Vacuum Gripper (VG)

EDCO ER-10L Coxial Venturi Technology

10L-series nozzles have been specifically tuned and optimized to provide the high-flow mid-range vacuum that a typical industrial system requires. This vacuum pump can efficiently handle a wide variety of both porous and non-porous applications at only 72 psi (5 bar) air supply.

Additional benefits of the EDCO ER-10L venturi are rugged metal nozzles, no internal flap valves to foul, and a large nozzle throat gap that allows ingested debris to pass through and out the exhaust. When coupled with the PP or LP purge options, debris too large to pass can be expelled between cycles.

Centralized Systems

A centralized system has one “central” vacuum pump supplying all vacuum cups in the system so all cups operate at the same system vacuum level. This vacuum level is affected by the flow capacity of the vacuum pump and the aggregate system leakage. System internal volume is increased by the necessary vacuum hoses, manifolds, and tubing in a centralized system. The increased volume results in a longer evacuation time for the system to attain a safe vacuum level.

Centralized vacuum pumps are necessarily oversized to provide enough extra vacuum flow capacity to overcome normal porosity and cup wear. However, in instances where there is gross leakage caused by non-sealing vacuum cups due to missing or damaged work pieces, pump capacity can’t overcome the leakage and system vacuum level can be reduced to the point where it is unsafe or impossible to pick up the work pieces. Interdependence of all suction cups in a system is not desirable so EDCO has developed components such as Flow Sensor Valves and Dual-Flow valves to make centralized systems perform better by limiting, the flow loss from non-sealing suction cups.

Part quick-release, or blow-off, is accomplished by injecting a blast of compressed air through an isolation check valve and into the centralized vacuum system somewhere prior to the suction cups. This pulse of air quickly dissipates system vacuum but, since flow follows the path of least resistance, most of the air can flow out of the pump exhaust instead of to the suction cups.

Operating Pressure

Operating a vacuum generator at a lower pressure will not, per se, result in reduced energy consumption. Energy usage of air-powered devices is measured by the volume flow rate of compressed air. Operating one machine device at 45 psi, for example, will not reduce the overall energy consumption of a manufacturing plant because of all the other machine devices that still require higher air pressures to function properly. The central compressed air system must be tuned to continuously provide at least the minimum air pressure required by any device in the plant.

To make direct comparisons possible, air consumption at different operating pressures must be converted to a "standard' or "naturalized" volume at standardized atmospheric conditions. For example, either 1.0 cfm (28.3 Nl/m) at 87 psi (6 bar) or 1.36 cfm (38.5 Nl/m) at 60 psi (4 bar) are equivalent to 6.9 scfm (195 Nl/m) at standard atmospheric conditions and are thus equivalent compressor loads.

Compressed air systems are designed with receivers (storage tanks) that are charged with high pressure air to serve as accumulators that can supply air flow in addition to what the compressor can produce for short periods of time. During extreme peak demands, the stored high pressure air may be drawn down, or depleted, causing the delivered system pressure to dip below optimum pressure. For this reason industrial machines are commonly designed to operate at only 80 psi, but some plants with marginal air systems may require machines to operate at only 60 psi. Systems that are optimized to operate at reduced air pressure should include air regulators set to deliver the proper minimum design pressure otherwise air consumption (energy costs) will be increased substantially whenever the system air pressure is higher.

Discrete Systems

A discrete system is made up of several mini-system units. Each unit consists of a small vacuum pump coupled to a single suction cup so that each unit operates independently of the others. Leakage at a non-sealing cup can only affect the vacuum level of that single cup so any leakage problems are automatically isolated. This gives the overall system the best possible chance to operate reliably even with a reduced number of active cups.

An EDCO Vacuum Gripper integrates a vacuum pump and suction cup into one compact unit to eliminate all excess system volume so that evacuation time is minimized.

A discrete system may be split into several zones that are each controlled by separate air supply valves to allow operation of one, several, or all zones as the application requirements change. All discrete units in a zone are simultaneously turned on or off via the compressed air supply - however, each mini-system unit still operates independently on the vacuum side.

Part quick-release is accomplished by blocking the pump exhaust with an air piloted piston which causes the pump air supply to flow directly into the vacuum cup because there is no other possible flow path. This positive pressure reverse flow not only provides a very fast part release but also provides a cleaning action to purge any debris that was ingested into the suction cup.

