Fig. 85
There is a sash center, known as the Tabor, that is constructed as shown in [Fig. 86]. This center is used for very large sash that are vertically pivoted; that is, arranged with a center at the top and bottom. Such sash as these are used extensively in office buildings, because, by their use, the entire window may be thrown open at one time. The Tabor device consists of a special sub-sill, which engages with a ribbed joint strip placed on the bottom of the sash. By this means, a weather-tight joint is secured, and the sash is firmly locked in a closed position. By throwing a lever, the sash is raised above the astragal, or sub-sill, and can then be operated. The top rail is supplied with a filling strip having an irregular joint at the intersection with the sash, and is held firmly by a coil spring encircling the top pivot.
In [Fig. 87] are shown several sash centers of the common type. These possess no particular merit, but are much used for common work.
Fig. 86
Fig. 87
70. Transom Lifts.—The transom lift illustrated in [Fig. 88] is distinctly an American device for operating and fastening the transom lights over doors. This device is used extensively in hotel and office buildings. It is made in various styles and sizes necessary to meet the several requirements. The transom lift consists of a vertical sliding rod that is placed on the door jambs, as at a, with an arm at the top connecting it with the sash, as at b. Near the bottom is a clamp, or grip, that holds the bar a in any desired position. By a vertical movement of the rod, the sash is caused to swing. Transom lifts may be had for transom sashes that are pivoted at the center or for those which are hinged at the top or the bottom. At (a) and (b) in [Fig. 88] are shown the types of transom lifts for center-pivoted sash; the former arranged so that the sash pitches outwards, while in the latter the sash pitches inwards. At (c), the device is shown where the sash is hinged at the top, while at (d) the sash is hinged at the bottom. The several kinds of transom lifts made by the various manufacturers are practically alike, except for variations in the form of the grip, or clamp. The range of sizes and quality of transom lifts is large. The commercial article may be obtained in steel, copper or bronze plated, or in bronze or brass. They are made in ¼-, ⁵/₁₆-, ⅜-, and ½-inch sizes, the size being determined by the weight of the sash and the degree of rigidity and solidity desired to be obtained and expressed. For good work, the ⅜" and ½" diameters are used. The rods may be obtained in lengths of from 3 to 12 feet. In specifying or ordering transom lifts, the rod should always be sufficiently long to reach within 5 feet of the floor.