Friday 9 January 09 - 02:52
 

Electro-mechanical

SP gets a grip on automation

To meet growing demand for its wire joining and tensioning devices, Gripple invested in its first fully automated assembly machine from SP Technology in 2005. The success of this project has ensured an ongoing working relationship between the two companies, with SP now supplying further machines to the Sheffield-based manufacturer.

SP’s latest machine for Gripple
SP’s latest machine for Gripple

SPs latest machine for Gripple, which incorporates Weiss Indexing Ring Technology, provides a highly flexible solution to the assembly of the four main components which together make an industrial wire hanger. The machine produces three product variants, each of which has unique dimensional characteristics for the pin and wire components. This presented a number of unusual design challenges to SP, not least the handling and manipulation of the wire and the demanding final assembly tolerances on the part.

To provide the required flexibility and to maintain machine cycle time, dual wire feeding and coiling stations are used. The coiled wire is located in the machine nest, before being picked up by an ABB robot. The robot delicately threads the 2.0mm diameter wire into a 2.5mm diameter hole, prior to the wire being hydraulically crimped to the main body of the part. A subsequent pull test ensures that the crimping operation has been successful before further component parts are presented and added to the assembly.

The intricate final assembly operation requires a pin to be assembled to a precise depth and SP developed an innovative solution to this problem using a combination of a vision inspection system and a servo operated press. As the pins are presented for assembly, the vision system is used to establish a datum by measuring each individual pin before the pin insertion operation takes place. The servo press is then used to assemble the pin to the precise depth by using the measurement data provided by the vision system.

A major consideration for machine builders and end users alike, is a machines footprint. It is essential to strike a balance between the need to have the machine as compact as possible, whilst enabling easy access for operators and maintenance personnel. Weiss wase able to make a positive contribution to solving this dilema using a precision indexing ring. This not only helps to solve footprint and access issues, it also becomes the heart of the machine, transferring the components and sub-assemblies quickly and accurately between the various assembly and process stations.

www.sptechnology.co.uk

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Stevens Rowsell is a specialist precision sheet metal engineering company in East Sussex