US2581737A - Safety device for motors - Google Patents

Description

Jan. 8, 1952 Filed Aug. 7, 1950 A. E. WEST SAFETY DEVICE FOR MOTORS 2 SHEETS-SHEET 1 Fig.

Ari/w! 5. West INVENTOR.

Jan. 8, 1952 E, W

SAFETY DEVICE FOR MOTORS Filed Aug. 7, 1950 Arthur E- West IN VEN TOR.

Patented Jan. 8, 1952 SAFETY DEVICE FOR MOTORS Arthur E. West, Ladysmith, Wls., assignor of onefourth to Jay E. West, one-fourthto William Walters, and one-fourth to Erwin B. True, all

of mill, Wis.

Application August 7, 1950, Serial No. 178,017

30laims. i

This invention comprises novel and useful improvements in a safety device for motors, and more specifically pertains to a control device for electric circuits of an internal combustion engine of a motor vehicle for preventing damage to the engine by operation of the same when some vital element of the same, such as the lubricating system, is not operating; together" with arrangements whereby the engine may be rendered temporarily operative during the starting operation of the same and to afford time whereby the startms of the engine may be enabled to render eflective the aforesaid vital element.

The present invention relates to subject matter which is somewhat similar to but, in general, constitutes an improvement over that set forth in the prior application of George L. Hilbert, Arthur 1:. West and Jay H. West, Patent No. 2,136,504, issued November 15, 1938, for safety device for motors.

- In said prior patent is disclosed a safety device for internal combustion motors which includes means for interru ting the ignition circuit of the motor if the oil pressure should cease or reach a dangerous condition by virtue of diminishing of the same.- In general, the device disclosed in said patent operated to ground the ignition circuit when the motor was not runnin but with the motorin operation utilized the oil pressure when the same attained a predetermined minimum value, to operate upon a diaphragm for closing contacts whereby the ignition system remained in operation. In order to prevent the device from interfering with the starting of the motor by virtue of the absence of an oil pressure at that time, an electromagnetic means was provided which was arranged to be energized by the closing of the starter switch and thereby rendering the grounding device inoperative to permit operation of the ignition system, and the build-up of the oil pressure during the starting operation was intended to maintain the safety device inactive and permit the continued operation of the ignition system.

H w ver, in such a system, it was frequently necessary to continue the operation of the starting circuit for a sufliciently long period of time to permit the oil pressure to increase to a value suillcient to maintain the safety device inoperative, and this frequently necessitated the using of the starter circuit for a period of time much longer than that necessary to actually start the It is therefore an object of the present invention to provide a mechanism which shall overcome the above-mentioned disadvantages and, in general, which will interrupt a vital function necessary to the engine operation as the ignition circuit. when some vital engine function, much as the oil pressure system, is not operating idequately; but at the same time to provide an automatic mechanism for overriding the safety device for a predetermined period of time to permit the engine to operate for an interval of time normally sumcient to bring the vital element of engine operation to a satisfactory working condition.

More specifically, the present invention contemplates the provision of a safety switch dis posed in series in the ignition circuit of the engine, which safety switch normally maintains the ignition circuit open except when the switch is closed in response to proper operation ofsome engine vital element, as, for example, an adequate pressure in the engine lubricating system. Further, the invention, as disclosed, includes an electrical by-pass circuit for by-passing the safety switch to maintain the ignition circuit in operative condition, this by-passing circuit having a relay switch controlling the same, which relay switch is automatically closed while the starter circuit is being energized. Still further, the invention includes a solenoid for energizing the relay switch, the solenoid itself being operative to connect the relay switch directly to the storage battery and thus retain the relay switch in operative position, together with a time-controlled switch for rendering the solenoid inoperative after a predetermined time interval.

