New Danfoss VLT® Decentral Drive E cient, reliable and powerful

Cantilever axis assists
tobacco-cutting skates
WINCHESTER-BASED
Garbuio Dickinson makes
tobacco-cutting machines
with a near-vertical action that
minimises compression of the
tobacco.
The machines are fed by
vibrating tray feeds that
need to be removed for
cleaning. The 1,800kg
feeds are usually moved
manually on air skates.
“One customer however, wanted to take things a stage further
and asked if we could devise something which would actually pull
the feeder accurately into the machine,” says Garbuio Dickinson’s
senior design engineer, Peter Todd. With only a 5mm clearance
between the feed tray and the cutting machine sidewalls, he
needed to find a linear motion system that would avoid contact
between the two, and tolerate contamination by tobacco dust.
Garbuio Dickinson chose HepcoMotion’s DLS3C linear actuator,
which uses an aluminium beam to provide rigid support for
cantilevered loads with minimal inertia. The actuator’s drive is
mounted on the carriage and not connected to the end-plate, so
the motor, carriage and cables remain stationary while the beam
moves. For added safety, an overload clutch on the motorised
gearbox limits the push/pull forces.
The tray actuator that Todd designed consists of two linear
systems, linked by a common shaft to ensure it moves in and out in
parallel. The moving tray is supported by a pivoting mount that
allows the connecting end of the tray to rise and fall as the feeder
is lifted by its air skates.
“In the event, with the air skates activated, the system wasn’t that
dependant on being powered,” says Todd, “but the design of the guidance
system has proved a major factor in the success of our product.”
Screwjack goes with the flow
A screwjack system is helping
to control the flow of one of
Britain’s shortest rivers – the
River Morar which links Loch
Morar to the sea, a few
hundred metres away, on
Scotland’s west coast. The jack
raises or lowers a sluice gate
at a weir near a hydroelectric
dam and fish ladder at the
west end of the Loch.
The 100kN rotating screwjack
in a ram-style linear actuator
design, is used, with a motor
and reduction gearbox, to
raise or lower the gate to
control local water flows.
Garbuio Dickinson’s feed tray movement
system relies on a pair of linear actuators
(under the tray) linked by a shaft
A screwjack controls the level
of Scotland’s River Morar
The screwjack operates over a
stroke of 2,350mm, pivoting on its integral trunnions located midway
on the ram's outer tube. At the end of the ram, a clevis end with
spherical bearing connects the jack to the weir gate.
When the jack was first installed in 2001, it was driven by a 2.2kW
geared motor with position feedback coming from end-of-stroke
limit switches and an absolute encoder that links back to the control
system. Since then, it has been upgraded by replacing the motor
with an alternative with an integrated handwheel. The screwjack was
supplied by Power Jacks, the Scottish linear actuation specialist.
No more
corkscrews
New: Chainflex ® CFBRAID.
Braided control cable. Corkscrews are now finally a
thing of the past, thanks to the way we braid our cables.
Available as 4-core or 8-core. Shielded and unshielded.
Also the very latest:
Chainflex ® CFLG.T: Now 21% thinner
Chainflex ® CFBUS: Now with UL/CSA
Chainflex ® CF98: Now 4xd
igus ® (UK) Limited 51A Caswell Road Brackmills Ind. Estate Northampton NN4 7PW
Phone 01604-677240 Fax 01604-677242 sales_uk@igus.co.uk
www.drives.co.uk November/December 2010 27