Equipment Focus: Automatic Couplers

Feb 21, 2020, 15:31 PM
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January/February 2020

By Megan Quinn

Automatic couplers are gaining popularity in North America as a way to change mechanical and hydraulic attachments without leaving the cab—a feature that could increase safety and help address labor shortage issues.

Equip FocusRecyclers and demolition businesses rely on an array of attachments to multiĀ­task at the job site. Operators have several options for how to change the tools on a base machine like an excavator, material handler, or skid-steer. The most labor-intensive and time-consuming option is to switch attachments by hand: A worker will manually drive out the attachment pins. “That might mean using a sledgehammer to bash away on the pin until it comes out, all while dealing with oil in your face and on your hands” as you manually disconnect and reconnect the hydraulic lines, says a sales rep from a Swedish equipment manufacturer with a U.S. headquarters in New Berlin, Conn. This process can take at least half an hour depending on the base machine and attachment, and the work sometimes requires two people to take off the old attachment, line up the new attachment, and safely attach it to the base machine, he says.

One popular solution is to install a quick coupler, an interlocking bracket system that allows an operator to forgo the hammer and hook the attachment to the machine from inside the cab. If the attachment requires hydraulic power or needs to be secured with an additional safety lock pin, however, a worker might still need to connect the hydraulic hoses or lock by hand. 

Enter the automatic coupler. This type of quick coupler allows workers to switch attachments, whether mechanical or hydraulic, without ever getting out of the cab, much less picking up a hammer. Equipment providers say automatic couplers are the fastest and safest option. They keep workers away from the hazards inherent in manipulating large, heavy attachments with hand tools when they might not be properly positioned or anchored to prevent their movement. It also avoids the mess and potential injury from hand-connecting the hydraulics, which can expose workers to dangerously high-pressure hydraulic fluids, they say.

Saving labor and time

Automatic couplers, sometimes called fully hydraulic couplers or “wet couplers,” are so popular in Germany, Sweden, and similar European countries that they are standard features on many excavator, skid-steer, and material handler models there, according to the New Berlin sales representative. Automatic couplers have been slow to gain popularity in the North American market, but customers have started to take notice in the last few years, these sources say. “The most major reason for the uptick in sales is the labor shortage here,” says a North America sales representative for another Swedish manufacturer with a U.S. headquarters in North Haven, Conn. The company introduced automatic couplers for excavators in North America in 2007, but few buyers were interested at the time, he says. Today, demolition contractors, construction companies, and a few recyclers are the company’s most common customers for these couplers. Automatic couplers turn a two-person job into a single person job, he says, and the time savings help customers stretch out the labor they have. “Everyone is having a hard time finding people to do the work. In some cases they’re telling me they can’t keep guys on the job site for more than four hours. They’re looking for ways to help with that.”

In addition to these couplers reducing labor costs, automatic coupler manufacturers say their products offer significant time savings when changing the attachments. A Swiss equipment manufacturer says its automatic couplers for excavators and material handlers increase productivity by 30% because they can quickly change both mechanical and hydraulic attachments in just one minute. The company’s marketing representative says changing attachments by hand can take as long as 45 minutes, and the standard quick couplers the company offers only shave off between 20 and 25 minutes. A Swedish company with its U.S. headquarters in Superior, Wis., says its automatic coupler can change attachments on excavators and material handlers in 10 to 30 seconds compared with an estimated 90 seconds for its quick couplers.

Automatic couplers also can save operators from downtime caused by damaged hydraulic lines, these companies say. Each has a slightly different design meant to protect the hydraulic hoses from getting tangled, ripped, or pinched when attaching and detaching tools. One North Dakota-based equipment company, for example, says the automatic coupler it offers for some of its skid-steer and track loaders connects the attachment’s hydraulics through an adapter plate on its quick coupler. The two hydraulic hoses on the loader lifting arm stay safe from jagged rebar and concrete because they are tucked away behind the mounting system, says a marketing manager for the company.

The New Berlin company’s design integrates the ends of the hydraulic hoses into the automatic coupler and holds them in place against the excavator arm. Users “find that they are breaking fewer hydraulic hoses because the hoses are no longer dangling down to the attachment,” where they can get damaged during tool changes, the sales rep says. “They are no longer wasting time running to the hose shop for a replacement.”