These, together with various ancillary features and objects of the invention which will later become apparent as the following description proceeds, are attained by the present invention, a preferred embodiment of which has been illustrated, by way of example only, in the accompanying drawings, wherein:

Figure 1 is a diagrammatic view illustrating the electrical circuits forming a part of the present invention;

Figure 2 is a vertical transverse sectional view through a pressure operated safety switch for the ignition circuit;

Figure 3 is a horizontal sectional view taken substantially upon the plane indicated by the section line 3-3 of Figure 2;

Figure 4 is a top plan view, with the cover removed. of a solenoid assembly forming a part of the automatic control mechanism of the by-pass circuit in accordance with this invention;

Figure 5 is a bottom plan view of the same; Figure 6 is a vertical longitudinal sectional view through the arrangement of Figure 4;

Figure 7 is a side elevational view of the arrangement of Figure 4, the cover being removed; and

Figure 8 is an end elevational view taken from the left of Figure 4 and the right of Figure '1.

Referring now more specifically to the accompanying drawings, wherein like numerals designate similar parts throughout the various views, attention is directed first to Figure 1 ,for an understanding of the various electrical circuits forming a part of the invention and the manner in which they are interrelated to effect the operation of this invention.

Indicated at I0 is any suitable source of electric power, such as -a storage battery, which is grounded as at l2, and which is provided with a conductor I4 for supplying current from the battery to any place of use. It will be understood that the battery I6 may be provided with a generator; or that any other desired source of power than the battery may be employed, as

desired.

From the terminal I6 01 the lead I4, current is supplied from the battery I0 to two separate conductors I6, 26.

The conductor I6, by means of a conventional form of starter switch 24, delivers current from I circuit which includes the customary and conventional ignition switch 34, a safety ignition switch 36, an ignition breaker cam 36 operating a breaker shaft 46, and the customary breaker points 42 for supplying current to a spark coil. indicated generally at 44, the primal-v of which is grounded as at 46. The secondary of the spark coil, 46, is connected by a conductor 50 to the spark distributor switch contact 52 which rotatably engages the plurality of stationary distributor contacts 64, each of which is connected to one of the conventional spark plug leads 56 from which current is delivered to the spark plug of the engine, in a manner well understood in the art, but not illustrated.

It will thus be apparent that the above described ignition circuit is energized or rendered operative at all times by the closure of the con-' ventional ignition switch. 34, except when the safety switch 66 is actuated to open the circuit.

However, a, by-pass circuit is provided for bypassing the safety switch 66 under certain conditions to be hereinafter set forth, so that when the conventional ignition switch 34 is closed, and the by-pass circuit is closed, the ignition circuit will be rendered operative, even though the safety switch 66 is open. This by-pass'circuit includes a conductor 66 connected to the conductor 20 between the switches 64 and 36 as by a connection 66, the conductor 66 in turn being connected as at 62 to a switch arm 64 having amovable contact 66 operatively engageable with a stationary contact 66 but yieldingly urged to its open position, as by a spring III, the arm 64 being held against a fixed stop or the like I2. However, when the arm 64 is actuated against the resistance of the spring 10 to close the contacts 66 and 66,

current supplied by the conductor ISB-is then delivered by a conductor I4 to a connection I6 which is in the ignition circuit on the other side of the-safety switch 36 from the connection 60,

whereby, when the contacts 66 and 68 are closed,

the safety switch will be effectively by-passed by a parallel connection.

In order to effect the actuation of the by-p circuit under certain conditions of engine operation, an automatic control mechanism is provided which is operatively connected with the engine starter circuit above described for initiation of its action, and is connected directly with the battery or source of electric current ID in order to complete its action.

This automatic control mechanism includes a pair of electromagnets or solenoids having magnetic cores I8 and 80, the former, when mag switch blade H6.

75 junction points 98 and 66 and through the coil netized, serving to attract the arm 64 to close the contacts 66 and 66 against the resistance of the spring III, an electromagnetic coil-82 being provided encircling the core 16, and being grounded. as at 64.

The core 60 is provided with a pair of electro magnetic coils 86 and 68, the former being connected with the conductor 30 leading from the electric conductors and fields of the starter motor 26, and having an end portion 96 which is grounded, as at 6i. The latter coil 66 is connected at one end, as at 96, to the ungrounded end of the above-mentioned coil 82, having its other end 94 connected, as at 62, to the lead I26; later to be described.

