Professional excavator operators’ have been able to benefit from recent advances in equipment technology that has led to fully automatic, quick coupling hydraulic systems. This has been developed due to pressures to make operations more efficient, with modern operators aiming to get in and out of their excavators as little as possible to change tools. When there is an absolute requirement to do so, any break in the work flow needs to be as short as possible, with little oil spill and with as small a risk as possible of injury to anyone. This needs to be accomplished with as much efficiency and flexibility as possible – hence the development of automatic attachment systems.
The advent and development of quick auto-connect excavator-attachment systems have enabled construction businesses, in all areas of the industry, from quarrying to demolition, to move easily and efficiently between various attachments, making quick coupling systems a powerful and competitive asset for any business. Factors such as increasing industry demands for improved safety, efficiency and increased material separation in the workplace, and correspondingly, the need to change tools more often, has also increased. Below we look at how the market for quick auto-connect coupling systems came about, and how some of the leading manufacturers in the U.S. and abroad cater to this rapidly developing market.
Four well known systems and a new entrant from the U.S.
Four automatic quick coupling systems have dominated the market: Likufix, VarioLock, OilQuick and EC-Oil. The Likufix system is owned by Liebherr and is very strong in German-speaking countries, with a corresponding linkage to owners and operators of Liebherr excavators. Lehnhoff is truly global and is currently owned by Komatsu and manufactures VarioLock, while OilQuick is a particularly well known system in many parts of Europe and further afield, being used as a quick coupler system by demolition contractors. Engcon, as with OilQuick, is a Swedish manufacturer, and has developed EC-Oil. Bobcat has recently entered the market with the Bob-Tach and Bob-Dock attachment mounting system, allowing attachments to be combined quickly and safely with a very wide choice of Bobcat attachments. As with all the other mentioned systems, this delivers versatility and time-saving efficiency across a range of different applications.
What generally differentiates the fully automatic quick couplings is the design which effectively divides the manufacturers into two groups. This is most clearly apparent in the locking mechanism where the quick coupling closes and the connections are thus protected. Likufix and VarioLock’s female sides of the connection are exposed horizontally, while the OilQuick and EC-Oil’s female sides in the coupling are vertically exposed. The vertical locking function has proven preferable to many as it more efficiently prevents dust and harmful particles getting into the sensitive parts of the system.
Changing the task in an instant
In what could be said to be one of the most recent developments in quick auto-connect solutions, Engcon has recently upgraded its EC-Oil system for the hydraulic and electrical connection of hydraulic tools and attachments. The EC-Oil system is designed for maximum operational safety in demanding environments, being what is said to be the market’s only fully hydraulic hitch that can tackle connecting pressurized tools and attachments at full system pressure. The system’s proprietary oil and electrical connectors are designed to be even more resistant to the often tough working conditions for excavators. The connectors are claimed to be the most durable on the market, which has been proven through “destructive” testing at 400 bar operating pressure and innumerable tests in contaminated environments.
Arden Equipment expands its quick coupling offering
More developments have seen French manufacturer Arden Equipment now offering the Quick Arden (QA) quick-coupler for excavators from 0.8 – 32t and the Uni Arden (UA) quick coupler for 8 – 11t excavators. The new AIO 50 is the latest all-hydraulic quick hitch from Arden Equipment and this attachment is designed for the quick coupling of excavators with various hydraulic attachments. These include such items as tilt ditching buckets, Arden Tiltrotors, sorting and demolition grabs or even hydraulic concrete crushers as well as concrete and metal shears. It allows instant and direct hydraulic connection from the cab, with the hydraulic hoses connecting simultaneously within 10 seconds.
The AIO 50 fits excavators from 20 – 26t and allows all the fluids (hydraulic oil, water, grease) as well as electric wires to run through the quick hitch automatically. The AIO 50 includes a high flow double acting line (for example, jaw opening and closure), a low flow double effect line (for example, tool rotation) and two single auxiliary lines as well as a centralized lubrication line. This all means the operator can now change tools without having to move out of the cab, which saves valuable time as well as reduces accidents on sites.
