GB2130341A - Rotary cylinder assembly including a heated oil-bath - Google Patents

Abstract

The assembly comprises a hollow cylindrical roller (2) coaxially of which an electric resistance heater (3) is arranged in an oil-bath (7) not completely filling the interior of the roller, the electric resistance being received within a tubular core (5) communicating with the hollow of the roller and provided with a plurality of radially extending holes (6) for the passage of the heated oil to the roller surface. Suggested applications are treating textiles and paper, e.g. to dry printed patterns or effect thermosetting, the assembly providing for uniform heating of the roller. <IMAGE>

Description

SPECIFICATION Cylinder assembly including a heated oil-bath The present invention relates to a cylinder assembly, heated by oil-bath electric resistances, particularly forfabricthermoprinting apparatus and calendars for finishing ironing fabrics and the like.

As it is well known, in several industrial fields, such asthetextilefield and the paper making field, it is frequently required to heat processthefabric or paper in orderto dry printed patterns orthermoset, said fabrics.

To this end there are presently used heating cylinder assemblies which, however, are not capable of ensuring an even distribution of the heat on their surface.

Because of the mentioned drawback, the quality of the product being processed is rather poor.

Accordingly,thetaskofthe present invention is that of obviating the thereinabove mentioned drawbacks, as well as yet other drawbacks, by providing a cylinder assembly, heated by oil-bath electric resistances, which is effective to provide an even distribution ofthe heat across its overall surface, thereby providing an even thermosetting and thermoprinting ofthe polyesterfiberfabrics.

Within that task, it is a main object ofthe present invention to provide such a heating cylinder assembly which is structurally very simple and which, moreover, does not require any outside fittings susceptible to cause the heating circuittemperatureto drop and become uneven.

Yet another object of the present invention is to provide such a heating cylinder assembly which is effective to be brought to high surface temperatures with a reduced power, thereby providing great advantages from the mere economical standpoint.

According to the present invention there is provided a cylinder assembly, heated byan oil-bath immersed electric resistance comprising a hollow cylindrical roller, with an electric resistance mounted coaxially thereof and immersed in an oil-bath,which oil-bath does notfill completelythe interior of said cylindrical roller.

The invention will now be described further by way of example with reference to the accompanying drawings in which: Figure lisa cross-section ofthe heated or heating cylinder assembly according to the invention; and Figures 2 is a cross-sectional viewtaken along the line Il-Il of Figure 1.

With reference to the accompanying drawing, the cylinder assembly according to the invention, which is indicated generally at 1, comprises a cylindrical roller 2 made of any suitable material and of hollow construction.

Coaxiallywithsaid roller2,there is provided an electric resistance 3, consisting preferably of an electric immersion heater, which is coupled to sliding contacts 4 effective to supply it with power during the rotation of said cylinder.

More specifically, said electric resistance 3 is arranged inside a tubular central core 5, which is provided with a plurality of radially extending holes 6, connecting the inside of said tubular core 5 with a hollowofsaid roller 2.

Insidethe hollow of said roller 2, there is provided an oil-bath, indicated at 7, which is held at such a level as to always hold the electric resistance 3 completely immersed, even during the rotation of said roller, which oil-bath does notcompletelyfill said hollow 2.

Aboutthe mentioned tubular core 5there are provided oil inlet gaps 10 mainly effective to reduce the oil amount in the inside of the rollerasthe latter is not used.

During the rotation ofthe roller, the oil 7, as heated byconduction bythe electric resistance3, is evenly spread at the lower walls of said roller, thereby providing an even heating oftheworking surface of the roller itself.

More specifically, during the rotation of said roller, the oil is naturally circulated and, from thetubular core 5,through the holes 6, is directed towards the inner walk ofthe roller 2, thereby providing a quick transmission of heat from the electric resistance to the operative roller surface, thereby reducing to a mini mumthethermal Iossesandfacilitanting an even distribution ofthe heat.

Thus, owing to the above disclosed structure, the possibility is afforded of reaching high surface temperatures, ofthe order of 300"C, with a reduced operative power for the electric resistance.

The operation ofthe heated or heating cylinder asssembly according to the invention is very simple.

In fact, in normal operation, the electric resistance 3 is supplied, which quickly and evenly heats the oil as contained within said tubular core 5.

That oil, because of the natural circulation due to the rotating cylinder, directlytransports through the holes 6, to the operative surface ofthe roller, thereby providing a quick and even heattransmission, with a consequent high quality production.

Another important aspect ofthe invention consists ofthe provision ofthe gaps 10which practically provide zones thereinto said oil- is not capable of penetrating, and which, accordingly, afford the possi bility of remarkably reducing the amount of oil to be used and moreover afford the possibility of quickly cooling the cylinder at the end of the operation thereof.

From the above disclosure is should be notedthat the invention fully achieves the intended objects.

In pa rticularthe fact isto be pointed outthatthe heated or heating cylinder assembly according to the invention is effective to provide a sure and even surface distribution ofthe heat, which is transmitted to the operative surface ofthe cylindrical roller by the circulating oil, the circulation whereof is naturally induced by the rotating cylinder.

Since the oil is contained in the closed inside hollow ofthe roller,the need is obviated of using circulating pumps or level tanks, as the desired oil level is set during the making of the roller, and the oil may not leak and damage the fabric.

While a preferred embodiment ofthe invention has been thereinabove disclosed, it should be noted that the illustrated embodiment is susceptible to several modifications and variations all whereoffall within the scope ofthe invention.

Moreover all of the details may be replaced by other technically equivalent elements.

Claims (6)

1. A cylinder assembly, heated by an oil-bath immersed electric resistance comprising a hollow cylindrical roller, with an electric resistance mounted coaxiallythereofand immersed in an oil-bath, which oil-bath does not fill completely the interior of said cylindrical roller.

2. Acylinder assembly as claimed in claim 1 in which said electric resistance is housed within a tubular core communicating with the interiorofthe cylindrical roller.

3. Acylinder assembly as claimed in claim 2, in which said tubular core is provided with a plurality of radially extending holes effective to allowfor said oil to reach the surface of said roller.

4. A cylinder assembly as claimed in Claim 1, which comprises, within said roller interior, a plurality of gaps, through which said oil does not pass and effective to reduce the oil amount inside said roller.

5. Acylinderassembly as claimed in claim 1, in which said oil is naturally circulated inside said roller as the latter is rotated.

6. A cylinder assembly substantially as herein described with reference to and as illustrated in the accompanying drawings.