The numeral 96 designates both a pivot and an electrical connection for the end of a movable switch arm I00, the latter being urged as by a spring I02 against a stop I64, whereby the movable switch contact III6 will be normally retained away from the fixed contact I08, thereby breaking the circuit between these contacts. A conductor I I0 leads from the contact I66 and is connected to a conductor III, as at II3, which is further connected to the terminal 62 on the switch arm 64. Also connected to the terminal 66 is a conductor II4 whose other end is connected to an electric resistance heating element II6 which surrounds the bimetallic thermostatic The other end II5 of the heating element H6 is connected to the lead 30. as at I". The electric resistance heater II6 preferably surrounds the bimetallic element H8 throughout its entire length to better effect its operation. A fixed contact I26 cooperates with a movable contact I24 carried by the bimetallic element, and is connected to the above mentioned connection 92 by a conductor I28.

As so far described, it will beseen that when the starter circuit is energized, current will flow through the starter motor and thence by way of conductor 30 to the terminal point I" wherein thereare two paths of conduction provided; One path of conduction is through the coil 66 to the ground 9| as by conductor 66, thereby providing current to energize the coil 66 and thereby close the contacts I06 and I 06. Theother path of conduction leading away from the terminal point I I1 is by the lead II5 through the heating element H6 and then, as by leadv II4, to the terminal or ll the ground 34.

33 and then, as by lead I, through the normally closed contacts I and I", and thence through the bimetallic element III to the ground connection 32. mm the foregoing, it will be noted that the core II will be energized, thereby closing the contact points i and 3, whereby the switch 30 will be bypassed and the ignition circuit will be rendered operative if the ignition.

spring II if it were not for a separate source ofconduction provided by the lead III, the closed ignition switch 3| and the conductor I8 to the terminal point 62. The various operations of these circuiting devices after the system has once been placed in operation will subsequently be explained.

It will be evident that the electric heating element I I3 and the characteristics of the bimetallic thermostatic element I I3 may be so selected as to cause the normally closed contacts I24 and I23 to be opened at a predetermined interval of time, thereby deenergizing the coil 33 and thence openingthe ignition circuit in a manner subsequently to be explained.

Referring now again to the safety switch 36,

Also from the Junction poin 30, currentispermlttedtoilow through the it will be understood that the same is normally maintained in an open position, but is urged to closed position by an actuator which is dependent upon a predetermined condition of engine operation.

Referring now more particularly to Figures 2 and 3, it will be seen that this actuator, designated generally by the numeral I30, comprises a body I32 having an internally threaded connection I34 by means of which the same may be attached to ay suitable source of pressure, as by a conduit I36, which source of pressure is vital to the engine operation.

The body I3! is provided with a recess or chamber I38 which is open at its upper end and communicates with the conduit I38 through the coupling Ill. The chamber I38 is provided with a flexible top wall in the form of a diaphragm or the like Ill, the latter being maintained in position by a dielectric body I42 having a central aperture for slidably receiving a plunger I. A

second body I is secured to the body I42, and

the bodies It! and I48 have complementary recesses defining a chamber In therebetween which constitutes a switch chamber and into which the plunger I extends. A pair of terminals or connectors I50 and I52 are mounted in the body I" and extend into the chamber I", the terminal I" having a resilient switch blade I34 which is normally inherently biased or spring urged away from connection with the contact I52, but is moved against said contact by the plunger I upon upward movement of the diaphragm I in response to the attainment 01' a predetermined pressure in the chamber I33.

It will thus be apparent that when a predeterminedpressure is present in the conduit I38. the safety switch 33 will be urged to closed position.

It is to be understood that any suitable fluid pressure medium may be supplied through the conduit I36, and by properly calibrating the in Figure 1.

safetyswitch 33 may be caused to open' or close at any desired pressure, this pressure corresponding to that found to be essential for proper operation of that element of the engine which is being utilized as the control for the safety device. Thus, any suitable fluid pressure could be employed as the actuating medium, and while the pressure of the lubricating system has been disclosed in the above-mentioned patent as specifically referred to hereinbeiore, it will be readily understood that other pressure, such as water pump pressure, intake manifold pressure, exhaust pressure, fuel pump or supercharger pressure, and the like, all within the scope and principles of this invention, could be employed.

