US1667027A - Temperature-indicating apparatus for vehicle-propelling motors - Google Patents

Description

April 24, 1928.

l H. H. BoYcE TEMPERATURE INDICATINGAPPARATUS FOR VEHICLE PROPELLING MO-TORS Filled July 29. 1925 Patented Apr. 24, 1928. l

UNITED STATES PATENT oFFlcE.

HARRISON H. BOYCE, OF JERIQHO, NEW YORK.

Applicatia mea July 2a, 1925. serial No. 46,731.

. In my Patent No. 1,206,781?, dated November 28th, 1916, I have, disclosed an invention in means for indicating the thermal condition of internal combustion engines of automobiles,l aeroplanes. and the like, v by which it is possible to secure at all times an indication of the thermal condition of the engine, said indication being rendered readable at the desired location as by means of l an indicating instrument located on the vehicle dash board, which is connected by suitable operative means with a temperature responsive element thermally associated with the engine or cooling system.

In the construction illustrated in said patent, the instrumentality employed comprises a temperature responsive element which isshown as immersed in the cooling liquid in the return pipe of the engine, this temperature responsive element being connected by a flexible tube to an indicating strument mounted on the vehicle dash. The

present invention relates to a system of the general character set forth in said atent and comprises particularly anim rov or alternative mode of applying te temperature responsive element'to the engine.

The specific construction illustrated in my patent embodying the immersion of the d bulb'or temperature responsive element in the cooling` liquid, while'very eifective in securing the thermal responsiveness `of the instrument, is vopen to certain objections from'a' mechanical standpoint in that it req'uires the making of an aperture in some part of the wall of the cooling system to admit the bulb and it also requires the conv structionr and maintenanceof a iiuid tight joint so as to prevent leakage. While a 1,40 satisfactory construction of this character is vperfectly feasible with the exercise of proper care there nevertheless exists the danger that when an attachmentof thel bulb 1s attempted by unskilled Ahands or in a careless.

In accordance withthe temperature of an outer surface of a motor wall, as for example the cooling jacket of an air cooled motor or the cylinder wall of a'motor of the air cooled type, may

for practical purposes be taken asv a sufficiently accurate measure of the temperature of the engine cylinder.

In the present a plication I propose to describe and claim t e invention with particular reference to air cooled motors. Inaddition, however, it is my intention to cover herein other features of my invention which are applicable to a water cooled as well as an air 'cooled type of motor.

In the accompanying drawingsLin which I have illustrated certain preferred embodiments of my invention:

Figure 1 is a side elevation, diagrammatic in'character, of an engine of the air cooled type, hood and a portion of the dash of an automobile.

Figure 2 is a detailed view in side elevation of thev means for securing the temperature responsive element to the cylinder jacket.

Figure 3 is' an enlarged vertical sectional 'view through a portion of the engine cylinder and a temperature responsive element attachedgthereto.

Figure 4 is a vertical sectional View of a form of indicating instrument which may be employed in carrying out my invention.

Figure 5 is a' face view of the instrument, parts being broken away to show the interior construction.

Figlure 6 is a diagrammatic view illustratmg t e application of one feature of the invention to a water cooled motor.

Referring to the drawings in detail, and particularly to Figures 1 to 5, the numeral 1 designates an automobile engine provided with lcylinders .2 containing the customary l pistons 2. As shown, the side walls of the cylinders are'surrounded by cooling fins 3. As the i nitionand combustion or explosion of the c arge takes place primarily in the upper ends of the cylinders when the istonsd are at or near the upper limits o their strokes, it will be seen that these portions of the cylinders constitute combustion chambers (designated by the numeral 4) Where the greatest temperature is reached.

The engine ,described is shown connected with the usual instrument board 16 which forms a part of the vehicle body and which is as customary located immediately'in front being enclosed on the outer side b of the drivers seat so that instruments placed thereon may be readily observed by the driver whenoperating the car.

