Turnbuckle

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80 mm (3+5/32 in)) turnbuckle Turnbuckle.jpg
Small (80 mm (3+532 in)) turnbuckle

A turnbuckle, stretching screw or bottlescrew is a device for adjusting the tension or length of ropes, cables, tie rods, and other tensioning systems. It normally consists of two threaded eye bolts, one screwed into each end of a small metal frame, one with a conventional right-hand thread and the other with a left-hand thread. The tension can be adjusted by rotating the frame, which causes both eye bolts to be screwed in or out simultaneously, without twisting the eye bolts or attached cables. [1]

Contents

Uses

Turnbuckles are most commonly used in applications which require a great deal of tension; they can range in mass from about 10 grams (38 oz) for thin cable used in a garden fence, to tonnes for structural elements in buildings and suspension bridges.

Aircraft

Turnbuckles have been used in aircraft construction, especially during the early years of aviation. Historically, biplanes might use turnbuckles to adjust the tension on structural wires bracing their wings. Turnbuckles are also widely used on flexible cables in flight control systems. In both cases they are secured with lockwire or specifically designed wire clips to prevent them from turning and losing tension due to vibration.

Shipping

Turnbuckles are used for tensioning a ship's rigging and lashings. A variant of the turnbuckle called a bottle screw features an enclosed tubular body.

Sports

Turnbuckles are used to tension the ropes in professional wrestling rings and boxing rings, where they serve as the attachment between the ring ropes and ring posts, and are padded.

Entertainment industry

Turnbuckles are used in nearly all rigging performed in the entertainment industry, including theatre, film, and live concert performances. In entertainment rigging, turnbuckles are more commonly used to make small adjustments in line lengths. This is generally to make a flown (hoisted) unit sit parallel to the stage. Another way a turnbuckle could prove helpful is with making very minor height or angle adjustments.

Pipe systems

Turnbuckles are used in piping systems as a way to provide minor adjustments for field inconsistencies. This also allows for a minimum amount of resistance when transferring the load to the support components.

Orthopaedics

A type of splint is used for upper limb to produce gradual stretching over contracted joint by its turn buckle mechanism. Used to treat stiff elbow and Volkmann Ischemic Contracture.

See also

Related Research Articles

<span class="mw-page-title-main">Rigging</span> Ropes, cables and chains which support masts of sailing ships

Rigging comprises the system of ropes, cables and chains, which support and control a sailing ship or sail boat's masts and sails. Standing rigging is the fixed rigging that supports masts including shrouds and stays. Running rigging is rigging which adjusts the position of the vessel's sails and spars including halyards, braces, sheets and vangs.

<span class="mw-page-title-main">Boxing ring</span> Space in which a boxing match occurs

A boxing ring, often referred to simply as a ring or the squared circle, is the space in which a boxing match occurs. A modern ring consists of a square raised platform with a post at each corner. Four ropes are attached to the posts and pulled parallel under tension with turnbuckles to form the boundary of the competition area.

<span class="mw-page-title-main">Shackle</span> Metal assembly which functions as a removable connecting link

A shackle, also known as a gyve, is a U-shaped piece of metal secured with a clevis pin or bolt across the opening, or a hinged metal loop secured with a quick-release locking pin mechanism. The term also applies to handcuffs and other similarly conceived restraint devices that function in a similar manner. Shackles are the primary connecting link in all manner of rigging systems, from boats and ships to industrial crane rigging, as they allow different rigging subsets to be connected or disconnected quickly. A shackle is also the similarly shaped piece of metal used with a locking mechanism in padlocks. A carabiner is a type of shackle used in mountaineering.

<span class="mw-page-title-main">Bowden cable</span> Flexible cable used to transmit force

A Bowden cable is a type of flexible cable used to transmit mechanical force or energy by the movement of an inner cable relative to a hollow outer cable housing. The housing is generally of composite construction, consisting of an inner lining, a longitudinally incompressible layer such as a helical winding or a sheath of steel wire, and a protective outer covering.

<span class="mw-page-title-main">Fastener</span> Hardware device that mechanically joins or affixes two or more objects together

A fastener or fastening is a hardware device that mechanically joins or affixes two or more objects together. In general, fasteners are used to create non-permanent joints; that is, joints that can be removed or dismantled without damaging the joining components. Steel fasteners are usually made of stainless steel, carbon steel, or alloy steel.

<span class="mw-page-title-main">Bolted joint</span> Mechanical joint secured by a threaded fastener

A bolted joint is one of the most common elements in construction and machine design. It consists of a male threaded fastener that captures and joins other parts, secured with a matching female screw thread. There are two main types of bolted joint designs: tension joints and shear joints.

<span class="mw-page-title-main">Clevis fastener</span> Fastener consisting of a U-shaped bracket through which a pin is placed

A clevis fastener is a two-piece fastener system consisting of a clevis and a clevis pin head. The clevis is a U-shaped piece that has holes at the end of the prongs to accept the clevis pin. The clevis pin is similar to a bolt, but is either partially threaded or unthreaded with a cross-hole for a split pin. A tang is a piece that is sometimes fitted in the space within the clevis and is held in place by the clevis pin. The combination of a simple clevis fitted with a pin is commonly called a shackle, although a clevis and pin is only one of the many forms a shackle may take.

