US2274839A - Electrically heated hose - Google Patents

Description

March 3, 1942. MARICK 2,274,839

ELECTRI CALLY HEATED HOSE Filed May 21, 1941 1 N VENTOR.

ATTORNE Y Patented Mar. 3, 1 942 ELECTRICALLY HEATED HOSE Louis Marick, Grosse Pointe Farms, Mich assignor to United States Rubber Company, New York, N. Y., a corporation of New Jersey Application May 21, 1941, Serial No. 394,435

5 Claims.

This invention relates to electrically heated hose and more particularly to electrically heated means embodied in a hose or tube to heat the same.

It may be desirable from time to time to heat various gas or liquid fluids such as gases, oil, water, milk and solutions of inorganic and organic chemicals. These fluids may be easily heated to a moderately high temperature by passing them through an electrically heated hose such as contemplated by the present invention.

Various types of hose may be provided with the electrically heated means h'erein contemplated but the heating means is preferably embodied in hose having a sufliciently thick wall to permit the heating means to be confined between the inner and outer walls of the hose where it will be protected by the covering layers or other material forming the body of the hose.

The hose heating element comprises a strip of fabric or other sheet material that is treated with an electrically conductive plastic such for example as rubber composition containing electrically conductive carbon and having conductor wires secured along the side edges of the strip;

so that when a diiferent electric potential is maintained between these wires the current will now across the conductive strip from one wire to the other and generate heat uniformly throughout the area of the strip.

The heating element herein contemplated may be wound helically about an inner layer of the hose structure throughout the length thereof and then a covering layer of the hose structure may be applied over such heating element In another construction the heating element may be arranged lengthwise of the incompleted hose so that the heating wires extend parallel to the hose opening and the current conducting material extends part way around the hose in the form of an are having as many degrees as desired, whereupon the outer plies or other cover forming material may be applied over such heating element to protect the same.

One end of each conductor wire should project from such hose so that the two wires may be connected to a suitable source of electric energy and thereby cause current to flow across the current conducting strip to generate heat along the tube throughout the strip area.

The above and other features of the invention will be further understood from the.following description when read in connection with the accompanying drawing wherein:

Fig. 1 is a side elevation of a piece of hose embodying the features of the present invention and having the outer cover partially removed to disclose the electric heating element.

Fig. 2 is a side elevation of the hose of Fig. 1, the heating element being shown in dotted lines within the hose wall.

Fig. 3 is a view similar to Fig. 1 showing a modified type of heating element extending lengthwise of and partly around the inner wall structure of the hose; and

Fig. 4 is an enlarged sectional view taken on the line 4-4 of Fig. 3.

The present invention may be embodied in various types of hose such for example as rubber hose, garden hose, hose formed of various types and numbers of layers or plies as well-as hose formed of various plastic materials.

'In the embodiment of the invention illustrated in Figs. 1 and 2 of the drawing, the hose is shown as provided with an inner wall structure Ill and outer wall structure II and between these walls It and II is provided the heating element which 'is shown as wound helically about the tubular member III as indicated by the coils I2.

This heating element is preferably formed of a strip I! of woven fabric or other sheet material that is treated with an electrically conductive plastic material such for example as rubber containing electrically conductive carbon, to thereby render the strip capable of generating heat when a diiferent ele'ttric potential is maintained between spaced portions thereof. The operating current is preferably supplied to this strip l3 by providing the conductor wires H and I5 secured along the side edges of the strip, preferably by folding the marginal side edges of the strip around and in contact with the wires so as to form a good electrical contact therebetween. The adjacent edges of the helically coiled heated element should be spaced as shown so as to prevent these edges containing wires of different potentials from contacting and forming a short circuit.

After the heating element l3, I4 and I5 is wound helically upon the tubular wall III as shown in Fig. 1 the covering wall ll may be applied directly over such heating element to conceal and protect the same, and if the walls l0 and II as well as the sheet it contain a substantial amount; of rubber the complete hose may be vulcanized to form a firm bond between the rubber of the strip l3 and the walls Ill and II. The wires l4 and I5 preferably protrude at one end from the finished tube as shown in Fig. 2 so that they may be connected to any suitable source of electric energy such'as the ordinary household current or it desired to a current of considerably lower voltage, such for example as volts.

In the modified construction of Figs. 3 and 4 the hose is shown as provided with an inner wall portion HI and outer wall portion II as in Figs. 1 and 2, but in this modified construction the heating element is not wound helically about the inner wall ill but extends longitudinally thereof, and comprises a current conductive strip of sheet material l6 similar to the strip I: of Fig. 1 and has its marginal edge portions secured to the current supply wires l1 and It, as in Fig. 1. These wires it will be noted extend lengthwise of the hose and the heating strip l6 encircles as large a portion of the inner tube structure HI as desired, so that when a difierent electric potential is maintained between the wires I l and I8 current will fiow transversely of the strip l6 from one wire to the other to heat this strip and the hose in which it is embodied. If the portions III, II and ii of the hose are formed of rubber or contain a substantial amount of rubber then they all may be vulcanized together.

The strip l3 or [6 is rendered electrically conductive by treating it with a rubber cement or rubber dispersion or other plastic material containing conductive carbon particles. One example of a good practical electrically conductive cement which may be used to coat the strip ll or I is as follows:

- Parts by weight Rubber 100.

The hose construction of the present invention has been designed more particularly to supply a moderate amount of heat, below the temperature of boiling water, but a. higher temperature may be employed if the strip 13 or ii is formed of non-combustible material such as woven asbestos which has been treated with conductive rubber and the other structure of the hose is capable of operating at such higher temperatures.

It will be apparent from the foregoing that a heating element such as herein contemplated may be embodied in various types of flexible hose without appreciably increasing its size or decreasing its flexibility, and that by placing such heating element in the interior of the hose structure it will be concealed and protected from injury. The present hose is well adapted for use in aircrafts to heat the oil lines but as above stated may be employed to heat various fiuids.

Having thus described my invention, what I claim and desire to protect by Letters Patent is:

1. An electrically heated hose formed of a plurality of layers that provide an inner wall and outer wall, a heating element confined between two of said layers along the hose, and consisting of a strip 01' sheet material treated with electrically conductive rubber and having current supply wires secured along the side edges of the strip and adapted when a difierent electric potential is maintained between the wires to cause current to flow across said strip and heat the hose.

2. A rubber hose formed of a plurality of layers, a heating element confined between two of the layers, and consisting of a strip of sheet material treated with electrically conductive plastic material and having current supply wires secured along the side edges of the strip and adapted when a different electric potential is maintained between the wires to cause current to fiow across the strip and thereby heat the hose.

3. A rubber hose formed of rubber containing layers, a heating element confined between two of the layers, and consisting of a strip of sheet material treated with electrically conductive rubber adapted to be vulcanized in place between said layers and provided with current supply wires secured along the side edges of the strip and adapted when a different electric potential is maintained between the wires to cause current to fiow across the strip and thereby heat the hose. 4. A hose formed or a plurality of layers, a heating element wrapped helically of the hose between two or the layers, and consisting of a strip of sheet material treated with electrically conductive plastic material and having current supply wires secured along the side edges 01' the strip and adapted when a diflerent electric potential is maintained between the wires to cause current to fiow across the strip and thereby heat the hose. 5. A hose formed at least in part of plastic material and provided with a heating element disposed between its inner and outer walls, said element consisting of a strip of sheet material treated with electrically conductive plastic material and having current supply wires secured along the side edges of the strip and adapted when a dififerent electrical potential is maintained between the wires to cause current to flow across the strip and thereby heat the hose.

LOUIS MARICK.

Images