An interesting features of Arden’s QA Series 3, which was launched at bauma this year, means that the quick couplers are equipped with presence sensors that tell the operator by an audible and visual signal that the QA is set up and that the locking mechanism has been properly engaged. The connected QA Series 3 is compatible with the older generation Arden Equipment buckets and, of course, the new buckets.
Quick coupler systems from Liebherr
Liebherr’s innovative attachments and quick coupler systems can be used for both hydraulic excavators and material handlers from Liebherr as well as with machines from other manufacturers. The Liebherr product portfolio means that its quick coupler systems are designed for all applications, from digging tools for the earthmoving sector to grabs for diverse applications in material handling. The choice of the appropriate tool having a significant impact on the success of a project led Liebherr to develop a wide range of attachments, with each being optimally adapted in terms of shape, properties and technical equipment to meet the specific application and machine size. Practice and continuous product development helps ensure that new developments are customer-focused and compatible with the existing product range, so that retrofitting or replacement of individual modules is possible.
For increased productivity, efficiency and safety on the construction site, Liebherr provides different levels of configuration for its quick coupler systems to suit specific applications. This way the machine’s quick coupler system and attachment form a high performance unit for maximum efficiency and economy. With the Liebherr quick coupler system, a simple and safe change of mechanical tool attachments is possible from the cab. The company states that if the patented hydraulic coupling system Likufix® is added, then the quick and safe changeover of hydraulic tool attachments can happen at the touch of a button. With Likufix, the hydraulic excavator’s range of uses and machine productivity can be increased by up to 30%. All current official standards, as well as the forthcoming IS0 13031 standard, are met thanks to the hydraulic quick-coupler’s specially developed safety features.
OilQuick announces developments at bauma
OilQuick quick couplers have been developed to enable the quick and safe switching of hydraulic attachments directly from the cab. The company has been operating for more than 25 years and has sold more than 26,000 systems worldwide. It recently used the bauma show in Munich, Germany, to present its latest developments. One of the new products is OilQuick’s front pin guide (FPG), a control system for safe attachment connection (patent pending). This enables centered and safe guiding of the coupler in the attachment frame, thus ensuring stress free connection of the electrical and oil connections.
New and innovative safety solutions have also been launched with an electronic monitoring system, OQ-LockSupport (OQLS), which is an advanced safety system for excavators. OQLS guides the operator through the entire attachment switching process, standardizes operation of the locking function and provides the operator with information via a cab control panel. A new “fall” protection system has also been launched: the OQSH and a mechanical lock indicator, MRL. OQSH lessens the hazard of attachments dropping around the machine in the event of careless or incorrect coupling by the operator with OQSH’s safety hooks catching the attachment in all positions. OQSH can be compared to a safety belt in a car, which automatically deploys tension in the event of an incident or risk of personal injury.
MRL is a mechanical lock indicator that clearly informs the operator whether the coupler’s locking plungers are in the locked or unlocked position. MRL indicates that the attachment is correctly connected and locked only when the locking plungers are in the correct position under the frame pin. OQLS, OQSH and MRL are independent safety solutions that can be used independently or in different combinations with each other. Further product innovations recently introduced include a newly developed 17-pin vertically-mounted V90 electrical connector, which allows simultaneous operation of two separate “can bus” systems and control electronics on the same connector. OilQuick also launched a special coupler this year, OQRail, for rail excavators and an improved coupler system OQC for pendulum mounted attachments.
Lehnhoff’s VarioLock Quick coupler system
The Komatsu-owned German company’s VarioLock auto-connect system is based around the concept of “one system concept, two components,” which was developed over 25 years ago and has now been installed in over 140,000 excavators worldwide. With the quick-coupler on excavators and the adapter on the attachments, Lehnhoff has created a universal interface which allows the use of all attachments on different excavator makes.
