Abstract: A hydraulic pump has a rotor and a hollow housing with a main interior chamber. The rotor is rotatably mounted in the main interior chamber. A smaller interior chamber is separated from the main interior chamber such that the smaller interior chamber retains gas therein when the main interior chamber is filled with a liquid. There is also a method for accommodating changes in volume of hydraulic fluid within the main chamber of the hydraulic pump housing. The method comprises providing the smaller interior chamber separated from the main chamber and retaining gas within the smaller chamber when the main interior chamber is filled with liquid, whereby expansion or contraction of the gas accommodates changes of volume of the liquid within the housing.

Abstract: A link for a chain, which is used in a linear actuator, comprises a base member and a plate pivotably mounted on the base member. An arm extends from the plate. A first connecting means is disposed on a distal end of the arm to connect the link with a first adjacent link. The plate has a protrusion for releasably engaging a second adjacent link. A second connecting means is disposed on the base member to connect the link with the second adjacent link.

Abstract: A hydraulic cylinder unit comprises a cylinder, a piston disposed within the cylinder, and piston rod connected to the piston. The piston rod is reciprocatingly received within the cylinder, and the piston rod being movable between a first position in which the piston rod is substantially disposed within the cylinder and a second position in which the piston rod is fully extended outside the cylinder. A first hydraulic port and a second hydraulic port hydraulically connecting the cylinder unit to a reservoir. Hydraulic fluid is received by the first hydraulic port and hydraulic fluid is discharged by the second port when the piston rod is actuated to move towards the first position. Hydraulic fluid is received by the second hydraulic port and hydraulic fluid is discharged by the first hydraulic port when the piston rod is actuated to move towards the second position.

Abstract: A linear actuator comprises a pair of chains. Each chain has a first link and a second link. The second link of each chain is adjacent to the first link of the chain. A pivotal connection pivotally connects the first and second links. The first link is pivotable about a pivot axis which is non-perpendicular to a longitudinal axis of the first link. A chain connecting member connects the chains at distal ends thereof. A drive mechanism moves the chains between an extended position and a retracted position. At least a portion of each chain is helically wound when the chains are in the retracted position.

Abstract: The present invention relates to a steering apparatus for a marine craft. The marine craft has a stern and a propulsion unit. The steering apparatus includes a stern bracket connectable to the stern of the marine craft. A swivel case is connected to the stern bracket. The swivel case defines a steering axis. The steering apparatus includes an electric motor coaxially disposed within the swivel case for swivelling the propulsion unit about the steering axis. The steering apparatus includes a gear reducing unit having an input operatively engageable with the electric motor and an output. A first member operatively extends from the output and is connectable to the propulsion unit.

Abstract: The system herein disclosed automatically detects whether an engine control unit instance number of a multi-engine marine vessel needs changing. Each engine control unit is electronically paired with a respective servo controller. A vessel controller is in communication with the servo controllers. The vessel controller commands in turn each servo controller to switch on its paired engine control unit, read the instance number of its paired engine control unit, switch off its paired engine control unit, and convey the instance number back to the vessel controller. The vessel controller then compares the instance numbers of the engine control units. If at least two instance numbers of the engine control units are duplicates of each other, the vessel controller ascertains that at least one of the instance numbers of the engine control units needs to be changed and assigns a new instance number to one of the engine control units.

Abstract: A combination check valve and relief valve has a valve body with an inlet, an outlet, and a valve chamber operatively interposed between the inlet and outlet. A check valve may be integrated with the relief valve and therefore simplify a hydraulic system. The valve includes a relief valve member which is within the valve chamber. The valve also includes a resilient member with a first end and a second end. The first end of the resilient member operatively engages the relief valve member. The valve includes a setting member pressure-fit within the valve chamber to operatively engage the second end of the resilient member. The resilient member is resiliently biased between the setting member and the relief valve member to bias the relief valve member against a relief valve seat, whereby, when pressurized fluid communicates with the inlet, the resilient member is compressed, and the relief valve member disengages its seat to enable the fluid to pass through to the outlet.

Abstract: A method for configuring a hydraulic actuator to provide energy dissipation capabilities during low energy collisions while controlling energy dissipation during high energy collisions comprises biasing a valve member towards a closed position with a resilient member having a rigidity of between 600 and 1500 lbs/in, applying a low preload to the resilient member, and restricting the flow of fluid by using a stop to limit movement of the valve member away from the closed position.

Abstract: A heater for a liquid has a combustion chamber, a jacket for the liquid extending about the combustion chamber and a burner head assembly connected to the combustion chamber. The burner head assembly includes a housing having a burner mounted thereon and a hollow interior. A control module and a fan are mounted in the hollow interior, the fan being connected to an electric motor. A compressor and a fuel pump are mounted on the housing and are operatively connected to the electric motor. The control module may include controls for exercising components of the heater prior to combustion, thereby verifying operation of these components. Preferably there is a speed control for the motor, such as a closed loop speed control which regulates motor speed and accordingly output of the heater. Preferably there is a backup system using a lookup table in the event that the closed loop speed control fails.

