Pallet stop module for automated conveyors: sizing a damped stop gate or stopper cylinder by pallet mass, speed and queue
The stop module that halts a workpiece pallet at a station on an automated conveyor · permissible pallet mass falling from 200 kg at 6 m/min to 35 kg at 30 m/min, impact force from mass, speed and buffer travel, lateral force from the queue behind, and rigid versus damped stops
On a pallet-based assembly or machining line, the conveyor never stops; the pallets do. At each station a stop module rises into the pallet's path, absorbs its momentum, holds it while the belt or rollers keep running underneath, and drops to let it go. Choosing one is a sizing exercise: how heavy the loaded pallet is, how fast the conveyor runs, how many pallets queue behind it, and whether the stop must be damped to protect what rides on the pallet.
Stop modules for workpiece-pallet and carrier conveyors: pneumatic stop gates and stopper cylinders, rigid and damped, with roller or cam stops and locking levers, sized by pallet mass, conveyor speed, impact force and the lateral force from accumulated pallets. Complete pallet-based assembly lines are covered on the Automated assembly line on workpiece pallets page; heavy cabinet transport lines with their stations on the Cabinet assembly transport line page; flexible-chain small-part lines with electric stoppers on the Automated small-part assembly conveyor page; modular straight and curve sections on the Conveyor section page; chain transfers, roller transfers and turntables on the Pallet conveyor system transfer modules page; conveyor systems as a whole on the Conveyor systems page.
CNFX editorial research · Sources checked October 12, 2026 · 5 sources
Permissible pallet mass falls with conveyor speed: 200 kg at 6 m/min, 35 kg at 30 m/min
Bosch Rexroth's damped stop gate VE 2/D-200 for the TS 2plus transfer system, which stops pallets in a controlled way and separates them for the next station, publishes the permissible total pallet weight at each nominal speed: [1]
The same stop gate needs a pallet of at least 5 kg, compressed air between 4 and 6 bar, and works at 0 to 60 °C; it has a hard-anodised aluminium housing and a hardened steel stop cam. [1] Editorial reading of the energy column: up to 12 m/min the limit is the 200 kg mass rating, while from 18 m/min the permitted mass falls so that the energy stays at about 4.4 to 4.5 J; doubling speed then means roughly quartering the pallet mass.
Festo's STAF-80 stopper cylinder, a pneumatic roller stopper with spring return that Festo lists for heavy loads, takes workpiece carriers, pallets and packages up to 150 kg, its mass-versus-speed chart assuming a flexible buffer on the carrier with 1 mm deformation; at 10 m/min the permissible load is 150 kg. [3]
State the heaviest loaded pallet, the conveyor speed and the minimum pallet mass; a stop rated for mass at low speed may not hold the same pallet if the line is later speeded up.
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When pallets queue: impact force from the buffer travel and lateral force from the line behind
Festo's selection aid for the STAF works through a separating stop with pallets accumulating behind it: friction factor 0.1, conveyor speed 10 m/min, 40 kg per pallet, 6 bar, five queued pallets and a 1 mm pallet buffer. [3]
Festo defines the impact force as the maximum of a force-time curve during braking, acting perpendicular to the piston rod, and notes for it that “the stopper must not be switched below this force”; the permissible lateral force is the static load still pressing on the rod after braking, from belts still running or the downhill force of a steep raceway, and below it “the stopper can be switched”. It calls a buffer between accumulating pallets vital, and gives 13,300 N as the permissible impact force of the 40 mm stroke version. [3]
Editorial calculation from the same formula: the impact force rises with the square of speed and falls in proportion to buffer travel, so the same 40 kg pallet at 20 m/min on a 1 mm buffer gives about 4,400 N, and a 2 mm buffer halves it. A pallet with no elastic buffer makes the force indeterminate, which is why the buffer belongs in the pallet specification.
Give the number of pallets that can queue against the stop, the friction between pallet and conveyor, any incline, and the buffer fitted to the pallet.
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Rigid or damped, and holding against a pallet pushed backwards
Woerner Automatisierungstechnik's patent application US 2019/0359432 divides stop modules into two classes: rigid stops that only extend and retract, braking pallets abruptly and so unsuited to sensitive or fragile workpieces, though mechanically simpler; and damped stops that brake the pallet gently, as when jars or bottles are filled and closed at a series of stations. [4]
The patent describes stop modules, also called separating stops, that position individual objects at a processing station or isolate them from an accumulated group, while the conveyor keeps moving. [4] Rexroth's undamped VE 2/M stop gate, by contrast, is offered for accumulation loads up to 200 kg, stopping accumulated pallets at a defined stop surface within the conveyor tracks. [2]
SMC's patent US 7,484,615 B2 covers a stopper cylinder for roller conveyor lines: a lever with a guide roller rises between adjacent rollers to stop the load, a lock mechanism holds the lever, and the design lets the lock release if an operator pushes the load back against the transport direction, which an earlier locked lever did not allow. [5] Editorial note: ask whether the stop locks against rebound, and whether it lets pallets be pushed back by hand during setting-up.
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What to send when ordering pallet stop modules
Paste it into your enquiry below or into an email to a maker, then replace every bracket.
Pallet: [loaded mass max and min; size; buffer type and travel]
Conveyor: [type; speed; incline; friction pallet-to-conveyor]
Duty: [single stop / separating stop; pallets queued behind]
Stop: [damped or rigid; roller or cam; locking; release against reverse push]
Control: [air pressure; valve; position sensing]
Environment: [temperature; washdown]
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Compiled and source-reviewed by the CNFX editorial team.
Each manufacturer above links to the page on that company's own website where the product is listed, with the date we checked it. How we source and review
· Page last updated 13 October 2026
Buyer questions
How heavy a pallet can a conveyor stop gate hold?
It depends on speed: Rexroth's damped VE 2/D-200 allows 200 kg at 6 m/min, 100 kg at 12–18 m/min and 35 kg at 30 m/min. [1]
How do you calculate the impact force on a stopper?
Festo uses mass × speed² ÷ buffer travel: a 40 kg pallet at 10 m/min on a 1 mm buffer gives about 1,100 N. [3]
Why does the queue behind the pallet matter?
It adds friction force — about 200 N for five 40 kg pallets at μ 0.1 in Festo's example — which acts as lateral force while the stop retracts. [3]
When is a damped stop needed?
Woerner's patent application says rigid stops brake abruptly and do not suit sensitive or fragile workpieces; damped stops brake gently. [4]
Sources and what still needs a direct check
Sources checked 2026-10-12. Mass and speed ratings come from Bosch Rexroth's VE 2/D-200 and VE 2/M data and Festo's STAF datasheet, whose selection aid gives the force calculations; rigid and damped stop classes from a Woerner Automatisierungstechnik patent application; locking stopper design from an SMC patent.
