US2318989A - Automatic safety switch for automotive vehicles - Google Patents

Description

y 11, 1943- c. E. DEARBAUGH 2,318,989

AUTOMATIC SAFETY SWITCH FOR AUTOMOTIVE VEHICLES Filed April 7, 1941 Jnventoi' Www (Ittorneg 62 lFFOKO E. OEAmm/ H.

Patented May 11, 1943 UNITED STATES PATENT OFFICE AUTOMATIC SAFETY SWITCH F OR AUTOMOTIVE VEHICLES 7 Claims.

The present invention relates broadly to automatic switches and more particularly to an improved safety device for automotive vehicles which is operable, upon excessive shock to or tilting of the vehicle beyond a predetermined angle. to cut off the flow of current to the ignition and other electrical circuits associated with the motor.

Although especially designed for-automobiles, the invention is readily adaptable to commercially flown airplanes, where the normal operating position of the plane is substantially constant, and in fact to any type of vehicle powered by an internal combustion engine having an electrical ignition system and which uses a volatile, highly inflammable fuel.

One of the greatest hazards attendant upon automobile collisions or upsets and airplane crashes is the danger of fire or explosion due to the igniting of vapors of spilled gasoline which, when mixed with air in proper proportions, form a dangerously explosive gas. Ordinarily, manifolds and exhaust pipes do not become sufliciently hot to ignite gasoline, but I have found that the fires and explosions which so often follow accidents are almost invariably caused by contact of the highly combustible fumes or vapors of escaping fuel with high tension wires or short circuits in the electrical system, or by flames from the exhaust in cases where the motor continues to operate after overturning of the vehicle.

It is therefore an important aim of my invention to provide an automatic safety switch of novel construction and design which, when properly installed in an automobile, will instantly open the electrical circuits to the motor and stop the engine whenever the car sways or tilts to what has been determined to be a dangerous angle, and which will cause these circuits to be positively and permanently broken in the event of an upset or serious collision.

Another object of the invention is the provision of an automatic switch of the above character which will insure a constant and uniform supply of current to the motor during normal operation of the vehicle by maintaining the electrical circuits closed during any and all non-hazardous operating conditions.

Still another object is the provision of an automatic safety switch of this kind which can be completely assembled before shipping and can be readily put into operating condition after installation without any special adjustments.

Further objects and advantages will be apparent during the course of the following description when taken in connection with the accompanying drawing.

In the drawing wherein like numerals are employed to designate like parts throughout the same:

Fig. 1 is a vertical section through a complete switch as received from the factory and ready for installation;

Fig. 2 is a Vertical section through the switch after it has been installed in an automobile and is ready for operation;

Fig. 3 is a section taken substantially on line 3-3 in Fig. 2;

Fig. 4 is a diagrammatic view showing the position of the mercury receptacle when the automobile has been tilted to a dangerous angle;

Fig. 5 is a view similar to Fig. 4 showing the position of the mercury receptacle when the automobile has been partially overturned; and

Fig. 6 is a section taken substantially on line 6-6 in Fig. 2.

Referring now more particularly to the drawing, wherein has been illustrated a preferred embodiment of my invention, the letter A designates in its entirety an automatic safety switch adapted to be attached to the front face of a dashboard B of an automobile (Figs. 2, 3 and 6). As here shown, the switch A comprises a cylindrical, outer casing ll), of metal, plastic or other desired material, within which is arranged a mercury cup" or receptacle II,

The receptacle II is supported by a pair of downwardly extending wire electrodes l2 and I3, mounted at their upper ends in the square heads 14 and I5 respectively of threaded posts I6 and I1 passing through suitable openings in the side walls of the casing l0. Threaded upon the posts [6 and I! in a manner to rigidly secure them to the casing III are nuts I8 and I9 respectively, said posts and nuts being insulated from the casing by means of fiber washers or the like 20 clamped therebetween. Held tightly against cylindrical extensions 2| and 22 of the nuts l8 and ill, by means of screws 23 and lock washers 24, are termlnals 25 and 26 whereby the switch A may be interposed in the electrical circuit of the automobile.

