GB2224172A

GB2224172A - Suction cleaner with alarm and fault control

Info

Publication number: GB2224172A
Application number: GB8824488A
Authority: GB
Inventors: Jean-Claude Metral
Original assignee: HOOVER PLC
Current assignee: HOOVER PLC
Priority date: 1988-10-19
Filing date: 1988-10-19
Publication date: 1990-04-25
Anticipated expiration: 2008-10-19
Also published as: GB8824488D0; GB2224172B

Abstract

A vacuum cleaner has a suction wand (18), a flexible hose (14) connecting the wand to a main body (10) of the cleaner, and controls (36) on a hand grip (16) of the wand. A power nozzle (20) has a motor (42), powered by live and neutral lines (40, 34) extending along the hose. Fault detecting means, eg. microprocessor (30), determine when a fault condition is present and actuate a switch (54) in the live line to switch off the power nozzle motor (42) and the main fan motor (44). An audible alarm, for example a voide synthesis unit (56), indicates the fault to the user. The fault may be a blockage detected by sensing pressure or air flow. <IMAGE>

Description

SUCTION CLEANER The present invention relates to suction cleaners, and particularly to a cleaner having audible warning signals such as voice synthesis.

According to the present invention, a suction cleaner has fault detecting means, alarm control means arranged to actuate an audible alarm when the fault detecting means determines that a fault condition is present, and switch control means arranged to actuate switching means when the fault condition is present thereby switching off a motor of the cleaner.

The motor affected can either be the main suction (fan) motor or it could be a separate motor provided on a power nozzle of a canister cleaner. A power nozzle is a floor cleaning nozzle for connection to a canister cleaner whereby suction cleaning at the nozzle is enhanced by mechanical agitation of the surface being cleaned typically by a rotating brush arrangement powered by an electric motor located in the nozzle structure, such motor having a power supply from the cleaner body via electrical conductors integrated in the flexible suction tube. If a power nozzle is provided, however, it is desirable, for maximal audibility of the alarm, for the switching means to switch off both the main and the power nozzle motors.

Separate switching means could be provided for each motor, or alternatively each motor could have its own switching means, the two switching means being controlled by a common switch control means.

The switching means may be any convenient type of automatic semi-conductor or mechanical switch, for example a relay or a triac. In the latter case, suitable signals provided- to- a main motor contrallinq triac; (normalLy used to provide motor power con-trol) could. be used as the switching means.

To allow for different voltage levels between the switching means and the control means,; the two may be separated by isolating means such as an-opto coupler or a transformer.

It is preferred that the audible alarm comprises a speaker or other voice synthesising unit, controlled by a voice synthesis control means, for example, a conventional TSP 50 C43 chip.

For maximal flexibility, it is convenient for the switch control means to comprise a micro-processor the outputs of which are used both to actuate the switching means and also to control the voice synthesis control (where present). Alternatively, the switching could be effected by an output of the voice synthesis control.

The fault detecting means may then comprise the said micro-processor in combination with one or more detectors, for example pressure and/or flow detectors.

Thus, the audible alarm can be arranged to operate and the motor or motors switched off, when the micro processor and detectors determine that a "bag full" condition or a "blocked input" condition is present.

In cleaners of the type having controls mounted on a hand-grip attached to the upper end of the suction wand, i.e. remote from the body of the cleaner, it is best if the operation of the alarm and the consequent switching off of the motor does not cause disabling of the hand grip controls. Frequently, these hand grip controls impress control signals on a control line which passes down a flexible hose into the main body of the cleaner. A neutral line (connected with the mains neutral line) acts as the zero volt reference line.

In a preferred form of the invention, the switching means is positioned on the live side of the motor, desirably in a live power line which transmits mains power to a motor of a power nozzle. Although the switching means could be positioned in a common live power line, which also provides power to the main motor, it is in many ways desirable if the power nozzle motor and the main motor are switched off separately, the switching means for the main motor being the main motor power control means (for example a triac).

A current technical prejudice against switching the live line concerns potential differences on the circuit boards and their implications for reliability and safety. A triac connected in the live line is subject to voltages as high as 240V above or below the neutral line, whilst the control voltage on the triac is less than 10V. Hence there is a potential difference of 240V or more on the board in the immediate vicinity of the switching device.

