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Vacuum handling systems stress safety and speed
By Mary Gannon | August 26, 2020
Ergonomic and versatile vacuum lifters address today’s logistic bottlenecks.
Grant Welch, Manager, Handling Systems, Schmalz Inc.
Online shopping has been growing at a rapid clip in recent years and, with the Covid-19 pandemic, that trend is further accelerating. Web sales are up significantly year over year as the widespread coronavirus keeps many shoppers at home and away from physical stores. Total U.S. online sales reached $73.2 billion in June, up 76.2% compared with $41.5 billion a year earlier, according to research from Adobe Analytics.
Manufacturers, distribution centers and transporters are facing added pressure to move more goods quickly and safely. That holds for both the logistical flow of wares in fulfillment and distribution centers, as well as for producers that must handle, transfer and package products within individual plants.
The often-manual tasks mostly involve lifting, rotating and carrying. For instance, products are typically loaded into cardboard boxes or crates, which are then picked up and moved from conveyor belts to a transport trolley or stacked on pallets.
Companies therefore need to optimize their handling processes in terms of speed and efficiency, but at the same time protect the health and safety of their employees. Thus, there is a heightened interest in ergonomic lifting devices.
Vacuum tube lifter
Schmalz, an experienced manufacturer in this field, designs individual handling systems and crane systems that improve the pace of material flow and reduce costs — all while maintaining a keen focus on ergonomics.
As one example, Schmalz has developed the JumboFlex vacuum tube lifter for dynamic handling of workpieces weighing up to 110 lb (50 kg). It consists of a vacuum generator, lifting unit, operating unit housed in the handle, and a vacuum gripper. The device attaches to a supporting bridge, gantry or jib crane.
The JumboFlex is characterized by its lifting unit, essentially a flexible tube that contracts and extends to raise and lower loads. To pick up and lift a product, a vacuum pump, blower or ejector generates a vacuum in the system by continually evacuating air. The resulting difference between negative pressure and ambient pressure draws the workpiece to the gripper. Once the item has been secured, a change in flow rate causes the lift tube to contract and lift the load.
To lower and release, the control element feeds atmospheric air back into the system. Vacuum level reduces and causes the lift tube to expand and lower the load. Height is precisely controlled by metering the amount of atmospheric air that is fed into the system. Maximum venting via the operator handle completely eliminates the vacuum and releases the load.
The control handle fits comfortably in one hand and lets the operator work for extended periods of time without fatigue. Operation is extremely intuitive with simple one- or two-finger control.
The system is suited for machine loading, shipping and picking, and many other lifting applications. An extensive range of available grippers makes the lifter ideal for a wide variety of objects such as boxes, bags, barrels and wooden boards. These include simple, round vacuum cups for compact goods such as cardboard boxes and buckets, and cups with a skirt for optimal sealing on plastic bags and shrink-wrapped packages. Other versions include double- and four-head suction cups for open, clamped, glued or larger flat workpieces. And universal grippers with multiple cups are suited for boxes that vary in size and shape. Such devices can safely lift a load even when the suction area is not completely covered.
Operators can swap out grippers quickly and easily without tools using an integrated quick-change adapter. And with a 90° slewing mechanism, workpieces can be gripped on the side and automatically swung into a horizontal position.
Like the vacuum grippers, other system components can be configured to meet individual customer specifications. That includes several types of vacuum generators. For instance, EVE electric vacuum pumps feature short evacuation times, low power consumption and are available in versions with 25, 40, 50 or 67 m³/hr suction capacity. Or users can opt for the SBPL, a basic ejector with low compressed-air consumption and a maximum suction rate of 52 m³/hr.
An optional SRC remote control for vacuum generators lets workers switch the unit off and on during work breaks directly at the operating element. The SRC has an integrated induction generator and requires no external energy. It operates at the push of a button and saves up to 40% of the energy consumed versus systems that run continuously.
The JumboFlex vacuum tube lifter provides a maximum lifting stroke of 5.9 ft (1.8 m) and maximum lifting speed is 3.28 ft/sec (1 m/sec). The large effective suction area confers safe, secure and damage-free gripping by using vacuum. Only one person is needed for handling, productivity increases thanks to reduced loading times, and there’s minimal downtime due to employee injury.
