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 the end loop of the 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 wires.

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.

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 swinging of lighting electrical wiring, guy ropes must be installed on the steel rope.

After tensioning the supporting cable, it is grounded.

The cable thimble is currently an integral and indispensable part of most lifting, tensioning, holding, towing, fastening and many other similar machines, mechanisms and structures used in the most various fields production and human activity. It is quite reasonably believed that thimbles (kous) were first used to equip ship cables and ropes with them, and by Dutch sailors, which is confirmed by the translation of this word from the native language of Holland - “stocking”.

1

A thimble is a special mandrel for a loop (fire) of a cable (steel or made of soft materials), protecting it from damage, breakage and rapid wear (abrasion). What does it consist of and how is it actually carried out? protective function this product? The outer side of the thimble is made in the form of a groove (has a groove), into which the cable, that is, its loop, is placed, quite tightly. And this mandrel itself has a shape as close as possible to the contour of the fire.

Thanks to this design of the thimble, the cable, being in its groove, does not come into direct contact with the part (element) to which it is attached with its loop. The shape and dimensions of the mandrel ensure that the rope fits evenly and without kinks. The sides of the thimble groove do not allow the loop to come off, and also protect the cable from damage from the side, although there it is least susceptible to wear and other mechanical stress.

Since thimbles are used in so many areas of production and human activity, several types are produced, which are listed and briefly described in the corresponding publication on the site. This is an article. Within the framework of this publication, we only note that in form ( appearance) this mandrel can be round, triangular or teardrop-shaped. Thimbles in the latter version are the most common and are used in almost all cases where such cable protection is necessary.

Thimbles are made mainly from carbon steel, but there are also plastic ones. Steel ones are made by casting, stamping or forging, followed by galvanizing or painting to ensure their protection against corrosion. Structurally, the thimble can be made one-piece or composite, consisting of several parts. One of the types of such mandrels is shown in the photographs below. Moreover, this is a teardrop-shaped thimble.

Of course, each rope (a certain range of diameters) has its own thimble, that is, with the corresponding external, internal and groove dimensions.

Moreover, for the same cable, the dimensions, dimensions and weight of thimbles produced in accordance with different GOSTs differ. As an example, we can compare the two most common and most popular types of mandrels. These are of the same shape, but produced in accordance with GOST 19030-73. The drawings according to which they are made are presented respectively in Fig. 1 and 2. Taken from these GOSTs.

Rice. 1. Throngs standard 2224

Rice. 2. Throngs standard 19030

Let's compare the characteristics of these two products, designed for a cable with a diameter of 3 mm. Both standards produce thimbles used to protect the fire of ropes with diameters in the range of over 2.5 and up to 3.5 mm inclusive. But the characteristics of these mandrels differ, as can be seen from the table presented.

Table 1. Dimensions and weight of thimbles for cables with a diameter over 2.5 and inclusive up to 3.5 mm (including 3 mm) standards 2224 and 19030

GOST products	Size designation on the corresponding drawing and its value, mm

The weight of thimbles of these standards for a rope with a diameter of 3 millimeters, as can be seen from the table, is only 8 and 1.1 grams. But the weight of mandrels for powerful cables is already measured in kilograms and even tens of kilograms.

2

Of course, you first need to choose a suitable cable. In this case, first of all, one should be guided by the value of the maximum breaking force of the rope. That is, such a tensile force that cannot be exceeded, and it is able to withstand it without any damage. No less important are the conditions, method and purpose (for what work it is intended) of using the cable. Only by taking into account all these parameters will it be possible to choose the right ones, either soft ones from natural or synthetic materials.

Selection of the necessary ropes for the thimble

Only after choosing the type of cable, and then its diameter, can you begin to select a suitable thimble. First his appearance. In this case, first of all, one should proceed from what type of rope is used (steel or soft) and, again, be guided by the conditions, method and purpose of its use. The thimble standards reflect this information, including restrictions on use. And only after deciding on the type of mandrel, you can begin to select a specific product, that is, to match the diameter of the existing cable. The standards for thimbles contain tables of their standard sizes, which indicate what dimensions the mandrel should be taken for each rope thickness. So, when using GOSTs or reference books, the process of choosing a thimble at all stages (from selection by type to mandrel dimensions) will not cause any difficulties.

