This section is from the book "Modern Buildings, Their Planning, Construction And Equipment Vol6", by G. A. T. Middleton. Also available from Amazon: Modern Buildings.
Messrs. James Hill & Co.'s combination bolts and locks for folding doors are made either to shoot two ways and with 2-bolt mortice lock or to shoot three ways and with 1-bolt mortice lock.
Panic bolts consist practically of an Espagnolette bolt with a projecting hinged bar across the whole width of the door or doors on the inside, at a height of about 3 feet 6 inches above the floor, and connected to the opening levers which are so arranged that direct pressure against the bars withdraws the bolts and allows the doors to open. They cannot, however, be opened from the outside unless they are so arranged and provided with a key for this purpose. There are several makes of these bolts on the market, some of which can, if desired, be arranged to bolt and open from the outside, but never to be so locked as to prevent the doors from being opened by pressure on the bar inside. Fig. 198 illustrates a pair of " X-IT " panic bolts applied to a pair of swing doors. For a pair of folding doors opening one way only a single bolt with two cross arms is usually supplied, the ends of the arms fitting together on splay in order to convey the pressure from the bar on the free leaf to the bar on the bolted leaf. This arrangement acts well enough for emergency exits only, but the leaves require to be carefully closed in their right order, otherwise the ends of the cross bars will strike the edge of the opposite leaf, and on this account the arrangement is unsuitable for doors in regular use, especially if they are hung on spring hinges, in which case the edges of the leaves are soon much knocked about. In such cases the double bolts as supplied for swing doors are the proper pattern to use, and care must be taken in fixing them that the ends of the cross bars will not catch against the opposite leaves as the doors swing. For positions where it is not considered necessary to have the long cross bars the "Collins" panic bolt or panic mortice locks, manufactured by Messrs. Colledge & Bridgen, may be used. They are actuated from the inside by a small push plate, but are not adapted to be opened unconsciously by a panic-stricken crowd.
Of the fittings and fasteners for double-hung sash windows the two ordinary forms of sash fastener are shown in Fig. 199, A and B. Their weak point is that they can be operated from the outside by means of a knife or piece of flexible steel inserted between the meeting rails. Many devices have been invented to overcome this defect, one of the simplest of which consists of a guard arm actuated by the knob, but swinging round in the opposite direction against the back of the arm. The " Ives," an American pattern, is very simple and effective. It has an eccentric action, is self locking, and draws the sashes together. Robert Adams' " Triumph" patent is designed so that the window may be either quite closed or left slightly open for ventilation; but in neither case can it be opened from the outside. James Hill & Co. make a set of fittings, illustrated by Fig. 2co, consisting of a combined sash lift and fastener on the lower sash, a top catch actuated by a cord which also lowers the top sash, and a pulley and cord for raising the top sash. The same firm also makes a top catch actuated by a special ash long arm, without cords and pulleys.
Meakin's sash fastener and opener consists of two top pulleys (one screwed on either side into the head of frame), two cord plates to secure the cord to the stiles of upper sash, and a catch on the meeting rail of the lower engaging a catch plate on one stile of the upper sash, the catch being actuated by the opening cord of the top sash, which passes over one pulley and under another in the body of the catch.
A spring catch for leaving windows either closed or slightly open for ventilation is shown at Fig. 199, C.
Sash pulleys, like all other fittings, should be well made. The cheapest should have brass face and wheels, steel axles, and brass bushes (that is, the holes in which the axle works should be lined with brass), and the checks should be of wrought iron. The better quality have gun-metal in place of brass, while some are made with roller bearings, and the best of all have ball bearings.
The usual casement furniture consists of fasteners and stays. The general form of fastener is known as a "Cockspur," and may be had in a variety of materials and designs, a plain pattern being illustratea by Fig. 199, D.
Casement stays, for holding the casement open to any desired degree, vary considerably in detail and their method of fastening, but all consist of some form of hinged bar. Fig. 199, E, shows a simple kind, with the hinge plate screwed to the bottom rail of casement and the pin plate to the sill. That shown at F also acts as a fastener.
A simple fanlight catch is shown by Fig. 199, G, the catch being attached to the top rail of fanlight. It can be opened by a long arm, which is a rod, usually of ash, with a brass hook on the end. A catch for use with lines and cleat is shown by Fig. 199, H.
Quadrant stays for fanlights, skylights, etc., consist in their simplest form of a quadrant shaped bar, such as is shown in Fig. 199. k, hinged to the sash and running on a pulley fixed to the frame. On the end of the stay is an eye for attaching a cord, which then passes over a pulley fixed to the frame and down to within reach of the ground, then back over another pulley, and is finally attached to an eye on the sash. Near the bottom of the cord a cleat is attached to the wall to secure it, so as to keep the sash shut or open at any desired angle. There are a number of different arrangements based on the quadrant principle for opening fanlights and skylights, some of them adapted for fanlights within reach and others to work with pulleys and cords. Fig. 199, L, illustrates a simple form for use within reach, made in four different styles to suit top, bottom, or centre-hung sashes opening either inwards or outwards. The illustration shows a bar for a top or centre-hung window opening outwards at bottom. In this case the hinged end of the stay bar is screwed to the sash.
Of those to open with cords, one of the simplest and best known is Leggott's system, which consists of a rack and pinion actuated by a worm (see Fig. 201, A). A neat and simple arrangement for fanlights is the " Invisible" patent opener illustrated at B. As the window is closed the screw disappears in a hole in the frame instead of projecting into the room. For heavy fanlights a side adjustment is provided to support the opposite side.
Screw and twin-screw pattern openers are adaptable to either fanlights or skylights opening in any direction.
They have no projecting arms, and may be had to work either with an endless cord or with rod and handle. Fig. 201, C, illustrates a twin screw actuated by rod and handle, adapted to a set of fanlights opening outwards at bottom. It will be seen on reference to the illustration that on one side of the centre of each fanlight the screw has a right-hand thread, and on the opposite side a left-hand thread, so that when the screw revolves in one direction the hinged arms are drawn together and so open the light. When the screw is revolved in the opposite direction the arms are forced apart and the light closed. Fig. 201, D, shows a screw opener for casements hinged at side, the action of which will be readily traced from the illustration. In this case the screw is revolved by means of an endless cord, but it can also be made with rod and handle, as is shown at C, which pattern may in turn be made with an endless cord.
Fig. 201, E, illustrates the "Walfruna" lantern light opener for lantern lights, conservatories, etc. In this the horizontal rod is revolved by means of a crank, actuated by a vertical rod which is raised or lowered by a handle. As the horizontal rod turns it opens or closes the sashes by means of a hinged crank. The vertical rod may communicate with the crank through any number of bends by means of other cranks and connecting rods as shown.
Fig. 201, F, shows the rod-and-crank system applied to open louvres, and the action will be readily traced from the illustration.
Fig. 201, G, illustrates Robert Adams' patent folding gusset side - draught preventer for fanlights. It is composed of metal plates which fold up on the face, or in the joint of the fanlight out of sight, as preferred.
There are a great many other varieties of fanlight and skylight openers on the market, but enough has been said to indicate the general principles and arrangement of some of the simplest and best known. In making a selection, simplicity of construction and good workmanship should be sought. Beyond this, a pattern suitable to its particular use and position should be chosen, each case being decided on its own merits.