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4075

GMK 4075

Training Information

Telescope System
 Deutsche Grove GmbH

1.0 General description .................................................................................................1

1.1 Boom and telescope cylinder locking system ..................................................................... 1
1.2 Telescope cylinder ............................................................................................................... 1
1.3 Length and locking sensors ................................................................................................. 2
1.4 Service/emergency operation .............................................................................................. 2
2.0 Boom profile ...........................................................................................................3
3.0 Overview of telescope system.................................................................................4
3.1 Boom section & telescope cylinder locking pin arrangement............................................. 5
3.2 Operating principle.............................................................................................................. 6
4.0 Boom section locking pins ......................................................................................7
5.0 Telescope cylinder components ..............................................................................8
5.1 Slave cylinder proximity switches & solenoid valves......................................................... 9
5.2 Telescope cylinder locking pin proximity switches .......................................................... 10
6.0 Boom length cable drums......................................................................................11
6.1 Internal length drum .......................................................................................................... 11
6.2 Precision length sensor...................................................................................................... 12
6.3 External length drum ......................................................................................................... 12
7.0 ECOS brake range parameters ..............................................................................13
8.0 Emergency operation.............................................................................................14
9.0 Appendix drawing .................................................................................................15
9.1 Telescope control overview............................................................................................... 15

GMK 4075. Training information: Telescope system:

 Deutsche Grove GmbH

Telescope system
It is intended that the reader should make reference to the
electrical and hydraulic circuit diagrams for complete sys-
tem detail.

1.0 General description

See Appendix 9.1 for The boom consists of five sections with four fully powered
system control over- telescopic sections. Maximum section length configurations
view are 11.2 m / 19.2 m / 27.2 m / 35.2 m and 43.2 m. The boom
is lighter due to a new design shape (Megaform), which uti-
lises the lower radius of the sections for total area contact on
a continuous wear pad housed in each boom collar. This
design technology thus allows removal of high point-loading
areas and use of lighter materials.

The boom alignment is further maintained by two plastic

pads in the topside of each collar and two plastic pads on the
rear topside of each section. Additionally, in pinned posi-
tions, by steel side-pucks, which are installed in the rear of
each section. These align with, and butt against an adjustable
contact pad in the pinned positions.

1.1 Boom and telescope cylinder locking system

External boom section locking pin actuators are no longer
visible on the boom exterior. This new design uses an inter-
nal mechanism to operate the boom section and telescope
cylinder pinning. The telescoping sections are all locked
with two spring-engaged pins for each section. The pins each
have an internal connecting yoke, which engages with a trav-
elling hydro/mechanical mechanism on the telescope cylin-
der for operating each pair of pins.

1.2 Telescope cylinder

The telescope cylinder is single stage and uses a pin and
push principle to obtain the selected boom lengths with the
cylinder rod remaining anchored in the base section. The

GMK 4075. Training information: Telescope system: General description 1

 Deutsche Grove GmbH

cylinder barrel is positioned in the boom sections on guide

rails with support pads.

The telescope cylinder has two spring engaged, hydraulically

retracted pins, which engage in sockets at the base of each
boom section to lock the cylinder to the selected telescope
section. A small hydraulic slave cylinder is attached to and
mounted on top of the cylinder barrel. It is actuated with
hydraulic pressure via a transfer tube contained within the
main cylinder and is used to unlock the individual boom sec-
tions from each other. This is only possible when that partic-
ular section is locked to the telescope cylinder. When the
telescope cylinder is locked to a boom section, mechanical
butterfly levers (actuating arms) that are connected to the
slave cylinder automatically engage with the yokes on the
boom section locking pins. Operation of the slave cylinder
then unlocks the boom section. Subsequently, the cylinder
extends or retracts the telescopic section to the desired
length.

Selection control of telescope cylinder locking or boom sec-

tion locking function is by two solenoids, mounted on the
telescope cylinder barrel.

1.3 Length and locking sensors

Thirteen proximity switches, which travel with the cylinder,
indicate when the cylinder is in the correct pinning (locking)
position within the boom and the lock/unlock status of the
pins for both ECOS and EKS 4. Proximity switch informa-
tion is routed to ECOS-ESX 1 & EKS 4 via a recoil drum,
which is mounted on the rear of the boom base section.
Housed within the recoil drum are two potentiometers, which
provide telescope cylinder length information to EKS 4.

An additional precision length sensor, internally mounted to

the rear of the base section and driven by a steel cable
attached to the telescope cylinder provides telescope cylin-
der length information to the ECOS system. The sensor is
connected to ECOS via CAN-Bus and is set to a specific
channel by a selector switch under the housing.

