Moving Picture World (Mar-Dec 1907)

THE MOVING PICTURE WORLD. 566 Fig. 3 has a toggle joint connection with the carriage. An ingenious arrangement of gearing is provided by which constant gear connection is maintained between the crank shaft mounted on the main frame of the machine and the spindle of the sprocket wheel, which is mounted on the framing carriage. As the framing carriage is light and easily moved up and down by means of the framing lever, the framing of the picture in the projection aperture can be effected instantly and without imparting vibration to the mechanism or the stand upon which it is mounted. The sprockets for feeding the film are all of steel, accurately cut and ground, the intermittent sprocket being especially worthy of mention on account of its extreme lightness, combined With great strength. The lightness of this sprocket is of obvious advantage in the operation of the mechanism on account of the small momentum developed in it at each impulse from the pin wheel. The tension rollers, by which the film is kept in proper engagement with the feed sprockets, are all mounted in pivoted brackets, controlled by springs, and are provided with set screws by which the space between the tension rojlers and sprockets may be accurately adjusted so as to insure proper engagement of the film with the sprockets with a minimum of wear upon the film. The aperture plate against which the film is held during exhibition, is of steel, highly polished and nickel plated. The film is held, in contact with the aperture plate by flat steel springs, carried by the film gate, and adapted to hold the film steady with the least possible amount of friction. The devices for protecting the film from fire are most complete, and it is difficult to see how the film can become ignited on this machine under any circumstances. The loop of film between the upper feed sprocket and the top of the film gate is protected from the heat of the lamp by means of a stationary film shield mounted on the film gate, as shown in Figures 3 and 4. That portion of the film between the lower magazine and the film gate is completely protected by the lower film shield, shown in Figure 4, which is hinged to the walnut baseboard upon which the mechanism is mounted. This lower film shield is held normally in contact with the film gate by means of a spiral spring around one of the hinge pivots, which permits the lower shield to be drawn back easily whenever necessary, but insures the retention of the shield in the proper position when the apparatus is in use. The automatic fire shutter supplied on the mechanism may be of either of the types illustrated in Figures 3 and 4. The shutter illustrated in Figure 3, and known as the “Style A” or “Lever” shutter, is operated by the working of a pin on the crank shaft in a cam slot formed in the sleeve of the crank itself, which encircles the crank shaft. This type of shutter is positive in operation and exposes the film at the projection aperture as soon as power is applied to the crank shaft. Its operation is characterized by very little friction and expenditure of power. The “Style B,” or “Centrifugal” shutter, illustrated in Figure 4, is operated by a centrifugal friction clutch, which is not brought into operation until the film has begun to move at a certain rate. This type of shutter operates with somewhat more friction than the “Style A” shutter, but is preferred by some users because it is impossible to operate the shutter so as to expose the film to the projecting light until the film has begun to move at suitable speed for exhibiting. Both types of automatic shutter close by gravity, and can be counted upon to cut off the light as soon as the motion of the film decreases substantially from the proper speed for exhibiting. The magazines are of the square type and have been demonstrated to be absolutey fire-proof on many occasions. The upper magazine is mounted on the mechanism itself and the lower magazine is furnished with a supporting device adapted for use at the front of the stand or underneath, as may be preferred. In either case, the lower magazine is provided with the patented take-up device shown to best advantage in Figure 2, and covered by United States Patent No. 818,047, dated April 17, 1906. This take-up device is susceptible of adjustment to produce exactly the right degree of tension upon the filrfi to insure proper winding on the take-up reel and to prevent excessive tension, which would tend to tear the film or pull it apart at the joints. The film valves on the magazines, for which patent is pending, are illustrated in Figure 4, and each comprises a narrow chute or guide-way provided at the ends with rollers to prevent frictional contact of the film with the sides of the guide-way. In addition to these rollers, there is provided at the outer end of each guide-way an additional roller, which is mounted in inclined slots, so that it is always held yi contact with the film by gravity. In case of fire, therefore, this third roller presses the film against the opposite friction roller and never fails to extinguish the fire. The lamp house is constructed of the highest grade of Russian iron, and is mounted on a bronze base casting or “spider,” provided with suitable eyes, which encircle the nickel-plated brass sliding ways. The top of the lamp house is lined w'ith mica and the lamp is supported within the lamp house upon a stand, which can be quickly and accurately adjusted from the Fig. 4 outside of the lamp house by means of an adjusting screw. The lamp itself, which is supplied for use with electricity, is of very simple construction, but is notable for the weight and strength of the bronze carbon holders and the ease and accuracy with which the lamp may be adjusted in position. The switch is mounted under the part which forms the top of the stand, and is not enclosed unless an enclosing box is specially ordered. The makers of the “Cameragraph” have consistently maintained that the enclosure of a switch in an iron box is more apt to cause short-circuiting than prevent it. When desired by the purchaser, the “Cameragraph” is supplied with an enclosed switch, but the use of such a switch is not advised. The line of rheostats supplied with the “Cameragraph” includes five different models, all having resistence coils of the celebrated Krupp wire. The rheostat regularly furnished with the equipment illustrated in Figure I, is known as “The Underwriters’ Rheostat,” and is constructed especially to meet the requirements of the New York Fire Underwriters and the Bureau of Water, Gas and Electricity. This rheostat is absolutely fire-proof, and is constructed to deliver twenty-five amperes of current from a no-volt circuit. It is not adjustable (adjustable rheostats being barred by the Bureau of Water, Gas and Electricity), and will pass inspection wherever installed. The stand on which the apparatus is mounted comprises a walnut table board and a set of telescoping tubular legs heavily nickel-plated and of sufficient rigidity to afford the required degree of solidity, but so light that the entire apparatus may be carried readily when packed in a suitable case. TO DEALERS ONI.Y Condensing Lenses, Objectives, &c., &c. KAHN <& CO. 194 Broadway, Now Y orK