GB2359985A

GB2359985A - Flow regulation mechanism for leaf blowing and suction apparatus

Info

Publication number: GB2359985A
Application number: GB0105422A
Authority: GB
Inventors: Velo Federico
Original assignee: VALEX SpA
Current assignee: VALEX SpA
Priority date: 2000-03-10
Filing date: 2001-03-06
Publication date: 2001-09-12
Also published as: FR2806109A3; FR2806109B3; GB0105422D0; ITTV20000010U1; IT251708Y1; DE20104080U1

Abstract

Flow regulation mechanism for leaf blowing and suction machines comprising a valve that intercepts the blowing channel (21, 22) and operates in conjunction with a shut-off device which shuts off a mouth to leaf collection means such as a bag or hopper. The regulation valve, which may consist of a hinged partition, allows the intensity during the blowing mode to be controlled and also allows switching between blowing and suction modes. Also disclosed is such a device comprising an electric motor and a fan with blades to effect blowing or vacuum. A leaf-grinding mechanism may also be incorporated.

Description

2359985 1 FLOW REGULATION MECHANISM AND LEAF BLOWING AND SUCTION APPARATUS

The present invention relates to a flow regulation mechanism and leaf blowing and suction apparatus.

The invention has particular, but not necessarily exclusive, application in 10 the sector involved in the manufacture of portable, usually electric, devices used for gardening and for the cleaning of park areas in general.

The object of this invention is a flow regulation mechanism, used particularly for leaf blowing and suction apparatus and similarly manufactured apparatus.

BACKGROUND ART

For those people involved in gardening, whether as a hobby or for professional reasons, the fact that leaves fall to the ground all year round, or at least a part of it according to the type of vegetation in question, is quite a problem.

Apart from the visual aspect of the leaves on the ground which suggests a certain lack of care, the removal of the leaves is necessary to promote the growth and spread of grass. This operation tends to be quite tedious for most people, because until recently certain tools were required, initially simple garden rakes which were later replaced by wide-angled fan-type rakes. These tools are used manually to collect the leaves into heaps, which are then picked-up by hand or by means of another tool, and transferred into large rubbish sacks.

2 The operation described above, if carried out on small areas and not too frequently, may be quite a simple task. However, if the area to be cleaned is large and there are a number of plants that shed their leaves, without a doubt the operation becomes extremely tiring, and more often than not the 5 use of specialised personnel is required.

In order to overcome this and other difficulties, special apparatus known as leaf-blowers have appeared on the market. They are usually portable and have:

- a drive means, usually electric; - a blowing and sucking means with a blade-type fan joined to the motor in order to create a flow of air in a screw-type chamber, and a tube with one or more passages to channel the air generated by the fan and convey the leaves collected, with an opening at the end to connect it to the said chamber; - a mechanism to switch-over from the blowing function to the suction function; - a means to collect the leaves collected which is made up of a removable sack; - if foreseen, a mechanism to grind-up the leaves collected.

The leaf-blowers designed in this way are conceived, therefore, to operate in a double way, blowing and suction. In detail, they initially create a flow of air that moves the leaves, so that the operator may collect the leaves into heaps. After this operation, by means of the switch-over mechanism, the operator switches to the suction mode to suck up the leaves previously collected into heaps. During the phase in which the heaps of leaves are formed, the operation is made easier by the large flow-rate of air that is generated and the speed at which the air is blown. This means that a large number of leaves may be moved very quickly. Following this operation, it is necessary to form the leaves into heaps, 3 and to do this the power of the airflow must obviously be lower, that is at a lower speed, in order to avoid spreading the leaves around the ground again.

STATE OF THE ART The companies involved in this sector have tried to solve the problem regarding the air-flow by following two routes. The first one involves acting upon the rotation speed of the motor, therefore on the flowrate generated by the fan attached to it. The mechanisms used in this case are of the electric or electronic type and have typical drawbacks, such as the reliability of the components used and the wiring circuits, the amount of protection against electric shock and the complex manufacturing involved, all of which lead to a higher cost. The alternative route has been followed by other companies, and involves the use of mechanical devices. These devices tend to convey the entire flow-rate generated by the fan into blowing channels.

