US3571538A

US3571538A - Inertially operated safety switch

Info

Publication number: US3571538A
Application number: US862298A
Authority: US
Inventors: William O Swanson
Original assignee: Individual
Current assignee: Individual
Priority date: 1969-09-30
Filing date: 1969-09-30
Publication date: 1971-03-23
Anticipated expiration: 1988-03-23

Abstract

A gravity or inertially operated safety switch for use with electrical systems of vehicles wherein liquid mercury or other electrically conductive fluid is normally contained between two axially aligned connectors for completion of an electrical circuit and wherein upon impact or sudden deceleration of the vehicle the housing containing the mercury rotates about the connectors so that the mercury is removed from between the connectors and the electrical circuit therebetween is broken. The housing also has an electrically conductive wire embedded therein for normally completing a second circuit through two detents whereby this second circuit is opened when the housing rotates upon impact and the wire is no longer in contact with the detents.

Description

United States Patent William O. Swanson 303 Leslie Laue, Columbia, Mo. 65201 862,298

Sept. 30, 1969 Mar. 23, 1971 Continuation-impart of application Ser. No. 829,911, June 3, 1969, now abandoned.

lnventor Appl. No. Filed Patented INERTIALLY OPERATED SAFETY SWITCH m13,571,s3s

Primary Examiner-Robert K. Schaefer Assistant Examiner-M. Ginsburg Attorney-Cushman, Darby and Cushman ABSTRACT: A gravity or inertially operated safety switch for use with electrical systems of vehicles wherein liquid mercury or other electrically conductive fluid is normally contained between two axially aligned connectors for completion of an electrical circuit and wherein upon impact or sudden deceleration of the vehicle the housing containing the mercury rotates about the connectors so that the mercury is removed from between the connectors and the electrical circuit therebetween is broken. The housing also has an electrically conductive wire embedded therein for normally completing a second circuit through two detents whereby this second circuit is opened when the housing rotates upon impact and the wire is no longer in contact with the detents.

PATENTEDHAH23I97! 3,571,538

a; INVENT OR M24 00/ 7 0. fkw/msa/v ATTORNEYS KNERTHALLY OPERATED SAFETY SWITCH This application is a continuation-in-part of application Ser. No. 829,911, filed Jun. 3, 1969 for lnertially Operated Safety Switch, and now abandoned.

The present invention relates to safety switches and more particularly to a gravity or inertially operated mercury safety switch which may be mounted on a vehicle to disconnect the electrical system thereof in the event of an accident to greatly reduce the potential of fire from sparks due to electrical shorts. The present invention provides for a unique arrangement of a weighted housing together with a mercury-receiving trough which is located between a pair of axially aligned electrical connectors whereby upon the sudden deceleration of the vehicle the mercury is removed from between electrical connectors to open the electrical circuit of the vehicle.

An object of the present invention is the provision of a gravity or inertially operated safety switch for use with vehicles.

Other objects and features of the invention will become apparent to those of ordinary skill in the art as the disclosure is made in the following description of a preferred embodiment of the invention as illustrated in the accompanying FIGS. in which:

H6. 1 is a side elevation view of the switch, partly in phantom, illustrating the direction of rotation of the hollow housing member of the switch;

FIG. 2 is a section of the device taken on the line 2-2 of FIG. 1 looking in the direction of the arrows; and

FIG. 3 is a fragmentary cross-sectional view of the trough portion of the housing member taken on the line 3-3 of FIG. 2 looking in the direction of the arrows.

With reference now to the drawings, wherein like reference characters designate like or corresponding parts throughout the several views, there is shown in FIGS. 1-3 a base member which is adapted to be mounted in close proximity to the vehicle battery by the fastening means 12, which may be screws or the like, and which are located in the lower portion of the base member. A pair of

connectors

14 and 16 are mounted in the base member 10 in fixed positions and in axial alignment with one another. These connectors are adapted to be connected into the electrical system, e.g. to the battery, of the vehicle and units have been built and successfully tested at currents up to 200 amps,

A hollow housing member 18 is mounted on the

connectors

14 and 16 and within the base member 10 for rotation about the common axis of theconnectors. The housing member includes a pair of

depressed portions

20 and 22 in the exterior surface of the housing member for receiving a pair of adjustable elements or

detents

24 and 26, respectively, which are located within the base member in adjustable relationship therewith. A weight member 28 is fixedly attached to the end of the housing member 18 which is located farthest from the connectors.

