Glossary of terms used on the website
Arms
FA1
"D" shape fixed arm.
FA2
"Hoop" shape fixed arm.
HAA
Height Adjustable arm.
HAT
Height and twist adjustable arm, which allows the user to get closer to the workstation.
In addition to vertical adjustment, the arm pads can be raised and twisted inwards or outwards. This is a useful feature for enabling the user to get closer to the work surface for certain tasks.
AFT
Height adjustable arms with fore/aft sliding arm pads.
FDA
Height adjustable and fold down arms. Allows the user to fold the arms down either to get closer to the workstation or when tasks are being performed and arms are not required.
HAW
Height and width adjustable arms.
Castors
Normal industry standard commercial castors will be fitted unless otherwise specified. Special castors are available for particular applications.
HFC
Hard floor castors, suitable for tiled and wood floors. These castors have a softer feel, are less abrasive and most importantly reduce the level of noise when being moved over the surface compared to standard castors.
BLC
Brake loaded castors. The castors lock in position holding the chair firm when sitting in the chair.
BUC
Brake unloaded castors. The castors are locked when weight is taken off the chair preventing chairs being repositioned when not being used.
LC
Locking castors that have a manual lever on the castor to be activated as desired by the user.
Mechanisms
Back Rake Angle Mechanism
Allows seat height adjustment and the back rest to be adjusted for rake angle by means of a lever. The desired angle is located and then locked off. The backrest height is adjusted by means of a hand wheel. Typically this is an operator chair type mechanism as are the three that follow.
Back Rake Angle Mechanism With Ratchet Back Height Adjustment
Chairs fitted with this mechanism operate as above but the height of the backrest is altered by means of a ratchet action. The backrest returns to the lowest position, once the highest position is passed.
Three Lever Mechanism (TLM)
This mechanism operates in a similar way to those above but there is an additional lever to adjust the angle of the seat independently in any position from a few degrees down to a few degrees back. This makes it possible to get the ideal seating position.
This mechanism can also have a ratchet back height adjustment.
Permanent Contact Mechanism
Chairs fitted with this mechanism have seat height adjustment and the back rest can be adjusted for height and travel. The angle of the back rest can be locked off in any position, or left free-floating – (in permanent contact with your back!). The height of the backrest is adjusted by means of a hand wheel.
Asynchronous Mechanism
Allows seat height adjustment and the back rest can be adjusted for height usually on a ratchet action. The angle of the backrest can be changed or left free-floating, operated by a lever. The seat angle can also be fixed or left free-floating from a few degrees forward to a few degrees back, independently of the backrest. This lets the user find the ideal seating position. The mechanism will also have bodyweight tension control allowing the user to adjust the resistance to movement of the chair to suit their own bodyweight. This type of mechanism is used extensively in good quality task chairs and ergonomic seating.
Lock-tilt Mechanism
Chairs with this mechanism have seat height and tilt angle adjustment, usually operated by a single lever. These mechanisms can either be locked in an upright position or left to free-float with the user. The mechanism also has bodyweight tension control and is frequently fitted to management type seating, as are the four that follow.
Synchronous Mechanism
Fitted with two levers the first adjusts seat height adjustment. The second the angle of the seat and backrest which can be adjusted simultaneously, in a synchronised ratio of approximately 2:1 (this can vary slightly according to the manufacturer). For every 1° of seat tilt the back tilts by 2°. The mechanism can be left to free-float or be locked in position. Bodyweight tension control is also provided. Often this type of mechanism features an integral “anti-shock” feature, which requires back pressure to release the mechanism. Usually the backrest height is adjusted on a ratchet. This is a versatile mechanism typically used on management and executive seating but also on operator/task seating
Synchro-glide Mechanism
The Synchro-glide mechanism is similar to the synchronous mechanism but has variable ratio synchronicity. The normal synchronous (back to seat) 2:1 ratio, that is active in the back upright position, decreases the more the back is reclined.
Knee Tilt Mechanism
This mechanism allows seat height adjustment, and to lock the chair in any one of five tilting positions or alternatively to free-float. The point of pivot is located near the front of the seat so that the user’s feet remain in comfortable contact with the floor. The mechanism also has bodyweight tension control and “anti-shock” release.
Knee Tilt Synchronous Mechanism
This mechanism is similar to that above but is for use on split seat and back chairs giving a synchronised 2:1 adjustment action. The backrest height can be fixed or adjustable, subject to the design of the chair.
Sliding Seat Mechanism (SSL)
This mechanism provides seat depth adjustment for different user leg lengths.
Other Options
CCO
Coccyx cut out. A section of the seat foam is cut out to help relieve pressure at the base of the spine and is particularly recommended with certain medical and back care problems. Please note that all our chairs have the cut out upholstered over so it is totally disguised and looks as a normal chair seat.
ILS
Inflatable lumbar support. This can be fitted to most high back chairs and comes as a standard feature with many of our task and executive chairs please see detailed description of models. The lumbar support is a single cell air bag fitted in the back of the chair at the time of manufacture and allows the user to hand pump the air bag to give additional support in the small of the back. The pump also has a release valve to adjust the pressure as required.
TLS
Triple lumbar support. Similar to the lumbar support above a larger bag is placed in the back of the chair which is split into three cells. As the user moves in the chair air passes from one cell to another as required to give ideal support. The TLS is operated in exactly the same way with a single hand pump and release valve.
MEM
Memory foam seat. This retains the shape in the foam and is a softer more comfortable foam that can be specified as an optional extra on most chairs.
PDB
Polished domed base.
PSB
Polished spider base.
RBR
Ratchet Back mechanism. This is a standard feature on many task and executive chairs and an optional extra for other swivel chairs.
WTB
Writing tablet. It is only possible to fit these to certain conference and meeting room chairs and may be specified either left or right handed. If a preference is not stated right handed will be supplied as standard.