BGU ZWK 790-2 User manual

USER‘S MANUAL
LOG CUTTING SAW
ZWK 790 - 2
Südharzer Maschinenbau GmbH
Helmestraße 94 ∙ 99734 Nordhausen/Harz
Receptionist: 03631/6297-0 ∙ -111
Internet: www.bgu-maschinen.de
e-mail: [email protected]
Made in
Germany
Set-up & instal-
lation
Use
Maintenance
Accessories
Carefully read these instructions
before starting and using your saw!

2
CONTENT
1. GENERAL INFORMATION 3
1.1 About this manual 3
1.2 Delivery and transport claims 3
2. PRODUCT OVERVIEW 5
2.1 Circular log cutting saw with PTO drive 5
3. SAFETY PICTOGRAMS AND WARNING 6
LABELS 6
4. SAFETY 8
4.1 Safety rules about saw blade 9
4.2 Mandatory application field 9
5. OPERATING INSTRUCTIONS 10
6. CONNECTION AND DISCIONNECTION 11
TO PTO DRIVE 11
6.1 Safety rules 11
7. REPAIRS AND MAINTENANCE 12
7.1 Regular maintenance 12
7.2 Cleaning after use 12
7.3 Replacing the saw blade 12
7.5 Tensioning and replacing the V-belt 13
7.6 Consumables 13
8. HANDLING AND TRANSPORTATION 14
9. DISMOUNTING AND DISCARDING 14
AN OBSOLETE MACHINE 14
10. TECHNICAL DATA 15
10.1 Noise emissions 15
11. TROUBLESHOOTING CHART 17
12. OTHER AREAS OF POSSIBLE HAZARD 17
12.1 Mechanical dangers 17
12.2 Environmental dangers 17
13. WARRANTY 18
14. EC STATEMENT OF COMPLIANCE 19

3
Dear customer,thank you very much for your trust and preference in
choosing our equipment and joining the number of our best customers
in the world. We are confident that our equipment will be up to all your
expectations and assure you a long lasting quality and performance.
1.1 About this manual
Please take time to read this manual and learn to how operate and
maintain the saw safely.
For your easier reading this manual is laid out in several sections.
The sections are progressively numbered 1 through 13 and listed on
the “content” page.
The information, pictures and technical data in this document reflect
current or planned product features, functions, and characteristics as
of the publication date. Because of on-going product improvements
and feature additions, information in this document is subject to
change without notice.
If you are experiencing a problem or functional trouble on your ma-
chine, please read the “trouble-shooting” section to identify possible
causes and remedies.
When you have checked all the possible causes listed and you are
still experiencing the problem, ask your Authorized Service Centre for
help.
When you order parts maintenance or repair services, your Authorized
Service Centre, your dealer or eventually the manufacturer need your
machine serial number and engine serial number. These are the num-
bers that you have recorded on the product identification label of the
manufacturer on the machine.
1.2 Delivery and transport claims
Upon delivery of the machine please check for visual machine dama-
ges such as damaged packing or scratched buckled parts. If so, make
a remark on all copies of the delivery bill before signing for accep-
tance.
Should your shipper or the truck driver refuse to accept your claim,
fully reject delivery and make sure to inform us (the manufac-
turer) immediately. No claims shall be taken into account by the ship-
per or by the insurance company, if a reservation note is not made on
the delivery bill. All transport damages must be notified within latest 2
days from delivery.
1. GENERAL INFORMATION

4
Therefore delivery must be collected and inspected within this term.
Later claims shall be disregarded.
In case of assumed but not visually clear transport damages make
sure to mark the following sentence on the delivery bill : „Reserved
delivery due to assumed transportation damages“. Insurance
and shipping companies act with extreme caution in case of transport
damages and sometimes refuse to accept responsibility. Please make
sure to provide clear and exhaustive evidence (photos) of the claimed
damages.
Thank you in advance for your help and understanding in this matter.

