GB2304383A

GB2304383A - Appliances for cleaning floors or other surfaces by the application of liquid

Info

Publication number: GB2304383A
Application number: GB9516714A
Authority: GB
Inventors: Nicholas James Fletcher
Original assignee: Vax Ltd
Current assignee: Vax Ltd
Priority date: 1995-08-15
Filing date: 1995-08-15
Publication date: 1997-03-19
Also published as: GB9516714D0

Abstract

A floor cleaning appliance in which a cleaning solution is delivered from a storage tank (10) to a cleaning head (11) by means of a pump (12) in a pipe line (14,15) extending between the tank and the cleaning head is provided with a float chamber (16) connected in the pipeline (14,15). An associated float-operated switch (18) is connected in a supply circuit (19) to an electric motor (13) which drives the pump (12). The float-operated switch (18) is arranged to de-energise the motor (13) when the cleaning liquid is used up, and the float chamber (16) is preferably arranged upstream of the pump (12). The pump may be of the reciprocating piston kind.

Description

Title: "Appliances for cleaning floors or other surfaces by the application of liquid thereto." Description of the invention This invention relates to appliances for cleaning floors or other surfaces by the application of liquid thereto, and in particular concerns such appliances of the kind in which liquid is delivered from a reservoir by means of a power-operated pump.

Such appliances may serve to deliver a cleaning solution to any appropriate form of cleaning head, which may include static or power-driven brushes and/or a suction chamber for picking up such liquid and drying the floor or other surface to which it is applied for cleaning purposes.

Various different kinds of electrically driven pump may be employed for delivering the liquid from the reservoir, but these are often susceptible to damage if they are operated for excessive periods of time when the reservoir is empty or liquid is not being delivered for any other reason.

This is not always obvious to the user, particularly where the appliance is of the kind which includes a suction head which picks up the liquid shortly after it has been applied to the floor or other surface.

There have been various proposals for ensuring that the pump does not run when dry, but none of these have been entirely satisfactory. For example, in some cases a float valve has been provided in the reservoir with contacts which open to interrupt the supply of electricity to a motor which drives the pump, but this arrangement has the disadvantage of requiring a releasable electric connection to be established where, as is usually the case, the reservoir is removable for the purposes of cleaning and refilling. To avoid this requirement, use of contactless signal transmission devices has been proposed, but such devices tend to be unacceptably expensive for such applications.

The object of the invention is to provide an appliance of the kind in which a liquid is delivered by means of an electrically energised pump along a liquid flow passageway from a reservoir to an applicator head, having means to prevent the pump running continuously when dry.

In accordance with the invention a float chamber is provided in the liquid flow passageway at some point between the outlet of the reservoir and the cleaning head, and the flow chamber contains a float-operated switch which is connected in the electricity supply to the pump motor so that the motor is deenergised when the float chamber is empty.

Most conveniently, the float chamber is provided in a section of the flow passageway between the outlet of the reservoir and the inlet of pump, but alternatively the float chamber could be provided in a part of the passageway between the pump and the applicator head, in the former case preferably close to the reservoir and in the latter case preferably close to the pump.

To enable the pump to be primed, a manual override button may be provided, whereby a pair of normally open contacts can be held closed by the user for a period of time sufficient to draw liquid from the reservoir sufficient to fill the float chamber and establish an independent electrical connection to the pump motor.

One embodiment of the invention is illustrated in the accompanying drawing by way of example.

As shown, liquid from a reservoir 10 is supplied to a cleaning head 11 by means of a pump 12, which may be of the reciprocating piston kind, driven by an associated electric motor 13. An inlet tube 14 extends from the interior of the reservoir 10 to the inlet side of the pump 12, and a further, outlet tube 15 extends from the outlet side of the pump 12 to the cleaning head 11.

In accordance with the invention a float chamber 16 is connected in the inlet tube 14. A float 17 within the chamber is arranged to operate the contacts of a switch 18 which is connected in the wiring 19 associated with the pump motor 13. A manual override switch 20 is connected electrically in parallel with the switch 18.

To begin the delivery of liquid from the reservoir 10 to the cleaning head 11, the button 20 is pressed so as to energise the motor 13 to drive the pump 12, with the result that liquid is drawn through inlet tube and into the float chamber 16. As the chamber 16 fills, the float 17 rises and closes the contacts of the associated switch 18, whereupon the manual switch 20 may be released. The motor 13 continues to operate so that liquid can be delivered to the head 11 until the reservoir 10 becomes empty. At that stage, as the float chamber is emptied by continuing operation of the pump 12, the float 17 drops, opening the contacts of the switch 18 to de-energise the motor 13.

Whilst the float chamber 16 as illustrated is a structurally separate unit connected in the inlet hose 14, it could be formed integrally with a closure cap 10a through which the tube is taken from the interior of the reservoir, or it could be integrated with the pump 12. Indeed both the float chamber 16 and the pump could be mounted on the closure cap 10a. However, it is generally preferred for the pump and the float chamber to be disposed at a position somewhat remote from the reservoir 10 in order to facilitate the removal of the latter for re-filling.

In an alternative arrangement, the float chamber may be provided in the outlet tube 15.

The features disclosed in the foregoing description, or the accompanying drawing, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, may, separately or in any combination of such features, be utilised for realising the invention in diverse forms thereof.

Claims

CLAIMS:

1. An appliance of the kind in which a liquid is delivered by means of an electrically energised pump along a liquid flow passageway from a reservoir to an applicator head, wherein a float chamber is provided in the liquid flow passageway at some point between the outlet of the reservoir and the cleaning head, and the flow chamber contains a float-operated switch which is connected in the electricity supply to the pump motor so that the motor is de-energised when the float chamber is empty to prevent the pump running continuously when dry.

2. An appliance according to Claim 1 wherein the float chamber is provided in a section of the flow passageway between the outlet of the reservoir and the inlet of pump.

3. An appliance according to Claim 1 wherein the float chamber is provided in a part of the passageway between the pump and the applicator head.

4. An appliance according to any one of the proceeding claims wherein to enable the pump to be primed, a manual override button is provided, whereby a pair of normally open contacts can be held closed by the user for a period of time sufficient to draw liquid from the reservoir sufficient to fill the float chamber and establish an independent electrical connection to the pump motor.