Washing And Spin-drying Machine With Auxiliary Mass

Abstract

Washing and spin-drying machine having a tub in which a rotatable drum is mounted and an auxiliary mass which disposed at the end of a lever which is connected to the machine frame and to the tub.

Description

The invention relates to a washing and spin-drying machine for textile materials in which a tub for containing the wash liquid is accommodated in a cabinet and itself accommodates a rotatable drum for the washing load, an auxiliary mass being provided to restrict oscillations during the operation of the machine.

In washing machines of this type it is common practice to rigidly secure the auxiliary mass, in the form of blocks of cast iron or concrete, to the tub. However, to achieve a beneficial effect, which is particularly aimed at when passing through the critical speed in the process of accelerating from a washing speed to a spin-drying speed, very large masses are required, so that the machines become very heavy, and this obviously is a considerable disadvantage.

This disadvantage is substantially eliminated by the use of the invention which is characterized in that the auxiliary mass is disposed at one end of a lever which is movably connected to a fixed point within the cabinet and to the tub, the part of this lever which extends between the fixed point in the cabinet and the tub being smaller than the part which extends between the tub and the auxiliary mass.

This arrangement of the auxiliary mass produces an apparent increase of the tub mass without the weight of the washing machine being appreciably increased.

The invention may be used to advantage in a washing machine provided with a balancing device as described in co-pending application, Ser. No. 284,965, filed Aug. 30, 1973. Thus this embodiment of the invention is characterized in that the auxiliary mass is disposed at the end of the conduit portion at the area of the nozzle of the said balancing device. This embodiment is particularly advantageous because in general the said balancing device becomes operative only after the drum has passed through the critical speed, so that the use of the invention provides a simple means of keeping the amplitudes of the tub and the drum within acceptable limits duringthe passage through this speed.

An embodiment of the invention will now be described, by way of example, with reference to the accompanying diagrammatic drawings, in which:

FIG. 1 is a schematic sectional view of a washing machine which is provided with a balancing device as described in the aforementioned Patent Application, and

FIG. 2 shows a detail of this machine on an enlarged scale, in which the invention has been used.

Referring now to FIG. 1, the domestic washing machine shown is of a known type and comprises a cabinet 1 in which a tub 2 is resiliently suspended from four springs 3, at least one shock absorber 4 being provided between the bottom of the tub wall and the end of the cabinet. A washing drum 5, which is open at its front for loading and unloading, is rotatably mounted in this tub. Corresponding openings are formed in the front walls of the tub 2 and of the cabinet 1 and can be closed by a door 6 which is hingedly connected to the front wall of the cabinet 1. The drum 5 has a cylindrical wall 7 made of perforated stainless steel sheet. To the rear surface of the drum 5 is secured a shaft 8 which is supported in a bearing mounted in the rear wall of the tub 2. An electric motor 9 for driving the drum 5 is secured to the tub wall. The drum is driven via pulleys 10 and 11 which are secured to the motor shaft and the drum shaft 8 respectively and over which a belt 12 runs.

The motor has two speeds, enabling the drum 5 to be given a speed of about 50 r.p.m. for washing and a speed of about 1,000 r.p.m. for spin-drying the washing load. The drum is internally provided with ribs 13 which keep the load moving during the wash cycle.

Parts of a front wall 14 and a rear wall 15 of the drum 5 are doubled, the front wall being double from the loading opening to the outer circumference and the rear wall between the area at which the shaft 8 is secured and the outer circumference. The spaces between these double walls are interconnected via the rims 13 through suitable openings formed in the inner parts of the front and rear walls 14 and 15. The double-walled spaces are each divided in five receptacles by means of five radially extending partitions 17. In the balancing process balancing fluid is supplied to these receptacles and consequently they form part of the balancing device. This device further comprises a conduit portion 18 through which the balancing fluid is conveyed and which at one end is connected to a bracket 19 secured to the tub and at the other end to a support 20 secured to the cabinet 1.

The said conduit portion 18 is shown on an enlarged scale in FIG. 2. It is mounted in a bracket 19 and the support 20 by means of ball joints which comprise rings 22, which encircle the pipe 18 and are externally spherical, and rings 23, which are internally spherical and are mounted in openings in the elements 19 and 20. One of the rings 22 is rigidly secured to the cabinet, but the other is free to slide over the pipe. At the free end of the pipe 18, where it forms a nozzle, there is disposed a weight 24 which serves as an auxiliary mass. The length A of the conduit portion between the point at which it is secured in the bracket 19 and the fixed point in the support 20 is made smaller than its length B between the first-mentioned securing point and the auxiliary mass. When the length B is n times the length A, the amplitude of the auxiliary mass 24 is (n + 1) times the amplitude of the tub. As a result, the forces exerted on the tub are increased (n + 1).sup.2 times, so that when the lever ratio n is 4 and the auxiliary mass 24 is 1 kg an apparent increase in mass of 25 kg on the tub is obtained.

Claims

What is claimed is:

1. Washing and spin-drying machine for textile materials comprising a cabinet, a tub for containing the wash liquid accommodated in said cabinet, a rotatable drum for the washing load accommodated within said tub, a lever movably connected to a fixed point within the cabinet and to the tub, an auxiliary mass for restricting oscillations during the operation of the machine disposed at one end of said lever, the length of the lever which extends between the fixed point in the cabinet and the tub being smaller than the length of the lever which extends between the tub and the auxiliary mass.

2. Washing and spin-drying machine as claimed in claim 1 further comprising balancing means including a conduit for supplying balancing fluid, said conduit having a nozzle at one end thereof, said conduit forming said lever, and wherein the auxiliary mass is disposed at the end of said conduit at the location of said nozzle of the said balancing means.