We can safely say that almost every person has seen this useful device, like a cable tensioner. Many people even know how to use this device. However, few people know that of this device there is a name - it's a lanyard. This word was coined by professional riggers. In our article we will talk about lanyards, their key features, as well as tips for proper use.
Application of lanyards - where are they used?
This type of tensioner is widely used in the field of cargo and maritime transport. Today it is impossible to imagine a single heavy or oversized load that would be secured without the help of lanyards. Thanks to special design, the device has the ability to cope with very heavy loads, the mass of which reaches several tens of tons. Initially, craftsmen used a mechanism to connect metal and wooden structures different types and types.
A lanyard is a device that is ideal for securing loads when rigging work ah, and also the transportation of goods. For example, the mechanism will be indispensable in cases where it is necessary to install bulky antennas or metal structures.
Modern lanyards are made from high quality of stainless steel. Due to this, the mechanisms are resistant to the destructive effects of corrosion. To enhance performance characteristics, as well as to increase the level of reliability, strength and durability of the device, they are often coated with various coatings. Galvanized lanyards are very popular, the cost of which is slightly higher average price for similar devices.
At the same time, the cost is completely justified. The bottom line is that metal cable tensioners are usually used to secure loads outside, under open air. Therefore, they are exposed to environment. If you purchase a tool coated with zinc, then you can forget about the problems associated with deformation or destruction due to precipitation.
When purchasing cable tensioners, the first consideration should be the thickness and length of the ropes and cables that require a turnbuckle to handle. Despite the fact that they are capable of withstanding colossal loads created by multi-ton objects, the parameters of the lanyards themselves are compact. Thus, the sizes range from several to tens of centimeters. By choosing the right mounting tensioner for cables, you can count on successfully securing the necessary objects.
Lanyard from the inside - how it works
Externally, the lanyard resembles a regular coupling, which consists of several screws. The peculiarity is that the screws have threads with the opposite direction. Another important element any lanyard is a metal base onto which screws are screwed. As a rule, the base has a cylindrical shape. However, reasons are not always used. Simpler and more primitive models are equipped with special rings. Naturally, the metal base provides greater strength and reliability of the device. In any case, the mechanism works by tightening the screws closer to the center. The result is the maximum tension of cables, ropes, belts or ropes, depending on what exactly is being tightened by the lanyard.
Cargo transportation and rigging are not the only areas where tensioners are used. For example, lanyards can be used in everyday life, in particular, for tuning a piano (tensioning the strings to achieve a better sound), as well as, if necessary, tightening fastenings for curtains.
In most cases, devices for working with cables are made open, that is, the screws for adjusting the tension force are visible. The body can be made by casting, welding or forging. Next stage technological process consists of milling two holes, through which you can change the force and length. Regardless of the production method of each specific part that makes up the tensioner, the device itself is made by turning.
The design of any lanyard is represented by the following main components:
- Metal body
- Two screws with opposite threads
- The head of a screw, which is made in the form of a ring, hook or fork.
It should be noted that there are also models with closed type screws that are required to ensure additional protection transported goods, since it will take more time to loosen the screws. In addition, closed lanyards are in demand when working with heavy, huge objects in difficult weather conditions.
Turnbuckles for ropes - their main types
When buying a lanyard for tensioning cables, you must decide on its marking, as well as the features of each specific model. There are several types of devices for fastening goods:
- 1. O+O – there are rings on each screw head
- 2. C+O – there is a ring and a hook on the heads
- 3. C+C – the lanyard is presented in a configuration with two hooks
- 4. B+B - there are plugs on the screws
These are the most popular models that are this moment presented on the market. To increase the tension or loosen it, you need to rotate the screws, as a result of which they will move either from the center or towards the central part of the device. In the first case, the tension force will decrease, while the movement of the screws towards the center indicates an increase in the tension force of the cable. There are reinforced models called cargo lanyards. A special feature of such devices is strong and durable steel that can withstand enormous loads. Thus, cargo mechanisms weighing about 25 kilograms ensure the securing of objects with total mass up to 90 tons.
