This invention relates to machines with internal combustion engines that an unauthorized person may at¬ tempt to start, and in which such unauthorized starting or subsequent use could lead to harm, and in which prac- tical apparatus that prevent such starting are provided- Particularly, this invention utilizes novel practical apparatus and methods of operation including user-input of an authorization code to prevent unauthorized starting of an internal combustion engine; and, which does not substantially interfere with authorized use. Contributions of the invention include novel use- control means to prevent unauthorized starting that comprises apparatus which require the user to input an authorization code before the internal combustion engine will start. The invention also includes novel anti- bypass means to prevent an unauthorized person from bypassing use-control means, such that if the unauthorized person understands the system, and has special tools and replacement parts, the apparatus cannot be feasibly bypassed within a practical amount of time.

The invention also includes recognition of limitations of the prior art and the analysis of methods to prevent unauthorized starting which lead to the selection of novel apparatus and methods of operation described below. The advantages and contributions are discussed with detailed descriptions of drawings that illustrate such contributions in which:

Figure 1, a block diagram, illustrates the functional components of the machine of the invention;

Figure 2, a schematic view, partially in cross- section, illustrates an example prior art machine for comparison;

Figure 3, a schematic view partially in cross- section presents a preferred embodiment of the machine of the invention;

Figure 4, a plan view, illustrates the one-way stove-bolt head of the invention;

Figure 5, a schematic view partially in cross section of an alternate embodiment of the machine of the invention;

Figure 6, a section along 6—6 of FIG. 5, showing the hexagonally shaped aperture for attaching an alien wrench to the distal end of the one-way bolt of the invention;

Figure 7, a block diagram, presents a preferred method of operation of the invention, including the starting-sequence;

Figure 8, an electrical schematic, presents a preferred embodiment of the use-control circuit;

Figure 9, a schematic view of an automobile or truck presents an example of a machine of the invention.

The machine of the invention 10 of Figure l comprises a source of combustible fluid fuel 12 to supply fuel flowing to an internal combustion engine 14 to convert the fuel into work for the machine. Source of starting-energy 16 is connectable through starting power-regulation means 18 in order to regulate the flow of starting-energy to starter-motor 22 which converts the starting-energy to starting-work. Source of engagement energy 24 is connectable through engagement power-regulation means 26 in order to regulate the flow of engagement energy to engagement means 28 which enable transfer of starting-work from the starter-motor to the engine in order to increase the speed of the engine to a minimum starting speed to start the engine.

A source of control-energy 30 is connectable to control means 32 which read inputs, determine whether the inputs comply with pre-defined requirements, and depending upon such determination, respond by generating outputs. Such inputs include input-signals from user- input means 34 comprising code-input means 36 to generate code-signals, and starting-control means 38.

A user inputs an authorization code into code-input means 36 which transmits code-signals to control means 32. If the code-signals comply with pre-defined authorization code requirements, the control means output control-signals to engagement and starting power- regulation means 18,26 to enable engine starting. Then the user activates starting-control means 38 to generate a starting-sequence initiation input-signal transmitted to control means which output control-signals to engagement power-regulation means 26 to control engagement; and output control-signals to starting power-regulation means 18 to control operation of starter-motor 22. Finally, the user activates starting- Control means to generate a starting-sequence termination input-signal transmitted to control means 32 which output control-signals to terminate such starting- sequence. The machine enforces a minimum delay between each authorization code input to prevent guessing such authorization code as a feasible means of unauthorized starting. For example, in one embodiment whenever a starting-sequence initiation signal is received by control means 32 starting power-regulation means 18 is signaled to provide starting-energy to operate starter- motor 22, but control means will not signal engagement power-regulation means 26 to supply engagement energy to operate engagement means 28 unless the control means has received code-signals that comply with pre-determined authorization code requirements. The machine does not disclose any indication of authorization code input

error except that the engine does not start thus requiring an unauthorized person to test each authorization code guess.