5
Upper hood
Wheels
Log carriage
Saw blade
2. PRODUCT OVERVIEW
PTO with
gear
2.1 Circular log cutting saw with PTO drive
Blade shaft
Steel stand
Grip handle
Lower hitch
pins
Top hitch point

6
LABELS
1. Warning label
„Do not operate the machine in-doors!“
Never run the machine inside a closed area.
Exhaust fumes are toxic!.
2. Safety pictogram „Wear ear plugs and goggles!“
Loud noise can cause impairment or loss of hearing, wear a suitable
protective device such as ear plugs and safety goggles.
3. Safety pictogram „Direction arrow“
Motor, PTO shaft and driveline must be turning in the same direction
as shown by this arrow.
4. Warning label
max. 540 Rev./min. This label shows the
max admissible number of PTO shaft revolutions.
5. Identifi cation label „Product identifi cation“
This label shows the company details of the manufacturer and the-
main machine technical data.
6. „BGU-Maschinen Blue Line“
Manufacturer‘s Logo
7. Personal protection sign
Mind these instructions for safe operation!
3. SAFETY PICTOGRAMS AND WARNING
Fabriknummer
Typ ZWK 790 / 2
2132 12 Bj.12
Gewicht 198 kg
Sägeblattdurchmesser
max. Zapfwellendrehzahl
750/30 mm
540 1/min
Südharzer Maschinenbau GmbH
Helmestr. 94 99734 Nordhausen
179
Bezeichnung Wippkreissäge

7
8. Machine safety label
„Before operating the machine read this manual
and mind all safety instructions“
To avoid personal injury or death, carefully read and understand all
instructions pertaining to the saw including the engine manufacturer’s
operating and maintenace instruction manual.
9. Personal protection sign
“Wear suitable protective boots!”
This label shows that you must wear safety boots when working with
the saw.
10. Personal protecion sign
“Wear suitable protective gloves!”
This label shows that you must wear safety gloves when working with
the saw.
11. Machine safety label
Before setting-up, servicing, maintaining and cleaning the machi-
ne, disengage power and stop the engine. Lock the tool and secure
against accidental start.“
Keep your hands away from all moving parts!
Pinched hands danger!!
12. Machine safety label
„Read, understand, and follow all instructions in this manual and on
the splitter before starting“Keep at safety distance from the dange-
rous zone!
13. Safety-alert symbolmax. 540 Rev./min.
Read and recognize safety information. Be alert to the potential for
personal injury when you see this safety-alert symbol.

8
Strictly perform installation, set-up, maintenance, cleaning
and transportation with the motor switched off and the blade
firmly secured against accidental operation.
Immediately disconnect power off the machine in case of any
eventual fault or trouble.
The user shall strictly comply with these operation, set-up, mainte-
nance, repair and trouble-shooting instructions in order to assure safe
operation and no damages to the equipment. Moreover we recom-
mend to let the machine be run only and strictly by trained and skilled
staff who must be familiar with the applicable occupational safety and
health administration rules as well as applicable transportation rules.
Incorrect use of the saw can cause serious injury or death.
No person under school leaving age should operate a circular saw.
Those who have reached school leaving age but are below the age of
18 may operate a circular saw if supervised by a competent person of
18 years or over. The machine shall be installed and kept in a suitable
location selected by the customer for safest operation.
The working area around the machine must be kept as clear as pos-
sible from surrounding obstacles and slippery foundation floors should
be duly treated (do not use saw dust or wood ash for this purpose).
Make sure that the equipment stands on a safe stable foundation.
Do not allow within the hazardous zone any unauthorized third or per-
sons who are not familiar with the dangers related to use and opera-
tion of the machine. Allow no bystanders, especially children and pets
in the working area.
Also make sure to comply with the following provisions:
● Due and proper illumination of the working site must be provided at
all times.
● The saw blade must be duly sharpened for maximum performance
and no recoil danger. Flash and chips must be removed off the
crown wheel.
● Damaged or buckled blades (very likely to break during operation)
should not be used.
● Strictly ask a skilled licensed electrician for any repair of the electric
system.
● Always wear suitable hearing (ear plugs or muffs) and eye protec-
tion (goggles or safety glasses) while operating the machine.
● Ensure that a wide but confined area is available around the machi-
ne and assure maximum working freedom.
4. SAFETY