Disclosed in Figures 4-8 is a conventional arrangement for housing and mounting the various elements of the automatic means for regulating the by-pass circuit. Although this construction does not, in itself, form any part of the present invention, the same has been illustrated to render 9. practical application of the invention more readily understood. Conveniently, all of these instrumentalities are housed in a single casing, being carried by a single base or supporting plate I56 having a mounting bracket ISI whereby the same may be mounted any convenient place upon a motor vehicle, a suitable covering body I 82 being removably secured to the base I56 as s by a fastening screw or the like I. Mounted upon the base I56 is a suitable insulating plate I68 or a similar plate I63 is mounted below the base as shown in Figures 5 and 6.

A pair of electric solenoids are mounted upon the insulating pad I88 on the base I56 in any suitable manner as shown, these solenoids being indicated by the numerals I10 and I12, the former being the solenoid which houses the coil 32 and the core I8, while the latter solenoid contains the two previously described electric coils Since the actual housing, mounting and con-- struction oi the solenoids and the switches controlled thereby are-generally conventional, further explanation of the same is believed to be unnecessary, since the actual construction of these elements forms no part of the present invention, which resides primarily in the use made of these elements to obtain a novel result from the assembly.

The operation of the invention, in view of the foregoing explanation, will now be readily understood.

When the engine with which the device is associated is idle, that is,-not running, there will be no fluid pressure in the conduit I38 and consequently the safety switch 38 will'be open as shown Therefore, regardless of whether the ignition switch 34 is open or closed, no current can flow through the ignition circuit, the device thereby preventing an unintentional drain upon the battery or source of electric current It by inadvertently closing the switch :4 when the motor is not running. Moreover, since no curstrength of the diaphragm I43 and tensioning vof the switch member Ill, it is evident that the rent is flowing through the starter circuit because the starter switch 20 is open as shown in Figure 1, the various electric coils 82, 86 and 08 will be deenergized, so that the switch members 64 and I will be raised by their springs i0 and I02 against their stops it and I106 into their in operative position, whereby the by-pass circuit will be deenergized; whereby the coil 82 will be current now flows through the starter motor and from thence through the conductor 30 to the coil 86 which is in series with the starter motor, and from the coil 86 through the conductor 00, to the ground 9|. The current passing through the coil 88 thus magnetizes the core 80 and causes the same to draw the armature or switch blade i00 downwardly, thereby closing contacts 800 and I08. The closing of these contacts now establishes a circuit directly from the battery or source of current I0 by way of the conductor 20, the closed ignition switch 3t, terminal 50, conductor 58, terminal 62 on the movable arm 64, conductors H0 and MI to the closed contacts I06 and I08, and from thence through the movable arm I00 to the junction point 98 and thereby through the coil 82 to ground 4. This current flowing through the coil 02 magnetizes the core 18, thus drawing the member or movable armature 64 downwardly and closing the contacts 66 and an, thereby establishing a by-pass circuit around the safety switch 30 whereby current, despite the absence. of a suitable pressure in the conduit I36, may flow through the ignition circuit, permitting the engine to be started.

Moreover, the current flowing through the conductor 20, in the manner just described, will pass from the connection 06 through the coil 80, and by way of the conductor 94 to the connection 92, from whence the same will be grounded through the closed contacts 524 and lit, through the bimetallic element M0 to the ground 32. Finally, current flowing through the conductor 30 to the terminal point iii and thence by way of conductor II through the heating element lit passes to the junction point- @t and is grounded in the same manner as coil be. It will thus be seen that the heating circuit of the bimetallic element IIB, the solenoid d2 of the relay controllin the switch of the by-pass circuit, and the solenoid 86 controlling the normal or steady supply of current to both the heating circuit iii; and the relay solenoid 88, will all be energized. Assume, now, that the internal combustion engine has been started without any dificulty or delay, and the starter switch it is now released, or moved to its open position as shown in Figure 1. Since the starter circuit is rendered deenergized, no current will flow by way of the conductors it, 30, or the motor at from the sourceof current I0. However, the contacts 906 and 800 are still maintained closed, because once the same have been closed, current is flowing by the conductor through these contacts and through the coil 88 to ground, thus maintaining the core a energized and maintaining this solenoid in an actuate-d condition. It will be further noted that when the switch 24 is opened,-there will be a shifting of current and voltage relationship throughout the entire circuit, but most notably in the conductor M4, the heating element Hi, the conductor H5, and the coil 88 to ground OI. The result is that current is still maintained in the heating element and the solenoid by means of the conductor 20 through the closed contacts 06 and 608. Since the contacts I00 and I00 are maintained closed, current continues to flow through the coil 82, thus retaining the by-pass circuit in an operative condition.

