Choosing excavator quick couplers - Bonovo
The tools used by the building demolition industry are extensive and constantly improved. Sledgehammers evolved into hand-held crushers and shovels evolved into excavator buckets. Wherever possible, manufacturers strive to improve the productivity and safety of the tools contractors use every day.
Fast connectors are no exception. These aftermarket excavator accessories eliminate the need to manually remove mounting pins, thereby increasing efficiency and greatly reducing the time required for excavator operators to switch between accessories. Like all other tools, fast couplers are constantly being improved. When making purchase decisions, contractors should consider applications, hydraulic or mechanical configurations, safety features, and other performance characteristics, such as tilting capability, to get the most out of their investment.
Fast couplers are an investment that can add fleet convenience and flexibility in almost all applications. Without a coupler, switching between a bucket, a ripper, a rake, a mechanical grab, etc., can consume valuable time. While the couplers may make the machine heavier, slightly reducing the force of the breakthrough, they increase the speed and flexibility of the accessory replacement. Considering that traditional replacements can take up to 20 minutes, fast couplers can reduce the time required to handle jobs that require different accessories.
If the operator changed the attachment every few days instead of a few hours, the coupler might not be needed. But if a contractor is using a variety of accessories all day, or wants to increase productivity with one machine at a site, a coupler is a must-have device. Fast couplers can even reduce required maintenance and costs, as an operator may refuse to switch attachments when manual replacement is needed if he or she doesn’t want to bother. However, using the wrong accessory for the wrong job can definitely increase wear and tear.
Notes on hydraulic and mechanical couplers
Most manufacturers offer couplers in two configurations: hydraulic or mechanical. There are pros and cons in terms of scale, cost and operating system.
Mechanical (or manual) couplers can provide lower cost, fewer components and lighter overall weight. They are often the best option if a job doesn’t require multiple accessories to be replaced daily, or if price is the most important consideration. The purchase price of mechanical couplings is similar to that of hydraulic couplings, but the necessary complex installation procedures often vary widely in cost.
However, with mechanical couplers, convenience and safety may be compromised. Requiring the operator to leave the machine’s cab and use manual force to position the pins in place resulted in the replacement process taking longer. It usually involves two workers and is an overall more difficult process. Due to the easy-to-use characteristics of the hydraulic coupler, the operator can complete this process in the cockpit, saving time and effort. This improves efficiency and safety.
Safety benefits of hydraulic couplings
Most injuries related to couplers are due to operators not properly securing safety pins on semi-automatic or manual models. Poor couplers and falling buckets have resulted in numerous injuries, some even deaths. According to a study by the Occupational Health and Safety Administration (OSHA), there were 15 injury-related incidents in the United States between 1998 and 2005 involving excavator buckets on hydraulic excavators that were accidentally released from quick joints. Eight of the incidents resulted in fatalities.
In most cases, failure to engage and lock couplers correctly is likely to be the cause of the accident.According to OSHA, accidental release of couplers can occur because users may not be aware of the hazards of replacement, they do not insert locking pins properly, or they are not adequately trained in installation and testing procedures. To reduce the likelihood of accidents, manufacturers have developed solutions through hydraulic couplers to ensure proper engagement and minimize the possibility of injury due to operator error.
Although hydraulic couplers do not eliminate the risk of all accessories falling off, they are safer than mechanical couplers in preventing on-the-job injuries.
To ensure operators are using the locking pins correctly, some systems are equipped with red and green LED lights, as well as a warning buzzer to let the user know if the pairing has been successful. This increases operator awareness and helps them manage systems and prevent dangerous situations.
Since most serious accidents occur within the first 5 seconds of locking the attachment, some manufacturers have added features that make it nearly impossible for the operator to accidentally drop the attachment.
One of these features is the wedge locking principle to counter incorrect locking pins. This requires the coupler to be connected to the attachment in two separate places. This constant application of working pressure constantly adjusts the wedge, keeping the two pins firmly on the quick knot and the attachment securely in place.
The advanced design also provides a safety joint that can be securely locked immediately and automatically on the first of the two pins. This prevents attachments from being removed even if the operator forgets to complete the process. The safety knuckle operates independently of the wedge that holds the second pin, preventing the release of the first pin in the event of a hydraulic system failure. When replacing the attachment, the operator first releases the wedge, then places the attachment in a safe position on the ground, and then releases the safety joint.
For added safety, operators can look for time-out features offered by some manufacturers that automatically reengage safety joints. If the operator does not completely disengage from the safety joint within the timeout period, the joint will automatically reset. This timing feature is customizable, but usually occurs after 5 to 12 seconds to help prevent dangerous situations. Without this feature, the operator could forget that the attachment was unlocked and then fall after lifting it off the ground or unlocking it in the air.
Additional features and options
Simply adding a standard coupler to a fleet can save time and money, but there are additional features that can improve productivity.
Some hydraulic couplers and their paired accessories provide 360 degree rotation. To increase capacity, some manufacturers offer a universal joint that can also be tilted — often called a tilter. This natural ability to continuously rotate and tilt couplers makes them even more efficient and productive than standard couplers. They are often streamlined in design, which makes them ideal for narrow areas and applications such as road construction, forestry, landscaping, utilities, railways, and urban snow removal.
Tilt-rotors cost more and weigh more than standard hydraulic couplers, so users should consider their features before choosing.
Another aspect couplers users should consider is whether the device is fully hydraulic. Some manufacturers have developed systems that can connect up to five hydraulic loops comfortably and safely from the cab. A special locking system absorbs the dispersing forces generated between valves without transferring them to the fast coupler. The full hydraulic unit allows quick replacement without additional manual work. Systems of this nature represent the next logical step for couplers, and the development of fully hydraulic directions may lead to greater safety standards.
Make wise decisions
As tools and technologies evolve, contractors will find more options. Efficiency and safety often go hand in hand and are equally important. Fortunately, by analyzing the application, understanding the risks, and optimizing the system for the company’s specific needs, contractors can find a fast coupler that improves both efficiency and safety.