Special thanks to Randy Wilson of M3 Associates.
I went to the web looking for the type of latch and hasp used to secure truck doors. My application was a little different. I wanted to use the mechanism horizontally to secure the trailer ramps to the trailer walls.
I found M3's web site. http://www.m3assoc.com/products.html
They had a list of stainless and aluminum closure devices that were suitable but all had three bar supports and I wanted four. I contacted the office and the young lady I spoke to was very nice and very helpful. She asked what the application was and I told her that it was a custom trailer.
She said, "I think Randy would like to talk to you but he'd out doing something involving needles and elbows." I left her this web site's address and I got a call from Randy the next day.
He said he spent 2 hours reading the entire build and told me that he was impressed. He told me that my shop's attention to detail was amazing. When I told him that I had built it myself the line went quiet for a moment. I took that as high praise.
Randy told me that there is nothing new or novel in his industry nor has there been, for a very long time. He found my concept exciting and insane at the same time.
I finally got him to talk about his product and he told me that he had the perfect parts for my application, and he was right.
But first, he had to tell me that my garage door springs were wound too tight. He knew because he was able to calculate, just by looking at the pictures, that one of my worst mistakes could have been avoided by having bigger springs. The largest I thought were available were 160 lb units. It wasn't sufficient to lift the tail gate with the huge spare tire attached. The tire and wheel weigh about 90 lbs.
Randy told me that I needed 205 lb springs to lift the load with the spare attached to the ramp, as I've always envisioned. I was exstatic to think that I could go back to the original design. Randy judged it so closely that he was able to tell me that 7 360° turns would yield the proper amout of force to lift the spare and ramp combined. Thanks again Randy.
He then asked me for my shipping address. I asked if he could take a credit card and he said he would be satisfied if I mentioned his company's name. Done. Two days later I received a new set of springs and the parts I needed to fit my highly specialized need.
The aluminum shaft passes through two carriers allowing it to slide sideways and rotate. The claw is welded to the end of the shaft and rotated to engage the catch by the handle at the other end of the shaft. The shaft will have a spring to automatically retract the claw to clear a cable and the upper door piston.