To increase tension, you need to rotate the screws
We also note that lanyards of the “hook-hook” type have found application in cases where the load is attached to durable products such as antennas, masts, as well as cables or ropes. If you purchased a device with the “ring-ring” type, then to secure such a lanyard you will need a hook-shaped object. Otherwise, it is not possible to secure the O-shaped tensioner. The moving elements of such mechanisms contain a special thread necessary for adjusting and changing the length of the cable. IN modern devices additional devices appear, the task of which is to change the level of tension smoothness. The area of application of such devices is stretching fiber-optic cables under light loads.
When working with lanyards of the above varieties, you should take into account the fact that their use is strictly prohibited for fastening load-bearing structures. In this case, the “fork-fork” option on the heads of the screws can help. A very popular and sought-after version of tensioners. Using such a device, riggers are able to quickly adjust the length of the cable and its tension level. However, this tool is not suitable for lifting objects. Its main purpose is to belay, stretch, and adjust the suspension.
In some situations, chain lanyards are used, which can boast a significantly longer length. Thanks to this feature, the tool can be used to grab two or even more objects in order to pull them together, setting a certain level of tension.
Proper operation of lanyards - what is the secret of successful operation
The cable lanyard should only be subjected to the loads for which it is designed. In the event of deformation of any individual elements due to increased loads, it is necessary to immediately respond to what is happening: reduce the tension level of the cables and replace components that have failed. Moreover, such actions must be performed with the utmost care and attention, so that the tensioned cable does not destroy the mechanism and cause you harm.
Radial or lateral loads significantly reduce the lifespan of devices, since lanyards are not designed to test such loads. In this regard, constant monitoring of the tool is required before, during and certainly after work. Any deformations, even the smallest and insignificant at first glance, are unacceptable. Choosing correct device for working with loads of appropriate dimensions and weight, you will minimize the likelihood of device failure.
- Applying Lubricant
- Polishing with a felt wheel
- Flushing with gasoline
- Drying the tool
One of the most common problems with tensioners is a tightly stuck lanyard, the screws of which can be incredibly difficult to unscrew even for physically developed men. To avoid such problems, it is necessary to use special lubricants, including those containing molybdenum bisulfate or graphite, and also periodically rinse the device in clean fresh water.
As you can see, the lanyard is an excellent tool for performing complex work related to transporting heavy loads, as well as securing them. A proper care will ensure long and trouble-free operation of the mechanism.
When using metal ropes, it may be necessary to fasten them together or form loops at their ends. A steel cable clamp will help you cope with this task effectively. We will describe below what modifications exist and how to use them.
Purpose and design specifics
These devices are made of durable materials - it is thanks to metal that reliable fastening, withstanding increased loads. Structurally, the clamp consists of an arc and nuts.
It is advisable to use several clamps - professionals advise using at least three. However, if the load is excessively high, then it is better to choose other fixation methods and refuse installation large quantity clamps.
High-strength steel is additionally treated with galvanization. Such protective layer protects elements from corrosion and also minimizes the impact of other external factors.
To prevent disengagement and breakage, you should learn how to use the cable clamp correctly. There is nothing complicated about this - just put the ends under the arc and tighten it with nuts. They twist in different directions, and the rope remains in the spaces between them.
The nuts must be tightened until the cable is completely tightened. If a loop is being created, the cut end should be on top, above the whole piece, but directly below the arc. Clamping element– nuts – will be at the bottom.
Classification of devices
You need to select clamps taking into account the specific conditions of their use, the characteristics of the cable used and the planned load. In terms of size, you can choose a wide variety of modifications - they can be small 3-5 mm in diameter, but there are also larger ones up to 40 mm.
Most often used in everyday life conventional designs, which are made from second class steel after galvanization. They have a loop at the base that is clamped with bolts. However, professionals demand reinforced modifications with a more durable shutter. Therefore, they are oriented towards increased load levels.
Steel or copper is used for manufacturing, although in some cases it is permissible to use only an aluminum cable clamp. But galvanized steel will be a more expensive option, but will allow fasteners to be used in harsh climatic zones.
