GB2067601A - Clothes washing machine - Google Patents

Abstract

An industrial clothes washing machine comprising a drum (3) for the laundry and rotatable about a substantially horizontal axis and mounted in a fixed tub (7) which is provided with at least one opening (9) for access to the drum. The opening (9) is hermetically closable by at least one door (10) which is slidable within guides which are fixed to the wall of the tub, with sealing means being disposed between the tub and the door. The sealing means comprises seals (17 and 18) of anti-friction material and at least one tubular expansion element (24) which is connected to a pressure fluid source by way of control and regulating means, (29-31). The tubular element (24) is mounted around the periphery of the opening (9) in the tub and between said tubular element and said door there is disposed a further lip seal (19) which is fixed to said guides and whose edge is freely inserted in a recess provided along the whole periphery of said opening. <IMAGE>

Description

SPECIFICATION Industrial-type clothes washing machine The present invention relates to a door for industrial clothes washing machines having a high laundry-load capacity, which can be used for example for washing laundry for hospitals, work clothes in factories, etc.

Such machines comprise a drum of large dimensions, having perforated walls, which is adapted to contain the laundry to be washed and which can be driven in rotation by means of per se known motors and transmissions, the drum being disposed in a tub which is supported by an external frame structure.

The drum is preferably disposed with its axis horizontal, and it has an access opening provided in its peripheral casing wall, with a door for closing the access opening. The door can be operated automatically by means of pneumatic cylinders or similar means.

The tub of such machines is provided with a front opening for giving access to the drum, and a door for closing the front opening.

In turn, the opening in the tub is formed in line with the opening in the drum, in such a way that both the openings coincide with each other only when the drum is automatically moved, by per se known means, into a position for permitting the laundry to be loaded into and removed from the drum.

The door for closing the opening of the tub is slidable from the open position to the closed position and vice-versa, and is automatically operated by pneumatic cylinders or similar means which are each connected between the frame structure of the machine and the tub.

In order to prevent leakage of the washing liquid contained in the tub, said door is provided with at least one internal sealing means capable of bearing against the wall of the tub.

The seal is formed by a tubular chamber which is hermetically closed and which is connected by means of pipes to a pressure fluid source, for example for supplying compressed air, and can be inflated when the pressure fluid is passed into the chamber.

When the door of the machine is closed, the above-mentioned chamber is filled with pressure fluid whereby the seal is hermetically pressed against the wall of the tub.

Before the door is moved into its open position, the fluid contained in the above-mentioned chamber is discharged. Consequently, the seal is deflated and, as it no longer seals against the wall of the tub, it permits the door to slide into the open position.

However, in order for the seal to be able to operate correctly, the seal must be mounted on the door with given dimensional tolerances such as to maintain certain contact between the wall of the tub and the seal even when the latter is deflated.

Therefore, during the sliding movement of the door, the seal drags continuously against the wall of the tub, and progressively suffers wear.

The present machine is so constructed as to eliminate the above-mentioned disadvantage and to form an effective system for sealing between the door and the wall of the tub, while being of a simple and reliable type.

For this purpose, the machine is provided with a sealing means which is fixed at the wall of the tub, rather than on the door as hitherto, and is connected to an element which is inflatable and deflatable in accordance with the above-described modes of operation, while the door is not provided with any sealing means and consequently can slide without any obstacle whatever.

Thus according to the invention, there is provided an industrial clothes washing machine comprising a drum which is capable of containing the laundry and which is rotatable about a substantially horizontal axis and which is mounted in a fixed tub, the tub being provided with at least one opening for access to the drum, said opening being hermetically closable by at least one door which is slidable within guides which are fixed to the wall of the tub, sealing means being disposed between the tub and the door and comprising seals of anti-friction material and at least one tubular expansion element which is connected to a pressure fluid source by way of control and regulating means, said tubular element being mounted around the periphery of said opening in the tub and a further lip seal being disposed between said tubular element and said door, the further lip seal being fixed to said guides and having an edge freely inserted in a recess provided along the whole periphery of said opening.

The features and advantages of the invention will be more clearly apparent from the following description given solely by way of non-limiting example, and with reference to the accompanying drawings in which: Figure 1 shows a diagrammatic perspective view of an industrial clothes washing machine according to the invention, and Figure 2 shows a partly sectional detailed view of part of the machine of Figure 1.

Referring to Figure 1, shown therein is an industrial clothes washing machine comprising a drum 3 which is adapted to contain the laundry to be washed and which is of large capacity for loading the laundry.

The drum is rotatable by per se known means about a horizontal axis and is provided with a front opening 4 which can be closed by a slidable door 5 which is mounted on the peripheral casing portion 6 of the drum, the door being actuated by a pneumatic cylinder or similar means (not shown).

In turn, the drum 3 is disposed in a tub 7 which is adapted to contain from time to time the various liquids required for performing the laundry washing cycle, the tub being supported resiliently in per se known manner within an external frame structure 8.

The tub 7 is provided with a front opening 9 which can be closed by at least one door 10 which is mounted in front of the opening 9 and is actuable by means of a pneumatic cylinder 11 or similar means connected between the door and the side wall 12 of the tub 7.

The front opening 9 in the tub 7 is so disposed as to be in alignment with the opening 4 in the drum 3 only when the drum 3 is stopped in a given position so as to permit the laundry to be introduced into and removed from the drum.

Provided at a position corresponding to the closed position of the door 10 is an enabling device 13 such as an electrical end-of-travel switch or similar means, which is mounted on the front wall of the tub 7 and which is capable of co operating with said door in such a way as to be actuated by the door when the door is moved into its precise position of closing, by means of the cylinder 11.

