Abstract: A drive puck for use as a component in a demand drive system is disclosed herein in which a film roller is resiliently centered on a rotating drive shaft so that the tension of a film strip carried thereon selectively causes engagement of the film roller with the drive puck. The puck is secured to the drive shaft so as to rotate therewith and is provided with an external tread which projects into a lateral cavity of the film roller so as to engage with the underside of the film roller in response to the resilient centering movement of the film roller.

Abstract: An apparatus is described herein which when used in conjunction with a continuous film duplicator or printer, stores and transports micrographic, motion picture, and other masters during the printing cycle to eliminate rewinding when making multiple duplicate copies. The apparatus is modular utilizing a pair of carriages so that it may be expanded either horizontally or vertically to accommodate more footage. A single motor is employed to adjust the spacing between top and bottom roller sets disposed on the carriages for various lengths of film while a three-position sensor arm controls the motor. A slack sensor controls the speed of rollers mounted on shafts on the carriages and a motor drives each shaft controlled by the sensor. Low-mass plastic film rollers equipped with soft-touch rubber surfaces are employed for transporting the film and low inertia PM motors provide high acceleration and torque for driving the shafts.

Abstract: A solar heating apparatus is disclosed herein useful as a swimming pool cover whereby the sun's rays can penetrate the apparatus and heat the water therebeneath. The apparatus includes a plurality of individual and separate units of a predetermined geometry which cooperate with each other to cover a given body of water. Each unit includes an upper panel of transparent, plastic material and a bottom panel of opaque, plastic material. The panels are joined at peripheries to provide an integral unit and spacers or ribs are provided to maintain separation between the opposing panel surfaces so that a thermal compartment is defined therebetween. In one form, the bottom panel may be a continuous strip of plastic material shared in common with separate top panels.