Besides the folding shutters described in the preceding section, there are three other styles of inside window blinds, viz., sliding, rolling and Venetian, that are more or less used in place of shutters or cloth shades, and with which the architect should be familiar.
Sliding blinds are made in vertical sections to slide up and down between the jambs of the window in the same way as the sash. The blinds may operate within the height of the window or they may run into a bottom pocket, or into a top pocket, or into both a top and bottom pocket, so that the window can at any time be either wholly or partly uncovered by the blinds.
The different sections operate independently of each other, each sliding by the others, so that any section may be raised or lowered without uncovering the other portions of the window.
The sections may be balanced by weights or held in place by springs that press against the guides or runways. For narrow windows the springs answer very well, but when the blinds are more than 3 ½ feet wide it is much better to balance them by weights, and balanced blinds will probably give better satisfaction even in narrower windows.
The number of sections to be used in any given window will depend upon the height of the window and the amount of money that can be expended, the cost increasing with the greater number of sections. For windows between 4$ and 6 feet in height three sections are recommended, and for windows over 6 feet in height four or six sections will give the best satisfaction. The total height of the sections should be such that the entire window between the sill and head may be closed, allowing the sections to lap over each other about 1 inch.
Each section should be divided into a number of divisions or panels, which should be between 6½ and 9 ½ inches in width, measured between the centres of the stiles. These divisions may be filled with panels or slats in any arrangement desired.
To use sliding blinds to the best advantage and without sacrificing the appearance of the window, the window frames or inside finish should be made to accommodate the kind of blind selected, as special arrangements are necessary for the runways, and in fine dwellings pockets should be provided for the blinds to shut into when not in use. When the wall is thick enough the best appearance will usually be obtained by having a panel back between the casings and letting this form the front of the pocket for the blinds.
In chambers, school rooms, offices, etc., the pocket may be dispensed with, as by using three sections two-thirds of the window can be uncovered, which is usually all that is necessary, and the appearance of the blinds is not in such places objectionable. The usual thickness of sliding blinds is 5/8 inch, although they are made 1/3 inch and 1 inch in thickness. The sections slide in a grooved runway, which should preferably be secured to the jamb casings or take the place of them, and in such a way that the stop beads for the sash may be removed without disturbing the runways.
Fig. 259.-Deisil far Sliding Blinds.
Fig. 259 shows what is perhaps the best arrangement for inside sliding blinds of three sections, the sections all sliding into a pocket behind the panel back and a hinged stool being provided to cover the pocket when the window is uncovered. Four sections may be arranged in the same way by providing for an additional groove in the runway.
This detail is applicable to all makes of sliding blinds that are held in place by springs at the sides, although some makes may require a greater space between the grooves in the guideway. Weight-balanced blinds may also be fitted in the same way, but for these the pockets for the weights are generally placed in the guideway. Fig. 260 shows a section of the guideway as used with Poppert's weight sliding blind and the manner of applying where the window has a sub-jamb. In this detail the blinds stop on the stool ; if a pocket beneath the stool is desired, the guideway should be extended to the floor and a panel back and hinged stool provided, as in Fig. 259. The Poppert blinds do not run in a groove, but are guided by ornamental metal guides, which run in narrow grooves in the guideway as shown.
When sliding blinds are used in frame buildings or in brick buildings with 9-inch walls, it is generally necessary to place the guideway against the pulley stile, allowing it to take the place of the stop bead, as shown in Fig. 261. In 9-inch brick walls, and often in old frame buildings, it will be necessary either to box out the casings or to project the guideway beyond the casings.*
Fig. 260. - Poppert's Weight Sliding Blind.
In new buildings the guideways should be put up when the building is finished, but the blinds themselves may be put in or removed at will. Sliding blinds may be made at any woodworking shop, but much better blinds for the same amount of money will be obtained by purchasing of those who make a specialty of them, besides obtaining better trimmings than one would be likely to get elsewhere.