EP0114114A1

EP0114114A1 - Apparatus for collecting debris

Info

Publication number: EP0114114A1
Application number: EP19840300247
Authority: EP
Inventors: Brian Henning
Original assignee: Black and Decker Inc
Current assignee: Black and Decker Inc
Priority date: 1983-01-18
Filing date: 1984-01-16
Publication date: 1984-07-25
Also published as: DE3474104D1; EP0114114B1

Abstract

A debris collecting apparatus includes a debris conduit (2) one end of which is an operating end (4) and the other end of which is a collecting end with a collecting bag (6) attached thereto. An impeller (8) discharges air into a straight part of the conduit. A switch arrangement is provided to switch the air flow between first «vacuum» flow in which air discharged from the impeller induces an air flow in the debris conduit (2) from the operating end (4) to the collecting end and a second «blow- ing» flow in which air is discharged from the impeller through the operating end.

Description

This invention relates to a debris collecting apparatus, and in particular, but not exclusively, an apparatus for collecting garden debris, of the kind which may be used either in a vacuum mode to suck debris into the apparatus or in a blowing mode to discharge a stream of air from a nozzle so that debris can be blown into piles.
Such debris collecting apparatus is already known. In one such apparatus, a centrifugal impeller is used to blow air through an outlet to which, in the blowing mode, a length of pipe is connected. To operate the apparatus in the vacuum mode, the pipe is disconnected from the outlet of the impeller and connected to its central inlet; in this mode, debris passes through the impeller which will inevitably result in wear to the impeller even though a chopping blade may be mounted on the impeller shaft immediately upstream of the impeller.
In another form of apparatus, air is discharged longitudinally in a jet into the centre of a first tube at a location where a second tube is joined at right angles. In the vacuum mode of the device, air is drawn from the second tube into the first by the jet of air; debris is sucked into an open end of the second tube and passes from there into the first tube to a collecting bag. In the blowing mode, the first tube is closed downstream of the junction with the first tube so that the air discharged into the first tube is forced to travel up the second tube and is blown out of its open end. This apparatus avoids the problem of passing debris through the impeller but there is a danger of debris becoming stuck as it passes from the second tube into the first in the vacuum mode. The very nature of garden rubbish including long thin objects such as twigs makes this is a real problem.
It is an object of the invention to provide an improved form of debris collector that can be operated in the vacuum or blowing mode.
According to the invention, there is provided a debris collecting apparatus including a debris conduit one end of which is an operating end and the other end of which is a collecting end, an impeller arranged to discharge air into the conduit in a region where the conduit is devoid of any sudden and substantial change in direction, a switch arrangement to switch the air flow between a first "vacuum" flow in which the air discharged from the impeller induces an air flow in the debris conduit from the operating end to the collecting end and a second "blowing" flow in which air is discharged from _I the impeller through the operating end.
An arrangement of this kind has the advantage that while it is still possible to use the apparatus either as a vacuum device or as a blower, the debris conduit can be designed without any corners or obstructions where debris might become trapped.
Preferably air is discharged into the conduit from the side with a component of its flow towards the collection end of the conduit. Introducing the air flow from the side of the conduit does not impede the passage of debris along the conduit. The air may be discharged through one or more openings in the side of the conduit; if desired the air may be discharged into the conduit in a ring around the whole of the conduit.
The debris conduit is preferably substantially inflexible and substantially straight in the region where air is discharged into the conduit and preferably along its whole length. Flexibility is undesirable as any bend in the debris conduit can result in twigs or other objects being stuck in the conduit.
The impeller may be a cross flow fan and may be driven by an electric motor.
In one embodiment of the invention a debris collector in the form of a collecting bag is removably connected to the collecting end of the conduit and the switch arrangement is held in the "blowing" flow position when the collecting bag is detached from the collecting end of the apparatus.
The switch arrangement may comprise a valve member which is inoperative in a first position corresponding to "vacuum" flow but which when switched to a second position corresponding to "blowing" flow blocks the debris conduit between a point at which air is discharged into the conduit and the collecting end. The valve member may be located in the discharge region and may be shaped to direct the air discharged into the conduit towards the operating end. This improves the efficiency of the apparatus in the blowing mode.
Alternatively, the switch arrangement may comprise an air flow guide movable between a first position corresponding to "vacuum" flow in which the air discharged from the impeller induces an air flow in the debris conduit from the operating end to the collecting end and a second position corresponding to "blowing" flow in which air is discharged from the impeller through the air flow guide into the conduit and is diverted by the guide to flow towards the operating end of the conduit.
The air flow guide may comprise one or more vanes carried on a member slidably mounted in the conduit wall.
In an embodiment to be described the conduit wall has an opening through which air is discharged into the conduit by the impeller. In its first position, the air flow guide leaves the opening substantially unblocked but in its second position the vanes are located in the opening. In an advantageous arrangement, in its first position, a part of the air flow guide is arranged to guide air discharged into the debris conduit.
According to another aspect of the invention, there is provided a debris collecting apparatus including a debris conduit one end of which is an operating end and the other end of which is a collecting end, an impeller arranged to discharge air into the conduit, an air flow guide movable between a first position corresponding to "vacuum" flow in which the air discharged from the impeller induces an air flow in the debris conduit from the operating end to the collecting end and a second position corresponding to "blowing" flow in which air is discharged from the impeller through the air flow guide into the conduit and is diverted by the guide to flow towards the operating end of the conduit.
By way of example, an embodiment of the invention will now be described with reference to the accompanying drawings, of which:

