Abstract: A propeller driven propulsion unit is pivotably mounted upon the transom of a boat. A fluid operated cylinder having an extendable shaft is mounted between the propulsion unit and the transom so that at least a portion of the thrust developed by the propeller is transmitted back to the boat through the cylinder. Accordingly, changes in propeller thrust produce changes in the fluid pressure acting on the cylinder. A pump provides fluid to the cylinder to either extend or retract the shaft to adjust the position of the unit. The pressure of the fluid in the cylinder is measured by a guage which is calibrated to convert pressure readings into thrust readings. This thrust information is used by the boat operator to adjust the boat trim or make other adjustment that provide for more efficient and safer boat operations.

Abstract: An elevator system that includes a pair of tubular guide rails that are positioned forward of the center of gravity of the elevator car. One of the hollow rail members contains electrical wiring for servicing elevator control and indicator circuits while the other rail member slidably contains a counterweight that is attached to the car to reduce the amount of energy required to raise and lower the car. Placing the guide rails so as to favor the front or door side of the car provides for shorter electrical conduit runs and also allows the rails and the stiles of the car frame to be superimposed within the hoistway thereby saving a considerable amount of space. The car frame is also formed of hollow tubular members in which is contained the electrical service to the cab.

Abstract: An electrical machine in which a frame supporting the rotor windings is coupled to the machine shaft through a planetary gear system housed within the rotor structure. The internal ring gear of the planetary system forms a part of the motor rotor structure. Further locking devices are provided to lock the various movable components making up the drive system together or to the motor casing so that a variety of speeds can be selectively attained at the output shaft or shafts of the motor without changing the motor speed.

Abstract: Apparatus for use in conjunction with a hydraulically operated lift for detecting an overheated condition in the lift equipment and, in response thereto, automatically carrying out measures to prevent the equipment from being damaged.