Abstract: A propeller for a marine propulsion system is disclosed which comprises a propeller hub having a casing formed from three segments (16a, 16b, 16c), each of which has a part of an opening (28) for mounting a propeller blade (34). A locking and unlocking mechanism (51, 54, 95, 100) is provided for disengaging the propeller blades to enable pitch adjustment of the blades. A push rod (50) is connected to the mechanism (100) to cause disengagement and adjustment of the pitch of the blades. The mechanism (100) includes a claw (101) having pivotally connected fingers (95). The hub also has a slide ring (51) having a load surface (61) is provided for receiving load when the propeller blades are unlocked to enable pitch adjustment to take place.

Abstract: A marine propulsion system comprising a push rod activated pins (170) which engage eccentric shaft (174) for unlocking a propeller base (190) so the base (190) can rotate around a transverse axis. The base (190) has an inclined surface (192) which engages with an inclined surface (159) defining an opening in the propeller's hub therefore locking the propeller blade (34) in position. The inclined surfaces (159, 192) are disengaged by rotation of the eccentric shaft (174) thus the propeller blades (34) can be rotated to adjust the pitch and then the inclined surfaces (159, 192) re-engage to locking the propeller blade (34) in the pitch adjusted position.

Abstract: A potentiometer is disclosed which comprises an opaque screen element (10) and light emitters and collectors (92) for transmitting light through the screen and detecting the light transmitted through the screen. The screen has three sections (A, V and B). The sections (A, V and B) have bars which are parallel to one another and extend transverse to the direction of movement of the screen (10). The section (A) has bars which are arranged in groups comprising the same number of bars, but each of a different thickness. The section (V) has two parts (35, 36), the first part has bars which are formed in the same manner as the section (A) except they are a mirror image to the bars in section (A) and each group comprises less bars than are in the groups in section (A). The second part of section (V) has individual bars which increase in thickness. Section (B) is a mirror image of section (A).

Abstract: A propeller for a marine propulsion system is disclosed which comprises a propeller hub having a casing formed from three segments (16a, 16b, 16c), each of which has a part of an opening (28) for mounting a propeller blade (34). A locking and unlocking mechanism (51, 54, 95, 100) is provided for disengaging the propeller blades to enable pitch adjustment of the blades. A push rod (50) is connected to the mechanism (100) to cause disengagement and adjustment of the pitch of the blades. The mechanism (100) includes a claw (101) having pivotally connected fingers (95). The hub also has a slide ring (51) having a load surface (61) is provided for receiving load when the propeller blades are unlocked to enable pitch adjustment to take place.

Abstract: A marine propulsion system comprising a push rod (50) for adjusting the pitch of propeller blades (34). The push rod (50) has a screw-threaded bolt (60) engaged with a nut (78). The nut (78) carries a bevel gear (84) by which the nut (78) can be rotated to cause the bolt (60) and therefore the push rod (50) to move longitudinally. The push rod (50) is connected to a claw with arms couple with pins (170). The pins (170) engage eccentric shafts (174) for unlocking a propeller base (190) so the base (190) can rotate around a transverse axis. The base (190) has an inclined surface which engages with an inclined surface defining an opening in the propeller's hub therefore locking the propeller blade (34) in position. The inclined surfaces are disengaged by rotation of the eccentric shaft (174) thus the propeller blades (34) can be rotated to adjust the pitch and than the inclined surfaces re-engage locking the propeller blade (34) in the pitch adjusted position.

Abstract: An apparatus for varying the motion characteristics of a valve typically in an engine includes a rotating member such as a valve crank shaft having a conrod with a sliding pin. The sliding pin is constrained to move along a path in a guide member. The guide member is adjustably attached to the engine, and by adjusting the position of the guide member, the trajectory taken by the pin can be varied. The pin also moves along a path of a pivotally attached rocker arm, the path of the rocker arm being different to the path of the guide member. The difference in the paths causes the rocker arm to pivot, and this in turn causes motion in a valve in contact with the end of the rocker arm. By moving the guide member, the differences in the path of the guide member and rocker arm can be accentuated or minimised, thereby altering the motion characteristics of the rocker arm and in turn the valve. This enables the valve opening duration and/or valve lift to be varied.