UPSET-PREVENTING DEVICES FOR TRACTORS

• US 3,763,956 A
• Filed: 12/23/1971
• Issued: 10/09/1973
• Est. Priority Date: 12/23/1971
• Status: Expired due to Term

• Current Assignee: Herbert L. Ruff
• Original Assignee: Herbert L. Ruff
• Inventors: Ruff, Herbert L.
• Primary Examiner(s): Forlenza, Gerald M.
• Assistant Examiner(s): Mannix, John
• Application Number:
  US05/211,599
• Time in Patent Office: 656 Days
• Field of Search: 180/82,103,104,100 280/15C,150.5,111,293,112 200/61.52
• US Class Current: 180/283
• CPC Class Codes: B62D 49/08 having means for preventing overturning or tipping safety devices for propulsion-unit control, specially adapted for, or arranged in, vehicles B60K28/00

Abstract

A tractor is given some vertical play between the front wheel supported carriage and the tractor frame. One or more downwardly spring-biased rods recipocatingly supported by the frame each have its lower end in contact with a portion of the carriage and its upper end operatively supporting the operating lever of a normally open switch to hold the switch closed. The switch is connected between the tractor battery and the engine coil so as to cut off ignition to the engine when the front end of the tractor is raised enough to drop the carriage downward with respect thereto. A dashpot device is arranged between the carriage and the frame to prevent cutting off the ignition by quick downward movement of the carriage-operated rod with respect to the frame-carried switch caused by passage over rough ground. A mercury switch has its contacts arranged to complete a shutoff circuit when the tractor is tipped to a critical angle sidewise. The cutoff circuit includes a solenoid operated switch to cut the engine ignition circuit and two other solenoids arranged to initiate the transverse swinging out of a tip-over preventing arm at each side of the tractor.

Claims

1. An unupsetable tractor vehicle having front and rear wheels, a body frame, a motor for driving the rear wheels and a front wheel carriage directly supported by the front wheels and connected to the frame, comprising:

a portion of the carriage having vertical play with respect to the frame, a casing secured to the frame, an elongated member oscillatably carried by the casing, one end of the member being biased downward against the carriage portion and the other end of the member normally being operatively engagEd with the operating arm of a frame-carried first cutoff switch, the cutoff switch being electrically arranged to shut off the vehicle motor when the member other end moves with respect to the cutoff switch in response to the front wheels rising off the ground and, supported by the carriage, are carried by the frame elevated above the ground;

a dashpot timer device connected between the frame and the carriage portion to prevent operation of the cutoff switch by rapid up and down movement of the carriage portion;

mercury switch means secured to the frame and having electrical contacts arranged to initiate operation of frame-carried motor means when the frame tips transversely to a critical angle, the motor means including motor means for operating a second cutoff switch to stop the vehicle motor; and

at least one arm oscillatably secured to the frame and transversely moveable to an extended position for contacting the ground at the side of the vehicle to prevent transverse tipping beyond the critical angle, the motor means including means for initiating transverse extension of the arm.

2. In a tractor vehicle having front and rear wheels, a body frame, a motor mounted on the frame for driving the rear wheels and including a source of electrical current and motor cylinder ignition devices connected in an ignition circuit, and a front wheel carriage directly supported by the front wheels, the carriage having fore and aft extending shaft means and the frame having bearing block members providing journals for the shaft means for pivotally securing the carriage to the frame, means for preventing the upending of the tractor by pulling too heavy a load, comprising;

the shaft means of the carriage having substantial vertical play with respect to the block members of the frame, a vertically disposed elongated member oscillatably carried by each block member and guided for axial movement with respect thereto, one end of each elongated member being biased downward against the carriage shaft means and the other end of the elongated member normally being operatively engaged with the piston rod of a dashpot timer device, the timer cylinder being secured to the frame and adapted to axially align the piston rod with the elongated member and guide the rod for vertical axial movement within the cylinder, a cutoff switch supported by the frame above each block member, the cutoff switches being electrically connected in series in the ignition circuit, each timer rod being adapted to normally hold its respective switch contacts closed and to adapt the switch contacts to open when the front wheels rise off the ground and, supported by the carriage, are carried above the ground causing the carriage shaft means to fall within its block means because of the play so that the elongated members fall;

the timer means being adjusted for a time delay in the falling of its rod after the elongated members fall to prevent opening of the switches when the front wheels bounce rapidly over rough ground and whereby the motor is stopped before the vehicle can rear over backwards when the vehicle is pulling too heavy a load.