Fasteners splice heavily loaded belts

A Flexco (Flexible Steel Lacing Company) product story

Edited by the Engineeringtalk editorial team Aug 7, 2003

The latest addition to the Flexco SR scalloped-edge rivet-hinged conveyor belt fastener system features a high-strength eight-rivet attachment.

Flexco RAR8, the latest addition to the Flexco SR scalloped-edge rivet-hinged conveyor belt fastener system, features a high-strength eight-rivet attachment anticipating the need for reliable splicing on longer, wider, more heavily loaded belts.

Designed for longer life on higher-tension belts with mechanical fastener ratings up to 1500PIW (263kN/m), these fasteners also offer the advantages of RustAlloy, a low-chrome stainless-steel alloy from Flexco that provides superior resistance to corrosion and wear resulting from acidic mine water, abrasive fines and chemical attack.

Developed as a step up from RAR6 five-rivet fasteners recommended for 1000 and 1200PIW conveyor applications, RAR8 fasteners will fit the same belt thickness range, from 10.5 to l7mm, and will wrap smoothly around the same minimum end-pulley diameter of 145mm under full-rated tension.

The SR fastener design grips the belt end between top and bottom plates, approximately 38mm wide and joined at one end by two wide hinge loops.

Each fastener segment is secured to the belt end with a hammer-driven, self-setting rivet attachment technique pioneered by Flexco to simplify installation and shorten downtime.

The patented scalloped edge design, recently introduced as an improvement to Flexco SR fasteners, results in a lower profile splice that passes more smoothly under belt cleaners and skirt boards.

Visibly different from other fasteners, the scalloped edge design features leading/trailing edges formed into a concave, scalloped shape with more-prominent edge coining (bevelling).

These features allow the fastener plate ends to embed deeper into the belt cover with less effort, reducing splice height even on belts with top covers too thin to allow skiving (countersinking).

Other features of scalloped edge design help assure proper installation.

Fasteners are supplied in continuous strips that provide uniform spacing and alignment across the belt.

Each fastener top plate contains a viewport, which allows the installer to see that the belt end is properly butted against a belt stop formed into the fastener's bottom plate.

By allowing visual confirmation, the viewport promotes accurate, uniform positioning across the squared belt end, which produces a straighter splice that results in longer splice life and a truer-tracking belt.

Fastener strips for RAR8 are offered in five lengths to suit standard belt widths of 1200, 1350, 1500, 1800 and 2130mm.

Strips are formed with breakaway bridges between fasteners, which allow any number of fasteners to be broken off by hand to trim the strip to any nonstandard belt width.

These easily separable connections also let RAR8 splices conform automatically to troughing idlers on first pass.

A strip of fasteners is installed on both belt ends, then the belt ends are brought together so the hinge loops mesh, and a hinge pin is inserted to lock the loops together into a hinged joint.

While the RAR8 can use any hinge pin currently offered for R6 fasteners, the pin recommended for RAR8 is Flexco's ACS6 10mm-diameter bare armoured 300 Series cable.

The RAR8 fastener is installed with one of five different rivet lengths, determined by belt thickness.

Manufactured of Type 409 stainless steel, the rivets are pre-assembled with special breakaway pilot nails that penetrate the belt without damaging or weakening the belt carcass.

Because the rivets are self-setting, they install easily from the top of the belt.

This method speeds and simplifies the installation process and reduces downtime by avoiding the time-consuming hole-punching and nut/bolt assembly required with some plate-type fasteners.

This high-strength SR rivet attachment technique pioneered by Flexco needs only a portable installation tool and a hammer.

The installation tool holds the belt end and fastener strip in precise alignment while the rivets are driven in.

The same hammer blows that set the rivets also compress the fastener plates into the belt cover.