Theatre Catalog (1948-49)

FIGURE NO. 6 The intermittent is often termed the “heart”? of a projector. Brenkert intermittents are made with an accuracy of 1/10,000 of an inch. These precise dimensions are maintained in operation by generous bearing surfaces and automatic lubrication. Note the long double bearing of the sprocket shaft and the cam shaft; the hardened steel roller on the index pin; the generous size of the star and cam, presenting three to four times the bearing surface of any other intermittent. Brenkert precision is maintained by the micrometer adjustment provided for the star and cam relation. Any heat generated in the intermittent is carried away by the continuously cir| culating oil stream, thus providing a cool-running, trouble-free intermittent. The heavy shaft with long, widely spaced bearings makes an _ outboard bearing on the intermittent sprocket shaft unnecessary. Consequently, the sprocket is removed for reversal or replacement by the simple loosening of one screw, and without the necessity of removing the intermittent from the projector head. This means quick and inexpensive sprocket replacement. Removable Sub-Assemblies A third important point common to all Brenkert projectors is that of separately removable sub-assemblies. Figure 5 shows on the left, the various sub-assemblies removed from the operating side of a Brenkert projector. The right hand side shows the corresponding sub-assemblies removed from the gear side. This type of construction insures quick and accurate servicing. All units are doweled to the main frame for correct and easy realignment of any part removed, thereby maintaining constantly the original accuracy built into the mechanism. Operating Compartment Figure 6 shows the operating compartment of the Brenkert 60 projector. The design and location of all components in the film compartment of the Brenkert 60 projector mechanism provide adequate space between all units to facilitate rapid and accurate threading of the film, and to simplify operational adjustments. The operating compartment is easy to keep clean. All assemblies can be removed separately and quickly for servicing. All sprockets are hardened and then precision ground for smooth, quiet and accurate running of all kinds of 35mm motion picture film. The intermittent sprocket, as well as the upper and lower feed sprockets, can be replaced in less than two minutes by removing one screw and sliding the sprocket off its shaft. All these sprockets can easily be reversed, which doubles their useful life. Film Trap and Film Gate Figure 7 shows the film trap and film gate. The film trap is constructed on a heavy, one-piece casting, especially heat FIGURE NO. 5 1948-49 THEATRE CATALOG treated to prevent warping. It is easily removed for cleaning and inspection; and replacement can be made quickly and accurately, because the entire unit is doweled to the main frame to insure perfect alignment with the intermittent sprocket and the optical axis. The film is guided the full length of the film trap, to prevent film side sway. The film tracks and the film guides are made of highly polished steel, hardened and precision ground. A framing aperture is built into the film trap exactly five picture frames above the picture aperture. This framing aperture facilitates accurate and rapid threading of the film, especially when the mechanism is tilted for a large projection angle. The film gate is mounted on an accurately ground sub-base and moves on two large diameter guide shafts, one at the top and one at the bottom of the gate, thereby holding the film gate in accurate alignment with the aperture at all times. The gate opening is adequate to provide plenty of room when threading the film in the mechanism and for inspecting the film trap shoes and gate pressure pads. Two sets of hardened, polished steei pressure pads are provided on the film gate to insure absolutely steady motion of the film through the film gate, and to hold the film firmly and accurately against the aperture plate when the picture is being projected. The gate can be removed quickly and easily for inspection and cleaning by simply loosening one screw. Framing The framing knob on the Brenkert 60 mechanism is located at the front of the projector, directly below the lens mount, where it is easily accessible from either side of the projector mechanism. Framing the picture at the aperture is accomplished by rotating the intermittent sprocket around its shaft so that the sprocket is always in its same relative position with respect to the picture aperture, regardless of the position of the framing knob. This is the most FIGURE NO. 7 407