The design also varies - they can be single or double, have a flat or arched design. Flat models have two galvanized steel plates with a diameter of 2-40 mm.
Fastening is done using bolts and nuts. Their use is effective when splicing cables and carrying out other similar manipulations. To connect, you need to install more than two devices.
Double cable clamps are distinguished by the presence of two fixing bolts, while single clamps have only one bolt-nut pair. Their operating principle is almost identical.
The arcuate structure has a cylindrical shape with an arched convexity. There are bolts at the ends that provide fixation. Most often they are used in connecting operations, but fastening a loop is also acceptable. This is an industrial version of fasteners that can withstand a load of at least 97 kg.
The crimp clamp is made from aluminum alloy. It looks like an oval piece of pipe with a slight flatness on both sides. The cable is inserted into this section, and the structure is flattened in two ways:
- impact with a hammer;
- manually by pressing.
Specific types of clamps
Since fastening units in construction experience dynamic loads, and loads often rise to a height, spring mechanisms are used here.
Thanks to them, not only the usual fastening of cables is carried out, but also the fixation of objects. Structurally, they have levers with moving brackets. As a result, the object can be fixed on the cable, regardless of its thickness.
Wedge connections are indispensable for working with copper and aluminum wires with a cross-section of 35-100 square meters. mm. They are a body made of cast iron steel with a wear-resistant wedge made of bronze or aluminum alloys.
For greater clamping reliability aluminum wires For large sections, special gaskets made of the same material are used. The fastening will be strong, but the bolts should be tightened every 7-10 days.
Selection and use
The photo of cable clamps shows various modifications that can be used for a specific installation purpose. It is important to check:
- presence of markings;
- absence of defects and defects;
- compliance of the clamp with the parameters of the rope.
When fixing the rope, the jumper should be on the side of the rope where the main load is present. Before use, check the tightness of the fastening. It is not allowed to influence the mechanism by welding.
The use of clamps allows for reliable and durable fastening when connecting cables or forming a loop. You can make them yourself, but purchasing factory-made products will ensure the durability of the fasteners.
Photo of cable clamps
A cable lanyard is a device that is widely used for installation, construction and rigging work. Thanks to this intermediate link, the tension of cables, ropes and cables can be easily adjusted. You are probably familiar with it, but you didn’t know its wonderful name!
What is this intricate tool used for?
Since the cargo lanyard has a special design, this allows it to withstand high stress and force, even when working with fairly heavy loads. Initially, this device was used to connect wooden and metal structures of the most various types. It is often used during rigging work, when it is necessary to secure transported or mounted equipment, or any other heavy load. If you need to install a metal mast or antenna, then this tool will help you cope with it.
Metal appliances tend to rust if they are exposed to moisture for some time. But a stainless lanyard is protected from this disease, since it is made of special steel or treated with a zinc coating. This measure was developed for the reason that this element is very often located outside the fixed structure, and therefore is always exposed to the influence of the atmosphere.
It is necessary to choose this device based on the length and thickness of the ropes or antennas, and, despite the impressive tasks, they are solved by such little ones as lanyards, their sizes vary from 5 to 20 mm. The overall success of any construction process depends on the choice of installation device. First of all, you need to decide why it is needed. Most often, such an element is used precisely to connect and tension cables or ropes on which a heavy load will be attached.
How does this mechanism work and why?
In order to understand the structure of this device, you need to pay attention to the drawing, The lanyard from the outside looks like an ordinary coupling, which consists of two screws. Moreover, the screws used are those on which the opposite thread is applied. They are then screwed into a metal structure, often cylindrical. If this device is not available, then you can use a special ring. Thanks to the metal structure or ring, the screws are “pulled” closer to the center, resulting in tension.
Also, in addition to rigging work, this device is widely used at home, mainly when it is necessary to tighten curtain fasteners, tune a piano (achieve a better sound, tighten the strings).
Often such a tool is made open, that is, the adjusting screws are visible. Its body is made by forging, welding or casting. After this, two holes are milled, which allow you to change the length and force using screws. They are made by turning. In cases where work is carried out in difficult weather conditions, a closed lanyard is used. Most often, this tool consists of three parts: a body, two screws (with right-hand and left-hand threads) and a screw head (fork, hook or ring).
