Screws are accurately positioned on the screwdriver

One of the main issues related to automated assembly of components is the precise feeding of the assembly components. Regardless of whether you are assembling extremely small screws or larger hexagon nuts - their availability on time and accurately positioned for the assembly process determines the productivity of a system. 30 years of experience in feeding technology for automatic feeding of screws, rivets, bolts, nuts, washers, O-rings, symmetrical and non-symmetrical components, form the basis for new developments guaranteeing nothing but the highest precision and reliability. Valuable additions to the wide assortment of feeding technology, tailormade to customer requirements, are to be introduced by the automation expert DEPRAG SCHULZ GMBH u. CO. at this year's MOTEK fair in Stuttgart.

The "6" Series program of vibratory bowl feeders for handheld screwdrivers will now be extended by a new size. In addition to the previous filling capacities of 0.15 l, 0.75 l and 2.5 l, a feed bowl with a capacity of 1.2 l now complements the standard range. Sales manager Jürgen Hierold explains: ''This feeder reflects the demands of our customers for whom the 0.75 l bowl was too small. The next larger 2.5 l bowl, however, was too large for this group of customers and therefore not cost-effective''. With the new feeder DEPRAG covers the gap. Jürgen Hierold underlines: "The new 1.2 l solution accurately satisfies the demand of these customers ".

The new 1.2 l feeder includes all the advantages of the new generation of screw feeders. In particular, the self-regulation of the vibration amplitude in the feed bowl (automatically responding to the actual bowl fill level) makes DEPRAG's Series 6 especially valuable for a rationalized assembly. Differences in feed rate can create problems with work flow. In this instance the continuously fluctuating volume of parts in the feed bowl and the consequent change in mass, lead to variations in the feed rate of the parts. As a result the components are not presented to the assembly point in sync with the tempo of the operator or machine sequence normally requiring a manual adjustment of the bowl vibration frequency.

The vibratory bowl feeder technology uses an oscillation magnet with alternating current, a spring assembly, and a built-in regulator to transport the screws along the bowl spiral via micro-throwing motions. If the bowl contains a large quantity of screws, then higher vibration amplitude must be applied to achieve a constant flow of parts. Ideally, the vibration amplitude should adapt to the changing mass in the vibratory bowl. Jürgen Hierold explains: "Otherwise, when the bowl is low in on parts, the remaining material would be subject to higher vibration leading to sporadic and unpredictable behaviour, ultimately affecting the feed rate." All in all, the DEPRAG Series 6 has now achieved what the industry has long been looking for: self-regulation independent of the bowl fill level. Both the high functionality and process reliability of the advanced feeders result from the innovation of a sensor mounted to the vibratory bowl which registers the vibration amplitude. This feature in conjunction with the series 6 controller allows the feeder to regulate itself. Sales manager Jürgen Hierold is convinced that "The screw Series 6 feeders will always insure that the parts or screws are presented for assembly at the correct feed rate."

In manual screw assembly the DEPRAG Series 6 feed system offers another novel advantage. The screw feeder can be adapted to the individual pace of the worker. An RFID-Interface-System (Radio Frequency Identification) enables up to 10 workers to log-in to the controller with an operator chip. Once the worker's operating parameters (operating tempo, feed rate etc.) are stored via the easy to use controller interface, it can be automatically retrieved at shift change using the individual ID tag. More importantly, the user feels more comfortable with the equipment contributing to a more comfortable, efficient working environment (A.K.A.: efficiency grows with acceptance).

For stationary applications DEPRAG has also added bowl feeders with a capacity of 1.2 l to their standard program. Here, feeders specifically designed for screws in the range M1-M20 shaft diameter, and with a shaft length of 5 mm to 130 mm are presently available (previously, the fill volume of the feed bowls on offer were 0.15 l, 0.75 l, 2.5 l and 6 l and 12 l). Now, the product range is completed by the 1.2 l feeder, which, of course, is also equipped with the self-regulating control of the vibration amplitude.

A completely new feeder for stationary assembly has also been developed. It can serialize miniature screws the size of a pin head.
The innovative DEPRAG 0.05 l vibratory bowl feeder enables a controlled feeding of hitherto problematic miniature parts. The piezo drive employed ensures the finest vibrations of the bowl with a frequency regulation of 60 to 400 Hz. Sales manager Jürgen Hierold stresses: "This extremely fine technique permits an adjustable feed rate with high accuracy. No little screw steps out of line.

This enables the precise feeding of even the smallest parts the size of a grain of rice." Ideally, the advanced feeding system serves to feed mini-screws with high accuracy to the where they can be assembled by the new NANOMAT Screwdriver- an innovative screwdriving tool for micro-assemblies. Jürgen Hierold explains: "Increasing technological miniaturization causes major issues in production. We are able to eliminate these problems now by means of our new Nano screwdriver and the complementing feeding technology."