Grit spreader for motor vehicles

Grit spreader for motor vehicles for spreading gritting material in front of a wheel of the vehicle, under the control of the operator of the vehicle, comprising

• a supply container for gritting material having a supply outlet,
• a housing defining a closed dispersion channel divided by an intermediate transition portion thereof into a first section extending generally horizontally and joined with the supply outlet, and a second section forming a continuation of the first section at the transition portion and extending generally downwardly therefrom to a spreader outlet which is adapted to be located adjacent a wheel of the vehicle for spreading gritting material in front of the wheel,
• and endless conveyor disposed on a pair of deflection pulleys in the first section, including an upstream supply pulley adjacent the supply outlet, and a downstream discharge pulley at the transition portion and overlying the second section, each pulley having an upper deflection part and a lower deflection part,
• the conveyor defining an upper conveying run and a lower return run extending between an upstream conveying supply end at the supply pulley and a downstream conveyor discharge end at the discharge pulley, in which the upper run is separated from the lower run and positioned to receive gritting material from the supply outlet and to convey such gritting material to the discharge end while maintaining the gritting material out of contact with the lower run,
• a plurality of spaced apart successive transverse webs provided on the conveyor to define a continuous line of successive individual chambers between corresponding pairs of successive webs, such that each chamber is formed between a leading web and a trailing web,
• a conveyor drive unit arranged to drive the conveyor for conveying the upper run towards the discharge end,
• closure means for closing the spreader outlet, including a closure flap operated by a linkage for moving the flap to close the spreader outlet, and a flap drive unit for driving the linkage for moving the flap, and
• a follow-up control, for operation while the conveyor drive unit is driving the conveyor and in response to the vehicle operator initiated shut off of the conveyor drive unit, for delaying the actual stopping of the conveyor drive unit until the next successive web reaches the adjacent upper deflection part ot the discharge pulley, whereby to assure complete discharge of the gritting material from the downstream chamber thereahead and retention of the gritting material in the next successive chamber, and in turn for further operation to cause the flap drive unit to drive the linkage for moving the flap to close the spreader outlet upon the stopping of the conveyor drive unit.