Ergonomics - Atlas Copco

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Drills One of the oldest hand-held tools, drills are used in practically all industries to make holes in a variety of sizes, from less than 1 mm in diameter up to more than 50 mm. Using a drill is not regarded as a high physical risk to the operator. Where are the tools used? Drills are used in almost all production situations. The use of drills has changed over the years. A century ago, ships were warm-riveted. Workers expended huge amounts of physical effort drilling thousands of holes, often with diameters of more than 30 mm, to prepare the plates for riveting. Today, holes are drilled in aircraft fuse- lages in preparation for riveting. However, these holes are only a few millimeters in diameter and the muscle effort required to produce them is acceptable. Drilling is a common operation in the aerospace industry. 37
38 Working environment In general, drills have a low impact on the working environment, particularly the small models. Large drills can be somewhat noisy. Most drills do not require lubrication. Design for good ergonomics The load on the operator depends on the size of the hole to be drilled. If a larger hole is to be drilled, more feed force must be applied to the machine by the operator. Larger holes can be pre-drilled to reduce the feed force. The type of grip chosen will influence the operator’s posture. A drill with a pistol grip conveys feed forces more efficiently than straight or angle grip drills. The handle must be designed to mini- mize the torque absorbed by the wrist when high feed forces are needed. The pistol grip should allow the operator to change his hold on the machine. He should hold the machine lower down the handle when applying a small feed force and higher up when high feed force is required. The high position should result in a straight line from the center line of the machine to the bones in the operator’s forearm. The torque in the operator’s wrist should be kept as low as possible at all times. The straight handle should only be used when low feed forces are required, particularly where a vertical hole is to be drilled in a workpiece. If high feed forces are necessary, a pistol grip machine may be used, provided the operator can work with his wrist held straight. If the hole requires a bent wrist posture, the position of the workpiece should be rearranged so that the operator can work with a straight wrist. The combination of bent wrist and high feed forces should always be avoided. The angle grip is used mainly for drilling in cramped spaces. The feed force needed should preferably be applied using both hands. The wrist’s capability to provide ulnar flexion torque is limited and one-handed operation of angle drills should be avoided. Safety Drills are not generally a risk. However, if the operator holds the drill bit and starts the tool he will damage his hand. Some drills have a guard covering the chuck, but the drill bit cannot be guarded easily. The guard allows a comfortable two-handed grip. When working with larger drill bits, there is always the risk of a jerk when the drill bit penetrates the workpiece, resulting in a shock reaction which is absorbed by the operator’s wrist. Most of the feed force is applied to the point of the bit to help it work
Page 1 and 2: Power Tool Ergonomics E V A L U A T
Page 3 and 4: Acknowledgements While doing resear
Page 5 and 6: How to get the best out of this boo
Page 7 and 8: Work with international standards I
Page 9 and 10: Good ergonomics is good economics W
Page 11 and 12: 10 SOCIOLOGY INDUSTRIAL SOCIOLOGY S
Page 13 and 14: 12 Work organization No organizatio
Page 15 and 16: 1 outside the production system, an
Page 17 and 18: 1 A seated operator usually has goo
Page 19 and 20: 1 without stretching the trunk. The
Page 21 and 22: 20 The arm sling as a preventive me
Page 23 and 24: 22 Extreme working postures in real
Page 25 and 26: 2 Working with high feed forces req
Page 27 and 28: 2 Working areas of a standing works
Page 29 and 30: 2 body is lifted or tilted, or the
Page 31 and 32: 30 The team is an important factor
Page 33 and 34: 32 Grinders Grinders and sanders ar
Page 35 and 36: 34 HanDle DeSiGn The hand grips on
Page 37: 36 DUSt anD oil Although the machin
Page 41 and 42: 40 SHoCK reaCtion Sudden changes in
Page 43 and 44: 42 practice. Sometimes the chisel h
Page 45 and 46: 44 SHoCK reaCtion These tools do no
Page 47 and 48: 46 heavy, assembly work is often hi
Page 49 and 50: 48 depends on its inertia. The same
Page 51 and 52: 50 bolts. Unfortunately there are a
Page 53 and 54: 52 The low reaction torque in impul
Page 55 and 56: 54 the working environment A typica
Page 57 and 58: 56 Today, the angle nutrunner can b
Page 59 and 60: 58 High torque nutrunners for use w
Page 61 and 62: 60 Wheel nuts on trucks and buses a
Page 63 and 64: 62 Introduction A basic ergonomic p
Page 65 and 66: 64 Handle design The handle of a ha
Page 67 and 68: 66 Arteries Veins (superficial) Vei
Page 69 and 70: 68 Handle size Since a tool handle
Page 71 and 72: 70 However, if the texture is too c
Page 73 and 74: 72 Bibliography Chaffin, D.B. and A
Page 75 and 76: 74 Fig. 3.3 The same feed force app
Page 77 and 78: 76 Pushing and pulling Pushing a to
Page 79 and 80: 78 the object, the shape of the obj
Page 81 and 82: 80 Safety factor a 2 Frequency of t
Page 83 and 84: 82 Comments for different tool type
Page 85 and 86: 84 The trigger is either operated b
Page 87 and 88: 86 used in one handed operations. T
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88 Weight The weight of a hand-held
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90 stability of grip, the center of
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92 Temperature Hand-held power tool
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94 To ensure physical comfort durin
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96 Score 40 30 20 10 0 Bibliography
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98 the dynamic properties of the ma
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100 High motor power and fast clutc
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102 Score 40 30 20 10 0 shock react
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104 piezo-electric crystal. When th
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106 EN 50144 and EN 60745. Both ISO
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108 hole of the wheel are wider tha
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110 In the GTG 40 grinding machine,
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112 RRH machines serves two functio
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114 be noted that declared values b
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116 Noise Noise was the first envir
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118 value for 8 hours’ exposure t
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120 We can start by looking at the
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122 This is done with a minimum inc
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124 microphones at a distance of 1
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126 coated with dust or damaged by
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128 This method has not been used b
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130 tool cabinet. Many workplaces h
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132 lubrication. Made from a compos
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134 Grinder GTG 40 F085 The relevan
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136 were simulated by fitting a whe
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138 Drill LBB 26 EPX-060 The releva
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140 applied to the center of the dr
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142 Chipping hammer RRF 31 The rele
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144 SHOCK REACTION There are no sho
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146 Riveting hammer RRH 06 The rele
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148 WEIGHT The weight is 1.3 kg, sc
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150 Screwdriver LUM 22 PR4 The rele
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152 This gives a score of 9. In pra
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154 Impulse nutrunner EP9 PTX80-HR1
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156 Due to friction in the hydrauli
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158 Electric nutrunner ETP ST32-05-
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160 WEIGHT The electric nutrunner i
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162 Angle nutrunner LTV 29 R30-10 T
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164 operator equal to installed tor
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166 Electric angle nutrunner Tensor
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168 WEIGHT The electric nutrunner i
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170 High torque nutrunner LTP 51 Th
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172 Score 40 30 20 10 0 NOISE The d
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Ergonomics - Atlas Copco

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