Wintriss Shadow 8, User Manual

Page: 131 / 159

1139300 Shadow 8 User Manual
D-18 Extracts from OSHA and ANSI
Extracts from ANSI B11.19-2003 Annex D
Annex D - Safety Distance (Informative)
The safeguarding devices listed below do not prevent an individual from reaching into a hazard area.
In order for these devices to be effective, they must either prevent the start of, or stop hazardous
motion (or situation) when an individual is exposed to the hazard. For the devices to accomplish this
requirement, they must be located at a distance from the hazard such that hazardous motion (or
situation) is prevented, completed or stopped before the individual can be harmed.
Devices that require location at a safety distance include, but are not limited to:
1) interlocked barrier guards;
2) two hand control devices;
3) two hand trip devices;
4) single control safeguarding devices;
5) electro-optical presence-sensing devices;
6) RF presence-sensing devices;
7) safety mat devices;
8) safety edge devices.
The first four devices protect individuals by positioning the individual at or beyond the safety distance
before hazardous motion can be initiated, or by maintaining the individual's position at the safety
distance after hazardous motion has been initiated. The remaining four devices protect individuals by
detecting an individual entering (or their presence within) a hazard area at or within the safety
distance.
NOTE - Barrier guards and movable barrier devices with various openings are located at a position
away from the hazard area based on the ability of the operator to reach through the opening. Figure
D.10 (and Table D.1) is one method that may be used to locate barrier guards.
The safety distance may be calculated using the following equation:
Ds = K(T) Equation (1)
Where: Ds = the safety distance
K = the maximum speed that an individual can approach the hazard
T = the total time to stop hazardous motion which includes various factors as
described below
The factor K is the speed constant and includes hand and body movements of an individual
approaching a hazard area. The following factors should be considered when determining K:
a) Hand and arm movement;
b) Twisting of the body or shoulder, or bending at the waist;
c) Walking or running.
One of the accepted values for K is the hand speed constant (it is usually considered as the horizontal
motion of the hand and arm while seated). Its common value is 1.6 m/s (63 in/s) although other values
(typically greater) are also used. The hand speed constant does not include other body movements,
which can affect the actual approach speed. Consideration of the above factors should be included
when determining the speed constant for a given application.
The factor T is the total time that it takes for the hazardous motion to stop, or for the hazardous portion
of the machine cycle to be completed. A power press may present a hazard during the closing portion
of its cycle or a machining center may present a hazard during a tool change or while the tool is
approaching the workpiece (trapping zone), but not present a hazard during the balance of the
machine cycle.