A stair lift is a mechanical device for lifting people, typically those with disabilities, up and down stairs.[1] For sufficiently wide stairs, a rail is mounted to the treads of the stairs. A chair or lifting platform is attached to the rail. A person gets onto the chair or platform and is lifted up or down the stairs by the chair which moves along the rail.
Stair lifts are known variously as stairlifts, stair-lifts, chair lifts, stair gliders and by other names. This type of chair lift should not be confused with the chairlift used by skiers. The term stair climber can refer either to stair lifts, or more commonly to the exercise equipment by the same name.
Some of the first stair lifts to be produced commercially were advertised and sold in the U.S. in the 1930s by the Inclinator Company of America. Many users at the time were victims of polio.[2]
Now they are seen for use in elderly, fall-prone individuals, and disabled people who are unable to navigate stairs safely.
History
In the 1920s, C.C. Crispen, a Pennsylvania entrepreneur, created a way to enable an ailing friend to travel from floor to floor. Crispen's idea was to design a seat that could climb stairs. A self-taught engineer, he built the first prototype of the inclining chair. He called it the Inclin-ator.[3]
Prior to this Frederick Muffett of Royal Tunbridge Wells invented and patented "An Invalid Chair with Tramway for use on Staircases".[citation needed]
Modern stair lifts can be found with a wide variety of features such as adjustable seat height, battery isolation switches, call stations, 'flip-up' rail, key switch, folding step, speed governor, seat belt, soft start and soft stop.
Rails
Straight rails for use on domestic staircases are usually made from extruded aluminum or steel and come in various cross-sectional shapes. These rails may, typically, weigh over 30kg (66lb), depending on the length. In most applications they are attached to the steps with metal brackets (sometimes called "cleats").
If a rail crosses a doorway at the bottom of the stairs or causes an obstruction, a hinge can be fitted so the end of the rail can be folded back out of the way when not in use.
Curved rails are made from materials such as steel or aluminum and come in various cross-sectional shapes according to the designer. Individual designs vary a lot and probably the key criterion is to make the curves with the smallest radius possible so they will wrap tightly around objects such as newel posts.
The sections of curved rails are usually packaged well to prevent damage in transit and are unwrapped and assembled on site.
Rails for wheelchair platform stair lifts may be secured to walls in addition to the step fixings.
Carriages
The carriage is the component which moves along the rail and normally runs on small diameter rollers. In most designs the carriage is pulled by a cable or chain, or driven along the inclined rail by a rack and pinion system or other drive arrangement.
Most domestic carriages have a seat with arms and a footrest. Some special models have a stand-on platform also known as a "perch" seat. For users with shorter legs a short seat can be fitted, to make the lift more comfortable to sit on. Seats can be tailored to suit individual needs.
The conventional layout for a typical domestic stair lift is to have the seat at right angles to the rail so the user travels "sidesaddle". At the top of the staircase the seat can be swiveled, commonly through around 45 degrees or 90 degrees, then locked in place to allow the user to alight from it onto a landing. Stair lifts are available with either a manual swivel or a powered swivel, depending on the users ability.
Most swivel seats have a safety switch so the stair lift will not move unless the seat is locked into its travel position. Special models with seats facing the bottom of the staircase have been produced for users with spinal or other conditions which prevent use of the conventional seat layout. More room is need on the landing with these special seats.
Popular types
Straight-rail stair lifts
A restaurant stair lift
These are the most common type of stair lifts used in private dwellings with straight stairs and have a straight rail (track) which is attached to the steps of the staircase. Straight-rail stair lifts can usually be installed within days of being ordered and, having a rail which is simply cut to length from a stock part, they are the least expensive stair lifts.
Curved-rail stair lifts
A curved stair lift
Curved stair lifts are made to follow the shape of an individual staircase (curved stairs). On staircases with intermediate flat landings they eliminate the need for multiple straight stair lifts by providing a continuous ride up the entire length of the staircase. Because the rail is custom-made to follow the staircase, and because the chair is more complex than on a straight-rail stair lift (it has to be able to remain level while traveling along a track which changes direction and angle), curved-rail stair lifts are more costly than stair lifts for straight stairs. Specifying a curved-rail stair lifts usually involves careful measurement, design and manufacturing, and the installation process usually takes longer than for a straight domestic stair lift, usually between 5 – 10 weeks. One manufacturer, Acorn, can provide a curved-rail stair lift made from modular parts. This has the advantage of quick delivery time, even next day. The installer brings many parts and picks from them. They are usually similar in price to a custom-made curved-rail stair lift.
