The Technique of FURNITURE MAKING
BOOKCASE FITTINGS
Loose shelves in cupboards and bookcases can be adjusted at various heights by several methods. Studs and sockets (272:1, 2) require holes to take the sockets drilled at regular intervals in the carcass sides back and front. Positions can be squared across the matched carcass sides and drilled before assembly, and if they are very numerous it will be convenient to prepare a wood or metal template bar bored out at the correct intervals—1 in (25 mm), 11/2 in (38 mm) or 2 in (50 mm) etc. according to the estimated use—which can be G-cramped/C - clamped to the carcass sides and the holes rapidly bored with a drill and bit, limiting the depth with a stop or a small block of hardwood on the drill. Figure 272:3 is the bookcase strip which requires grooves worked at two levels (272:3A), while 272:4 is the magic shelf wire which is completely invisible when assembled. Holes 1/8 in (3 mm) diameter are bored to take the wires at a distance apart (front to back) fractionally less than the overall length of the wire (272:4A) which is sprung in position with a corresponding stopped groove (272:4C) worked at each end of the shelf. The wires are obtainable in various lengths or in short sections (272:4B), two of which will be needed per shelf end. The system is very positive in action, and the wires cannot be displaced with the shelf in
position as there is only sufficient play in the groove depth to ensure an easy sliding fit.
CASTORS AND GLIDERS
Castors and wheels are available in great variety from light pattern swivel castors for tea-trolleys/ carts, etc. to heavy-duty ball-bearing castors for mounting machinery. Figure 273:1 shows a fixed wheel castor, 273:2 the orbit swivel castor, both with mounting plates either square, oblong, round or shaped for corners, while 273:3 illustrates the grip-neck method of fastening in which the socket with its pronged base is hammered into the leg and the peg pushed home, and 273:4 the wood screw type. Metal thread screws for metal are also available. Before choosing the type, usage and working conditions must be allowed for, and if maximum manoeuvrability is required then four swivel castors should be used; but for heavy loads and long runs two fixed and two swivel are better, with the trolley pushed from the swivel end. Cast-iron wheels are suitable for concrete and rough, gritty surfaces, while indoor use calls for hard - or soft-tyred rubber or plastic, or cast brass or brass-plated steel for the smallest types. The castors can be hidden behind a curtain rail (273:7), but the trolley must be wide enough to permit the full swing of the castor within the
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273 Castors and gliders
curtain without sacrificing overall stability.
Gliders or floor protectors are suitable for furniture which is not often moved. With their greater bearing surface there is less indentation or wear on floors and coverings; moreover, it is not advisable to fit very free-running castors to chairs or divan beds, particularly if used by old people or invalids. Types vary from the simple knock-in nickel-plated furniture glide, to the more sophisticated pattern shown in 273:6.
HEIGHT ADJUSTERS
These are often essential for four-point contact on uneven surfaces (three-point contact will automatically adjust itself). Figure 273:5 shows one version, which is screwed into a tapped socket mounted in the leg; but for heavy desks and tables, etc. either the stem should have a hexagonal nut or a small hole be bored through for a tommy bar so the adjuster can be raised or lowered under load.
