Lifting Door with Built-in Fail-Safe Mechanism
Open sesame... – new Lifting-Door System for individually constructed Enclosure Guard Systems.
Where a machine guard needs to be opened to allow access at regular intervals to a machine process, Lifting Doors are a popular solution - They take up little space, and when well designed are easy to operate, providing a solid barrier between operator and process.
Machine Building Systems now offers specially designed products to facilitate the construction of such equipment using the tried-and-tested Item MB Building Kit System. Lifting Doors with widths of up to 2m and a weight of up to 35kg can be accommodated in the new guide profiles. The door itself is guided by means of specially designed bearings which use tensioned-spring rollers to compensate for tolerances and heat expansion, and prevent jamming or canting of the door frame in the guides. The ball-bearing mounted rollers are spray-coated with a noise-reducing plastic surface to ensure very quiet, low-friction running and long durability.
The Lifting Door can be powered or opened manually, and the force required to raise it is remarkably low thanks to the sophisticated counterweight mechanism. The guided counterweights are linked to the Lifting Door by chains which run in completely covered ducts – which prevents injury to hands from moving components.
Counterbalanced lifting doors are frequently found in applications with cycle times as low as a few seconds, making millions of operations per year a very real possibility. This leads to wear and tear that can - and has -resulted in a very unwelcome event: that of sudden and unpredictable failure of the counterweight linkage system causing the door to drop uncontrollably. For this reason, Item has included a major safety feature in this new system. The door can be equipped with a gravity brake on both sides. In the unlikely event of a chain failing, this simple and effective spring-loaded eccentric brake system will trigger, instantly locking the door frame in its guides and preventing the door moving downwards.
And since the components are made by item, it goes without saying that all the components making up the new Lifting Door System are fully integrated in the modular MB Building Kit System. The Guide Profiles have line 8 system grooves on the outer sides which enables the door to be easily connected to other guard components. The grooves also provide universal fitting opportunities for any attachments such as other safety elements.