| 摘要 |
<p>The mechanism is able to maintain a constant rate of spreading per unit area irrespective of the speed of the carrying vehicle. this is achieved by arranging the pressure (P) at the discharge nozzles (11) to be governed by the pressure in a second supervisor pressure circuit linked to a wheel (25) moving with the vehicle. The supervisor pressure, obtained in a piston and cylinder device (30, 13) and derived by an adjustable pulley and cranking mechanism (26, 28, 29, 30, 34) is compared in a two chamber cylinder (21, 22) with the discharge pump (2) outlet pressure and the difference made to control a butterfly valve (36) in a pressure shunting chamber which governs the flow rate in the main supply pipe (4) from the reservoir (1). The device allows pressure control using bleed nozzles (19) and incorporates several variations.</p> |
