Method And System For Manufacture Of A Wire Cage

Abstract

A wire cage making machine includes a pair of rod supporting wheels decoupled from one another and capable of being rotated by respective motors at different speeds and/or directions to control the contour of a wire cage, such as twisting the rods. The machine includes a carriage to which the wheels are mounted, with one of the wheels maintained at a fixed position on the carriage and the other wheel movable along rails of the carriage. A welding head is positioned proximate the stationary wheel and is connected to the carriage by a pivot arm that allows the welding head to be moved closer to or farther away from the center of the stationary wheel. The pivot arm allows the position of the welding head to be moved in response to changes in radial positions of longitudinal rods carried by the wheels and to which wire is welded, to join the rods together to form a wire cage. The rods are held by clamps mounted to spokes of the wheels. The radial position of the clamps of the stationary wheel can be moved in real-time to change the diameter of the wire cage.

1 . An apparatus for manufacturing a wire cage, the apparatus comprising:
 a first rotating member configured to support a plurality of cage rods;   a second rotating member configured to support the plurality of cage rods, the second rotating member spaced from the first rotating member and the plurality of cage rods extending between the first rotating member and the second rotating member; and   a drive assembly that independently rotates the first rotating member and the second rotating member.   
   
   
       2 . The apparatus of  claim 1  wherein the drive assembly rotates the first rotating member and the second rotating member at different rotational speeds to effectuate twisting of the plurality of cage rods extending between the first rotating member and the second rotating member. 
   
   
       3 . The apparatus of  claim 1  wherein the drive assembly comprises a first drive motor coupled to the first rotating member to rotate the first rotating member and a second drive motor coupled to the second rotating member to rotate the second rotating member. 
   
   
       4 . The apparatus of  claim 1  further comprising a track along which the second rotating member may be translated to define the spacing between the first rotating member and the second rotating member. 
   
   
       5 . The apparatus of  claim 1  further comprising a wire feed that delivers wire to weld, in a spiral pattern, around the plurality of cage rods. 
   
   
       6 . The apparatus of  claim 5  further comprising a welding assembly to weld the wire to the plurality of cage rods, the welding assembly including:
 a welding head secured to a pivot arm; and   means for effecting selective pivoting movement of the pivot arm to control positioning of the linear welding head.   
   
   
       7 . The apparatus of  claim 6  wherein apparatus includes a frame, and wherein the pivot arm is pivotably mounted to the frame. 
   
   
       8 . The apparatus of  claim 6  wherein the welding assembly comprises a transformer that allows for maximum current transfer to the wire. 
   
   
       9 . The apparatus of  claim 6  wherein the welding assembly welds the wire to a cage rod at approximately 1000 Hz and at approximately 400 A current. 
   
   
       10 . The apparatus of  claim 1  wherein the cage rods are composed of high carbon steel. 
   
   
       11 . A method of manufacturing a welded wire structure, the method comprising:
 securing a plurality of longitudinal steel rods to a first wheel and a second wheel spaced from the first wheel;   independently rotating at least one of the first wheel and the second wheel; and   welding a circumferential wire to the plurality of steel rods as the first and second wheels are rotated and the second wheel is moved away from the first wheel.   
   
   
       12 . The method of  claim 11  wherein the step of rotating the first and second wheels includes rotating the first wheel at a first speed and rotating the second wheel at a second speed, different from the first speed. 
   
   
       13 . The method of  claim 11  wherein the step of rotating the first and second wheels includes rotating the first wheel in a first direction and rotating the second wheel in a second direction, different from the first direction. 
   
   
       14 . The method of  claim 11  further comprising changing the radial position of the longitudinal steel rods as the second wheel is moved away from the first wheel. 
   
   
       15 . A welding system comprising:
 a linear welding head having a copper contact; and   a pair of hydraulic pistons connected to the linear welding head to control positioning of the linear welding head relative to a longitudinal rod and spiral wire used to form a part of a reinforcing cage for a concrete structure.   
   
   
       16 . The welding system of  claim 15  wherein the copper contact is composed of soft copper. 
   
   
       17 . The welding system of  claim 15  further comprising a spool of wire that is controlled to present the spiral wire to the linear welding head. 
   
   
       18 . The welding system of  claim 15  further comprising a transformer that is connected to the copper contact in a manner that allows for maximum current transfer to the spiral wire and a longitudinal rod. 
   
   
       19 . The welding system of  claim 15  configured to weld at 1000 Hz and a 400 A current. 
   
   
       20 . The welding system of  claim 15  mounted adjacent an assembly that presents longitudinal rods to be weld to the spiral wire, the assembly including:
 a first rotating member configured to support a plurality of cage rods;   a second rotating member configured to support the plurality of cage rods, the second rotating member spaced from the first rotating member and the plurality of cage rods extending between the first rotating member and the second rotating member; and   a drive assembly that independently rotates the first rotating member and the second rotating member to effectuate orientation changes in the plurality of spinal rods as defined between the first rotating member and the second rotating member.   
   
   
       21 . An apparatus for use with a wire cage making machine and configured to change the radial spacing of longitudinal rods that form part of a wire cage, the apparatus comprising:
 a guide coupled to a wheel that holds the longitudinal rods and is rotated to present the rods and connecting wire to a welding unit that welds the connecting wire to the longitudinal rods, wherein the wheel includes a central hub, an outer rim, and spokes extending between the central hub and the outer rim;   longitudinal rod clamps mounted to the spokes;   a mounting member movable along the guide;   flexible elongated drive members coupling the clamps to the mounting member; and   an actuator that moves the mounting member along the guide, wherein movement of the mounting member changes the radial position of the clamps relative to the central hub of the wheel.   
   
   
       22 . The apparatus of  claim 21  wherein the actuator includes a cylinder coupled to the central hub and rotatable with the wheel and a ram rotatable with the wheel and connected to the cylinder and the chain mount. 
   
   
       23 . The apparatus of  claim 21  further comprising a post that supports the guide and a bearing interconnected between the post and the guide that allows the guide to rotate relative to the post in response to rotation of the wheel. 
   
   
       24 . The apparatus of  claim 21  further comprising a sensor that detects a position of the mounting member along the guide and provides feedback to a controller that determines the radial position of the clamps from the hub. 
   
   
       25 . A wire cage making machine comprising:
 a carriage;   a stationary wheel mounted to the carriage;   a movable wheel mounted to and movable along the carriage;   a welding unit for welding wire to longitudinal rods carried by the stationary wheel and the movable wheel, the welding unit having a welding head mounted to an arm; and   a bracket coupling the arm to the carriage, wherein the bracket allows the arm to pivot so as to move the welding head in response to changes in radial position of the longitudinal rods.   
   
   
       26 . The wire cage making machine of  claim 25  wherein a linear welding head has a copper contact and a pair of hydraulic pistons connected to the arm to control positioning of the linear welding head relative to a longitudinal rod and wire. 
   
   
       27 . The wire cage making machine of  claim 25  wherein the welding unit includes a pair of rollers and brushes to conduct welding current from a power source to a longitudinal rod and the wire.