Abstract: A low pressure drop air flowmeter (10) for an automobile engine is disclosed. The meter contains a main air flow passage (24), a relatively small venturi (20) to receive a portion of the air flow, pressure ports (98a and 120) for sensing stagnation and static pressure and a set of swirl vanes (22) disposed adjacent the outlet of the venturi and operative to impart a swirl to the remainder of the air in the main passage, thereby creating a reduced pressure at the venturi outlet for amplifying the pressure difference between the stagnation and static pressure without appreciably increasing the pressure drop across the flowmeter. A tertiary passage (28) provides a path of fluid communication between points upstream and downstream of the swirl vanes. This passage includes a flow restricting throat (29) which is manually calibrated during or after assembly. Air exiting the tertiary passage impinges upon the swirl to modulate the vortex velocities.

Abstract: A crane operating aid comprises a load moment computer and a number of transducers which monitor crane parameters such as boom length, boom angle, and boom reaction forces. The computer then calculates the percentage of load capacity as a function of the crane manufacturer's published load rating tables. The computer is disposed near the crane operator to facilitate interaction between the two and actively solicits crane condition information from him through a prompting scheme which initially poses a series of status requests to the operator. The operator must supply appropriate responses to the status requests prior to operating the crane. The computer also can display any of the input parameters monitored by the transducers. A plurality of alarms of ordered urgency are provided which indicate various overlimit conditions. Both minimum and maximum operator controlled set points are provided.

Abstract: A low pressure drop air flowmeter for an automotive engine is disclosed. The meter includes a main air flow passage, a relatively small venturi tube receiving a portion of the air flow, a pressure port for sensing stagnation pressure in the main passage, a pressure port for sensing static pressure in the throat of the venturi, and a set of stationary swirl vanes disposed adjacent the outlet of the venturi and operative to impart a swirl to the remainder of the air in the main passage, thereby creating a reduced pressure at the venturi outlet for amplifying the pressure difference between the stagnation and static pressures without appreciably increasing the pressure drop across the flowmeter. Also disclosed is a solenoid valve having a single valving member operative in one position to communicate the stagnation pressure to an absolute pressure transducer and operative in another position to communicate the static pressure to the transducer.