In forming the receptacle II a length of glass tubing is preferably used, said tubing being bent into a substantially V shape having a flattened apex which provides a restricted passageway 2! connecting the diverging arms 28 and 29 of the V. Each of the arms 28 and 29 is bent again as at 30 to form upwardly and inwardly directed portions 3| thereon, while a part of the edge of the tube, at either end, is turned sharply over to form inwardly directed lips 32. The shaping of the glass tubing in this manner forms a vertically elongated receptacle having two substantially vertical arms or compartments 28 and 29 which are open to the atmosphere at their upper ends and connected together at their lower ends by a restricted passageway 21 of relatively smaller cross section than the arms.

In order to retain and support the receptacle ll within the casing it, each of the electrodes l2 and I3, which extend downwardly into the tubular arms 23 and 29 respectively of the receptacle, is formed with an upper, hooked section 33 which embraces one of the lips. 32, a

straight intermediate section 34 which extendsacross to the opposite wall of its respective arm and into engagement therewith at thebend 30, and a 1 wer section 35 at an angle to the intermediate section 34 and which extends downwardly toward the apex of the V in spaced relation to the side walls of thearm.

The lower portion of the receptacle H contains a supply ofv mercury or other dispersible electrical conducting medium 36 which bridges the electrodes l2 and I3 and thus completes and maintains an electrical connection between the terminals 25 and 26 as long as the switch A is in a substantially vertical position. Due to the tubular shape of the receptacle I I, it is necessary to use only a Very small amount'of mercury. However, the amount is carefully measured because the height of mercury in the arms 28 and 29' of the receptacle-determines the angle to which the vehicle can. tilt before the electrical.

circuit; will be broken.

In order to permit the switch A to be readily mounted in an automobile, there ispermanently secured to the casing IS an encircling band 3T having laterally extending ears 38 and.39 provided with screw holes 46. The upper and lower ends of the casing- 10 are closed by plates 41 and 42 respectively, and it is preferred that these be made non-removable to prevent tampering with the interior of the switch, although.

penings 43-and 44 are provided therein for reasonsto be more clearly hereinafterset forth.

Aspointed out above, one of the features of my. invention is the fact that the automatic switch may be completely assembled,. adjusted 28 and 29 respectively of the receptacle H. The.

open ends of the receptacle are then closed airtightly and the legsof theretractible element sealed therein by means .of a suitable hardeningj sealing material 48; With the receptacle II closed inthis manner, the mercury 36 therein will not only be prevented from escaping but,: in

addition, will be held from any movement during handlingof the switch by the pressure of the air trapped within the arms 28 and 29 ofthe receptacle.

In installing the switch A in an automobile, it is preferably secured to. the engine side of the dashboard B by means of screws. 59 passing through openings Ml inuthe ears38 and'Sfi. Although not essential, it is desired that the switch be positioned as nearly as is practicable to the center of gravity of the automobile so as to minimize the tendency of centrifugal force to retain the mercury 36 within the receptacle Ii should the vehicle turn completely over at high speed. After being properly mounted, the switch is interposed in the electrical circuit of the automobile, preferably in series with the line from the ammeter to the coil, and this is accomplished by simply cutting the line and then attaching the cut ends 5i] and El thereof to the terminals 2.5..and 26.

The switch may then be placed in operatin condition by grasping the upper end of the retractible element &5, which projects upwardly throughthe opening 43 in the plate 4 I, and drawing'it up through the opening as shown in Fig. 2. The removal of the legs 46 and 41 from the receptacle II will break the seal at the ends of the arms 28 and 23 and in order to facilitate a complete removal of the sealing material 48, the legstfi and 41 are-providedwith hooks or projections 52 on thelower ends thereof.

With the removal of the retractible element 45, the receptacle II will bev open to the at.- mosphere. However, the sharply inclined walls of the V shaped. portion of the receptacle and.

the restricted passageway 21 therein will act to baffle the movement of the mercury 36 to such an extent that itwill beretained in sub-- stantially normal position during severe Vibratory motion, such as is. experienced in driving.

over extremely rough .roads; or against laterally applied centrifugal force, suchas that resulting. :from rounding curves at high speed; but will.

not affectthe tendency of the mercury 36 to flow freely under the influence of gravity, upon tilting of the vehicle to one side or. the other.

In other words, the' receptacle H has been so designed that themercury 36 will be maintained in position'to close the electrical circuits. during all adverse'but non-dangerous operating conditions but will bepermitted to flowreadily out of normal position to open the circuits. should the vehicle show a tendency to upset by assuminga lateral tilt.

