GB2067603A - Washing machine suspension - Google Patents

Abstract

A front loader type of washing machine provided with at least two spring suspension units (3) which support the drum unit (1) from the bottom of the outer frame or casing (2), has means for restraining the top of the drum unit comprising a substantially non-extensible cord, cable or like element (4), arranged to extend freely through a guide (6) at the top of the drum unit and connected at opposite ends to the front and rear of the outer frame or casing above the guide, with the rear connection incorporating a spring (8) so that the non-extensible element (4) provides resilient support for the top of the drum unit, and a stop (7) located on the element at a position between the guide and the spring so as to limit the extent of movement of the cord through the guide on displacement of the drum unit relative to the outer frame or casing. A single cord (4) passing through a control guide (6), Fig. 1, or a pair of cords passing through either respective spaced guides, Fig. 3 (not shown), or a single control guide, Fig. 4 (not shown), may be provided. <IMAGE>

Description

SPECIFICATION Washing machine suspension This invention relates to washing machines of the kind which incorporate an assembly comprising a container for liquid in an outer frame or casing, and a clothes drum mounted for rotation within the container about a substantially horizontal axis, which machines are generally known as front loader washing machines. For the sake of brevity the container for liquid and the clothes drum mounted therein are hereafter referred to as the drum unit.

It is known for a washing machine of this kind to be provided with at least two spring suspension units which support the drum unit from the bottom of the outer frame or casing and to restrain the drum unit against excessive movement in operation of the machine by means of either a tape between the drum and the outer frame or casing, or alternatively an additional spring means extending between the top of the drum unit and the top of the outer frame or casing.

According to this invention, a washing machine of the kind described provided with at least two spring suspension units which support the drum unit from the bottom of the outer frame or casing has means for restraining the top of the drum unit comprising a substantially non-extensible cord, cable or like element, hereinafter referred to simply as a cord, arranged to extend freely through a guide at the top of the drum unit and connected at opposite ends to the front and rear of the outer frame or casing above the guide, with the rear connection incorporating a spring so that the cord provides resilient support for the top of the drum unit, and a stop located on the cord at a position between the guide and the spring so as to limit the extent of movement of the cord through the guide on displacement of the drum unit relative to the outer frame or casing in use of the machine.

The guide may be formed by a single guide member located preferably at a position approximately centrally between the ends of the drum unit, although it could in some cases comprise two axially spaced members, through each of which the cord extends freely, located either the same or a different distance from said position.

The cord may be replaced by two cords passing freely through respective guides spaced apart at the top of the drum unit and connected at opposite ends to the front and rear of the outer frame or casing above the guides, with the rear connections each incorporating a spring, and each cord having a stop located between the respective guide and spring.

Alternatively the two cords may pass freely through a common guide mounted centrally at the top of the drum unit, and connected to the front and rear respectively of the frame or casing above the guide, the connections to the rear of the casing, at least, being spaced apart on opposite sides of, and equidistant from, the vertical plane containing the drum axis and each cord having a stop located between the respective guide and spring.

The stop on the or each said cord preferably comprises a separate member secured to the cord, although it may be formed by the cord itself, for example as by a knot, or other obstruction integral with the cord.

Three different embodiments of the invention will now be further described by way of example with reference to Figures 1 to 4 of the accompanying schematic drawings, in which Figures 1 and 2 show in diagrammatic form a sectional side elevation and a plan view of one front loader washing machine in accordance with the invention, and Figures 3 and 4 show diagrammatic plan views of two further front loader washing machines in accordance with the invention.

The machine illustrated in Figures 1 and 2 comprises a drum unit 1 consisting of a perforated drum 1.1 rotatable about a horizontal axis within an outer container 1.2.

The rear of the drum 1.1 carries a stub shaft 10 supported in bearings (not shown) mounted in the rear wall of the container 1.2, and is fitted with a drive pulley 11 coupled by means of a belt (not shown) to another pulley fixed to the drive shaft of an electric motor.

The drum is open at the front for loading and unloading through an access door 9 at the front of the casing 2, a resilient annular seal (not shown) of any suitable kind being provided between the edge of the door opening 9.1 and the rim 1.3 of a corresponding opening 1.4 at the front of the drum container 1.2, in the usual way.

The drum unit 1 is supported within the casing 2 by only a single pair of spring suspension units 3 (only one of which is shown) in the form of resilient struts extending between the unit and the base of the casing with their axes lying in a plane which lies at right angles to the axis of the drum through or adjacent to the centre of gravity of the unloaded drum unit, the struts being located one on each side of the drum unit equidistant from the vertical plane containing the drum axis and being equally inclined inwards from the base to the drum unit, for example at an angle of between 50 and 200 to the vertical.

