![](http://www.alamy.com/thumbs/6/604CC952-0877-4DBD-AE33-0B0DE72D056E/RHWN4F.jpg)
. The Bell System technical journal. Telecommunication; Electric engineering; Communication; Electronics; Science; Technology. 380 BELL SYSTEM TECHNICAL JOURNAL that it can be adapted to standardized housings, which are stocked, and especially where the tool is to be operated on high speed presses. In order that a better appreciation may be obtained of some of the more exacting requirements which are being met in building tools of this kind, several of the important reasons for accurate workmanship to limits as close as a few ten-thousandths of an inch or less on some of the tool parts, togeth
. The Bell System technical journal. Telecommunication; Electric engineering; Communication; Electronics; Science; Technology. 380 BELL SYSTEM TECHNICAL JOURNAL that it can be adapted to standardized housings, which are stocked, and especially where the tool is to be operated on high speed presses. In order that a better appreciation may be obtained of some of the more exacting requirements which are being met in building tools of this kind, several of the important reasons for accurate workmanship to limits as close as a few ten-thousandths of an inch or less on some of the tool parts, together with typical examples, will first be considered. Meeting the Accuracy Required of Piece Part, In order to obtain the correct functioning of the apparatus or equipment and also to insure interchangeability in assembly, many piece parts must be made with a. Fig. 5—Shaving and perforating punch and die for impulse wheel. considerable degree of accuracy, often within limits of ± .001 in. or less for some of the dimensions. This is one of the most important and common reasons for accurately built tools, especially in the case of parts made in sufficiently large quantities to require a number of similar tools producing the same part, as the product of each tool must be interchangeable with that of any other provided for the same operation, and also for subsequent operations. The bronze impulse wheel for No. 2 type dials and the pinion used in message registers. Fig. 4, are typical examples. Both of these parts are given shaving operations—the wheel after being blanked, and the pinion after being cut to length and swaged—in order to secure the required accuracy and smoothness of contour. Fig. 5. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original American Telephone and Telegraph Company. [Short Hills, N. J. ,
Size: 1958px × 1276px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1920, booksubjecttechnology, bookyear1