MARKET GUIDE: Quick Hitches

Peter Anderson reviews the latest developments in automatic excavator quick hitches

There is no doubt that excavator fully automatic quick hitches are one of the most successful labour-saving devices, both in terms of productivity and safety, to have been adopted by the machinery industry in recent times.

Although buckets directly-mounted to the end of the dipper arm are used on heavy duty mining excavators and the smallest of minis, the standard UK spec for everything in between is a quick hitch, allowing the rapid bucket changes. Some compact machinery applications work successfully with a manually-operated quick coupler, but hydraulically-operated quick hitches are now what is expected on most construction sites.

Following a series of fatal accidents, semi-automatic, hydraulic quick couplers were banned from UK sites at the end of 2008, prompting the widespread uptake of fully-automatic hitches. These allow the operator to quickly change buckets from the safety of the machine’s cab. To ensure the bucket is correctly coupled, this new generation of fully-automatic hitches came with a host of safety features, not only mechanical systems, increasingly they also digitally monitor attachment change-overs and their security while working.

Although quick couplers that feature either a tilting or a rotation function also have a role to play, but the UK construction industry is rapidly turning towards tilt-rotator hitches, to bring even more productivity and safety gains.

Like their colleagues in the demolition industry, such excavators are typically used with a selection of hydraulically-powered attachments. Tilt-rotators can automatically connect hydraulic and other services, at the same time as making the physical connection to the attachment, saving a lot of time and effort. Operators of demolition rigs have the same connectivity for their heavy-duty rotating attachments, avoiding the risk of working on the ground and encouraging the use of the most appropriate tool for the job.

HARFORD
Norwich-based Harford Attachments produces the Uni-Lok range, double-locking, fully-hydraulic quick hitches, suitable for excavators from 3 to 18 tonnes. They are said to be durable, easy to operate, with low maintenance program. They are also easy to fit, with Harford offering a full on-site fitting service if required.

The Uni-Lok is also available as a full 180-degree tilt coupler. As are the two mechanical couplers offered by Harford, the Pro-Lok and the Safelock, which are designed for compact excavators from 3 to 8 tonnes.

JCB
Designed to exceed current and anticipated legislation, JCB has developed a range of hydraulic and manual hitches to fit their excavator range from 1- to 36-tonnes. Their manual hitches feature a high visibility safety lock pin. This is mechanically operated, with the spring-loaded lock released, with the use of a tommy bar.

The stars of the JCB hitch range are their automatic hydraulic couplers. Mechanically, these feature a unique lock shape and double locking mechanism, ensuring the safety of the attachment even in the event of a hydraulic failure. The simple, low maintenance design requires no greasing and few replacement parts.

Where they differ from the rest is that they are fully integrated into the host JCB machine’s electrical and hydraulic systems, with no need for a separate in-cab control box. The in-built system monitors the security of the attachment while it is working and, together with boom position sensors, manages the attachment change-over procedure. The hitch will only operate in a safe zone, not with the working equipment up in the air, with the operator following a four-step process to release or attach buckets.

MILLER
Featuring a novel twin-locking independent back up system, the latest GT Series of automatic quick couplers from Miller are available to suit excavators from 1- to 50-tonnes. This modern design consists of only four component parts, a far cry from some other hitches, the streamlined design reducing repair and maintenance costs over the long term.

Its low-profile allows shorter pin to point distances, delivering maximum breakout force. With a dual radius front jaw on most models and variable OEM pick up on the rear jaw, provides versatility to use various attachments, all controlled from the cab.

OILQUICK
There are nine fully automatic quick hitches in the OilQuick range, designed for excavators up to 120 tonnes. In addition there are five specific models designed for use on OilQuick tilt-rotators, for host excavators up to 30 tonnes. If that wasn’t enough, there are also two models specifically designed for wheel loaders, and a further two for material handling applications.

OilQuick also offers the OQLS LockSupport system, offering user-friendly operator support for safe and secure attachment switching, on all the fully automatic quick couplers. The system provides a controlled connection process, sensor detection of attachment pins and locking cylinder position, together with automatic activation of the machine's hydraulics.

