Abstract: In machines for the continuous packaging of products inside a film of a plastic material, folded above the products, so as to form a continuous tubular wrapping, a device for changing the opening between the welding element and the counter-welding element permits the operating distance between the welding elements to be changed as a function of the height of the products in course of packaging, thus ensuring the highest packaging speed for both low- and high-thickness products.

Abstract: A packaging machine suitable for the continuous packaging of products, or of groups of products having a different shape and size in height, wherein, thanks to a particular combined movement of the transversal welding unit, both of sinking down towards the product, and of accompanying of the same product during the welding step, relatively to a car for its essentially horizontal shift, a quick and correct packaging of the products is obtained, even very different as regards the length in the direction of advancement of the packaging film, besides as regards the height, with the consumption of the packaging material being minimized to the strictly necessary amount, and the continuous packaging after each other being made possible of products or of product groups, having mutually different dimensions.

Abstract: A packaging machine suitable for the continuous packaging of individual products, or of groups of overlapped products having a different size in height, such as signatures, newspapers, magazines, books, and the like, and provided with at least one running-belt pressing device which is vertically shiftable and is made integral with a car which suitable for reciprocating inside the packaging machine, and which supports a transversal-welding unit, which is provided with a combined motion of the welding element both downwards towards and products and of accompanying of the same products, so as to make it possible said products to be correctly packaged and to be perfectly stacked, with the packaging of even one individual product being made possible, independently on whether it even contains an extremely small number of pages.

Abstract: A centralized drive device in a machine for packaging products in continuous plastic film which unwinds from a reel comprising essentially a feed unit for said products, an individual product feed unit, a unit for wrapping said products in said film, and a unit for welding and cutting the individual packaged products, in which a rigid transmission shaft extends along the entire length of the interior of the packaging machine from a central variable-speed drive. A series of individual motion transmissions, each operating one of the units of the machine, branches from the shaft, there being also connected to the variable-speed drive a further variable-speed drive which, by positive transmission, drives a belt for conveying the products to be packaged, in accordance with the predetermined succession.

Abstract: Longitudinal welding equipment in a machine for packaging products fed on a conveyor belt inside a continuous film of plastic material wrapped around the products with overlapping longitudinal side edges. The equipment comprises a longitudinal welding means positioned above the edges of the means for generating an oscillatory rotary-translational motion on a vertical plane. Furthermore, the equipment provides at least one pressure and accompanying belt a top of the products wrapped inside the film. The welding means and the pressure belt are operatively driven by the same central motor means which actuates said conveyor belt. The welding means is equipped with a means for temperature control operatively connected to the packaging speed.

Abstract: The invention relates to a device for controlling the unwinding of a plastic film in a packaging machine. The film before coming in contact with a conveyor belt for the products to be packaged passes in succession through a pair of dragging rollers and about a floating bar disposed between fixed guide rollers. The drive roller of the pair of rollers is driven by a variable speed motor by way of two alternately activated transmission of different ratio. Two microswitches disposed at different levels cooperate with the floating bar in order to activate one or the other of the transmissions.

Abstract: A loader for box-type feeders of packaging machines, bookbinding machines and the like, in which the products are loaded into a feed channel with an inclined base formed by a conveyor belt, to be brought into contact with a counteracting plate. Sucker arms cyclically withdraw one product at a time and transfer it to wheels provided with grippers which insert the product between pairs of belts by means of which the product is transferred until it discharges into the feeder box. Feeler elements cyclically determine the thrust of the products in the feed channel and enable the conveyor belt to advance through one step when the thrust is smaller than a predetermined value, whereas they prevent said advancement when the thrust is greater than said value.

Abstract: In a machine for wrapping individual articles with a thermoplastic film, a device is provided for correctly positioning the film, which is for example printed with certain symbols, relative to the articles. Said device comprises a mechanism for detecting at every instant the position of an article, a photoelectric cell for detecting the position of the film and a comparison circuit which receives signals from both the detecting means. The comparison circuit comprises logical gates (of AND type) and storage means and is associated to timing means for actuating a motor so as to increase or reduce the speed of the film consistently with the positive or negative results of the speed comparison made by the comparison circuit, or to leave said speed unaltered when the phase relationship between the film and the articles has been found correct.

Abstract: A machine for packaging sundry articles between two weldable plastics material sheets is disclosed, in which provision is made for the formation of a top sheet loop to cope with different tallnesses of the articles as they are being packaged and sealed between the plastics sheet: undue sheet tensions are prevented as well as undue slackening of the sheet.Waste of plastics material is also efficiently done away with.