Types of devices for tensioning cables
Before purchasing a tensioning device, you need to understand its markings., namely: C+C – hook and hook, C+O – hook and ring, O+O – ring and ring. These are the most commonly used, but there are others. In order to tighten or loosen the tension, it is necessary to rotate the “ring”, after which the screws will move either towards the center or away from it. The type of tool depends on what kind of work you are going to do. Galvanized tools are used when you need high tension force. The cargo type is used when it is necessary to either tighten the cables or attach a heavy load. Such devices can reach a weight of up to 25 kg, and this tool can withstand up to 90 tons.
The “hook-hook” type of device is used when it is necessary to change the length of a cable, mainly when installing masts or antennas. The “ring hook” is also used in such cases. The moving parts of this version of the device have threaded threads, thanks to which the length can be adjusted. There are also now options using modern technologies, using which you can adjust the smoothness of the tension. Such tools are used when working with fiber optic cables. In order to tension wires and cables under light loads, you can use closed tools.
In such cases there is no clear meaning permissible load, so you need to be guided by the facts. It should also be remembered that such devices are not used for load-bearing structures. The fork-fork option is very popular and is used quite often. It allows you to quickly change or adjust tension and length. However, this tool is not used for lifting loads. It was created in order to adjust suspensions, braces and belays. But the chain lanyard is longer than its counterparts; it is able to grab two objects that are relatively far from each other, and then pull it together, giving the required tension.
Successful work and proper operation of the lanyard
Forces that act on the mechanism of this instrument, should not cause deformation during loading. If this happens, then the tension must be reduced, and the parts that have undergone deformation must be replaced. If there is a chance of shock loading or critical mode, then before starting work, you must clearly select the product to be used. The permissible load is only permissible along the axis line. There should be no overload.
The products are also not designed to withstand lateral loads. The tensioner used must always be checked before and after work for compliance with safety standards, otherwise unacceptable critical deformations may occur. If you calculate the measurements correctly and follow everything the smallest details, and also carry out preventive work and inspection of the condition of the tool, it will last as long as possible long term, and the likelihood of its breakage or deformation will be minimized.
Before starting work, it is recommended to wash the tool with gasoline, if possible polish it on a felt wheel, apply lubricant and run it dry. The best lubricants in this case are those with the addition of graphite or molybdenum bisulfate. It is recommended to turn them during work (two or three times will be enough). If the work is carried out in difficult climatic conditions, where humidity is high, then spilling will not be superfluous. fresh water on the mechanisms, which will allow you to wash off salt water. Exactly these simple rules will deprive the user of many problems, in particular, the painful unwinding of a “stuck” lanyard.
Thus, thanks to universal tool, you can do both simple work (tensioning strings, curtains) and complex work (tensioning ropes or carrying heavy loads without using additional accessories). Also using this mechanism, you can achieve best indicator vertically when installing the antenna or mast.
Installation of cable wiring
Installation of electrical wiring is carried out in two stages.
At the first stage in the workshop they prepare electrical wiring elements, complete anchors, tensile structures and supporting devices.
Measuring the cable required length and “charge” one end of it into the lanyard ring, at the other end they make a loop under the hook or close it on the lanyard if tension couplings are used on both sides. The cables are connected to the end fasteners by installing a loop at the end of the cable. different ways, for example, using the so-called thimble and bolt clamps.
Drawing. Making the end loop of the cable: a – cable termination diagram; b – thimble; c – bolt clamp-clip.
The sequence of operations to complete the loop is as follows.
The cable is looped around the thimble and a clip-clip is attached to the end of the cable (stage 1). The second clamp is attached as close to the thimble as possible (step 2). Install the remaining clamps between the first two (step 3), while tightening the clamp nuts with force, but not tightening them completely. [ Total clamps in the loop is determined by the calculated pulling force of the cable, which in turn depends on the length of the cable wiring span, the mass and number of electrical products attached to the supporting cable.] If a “slack” of the cable has formed between the clips, then it is eliminated by tensioning the end of the cable that goes around the thimble , and then finally tighten the clamp nuts.
