Machine Guarding: Devices

  • It may stop the machine if a hand or any part of the body is inadvertently placed in the danger area;
  • Restrain or withdraw the operator's hands from the danger area during operation;
  • Require the operator to use both hands on machine controls; or
  • Provide a barrier which is synchronized with the operating cycle of the machine in order to prevent entry to the danger area during the hazardous part of the cycle.

Presence-Sensing Devices 

Photoelectric (optical)

Uses a system of light sources and controls which can interrupt the machine's operating cycle.

Radiofrequency (capacitance)

Uses a radio beam that is part of the machine control circuit. When the capacitance field is broken, the machine will stop or will not activate.


Has a probe or contact bar which descends to a predetermined distance when the operator initiates the machine cycle. If there is an obstruction preventing it from descending its full predetermined distance, the control circuit does not actuate the machine cycle.


Pullback devices utilize a series of cables attached to the operator's hands, wrists, and/or arms. This type of device is primarily used on machines with stroking action. When the slide/ram is up between cycles, the operator is allowed access to the point of operation.


The restraint (holdout) device utilizes cables or straps that are attached to the operator's hands at a fixed point. The cables or straps must be adjusted to let the operator's hands travel within a predetermined safe area. There is no extending or retracting action involved. Consequently, hand-feeding tools are often necessary if the operation involves placing material into the danger area.

Safety Trip Controls

Provide a quick means for deactivating the machine in an emergency situation. A pressure-sensitive bar, when depressed, will deactivate the machine.


Safety tripwire cables may also be located around the perimeter or near the danger area.

Two-Hand Controls

Requires constant, concurrent pressure by the operator to activate the machine. With this type of device, the operator’s hands are required to be at a safe location (on the control buttons) and at a safe distance from the danger area.

Two-Hand Trip

This device requires concurrent application of both the operator’s control buttons to activate the machine cycle, after which the hands are free.


A gate is a movable barrier which protects the operator at the point of operation before the machine cycle can be started. They are usually designed to operate with each machine cycle.

Webmaster, Earn Money Here!
@ Safety Information...ThinkSafe,WorkSafe


dayteen lea said...

nice info on ur blog

done follow u :)

man said...

always come to my blog.

thanks.. :)

Elih Japahar said...

Info ni lah yg sy cari2 selama ni...hehe, nice blog..ada related dgn DOSH ke?

man said...

saling berkongsi maklumat..

Kathy Tuah said...

penah study ni dulu tapi sekarang dah lupa..adeh..

man said...

bila dah pernah study, kita baca semula akan mudah ingat.

Harun Ar said...

Wah rumit nian mengenai mesin ya...., Sungguh menyenangkan bagi orang yang dapat menguasainya...

man said...

bagi yang belum pernah kendalikan mesin memang merasa rumit.

peranti keselamatan pada mesin sebenarnya untuk meminimumkan kemalangan kepada pekerja yang mengendalikan mesin tersebut.

Si Matatajam said...

Good info.. Bw n follow here..

man said...

Selalu lah blogwalking sini..

Thanks.. :)

Musafir Jalanan said...

assalamualaikum, kawan, anda di-tag di sini >> Mencari Cahaya

man said...


Genious Person said...

This is my first time i visit here. I found so many interesting stuff in your blog especially its discussion. From the tons of comments on your articles, I guess I am not the only one having all the enjoyment here keep up the good work machine guarding

Popular Posts