“QUARRY KING” Single Idler Belt Scale

For outdoor conveyor weighing of dusty fines and “stone like” aggregate materials where rugged construction and spill-proof/jam-proof suspension design are the most essential attribute. Working in combination with Thayer Scale’s proven “Rocking Flexure” fulcrums is a completely new “pipestem” single idler suspension system incorporating built-in storage means for its calibration weight (no test chains required).

This combination of unique elements provides important advantages for neglected-maintenance operations where ongoing dust build-up and spilled aggregates are known to foul conventional suspension designs. Applications include troughed belt conveyors of 14-48” belt widths (Series 1RF-3A for 14”, 18”, 24”, 30”; Series 1RF-4A for 36”, 42”, 48” belt widths) operating at speeds up to 600 fpm and inclines up to 18 degrees.

The “Quarry King” suspension system is fabricated from slim flat metal elements (carbon steel standard, stainless steel optional) which are precision laser cut from sheet stock and welded to, and branch outwardly from, a centrally positioned tubular “spine” shaft running axially to the conveyor and directly under the center line of the belting. These elements, two of which support the weigh idler, lie in a vertical plane so as to eliminate tare build up areas. There are no structural elements running parallel to and in close proximity with the conveyor side stringers as in conventional designs to trap and hold aggregate material spilling from the edge of the belting.

The suspension system is longitudinally restrained and pivoted at the in-feed (approach) end on Thayer Scale’s proprietary RF Fulcrum arrangement, while the downstream end is supported from a single NTEP certified strain gauge load cell loaded in pure tension, protected from effects of all extraneous lateral forces (belt tension, friction, torsion,etc.). A key advantage is that the load cell can be quickly and easily removed and replaced without disturbing the weigh idler itself, thereby eliminating the tedious task is re-setting and aligning the idler, and conducting another material test upon re-commissioning. The non-weighed Bridge Element that supports the load cell also includes the supporting brackets for storing the Test Weight which can be easily moved to its “calibration” position on the suspension system whenever desired.

BELT TRAVEL PULSER
Accurate belt speed measurement requires the use of a precision wheel in contact with the tension side of the belt in the area where the scale is located. The Thayer belt travel pulser assembly includes a precision cast/machined wheel with a “pre-calibrated” circumferential tolerance of ± 0.05%, has provisions to maintain constant pressure against the belt under all operating conditions, and is self-steering to avoid slip errors.

Heavy Duty Construction
Spring loaded to maintain positive tracking
Self-cleaning
Minimum surface area for material build-up
Located underneath belt-not affected by spillage
Easy to install
True Speed Measurement
Unaffected by temperature and voltage variations.