1、June 15,2001 1 SUBJECT 7700-2-5 OUTLINE OF INVESTIGATION FOR PORTABLE PNEUMATIC TOOLS; PART 2: PARTICULAR REQUIREMENTS FOR CIRCULAR SAWS AND CIRCULAR KNIVES Issue Number: 1 JUNE 15,2001 COPYRIGHT O 2001 UNDERWRITERS LABORATORIES INC. 2 SUBJECT 7700-2-5 JUNE 15,2001 No Text on This Page JUNE 15,2001
2、SUBJECT 7700-2-5 3 CONTENTS FOREWORD . .4 1 Scope . 2 Components . 5 3 Undated References . . 5 Glossary . 6 General Requirement 7 General Notes on Tests . . 5 . 5 . .6 1 O Electrical Circuits . . . . . .8 . .8 . .I1 12 14 Mechanical Strength . 15 Construction 16 Noise Emission . 17 Resistance to Co
3、rrosion . 18 Accessories and Attachments . 4 SUBJECT 7700-2-5 JUNE 15,2001 FOREWORD A. This Outline of Investigation contains basic requirements for products covered by Underwriters Laboratories Inc. (UL) under its Follow-Up Service for this category within the limitations given below and in the Sco
4、pe section of this Outline of Investigation. They are subject to revision as further experience and investigation may show is necessary or desirable. B. The observance of these requirements by a manufacturer is one of the conditions of the continued coverage of the manufacturers product. C. A produc
5、t which complies with the text of this Outline of Investigation will not necessarily be judged to comply with the Outline of Investigation if, when examined and tested, it is found to have other features which impair the level of safety contemplated by these requirements. D. A product employing mate
6、rials or having forms of construction which conflict with specific requirements of the Outline of Investigation cannot be judged to comply with the Outline of Investigation. A product employing materials or having forms of construction not addressed by this Outline of Investigation may be examined a
7、nd tested according to the intent of the requirements and, if found to meet the intent of this Outline of Investigation, may be judged to comply with the Outline of Investigation. E. UL, in performing its functions in accordance with its objectives, does not assume or undertake to discharge any resp
8、onsibility of the manufacturer or any other party. The opinions and findings of UL represent its professional judgement given with due consideration to the necessary limitations of practical operation and state of the art at the time the Outline of Investigation is processed. UL shall not be respons
9、ible to anyone for the use of or reliance upon this Outline of Investigation by anyone. UL shall not incur any obligation or liability for damages, including consequential damages, arising out of or in connection with the use, interpretation of, or reliance upon this Outline of Investigation. F. Man
10、y tests required by the Outline of Investigations of UL are inherently hazardous and adequate safeguards for personnel and property shall be employed in conducting such tests. JUNE 15,2001 SUBJECT 7700-2-5 5 1 Scope This Section of Part 1 is applicable except as follows: Modify I. I as follows: The
11、term ”tool” is replaced with ”circular saws and circular knives.” 2 Components This Section of Part 1 is applicable. 3 Undated References This Section of Part 1 is applicable. 4 Units of Measurement This Section of Part 1 is applicable. 5 Glossary This Section of Part 1 is applicable. 6 General Requ
12、irement This Section of Part 1 is applicable. 7 General Notes on Tests This Section of Part 1 is applicable. 8 Marking This Section of Part 1 is applicable except as follows: 8.1 Item (i), Add the following: Exception: Does not apply to saws designed specifically for cutting metal. Add paragraphs: 8
13、.1.101 An arrow indicating the direction of rotation. The arrow shall be raised, recessed, or distinguishable by other means no less visible and indelible. Exception: Does not apply to random orbit type sanders, polishers or buffers. 6 SUBJECT 7700-2-5 JUNE 15,2001 8.1.102 ”DANGER ”Risk of Injury to
14、 Persons. Keep hands and body away from blade. Contact with blade will result in serious injury.” 8.1.103 WARN1NG”Risk of Injury to Persons. Check to see that lower guard closes instantly! Hold saw with both hands. Support and clamp work.” Exception: For a circular saw blade with 140 mm (5.5 in) or
15、smaller diameter blade, the ”Hold saw with both hands” statement is not required. 9 Instruction Manual This Section of Part 1 is applicable except as follows: 9.2.3 Under Personal Safety, items (i), (j) and (k), Add the following: Exception: Does not apply to a saw designed specifically for cutting
16、metal. Under Personal Safety, Add the following items: I) DANGER! Keep hands and body away from cutting area and blade. Keep your second hand on auxiliary handle or motor housing. Contact with the blade will result in a serious injury . Note: For a circular saw with 140 mm (5.5 in) or smaller diamet
17、er blade, the ”Keep your second hand on auxiliary handle or motor housing” may be omitted. m) Keep your body positioned to either side of the saw blade, but not in line with the saw blade. Kickback could cause the saw to jump backwards. n) Do not reach underneath the work. The guard does not protect
18、 you from the blade below the work. o) Never hold a piece being cut in your hands or across your leg. It is important to support the work properly to minimize body exposure, blade binding, or loss of control. Under Tool Use and Care, Add the following items: i) Check lower guard for proper closing b
