Indicating device

Application filed December

The present invention relates to. a temperature indicating device, and particularly to devices fOi? indicating abnormal conditions in' the operation of engines, machin& erv, and the like.

One of the main objects of the present invention is to provide a device adapted to be mounted in a suitable plape for indicating abnormal temperatures, as for example, abnorIti mal temperatures arising during operation oi an internal combustion engine or the like, and of such character that it will give a sharp signal of sufficient emphasis to arrest or attract the attention whenever abnormal oper1 > ating conditions raise the temperature Or the indicating device sufficiently. . .

Another object of the invention is to provide an indicating device of this, character particularly adapted to be associated with -1 the cooling system of a water cooled engine and. responsive to temperature conditions of the liquid in the cooling system..

Other objects of the invention will be apparent from the following description when 15 taken in connection with the accompanying drawings in which: .

Fig. Ϊ represents an elevation of the present invention applied to the spout of a radiator ;· .' .,.-,, ³⁹ Fig. 2 is a central vertical section on tne line 2—2 of Fig. 1; . .

Fig. 3 is an elevational view, partly in.vertical section, of a· modified form of the invention; . - . ,.

V) Fig. 4 is a central vertical section ot a simplified form of the. invention;..

Fig. 5 is a plan vieav of a somewhat modified form of the invention; and.

Fig. 6 is a fragmentary sectional view ot >:o the invention as applied to a bearing.

As showing a preferred embodiment or the invention it/s herein illustrated and described as applied to the avell kn.oavn avater. cooled engine of conventional design. . , •el It is generally understood that in such internal combustion engines designed for use in connection, with automobiles and the lute, wherein the engine cylinders are cooled by a liquid such as water delivered to it from a at! radiator or the like, the temperature of the cooling avater in the radiator is. noimally somew’hat below the boiling point of the avater, and so long as the engine operates normally the temperature, of the. water remains f,5 normal. Howbver, upon abnormal operation

1,692,012 heat radiation losses therefrom result in such by a third layer of gum arabic. The temperature indicating· material is thus enclosed by a temperature difference between the indicatthe gum arabic which forms a protective ing material and the. water that the indicatcoating to protect the temperature indicating material from injury or deterioration. The triple layer of gum arabic and iodomercurate of copper, herein referred to as a whole as temperature indicating material, is designated by reference character 25 in Fig. 2.

While reference is made herein to a particular temperature indicating material, it will be understood that other temperature indicatingmaterials may be employed having critical or color-changing temperatures either above or below that stated, herein.. . It should also be understood that the method of applying the iodomercurate of copper and the materials employed, is susceptible of wide variation, including for example, the use of a relatively chemically inert varnish or other suitable material as a carrier for the iodomercurate of copper instead of the gum arabic, or the omission of part of the process described depending largely upon the particular materials em25 ployed.

Surrounding the temperature indicating material 25 and supported between the shoulder 26 formed by the upper end of the lower tube 22 and the shoulder 27 formed by the enlargement of the upper tube, is an inclosing structure for providing a dead air space about that portion of the: spout carrying the temperature indicating material 25. This inclosing structure consists of a glass tube 28 surrounding the tube 24 and indicating material 25 and spaced therefrom, the glass tube being held in position by means of supporting rings 29 which with the tube 24 form grooves to receive the glass tube 28. . The dead air space is sealed against the passage of air by means of rubber or other suitable packing rings 30 between . the glass tube 28 and the supporting rings 29.