Amongst this type, the leaf-blower manufactured by Bosch is well known. This, system, similarly to the other systems, consists basically of a tubular attachment which acts as a rigid extension, and which is divided internally into various channels with different diameters separated by a partition. From the mouth side, into which the air generated by the drive unit is conveyed, there is a valve that the operator manipulates externally in order to vary the operation mode from blowing to suction and two types of blowing, fast and slow. In this way, with the same amount of air generated, the speed of the air will be lower if it is channelled into the tube with the larger diameter, to create the blowing conditions required to accumulate the heaps of leaves before they are sucked up. On the other hand, under the same air generation conditions, if the air is channelled into the second blowing channel with the smaller diameter, the air flow 4 will be faster and more concentrated, the condition required to blow the leaves toward and into a given point.

in fact there This system of flow-deviation valve mentioned above is not the only one, is a well-known system proposed by Ryobi. This system has basically a cylindrical valve positioned inside the chamber in which the blowing and suction channel enters and is close to the access mouth for the sack used to collect the leaves. If this valve is rotated in one direction it closes the said mouth, causing the air generated to go towards the blowing channel, in order to switch the operating mode of the apparatus from the suction mode to the blowing mode. The suction mode is switched in by means of electrical devices that are controlled by the operator, and that act upon the rotation speed of the motor and, finally, on the amount of air generated by the fan attached to the shaft of the motor.

DRAWBACKS The first proposal mentioned, apart from the complex nature regarding its structure, leads to only a moderate variation on the speed of the air generated, which means that the air-blowing mode is not very practical. With the second case, on the other hand, electrical andlor electronic components are required in order to give the aforementioned mode, which are costly to buy and install.

If these considerations are taken into account, it is easy to imagine how important it is to find alternative solutions.

One of the aims of this invention is to overcome the aforementioned drawbacks.

SUMMARY OF THE INVENTION

This and other aims are achieved with the invention by means of a flowregulation mechanism for leaf blower and suction machines, which includes: an electric drive unit; a blowing and suction means including a fan with blades, attached to the motor to generate the required air flow and an extension to a number of ducts connected to a chamber, in order to channel the flow of air generated by the fan, and to convey the flow sucked up along with the 10 leaves collected; a means to deviate the flow of air generated by the fan, or to vary the intensity during the blowing mode, positioned upstream of the ducts; a mechanism to switch over from the suction mode to the blowing mode; is - collection means for the leaves sucked up; if foreseen, a mechanism to grind-up the leaves collected.

The said device for deviating the air flow generated by the fan and to vary the intensity during the blowing phase, comprises a regulation valve positioned at the mouth of the blowing channel. The said valve operates in conjunction with a shut-off device in order to shut off the mouth that proceeds the leaf-collection means.

ADVANTAGES In this way, through the creative contribution that has the effect of constituting an immediate technical progress, various advantages are achieved.

The first advantage is that this type of mechanism allows the operator to control the amount and speed of the air according to requirements that, 6 generated by the fan, flows out from the chamber towards the outside through a blowing channel.

The second advantage regards the structural aspect of the mechanism, giving a flow-regulation device that is extremely practical and reliable that requires only simple maintenance care.

Another advantage is that, thanks to this mechanism, the apparatus is very safe because, at least for this part, there are no electric or electronic components and, what is more, it is not in contact with moving parts or other dangerous items.

A further advantage, again regarding the structural aspect of the mechanism, is that the output of the apparatus is not altered, and it may be made out of plastics materials which are lighter and more economical. This helps to reduce its overall size and weight and to lower the manufacturing costs with obvious advantages for the production process at an industrial level.

These and other advantages, with the aid of the included drawings, will be outlined in the following detailed description of typical uses of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a complete, three-dimensional view of a leaf blowing and suction apparatus.

Fig. 2 is a cut-away side view of the leaf blowing and suction apparatus illustrated in Fig. 1, showing a mechanism for flow deviation and blowing intensity variation of air generated by a fan, 7 where the said mechanism is shown in a certain flow-modulation setting.

