Machine for producing venetian blinds and punching device therefor

Abstract: In a machine for producing venetian blinds, a strip of slat material is intermittently fed by a feeding device to a mounting station where slats (20, 20′) are mounted in a number of ladder tapes (17) at threading stations (12). Punching devices (30) for punching the strip of slat material comprise according to the invention a punching tool (30) which is movable laterally relative to longitudinal direction of the strip of slat material between an operative position in which the die (32) and punch (33) of the punching tool are in the correct position for punching the strip of slat material, and an inoperative position in which the die and punch of the punching tool are positioned laterally outside the strip of slat material. The punching devices can have at least one cutoff or separating punching tool for cutting or separating individual slats (20) from the strip of slat material. The punching device of the venetian blind production machine comprises a punching tool (30) with a die (32) and a punch (33) for punching or cutting a strip of slat material for the forming of slats (20). According to the invention, the punching device comprises a moving or driving mechanism (40-42) which moves the punching tool between an operative position in which the die and punch of the punching tool are in the correct position for punching the strip of slat material, and an inoperative position in which the die and punch of the punching tool are positioned laterally outside the strip of slat material.

Description: The present invention relates to a machine for producing venetian blinds and a punching device therefor. The development of venetian blind production machines has been going on for many years, and as examples of prior-art technique mention can be made of Swedish Patents SE-B-323,787, SE-B-323,501, SE-B-339,097, SE-B-361,915 (US 3,824,657), SE-B-441,941 (US 4,665,599 and EP-B-0,182,805) and SE-B-458,379 (US 315,799 and EP-A-0,331,657). A common feature of this type of machines for producing venetian blinds is that they comprise a feeding device for intermittently feeding from a slat material supply station a strip of slat material (normally a metal strip) in the longitudinal direction thereof through a number of ladder tapes at threading stations, and punching devices for punching the strip of slat material. In prior-art machines, the ladder tape holes have been punched at separate punching stations where the strip of slat material has been stopped before being finally introduced into a mounting station where the strip of slat material has been inserted in a number of ladder tapes that are to be included in the finished venetian blind. In old types of Prior-art machines it has therefore been necessary to use long machine beds where the punching devices intended for the ladder tape holes have been arranged at a punching station before the actual mounting station. An improvement of these machines is represented by Swedish Patent SE-B-441,941 in which a cutting station is positioned between two neighbouring mounting stations, thereby making it possible to manufacture at least two venetian blinds simultaneously. There are also examples of machines in which the strip of slat material is advanced by small steps for successive punching of the ladder tape holes. These machines suffer from the drawback that they are slows because of the repeated stops of the advancing of the strip of slat material in each punching operation. The prior-art machines have several advantages as compared to older technique, but it is a disadvantage that the machines must have long machine beds, and that the strip of slat material therefore need be transported over long distances through the machine, before it is finally mounted in the ladder tapes at the mounting station. One object of the present invention is to provide a venetian blind production machine and a punching device which make it possible to shorten the machine bed, while maintaining the machine capacity. A further object of the invention is to provide a punching device for the above-mentioned machine. One more object of the invention is to provide a machine for producing venetian blinds in which the punching and ladder tape folding operations can be efficiently coordinated. A further object of the invention is to provide a venetian blind production machine and a punching device which can punch ladder tape holes adjacent or at each ladder tape folding station. One more object of the invention is to provide a venetian blind production machine whose punching tools are movable between an operative and an inoperative position, the punching tool in its operative position straddling the strip of slat material and, in its inoperative position, being in a position laterally outside the strip of slat material. In short, the invention thus relates to a machine for producing venetian blinds, comprising a feeding device for intermittently feeding a strip of slat material from a slat material supply station to a mounting station where the slats of the intended venetian blind are mounted in a number of ladder tapes at threading stations. This machine is provided with punching devices for punching the strip of slat material. The punching devices comprise a punching tool which is laterally movable relative to the longitudinal direction of the strip of slat material between an operative position in which the die and punch of the punching tool are in the correct position for punching the strip of slat material, and an inoperative position in which the die and punch of the punching tool are positioned laterally outside the strip of slat material. Preferably, the