Fig. 1 is a side view, mainly in section,of a debris collecting apparatus embodying the invention,
Fig. 2 is a sectional view in the direction of the arrows II-II in Fig. 1,
Fig. 3 is a sectional view in the direction of the arrows III-III in Fig. 1,
Fig. 4 is a sectional side view of part of another form of debris collecting apparatus embodying the invention,
Fig. 5 is a side view of a vane assembly that may be employed in the apparatus of Fig. 4,
Fig. 6 is a plan view of the vane assembly of Fig. 5, and
Fig. 7 is a perspective view of the debris collecting apparatus of Fig. 1.

The debris collecting apparatus 1 shown in Figs. 1, 2, 3 and 7 is principally intended for collecting garden debris and has a debris conduit 2 of generally rectangular cross-section to one end of which is detachably connected a tube 3 having an operating end 4 and to the other end of which is detachably connected a diffuser 5 having a collecting bag 6 attached thereto. The tube 3 and diffuser 5 may be detachably connected to the conduit 2 by any suitable means, for example by screw threads.
A housing 7 to the side of the debris conduit is lined with acoustic foam and houses a cross flow fan 8 driven by a motor 28 housed in a motor casing 9. A subsidiary air inlet to the fan housing from the motor casing 9 is provided by an aperture 10 and a main air inlet (not shown) is provided in the fan housing approximately opposite the aperture 10. The fan has an outlet 11 through which air is directed into the conduit 2 at an angle of about 30° thereto.
The motor casing 9, which is secured to the fan housing, has a motor compartment 12 in which the motor 28 (and also, if desired, a motor cooling fan) is located. The motor armature shaft passes through a bearing 13 at the end of the motor casing and carries the fan 8 at its free end. As can be seen in Fig. 2, the end of the motor compartment adjacent the fan housing is surrounded by an annular air passage 14 which communicates with the motor compartment through slots 15 in the compartment wall. The air passage 14 in turn is connected to the fan housing through the aperture 10. At the opposite end of the motor compartment to the slots 15, air inlet slots 16 are provided.
A handle 17 is fixed to the motor compartment and carries an electric switch 18 for controlling the operation of the apparatus which is powered from the mains supply via a cable (not shown).
The fan 8 is in this particular example a double sided cross-flow fan having twenty blades, indicated by reference numeral 19 on each side.
The collecting bag 6 has an open mesh construction but over the side of the bag which in use lies against a user's body, the bag is rendered impermeable by the provision of a plastics sheet. The bottom of the bag is openable to enable collected debris to be emptied from the bag; the bottom of the bag may for example be open and a resilient strip of 'C' shaped cross-section provided to close the bag.
A valve member 20 is pivotally mounted on a pivot 27 in the side wall of the debris conduit 2 adjacent to the outlet 11 of the fan; the valve member 20 is movable between the position shown in solid outline in Fig. 1 to that shown in dotted outline and movement of the valve member is controlled by an actuating lever 21 mounted on a pivot 22 and connected to the valve member 20 by a link 23 pivotally connected at each end. A tension spring 24 biases the lever 21 to the position shown in Fig. 1.
An 'L' shaped member 25 is slidably mounted in a slot in the debris conduit 2 and is biased to the left (as seen in Fig. 1) by a compression spring 26, but with the diffuser 5 and bag 6 connected it is held in the postionshown in Fig. 1. In this position, the member 25 defines the rest position of the actuating lever 21 by virtue of its abutment therewith; if, however, the diffuser 5 is removed the member 25 slides to the left under the bias of the spring 26 and engagement of the member 25 with the lever 21 rotates the valve member 20 into the position shown in dotted outline in Fig. 1.
In operation, with the diffuser 5 attached, the lever 21 in its rest position and the switch 18 depressed to actuate the motor, the fan 8 which rotates clockwise as seen in Fig. 1, draws air through the main air inlet and also through the motor compartment and discharges the air through the outlet 11 into the debris conduit 2. The discharge of air induces a flow of air along the debris conduit from the operating end 4. The user holds the apparatus by the handle 17 with the tube 3 inclined downwardly (a position which the apparatus naturally adopts) and moves the operating end 4 over areas from which debris is to be collected.. The debris passes into the conduit through the end 4 and then has a straight and uninterrupted passage into the collecting bag 6.