On the other hand the voltage at the "neutral" side of the motor is never far above or below OV (owing to voltage drop across motor) and hence never greatly different from the switching device control voltage.

Conventional "conductor hoses" make use of three conductors. The problem of powering down the power nozzle motor whilst maintaining operation of the switch panel could be solved by adding an extra conductor, this separating neutral and OV reference. The present live line switching solution means that the established 3-conductor hose continues to be used for models with and without power nozzle. Thus the expense of new conductor hone, sockets, pIugs etc is avaided. The hose used-.in.the. present invention hasljust three conductors.

The present invention also extends to any one or more of the individual features described or mentioned in this specification, either taken alone or in any compatible combination.

The invention may be carried into practice in a number of ways and one specific embodiment and a number of modifications thereof will now be described, by way of example, with reference to the drawings, in which: Figure 1 is a diagrammatic representation of a suction cleaner; Figure 2 is a simplified circuit diagram for use in the cleaner of Figure 1; and Figure 3 is a modification of Figure 2.

Figure 1 shows a typical suction cleaner embodying the present invention. The cleaner comprises a cleaner body 10 incorporating a main suction fan (not shown) powered by external power lines 12. Extending from the body 10 is a tubular flexible hose 14 having, at its free end, a "petrol pump" - type hand grip 16.

Secured to this there is a rigid tubular-section wand 18, ending in a power driven suction nozzle 20.

Power to the suction nozzle 20 is provided from the cleaner body 10 along live and neutral power lines which pass along the hose 14, though the hand grip 16, and then extend adjacent the wand 18 within a cable 22.

The cable is conveniently clipped to the wand by resilient clips 24.

The hand grip 16 includes a control panel (not shown) having a number of switches by which the user can control certain functions of the cleaner, for example the suction power and the "power boost" function. There is also an on/off switch. Commands made by the user on the switch panel are transmitted to the cleaner body by a control line which extends along the length of the hose 14. The neutral line also serves as the zero volt reference for the controller.

Positioned on the main cleaner body 10 there is a speaker 26 (or other audio alarm device), the purpose of which is to give an audible indication of certain error or fault conditions, such as "bag full" or "hose blocked". In order for the warning to be easily heard by the user, however, it has been found desirable to switch off both the main cleaner motor and the power nozzle motor when the alarm is operating. The way in which this is achieved is illustrated in Figure 2.

Within the body of the cleaner 10 there is a DC supply unit 28 connected to the AC power lines 12 and arranged to supply a DC voltage to a micro-processor 30. Another input of the micro-processor is received along a control line 32, already mentioned, via the flexible hose 14 to the hand grip 16. The control line 32 is linked to the neutral line 34, again already mentioned, via a hand grip circuit 36. This circuit, which is conventional per se, is connected to the switch panel (not shown) of the hand grip, its purpose being to provide control signals along the control line 32 which the micro-processor 30 can interpret.

Also on the hand grip 16 is an on/off switch 38, actuation of which simultaneously cuts power within the live line 40 (again already mentioned) and the control line 32. This on/off switch can therefore be used to cut power to the power nozzle motor 42. Conveniently, the micro-processor 30 is also arranged to interpret an open control line 3Z-a-s an order to switch off the-main motor 44. The power nozzle motors can also be switched off, separately, by means of-a foot switch 46-on-the nozzle 20.

The main motor 44 is coupled between the live and neutral lines 40, 34, and is controlled by a triac or other motor control 48 by signals from the microprocessor 30.

The micro-processor 30 receives signals along lines 50 from detectors (not shown) on the cleaner which can indicate if an error condition is present.

These detectors might be, for example, pressure and/or air flow detectors which produce signals which the micro-processor interprets as an error if the bag is full or the air input to the cleaner is blocked.

When the micro-processor determines that an error is present, it sends a control signal to an opto coupler or transformer 52 which transmits it to a switch 54 in the live line 40. Actuation of this switch cuts the live line and consequently cuts out both the main motor 44 and the power nozzle motor 42.

