TECHNICAL FIELD 
     The present invention relates to an apparatus in a machine for the manufacture of venetian blinds and the like, in which slats are holepunched, cut and passed into cord ladders, for the optional alternation of slat rows of different types, eg, different colours. 
     BACKGROUND ART 
     In recent years, desires have been voiced for venetian blinds with differently coloured slats for realizing different colour patterns and colour combinations in each individual venetian blind. Thus, it may be desirable, in one and the same venetian blind, to have a plurality of identical and/or different width fields with slats of different colours. For producing such a venetian blind in a per se known machine, it is necessary manually to change the slat belts, which entails a considerably longer manufacturing time and, thereby, a drastic increase in production costs. Hence, there is a need in the art for an apparatus for the automatic alternation or changing of slat belts in a venetian blind producing machine. 
     OBJECT OF THE INVENTION 
     The task of meeting the above-mentioned need forms the basis of the present invention. 
     SOLUTION 
     This task is solved according to the present invention in that the apparatus disclosed by way of introduction is provided with a magazine with a number of different slat belts at the infeed end of the machine and that means are provided for switching the magazine for positioning desired slat belts in location for infeed into the machine. The magazine is disposed on rails extending transversely of the machine and is shiftable thereon by means of a piston and cylinder assembly to and from a slat infeed position in register with the infeed rollers of the machine. The magazine is provided with a number of slat belt rolls disposed in side-by-side relationship, the belt ends thereof being fixedly clamped between a clamping roller and a guide roller in such a manner that each belt end is free and grippable by means of the infeed rollers in the slat infeed position. The guide roller displays a groove for each slat belt and the clamping roller has a clamping or braking shoe for each groove and slat and for urging the slat belt against the bottom of the guide groove in the clamping or braking position. The clamping or braking shoe consists of a disk journaled on an excentric shaft and spring-loaded towards its clamping or braking position. The infeed rollers consist of a motor-driven roller and an urging roller which is arranged to urge the slat belt against the periphery of the driven roller for feeding the slat belt into or out of the machine. The urging roller is mounted on a pivotal arm which is switchable by means of a piston and cylinder assembly between a free position and a drive position. The piston and cylinder assembly is arranged, simultaneously with switchings of the arm to the free position, to switch the braking or clamping shoe to the clamping and braking position, and vice versa, so that the slat belts are braked or fixedly clamped partly outside the infeed position and partly when the urging roller is in the free position. 
     As a result of an apparatus according to the present invention, it is possible, in one and the same venetian blind producing machine, to manufacture venetian blinds with different-coloured slats in an extremely reliable and simple manner, whereby manufacture of the venetian blind may proceed without any unnecessary and costly machine down-time. The apparatus according to the present invention also permits automatic shifting or alternation of slat belts in accordance with any desired pattern card or the like. Thus, an apparatus according to the present invention makes for the manufacture of a venetian blind with fields of different coloured slats without any manual operations whatsoever. 
    
    
     BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS 
     The invention will now be described in greater detail below, with particular reference to the accompanying Drawings, in which: 
     FIG. 1 is a schematic side elevation of parts of a block diagram of an apparatus according to one embodiment of the present invention; 
     FIG. 2 is a view, in a direction from the machine, of parts of the apparatus of FIG. 1; and 
     FIG. 3 is a side elevation of a further part of the apparatus shown in FIGS. 1 and 2. 
    
    
     DESCRIPTION OF PREFERRED EMBODIMENT 
     The Drawings show only those parts which are necessary for clarifying the nature of the present invention and its aspects. In a magazine 1, there are disposed five rolls with slat belts 2, 3, 4, 5, and 6 of different colours. The magazine 1 is coupled to a piston and cylinder assembly 7 for movement thereof to and from an infeed position in register with a feeding or drive wheel 8 in the venetian blind producing machine proper. In FIGS. 1 and 3, the magazine 1 is shown in a position with one of the slat belts 2-6 in register with the feeding wheel 8 and, thus, ready for infeed of the belt into the machine. 
     For moving the slat belt into and out of the machine, the feeding wheel 8 cooperates with an urging roller 9. The urging roller 9 is rotatably journaled on a pivotal arm 10 which is switchable for urging the roller 9 towards the periphery of the feeding wheel 8 and for clamping the slat belt between the urging roller 9 proper and the feeding wheel 8, for passing the slat belt into or out of the machine. The pivotal arm 10 is switchable by means of a piston and cylinder assembly 11. 
