=69. Sash Centers.=—When a transom sash is hung at the top or the
bottom, regular hinge butts may be used; but where a sash is pivoted
at the center, either on the sides or at the top and bottom, a pivoted
arrangement, termed a =sash center=, is needed. For large sash or
heavy transoms, and especially for those that are exterior sash, the
rabbeted center should be used. This type of center is illustrated in
Fig. 84; its construction gives great strength and completely closes
the joint against light and water.
An excellent type of center, known as the _Howarth sash center_, is
illustrated in Fig. 85, the method by which it is attached to the frame
and sash being clearly indicated. By this arrangement, the two parts of
the center fold, or butt, against each other and form a tight joint,
the stop-bead for the sash at the top and bottom being arranged as
indicated at _a a_.
[Illustration: 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.
[Illustration: FIG. 86]
[Illustration: 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.
[Illustration: FIG. 88]
[Illustration: FIG. 89]
=71. Transom Catches.=—In Fig. 89 are illustrated types of =transom
spring catches=, or =bolts=. These devices are provided in the several
forms shown to meet various conditions. Those shown at (_a_), (_b_),
and (_c_) have a ring, or eye, in the handle, to which an operating
cord may be suspended, or into which a pull-down hook may be inserted,
to operate the sash. The transom catch at (_d_) is made expressly for
operation by means of a pull-down hook. In very wide windows, for the
purpose of limiting the opening of the sash, these catches should be
used in conjunction with chains instead of with transom lifts.
=72. Transom Chains.=—In Fig. 90 are illustrated several types of
=transom chains=. The chains shown at (_a_) and (_b_) are suitable
for sashes weighing not more than 25 pounds, while that at (_c_) is
sufficiently strong for sashes weighing over 25 pounds. These chains
are fastened to cleats furnished with countersunk screw holes for
securing readily to the frame and sash. When the sash is hinged at the
bottom, these chains are used to limit the opening of the sash. They
are sometimes employed as an additional guard, to prevent the sash from
falling in case the sash lifter becomes broken. The ordinary lengths
of sash chains range from 8 to 24 inches, the latter length being
sufficient for the opening of the largest sash.
[Illustration: FIG. 90]
=73. Casement Trim.=—The term _casement_ applies properly to any hinged
sash. It is, however, usually limited to windows that have a sill set
some distance above the floor. Where the casement sash extends to
the floor, the term _French window_ is generally applied, although
frequently the terms are confused. In designing casement windows,
the details of the hardware should be such that the casements can be
made weather-tight; and in laying out the full-sized details for the
mill work for a casement sash and frame, the available hardware should
be studied, so that the woodwork may be arranged to conform to it.
=74. Casement Bolts and Fasts.=—Casement sash may be provided with any
good form of top and bottom bolts or hinged sash fasteners, but these
should be supplemented by a good latch or cupboard catch at the center.
Special =turnbuckles=, or =casement fasts=, constructed as shown in
Fig. 91, are on the market. All of the catches shown will securely
fasten the sash, but the types shown at (_a_) and (_d_), Fig. 91, will
draw the sash tightly against the frame when the buckle, or fast, is
drawn in place. In countries where casement sash are in general use,
the necessary fastenings, including the top and bottom bolts, are
embodied in one structure, as described in the following article.
[Illustration: FIG. 91]
=75. Cremorne Bolts.=—In the best work, the =Cremorne bolt= is used for
casement windows. This device consists of a vertical rod divided at or
about the middle of its length, thus making two pieces, and is operated
by a knob, or handle, at that point. Types of ornamental Cremorne
bolts are illustrated in Fig. 92. As shown, the upper and lower ends
of the rods, or bolts, slide vertically and in opposite directions,
being operated by the turning of the knob, or handle. These bolts
are furnished with suitable strikes, either of the plate or the box
form, which are attached to the window at the top or the bottom. Since
the ends of the bolts are beveled, they press the two sashes tightly
together and against the sash frame when they are thrown in. A single
movement of the knob, or lever handle, is sufficient to release both
bolts.
