Guards movable

ISO 14120, Safety of machinery — Guards — General requirements for the design and construction of fixed and movable guards... 

The borders between European countries are equipped with movable road blocks that resemble the fold-r ing gates often used to prevent toddlers from falling down stairs or from entering off-limits rooms.The device has a sharpened spike at each pivot point and is anchored at one side of the road. A guard extends the obstacle into one or both lanes to block the road, and folds it out of the way to allow authorized vehicles to pass. 

An enclosure attached to the frame of a machine and interlocked so that the machine cycle cannot be started normally unless the guard, including its hinged or movable sections, are in position. In some situations, movement of the guards will interrupt the machine cycle. See also Machine Guarding. 

A form of guard that has a movable part connected with the machinery so that the parts of the machine causing a hazard cannot be set in motion until the guard is in place. Before the guard can be opened sufficiently to allow access to the work area, the power is turned off and the motion is braked to prevent potential injuries to workers. It may also be called Interlocked Barrier Guard. See also Barrier Guard Interlock Machine Guarding. 

Showing movable guard with opening small enough to give required protection for the smallest size wheel used. 

Showing movable guard with size of opening correct for full size wheel but too large for smaller wheel. 

In the context of safety-related control systems, the Essential Health and Safety Requirements of the Supply of Machinery (Safety) Regulations 1992 lay down generic requirements that must be considered by suppliers for the safety and reliability of control systems control devices starting and stopping devices mode selection failure of the power supply and the control circuit software and movable guards. 

Screw conveyors must be completely covered except at loading and discharging points. At those points, guards must protect employees against contacting the moving screw the guards are movable, and they must be interlocked to prevent conveyor movement when not in place. 

The most economical solution is to isolate the risk factor by a fixed or movable guard covering the dangerous area as closely as possible (enclosures, telescopic guards etc.) If this is not possible, safety devides connected with the functions of the machine shall be used (see Figure 7). They include ... 

Because most woodworking operations involve cutting, it is often difficult, although necessary, to provided guards at the point of operation. On most machines, the point of operation guard should be movable to accommodate the size and shape of the wood, balanced so as not to impede the operation, and strong enough to provide protection to the operator. 

FIGURE 2.26 Schematic of a typical transmission x-ray scattering beamline. The beam size is defined by slits SI and S2 S3 is a guard slit spaced more widely to reduce parasitic scatter. A simple intensity detector such as the ion chamber shown is used to monitor beam intensity at the sample then after the sample, a distance D away, scattered x-rays are detected. Area detectors such as a CCD (charge-coupled device) are commonly used however, higher-resolution data can be obtained using a movable point detector. 

All belts, pulleys, sprockets and chains, flywheels, shafting and shaft projections, gears, couplings, other rotating or reciprocating part, or any movable portion within 7 feet of the floor or working platform is to be eflectively guarded. 

Gate or movable barrier guard A device designed to enclose the point of operation to exclude entry prior to equipment operation. 

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