     In the magazine 1, there are disposed a guide roller 12 and a braking or clamping roller 13. The guide roller 12 is provided with a groove 14 for each slat belt 2-6 and the clamping or braking roller 13 is provided with a clamping or braking shoe 15 for each guide groove 14 for clamping or braking the slat belt 2 against the bottom of the guide groove 14. The clamping or braking shoe 15 consists of a circular disk which is excentrically disposed on a shaft 16. The disk 15 is machined on a cylinder 17 which displays an excentrically placed hole (not shown) for the shaft 16. Between the shaft 16 and the cylinder 17, there is disposed a spring 18, whose one end is fixedly anchored in the shaft 16 and whose other end is fixedly anchored in the cylinder 17. The spring 18 is so arranged as to pivot the cylinder 17 with the disk 15 clockwise in FIGS. 1 and 3, so that the periphery of the disk 15 will come into abutment against the bottom of the groove 14. Thus, a slat belt 2 placed between the two surfaces will be fixedly clamped therebetween with the free end 2A of the belt in the desired position (shown by ghosted lines in FIGS. 1 and 3). For releasing the slat belt 2, there is fixedly disposed on the cylinder 17 a radially extending pin 19, by means of which the cylinder 17 and the disk 15 are pivotal counterclockwise against the action of the spring 18, so that the slat belt is released (shown by solid lines in FIGS. 1 and 3). The rollers 12 and 13 are shown in greater detail in FIG. 2, although the pins 19 are not mounted. Moreover, the magazine 1 includes a further guide roller 22 with a guide groove for each slat belt 2-6. 
     It will be further apparent from FIG. 1 that an arm 20 is fixedly mounted on the piston rod in the piston and cylinder assembly 11 and serves to maneuver the disk 15 by the intermediary of the pin 19. The piston rod end of the piston and cylinder assembly 11 is connected to the pivotal arm 10 by the intermediary of a joint 21 so that the piston rod 11 may move vertically while the arm 10 pivots. 
     As has been mentioned above, lateral shifting of the magazine 1 is effected by means of a piston and cylinder assembly 7. To this end, the magazine 1 is carried on rails 23 and 24, via suitable bearings 25 and 26 (FIG. 3). 
     FIG. 2 illustrates more closely that the different rollers 12, 13 and 22 consist of parts journaled on a shaft and intended for each slat belt (2-6). This is, naturally, necessary, since the slat belts 3, 4, and 6 must be held fast, while the slat belt 2 is released and fed into the machine by means of the feeding wheel 8 and the urging roller 9. 
     It is further apparent from FIGS. 1 and 3 that the feeding wheel 8 and the urging roller 9 are located outside the rear of the machine, so that the slat belt 2 (ghosted line) may extend in between the feeding wheel 8 and the urging roller 9 without coming into conflict with any machine parts during lateral shifting of the magazine 1. 
     The arm 20 is fixedly mounted on the piston rod of the piston and cylinder assembly 11 in such a manner that its position in relation to the joint 21 is adjustable. As a result, it is a relatively simple operation to adjust the position in which the urging roller 9 is to be lifted from the feeding wheel 8 for releasing the slat belt. Naturally, this release operation must not take place until the slat belt 2 is reliably clamped between the bottom of the groove 14 and the periphery of the disk 15. Before this is effected, the slat belt must be backed out of the machine from its last cutting position, and this is effected by rotation of the the feeding wheel 8 clockwise in FIG. 1, while this wheel is rotated counter-clockwise for infeed of the slat belt 2 into the machine. By means of position sensors, the slat belt 2 is stopped before its free end 2A has left the nip between the feeding wheel 8 and the urging roller 9, whereby the free end 2A of the slat belts 2-6 will always be located in a suitable position so as to be inserted into the nip between the feeding wheel 8 and the urging roller 9. 
     The apparatus described in the foregoing is controlled by means of per se known valves, positional sensors and a suitable program. The piston and cylinder assemblies 7 and 11 may suitably be of the hydraulic type, like the motor which drives the feeding wheel 8. The control and regulation equipment requisite for the apparatus according to the present invention is, thus, per se known, and does not constitute any part of the body of the present invention.
The disclosure relates to a slat alternation apparatus in a machine for the manufacture of venetian blinds and the like, for optional alternation of slat belts (2-6) of different colors during the manufacture of a venetian blind, a magazine (1) with a number of different slat belts (2-6) being laterally shiftable at the infeed end of the machine, for positioning of the desired slat belt (2-6) in a position for infeed into the machine.