Patent GB-679669-A (GB)
Title: Improvements in and relating to fluid controlled clutches
IPC: F16D48/02
Filed: 1950-03-07
Abstract: 679,669. Clutches; change-speed gearing. ARCHAMBAULT, J. M. March 7, 1950 [March 7, 1949], No. 5745/50. Class 80 (ii). A clutch consists of two webs 1, 2, Fig. 1, keyed on a driving shaft 3, having frustoconical rims 4, 5 co-operating with members 6, 7 on flanges 10, 11 having hubs 12, 13 mounted to turn and slide in the hubs 14, 15 of the webs. The hubs 12, 13 form annular pistons in cylinders 16, 17 in the hubs 14; 15. Pressure fluid can be introduced through a bore 19 in the driving shaft 3 into a chamber 16<SP>1</SP>, thus effecting clutching of the members 6, 7 and 1, 2. By means of external grooves 20 in the shaft 3 pressure fluid can be supplied to the annular cylinders 16, 17 to produce disengagement of the' female members 6, 7 from the webs 1, 2. Lubricating holes 21 are provided in the flanges 10, 11, the evacuation of fluid through which, when declutching is effected, washes the frusto-conical surfaces and cools them. The two members 6, 7 have teeth on their peripheries, thus forming a pinion which may be clutched to the driving shaft 3. As applied to a change-speed and reverse power transmission device, a clutch 22, Fig. 2, of any type capable of being continuously slipped, is situated between a driving shaft 23 and a gear box, and is brought into engagement after the required speed has been chosen. Two oil pumps 24, 25 provide the pressure fluid, the pump 24, driven by the shaft 23, delivering oil under two pressures, a high pressure for engaging the gear ratios, and a low pressure for disengaging them. The pump 25 is driven by a driven shaft 28 and delivers oil at low pressure for general lubrication and to ensure disengagement of the gears when a vehicle (in which the box is mounted) is towed. Two oil-pressure regulators 31, 32, Fig. 3, are used with the pumps 24, 25, the regulator 32 being under the control of a supply of compressed air in a pipe 33 actuating the main clutch 22, in such a way as to increase the oil pressure during de-clutching to obtain energetic separation of the cones 6, 7 and thus avoid drag. The excess oil delivered by the pumps lubricates the gearbox through a passage 34. Oil distributers 35, Fig. 2, are fitted at the end of the shafts carrying the clutch pinions. Oil distributers 36, 37, Fig. 3, distribute the fluid under pressure as necessary to clutch or declutch the gear ratios, and may be controlled by mechanical, liquid, gaseous or electric means. The gearbox comprises the driving shaft 23 in a concentric hollow shaft 23<SP>1</SP>, these two shafts carrying the two parts of the clutch 22. The hollow shaft 23<SP>1</SP> carries a double sliding dog 38 by which it drives one or other of two pinions 39, 40. The pinion 39 is in direct engagement with the pinion 41 of an intermediate shaft 42 and the pinion 40 in engagement with a reversing pinion 44 meshing a pinion 43 also on the shaft 42. By these means a common shaft 47 is rotated through clutch pinions 45, 46 and in turn drives a clutch pinion 48 and a fixed pinion 50. The pinion 48 meshes with a fixed pinion 49, and the fixed pinion 50 with a clutch pinion 51, both pinions 49 and 51 being on the driven shaft 28. In the form shown, the servo-motor-type oil distributers 36, 37 are controlled by compressed air distributers 56, 57, Fig. 3, compressed air being supplied to the main clutch 22 through distributors 57, 37 and similarly to the oil regulator 32 through pipe 33. As many sets of the oil and air distributers shown in Fig. 3 are required as there are clutch pinions. A system of electrpmagnetically operated valves may replace the pneumatic distributers 56, 57, means being provided to ensure a gradual engagement of "first" gear.