If the search for the desired thimble is carried out without using regulatory documentation on it and only in size, then you should be guided by the following standardized requirements, which will ensure maximum service life of the rope and safety of work:

1. The inner diameter of the mandrel (in the above figures and tables these are D and d) should be approximately 4 times greater than the thickness of the cable. For a rope with a thickness of 3 millimeters indicated as an example, the thimble has D = 12 and d = 10 mm (according to GOST 2224 and 19030, respectively).
2. Groove dimensions per outside The thimble should be such that the rope fits into it ("sank" in it) from 2/3 of its diameter to a position almost flush with the edges.

Compliance with the last requirement can be determined by applying the cable to the mandrel, or by calculation - by measuring the thickness of the cable, the diameter of the groove and its depth. For the 3 mm thick rope indicated as an example, the thimble of standards 2224 and 19030 have a groove diameter of 4 and 3.4 mm, respectively. Divide by 2 to find the radius. We get 2 and 1.7 mm, respectively. Or we measure the depth of the groove: 2.5 and 1.7 mm, respectively. Judging by the diameter of the cable (3 mm), it will not fit completely into the gutter, and 2/3 of its thickness is 2 mm. That is, these thimbles are suitable for rope with this thickness.

3

There are many ways to attach cables and ropes to thimbles. Below in Fig. 3 presents almost all of them, at least the most frequently used ones.

Brief description of the options presented:

• a – the end of the cable that goes around the mandrel is braided onto it;
• b – the end of the rope is attached to it with special clamps, the number and location of which depends on its diameter;
• c – sealing into a thimble, the body of which consists of 2 halves, using its wedge and clamp;
• d – filling the unbraided end of the rope in the thimble body with a low-melting alloy;
• d – crimping with an oval steel or aluminum bushing (sealing) on ​​a special press.

The main and most common methods are options A and D. However, for high-quality crimping you need special equipment. But you can do the braiding yourself. How to do this correctly is discussed in the following chapters. The tools required for this are shown in Fig. 4.

Fig 4. Tools required for raking work

Moreover, this set is used both for working with steel rope and soft rope: 1 – pile; 2 – a bit like a pile driver, but this tool is called a wiring tool; 3 is a tamper; 4 – this is an awl, maybe different, but always quite powerful and sharp; 5 – wire cutters; 6 – steel rod or wooden stick; 7 – thin hemp rope; 8 – front sight (for shipbuilders) or simply wooden hammer; 9 – not necessarily this, but a sharp knife; 10 – any mechanic’s hammer. In addition, you may also need a bench vise and soft wire.

4

At a certain length from the end of the rope, we temporarily tie it with wire or a thin vegetable cable (rope). Then we unravel the rope into strands, which we also tie, but at the very ends. After this, as shown in Fig. 5, put the cable into the groove of the thimble and then fix it on it with wire or rope.

Then each of the loose strands must be passed (punched) under the corresponding strands of the descent (unraveled part) of the cable. Before doing this, it is recommended to rub the strands with wax.

Punching is carried out according to the rule “through one strand under one” and in the direction from the thimble, that is, in the opposite direction to the descent of the cable. In addition, punching should be done like this: we place each free strand over the nearest strand of the unraveled part of the rope and pull it under the next one using a pile. This is how all punches are performed. In total, you need to make 3-4 of them with each free strand. During the work process, after each punching, the strands must be tightened (tensioned) and beaten with a hammer or other wooden hammer.

The last punching should be carried out in strands, from which we first cut out half of the fibers (threads). Then we remove the temporary markers - the straps around the thimble and the unraveling end of the rope. We also carefully cut off the loose strands near the cable itself. The result should be what is shown in Fig. 6.

Sometimes, for greater strength, another punch is made, but in this case, half of the remaining fibers should be additionally cut out from each free strand. And to increase the strength and service life of such a thimble seal, half of the interweaving of strands is tied - tightly wound over the top and a cable of smaller diameter is tied. Shown in the far right image Fig. 7 for simple fires without thimble.

The piercing is carried out in the direction from the end of the punch to its middle. But after the middle, the cage is not applied to prevent the rope from becoming damp.