If the user wishes to use the device in the blowing mode, he merely depresses the free end of the lever 21 thereby rotating the lever and moving the valve member 20 into the position shown in dotted outline. In this position, air discharged through the outlet 11 is turned and directed along the tube 3 and out through the operating end 4. The valve member is positioned so that it defines an extension of the outlet 11 and is curved to assist in the re-directing of the air discharged from the fan.
As already described, when the diffuser 5 and collecting bag 6 are removed, the apparatus can only be used in the blowing mode so that there is no risk of a user being struck by debris flying out of the debris conduit 2.
In the illustrated embodiment the debris conduit is of rectangular cross-section but, alternatively, the conduit may be of circular cross-section.
Fig. 4 shows a modified form of the apparatus of Fig. 1. The description of this embodiment will be confined largely to the features not present in the apparatus of Fig. 1 and it should be understood that the various alternatives described in relation to Fig. 1 are also applicable to the apparatus of Fig. 4. Similar parts are designated by the same reference numerals in Figs. 1 and 4.
The main feature of the embodiment of Fig. 4 is the use of an air flow guide 30 to control the direction of air flow in the conduit 2 in place of the valve member 20. The air flow guide 30 comprises a wedge shaped part 31 and a vane assembly 32 and is integrally formed. with an actuating member 33, with an opening 34 provided between the member 33 and part 31.
The guide 30 is slidably mounted on the top of the debris conduit and the actuating member 33 carries a mounting for one end of a tension spring 54, the other end of which is anchored to the housing 7. A leaf spring 35 stressed between the top face of the actuating member 33 and an opposing face of the housing 7 presses the actuating member 33 downwards and, in the position shown in Fig. 4, the member 33 is held in position with the spring 34 tensioned by engagement of a pip 36 on the actuating member with a rib 37 on the end of the diffuser 5.
The vane assembly 32 is made up of a series of vanes 39 between which passageways 40 are provided. It will be seen that the passageways 40 turn through an angle of the order of 90° in passing through the vane assembly 32.
With the apparatus in the position shown in Fig. 4, it operates in the vacuum mode in substantially the same way as the apparatus of Fig.I. Thus air is discharged by the fan 8 in the direction of the arrows through the opening 34 and outlet 11 and the discharge of air induces a flow of air along the debris conduit from the operating end 4. The assembly 32 is housed in a recess in the housing 7 and does not affect the air flow although the wedge shaped part 31 does guide the discharge of air into the conduit.
In order to operate the apparatus in the blowing mode, a user lifts the free end of the actuating member 33 against the bias of the leaf spring 35 thereby disengaging the pip 36 from the peripheral rib 37. The actuating member then moves out from the housing under the bias of the tension spring 34 to its limit position in which the vane assembly 32 is located over the outlet 11 and the opening 34 lies over a closed part of the housing 7. In this position, air is discharged by the fan 8 in the direction of the arrows and passes through the passageways 40 in the vane assembly where it is turned and directed into the conduit 2 towards the operating end 4.
It will be seen that if the user removes the diffuser 5 and associated collecting bag, the rib 37 is removed so that the apparatus will always operate in the blowing mode. This makes the apparatus particularly safe as it is not possible to use it accidentally in the vacuum mode without the diffuser and associated collecting bag in place.
The arrangement described above with reference to Fig. 4 has certain advantages. In both the vacuum and blowing modes of the apparatus, the debris conduit is able to provide smooth boundary walls thereby reducing to a minimum the risk of the conduit being blocked. The arrangement can be used on ducts of different shapes and sizes so that, if desired, a duct of relatively large cross-section can be used thus reducing again the likelihood of blockages.
Figs. 5 and 6 show an alternative form of vane assembly 42 that may be used in the apparatus. The assembly 42 is made up of a central web 43 from each side of which vanes 44 extend. Passageways 45 are provided between adjacent vanes and these turn through an angle of about 150° from one end to the other. With this vane assembly the fan is arranged to discharge air at an angle of about 15° to the longitudinal axis of the debris conduit. The angle of entry of air into the conduit can be selected by experiment to give the optimum performance for the particular shape of debris conduit employed.