Fig. 3 shows a cut-away three-dimensional view of the leaf blowing and suction apparatus illustrated in Fig. 1, showing the mechanism for the flow deviation and blowing intensity variation of the air generated by the fan in another flow-modulation setting.

DESCRIPTION OF AN EMBODIMENT EXAMPLE

With reference to the above Figures, an apparatus for gardening purposes (A), in particular a leaf blowing and suction machine, is made up of a body (1) where a drive system is positioned on the inside (not shown).

The said drive system, for example an electric motor, generates a flow of air (fl, f2) that may be regulated according to the requirements of the operator, and may be used for either suction (f 1) or for blowing (f2). In the first case, the flow of air (f 1) uses a channel (21) made up of a rigid extension (2) fixed tightly to the body (1), with a mouth-part on one end to suck-up the leaves from the ground, and an exit part at the other end (210) which connects it to a chamber (3) inside the said body. The said chamber (3) has a bottom part (31) with an opening (32, 33) connected to a collection sack below (not shown) for the leaves thus collected. In this case, the opening (32) is intercepted by a partition (4) hinged on at least one side (41) along the walls of the body (1). This part may take up two positions as shown in Figs. 3 and 2, the first one in a position to seal- off the opening (32) and a second position that, when rotated, seals off the entrance (51) to a seating (5) that is positioned before the mouth of a second channel (22) adjacent to the chamber Q). Regarding the said channel (22), in this case it is parallel and adjacent to the channel (21) and is an integral part of the extension tube (2) which is a part of the body (1) of the machine.

8 Inside the said seating (5) there is a regulation valve (6) made from a cylindrical tube with opposite facing openings (61, 62) on the side walls. The said openings (61, 62) are geometrically formed in correspondence with the position of the opening (33) and of the mouth (220) that leads to the channel (22) in order to permit a complete range of regulation positions, with the valve (6) having a rotation of a maximum of 180'. The regulation valve (6) rotates Pn a horizontal axis (al) by turning of an external hand-wheel. In this way, the regulation valve (6) is positioned upstream of the blowing channel (22), which is part of the rigid extension (2), and is separated from the suction channel (21) by a partition (7). In the part below the regulation valve (6), there is an opening (33) which, by means of the regulation valve (6) in an operational position, connects the seating (5) and chamber (3) to the collection sack positioned below.

Under operational conditions, when the operator positions the partition (4) as shown in Fig. 2, the leaves sucked-up along the suction channel (21) of the extension (2), because of the vacuum effect generated by the fan connected to the motor, are fed directly to the collection sack in direction (fl). It is clear, therefore, that when the partition (4) is rotated, it seals-off the entrance (51) to the seating (5) where the regulation valve (6) is hinged, completely excluding it.

Vice versa, by acting upon the relative switch-over mechanism, the partition (4), as shown in Fig. 3, rotates and seals-off the opening (32) positioned before the collection sack joined to the bottom part of the body (1). Under these conditions, the entire air-flow generated by the fan is conveyed to the entrance (51) to the seating (5), and crosses the opening (61) of the regulation valve (6). According to the rotation angle at which the operator positions the valve (6) by means of the hand-wheel on the outside of the body (1), there is the simultaneous positioning of the opening (62) opposite the mouth (220) of the blowing channel (22). As a 9 result, the airflow (C) is completely intercepted when the opening (62) coincides peripherally with the mouth (220) of the blowing channel (22).

In order to reduce the blowing action, the regulation valve (6) has to be rotated in an anti-clockwise direction. In this way, the opening (62) is more or less in line with respect to the mouth (220) of the blowing channel (22), and blocks-off a certain portion. Therefore, while a part of the air generated by the fan, a reduced amount in this case, continues along the channel (22), the other part 0) is deviated in the collection sack positioned below, through the opening (33) on the bottom of the body (1). Under the conditions thus described, the blowing action of the machine is reduced because of the reduced flow-rate through the channel (22). The speed parameter is also reduced because of the continuous section of the exit. channel (22). It is evident, therefore, that the modulation of the blowing action foreseen for this apparatus (A) is carried out by rotating the external hand-wheel of the regulation valve (6) into one of the intermediate positions, between all the air generated conveyed through the channel (22) (maximum blowing action) and all the air generated conveyed through the opening (33) (minimum blowing action). In the latter case, the flow of air sent to the collection sack positioned below is released into the atmosphere due to the permeability of the sack itself, while only a small part flows along the channel (22).

