This section is from the "Modern Machine Shop Construction, Equipment, And Management" book, by Oscar E. Perrigo. Also see Amazon: Modern Machine Shop Construction, Equipment, And Management.
The blueprint room is located in the monitor roof in the center of the building, and thus over both the drawing room and the pattern shop. The space available is 18 feet wide. It is well lighted along one side and across the front end. In it are built a large dark room and other facilities and appliances for print washing and drying, as is shown in Fig. 102. The blueprint frames are opened and filled in the dark room and the smaller ones carried out the door to a platform built over the roof and on a level with the floor of the blueprint room. Instead of being supported by any kind of a rack, they are placed upon an adjustable blueprinting stand, as shown in Figs. 103 and 104. This may be easily turned to face the sun and the supporting board adjusted to whatever altitude the sun may happen to be at the time. The stand is made with a cast iron standard rising from the base which is supported on three caster wheels of not less than 3 inches in diameter. A cast iron support is pivoted between jaws formed in the standard, to which it is clamped in any desired position by a bolt and hand nut, as shown in Fig. 103. The board is attached to this support. When in the room the board may be brought to a nearly vertical position, thereby occupying less space. These stands may be kept in the room and the boards placed upon them and rolled out on the platform, if heavy printing frames are used, but this is not usually necessary.
Fig. 101. Arrangement of Offices under Drawing Room where there is a Vault.
Fig. 102. Plan of the Blueprint Room.
Fig. 103. Side Elevation. Fig. 104. Perspective View. Stand for Supporting Blueprint Frame.
Fig. 105 shows a device for supporting large printing frames. This rests on four caster wheels of not less than 4 inches in diameter. Trunnions are fixed on the sides of the printing frame in a position to exactly balance it, and either the collars of these trunnions should press tightly against the standards, or the trunnions should be considerably larger than those shown, so that the friction will hold the frame in any desired position for printing. The printing frame may be held in a horizontal position for filling by means of the rod pivoted at one end of the frame and having at the other a hook formed upon it which engages a staple in the end of the frame. When in use this frame is rolled to the door of the dark room, the tracing and blueprint paper put in, closed up, and rolled out on the platform, thus avoiding much of the usual manual labor in carrying heavy printing frames.
Where printing must be done out of a window various forms of tracks and frames must be resorted to, but there are many advantages in so locating the blueprint room as to utilize the roof for supporting a large, level platform, as here described. In cases where no monitor roof or similar facilities are offered, and the roof is nearly level, or with a slight pitch, it will be best to build a printing room on the roof with a platform outside of it, so as to be operated as here described.
A simple washing box is provided for soaking blueprints in the usual way. Also, an automatic print washer, as shown in Figs. 106 and 107. In this device a fixed box has pivoted in it a smaller box, whose bottom is composed of light slats. Upon this box is attached, but so as to be removable, a smaller box with a perforated bottom and divided by a transverse partition set exactly in the center. The operation of the device is as follows: The top box being removed by turning the buttons securing it, the blueprints are laid upon the slats, as many as six or eight at a time, and the top box replaced. The water is turned on at the faucet and one end of the pivoted box is depressed to either of the positions shown by dotted lines in Fig. 107, which will throw the water into the compartment at the higher end of the smallest box. A considerable portion of the water will trickle through the small holes of the top box and upon the blueprints, while the opposite ends of the prints are immersed in the water of the lower box, which is maintained at a constant height by the overflow pipe, as shown in Fig. 107.