Caterpillar® Product Information

Product Bulletin

For Dealer Sales Personnel

May 2007

GEJQ0199-01

Hydraulic Excavator Coupler Selection Guide

Dedicated 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 needs, sometimes the number of choices can be confusing.

The goal of this guide is to clarify the function, features and benefi ts 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.

2

It’s worth asking, why sell a quick coupler? The benefi ts are many:

Pin-Grabber CouplersThese 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 modifi cation, 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 signifi cantly. 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 CouplerPicks up most standard buckets and tools with no modifi cation. Tool must be equipped with stan-dard pins.

1The design of this cou-

pler makes it compat-

ible with a range of at-

tachment pin spreads

and widths.

32A check valve and

blocking bar prevent

tool disengagement

in the event of a hose

or hydraulic system

failure.

A double-acting hy-

draulic cylinder moves

a hook to engage or

disengage the work

tool pin.

4Integral lifting eye for

handling material with-

out the added weight

of a bucket.

• Provide more versatility — machines can do more things, simply by switching which tools they carry

• Provide increased production — the ability to switch tools quickly increases daily production and overall machine utilization

• Improve work tool and machine component life

• Increase sales of tools at the initial sale and in the aftermarket

• Take advantage of Cat® merchandising pro-grams for machines, couplers and work tools

3

Tilting Pin Lock CouplerCompatible with Wain-Roy, Gan-non and similar coupler systems, these couplers are offered in three styles depending on machine size.

Dedicated Wedge-Lock CouplerThis coupler style offers fl exibility without sacrifi cing breakout force.

Dedicated CouplersDedicated couplers require a spe-cial receiver on the bucket or work tool bracket hinge assembly. They cannot use conventional pin-on buckets or tools. Most hydrome-chanical tools (hammers, compac-tors, etc.) can work with a dedi-cated 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.

There are many types of dedicated coupler systems, few of which are cross-compatible. Caterpillar

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. Re-cently, 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 cou-plers to pick up tools from larger or smaller machines. While this

can offer some additional fl ex-ibility, it cannot be clearly sug-gested 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 simi-lar 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 ma-chine 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

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 unverifi ed 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 is prohibited.

For more complete information on Cat® products, dealer services, and industry solutions, visit us on the web at www.cat.com.Materials and specifi cations are subject to change without notice. Featured machines in photos may include additional equipment. See your Caterpillar® dealer for available options.

©2007 Caterpillar All rights reserved. Printed in USACAT, 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.

GEJQ00199-01

May 2007

1On the dedicated hy-

draulic coupler, spring

force and retraction

force of

the hydraulic cylinder

secures the wedge

into position.

2On the dedicated manual

coupler, two bolts with

spring tension washers

secure the wedge to the

coupler.

Dedicated Hydraulic vs. Dedicated ManualAs 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.