Patent GB-917675-A (GB)
Title: Improvements in or relating to change-speed gears
IPC: F16H3/093
Filed: 1959-02-16
Abstract: 917,675. Change-speed gear. RAMBAUSEK, H. Feb. 16, 1959 [Feb. 14, 1958; April 28, 1958], No. 5363/59; Class 80 (2). Change-speed gearing for motor-cars, machine tools, ships, aircraft or the like comprises a driving-shaft 1, constantly meshing gear pairs, 3, 7; 4, 9; Z 1 , Z 1 1 together with ratio establishing friction or positive clutches K 1  . . . K 3  and two ratio establishing friction ratchet clutches  1 ,  2  which can be completely disengaged by external means and are located at the extreme driven end of the change-speed gearing. The friction ratchet clutches  1 ,  2  may be locked to transmit drive in both directions. In the form shown, the two disengageable friction ratchet clutches  1 ,  2  transmit drive through shafts 6, 10 to a forward drive clutch V and a reverse drive clutch R selectively engaged to drive through gears Z v , Zr and a gear Z o  to a final driven shaft 2. Alternatively, the shafts 6, 10 may be the final shafts, each being connected to a driven device. The gears are so arranged that when a ratio has been established and drive is transmitted through one of the disengageable friction ratchet clutches  1 ,  2 , the other ratchet clutch does not transmit drive and can be disengaged by the associated external means. Establishment of another ratio can then be initiated by engagement or disengagement of the appropriate clutch K1 ... K3 so that on engagement of the disengaged ratchet clutch  1 ,  2 , the previously operative ratchet clutch overruns. In the form shown in Fig. 1, the first ratio is obtained by engaging the clutches K 1 , K 2  and the friction ratchet clutch  1 . Either the forward drive clutch V or the reverse drive clutch R is engaged to establish forward or reverse drive, respectively. To establish the second ratio, the ratchet clutch  2  which has previously been disengaged, is engaged. The ratchet clutch  1 ,through which torque was transmitted for the first ratio, now over-runs, and can be completely disengaged by the external control means, as can be the previously engaged clutch K 2 . To engage a third ratio, the clutch K 3  is engaged, so that when the disengageable ratchet clutch  1 is re-engaged, the ratchet clutch  2 overruns and third ratio is established. On re-engaging the clutch K 2 , the disengageable ratchet clutch  2  can be re-engaged, and the ratchet clutch  1  overruns, to establish the fourth ratio. In one modification. Fig. 6 (not shown), the driving- shaft 1 extends the whole length of the gearing and the gear-wheels Z 1  &c. are journalled thereabout. In another modification, Fig. 11 (not shown), the driving and driven shafts 1, 2 extend on the same side of the gearing. In another form, Fig. 16 (not shown), five clutches K are provided and the gear gives six forward ratios only. In further modifications of six ratio gears, Figs. 19, 20 and 22 (none shown), the two completely disengageable ratchet clutches  1 ,  2 are mounted on the same shaft, or are provided as a double controllable ratchet clutch. In a form giving six forward ratios, only, Fig. 24 (not shown), the driving and driven shafts 1, 2 are coaxial, and in another form, Fig. 27 (not shown), similar to the form of Fig. 1, six forward and six reverse ratios are obtained, a modification of this construction, Fig. 32 (not shown), having the driving shaft 1 extending right through the coaxial gears and clutches. In a further modification, giving six forward and six reverse ratios, a driving shaft 1, Fig. 39, is connected through positive clutches K 1 .. . K 6  and two completely disengageable friction ratchet clutches A³, B³ to a driven shaft 14, and engagement of the positive clutches, such as K 4 , K 5 , is synchronized by two friction clutches S 1 ,S 2  engaged only for purposes of synchronization and not for transmission of driving torque. Control of the disengageable friction ratchet clutches in any of the forms described may be effected mechanically, hydraulically, pneumatically or electrically. Specifications 757,549 and 916,969 are referred to.