We use Optical Character Recognition (OCR) during our scanning and processing workflow to make the content of each page searchable. You can view the automatically generated text below as well as copy and paste individual pieces of text to quote in your own work.
Text recognition is never 100% accurate. Many parts of the scanned page may not be reflected in the OCR text output, including: images, page layout, certain fonts or handwriting.
,
..^frj^ljr ^
All photographs used for the illustrations in this article by courtesy of International Projector Corp.
Mechanics of the Modern Projector
NEW mechanical principles and practices, utilized to obtain modern performance in projector mechanisms, are more readily visualized and understood with the help of special models prepared by International Projector Corp. These models, illustrated herewith, have been displayed in some of the larger cities. They are of two general types. Some consist merely of component mechanical assemblies removed from the projector and operated independently, whereby their functioning can easily be seen and studied. Others are enlarged or otherwise altered mechanical representations of projector parts, built to display the principle of operation with greater clarity and vividness.
Figures 1 and 2, carefully examined, reveal the secret of a ring-type governor.
By HENRY B. SELLWOOD
Fig. 1 shows the governor ring at rest; Fig. 2 shows the position it assumes under centrifugal force when the projector is in motion. D is the spring that opposes the centrifugal force. Part B, riding in slot C, is pushed to the left by the action of the spring when the mechanism stops, and is drawn to the right by centrifugal action of the ring when the machine is running. Part B, when drawn forward or backward in this way, causes a corresponding partial rotation of shaft B1, thus altering the position of E, which in turn controls the fire shutter.
A, seen more clearly in Fig. 1, indicates holes penetrating into but not through the governor ring. Others are located at the opposite side of the circumference, in the right instead of the left surface. The function of these holes is to create an uneven distribution of the weight of the ring: it is lighter where material has been removed by the drilling of holes A — A. When shaft C1 is put into rotation, the ring, mounted on trunnions D1 — D1, rotates with it, but by the unequal distribution of its weight it is impelled under centrifugal force to leave the reclining position of Fig. 1 and assume the rectangular position of Fig. 2. In doing so it draws slot C to the right, resulting, as already explained, in the angular lifting of pin E.
F is the motor which, in this demonstration model, drives shaft C1. In the actual projector C1 is the shutter shaft.
This type of governor is wholly silent in operation; flyweights can neither chatter nor bind because there aren't any. The ring performs their function in a different and more modern way. \ nen I the Fire Shutter
Figures 3 and 4 illustrate the action of the fire shutter — a double action. The shutter is controlled by both the governor and the safety device K1, with the latter overruling the governor and taking control away from it when circumstances require. The shutter itself is G, which in Fig. 4 is seen lowered to prevent film fire; in Fig. 3 it is raised to permit projection.
Under normal circumstances G can be raised in one of two ways: automatically, through the raising of pin E of Figs. 1 and 2; manually, by depressing lever H of Figs. 3 and 4. However, lever H oper
12
INTERNATIONAL PROJECTIONIST