For a great number of manufacturers, particularly the ones who use the automated assembly of products, the material handling and accurate positioning of parts and sub-assemblies is a critical task. For automated assembly to even work it is necessary for high speed, exact positioning to be done with robotics. With manual assembly processes positioning can also be very critical to get the assembly done. Proper positioning will mean the difference between a slow, cumbersome automated assembly process and a high-speed, cost effective one. The fact that parts are placed at an exact location for automated assembly has a direct bearing on the quality of the end product.To have the stream of parts flow correctly in the production process the equipment that is part of the automated assembly must do three very important tasks in material handling, feed, position, and manipulate the parts to their assembly destinations. The feeding task is just a process of selecting a single part ou t of a group of like parts and moving that part toward an orientation so that it can be added to an assembly. The positioning task is moving that single part into an exact orientation for its presentation to the assembly process. The manipulation task is the gripping and placement of the part into the assembly. Separating a group of parts into individual parts, sometimes called singulation, is also part of the procedure for getting parts to the assembly point.The beginning point for all parts that are going to be fed into the automated assembly operation is usually completely random. The feeding process must get those single parts into an orientation that is exactly the way the assembly process expects them. This is a totally different task from the positioning of parts. If a part has been positioned that means that it has been isolated and presented to a device that will add it to the assembly.Some of the more common types of feeding devices include vibratory bowls. These a re one of the most popular for the feeding of smaller parts. Parts are cascaded down spiraling grooves on the side of the bowl as the parts are positioned to be fed into the assembly process. Since there are a great variation in the types and sizes of parts that can be fed through vibrating bowls there is a great variation in the configuration of these bowls. It will be necessary to make sure that the configuration and the speed of delivery of the bowl meets the needs of the manufacturer. The bowl will need to be set up to the exact specifications of the parts to be fed. If parts are not oriented correctly as they are fed into the assembly process, they will be rejected by falling to bottom of the bowl, then fed into the process again.Inline tracks are also a very common feeders of small parts to the assembly. This type of feeding is done when parts are oriented in single file into a straight line slide or moving belt, so that only one part is presented at the end of the bel t to the assembly or other process. It is not uncommon for the vibratory bowl and the inline feeder to work in together to get parts to the operation that requires the individual parts. The vibrating bowl will get each part in an orientation so that each one can be moved into the inline feeding line, usually on a straight belt to the next process. The rate of feeding of parts with both these methods must be very high because the number of parts that are rejected from the process is high. The number of parts arriving at the next stage of assembly must be adequate enough to keep the cycle time of the assembly line at it required rate. The parts being moved by both these methods must be substantial, the parts cannot be susceptible to being easily broken or scratched. If so these methods of material handling will not be acceptable.Gravity feeders are ideal for the material handling movement of tubular shaped parts to assembly. Adding vibration to a gravity feeder keeps any of th e parts from being hung up in the process of going to assembly. If the track where the parts are fed can only have one part to occupy one space in the track then this can be a very high speed operation.Material handling is the process that supplies all the parts to an assembly line so that products can be constructed to specification.
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