Vapor Detector Safety System

Abstract

A combustible vapor detector system providing both a proportional visual reading and a simultaneous switching function in a common instrument includes a meter relay and a vapor sensor remotely located in a compartment likely to have an accumulation of combustible vapors which operably coupled to the meter relay to control its reading at an operator's console and a plurality of switching sectors associated with the meter relay arranged to sequentially operate several independent circuits within selected meter ranges so a "safe" or "caution" condition will be indicated with auxilliary elements, such as lights or audible elements, apart from the meter readings, and a "danger" condition will trigger a disabling circuit to stop or prevent the start-up of any machinery located in the compartment containing the sensor. The switching sectors may also be employed to operate a blower to purger the compartment of any accumulation of combustible vapors and the "danger" condition can also be employed to shut off all electrically controlled machinery located in the compartment having the vapor sensor or elsewhere.

Parent Case Text

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation-in-part of application Ser. No. 198,555 filed Nov. 15, 1971 by Arthur G. Hayden, and now abandoned.

Description

BACKGROUND OF THE INVENTION

In watercraft such as motor boats, and in particular inboard motor boats, it is possible for fumes to accumulate in the engine compartment, or other compartments, under a variety of circumstances. Since these fumes are often combustible, it is possible that a small spark from mechanical equipment located in such a compartment can cause an explosion capable of destroying the watercraft or causing a hazardous fire.

A number of patents have issued which provide various safety systems for such watercarft that often involve delay circuits so a blower can purge one or more compartments in the craft before the engine is started. Typical of such patents are U.S. Pat. No. 3,315,584 issued to Van Ranst; U.S. Pat. No. 3,675,034 issued to Abplanalp; and U.S. Pat. No. 3,489,912 issued to Hoffman. A related circuit employing a switch associated with a fuel tank cap is illustrated in U.S. Pat. No. 3,652,868 issued to Hunt.

While all the above safety systems will offer some degree of protection in watercraft when properly installed, they often tend to be limited in their effectiveness and/or complicated and complex. Further, the fixed delay type circuits will often unnecessarily prevent starting or restarting the engine when no accumulation of fumes of an explosive character has occurred in the monitored compartments of a watercraft containing mechanical equipment that might ignite these fumes. Obviously, in emergency situations, such as rough weather or imminent collision, a delay in the starting cycle could lead to hazardous situations of a different character.

It is therefore an object of the current invention to provide a simple, yet highly reliable, vapor detector safety system that is inexpensive, compatible with and easy to install on conventionally configured watercraft or the like.

It is another object of the instant invention to provide a vapor detector system that provides several separate indications of the conditions sensed by the system which can be conveniently designated as safe, cautionary and dangerous.

Still another object of the instant invention is the provision of a vapor detector circuit which does not introduce needless delay in the starting cycles of engines located in compartments where possible dangerous accumulation of combustible fumes might occur when such accumulations are not present.

Another object of the instant invention is the provision of a vapor detector circuit which provides a test mode whereby the actual conditions can be pre-monitored without activating other electrical circuits within the watercraft which could cause explosions should an accumulation of fumes be present and a malfunctionion such as electrical circuits also be pre-existing.

SUMMARY OF THE INVENTION

The above objects and others can be accomplished with a combustible vapor detector system which includes a meter relay located at an operator's console which includes three sequentially arranged independent switching sectors with separate circuits associated with each of the switching sectors so these circuits are independently operated with progressively increasing meter indications providing sequential operation of these circuits and a vapor sensor located in a monitored compartment and operable to sense the presence of organic fumes with the sensor connected to operate the meter relay when the sensor and meter relay are energized with a source of electric power. Switching means are included in the circuits so the meter relay can be operated independently to sense existing conditions or in combination with electrically powered machinery control circuits, so that the machinery control circuits need not be energized until a preliminary reading has been taken by the operator. Each of the circuits designated as a safe circuit, a caution circuit and a danger circuit includes means associated therewith to provide a separate particular indication or a disabling action when the particular circuit is energized through the meter relay.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a combination diagrammatic and general schematic illustration of the vapor detection system of this invention; and

FIG. 2 is a circuit wiring schematic of the system shown in FIG. 1.

