US 3871473 A
A vehicle safety system using an attitude-sensitive switch which shuts off the vehicle engine, if the vehicle begins to roll over.
Description (OCR text may contain errors)
United States Patent 11 1 1111 3,871,473 Castonguay Mar. 18, 1975  SWITCH gchmgerfi tern ur 1.4 [751 Invenm Casmnguay, wheelrght, 2,898,416 8/1959 CIurman ZOO/61.5 x Mass- 3,047,689 7/1962 Vardara 1 180/104 X 3,083,275 3/1963 Jones ZOO/61.51 X  Asslgnee' :f wheelwght 3,229,109 H1966 Wilson 180/104 x 3,550,717 12/1970 Doty, Jr. 180/103  Filed: May 1, 1972 Primary Examiner-Robert B. Reeves Appl' 249060 Assistant E.\'am1'nerDavid A. Scherbel Attorney, Agent, or Firm-Norman S. B10dgett; Gerry  US. Cl. .1 180/l04, ZOO/61.45 M, ZOO/61.52 A. Blodgett  Int. Cl 806k 27/08  Field 01 Search 180/103, 104; ZOO/61.45 R, [57 ABSTRACT ZOO/61.45 M,61.52,61.48,61.51,61.50,
61 53 A vehicle safety system using an att1tude-sens1t1ve  References Cited switch which shuts off the vehicle engine, if the vehi- UNITED STATES PATENTS cle begins to roll over. 1,855,581 4/1932 Meade ZOO/61.52 4 Claims 6 Drawing Figures PATEHTEB HARI 8 I975 sum 2 or g SWITCH BACKGROUND OF THE INVENTION It is a problem among various types of vehicles, especially those intended for off-the-road use, that, if the vehicle overturns, the engine continues to operate. The continued operation can result in a very dangerous situation. First, the sparks caused by normal operation of internal combustion or electric motors can ignite any fuel that might be spilled during the roll over. Often, severe bodily injury is caused when the vehicle rolls over on the operator and catches his hand or foot in its operating drive train. One solution to this problem has been the installation of an attitude-sensitive switch which grounds the vehicles ignition system when rollover occurrs. A switch activated by the flow of liquid mercury has been adapted to such a system. Although this system adds greatly to the safety of the equipment on which it is installed, there are some operational problems still to be solved. The fact that most attitudesensitive switch systems are triggered not only by the attitude of the switch, but also by vibrations and centrifugal force, can result in unsatisfactory vehicle operation over rough terrain. Furthermore, a normal attitude-sensitive switch will return the vehicle to operation automatically if it rights itself subsequent to rolling over. The operator is often able to shove the vehicle back into its operating position but falls from the vehicle in the process. The result is that the vehicle may continue on its way, colliding with the first thing in its path. These and other difficulties experienced with the prior art devices have been obviated in a novel manner by the present invention.
It is, therefore, an outstanding object of the invention to provide a vehicle safety system that will shut off the vehicles motor if the vehicle starts to roll over.
Another object of this invention is the provision of a vehicle safety system that includes a switch which is sensitive to attitude but not to vibration.
A further object of the present invention is the provision of a vehicle safety system that will not reactivate the vehicles motor on subsequent return to upright without overt action by the operator.
It is another object of the instant invention to provide a vehicle safetysystem in which circuit opening and closing takes place within a hermetically-sealed compartment, eliminating the likelihood of ignition of present explosive vapors.
A still further object of the invention is the provision of a vehicle safety system including an attitudesensitive switch which is simple in operation, easy to install, resistant to jamming, and designed so that failure of the system leaves the vehicle operable.
With these and other objects in view, as will be apparent to those skilled in the art, the invention resides in the combination of parts set forth in the specification and covered by the claims appended hereto.
SUMMARY OF THE INVENTION This invention is a vehicle safety system which shuts off the motor of a vehicle if the vehicle starts to roll over. The system includes an attitude-sensitive switch which grounds the motors electrical system when the vehicle assumes certain attitudes.
BRIEF DESCRIPTION OF THE DRAWINGS The character of the invention, however, may be best understood by reference to one of its structural forms, as illustrated by the accompanying drawings, in which:
FIG. 1 is a perspective view of a vehicle on which the present system could be used,
FIG. 2 is a schematic wiring diagram of the present system wired to a one-cylinder internal combustion engine,
FIG. 3 is a schematic wiring diagram of the present system wired to a two-cylinder internal combustion engine,
FIG. 4 is a top plan view of an attitude-sensitive switch of the present invention, the body of the switch being made of transparent plastic,
FIG. 5 is a front elevation view of an attitudesensitive switch of the present invention, the body of the switch being made of transparent plastic.
FIG. 6 is a front elevation view of an attitudesensitive switch made of transparent plastic, and oriented so that the switch contacts are closed.