1.4 Service/emergency operation

For service/repair operations the boom section locking pins
can be operated with manual release bolts that are accessible
from the outside of the boom. The telescope cylinder also
has hydraulic connections, which allow operation of the
locking functions with an external hydraulic supply (power
pack) for service or emergency operation, if required.

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 Deutsche Grove GmbH

2.0 Boom profile

The illustration below shows a cross-section view of the new
design shape (Megaform) with the continuous wear pad
arrangement. Although described as continuous, the lower
wear pad arrangement is in five segments with longitudinal
support ribs. These ribs are in graded sizes and are used to
correctly align the boom sections. It is therefore quite impor-
tant that they are identified and kept in their original loca-
Boom collar wear pads tions during any repair work (fig.1).

The rear section plastic upper wear pads have internal lubri-
cation hoses for grease application while the rear section
lower support pads are only lubricated on assembly (left).

Upper wear pads Anti-rotation weldments are fitted to each of the boom col-
lars to prevent rotational movement when installing the
swing-away jib.

Outer boom section

Wear pad segments
Lower support pads
Inner boom section
Adjustment ribs

Anti rotation weldments

FIGURE 1. Cross-section of boom profile & wear pad segments

Rear boom section steel side-pucks butt against adjustable

steel contact pads to maintain boom alignment between each
section in pinned positions (left).

GMK 4075. Training information: Telescope system: Boom profile 3

 Deutsche Grove GmbH

3.0 Overview of telescope system

This illustration shows the principle components with the
telescope cylinder located in telescope section 1. For longer
boom configurations it is necessary to extend the telescope
cylinder into the furthest required section to begin the tele-
scoping sequence.

Cylinder
locking pin
Cylinder
support pad

Tele cylinder
piston rod
Butterfly
levers
Tele cylinder
barrel
Slave Proximity
cylinder switches

Cylinder
guide rail

Tele 2
Tele 1
Base

Section
locking pin

Slave
cylinder
Butterfly
levers

Mechanical
release bolt Proximity
switches

Butterfly
levers
Section
locking pin Pancake
proximity
Cylinder switches
guide rail Tele cylinder
Cylinder
piston rod
locking pin
Cylinder Telescope
locking pin cylinder
Cylinder
support pad

FIGURE 2. Overview of principle components

GMK 4075. Training information: Telescope system: Overview of telescope system 4

 Deutsche Grove GmbH

3.1 Boom section & telescope cylinder locking pin arrangement

With all boom section pins locked, the telescope cylinder can
extend freely between sections whereby the butterfly levers
pass through or align with the relevant section locking pin
yokes depending on the selected configuration.

Two boom section engagement sockets in each telescope sec-

tion allow the telescope cylinder to lock to individual boom
sections. The telescope cylinder must be locked to a boom
section before the slave cylinder is allowed to operate.

Butterfly
levers

Cylinder
guide rail Tele cylinder
piston rod
Cylinder
locking pin

FIGURE 3. Telescope cylinder & boom pinning positions

GMK 4075. Training information: Telescope system: Overview of telescope system 5

 Deutsche Grove GmbH

3.2 Operating principle

The illustration shows the relationship of the telescope cyl-
inder to the boom and two pinning configurations. Fig. 4a
shows the cylinder pinned to telescope section 1 with the
boom section locked to the base section. Fig. 4b shows the
telescope cylinder pinned to telescope section 2 with the
boom section locking pins unlocked.

The boom configuration selection process can be carried out

in semi or fully automatic modes. Semi automatic requires
the operator to carry out the selection and pinning process
for each boom section, whereas in fully automatic the
selected final configuration is entered by the operator and
executed by ECOS control.

Fig. 4b Fig. 4a

FIGURE 4. Boom operating principle

GMK 4075. Training information: Telescope system: Overview of telescope system 6

 Deutsche Grove GmbH

4.0 Boom section locking pins

The boom section locking pins are operated (unlocked) by
engagement of the butterfly levers in the relevant pin yokes
and subsequent operation of the slave cylinder. The pins are
locked by an internal coil spring when the unlock command
is removed. For system safety the default (de-energised) set-
ting for all control solenoids is to lock the boom sections.

Boom section locking status is monitored by N/O proximity

switches, which are triggered by the slave cylinder position
to provide signals to ECOS and EKS4 for locked status and
only ECOS for unlocked status.

