Abstract: A multi-purpose gravity-fed feeder system comprising a timed-access control system configured to simultaneously provide a combination of different nutrient-rich feed attractants to a target animal at a feeder site during specific hours, the timed-access control system comprising a synchronizing actuator control board with LCD interface, linear actuators, two or more actuator push-pull arms, an actuator tower with assembly mount, a solar panel and charge controller. The feed storage system comprises at least one feed access control door assembly, a dividable hopper with a removeable baffle configured to separate the different nutrient, protein-rich feed attractants and feed metering devices.

Abstract: A multi-purpose gravity-fed feeder system comprising a timed-access control system configured to simultaneously provide a combination of different nutrient-rich feed attractants to a target animal at a feeder site during specific hours, the timed-access control system comprising a synchronizing actuator control board with LCD interface, linear actuators, two or more actuator push-pull arms, an actuator tower with assembly mount, a solar panel and charge controller. The feed storage system comprises at least one feed access control door assembly, a dividable hopper with a removeable baffle configured to separate the different nutrient, protein-rich feed attractants and feed metering devices.

Abstract: A gravity-fed protein feeder improvement comprising a timed-access control system configured to increase opportunities to attract or harvest a target animal at a protein feeder site during daylight hours, said timed-access control system comprising a programable timer switch, a battery, a solar panel, a feed access control door assembly, an electromagnetic coil relay, a linear actuator, actuator alignment bracket and assembly mount.

Abstract: A double wall heat exchanger for use in solar heaters and the like. An outer drawn copper tube of predetermined thickness and inside diameter is slid over a second drawn copper tube also of a predetermined thickness and outside diameter. A small axial groove, which is parallel to the longitudinal axis of the second or inner tube, is located in the surface of the inner tube and extends the entire length of the inner tube. The tubes are then placed in a furnace and annealed for a specified time and temperature. The double wall tubes are placed in a finning machine. Under a specified pressure and at a specified feed rate, integral fins are formed on the outside tube. While the fins are being formed on the outside tube, internal pressure is being applied forcing the inner tube to expand and conform to the inside diameter of the outer tube. The mating surfaces form a helical passageway which serves as part of the path of leakage.