United Standard Technologies Co., Ltd. 联标科技有限公司
Figure 2.1
Dimension A is the minimum opening area specified in Table 2.1 shade opening size for open designations.
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United Standard Technologies Co., Ltd. 联标科技有限公司
2.2 The assigned shade designations are:
OPEN TOP / OPEN BOTTOM – A shade has this designation when an opening exists above and below the lamp of the minimum size specified in Table 2.1.上下开口
OPEN TOP / CLOSED BOTTOM – A shade has this designation when an opening exists above the lamp of the minimum size specified in Table 2.1. Any opening below the lamp is smaller than that required for the shade to qualify as Open Top / Open Bottom.上开下闭 CLOSED TOP / OPEN BOTTOM – A shade has this designation when an opening exists below the lamp of the minimum size specified in Table 2.1. Any opening that exists above the lamp is smaller than that required to qualify as Open Top / Open Bottom. 上闭下开 CLOSED TOP / CLOSED BOTTOM – A shade has this designation if when the openings above and below the lamp are smaller than the minimum size specified in Table 2.1. The maximum marked lamp wattage is 7 watts. 全密封
2.3 Any obstructions to an opening in the shade, including 4 inches (101.6 mm) above and below dimension A in Figure 2.1 for open designations, must be deducted from the area calculation to determine compliance with Table 2.1. The lamp itself, the lampholder (or a maximum 1/2 inch diameter nipple or rod to support the lampholder), or a simple harp or wire to support the shade are not identified as obstructions.
2.4 A shade with an obstruction meets the intent of the requirement when the remaining unobstructed area is at least 10 percent greater than the amount required for an otherwise unobstructed shade. 2.5 Lamp-to-shade spacing
2.5.1 Lamp-to-shade spacing required in 1.3.1(b) is to be determined by measuring the minimum distance from any point on the lamp centerline to the nearest point on a shade in accordance with Table 2.2 – Open Top/Open Bottom, Table 2.3 – Open Top/Closed Bottom, or Table 2.4 – Closed Top/Open Bottom, as applicable. See Figure 2.2 for an example of lamp-to-shade spacing measurement. 根据判定灯罩的开口形式，确定灯－灯罩距离
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United Standard Technologies Co., Ltd. 联标科技有限公司
Table 2.2
Open top / open bottom shade minimum lamp-to-shade spacing
上下开口形灯罩的最小灯－灯罩距离
Table 2.3
Open top / closed bottom shade minimum lamp-to-shade spacing
上开下闭形灯罩的最小灯－灯罩距离
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United Standard Technologies Co., Ltd. 联标科技有限公司
Table 2.4
Closed top / open bottom shade minimum lamp-to-shade spacing
上闭下开形灯罩的最小灯－灯罩距离
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United Standard Technologies Co., Ltd. 联标科技有限公司
Figure 2.2
Dimension ?A??is the lamp centerline length, and dimension 距离A是灯泡中线，钨丝中点到灯泡底座距离?
B??is the minimum lamp-to-shade spacing. Dimension 距离B是灯－灯罩距离，钨丝中点到灯罩的最短距离?
C??is the minimum shade height for closed top/open bottom only measured
for the highest elevation point along the lamp centerline to the shade. See 2.5.
距离C是对玉上闭下开形灯罩，钨丝中点到灯罩顶的距离
2.5.2 The lamp-to-shade spacing shall be evaluated with the shade in the position that results in minimum spacings unless the shade is constructed such that it is not able to be repositioned. A shade supported by a harp or one that clips on to a lamp is determined to be adjustable.
Exception No. 1: A shade made of metal, glass, or porcelain is evaluated in only the normal use position.
Exception No. 2: A shade that has been determined to be ignition resistant in accordance with Lamp Shade Ease of Ignition Test, Section 140, and also been evaluated for flame resistance in accordance with the Standard for Flame Propagation of Fabrics and Films, UL 214, is evaluated only in the normal use position.
Exception No. 3: A shade that is secured by a lamp harp that is fixed by welding, brazing, or by mechanical means is not required to comply with the above requirement. Shades supported by harps complying with the Lamp Harp Torque Test in Section 139 are evaluated in only the normal use position. Adhesives or sealants shall be evaluated for
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