Patent GB-303032-A (GB)
Title: An improved charging regulator for disintegrating and like mills or other apparatus
IPC: B02C25/00
Filed: 1928-12-24
Abstract: 303,032. Hartstoff-Metall Akt.-Ges- Dec. 24, 1927, [Convention date]. Equalizing load on generator. - The current taken by a motor driving a mill or similar machine is controlled by a device which operates automatically the speed of the feeding apparatus by means of gearing put in and out of action by a clutch controlled by an electromagnet which is excited according to the current passing to the motor. The device comprises a casing 1 in which is mounted two horizontal shafts 2, 3; the shaft 2 being driven by a worm 4 from the mill or mill-shaft. Cog wheels 5, 6, fixed on the shaft 2 drive cogwheels 7, 8 which are loosely mounted on the shaft 3, the cog-wheel 7 being connected to a slidable clutch plate 15 by a pin 25 and the cog wheel 8 being loosely mounted on a fixed sleeve 9 and driving the shaft through a pawl 11 and ratchet wheel 10 fixed on the sleeve. A clutch member 16 loosely mounted on the shaft 3 is provided with a lug 35, Fig. 3, which floats between projections 36, 37 on the sleeve 9. A cam surface 17 on the rim and a cam surface 18 on the rear face of the clutch disc 16 are engaged by rollers 23, 30 provided on a bell-crank 20, 21 pivoted at 19 and a lever arm 27, 29 pivoted at 26, respectively. One arm 21 of the bell-crank is engaged by the clutch disc 15, and the arm 27 of the lever acts as an armature to an electromagnet 28 around which the current to the driving motor passes. The armature 27 is under the control of a spring 32, and engageable trip teeth 33, 34 are provided on the bell crank and lever respectively. A sprocket wheel 38 is fixed to the shaft 3 and operates the feeding device by means of a chain. The shaft 2 rotates in the direction of the arrow 13 and drives the shaft 3 in the direction of the arrow 14, the speed of the shaft 3 being either faster or slower than the shaft 2 according to which of the cogwheels 5 or 6 drives the shaft, i.e., whether the clutch 15, 16 is engaged or not. The rotation of the shaft 3 causes the cam 17 to raise the roller 23 so that the clutch part 15 slides along the shaft and engages the corresponding part 16, whereby the shaft 3 is driven at increased speed by the cogwheels 5, 7. When the cam 17 leaves the roller 23, the clutch is disengaged by the spring 24 and the quick rotation ceases. The cam 17 is in advance of, and is longer than, the projection 18 so that the trips 33, 34 may engage when the roller 23 leaves the cam 17. If the mill is working at full load the armature 27 is retained by the electromagnet so that the trips do not engage, and the clutch member 15 is retracted so that shaft 3 rotates at the slow or normal speed. If the armature is not retained by the magnet the trips engage and consequently the clutch 15. When the clutch is engaged it rotates freely on the shaft for about half a revolution until the lug 35 engages the projection 36, and the arrangement of the cam 17 and projection 18 to the lug 35 is such that the change of position of the levers 20, 21, and 27, 29 will be finished about one quarter of a revolution of the clutch 16 so that if the armature 27 is not attracted the throwing of the clutch in and out of gear has no effect and the shaft rotates at the speed of cog 8. Thus at every rotation of the clutch 16 the armature 27 is moved toward the electromagnet, but as long as the current is not that prescribed the clutch members remain engaged and the chain wheel 8 is rotated continuously at increased speed until the driving motor is again running at full load. If the strength of the current is that prescribed, the engaging and disengaging of the clutch members takes place while the member 16 runs idly between the projections 35, 36 on the shaft so that the rotations of the shaft 3 are not increased. The regulator may be arranged to operate the shaft 3 only when the strength of the current passing through the driving motor exceeds a predetermined limit. This is effected by omitting gear wheels 6, 8, connecting the clutch element 16 rigidly with the shaft 3 and mounting the cams 17, 18 upon a member rotated by the shaft 2, e.g. the clutch element 15.