The present invention relates to a conveyor system and in particular to a support system for a conveyor system which is adapted to facilitate simplified expansion or contraction of the length of the conveyor.
For many years conveyors have been utilised in underground mining and tunnel creation projects. The conveyors are usually of a type involving an endless belt system in which the belt moves in one direction when it is carrying whatever is being mined or removed with the belt returning in the opposite direction to the extremity when it changes from the return path to the load bearing path. An elaborate structure of load bearing and guide rollers must be established in order to define the belt path and to support both the weight of the belt and the weight of the payload. The rollers are typically supported on frames which are placed at discrete intervals and anchored in the underground tunnel by some means. The frames may rest upon the floor or alternatively may be hung by chains from a roof or brackets from a wall, or a combination of these in order to gain the requisite stability.
As underground mining or tunnelling operations progress it is necessary to lengthen or shorten the conveyor. For example, with long wall coal mining the main gate conveyors are continually being shortened after initial erection as the cutting apparatus at the coal face progresses back towards the trunk road. At the same time the trunk conveyor is typically being lengthened so as to accommodate further blocks to be mined.
Although loop take-up arrangements are available to facilitate lengthening or shortening of the belts associated with such conveyors by up to two hundred and fifty meter sections, the addition or removal of frames necessary to support the rollers associated with the conveyor system is a time consuming process. This process is also hazardous as the frames must be carried up and down the tunnels through which the conveyor passes, often whilst the conveyor is in operation. The erection and stripping down of the roller support frames is time consuming and results in down time for and damage to mining or tunnelling projects thereby resulting in considerable inefficiencies.
Accordingly the object of the present invention is to ameliorate one or more of the above-mentioned disadvantages associated with existing underground conveyor systems or alternatively to provide the market with an alternative conveyor system.
According to the present invention there is disclosed a support system for a conveyor comprising an overhead monorail of substantially closed form cross section pipe; carriages adapted to pass up and down the rail having load bearing, relative motion facilitating, low friction means adapted to run along one or more surfaces of the rail; hanging frames suspended from the carriages having guide and support rollers beneath their point of attachment with the carriages; the guide and support rollers being adapted to carry and guide an endless conveyor; means to slide the carriages and associated frames longitudinally along the rail so as to increase or decrease the spacing between adjacent frames and hence the length of the conveyor; means to attach the rail to an overhead support and means to lengthen or shorten the rail by adding or removing lengths of rail.
The term xe2x80x9csubstantially closed form cross section pipexe2x80x9d where used herein means a rail of a cross sectional view which is substantially closed in configuration unlike for example an I-beam but including a substantially box section rail as depicted in FIG. 10 hereof having a single continuous longitudinal slot which slot in cross-section appears as a small discontinuity in one side of the cross-sectional view.