The purpose of the enabling device is to permit actuation of particular control means which will be described hereinafter, only when the door 10 is in the closed position.

Referring now to Figure 2, it will be noted that the door 10 is slidable within two longitudinal recesses 14 which are disposed opposite each other and which are associated with the respective longitudinal edges of the opening 9 in the tub 7, the longitudinal recesses 14 being at least of the same length as the opening 9.

Each recess 14 is formed by means of two guides 15 and 16 which can be fixed against the front surface of the tub 7. The guides 1 5 and 1 6 are provided with respective seals 17 and 18 of suitable anti-friction material, each of which is fixed to a single surface of the respective guide.

For mounting the guides 15 and 16, it is first necessary to arrange a lip seal 19 of rubber or similar material, on the front surface of the tub 7, along the whole of the peripheral region of the opening 9, and then to fix the guides against the front wall, together with one end of the seal 19, by means of bolts 20 and nuts 21 or similar fixing means.

In this way, each recess 14 is covered by the three seals 1 7, 1 8 and 19 described above.

The free edge of the lip seal 1 9 is then freely inserted in a recess 22 formed all around the peripheral region of the opening 9, together with a seat 23.

Before the seal 19 is fitted into place, a tubular expansion element 24 of suitable resilient material is introduced into the seat 23 over the whole length thereof, whereby the seal is then disposed against the element 24 and remains permanently in contact therewith.

The tubular element 24 is provided with an internal chamber 25 which is hermetically sealed and which is connected to a compressed air supply 26 or a source of other suitable pressure fluid, by way of a connection 27, a pipe 28, a safety valve 29, a three-way electrically operated valve 30 of pneumatic type, and a pressure regulator 31, these components being known per se.

The sliding movement of the door 10 in the recesses 14 is produced by the pneumatic cylinder 11 which is controlled by means of pushbuttontype electrical switches 32 and 33 which are actuable by the operator of the machine and which are adapted respectively to cause the door 10 to be moved from the open position to the closed position and vice-versa.

In turn, the valve 30 is provided with an input and two switchable outputs which are respectively connected to the pneumatic supply 26 and to the outside air.

In its first switching position, the valve 30 forms a direct communication between the internal chamber 25 of the tubular element 24, and the exterior, interrupting the connection to the pneumatic supply 26, while in its second switching position, the valve 30 interrupts the communication between the internal chamber 25 and the outside air, and forms a direct communication between the internal chamber 25 and the pneumatic supply 26.

The mode of operation of the present clothes washing machine is described hereinafter, assuming that the door 10 is initially closed.

As soon as the switch 33 is actuated, the cylinder 11 moves the door 10 into its open position. In this phase of operation, the door 5 of the drum 3 is also opened whereby the opening 4 in the drum 3 and the opening 9 in the tub 7 are both accessible from the exterior and are aligned with each other.

In consequence, the laundry to be washed can be introduced into the drum 3.

In this phase moreover, the valve 30 is switched into its first position as described above, whereby the tubular element 24 is deflated and the seal 19 is not pressed against the door 10, thereby permitting sliding movement thereof virtually without friction.

When all the laundry has been loaded into the drum 3 and before the washing cycle of the machine is begun, the machine being predisposed in per se known manner for example by means of a control arrangement of perforated card type, the switch 32 has to be actuated in order for the cylinder 11 to move the door 10 into its closed position.

As before, the movement of the door 10 occurs with the tubular element 24 being disconnected from the source of compressed air, whereby the movement of the door occurs without hindrance.

In its precise closed position, the door 10 is stopped and operates the device 13 which in turn switches in perse known manner the valve 30 into its second operative position.

In consequence, the tubular element is supplied with compressed air and, by being thereby inflated, resiliently compresses the seal 19 against the door 10, thereby preventing any leakage of washing liquid contained in the tub 7. The resilient movement of the seal 1 9 is permitted because the free edge thereof can move, even if with a limited movement, within the recess 22, without nonetheless coming out of the recess.

The door is held in the closed position as long as the various phases of the cycle of the machine are being carried out.

As soon as the cycle of the machine is concluded, the machine operator again actuates the pushbutton switch 33 to move the door 10 back into its open position, as described hereinbefore. In this case, the door is first disengaged from the device 13, stopping briefly to switch the valve 30 into its first operative position and thereby producing discharge of the air contained in the tubular element 24, and then opens when the element 24 is completely deflated.

From the foregoing description, it follows that the door can slide from its closed position to the open position and vice versa, without dragging against the seal 19 as happened in the prior art, thereby easily and reliably ensuring an improved service life in respect of the seal and improved operation of the machine constructed in the above-described manner.

It will be appreciated that, rather than having a single door, the present machine may also be provided with two doors which are actuated in opposition to each other, each door being controlled by a pneumatic cylinder and cooperating with an enabling device, in the same manner as described above, without thereby departing from the scope of the present invention.

Claims (2)

1. An industrial clothes washing machine comprising a drum which is capable of containing the laundry and which is rotatable about a substantially horizontal axis and which is mounted in a fixed tub, the tub being provided with at least one opening for access to the drum, said opening being hermetically closable by at least one door which is slidable within guides which are fixed to the wall of the tub, sealing means being disposed between the tub and the door and comprising seals of anti-friction material and at least one tubular expansion element which is connected to a pressure fluid source by way of control and regulating means, said tubular element being mounted around the periphery of said opening in the tub and a further lip seal being disposed between said tubular element and said door, the further lip seal being fixed to said guides and having an edge freely inserted in a recess provided along the whole periphery of said opening.

2. An industrial clothes washing machine constructed and arranged to operate substantially as hereinbefore described with reference to and is illustrated in the accompanying drawings.