Rivet rods & connector rods may be covered to reduce crop damage, or to increase rod diameter and so reduce rod gap clearance. Options are listed below in order of increased crop protection:
- Hard black LDPE tubing: Offers no crop cushioning protection, mainly used to increase rod diameter/reducing rod clearance.
- “Split type” LDPE: This is a lengthwise cut tubing, so may be fitted or removed later. Its friction fit permits a second layer of larger diameter. May be ordered cut to length or in coils.
- Rubber ‘cushion’ tubing: Fitted at time of manufacture. Undersized friction fit with a bonding agent if sprocket run clearways are needed. Without such clearways covering may be at, or greater than rod diameter. The latter increases cushioning effect. For covering joining rods, order cut to length or in coils.
- Plastic internal star profile: Fitted at time of manufacture. A soft plastic tube with goods cushioning effect, which improves when internal diameter need not be a friction fit on rods. For covering joining rods, order cut to length or coils.
- Rubber internal star profile: Same observations as for plastic type.
- PVC ‘Pillow Cushion’ tubing: Fitted at time of manufacture. Available either with friction fit to rods or with bonding agent. Internal cavities offer good crop drop protection, ideal for conveyors without sprocket run clearways. If they are needed, select a rod pitch & covering diameter combination representing an acceptable bare rod sprocket run clearance. Available cut to length or in coils.
- Bonded or vulcanized C-flex covering: Made at time of manufacture. Offers the highest possible level of crop drop & change of direction protection. The highly flexible upper C-profile remain clean of soil with good tear resistance. The bonded type is not subject to mold size, rod length, or rod crank limitations. An 11 mm rod is used for the vulcanized type in two or more traction belt applications. Some mold sizes also offer ‘Side Ear’ protection, which keep the crop from scrubbing against the machine’s stationary sides.
- Flexible rubber cover profile: Used for completely closed belts without gaps between the rods. Designed for high profile belt pitches or other profile types at 40 or 50 mm pitch, where no sprocket clearways are needed. These sections bridge over two pitches, reducing rod quantity and conveyor weight.
35 mm wide sprocket runs required for tooth drives of the types HS, RT, Z, NC, and 3TB. Rod covering may be full width between traction belting for types FR, FRD, KW and N. Rod clearance is determined by deducting external diameter from the rod pitch.