98. In order to prevent the strong sunlight from streaming through the windows of a dwelling or other structure, these openings are usually provided with "blinds, or shutters, which may be of several different forms, or combinations of two or more forms. Blinds are divided into two general classes, namely, inside blinds and outside blinds. The former may be either folding blinds, or rolling or Venetian blinds, while outside blinds are nearly always of the same general pattern, and are known as shutters. The method of construction in each case is influenced largely by atmospheric conditions, but the general principle is the same in all cases. Inside blinds are usually made of hard wood to match the trimming of the room containing them, while outside blinds are nearly always framed of pine and painted to protect them from the elements. Outside blinds must also be constructed with consideration of the fact that they are likely to be subjected to rather rough usage through the influence of high winds and rapid changes of temperature.

Blinds 404

Fig. 61.

99. Inside folding blinds make a very neat, as well as a most useful fitting for the inside of a window, and they should be so arranged that, when closed into their box, the exposed blind will show a panel finish on the inside of the room, as shown at d, Fig. 61 (a). These shutters are usually built in a square jamb, as shown in the plan, Fig. 61 (b), though, when circumstances will permit, they may be built in a splayed opening, such as is shown in Fig. 61 (c), in which case the panel work shows up to better advantage, and the room is rendered lighter.

In Fig. 61 (b) the full plan of the window is shown with the shutters closed into the box at a, while the dotted lines at b indicate the position of the shutters when opened out of the box and closed over the window sash. The extreme width of the shutters between the outside hanging stiles n is 1 1/2 inches more than the width of the window between the pulley stiles, and is divided into four parts, each one of which represents the width of a leaf, or wing of the inside blinds. Two of these leaves are usually paneled, as shown at g, and the other two are provided with fixed or movable slats, as shown at j. The slatted portion is hinged to and folds behind the panel, as at A, and the two then revolve on hinges connecting the paneled leaf to the casing and close into the box with the panel on the exterior as shown at B.

These blinds are framed together in one piece, from the inside sill to the window head, in the same manner as the rails and stiles of a door, except that the outer leaf j of the blinds is filled with fixed or movable slats of louvers, instead of paneling, as is the inside leaf as seen at d, Fig. 61 (a).

The space between the sill of the window and the floor is usually covered by a panel back shown in section at a', Fig-. 61 (a), and its return under the blind box is shown at c. This panel back is usually paneled similarly to the blinds above, and is constructed in the same manner as the paneled shutters. At (d), Fig. 61, is shown a section through the panel back and blind box; at f is seen the bottom of the box, housed into the lining c', which forms the back of the inside of the blind box and is secured at the top by a tongued-and-grooved joint into the soffit piece d. This soffit piece d is paneled to match the blinds and panel back in the jambs, as shown at g', Fig. 61 (a), and is secured by a tongue worked on its edge and let into the window casing at f. The inside lining e of the weight box, Fig. 61 (b), in the window frame, forms the outer lining of the shutter box, and the inner lining of the latter, as shown at h, is attached to and forms a part of the interior trim. The paneled blinds g are hinged to the hanging stile as shown at ft, while the slatted blinds j are hinged to g, so that the knuckle of the hinge is entirely within the edge of the stile of g. This method of hanging permits the blind j to swing back sufficiently from the edge of the stile to secure it against any danger of catching on or against the edge of the architrave, or the blind stop v, when the blind is closed into the box as shown at B. This is still further accomplished by making the blind j 3/4 inch narrower than g, so that there will be no tendency for it to become jammed in the box. The rabbeted joint between the two blind flaps gand j is only 3/8 inch deep, and is provided simply to secure a light-tight joint.

100. When the jambs of the window are splayed, as shown in Fig. 61 (c), there is but a slight difference in the construction of the blinds themselves, though the box requires a little extra attention. At the outside edge of the box, on the side next to the window, the extra hanging stile b' is introduced, to provide at the front edge of the box a proper depth for the paneled shutter k' to shut into, as without it the blind would close back no further than in the square jamb shown in Fig. 61 (b). The box jamb d' is also necessary at the inner side of the box, to form a satisfactory stop for the blinds, and to make a neat finish to the box itself. In splayed window jambs, the blind e' which folds inside, must be made from 1 1/2 to 2 inches narrower than the exterior blind k'.