5

We measure approximately 500–700 mm from the end of the rope and apply a temporary but durable bandage in this place using soft wire. Then we bend the cable around the thimble. In this case, the dressing site must be set in the same way as shown in Fig. 5 for soft rope. Then we fix the cable to the thimble in several places, tying them tightly with wire. After this, we unravel the free end of the rope (with a dressing) into strands, which are then slightly separated into different sides in the form of a spider.

The ends of the strands, if they consist of several strands, are tied with wire. If there is a soft core (organic or synthetic), then we cut it out along the entire length of the unbraided end of the cable.

Then we clamp the rope in a vice with the thimble towards us and so that the running (loose) strands are on the right. Select the first strand for punching (No. 1). This must be done so that upon completion of the work and removal of the dressing, the cable does not unwind or twist. Then, using an awl, prying up the strands of the unbraided (root) part of the rope, we punch it with running (unbraided) strands. There are several ways to do this, but the most common is shown in Fig. 9.

We carry out the first punching (middle diagram of the upper half of Fig. 9). In the first punch we pass running strand No. 1 through the cable from right to left and in the direction from the thimble, that is, in the opposite direction to the descent of the rope. In this case, strand No. 1 needs to be threaded under 1 molar. Then we break through the strands in the same direction: No. 2 - under 2 molars, No. 3 - under 3. All 3 strands, as seen in Fig. 9 must be punched in one place. We start running wires No. 4 and No. 5 in the same place as the first 3, but in the opposite direction, punching them under two and one root strands, respectively. Running wire No. 6 is threaded as shown in Fig. 9, covering with it strand No. 1 and the one that it broke through.

All subsequent punches are made from right to left and according to the third (right) diagram of the upper half of Fig. 9. That is, the running strands are threaded through one adjacent one under the next two root veins. The last punching must be done with only half of the total number of strands (for example, No. 1, No. 3 and No. 6).

The total number of punches depends on the rope diameter:

Upon completion of each punching, the running strands must be tightened. Depending on the thickness of the cable, this is done manually with pliers or using a bench vice or manual and electric hoists. And after the final punching and wrapping, the ends of the running wires must be cut off at the cable itself. Then, for greater strength and durability of the rope, the entire punched area is tightly wrapped (wrapped) with soft, preferably tinned wire. Finally, remove all the straps.

It is best to tie the rope directly onto the thimble, as suggested above, when it is thin or not large diameter. With powerful cables they do things differently. First, they make a fire (loop), in exactly the same way as suggested above, and only then they insert a thimble of suitable size into it.

If you ask the question what kind of lanyard device this is, few will answer it right away, although such a device has been known and actively used for decades. In many situations, there is a need to tighten ropes, chains, cables or other rigging, which must be done to more securely fix the guy wires. It is not always possible to achieve such a stretch using only your physical strength. It is to solve this problem that lanyards are designed, which we will talk about in this article.

What is a lanyard?

With the help of such a simple, but very convenient and reliable device as a lanyard, the performance requirements of which are regulated by the standards DIN 1748, DIN 1480 and GOST 9690-71, tension is ensured and they are kept in a tense state for a long period of time.

Lanyards used to be called differently: PTR-7-1, and the numbers in their designation varied depending on the model of the device and its technical characteristics. The numbers in the designation, in particular, characterize the magnitude of the destructive load (in tons-force) that a specific model of such a device can withstand. Devices for tensioning cables used earlier did not have such a wide variety of heads as is implemented in modern lanyards. Almost all models of such devices had heads made in the form of oblong loops at their ends, to which steel cables were attached. A little later, the magnitude of the breaking load of a particular lanyard began to be measured in kN. For example, if you decipher the name of the T-30-01 model, it will become clear that such a lanyard can successfully withstand a load of 30 kN, which corresponds to 3 tons-force.

Important characteristics of lanyards

To ensure that lanyards do not become deformed or destroyed during operation, it is necessary to take a very responsible approach to their selection. In addition, one should take into account both the dimensions of such devices and their features. geometric shape so that they are able to perform the tasks assigned to them. There are special tables that every seller should have: using them you can compare the marking of the lanyard model with its technical characteristics, size and shape. Both the characteristics, dimensions and type of such devices are specified by a number of international and domestic standards: DIN 1478, DIN 1480, GOST 9690-71, etc.

