Log trailer load extension axle assembly

A load extension axle assembly for extending load-carrying capacity of steerable chassis carried on tandem axles, the assembly comprising:

• an elongate load transfer beam including a forward, load-bearing portion and a rearward, load-transfer portion;
• a tag axle connected to support the rearward portion of the load transfer beam at a position spaced rearward of the tandem axle;
• trunnion means connecting the forward portion to the chassis for angular movement of the load transfer beam about a horizontal axis parallel to the tandem axle;
• load bearing means mounted on the forward portion of the load transfer beam for supporting a load;
• load transferring pivot means interconnecting the forward and rearward portions of the load transfer beam for transferring a portion of the load to the rearward portion while permitting angular movement of the rearward portion relative to the forward portion about an approximately vertical axis so that the rearward beam portion and tag axle can swing laterally behind the chassis independently of the load;
• the trunnion means and pivot means being spaced apart lengthwise of the assembly, and the load-bearing means being spaced between the trunnion means and the pivotal means so that the load-bearing means remains laterally static as the tag axle swings laterally during turns;
• said pivot means being tilted about 2.degree. forward from a true vertical axis so that the portion of load transferred to the tag axle is at a minimum when the tag axle is tracking in a centered position in parallel alignment behind the tandem axles.

A tractor-trailer and load extension assembly for carrying a load of logs, comprising:

• a tractor having a first, axle-driven chassis and a first log bunk mounted on the chassis for carrying a front portion of the load;
• a trailer having a second chassis mounted on a trailer axle and steerably hitched to a rear end of the first chassis;
• a load extension assembly including a load transfer beam connected at its front end to the second chassis and a rear carried on a tag axle to trail behind the trailer;
• a trunnion pivotally connecting the front end of the load transfer beam to the second chassis;
• a second log bunk mounted on the load transfer beam at a position spaced between the trunnion and the tag axle for supporting a rear portion of the load;
• and
• a pivot in the load transfer beam spaced between the log bunk and the tag axle;
• said pivot having an axis tilted at an angle from vertical such that swinging of the rear portion of the load extension beam laterally of the second chassis increases loading of the tag axle and thereby induces the tag axle to track in a centered position behind the trailer axle.

A tractor-trailer and load extension assembly for carrying a load of logs, comprising:

• a tractor having a first, axle-driven chassis and a first log bunk mounted on the chassis for carrying a front portion of the load;
• a trailer having a second chassis mounted on a tandem axle and steerably hitched to a rear end of the first chassis;
• a load extension assembly including a load transfer beam connected at its front end to the second chassis and a rear carried on a tag axle to trail behind the trailer;
• a trunnion pivotally connecting the front end of the load transfer beam to the second chassis;
• a second log bunk mounted on the load transfer beam at a position spaced between the trunnion and the tag axle for supporting a rear portion of the load;
• and
• a pivot in the load transfer beam spaced between the log bunk and the tag axle;
• extension means between the pivot and the tag axle for adjusting the length of the load transfer beam, the extension means including a remotely-controllable actuator selectably operable to enable adjustment of the length of the load transfer beam;
• and
• a brake control circuit operable by a first driver control means to actuate brake means for braking the tandem axle and tag axle, the circuit including a subcircuit operable by a second driver control means and coupled to the actuator and to a brake means for simultaneously enabling adjustment of the length of the load transfer beam and braking the tag axle without braking the tandem axle so that the tandem axle can be rolled while the tag axle is immobilized to extend or retract the load extension beam.

A load extension axle assembly comprising:

• an elongate load transfer beam including a forward portion and an elongate rearward portion;
• means for mounting the forward portion of the load transfer beam on a chassis carried on a first axle;
• means for mounting the rearward portion of the load transfer beam on a second axle so that the assembly trails behind the chassis and the first axle;
• means for supporting a load on the forward portion of the load transfer beam so that a first portion of the load is borne by the first axle and a second portion of the load is transferred rearward by the load transfer beam to be borne by the second axle;
• and
• slidable adjustment means for slidably positioning the second axle along the rearward portion to extend or retract the load extension beam,
• the slidable adjustment means including a sleeve slidably receiving the rear portion of the load transfer beam and clamping means actuable for selectably clamping and releasing the rear portion within the sleeve means;
• and
• actuator means for actuating the clamping means, the clamping means including a band surrounding the rear portion of the load transfer beam within the sleeve and the actuator means including a linear actuation member connected to the band for tightening and loosening the band around said rear portion.

A load extension axle assembly comprising:

• an elongate load transfer beam including a forward portion and an elongate rearward portion;
• means for mounting the forward portion of the load transfer beam on a chassis carried on a first axle;
• means for mounting the rearward portion of the load transfer beam on a second axle so that the assembly trails behind the chassis and the first axle;
• means for supporting a load on the forward portion of the load transfer beam so that a first portion of the load is borne by the first axle and a second portion of the load is transferred rearward by the load transfer beam to be borne by a second axle;
• and
• slidable adjustment means for slidably positioning the second axle along the rearward portion to extend or retract the load extension beam;
• the slidable adjustment means including a structural sleeve having a pentagonal cross section;
• the rear portion having a hexagonal cross section nested loosely within the pentagonal cross section;
• and
• the sleeve including bushings shaped to fit comformably between the hexagonal and pentagonal cross sections.

A load extension axle assembly comprising:

• an elongate load transfer beam including a forward portion and an elongate rearward portion;
• means for mounting the forward portion of the load transfer beam on a chassis carried on a first axle;
• means for mounting the rearward portion of the load transfer beam on a second axle so that the assembly trails behind the chassis and the first axle;
• means for supporting a load on the forward portion of the load transfer beam so that a first portion of the load is borne by the first axle and a second portion of the load is transferred rearward by the load transfer beam to be borne by a second axle;
• and
• slidable adjustment means for slidably positioning the second axle along the rearward portion to extend or retract the load extension beam;
• an assembly in which the slidable adjustment means includes means defining a sleeve slidably receiving the rear portion of the load transfer beam and clamping means actuable for selectably clamping and releasing the rear portion within the sleeve means;
• an assembly including a remotely controllable actuator means for actuating the clamping means;
• and
• a brake control circuit operable by a first driver control means to actuate brake means for braking the first and second axles, the circuit including a subcircuit operable by a second driver control means and coupled to the actuator means and to a brake means for simultaneously unclamping the clamping means and braking the second axle without braking the first axle so that the first axle can be rolled while the second axle is immobilized to extend or retract the load extension beam.