January 31, 2019
Conveyor backstops protect inclined conveyors from gravity, notably when it comes to accelerated reverse runway. Backstops are safety mechanisms that stop product rollback on a stopped conveyor or drive failure. This is particularly important on fully loaded belt, as accelerated material will spill and create substantial liabilities or catastrophic damage to critical conveyor components.
Essentially, conveyor backstops are significant components to your overall conveyor system because they only allow conveyor belt to run in one direction when they’re installed correctly.
Materials transported by a conveyor may include:
Also known as anti-runback devices or holdbacks, backstops keep the belts from running in reverse when they’re moving product on a conveyor.
In addition to their role on incline conveyors, many operators choose to equip flat conveyors with backstops as well. This is because backstops help prevent product damage in shock loading situations, where the loaded belt may sag between the idlers when the conveyor is started.
Generally speaking, if you're running a conveyor in which the force needed to lift the load in a vertical direction is greater than half the force used to move the load in a horizontal direction, you need a conveyor backstop.
Backstops aren’t just critical to preserving capital investments, they can also play an important safety role. For instance, conveyors that reverse can accelerate to high speeds, which could potentially lead to worker injury or even death.
Additionally, belts in this runaway state may damage other conveyor components, such as the belt drive or the belt itself.
Noting all of this, conveyor backstops reduce maintenance and the potential of on-the-job injury.
The conveyor backstop is typically defined by low-speed or high-speed use.
If your motor HP exceeds 50HP then a low-speed backstop is advised.
There are three main types of low-speed conveyor backstops: ratchet and pawl, differential handbrake and overrunning clutch design.
These budget friendly backstops are subject to wear and can be affected by dirt. However, they do not require adjustment and have a high-stress concentration.
This type of backstop is also budget-friendly. Unlike ratchet and pawl backstops, differential handbrakes do require adjustment. They also do not have a high-stress concentration.
These are higher end, low-speed backstops and are available in roller clutch and spring clutch formats. They’re designed for very precise operation, and work to automatically engage transmit torque based on the direction of relative motion.
So how do you choose the right conveyor backstop?
Here’s a list of some of the variables that you should be considering when making your choice.
We already discussed some of the considerations that go into selecting whether a high- or low-speed backstop is better for your conveyor. Low-speed backstops typically run at conveyor drive pulley speeds and mount to the head opposite the drive.
Torque ratings are one of the most important specifications you’ll need to consider. Generally, backstops are sized by matching the peak torque of the conveyor. Sizing in this manner helps ensure the backstop won’t get damaged if there’s an issue with the belt or there’s an overload on the belt. If you’re unsure what your system requires, West River is here to help.
The conveyor backstop is rated in the maximum force they are able to sustain. Noting this, it’s important to select the right backstop for your conveyor based on the product and application.
Some folks perform installation themselves, others rely on professional installation.
Certain backstops are much easier than others to install and should be taken into consideration when selecting the right product. Ease of installation can play a role as far as maintenance is concerned especially if you need to replace the conveyor backstop down the road.
As you can see, there's more than what may initially meet the eye when it comes to selecting the right conveyor backstop for your system. Be sure to assess all of the key factors to make a well-informed decision.
There are a variety of different conveyor backstop manufacturers from which you can choose including Ringspann, Formsprag, Marland or Falk. You may also have the option of selecting a new or used conveyor backstop.