Adjustable Weight Distribution Hitch System

Abstract

A weight distribution hitch system used with a hitch on a vehicle and a trailer, the system comprising: a jack with a foot and a motor configured to raise and lower a front portion of the trailer; a moment bar with a forward end attached to the hitch so as to pivot about a generally vertical axis, and a rearward portion, the moment bar configured to exert a forward moment on the vehicle in response to an upward force on the rearward portion; an engagement member configured to increase the upward force on the rearward portion of the moment bar upon movement of the jack in one vertical direction and to decrease the upward force upon movement of the jack in an opposite vertical direction; a sensor configured to determine at least one of current and voltage across the motor, to thereby infer the upward force on the rearward portion; and a switch configured to turn the motor on or off depending on the inferred upward force is disclosed.

What is claimed is: 
     
         1 . A weight distribution hitch system used with a hitch on a vehicle and a trailer, the system comprising:
 a jack with a foot and a motor configured to raise and lower a front portion of the trailer;   a moment bar with a forward end attached to the hitch so as to pivot about a generally vertical axis, and a rearward portion, the moment bar configured to exert a forward moment on the vehicle in response to an upward force on the rearward portion;   an engagement member configured to increase the upward force on the rearward portion of the moment bar upon movement of the jack in one vertical direction and to decrease the upward force upon movement of the jack in an opposite vertical direction;   a sensor configured to determine at least one of current and voltage across the motor, to thereby infer the upward force on the rearward portion; and   a switch configured to turn the motor on or off depending on the inferred upward force.   
     
     
         2 . The system of  claim 1 , wherein the sensor is an amperage meter configured to determine current draw of the motor. 
     
     
         3 . The system of  claim 1 , wherein the sensor is a voltmeter configured to determine voltage drop across the motor. 
     
     
         4 . The system of  claim 1 , wherein the switch comprises a processor configured to receive signals from the sensor and to operate the switch. 
     
     
         5 . The system of  claim 4 , wherein the processor is programmable by a user. 
     
     
         6 . The system of  claim 4 , further comprising a communication module configured to advise a user of balanced and unbalanced conditions. 
     
     
         7 . The system of  claim 1 , further comprising a level sensing mechanism and a limit switch configured to stop the jack from lowering when the level sensing mechanism detects a predetermined level. 
     
     
         8 . The system of  claim 1 , further comprising a load sensor configured to measure the load on the jack. 
     
     
         9 . The system of  claim 8 , further comprising a limit switch configured to stop the jack from lowering when the load sensor detects a predetermined load. 
     
     
         10 . The system of  claim 1 , wherein the jack further comprises one or more electrical switches allowing the jack to be raised or lowered manually. 
     
     
         11 . The system of  claim 1 , wherein the jack further comprises one or more electrical switches allowing the jack to be raised or lowered automatically. 
     
     
         12 . The system of  claim 1 , wherein the engagement member further comprises a flexible tension member connected to the moment bar to transfer force to the rearward portion of the moment bar. 
     
     
         13 . The system of  claim 1 , further comprising a load sensor configured to detect changes in the load on the system and communicate to the motor to adjust the upward force. 
     
     
         14 . The system of  claim 1 , further comprising a dual coupler ball. 
     
     
         15 . The system of  claim 1 , wherein the engagement member further comprises a cam on a foot of the jack. 
     
     
         16 . The system of  claim 15 , wherein the flexible tension member comprises:
 a flexible tension member with a first portion contacting the frame of the trailer,   a second portion contacting the jack, and   a third portion contacting the rearward portion of the moment bar,   wherein the tension on the flexible tension member is increased by the jack moving in one generally vertical direction and decreased by the jack moving in an opposite direction.   
     
     
         17 . The system of  claim 16 , wherein the first portion of the flexible tension member is attached to the frame of the trailer, wherein the third portion of the flexible tension member is attached to the rearward portion of the moment bar and the second portion of the flexible tension member slides across a glide attached to the jack. 
     
     
         18 . A weight distribution hitch system, comprising:
 a jack with a foot and a motor configured to raise and lower a front portion of a trailer;   a moment bar, comprising:
 a forward end attached to a vehicle hitch so as to pivot about a generally vertical axis, and 
 a rearward portion, the moment bar configured to exert a forward moment on the vehicle in response to an upward force on the rearward portion; 
   an engagement member on the foot, comprising:
 a cam adapted to engage the rearward portion of the moment bar, and 
 configured to increase the upward force on the rearward portion of the moment bar upon upward movement of the jack and to decrease the upward force upon downward movement of the jack; 
   a sensor configured to determine at least one of current and voltage across the motor, to thereby infer the upward force on the rearward portion; and   a switch configured to turn the motor on or off depending on the inferred upward force.   
     
     
         19 . The system of  claim 18 , further comprising a level sensing mechanism and a limit switch configured to stop the jack from lowering when the level sensing mechanism detects a predetermined level. 
     
     
         20 . The system of  claim 18 , further comprising a load sensor configured to measure the load on the jack.