19、efore each use. Do not operate saw if lower guard does not move freely and close instantly. Never clamp or tie the lower guard into the open position. If saw is accidentally dropped, lower guard might be bent. Raise the lower guard with the retracting handle and make sure it moves freely and does no
20、t touch the blade or any other part, in all angles and depths of cut. Note: Alternate wording may be substituted for ”retracting handle.” j) Check the operation and condition of the lower guard spring. If the guard and the spring are not operating properly, they must be serviced before use. Lower gu
21、ard might operate sluggishly due to damaged parts, gummy deposits, or a buildup of debris. k) Lower guard should be retracted manually only for special cuts such as ”pocket cuts” and ”compound cuts.” Raise lower guard by retracting handle. As soon as blade enters the material, lower guard must be re
22、leased. For all other sawing, the lower guard should operate automatically. JUNE 15,2001 SUBJECT 7700-2-5 7 Note: Alternate wording may be substituted for “Retracting Handle.” I) Always observe that the lower guard is covering the blade before placing saw down on bench or floor. An unprotected, coas
23、ting blade will cause the saw to walk backwards, cutting whatever is in its path. Be aware of the time it takes for the blade to stop after switch is released. m) When ripping, always use a rip fence or straight edge guide. This improves the accuracy of cut and reduces the risk of the blade binding.
24、 n) Always use blades with correct size and shape (diamond vs. round) arbor holes. Blades that do not match the mounting hardware of the saw will run unpredictably, causing loss of control. o) Never use damaged or incorrect blade washers or bolts. The blade washers and bolt were specially designed f
25、or your saw, for optimum performance and safety of operation. p) When blade is binding, or when interrupting a cut for any reason, release the trigger and hold the saw motionless in the material until the blade comes to a complete stop. Never attempt to remove the saw from the work or pull the saw b
26、ackward while the blade is in motion or KICKBACK may occur. Investigate and take corrective actions to eliminate the cause of blade binding. Add the following Section: Kickback, Causes and Operator Prevention of: Kickback is a sudden reaction to a pinched, bound, or misaligned saw blade, causing an
27、uncontrolled saw to lift up and out of the workpiece toward the operator. When the blade is pinched or bound tightly by the keif closing down, the blade stalls and the motor reaction drives the unit rapidly back toward the operator. If the blade becomes twisted or misaligned in the cut, the teeth at
28、 the back edge of the blade can dig into the top suiface of the wood causing the blade to climb out of the keif and jump back toward the operator. Kickback is the result of tool misuse and/or incorrect operating procedures or conditions and can be avoided by taking proper precautions as given below:
29、 a) Maintain a firm grip on the saw and position your body and arm in a way that allows you to resist KICKBACK forces. KICKBACK forces can be controlled by the operator, if proper precautions are taken. b) When restarting a saw in the workpiece, center the saw blade in the kerf and check that teeth
30、are not engaged into the material. If saw blade is binding, it might walk up or KICKBACK from the workpiece as the saw is restarted. c) Support large panels to minimize the risk of blade pinching and KICKBACK. Large panels tend to sag under their own weight. Supports must be placed under the panel o
31、n both sides, near the line of cut and near the edge of the panel. d) Do not use dull or damaged blade. Unsharpened or improperly set blades produce narrow keif causing excessive friction, blade binding, and KICKBACK. a SUBJECT 7700-2-5 JUNE 15,2001 e) Blade depth and bevel adjusting locking levers
32、must be tight and secure before making cut. If blade adjustment shifts while cutting, it will cause binding and KICKBACK. f) Use extra caution when making a “pocket cut“ into existing walls or other blind areas. The protruding blade might cut objects that can cause KICKBACK. 10 Electrical Circuits T
33、his Section of Part 1 is applicable. 11 Rotating Output This Section of Part 1 is applicable. 12 Surface Temperatures This Section of Part 1 is applicable. 13 Accessibility of Moving Parts This Section of Part 1 is applicable. 14 Mechanical Strength This Section of Part 1 is applicable except as fol
34、lows: 14.1. I Add the following: Note: Not applicable to lower guard. 15 Construction This Section of Part 1 is applicable except as follows: 15.6 Replace item (a) with the following: a) Be positive On-Off type, and 15.14 Add the following: Exception: Does not apply to a saw designed specifically fo
35、r cutting metal. Add paragraphs: JUNE 15,2001 SUBJECT 7700-2-5 9 15.101 A circular saw blade or knife shall be guarded to reduce the risk of unintentional access to the rotating blade or knife as far as conditions of use will permit. Compliance is checked by inspection and by measurement as follows.