9
● Operators must wear steel toe safety shoes and snug-fitting tear-re-
sistant work cloths.
● No additional customised protections or tools should be provided on
board of the machine, other than the ones designed and supplied by
the manufacturer.
● Do not apply pressure (for instance by means of the wood stock)
against the blade to make it come to a quicker stop.
● The machine is not designed for indoor use (dust release).
● Never leave the machine unattended with the running motor.
● Before leaving the operator‘s station for any reason, stop the machi-
ne motor, disconnect power and secure the machine against acci-
dental operation.
4.1 Safety rules about saw blade
The unit is strictly designed for use with a 750mm (outer diameter)
blade.
Strictly use blades as per EN Standard 847-1.
Do not ever use worn out blades in need of sharpening.
Make sure that the blade shows good conditions, no damages, no
cracks, no buckling and no missing/broken teeth/bits.
Hard metal blades require special care and handling. Make sure that
the blade bits do not ever hit against hard surfaces (for example con-
crete floors), which might cause invisible bits damage.
Hard metal blades must be suitable to operate at 1800 revolutions per
minute.
4.2 Mandatory application field
These log-cutting saws are strictly designed for preparation of fire-
wood. Sawing to be strictly performed with wood stock on the log car-
riage. All other applications are forbidden and considered as “misuse”.
The manufacturer is not liable for any damage or injury resulting from
misuse!
The machine is capable to handle wood stocks in diameter of 8-30
cm. Shrubs and tiny branches bundles must be loaded on the carraige
and securely hold on both sides of the blade.
The machine is strictly conceived for ONE-MAN OPERATION ONLY.
Misuse will completely void your warranty. The manufacturer
accepts no liability for personal injuries and damages to other
equipment caused by misusing the machine.

10
This PTO-powered version „ZWK 790-2“ is an excellent machine with
inbuilt hydraulic system and PTO drive suitable both for firewood pre-
paration directly in the forest/wood (by simply powering it off your
tractor via a cardan shaft) and for stationary use in your yard.
A rugged all-steel construction assures longest machine life at any
operative condition.
This machine is specially designed to work with a 750 mm blade
approved and manufactured to EN 847-1.
When you switch the machine on make sure to check that the blade is
mounted to rotate in the proper direction before cutting any material.
The tool must rotate against the operator that is upward toward the
operator. If not, immediately switch the polarity in the plug of main
power cord using a phase changer. If you don’t feel familiar with
phase changing ask a licensed electrician to reset the saw cord.
Load the log in the carriage and smoothly push it to the blade.
If you working with twisted or crooked logs make sure to load
the log on the carriage, so that the bolged side of the log is
turned to the blade in order to avoid the log from tipping over
or jamming during cutting and consequent possible even ma-
jor damages to the blade.
Now fasten the grip on the log carriage and push to smoothly tilt it
over towards and through the blade.
NOTE: avoid excessive pressure on the carriage through the blade
with cutting. Excessive hold-down pressure may slow the blade down
and cause dangerous jamming!
When doing so avoid all jerky, bumpy movements that could lead to
risky and dangerous situations. Timber in maximum length of 1.1 m
must lay on the trough by the entire length with no projecting end. After
the first log is cut off the timber, let the carriage swing down to start-po-
sition (wide opened) before advancing the remaining timber to the blade
and starting a new sawing cycle. If you try to feed the stock forward and
cut before the carriage reaches back to start position, you may run the
risk of hitting the stock against the blade guard consequently causing se-
vere personal injuries and machine damages for which the manufacturer
carries no liability.
The ZWK790-2 model is provided with a PTO power arrangement. A PTO
shaft is an efficient means of transferring mechanical power between farm
tractors and implements. This makes the ZWK 790-2 model an ideal pi-
ece of equipment for those who want to process their timber in the forest
producing clean logs directly on the felling site with great savings in terms
of later cleaning and disposal of wood chips, bark and sawdust.
5. OPERATING INSTRUCTIONS

