Torque the right language
A patented conveying system prevents goods from being damaged, while specialised CAD software can design better systems. Dean Palmer reports
A conveyor may appear to be a simple piece of kit, but the latest systems are being developed with specific environments in mind.
Take the patented ‘Slip-Torque’ conveyor technology, which is not new but has spawned innovative conveyor products over the years. The technology, pioneered by Shuttleworth in 1972, is based on polished stainless steel shafts, individually powered by flexible belts on a line shaft or by a continuous chain. These shafts are covered with segmented, loose-fit rollers, which become the surface of the conveyor.
The weight of the product being conveyed – combined with the coefficient of friction between the shafts and the inside diameter of the rollers – provides the driving force. As the weight of the product increases, there is a corresponding increase in the driving force. As products stop, the segmented rollers beneath them also stop, creating low back-pressure accumulation and reducing damage to products.
‘Slip-Trak’ conveyors, a more recent development, use the ‘Slip-Torque’ principle in a novel way by sealing the Slip-Torque drive components. This makes standard Slip-Trak conveyors suitable for clean rooms up to Class 10, as well as other applications.
An open-bed version of Slip-Trak provides product edge drive with a fully open bed for optimal airflow. A separate line shaft drives each side of the conveyor and each, along with drive belts, bushings, and bushing holders, is fully enclosed in an evacuation chamber to eliminate airborne particulate contamination. The through-shaft version of Slip-Trak uses and encloses only one line shaft in an evacuation chamber along with drive belts, bushings and bushing holders. Products are edge-carried on segmented rollers and the balance of the bare stainless steel shafts extend across the width of the conveyor bed, with only minimal effects on clean room airflow.
A new class of Slip-Trak ‘CleanGlide1’ has been developed and certified for Class 1 clean rooms. CleanGlide1 has fewer surface components, minimising the disruption of laminar airflow through the surface of the conveyor. One of the noticeable features of the system is a ‘plenum’ to capture, evacuate and filter out any particles. Other nice features are the latest pneumatics and skirting to control the airflow. The system has soft product stops to meet critical vibration requirements and the complete system looks ideal for overhead transport.
Jan O’Connor, managing director of Shuttleworth’s UK distributor, Contax, commented: “Pharmaceutical and medical applications will benefit from this technology. These industries require the highest levels of cleanliness and especially careful product handling.”
To further assist designers of conveying systems, CAD-type software programmes are becoming increasingly popular. ‘CADmenu’ construction software from MiniTec, a UK supplier of machine building systems and conveyors, automatically calculates and specifies complete conveyor systems and generates a complete parts list of components to reduce design time and simplify purchasing for the customer.
MiniTec’s ‘Transfer System’ consists of standard modules that can be combined to create tailor-made solutions for component assembly, inspection stations and automated manufacturing systems. A number of system concepts are suggested in the company’s new catalogue, including basic loop, vertical and U-type circuits.
Specifying MiniTec’s machine building system is made easy with a choice of hard copy or PDF catalogues, an on-line e-catalogue, ICAD software for AutoCAD and CADmenu for other systems, or with the web-based i-CAD interactive software that allows customers to view, examine and download 2D or 3D CAD files for each component in the range and produce complete parts lists for simplified ordering.