An important parameter of any device for tensioning steel cables is the thread diameter, and it is not necessary that both screws of such a device will have the same thread. Modern industry produces lanyards with different thread parameters: M5 (“baby”), M8, M10, M12, M16, M20, etc. But you will not find thread parameters in the designation, for example, of a lanyard model T-10-01, T- 30-01, etc. It is very convenient that such marking allows you to accurately determine which load is critical for these devices. It is the first digit in such designations that indicates that the lanyard can withstand a certain level of load, expressed in kN. More detailed information all characteristics of a particular model of such a device, including its exact drawing, can be found in the corresponding GOST.

Most steel braces and, accordingly, devices for tensioning them are used in conditions open air where they are exposed negative impact high humidity and temperature changes. To eliminate the harmful effects of such factors, lanyards must be reliably protected, which is ensured by their zinc coating or treatment paint and varnish materials. Thanks to such protection methods, such devices can be successfully operated for decades.

Lanyards according to DIN 1480 standard

Lanyards produced according to the DIN 1480 standard, if you understand their design, are a fairly simple device. The basis of their design is the body, which can be made in the form of a cylinder or an oblong ring. On both sides of the case there are threaded holes into which the working elements of such a device are screwed. These elements, depending on need, can have heads in the form of rings, hooks or forks. It is to the heads that it is attached steel rope, the tension of which must be ensured. What is important is that the working elements are screwed into the housing holes in different directions.

The lanyard bodies, made in the form of a cylinder, can have different design. So, it can be an open or closed cylinder, which is used in cases where it is necessary to protect threaded connections from the harmful influence of external factors: high humidity, dust and dirt. Cylindrical turnbuckles open type(even if you look at their photos) allow you to see how the threaded ends of the working elements converge when they are tightened.

It is no coincidence that lanyard heads are so diverse. Moreover, in one such device, heads of both the same and different types. For example, in practice you can often find devices for tensioning cables and ropes with fork-fork, hook-hook, ring-hook heads, etc. Such heads are selected depending on the design of the counter fastener: the end of a steel rope or cable. Thus, a lanyard with a fork head is used to tension ropes, at the end of which a loop can be formed that fits tightly (tightly) between the legs of such a fork.

Chain type lanyard - ratchet

If the head of the tensioning device has the shape of a hook, then, accordingly, the tensioned cables or ropes must end in rings or other elements that will not slip out of engagement with the hook when a tension force is applied to them. If a lanyard with a ring-shaped head is used, the ropes and cables must end with hooks, which also must not slip out of gear.

A separate category consists of chain-type lanyards, which have a ratchet in their design. Such a device is often also called a ratchet, and it is used in cases where it is necessary to bring together and tension elements that are located at a considerable distance from each other. The area of ​​use of such models is quite narrow, which is explained by their limitations in the degree of distance of the tensioned elements from each other. In addition, the design of such lanyards is quite bulky and includes a handle, which does not make it possible to use them in places with very limited free space.

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:

Horseshoe type cable clamp, manufactured according to DIN 741 standard. Made only from galvanized or of stainless steel, include a U-shaped threaded stepladder, a washer-plate for the cable loop, a block with a cable socket and two nuts. Such clamps are used for relatively small loads, mainly when transporting or towing cargo or equipment.

Simplex single clamps, which consist of a steel plate with flanges at the edges, and a steel clamping plate located between the plate and the cable. To fasten the elements together, Simplex type clamps have a bolt and a nut. This design is more intended for connecting the ends of the cable to each other when splicing it.

Double type or Duplex cable clamp. The principle of operation remains the same as in the previous type of clamp, but the pad and plate are twice as long, which allows you to place a second bolt-nut fastening pair. Accordingly, the reliability of the double grip increases, as does its size.

A “barrel” type clamp, which consists of two somewhat flattened hollow half-cylinders, which are connected to each other using a screw (one half-cylinder has a threaded boss, and the second has a hole for the screw). In the end parts of each half-cylinder there are two semicircular grooves for passing the cable and forming a loop.

Wedge clamp. It is one of the specialized ones and is suitable for connecting rigging cables or ropes of large diameter (up to 100 mm). Wedge clamps are different increased wear resistance, since bushings made of antifriction bronze are used for connection, and washers made of soft aluminum are used to securely grip the cable or rope.

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 For flat clamps, threads in accordance with 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.

