GB703224A - Ratchet driving device - Google Patents

Abstract

703,224. Ratchet gearing. HARD, C. G. July 25, 1952 [May 16, 1952], No. 18881/52. Class 80 (3) In a ratchet gear device in which two or more driving units operate on the same driven element means are provided for adjusting the working phase of one or more of the units in dependence on the working phase of one or more of the other units. As shown, four separate driving units 6, 7, 8, 9 operated by fluid-pressure impulses work in pairs 6, 8 and 7, 9 for driving a ratchet wheel 14 through spring-loaded pawls anti-clockwise or clockwise respectively. The two units of each pair may operate simultaneously to give a greater driving force or alternately to give a lesser driving force but a greater rate of rotation of the driven wheel 14 under control of devices 19 and 20 showm in more detail in Fig. 2. These devices each comprise a spring-loaded piston valve 26 subjected at one end to the pressure in the associated driving unit from pipes 21 or 22 and having lands 31, 32, 33 controlling the pressure fluid from an inlet port 34 to an outlet port 35 leading to the ether driving unit through either of passages 37 or 38 as controlled by a changeover valve 36. With the valve in the position shown port 34 is put into communication with port 35 only when pressure is supplied to the end of piston 26 from pipe 21 or 22 so that both driving units will work in phase. In the other position of valve 36 pressure is only supplied -to port 35 when the fluid-pressure on piston 26 is released so that the two driving units operate alternatively. A port 39 is provided for the exhaust of the fluid-pressure from the port 35 on completion of a stroke of the associated driving unit. The pair of driving units for one direction may be adjusted to operate with greater force at low speed whilst the pair for the opposite direction may operate with a smaller force at greater speed. Also the valve 36 may be set to cut out the second driving unit completely if desired. Pawls 45, 46 coupled to the pairs of driving units through linkage 42, 43, 44 may be provided to prevent backward running of the wheel 14 according to whichever direction the wheel is being driven. A manual operating lever 50 for setting either of the pawls 45, 46 in a blocking position or both in a neutral position as desired. The driving units 6, 7, 8, 9 may be electrical or mechanical mechanisms instead of hydraulic or pneumatic and may be other than the reciprocating type. Any number of driving units may be utilised.