Telescope cylinder ‘pinning position’ position status is mon-

itored by two N/O pancake proximity switches (left) for
EKS4. Too low/too high and ‘pinning position’ status for
ECOS is monitored by two N/O pancake proximity switches
(right). All pancake switches are triggered by the boom sec-
tion pin yokes with circuit integrity for all boom proximity
switches being continuously checked via integrated resistors.

S2111 Locked S3702 Locked

Boom section locking pins S2110 Unlocked

Safety lip
S3710 RCI 2 S2116 Too low
S3709 RCI 1 S2117 Too high

Manual release bolt

Coil spring Proximity switch trigger by pin yoke

FIGURE 5. Boom section locking pins & proximity switch layout

GMK 4075. Training information: Telescope system: Boom section locking pins 7
 Deutsche Grove GmbH

5.0 Telescope cylinder components

The telescope cylinder is connected to the boom base section
by the cylinder rod with the cylinder barrel and connected
pinning head providing the motion for pinning/telescoping
functions. Hydraulic supply to the cylinder for pinning func-
tions is via an internal transfer tube with two cylinder
mounted electrical solenoids controlling the selection of pin-
ning and holding functions.

The telescope cylinder rides on guide rails (fig.6 item 15)

within the base of each section with the head of the cylinder
riding on a support assembly within the sections (left).

1 2 3 4 5 6 7 8 9 10 11

12 13 14 15
Cylinder component legend:
1. Differential relief valve
2. Holding valves x 2
3. Emergency hydraulic connections
4. Electrical connection (Canon plug)
5. Pancake proximity switches x 4
6. Butterfly levers
7. Slave cylinder proximity switches x 3
8. Slave cylinder
9. Control solenoid Y2130
10.Control solenoid Y2131
11.Electrical connection box
12.Emergency ball valves x 2
13.Telescope cylinder locking pin
14.Telescope cylinder locking pin proximity switches x 6 (3 right + 3 left)
15.Telescope cylinder guide rails

FIGURE 6. General view of telescope cylinder components

GMK 4075. Training information: Telescope system: Telescope cylinder components 8

 Deutsche Grove GmbH

5.1 Slave cylinder proximity switches & solenoid valves

The slave cylinder is hydraulically operated with an availa-
ble pressure of 100 bar via the internal transfer tube. Two
leak-free solenoid valves are installed for cylinder functions.

Solenoid Y2130 is used to select slave cylinder or telescope

cylinder functions, and defaults (de-energised) to slave cyl-
inder (boom section pins).

Solenoid Y2131 is used for holding functions to maintain the

selected function position e.g. unlocked boom section pins
while the telescope cylinder extends or retracts. This is nec-
essary as the transfer tube supply would otherwise be
adversely affected by the volumetric change due to extension
or retraction.

The three N/O proximity switches monitor the position of

the slave cylinder and provide locked/unlocked status signals
to ECOS and EKS4.

To ensure system safety, hydro-mechanical safety interlocks

prevent the boom section and telescope cylinder pins being
unlocked together.

See superstructure hydraulic system for interlock details.

S2110N: Unlocked boom section (ECOS)

S2111N: Locked boom section (ECOS)
S3702N

S3702N: Locked boom section (EKS4)

S2111N

S2110N

Y2130: Select boom/Tele-cylinder pins

Y2131: Hold selected function position

Y2131 Y2130

Slave & telescope

cylinder interlocks

See fig.5 for detail of pancake switches

FIGURE 7. Detail of slave cylinder proximity switches & solenoids

GMK 4075. Training information: Telescope system: Telescope cylinder components 9

 Deutsche Grove GmbH

5.2 Telescope cylinder locking pin proximity switches

To monitor the locking status of the telescope cylinder pins
six N/O proximity switches are installed with three switches
for each of the left and right pins.

The switches have integrated resistors, which allow continu-

ous checking of the circuit integrity. Any detected switch
errors will be displayed on the ECOS display.

Each set of switches is installed on a mounting plate, which

is recessed into the cylinder pinning head and retained by
two capscrews. Prior to changing a switch the installation
depth of the switch should be checked.

See super electric/electronic for further switch details.

S2113N: pin unlocked (ECOS)

S2115N: pin locked (ECOS
S3708N: pin locked (EKS4)

S2115N S3708N

S2113N

Right hand view of telescope cylinder

S2112N: pin unlocked (ECOS)

S2114N: pin locked (ECOS)
S3706N: pin locked (EKS4)

S3706N S2114N

S2112N

Left hand view of telescope cylinder

FIGURE 8. Views of telescope cylinder proximity switch installation

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 Deutsche Grove GmbH

6.0 Boom length cable drums

There are three length measuring drums for the boom func-
tions.

