Patent GB-190716713-A (GB)
Title: New or Improved Speed Gear.
Inventor: BERCKENHOFF HEMKE
Filed: 1907-07-22
Granted: 1908-10-22
Abstract: 16,713. Berckenhoff, H. July 22. Driving-mechanism. - Relates to variable-speed gearing for cycles &c. of the class comprising opposed separate planetary systems and separate encircling annuli and devices for coupling either of the planetcarriers to the annulus of the other system. The clutch device used can slide and rotate and is separate from the sun-wheels which are stationary. In the three-speed gear shown in Fig. 1, the carrier C of planet-pinions F is the driving-element, and the carrier C' of pinions F' is the driven element, in this case a cycle hub. The sun elements B', B<1> are secured to a fixed axle B, and the corresponding annuli D, D<1> are loose and provided with internal clutch-jaws d, d<1>. The movable clutch A is provided with holes for engaging the ends of the planet-wheel spindles and with external jaws a, a' for engaging the jaws d, d<1>, respectively. The clutch A rotates freely about the axle B, and is actuated longitudinally by a key G and internal rod &c. In the configuration shown, with the jaws a', d' in engagement, the clutch A rotates solid with the carrier C and the system on the left is driven from its annulus D<1> giving a reduced speed. A direct drive is obtained when the clutch A is moved to the left until the jaws a<1>, d' are disengaged and the ends of the planet - wheel spindles of both systems are engaged at once. Upon a farther movement of the clutch A until the joints a, d come into engagement, the system on the left still rotates solid with the clutch A and the system on the right becomes operative, yielding an increased speed. In an alternative class of gear, the annuli are the driving and driven members and the carriers are loose. In a modified form of the arrangement shown in Fig. 1, ratchet clutches are employed instead of the jaws a, a'. In Fig. 4 a gear of the second class is shown in combination with ratchet clutches. Spring pawls a<2>, a<3>, carried by the clutch A and inclined in opposite directions are adapted to engage ratchet teeth formed on the driving and driven annuli D, D', respectively. Free-wheeling on the middle speed is obtained by bevelling the ends of one set of planet-spindles or by dispensing with the prolonged ends of the planet-wheel spindles altogether. The gear may be adapted to yield four speeds by making the parts of the planetary systems of different relative sizes and arranging that for one speed they drive at the same time differentially. In such a gear of the class in which the carriers are the driving and driven elements, two clutch rings are arranged on one annulus and one set of spindles are cut away in a manner similar to the arrangement of Fig. 6, which shows a gear of the other class. The spindles of the other system on the left are cut away at f, and the clutch A is cut away leaving a flange f<1>, the arrangement being such that in its extreme position on the right the clutch A becomes again disengaged from the carrier C'. The jaws a' then come into engagement with a second set of jaws d<3> connected to the annulus D', yielding the direct drive. The extra speed is obtained when the carriers C, C' are directly coupled through the clutch A.