GRAVITY SAFETY SWITCH

• US 3,599,745 A
• Filed: 07/28/1969
• Issued: 08/17/1971
• Est. Priority Date: 07/28/1969
• Status: Expired due to Term

• Current Assignee: Benjamin F. Hughes
• Original Assignee: Benjamin F. Hughes
• Inventors: Hughes, Benjamin F.
• Application Number:
  US04/845,278
• Time in Patent Office: 750 Days
• US Class Current: 180/284
• CPC Class Codes: H01H 29/22 wherein contact is made and broken between liquid and solid
• CPC Class Codes: H01H 3/141 Cushion or mat switches

Abstract

A gravity operated switch includes a movable electrically conductive member in a housing. The conductive member bridges a pair of fixed spaced electrical contacts. When the housing is tilted the movable conductive member moves off or out of contact with the electrical contacts to open an associated electric circuit. The switch has particular utility in tractors and other machines to stop operation when the machine is tilted to an unsafe operating position. The switches control flow of fuel to the engines of the machines, ignition, or other engine control components.

Claims

1. A gravity switch combination for protecting a machine subject to tilting at an unsafe operating angle, comprising a housing mountable in a fixed position on said machine, a seat in said housing, an external circuit, a pair of fixed spaced electrical contacts at said seat connectable in said external electric circuit, an electrically conductive ball normally seated on said seat and bridging said contacts to close said circuit, and means for retaining said ball displaced from said contacts once the housing has been tilted to displace the ball from said seat, in which said housing comprises a plurality of tubular wings, said seat being a pocket centrally located with respect to said wings, the last named means comprising other pockets for receiving said ball at ends of the wings, and other spaced fixed contacts at said ends of the wings in said pockets, said other contacts being connectable in other external electrical circuits, any one of said other electrical circuits being closable when said ball is deposited in the pocket of one of the wings to bridge the contacts thereat.

2. A gravity switch combination for protecting a machine subject to tilting at an unsafe operating angle, comprising a housing mountable in a fixed position on said machine, a seat in said housing, an external circuit, a pair of fixed spaced electrical contacts at said seat connectable in said external electric circuit, an electrically conductive ball normally seated on said seat and bridging said contacts to close said circuit, and means for retaining said ball displaced from said contacts once the vehicle has been tilted to displace the ball from said seat and returned to a safe operating angle, and means selectively movably mounting the housing for restoring the ball to said seat, and other fixed spaced contacts located at the means for retaining the ball displaced from the first named contacts, said other contacts being connectable to another external electric circuit, whereby said first named external circuit is opened and the other external circuit is closed when the ball is displaced from the first named contacts and bridges said other contacts.

3. A gravity switch combination as defined by claim 2, wherein said ball is a globule of mercury.

4. A gravity switch combination as defined by claim 2, wherein said housing comprises a plurality of tubular wings, said seat being a pocket centrally located with respect to said wings, the last-named means comprising other pockets for receiving said ball at ends of the wings.

5. A gravity switch combination as defined by claim 4, wherein at least two of said wings are disposed at angles to each other for receiving the ball in one of the other pockets when the housing is tilted.

6. A gravity switch combination as defined by claim 2, wherein said housing is hemispherical in form and wherein the seat is centrally located so that the globule is displaced from the seat regardless of the direction in which the housing is tilted.

7. A gravity switch combination as defined by claim 6, wherein the means for retaining the globule when displaced from said seat is a groove surrounding the seat, said seat being elevated above said groove axially of the housing.

8. A gravity switch combination as defined by claim 7, further comprising spaced annular contacts in said groove disposed for bridging by said globule when the globule is displaced from said seat.

9. A gravity switch combination as defined by claim 2, wherein said first-named external circuit comprises a solenoid coil arranged to close a fuel supply line of said machine, said coil being connected to saId contacts so that the coil is energized when the ball is on the seat and is deenergized when the ball is displaced from the seat.

10. A gravity switch combination as defined by claim 2, wherein the first-named external circuit is the ignition circuit of an engine said ignition circuit being connected to said contacts so that the ignition circuit is energized when the ball is on the seat and is deenergized when the ball is displaced from said seat.