When carrying out rigging, installation and construction work often there is a need to fix and lengthen the used steel ropes, as well as creating loops and eyes at their ends. For these purposes, rope clamps (cable clamps) are used.

A rope clamp is a device used to fix and secure a steel rope.

This type of rigging is not intended for work related to lifting, moving, holding and lowering loads. Its main purpose is to ensure strong tension on ropes and cables during installation of structures and securing objects in a stationary position, for example, on a vehicle platform during transportation.

Clips (rope clamps) are used in conjunction with a pear-shaped asymmetric thimble to secure the rope in a device for splicing the rope.

The size of the steel cable clamp is determined by the diameter of the rope used.

Types of Rope Clamps

There are clamps for ropes and cables of the following types:

1) U-clamp

The clamp is a threaded u-bolt. The threaded ends of the bolt are inserted into the clamping element. When the steel clamp nuts are tightened, the element presses the cable against the bolt.

2) Flat cable clamp

Manufactured from carbon steel. Consists of a clamping element, a clamping plate, screws and nuts with metric thread. Depending on the number of screws in the design flat clamp There are single (simplex), double (duplex) and triple (triplex) cables. Tightening the nuts clamps the cable between the plates.

3) Tubular clamp

Aluminum bushing clamps are used for ordinary cables, copper - for acid-resistant ones, for working in aggressive environments Stainless steel clamps are used. The tube clamp is an aluminum flattened hollow cylinder.

Recommended for connecting cables to each other, as well as for making loops at the ends of the cable. Tubular clamps for steel ropes are compressed using a press or hand pliers. They are one-time non-removable elements.

Depending on the design and installation method, the clamps for metal cable are divided into:

• wedge
• bolted
• screw
• jammed
• pressable
• canine

All rope clamps are manufactured in accordance with DIN and GOST. IN lifting devices for the purpose of connecting the ends of ropes, it is recommended to use arc-shaped clamps DIN 1142. The cable clamp DIN 741 compared to DIN 1142 has less strength, therefore it is recommended for use in work not related to moving and lifting loads.

Types of materials and coatings

Most often, cable clamps are used in work with large weights and heavy loads, so their production is subject to strict product quality control standards. Clamps for steel cables are made exclusively from high-quality and durable materials: steel, copper, aluminum, stainless steel.

In addition, rope clamps can be galvanized. Galvanized clamps have additional protection from corrosion. When working in adverse weather conditions and aggressive environments, stainless steel cable clamps are used.

Installation of rope clamps and fastening

When using arc clamps, it is recommended to install at least three clamps on one rope. If the load is higher than these types of clamps can withstand, then you need to use another type of this clamp, and not increase their number.

The rope clamp is installed on the steel cable so that the jumper of the clamp is always on the load-bearing side of the rope. There is a U-shaped clamp bolt at the tail end of the rope or cable. The long part of the cable is bent so that the minimum required number of clips can be positioned to create a strong loop. The distance between the clamps and the length of the free end of the rope from the last clamp must be at least 6 rope diameters.

Operating rules

Before starting work, you need to check the strength of the rope clamps. After the first application of load on the cable, the tightening torque must be checked again and adjusted if necessary. It is necessary that products are regularly inspected and tested. This is necessary due to the fact that during operation the products are subject to wear and overload, which will lead to deformations and changes in the structure of the material. Rope end clamps should be inspected at least once every six months, and even more often if the products are used in harsh working conditions.

It is not allowed to bend or adjust the shape of the clamp, as this will deteriorate the quality of the product and reduce its ultimate strength.

The following factors can negatively affect the tightness of the clamps on the cable:

• the nut sits tightly on the thread, but not tightly in relation to the jumper;
• the thread is clogged with dirt, oil, and corrosion products, preventing the necessary tightening of the nut.

Before choosing a specific product, you need to make sure of its quality. To do this, you should pay attention to the following points:

• the clamps must be legibly marked;
• there should be no visible burrs, cracks, grooves or other manufacturing defects on the surface;
• clamps must be selected in accordance with the characteristics of the cables used;
• The type of material/covering of the clamp must match external factors and the conditions in which the work is carried out.

All of these types of rope clamps are designed and manufactured to order by GPO-Snab. You can select and order them in our catalog of rigging products.