The Lehmatic quick coupler system turns any hydraulic excavator – from a mini excavator to large hydraulic excavators – into a multifunctional tool carrier for buckets, grabs and demolition tools in its size and weight category. The fully hydraulic VarioLock energy circuit coupling system makes changing all attachments easy, safe and quick. The driver can comfortably change all tools including the hydraulic connection at the press of a button from the cab. The hydraulic unit, and the tried and tested original Lehnhoff quick coupler, form a compact unit, with the locking operation being carried out via a lockable push button or optional Lehmatic Control (control panel).
A new and radical solution from Sweden
A new development was seen in 2017, which shocked the market, when a new Swedish manufacturer appeared. Steelwrist has developed a new automatic quick coupling system, which also possesses a vertical locking function to better protect the sensitive connection area. The new quick-coupling system is called the SQ and offers quick and safe tool replacements in just a few seconds directly from the cab. Initially the products were launched solely into the Swedish market, but success has seen the range now available internationally.
Today, Steelwrist’s fully automated quick couplers include SQ auto connect systems in two models: SQ60-5 for 12 – 20t excavators, and SQ70 for excavators from 18 – 33t. The company is also developing (and is set to launch) the next size up – the SQ80 for excavators from 25 – 43t. Steelwrist has developed its line in response to users in the field whose investment in a fully automated quick coupling system results in a significant increase in both efficiency and safety in the workplace. It is also considerably more environmentally friendly, as any oil spill is radically decreased due to the fitting. The end result is that the amount of material sorting at the worksite can be increased through the easier use of several types of attachments.
New system for quickly changing hydraulic attachments
Bobcat is the latest entrant into the auto quick-change attachment market through its new Bobcat® Bob-Dock™ system. The Bob-Dock mounting system is designed for strong, easy and repeatable hydraulic connections, without operators having to leave the Bobcat compact loader cab. The system will be available for its M2-Series T630, T650, T740 and T770 compact track loaders; S630, S650, S740 and S770 skid steer loaders; and the A770 all wheel steer loader.
The system works by allowing an operator to line up the loader with the attachment’s Bob-Dock adapter plate when connecting an attachment to a compact loader equipped with the Bob-Dock system. The operator then presses the Power Bob-Tach® switch inside the cab. The Bob-Tach system secures the attachment, while the Bob-Dock system automatically connects the hydraulics. The attachment is then ready to use. When the use of the attachment is finished, the operator simply retracts the Bob-Tach wedges and pulls away, with the hydraulics instantly being released, providing simple, hands-free removal.
If a loader has a Bob-Dock attachment mounting system installed and the operator wishes to use an attachment that lacks a Bob-Dock adapter plate, it’s not a problem. While the Bob-Dock attachment mounting system’s floating coupler block equips the loader with a hands-free connection point, the standard couplers located on the lift arm remain ready to use. This means that it is possible to utilize the full lineup of approved Bobcat attachments, with or without the Bob-Dock adapter plate attached.
Doherty and Kinshofer combined
A very recent development which may have global implications for the auto-connect market is the acquisition of the innovative New Zealand company Doherty by the Kinshofer Group, with Doherty Couplers & Attachments being manufacturers of the fully compliant Snaplock+ range. Parent company Kinshofer provides a wide range of tools for a variety of industries, with the recent acquisition of Doherty providing what is said to be an excellent fit.
The simple design of the Snaplock+Hydraulic combined with highly innovative safety features makes the Snaplock+Hydraulic, according to Doherty, “the safest coupler on the market today.” The Snaplock+ coupler is dual locking, meaning attachments remain securely engaged on both pins in the event of loss of engagement force. Compliant with Australian standard AS4772-2008, European standard EN474 and all major contractor policies, the system possesses a compact design with only two hoses, minimal moving parts, no greasing and no complicated operating sequence