What is an Anti-two-block (or A2B) system?
An anti-two-block system is used to prevent or warn the operator of a two-block condition on a crane. Two-blocking is the dangerous condition where the lower hook block is raised until it contacts any part of the boom tip hardware. The term comes from block and tackle terminology, describing when the blocks (or pulleys), upper and lower, come into contact with each other.
Two-blocking may occur while winching up, while telescoping the boom out, or when booming down (unless the winch is mounted on the boom). Continuing any of these actions will cause the lower hook block to be drawn over the top sheave or cause the wire rope to break - either of which will cause the load to fall out of control to the ground.
Why have an A2B system?
Required by jobsite rules. Get work on more jobsites with an A2B system.
Required by OSHA for manbasket work, lockouts also required.
Owner recognizes a cost savings due to reduced damage, downtime and repairs.
Owner wants accident protection for men and equipment.
Owner wants to meet current industry safety standards.
Why use a radio or wireless A2B system?
Eliminates cable reel cable problems and downtime.
Much easier, faster installation.
Lower purchase price and operating costs
Why buy a LIFTek A2B system?
Guaranteed lowest total cost: purchase price + operating cost = total cost
Most rugged stainless steel construction - OEM's agree
Longest battery life, 5 year battery warranty on the L25, with 8 year design life.
Fail-safe design - if the unit is damaged or stops working - it alarms within 30 seconds
"Portable" design, easily swapped or stowed, No DIP switches to set.
Designed for rugged boom truck service - use on any crane.
Fastest service - 99% same day turnaround on warranty or repair work
Pay for themselves in reduced downtime and repairs expense of cable reel systems
Made in U.S.A. - no shipping hassles
Always in stock for same day shipment
Free technical support for the life of the product
Works with any existing lockout hardware or use our low cost kits
Why is the transmitter battery so important in an A2B system?
The battery used in an A2B boom switch is critical to the reliability and operating cost of the entire system. LIFTek uses a high capacity lithium primary cell which costs about $45 to replace once every 5 to 8 years. This replacement cost may seem high initially, but using a battery of this type is actually far less expensive than using alkaline batteries.
The true cost of batteries is not just the cost of the cells (example: about $26 for AA alkaline batteries over the same time period), but the time and aggravation spent changing them when they get low every 6 to 12 months. Alkaline batteries have to be changed 8 to 16 times during the 5 to 8 year life of a LIFTek lithium cell. In rental fleets, sending someone out to change batteries for a customer can cost $50 or more every time. Downtime costs over the life of the system can really add up.
Also, the LIFTek battery has welded leads and gold contacts which do not corrode like other battery contacts in this low current application. In addition, the LIFTek cell has a 10 yr shelf life, and is much more reliable at low temperatures.
Why does LIFTek use an external antenna on the boom switch?
LIFTek uses an external antenna on the boom switch so that the boom switch enclosure can be made of steel (powder coated 304 stainless steel in fact). Internal antenna designs require that the switch enclosure be made of a plastic (non-metallic) material which leaves the entire switch weaker and more vulnerable to impact. The external antenna is coated stainless steel cable, which is very tough and because of its size, provides a very reliable and uniform radiation pattern.
Lift Truck Camera Systems
What is a Lift Truck Camera System?
A Lift Truck Camera System provides the lift operator with a clear view of the forks as they engage the load. Optionally, a wide angle view of the area behind the lift truck can be shown when the truck is put in reverse.
Why have a Lift Truck Camera system?
The main benefit of a fork camera system is fork HEIGHT information which can be very difficult for an operator to determine, except by trial and error.
As a result, the fork camera system...
- Reduces damage to goods, racking, containers, trucks, and forklifts
- Reduces safe cycle time, for new and experienced operators
- Reduces operator fatigue and safety hazards to personnel
When is a Lift Truck Camera System Used?
The LIFTek L70 Forklift Camera System is most cost effective when used for: high racking, non-standard rack heights, reach trucks, narrow aisles, truck unloading (eliminates blind spot at bed level), ordnance handling, label reading, cargo container handling, chemicals, push-pulls, roll handling and handling high value merchandise.
How does the L70 Lift Truck Camera System work?
The L70 uses a high quality 7" Color LCD monitor and advanced camera technology to provide ForkView and RearView images to the operator.
The view provided by the ForkView camera varies depending on the mounting location. A camera mounted near the center at fork level provides a view similar to that shown above. A fork mounted camera (usually the right fork) provides a view of both fork tips offset to one side. Either camera mounting provides the operator with fork tip HEIGHT information which is necessary for rapid, safe fork insertion.
Note that images from a ForkView camera can have "fisheye" distortion when wide angle lenses are used. This distortion tends to make straight edges look curved near the edges of the display, and there is little or no distortion in the center of the display where the forks engage the load.
The video from the ForkView camera may be sent to the display using a number of different methods depending on your application. Hardwire methods are preferred as there is no limitation on channels, the video quality is better and there is no video transmitter battery to maintain. Wireless video transmission may also be used in some applications.
The system also allows an optional RearView camera to be mounted on the operator's cage. This option is usually used on forklifts. RearView is automatically displayed (if a reverse signal is available) when the forklift is put in reverse. This provides the operator with a superior view of personnel, racking or other obstacles behind the forklift which are difficult to see under normal circumstances.
What about wireless?
Wireless video transmission is used when there is no hardwire video connection from the moving fork carriage to the drivers' station. In addition, typically there is no lift truck power available either on the fork carriage - so the camera and the video transmitter must be battery powered.
