EP1368522B1

EP1368522B1 - Reciprocating washing machine

Info

Publication number: EP1368522B1
Application number: EP02727412A
Authority: EP
Inventors: R. HINDUSTAN LEVER LTD Research Centre BANERJEE; Vijata Milind c/o HINDUSTAN LEVER LTD BARGAJE
Original assignee: Unilever PLC; Unilever NV
Current assignee: Unilever PLC; Unilever NV
Priority date: 2001-03-13
Filing date: 2002-03-11
Publication date: 2005-05-25
Anticipated expiration: 2022-03-11
Also published as: CA2439824A1; CN1496421A; ZA200306574B; WO2002072939A3; US20020129627A1; EP1368522A2; AR034296A1; BR0207993A; WO2002072939A2; AU2002257658A1

Description

Technical Field

The invention relates to a washing machine suitable for washing articles using a system of at least two immiscible liquid phases. More particularly, the invention relates to a reciprocating washing machine that can be mounted either horizontally or vertically.

Background and Prior art

Washing of fabric is generally carried out either by hand washing or by machine washing, using water in presence of a detergent.

Conventionally fabric is cleaned using water and a detergent surfactant system which is known as wet washing. Surfactants adsorb on both fabric and soil, thereby reducing the respective interfacial energies, facilitating removal of soil from the fabric. Alternatively it is done by a process called dry cleaning where organic solvents such as perchloroethylene (PCE), petroleum based or Stoddard solvents, CFC-113 and 1,1,1-trichloroethane are used, all of which are generally aided by a surfactant. The organic solvent helps in removal of oily soil in the presence of detergents. Soil removal can be achieved by a small reduction in interfacial tension. The particulate soil is largely removed by providing agitation.

In our copending application (469/Mum/2000) it has been found that efficient removal of both soluble and insoluble soils may be achieved by the cleaning of fabric using the liquid-liquid interface of at least two immiscible liquid phases with an interfacial tension greater than 10mN/m, under agitation. It is also found that superior cleaning may be achieved economically by the use of water as a major component along with an organic solvent with the use of little or no surfactant. However, the cleaning performance of this liquid-liquid interface system in conventional washing machines could still be improved.

Conventional washing machines are almost always of a rotary type that may have the provision for loading the fabric from the front or top whereby clothes and wash liquor is rotated. These machines suffer from the disadvantage that this rotary action limits the amount of mechanical action that can be provided. The front loading washing machines with a horizontally oriented drum clean utilising the tumbling action of the clothes. But this is unable to produce a high degree of mechanical action. This mechanical action is even less with top loading machines with vertically oriented drums. To clean heavily soiled garments high mechanical action is essential. Patent Abstracts of Japan (1999-01-29) JP 1027786, GB 895 588 and US-A-5 749 250 disclose washing machines for conventional aqueous washing.

WO9521954 discloses a washing machine wherein the wash vessel is oscillated to introduce air bubbles into the wash liquor to improve the cleaning action of the washing machine. However, with this arrangement the shape and the movement of the washing vessel is restricted to the guide provided. The movement is essentially vertical and is dependent on the mass of the wash load and makes it necessary to have the mass uniform in order to achieve controlled reciprocation. The amplitude of motion is essentially fixed. It is essential to have the balancing means for absorbing the unbalanced forces created by the motion. Since the reciprocation is on a vertical axis the system experiences differences in the upward and downward strokes. It will be very difficult to mount this machine horizontally and obtain the desired results.

The applicants have found that one or more of these disadvantages of rotary type and the known reciprocating type machines can be solved by the use of a reciprocating washing machine as described below. It can be mounted either horizontally or vertically. The benefit of making it horizontal is that one does not need balancing means and shock absorbing mechanism which is essential if the wash vessel is moving up and down. By eliminating the guide for the wash vessel it is possible to have varied shapes of the washing vessel. In this machine the mass of the wash load is not a criteria for the motion and hence it can also be suitably varied.

Thus, one aspect of the present invention relates to a reciprocating washing machine comprising:

(i) reciprocating means capable of reciprocating movement;

(ii) a wash vessel connected to the reciprocating means and capable of movement in co-ordination with the reciprocating means characterised in that the reciprocating means is provided with means for restricting the reciprocating movement to a predetermined number of degrees of freedom and (iii) means to vary the amplitude of the reciprocating movement. Preferably the reciprocating movement is linear. It is also desirable that the reciprocating movement is restricted to one degree of freedom. The washing machine preferably includes a frequency controller for controlling the frequency of the reciprocating movement to obtain the desired cleaning performance.

The washing machine preferably comprises a prime mover which is a device capable of delivering a drive of the desired power and can be selected from any one of an electrical motor, induction motor, petrol engine or any other device known in the art. It is preferred that the prime mover is electrically operated and is provided with a frequency controller. The frequency control may be achieved by using an electrically or mechanically operated means.

According to a preferred embodiment the prime mover is connected to a frequency controller acting in conjunction with the means capable of converting the rotary movement into reciprocating movement.

