Trailer anti-jackknifing device

Claim 1

Trailer anti-jackknifing device in combination with a conventional tractor-drawn trailer wherein the tractor includes a forwardly disposed operator''s cab and rearwardly disposed fifth wheel assembly unit having a skid-plate that includes a generally circular forward major portion and a bifurcate rearward minor portion and including therewithin a kingpin extending along the tractor-trailer vertical pivot-axis, the trailer underside including a frontal base-plate having a depending kingpin overlying the fifth wheel unit skid-plate bifurcate portion, and the trailer extending longitudinally rearwardly from and in pivotably associated relationship with the tractor through said kingpin vertical pivot-axis, said anti-jackknifing device comprising: A. At least one vertically reciprocatable upright locking-pin as the reciprocatably movable plunger of a fluid-actuatable piston of the casing-plunger type, the stationary casing portion of the piston nestably supported within the recess lower horizontal shelf of a generally C-shaped support member and the plunger locking-pin portion of the piston being surrounded by the upper horizontal shelf of said C-shaped support member, the locking-pin being ultimately attached to the fifth wheel skidplate by removably abuttably attaching the C-shaped support upright intermediate concave portion to the skid-plate generally circular forward peripheral portion, said plunger locking-pin having a lower normal-station located wholly downwardly below the trailer base-plate and an upward extendedstation; B. Actuation means for causing the plunger locking-pin to vertically reciprocate between said lower normal-station and said upward extended-station, said locking-pin actuation means including a control means located within the operator''s cab and hence remote from the tractor fifth wheel unit skid-plate; and C. Sectorially extending confinement means for the locking-pin and effective at extended-station only thereby preventing trailer jackknifing about the tractor-trailer vertical-axis during panic situations but not interfering with sharp tractor turns during normal driving, said horizontal sectorial confinement means having a continuous sectorial extent within the range of 15*-25* and being attached to the trailer frontal base-plate and located radially outwardly from the tractortrailer vertical pivot-axis and in common elevation with the locking-pin upward extended-station, the confinement means central portion being in registry with the locking-pin when the pivotal trailer is in rearwardly longitudinally extending relationship with the tractor fifth wheel unit and the kingpin pivot-axis thereat and wherein the trailer base-plate in addition to the sectorial confinement means and spaced from the respective terminii thereof includes at least two safety-holes spaced a constant-radius from the kingpin pivot-axis.