Tilt hoists and lumber unstacking systems

Abstract

The present disclosure provides embodiments of tilt hoists and lumber unstacking systems with a rotation table, a tier alignment system, or both. The rotation table may include a base and a tilt frame supported on the base. The tier alignment system may include an alignment beam and an actuator operable to raise and lower one end of the alignment beam relative to the opposite end to thereby adjust the lateral slope of the spill edge. Optionally, a control system may include distance sensors to detect tiers of lumber as they approach the spill edge and a computer system configured to determine a difference between the lateral slope of the tier and the lateral slope of the spill edge. The computer system may also be configured to automatically adjust the slope of the spill edge to match the slope of the tier before the tier is spilled over the spill edge.

What is claimed is: 
     
         1 . A tilt hoist comprising:
 a rotation table, wherein the rotation table includes
 a tilt frame with an arcuate lower surface; and 
 a support base with a frame and a plurality of contact members coupled to the frame, wherein the support base is configured to support the tilt frame on the contact members, and the contact members are configured to moveably engage the arcuate lower surface of the tilt frame, such that the tilt frame is movable in opposite directions along the contact members between an upright position and a tilted position. 
   
     
     
         2 . The tilt hoist of  claim 1 , wherein the support base includes a plurality of plates arranged generally in parallel across a flow direction, and the plurality of contact members includes a plurality of rollers rotatably coupled to the plates, and wherein the tilt frame is supported on the rollers. 
     
     
         3 . The tilt hoist of  claim 1 , wherein the tilt frame has a plurality of generally parallel plate members with respective arcuate surfaces that collectively form the arcuate lower surface of the tilt frame, and wherein the contact members are arranged in pairs to contact the respective arcuate surfaces. 
     
     
         4 . The tilt hoist of  claim 1 , further comprising a platform assembly coupled to the tilt frame, wherein the platform assembly includes a platform rigidly coupled to the tilt frame and a primary knee assembly movably coupled to the platform assembly, wherein the platform is substantially vertical when the tilt frame is in the upright position and the platform is inclined when the tilt frame is in the tilted position. 
     
     
         5 . The tilt hoist of  claim 1 , further including a drive system selectively operable to move the tilt frame between the upright position and the tilted position. 
     
     
         6 . The tilt hoist of  claim 5 , wherein the drive system includes a chain connected to opposite ends of the arcuate lower surface of the tilt frame and a motor operatively coupled with the chain. 
     
     
         7 . The tilt hoist of  claim 6 , wherein the drive system further includes a shaft coupled with the support base and a sprocket disposed along the shaft, the motor is connected to the shaft, and the chain is engaged by the sprocket, such that rotation of the shaft and the sprocket by the motor drives the chain to thereby move the tilt frame between the upright position and the tilted position. 
     
     
         8 . The tilt hoist of  claim 6 , wherein the motor is an electric motor. 
     
     
         9 . A tilt hoist comprising:
 a support frame; and   a tier alignment system, wherein the tier alignment system includes
 one or more spill arms movably coupled with the support frame and spaced apart across a direction of flow, wherein the spill arms collectively define a spill edge; and 
 one or more actuators coupled to the support frame and the spill arms, wherein the one or more actuators is selectively operable to raise and lower the spill arms relative to the support frame to thereby adjust a lateral slope of the spill edge. 
   
     
     
         10 . The tilt hoist of  claim 9 , wherein the one or more actuators includes a first actuator, the tier alignment system further includes an alignment beam pivotably coupled to the support frame and coupled to the first actuator, and the first actuator is selectively actuable to raise and lower a first end of the alignment beam relative to a generally opposite second end of the alignment beam to thereby adjust the lateral slope of the spill edge. 
     
     
         11 . The tilt hoist of  claim 9 , wherein the one or more actuators includes a plurality of actuators, each of the actuators is coupled to a respective one of the spill arms and to the support frame, and the actuators are independently actuable to thereby raise and lower the respective spill arms. 
     
