EP0599477A1

EP0599477A1 - Improvements in and relating to collection devices

Info

Publication number: EP0599477A1
Application number: EP93308364A
Authority: EP
Inventors: John Samuel Davies
Original assignee: Electrolux Outdoor Products Ltd
Current assignee: Husqvarna UK Ltd
Priority date: 1992-11-23
Filing date: 1993-10-20
Publication date: 1994-06-01
Also published as: GB9224582D0

Abstract

An apparatus for collecting material from a surface wherein the material to be collected is carried by pressurised air in a duct (D), and the duct (D) has an access port (2,3,4) for imparting energy to the stream of pressurised air in the duct (D). This lowers the pressure in the downstream region of the duct (D) and increases the suction in the duct (D).

Description

This invention relates to an apparatus for collecting material from a surface.
As well as vacuum cleaners collection devices are known which collect material by applying a stream of pressurised air to the material and carrying the material through a duct to a refuse receptacle. The material to be collected may, for example, be paper or leaves from streets, gardens, etc.
One disadvantage of known collection devices is that collection is effected by suction or by applying a stream of pressurised air. While both of these methods work, it would be an improvement to combine the two..
It is an object of the present invention to provide an apparatus for collecting material which has an improved collecting effect which has an improved collection performance resulting from an increased suction in the duct.
According to the present invention, an apparatus for collecting material from a surface comprises a duct for transporting material entrained in a stream of pressurised air from a collection mouth at an upstream end of the duct to a downstream region of the duct for collection;
at least one air inlet opening into the duct for delivering pressurized air to form a primary stream of air directed generally downstream at the duct; and
a source for generating the pressurised air and passing the air to the said at least one air inlet, characterised in that the duct includes an access port disposed downstream from the collection mouth and in that the apparatus includes a source for imparting energy to the stream of pressurised air in the duct via the access port thereby increasing the section in the duct.
According to one embodiment of the present invention, a first pressurised air stream is blown into the duct past a collection mouth. Material is carried into the duct with the pressurised air stream. The pressure in the duct is lowered by use of a secondary air stream applying suction downstream at the collection mouth.
According to another embodinment, the pressure in the duct is reduced by blowing the stream of secondary air into the duct in the downstream direction.
Embodiments of the present invention will now be described by way of example, with reference to the accompanying drawings:

Fig. 1 is a longitudinal section of the collection apparatus according to a first embodiment;
Fig. 2 is a longitudinal section of the collection apparatus according to a second embodiment.

Figure 1 shows the collection apparatus according to a first embodiment of the present invention in an operating position relative to a surface S from which material is to be collected. The surface S is drawn obliquely for reasons of clarity only.
The apparatus comprises a duct D, a plenum chamber P, a handle member H, a suction pump G and a collection receptacle CB. The suction pump G includes an impeller I and an electric motor M. An inlet opening 1 and a collection mouth CM are positioned at the upstream end of the duct D. An access port 2 and an outlet leading to the collection receptacle CB are positioned in the downstream region DS of the duct D.
In operation air is drawn into the suction pump G through pump inlets (not shown) and also through the access port 2. Air under pressure is directed into the plenum chamber P, as indicated by arrow PA. After passing through the inlet opening 1 pressurised air forms the first stream of pressurised air which picks up material disposed in the region of the collection mouth CM, and carries it into the duct D in the direction indicated by arrow DA.
In the downstream region DS of the duct D the stream of pressurised air is directed to a collection receptacle while a part of the first stream of pressurised air is sucked through the access port 2 into the suction pump G. This separated air stream forms a secondary stream of air which is sucked out of the downstream region DS of the duct D thereby producing a lowered pressure in the duct D.
The secondary air stream is sucked into the outlet region of the suction pump G (arrow A1) by the passage of the pressurised air from the suction pump G past the secondary stream of air. Furthermore, the secondary air stream can be urged into an inlet of the suction pump G (arrow A2), by the suction of the impeller I.
According to another embodiment, the stream of pressurised air passes out of the downstream end of the duct and directly into a closed collection receptacle where the collected material is deposited. The cleaned air is then sucked into the suction pump G. This causes a lowering of pressure in the duct, and therefore, increases the suction at the collection mouth of the apparatus.
Figure 2 shows an apparatus for collecting material according to a second embodiment of the invention. The common components in Fig. 1 and Fig. 2 are labelled with the same reference signs.
A stream of pressurized air carrying the material is directed through the duct D into the collection receptacle CB.
A stream of secondary pressurised air is directed from the positive pressure pump G into a portion of the duct D downstream of the collection mouth CM through an access port. This is shown by arrow A3. The secondary stream of pressurised air is directed into the duct D in a substantially downstream direction, thereby urging the primary stream of air in a downstream direction. This results in a decreased pressure in the duct and, therefore, increased suction at the collection mouth CM.
The access port may be formed with a lip to deflect a part of the pressurised air through the access port.
In another arrangement, the stream of secondary pressure air is directed into the collection receptacle CB, but it still has the same effect of lowering the pressure in the duct. This is shown by arrow A4.
The pressure pump G comprises one or more impellers which are driven by one or more electric motors The pressurised air is generated in one common chamber or more than one chamber, each chamber separated from the others. The pressurised air is directed to the plenum chamber P. In the second embodiment the pressurised air is directed to the access ports 3, 4, respectively.
It is apparent from the structure of both illustrated embodiments that it is possible to produce a collection apparatus according to a further embodiment which combines both embodiments. For example, the apparatus may include an access port 2 for directing the secondary stream of air between the duct and the pump and also an access port 4 for passing a stream of secondary air from the pump into the collection receptacle. Such a structure results in a further reduction in the pressure in the duct and, therefore, an improvement to the suction at the collection mouth CM.
The collection apparatus as illustrated is a movable device manually operable by a single person. It is apparent that the device of the present invention can also be used with a remote pump or with a remote collection receptacle.
Another embodiment may include a valve disposed within the access port for adjusting the secondary air stream. In some circumstances, it may be desirable for the user to close off the access port altogether.

Claims

Apparatus for collecting material from a surface, the apparatus comprising:
a duct for transporting material entrained in a stream of pressurised air from a collection mouth at an upstream end of the duct to a downstream region of the duct for collection; and
at least one air inlet opening into the duct for delivering pressurized air to form a primary air stream directed generally downstream of the duct;
a source for generating the pressurized air and passing the air to the said at least one air inlet, characterized in that the duct includes an access port disposed downstream from the collection mouth and in that the apparatus includes a source for imparting energy to the stream of pressurized air in the duct via the access port thereby increasing the suction in the duct.
Apparatus according to claim 1 characterized in that the source for imparting energy is a positive pressure pump for generating a stream of secondary pressure air.
Apparatus according to Claim 1 characterized in that the source for imparting energy is a suction pump connectable to the access port whereby a stream of secondary suction air applied to the access port increases the pressure of the stream of pressurized air in the duct.
Apparatus according to Claim 3 characterized in that a barrier element is positioned for preventing the passage through the port.
Apparatus according to Claim 1 characterized in that the access port opens in a generally downstream facing direction for allowing the passage of the secondary air stream into the duct.
Apparatus according to Claim 5 is characterized in that an outlet of the pump is connected to the access port for delivering the secondary air stream into the duct.