Redesigned Lawn Spreader Control Cable

• withstands corrosion

• eases manufacturing

This cable connects an adjustable micrometer mounted on the handle of a lawn spreader to a shut-off plate at the bottom of the spreader. The assembly lets the user manually adjust the flow of granulated lawn material. The ends of the steel cable must be modified in some way to prevent the cable from sliding completely out of a hole in a plastic screw and housing. Originally, the cable was solid steel. The manufacturer bent the cable ends over a rivet shell and dipped it in solder, forming a stop at each cable end.

To enhance production safety and eliminate the exhaust systems required with the use of solder, The Scott’s Company investigated crimping a tube and flange fastener on the cable ends. This worked, but the components were available only as loose pieces. They were not capable of application by high-speed automatic production equipment, nor were they conducive to manufacturing techniques on the assembly line. In addition, they would not maintain accurate placement of the fittings to control the working length of the cable assembly while quickly and easily changing over to different finished cable lengths.

One other possible solution came in the form of a tin-plated steel splice for electrical applications available in continuous strips on reels. These components are commonly applied by automated applicators and presses. While this solution looked promising, the crimped splices on the cable assembly didn't meet the company’s 80 lb tensile requirement. In addition, undesirable lawn chemical and weathering corrosion was a potential problem.

Two changes addressed these problems and led to a successful solution. The spreader manufacturer switched from a solid to a stranded cable. This gave the splice more gripping leverage. Two "windows" in the splice bend over the steel strands, providing sufficient bite to meet the 80 lb requirement. Additionally, the splice manufacturer switched the material for the splice to phosbronze, which would stand up to the expected corrosive conditions.

At Scott's Temecula operations, an AMP-O-LECTRIC splice terminator from Tyco Electronics automatically applies splices to the cable. Equipped with a G-Splice applicator, this machine offers front and rear access to maximize production efficiency. It includes fine crimp height adjustment, guarding with interlocks for operator safety, total and batch counter, and capabilities for jog and split cycle. A special fixture designed for the applicator permits accurate positioning of the splice to the cable. The crimping machine allows the operator to perform the required two crimps per unit and assemble the entire cable assembly in the required takt time (time involved in a process step or total process time). Each hour, the operator subjects a sampling of assembled cable splices to a pull test to check that they meet the 80 lb tension requirement.