11
PTO-driven ZWK 790-2 models are equipped with a three-point linka-
ge to fit on the one available on your tractor. The drive shaft is going
to act as linkage and driving element between the tractor and the saw
and should be therefore duly mounted and secured by the special pins
available on the machine.
Make sure to perform accurate connection of your PTO drive shaft
both on processor and power input side. A pictogram on the drive
shaft showing a little tractor tells you which side must be connected to
tractor power output.
Press the detent lock inwards as you slide the machine shaft onto the
tractor PTO stub shaft. Slide the machine shaft forward far enough to
make sure the detent lock has snapped into the lock position.
Secure the drive shaft with the special restraining chain to avoid dange-
rous twisting.
For increased safety make sure that a minimum wrapping of 1/3 of
the total useful length is achieved. (see Figure 1).
Do not perform any repair, adjustment, cleaning or maintenance work
whatsoever while the machine is running (disconnect PTO-drive or
switch the motor off)!
Strictly use approved drive shafts of certified construction.
Always connect and secure the driveline in compliance with shaft ma-
nufacturer instructions.
Never use a PTO driveline without safety shield or with a damaged gu-
ard and make sure that the shield is of the correct size and length for
the drive shaft.
Before connecting/disconnecting the PTO-shaft make sure to switch
the tractor off to avoid possible damages to the shaft of the saw blade!
PTO-versions are stationary machines to be strictly operated on
ground.
6.1 Safety rules
Before connecting the drive shaft make sure that there are no by-
standers in the area between the tractor and the saw.
The working area around the machine must be kept as clear as
possible from surrounding obstacles. Standing in the dangerous
area of the machine will void any liability of the manufacturer.
6. CONNECTION AND DISCONNECTION
TO PTO DRIVE
Fig. 1
„Driveshaft coupling sche-
me“
Lu= useful length
Closed length = longest telescopic half
fully overlapping shortest one
Operating length = joint overlap by
approx 2/3 Lu
Longest (fully extended) length = joint overlap by
at least 1/3 Lu

12
7. REPAIRS AND MAINTENANCE
Fig. 2
„Direction of blade rotation“
Make sure that the machine is fully disconnected and all moving parts are
secured before performing any maintenance/repair work on the machine.
In the event of any malfunctioning, switch the machine off before trouble-
shooting.
7.1 Regular maintenance
The following tasks belong to ordinary maintenance works:
● Clean the machine from eventual residual wood, chips or dirt.
● Lubricate all moving parts.
● Grease all pivoting parts of the log carriage
Radial thrust bearings are to compensate the unavoidable production-
related range of tolerance. Lubrication of radial thrust bearings is NOT
required, as the thrust function is only used once at the time of as-
sembly, which means that the existing lubricant fi lm will remain on.“
7.2 Cleaning after use
Remove wood chips and saw dust produced and left on the machine
during work.
Clean the log carriage assembly removing all wood rests.
7.3 Replacing the saw blade
Safety note ! Wear safety gloves - pinched hands danger.
Before replacing the blade make sure to disconnect the machi-
ne from power (unplug the machine or turn the tractor off).
Following instructions apply for safe and proper blade replacement:
● Disconnect power off the machine (unplug power cord or stop the
motor of the tractor) and wait for the blade to come to a complete stop
.
● Tipp the upper blade hood over by releasing the hex-nuts.
● Release and undo the fi xation bolt on the blade clamping fl ange
using a spanner and hold the blade using another spanner to
secure the blade fl ange on the motor side as you undo the nut.
(this to prevent the blade from turning as you undo the bolt.)
● Remove the clamping fl ange.
● Pull the old blade off the shaft (make sure to wear tear-resistant
gloves. DANGER!).
● Fit the new blade on the shaft. Note direction of rotation. (see Fig. 2)
saw blade
log
carriage

13
● Mount the locking flange back on the blade shaft minding the right
position of the feather-key in the flange.
● Tighten the shaft nut to hold the flange securely in place! ATTEN-
TION to assemble the new blace follow the sequence: blade, exter-
nal clamping flange, washer, fixation bolt.
● Refit the blade hood in the original position duly set and clamped.
7.5 Tensioning and replacing the V-belt
If you are operating a ZWK790-2, proper maintenance requires
retensioning of the belt after a certain number of operation
hours.
To perform stretching of the V-belt, you need adjusting the special
screw after removig the gearbox cover and releasing the motor
fixation mount.
Adjust the V-belt so that you can still provoke an approx. 10 mm
of deflection by applying one finger tip pressure (see figure 3 -
Stretching a V-belt).
Refit the gear casing and the motor mount back in place before
operating the machine again.
Running the saw with a loose V-belt will cause increased wear
and shorten you belt life.
To replace the belt release the clamp-screws and remove the
safety guard from the V-belt drive area. Remove the old belts
from the sheaves and fit the new ones on. Make sure to refit the
V-belt casing back in place before operating the machine again.
7.6 Consumables
The machine is equipped with the following consumable parts for
which no warranty is given!
Circular saw blade (Part no. 90076 HM)
Wood strips (left:Part no. 56534, right:Part no. 56535 and
56536)
V-belt (Part no.54591)
Fig. 3 "Stretching a V-belt"
Center between
sheaves middle
axis
Approx. 10 mm deflection load

