This Gunnebo Johnson SB 2S 3B T single sheave snatch block with tailboard has a 2.2-ton working load limit. The 3" sheave can be used with wire ropes from 5/16 to 3/8" thick (sold separately). This single sheave snatch block with tailboard is suitable for use in industrial lifting applications.
Hoists are devices that use relatively small amounts of force to lift, lower, and pull heavy loads. Manual hoists transfer a small, hand-exerted force either across a series of gears to multiply the force into one large enough to lift the designated load, or over a pulley, drum, or sheave to leverage the force into one strong enough to lift the load. This makes it possible for an operator to manage heavy loads. The manual force is usually applied using a hand chain, lever, or lever ratchet, lifting the load by a hook attached to a chain, rope, or wire. Hand chain and lever hoists commonly use mechanical disk brakes called Weston-style brakes that hold the load in place while the operator's hands are released to make the next pull, secure the load once it has been lifted, and control the descent of the load as it is lowered. Ratchet puller hoists commonly use ratchets instead of mechanical brakes to secure and control the load. Manual hoists are commonly attached to or suspended from structures by hook or trolley mounts, and are used in the transportation, construction, manufacturing, mining, and material handling industries, among others.
Load capacity is the maximum rated load a hoist can handle. While manufacturers may indicate they have tested a hoist beyond its limits, operators should never attempt to lift a load heavier than the maximum rated load. Pull force describes the amount of force that needs to be applied to lift a load. If a 1/2 ton manual hoist specifies a pull force of 40 lbs., for example, the operator needs to be able to pull a 40 lb. weight in order to lift the maximum 1/2 ton (500 lb.) load. Headroom is the distance from the bottom of the load hook to the top of the hoist. This is the minimum amount of vertical space needed for the hoist to hang freely and operate correctly. Lift is the maximum vertical distance the load hook can move a load.
Gunnebo Johnson manufactures lifting systems, fastening systems, traction systems, block products, and telesteps, among others. The company, founded in 1879, is headquartered in Tulsa, OK.