From the foregoing it will be seen that the temperature indicating material is in heat conducting connection through the parts 24,. 22 and 23 of the radiator with the coolingwater 31, and as a result the. temperature of the indicating material .25 will rise or fall th< with a rise or fall in the.temperature of the water. But since the critical temperature of the indicating material is about 150° F. whereas it is not desired to receive a temperature change indication until the water in the radiator reaches substantially its boiling ternperature, it is of the essence of the invention that the indicating material 25 bo of such thermal remoteness from the cooling water 31 that it will not reach its critical temperature, and hence give a temperature change indication, until· the water reaches substantially its boiling temperature. This is accomplished in the present invention by securing the band of indicating material 25 to the radiator spout which spout is so exposed that the ing material reaches its critical or colorchanging temperature at substantially the same time as the water reaches its boiling point. It will be understood that the temperature differential between the boiling water and the indicating material may be varied widely to meet the varying requirements of various temperature indicating materials,: radiators; and the^: like, by suitable changes in the size, proportion or location of the various parts, or the provision of heat insulation about certain of the parts, so as to establish a proper relation between the amount of heat being conducted from the .water to the indicating material, and the amount of heat losses, whether by conduction, radiation or convection.

The inclosing structure formed by the glass tube 28 and associated parts provides a dead air space about the temperature indicating material 25 and thereby protects the indicating material 25 from the elements, prevents the condensation of water thereon under certain conditions, and assists in controlling the amount of heat radiation from the spout. It. is apparent also, in this connection, that the inclosing structure may be of simple!’ con- ⁹⁵struction than herein illustrated and in some cases may be omitted entirely.

Since there is generally more or less water vapor in the radiator and since this vapor may rise in the spout to heat .the. indicating ¹⁰⁰material and give a premature temperature indication, it may be desirable, in some instances, to provide a deflector or wall 32. which, as shown in Fig. 2, may consist of an imperforate cylindrical tube spaced from the 105 upper spout tube 24 and secured thereto by means of the outturned flanges 33.

The present invention.'is preferably pro-.

vided with indicating symbols orrindicia 34 such for example as the letters H Ο T, which no symbols consist of .material of fixed color superimposed on the indicating material, the- . indicating symbols having the same, color -as indicating material when, the latter is:he....... its critical temperature, and being nor- 115 mally not distinguishable from the driver’s seat. When the indicating-material· reaches its critical temper attire and changes color it . forms a background.for .the symbols 34, the ^; outlines of'which are then'visible. The sym- 120 bols thus give a signal of considerable, empha-. sis to'the Operator of the engine and .when the symbols are in the form of letters .which spell , a word such as Hot, then the indicator actu-. ally states in plain language the condition. 125 of the engine and cooling water .so that it may . be readily understood by one who may not. be familiar with the significance of the change in color of the indicating material itself.

Referring now to Fig. 3, which shows a iso

1,692,012 modified form of· the invention, the radiator spout consists of a lower tube 122 and an upper tube 124 which has screw threaded or other engagement with the external surface of the lower tube 122. The . upper tube is screw threaded to receive tlie radiator cap 121'. In this form of the invention, like that shown in Fig. 2, the temperature indicating material 25 is applied to the outer portion or tube 124 io of the spout, and the indicating material is also surrounded by an inclosing structure for providing a dead air space around the indicating material 25. The inclosing structure is similar in construction'to that -above-de.15 scribed and consists of a glass tube .28, supporting rings 29 and gaskets 30, the supporting rings being secured directly to the cylindrical wall of the tube 124. The upper ends of the tubes 122 and 124 are provided with in20 turned flanges 135 and 136 which constitute spacing and .supporting means for the cylindrical vapor deflector or protecting wall 132, having an outturned flange 137 for engagement with the flange 136. This form of the 25 apparatus may also, if desired, be provided with indicating symbols of the type herein described. \ - . '

In the preferred form of the invention the temperature indicating material is preferably ³⁰ secured-.to the spout of the radiator where it may be readily seen from the driver’s seat, but it should be understood that the indicating material may be applied to any other.suitable or convenient part of the engine or motor ³³ vehicle which changes its temperature in accordance with the temperature of the water in the cooling system.