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Log & timber cutting saws are light equipment that can be easily mo-
ved on short-distance by means of two caster wheels and an ergono-
mic, comfortable grip handle located on the chassis on the opposite
side as the log carriage. In order to avoid infringement of the clearan-
ce area around the machine, the grip handle is retractable (push/pull)
on the model ZWK 790-2.
Simply fasten the grip and lift the saw for safe and rapid hauling of
the machine.
For safety reasons the grip handle should remain retracted (or lifted
up) during work to avoid risk of tripping or entanglement.
8. HANDLING AND TRANSPORTATION
When the machine is fully obsolete and cannot be of any longer use,
it should be duly dismounted ahead of discarding. Certain components
need deactivation and dismantling in order to assure that no further
use is made by other parties and that no worn out parts are recycled
for other applications.
During dismantle be alert for possible recyclable materials and compo-
nents that belong to differentiated waste collection procedures applica-
ble in your country.
The manufacturer is not liable and undertakes no responsibility for
personal injuries or damages that may result from the recycling of
worn out machine parts and eventual re-use in other applications dif-
ferent than originally stated in this manual.
Dismantling procedure:
Take good note please: each and every dismantling task must be performed
by authorized service centres or trained skilled staff only!
• Pull the machine down into single components
• Lock and clamp all moving machine parts
• Deliver each single component only to authorized waste management faci
lities
• Remove rubber and plastic parts from the machine that must be separately
disposed of.
Deactivated, clamped moving/driving parts and components are of no
further risk and danger.
Electric components must be separately disposed to avoid substantial en-
vironmental threat. In the event of fire on the electric deployment system
of the machine, use of an explosion-proof extinguish system is required
(for example powder fire extinguishers).
9. DISMOUNTING AND DISCARDING
AN OBSOLETE MACHINE

15
10. TECHNICAL DATA
ACCESSORIES*
On request the machine may be equipped with a special jaw for effi-
cient and safe clamping of the log after cutting.
(Code Nr.:91274)
10.1 Noise emissions
The noise level was measured in compliance with the general rules for
establishment of noise and acoustic pollution of garden and agricultu-
ral equipment on work sites as well as with other national standards
for noise measurement.
The applicable measuring parameters were:
Measurement on the machine front edge at 1600 mm height and
400mm away from the blade on the right hand side, while processing
beech wood in the size of 80+/-5% of the admissible timber diameter
as per this instruction:
Without
load
86 db(A)
With full
load
89 db(A)
Use of ears protectors is mandatory!
Technical data Unit of measurement ZWK 790 -2
Max. timber diameter mm 300
Saw blade diameter mm 750/30
Tractor power requirements kW 15
Max. driveshaft rev. number RPM 540
Speed Saw blade RPM 1480
Dimensions with opened carriage
Length mm 1120
Width mm 820
Height mm 1170
Weight kg approx. 198
* Accessories are no basic equipment, if requested, however, availably and there fore additional costs .

16
The above mentioned values are emission measurements and
may not be therefore assumed as for a safe work environment.
Although there is a relationship between noise emission and im-
mission levels, this is not a sufficient basis to determine the ex-
tent of on-site required protection. There are a lot of other fac-
tors that can influence site work and risk of injuries and namely:
the actual site/buildings configuration, the concomitant presence
of other noise sources (for instance other machines performing
other works in the neighbourhood) etc... The factors applied for
determining safety of a workplace may also very from one coun-
try to the other. We are reporting here the noise values detected
in the facility of the manufacturer on order to allow the user per-
forming a better evaluation of the possible risk/disturbance.

