Search Images Maps Play YouTube News Gmail Drive More »
Sign in
Screen reader users: click this link for accessible mode. Accessible mode has the same essential features but works better with your reader.


  1. Advanced Patent Search
Publication numberUS3281783 A
Publication typeGrant
Publication dateOct 25, 1966
Filing dateJan 22, 1964
Priority dateJan 22, 1964
Publication numberUS 3281783 A, US 3281783A, US-A-3281783, US3281783 A, US3281783A
InventorsAdams Frank C
Original AssigneeAdams Frank C
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Engine overload indicator
US 3281783 A
Abstract  available in
Previous page
Next page
Claims  available in
Description  (OCR text may contain errors)

Oct. 25, 1966 F. c. ADAMS ENGINE OVERLDAD INDICATOR Filed Jan. 22, 1964 mmQmOU mm mun HEM:

INVEN TOR. FRANK C. ADAMS Barg w United States Patent 3,281,783 ENGENE OVERLQAD llNDIiCATOR Frank C. Adams, 48 Evans Ave, Albertson, NCY. Filed Jan. 22, 11964, Ser. No. 339,386 3 Claims. (U. 340-53) This invention relates to overload indicators for internal combustion engines and more particularly to those in vehicles.

Overloading engines is a major cause of engine and clutch trouble in trucks and vehicles and leads to costly repairs. By overloading is meant running the engine in too high a gear for the conditions, for instance, running in second gear or climbing a hill in high gear when it should be in second gear.

The present invention provides means to warn the driver of overload conditions and also provide recording means to note the number of times and the duration of overload conditions. The invention is useful in training drivers, and checking the performance of drivers. For instance, the supervisor of a truck fleet would have a check on the efficiency of his drivers with respect to overloading conditions. This will minimize repair work by minimizing the amount of driving under overload conditions.

The present invention provides means for indicating overloading of internal combustion engines of the type having an intake manifold and a generator connected to the engine. A pressure responsive switch is connected to the intake manifold. The switch has adjustment means to adjust it to make contact at a predetermined manifold vacuum for instance, two inches of vacuum. Under overloading conditions the vacuum decreases. The switch is energized by the generator and when overloading conditions occur a warning device such as a light or buzzer is energized. A recorder is also connected in parallel with the warning device. The recorder may be a sealed instrument which may be the owner or supervisors to check the drivers efficiency of the driver.

Accordingly, a principal object of the invention is to provide new and improved means for indicating overload engine conditions.

Another object of the invention is to provide new and improved recording means for recording the number of overloading times and duration of such overloading.

Another object of the invention is to provide new and improved means for indicating overloading of an internal combustion vehicle engine having an intake manifold, a generator, a pressure responsive switch connected to said intake manifold, means to adjust said switch to a predetermined manifold vacuum corresponding to a predetermined overlapping condition and an indicator means connected to said switch and recording means connected to said switch.

These and other objects of the invention will be apparent from the following specification and figure which shows an embodiment of the invention with a schematic circuit.

Referring now to the figure, the invention generally comprises a diaphragm device 1 which is connected to the intake manifold 2 of the internal combustion engine. The pressure responsive diaphragm device may be similar to a conventional spark advance device generally used in motor vehicles. It comprises a casing with a flexible diaphragm 3 in the center thereof. The diaphragm is connected by means of the member 4 to a switch 5 and the member 4 is spring loaded by the spring 6 in the direction to close the switch.

The switch will be kept opened by normal manifold vacuum which will cause the diaphragm to move to the left of the figure. When the vacuum decreases to a pre determined level, then the switch will be closed.


One contact of the switch is connected to the generator 7, which is connected to the engine in a conventional manher. The other contact of the switch is connected to a warning light 8, an audio alarm 9, and a recorder 10 in parallel. The alarm 9 may be a buzzer or other audio warning devices. The recorder 10 may be a conventional recorder of the type indicating the number of instances of overloading and also indicating the cumulative time of the overloading of the engine. A flasher 11 is preferably connected in series with the parallel connection of light 8 and alarm 9.

The switch 5 is adjustably mounted by means of the slotted bracket 12 which is connected to the vehicle frame. The switch is adjusted by means of the nut 14 fixed to the switch case and threaded shaft 15 which passes through the nut 14. The position of the switch with respect to the slots may be chosen by handle 16 so that the switch may be energized at a predetermined manifold vacuum corresponding to an engine overloading condition. The handle 16 may be calibrated by index 16' on the vehicle frame and a corresponding index on the handle.

The power supply is from the generator rather than the battery so that the indicator will not indicate when the engine is stopped, but only when the engine is operating under overload conditions. The recorder 10 may be a sealed recording device so that the owner or supervisor for instance, of a truck fleet, may inspect the recorder to check the efliciency of the driver and also provides an indication of the amount of overloading which in turn will indicate the possibility of repair work required on the engine.

In operation, the recording and warning devices will minimize overloading whereby minimize expense of repair work. Also, the invention eliminates a great number of emergency calls which are an expensive part in operating a fleet of vehicles.

Many modifications may be made by those who desire to practice the invention without departing from the scope thereof which is defined by the following claims:

I claim:

1. Means for indicating overloading of an internal combustion engine of the type having an intake manifold and a generator connected to said engine comprising,

a pressure responsive switch connected to said intake manifold,

said switch comprising a stationary contact and a movable contact,

means to adjust said switch to operate at a predetermined manifold vacuum corresponding to a predetermined overloading condition,

said means to adjust comprising means to move said movable contact with respect to said stationary contact,

and an overload indicator, said switch being connected to said generator, whereby said indicator will be energized when said engine is overloaded but will not be energized when said engine is stopped.

2. Apparatus as in claim 1 having index means to calibrate and set the position of said movable contact.

3. Apparatus as in claim 1, wherein said indicator has recording means to indicate the number of times and cumulative amount of time said engine has been overloaded.

References Cited by the Examiner UNITED STATES PATENTS 2,455,573 12/1948 Pant 123-103 X 2,692,980 10/1954 Platt 34052 NEIL C. READ, Primary Examiner.

A. H. WARING, Assistant Examiner.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US2455573 *Jul 7, 1945Dec 7, 1948Bendix Aviat CorpSignal mechanism
US2692980 *Mar 29, 1952Oct 26, 1954Ernest C PlattEngine condition signal arrangement for automotive vehicles
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3938074 *Dec 12, 1974Feb 10, 1976Borg-Warner CorporationFuel economy indicator
US4453154 *Aug 14, 1981Jun 5, 1984Tech Nomadic CorporationAltitude monitor
US4733644 *Jul 23, 1987Mar 29, 1988Brunswick CorporationFor an internal combustion engine
US4904982 *Feb 18, 1988Feb 27, 1990Outboard Marine CorporationVisual and audible warning device
US4945759 *Feb 27, 1989Aug 7, 1990Gary F. KrofchalkVehicle performance monitoring system
US5074144 *Jun 8, 1990Dec 24, 1991Gary F. KrofchalkManifold pressure speed
US5203302 *Jan 27, 1992Apr 20, 1993Tecumseh Products CompanyOverload warning apparatus for internal combustion engines
WO1989000933A1 *Jul 14, 1988Feb 9, 1989Brunswick CorpEngine overspeed control circuit with defeat detection
WO1990010210A1 *Feb 27, 1990Sep 7, 1990Gary F KrofchalkVehicle performance monitoring system
U.S. Classification340/439, 123/351, 340/326, 340/815.69, 200/83.00R
International ClassificationG08B17/04
Cooperative ClassificationG08B17/04
European ClassificationG08B17/04