Overhead power-and-free conveyor with load carriers for vehicle body, paint and assembly shops

01

Pick the track system and chain for the load per carrier

Jervis B. Webb Company's announcement of its Unibilt 348 system, reported by Material Handling & Logistics in 2004, describes a power-and-free conveyor that runs X-348 rivetless power chain in Unibilt enclosed track with a four-wheel steel trolley engaging heavy-duty free trolleys. It offers the same 1,500 lb (680 kg) load capacity as conventional 3 in I-beam power-and-free conveyors, with a more compact profile and cleaner, quieter running, and supports unassisted chain-to-chain transfers. [1]

Hangzhou Color Powder Coating Equipment, a Chinese coating-line maker, lists two overhead conveyor families: a lightweight track conveyor with single-point loads under 100 kg, and X348, X458 and X678 I-beam heavy-duty conveyors for 100–500 kg loads, with rivetless chain drop-forged from high-strength carbon steel. It names rails or I-beam, chain, drive unit, hangers, trolleys and a tension device as the parts of a complete system. [2]

USA Roller Chain's table lists pitch, ultimate strength and weight for these chains: X348 3.031 in pitch, 24,000 lb, 2.2 lb/ft; X458 4.031 in, 48,000 lb, 3.2 lb/ft; X678 6.031 in, 85,000 lb, 6.7 lb/ft. It notes the chain is used in automotive manufacturing, trolley systems and overhead conveying. [3]

Editorial calculation: those pitches are about 77.0, 102.4 and 153.2 mm, and the strengths about 106.8, 213.5 and 378 kN (1 lbf = 4.448 N). The 1,500 lb carrier rating is 1/16 of X-348's 24,000 lb ultimate strength, but chain pull depends on the total loaded length, curves and drives, so ask the supplier for the chain-pull calculation, not the carrier rating alone. [1] [3]

Give the supplier the load (body or part, mass, centre of gravity, size), carriers needed and pitch between them, the route with curves, inclines and elevation changes, the stations where carriers must stop, queue, transfer, lift or lower, line rate, ambient (including paint ovens), drive and tension positions, the controls interface and the plant's safety rules for overhead loads.

02

Plan where carriers stop, queue and transfer

Hanna Technology's product page describes a power-and-free overhead conveyor as one that can transport and temporarily store workpieces on the line, stopping workpieces from continuing and adjusting their spacing and movement; it lists an automatic lift system for loading and unloading and automatic fast and slow chain-speed transfer. [4]

Webb's enclosed-track version is described as offering unassisted chain-to-chain transfers and longer runs with fewer drives. [1] Editorial note: list every station where a carrier must stop and every buffer the line needs, because stops, switches and lifts are where power-and-free cost and controls differ from a simple I-beam trolley conveyor that moves all carriers at chain speed.

03

Light track, I-beam or enclosed-track power-and-free: load per carrier

The four overhead types differ first in how much one carrier may hang, from under 100 kg on light track to 680 kg on Webb's enclosed-track power-and-free.

04

Two Chinese coating-line builders with overhead and power-and-free conveyors

Hangzhou Color and Hanna Technology both build these conveyors as part of powder coating lines; neither page shown here describes a body-shop or final-assembly installation.

The listings kept come from coating-line builders; ask each for the track and chain sizes, carrier rating and chain-pull calculation for your loads.

05

Track, X-series chain, drives, trolleys, body carriers and stops

Hangzhou Color names rails or I-beam, chain, drive unit, hangers, trolleys and a tension device as a complete system; power-and-free adds the stops, switches and lifts Hanna describes.

06

Overhead conveyor quotation: carrier rating, chain pitch and stop positions

Carrier ratings come from Webb and Hangzhou Color, and chain pitch from the chain table; drive power, speed and stop repeatability depend on your route and must come from the supplier's chain-pull calculation.

07

Send the load, route and station data together

Paste it into your enquiry below or into an email to a maker, then replace every bracket.

Load: [body or part; mass; size; centre of gravity]
Carriers: [number; spacing]
Route: [length; curves; inclines; ovens]
Stations: [stops; queues; transfers; lifts]
Rate: [jobs per hour; chain speed]
Chain and track: [X-348, X-458 or X-678; enclosed or I-beam]
Controls: [interface; safety rules]

See manufacturer records Send an enquiry through CNFX