DESCRIPTION OF THE PREFERRED EMBODIMENT Referring first to FIG. 5, wherein are best shown the general features of the attitude sensitive switch of the present invention, the switch is indicated generally by the reference numeral 10. The switch is shown to have a main body 11. Within the body, are formed three subcavities which, because they intersect, form a single main cavity. The sub-cavities, include one circular and planar sub-cavity 12 and two cylindrical subcavities, 13 and 14. The circular and planar sub-cavity 12 contains a gate 15 which is rotatably mounted on the circular axis 16 of the sub-cavity and rotatable in the plane of the sub-cavity. A vee is formed by the intersection of the cylindrical sub-cavities, and straddles the circular axis 16. The cylindrical sub-cavities 13 and 14 extend beyond the circular periphery of the sub-cavity 12 and beyond its planar thickness. The gate 15 is able to rotate through the cylindrical sub-cavities but spherical contacters 17 slidable within the cylindrical subcavities cannot escape the confines of the cylindrical cavities. The result, is that a contacter 17 can be restricted to a position in the cylindrical sub-cavities 13 or 14 beyond the periphery of the circular sub-cavity 12 by the gate 15 entering the cylindrical sub-cavity volume. I
Adjacent to each the cylindrical sub-cavities 13 and 14 and adjacent to the intersecting ends, are two contacts 19 and 23, each pair of which are arranged so that they are capable of simultaneous electrical contact by the contacter 17. At the intersecting ends of the cylindrical sub-cavities l3 and 14 is a magnet 18 which is movable along a line perpendicular to the plane of the circular sub-cavity 12.
In its normal position, where it is held by spring 20,
the magnet is capable of holding one of the contacters 17 against the contacts and disallowing subsequent separation. Movement of the magnet, instigated by pressure on a button 21 external to the body, allows separation by imposing a wedge 22, concentric to the magnet, between the magnet and the contacter 17.
Having examined the structure of the attitudesensitive switch, the manner in which electrical continuity is made between contacts 19 and 23 will be understood by one skilled in the art. In a normal upright position shown in FIG. 5, the switch is in its first state, with the contacters in their first position, beyond the periphery of the circular sub-cavity. The contacters are not allowed to reach the contacts by simple vibrations because the gate 15 obstructs passage. Should the switch be tilted as in FIG. 6,'gravity will swing away the gate 15 and carry the contacter 17 down the cylindrical sub-cavity 13 to rest in a second position against the contacts 19 and 23, moving the switch to a second electrical-system interupting state. The electrical continuity thus formed, is maintained by the action of magnet 18 on the contacter 17 even if the switch is returned to its upright position. If the switch is returned to its upright position, the continuity can be broken by application of pressure to button 21 which separates the magnet and the contacter, and allows the contacter to return to its first position. It should be understood, that the angle between the cylindrical sub-cavities l3 and 14, determines the degree of tilt necessary to cause transition from the first state of the switch to the second state. The contacting elements of the switch are hermetically sealed in the body 11, thereby, isolating any sparking from a possible explosive atmosphere.
Having viewed the working of the attitude-sensitive switch, the details of a vehicle safety system in which the switch might be used, will be described. It should be recognized that although the present description involves a vehicle of the type commonly known as snowmobiles and shown in FIG. 1, a modified version of this safety system is equally effective on a motorcycle or any motor vehicle where roll over is a potential danger.
FIG. 2 shows the wiring diagram for use of the present safety system on a one cylinder engine. Switch is rigidly attached to the body of the vehicle 30 so that an over turning of the vehicle transforms the switch 10 from its open, first state, to its closed, second state. The result is that electric energy needed to operate the spark plug 31 is diverted from splice 32 to ground 32. Subsequent return of the vehicle body to an upright position, only returns the engine to an operable state, if the operator presses the button 21 of the switch.
FIG. 3 shows the wiring diagram for a safety system to be used on a two cylinder engine. In this case, because the two spark circuits are alternately charged and grounded, a simple short circuit containing the switch 10, between the spark circuits, makes the engine inoperative when the switch is in its closed state.
It is obvious that minor changes may be made in the form and construction of the invention without departing from the material spirit thereof. his not, however,
desired to confine the invention to the exact form herein shown and described, but it is desired to include all such as properly come within the scope claimed.
The invention having been thus described, what is claimed as new and desired to secure by Letters Patent 1. A vehicle safety system, comprising:
a. a vehicle,
b. a motor having an electrical system, said motor being adapted to drive said vehicle,
c. an attitude-sensitive switch located in said electrical system rigidly mounted in the vehicle, and residing in a first state when the switch is positioned in a usual attitude with respect to a horizontal reference plane, but being transferred to a second state when the attitude of the switch assumes a predetermined deviation from said usual attitude, said second state involving an interuption of said electrical system to shut off said motor d. holding means adapted to retain the switch in said second state regardless of the subsequent attitude of the switch,
e. releasing means adapted to inactivate for a time the ability of the holding means to retain said switch in said second state, and
f. retaining means adapted to allow the switch to move from its first state only if the switch assumes said deviation, wherein a channel is provided with a first and a second end, wherein a contactor is provided movable in the channel, and wherein the retaining means includes a pendulum which can swing into the channel and thereby restrict movement of the contactor.
2. A vehicle safety system as recited in claim 1,
wherein the pendulum lies in the channel when the deviation has not yet been reached and swings out of the channel when the deviation is reached. 3. A vehicle safety system as recited in claim 1,
wherein the releasing means includes a non-magnetic wedge which surrounds a portion of the magnet.
4. A vehicle safety system as recited in claim 1, wherein two channels are provided which are directed toward one another to form a V-shape, a contactor is" provided which is movable in each channel, and an electrical contact point is provided on the periphery of each channel for engagement by the contactor.