Use-control means comprise starting power-regulation means 18, engagement power-regulation means 26, and control means 32. Parts of such use-control means are contained within a shielded enclosure 40 which is contained within an enclosing-component of machine 10. Combustible fluid fuels 12 include gasoline, and diesel oil, hydrogen, and natural gas, and similar fuels; and internal combustion engines include turbine, rotary, piston, and similar engines. The sources of energy 16,24,30 can be the same source or different sources of electrical, hydraulic, pneumatic energy, or any other source of controllable energy, or combinations of such sources. ^' User-input means 34 can be one means or multiple means including push-buttons, sliding, or presence indication switches. The code-input means may comprise multiple momentary-contact push-button code- input switches for sequential code-input or may comprise one switch for inputting code as timed pulses, which may be a rotatable key switch. Starting-control means comprise one or two user-input switches. When one starting-control switch is used it may be a rotatable ignition switch which combines starting-control and control-energy connection functions. The control means and power-regulation means may comprise any combination capable of providing the required control and regulation functions that include reading code-signals, determining whether such code-signals comply with pre-defined authorization code requirements, regulating starter- motor operation to operate whenever starting is initiated, and regulating engagement to only engage after the control means has determined that pre-defined authorization code requirements are met. Engagement means may be any device capable of the regulation of transfer of starting-work including mechanical means

moveable into or out of contact such as a friction clutch or pair of gears, or valve-controlled pneumatic or hydraulic means.

Shielded enclosure 40 within an enclosing-component has general utility for protecting enclosed parts, such as mechanical and electrical components, from external environmental hazards, manipulation by unauthorized persons, and internal environmental hazards. Furthermore, the enclosing-component and enclosed use- control means parts are selected to prevent manipulation of use-control means as a feasible method of bypassing such use-control means. The enclosing-component could be any component of the machine such as the solenoid component, engine, or starter-motor as long as enclosed parts are shielded from external and internal hazards and protected from unauthorized manipulation, and have protected access to regulate power in order to enable control and coordination of engagement and starter-motor operation. In Figure 2, a prior art automobile 110 comprises a gasoline tank 112 connected to a piston engine 114 for converting the gasoline into vehicle movement for land transportation. Battery 116 is connectable through solenoid component 118 to regulate the flow of electricity to energize starter-motor 120 which converts the starting-energy to starting-work. Battery 116 is also connectable through cylindrical solenoid component 118 to regulate the flow of electricity for energizing engagement means 124 which regulate the transfer of starting-work from starter-motor 120 to engine 114 to increase the speed of the engine to a minimum starting speed to start the engine. Battery 116 also supplies control-energy for solenoid component 118 which contains a controller-switch 128 that communicates with a rotatable starter-switch 130 which the user turns in a first direction to initiate a starting-sequence and

releases, allowing it to spring back in an opposite second direction to terminate the starting-sequence. Engagement means 124 includes an engager 132 - a gear that communicates with starter-motor 114 and is moveable to communicate with a second gear 134 that communicates with engine 114 to transfer starting-work from the starter-motor to the engine. The engager is moveable into a position-for-starting in which the two gears 132,134 mesh to transfer starting-work produced by the starter-motor 120 to the engine 116 for starting the engine; and movable out of position-for-starting, as shown, enabling the engine to operate without communicating with starter-motor 120. If such gears are moved together while the starter-motor is operating the gears will not mesh and may be damaged. Therefore, the controller-switch 128 of the solenoid component 118 controls the flow of electricity to starter-motor 120 to coordinate starter-motor operation with completion of engagement required to prevent such damage. Spring 138 is a means to generate force which prevents the engager from moving into position-for-starting until both coils are energized to cooperate in generating sufficient magnetic field strength for the core of engagement plunger 136 to generate sufficient forces and movement to overcome the force generated by spring 138 such that force and movement are transferred to engager 132 by engagement linkage 140 to move the engager into position-for-starting.

The user initiates the starting sequence by activating starter-switch 130 which directly energizes holding coils 144 and pulling-coils 146 of engagement coils 142 which generate a magnetic field to move the engagement core of the engagement plunger 136 toward the center of the engagement coils. The engagement plunger communicates with the engager such that when the engager is in position-for-starting the position of the

engagement plunger indicates that the engager is in position-for-starting.

One end of switch shaft 160 is an engagement sensor positioned to detect engagement. As the engagement plunger moves the engager into position-for-starting the engagement plunger also pushes against the engagement sensor of switch shaft 160 overcoming the force of spring 162 to move switch shaft 160 into a position indicating that the engager is in position-for-starting. Switch conductor 164 is mounted on switch shaft 160 by insulator 166 such that when the switch shaft is in a position indicating that the engager is in position- for-starting, the switch conductor is also in position- for-starting in which it connects between starter- contacts 168 and 170 which energizes starter-motor 120, and which de-energizes pulling-coils 146.

