Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
463 words
A reduction ratio controlling mechanism incorporated into a hydraulic control system with a pressure source (50) for a continuously variable automatic transmission including an input pulley combined with a hydraulic servomechanism for varying the effective diameter thereof, an output pulley combined with a hydraulic servomechanism for varying the effective diameter thereof, and a V-belt extended between said input pulley and said output pulley comprising: a first passage (1) connected between said pressure source (50) and said hydraulic servomechanism of said output pulley; a reduction ratio control valve (81) having a spool (812), a spring means (811) urging said spool (812) in one direction, an input port (817), a first chamber (816), a second chamber (815), a pressure regulating chamber (819), and a middle chamber (810); a second passage connected between said pressure source (50) and said first chamber (816); a third passage connected between said pressure source (50) and said input port (817) to communicate selectively with said pressure regulating chamber (819); a fourth passage connected between said pressure source (50) and said reduction ratio control valve (81) to communicate selectively with said middle chamber (810); a fifth passage (2) connected between said pressure regulating chamber (819) and said hydraulic servomechanism of said input pulley; a sixth passage (1A) connected between said middle chamber (810) and said second chamber (815); a first drain port (813) selectively communicated with said middle chamber (810); a second drain port (814) selectively communicated with said pressure regulating chamber (819); a down-shaft electromagnetic valve (85) provided in said first chamber (816) to control hydraulic fluid in said first chamber (816); an up-shift electromagnetic valve (84) provided in said second chamber (815) to control hydraulic fluid in said second chamber (815); whereby upon up-shifting operation, said up-shift electromagnetic valve (84) allows hydraulic fluid in said second chamber (815) to exhaust, while the hydraulic fluid in said first chamber (816) permits said spool (812) to move toward said second chamber (815) against the urging force of said spring means (811), interrupting said fifth passage (2) from communicating with said second drain port (814) to communicate with said input port (817), and at the same time, interrupting said sixth passage (1A) from communicating with said first drain port (813) to communicate with said fourth passage; upon down-shifting operation, said down-shift electromagnetic valve (85) allowing hydraulic fluid of said first chamber (816) to exhaust while the hydraulic fluid of said second chamber (815) and said spring means (811) permits said spool to move toward said first chamber (816), interrupting said fifth passage (29 from communicating with said input port (817) to communicate with said second drain port (814), and at the same time, interrupting said sixth passage (1A) from communicating with said fourth passage to communicate with said first drain port (813).
Claim 2
Dependent Claim
463 words
A reduction ratio controlling mechanism incorporated into a hydraulic control system with a pressure source (50) for a continuously variable automatic transmission including an input pulley combined with a hydraulic servomechanism for varying the effective diameter thereof, an output pulley combined with a hydraulic servomechanism for varying the effective diameter thereof, and a V-belt extended between said input pulley and said output pulley comprising: a first passage (1) connected between said pressure source (50) and said hydraulic servomechanism of said output pulley; a reduction ratio control valve (81) having a spool (812), a spring means (811) urging said spool (812) in one direction, an input port (817), a first chamber (816), a second chamber (815), a pressure regulating chamber (819), and a middle chamber (810); a second passage connected between said pressure source (50) and said first chamber (816); a third passage connected between said pressure source (50) and said input port (817) to communicate selectively with said pressure regulating chamber (819); a fourth passage connected between said pressure source (50) and said reduction ratio control valve (81) to communicate selectively with said middle chamber (810); a fifth passage (2) connected between said pressure regulating chamber (819) and said hydraulic servomechanism of said input pulley; a sixth passage (1A) connected between said middle chamber (810) and said second chamber (815); a first drain port (813) selectively communicated with said middle chamber (810); a second drain port (814) selectively communicated with said pressure regulating chamber (819); a down-shaft electromagnetic valve (85) provided in said first chamber (816) to control hydraulic fluid in said first chamber (816); an up-shift electromagnetic valve (84) provided in said second chamber (815) to control hydraulic fluid in said second chamber (815); whereby upon up-shifting operation, said up-shift electromagnetic valve (84) allows hydraulic fluid in said second chamber (815) to exhaust, while the hydraulic fluid in said first chamber (816) permits said spool (812) to move toward said second chamber (815) against the urging force of said spring means (811), interrupting said fifth passage (2) from communicating with said second drain port (814) to communicate with said input port (817), and at the same time, interrupting said sixth passage (1A) from communicating with said first drain port (813) to communicate with said fourth passage; upon down-shifting operation, said down-shift electromagnetic valve (85) allowing hydraulic fluid of said first chamber (816) to exhaust while the hydraulic fluid of said second chamber (815) and said spring means (811) permits said spool to move toward said first chamber (816), interrupting said fifth passage (29 from communicating with said input port (817) to communicate with said second drain port (814), and at the same time, interrupting said sixth passage (1A) from communicating with said fourth passage to communicate with said first drain port (813).
Claim 3
Dependent Claim
60 words
A reduction ratio controlling mechanism according to claim 1, wherein said spool (812) has one end land (812C), an intermediate land (812B) and another end land (812A), said pressure regulating chamber (819) formed between said intermediate land (812B) and said other end land (812A), said middle chamber (810) formed between said one end land (812C) and said intermediate land (812B).
Claim 4
Dependent Claim
32 words
A reduction ratio controlling mechanism according to claim 2, furthermore comprising grooves (817a, 813a, 814a) formed in said input port (817), said first drain port (813), and said second drain port (814).