These coupler designs also avoid common human errors that can damage hydraulics or cause them to perform at a less-than-optimal level, the Swiss manufacturer rep points out. The precision with which this company’s automatic coupler lines up hydraulic hoses provides “better flow rates than couplings that are connected by hand,” she says. The North Dakota skid-steer company adds that its design also “prevents many common operator errors, like failing to disconnect hydraulic hoses before backing away from an attachment,” its marketing manager says.

Stepping up safety

These sources also tout the safety advantages of automatic couplers. Hydraulics hoses can be tricky to connect by hand, especially in bad weather or when operators are rushing to get through a hectic day, the North Haven representative says. Hydraulic lines also pose safety issues. At best, a hydraulic fluid leak is an annoying and slippery signal that it’s time for maintenance. At worst, an unexpected high-pressure burst of hydraulic fluid can cause burns and other serious injuries to hands and eyes, he says.

Struck-by injuries are an even worse risk. The North Haven representative often hears from customers concerned about buckets or other hanging attachments dropping unexpectedly during a changeout. “Our big thing is safety,” he says. The company’s automatic coupler only engages when the attachment rests on the ground, not when it’s dangling in the air, eliminating the possibility that an attachment could drop and cause a serious or fatal crushing injury. “You don’t have to worry about the operator hurting himself trying to tug [the pins], and you don’t have to have another guy on the ground manipulating the attachments” while another worker is inside the cab, he says.

Many quick couplers and their automatic counterparts also include special safety locking features beyond what European Union safety regulations require, according to an equipment manufacturer in Ireland that makes excavator quick couplers with patented safety locks. Most manufacturers offer designs that give operators a clear view of the front locking pin from inside the cab so they can visually confirm the tool is attached correctly. The New Berlin company’s front pin lock is fully mechanical, “so it’s not dependent on a sensor or hydraulics to make sure it works,” the sales representative says. It also has color-coded its locking pins with red and green paint to make visual confirmation easier, he says. Manufacturers also have designed methods to monitor the back locking pins automatically. Those pins are not usually visible from the cab. The Swiss company has an electronic sensor that monitors the position of the locking pin and a proximity sensor that makes sure attachments are lined up correctly. Similarly, the Wisconsin company’s sensor scans the adapter pins and the position of the locking cylinder.

Another safety feature is the in-cab control panel, which typically includes flashing alert lights that change from red to green and loud buzzing alarms “that will not stop until there’s a solid connection with the next attachment,” the North Haven rep says. Check with your dealer or manufacturer to determine what the various alert lights and buzzers mean when they go off—each manufacturer has created a different style of alert system, the New Berlin representative adds.

Finding the right fit

All these automatic coupler manufacturers promise easy attachment of both mechanical and hydraulic tools without leaving the cab. Each company offers slight variations on its models based on the size and type of machine it’s meant for and the various niches it serves. Some manufacturers, such as the North Haven company, specialize in couplers for excavators, while the Wisconsin company offers automatic coupler models for excavators, material handlers, wheel loaders, tilt rotators, and forklifts. The North Dakota company makes automatic couplers for select models of its skid-steers and track loaders.

These companies tout design features meant to stand up to environments such as demolition job sites and scrap recycling facilities. The New Berlin company says its couplers are cast steel instead of welded together, thus avoiding possible weak spots. The Wisconsin company, which first offered automatic couplers in 1993, says its models are the most advanced because they have been on the market the longest. Its excavator coupler has an H-cylinder and double hose valves, which it says allows operators to lock attachments in place at full system pressure, saving time during the attachment process. The North Haven company says its coupler also can connect tools at full system pressure because of a built-in pressure relief valve.

 One Massachusetts-based attachment manufacturer discontinued its automatic coupler a few years ago, but the company says it offered a unique seal design that held up to stress from vibrations caused by compactors and hammers. The company still lists the automatic coupler on its website in the hope that the recent increase in North American sales might revive interest in its model. “If we receive considerable interest, perhaps we will reintroduce in the future,” the company’s president says.

All automatic couplers require installing the correctly-sized coupler to the end of the base machine, then a corresponding bracket on each attachment you want to automatically connect. Take a look at the base machines you own and decide which are the best candidates for automatic couplers based on how often you must change attachments throughout a shift or project. For some tasks, such as demolition jobs, “an automatic coupler is a no-brainer” because of the number of attachments needed to get a single job done, the New Berlin representative says. For other jobs “where your machine is doing the same thing over and over,” it might not make sense to invest in an automatic coupler, the Swiss marketing manager says. If you’re on the fence about whether an automatic coupler is the right investment, equipment manufacturers or dealers can usually help you estimate the time or labor savings an automatic coupler might provide.