A band of electrically conductive material such as a strand of wire 29 is partially embedded in or located on the outer surface of the housing member 18 and preferably just off of the center of the

depressed portions

20 and 22. This wire normally contacts the

detents

24 and 26, which may be electrically conducting screws or similar fastening means, when the housing member 18 is in the upright position, and the detents can be conventionally connected to electrical conductors 31 and 33 which are connected into the electrical system, egg. to the alternator (not shown). The strand 29 may completely encircle the housing member or may extend only halfway around so as to complete an electrical connection between the

detents

24 and 26 when the housing member is upright.

The housing member 18 also includes a mercury or other electrically conducting fluid material receiving trough which is located between the

connectors

14 and 16 and which normally contains a small amount of electrically conductive fluid material 32, such as mercury, to enable the completion of an electrical circuit between the connectors and throughout the electrical system of the vehicle.

The base member 10 and the housing member 18 are preferably comprised of electrically insulating material and the

connectors

14 and 16 are preferably threaded and contain the

nuts

34, 36, 38 and 40 thereon for enabling the connection of the battery cables or other electrical conductors to the connectors.

In the operation of the switch, the

adjustable detents

24 and 26 are set so that they will not permit the unlatching of the housing member 18 therefrom under normal braking loads, but will permit the unlatching upon impact of the vehicle, such as might occur in an accident. Under normal conditions of operation, the housing member 18 is oriented in a vertical direction, as shown in the FlGS., so that the mercury 32 is located at the bottom of the V-shaped trough 30 and between the connectors 1d and 16 to enable the completion of the electrical circuit of the vehicle therethrough. Also the wire strand 2? is in electrical contact with

detents

24 and 26 to enable completion of the electrical circuit therethrough. As an example, the

connectors

14 and 16 are connected to the battery (not shown) while the detents and the wire 29 complete the circuit with the alternator of the vehicle (not shown). ln the event of an accident, the impact causes the weighted housing member 18 to become unlatched from the

detents

24 and 26 so that the detents no longer rest within the slightly depressed portions of the

housing

20 and 22 and no longer contact the wire 29. The force of inertia then causes the rotation of the housing member and the weight member about the

connectors

14 and 16 so that the mercury 32 runs out of the trough between the connectors M and 16 and breaks the electrical circuit. As a result, the ignition or alternator circuit will initially be opened with the same effect as if the ignition switch of the vehicle had been turned off. As the rotation of the housing continues the battery circuit through

connectors

14 and 16 and mercury 32 will also be opened.

Thus, all power from the vehicle battery to the electrical system and from the alternator is disconnected and the electrical system of the vehicle is completely inoperative so that the potential for fire is greatly reduced since the hazard of sparks from electrical shorts is eliminated. The weighted housing acts as a pendulum so that once detented it always swings to a position in which the circuit is opened. After the housing member and the weight member have been rotated from their normal position it is a simple matter to reset the switch and to restore the power when needed by simply rotating the housing member back into its normally vertical position so that the

detents

24 and 26 again engage the

depressed portions

20 and 22 and the wire 29 of the housing member 18.

It can also be seen that in addition to breaking the circuit upon the impact of an accident the present safety switch operates by means of gravity to open the circuit of the vehicle in the event that the vehicle flips over. When this occurs, the mercury 32 also runs out of the trough 30 so that the electrical circuit between

connectors

14 and 16 is broken. Thus, the

switch of this invention is both an inertially operated and a gravity operated safety switch.

