Flexible Skatewheel Conveyor

Overview

A flexible skatewheel conveyor is an expandable gravity conveyor used to load and unload trucks, containers, and trailers. It has no motor: cartons roll along it by gravity over rows of free-spinning wheels, set on a slight downhill slope. Its defining feature is the lazy-tong frame, which lets the conveyor stretch from a compact parked length out to several times that length, curve around obstacles, and then compress back to store against a wall or dock. A worker pulls the free end deep into a trailer, then feeds boxes on at the dock so they roll all the way in, which saves carrying every box by hand.

The conveyor is built on a Pantograph Frame frame that carries the Skatewheel Banks. It rolls and parks on the Casters and Brakes casters, sets its working height and slope through the Height and Slope Adjust legs, keeps loads on track with the Side Guides, and joins to other sections through the End Connectors.

The pantograph frame

The expandability comes entirely from the Pantograph Frame frame. It is a lazy-tong structure of Scissor Link members crossed in pairs and joined at each crossing by a Pivot Pin running in a Pivot Bushing. When the conveyor is pulled lengthwise the scissors open and the frame extends; when pushed together they close and it compresses, the same geometry as an extending security gate. Spanning the frame are Axle Rail rails that hold the wheel axles and keep the pitch even as the frame moves. A Stretch Stop at each end limits the extension so the frame cannot be pulled past its safe length and come apart. Because the frame curves as well as stretches, the conveyor can be snaked around a corner or steered around a pallet on the dock.

Skatewheels and how product moves

The rolling surface is the Skatewheel Banks, rows of small Skatewheel wheels staggered so that a carton always rests on several wheels at once. Each skatewheel is a Wheel Body hub spinning on a built-in Ball Bearing with a Wheel Tread running surface, so it turns freely under the lightest push. The wheels sit on Wheel Axle rods, separated by Wheel Spacer sleeves and held by Axle Clip clips. Because the wheels are free, the conveyor needs only a gentle downhill slope to keep cartons moving: gravity supplies all the energy, and an operator only nudges boxes to start them. Skatewheels suit firm flat-bottomed cartons, the same loads that suit a roller conveyor, and they let the bed stay light enough to push by hand.

Mobility and setup

A loading conveyor must be moved into position and then held still, so the Casters and Brakes system carries it on Swivel Caster swivel casters. Each caster is a Caster Wheel in a swiveling Caster Fork, so the conveyor can be steered down a dock and snaked into a trailer. A Caster Brake on several casters and a Floor Lock pin the conveyor in place once it is set, so it does not creep while boxes pour over it. The frame rests on Leg Pair supports at intervals along its length.

Height and slope

Trucks sit at different dock heights and the conveyor must run slightly downhill, so the Height and Slope Adjust system sets both. Each Telescoping Leg is a telescoping tube locked by a Height Pin, so the operator matches the bed to the trailer floor and steps it down across the length. A Slope Ratchet tilts the bed to set the gravity slope, typically a few degrees, enough that cartons roll steadily without running away. Coil Spring assists take some of the weight when raising a loaded section. Too little slope and boxes stall; too much and they roll too fast to control, so the slope is set for the weight of the product.

Guides and connections

Cartons can wander off a curving bed, so the Side Guides add a folding Side Rail down each edge, built from Rail Link segments on Rail Bracket mounts that extend and curve with the frame. The End Connectors let several conveyors work as one line: an End Hook latches one section to the next, a Section Coupler aligns them so cartons cross the joint smoothly, and an End Stop catches the last box at the free end. A flexible conveyor often feeds from a fixed powered conveyor at the dock, so the connectors also let it dock onto that line.

Use and limits

The flexible skatewheel conveyor earns its place at the truck dock, where its reach and storage matter most. Extended, it brings the conveyor end to the worker deep inside a trailer so boxes need only be lifted off the wheels, not carried; compressed and rolled aside, it frees the dock for other work. It is cheap, needs no power, and adapts to any trailer, but it depends on gravity and on firm flat-bottomed product, so soft bags, drums, or very heavy cartons do not roll well, and a long run needs enough slope to keep moving without letting boxes accelerate dangerously. For high-volume or powered handling a belt or driven extendable conveyor takes over, but for flexible, low-cost manual loading the gravity skatewheel conveyor remains the common dock tool.