The action of the switch'n'during tilting of the vehicle in which it is installed can best be understood by, reference: to Figs; 4 and 5 hicle assumes alateral tilt to theright of more than ifixdegrees (this has been'determined tobe a dangerous angle), the receptacle H of the.

switch A will assume the position shown in Fig. 4

which will cause theimercury 36 to flow into.

the :arm 29hr. the receptacle, and away-from theelectrode 52, to open the electrical circuit and. As the engine stops, the.

turn oil the. engine. car will of course slowdown and should it then regain an upright positionthe. circuit will be automatically reestablished andthe engine'again permittedto operate. However, shouldthe automobile lose its equilibrium and fall. onto its side or turn upside down, thereceptacle II will 7 pass throughtheposition shownin Fig. Sand the mercury will'fl'ow out through the endof' the arm 29 and into the'casing.iil'from'which' it will discharge through oneof" the openings 43' and 4 1. The exhausting ofthe mercury 36 from the'switch will of course permanently break the circuits and they can not again be closed without replacing the mercury. This will be the case regardless of whether or not the Garcontinues to 'roll over and even though it-final-ly returns to-its normal upright position.

For example, when the Ve In connection with the reestablishment of the electrical connection after a temporary opening of the circuits, it will be noted that the ends of the electrodes 12 and I3 are flattened at their lower ends to form a relatively sharp edge 53 which will quickly break the skin or surface tension of the mercury. On the other hand, the fact that the lower sections 35 of the electrodes l2 and I3 are spaced from the walls of the receptacle II will prevent any possibility of an accidental connection between the electrodes after the mercury has been exhausted by contact with a film of mercury on the receptacle walls.

In addition to providing protection from fires resulting from upsets, my invention also contemplates the added feature of means for breaking the electrical circuits in case of a serious collision in which the vehicle does not overturn. As best shown in Fig. 6, this construction includes a swingably mounted weight or hammer 54 and an anvil 55 both arranged within the casing H1 at opposite sides of the receptacle, II. The hammer 54 is carried at one end of a strip of spring steel or the like 56 secured at its op posite end to the inner wall of the casing ID as at 51, so that as the hammer 54 swings to the right, it will strike the receptacle II at about the apex of the V. The anvil 55 is fixed to the opposite wall of the casing l and so positioned that the relatively sharp edge 58 thereof is very near or in contact with both arms 28 and 29 of the receptacle ll near the bend 30.

The length and resilience of the strip 55 is such that sudden stopping of the vehicle or ordinary impacts will not swing the hammer 54 far enough to contact the receptacle I I. However, upon severe shock, such as that resulting from a serious collision, the hammer 54 will be thrown against the receptacle II with suflicient force to break it on the anvil 55 and spill the mercury 36 therefrom.

It will be noted from the above that in the event of either an upset or a collision, the electrical circuits to the motor will be instantly and permanently broken by exhausting the mercury from the switch A. This feature is an extremely important one because once an automobile has turned over or sufiered excessive shock, the vapors from the gasoline spilled thereby will burst into flame or lead to an explosion, upon contact with a spark from the electrical system or flame from the exhaust, even though the car is in an upright position at the time. Further, the fact that an element of the switch must be replaced, after an upset or collision, before the ignition circuit can again be closed has the additional advantage of preventing unauthorized persons from driving away a car, when injuries have forced the occupants to temporarily abandon it after an accident.

It is to be understood that the form of the in vention herewith shown and described is to be taken as the preferred embodiment of the same, and that various changes in the shape, size and arrangement of parts may be resorted to without departing from the spirit of the invention or the scope of the subjoined claims.

I claim:

1. In an automotive vehicle including an electrical circuit, an automatic safety switch interposed in said circuit comprising an open receptacle formed of a tubular member having two spaced, substantially vertical arms communicating directly with the atmosphere at their upper end and a passageway connecting said arms at their'lower ends, a pair of spaced electrodes mounted outside of said receptacle and extending downwardly one into each of the arms of said tubular member to support the same, and a measured amount of mercury within the receptacle and bridging said electrodes whereby the electrical circuit will be maintained closed during normal operation of the vehicle but will be opened whenever the vehicle is tilted to a dangerous angle and permanently broken should the vehicle tilt beyond such angle to a degree suflicient to permit the mercury to flow from said open receptacle into the atmosphere.