The apparatus may, in some cases, be simplified by the omission of the enclosure for 40 providing a dead air space about the temperature indicating material. Such, a simplified construction is illustrated in Fig. 4 in which·. 20 designates the filler opening or spout-and21 the cap, both of-which may be of usual and well 45 known construction. Upon the exterior surface. of .the spout is painted or. otherwise applied a band 25 of temperature indicating material, which may be of the triple layer compo-.' sition·,, above.described,.-or- simply a layer of so tlietempeiature indicatingmaterial secured to the spout in any suitable manner. The band of temperature indicating material may be protected by applying over the'surface of the spout and the band 25. a coating of varnish. 55 or other transparent protective material 35.

•In Fig. 5 is shown still another slightly modified form of construction. In this form of construction the indicating material 25 is applied to a damping ring 150, of conven60 tional mechanical construction,, which may be clamped about the radiator spout, thus providing an indicating device of the character described above, The thickness of the clamping ring may be controlled as desired 0» to give the desired temperature drop between the indicating material, which as stated above, will normally change color at approximately 150° F„ and'the material whose'temperature is to be indicated, in the particular embodiment illustrated that material being the water 70 within the radiator. In such a construction, it may be necessary to provide heat insulating material 151 in addition to the thickness of the . clamping member in order to interpose srdlicieni resistance-to the transfer of heat'to that ⁷⁵indicating material,—that is, to provide the necessary temperature drop between the body whose temperature is being indicated and the temperature indicating material.

It is not essential that this be done by means 80 of the interposition of heat insulating material, as it may be just as well done by controlling the thickness of the layer of metal or other material interposed between the indicating material and the body whose tern- 85 perature is being indicated. Furthermore this control may also be secured by properly varying the character of the material of which the clamp, or analogous part, is constituted; some metal such as copper for example being ⁹⁰better conductors of heat than other metals, so that by properly controlling the nature of . the material upon which the indicating means is mounted the proper temperature controls may be secured, .

Tn Fig. 6 is 'shown still another slightly modified form of construction in which the . indicating device is attached to a. bearing for an engine to indicate abnormal temperature conditions at such bearing, As illustrated ¹⁹⁹this is done by applying the indicating material 25 to the face of a disk or plate 160, which is in turn bolted or otherwise suitably secured to the bearing 161. Here again the necessary heat transferring resistance should ⁷⁹⁵be incorporated, and this may be done by varying the thickness of the plate 160, varying'the material of which it is composed, interposing suitable heat insulating material, or in any other similar way. , no

Of course indicating characters may be used if desired in the clamping ring form of Fig. 5, or the plate form of Fig- θ·

To facilitate application of .the temperature indicating material the latter may be pre- Π5 pared as a transfer by mounting it on a paper or other suitable backing from which it may be transferred to the object the temperature of which is to be indicated, in the manner of a decalcomania transfer.- One method of pre- ¹²⁰paring such a transfer is to coat one face of the paper with a water-soluble compound, apply thereon a coating of insoluble material such'as collodion, then a layer of the iodomercurate of copper or other indicating material ⁷²³in the shape of the indicating symbol desired, then cover this with a layer of water insoluble material such as collodion, and, finally, apply a coating of water-soluble adhesive. The temperature indicating material is thus en- ⁷⁹⁹

1,693 cased in a protective coating of collodion, and tlie whole may be transferred from the paper backing to any desired object by soaking the transfer in water applying the adhesive sur• ⁵ face to the object and then peeling off the backing, thus leaving the collodion-covered indicating material adhering to the object. While one method of preparing the transfer has been described it should be understood 10 that this is merely illustrative and that any other suitable method may be employed.. In the present instance the indicating symbol is in the form of a band or ribbon, but it will be obvious that it may take any desired form.

While the indicating material is herein described as forming a complete ring about the spout, it should be understood that in either form of the device, the indicating material may be omitted from certain parts and re²⁰ tained only on that surface which is visible from the driver’s seat.

While, the forms of apparatus herein described constitute preferred embodiments of the invention, it is to be understood that the invention is not limited to these precise forms of apparatus, and that changes may be made in either without departing from the scope of the invention which is defined in the appended claims.