Abstract: A method and apparatus for preparing the start of a material web of a stock roll (5) in a roll exchanger comprises the steps of bringing a surplus roll (20) removed from a stock-roll holder (3), which surplus roll (20) is incorporated in a frame of web-takeup (11) and to which surplus roll (20) an adhesive is applied, into contact with the material web of the stock roll (5), taking up the material web from the stock roll (5) on the surplus roll (20), winding up a length of the material web from the stock roll (5) on the surplus roll (20), winding up a length of the material web of the stock roll (5) on the surplus roll (20) and severing the material web between the portion of the material web wound on the surplus roll (20) ant the stock roll (5). The roll exchanger is provided with means including, in particular, a web-takeup device (11), in which a surplus roll (20) is or can be mounted so that it can rotate, with which the method can be carried out.

Abstract: A method for measuring and regulating the elongation of a moving material web that includes the steps of measuring the length change or speed change occurring over a drive roller, from which the elongation is calculated and, if it deviates from the desired elongation, the web tension is corrected in order to set the elongation. Such a method is preferably used in a web tension device disposed between a roll exchanger and a printing press. The web tension is preferably adjusted through the use of a dancer roller, whose force exerted on the material web is regulated by a controlled dancer cylinder.

Abstract: An auxiliary transport device for transporting a chain part of a web conveying mechanism, which mechanism guides the start of a web of material through a processing device, comprises a transport device, having a length of at least the transit path of the web of material, for engaging and moving the chain part of the web conveying mechanism, as well as a drive device arranged outside the device for moving the transport device and guide, which are arranged along the transit path of the web of material, for guiding the transport device and the chain part through the device.

Abstract: The invention relates to a drier for printed strips, comprising a housing through which the printed strips are carried, means for supporting the strip, a feed means for feeding heated gas to the housing, a discharge means for discharging gas from the housing, and a recirculation device for recirculating the gas present in the housing during standstill of the strip, wherein the recirculation device has been adapted for maintaining recirculation parallel to the direction of movement of the strip. As a consequence of these features the temperature prevailing in the space in the housing is kept substantially uniform during standstill of the strip. By maintaining the operating temperature there is hardly any need for temperature increase to take place during the start-up procedure, so that this procedure will proceed quickly.

Abstract: A device for drying strips of printed material includes a drying chamber through which the strips of printed material are carried, the drying chamber being divided into at least two sections by walls and being as gas-tight as possible in relation to the environment, at least one burner connected to the drying chamber by an outlet duct for discharging at least a portion of combustion gases and connected to the drying chamber by a feed duct for feeding to the burner gases saturated with solvents and structure for feeding fresh air to a first of the at least two sections being located at a first outer end of the drying chamber. The feed duct is connected to a second of the at least two sections.

Abstract: Apparatus and method for joining, while stationary, an expiring web to a new web in such a way that the joined webs lie in one plane. To this end, the new web and the expiring web are brought together and are simultaneously cut through along one cutting line. Subsequently, at least on one side, a bonding strip is applied over the web parts to be joined. The beam-shaped unit has a first contact surface for the new web. In line therewith and on the same side of the travel path, a second contact surface is arranged for the expiring web. That part of the new web which is located downstream of the cutting line, is situated at a distance from the expiring web. By retaining each of the web parts to be joined against an associated contact surface, it is possible to achieve an accurate join.

Abstract: A burner unit for heating a gaseous medium includes a heat exchanger provided with tubes, a space between the tubes connected on the upstream side to a feed duct for the gaseous medium; a combustion chamber connected to the downstream side of the space between the tubes; a burner placed in the combustion chamber; and a fuel supply duct connected to the burner. The side of the combustion chamber remote from the heat exchanger is connected to a first end of the tubes; and a flue gas outlet duct is connected to the other end of the tubes. The elongation of the tubes forming part of the heat exchanger renders the use of a conventional tube plate superfluous. Thus, damage resulting from thermal stresses is avoided.