Energizing both holding coils 144 and pulling-coils 146 is required to generate a sufficient magnetic field to move the engagement plunger into position-for- starting; but once position-for-starting is achieved, energizing only holding coils 144 generates sufficient field strength to overcome force generated by springs 138 and 162 to maintain engager 132 and switch conductor 164 in position-for-starting. Therefore, once position- for-starting is achieved, pulling-coils 140 are de- energized to reduce starting-energy requirements and the holding coils remain energized until starter-switch 130 is released to terminate the starting-sequence.

Solenoid component 118 comprises enclosing-shell 180 that encloses the components of the solenoid component to protect them from external environmental hazards such as water, dirt, oil, rocks, loose wires, falling tools that might damage or prevent movement of enclosed components. Flexible diaphragm 186 prevents contaminants from entering the solenoid component through the aperture for engagement linkage 140. The enclosing-shell is connected to the starter-motor by

stove-bolts 188,190. Wall 192 separates the solenoid component into two sections. An engagement section which contains engagement coils 142 and engagement plunger 136; and a switch section contains switch conductor 164 and starter-contacts 168,170. The wall also provides bearing 194 which is a slideway to provide restraint in all lateral directions to the switch shaft to restrict switch shaft motion to only move axially. In Figure 3, a preferred embodiment of the machine 200 of the invention, includes a source of combustible fluid fuel 202 connected to an internal combustion engine 204 and a starting-system to start the engine. A single battery 206 provides a single source for engagement, control, and starting energy. A solenoid component 208 shown as a cylindrical section contains control means and power-regulation means to control and regulate the flow of electricity to starter-motor 210 and to engagement means 212 including an engager 214, a gear, communicating with the starter-motor, and which is moveable to mesh with a second gear 216 communicating with the engine to transfer starting-work from the starter-motor to the engine to increase the speed of the engine to a minimum starting speed to start the engine. In the preferred embodiment the enclosing-component is solenoid component 208 that contains shielded enclosure 220 which is surrounded by metal walls that form a barrier to protect enclosed parts of use-control means from internal and external environmental hazards and to prevent manipulation by unauthorized persons. Such parts are longitudinally enclosed between walls 222,224 and radially enclosed between wall 226 and enclosing-shell 228.

Additional parts have been included in the machine of the invention to provide use-control means to prevent an unauthorized person from starting engine 204; and to provide anti-bypass means to prevent an unauthorized person from bypassing use-control means. Use-control

means include controller 230, code-input means 232, and power regulator 234. The controller is connected to battery 206 through source switch 236 to enable the user to de-energize the controller when the machine is not in use and to enable resetting the controller as described later. Code-input means 232 comprises a keyboard containing multiple push-button momentary-contact input- switches, typical of keyboards, to allow sequential entry of an authorization code by the user. Code-input means are connected to the controller for user-input of an authorization code and transmission of code-signals to the controller. Code-signals that match pre-defined authorization code requirements must be received by the controller before the controller will generate control- signals to enable the engine to start. Controller 230 is connected to provide control-signals to power regulator 234 to regulate flow of electricity to starter-motor 210 and engagement means 212.

Electricity flows from battery 206 to power regulator 214 through starter-switch 238 to enable a user to initiate a starting-sequence to be performed by the use-control means. Engagement energy flows from the power regulator to engagement coils 240 to control engagement. Pulling-coils 242 are controlled directly by the starter-switch such that whenever the starter- switch is first activated, electricity flows through the pulling-coils. However, the pulling-coils acting alone do not generate a magnetic field sufficiently strong to move engager 214 into position-for-starting. When code-signals that comply with pre-defined authorization code requirements have been received by controller 230 and the user initiates the starting- sequence by activating starter-switch 238, the controller outputs control-signals to power regulator 234 in order to energize holding coils 244. Engagement energy flows from battery 206 through starter-switch 238 through the pulling-coils 242 and also through the power

regulator and through the holding coils; the resulting magnetic field of the cooperating coils 242,244 provide a high strength magnetic field that communicates with the engagement core 250 to provide a sufficient force to overcome means to generate force 252 - a spring to move engagement plunger 254 upward to transfer such movement through engagement linkage 256 to move engager 214 into position-for-starting; and move the engagement plunger up against one end of switch shaft 262 which acts as a detecting-sensor 260 to determine whether the engager is in position-for-starting and respond by moving the switch shaft such that when the engager is in position- for-starting the switch conductor 264 is in position- for-starting to connect between starter-contacts 266,268 to conduct starting-energy to energize starter-motor 210.