Vertical platform lifts come under the general definition of a stair lift and are usually of a much heavier construction than a domestic stair lift due to the fact they are going to transport a wheelchair or scooter and the person.
Most platform stair lifts are used in public access buildings and / or inside and outside private homes.
The platform is large enough to accommodate a wheelchair or scooter and its user, and may have folding edge flaps which drop down and act as ramps to allow for variations in floor levels. These flaps also prevent the wheelchair from going over the edge of the platform.
The rails are, necessarily, of heavy construction to support the load and the drive system is usually accommodated within a tubular section rail or aluminumextrusion. Some models have steel cables inside the tube, others have chains; yet others may use a rack and pinion system.
Many wheelchair platform stairlifts are designed and built to order. Others may comprise a standard platform and carriage, with the only special requirement being the length of rails or tracks.
Some stair lift chairs can also be moved and used as indoor wheelchairs.
Outdoor stair lifts
Outdoor stair lifts are available for straight and curved staircases. They operate similar to indoor stair lifts but include weather-resistant features to help the unit withstand extreme harsh temperatures and weather conditions. Most often, outdoor stair lifts are used on staircases for decks, home entryways or lake access.
Previously owned stair lifts
There is a second-user market for some types of stair lift. This is most common with straight rail domestic types. The rails can be cut to length if too long, or extended with a "joining kit". Most models allow the carriage to be "re-handed" so it can be used on the left or right side of the staircase.
During the early days of curved rail stair lifts there was no second user market because of the difficulty of matching rails to a different layout. Even staircases built to the same design specification in neighboring houses have variations, but in most attempted "transplants" there are too many differences to make it practicable. Many owners have had to pay to have unwanted curved stair lifts removed.
More recently, some curved rails have been produced to a modular design so components can be unbolted and used elsewhere, subject to design and safety considerations. In some cases, tubular section rails which are welded during manufacture, are produced by specialist rail companies so they can be used with a previously owned carriage, controls, and other components. This is, perhaps, like putting an old locomotive on new railway lines. It provides a lower cost solution than buying a totally new system.
Some insurance companies have offered breakdown policies for stair lifts. Manufacturers and installers have offered an extended warranty, rather like those available for domestic white goods and brown goods.
Goods stair lifts
Some manufacturers produce stair lifts with trays instead of seats for moving goods between different levels, usually in commercial or industrial buildings. Some businesses have purchased normal domestic stair lifts purely as goods transporters and put items such as boxes of stationery on the seat.
AC and DC power
Early stair lifts mostly had alternating current (AC) drive motors which ran at full mains voltage (around 115 volts in North America, 230 volts in Europe). An "energy chain" ran alongside or through the rail to carry the power cable from the supply point to the carriage.
More recently, domestic stair lifts have been powered from rechargeable batteries and use direct current (DC). One of the selling points is that a DC stair lift will continue to function during a power outage, provided the batteries are sufficiently charged. Most stair lifts have a 'charge point' where the unit will 'park' to charge its batteries. Some straight stair lifts have the ability to charge continuously no matter where they are left along the track.
With most DC models the batteries are accommodated within the carriage and travel with it.
Some models, however, were designed with three phase motors and the batteries (three in total) were housed in a cabinet mounted near the top or bottom of the rail. An inverter system was used to convert the DC energy to three phase AC.
The power rating of drive motors for domestic straight rail stair lifts may be around 250 watts. The power requirement will be greater for heavy loads, very steep inclines, and wheelchair platform stair lifts.
Controls
Stairlift with remote control
Stair lifts are largely operated using a control on the arm of the lift. This is either a switch or a toggle type lever. This larger toggle switch enables users even with limited mobility or painful condition to use stair lifts easily and safely.
Electronic controls are used extensively. Many stair lifts have radio frequency or infrared remote controllers. It is known that radiation from devices such as fluorescent lights can interfere with infrared stair lift controls. Also, heat and incandescent lights can, in some circumstances, have an adverse effect.
Control circuit design varies greatly among the different manufacturers and models. Curved rail stair lifts have more complex controls than those with straight rails.
