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US 4,305,306 AGranted
Drive assembly
AssigneeCam Gears Limited
InventorFrederick J. Adams
Life of this patent
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AssigneeCam Gears Limited
InventorFrederick J. Adams
Estimating the term…
A rotatable input shaft (1) drives a rotatable output shaft (18) through a roller (7) which roller is displaceable along its rotational axis (8) while maintaining driving engagement with drive faces (6 and 14) of the shafts (1 and 18) respectively to vary the drive ratio through the assembly. The roller (7) is controlled in its displacement by a piston and cylinder device (10, 11) to which fluid pressure is directed under control of a spool valve (22). The spool (26) of valve (22) is displaceable to determine fluid flow towards and from the piston chambers (12 and 13) of the piston and cylinder device under control of the speed of rotation of the output shaft (18) through a centrifugal governor (34) and a push rod (33) reacting between the spool (26) and the governor (34). If the rotational speed of shaft (18) varies substantially from a predetermined value (for example by variations in rotational speed of the input shaft (1)) the governor (34) reacts to displace the spool (26) in a manner which directs fluid pressure to piston chambers (12 and 13) and displaces the roller (7) in a sense to increase or decrease the mechanical advantage at which drive is transmitted between the input and output shafts to adjust the rotational speed of the output shaft (18) and maintain it substantially constant.
A drive assembly comprising an input member rotatable about a first axis, an output member rotatable about a second axis, a transmission member rotatable about a third axis which extends transverse to said first and second axes and cooperates with said input and output members to rotatably drive said output member in response to rotation of said input member, said transmission member being displaceable along said third axis to change the ratio at which drive is transmitted from said input member to said output member, fluid pressure operated means for controlling said displacement of said transmission member, and valve means for controlling fluid flow to said fluid pressure operated means, said valve means being adjustable in response to variation in speed of said output member to maintain the speed of rotation of said output member substantially constant when said speed attains a predetermined value.
Dependencies are inferred from the claim text.