Conversely, when code-signals that comply with such requirements have not been received, and the user initiates the starting-sequence, controller 230 signals power regulator 232 to provide solenoid-energizing current to switch coils 270, and to provide solenoid- energizing current to holding coils 244 in a direction opposite to the direction provided when code-signals comply with such requirements. Control-energy flows from battery 206 through the starter-switch and directly to the pulling-coils 242 and also through the power regulator and through holding coils 270. The electromagnetic effects of the two engagement coils cancel out to produce a lower strength magnetic field. Means to generate force 252 prevent the lower strength field from moving engager 214 into position-for- starting. Control-energy flows from battery 206 through the power regulator and through switch coils 270. The magnetic field generated by switch coils moves switch core 272 mounted on switch shaft 262 such that switch conductor 264 connects between contacts 266,268 to energize starter-motor 210 and de-energize pulling-coils

11

242. The starter-motor operates without moving engager 214 into position-for-starting; therefore the engine doesn't start, but sounds like normal starting. The enclosing-component of the invention is connected to the machine using one-way fasteners 280,281 to prevent replacing the enclosing-component of the invention with a conventional component thus preventing an unauthorized person from bypassing the use-control means by such replacement. Each fastener typically includes external treads 282 which engage the internal threads 283 of a part of the machine such as the starter-motor. The fasteners have one-way heads 284,286 at the front-end of the bolts which enable installation from the front-end using hand tools, but which prevent removal from the front-end without drilling or grinding. In the novel one-way fasteners of the invention back-ends 288,290 are configured to enable easy removal by hand tools from the back-end once access to back- ends 296,298 is obtained. The enclosing-component is mounted such that some other component of the machine must be removed before access to back-ends 288,290 can be obtained.

In a specific embodiment, the fasteners are one-way stove-bolts with one-way heads that can be installed using the blade of a screwdriver, and the back-ends

288,290 have hex-shaped tips to enable attachment with a crescent wrench. Alternatively the back-ends could be configured with a hex-shaped hole for attachment with an alien wrench or a groove for attachment of a flat blade screwdriver or some other means for turning bolts known in the art. The solenoid component is mounted on the starter-motor and the starter-motor must be removed from the engine to access the back-ends of the bolts.

Figure 4 illustrates the preferred one-way head 284 comprising diametrical slot 296 for engagement with the flat blade of a conventional screwdriver to turn the head clockwise to install the bolt. Angled sections

297,298 are surfaces which angle between the bottom surface of slot 296 and the semi-circular periphery of the head to prevent removal using a screwdriver from the front-end 284. Alternatively, other one-way heads known in the art may be used.

The shielded enclosure could be located in another area of the solenoid component, such as above the switch section or below engagement coils 208. Source switch 236 and starter-switch 238 are shown as separate switches, but could be one switch as commonly provided in automobiles. Starter-contacts 266,268 are shown configured to enable contact if switch-windings 270 pulls the switch core 272 toward the engagement section. However, the contacts could simply be flat plates if the switch-windings and switch core were configured to move the switch core away from the engagement section.

Advantages of the preferred embodiment include that the solenoid component provides a convenient location for a shielded enclosure containing parts of the use- control means because energy flow to both the engagement means and starter-motor can be conveniently accessed for regulation from within the solenoid component, and manipulation by an unauthorized person thus prevented. The preferred embodiment of the use-control means consists essentially of a keyboard, a connecting cable and the solenoid component of the invention which is installed in a manner similar to conventional solenoid components. A skilled mechanic can install the use- control means of the invention in a few minutes. If a component of the use-control means fails and replacement parts are not available, the solenoid component can be temporarily replaced by a conventional solenoid component. Replacing the solenoid component of the invention requires removal of the starting motor, removal of the solenoid component of the invention, reinstalling the starter-motor, and installing a new solenoid component, which requires about an hour for a

skilled mechanic with a lift and conventional tools of his trade. A user-input error does not disable the car, which could be dangerous, or sound an annoying siren which could be used by an unauthorized person to signal an incorrect authorized-code guess.