The seat of a curved rail stair lift may have to be tilted so it remains horizontal whilst going around curves and negotiates different angles of incline. This requires an additional motor and link system.
Also, the carriage is slowed down on bends but travels faster on straight runs. This means a more complex control system. Modern controls have small microprocessors which "learn" the characteristics of the journeys and keep the data in memory. They also record the number of journey and direction. This assists service engineers on maintenance calls.
Some development of self-diagnostic controls began at the onset of the 21st Century. The idea was that stair lifts would predict when components were starting to deteriorate and automatically pass the information to the service provider so a visit could be arranged.
Safety
To satisfy safety codes stair lifts usually have cut-out switches connected to "safety edges" and other protective devices so the drive power is disconnected if something goes wrong. Modern lifts have a high degree of comfort, but safety is always paramount. "Safety edges" are a common feature to the power pack and footplate. "Safety edges" ensure that if there is any obstruction on the stairs the stair lift will automatically stop and only travel away from the obstruction.
Stair lifts are used by people of all ages and child car seats can usually be fixed a standard stair lift seat using the seat belt provided with the stair lift system.
Many stair lifts are also fitted with a key, to allow the user to prevent others from using the lift.
Codes of practice and technical specifications apply to stair lift manufacture.
In North America these codes may be relevant:
ASME A17.1 - 1990, Safety Code for Elevators and Escalators
ASME A18.1 - 2005 Safety Standard for Platform Lifts and Stairway Chairlifts
An important specification used by stair lift manufacturers in Europe was British Standard BS 5776: 1996 Specification For Powered Stair lifts, produced by The British Standards Institution.[4] It has since been replaced by BS EN 81-22:2021: Safety rules for the construction and installation of lifts.'[5]
Note: codes of practice and technical specifications are updated occasionally. These references may be out of date by the time they are read and are shown as examples.
Self-installation
Today, self-installation of stair lifts is becoming a common trend for people interested in DIY projects. Stair lifts are available for purchase that can be self-installed.
Professionals within the home medical equipment industry do not recommend that people attempt to install these products themselves. They believe that in terms of warranty, long-term care, and service, it is much more economical to have a trained professional install these products. In addition, these professionals are also aware of all safety measures and concerns associated with the proper installation of stair lifts, as well as the applicable local elevator codes.
Travel speed
Stair lifts normally have "soft" starts so the user is not jerked as the carriage starts to move. Typical travel speed for domestic straight rail stair lift carriages range between 0.07 metres per second (13.78 feet per minute) and 0.15 metres per second (29.53 feet per minute) (0.34 miles per hour). The speed of curved rail stair lift carriages may vary on the journey if the controls cause them to slow on inclines and bends.
Costs
Stair lifts are highly individualized units that vary in price significantly. However, many base units begin between $3,000 and $5,000. Many options affect this base pricing including: length of railing needed, any curves involved, seat upgrades, motor upgrades, seat swivel, seat and foot pedal folding, and power type.
Stairs are a structure designed to bridge a large vertical distance between lower and higher levels by dividing it into smaller vertical distances. This is achieved as a diagonal series of horizontal platforms called steps which enable passage to the other level by stepping from one to another step in turn. Steps are very typically rectangular. Stairs may be straight, round, or may consist of two or more straight pieces connected at angles.
A chair is a type of seat, typically designed for one person and consisting of one or more legs, a flat or slightly angled seat and a back-rest. They may be made of wood, metal, or synthetic materials, and may be padded or upholstered in various colors and fabrics.
A terrain park or snow park is an outdoor recreation area containing terrain that allows skiers, snowboarders and snowbikers to perform tricks. Terrain parks have their roots in skateparks and many of the features are common to both.
In rail transport, a derailment is a type of train wreck that occurs when a rail vehicle such as a train comes off its rails. Although many derailments are minor, all result in temporary disruption of the proper operation of the railway system and they are a potentially serious hazard.
A passenger railroad car or passenger car, also called a passenger carriage, passenger coach, or passenger bogie is a railroad car that is designed to carry passengers. The term passenger car can also be associated with a sleeping car, a baggage car, a dining car, railway post office and prisoner transport cars.
