The armature laminations, Fig. 1, can very easily be drawn, since the designer has given all the necessary data as to dimensions, and it is only necessary for the draftsman to put this data on a drawing for the use of the shopman.
It will be noted that the slots are very carefully detailed, Fig. 3, the dimensions in all cases being given in decimals and figured to several decimal places, depending upon the accuracy necessary. The actual dimensions of the piece and the slots are taken from the engineer's design data.
The punchings are assembled as shown in Fig. 2 of this plate to give over-all dimensions as shown; that is, the number of pieces is determined in assembling only by the total thickness required. A ¾"X5/16" keyway is provided, the use of which will be understood when the spider is drawn. The space blocks are inserted at intervals in order that openings may be left through the armature for ventilation. These space blocks are not detailed on this drawing and consist merely of metal pieces which, it will be noted, are riveted to two laminations, so that they are held rigidly in place.