Patent GB-266567-A (GB)
Title: A milling machine for cutting gears
IPC: B23F1/06
Filed: 1926-05-07
Abstract: 266,567. Romanoff, H. May 7, 1926. Gear-cutting. - A machine for milling spur gears is provided with a chain drive for the forward movement of the work-slide, the return movement being effected by springs under dashpot control. The cutter 2 is mounted on a shaft 3 driven from an electromotor 6. Parallel slide-bars 7, 8 which serve as guides for the work-slide are secured to the frame through collars 9<1> and bolts 10<1>. A plate 15, secured to sleeves 12, 13 sliding en the bar 7 and to a sleeve 14 sliding on the bar 8, carries a verticallyadjustable angle plate 18 supporting the workspindle. A chain 19 secured at one end to the sleeve 12 is guided by a pinion 24 over a wheel 22 on the feed-shaft 23 and thence round a pinion 20 on the sleeve 13. The feed-shaft is rotated intermittently to effect the working feed bv means of an eccentric 29 on the cutter-spindle which rocks an inclined roll 31 and operates an arm 37 having a ratchet pawl engaging the feed-wheel 27. The amount of the feed movement may be varied by adjusting the inclination of the rail 31. Reverse rotation of the feedwheel is prevented by a pawl 40. The wheel 22 is integral with a drum 56 secured by a chain to a dash-pot 59 comprising a perforated piston working in an oil-filled cylinder and having a spring located above the piston. During the slow working feed of the slide, the wheel 22 is locked to the hollow feed-sbaft 23 by a pivoted member 60 spring-pressed against a conical surface 67 and engaging a wheel 62 on the feedshaft. At the end of the working movement an adjustable stop-rod 45 on the work-slide (acts through lever mechanism, Fig. 6, to move a roller 55 so as to move axially a rod 63 pinned to the conical member 67. This releases the wheel 22 from the feed-shaft whereupon the spring contained in the dash-pot 59 which is compressed during the working movement causes the rotation of the drum 56 for the quick return movement of the slide, this movement being controlled by the braking effect of the oil passing through the perforations of the dash-pot piston. At the end of the return movement a second stop on the work-slide again actuates the lever mechanism to release the rod 63 and lock the wheel 22 to the feed-shaft for another forward movement. The work-support comprises a bearing-sleeve 68 having collars 69, 70 secured to rods 71, 72 which pass through oval holes in the plate 18 so that both vertical and lateral adjustment of the work-spindle 74 may be obtained. The work-spindle carries an indexing-wheel 76 having semi-circular notches and normally locked by a roller which is adjustable in a pivoted frame 79. A cylindrical pivoted member 88 provided with an inclined forwardly-extending blade 89 is mounted on a fixed bracket 85. During the return movement of the work-slide an edge 90 between the semi-circular notches engages the inclined blade, whereupon the locking-roller is lifted from its groove and the work is indexed. On the next forward movement the blade 89 can move idly by the pivoting of the cylinder 88. A contact 92 of an electrical circuit is arranged at the commencement of the operation opposite a contact 94 on the indexing-disc and when the blank is completed after a revolution of the index-wheel, the contact 94 closes the circuit at the end of a work-slide return movement and actuates a bell mechanism. The work-slide carries an oil-pan 95 covered by a metal filter for catching the cuttings, the pan being connected by a flexible pipe to a cylinder 99 moving over the slide-bar 8 which serves as a piston. The delivery from the cylinder passes through a pipe 103 to lubricate the cutter. The movement of the cylinder is effected by the movement of the work-slide through the link mechanism shown in Fig. 1, the arrangement being such that the oil is drawn from the oil-pan during the return stroke and discharged over the cutter during the working stroke of the slide.