A mobility scooter is an electric personal transporter used as mobility aid for people with physical impairment, mostly auxiliary to a powered wheelchair but configured like a motorscooter. When motorized they function as micromobility devices and are commonly referred to as a powered vehicle/scooter, or electric scooter. Non-motorized mobility scooters are less common, but are intended for the estimated 60% of wheelchair users who have at least some use of their legs. Whilst leg issues are commonly assumed to be the reason for using scooters, the vehicles are used by those with a wide range of conditions from spinal injuries to neurological disorders.
A wheelchair-accessible van is a vehicle that has been modified by increasing the interior size of the vehicle and equipping it with a means of wheelchair entry, such as a wheelchair ramp or powered lift.
A horse-drawn vehicle is a piece of equipment pulled by one or more horses. These vehicles typically have two or four wheels and were used to carry passengers or a load. They were once common worldwide, but they have mostly been replaced by automobiles and other forms of self-propelled transport but are still in use today.
A swivel, swivelling, spinny, or revolving chair is a chair with a single central leg that allows the seat to rotate 360 degrees to the left or right. A concept of a rotating chair with swivel castors was illustrated by the Nuremberg patrician Martin Löffelholz von Kolberg in his 1505 technological illuminated manuscript, the so-called Codex Löffelholz, on folio 10r. It is purported that Thomas Jefferson drafted the United States Declaration of Independence in 1776 while sitting on a swivel chair of his own design.
A wheelchair lift, also known as a platform lift, or vertical platform lift, is a fully powered device designed to raise a wheelchair and its occupant in order to overcome a step or similar vertical barrier.
A mobility aid is a device designed to assist walking or otherwise improve the mobility of people with a mobility impairment.
An escape chair or evacuation chair is a device manufactured for the smooth descent of stairways in the event of an emergency. It was invented in the United States in 1982. The single-user operation device does not require heavy lifting to evacuate a person. An escape chair always comes with a green seat, head rest and dust cover. At airports and other large, multistory buildings, escape chairs can be used to assist persons with reduced mobility during emergency evacuation.
A transfer bench is a bath safety mobility device on which the user sits to get into a bathtub. The user usually sits on the bench, which straddles the side of the tub, and gradually slides from the outside to the inside of the tub. Tub transfer benches are used by people who have trouble getting over the tub wall or into the shower, either because of illness or disability.
An escalator is a moving staircase which carries people between floors of a building or structure. It consists of a motor-driven chain of individually linked steps on a track which cycle on a pair of tracks which keep the step tread horizontal.
A wheelchair is a mobilized form of chair using 2 or more wheels, a footrest and armrest usually cushioned. It is used when walking is difficult or impossible to do due to illnesses, injury, disabilities, or age related health conditions.
A motorized wheelchair, powerchair, electric wheelchair or electric-powered wheelchair (EPW) is a wheelchair that is propelled by means of an electric motor rather than manual power. Motorized wheelchairs are useful for those unable to propel a manual wheelchair or who may need to use a wheelchair for distances or over terrain which would be fatiguing in a manual wheelchair. They may also be used not just by people with 'traditional' mobility impairments, but also by people with cardiovascular and fatigue-based conditions.
Stannah Lifts Holdings Ltd is a provider of elevators, escalators and moving walkways and manufacturer of stairlifts and platform lifts. The headquarters are in Andover, Hampshire, Great Britain. The company makes various commercial lifts, but it is best known for its stairlifts, with which its name has become synonymous.
A folding seat is a seat that folds away so as to occupy less space. When installed on a transit bus, it makes room for a wheelchair or two. When installed on a passenger car, it provides extra seating.
An inclined elevator or inclined lift is a form of cable railway that hauls rail cars up a steep gradient.
A home lift not to be confused with a home elevator is a type of lift specifically designed for private homes, where the design takes into consideration the following four factors:
References
↑ Smith, Melanie (2006). Using the Building Regulations: Part M Access. Routledge. p.63. ISBN1136349995.
Hansard, UK Parliament House of Commons Daily Debates record. References to stair lifts: 16 Mar 1990: Column 395; 7 May 2002: Column 3WH; Westminster Hall, Sylvia Heal in the chair; 14 Jun 2004: Column 744W
Original page, including the definition of stair lift, created for the Wikipedia in April 2006 by Philip W Baker, founder member of The Stair lift Institute, a charity which at the time was a registered member of the National Council for Voluntary Organisations.
This page is based on this Wikipedia article Text is available under the CC BY-SA 4.0 license; additional terms may apply. Images, videos and audio are available under their respective licenses.
