Free and loose object detection system

Claim 3

The combination of claim 1 in which the leading edge of said first gating pulse coincidEs with the lagging edge of said second gating pulse and the lagging edge of said first gating pulse coincides with the leading edge of said third gating pulse.

Claim 4

The combination of claim 1 in which is provided first indication means responsive to signals in said first channel to provide an indication of the presence of loose objects and second indication means responsive to signals in said second channel to provide indication of the presence of free objects.

Claim 5

The combination of claim 2 in which said first indication means and said second indication means individually include indicators for indicating a level of signal above a predetermined level.

Claim 6

Apparatus for detecting and differentiating between free and loose objects in a device comprising means for producing vibrations of a predetermined frequency in said device whereby movable objects produce impacts on said device, a transducer mechanically coupled to said device for sensing vibration produced by said impacts and for developing electrical signals in accordance with said impacts, a loose object producing a signal including pulses synchronized with the vibrations of the device and each pulse occurring in a predetermined time relationship to a reference phase of the vibration producing means, and free objects appearing as pulses non-synchronous with said predetermined frequency, means for producing a sawtooth wave synchronized with said predetermined frequency, means responsive to a first occurring level of amplitude of said sawtooth wave and to a second occurring level of amplitude of said sawtooth wave for producing a first gating pulse having a leading edge corresponding to the first occurring level and having a lagging edge corresponding to the second occurring level, said first level and said second level separated by an interval which encompasses the occurrence of said pulse corresponding to a loose object, means responsive to a timing pulse having a leading edge coincident with the starting point of said sawtooth wave and a lagging edge corresponding to the peak level of said sawtooth wave and to said first gating pulse to produce a second and a third gating pulse, said second gating pulse having a leading edge coincident with said starting point and the lagging edge coincident with said first occurring level of said sawtooth wave, said third gating pulse having a leading edge coincident with the second occurring level and the lagging edge coincident with the peak level of said sawtooth wave, a first switching channel responsive to said first gating pulse for passing pulses occurring during said interval and for rejecting other pulses, a second switching channel responsive to said second and third gating pulses for passing signals including pulses lying outside of said interval and representing pulses non-synchronous with said vibrations and for rejecting other signals, means for applying said signal from said transducer to said channels whereby at the output of said first channel appear signals corresponding to a loose object and at the output of said second channel appear signals corresponding to free objects.

Claim 7

Apparatus for detecting and differentiating between free and loose objects in a device comprising means for producing vibrations of a predetermined frequency in said device whereby movable objects produce impacts on said device, a transducer mechanically coupled to said device for sensing vibration produced by said impacts and for developing electrical signals in accordance with said impacts, a loose object producing a signal including pulses synchronized with the vibrations of the device and each pulse occurring in a predetermined time relationship to a reference phase of the vibration producing means, and free objects appearing as pulses non-synchronous with said predetermined frequency, means for producing a sawtooth wave synchronized with said predetermined frequency, means responsive to a first occurring level of amplitude of said sawtooth wave and to a second occurring level of amplitude of said sawtooth wave for producing a first gating pulse having a leading edge corresponding to the first occurring level and having a lagging edge corresponding to the second occurring level, said first level and said second level separated by an interval which encompasses the occurrence of said pulse corresponding to a loose object, means responsive to a timing pulse having a leading edge coincident with the starting point of said sawtooth wave and a lagging edge corresponding to the peak level of said sawtooth wave and to said first gating pulse to produce a second and a third gating pulse, said second gating pulse having a leading edge coincident with said starting point and the lagging edge coincident with said first occurring level of said sawtooth wave, said third gating pulse having a leading edge coincident with the second occurring level and the lagging edge coincident with the peak level of said sawtooth wave, a first switching channel responsive to said first gating pulse for passing pulses occurring during said interval and for rejecting other pulses, a second switching channel responsive to said second and third gating pulses for passing signals including pulses lying outside of said interval and representing pulses non-synchronous with said vibrations and for rejecting other signals, means for applying said signal from said transducer to said channels whereby at the output of said first channel appear signals corresponding to a loose object and at the output of said second channel appear signals corresponding to free objects.

Claim 8

The combination of claim 5 in which an oscilloscope is provided for displaying said signals, means for applying the output of said channels to one coordinate of said oscilloscope, means for synchronizing the other coordinate of said oscilloscope with said predetermined frequency whereby loose objects appear on said oscilloscope as pulses relatively fixed in position along said other coordinate and free objects appear as pulses non-synchronous with said predetermined frequency, and said first and second levels are represented as lines along said other coordinate, the distance between which encompasses said interval.

Claim 9

The combination of claim 5 in which said channels are operated for a time period encompassing a predetermined number of cycles of vibration.