DESCRIPTION OF THE EMBODIMENT

Referring to FIG. 1, the vapor detector circuit 10 is shown diagrammatically as it would be installed on a watercraft or the like (not shown). In this figure, broken lines represent generally the wiring connections between the several remotely located components of this system and the meter relay 11 which is preferably located on the control panel of the watercraft or the like on which the system is installed. As can be appreciated when the system has been installed on a water craft or the like, the battery, the vapor sensor 19, the blower 21, the starting motor and relay 23 and the circuit breaker 25 will all be located remotely of the operator's console or control panel which is not shown. FIG. 2 shows the actual wiring schematic of the various components of the detector system in greater detail than FIG. 1.

More particularly, from the drawings it can be appreciated that key switch 24, which includes an "on" and a spring resisted "start" position, is employed to activate the vapor detector system by closing an integrally contained switch 24b that couples the battery to a three-position switch 12 in the system when the key switch is in the "on" or "start" position. This three-position switch can be rotated from the "off" position to a test position 12 b. In this test position, the vapor detector circuit is energized, but the main electrical bus bar of the watercraft, shown in FIG. 2, is not coupled to the battery when the system is in the test mode.

In the test mode, power is supplied to pointer 31 of the meter relay 11 and is also coupled, through meter coil 38 and vapor sensor 19 to ground. With respect to the vapor sensor, it can be appreciated that multiple sensors can be employed. These sensors are commercially available and is referred to in the aforementioned U.S. Pat No. 3,489,912. Since the vapor sensor is remotely located in a compartment which is to be monitored for combustible organic fumes, such as the engine compartment of a watercraft, and is arranged to proportionately decrease its resistance as the level of combustible vapors in the compartment increase, the pointer 31 will indicate a reading which is directly proportional to the level of combustible fumes which have accumulated in the monitored compartment at all times.

As the pointer 31 of the meter relay 11 gives a proportional reading of the accumulated fumes which could lead to explosions or fire, its scale can be divided into three separate independent switching sectors which sequentially with increasing meter readings are designated as the safe sector 16, the caution sector 17 and the danger sector 18. For purposes of illustration, this meter relay is shown in a most simplistic embodiment where the pointer 31 sequentially engages the sectors in a brushing contacting relationship in order to connect battery power with each of the sectors when the pointer is in contact with a sector. However, since the power utilized in the several independent circuits associated with the sectors is small, this arrangement is adequate. It is to be appreciated that should a more sophisticated embodiment be desired, other types of meter relays, such as that shown in U.S. Pat. No. 2,967,278 issued to Sullivan et al, could be employed. Further, the meter relay can be completely sealed with a glass panel 15 so the contacts within the relay will not corrode.

As can be seen from the drawings and the simple meter relay embodiment illustrated, each separate sector has a separate electrical circuit associated therewith. Safe sector 16 is connected through a filament of the green light bulb 13 to ground and when pointer 31 brushingly engages this sector, which is the safe range and when the pointer is in this range, the green light will be lit.

In a similar manner, when caution sector 17 is brushingly engaged by pointer 31, the caution range, power is supplied via a lead 32 to horn 14 and via lead 22 to blower 21.

The horn provides an audible alarm any time the pointer is in the caution range and at the same time energizes blower 21 which is connected to the monitored compartment in a manner so that it can purge the compartment of accumulated fumes. As a result of the above described circuits and arrangements, the operator is provided with at least two independent indications of both the safe and caution conditions of the monitored compartment as well as automatic operation of the blower 21 in the caution range.

Because the circuit associated with danger sector 18 is essentially a disabling circuit, its discussion will be deferred until the operating circuits that it disables have been described. However, it should be noted that when a dangerous condition is indicated, i.e. when pointer 31 is brushingly contacting sector 18, the operator can depress a spring closed manual switch shown in FIG. 2 to connect lead 22 to the battery to operate the blower so an attempt can be made to purge the monitored compartment of any accumulation of explosive fumes then being monitored by the sensors. If the operation of the blower removes the accumulation of fumes in the monitored compartment, the meter reading will swing back through the caution range to the safe range, at which time pointer 31 will be in contact with sector 16. When the manual switch is released, lead is reconnected as shown in FIG. 2.

