Patent GB-369704-A (GB)
Title: Improvements in the manufacture of vehicle wheels
IPC: B21D53/26
Filed: 1931-01-26
Abstract: 369,704. Drilling-machines. DUNLOP RUBBER CO., Ltd., 32, Osnaburgh Street, London, and SHARP, G. E., of Dunlop Rubber Co., Foleshill, Coventry. Jan. 26, 1931, No. 2495. [Class 83 (iii).] In a machine for drilling the hubs of wirespoked vehicle wheels &c. having synchronized mechanism for intermittently rotating, locking, and drilling the hubs in a number of places located in one or more zones, a number of independently driven electrical drill units is provided, each of which is adjustable relatively to the hub. The hub 64, Fig. 1, is secured by clamping means 70 to an indexable table 65 and the drill spindles 44a are attached by blocks 44, adjustable to compensate for wear of the drills, to racks 42 which are reciprocated to feed and withdraw the drills by pinions 39 on shafts oscillated through levers and links 36, pinions 30, and a rack 27. A roller 28 on the rack is kept in contact with a double cam 67, 68 by a weight 43, the cam being secured to a shaft 69, Fig. 3, which also carries a crank 25 for reciprocating the indexing rack 54. The shaft 69 is driven through gearing 22, 20, change wheels 17, shaft 15 and main feed clutch 49 from a chain wheel 12 which drives through a yielding friction clutch 13, the wheel 12 being driven at one of two speeds from a motor 1 through either of the chains 4, 5 and a clutch 8. In operation with the rapid drive engaged as shown in Fig. 3, the rack 54 moves to the left oscillating a sector 55 to cause a spring pawl 58 thereon to move on its idle stroke on the index disc 59 attached to the work spindle 56. Simultaneously, the drills are fed rapidly towards the work by the cam 67 until a cam 75 on the rack 54 engages a roller 77 on a " load and fire " lever 79 so as to move the clutch 8 to the slow-drive position for feeding the drills into the work. The cams 67, 68 are set ahead of the crank 25 so that the drills will be withdrawn from the work before the rack 54 reverses. Towards the end of the stroke of the rack 54 a cam 63 on the sector causes a spring locking-dog 61 to release the disc 59, whereupon the pawl 58 engages the next notch 60a in the disc and then effects the indexing stroke, a spring pawl 66 preventing the disc from rotating when released by both the pawl 58 and the dog 61. As soon as the drills have been withdrawn a second cam 76 on the rack 54 engages a roller 78 on the lever 79 to reengage the rapid drive. On completion of a single revolution of the work a cam 52 on the spindle 56 engages a lever 51 on a shaft 48 connected to the main clutch 49, thereby throwing out the clutch to stop the drive of the shaft 15 whilst the work is being changed. A hand-lever 47 on the shaft 48 restarts the machine and a handle 16a, Fig. 1, is attached to one of the gears 16 for setting up the machine. The drill spindles 44a are independently driven by electric motors 46 mounted on interchangeable brackets 71 which are set at the required inclination to the hub 64, the drive being through pairs of gears 46a so as to enable two tiers of drills to be superposed as shown in Figs. 1 and 2. Jigs.-The drills are supported at their operative ends by hardened bushings 73 carried by arms 72 adjustably secured to the drillheads 87.