A shielded enclosure within the solenoid component has general utility for protecting enclosed parts such as mechanical and electrical components. The enclosing- shell is a sealed metal container to protect enclosed components from external environmental hazards such as water, dirt, oil, rocks, loose wires, falling tools. The enclosing-shell is constructed with welded or mechanically locking connections to provide that the solenoid component cannot be disassembled or enclosed parts manipulated without damaging the functioning of the solenoid component; thus the shielded enclosure provides a tamper-proof location for preventing manipulation of such enclosed parts by unauthorized persons. The shielded enclosure is surrounded by a metal barrier to protect enclosed parts from internal environmental hazards such as high magnetic fluxes generated by coils, and sparks generated when the switch conductor connects between starter-contacts.

In the preferred embodiment of the machine, bypassing the use-control means is not feasible because manipulation of engagement means is prevented. The enclosed parts of the use-control means have been selected such that there are no external connections which can be energized to move the engager into position-for-starting. No method of rewiring or disabling engine components can be used to bypass the use-control-system. The solenoid component is attached to the starter-motor such that engagement means are physically enclosed within the solenoid component, starter-motor and engine, preventing mechanical manipulation of engagement means to move the engager into position-for-starting. Replacement of the solenoid

component is prevented by the one-way bolts of the invention. It is not feasible that an unauthorized person may have the time, tools, and skill required to remove the starter-motor, remove the solenoid component, replace with a conventional solenoid, and replace the starter-motor.

Furthermore, it is not feasible to guess the authorization code. There is no indication of incorrect code-input, and initiating a starting-sequence always results in starter-motor operation which sounds like normal starting regardless of incorrect authorization code input. The unauthorized person must test each guessed code by turning off the ignition switch, turning on the ignition switch, entering the code guess, initiating an engine starting-sequence and waiting to determine if the engine will start which requires a delay between guesses and drains the battery such that only a small number of-guesses can be tried before the battery is drained. For a four-digit authorization code an average of five thousand guesses would be required in order to guess the proper code. It is common for internal combustion engines to require significant and unpredictable amount of starting time, thus an unauthorized person could never be certain that an attempted guess is incorrect; and even if the correct authorized-code is guessed, if the engine fails to start immediately then the unauthorized person may decide to try another guess before the engine starts.

An alternate embodiment of the invention is illustrated in FIG. 5. Shielded-enclosure 220 is defined by the metal sidewall of the enclosure and a cup-like wall section 273. Small preferably sealed penetrations 274, 275, 276 conduct wires into and out of the shielded-enclosure. The cup-like wall section 273 is welded or otherwise permanently bonded to the solenoid component and constituted of sufficiently thick metal such that it cannot be removed or opened within

15 sufficient time for unauthorized access. Thus, the shielded-enclosure protects enclosed parts from external hazards and internal hazards such as the high strength magnetic field produced by coils 242, 244 and hazards associated with arcing between connector 164 and contacts 168, 170; and prevents tampering with the enclosed parts by unauthorized persons.

The controller 230 and power regulator 234 are positioned within the shielded enclosure so that an unauthorized person cannot activate the solenoid without knowing the authorization code.

The solenoid of FIG. 5 is attached to the starter motor utilizing the one-way bolts of the invention. For the one-way bolts shown in this embodiment, the solenoid may be removed from the starter motor, once access to the inside of the starter motor is achieved, by utilizing an alien wrench. The end of the alien wrench is inserted into a hex-shaped hole 278 of FIG. 6 at the end of the one-way bolt to rotate the bolt clock-wise about its axis for removing the bolt.

In the specific embodiment of FIG. 5, when an incorrect authorization code is entered the motor does not sound like normal starting. The motor does not turn over at all. The invention requires that another method of delay between guesses must be provided to prevent an unauthorized user from testing a series of guesses for bypassing the use-control system. Alternate means for providing delay between guesses are disclosed below. A diagram of preferred machine operation 300 of Figure 7, illustrates that the engine must be connected to a source of combustible fluid fuel 302, a source of starting-energy 304, a source of engagement energy 306, and a source of control-energy 308. After control- energy is connected the user inputs an authorization code 310 into a code-input means which transmits code- signals to control means which determine whether code- signals comply with pre-defined authorization code

requirements, and generate control-signals that enable starting only if such requirements are met. Then the user initiates starting 312.