Abstract: An apparatus and method for providing power assisted steering for a marine craft having a manually operable steering pump and a hydraulic steering actuator. A powered hydraulic pump is hydraulically connected between the manually operable pump and the actuator. Hydraulic fluid volume output of the steering pump and hydraulic fluid volume output of the powered pump are sensed. The fluid output of the steering pump is compared with the fluid output of the powered pump and the powered pump is operated so that the output of the powered pump is commensurate with output of the steering pump.

Abstract: A hydraulic steering system comprises two hydraulic actuators, each having two actuator ports. There is a helm for steering the system in a first direction and a second direction. The helm is operatively connected to a helm pump. The helm is operatively connected to a first actuator port and a second actuator port. There is a power hydraulic steering pump hydraulically connected to a third of the actuator ports and a fourth of the actuator ports. There is a sensor capable of detecting steering of the system. The sensor is operatively connected with the power steering pump such that the power steering pump pumps hydraulic fluid towards the third of the actuator ports when the helm is steered in the first direction and pumps hydraulic fluid towards the fourth of the actuator ports when the helm is steered in the second direction.

Abstract: A heater for a liquid has a combustion chamber, a jacket for the liquid extending about the combustion chamber and a burner head assembly connected to the combustion chamber. The burner head assembly includes a housing having a burner mounted thereon and a hollow interior. A control module and a fan are mounted in the hollow interior, the fan being connected to an electric motor. A compressor and a fuel pump are mounted on the housing and are operatively connected to the electric motor. The control module may include controls for exercising components of the heater prior to combustion, thereby verifying operation of these components. Preferably there is a speed control for the motor, such as a closed loop speed control which regulates motor speed and accordingly output of the heater. Preferably there is a backup system using a lookup table in the event that the closed loop speed control fails.

Abstract: An apparatus for regulating a transient response of an output signal of an electrical generator. The apparatus comprises a tapped output winding means for providing a first AC signal and a second AC signal. The first and second AC signals have respective RMS values. The RMS value of the first AC signal is greater than the RMS value of the second AC signal. An AC switching means for selecting between the first AC signal or the second AC signal, and thereby providing a switched AC signal which has a duty cycle. A rectifier means for rectifying the switched AC signal and providing a rectified DC signal. The rectified DC signal has a DC signal component, a square wave signal component and a ripple signal component. The square wave signal component has a duty cycle. The duty cycle of the square wave signal component is equal to the duty cycle of the switched AC signal. A filter means for filtering the rectified DC signal and for providing the output signal.

Abstract: There is provided an adjustable integral component in a feedback loop of a closed loop control system. The closed loop control system controls an output signal of an electric generator. The adjustable integral component provides an integral signal. The integral signal is proportional to the output signal in a first operational mode. The integral signal is proportional to a time integral of an output signal in a second operational mode. According to another aspect of the invention there is provided a non-linear component in a feedback loop of a closed loop control system. The closed loop control system controls an output signal of an electric generator. The electric generator having non-linear characteristics. The feedback loop has an error signal, of which the output signal is responsive to. The non-linear component receives a load signal and provides a non-linear signal related to the non-linear characteristics of the electric generator. The error signal is responsive to the non-linear signal.

Abstract: A method and apparatus are provided for maintaining a temperature between a first value and a second value. The method and apparatus utilize a heat transfer device capable of cycling through a series of cycles, the device being capable of changing the temperature from the second value to the first value when operational. During each cycle the device transfers heat for a first period of time when the temperature reaches the second volume until the first value is reached and thereafter the device stops transferring heat. The first period of time is compared to a desired cycle-on period of time during each cycle and the second temperature value then is adjusted for a subsequent cycle of the device so the first period of time when the device transfers heat approaches the desired cycle-on period of time. There may also be provided temperature controls for a liquid heater having a jacket containing the liquid. The jacket has an inner heated wall and an outer wall spaced apart from the inner wall.

Abstract: A device for rotating with a rotatable first member includes a second member having a portion engageable with the first member. The portion has a first part and a second part which is resiliently biased away from the first part. The second member tightly engages the first member. There may be a device for measuring rotation of the shaft such as a potentiometer. The rotation measuring device may include an electrical connector for the potentiometer including a socket and a post which is pressable into the socket. The device may also include a rotationally adjustable connector. There may be a coupling connected to the second member which includes a third member with a portion having n sides and a fourth member with a portion having n sides which receives the portion of the third member in a mating relationship, thereby allowing the device to be adjusted to a total of at least m.n rotational positions.

Abstract: A burner head assembly for a burner includes a housing having a hollow interior and an exterior. There is a control module within the hollow interior. The module has internal connectors within the hollow interior and external connectors on the exterior of the housing, whereby electrical connections to the module can be made internally and externally with respect to the housing without requiring apertures in the housing and wiring extending through the apertures. For example, the control module may include a circuit board, the circuit board having a portion within the hollow interior and which extends to the exterior. The exterior and interior connectors are connected to the circuit board. The housing may have two portions, the control module being fitted between the two portions of the housing. Preferably the control module is sealingly received between the two portions of the housing.