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About Front Pin Lock

Steelwrist Front Pin Lock is a patented mechanical solution that enhances safety on symmetrical quick couplers. The Front Pin Lock is the only solution that works equally well on all types of excavators. The result of a dropped bucket can be devastating and several serious accidents occur each year. With a front pin locked quick coupler, you and co-workers are safe at work. This is how it works.

The Front Pin Lock consists of two innovations that, when combined increases safety considerably:

  • Snap Locked front shaft – locks the front shaft of the attachments as soon as it enters in the front jaw.
  • Positive lock indication – intuitive indication with red indicator when the bracket is open and green indicator when the bucket is in a safe position.

Front Pin Lock works on all types of excavators:

  • On Quick Couplers
  • On Tiltrotators
  • On wheel- and crawler excavator with advanced control systems (two-hose systems)
  • On compact excavators with basic proportional control from the machine (four-hose systems)
  • On used excavators in the field (completely independent of control system)

Front Pin Lock is today standard on all our tiltrotators and quick couplers with symmetrical brackets.

Frequently Asked Questions about Front Pin Lock

Answers to the most common questions we have received about safety around Quick Couplers

When do accidents actually happen?

In our analysis 2012 we saw that accidents in principle only happen on two different occasions.

  1. The operator connects the front jaw of the coupler in the bucket, but for some reason misses to connection in the rear pin properly, (the rear pin = the pin that the driver can not see from the cab). At the same time the operator for some reason, forgets och does not verify properly, the physical verification that the bucket is securely connected (the driver usually gets disturbed by for instance a telephone call and can be mistaken on where in the connection process, he stopped) and the work begins.
  2. The operator just want to move the bucket alternatively lift the buckey to a trolley. The operator connects the front jaw of the coupler in the bucket bud he does not maneuvre the lock at all since his intention “only” is to move a bucket. (Why? Can be beacuse the buzzer starts as soon as the driver starts to unlock the coupler – and the sound can be high and annoying.) At this stage the driver starts to move the bucket and since the bucket is not secured it can easily fall off in case the bucket hits the side of the waggon. The goal with Front Pin Lock has been to protect against both these risks.

Why have you chosen a mechanical solution instead of sensors?

We evaluated several different sensor solutions at the beginning of the project but concluded that it is sensitive with sensors and wiring to sensors in the affected environment that we work in. Another reason is that sensors becomes dependent on control systems, and therefore excludes many excavators. In many cases it will also be different approaches for tiltrotator and a quick connection for the operator.

Is it impossible to drop a bucket with a Front Pin Locked quick coupler?

Since this is an excavator with an operator, which in itself can be dangerous, it is obviously not possible to completely remove the risk of dropping a bucket. Just as nobody can design an excavator that can not be hurt anyone or a car that can not have an accident you can not build a quick coupler than never can not have an accident, regardless of what the operator is doing. What it’s all about is to try to eliminate the risk of an accident when the operator accidentally connects the bucket erroneously without noticicing it. In these cases, no buckets are droppec with our Front Pin Locked quick couplers or tiltrotators.

Why positive green instead of the usual red indicator?

The basic philosophy is that we want to indicate green when the bucket is in a safe position instead of as usual only indicate red when the quick coupler is open. Imagine a traffic light that only had one red light. If the red light is on then it would be a stop signal. If ther is no light then it means OK do drive (this is how most couplers work today). It is easy to imagine a number of other reasons why the red light is not lit up, but it would still not ok to drive. We therefore indicate green when the bucket is in a safe location. Red is as today a warning signal that the coupler is open.

What happens you pinch the rear pin?

Locking directly on the rear pin is a relatively big problem for some manufacturers, especially those that lock with full pressure and has a flat nosed wedge.

If you have flat nosed wedge it it relatively easy to lock directly on the rear pin and the bucket would be “half connected”, the bucket will not fall off immediately but it will fall off sooner or later. This can not happed on a Steelwrist Front Pin Locked quick coupler since Steelwrist uses a rounded nose wedge. The round shape will force the rear pin either up or down and in both cases the bucket will be in a safe position.