The fuel may be any flowable combustible fluid, and sources of energy may be any controllable energy. The code-input means may be a keyboard containing multiple momentary-contact push-button code-input switches or a single code-input switch for inputting an authorization code in the form of timed pulses; and the starting- sequence can be initiated by correct number of input- code digits, or by a momentary-contact push-button switch on a keyboard or by a separate rotatable switch, etc.

If control means determine that authorization code requirements are met 314 and the user initiates starting, then control means initiates engagement 316 between the starter-motor and engine by signalling power-regulating-means to energize engagement means; and, then control means wait for engagement 318 to complete before continuing the starting-sequence. Otherwise, if control means determine that authorization code requirements are not met 314, engagement is not initiated and the engine will not be able to start. Engagement is communication between a starter-motor and the engine that enables transfer of starting-work from the starter-motor to the engine. Engagement means may be any means to regulate the transfer of such work. Generally for mechanical engagement means, engagement must be completed before the starter-motor can be energized, but for hydraulic engagement waiting is not required. If not required, the wait for engagement 318 step may be eliminated.

Next, the starter-motor is energized 324 to convert starting-energy into starting-work. The starter-motor operates regardless of whether the required authorization code was received by control means and in

the preferred embodiment of the machine does not provide any indication of authorization code input error or non- engagement except the failure of the engine to start, thus an unauthorized user cannot easily determine whether an authorization guess was correct. If the starter-motor is engaged, starting-work is transferred to the engine to increase the engine speed to a minimum starting speed to enable engine starting.

If the engine starts 326, starting is terminated 328 either automatically or by user-input; then the controller de-energizes the starter-motor 330 and initiates disengagement 332 of the starter-motor from the engine; and the starting-sequence ends 334. Otherwise, if the engine does not start, the starting-sequence is terminated automatically or by the user 336; then the controller de-energizes the starter- motor 338 and initiates disengagement 340 of the starter-motor from the engine. The user can abandon starting 344; or the user can choose to retry the same authorization code 346 by re-initiating starting 312; or the user can re-input an authorization code 310 and then re-initiate starting 312.

In Figure 8, the preferred embodiment of the use- control circuit 400 comprises a control-circuit and a power-regulation circuit. The control-circuit comprises: (a) controller 402 located within the shielded enclosure of the solenoid component, (b) user- input means which includes a source switch 236 connecting the source of control-energy 206 to controller 402, and (c) keyboard 404 connected by a cable of wires 406 to controller 402. The power- regulation circuit comprises: (a) power regulator 408 located within the shielded enclosure of the solenoid component and communicating with controller 402, (b) engagement solenoid including a high current pulling- coil 242, and a low current holding coil 244 to regulate engagement, (c) switch-solenoid 270 having one low

current coil to position switch conductor 264 in relation to starter-contacts 266,268 to regulate flow of starting-energy from the source of starting-energy 206 to the starter-motor 210. Keyboard 404 comprises valet switch 410, and ten code-input switches. Four of the code-input switches 412,414,416,418 are combination-switches that must be pressed in correct sequential order to transmit the authorization code before the engine will start. Pushing any other code-input switch 420,422,424,426, 428,430 locks the controller; as does pushing any combination-switch out of correct sequential order.

The number of code-input switches can be varied, but a sufficient number of combination-switches must be provided such that guessing the authorization code is not feasible.

Cable 406 comprises one wire for each code-input switch, and one wire for valet switch 410. The wires may be colored, but are not color-coded such that an unauthorized user can not determine which code-input switches are combination-switches or determine the authorization code from the color of the connected wire. The authorization code can be changed by rearranging the connections between the combination-switches and wires that connect to the combination-switches.

