Trailer stabilizer and method

A method of stabilizing trailers of a multi-trailer rig having a dolly between trailers comprising the steps of:

• exerting a pulling force between a back of a first trailer and a wheeled connecting dolly urging said dolly in a direction to overcome misalignment;
• simultaneously exerting a transversely spaced pushing force between said back of said first trailer and said dolly urging said dolly in said direction to overcome misalignment;
• and
• maintaining the application of said forces as a force couple during periods of misalignment of said trailers at all times urging said trailers toward alignment through control over the dolly.

A fluid operated cylinder assembly for exerting a stabilizing force comprising:

• an elongated cylinder having a source of pressurized fluid on one end;
• a stop member fixed internally of the cylinder intermediate its ends having an open central portion;
• a first piston slidably carried on one side of said stop member;
• a second piston freely moveable within said cylinder on the other side of said stop;
• an elongated piston rod, slidably carrying said first piston, extensible through the open central portion of the stop member for pushing said second piston and projecting outwardly through one end of the cylinder;
• a fluid connection between respective end portions of said cylinder;
• and
• an engaging member carried by said piston rod limiting said sliding movement of the first piston thereon;
• whereby said cylinder assembly resists compressive forces by pushing as a result of a build up of pressure at the other end of the cylinder due to pushing of the second piston by said piston rod until the second piston moves responsive to such build up of pressure to engage said stop member after which further movement of the piston rod causes movement of the first piston to result in pulling.

An air operated cylinder assembly for exerting a stabilizing force upon a wheeled dolly between trailers of a multi-trailer rig comprising:

• an elongated cylinder having a source of pressurized fluid on one end;
• a stop member fixed internally of the cylinder intermediate its ends having an open central portion;
• a first piston slidably carried on one side of said stop member;
• a second piston freely moveable within said cylinder on the other side of said stop;
• an elongated piston rod, slideably carrying said first piston, extensible through the open central portion of the stop member for pushing said second piston and projecting outwardly through one end of the cylinder;
• a fluid connection between respective end portions of said cylinder;
• an engaging member carried by said piston rod limiting further sliding movement of the first piston thereon;
• pivotal connections between said cylinder assembly and a rear of a front trailer on one end and on the other end to said dolly;
• whereby said cylinder assembly resists compressive forces by pushing as a result of a build up of pressure at the other end of the cylinder due to pushing of the second piston by said piston rod until the second piston moves responsive to such build up of pressure to engage said stop member after which further movement of the piston rod causes movement of the first piston to result in pulling controlling alignment of the dolly.

An articulated tractor trailer rig stabilized by a stabilizer having a front trailer and a pivotally connected wheeled dolly including an extensible cylinder assembly pivotally mounted between said front trailer and said wheeled dolly exerting a force at all times tending to bring the dolly into alignment and hence bring a rear trailer which follows the dolly into alignment, said stabilizer further including a center stop carried in said cylinder assembly and a front and a rear piston on respective sides of said center stop for effectively moving to pull or push until such action is stopped through engagement thereof with the center stop, comprising:

• an abutment carried by a bottom front portion of said front trailer;
• fluid power operated means moving said abutment into and out of engagement with a fifth wheel of said tractor for limiting the angle between the front trailer and the tractor;
• and
• extensive fluid power operated means pivotally connected at respective ends to a rear of said front trailer and to said dolly for controlling alignment of said dolly;
• whereby jackknifing is avoided.