reciprocating punching tools are mounted adjacent the threading stations of the venetian blind production machine. In a preferred embodiment, the punching devices comprise punching tools for punching lift cord holes. In one more preferred embodiment, the punching device also comprises at least one cutoff or separating punching tool for cutting or separating individual slats from the strip of slat material. The invention also relates to a punching device for a venetian blind production machine, said punching device comprising a punching tool having a die and punch for punching or cutting a strip of slat material for the forming of slats. This punching device comprises a moving or operating mechanism for moving the punching tool between an operative position in which the die and punch thereof are in the correct position for punching the strip of slat material, and an inoperative position in which the die and punch of the punching tool are positioned laterally outside the strip of slat material. The invention will now be described in more detail with reference to the accompanying drawings in which: Fig. 1 is a side view of a basic sketch of a machine according to the present invention, Fig. 2 illustrates in more detail a ladder tape threading station and a punching station in the venetian blind production machine, Fig. 3 is a cross-sectional view along the line III-III in Fig. 2, Fig. 4 is a top plan view of the stations according to Figs 2 and 3, Figs 5, 6 and 7 are the same views as Figs 2-4, however illustrating the punching tool in its operative position, Figs 8, 9 and 10 are the same views as Figs 2-7, however illustrating the tool in its inoperative position, Fig. 11 is an end view of an embodiment of the tool according to the present invention, Fig. 12 is cross-sectional view along the line XII-XII in Fig. 11, Fig. 13 is a top plan view of the tool in Figs 11 and 12, Fig. 14 is a view corresponding to Fig. 12, illustrating a further embodiment of the tool according to the invention, Fig. 15 is a top plan view of the tool in Fig. 14, Fig. 16 is a cross-sectional view, corresponding to Fig. 12, of a different embodiment of the tool according to the present invention, Fig. 17 is a top plan view of the tool in Fig 16, Fig. 18 is an end view of a further embodiment of the venetian blind production machine according to the present invention, the tool being shown in its inoperative position, Fig. 19 is a cross-sectional view along the line XIX-XIX in Fig. 18, Fig. 20 is a top plan view of the machine according to Figs 18 and 19, Figs 21, 22 and 23 are the same views as Figs 18-20, however illustrating the punching tool in its operative position, Fig. 24 is an end view of a further embodiment of the venetian blind production machine according to the invention, Fig. 25 is a cross-sectional view along the line XXV-XXV in Fig. 24, and Fig. 26 is a top plan view of the machine according to Figs 24 and 25. Fig. 1 is a side view of a basic sketch of a machine for producing venetian blinds. The machine comprises a frame 10 supporting a bed 11. Ladder tape threading stations 12 are arranged along the bed 11. These stations can be movable along the bed according to e.g. Swedish Patent Specification SE-B-458,379 (US 315,799 and EP-A-0,331,657) which is incorporated in this specification by reference. Adjacent the threading stations there are ladder tape stores or magazines 13 from which ladder tapes are pulled upwards in a manner which will be described below. The machine comprises a slat material supply station in the form of a supply reel 14 from which a strip of slat material 15 is unwound during operation of the machine. The slat material can be a strip of metal, plastic, fabric, wood or paper and is advanced along the machine bed by driving means 46 which are not shown in detail. These driving means may be designed as described in Swedish Patent Specification SE-B-441,941 (US 4,665,599 and EP-B0,182,805) which is also incorporated in this specification by reference. The machine also comprises in a per se known manner a numerical control means 16 for controlling the various functions of the machine. Figs 2-4 illustrate a ladder tape threading station which is included in the venetian blind mounting station and which is combined with a punching station. In the embodiment shown, use is made of a ladder tape folding mechanism and a slat retaining mechanism of the type disclosed in the above-mentioned Swedish Patent Specification SE-B-441,941. As is apparent, the ladder tape 17 is supplied from below and passes clamping means 18 on its way up to the actual threading station and to a store 19 in which slats 20 which have already been passed through the ladder tape are retained. After threading and separating the slats, they are raised or lifted by a lifting means 21 towards the lower side of the slats already in the store 19. The slats are then retained in the store in a prior-art manner. For folding the ladder tape, use is made of a ladder tape guide 22 which is moved sideways between one position as shown in Figs 2-4, and another position as shown in Figs 8-10. The moving of the ladder tape guide 22 is effected in that this is movably mounted and is driven back and forth by means of a drive mechanism 23. Thus the ladder tape guide 22 sees to it that the rungs of the ladder tapes are placed alternatively on one and the other side of the lift cord holes of the different venetian blind slats 20. According to the invention, the venetian blind production machine comprises a punching device which is generally designated 30. The punching device comprises a punching tool 31 having a die 32 and a punch 33. The design of the tool, which is shown as an example, is