Controller 402 consists essentially of control- relays connected to perform required control functions, and comprising lock-relay 432, four combination-relays 434,436,438,440, and valet relay 442. Each combination- switch 412,414,416,418 of keyboard 404 is connected to one combination-relay, and each combination-relay is connected to one combination-switch, such that the combination-switches have to be activated to set the control-relays in correct sequential order or the lock- relay is activated (set) to lock the controller. Each code-input switch of keyboard 404 which is not a combination-switch is connected to activate the lock-

relay. Activating lock-relay 432 locks the controller so that the controller will not accept an authorization code or enable engine starting. Turning source switch 236 off clears the lock-relay so that the controller will always permit authorization code entry when the supply switch is reactivated. After starting, the combination-relays may be cleared without affecting the operation of the machine.

The one-to-one correspondence between .combination- switches and combination-relays could be modified and such parts connected so that simultaneous activation of certain combinations of combination-switches would be required to activate certain combination-relays, or the combination-relays could be connected such that combination-switches could be activated in any order; or combination-relays connected to require certain combination-switches to be activated repeatedly; but the preferred embodiment provides advantages such as a simple circuit and friendly user interface. Valet switch 410 is connected to valet relay 442; the valet switch activates the valet relay only if all the combination-relays are activated. The valet switch is separately connected 411 to battery 206 such that once activated, the valet relay remains activated until the valet switch is turned off, regardless of source switch 236 cycles or code-input switch activations. Thus, after a proper authorization code has been input the valet switch can be used to deactivate the use- control means to allow another person to temporarily use the system without revealing the authorization code to such person. Thus the need to change the authorization code after each such temporary use is eliminated.

When either all the combination-relays are activated or when the valet relay is activated then the controller outputs an enabling signal which is an On signal which enables regulator 408 to start the engine; otherwise the

controller outputs a default-signal which is an Off signal which prevents engine starting.

Whenever the controller is de-energized and the valet relay is not activated, and then the source switch is activated to energize the controller then the controller begins to operate in a clear-state in which all the relays are clear. Whenever the controller is operating in a clear-state it outputs a default-signal to the power regulator which is an Off signal in which no current flows. Whenever the controller is operating in a clear-state and a combination-switch is activated in the correct sequential order, then the controller begins to operate in an input-state and continues to output a default-signal. Whenever the controller is operating in an input-state and then the correct number of combination-switches are activated in the correct sequential order, then the controller begins to operate in an authorized state in which the controller outputs an enabling signal to the power regulator which is an On signal in which current flows to set the regulator- relay. Whenever the controller is operating in an authorized state and the valet switch is turned on then the valet relay is set, and the valet-function is activated and the controller will continue to operate in an authorized state regardless of changes in the source- switch or code-switch activations, until the valet switch is turned off. Whenever the valet-function is activated the controller will output an enabling signal when the starter switch is activated. Whenever the controller is operating in an input-state or a clear- state and a code-input switch is activated that is not in the correct sequential combination order, then the controller begins to operate in a locked state, and the controller will not accept authorization code input, or output an enabling signal until the supply switch is deactivated and then reactivated which results in clear- state operation.

Reset-means include that whenever the source switch is deactivated and then reactivated, the controller is reset to begin to operate in a clear-state.

Clear-relay 432, valet relay 442, and combination- relays 434,436,438,440 are double-pole double-throw miniature relays such as MAGNECRAFT W7PCK7's.

The use of a valet switch and a valet relay is an important contribution of the invention but they may be eliminated to reduce cost without interfering with other contributions.

Regulator 408 comprises regulator-relay 444 connected to controller 402 through conductors 446,448, such that when the controller is outputting an enabling signal to regulator 408 then the regulator-relay is set and if starter-switch 236 is activated (turned on) then solenoid-energizing current flows through both holding coils 244 and pulling-coils 242 such that they work together to move engagement core 250 into position-for- starting. When the controller 402 is outputting a default- signal (no current) to regulator 408, regulator-relay 444 is clear; and if starting-switch 236 is activated then current flows in the reverse direction through holding coils 244 to reduce the magnetic field generated by pulling-coils 242 such that the engagement core does not move into position-for-starting. Furthermore, current flows through switch coils 270 to move switch core 272 into position to energize the starter-motor and de-energize the pulling-coils. Regulator-relay 444 is a double-pole double-throw miniature relay such as MAGNECRAFT W76URCPCX34.

