The Stovebolt Site Forums The Parking Lot Big Bolts Dump Mechanism

I am looking for a picture, sketch, engineering drawing or something to prove or dissprove a design I am thinking about. I want to put a dump mechanism on a "vintage" trailer that I am buliding. (30 Pontiac springs and axle). I seem to remember that many many years ago some of the dump boxes were raised by a wedge that was forced rearwards between the tilting and the stationary parts of the dump. I have seen a hoist mechanism used on the front end of small dumps like I want to build but can find no information about the wedge style. Or am I just dreaming and never really saw such a mechanism?????
Thanks for your help.

1911commer

Over here (& I guess many other countries too) a lot of lighter dump trucks were fitted with pretty much what you are describing. Here they were called "cam & roller" tippers. Two wedge shaped cams were bolted to the underside of the truck deck near the hinge pin,& a hydraulic cylinder mounted between the chassis rails forced a shaft carrying 4 rollers back to these cams. The outer two rollers ran on tracks fixed to the top of the chassis rails,while the inner two rollers were forced in under the cams, lifting the deck to dump the load.Hope this description is understandable !

Prior to 1925 most dumps were graviity dumps where the dump box was cantilever over the rear of the frame so that when the lever was released the weight of the load raised the box. The box pivot was forward of the load centerline. I know in 1935 "Gar-Wood Industries" from Detroit, MI was making a dump hoist Type F4C Hoist that had two rollers on a cross shaft attached to a horizontally mounted hydraulic cylinder that pushed on two 1/4 round "wedges" mounted to the dump box. I have a picture of it.

The basic designs used as underbody dump hoists are in order of succession;
1.gravity
2.winch (hand or axle engagement)
3.direct push hydraulic
4.cam & roller
5.twin arm underbody
6.scissor

Also common these days and most efficient are head lift telescopics which come in three basis designs, direct telescopic, inverted telescopic and bail mount telescopic.

None of these cam be described as a "wedge" design. After 40 years in the business I have yet to run across or even hear of anything called a wedge. Who knows, maybe you have a unique idea.

I think you have answered my question. I wa about six when I saw one working. Now I am sure it was cam and roller.
Thank you very much.