اختبار الجرافة لتوصيل قارنة التوصيل الآمن

إن تركيبات التوصيل السريع عبارة عن جهاز هيدروليكي مناسب يسهل ربط الجرافة بذراع الحفار. It is becoming standard equipment and a popular aftermarket accessory for many manufacturers. Couplers are versatile and convenient in design: simple to connect, operators can stay in the cab multiple times, quick changeover times, and fit a variety of manufacturer’s accessories.

لكن, construction safety experts have noted that as the number of contractors applying quick couplers has increased, so has the number of accidents involving the devices. Accidental release of a bucket is the most common occurrence. What we saw was a worker falling from a connector. It happened so fast that he couldn’t get around the falling bucket quickly enough. The bucket traps him and sometimes kills him.

A study of more than 200 accidents involving the separation of a bucket from a quick-connector showed that 98% of the accidents were related to a lack of operator training or operator error. The operator is the last line of defense for safe operation.

Some couplers are configured in such a way that it is difficult for the operator to see from the cab’s perspective whether the connection is locked. There is essentially no visible sign of a locked connection. The only way for an operator to safely determine if a coupler is secure is to perform a “bucket test” each time the bucket is changed or opened.

Ensuring a secure coupler connection

Position the bucket bar and bucket vertically on the side of the cab. A side check provides a good line of sight.

Place the bottom of the bucket on the ground with the teeth facing the cab.

Apply pressure to the bucket until the bucket belly is off the road and the bucket is resting on the teeth.

Continue downward pressure until the excavator tracks are lifted about 6 feet from the roadway. Increase speed for ease of measurement.

If the bucket takes the pressure and holds, the coupler locks into place.

Although some couplers have redundant locking characteristics, the best method is to perform a bucket test each time.

The responsibility for coupler accidents does not all fall on the operator’s shoulders. While the coupler itself may be working properly, incorrect installation can also lead to accidents. Sometimes contractors try to install their own couplers or hire unqualified installers. If an aftermarket coupling system is installed incorrectly, possibly to save a few dollars, the visual warning device may be ineffective and the operator unaware that there is a problem with the coupler.

If the excavator’s arm wobbles too fast and the hook connection is not locked, the bucket will fall off and transfer to nearby workers, equipment and structures.