17
11. TROUBLESHOOTING CHART
The following section will detail procedures for checking your saw, should
you encounter a malfunction.
Important! Before setting, operating, cleaning, maintaining or repairing
the saw, read the manufacturer’s operating and maintenance instructions.
Trouble description Possible causes Remedies
The saw starts but the
blade doesn‘t operate
- Locking flange of the blade
shaft or of the motor is not
tight
- V-belt splits
- Tighten the bolt/nutn
- Optimize V-belt tension
Blade runs but in the
wrong direction
- Inverted phases - Change the polarity in the pha-
se changer or in the switch
Blade chops - Stump blade - Sharpen or replace the blade
Loud noise out of the
gearbo
- Oil in the gearbox is finished
or not enough
- Defective gearbox
- Provide oil touchup l
- Replace with new gearbox
12. OTHER AREAS OF POSSIBLE HAZARD
12.1 Mechanical dangers
Possible dangers related to machine moving parts (for example chain-
saw and v-belts) are minimized by means of suitable safeties and
protections that cannot be dismounted unless special tools and equip-
ment are used.
DANGER: removing or by-passing inbuilt machine safeties may result
into serious operator’s personal injuries.
12.2 Environmental dangers
The machine is strictly designed for outdoor applications.
DANGER: do not operate the machine indoors to avoid risk of inhaling
wood dust.

18
13. WARRANTY
All BGU machines are covered with warranty terms in accordance with
the law. Customers should promptly notify the manufacturer eventual
material or production claims on their detection. While asking for war-
ranty service, customer should show copy of their purchase invoice
or receipt. The warranty does not cover for faults due to natural wear,
temperature or weather agents as well as misuse, faulty installation
or set-up, improper operation and lubrication or acts of vandalism.
No warranty will be given on parts damaged by improper handling,
use and application. The manufacturer is further not responsible for
warranty service on machines used for other applications than men-
tioned in this manual, altered or modified by the customer or other
thirds, or overloaded. Never attempt to use an incomplete machine or
one fitted with unauthorized modification.
Any modifications to your machine can cause personal injuries, and
will void your warranty. Consumable parts with a prescribed life (i.e.
pulleys, tools and various auxiliary materials) are excluded from the
warranty as well as adjustment, optimization and fine-setting or retro-
fitting works.

19
We hereby declare that the equipment described in this manual responds in full to the actual version
brought on the market. We, the manufacturer further declare that this equipment was duly designed
and manufactured in accordance with the actual European Safety and Health Standards settled by the
relevant EEC directives as well as the latest electromagnetic standards issued by the European Council
by all member states.
This statement of compliance does not apply to customer modifications of the equipment without wit-
hout manufacturer’s written approval.
Date Jörg Kernstock (Management)
Official user language: English (User’s release)
04.09.2010
Machine type: Log cutting saw
Models: ZWK 790-2
Production Nr: see model label
Applicable European Standards: EC Machine Directive No. 42/2006
EMV (Low Voltage) Directive 95/2006
EC-EMV (ElectroMagnetic Compatibility) Directive 108/2004
Other applicable Standards: Full compliance to the European safety rules was assured by
enforcement of the following harmonised Standards:
EN ISO 12100-1:2009, EN ISO 12100-2:2009, EN ISO
13857:2008, EN 60204-1:2007, EN 1870-6:2010;
EN 847-1:2007; EN 55014-1:2006 ; EN 55014-2:1997+A1:2001;
EN 61000-3-2:2006;
Type-certification tests have been carried out by the following Official Certification Body, number
2157, in accordance with Annex IX of the EC Directive no. 42/2006. The product specimens were
found fully conformant to the applicable technical Standards and to the related control type which is
described in the technical documents and for which a type-approval certificated was already released.
Prüf-und Zertifizierungsstelle des
Spitzenverbandes der Landwirtschaftlichen Sozialversicherung
Weißensteinstraße 70-72
34131 Kassel
Registered with no. 2157
Person in charge of the technical documents: Jörg Kernstock (Management)
In accordance with the EC Machine Directive No. 42/2006 and EMV (Low Voltage) Directive 108/2004
14. EC STATEMENT OF COMPLIANCE
Südharzer Maschinenbau GmbH
Helmestraße 94 ∙ 99734 Nordhausen/Harz
Service-Tel. [phone] ∙ Fax [phone]
Internet: www.bgu-maschinen.de
e-mail: [email protected]

Südharzer Maschinenbau GmbH
Helmestraße 94 ∙ 99734 Nordhausen/Harz
Service-Tel. [phone] ∙ Fax [phone]
Internet: www.bgu-maschinen.de
e-mail: [email protected]
Subject to changes without notice
Form: 2132.31.05.2011 - Rev. A