The switch 54 is conveniently a triac Alternatively, a relay could be employed, in which case the opto coupler 52 could be dispensed with.

Simultaneously, the micro-processor 30 sends a signal to a voice synthesis control unit 56 which actuates a speaker 58 to provide an audible warning of the error condition. In another arrangement (not shown) the motor switching could be controlled by an output from the voice synthesis controller rather than directly from the microprocessor.

In an optional arrangement, the micro-processor contains a timer which is arranged to switch back on the switch 54 after a predetermined period provided that the error detected is not too serious.

One difficulty with the circuit shown in Figure 1 is that the switch 54 would need to be reasonably large to switch off both the main cleaner motor 44 and the power nozzle motor 42. This problem is overcome in the circuit of Figure 3 which will now be described.

In Figure 3, the components are identical to those in Figure 2 except that the switch 54 has been repositioned on the far side of the main motor 44 from the AC mains lines 12. This has the advantage that when an error is detected by the micro-processor, the switch 54' is required only to cut power to the power nozzle motor 42, and not to the main motor 54. The cutting out of the main motor 44 is effected by a suitable control signal from the micro-processor to the main motor control 48.

In another embodiment of this invention (not illustrated) the cleaner has a power nozzle 20 but no separate switch panel on the hand grip 16, all control of the cleaner being effected by controls on the main cleaner body 10. In this arrangement the power nozzle 20 is powered from a power take off socket on the cleaner body. This simplifies matters considerably since no problem is experienced in using a switching device (for example a triac or relay) to cut the neutral line to the power nozzle when the microprocessor determines that an error condition is present. It will be appreciated, of course, that the solution of cutting the neutral power line when a fault is detected cannot be used with the circuits of Figures 2 and 3 since cutting of this line would disable the hand grip controls.

Claims

CLAIMS'

1. A suction cleaner having fault detecting means, alarm control means arranged to actuate an audible alarm when the fault detecting means determines that a fault condition is present, and switch control means arranged to actuate switching means when the fault condition is detected thereby switching off a motor of the cleaner.

2. A suction cleaner as claimed in Claim 1 in which the motor switched off is a main fan motor of the cleaner.

3. A suction cleaner as claimed in Claim 1 in which the cleaner has a main fan motor and a separate power nozzle motor, the motor switched off being the power nozzle motor.

4. A suction cleaner as claimed in Claim 3 in which the switching means are also arranged to switch off the main fan motor when the fault condition is present.

5. A suction cleaner as claimed in any one of the preceding claims in which the switch control means is electrically isolated from the switching means.

6. A suction cleaner as claimed in Claim 5 including an optocoupler between the switch control means and the switching means.

7. A suction cleaner as claimed in any one of the preceding claims in which the audible alarm comprises a voice-synthesising unit.

8. A suction cleaner as claimed in any one of the preceding claims in which the switch control means comprises a microprocessor, outputs of the microprocessor controlling the switch control means and the alarm control means.

9. A suction cleaner as claimed in any one of the preceding claims in which the fault detecting means includes a pressure or flow detector.

10. A suction cleaner as claimed in any one of the preceding claims of the type having a suction wand, a flexible suction hose connecting the wand to a main body of the cleaner and cleaner controls on a hand grip of the wand, the controls being connected between neutral and control lines extending along the hose.

11. A suction cleaner as claimed in Claim 1O in which the switching means are positioned in a live power line extending along the hose.

12. A suction cleaner as claimed in Claim 11 when dependent upon Claim 3, in which the live power line provides power to the power nozzle motor.

13. A suction cleaner as claimed in Claim 11 or Claim 12 in which the switching means are positioned in the live power line between a mains power input and the live side of the main fan motor.

14. A suction cleaner~ as claimed-in--Claim 12 infflwhich the switching means includes power nozzle switching means positioned in the mains power line between a live side of the main fan motor and a live side of the power nozzle motors and main fan motor switching means arranged to switch off the main fan motor when the fault condition is detected.

15. A suction cleaner as claimed in Claim 11 in which the flexible hose carries exactly three electrical lines, and no more: the live and neutral power lines and the control line.

16. A suction cleaner substantally as specifically described with reference to Figures 2, or to Figure 3.