In accordance with the present invention, I have provided means for indicating the thermal condition of the engine comprising an indicatingdevice or instrument proper locatedin a position convenient for observation and connected in an operative manner with temperature responsive or sensitive element applied in suitable thermal relation to the engine, preferably to the outside of an engine cylinder, when the element is applied to a finned cylinder it is preferably applied to a portion of the exterior surfaces unprovided with coolingiins 3. As illustrated, an indicating instrument 22 is mounted on the dash or instrument board 16 and is connected by means of a flexible tube 21 to bulb 20 preferably of metal attached' to the cylinder, and preferably containing an expansible fluid, eitherv gas ory liquid. The bulb and its contents thus lconstitute the temperature responsive part of thel apparatus. The specific construction of the indicating instrument proper is no part of the present invention and this instrument may be of any suitable character. As illustrated, it comprises a Bourdon tube 23 which is in communication with the tube 21, the free'end of the Bourdon tube being connected-with a lever 24, pivoted at 25 and carrying on its outer end a toothed segment 26 which meshes with a pinion 27 carrying an indieatingl hand 28 which is adapted to move over a scale 29. Changes in pressure or volume due to the expansion and contraction of the fluid in the bulb 20 will cause corre- -spending movements of the indicating hand in a well understood manner.

As will be understood, the arrangement herein disclosed aims to dispose the temperavture responsive element or elements so as to secure the desired influencing thereof, lin

accordance with the thermal condition of the' engine without having to tap the cylinders` or when applied to the water cooled engine, without having to tap the cooling system.

Therefore, I. apply a bulb or other temperature responsive element or casing containing the same in intimate thermal Contact with a heated part of the engine, for instance to thel wall of a cylinder unprovided 'with cooling fins, or to a part of the cooling system containing heated cooling'fluid. I also preferably shape the bulb or other temperature responsive element so as to secure a large surface of contact, and'insulate the outer side of the hulb so as to retain heat, as illustrated. Bulb 20 is shown flattened out and appliedto the top portion of the cylinder, it a layer 30 of asbestos or otherl heat insu ator, the bulb and asbestos layer being clamped in position by a metal casing 31,"notched at 32 to permit passage of the tube 21 and attached to the cylinder jacket in any suitable manner, as by means of three screws 33,-'e'ngaging ears 34 formed in the casing, the casing and `ears being preferably formed of an integral sheet metal stamping, although other construction inay be employed. Preferably, and as shown, the insulating layer 30 extends over an area substantially larger than that of the bulb or othertemperatiire responsive instrument whereby radiation from the area of the cylinder wall surface in contact With the bulb is minimized and a more accurate measure of the cylinder temperature 0btained. In order to improve the thermal contact between the flattened bulb and the jacket wall, the bulb is preferably united to the wall'by a metallic film 35 formed by soldering, brazing, welding or by other means. While other heat conducting films may be employed, I. prefer those of metal.

Figure 6 illustrates my invention in connection with a motor of the water cooled type. 'As shown, a temperature responsive element and covering therefor, designated generally by 40, is attached to the cylinder jacket 41, the construction of the instrument 40 and its manner of attachment to the jacket 41 being in all respects similar to what has been disclosed in connection with Figures 1 to 3, inclusive.

From ythe foregoing it will be seen that I have provided a means for indicating the thermal condition of the engine which does not necessitate the modification of or the interference with any part of the engine or its auxiliaries. It will be further seen that I have provided an effective and elicient means for indicating the thermal condition of an air cooled engine and an improved means for insuring intimate thermal contact between the temperature responsive element and the engine cylinder or jacket in the form preferably of a met-al film, this latter feature being applicable to both air and Water cooled types of motors. i

While I have described my invention with reference to thetemperature responsive instrument of a fluid filled type, it will be understood that other types, as for example,

those employing an electric current, may be used.

flattened side in intimate thermal conductivel contact with a portion of the louter surface of a cylinder wall of the motor, said means comprising a metallic casing extendin over the bulb and secured to the motor wal and ieu This application is a continuation` in part of my copending application, Serial No.

a layer of non-conducting material between said casing and the bulb, an indicating instrument located in a position to be observed by the driver when operating the vehicle, and a means connectlng said instrument for operating from bulb.

2. In temperature indicating .means for air cooled internal combustion motors of motor vehicles, the combination of a temperature responsive element having an extended surface substantially conforming to and secured in thermal contact on the outer surface of a cylinder wall defining a combustion s aceV of the motor, a casing contamng said e ement and securin same to said wall, l5

said instrument, and indicating means oper- 20 ated by said element.

In testimony whereof I have aixed my signature to this specification;

HARRISON H. BOYCE.

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