This over-all condition of the circuit persists until such-time as the heating element IIG has heated the bimetallic thermostat us to such an extent that the latter opens the contacts I24 and E26, thus deenergizing the coil 88, which in turn opens the contacts I06 and I08; whereby the opening of these contacts I06 and I08 in turn deenergizes the coil 82 and permits the spring 10 to open the contacts 66 and 68, thereby rendering the by-p s circuit inoperative.

If, previous to the predetermined time which the bimetallic element was set to kick out, sufllcient pressure has built up in the conduit I36, this pressure will maintain the safety switch closed, thereby maintaining the ignition circuit in operative condition. If, however, suiilcient pressure has not built up in the conduit I36, thus indicating an unsafe engine operating condition. the safety switch will open and the ignition circuit will be deenergized, thereby stopping the enine.

From the foregoing, the construction and operation of the invention, together with its many advantages, will be readily understood and further explanation is believed to be unnecessary. However, since numerous modifications and changes will readily occur to those skilled in the art after a consideration of the foregoing specification and accompanying drawings, it is not desired to limit the invention to the exact construction shown and described, but all suitable modifications and equivalents may be resorted to,

falling within the scope of the appended claims.

Having thus disclosed and described the invention, what is claimed as new is as follows:

1. In combination, a source of electric energy, an ignition circuit for an internal combustion engine and connected with said source, a switch in said ignition circuit, means responsive to lubricant pressure of an internal combustion engine for operating said switch, a starter motor circuit for an internal combustion engine and connected with said source, a by-pass circuit connected with said ignition circuit and operable to by-pass said switch, a relay switch controlling said bypass circuit, a solenoid for operating said relay switch, means responsive to energlzation of said starter circuit for actuating said solenoid.

2. In combination, a source of electric energy. an ignition circuit for an internal combustion engine and connected with said source, a switch in said ignition circuit, means responsive to lubricant pressure of an internal combustion engine for operating said switch, a starter motor circuit for an internal combustion engine and connected with said source, a by-pass circuit connected with said ignition circuit and operable to by-pass said switch, a. relay switch controlling said by-pass circuit, a solenoid for operating said relay switch, means responsive to energization of said starter circuit for actuating said solenoid,

said last means being connected in series with saidstarter circuit.

3. In combination, a source of electric energy, an ignition circuit for an internal combustion engine and connected with said source, a switch in said ignition circuit, means responsive to lubrioant pressure 0! an internal combustion engine for operating said switch, a starter motor circuit for an internal combustion engine and connected with said source, a by-pass circuit connected with said ignition circuit and operable to lay-pass said switch, a relay switch controlling said by-pass circuit, a solenoid for operating said relay switch, means responsive to energization of said starter circuit for actuating said solenoid, additional means responsive to energization of said starter circuit for connecting said source to said solenoid for maintaining said relay switch in-closed position for a predetermined time.

REFERENCES CITED tile 01 this patent:

UNITED STATES PATENTS Number Number ARTHUR E. WEST. 30

Name Date Jackson Apr. 1, 1919 Johnstone Dec. 27, 1927 Pilla Apr. 18, 1933 Finnegan Apr. 23, 1937 Hilbert et al. Nov. 15, 1938 Gill July 22. 1941 FOREIGN PATENTS Country Date Great Britain July 1. 1934

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