Claims

1. Flow regulation mechanism for leaf blowing and suction machines, in which there is a regulation valve that intercepts a blowing channel upstream thereof and operates in conjunction with a shut-off device in order to shut off a mouth to leaf-collection means.

2. Flow regulation mechanism according to claim 1, wherein the regulation valve rotates on an axis through a rotational angle of not more than 180'

3. Flow regulation mechanism according to claim 1 or claim 2 wherein the regulation valve comprises a cylindrical tube with openings geometrically formed in correspondence with the position of an opening and of a mouth that leads to the blowing channel.

4. Flow regulation mechanism according to claim 3, having a body in which is a seating positioned before the mouth of the blowing channel and adjacent to a connecting chamber, the seating having the opening on one side that connects it to leaf-collection means and is used also to house and fix the regulation valve.

5. Flow regulation mechanism according to claim 4 wherein the connecting chamber communicates with an air-suction channel and has an opening which connects it with leaf-collection means and which is intercepted by the shutoff device.

6. Flow regulation mechanism according to claim 5 wherein the shutoff device is a hinged partition which in one rotated position closes-off access to the seating where the regulation valve is housed and fixed, completely cutting off the seating.

11

7. Flow regulation mechanism according to any preceding claim, wherein modulation of the blowing action which can be obtained is provided by rotation of an external hand-wheel of the regulation valve to set the regulation valve into one or more intermediate positions between all the air generated being conveyed through the blowing channel (maximum blow ing action) and all the air generated being conveyed through the opening (minimum blowing action).

8. Leaf blowing and suction apparatus comprising: 10 - an electric drive unit; - a blowing and suction means including a fan with blades attached to the drive unit to generate the required air flow and an extension to a number of ducts connected to a chamber, in order to channel the flow of air generated by the fan, and to convey the flow sucked up along with leaves 15 collected in use of the apparatus; - deviation means to deviate the flow of air generated by the fan, or to vary the intensity during the blowing mode, positioned upstream of the ducts; - a mechanism to switch over from the suction mode to the blowing mode; 20 - leaf collection means for the leaves sucked up; - if foreseen, a mechanism to grind-up the leaves collected; and wherein the deviation means comprises a regulation valve positioned at a mouth of a blowing channel connected to the chamber, the regulation valve working in conjunction with a shut-off means at the chamber which 25 blocks-off the access to the leaf-collection means.

9. Leaf blowing and suction apparatus according to claim 8, which includes a body containing the drive unit and in which the path of the air flow during suction uses a suction channel that has a diameter larger than the blowing channel, the suction and blowing channels being provided in 12 a rigid extension fixed to the body and the blowing channel being separated from the suction channel by a partition.

10. Leaf blowing and suction apparatus according to claim 9, wherein the regulation valve is rotatable by means of a hand-wheel positioned on the outside of the body, and according to the rotation angle of the valve there is positioning of the opening of the regulation valve with respect to the mouth of the blowing channel resulting in a flow of air that is completely intercepted when the opening coincides peripherally with the mouth of the blowing channel, and a reduction in the blowing action when the valve opening is more or less out-of-line with respect to the mouth of the blowing channel, closing a part of it.

11. Leaf blowing and suction apparatus according to claim 9 or claim 10, wherein a reduced amount of the air generated by the fan continues along the blowing channel while the remainder of the air is deviated to the leaf collection means, through an opening in the body.

12. Flow regulation mechanism for leaf blowing and suction means substantially as described herein with reference to the accompanying drawings.

13. Leaf blowing and suction apparatus substantially as described herein with reference to the accompanying drawings.