Two horizontal steel rollers roll the dough or pastry between them, and then roll it again after the rotation is reversed. Between reversals, the distance between rollers is reduced to bring the dough or pastry to the required thickness.

Figure 1: Dough brake

Dough brakes

Tasks

Task – Feed dough to machine/roll dough

Hazard

Trapping between dough rollers
Entanglement with turning parts

Harm

  • Trapping between dough rollers
  • Entanglement with turning parts
  • Slips, trips & falls
  • Entanglement from unexpected movement (during maintenance, cleaning & repairs)

Controls

  • DO NOT wear loose clothing or jewellery.
  • FIX guarding to prevent reach into moving parts:
    • Static fixed guard
    • Adjustable fixed guard P Automatic guard
  • Prime movers and transmissions MUST be guarded.
  • TEST SAFETY FEATURES at the start of each shift.

Some dough brakes have a smooth table rather than a belt conveyor, where operator’s hands will reach closer to the nip, and may become entangled while feeding dough or during cleaning.

A nip is measured from where rollers close within 19 mm. 19 mm is the distance where fingers are caught.

Figure 2

Guards

Guards

A static fixed guard has a feed opening at a safe distance from the nip.

An adjustable fixed guard moves up to increase the size of the opening as the distance between rollers increases. While fingers and even hands can reach between rollers, the opening is limited to prevent reach which can cause harm. As the rollers are closed to roll dough or pastry thinner, the guard moves down to decrease the size of the opening.

An automatic guard includes a switching arrangement that reverses the motion of the rollers when the guard opening increases 6 mm above the set amount. Interlocked with the guard, an interlock switch reverses power to the motor which drives the rollers when the guard is pushed up.

Hazard

Slips trips and falls

Harm

  • Injuries from falls or entanglement:
  • Bruising
  • Fractures
  • Concussion

Controls

  • KEEP up-to-date housekeeping procedures.
  • KEEP the area around dough brakes clean and clear of slip and trip hazards.

Task – Maintenance, cleaning & repairs

Hazard

Entanglement from unexpected movement

Harm

  • Trapped hands or fingers
  • Crush injuries

Controls

  • LOCK-OUT all power before maintenance, cleaning and repairs.
  • TEST emergency stops at the start of each shift.

Instructions MUST be in a language understood by the operators.

Table 1: Separation distances (mm) using fixed guards

Maximum size of feed openingMinimum separation between opening and trapping point
20 140
30 240
40 340
50 440
60 540
70 640
80 740
83 840

Operation with fixed guards

  • Guard is secured to the dough moulder and is fixed in position.
  • Guard cannot be moved without using tools.

Figure 3: Operation of an adjustable fixed guard

Separation distances (mm) using adjustable fixed guards

illustration operation of an adjustable

Figure 4: Separation distances using adjustable fixed guards

Sepration distances using adjustable fixed guards

Table 2: Separation distances (mm) using automatic guards

Maximum size of feed openingMinimum separation between opening and trapping point
25 150
38 255
52 330
64 380
76 435
89 470
102 510
114 535
127 560
152 610
178 660

Figure 5: Operation of an automatic guard

Operation of an automatic guard

Figure 6: Phases of the electrical supply

Phases of the electrical supply

Electric reverse starter circuit (there are more components needed for a working circuit).

Operation with fixed guards

  • An automatic guard moves freely to reverse the rollers of the dough moulder when the guard is raised to increase the size of the feed opening more than specified.
  • The guard must be interlocked with motor controls.
  • Table 2 measures opening sizes on the feed side of the rollers.
  • Table 2 is from measurements agreed between representatives of the baking industry and what was the Department of Labour.
  • The trapping point is where the rollers close to 19 mm (explained on page 2).