PATENTS SUMMARIZED.
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A Wolseley Electric Control.
Patent No. 121616, Wolseley /diatom, Ltd., brings us a step nearer to the time when the control of a motor lorry or car' Will be by buttons and switches rather
than by levers. A simple combined epicyclic change speed gear, which is controlled electrically, is the substance of the invention Two designs are shown and described in the specification. We will deal with one of them.
The driving shaft carries at its inner or gearbox, end a pair of circular elec. tro-magnets. The armature of one of these electro-magnets is keyed to a central spindle co-axial with the driving shaft, which carries one sunwheel of an epicyclic gear. The ,armature of the other is similarly secured to a sleeve which is mounted on the first-named spindle. This 'sleeve carries enother.stinwheel larger than that on the spindle. The driven shaft, the outer end of which emerges from the gearbox; and transmits the drive., to the propeller shaft, also carries a .sunwheel larger than either
of the other two. '.I'hese three sunwheels gear into three sets of Planetary pinions which are carried in a casing of the Customary form. These pinions are arraueed to revolve in unison,. no matter how the gears are employed. Two other electro-magnets as provided. They are stationary, being secured to the actual gearbox casing.
The mode of operation is as follows:— For the first, speed, that electro-magnet which is in communication with the armature on the inner spindle is energized,. and so also is one of the stationary electro-magnets, the one whic.h ;prevents the ease holding the planetary pinion4from revolving. The drive thenrruns from the driving shaft via the electro-magnet and armature to the inner spindle; from its sun wheel to the, corresponding planetary piniorts, causing all three of these pinions to revolve, and Tmovement to take place ia the final drivenishaftrthrough the sunwheel which is secured to it. For second speed, .the armature coupled to the sleeve upon the inner spindle is .driven, this communicating through the sunwheel on that sleeve, the planetary pinions, etc., and revolving the driven shaft at a higher relative speed. For the direct drive both those armatures on spindle and sleeve are driven, and atsthe came time the electro-magnet which through its corresponding armature is holding the planetary (pinion case is deenergized. In consequence, all the wheels, planetary pinion case, and driven shaft revolve as one, and this constitutesoa direct drive. For the reverse gear the fourth electro-magnet is energized, and this holdslthe sleeve en the inner spindle stationary; That magnet and its armature which couples the driving shaft to the inner spindle is also made effective, but the planetary pin:on case is left free to revolve. The drive thus goes from driving shaft to inner
spindle. This drives the planetary pinions and case round, but owing to the difference in ratio is between the sunwheel on the spindle and its 'corresponding pinion, and the sunwheel on the driven shaft and its pinion,the effect is to reverse the motion of the driven spindle.
Detail Improvements.
An ingenious method of liniiting the action of a. differential gear is the sub ject of 112278. Gearing within the differential care is so arranged that two wheels of different diameters revolve upon an enlarged part of one of the livo axle shafts. One of them revolves more slowly than the differential shaft, the other. more quickly. The engagement between the shaft and either of the two wheels is effected by an automatic friction clutch, so that if that shaft by reason of its wheel losing grip on the ground tends to overtake the more quickly revolving of these .wheels, the clutch is engaged and such overtaking is
prevented. In .the case of the other
• wheel of the vehicle tending to overtake, the effect is for the shaft with which this gear engages to fall below the average speed of the differential case, whereupon the friction gearing of the other wheel operates with the same effect. (J. 0. Woodward).
An interesting Variation of the construction of chain tracks is the subject of 116076, by Renault, in which ropes or other similar flexible material form the basis of the construction of the track.
116720 (Gabet) describes an additional driving wheel for a tractor which is so arranged that it need only be made effec tive when the tractor is actually on soft ground. Its effectiveness, moreover, is increased in proportion to the pull on the drawbar.
Another tractor improvement, 121653,, by Boon Tractors, Ltd., refers to the two-wheeled type of, tractor, and concerns a detail in connection with the control of the gear. In 121671, R. W. Maudslay describes a construction of lifting jack. A broad base with upturned enas combined with a jack table, provided with a 'wall or stop. The I3.T.H. Co. have patented in 1.21A80 a magneto contact breaker in in order to .reduce the •effects of inertia, both contact points are caused to move instead of one, as is customary.
W. 10Wardle provides safety for tractor drawn ploughs byso arranging the coulter that, if the latter strikes an obstruction, the, plough is automatically caused to climb over that obstruction rather than strike it.