Patent Number: 053135059
Section: summary

BACKGROUND OF THE INVENTION My invention, ROD HANDLING APPARATUS, applies to the processing of tubes, especially the heat treating of nuclear fuel rods, hereinafter called rods, which are used in the core of nuclear reactors. While these are actually thin walled tubes, they are called rods in the nuclear industry. The rods are sealed on one end, then heat treated at that end. This is in addition to processing such as welding, deburring, cleaning, pressure testing, etc. After heat treating, nuclear fuel pellets are inserted into the rods and the other end is sealed. The filled rods are then grouped into bundles and placed inside the core of a nuclear reactor where water is circulated, heated by the rods and used to generate electricity. Until now, walking beam devices were one of the main machines used to transport the rods for processing. The problem is that walking beams must move in a rectangular or square transfer path. The rod must first be lifted, then transferred forward, lowered and placed in a support. Then the walking beam must travel below the rods in the supports in order to return to pick up another rod and transfer all of the rods one step at a time. My invention processes multiple rods which may be up to thirty or forty rods at a time. The accompanying drawings shows twelve rods being processed for clarity and brevity. Transferring these with a walking beam requires thirty or forty individual lifts, transfers and lowerings making this inefficient, time consuming and costly. In addition, a walking beam complicates the design of the machine and causes handling problems with possible rod jams, loss of control, or increased machine maintenance. Another problem is that after the heat treating operation is complete and the rods are on the walking beam supports again, the rods must be removed from the machine. This means that the walking beam would have to make a cyclic motion to remove each rod from the system meaning another thirty to forty motions. Another drawback is that a walking beam is not suited for ease of changeover for different diameters of rods. Other machines are based on pneumatic devices, endless conveyor belts, rotary motion with cams, or shafts, and hydraulic units but cannot meet all the benefits of my invention. My invention is a modified walking beam which can continually and automatically process multiple rods and which can accommodate rods of varying lengths and diameters and is precisely controlled using computer and servomechanism technology resulting in high efficiency and the ability to be operated by unskilled labor. Since the rods must be kept straight, my invention consists of numerous supports to guard against flexing and bending. My machine answers the need for one which will result in economies of time and labor, needing little maintenance, yielding a superior product and which has a ready market. This machine can also be used to perform many physical and chemical operations on rods, tubes, bars, pipes, etc., on either one or both ends. SUMMARY OF THE INVENTION A primary object of my invention, ROD HANDLING APPARATUS, is to fill a long felt need for a novel apparatus using a new method incorporating the latest technology which is simple to operate and greatly increases the efficiency of processing nuclear fuel rods, hereinafter called rods. A further object is to provide a machine which is precise in performance, is easily controlled, is safe to operate and can be operated by unskilled workers. It is also an object of the invention to provide a machine for processing multiple rods at one time with treatment precisely duplicated for each rod, controlled by computer and servomechanisms, which is efficient and requires little maintenance. A notable object is to provide a machine which can process different lengths of rods with a simple set-up. Another prime object is to furnish a system which can process various diameters of rods with ease by programming the software of the machine's computer without any physical changes to the machine. To achieve the above and other objects, it is the aim of my invention to agree with the following preferred embodiments, comprising an infeed ramp with an escapement device which is mounted on a conveyor support. This is where the operator loads the rods for heat treating. An rod end guide on the side where a heat treating unit is located evens up the rod ends. A stop at the end of the ramp lines up the rods and a lift finger feeds the rods into conveyor V-blocks mounted on the conveyor. The conveyor consists of an over/under indexing chain with conveyor V-blocks of predetermined spacing. Numerous chains and conveyor V-blocks are used to support the rods and keep them from bending and flexing. Each chain is supported by a rail to prevent its sagging. At one end of the conveyor there is a sprocket driven by a conveyor servomotor which advances the conveyor V-blocks. The other end of the chain has a spring-loaded takeup to keep a constant tension on the chain. The conveyor servomotor indexes any length of travel programmed into the unit, allowing the rods to be fed into adjacent conveyor V-blocks or skipping a predetermined number of conveyor V-blocks. After a rod has been lifted from the infeed ramp, it rolls into a conveyor V-block on the conveyor chain and the conveyor servomotor indexes the chain to the next appropriate conveyor V-block. When the proper amount of rods have been loaded into the conveyor V-blocks, with the proper spaces required, they are indexed to a position that will line up the rods with the receptacles in the heat treater units. Lift plate V-blocks attached to the conveyor support then raise the rods from the conveyor V-blocks to the proper height for insertion into the receptacles. The lift plate V-blocks are elevated by an eccentric arm powered by a lift plate servomotor which can be programmed for variation in height necessary for different diameter of rods. The heat treater units move transversely so that the ends of the rods are inserted a set distance into the receptacles for the heat treating cycle. After completion of this cycle, the heat treater units are retracted and the lifting V-blocks lower the rods into the conveyor V-blocks. The conveyor servomotor then moves the conveyor forward in one continuous motion unloading the rods from the conveyor V-blocks into an eject ramp where they are removed for further operation. This machine has additional uses comprising, but not limited to, physical and chemical treatments of the rods, tubes, bars, pipes, etc., to one or both ends, including, but not limited to etching, cleaning, deburring, polishing, attaching fittings, coding, machining, etc. Other objects of my invention as well as accompanying novel features will appear in the contents of the following description and recited in the claims.