Drawing. Bolt clamp K676 for making an end loop support cable
Below are several videos that show the principle of making an end loop on a support cable using various clamps.
Drawing. Making a loop on a support cable using a pressed sleeve
The sequence of operations is as follows. The cable is threaded into the sleeve with a loop so that its end protrudes from the sleeve by 1-2 cm. Next, the sleeve will be crimped using a special tool - a press (manual, electric, hydraulic), having previously selected a matrix for it (the size of the matrix depends on the type of sleeve, used for crimping). Crimping begins from the middle of the sleeve, then crimping is performed from the edges of the sleeve. After crimping is completed, its quality is checked using special templates.
You can make the end loop of the support cable without using special devices(clamps, sleeves, etc.) and tools. In this case, the end of the cable is woven in a special way into the main part of the supporting cable. It should be noted that making a loop using this method requires much more time.
If steel wire or rod rod is used as a cable, loops at the ends are made without the use of clamps, by simply twisting the wire into a spiral at a length of 60-80 mm.
In addition, execute end seal the support cable can also be installed without organizing a loop, using special tips mounted on the cable by crimping. An overview of these mounting products, as well as an example of how to terminate a support cable, is shown in the video below.
After completing the end seal of the supporting cable, branch, connection and input boxes are installed on the cable wiring and secured. Pre-measured wires and cables are attached to the supporting cable; the distance between the points of attachment of the cable to the supporting cable should not exceed 50-60 cm.
At the second stage carry out installation of cable wiring to building structures at the installation site. Lamps are attached to the wiring, as a rule, at the second stage of installation, when the cable wiring is unwound on the floor, temporarily suspended at a height of 1.2-1.6 m for straightening the wires, hanging and connecting the lamps (if they were not mounted on the cable line in workshops). Then the electrical wiring is raised to the designed height.
Install the end fastening structures to building elements buildings and structures.
The most reliable fastenings of anchor structures to building surfaces are fastenings in brick and concrete walls and floors using through bolts and through anchors or fastening anchors using through studs with installation with reverse side fastening of enlarged square washers. In anchors with such fastenings, the pulling forces correspond to the actual strength of the material from which the anchor is made, depending on the grade of steel and the cross-section of the threaded part of the fastening rods.
Drawing. Execution diagram end fastening using a through anchor bolt
Fastening of anchor structures to walls and ceilings is also carried out using grease-in pins or expansion dowels. Such fastenings are less reliable, since they largely depend on the quality of workmanship and the accuracy of the prepared holes in size and the reliability of embedding anchors in them. Therefore, these methods of fastening anchors are used for less responsible intermediate fastenings load-bearing cables and guy ropes.
Drawing. Scheme for performing end fastening using: a – grease-in pins; b – spacer dowels.
Fastening of anchor structures to metal trusses and building structures is carried out using crimped steel fasteners or similar parts, as well as using bolted connections or welding the anchor along its perimeter using electric welding.
Drawing. Diagram of end fastening to metal elements building structures using: a – crimping steel fasteners; b – welding.
TO wooden bases The tension cable is secured with metal screws and a hook.
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In each individual case, the choice of anchor design and method of fastening is made depending on specific local conditions, the material from which the parts of the anchor structures are made, and the compliance of the design with the calculated pull-out force created by the cable wiring.
Drawing. Installation of cable wiring
The suspension of the supporting cable and its tension is carried out as follows. First, the cable is pulled along the length of the wiring and one end is secured to the end anchor structure. Tensioners(turnbuckle, anchor bolts) must first be loosened (so that there would be movement afterward to adjust the degree of tension of the cable). Then the support cable is pre-tensioned. Depending on the length of the span, pre-tensioning is carried out: for small spans - manually, and for large spans - using blocks, pulleys or winches. The cable is tensioned until the calculated sag is obtained, but with a force not exceeding that permissible for a given load-bearing cable. The tension force of the supporting cable is monitored by a dynamometer connected in series with the cable of the pulley or pulley. The final tension and adjustment of the supporting cable is carried out by tightening the previously loosened tensioning devices: turnbuckle (tension coupling), anchor bolts.