Claims

1. A debris'collecting apparatus including a debris conduit one end of which is an operating end and the other end of which is a collecting end, an impeller arranged to discharge air into the conduit in a region where the conduit is devoid of any sudden and substantial change in direction, a switch arrangement to switch the air flow betwen a first "vacuum" flow in which the air discharged from the impeller induces an air flow in the debris conduit from the operating end to the collecting end and a second "blowing" flow in which air is discharged from the impeller through the operating end.

2. An apparatus according to claim 1 in which one or more openings are provided in the side of the conduit for discharging air into the conduit from the side.

3. An apparatus according to claim 1 or 2 in which the debris conduit is substantially inflexible in said discharge region.

4. An apparatus according to claim 3 in which the debris conduit is substantially inflexible along its length.

5. An apparatus according to claim 3 or 4 in which the debris conduit is substantially straight in said discharge region.

6. An apparatus according to claim 5 in which the debris conduit is substantially straight along its length.

7. An apparatus according to any preceding claim in which the impeller is a cross-flow fan.

8. An apparatus according to any preceding claim further including a debris collector removably connected to the collecting end of the conduit, in which the switch arrangement is held in the "blowing" flow position when the collecting bag is detached from the collecting end of the conduit.

9. An apparatus according to any preceding claim in which the switch arrangement comprises a valve member which is inoperative in a first position corresponding to "vacuum" flow but which, when switched to a second position corresponding to "blowing" flow blocks the debris conduit between a point at which air is discharged into the conduit and the collecting end.

10. An apparatus according to claim 9 in which the valve member is located in the discharge region and is shaped to direct the air discharged into the conduit towards the operating end.

11. An apparatus according to any of claims 1 to 8 in which the switch arrangement comprises an air flow guide movable between a first position corresponding to "vacuum" flow in which the air discharged from the impeller induces an air flow in the debris conduit from the operating end to the collecting end and a second position corresponding to "blowing" flow in which air is discharged from the impeller through the air flow guide into the conduit and is diverted by the guide to flow towards the operating end of the conduit.

12. An apparatus according to claim 11 in which the air flow guide comprises one or more vanes carried on a member slidably mounted in the conduit wall.

13. An apparatus according to claim 12 in which the conduit wall has an opening for discharging air into the conduit, in which the air flow guide leaves the opening substantially unblocked in its first position, and in which the vanes of the air flow guide are located in the opening in the second position of the guide.

14. An apparatus according to claim 13 in which, in its first position, a part of the air flow guide is arranged to guide air discharged into the debris conduit.

15. A debris collecting apparatus including a debris conduit one end of which is an operating end and the other end of which is a collecting end, an impeller arranged to discharge air into the conduit, an air flow guide movable between a first position corresponding to "vacuum" flow in which the air discharged from the impeller induces an air flow in the debris conduit from the operating end to the collecting end and a second position corresponding to "blowing" flow in which air is discharged from the impeller through the air flow guide into the conduit and is diverted by the guide to flow towards the operating end of the conduit.