6.1 Internal length drum

An internal length drum mounted on the rear underside of the
base section carries the telescope cylinder circuits for sole-
noids and proximity switches. Additionally, it carries two
potentiometers and A/D boards to provide telescope cylinder
length information to EKS4.

The drum carries 26 slip rings of which six are silver with
the remainder being rhodium. Typically, silver circuits are
used for large current loads (valves etc.) with rhodium cir-
cuits for small current loads (proximity switches).

Drum cable con-

nects directly to
canon plug on tele-
scope cylinder

Installed view of internal length drum

Access plug for

potentiometer
adjustment

EKS 4 analogue to digital

CAN bus transmitter boards
View of internal length drum with cover removed

FIGURE 9. Internal length drum

See electrical schematic 03054330 for drum detail and EKS4

documentation for further details.

GMK 4075. Training information: Telescope system: Boom length cable drums 11
 Deutsche Grove GmbH

6.2 Precision length sensor

For pinning function length calculation ECOS uses a preci-
sion length sensor with a measurement resolution of 1-mm.
The unit is bolted to the rear diaphragm plate of the base sec-
tion and is driven by a wire cable, which is attached to the
telescope cylinder.

The length data is transmitted to ECOS by CAN bus link and

requires a channel setting of 4 beneath the access plug on the
cover. If the unit is replaced the channel must be set prior to
installation and a length offset calibration must be made with
the GMK 4075 Service software.

Set channel to pos 4

beneath access plug

FIGURE 10. Precision length sensor

6.3 External length drum

An external length drum is installed on the boom base sec-
tion and carries out total length measurement for EKS4 and
provides hoist limit, anemometer and swingaway lattice/
power tilt jib control functions.

The drum carries 18 slip rings of which six are silver with
the remainder being rhodium. Typically, silver circuits are
used for large current loads (valves etc.) with rhodium cir-
cuits for small current loads (signals).

For length measurement two potentiometers and respective

A/D boards are contained under the plastic cover housing.
An access plug in the housing allows easy adjustment of the
length potentiometers.

See electrical schematic 03054331 for drum detail and EKS4

documentation for further information.

GMK 4075. Training information: Telescope system: Boom length cable drums 12
 Deutsche Grove GmbH

7.0 ECOS brake range parameters

To enable precise pinning functions it is neccessary that
ECOS takes control of the telescope cylinder speeds while
travelling in the base (foot) of each section and on the
approach to pinning positions.

Brake range1 = Inhibit high-speed and reduce to joystick

command level. This dimension is 500-mm on retracting and
extending.

Brake range 2 = Control block ramp down from joystick

command to (3) 10%. This dimension is 150-mm on retract-
ing and extending.

Brake range 3 = 20-mm approach to pin hole target.

Speed = 10%.

Brake range 4 = 50-mm approach to pin hole target.

Speed = 3%.

10% (3)
3% (4)

20 mm 50 mm
Pin hole
Brake Brake Brake Brake
range 1 range 2 range 3 range 4

Section 1 Boom section pin

Tele cyl pin will travel needs 18-mm to lift
5-mm to pick up section from setdown
boom section to reach hole centre
Base

Offset boom pins = distance for tele cyl to pick up section = +5-mm +18-mm to
lift boom section pin to hole centre = 23-mm.

FIGURE 11. Brake range diagram

Note: the above is only an example, do not change parame-

ters without engineering approval.

GMK 4075. Training information: Telescope system: ECOS brake range parameters 13
 Deutsche Grove GmbH

8.0 Emergency operation

Should it ever be necessary, the telescope cylinder carries
emergency hydraulic connections, which allow operation of
the slave cylinder (boom locking) or telescope cylinder lock-
ing pins.

The emergency connections consist of two quick-connect

couplings for hydraulic supply and two ball valves, which
are used to select slave cylinder or telescope cylinder lock-
ing pin operation.

Emergency
hydraulic
connections

Ball valve for

Tele cylinder
locking pins

Ball valve for

boom section
locking pins

FIGURE 12. Emergency connections

See operators manual for further details.

GMK 4075. Training information: Telescope system: Emergency operation 14

 9.0 Appendix drawing

9.1 Telescope control overview

GMK 4075. Training information: Telescope system: Appendix drawing

Int length drum

13 proximity switches monitor all pinning positions
Precision length
Control
block

Joystick

LS

Engine

Hyd pump P1 Accelerator

Deutsche Grove GmbH

Active display
15

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