101. When inside blinds are required for a window, it it, first necessary to lay out a measuring- rod with the stiles, rails, and panels marked as described for the framing of doors, etc. The entire blind, from the sill to the window head, is laid out and constructed in one piece, and then sawed apart at the center of the meeting rails, as shown at h in Fig. 61 (a). The shutters are temporarily hinged and hung in place, so as to insure their proper fit, and the marks are then made at the meeting rails, to which the blinds are afterwards sawed, thus forming a separate set of shutters to cover the upper and lower sashes independently.

102. Outside blinds differ from inside blinds only in such details of construction as their more exposed situation requires. Fig. 62 shows at (a) the inside elevation of an outside blind, and at (b) is shown its plan. The hanging stile for the blind on the window frame is shown at c, and the form of hinge necessary to permit the blind to open around the angle of the brickwork is shown at b. The shape of this hinge and its attachment to the shutter is shown by the dotted lines at f. The angle in the hinges permits them to extend over the joints at the top and bottom rails, and adds strength to the shutter, besides rendering it more secure in high wind storms than would the ordinary hinge.

The extreme length of the arm o b, carrying the pin half of the hinge, permits the shutter to swing around the outside of the brick wall clear of the opening, as shown by the dotted lines, but the corresponding length od causes the blind when opened to move first in the direction da, and is likely to cause the shutters to bind when they are opened. This tendency, however, is compensated by the thinness of the metal of which the hinges are made, as they can be easily sprung out of place a sufficient distance to permit the blinds to open at the center and swing clear.

Blinds 405

Fig. 62.

103. Outside blinds are laid out with a measuring rod, in the same manner as doors and other framed work, the lengths of stiles and rails, the positions and lengths for tenons, and the location of relishes, etc. being all marked on the measuring rod before any of the actual framework is even started. The positions and proportions of the mortises and tenons in this blind are shown by the dotted lines at e, as are also the tightly driven pins which hold the joints in place.

As glue would be useless to secure the joints of outside blinds, owing to their exposed situation, the fixed parts are put together with white lead, as described in Art. 193, of Carpentry. The movable joints of the slats, however, require nothing to make them secure, except a proper consideration for the accuracy of construction and the effects of probable expansion and contraction.

104. Fig. G3 shows a section of the top rail of the shutter and four of the slats, or louvers. The thickness ab of the stile varies, but is never less than 1 1/8 inches, and the holes shown dotted at d are the same in diameter as the slats are in thickness, which thickness varies with the size and weight of the blind. The holes are bored from 3/8 to 5/8 inch from the outside of the stile, and should be exactly \ inch deep. The pins on the ends of the louvers are exactly 11/32 inch in length, thus leaving at each end of the slats 3/32 inch to allow for painting, and to permit freedom of movement.

The louvers are operated by a rod which is attached to each slat by means of two U-shaped staples, one of which is forced into the middle of the edge of the slat, and the other driven into the rod itself, as shown at e. Thus, when the rod f is pulled down, each of the louvers is thrown to the horizontal position shown by the dotted linesj, thereby admitting light and air through the blind.

Blinds 406

Fig. 68.

The top stile c is cut out, as shown at h, to receive the upper end of the rod f and the upper staple when the slats are closed in the position indicated in the illustration.

Blinds of this character are made with two, three, or four panels of louvers, according to the height of the window on the stile of which they are hung, each panel being separated by a horizontal rail from the one next above or below, and each set of louvers being operated by a separate rod, as shown in Fig. 62, except in the case of an unusually high blind, when the upper two sets are sometimes operated by one long rod extending over both panels, and moving in a groove cut across the separating rail when the slats are closed.