Abstract: A method and apparatus are provided for inspecting vacuum-packed containers. The invention comprises automatically subjecting each container to be inspected to a predetermined force so as to cause each container to emit a click as a result of relative displacement of the container and its liquid contents, and determining whether the container has adequate vacuum by measuring the time interval between application of the predetermined force and the occurrence of the click. In a modification of the invention the pressure determenation is made by generating a signal having an amplitude that varies according to the intensity of the click.

Abstract: Comingled particles, such as nut meats and shell fragments, are segregated by directing the particles one after the other onto a sounding plate, from which they deflect into a rebound trajectory. Each particle upon striking the plate imparts ultrasonic vibrations to the plate, and these vibrations are converted by a transducer into an electrical input signal that oscillates at the frequency of the vibrations and undergoes corresponding changes in amplitude. After amplifying the input signal and filtering low frequency signals from it, a comparator converts those original oscillations which exceed a predetermined threshold amplitude into voltage pulses that are counted in a counter. If the count exceeds a minimum set into the counter, the counter produces a signal itself. This signal initiates an output signal of predetermined duration, which after undergoing a delay, operates an air valve that is connected with an air nozzle located along the rebound trajectory.

Abstract: Apparatus for detecting and separating out articles having pits therein after the product has been passed through a pit removing device. The apparatus includes a pair of detector wheels supported to rotate in the same plane. Each of these wheels is power driven. The adjacent peripheries are spaced apart to receive the articles such that the articles having a greater thickness due to the presence of pits are indicated by the separating force on the wheels.

Abstract: An apparatus and method for monitoring the internal pressure or vacuum in a sealed container is provided which measures the amount of deflection of a flexible wall of the container as a function of the internal pressure. The apparatus provides a first electrical signal representative of the distance between a first point on the flexible wall and a first sensing means and a second electrical signal representative of the average of the distances between at least two other points of the flexible wall and second sensing means. The two signals are compared and a third signal indicative of the deflection of the flexible wall is provided.