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Fig. 160.--Showing How the Starting Switch and Shifting Pinion are Interconnected in the Bijur-Hupmobile
in this manner the drive is by a double universally jointed shaft to a small silent chain sprocket, which connects to a much larger member attached to the engine flywheel or crankshaft.
The complete system shown at Fig. 159, B, is the next most popular of all that have been used. This shows the application of the starting motor, outlined at A-4. The mechanical interlock between the sliding pinion on the intermediate shaft and the starting switch is clearly shown. Before the pinion engages the gear on the flywheel rim the switch makes contact, but owing to the resistance interposed in circuit the motor will turn slowly to permit of more ready engagement of the sliding pinion. As soon as the pinion is fully engaged with the large gear the resistance is cut out and the motor draws what current it needs from the storage battery, this being enough to produce the torque necessary to turn over the engine flywheel and the crankshaft to which it is attached at such speed as will produce prompt starting. A system of this nature used on the Hupmobile in connection with the Bijur starter is shown at Fig. 160. In this the pinion is shifted by a spring connection as outlined at A instead of a direct rigid coupling. This makes it easier to engage the pinion as the switch can make contact as at D and the spring will draw the pinion in mesh. The spring is also useful under the conditions shown at B where the pinion engages readily but the switch has not yet made contact.
The actual application of the system, shown at A-1, Fig. 159, is outlined at C, Fig. 161. It will be observed that the starting motor is attached to the side of the engine in a vertical position and that it drives the intermediate shaft by means of a worm on the motor armature, which engages with a worm gear on the intermediate shaft, which also carries the driving sprocket, as shown at B. A further reduction in speed is obtained owing to the difference in size of the small sprocket on the intermediate shaft and that attached to the clutching member normally revolving free on the motor crankshaft. It will be seen that the motor armature is supported on ball bearings, and that one of these, backing the worm, is a double row form capable of sustaining both the end thrust and radial load imposed by the driving worm. In order to resist the end thrust on the worm gearing successfully a ball thrust bear
Fig. 161.—Diagram Showing Application of Worm Reduction Gear to
Turn Over Engine Crankshaft Through Supplementary Chain and Sprocket Reduction.
ing is used, as shown at B. When it is desired to start the motor the clutch actuator, which is shown in the diagram at A, is pushed in until it engages the ratchet teeth cut on the face of the large sprocket. When the sprocket turns it must turn the engine crankshaft in the same direction, but just as soon as the engine runs faster than the large sprocket the clutching action will be released automatically by the ratchet teeth being thrown out of engage
ment. If it is necessary to start the engine by means of a hand crank this may be done by inserting the starting crank in the starting ratchet provided on the extreme end of the crankshaft. The large sprocket is normally free and the engine crankshaft turns without producing a corresponding movement of the sprocket member. The general arrangement of the parts is so clearly shown that no further description will be necessary.
The construction of a typical overrunning clutch is clearly shown at Fig. 162. The electric starting motor is secured to a base on the crankcase of the gasoline engine and the motor power is imparted through the medium of the small gear F carried by the armature shaft. This drives gear E, which turns at a lower speed on account of being larger, and that in turn engages with gear D, which is still larger in diameter. The small pinion C, which turns much slower than the motor pinion F, meshes with the large gear B attached to the clutch body. The use of this gearing provides a
Fig. 163.—Showing Interconnection Between Starting Switch and Inter
mediate Pinion of 1914 Delco-Cole System.
reduction of 40 to 1, which means that gear F must make 40 revolutions to one of the clutch body.
The ratchet or driven member of the overrunning clutch L is pinned to the engine crankshaft and revolves with it when the motor is operating, rotating inside of the gear B, having a bearing at K and turning in the direction of the arrow. The member L has three flat surfaces, M, cut at an angle to the inside of the gear B. On each of these a hardened steel roller, A, is held inside of the gear by a light spring and against the flat surface of the member