<span class="mw-page-title-main">Guy-wire</span> Tensioned cable designed to add stability to a freestanding structure

A guy-wire, guy-line, guy-rope, down guy, or stay, also called simply a guy, is a tensioned cable designed to add stability to a freestanding structure. They are used commonly for ship masts, radio masts, wind turbines, utility poles, and tents. A thin vertical mast supported by guy wires is called a guyed mast. Structures that support antennas are frequently of a lattice construction and are called "towers". One end of the guy is attached to the structure, and the other is anchored to the ground at some distance from the mast or tower base. The tension in the diagonal guy-wire, combined with the compression and buckling strength of the structure, allows the structure to withstand lateral loads such as wind or the weight of cantilevered structures. They are installed radially, usually at equal angles about the structure, in trios and quads. As the tower leans a bit due to the wind force, the increased guy tension is resolved into a compression force in the tower or mast and a lateral force that resists the wind load. For example, antenna masts are often held up by three guy-wires at 120° angles. Structures with predictable lateral loads, such as electrical utility poles, may require only a single guy-wire to offset the lateral pull of the electrical wires, at a spot where the wires change direction.

<span class="mw-page-title-main">Safety wire</span> Locking device for bolts etc.

A safety wire or locking-wire is a type of positive locking device that prevents fasteners from falling out due to vibration and other forces. The presence of safety wiring may also serve to indicate that the fasteners have been properly tightened.

<span class="mw-page-title-main">Fly system</span> Rigging above a theater stage

A fly system, or theatrical rigging system, is a system of ropes, pulleys, counterweights and related devices within a theater that enables a stage crew to fly (hoist) quickly, quietly and safely components such as curtains, lights, scenery, stage effects and, sometimes, people. Systems are typically designed to fly components between clear view of the audience and out of view, into the large space, the fly loft, above the stage.

<span class="mw-page-title-main">Deadeye</span>

A deadeye is an item used in the standing and running rigging of traditional sailing ships. It is a smallish round thick wooden disc with one or more holes through it, perpendicular to the plane of the disc. Single and triple-hole deadeyes are most commonly seen. The three-holed blocks were called deadeyes because the position of the three holes resemble the eye and nose sockets of a sheep's skull.

<span class="mw-page-title-main">Wire rope</span> Metal rope

Wire rope is composed of as few as two solid, metal wires twisted into a helix that forms a composite rope, in a pattern known as laid rope. Larger diameter wire rope consists of multiple strands of such laid rope in a pattern known as cable laid. Manufactured using an industrial machine known as a strander, the wires are fed through a series of barrels and spun into their final composite orientation.

<span class="mw-page-title-main">Wrestling ring</span> Space in which a professional wrestling match occurs

A wrestling ring, also known as the squared circle, is the stage on which a professional wrestling match usually occurs. It is similarly constructed to a boxing ring and is traditionally square-shaped.

<span class="mw-page-title-main">Eye bolt</span> Type of bolt

An eye bolt is a bolt with a loop at one end. They are used to firmly attach a securing eye to a structure, so that ropes or cables may then be tied to it.

<span class="mw-page-title-main">Tensioner</span>

A tensioner is a device that applies a force to create or maintain tension. The force may be applied parallel to, as in the case of a hydraulic bolt tensioner, or perpendicular to, as in the case of a spring-loaded bicycle chain tensioner, the tension it creates. The force may be generated by a fixed displacement, as in the case of an eccentric bicycle bottom bracket, which must be adjusted as parts wear, or by stretching or compressing a spring, as in the case of a spring-loaded bicycle chain tensioner; by changing the volume of a gas, as in the case of a marine riser tensioner; by hydraulic pressure, as in the case of a hydraulic bolt tensioner; or by gravity acting on a suspended mass, as in the case of a chair lift cable tensioner. In the power sector, the tensioner is a machine for maintaining constant tension of the conductors during work of hanging the transmission network..

<span class="mw-page-title-main">Screw</span> Type of fastener characterized by a thread wrapped around a cylinder core

A screw is an externally helical threaded fastener capable of being tightened or released by a twisting force (torque) to the head. The most common uses of screws are to hold objects together and there are many forms for a variety of materials. Screws might be inserted into holes in assembled parts or a screw may form its own thread. The difference between a screw and a bolt is that the latter is designed to be tightened or released by torquing a nut.

<span class="mw-page-title-main">Bolt (fastener)</span> Threaded fastener with an external male thread requiring a matching female thread

A bolt is an externally helical threaded fastener that fastens objects with unthreaded holes together. This is done by applying a twisting force (torque) to a matching nut. The bolt has an external male thread requiring a matching nut with a pre-formed female thread. Unlike a screw, which holds objects together by the restricting motion parallel to the axis of the screw via the normal and frictional forces between the screw's external threads and the internal threads in the objects to be fastened, a bolt prevents that linear motion via the frictional and normal forces between the bolt's external threads and the internal threads of the matching nut, which can be tightened by applying a torque which moves the nut linearly along the axis of the bolt and compresses the objects to be fastened.

<span class="mw-page-title-main">Rigging (material handling)</span> Equipment and procedure in material handling

Rigging is both a noun, the equipment, and verb, the action of designing and installing the equipment, in the preparation to move objects. A team of riggers design and install the lifting or rolling equipment needed to raise, roll, slide or lift objects such as heavy machinery, structural components, building materials, or large-scale fixtures with a crane, hoist or block and tackle.

In aeronautics, bracing comprises additional structural members which stiffen the functional airframe to give it rigidity and strength under load. Bracing may be applied both internally and externally, and may take the form of struts, which act in compression or tension as the need arises, and/or wires, which act only in tension.

References

  1. "Special Hardware You Should Know About". Popular Science Monthly. Bonnier Corporation: 169. Dec 1959.