The cable sag in spans should be within 1/40-1/60 of the span length. Splicing of cables in the span between the end fastenings is not allowed. To prevent lighting wiring from swinging on steel rope guy wires must be installed.
After tensioning the supporting cable, it is grounded.
To connect the ends of a cable or rope, as well as to form loops at the ends, they are used different varieties steel, copper or aluminum clamps. Relating to rigging fasteners, cable clamps are used in elevator facilities, when carrying out various installation work, as well as in everyday life.
Types of clamps
To ensure durability and reliability, everything structural elements Clamps are made of stainless steel, and for light operating loads - also of copper, brass or aluminum.
The most popular are:
Features of using different types of cable clamps
Main technical parameters of the products under consideration are the maximum cable diameter and the guaranteed clamping force. The dimensions of the clamp are also important, since it is recommended, regardless of the type, to use several clamps in series (at least three), especially if the weight of the load does not guarantee its safe movement or lifting.
Clamps according to DIN 741 are used for ropes with a diameter of 5...62 mm, in the presence of a spring washer in accordance with GOST 6402-70 and a nut in accordance with GOST 5915-70. The design of this clamp allows for the installation of a locking bar, which provides more reliable clamping of the cable to the bracket. The clamping block must be made by stamping from steel grade no lower than St.3kp in accordance with GOST 380-94 (only for small clamping forces cast blocks made of steel 25L in accordance with GOST 977-75 are allowed). It is not allowed to use cable clamps whose parts do not have a protective anti-corrosion zinc coating.
IN fasteners flat clamps thread according to GOST 24705-81 must be used. The material of the linings is steel St. 3, the plates should be used for fastening cables with a diameter of 4.6...30 mm.
If several clamps are used in series, the distance between them should not be less than six cable diameters.
In Duplex type double clamps the shear force is absorbed exclusively bolted connection, therefore the choice of fastener diameter is determined by the diameter of the cable. The following ratios are recommended:
- For cables with a diameter of 2 mm and 3 mm - M4 fasteners;
- For cables with a diameter of 4 mm and 5 mm - M5 fasteners;
- For a cable with a diameter of 6 mm - M6 fasteners;
- For a cable with a diameter of 8 mm - M8 fasteners;
- For a cable with a diameter of 10...12 mm - M10 fasteners.
Wedge clamps are not recommended for lifting loads. Because the operational loads on the fastener are reduced, since the axes of force during operation of such a clamp coincide, and, therefore, shear stresses do not arise. The operational parameters of wedge-type clamps are regulated by DIN 15315. For screw clamping of a cable or rope to the supporting surface of the wedge, high-strength fasteners are used (strength class not lower than 5.6), with a protective anti-friction coating. The connection needs to be tightened periodically.
The barrel clamp is often made of aluminum, and is not designed for large cable diameters: the rational range of diameters is 2... 8 mm. The absence of protruding elements and the compactness of this clamp allows it to be used in cramped spaces.
Is it possible to make a cable clamp with your own hands?
The price of clamps, depending on their size and permissible load capacity, is, rub/piece:
- For Simplex type clamps - 4…14;
- For Duplex type clamps – 7…24;
- For clamps according to DIN 741 - 4…160;
- For wedge clamps – 200…250;
- For barrel type clamps - 3...40 (made of aluminum), and 60...160 (made of stainless steel).
In everyday life (for example, for car enthusiasts), there is often a need to make a cable clamp with your own hands. To form a reliable loop, it is advisable to use a regular aluminum (not duralumin!) tube, into which the cable should fit freely required diameter. The tube is bent in an arc, after which a cable is inserted there at a distance of 120...150 mm, its ends are covered with staples, and connected with a bolt.
When building up parts of the cable, the diameter of the pipe is chosen so that both cables can fit in freely, and from different ends. All other actions are performed in the same way. It should be noted that load bearing capacity such a cable clamp will be determined by the bending strength of the pipe material, so the permissible force homemade device the clamp will be noticeably lower than that manufactured by a specialized enterprise.
