| 摘要 |
1,272,199. Sliding roofs. RHEINSTAHL SIEGENER EISENBAHNBEDARF G.m.b.H. 6 Nov., 1970 [7 Nov., 1969], No. 52965/70. Addition to 1,200,623. Heading B7L. [Also in Division F2] In a railway goods wagon as claimed in claim 1 of Specification 1,200,623, means is provided for rotating the rope drum including a hand wheel 16 and a two ratio gear assembly which is arranged to transmit the force applied to the hand wheel to the rope drum via a drive shaft 76 and a driven shaft 79 connected by a wheel 92 and chain 93 to the rope drum, the gear assembly adopting a first or second "state" depending on the magnitude of the applied force. The gear assembly includes, in addition to the shafts 76, 79, two pairs of chain wheels 80, 82 and 81, 83 arranged on the shafts, the wheels 82, 83 being fast for rotation with the shaft 79, and being connected respectively to the wheels 80, 81 by chains 84, 85, and a spring biased clutch mechanism on the shaft 76 arranged between the wheels 80, 81. The clutch mechanism 13 in the form a dog coupling including two coupling sleeves 86, 87 having coupling dogs 86a and 87a respectively, the dogs 86a being engageable with corresponding frusto-conical dogs 80a on the wheel 80, and the dogs 87a being engageable with corresponding rectangular dogs 81a on the wheel 81. The sleeve 86 can slide within the sleeve 87 and the two sleeves are rendered fast for rotation with the shaft 76 by a key 88 arranged through slots in the sleeves and shaft, the slots in the sleeve 87 and shaft being of such a length that the sleeves 86, 87 are longitudinally movable on the shaft. A compression spring 89 tends to separate the two sleeves, and is opposed by a tension spring 91 arranged within the shaft 76 and secured to the key 88. The springs are so adjusted that when the gear assembly is not subjected to load the dogs 86a are engaged with those of the wheel 80, and the sleeve 87 is disengaged from the wheel 81, as shown in the Figures, the gear assembly then being in a first "state". On rotation of the hand wheel the coupling sleeve 86 remains engaged with the chain wheel 80 until the magnitude of the force applied to the hand wheel is greater than the friction produced by the spring 91, and causes slip due to the shape of the dogs 80a and 86a, whereby the sleeve 86 becomes disengaged. The force of the compression spring 89 then effects engagement of the sleeve 87 with the wheel 81, this corresponding to a second "state" of the gear assembly. The spring 91 is adjusted so that the changeover from first to second "states" occurs when the roof part is being lifted, a smaller applied force being necessary in the second "state", the first "state" being adapted by the gear assembly in rest and when the roof parts are being moved horizontally. |
