Method and apparatus for determining the angle of gyration and/or the pressure in a gyratory compactor

A system adapted to dynamically measure a pressure exerted on a sample contained within a cylindrical mold of a gyratory, compactor said system comprising:

• an open-ended cylindrical mold having an inner diameter, the mold being adapted to contain a sample therein for compaction by the gyratory compactor;
• a rigid disk-shaped plate defining an axis and a periphery and having a diameter corresponding substantially to the inner diameter of the cylindrical mold, the plate being adapted to be disposed within the mold in communication with the sample;
• and
• at least one proximity-sensing device operably engaged with the plate, the at least one proximity-sensing device being configured to dynamically measure a proximity of a reference member with respect to the at least one proximity-sensing device and to produce therefrom a signal corresponding to the pressure exerted on the sample within the mold.

A system adapted to dynamically measure a pressure exerted on a sample contained within a cylindrical mold of a gyratory compactor, said system comprising:

• a gyratory compactor apparatus;
• an open-ended cylindrical mold having a wall defining an inner diameter, the mold being configured to be operably engageable with the gyratory compactor apparatus and adapted to contain a sample therein for compaction by the gyratory compactor;
• a rigid disk-shaped plate defining an axis and a periphery and having a diameter corresponding substantially to the inner diameter of the mold, the plate being adapted to be disposed within the mold in communication with the sample;
• and
• at least one proximity-sensing device operably engaged with the plate, the at least one proximity-sensing device being configured to dynamically measure a proximity of a reference member with respect to the at least one proximity-sensing device and to produce therefrom a signal corresponding to the pressure exerted on the sample within the mold.

A method of determining a pressure exerted on a sample contained within a cylindrical mold for a gyratory compactor said method comprising:

• inserting at least one proximity-sensing device into an open end of the mold, the mold having an inner diameter, the at least one proximity sensing device being operably engaged with a rigid disk-shaped plate defining an axis and a periphery and having a diameter corresponding substantially to the inner diameter of the mold, the plate further comprising a disk-shaped base portion having a center and opposing faces and a ring-shaped portion coaxial with the center and extending from the periphery of one of the faces, the center being configured to experience a deflection with respect to the periphery in response to pressure applied across the other face of the base portion, the at least one proximity-sensing device being mounted on a distal end of an arm having a proximal end mounted at the center and extending to the distal end substantially parallel to the base portion;
• and
• dynamically receiving a signal from the a least one proximity-sensing device as the mold is being gyrated by the gyratory compactor, the signal corresponding to a proximity of a reference member with respect to the at least one proximity-sensing device, the reference member being mounted on the base portion of the plate, away from the center and adjacent to the ring-shaped portion, so as to be adjacent to the at least one proximity-sensing device, the deflection of the center in response to pressure resulting in a corresponding displacement of the arm and the at least one proximity-sensing device parallel to the axis, the reference member being configured with respect to the at least one proximity-sensing device such that the displacement of the arm parallel to the axis and away from the reference member is sensed by the at least one proximity-sensing device, the corresponding signal produced by the at least one proximity-sensing device thereby being indicative of the pressure exerted on the sample within the mold.