GB968748A - Improvements in barrel apparatus - Google Patents

Abstract

<PICT:0968748/C6-C7/1> <PICT:0968748/C6-C7/2> <PICT:0968748/C6-C7/3> <PICT:0968748/C6-C7/4> <PICT:0968748/C6-C7/5> <PICT:0968748/C6-C7/6> <PICT:0968748/C6-C7/7> Apparatus for plating comprises a rotatably mounted barrel 13 having a door opening formed therein, two sets of catch means mounted on the barrel on opposite sides of the door opening, a door 20 slidably mounted on the barrel and slidable under gravity across the door opening from an open position to a closed position and vice-versa, projections 22 mounted on the door adjacent the edges thereof, one of the projections being engageable by one of the sets of catch means and the other projection being engageable by the other set of catch means, and operating means mounted on the apparatus and selectively engageable with either one of the sets of catch means dependent upon the angular position of the barrel to release one of the sets of catch means from engagement with the door whereby the door may slide under gravity from its open position to its closed position or vice-versa and be held therein by the other set of catch means. A casing 10 mounted in a frame 11 has a door 29 operated by a motor 14. The frame 11 carries shot blasting apparatus comprising an impeller 17 driven by a motor 16. Shot is recirculated into the impeller by a conveyer 18 driven by a motor 19. The barrel 13 is perforated and has rims 33 resting on rollers 32 driven by a motor and driving gear 12 carried by the frame 11. Each set of catch means comprises a spring-loaded pivoted pawl 21 having a hook 23 to engage the projection 22 on the barrel door 20 and a tail 25 co-operating with a cam 27 mounted on a pivot pin 28. At the beginning of the cycle, Fig. 4, the casing door 29 is open, the barrel 13 is at rest with its door opening opposite the casing door opening, and the barrel door 20 is held open by one pawl 21. Workpieces are loaded into the barrel through shoot 30, and casing door 29 is shut. The motor 12 is started to rotate the barrel and the cam 27 is then operated mechanically or electronically to bear upon the tail of the pawl thereby releasing the barrel door 20 which shuts by gravity and is held shut by the other pawl 21. This position is shown in Fig. 5. The cam 27 is released and the barrel rotated for a predetermined time after which at the position shown in Fig. 7, the casing door 29 is opened and the cam 27 again operated so that as the barrel rotates the cam bears upon the tail of the pawl which is holding it shut thereby releasing the barrel door 20 which opens by gravity and is held open by the other pawl, this position being shown in Fig. 8. As the barrel door opening reaches its lowest point, Fig. 9, the workpieces discharge under gravity on to a shoot 31 built into the casing 10 and the barrel is then brought to rest with the barrel door opening opposite the casing door opening. Alternatively the barrel may be braked so that as its door opening comes to the bottom of the casing the barrel comes to rest and the workpieces discharge themselves on to the shoot 31, the barrel then being further rotated into the loading position.