2. In an automotive vehicle including an electrical circuit, an automatic safety switch interposed in said circuit comprising an open receptacle formed of a substantially V shaped tubular member having diverging arms open at their upper ends and connected together at their lower ends by a passageway at the apex of the V, a pair of electrodes mounted outside of said receptacle and extending downwardly one into each of the arms of said tubular member, each of said electrodes being shaped to engage the walls of said arms in a manner to support the receptacle but having their lower portions spaced from said walls, and a measured amount of mercury within the receptacle and bridging said electrodes whereby the electrical circuit will be maintained closed during normal operation of the vehicle but will be opened whenever the vehicle is tilted to a dangerous angle and permanently broken should the vehicle tilt beyond such angle to a degree sufllcient to permit the mercury to flow from said open receptacle.

3. In an automotive vehicle including an electrical circuit, an automatic safety switch interposed in said circuit comprising a casing, an open receptacle formed of a substantially V shaped tubular member having diverging arms communicating directly with the atmosphere at their upper ends and connected together at their lower ends by a passageway at the apex of the V, a pair of spaced electrodes carried by said casing and extending downwardly one into each of the arms of said tubular member for supporting the same, and a measured amount of mercury within the receptacle and bridging said electrodes whereby the electrical circuit will be maintained closed during normal operation of the vehicle but will be opened whenever the vehicle is tilted to a dangerous angle and permanently broken should the vehicle tilt beyond such angle to a degree sufllcient to permit the mercury to flow from said open receptacle into the atmosphere.

4. In an automotive vehicle including an electrical circuit, an automatic safety switch interposed in said circuit comprising a casing, an open receptacle formed of a substantially V shaped tubular member having diverging arms connected together at their lower ends by a passageway at the apex of the V and provided with upwardly and inwardly directed extensions open at their upper ends, a pair of spaced electrodes carried by said casing and extending downwardly one into each of the arms of said tubular member, said electrodes being shaped to engage the walls of the tubular member in a manner to provide a supporting and retaining means therefor, and a measured amount of mercury within the receptacle and bridging said electrodes whereby the electrical circuit will be maintained closed during normal operation of the vehicle but will be opened whenever the vehicle is tilted to a dangerous angle and: permanently: broken should the vehicletilt-'- beyond such angle tore. degree sufficient'toi permit 1 the mercuryi'toflowifromsaidopenireceptacle.

5; In an" automotive:vehicle-including anielec= trical circuit; an: automatic safety: switch. inter posed in said' circui-tficomp-rising an openi receptacle formed or T a tubulari member having two I spaced; substantially vertical-armscommunicat ing directly with the 'atmospliere at their upper" ends and a constricted I passageway of smaller cross section than said. arms connecting the arms at their lower ends, a pair of'spaced electrodesarranged one within each-or said arms, an'cl'a measured amount of mercury within thereceptacle" and bridging said electrodes whereby" the electrical circuit will lee-maintained closed; during" ends, a pair of spacedelectrodes arrangedonewithinzeach'of said-arms, and ameasuredamount of mercury: within: the: receptacle: and: bridging said' electrodes whereby-the: electrical circuit 'will be maintained closed fduringsnormal o-peration of' the vehicl'e but will be? opened whenever the:

VehicIe -is tiIted to a dangerous angle and permanently broken should the vehicle-tilt beyond such angle to-- a degree sufficient to permit the mercury to -fibw from said open receptacleint'o the atmosphere:

7! Inan" automotive vehicle-including an elec-' tricalcircuit, an automatic safety switch interposed-"in said circuit comprising-an-open receptacle formed of a substantially V shaped tubular member having arms communicating directly witntheatmosphere'at'tlieir'upper ends and conn'ectedtogether' at their lowerendsby a constricted.passagewayxofflattened cross section at theaperofthev, a pair of spvaced'electrodes arrangedone withineach of said arms, and a measuredainountl'of mercury'within the receptacle and" bridging saidelectrodes whereby. the electrical circuit'will be'maintained closed during normal-operation of the vehicle but will be opened whenever the vehicle istilted to a dangerous angle and permanently broken should'the vehicle tilt beyond-such angle toa degree sufiicient to permit the mercury. to vflow from said open receptacle into the atmosphere" CLIFFORD E. DEARBAUGH.

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