     
         12 . The tilt hoist of  claim 9 , further including:
 a rotation table, wherein the rotation table includes a tilt frame with an arcuate lower surface; and   a support base with a frame and a plurality of contact members coupled to the frame, wherein the support base is configured to support the tilt frame on the contact members, and the contact members are configured to moveably engage the arcuate lower surface of the tilt frame, such that the tilt frame is movable in opposite directions along the contact members between an upright position and a tilted position.   
     
     
         13 . The tilt hoist of  claim 12 , wherein the support base includes a plurality of plates arranged generally in parallel across a flow direction, and the plurality of contact members includes a plurality of rollers rotatably coupled to the plates, and wherein the tilt frame is supported on the rollers. 
     
     
         14 . The tilt hoist of  claim 12 , wherein the tilt frame has a plurality of generally parallel plate members with respective arcuate surfaces that collectively form the arcuate lower surface of the tilt frame, and wherein the contact members are arranged in pairs to contact the respective arcuate surfaces. 
     
     
         15 . The tilt hoist of  claim 12 , further comprising a platform assembly coupled to the tilt frame, wherein the platform assembly includes a platform rigidly coupled to the tilt frame and a primary knee assembly movably coupled to the platform assembly, wherein the platform is substantially vertical when the tilt frame is in the upright position and the platform is inclined when the tilt frame is in the tilted position. 
     
     
         16 . The tilt hoist of  claim 12 , further including a drive system selectively operable to move the tilt frame between the upright position and the tilted position. 
     
     
         17 . The tilt hoist of  claim 16 , wherein the drive system includes a chain connected to opposite ends of the arcuate lower surface of the tilt frame and a motor operatively coupled with the chain. 
     
     
         18 . The tilt hoist of  claim 17 , wherein the drive system further includes a shaft coupled with the support base and a sprocket disposed along the shaft, the motor is connected to the shaft, and the chain is engaged by the sprocket, such that rotation of the shaft and the sprocket by the motor drives the chain to thereby move the tilt frame between the upright position and the tilted position. 
     
     
         19 . The tilt hoist of  claim 17 , wherein the motor is an electric motor and the one or more actuators includes at least one electric actuator. 
     
     
         20 . The tilt hoist of  claim 9 , further including an outfeed with a plurality of conveyors, wherein upstream ends of the conveyors are pivotably coupled with respective ones of the spill arms, such that the upstream ends of the conveyors are vertically adjustable in concert with the respective spill arms. 
     
     
         21 . The tilt hoist of  claim 12 , further including an outfeed with a plurality of conveyors, wherein upstream ends of the conveyors are pivotably coupled with respective ones of the spill arms, such that the upstream ends of the conveyors are vertically adjustable in concert with the respective spill arms 
     
     
         22 . The tilt hoist of  claim 9 , further including a control system operatively coupled with the tilt hoist, wherein the control system includes a plurality of distance sensors positioned to detect a tier of lumber proximal to the spill edge of the tilt hoist and a computer system configured to determine a lateral slope of the tier of lumber based at least on data from the sensors. 
     
     
         23 . The tilt hoist of  claim 22 , wherein the computer system is operatively coupled with the one or more actuators and configured to control the one or more actuators based at least on the determined lateral slope of the tier of lumber. 
     
     
         24 . A method of upgrading a tilt hoist, the method comprising:
 movably coupling a plurality of spill arms to a support frame of the tilt hoist; and   coupling one or more actuators to the support frame and the spill arms, such that the one or more actuators is selectively actuable to raise and lower the spill arms relative to the support frame to thereby adjust a lateral slope of a spill edge of the tilt hoist.   
     
     
         25 . The method of  claim 24 , wherein at least some of the spill arms are coupled to a beam, and the one or more actuators includes a first actuator, and movably coupling the spill arms and the one or more actuators to the support frame includes movably coupling the beam to the support frame. 
     
     
         26 . The method of  claim 24 , further comprising operatively coupling the tilt hoist with a control system, wherein the control system includes a plurality of distance sensors positioned to detect a tier of lumber proximal to a the spill edge of the tilt hoist and a computer system configured to determine a lateral slope of the tier of lumber based at least on data from the sensors. 
     
     
         27 . The method of  claim 26 , wherein the computer system is operatively coupled with the one or more actuators and configured to control the one or more actuators based at least on the determined lateral slope of the tier of lumber.