GB538158A - Improvements in or relating to ratchet devices and mobile machinery employing such devices - Google Patents

Abstract

538,158. Locking vehicle wheels &c. RUSTONBUCYRUS, Ltd. Oct. 19, 1939, No. 28263. Convention date, Oct. 22, 1938. [Class 103 (i)] Relates to means for locking the propelling- mechanism of a mobile crane, power-shovel, &c. against motion in one or the other or both directions by means of a two-way ratchetwheel 28, Figs. 3 and 4, and opposed pivoted dogs 32, 33, either or both of which can be engaged with the ratchet. The dogs are operated by bell-crank levers 40, 41, which are connected by a rod 42. An arm 36 on the dog 32 is connected by a rod 43, having a slotted end, to an arm 38 on the dog 33. As the lever 40 is raised by the operation of a hand-lever from its lowest position, in which both dogs are out of engagement, as shown in Fig. 3, the dog 32, a boss 37 on which bears against the lever 40, is slightly lowered, and the link 43 allows the dogs 33 to engage the ratchet, as shown in Fig. 4. On further raising of the lever 40, the dog 32 also engages the ratchet. the next rise of the lever acts through the rod 42 and lever 41, which engages a boss 39 on the dog 33 to lift that dog out of engagement. The last movement of the lever 40 disengages the dog 32 also, by the action of the lever 41 on the rod 43. Both dogs are thus disengaged in the two extreme positions of the lever 40. In a modification, the bell-crank levers 40, 41 are omitted, and the dogs are operated by a sliding slotted bar 44, Fig. 8, and are also connected by a link 43 having a slot in one end. In other forms, the dogs are operated by sliding cam-bar, which can occupy five different positions, or by a bell-crank lever having pivoted at its ends two slotted links, which operate the dogs. In the case of a mobile crane &c. mounted on a turntable, the locking- device is operated from a hand-lever mounted on the turntable and acting through a rod passing through the hollow shaft of the table.