Caterpillar ® Product Information
Product Bulletin May 2007
Hydraulic Excavator Coupler Selection Guide
Dedicated Wedge-Lock Wedge-Lock Coupler
Pin-Grabber Coupler
Pin Lock Coupler
Caterpillar offers a range of quick coupler systems for hydraulic exca vators. While this offering can meet a diverse range of customer nee ds, sometimes the number of choices can be confusing. The goal of this guide is to clarify the function, features and benefits of a range of coupler systems and offer pointers to aid in selection. The couplers covered are: pin-grabber, dedicated wedge-lock, and pin lock.
GEJQ0199-01
For Dealer Sales Personnel
It’s worth asking, why sell a quick coupler? The benefits are many: • Provide more versatility — machines can do more things, simply by switching which tools they carry
• Improve work tool and machine component life • Increase sales of tools at the initial sale and in the aftermarket
• Provide increased production — the ability to switch tools quickly increases daily production and overall machine utilization
• Take advantage of Cat ® merchandising programs for machines, couplers and work tools
Pin-Grabber Couplers These couplers work by “grabbing” the bucket pins of a standard bucket or work tool. They can pick up most standard buckets and tools with no modification, provided the tool in question is equipped with pins. This allows a customer to utilize an already existing inventory of work tools, including some competitors’ buckets. With few exceptions, pin-grabber couplers can pick up buckets in the reverse (front shovel) position. One drawback is that pin-grabber couplers are heavier than dedicated couplers. They also increase the tip radius significantly. These two factors can negatively impact breakout force and loading performance. However the sheer convenience of the pin-grabber style coupler has made them popular with customers. Pin-Grabber Coupler Picks up most standard buckets and tools with no modi fication. Tool must be equipped with standard pins.
1
The design of this coupler makes it compatible with a range of attachment pin spreads and widths.
2
A check valve and blocking bar prevent tool disengagement in the event of a hose or hydraulic system failure.
3
4
A double-acting hydraulic cylinder moves a hook to engage or disengage the work tool pin.
Integral lifting eye for handling material without the added weight of a bucket.
2
Dedicated Couplers Dedicated couplers require a special receiver on the bucket or work tool bracket hinge assembly. They cannot use conventional pin-on buckets or tools. Most hydromechanical tools (hammers, compactors, etc.) can work with a dedicated system by using the correct bracket. The advantage of this type of coupler is that, in most cases, there is no increase in tip radius or decrease in breakout force. There is a slight increase in weight, but not as much as with a pin-grab ber coupler. This type of coupler is recommended for hammers and other hydromechanical work tools. Dedicated couplers cannot use buckets in the reversed front shovel position.
offers two types on excavators: wedge-lock and pin lock systems. Dedicated Wedge-Lock couplers are what are usually meant when talking about dedicated couplers on hydraulic excavators. A range of buckets, hammer/compactor brackets, grapples and other tools are available for this coupler style. Dedicated couplers are available for the 312–345 machines. Recently, Caterpillar has introduced dedicated couplers for 365 VB and 385 HB linkages. While similar to their smaller brethren, they do have a slight increase in tip radius (6"-8") which is still about half the tip radius increase of similarly-sized pin-grabber couplers.
It is possible for wedge lock couThere are many types of dedicated plers to pick up tools from larger coupler systems, few of which or smaller machines. While this are cross-compatible. Caterpillar
can offer some additional flexibility, it cannot be clearly suggested as an advantage. Before recommending this to a dealer, it is worth considering whether the tools or the machine might suffer damage or decreased performance when used like this. Pin Lock couplers are the second dedicated type coupler offered for hydraulic excavators. Available for the 307–322 machines, their primary advantage is compatibility with Wain-Roy, Gannon and similar coupler systems. This can be a key selling feature for customers with a large existing inventory of this type buckets. Pin lock cou plers are available with a tilting function, allowing the bucket to be used at an angle.
There are three sub-types of pin lock couplers, depending on machine size: • ¼ yard for 416, 420, 430, 307 • ½ yard for 446, 311, 312, M312, M315 • ¾ yard for 314 through 322 and M318 through M322
Tilting Pin Lock Coupler Compatible with Wain-Roy, Gannon and similar coupler systems, these couplers are offered in three styles depending on machine size.
Dedicated Wedge-Lock Coupler This coupler style offers fl exibility without sacri ficing breakout force.
3
Dedicated Hydraulic vs. Dedicated Manual As the name suggests, dedicated hydraulic couplers are operated by the machine’s hydraulic system, allowing actuation by the operator without leaving the cab. They are convenient, quick (10-15 second cycle times). They require a hydraulic circuit and installation of boom and stick hydraulic lines. Dedicated manual couplers are usually easier and less expensive to install, however they require the operator or a second person to engage the coupler fastening system by hand; a process which can take several minutes.
1
On the dedicated hydraulic coupler, spring force and retraction force of the hydraulic cylinder secures the wedge into position.
2
On the dedicated manual coupler, two bolts with spring tension washers secure the wedge to the coupler.
The information contained herein is intended for circulation only to Caterpillar and dealer employees whose duties require knowledge of such reports and is intended exclusively for their information and training. It may contain unverified analysis and facts observed by various Caterpillar or dealer employees. However, effort has been made to provide reliable results regarding any information comparing Caterpillar built and competitive machines. Effort has been made to use the latest available spec sheet and other material in the full understanding that these are subject to change without notice. Any reproduction of this release without the foregoing explanation i s prohibited. For more complete information on Cat® products, dealer services, and industry solutions, visit us on the web at www.cat.com. Materials and specifications are subject to change without notice. Featured machines in photos may include additional equipment. See your Caterpillar® dealer for available options.
GEJQ00199-01
May 2007 ©2007 Caterpil lar
All rights reserved .
Printed in USA
CAT, CATERPILLAR, their respective logos, “Caterpillar Yellow,” and the POWER EDGE™ trade dress, as well as corporate and product identity used herein, are trademarks of Caterpillar and may not be used without permission.