When the operator of the watercraft has completed his test check, the three-position switch 12 can be changed to the "on" position 12c that will energize the other electrical circuits in the watercraft via leads 40 and 41, the latter being connected to the main electrical bus of the watercraft through circuit breaker 25. Alternatively, the operator may choose to skip the test mode of the vapor detector position and go directly to the "on" position without danger, since the system will function properly in either mode.

With the three-position switch 12 in the "on" position 12c, key switch 24 may be rotated further counterclockwise in the "on" position against its spring to momentarily close internal switch 24c that will temporarily energize the starting relay via lead 27 in the starting motor and relay 23, causing the battery to be coupled directly to the starting motor by heavy-duty lead, provided the circuit breaker is closed. After the engine has been started and the key switch released, the spring within the key switch will open switch 24c, de-energizing the starting relay. Further, it should be appreciated that when the key switch is rotated to the start position, internal contact 24b remains closed.

Also, when the circuit breaker is closed and the vapor detector circuit switch 12 is in the "on" position 12c, the main electrical bus of the watercraft will be energized by a lead 41 connected to the circuit breaker which is directly coupled to the main electrical bus through the circuit breaker as illustrated in FIG. 2.

However, if any accumulation of combustible fumes are present or subsequently accumulate in the monitored compartment at a level which is dangerous, the needle pointer will contact sector 18 of the meter relay 11 and connect battery power to the circuit breaker 25 via lead 28. Conventionally, the circuit breaker will be a multiple contact, normally closed relay, and when battery power is connected to the ungrounded side of its coil 43, the armature (not shown) will open the contacts, breaking the connection of circuits connected through the relay. When this occurs, if the engine is not running, it will be impossible to start the engine, as the starting relay cannot be actuated due to the open contacts between switch 24c and lead 27. Further, if the engine is running, it will stop, since the distributor will be conventionally powered by the main electrical bus which is disconnected from lead 41 when pointer 31 is in the danger range by the circuit breaker relay.

Thus, as a result of the above arrangement and operation, the instant vapor detector system provides a simple, reliable, fail-safe vapor detector circuit which is suitable for the environmental operating conditions of watercraft at a reasonable cost. Further, the system is easy to maintain and simple to operate as well, as providing an automatic control against mis-operation of watercraft by inexperienced personnel.

Claims

Having described my invention, I claim:

1. A vapor detector control system comprising:

a source of electrical power;

a meter relay having at least three sequential independent switching ranges and a visual reading in all of said ranges, said meter relay operably coupled to said source;

a first circuit having a first indicating means coupled to a first switching range of said meter relay and being operably connected to said source by said meter relay when said visual reading is in its first switching range;

a second circuit having second indicating means coupled to a second switching range of said meter relay and being operably connected to said source when said visual reading is in its second switching range;

a third circuit having a disabling means to render machinery in a monitored compartment inoperable coupled to a third switching range of said meter relay when said visual reading is in its third switching range; and

a vapor sensor electrically coupled to said meter relay and located in said monitored compartment where explosive organic fumes are likely to accumulate, said sensor operable to control said visual reading together with the respective said indicating means and disabling means in direct relationship to the concentration of said fumes whereby auxiliary warnings are provided when said meter reading is in said first and second switching ranges and said disabling means renders the machinery in said monitored compartment inoperable when said meter reading is in the said third switching range.

2. The vapor detector system defined in claim 1 wherein the first indicating means is an electrical lamp and the second indicating means is an audible alarm.

3. The vapor detector system defined in claim 1 wherein the second circuit includes a blower means connected to the monitored compartment and operable to purge said monitored compartment of accumulated fumes when the meter of the meter relay reading is in its second switching range.

4. The vapor detector system defined in claim 1 wherein a multi-position switch is coupled between the source and the meter relay whereby the vapor detector system can be operated independently and in combination with other electrical circuits.

5. The vapor detector system defined in claim 1 wherein the disabling means is a normally closed circuit breaker which opens its contacts when activated by said power source through the meter relay.