Rugged Shear Mount Key

Two-point mount with shear keys eliminates the possibility of pumps shifting out of position during operation. Work loads are efficiently and directly transferred to the mounting profile so that mounting screws carry only tensile loads.

Simple Installation and Flexible Positioning

Vacuum Grippers mount easily to extrusion profiles having 5/16" (8mm) T-slots so they can be easily repositioned to accommodate changing handling conditions. The two-point mount provides security and rigidity.

Positive Pressure Purge (PP)

Air pressure supplied to the venturi is diverted to the vacuum port by blocking the venturi exhaust with a piston operated by a pilot pressure signal. Push-in tube connector swivel accepts 5/32 (4MM) tubing. Tool separation movement must begin immediately (no dwell) when purge signal is initiated to prevent excessive positive pressure inside suction cups due to forces pressing the tool onto the work surface. Do not use PP option with vacuum switches due to the limited over-pressure capability of switches.

Limited Pressure Purge (LP)

Similar to Positive Purge except includes an orifice in the purge piston. Purge air flow is not as robust as with the PP option, but air pressure is limited inside the suction cups.

How to Order

	Vacuum Port		Venturi		Purge (10L Venturi Only)*		Swivel Mount^a		Sensor Port		Cup Selection
VG	38	—	10L	—	PP	—	PS	—	A5F	—	B50N
	38 = 3/8 NPSF 18 = G1/8 NPS		10L 10 09 07 05		(Blank) = No Purge PP = Positive LP = Limited		(Blank) = No Swivel Mount BS = Ball Swivel PS = Pin Swivel		(Blank) = No Port A5F B5F^b		(Blank) = No Cup
	38 = 3/8 NPSF 18 = G1/8 NPS		10L 10 09 07 05				^aonly available on VG38		^bSwivel not available with this option on VG38		See Information Below
					*VG38 or VG18: For non-porous applications, any ER-series venturi nozzles can be selected for reduced air consumption. However, the PP and LP purge options are not available with these nozzles.

Cup Selection

Choose suction cup style, size and rubber material from section 2 of this catalog and add this information as a suffix to the VG pump model number. For example; VG38-10L-PP pump and XP-B50N cup are selected, so the complete Vacuum Gripper model number would be VG38-10L-PP-B50N. For simplified ordering, several Vacuum Gripper model numbers are tabulated, but other combinations are readily available at standard prices – contact your local EDCO USA distributor or call EDCO for assistance.

VG18 style pumps should only be used with 10 to 50mm cups due to the availability of fittings required to adapt to the G1/8" NPSF vacuum port.

VG38 style pumps should only be used with 40 to 150mm cups due to the availability of fittings required to adapt to the G3/8" BSPP vacuum port.

ER-10L Performance in Non-Porous Systems
Cup¹	B30	B40	B50	B75	B110	BF80	BF100	F75	F110	FC75	FC100
Volume: cu.In (cc)	0.61 (10)	0.9 (14.7)	2.0 (32.8)	6.7 (110)	19 (311)	1.8 (29.5)	4.9 (80.3)	1.2 (19.7)	4.3 (70.5)	2.3 (37.6)	4.9 (80.3)
Evacuation Time²: sec.	0.013	0.02	0.04	0.15	0.42	0.04	0.11	0.03	0.1	0.05	0.11
Force @ 15 inHg: lb (N)	4.1 (18.2)	7.3 (32.5)	12.1 (53.8)	30.8 (137)	64.1 (285)	35 (156)	65 (289)	37.5 (167)	78.3 (348)	29.1 (129)	53.3 (237)
¹Values apply to all cup materials. ²Evacuating to 15 inHg (50.8 -kPa) at 72 psi (5 bar).

Evacuation Time

In a non-porous system evacuation time for any vacuum cup is calculated by multiplying the internal cup volume by the time factor for the desired vacuum level from the Evacuation Time Calculation Table.

For example: XP-B75 @ 15 inHg (50.8 kPa):

	Volume cu. in.		Time Factor sec. / cu. in.
Evacuation Time =	6.7	x	.022	= 0.15 sec

RS18-10L Evacuation Time Calculation Table
TableVacuum Level: inHg (-kPa)	9 (30.5)	12 (40.6)	15 (50.8)	18 (61)	21 (71)
Time Factor: sec./cu. in.	0.008	0.014	0.022	0.036	0.061