Described is a device for synchronization of a reverse gear for a vehicle gearbox including: a support shaft fixed in rotation; an idle gear wheel for engagement with a first reverse gear wheel on a gearbox primary shaft and a second reverse gear wheel on a gearbox secondary shaft, said idle gear wheel mounted rotatable and axially slidable on said support shaft and having a hub including a first friction surface; and a synchronizer ring mounted mobile on said support shaft along an axial travel and countered axially by an elastic element along said axial travel, said synchronizer ring having a second friction surface for engagement with said first friction surface. Axial movement of the idle gear wheel towards an engagement position of the reverse gear causes drawing of the synchronizer ring implementing, prior to reverse gear engagement, braking of rotary movement of the idle gear wheel.

Described is a device for synchronization of a reverse gear for a vehicle gearbox including: a support shaft fixed in rotation; an idle gear wheel for engagement with a first reverse gear wheel on a gearbox primary shaft and a second reverse gear wheel on a gearbox secondary shaft, said idle gear wheel mounted rotatable and axially slidable on said support shaft and having a hub including a first friction surface; and a synchronizer ring mounted mobile on said support shaft along an axial travel and countered axially by an elastic element along said axial travel, said synchronizer ring having a second friction surface for engagement with said first friction surface. Axial movement of the idle gear wheel towards an engagement position of the reverse gear causes drawing of the synchronizer ring implementing, prior to reverse gear engagement, braking of rotary movement of the idle gear wheel.

The invention relates to a pool cleaner. Rotation from a turbine is transmitted to a first wheel that is forwardly driven. A second wheel is switched between corresponding forward rotation and rearward rotation. An axle of the first wheel rotatably supports a sleeve that carries the second wheel. The reverse transmission is effected by a double-sided dog clutch member slidably supported between a pair of clutch gears freely rotatable on a rotating lay shaft. A first clutch gear is connected for reverse rotation and a second clutch gear for forward rotation of the sleeve. A switching mechanism includes a movably mounted lever arm engaging the double-sided clutch member with a cam follower engaging a cam formation carried on an independently supported control gear connected to the turbine and in mesh with a worm gear on the lay shaft.

The invention relates to a pool cleaner. Rotation from a turbine is transmitted to a first wheel that is forwardly driven. A second wheel is switched between corresponding forward rotation and rearward rotation. An axle of the first wheel rotatably supports a sleeve that carries the second wheel. The reverse transmission is effected by a double-sided dog clutch member slidably supported between a pair of clutch gears freely rotatable on a rotating lay shaft. A first clutch gear is connected for reverse rotation and a second clutch gear for forward rotation of the sleeve. A switching mechanism includes a movably mounted lever arm engaging the double-sided clutch member with a cam follower engaging a cam formation carried on an independently supported control gear connected to the turbine and in mesh with a worm gear on the lay shaft.

A transmission reverser for reversing a direction of an output gear carried by an output shaft includes a reverse shaft, a reverse clutch mounted about the reverse shaft and having engaged and disengaged conditions, and a reverse disconnect synchronizer mounted about the reverse shaft and having engaged and disengaged conditions. When the reverse clutch and the reverse disconnect synchronizer are in the engaged conditions, the reverse shaft rotates the output gear in a reverse direction of rotation opposite a direction of rotation of the output shaft. When the reverse disconnect synchronizer is in the disengaged condition, the reverse clutch is disconnected from the output gear.

A transmission reverser for reversing a direction of an output gear carried by an output shaft includes a reverse shaft, a reverse clutch mounted about the reverse shaft and having engaged and disengaged conditions, and a reverse disconnect synchronizer mounted about the reverse shaft and having engaged and disengaged conditions. When the reverse clutch and the reverse disconnect synchronizer are in the engaged conditions, the reverse shaft rotates the output gear in a reverse direction of rotation opposite a direction of rotation of the output shaft. When the reverse disconnect synchronizer is in the disengaged condition, the reverse clutch is disconnected from the output gear.

Apparatus and methods for bi-directional drilling using a bi-rotational bottom hole assembly. In preferred embodiments, the bottom hole assembly combines electric and mud motors. A central combination retrieval and electrical power cable supplies power to the motor and provides for retrieval of the bottom hole assembly to the surface. The pipe string is bi-rotational combination drill and casing pipe and connections.

A gear reduction unit for coupling the output member of a prime mover to the input member of a device that is to be driven thereby. The gear reduction unit includes an input shaft, an output shaft, a primary gear set arranged between the input shaft and the output shaft, a secondary gear set arranged between the input shaft and the output shaft, and a gear selection device. The gear selection device is configured to selectively and alternately couple the input shaft to the output shaft for driving thereof by one of the primary gear or the secondary gear set.

A gear reduction unit for coupling the output member of a prime mover to the input member of a device that is to be driven thereby. The gear reduction unit includes an input shaft, an output shaft, a primary gear set arranged between the input shaft and the output shaft, a secondary gear set arranged between the input shaft and the output shaft, and a gear selection device. The gear selection device is configured to selectively and alternately couple the input shaft to the output shaft for driving thereof by one of the primary gear or the secondary gear set.

A propulsion device for a ship capable of preventing idling of a propeller without any limitation on the type of clutch. The propulsion device includes: a forward and reverse switching clutch for transmitting the driving power from an input shaft to a forward gear or a reverse gear; a forward one-way clutch, disposed between the input shaft and the forward gear, for connecting the forward gear and the input shaft when the forward gear is rotated at a higher speed than that of the input shaft; and a reverse one-way clutch, disposed between the input shaft and the reverse gear, for connecting the reverse gear and the input shaft when the reverse gear is rotated at a higher speed than that of the input shaft.