evident from Figs 11-13. The die 32 is arranged on a lower holder 34, while the punch 33 is arranged on an upper holder 35. The upper holder 35 is guided to move towards and away from the lower holder 34 by means of guide pins 36. The punching movement is accomplished by a driving motor 37 which is mounted under the tool and which can be, for example, a pneumatic or hydraulic motor, but which also can be a mechanical driving element. The driving motor 37 moves a connecting rod 38 upwards and downwards for operating the upper tool holder 35. For retaining punched out material there is provided an elastomer ring 39 which is mounted around the punch 33 on the lower side of the tool holder 35. The tool 30 is mounted on a tool holder 40 which is reciprocable along guides 41 under the action of a driving motor which in the embodiment illustrated has the form of a piston-and-cylinder assembly 42. The tool can thus be moved between an operative position as illustrated in Figs 5-7 and an inoperative position as shown in Figs 2-4 as well as in Figs 8-10. Owing to this movability, the tool can be pulled out laterally from the area of the strip of slat material 15, when this is to be moved lengthwise or raised to the store 19 after the individual slat has been cut. By this arrangement, the bed of the machine can be shortened to substantially half its length, while maintaining the same production capacity of the machine. In the embodiment of the invention as illustrated in Figs 3-13, the tool is designed to perform a translational motion transversely of the direction of travel of the strip of slat material. The principles of the invention may, however, also be used for other motions of the tool. Fig. 14 illustrates an embodiment of a tool 30' which is nonrotatably connected to a journal 43 by means of e.g. wedge joints. The journal 43 is in turn connected to a driving motor (not shown) for pivoting the tool 30' between an operative position A and an inoperative position B or an inoperative position C. In the positions B and C, the tool is located laterally outside the path of the strip of slat material 15. While using a pivotable tool, the pivoting movement may also be coordinated with the movement of the ladder tape folding mechanism 22, 23 and, optionally, the actual folding of the ladder tape can be accomplished by the punching tool itself or by some projection formed thereon. In the embodiment shown in the drawing, the tool comprises two punching tools which are arranged at an angle of 180° to one another. The same principle may be used for a number of tools, for example three or four, which are distributed equiangularly around the journal 43. In the embodiment shown, the pivoting occurs about a vertical axis. The pivoting can also occur about a horizontal axis, the tool being mounted on an arm whose one end is mounted on a horizontal journal and whose other end carries the tool for moving it, while the pivoting of the arm is limited, from its operative to its inoperative position, and vice versa. Figs 16 and 17 illustrate a further embodiment of the punching tool according to the invention. In this case, the tool is doubled, thus having a die and punch at both ends. This embodiment may be used to facilitate quick shifting between different widths of the strip of slat material. Figs 18-20 and 21-23, respectively, illustrate a further embodiment of a venetian blind production machine according to the present invention. Figs 18-20 illustrate the punching tool in its inoperative position, and Figs 21-23 in its operative position. In these Figures, the same reference numerals are used for the same parts as in the embodiments described above. The difference between this embodiment and those described above resides in the positioning of the punching tool 30'' which is used to punch the lift cord holes in the strip of slat material. As shown in the Figures, this punching tool is positioned adjacent the actual threading station, but inside the slat mounting station. When using this embodiment of the invention, the feeding of the strip of slat material is temporarily stopped at the punching tool 30'' for punching the lift cord holes, before the strip of material is advanced to the final mounting position. In this embodiment, use is preferably made of a punching tool at each threading station. Figs 24-26 illustrate one more embodiment of the venetian blind production machine according to the invention. This embodiment distinguishes from the one in Figs 2-10 merely regarding the presence of a cutoff or separating punching tool 47 which is mounted on a tool holder 48. This tool holder is reciprocable along guides 49 under the action of a driving motor which also in this case has the form of a piston-and-cylinder assembly 50. The Figures show the tool in its inoperative position, but like the tools 30, 30' and 30'' described above, this tool can be moved forwards to an operative position in which it can cut a slat 20 from the intermittently supplied strip of slat material 15. This cutting operation is suitably effected at the same time as the lift cord hole is punched by means of the punching tool 30. The cutoff or separating punching tool 47 can suitably be designed as described in the above-mentioned Swedish Patent SE-B-441,941. As is evident from what has been said above, the invention provides a venetian blind production machine and a punching device which permit a considerable shortening of the machine bed, thereby making it possible to use the machine more efficiently. The invention may be used either to shorten the machine bed or to double the capacity of the machine according to the principles described in the above-mentioned Swedish Patent SE-B-441,941.

