Components for conveying

Fortunately, products that have been specifically developed to meet the needs of the mechanical handling sector are giving designers the options they need to address these challenges conveniently and cost-effectively.

Typical of these innovative products are rodless pneumatic cylinders, which offer powerful yet precise movements yet are compact and self contained so easy to fit.

These devices achieve big space savings by integrating the guiding and cylinder profiles, thereby eliminating the need for a separate guiding profile. It is important to note that this approach allows the size and weight of the guide to be reduced without compromising durability or load capacity. However for heavy duty applications, bolt-on guide units ensure optimal performance and maximum service life.

The best rodless cylinders, such as the Origa, incorporate features such as integrated grease nipples for ease of re-lubrication, and wiper elements in the guide carriage to remove contamination from the slides and to ensure that the slide surfaces are continually lubricated. For signalling purposes, magnetic pistons are fitted as standard and compact position sensors may be directly mounted in the cylinder profile without the need for additional fittings or brackets.

While these integrated guides are ideal for the vast majority of applications, in those cases where very high loads and operating speeds are involved, it may be preferable to use roller guides. Units of this type can be expected to incorporate precision ground hardened steel guide tracks, together with low friction rollers supported on needle bearings. This combination will provide smooth low-noise operation and excellent dynamic characteristics.

There are occasions when pneumatic actuation is not appropriate, so an electric drive alternative has to be considered. Origa, for instance, offers a full range of such units which are completely compatible with the pneumatic cylinders. For even higher loads, especially where high levels of precision are required, re-circulating ball bearing guides are also worth considering. In transfer applications the size, mass and speed of conveyed product can vary considerably which will directly and significantly affect the loads and moments transmitted to the guidance system, hence careful consideration of the appropriate guidance system is critical to ensure reliable and trouble-free operation.

Very common requirements in mechanical handling systems are accumulation, holding and sequencing, and a popular solution in all of these cases is the use of pneumatically operated blade stops. Given the arduous duty cycles to which many of these stops are subjected, an essential feature to look out for is robust construction. Ease of installation is another important attribute, and stops with fully integrated guidance, sensing and control functions are to be preferred.

Since blade stops are used in a wide variety of applications, versatility is another key issue engineered bespoke ranges offering different sizes, formats and mounting options. In some applications, it may also be necessary to select stops that can be installed in multiple sets, so that, for example, work-pieces of different sizes on a conveyor can be stopped at slightly different positions: the Origa blade stop unit for this reason can be readily assembled into multiple sets that can accommodate stop positions at single roller intervals.

In spite of their many applications, blade stops have one shortcoming – they cannot be used to provide smooth controlled stopping of the work-piece. Where this is needed, as it may be, for example, when handling delicate and easily damaged or very heavy items, stop cylinders are the preferred choice.

A new range from Parker-Origa features integrated hydraulic shock absorbers, these versatile products provide damped braking for even the heaviest of work-pieces, bringing them safely to a stop, and eliminating the risk of rebound. Stop cylinders can also be used to hold work-pieces securely in place after they have been brought to a stop.

The integrated shock absorbers are interchangeable, so that the operation of the stop can be tailored quickly and conveniently to match the requirements of the application. Another useful feature is a convenient method of releasing the stop manually without the need for tools, as this is an invaluable aid to maintenance and fault finding.

Another frequent requirement in mechanical handling systems is to centralise the work-piece on a conveyor, so that, for example, labels can be affixed in a consistent position. While it is perfectly possible to achieve centralisation with a combination of conventional pushers and guides, a much neater and more convenient option is offered by dedicated bi-parted belt-driven actuators.

Available in electrically and pneumatically driven versions, these gently push the work-piece from the appropriate side until it is accurately centred on the conveyor. An essential feature in many applications is an integrated force control mechanism to ensure that the work-piece cannot be crushed between the pusher plates.

These innovative components for mechanical handling and conveying systems, making life easier for designers, and offers them the potential to provide end users with installations that satisfy their ever increasing expectations for performance and reliability.