Ross Controls CATEGORY 4 - 5_2 VALVES CROSSMIRROR SERIES 77 - Manual (Page 2)

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ROSS safety-related technology
has a long tradition...
For almost 40 years ROSS has been developing double
valves which have made a significant contribution to the
operating safety of pneumatically controlled presses. Du-
ring this period our range of double valves has been de-
veloped continuously in response to the needs of press
manufacturers and users. Monitoring devices have also
been offered in a variety of designs to satisfy different re-
quirements.
The range of double valves in 5/2-way configuration featu-
ring the all-new C
ROSS M IRROR ® -sensing system presented
in this leaflet incorporates all our experience and repre-
sents the state-of-the-art in ROSS double valves.
Selecting the double valve best suited to each application
requires considerable technical knowledge. If you need
further information or technical advice, please contact
ROSS or your nearest ROSS distributor or sales office.
CAUTION: On mechanical presses and other hazardous
machines with pneumatically operated clutches and bra-
kes double valves at least should be used. Double valves
without self-monitoring should be used only if current regu-
lations permit.
If the valves are used on presses in Germany, the
„Safety Regulations For Control Systems On Power-dri-
ven Presses for Metalworking zH 1/457“ must be obser-
ved.
For applications not covered by standard valves, please
consult ROSS. We reserve the right to make technical mo-
difications in the course of further product development.
Product description ........................................ Page 2
Specifications, model numbers ..................... Page 3
Dimensions ................................................... Page 4
Replacement parts ........................................ Pages 5, 6
Flow characteristics, valve response times ... Page 7
General information ....................................... Page 8
Cautions ........................................................ Pages 9, 11
Operating instructions ................................... Page 10
ROSS 5/2-way Double Valves with
C
ROSS M IRROR ® -Sensing
This all-new ROSS-Crossflow double valve with C ROSS M IR-
ROR ® -sensing is a 5/2-way valve with two individual soleno-
id pilot valves each actuating its own individual metal-
spool-sleeve valve element.
The spool-and-sleeve valve elements are arranged in par-
allel design and - as a safety-related feature - they are con-
nected by „crossflow“ channels. In case of normal valve
operation both spools move synchronously; when de-ac-
tuated, the spools are in the upper position; and when ac-
tuated, they are in the lower position. Because of their red-
undant design and their self-monitoring capabilities, ROSS
5/2-way-Crossflow double valves with C
ROSS M IRROR ® -sen-
sing provide a very high safety standard for the control of
single- or double acting cylinders or rotary drives.
Additional safety features are incorporated in the base. In
the event of loss of air pressure at the inlet port a check
valve is installed to trap the downstream air, a small bleed
orifice slowly relieves the trapped air. Additionally a small
two-way valve provides safety in the case where inlet pres-
sure is restored whilst the solenoids are still energized. To
guard against any sudden cylinder movement, this valve
provides a path to exhaust for one of the pilot valves which
puts the valve into an inoperable state until both solenoids
have been de-energized.
The new ROSS C ROSS M IRROR ® -sensing system is desi-
gned to exhaust the pilot supply to one solenoid pilot when
only one half of the valve is in an actuated position. This is
accomplished by connecting the pilot air supply system to
the main valve spool and sleeve. The connection is made
such that as the spool moves toward the actuated position
the pilot supply is vented to exhaust via the second valve
element. When the second valve element moves to the ac-
tuated position, it blocks the exhausting pilot air thereby
maintaining a constant supply. Pilot supply to the opposite
pilot is connected in a mirror image of the first pilot supply,
hence the name „cross mirror“.
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