Advantages of the preferred use-control circuit include that delicate electronic parts (e.g. parts which would not be sufficiently reliable for commercial purposes within the environment of the circuit and shielded enclosure such as integrated circuits or transistors) are not required. When the valet function

has been activated and source switch 236 is off only the valet relay remains active requiring only about one watt of power. The power regulator consists of only a single regulator-relay which may be a low-power relay because the high current through the pulling-coils of the engagement solenoid is not directly regulated.

The regulator is connected to the coils such that, unless the controller sets the regulator-relay, whenever the pulling-coil is energized the holding coil will be energized in such a way as to cancel the electromagnetic effect of the pulling-coil. Thus the machine can not be re-wired to electrically move the engager into position- for-starting.

Other use-control circuits could be substituted for the preferred circuit to perform the same control functions without interfering with other contributions of the machine of the invention. For example the controller could be modified to use an Integrated Circuit along with resistors, capacitors, etc., to reduce or eliminate use of relays in the controller.

Such a circuit might be cheaper in mass production, but may be less reliable or more expensive to manufacture in small numbers. Similarly, the preferred power regulator could be modified to use a higher power relay to directly control current through pulling-coils 242 instead of or in addition to directly controlling current through holding coils 244; such a high power regulator would be larger and more expensive than the preferred power regulator. In the preferred embodiment, when controller 402 is outputting a default signal to power regulator 408 and the starter-switch is activated, then the current flowing through pulling-coils 242 is high enough to significantly drain the battery during each attempted start. Switch coils 270 and switch core 272 could be eliminated to reduce the cost of the use-control means. However, the starter-motor would make a significantly

different sound than in normal starting thus allowing a knowledgeable user to confidently test authorization code guesses, thus reducing the effectiveness of the system. In the preferred embodiment the user can not determine whether the use-control means is working properly or whether an incorrect authorization code has been input. Alternatively means could be provided to signal the user for code confirmation when the controller determines that a proper authorization code has been received. Such a signal would compromise the delay means of the preferred embodiment in which an unauthorized user must test each authorization code guess by initiating a starting sequence. Therefore another delay means to enforce a minimum time between authorization code inputs would be required to prevent using multiple guesses as a feasible means of unauthorized starting of the engine. Such alternative means to enforce a minimum time include (a) the user to turn the supply switch off to clear the controller between each code input, or (b) delaying output of such confirmation signal until a minimum time after each code input.

A means to signal the user for confirmation of code input could be for example a red light 452 that is on when the controller is properly operating until a proper authorization code is received.

For example, a simple capacitor circuit 470 may be provided to enforce a timed delay between reset and clearing the code relays for authorization code input. Such delay is preferred when an embodiment such as in FIG. 5 which does not sound like normal starting is used, or light 452 is provided for code input confirmation. Means may be provided for warning the user when the valet switch is engaged and the key is removed from the ignition switch and/or whenever a car door is opened.

Preferably a buzzer such as 460 is provided to sound an alarm for a short time when the key is removed or while the door is opened if the valet switch is engaged.

In the specific embodiment of FIG. 8 whenever the valet switch 411 is engaged and switch 236 is on then green light 462 is illuminated and relay 464 is set thermal relay 466 is heated and set. If switch 236 is turned off when the valet switch is on then buzzer 460 sounds until the thermal relay cools (about 5 seconds). Thus the system prevents the user from accidentally leaving the valet switch engaged.

Valet switch 410 may be a double-pole, double-throw switch or equivalent; preferably a shorting switch to maintain the controller in an authorized state during valet switch activation/-deactivation. Relay 446 may be a Chrysler Part No. 2889565.

An example of a machine of the invention is a steerable motor vehicle for land transportation 500 of Figure 9 such as a truck or car. Frame 502 and body 504 support and enclose components of vehicle 500. Fuel tank 202 is connected to engine 204 for converting combustible fluid fuel into work to move the vehicle. Battery 206 supplies starting-energy to starter-motor 210 and control-energy to solenoid component 208 of the invention. Engine 204 communicates with air intake system 506 which conducts air from an intake region of fresh air, and exhaust system 508 which delivers engine exhaust to a region remote from the air intake region. The machine includes wheels typical of 510 to support the vehicle, and which communicates with the engine to provide motion for the vehicle; and which often includes at least one seat for a passenger 512.

While the invention has been particularly illustrated and described with reference to preferred embodiments, it will be understood by those skilled in the art that changes in form and detail can depart from such embodiment without departing from the spirit and scope of the invention.