The Joy Varitrough conveyor structure has been the most popular conveyor structure used for underground mining for decades. The variable trough concept was originally developed to enable good belt to roller surface contact in the unladen condition for effective belt tracking. The outer rollers in the trough sets incorporate an internal spring mechanism to allow the trough angle to vary depending on the load applied to the trough set
The stringer-to-support-frame connection is designed so the support frame remains perpendicular to the stringers allowing the structure to remain rigid. This also prevents the stringers from being misaligned which would create unequal load sharing on the idlers. The rigid stringer-to-support-frame connection also assists in maintaining alignment as the structure is installed.
A feature common to all Joy conveyor structure types is a focus on belt protection. This is achieved through careful selection of profiles and fixings along with engineered belt tracking control. In addition, Varitrough carry sets have two degrees of lead, enabling natural belt tracking.
In addition, consider the following features:
- Varitrough is quick and easy to assemble with legs and stringers connected to the support stand via cloven pins chained to the support stand.
- The carry trough sets have handles on the hooks for ease of assembly and removal.
- The support stand has a three-slot return roller outer bracket to enable easy tracking on return side of belt.
- The Vee return rollers have a shaft extension on the outside to assist in tracking.
- Optional roof brackets for support stand enabling the structure to be roof mounted
- Optional adjustable leg design for assembly onto an uneven base
- Optional diagonal bracing to provide added stiffness to the stringer/support frame connection
- Structure can be supplied with adjustable legs if required for floor mounting. These adjustable legs have been designed to ensure easy leg insertion/retraction.