Patent ID: 6326751
Filing Date: 2001-12-04
Classification: E05D,E05F,E05Y

Abstract:
An internal entrapment system for a garage door controlled by a garage door operator, comprising:a counter-balancing system for transferring the garage door from a first to a second position, wherein said counter-balancing system includes a motor with a drive shaft that drives the door between said first position and said second position;said counter-balancing system further comprising at least one cable drum connected to said drive shaft;at least one lift cable having one end connected to a bottom section of the garage door and an opposite end connected to said cable drum;at least one upper cable having one end connected to a top section of the garage door and an opposite end connected to said cable drum, wherein said lift cable and said upper cable are under tension as the door is transferred between positions;a tensioning device connected between said upper cable and said cable drum, said tensioning device facilitating the application of a constant tension force on said upper cable during door transfer, wherein said tensioning device comprises:a hinge bracket secured to said top section;a pivotable member coupled to said hinge bracket by a pin, wherein said pivotable member pivots about said pin and said pin is at a top edge of said top section when the door is in a closed position; anda spring connected between said pivotable member and said upper cable, wherein said pivotable member rotates as needed during door transfer;means for detecting a speed of the garage door during transfer between first and second positions solely from said drive shaft;means for determining a plurality of positional locations of the garage door during transfer between first and second positions, wherein said determining means is separate from said detecting means; andcontroller means for calculating a motor torque value from said detecting means for each of said plurality of positional locations from said determining means to compare with a plurality of door profile data points, wherein said controller means takes corrective action if the difference between the motor torque value for any one of said plurality of positional locations goes beyond a predetermined threshold for a respective one of said plurality of door profile data points, otherwise said controller means updates said plurality of door profile data points to the motor torque values for each respective said plurality of positional locations.