The washing machine is preferably provided with means capable of converting rotary movement into the reciprocating movement comprising a crank (device) rotatably connected to a piston rod which is connected to the wash vessel. Thus according one embodiment, the prime mover is attached to means capable of converting rotary movement into a reciprocating movement comprising a crank with a rotatably installed connecting rod, which itself is connected to one end of a piston rod. The other end of the piston rod may be connected detachably to a wash vessel. Preferably, the piston rod is provided with means for restricting the reciprocal movement to a predetermined number of degrees of freedom. For example, guides such as bearings, plain guides, flat guides, dove tail guides etc. may be provided on the piston rod constraining and/or directing the movement of the piston rod in preferably one direction.

The washing machine comprises means to vary the amplitude of the reciprocating movement. The amplitude of the reciprocating movement can varied by suitably elongating or reducing the effective length of the cranking arm, the coupling between crank and piston rod such as a connecting rod. In addition, when the crank is a crank wheel, the diameter of the crank wheel may be varied for the same purpose. It will be obvious to the skilled person that the same effect may be achieved by varying the position of the connecting rod relative to the axis of the crank.

The washing vessel may be detachably connected to the reciprocating means. Thus, the washing vessel may be detachably connected coupled to the piston rod and may be designed to have any suitable geometric shape for e.g. Cylindrical, spherical, cuboid or conical. The mouth of the washing vessel is preferably provided with a leak proof sealed door. A solvent proof gasket and a handle for locking are preferable requirements. The door is sized to facilitate introduction and removal of garments. The vessel is further fitted with tubes that allow inlet and outlet of liquids.

It is preferred that the washing machine reciprocates on a horizontal axis or level.

The reciprocating washing machine of the present invention is particularly suitable for washing fabric using a system of immiscible liquids as described in (469/Mum/2000) with high interfacial tension without the need to use additional detergency benefit agents or only in small amounts. The machine is capable of handling flammable and/or hazardous solvents with minimal risk.

For the avoidance of doubt, any feature of one aspect or embodiment of the present invention may be utilised in any other aspect or embodiment of the invention.

The invention will now be illustrated with reference specific non-limiting embodiments, shown in the accompanying drawings in which

Fig 1. Side view of the design of the horizontal reciprocating washing machine.

Fig 2 Top view.

Fig 1 shows the side view of the machine control panel that has a power on switch (1), frequency control drive (frequency controller)(2) and another switch to regulate the liquid pumps. The liquid pumps (10) are connected to the wash vessel (9) by means of inlet (11) and outlet (12) pipes. The control panel is electrically connected to a foot mounted flange type AC induction motor (3) as prime mover. A crank wheel (crank device) (5) is bolted on to the 'L' bracket (4). The diameter of the crank wheel depends on the desired amplitude of the reciprocating motion. A connecting rod or crank shaft/arm (14) is attached to one end of the crank wheel using a rotary pin (15). The other end of the connecting rod is connected to the piston rod (6) by means of a ball joint (13) which is further supported with the help of two cylindrical linear bearings (7). The other end of the piston is threaded and forms the male end of the coupling (8). The wash vessel (9) has the female member of the coupling. The coupling is designed for quick replacement of the wash vessel. The wash vessel has a door (16) and inlet and outlet tubes.

Claims

A reciprocating washing machine comprising

(i) reciprocating means capable of reciprocating movement;

(ii) a wash vessel connected to the reciprocating means and capable of movement in co-ordination with the reciprocating means wherein the reciprocating means is provided with means for restricting the reciprocating movement to a predetermined number of degrees of freedom; and characterized by

(iii) means to vary the amplitude of the reciprocating movement.
A washing machine according to claim 1 wherein the reciprocating movement is linear.
A washing machine according to any one of the preceding claims wherein the washing machine includes a frequency controller {2} for controlling the frequency of the reciprocating movement.
A washing machine according to any one of the preceding claims wherein the wash vessel {9} is detachably connected to the reciprocating means.
A washing machine according to any one of the preceding claims wherein the reciprocating movement is restricted to one degree of freedom.
A washing machine according to any one of the preceding claims characterised in the provision of means of converting rotary movement into the reciprocating movement comprising a crank {14} rotatably connected to a piston rod {6} which is connected to the wash vessel {9}.
A washing machine according to claim 6, wherein the piston rod {6} is provided with means.for restricting the reciprocal movement to a predetermined number of degrees of freedom.
A washing machine according to any one of the preceding claims wherein the washing machine reciprocates on a substantially horizontal level.
A washing machine according to any one of the preceding claims wherein the washing machine includes a prime mover {3} connected to a frequency controller {2} according to claim 3 acting in conjunction with the means capable of converting the rotary movement into reciprocating movement.
A washing machine according to claim 1 wherein the washing machine comprises:

i. a prime mover {3} acting in conjunction with a means capable of converting the rotary movement into reciprocating movement comprising a crank {5} with a rotatably installed connecting rod connected to a piston rod {6} which in turn is connected at the other end detachably to the wash vessel {9};

ii. at least one guide provided on the said piston rod {6} constraining and/or directing the movement to one degree of freedom;

iii. a washing vessel {9} capable of movement in co-ordination with the reciprocating member.
A washing machine according to claim 10 wherein frequency control is achieved by using an electrically or mechanically operated means.
Use of a washing machine according to any one of the preceding claims for washing fabric using a system of at least two immiscible liquid phases with an interfacial tension greater than 10mN/m.