BS ISO 22880:2016 pdf download

BS ISO 22880:2016 pdf download.Castors and wheels — Requirements for castors for swivel chairs
1 Scope
This document specifies the technical requirements, the appropriate dimensions and the requirements for the testing of castors, with or without braking devices, which will normally be used on swivel chairs.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 22878:2004, Castors and wheels — Test methods and apparatus
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 22877 apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— IEC Electropedia: available at http://www.electropedia.org/
— ISO Online browsing platform: available at http://www.iso.org/obp
NOTE Symbols are given in ISO 22878:2004, Annex A.
4 Dimensions and classification
4.1 Characteristics
The characteristics of a castor are as follows:
— fixing system;
— castor type;
— dimensions.
4.2 Fixing system
The fixing system includes the stem and circlip, threaded stem and other fixing systems.
4.3 Castor type
4.3.1 General
Castors are classified into four types (H, W, C and U). These all apply to the castor designs illustrated in Figure 1 and Figure 2.
4.3.2 Type H
Castors with plain wheels are defined as Type H, hard tread. The wheel shall be one colour over the entire surface.
These castors are suitable for carpeted floors.
4.3.3 Type W
Castors with resilient tyred wheels are defined as Type W, soft tread. The tread shall be of a clearly different colour from the wheel centre.
These castors are suitable for hard stone, wooden or tiled floors, or those featuring non-textiled covering.
4.3.4 Type C
These castors are antistatic or electrically conductive.
These castors should have either Type H or Type W wheels. They may also conform to Type U.
4.3.5 Type U
These castors are for swivel chairs with a built-in braking mechanism.
The castors should have either Type H or Type W wheels. They may also conform to Type C.
NOTE 1 For certain applications, castors for swivel chairs require a built-in braking mechanism that is released when a person sits on the chair to which the castors are fitted, allowing ease of mobility in that position.This braking action is automatically re-applied as the person leaves the chair to prevent the chair rolling away unintentionally.
NOTE 2 The decision regarding the type of castors to be fitted to swivel chairs depends on the chair design and the type of floors and covering in use.
Castors with permanent braking systems are not acceptable.
4.4 Dimensions
Figure 1 and Figure 2 show typical castor designs. Table 1 shows the specified dimensions and the corresponding symbols.