[Illustration: FIG. 92]
=76. Espagnolette Bolts.=—In Fig. 93 is shown the =Espagnolette bolt=,
which is similar in construction to the Cremorne bolt. This bolt
consists of a vertical rod, but instead of being in two pieces, as
in the Cremorne bolt, it is in one piece. This rod has hooks at each
end, and, by a rotary motion, engages pins, or plates, in the window
frame and thus draws the sashes together and against the frame. These
bolts are usually operated by a pendant handle, which, when lifted to
a horizontal position, will release the rod so that it may be rotated
to fasten or to release the sash. For very high sash, a supplemental
design may be used by providing a tapered hook on the opposite sash
for the pendant. The Espagnolette bolt is usually heavier than the
Cremorne and exerts more power in forcing the sashes against the frame;
it is also more expensive. Both bolts, however, are available for
use on doors as well as on windows, and lend themselves admirably to
decorative treatment, as shown in the illustrations.
[Illustration: FIG. 93]
The same care should be exercised in the selection of these bolts
as for other hardware, and when ordering them, full-sized details
should accompany the order, showing sections through the top rail and
head-jamb, the bottom rail, the sill, and the lock stile. The exact
measurement of the height and the width of the openings should also be
given, and the information should state whether the sash swings inwards
or outwards. The hand of the active leaf, as well as the height of
the handle from the floor, should also be given. In Fig. 94 are shown
sections through a casement sash, illustrating the conditions requiring
the use of Espagnolette bolts, and, as just stated, sections similar to
these should be furnished the dealer, or manufacturer, so that these
bolts will fit the construction when they are delivered.
[Illustration: FIG. 94]
[Illustration: FIG. 95]
[Illustration: FIG. 96]
=77. Casement Adjusters.=—In order to hold pivoted or hinged sash in a
partly open position, it is necessary to use =casement-sash adjusters=.
These adjusters, and the method of applying them, are illustrated in
Fig. 95. In this figure is shown the adjuster applied to a sash pivoted
at the top and the bottom, but the device can as well be applied to a
casement sash hinged at the sides.
There are many forms of casement-sash adjusters, the common types being
illustrated in Fig. 96. They are arranged for sash that open either
inwards or outwards, and may be applied to either pivoted or hinged
sash. Most casement-sash adjusters usually consist of a rod or a bar
attached to the sash by a hinged or pivoted joint. The rod passes
through a clamp on the frame, or sill, and this rod, when the clamp is
tightened, holds the sash firmly in any desired position.
=78. Window and Shutter Operating Devices.=—The sash-operating device
is provided for the purpose of controlling a number of sash in a line
by one piece of mechanism. Frequently, divided sashes are arranged side
by side in skylights, clearstories, and monitors. These windows are
usually some distance from the floor, and the operating device must be
so arranged that it can be worked conveniently. The device illustrated
in Fig. 97 is known as the _Lovell window and shutter operating
device_, and consists of two longitudinal sections of pipe shafting _a_
connected to cog racks _b_ at the end. These cog racks in turn engage
with a cog, or wheel, shaft _c_, as indicated in the figure. Connecting
arms _d_, with swivel joints at each end, are arranged between the pipe
shafts and the sash. The ends connected to the sash are secured to the
same by means of plates and wood screws, and the swivel joint at the
other end is provided with a sleeve, or socket, that is secured to the
pipe shafts with a setscrew. The commendable feature of this device is
that it is operated by a straight push or pull of the arm, instead of a
twist, as in some other devices on the market. When the chain, or rope,
around the large chain wheel is pulled, the cog is turned, and as it
engages the racks, it thrusts one pipe horizontally in one direction
and the other in an opposite direction. By this means, the connecting
arms to the sash approach one another and lengthen the distance between
the shafting and the sash, which movement tends to push the sash open,
the sash being closed by the opposite operation. By this device as much
as 500 feet of sash may be operated by one wheel, or “power,” as it is
called. This chain wheel, or power, may be located either in the center
or at the terminals, and by careful adjustment will simultaneously
close all the sashes tight against the frame.
[Illustration: FIG. 97]