Obviously many modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

l claim:

1. A gravity or inertially operated safety switch for use with electrical systems of vehicles, comprising:

a base member for mounting the switch on the vehicle;

fastening means affixing said base member to the vehicle in a fixed position;

a pair of connectors mounted in said base member and positioned in axial alignment with one another;

said connectors being adapted to be connected into the electrical system of the vehicle;

a hollow housing member mounted on said connectors and within said base member for rotation about the common axis of said connectors and including a pair of depressed portions in the exterior surface of said housing member;

a weight member fixedly attached to the end of said housing member located farthest from said connectors;

said housing member including a mercury-receiving trough therein between said connectors and normally containing a small amount of electrically conductive mercury to ena ble the completion of an electrical circuit between said connectors; and

a pair of adjustable elements mounted in said base member for normally contacting respective ones of said depressed portions in said housing member whereby said housing member is normally maintained in an upright position with the mercury located in said receiving trough and whereby said elements unlatch from said depressed portions to enable the rotation of said housing member about said common axis of said connectors and to enable the movement of said mercury out of said trough to break the electrical circuit between said connectors when the vehicle is abruptly decelerated as upon the occurrence of an impact in an accident.

2. A safety switch as in claim 1 wherein said base member is comprised of electrically insulating material.

3. A safety switch as in claim 2 wherein said housing member is comprised of electrically insulating material.

4. A safety switch as in claim 1 wherein said adjustable elements are positioned in axial alignment with one another.

5. A safety switch as in claim 4 wherein said adjustable elements are detents which are adjustable so as not to unlatch under normal braking conditions.

6. A safety switch as in claim 1 wherein said receiving trough is a generally V-shaped trough.

7. A safety switch as in claim 1 wherein said adjustable elements are adapted to be connected into the electrical system of the vehicle including electrically conducting means affixed to said housing member and in normally electrically conducting relationship with said adjustable elements.

8. A safety switch as in claim 7 wherein said electrically conducting means includes a strand of wire at least partially encircling said housing member.

9. A safety switch as in claim 8 wherein said wire is partially embedded in the outer surface of said housing member and wherein said wire is located within said depressed portions.

10. A gravity or inertially operated safety switch for vehicles, comprising:

means for mounting the switch on the vehicle;

connector means mounted in said mounting means;

housing means rotatably mounted with respect to said connector means; said housing means having an electrically conductive fluid receiving portion therein for normally containing an amount of electrically conductive fluid between said connector means and in electrical contact therewith; and

means operatively associated with said housing means and with said mounting means for normally maintaining said housing means in an upright position and including an inertial element whereby said maintaining means enable the rotation of said housing means upon the occurrence of an impact as in an accident to permit the movement of said fluid from between said connector means to break the circuit of the vehicle.

Claims

1. A gravity or inertially operated safety switch for use with electrical systems of vehicles, comprising: a base member for mounting the switch on the vehicle; fastening means affixing said base member to the vehicle in a fixed position; a pair of connectors mounted in said base member and positioned in axial alignment with one another; said connectors being adapted to be connected into the electrical system of the vehicle; a hollow housing member mounted on said connectors and within said base member for rotation about the common axis of said connectors and including a pair of depressed portions in the exterior surface of said housing member; a weight member fixedly attached to the end of said housing member located farthest from said connectors; said housing member including a mercury-receiving trough therein between said connectors and normally containing a small amount of electrically conductive mercury to enable the completion of an electrical circuit between said connectors; and a pair of adjustable elements mounted in said base member for normally contacting respective ones of said depressed portions in said housing member whereby said housing member is normally maintained in an upright position with the mercury located in said receiving trough and whereby said elements unlatch from said depressed portions to enable the rotation of said housing member about said common axis of said connectors and to enable the movement of said mercury out of said trough to break the electrical circuit between said connectors when the vehicle is abruptly decelerated as upon the occurrence of an impact in an accident.

10. A gravity or inertially operated safety switch for vehicles, comprising: means for mounting the switch on the vehicle; connector means mounted in said mounting means; housing means rotatably mounted with respect to said connector means; said housing means having an electrically conductive fluid receiving portion therein for normally containing an amount of electrically conductive fluid between said connector means and in electrical contact therewith; and means operatively associated with said housing means and with said mounting means for normally maintaining said housing means in an upright position and including an inertial element whereby said maintaining means enable the rotation of said housing means upon the occurrence of an impact as in an accident to permit the movement of said fluid from between said connector means to break the circuit of the vehicle.