Schmalz also offers several other versions of vacuum tube lifters which differ in form and function, and are designed for specific applications. For example, the JumboFlex High-Stack helps ensure optimal use of vertical space in storage areas and transport equipment for workpieces weighing up to 110 lb (50 kg). With traditional lift systems, maximum stack height is usually 1.70 m, about 5.5 ft. To facilitate ergonomics, the company developed the JumboFlex High-Stack that can pick up boxes and bags off the floor and stack them to a height of 8.4 ft (2.55 m), all while maintaining an upright posture.
It includes a sturdy lifting tube and integrated rotary union for continuous swiveling of the device. An extended, ergonomic one-hand control handle and guide bar controls up and down movements. A second guide bar lets the operator use the other hand to easily maneuver the vacuum tube lifter. Handle length and guide bars are adjustable.
To prevent the unintentional release of workpieces from a sizeable height, the High-Stack is equipped with a special release mechanism that ensures the operator can only release an object using a second control button. Again, the standard quick-change system lets operators replace the extensive range of grippers without tools. Vacuum generation is by means of an electric-driven pump or ejector.
If jobs call for handling larger and heavier loads, Schmalz’s JumboErgo shares many characteristics of the JumboFlex but with a lift capacity of up to 660 lb (300 kg). One main difference between the two is the configuration of the operator handle. Instead of using just one hand, the user operates the JumboErgo with both hands, to always maintain full control over heavy objects regardless of size and shape.
A twist grip on the JumboErgo is designed like a motorcycle throttle for lifting, lowering and releasing the workpiece. The length of the operator handle can be varied, which helps ensure that workers always maintain a safe distance from the load. Thus, outsized or hefty items like boards, boxes, sacks and rubber bales can be moved gently and precisely.
A modular system lets users easily configure multiple vacuum grippers that can be custom tailored to a specific application. And among the vacuum pumps offered is the SBV electric vacuum generator. This continuously variable, frequency controlled blower adjusts power consumption to match changing loads and thus operates with high efficiency. The SEM ejector, another option, is a compact, high flow rate compressed-air vacuum generator for workpieces weighing up to 187 lb (85 kg).
To complement the various handling devices, Schmalz makes an extensive range of crane systems with lift capacities to 2,204 lb (1,000 kg). Column-mount or wall-mount jib cranes made of aluminum are often recommended. They combine low-friction operation with lightweight components. This increases efficiency and working speed without impairing positioning accuracy or ergonomics.
With a maximum jib length of 6 m and a swivel angle of 270° for the column-mounted jib crane or 180° for the wall-mounted jib crane, a vacuum tube lifter can cover a significant operating range. The crane system can be adapted to the existing infrastructure at a minimal cost while permitting a high degree of flexibility.
Get a grip
Engineers at Schmalz have collaborated with ergonomics researchers at the Technical University of Munich to design three new operator handles for the JumboFlex vacuum tube lifter. Regardless of whether users are right or left-handed, the devices enable load movement with minimal effort and fingertip control over lifting, lowering and releasing of goods. The new control handles can increase safety, and simplify or accelerate the handling process.
The JumboFlex Safety+ operator handle focuses on optimum safety. To release a workpiece from the vacuum tube lifter, workers must use both hands to operate a release lever and a control button at the same time. The two-hand concept controls release and protects particularly delicate items. Disabled users can also work safely with the Safety+. The option to adjust the lowering speed directly on the handle using a screw provides additional protection. The unit accommodates all JumboFlex lift capacities (44, 77 and 110 lb).
The JumboFlex Easy-Release control system also has an additional release lever. However, its function and operation are entirely different. Pressing the control button and auxiliary lever immediately reduces residual vacuum. This makes it much easier to set down a load, especially when handling airtight objects or when using large suction cups or grippers with bellows cups.
To prevent the release lever from unintentional actuation that prematurely reduces the residual vacuum, the lever remains locked until the control button is fully depressed. In contrast to the Safety+, the user can carry out the handling process with one hand — leaving the second hand free to align the vacuum-gripped load.
Whereas the Flex Easy-Release is designed to be locked in place, the JumboFlex Quick-Release allows loads to be deliberately ejected during lifting. With this product, the aim is to shorten cycle times when robust workpieces need to be moved quickly — for example when handling baggage at an airport. A second control element releases the goods immediately. Like on the Easy-Release, the release lever is attached to the operator handle but is not locked in position. Workers can actuate the lever at any lifting height.
Both the Easy-Release and Quick-Release products are only designed to accommodate the largest JumboFlex configuration with a lift capacity of 110 lb. As always, different suction cups can be used for different workpieces.