A collection device having a duct for transporting material entrained in a stream of pressurized primary air from a collection mouth at an upstream end of the duct to a downstream region of the duct for collection. The device provides at least one primary air inlet opening into the duct for delivering pressurized air to form a primary air stream directed generally downstream of the duct and at least one secondary air outlet for delivering pressurized air to form a secondary air stream directed onto an area of the surface confronting the collection mouth. The secondary air stream serves to dislodge material on the confronting area for entrainment in the primary air stream and transportation from the collection mouth to the downstream region of the duct for collection.

A clean fan debris collecting apparatus is disclosed in which the suction of debris is performed by an entrained stream of air (34). The apparatus comprises a motor (24) which drives an impeller (20) which generates at air steam which is directed down an air supply duct (6). The air stream is then directed into a collecting duct (4) through an air inlet (8) which is located adjacent to a collecting mouth (5) of the collecting duct. The air stream, upon entering the collecting duct (4) generates the entrained stream of air (34) which sucks debris into the collecting mouth (5) and transports it up the collecting duct (4) to a collecting bag (30). An air stream dispersing apparatus (26) is located adjacent to the air inlet (8) to disperse the air stream as it enters to collecting duct (4). This dispersion improves the efficiency with which the entrained stream of air can be generated. Alternatively the air inlet (8) can be formed to include the static air dispersing apparatus.

This invention relates to an apparatus for collecting debris including grass cuttings, vegetation, fallen leaves and other rubbish frequently encountered on gardens, public highways and parklands. In particular, the apparatus for collecting debris from a surface includes a collection duct having a mouth for receiving debris and an outlet through which debris is discharged into a receptacle, an impeller for establishing a flow of pressure air along the duct for collecting and conveying entrained debris therealong from the mouth to the outlet of the collection duct to the receptacle, and a cutting chamber including a cutting blade or cutting line disposed within the cutting chamber for reducing the size of at least a portion of the collected debris to be discharged into the receptacle.

A debris blowing apparatus with a motor, a fan driven by the motor, an inlet to the fan and an air outlet from the fan. A portion of the air which is emitted through the outlet is recycled through a metering aperture into the air inlet to maintain a constant load on fan whilst varying the air output.

With one or several pressure streams projected at an acute angle (.alpha.) in relation to the surface to be processed, shearing forces can be reached that are high enough to move solid particles and/or fluid media and thus make it easier to suck them away. The recognition of this fact is used in a delivery/suction nozzle arrangement together with the per se known Coanda effect. The invention may be used with all fluid media, preferably for cleaning practicable and passage surfaces; also for drying and/or degassing surfaces, as well as for industrial processes, in particular substance separation processes.