A stacker having platforms movable along a path by chains. Cam followers on the platforms engage a cam surface which controls the platform path. The chains are driven by a motor in a closed-loop system which monitors the platforms and controls their speed. The closed-loop system first decelerates the platforms and thereafter stops one platform in the intercept-ready position. The platform cam follower enters a claw which moves the end of the platform through the stream to collect signatures when the downstream platform reaches a predetermined count and deposits the stack on a turntable. A piston assembly rotates the turntable one-half turn after each deposit. Different pressure values are selectively applied to the piston assembly to slow the turntable before it is halted. A rotatable motor coaxial with the turntable axis drives the pushers through drive chains maintained under tension by gas springs which impose opposing forces upon these chains to maintain chain tension regardless of the direction the chains are driven. Jets on the surface of the turntable selectively emit air when a signature is deposited thereon to facilitate removal of a batch. A microprocessor-based controller continuously monitors and periodically adjusts the drop delay and stacking speed of the chains and the stacking platforms to allow the platforms to collect signatures at the lowest speed commensurate with stack size, to form neat stacks, the latter operation being accomplished by either a table look-up or an on-line calculation technique.
Newspapers and other printed matter fed from a printing press or inserting machine are generally folded or delivered in a continuous stream with the papers oriented in an overlapped or imbricated relationship. The stream of papers are received and stacked by the stacking apparatus or stacker which must operate at high speeds. The stacker orients the papers in the stacks and ejects the bundles of papers. The present invention relates to devices intended to reduce the prospects for inadvertent interference with the stacking mechanism or to reduce the potential for injury.
The stacking device for printed products includes a rotatable turntable platform for stacking articles, an ejection assembly for ejecting stacks of articles from the platform, and a positioning device for positioning the turntable for two direction ejection. The positioning device allows the turntable to be arranged for ejecting stacks either parallel or normal to a direction in which articles are fed into the stacking device. This versatility of output allows the stacking device to be incorporated into a plant arrangement more easily and reduces floor space and expense of the entire system. The stacking device also includes an article receiving portion which receives and accommodates articles of differing heights without changing an infeed location of the stacking device. According to one embodiment, the stacking device includes an ejection assembly including two chains received in tracks in the turntable and two posts mounted on the chains which eject the stacks without imparting a rotational moment to the stacks.
A system for converting a digital input signal having a vertical and horizontal dimension into a digital output signal having a different horizontal and vertical dimension than that of the digital input signal. The digital input signal is fed into a first memory which stores the input signal. A horizontal resampling filter is used for converting the horizontal dimension of the digital input signal to the horizontal dimension of the desired output signal. The output from the horizontal resampling filter is transposed so that the vertical dimension of the output signal is oriented in a horizontal orientation. The transposed signal is then stored in a second memory. The transposed signal with the resampled horizontal dimension from the second memory is fed into a vertical resampling filter which converts the vertical dimension information of the transposed signal to the desired format of the output signal. This vertically resampled signal is then transposed so that the horizontal and vertical dimensions are oriented like that of the digital input signal. The re-tranposed signal is then stored in a third memory as the digital output signal.
A shingle bundle palletizer includes a bundle metering conveyor, an incline conveyor, a pattern conveyor, a lug conveyor, an adjustable height transfer conveyor, a shuttle conveyor, and a pallet removal conveyor. The bundle metering conveyor includes one or more upstream and downstream belts. Each upstream belt is driven by an in-roller, variable speed motor that is independent of each downstream belt. The pattern conveyor includes a pair of outer pattern belts rotatably mounted on a pair of outer pulleys, and a center pattern belt rotatably mounted on a center pulley. The pair of outer pulleys is keyed to a pulley shaft and the center pulley is free-rotating about the pulley shaft to decouple the center pattern belt from the pair of outer belts. The pair of outer pattern belts and the center pattern belt are independently driven by separate motors and belts made of elastomeric material. The shuttle conveyor includes a belt made of an elastomeric material driven by a motor connected to a drive shaft. An encoder reads indicia on the drive shaft to determine the precise location of the shuttle conveyor during the reciprocation process.
