Device for splicing two webs of material each originating from a roll

#The present invention relates to a device for splicing the trailing (downstream) end of a first web of material (the expiring web) originating from a first roll to the leading (upstream) end of a second web of material (the new web) originating from a second roll, during stoppage, comprising a frame which accommodates at least a festoon, a web splicing unit and two roll holders having horizontal axes, each roll holder comprising two rotatable chucks for receiving a roll, which chucks are situated opposite each other coaxially and at least one being movable in the horizontal direction and at least one vertically arranged drive belt unit situated between the two chucks for each roll holder, for rotationally driving a roll received between the chucks.

#A device of this type is known, for example, from German Patent Specification No. 3.311.746 and can be used in printing machines. Splicing of the two material webs during stoppage has, inter alia, the advantage that a very good splice can be made. In the known device the chucks are rotatably mounted in two opposite side walls of a roll support frame. One chuck of a pair of chucks of a roll holder is axially displaceable by means of a cylinder-piston unit, so as to enable the receipt of a roll between a pair of chucks. The other chuck of the pair of chucks is coupled with a braking device to decelerate a roll received between the pair of chucks. Furthermore, means are provided for pressing a section of the drive belt of the drive belt unit against a section of the circumference of the roll received between a pair of chucks.

#However, the known device has a number of drawbacks. It is rather difficult to place a roll between the chucks of a roll holder, thus necessitating the use of a crane or other lifting device. Furthermore, the device is suitable for rolls with only one width. Finally, the whole drive belt unit must be tiltable so as to be able to press the drive belt against the roll.

#The invention will now be explained in the description below of an exemplary embodiment on the basis of the drawings.

#FIG. 1 is a perspective view of a first embodiment of the device according to the invention.

#FIG. 2 is a perspective view of the device of FIG.1 from the other side.

#The embodiment of a device according to the invention shown in FIGS. 1 and 2 comprises a frame 1 which includes an upper horizontal frame part 1a and two downwardly-extending verticle frame parts 1b and 1c, a festoon consisting of a fixed roller assembly 2 and a moveable dancer roller assembly 3, a web joining unit 4 and two roll holders 5, 6.

#Each roll holder 5, 6 comprises two rotatable chucks 7, 8, situated coaxially opposite each other for receiving a roll 9 or 10, respectively, of a web of material. The chucks 7, 8 are rotatably mounted in the ends of two arms 11, 12 or 13, 14, respectively, which can be tilted about a horizontal axis and can be displaced in the horizontal direction, the arms 11, 12; 13, 14 of each of the two roll holders 5,6 being fitted so as to be slideable in axial direction and non-rotatable, on a pivot shaft 15, 16 mounted horizontally in the frame. The arms 11, 12; 13, 14 can be displaced along the pivot shaft 15; 16 by means of racks 17 fitted in the longitudinal direction on the pivot shaft 15; 16, the electric motors 18 and 19 on the arms providing the drive. An electric motor 20 serves to displace the roll holder 5; 6 in its entirety laterally for the purpose of lateral corrections.

#To receive the roll in, for example, the roll holder 5, the arms 11, 12 are moved apart by means of the motors 18, 19 and a roll presented by a simple transport means such as a hand truck is placed between the arms, care being taken to ensure that the chucks 7, 8 are sited opposite the central cylindrical sleeve of the roll 9. The arms 11, 12 are then moved towards each other and the chucks 7, 8 are inserted into the ends of the cylindrical sleeve of the roll and are subsequently clamped therein by expanding them. In order to be able to tilt the arms 11, 12; 13, 14 of the two roll holders 5, 6, the pivot shafts 15, 16 are each coupled to a rotating mechanism which, in the embodiment shown, consists of a lever 21 rigidly attached to the pivot shaft 15; 16, and a spindle structure 23 fitted between the end 22 of the lever 21 and the frame 1 and which can be driven by an electric motor 24. Since the arms 11, 12; 13, 14 are unrotatably connected to the associated pivot shaft 15; 16, operation of the spindle structure 23, which causes the lever 21 to tilt, will cause the arms of the roll holder 5; 6 concerned to tilt about the axis of the pivot shaft 15; 16. In this manner, a roll received in the roll holder can be moved up and down in the vertical direction.