Workstation Cranes: An Ergonomic Solution For Workpiece Handling
Article by MHI Industry Group Blog, MHI Ergonomics and Safety
To help workers lift, handle, and move heavy objects both safely and ergonomically, workstation cranes can be installed within individual manufacturing and assembly work cells. Designed to handle loads up to 4,000 pounds, these systems reduce the physical exertion, fatigue, and risk of injuries associated with lifting and pushing or pulling loads. They also provide precise load positioning and improve productivity while enabling load handling to be managed by one individual, enhancing safe distancing practices.
Workstation cranes are dedicated to a specific area or location. They are typically equipped with a hoist, balancer, vacuum lifter, or intelligent lifting device with holding and orienting devices such as slings, grabs, spreader bars, custom end effectors and magnets. Once connected to the load, the system moves it throughout the work area, reducing the need for a worker to bend, stretch, or strain to position the item.
Once the load has been raised, the operator guides and positions the full system manually; alternately a powered end truck or trolley moves it mechanically. Either way, the effort required to push and pull heavy loads is significantly reduced — typically to 1 pound of force required for every 100 pounds of load — enhancing operator ergonomics.
Two main styles of workstation cranes are offered, including:
Freestanding: Also known as “floor mounted,” this style features supports that hold the crane in place by being securely mounted to the floor. Normally designed for a rectangular work area, these cranes put no stress on the building’s structure. These systems require a reinforced concrete floor and are easy to relocate if processes or production needs change.
Ceiling Mounted: To keep the work area as open as possible, many companies turn to ceiling mounted cranes that place all parts above the work being performed. By mounting to the overhead support structure of the building, these cranes allow for more freedom of movement since the floor mounted support pillars are eliminated.
The selection of a floor mounted workstation crane versus a ceiling mounted crane is based on numerous factors. Many older facilities may not be able to adequately support a crane from the building’s structure, which eliminates the possibility of using the ceiling mounted crane. Additionally, depending on the work being performed, there may be numerous parts, lines, pipes, etc., already running overhead. At times, these can interfere with an overhead crane, and makes a floor-mounted system more appealing.
While workstation cranes are an ideal choice for users who view ease of movement and ergonomic benefits as high priorities, other options exist for moving products within a manufacturing plant:
Jib Cranes: The most common type of these cranes features a rotating boom attached to a vertical mast that is affixed to the floor. Many floor mounted jib cranes may rotate a full 360 degrees, thus providing a large circular area in which work may be performed. Most of these cranes feature heavy-duty base plates for installing to the floor, however, some may require a new foundation depending on the size, span, and capacity of the crane. Jib cranes may also be designed for affixing to a wall or pillar, and some come with “fold-away” features that allow the user to place the crane against the structure when not in use. An electric chain hoist affixed to the boom via a trolley is the most common form of lifting device used with jib cranes.
Gantry Cranes: Mobile, these cranes feature a beam supported by two (or more) legs that travel on wheels, casters, or on rails embedded in the floor. This crane is frequently used by maintenance crews who must work in numerous areas throughout the factory. A trolley and hoist connected to the beam handle the lifting and positioning of the load; the wheels provide lateral movement. Gantry cranes come in multiple configurations to accommodate a variety of application needs and are not dependent on the building structure.
Want more recommendations for improving the ergonomics of your workforce? The members of the Ergonomic Assist Systems & Equipment (EASE) Industry Group of MHIrecently discussed the topic in MHI Solutions, in the article “Ergonomic Workstations: It’s Not a One-Size-Fits-All Approach.”