Abstract: A cooling system and method of cooling an engine are disclosed. The cooling system includes a first closed loop that circulates coolant at a first temperature and a second closed loop that circulates coolant at a second temperature that is different than the first temperature. Such a construction provides two separate cooling temperature circuits for cooling equipment at different cooling temperatures.

Abstract: A system and method for constructing a reverse gate for a watercraft is disclosed. The reverse gate is independently rotatable relative to a watercraft and a steering nozzle and includes at least two curved surfaces. The curved surfaces are attached to one another to form an apex that is offset from a midpoint of the reverse gate and the reverse gate is attached to the watercraft so that the apex is also offset from a center axis of a steering nozzle oriented relative thereto. Water discharged from the steering nozzle can be diverged at the apex of the reverse gate to provide lateral and reverse thrust to the watercraft. The reverse gate includes an additional curved section contained within one of the at least two curved sections to provide improved lateral thrust to the watercraft.

Abstract: A system and method for constructing a reverse gate for a watercraft is disclosed. The reverse gate is independently rotatable relative to a watercraft and a steering nozzle and includes at least two curved surfaces. The curved surfaces are attached to one another to form an apex that is offset from a midpoint of the reverse gate and the reverse gate is attached to the watercraft so that the apex is also offset from a center axis of a steering nozzle oriented relative thereto. Water discharged from the steering nozzle can be diverged at the apex of the reverse gate to provide lateral and reverse thrust to the watercraft. The reverse gate includes an additional curved section contained within one of the at least two curved sections to provide improved lateral thrust to the watercraft.

Abstract: A non-steerable reverse gate having a structure which reverses the lateral flow component when the steering nozzle is turned. The reverse gate produces high reverse and steering thrusts, while requiring low operating loads. The steering response in reverse is the same as an outboard or inboard/outboard. In effect, the transom thrusts to the side that the steering wheel is turned to. The reverse gate has a pair of flow-reversing passages for providing reverse thrust, a lateral steering passage for producing a lateral thrust when the steering nozzle is turned, and a fixed or pivotable central deflector body. The deflector body has three vertical walls connected to a juncture. One vertical wall is straight and extends forward of the juncture. The other vertical walls are curved and extend rearward and laterally outward from the juncture on opposite sides of a plane of symmetry. Each curved vertical wall has a flow-deflecting surface which is concave and faces a front opening of the reverse gate.

Abstract: A non-steerable reverse gate having a structure which reverses the lateral flow component when the steering nozzle is turned. The reverse gate produces high reverse and steering thrusts, while requiring low operating loads. The steering response in reverse is the same as an outboard or inboard/outboard. In effect, the transom thrusts to the side that the steering wheel is turned to. The reverse gate has a pair of flow-reversing passages for providing reverse thrust, a lateral steering passage for producing a lateral thrust when the steering nozzle is turned, and a fixed or pivotable central deflector body. The deflector body has three vertical walls connected to a juncture. One vertical wall is straight and extends forward of the juncture. The other vertical walls are curved and extend rearward and laterally outward from the juncture on opposite sides of a plane of symmetry. Each curved vertical wall has a flow-deflecting surface which is concave and faces a front opening of the reverse gate.

Abstract: A water jet apparatus having a single drive shaft rotatably supported by a pair of bearings installed in an inlet housing. The impeller is securely mounted on a splined end of the drive shaft which extends out of the inlet housing in the aft direction. The drive shaft is not supported by the stator housing, thereby eliminating the need to install bearing inside the stator housing during assembly. Oil seals are arranged between the drive shaft and an inlet housing projection which extends into a cavity formed in the front end of the impeller.

Abstract: A water jet apparatus mounted to a horizontal hull section and having a shift and steering control assembly which penetrates a hole in that hull section. The shift and steering control assembly has a modular lever and shaft subassembly which is installed in the inlet housing, before the inlet housing is installed in the hull. The modular lever and shaft assembly includes a shift and steering control housing mounted to the inlet housing and having respective bores for housing shift and steering shafts. Upper shift and steering levers are coupled to the upper ends of the shift and steering shafts respectively, while lower shift and steering levers are coupled to the lower ends of the shift and steering shafts respectively. Respective control cables are attached to the upper levers inside the hull; respective control rods for operating a steering nozzle and a reverse gate are attached to the lower levers outside the hull.

Abstract: A marine craft has with an inlet ramp, which increases in height as the inlet ramp extends rearward, and a cavity which communicates at its front with the rear of the inlet ramp. The cavity is open at its bottom and its rear. The marine craft is propelled by a jet pump apparatus having an inlet housing which is installed in the aforementioned hull cavity. The inlet housing defines an inlet volume in flow communication with the inlet ramp and a water tunnel in flow communication with the inlet volume. The inlet volume has a height which increases as it extends rearward. The inlet ramp and the inlet housing each have a lower U-shaped boundary, which boundaries are connected to form a generally rectangular inlet for water being sucked in by the water jet.

Abstract: A water jet apparatus has a reverse gate which allows a boat or other marine craft to be steered in reverse in the same manner as an automobile. The reverse gate accomplishes this by reversing the flow exiting the steering nozzle. When the steering nozzle is positioned to the left, causing the rearward exit flow to be directed to the left side of a midplane of the water jet apparatus, the reverse gate redirects that leftward and rearward flow so that it flows rightward and forward. Conversely, when the steering nozzle is positioned to the right, causing the rearward exit flow to be directed to the right side of the midplane, the reverse gate redirects that rightward and rearward flow so that it flows leftward and forward.

Abstract: Poor inlet suction characteristics in regenerative pumps may be avoided in a construction including a housing (10) having an impeller receiving cavity (20) with a circular impeller (22) therein. Channel-like annular grooves (32, 34) are disposed in the housing (10) and open to the cavity (20) at sides (36, 38) of the impeller (22). An outlet seal (63) is located in each of the grooves (32, 34) and outlet ports (62) opening to the grooves (32, 34) are located just upstream of the outlet seal (63). Peripheral recesses (42, 44) are located in the impeller sides (36, 38) and have radially inner extremities (59) located radially inward of the channels (32, 34). A plurality of blades (52) are mounted to the impeller (22) within the recesses (42, 44) around the periphery thereof and have radially inner edges (54) spaced from the radially inner recess extremities (59) while being isolated from recirculation within the channels ( 32, 34).

Abstract: A method of operating a pitot pump that pressurizes a first fluid of a first viscosity and first density wherein the pump includes a rotatable housing and a stationary probe disposed within the housing includes the steps of providing a source of a second fluid having a second viscosity and second density less than the first viscosity and first density, detecting a physical condition in the housing indicative of the presence of the first fluid at a second radial position inside the first radial position and connecting the source of the second fluid to an inner annular chamber of the housing when the detected physical condition indicates that the first fluid is present at the second radial position.

Abstract: A variable pressure and variable flow rate pump in accordance with the invention includes a stationary pump housing (1), a rotating pump housing (10), rotatably mounted with respect to the stationary pump housing including a fluid receiving chamber (12) for receiving fluid to be pumped which is driven by a drive (11); a pitot probe (5) rotatably mounted in the stationary pump housing having a tip (5a) disposed in the fluid receiving chamber radially offset from an axis of rotation of the probe for receiving fluid from the fluid receiving chamber; a brake (15) for selectively braking a rotational speed of the probe to control the rotational speed of the probe independently of a rotational speed of the rotating pump housing to provide a fluid output from the output with a variable pressure and flow rate; a thermal insulator (44) mounted between the brake and the fluid receiving chamber for thermally insulating the fluid receiving chamber from heat generated by the brake; and a control (C) coupled to the brake f