Once you’ve identified which machine or machines could benefit from having an automatic coupler, find a compatible model. If you already have a quick coupler on your base machine and attachments, check to see if your preferred dealer or manufacturer offers adapters that turn a quick coupler into an automatic coupler—each company mentioned in this article sells both. Providing information about your base machine, such as its “operating weight, shaft dimensions, and breakout forces,” will also help dealers find you the coupler that is the best fit for the machine, attachments, and jobs, the Swiss marketing manager says. Be sure to ask how an automatic coupler might affect the machine or tool’s performance. Some couplers may slightly lower a machine’s lift capacity because of the additional weight of the coupler, which can add several hundred pounds depending on the weight class of the machine, she says.

These companies also offer a range of automatic coupler sizes, especially for excavators. The Wisconsin company offers models for excavators from 1 to 132 tons that can distribute hydraulic oil, grease, water, and electricity, while the North Haven manufacturer makes models for excavators weighing 8 to 40 tons. The New Berlin company’s most popular couplers fit excavators between 30 and 40 tons, and the company plans to release one for machines up to 55 tons in 2020, its sales representative says.

If you plan to install automatic couplers on multiple machines or have attachments made by a variety of companies, consider models that can work on various brands of equipment, the North Haven sales rep says. Talk with dealers for their recommendations, the New Berlin rep suggests—most of the companies that make automatic couplers understand that businesses often own “a CAT, a Hitachi, and a Volvo,” and customers want to multitask as much as possible. The New Berlin manufacturer, which offers automatic couplers only for excavators, makes an array of coupling sizes designed in a special S shape that can pick up attachments with locking pins of different diameters, he says. The Wisconsin company says its material handler couplers “fit any manufacturer attachment,” while its excavator couplers “can be adjusted to fit most excavators in the weight class.” The Swiss company’s automatic coupler also fits hydraulic attachments from other manufacturers, it says. The North Dakota company only makes automatic couplers for its own brand of skid-steers.

Installation and maintenance

Costs can vary widely depending on the size of the base machine and how many attachments you want to attach automatically, the New Berlin sales representative says. Its automatic coupler, for example, starts at around $13,700, and each bracket is between $3,500 and $5,500 depending on what kind of attachment it is and how many hydraulic lines a tool has, he says. The North Haven company representative estimates the cost could be about $10,000 for the coupler and $4,000 for each bracket, depending on size and function.

Before installation, the dealer or manufacturer tests each coupler to make sure it is fully functional before sending it to the customer, these companies say. Some companies prefer to send a technician to lead the installation, while others have experts on hand at a customer’s request. The customer usually provides its own hydraulic lines, “since they vary in length and number, and the customer knows how many and how long they need to be for each machine,” the North Haven rep says, but otherwise operators do not need to purchase any other tools or accessories to keep their new couplers functioning correctly once they’re bolted on.

Manufacturers say the couplers shouldn’t require much maintenance. Depending on the model, operators will likely need to check the grease points about once a shift and inspect the hydraulic seals to make sure there’s no damage or leakage, the New Berlin sales rep says. This company’s automatic couplers come with an extra seal kit so operators can replace worn seals—a process that takes four or five minutes and requires only a standard tool like a screwdriver. Because most automatic coupler models rely on making tight, precise connections that lock the machine and attachment together and provide good hydraulic flow, operators should always do a visual inspection of the coupler and the bracket before attaching them to make sure no excessive dirt, dust, or other debris could interfere with the connection, the marketing manager for the North Dakota company says.

With the right maintenance, most companies say, their automatic couplers can last as long as the life of the machines to which they are attached or longer. This can be about 10,000 hours in the case of an excavator, the Swiss, New Berlin, and North Haven companies say. In Sweden, it’s common for businesses to take off an automatic coupler when a machine reaches its end of life and bolt it on to a new machine, the New Berlin rep says. “These are really designed to last,” he says.

Megan Quinn is senior reporter/writer for Scrap.

By allowing operators to change attachments without leaving the cab, automatic couplers can increase safety and productivity. 
  • 2020
  • Jan_Feb

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