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Mechanical Devices Sourcebook 3rd ed mcgraw hil 2001 Episode 1 Part 3

Tham khảo tài liệu 'mechanical devices sourcebook 3rd ed mcgraw hil 2001 episode 1 part 3', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | CHAPTER 3 PARTS-HANDLING MECHANISMS MECHANISMS THAT SORT FEED OR WEIGH ORIENTING DEVICES Here s a common problem Parts arrive in either open-end or closed-end first you need a device that will orient all the parts so they feed out facing the same way. In Fig. A. when a part comes in open-end first it is pivoted by the swinging lever so that the open end is up. When it comes in closed-end first the part brushes away the lever to flip over headfirst. Fig. B and C show a simpler arrangement with pin in place of lever. A part with its open-end facing to the right part 1 falls on a matching projection as the indexing wheel begins to rotate clockwise. The projection retains the part for 230 to point A where it falls away from the projection to slide down the outlet chute open-end up. An incoming part facing the other way 2 is not retained by the projection hence it slides through the indexing wheel so that it too passes through the outlet with its open-end up. The important point here is that the built-in magnet cannot hold on to a part as it passes by if the part has its pointed end facing the magnet. Such a correctly oriented part part 1 will fall through the chute as the wheel indexes to a stop. An incorrectly oriented part part 2 is briefly held by the magnet until the indexing wheel continues on past the magnet position. The wheel and the core with the slot must be made from some nonmagnetic material. 52 Orienting U-shaped parts The key to this device is two pins that reciprocate one after another in the horizontal direction. The parts come down the chute with the bottom of the U facing either to the right or left. All pieces first strike and rest on pin 2. Pin 1 now moves into the passage way and if the bottom of the U is facing to the right the pin would kick over the part as shown by the dotted lines. If on the other hand the bottom of the U had been to the left the motion of pin 1 would have no effect and as pin 2 withdrew to the right the part .