Further safety features also include double hose break valves, a system for constantly readjusting the locking bolts hydraulically, a lock switch with double function, and a warning light and alarm.

ARDEN EQUIPMENT
French based Arden Equipment has recently introduced the Series 3 QA05H-23H compact quick coupler to their range, suitable for excavators from 800kg to 12 tonnes. Any excess play is automatically removed, they can be used with reversed buckets and feature a lifting eye. In addition to the Series 3 QA range, Arden offers a seven-model range of S-type couplers, suitable for excavators up to 40 tonnes.

CATERPILLAR
Caterpillar offers a 5-model range of hydraulic connecting S-type (HCS) couplers, suitable for excavators from 19 to 40 tonnes. These are designed to provide significantly higher oil flow through the hitch than is the norm, to power heavy duty attachments, with the lower hydraulic restriction resulting in better fuel efficiency of the host machine.

The quick disconnect design prevents contamination of the hydraulic system, while the design of the coupler protects hoses and components from damage. Cat HCS couplers feature cutting-edge sensor technology and multiple sub-systems to keep attachments connected in the event of a hydraulic pressure loss.

HILL ENGINEERING
The Terra range of automatic hitches was launched by in 2010 by Hill Engineering, suitable for excavators from 2 to an impressive 120 tonnes. They features a wide pin pick up range, offering maximum flexibility when handling many different types of attachments. They also feature a ‘Smart Valve’, which restricts oil flow to the operating mechanism of the hitch, until the coupler is orientated towards the operator. Part of a suit of measures to ensure safe connection and disconnection of attachments.

The range was enhanced with the introduction of Tefra-Tilt, offering 180-degrees of movement, available for excavators from 3 to 25 tonnes. Last year, a further variant, the Tefra-Connect, was launched, which features a unique method to automatically connect and disconnect hydraulic services, while maintaining the benefits of being able to also use the full capability of the pin pick up hitch.

KINSHOFER
German manufacturer Kinshofer offers a huge range of automatic quick couplers across different industry sectors, including excavator standard, tilting and tilt-rotating hitches.

Kinshofer’s SmartFlow system allows the automatic connection and disconnection of hydraulically-powered attachments. An interesting option for SmartFlow is a retrofittable electric coupling, providing a total of 16 connections each rated at 10 Amps. This can be used for a variety of purposes, including powering the attachment, connecting to sensors or a Can-Bus component, or controlling a tilt-rotator.

STEELWRIST
Best known for their tilt-rotators, Steelwrist also offers an impressive 11-model range of fully automatic, oil-connecting quick couplers, for excavators from 2 to 70 tonnes. These feature an upgraded system to provide higher oil flow, but with reduced long-term maintenance, designed to meet the Open-S SQ standard.

A quick coupler controller is available for controlling and monitoring the coupler functions such as locking, unlocking, and an optional pressure relief valve. The system module is installed in the cab and the indictor panel provides clear and easy indications of the various functions.

ROTOTILT
The new Rototilt Control (RC) system is said to promote better utilisation of all the tilt-rotator’s functions. There a sleekly-designed minimalist touch screen in the cab, controlling not on the tilt-rotator, but also the SecureLock hitch/attachment coupling monitoring system. RC tilt-rotators can be retrofitted with the QuickChange automatic hydraulic services connector system.

LENHOFF
Sold and supported in the UK by Worsley Plant, in addition to three mechanical quick couplers, Lehnhoff offer a wide range of automatic quick hitches, including the four-model HS Series.

Featuring fully automatic hydraulic service connections, the four model HS-V Variolock range caters for host machines up to 130 tonnes. The SQ quick coupler range consists of six models for excavators from 8 to 43 tonnes, featuring automatic oil connections to the emerging SQ standard.

SMP
Swedish manufacturer SMP offers Three heavy duty quick couplers for excavators from 30 to 90 tonnes, together with six Hardlock models for excavators up to 50-tonners, offering reversible S-type hitch. The SMP Fast Change (FC) range features integrated hydraulics, lubricant and electrical connections, suitable for excavators up to 70 tonnes.

This article featured in the May 2023 issue of Earthmovers Magazine. 

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