H. Chorman