The drum unit is also supported in part at the top by a restraining cord 4 which extends from a fixture 5 at the upper part of the front of the casing, through a guide 6 attached to the top of the unit and is fastened at its opposite end to an end of a spring 8, the latter being fastened at its other end to the upper part of the rear of the casing 2. A stop 7 is fixed to the cord between the guide 6 and the spring 8. The cord 4 which is preferably a nylon coated steel wire, is kept tensed by the spring 8 which provides a restoring force to the drum unit if the latter is displaced from its position at rest as may occur when the washing machine spins an unevenly distributed load or when the drum unit contains a heavy load of wash liquid.

Due to its asymmetrical construction, the centre of gravity of the drum unit 1 moves as it is filled with wash liquid, to the rear of the plane containing the axes of the suspension units 3. The suspension units 3 also decrease in length under this condition. Both of these movements cause an increase in the tension of the restraining spring 8 and the guide 6 may come into contact with the stop 7 thereby preventing excessive rearward movement of the drum unit 1.

When the machine is in the spin mode, the wash liquid having been pumped out, the guide 6 is clear of the stop 7 and a restoring force is available to the front or rear to combat out-ofbalance conditions.

This invention is an improvement over the previously known restraining means referred to above in that it provides better damping of rearward and other motions of the drum unit and enables a lighter spring to be used than is needed in existing forms of washing machine utilising springs only to provide the upper drum unit restraint.

Although in the embodiment described only a single restraining cord and spring are used, the restraining means of a washing machine in accordance with the invention may alternatively include a pair of restraining cords passing through respective guides 6 spaced apart at the top of the drum unit as shown in Figure 3, the guides and the connections of the cords 4 and springs 8 to the cabinet 2 being located on opposite sides of, and preferably equidistant from, the vertical plane containing the drum axis, with each cord provided with an appropriately positioned stop 7 between the respective guide and spring. Although in Figure 3 the connections of the cords 4 and associated springs 8 to the cabinet 2 are shown spaced from the vertical plane containing the drum axis the same distance as the guides, they may be closer to or further from said plane as may be found desirable or expedient.

In yet another embodiment of the invention employing a pair of restraining cords as illustrated in Figure 4, the cords 4 and associated springs 8 are shown attached to the front and rear respectively of the cabinet 2 at spaced positions on opposite sides of said vertical plane, with the cords passing through a common guide 6 mounted centrally at the top of the drum unit. The connections of the cords to the frame or casing may be closer together (but preferably not further apart) than the connections of the springs, and in a modification the cords may be attached to the frame or casing in or adjacent to said plane with the springs connected to the rear of the frame or casing at spaced positions equidistant from the plane.

In any of the embodiments described the drum unit, instead of being supported on only two suspension units, may be supported on three or four appropriately positioned units.

Claims (8)

1. A washing machine of the kind referred to provided with at least two spring suspension units which support the drum unit from the bottom of the outer frame or casing, having means for restraining the top of the drum unit comprising a substantially non-extensible cord, cable or like element, hereinafter referred to simply as a cord, arranged to extend freely through a guide at the top of the drum unit and connected at opposite ends to the front and rear of the outer frame or casing above the guide, with the rear connection incorporating a spring so that the cord provides resilient support for the top of the drum unit, and a stop located on the cord at a position between the guide and the spring so as to limit the extent of movement of the cord through the guide on displacement of the drum unit relative to the outer frame or casing in use of the machine.

2. A washing machine according to Claim 1 wherein said cord is a plastics coated steel wire.

3. A washing machine according to Claims 1 or 2 wherein said cord is replaced by two cords passing freely through respective guides spaced apart at the top of the drum unit and connected at opposite ends to the front and rear of the outer frame or casing above the guides, with the rear connections each incorporating a spring, and each cord having a stop located between the respective guide and spring.

4. A washing machine according to Claim 3 wherein said guides are equidistant from the vertical plane containing the drum axis.

5. A washing machine according to Claims 1 or 2 wherein said cord is replaced by two cords passing freely through a common guide mounted centrally at the top of the drum unit, and connected to the front and rear respectively of the frame or casing above the guide, with the rear connections each incorporating a spring, the connections to the rear of the frame or casing, at least, being speaced apart on opposite sides of, and equidistant from, the vertical plane containing the drum axis and each cord having a stop located between the respective guide and spring.

6. A washing machine according to any preceding claim wherein the drum unit is supported by single pair of suspension units in the form of resilient struts extending between the drum unit and the bottom of the frame or casing with their axes lying in a plane which lies at right angles to the axis of the drum through or adjacent to the centre of gravity of the unit, the struts being located one on each side of the drum unit equidistant from the vertical plane containing the drum axis and being equally inclined inwards towards the drum unit from the bottom of the frame or casing.

7. A washing machine according to any preceding claim wherein the stop on the or each said cord comprises a separate member secured to the cord.

8. A washing machine substantially as hereinbefore described with respect to the accompanying drawings.