Benefits at a glance:
- Ideal for realizing long strokes, especially for
applications where space is limited
- Compact storage, also in multi-axis applications
- Constant, shock-free motion
- Synchronous operation for horizontal or vertical motion
PushPull Chains are made from precision manufactured chain links of a special design which enables the chain to push, as well as pull heavy loads.
The chain links have a special profile with interlocking fingers at one end enabling the chain to roll or fold-up in one direction only. When unfolded, the fingers latch together to form a rigid thrust device. The close tolerance manufacture of the chain links and other components means that both push and pull linear motion with low backlash and high repeatability is achieved.
When retracted, the PushPull Chain folds up to occupy minimum space in relation to the required stroke. This feature is especially beneficial where long stroke push-pull movement is required; stroke lengths of 16 ft or more are not uncommon.
The PushPull Chain is an alternative to standard solutions using rack and pinion, screw-jacks, hydraulic and pneumatic cylinders or hoist mechanisms and can often present a unique solution where space is severely limited.
The PushPull Chain can be selected for thrust loads from a few pounds to several tons – even where longer strokes are required. A PushPull Chain drive system can be configured with standard Chain Guide Rails where there is a danger of bending movement occuring. It is also possible to configure systems using several chains in a parallel drive geometry where higher thrust loads are required.
Chain Redirection and Storage Examples
LinearChain’s main task is to move average and large loads in any direction (also vertically).
A sprocket wheel integrated in a drive housing actuates the chain.
According to the thrust power, the stroke length and the speed (all individually definable), LinearChain can perform its task running on a sliding surface or in a guide rail. One of the superior advantages is the combined ability to perform high push and pull forces and fold or roll up into a magazine when retracted.
- LinearChain Drive Systems
The chain drive system comprises a special housing with internal chain guides, spocket drive wheel and a keywayed drive shaft. This can be connected to a standard gear motor. Alternatively, a Framo Morat Compacta slip-on Rotary Actuator, a gear motor with integral multi-turn limit switches and optional reversing contactors or potentiometer can often be used (see separate catalogue). To prevent the Push-Chain from folding during the linear thrust motion, a special front end link is provided. This ensures that the force-line is off-center to the chain pins creating a bending moment which forces the chain fingers to lock tightly. The Push-Chain can be used for reciprocating push and pull movement, horizontally or vertically. Where possible, chain guide rails should be used to support and guide the chain.
The Guide Rail is unnecessary when:
- The Push-Chain runs across a flat surface (eg. steel plate)
- The linear travel (stroke) is within prescribed limits
- There is no danger of radial loads occurring along the thrust axis
- Chain Types and Performance Criteria
The selection of the correct chain size and type will depend on the application, the required performance and operating criteria.
The following information is required:
- Thrust force
- Working stroke
- Linear speed
- Operating frequency
The Push-Chains are manufactured with a standard pitch of 25 mm, 40 mm and 60 mm (pitch is the distance between the pivot pins).
- Material Used
The Push-Pull Chains are manufactured from treated alloy steels. The chain can withstand temperatures of up to 356°F and for short periods even higher temperatures.
For special cases where temperatures of up to 1022°F may occur, the Push-Chain can be supplied in heat-resistant steels.
- Typical Applications
The LinearChain has been sucessfully used in the following sectors: Industrial furnaces, cold sheet metal working, casting shops, rolling mills, machine tools, automotive manufacturing, warehousing, internal works transport systems, chemical industry, nuclear industry.
- Safety Regulations and Permitted Use
The Push-Pull Chains should not be used for applications involving the movement of loads which could endanger working personnel as a result of operation or system failure. Use of the Push-Pull Chain for personnel transport systems is not permitted without prior written approval.
We refer users to the applicable regulations and recommended practices regarding the provision of guard rails or covers to all moving parts of machines. Furthermore overhead hoist mechanisms for heavy loads using the Push-Pull Chain are not approved.