There are number of issues with using wireless in this type of application.
Battery Power: since the transmitter and camera are usually battery powered, the battery must be recharged or swapped on a regular basis. Depending on the size of the battery, operation times typically range from a few hours to 40-50 hours. Ok for occasional use - but not practical for multiple shift or high use.
Channel and Power Limitation: most analog video transmission is in the 2.4GHz band. There is room for only four (4) legal channels in the band at any one time and the FCC severely restricts transmission power. Unfortunately, many illegal transmitters (some with 8 channels, many with higher power) are imported and sold in the US. These transmitters use military bands below 2.4GHz and not for commercial sale or use. All are subject to recall if the seller or user is caught.
Signal Drop Out (multi-path fade): a common problem with wireless video is erratic signal loss when the transmitter is moving relative to the receiver (i.e. the fork carriage is moving relative to the drivers' station). This problem is reduced (but not eliminated) by transmitting at higher illegal power levels or at illegal lower frequencies.
Interference: 2.4GHz analog video systems operate in the same band as 802.11 digital wireless networks, 2.4GHz wireless phones, microwaves and many other devices. Operating a single video link is not usually a problem because the more adaptive data links can work around the analog channel. As more channels are used, data bandwidth (network capacity) is reduced or lost.
802.11 Cameras: So called "network cameras" can be used. The typical 802.11 digital network can handle about 3 cameras at one time which consumes most of the network bandwidth or capacity. Network cameras are a good way to transmit occasional video from a camera or DVR (digital video recorder) to a central location for review by management - if you have a wireless network already in place. Network cameras are not a cost effective way to provide an operator video from his forks.
Video Transmission in the 5.8GHz band is possible. At this time it is more expensive and is much more prone to signal drop out during motion unless special measures are taken.
Bluetooth operates in the 2.4GHz band also and - as of this time - is not capable of sending full motion video. A new standard for Bluetooth video is in the works, but even when implemented, will have about the same limitations as 802.11 video (see above).
In summary: hardwire video has the advantages of no batteries to charge or change, no limit on the number of systems working together, and no problems with radio interference between video and wireless networks, etc.
Can't I just buy a wireless camera and monitor myself?
Even a good quality wireless system has a number of issues (see above). Low cost "baby monitor" or security camera type wireless cameras systems have additional problems in this application as well: poor durability, very short battery life, poor picture quality, poor low light performance, difficulty of permanent installation, susceptible to voltage source noise on the truck, poor performance while forks in motion, etc. If you need a camera for a couple of lifts or for very rare use - something like this might work for you.
Is hardwired over the mast (OTM) or inside the mast better?
It depends. Coaxial cable for video over the mast has a very poor track record and typically fails due to fatigue of the inner conductor. Specialized high flex cables for video in built into the mast wiring is probably the best solution for reach trucks. LIFTek offers a selection of long life OTMV cables that will fit most reach trucks. Cable reels used on the mast are OK for low cycle use (unless a very expensive cable reel with long spring life is used). For most types of lift trucks, LIFTek hardwire coil cable systems are easy to install, easy to replace, cost less to start with and have a very long life.
Where is the best place to mount the camera?
In typical applications (forklift or reach truck) the operator is usually best served by having a camera at fork level or slightly above. You can place a camera most anywhere on the fork backrest and get a view that is somewhat useful for picking a load. Note that, as the camera gets higher above fork level, it is more difficult to determine fork height from the video image. In addition, with a high camera mounting, the view will likely be blocked by the load and not usable for placement.
Locating the camera lower is usually more difficult from a mounting standpoint but allows the operator to place the forks at precisely the right height and to see through the pallet and below the pallet - which is helpful when placing the load. Most LIFTek cameras are specially designed for mounting at fork level - to give you the best possible working view.
In non-standard applications, the best mounting depends on what you need to see in your application. LIFTek will work with you to determine the best possible mounting that your conditions will permit. We have a wide selection of special brackets and camera models and can make changes as needed to meet your requirements.
Which is better: color or black and white?
Historically, black and white cameras have had an advantage when it comes to low light and crisp high resolution images. However, because of the advances in color cameras, they work nearly as well in low light (or switch to black and white for low light) and are available in very high resolution at about the same cost. Operators tend to like the color better since it is easier use. Nearly all systems we sell are color.
What technical information is needed to order a system?
LIFTek needs to know the model number of your lift truck, the voltage, the maximum fork height, and the collapsed mast height. We will also ask about the application, the type of racking, the environment (lighting, indoor/outdoor, temperature, etc). This information is needed to specify the right components for your system. In special applications and on certain models we may request a few measurements and digital photos. LIFTek will also work with your local lift truck supplier to obtain the technical information needed.
What about installation?
LIFTek makes every effort to design and build systems that are easy to install. Installation time varies with the truck and type of system. The typical fork view system takes about 4 to 6 hours on the first unit and drops to about 3 to 5 hours for additional units of the same model. Rearview only systems are simpler and usually take about 2 hours. Most systems do not require drilling or welding and are powered by connection to a filtered and fused accessories terminal on the truck. Having wiring diagrams for the truck is best.
Facilities that have "in house" maintenance for their lift trucks can do the installation themselves. We recommend that facilities which use an outside vendor for lift truck service should also use that service for installation of the system. LIFTek provides free telephone support for whomever installs the system.
LIFTek can also provide on-site installation assistance, working with your in-house staff or lift truck service provider as needed. Contact LIFTek for details.