Automatic truss jig setting system

Abstract

A automatic truss jig setting system is disclosed that includes a table including a plurality of segments with a side edge of adjacent segments defining a slot. At least one pin assembly, and optionally a pair of pin assemblies, is movable independently of each other along the slot. Movement apparatus is provided for independently moving the pin assemblies along the slot. Each of the side edges of the segments associated with the slot defines a substantially vertical plane with a zone being defined between the substantially vertical planes of the side edges, and the movement apparatus is located substantially outside of the zone of the slot. The invention may optionally include a system for handling the obstruction of pin assembly movement, and a system for keeping track of the position of the pin assembly when the pin assembly has encountered an obstruction.

1 . A truss jig positioning system for use on a table including at least a pair of adjacent segments with a slot defined by adjacent side edges of the pair of adjacent segments, the table having a support plane on which work pieces are supported, each of the side edges of the segments of the table associated with the slot defining a substantially vertical plane with a zone being defined between the substantially vertical planes of the side edges, the system comprising: 
 a pair of pin assemblies mountable on the table adjacent to a slot between the pair of adjacent segments with a portion of each of the pin assemblies extending through the same slot;    movement means for moving the pin assemblies independently of each other along the same slot;    wherein the movement means is configured in a manner such that, when the movement means is mounted on the table, the movement means is located substantially outside of the zone of the slot.    
   
   
       2 . The system of  claim 1  wherein the movement means comprises a pair of rods, each of the rods engaging one of the pin assemblies for moving the pin assembly.  
   
   
       3 . The system of  claim 1 , wherein the movement means comprises a pair of rods, the pair of rods being configured such that the rods are spaced in a substantially horizontal plane when the movement means is mounted on the table.  
   
   
       4 . The system of  claim 1 , wherein each of the pin assemblies comprises a pin carriage and a pin mounted on the pin carriage, the pin carriage extending laterally outward from a longitudinal axis of the pin for extending below the segments adjacent to a slot when the pin assembly is mounted on the table and the pin is positioned in the slot.  
   
   
       5 . The system of  claim 4  wherein the pin carriage of each of the pin assemblies extends laterally outward in opposite directions with respect to the longitudinal axis of the pin.  
   
   
       6 . The system of  claim 1 , wherein the movement means comprises a pair of rods, and each of the pin assemblies comprises a pin carriage and a pin mounted on the pin carriage, the pair of rods extending through each of the pin carriages, the pin carriages being configured such that the rods are spaced in a substantially horizontal plane when the movement means is mounted on the table.  
   
   
       7 . The system of  claim 1  additionally comprising a side channel-defining structure for mounting on the table below each of the side edges of the adjacent segments, the movement means being located in the side channels of the adjacent segments of the table.  
   
   
       8 . The system of  claim 1 , wherein the movement means comprises a pair of rods, and each of the pin assemblies comprises a pin carriage, both of the rods extending through each of the pin carriages and a pin mounted on the pin carriage, the pair of rods extending through each of the pin carriages, the pin carriages being configured such that the rods are spaced in a substantially horizontal plane when the movement means is mounted on the table.  
   
   
       9 . The system of  claim 1  wherein the movement means comprises: 
 rotation means for producing rotational motion;    converting means for converting rotational motion into translational motion by one of the pin assemblies; and    rotation transferring means for transferring rotational motion of the rotation means to the converting means, the rotation transferring means permitting slippage between the rotation means and the converting means when translational movement of the pin assembly is resisted.    
   
   
       10 . The system of  claim 9  additionally comprising a position sensing means for sensing rotation of the converting means to determine a position of one of the pin assemblies along the slot, wherein the sensing of rotation by the position sensing means is not affected by any slippage of the rotation transferring means.  
   
   
       11 . The system of  claim 9  wherein the movement means includes detecting means for detecting interference with movement of one of the pin assemblies.  
   
   
       12 . The system of  claim 11  wherein the detecting means comprises: 
 means for determining when rotational motion by the rotation means is not transferred to the converting means by the rotation transferring means;    means for temporarily delaying for a predetermined time period further actuation of the rotation means when rotational motion by the rotation means is not transferred to the converting means by the rotation transferring means;    means for reinitiating rotational movement of the rotation means when the predetermined time period has passed.    
   
   
       13 . The system of  claim 12  additionally comprising means for canceling further movement of the pin assemblies after a preset number of attempts to reinitiate rotational movement of the rotation means does not result in rotational motion by the rotation means being transferred to the converting means by the rotation transferring means.  
   
   
       14 . The system of  claim 1  wherein the movement means comprises: 
 a rod operatively coupled to one of the pin assemblies;    a motor;    a driver pulley mounted on the motor for being rotated by the motor;    a driven pulley;    a belt connecting the driven pulley to the driver pulley for transferring rotation of the driver pulley to the driven pulley in a manner permitting rotational slippage between the belt and one of the pulleys if rotation of the driven pulley is resisted;    means for operatively coupling the driven pulley to the rod in a manner preventing rotational slippage between the driven pulley and the rod such that rotation of the driven pulley directly corresponds to rotation of the rod; and    a position sensor operatively connected to the driven pulley for sensing rotation of the driven pulley and thereby sending rotation of the rod.    
   
   
       15 . The system of  claim 1  wherein the movement means comprises a first and second rod, the first rod having a threaded exterior surface; and 
 wherein at least one of the pin assemblies comprises:    a pin carriage moveable along the slot;    a pin mounted on the pin carriage and extending through the slot above the support plane;    a first passage extending through the pin carriage with the first rod passing through the first passage, the first passage having an interior surface adapted to engage the threaded exterior surface of the first rod such that rotation of the first rod produces movement of the pin carriage; and    a second passage through the pin carriage with an interior surface that is adapted to permit free movement of the second rod through the second passage when the first rod causes movement of the pin carriage.    
   
   
       16 . A truss jig positioning system for use on a table including at least a pair of adjacent segments with a slot defined by adjacent side edges of the pair of adjacent segments, the table having a support plane on which work pieces are supported, each of the side edges of the segments of the table associated with the slot defining a substantially vertical plane with a zone being defined between the substantially vertical planes of the side edges, the system comprising: 
 a pair of pin assemblies mountable on the table adjacent to a slot between the pair of adjacent segments with a portion of each of the pin assemblies extending through the same slot;    a pair of rods configured to move the pin assemblies independently of each other along the same slot, each of the pin assemblies being mounted on both of the rods;    wherein the pair of rods extend through each of the pin assemblies in locations configured in a manner such that, when the portion of each of the pin assemblies is positioned in the same slot on the table, the rods are located substantially outside of the zone of the slot.    
   
   
       17 . The system of  claim 1 , wherein the movement means comprises a pair of rods, the pair of rods being configured such that the rods are spaced in a substantially horizontal plane when the movement means is mounted on the table.