1 Sc. sometimes called Sole.
Fig. 541. Fixed Sash in Solid Frame
Fig. 5 46 is an interior elevation of part of the sash and frame, with the inside lining removed, so as to show the interior of the case.
These figures are necessarily broken into portions for want of space.
The exterior elevation of this window is shown in Fig. 547, and the interior elevation in Fig. 548. Both of these figures are on a reduced scale.
Each box or case consists of the back lining1 (bl), the inside lining (il), and the outside lining (ol), the side nearest the sash (ps) being called the "pulley style" because it carries the pulleys over which run the sash lines supporting the weights.
These portions of the casing should be grooved and tongued together, as shown in Fig. 544, but in common work the grooves and tongues are often omitted.
The upper end of the pulley style is dovetailed (or, more often, grooved) into the head of the sash frame (H), and the lower end is housed into the sill, and there secured by a horizontal wedge (x, see Fig. 546).
Down the centre of the pulley styles is formed a groove, into which fits a narrow strip (pb), called the "parting bead," because it separates one sash from the other.2
1 Sc. Back boxing.
2 The parting bead is sometimes carried round the upper part of the frame, being attached to the under side of the head, as in Fig. 549. This is an advantage, as it helps to keep the sash steady, and to tighten the joint.
The parting bead is not fixed, as the outer sash cannot be put in without removing it temporarily.
The inside bead should be fixed with screws, so that it also can easily be removed if required to put in or take out the sashes.
The inside bead (ib) is made deeper than the thickness of the inside lining (il), so as to cover the joint between the inside lining and the pulley style (ps, see Fig. 544).
The projecting end of the outside lining (ol) is sometimes rounded, as shown in Fig. 549.
It will be understood that there are two sashes - an upper and a lower. The upper sash slides in the outer half of the frame, between the parting bead (pb) and the end of the outside lining (ol); the lower sash slides in the inner half of the frame, between the parting bead (pb) and the inside bead (ib).
The sill is similar to that already described at p. 270. A notch is formed in its upper surface to receive the lower end of the parting bead. The penetration of water between it and the stone sill upon which it rests is prevented by a metal water bar, as previously described.
The upper parts of the styles of the sashes have grooves taken out of their sides about 1/2 inch square, and extending downwards about 6 inches from the top, to receive the ends of flax ropes or "sash lines" (about 3/8 inch in diameter); these pass over iron or brass pulleys (pp, Figs. 545, 546) fixed in slots near the top of the pulley styles, and are attached to the weights (ww) which counterbalance the sashes.
The direction of the sash line in Fig. 546 is shown by the dotted line. The lower end of the line, after passing through the groove in the sash style above mentioned, enters a hole bored obliquely inwards for 3 or 4 inches in depth, until it meets a larger hole sunk in the side of the style, in which it is secured by a knot which is nailed to the style. This knot is not shown in Fig. 546, as it would occur just where the figure is broken.
The weights are of common cast iron, 14 to 24 inches long, and either circular or rectangular in section. The weights should be together slightly lighter than the sash, and they hang in the boxes, being separated (to prevent them fouling) by the parting slip l (psl), which may be either of wood or zinc.
The upper end of the parting slip is passed through the head of the frame and suspended by a nail driven through it, as shown in Fig. 546.
1 Sometimes called Pendulum Slip.
Nearly at the foot of each pulley style a rectangular hole is cut to admit the weights, which can thus be got at whenever necessary.
This hole is called the "pocket" and is covered by a flush lid or "pocket-piece"l the lower end of which is rebated, and the upper side both rebated and undercut, so as to fit into the pulley style (see Pp, Fig. 546).
The pocket is sometimes placed in the centre, immediately behind the parting bead, as in Fig. 545, but it is more convenient and easier to open if placed in the pulley style, forming the face of the inner box, so that it is just behind the lower sash when closed.
To open the window the lower sash is thrown up or the upper one pulled down, or both. When the window is closed, the sashes are secured in position by a small clip or sash fastening fixed on the meeting rails.
In the example shown in Fig. 545, the inside lining above the head is stiffened by a bracket. B: very often a small block is placed in each of the lower corners for the same purpose, as in Fig. 549.
1 Jr. Foxing.
As this part of the Course does not include linings of any description, the case selected for illustration in Figs. 544, 545 is one of a window in a thick wall of a somewhat inferior building. The jambs inside the window are merely plastered, whereas in a superior building they would be lined, as described in Part II.
The ledge formed by the thickness of the wall within the sill is, however, protected by a window board (Wi Bd) tongued into the back of the sill, and grooved to receive the edge of the plastering.
The inside lining is also grooved for a similar purpose.