Abstract: A double support wall roof curb linear form fabricated from a continuous strip of metal of substantially uniform thickness into an elongated structure having both inner and outer support walls. The linear form has a top member extending the length of the form, an inner portion bent from one edge of the top member and an outer portion bent from the other edge of the top member. Both the inner and outer portions function as supports for equipment mounted upon a finished roof curb incorporating the linear form. The roof curb linear form is fabricated by first forming the inner and outer portions before formation of the top member is begun. Thereafter, the top member is formed by applying pressure to the strip of metal on opposite sides of the strip at the location of the top member. If the bottom of the linear form is to be open, pressure may be applied by a ram having an offset portion to accommodate the formed bottom member of the linear form as the form is fabricated.

Abstract: A dynamically balanced vibratory feeder system having a material handling component and a counterweighting component, the two components being drivingly interconnected and driven in opposed relative directions in a balanced fashion. The material handling component includes an elongated platform formed to accommodate a material conveying trough. The counterweighting component includes a rigid plate and a balancing counterweight secured to the plate and located between the elongated platform and the plate. The material handling and counterweighting components are periodically driven in opposed relative directions by an electromagnet driver which includes a driving portion and a driven portion. The driving portion is essentially isolated from the reciprocal movement of the material handling and counterweighting components, while the driven portion is connected to drive the material handling and counterweighting components.

Abstract: A dynamically balanced vibratory conveyor system for conveying or feeding particulate material. The system comprises a horizontal trough, a counterweighting frame positioned adjacent to and generally coextensive with the trough, and a plurality of spaced, resilient elements interconnecting the trough and the frame. A driving device is connected between the trough and the frame to drive both the trough and the frame in reciprocating movement in opposed relative directions. The entire system is supported by a pair of trunnions or similar means which is connected to the resilient elements at a vibrationally neutral position so that practically no vibration is transmitted to the structure which supports the system.