Abstract: The invention relates to a drier for elongate strips of material, wherein a fan for supplying a drying gas mixture to an array of nozzles is not located in the same height as the nozzles, as is common in the field of driers to allow supply of drying gas to the nozzles with a minimal amount of curves in the supply path. Instead thereof the fan is located above or below the nozzles to save ground area, and nevertheless maintaining a feed path towards the nozzles with a minimal amount of curves.

Abstract: A device is provided for connecting the trailing end of a web of material to the leading end of the following web of material. The web of material undergoes a processing operation downstream from the device. The device includes a frame having guide rollers for determining the travel path for the web of material. Pressure elements are provided in the device which are movable towards and away from each other at right angles to the travel path of the web of material. In addition, cutting elements for cutting through the web of material are also provided. The device can be made wide for interconnecting wide webs of material but it is also compact in structure.

Abstract: The invention relates to a method and apparatus for drying lengths of carrier material which have been printed with ink comprising an evaporable solvent. To maintain the concentration of the solvents evaporating from the printing ink, this concentration has to be determined. As known apparatuses for measuring the concentration are expensive, prone to faults and need regular calibration, the present invention provides a method for calculating that concentration. According to said method the concentration of the evaporated solvents in the gas mixture is determined by measurement of the temperature and flow rate of a mixture to be supplied to the burner, and by measurement of the temperature of the gas mixture heated by the burner and by measurement of the flow rate of the fuel supplied to the burner.

Abstract: A cooling device for cooling a web of material coming out of a drier, in particular a paper web of an offset printing machine coming out of a drier, which cooling device comprises a substantially closed housing with an inlet and an outlet slit for the web of material, said housing being provided at the outlet slit side with a feed aperture for feeding in outside air and at the inlet slit side with a discharge aperture for discharging air from the housing, the air being fed through the housing in counterflow to the direction of movement of the web of material, wherein the housing in the direction of movement of the web of material is provided with two or more cooling units placed in series which bring the infed air successively into contact with the web of material.

Abstract: A drier for a web of material in particular for a offset printing machine, consisting of an housing with an inlet slot and an outlet slot for the web of material. The housing is provided with air nozzles which are fed via one or more fans with the atmosphere in the housing. The housing also have at least one heating appliance provided with a combustion unit for treating the atmosphere inside the housing. The interior of the housing is divided by a partition into a heating section and an evaporating section. The heating appliance is provided with an incinerating portion and part of the combustion gases is via an opening discharged to the heating section, while the remaining combustion gases are discharged into the outside air, and the atmosphere of the evaporating section is used as combustion air for the burner of the combustion unit.

Abstract: In a device for continuously feeding a web of material from a stock roll, a conveyor means for conveying the unwinding roll and the remnant roll through the device comprise two parallel essentially U-shaped guide tracks for the rolls. The legs of the U extend in lengthwise direction of the device, such that both loading of a new roll and picking up and discharging of a remnant roll can take place at the front side of the device. For controlling the speed of an unwinding roll two driving belt units are provided which can cooperate with the periphery of the unwinding roll one after another. For running a new roll up to the required peripheral speed for making a splice with an unwinding web and keeping said roll at that speed until the splice is made a core drive is provided which acts upon the shaft of the new roll, and which can work independently of the driving belt units. A new roll can thus be prepared with an adhesive strip over the whole width of the roll, which will result in an uninterrupted splice.

Abstract: A heating appliance particularly for a drier of a web of material comprising a combustion unit having a burner and a combustion chamber. The combustion chamber consists of an elongated first section extending away from the burner and merging into a second portion via a bend of 180.degree. said two portions defining an U-shaped path for the combustion gases and being approximately of equal lengths. The combustion chamber also being provided with one or more discharge openings for discharging part of the combustion gases, said opening(s) being controllable by means of a valve.