36、 Above the platen, access to the periphery of the blade or knife from the rear or the side of the tool shall be restricted by a fixed guard. Where conditions of use so require, access to the periphery from the front of the tool shall be such that the periphery of the blade or knife is not accessible
37、 to contact by the cylindrical test probe, shown in Figure 104. Below the platen, the periphery of the saw blade or knife shall be screened by a movable guard. In the closed position of the guard, the angle between the front edge of the guard and the platen subtended to the axis of rotation shall no
38、t exceed: a) 10 degree if the outboard circumference of the platen does not enclose the diameter of the saw blade or knife on its front side opposite the machine; b) 25 degree if the outboard circumference of the platen encloses the saw blade or knife on its front side opposite the machine. 15.101.1
39、 The probe specified in 15.101 shall not contact the saw blade when the saw is set for a 90 degree cut and the probe is advanced perpendicular to the blade and parallel and above the platen. The probe is to be advanced: centered on the blade, 12.7 mm (0.5 in) to the right, and then 12.7 mm to the le
40、ft of the blade. See Figures 101 - 103. 15.102 The total mass of a circular saw intended to be operated by one person only shall not exceed 16 kg (42.9 lb-mass). The total mass is the mass of the tool fitted with the heaviest accessory recommended by the manufacturer. Compliance is checked by inspec
41、tion and by measurement. 15.103 A circular saw lower guard shall close - retract from the full open position to the full closed position - in 0.3 s or less. A circular saw lower guard shall be resistant to abuse. The guard shall extend to at least the root of the teeth. Compliance is checked by the
42、following test. The closing time of a circular saw lower guard is to be measured without restoration of the guard in case of bending after a single sample is subjected to each of the following. a) Sawing 60 m (197 ft) of 12-mm (0.47-in) thick plywood that has been stored indoors for 72 h prior to th
43、e sawing. The saw is then to be conditioned for 24 h in air at a relative humidity of 90 (plus 5, minus O) percent at a temperature of 32 I2“C (89.6 I3.6“F). Exception: The saw need not be conditioned by cutting plywood if it is obvious that accumulation of sawdust will not affect the closure time o
44、f the guard. b) The saw, set for a 90 degree cut of maximum depth and oriented so that the lower guard will strike the floor with the table parallel to the floor, is to be dropped from a height of I m (3.3 ft) onto a concrete surface. 10 SUBJECT 7700-2-5 JUNE 15,2001 c) The saw, set for a 90 degree
45、cut of maximum depth and oriented in the hand carrying position intended for the particular tool, is to be dropped from a height of 1 m onto a concrete surface. 15.104 A circular saw lower guard shall close - retract from the full open position to the full closed position - in 0.3 s or less after ex
46、tended use. Compliance is checked by the following test. The saw is to be set for a 90 degree cut and oriented in the horizontal plane. The lower guard is to be cycled from the full closed position to the maximum open working position and then released for 50,000 cycles at a rate not less than 10 cy
47、cles per min. Exception: The sample used for this test may be positioned in a manner other than horizontal provided that it can be shown that the alternate position is equivalent. Following the cycling, the closure time is to be measured, the guard shall be fully functional and the guard stops shall
48、 remain intact. If agreeable to all concerned, the guard may be tested at a rate faster that 10 cycles per minute. 15.105 An opening provided for the ejection of dust in the fixed blade guard of a circular saw shall comply with the following: a) The openings shall be located beyond the outer circumf
49、erence of the blade, including the teeth, or b) The rigid test probe of Figure 104 shall not contact the blade teeth when inserted at any angle. 15.106 The control device on a circular saw shall be equipped with a mechanism that automatically locks the control in the off position when the actuator is released so that two distinct motions are required to actuate the tool; or the part of the control device that has the greatest travel shall not be less than 6.4 mm (0.25 in). Compliance is checked by inspection. JUNE 15. 2001 SUBJECT 7700-2-5 11 16 Noise Emission This Section of Part 1 is appl