Claims: Machine for producing venetian blinds, comprising a feeding device (46) for intermittently feeding from a slat material supply station (14) a strip of slat material (15) in the longitudinal direction thereof through a number of ladder tapes (17) at ladder tape threading stations (12), and punching devices (30, 30', 30'', 47) for punching the strip of slat material, characterised in that said punching devices (30, 30', 30'', 47) comprise a punching tool (30, 30', 30'', 47) which is movable laterally relative to the longitudinal direction of the strip of slat material (15) between an operative position in which the die (32) and punch (33) of the punching tool are in the correct position for punching the strip of slat material, and an inoperative position in which the die and punch of the punching tool are positioned laterally outside the strip of slat material. Machine as claimed in claim 1, characterised in that the punching tools (30, 30', 30'', 47) are mounted at the threading stations (12) of said venetian blind production machine. Machine as claimed in claim 1 or 2, characterised in that the punching devices also comprise at least one cutoff or separating punching tool (47) for cutting or separating individual slats (20) from the strip of slat material (15). Machine as claimed in claim 3, characterised in that also the cutoff or separating punching tool (47) is movable sideways relative to the longitudinal direction of the strip of slat material (15) between an operative position in which the die and punch of the punching tool are in the correct position for cutting or separating a slat (20) from the strip of slat material, and an inoperative position in which the die and punch of said punching tool are positioned laterally out-side the strip of slat material. Machine as claimed in any one of claims 1-4, characterised in that said punching tool (30, 30', 30'', 47) is arranged to perform a translational motion between its operative and inoperative positions (Figs 2-10, 18-26). Machine as claimed in any one of claims 1-4, characterised in that said punching tool (30') is arranged to perform a pivoting motion between its operative and inoperative positions (Figs 14-17). Machine as claimed in any one of claims 1, 2 and 6, characterised in that said punching tool (30', 30'') is coordinated with a ladder tape folding mechanism for coordinating the punching operation and the ladder tape folding operation. Machine as claimed in claim 7, characterised in that said punching tool (30', 30'') for punching lift cord holes is arranged to pivot back and forth between its operative and inoperative positions, and that the driving means of said ladder tape folding mechanism is drivingly connected to said punching tool. Punching device for a venetian blind production machine, comprising a punching tool (30, 30', 30'', 47) having a die (32) and a punch (33) for punching or cutting a strip of slat material (15) for the forming of slats (20), characterised in that said punching device comprises a moving or driving mechanism (40-42; 43; 48-50) which is arranged to move said punching tool (30, 30', 30'', 47) between an operative position in which the die (32) and punch (33) of said punching tool are in the correct position for punching the strip of slat material (15), and an inoperative position in which the die and punch of said punching tool are positioned laterally outside the strip of slat material. Punching device as claimed in claim 9, characterised in that the moving mechanism (40-42, 48-50) is arranged to impart to said punching tool (30, 47) a translational motion between the operative and inoperative positions thereof. Punching device as claimed in claim 9, characterised in that said moving mechanism (43) is arranged to impart to said punching tool (30', 30'') a pivoting motion between the operative and inoperative positions thereof.

Inventors: NILSSON BERNDT ROLAND, NILSSON, BERNDT ROLAND
Applicants: SANI MASKINER AB, AKTIEBOLAGET SANI-MASKINER
Application year: 1992
Main classification: E06B9
IPC codes: B21D28, B21D53, B26F1, E06B9