GB2227040A

GB2227040A - Manufacture of venetian blind slats

Info

Publication number: GB2227040A
Application number: GB8900771A
Authority: GB
Inventors: Francois Rudolphe Eschauzier; Guy Humphrey Lim
Original assignee: Hunter Douglas Industries BV
Current assignee: Hunter Douglas Industries BV
Priority date: 1989-01-13
Filing date: 1989-01-13
Publication date: 1990-07-18
Also published as: GB2229215A; GB8906238D0; GB8900771D0; GB2229215B

Abstract

A method for the automatic manufacture of venetian blind slats from a preferably continuous strip of slat material, said method comprising the steps of: feeding said strip of sat material to a cutting unit; cutting first sections, each of a given length, from said strip of slat material; punching holes in said first sections; cutting second sections from parts of said strip of slat material immediately following said cut-off first sections; rejecting said second sections, and passing said first sections to a lacing station for assembly into a venetian blind.

Description

METHOD AND APPARATUS FOR MANUFACTURE OF VENETIAN BLIND SLATS FROM CONTINUOUS STRIP SLAT MATERIAL HAVING A REPETITIVELY PATTERNED SURFACE The present invention relates to method and apparatus for the manufacture of slats for Venetian Blinds from preferably continuous strip materials printed or embossed with a repetitive pattern.

Venetian Blinds are manufactured with a variety of decorations and finishes, often applied to the slats thereof, which, being formed of a substantially flat or slightly crowned material, are easily printed upon. The slats are usually cut from a continuous strip material and fed straight into an automatic assembling machine. A repetitive design is usually applied to the continuous strip before it is cut into slats and the slats assembled. If the repetition length of the pattern, for example, 1000 mm, is similar but not the same as the length of each slat, for example, 1010 mm, the assembled blind shows an additional secondary pattern, in this case a slanting pattern, between repetitions of the preprinted pattern on adjacent slats.

This secondary pattern is often undesirable, especially in the case where the preprinted pattern is a marble or wood grain effect, and spoils the visual effect of the preprinted pattern.

One method of avoiding such an secondary pattern is to scramble the slats by hand before they are fed into an automatic blind assembly machine. However, such a process is time consuming and expensive and negates the advantages of having an automatic combined cutting and assembly machine.

It may also be desirable for the assembled blind to show a secondary pattern different from that which would occur if the cut slats were simply assembled in the order they left the cutting machine.

According to the present invention there is provided a method for the automatic manufacture of venetian blind slats from a preferably continuous strip of slat material, said method comprising the steps of: feeding said strip of slat material to a cutting unit; cutting first sections each of a given length from said strip of slat material; punching holes in said first sections; cutting second section from parts of said strip of slat material immediately following said cut-off first sections; rejecting said second sections; and passing said first sections to a lacing station for assembly into a venetian blind.

By using the method of the present invention, secondary patterns in the assembled blind may be eliminated or modified as desired to obtain a pleasing finish. This may be done without substantially slowing down and without major modification of the assembly process.

Also according to the invention there is provided an automatic venetian blind slat cutting apparatus, wherein sections are cut from a preferably continuous strip of slat material, and passed to a lacing station for assembly into a venetian blind, said apparatus comprising; feed means for feeding said strip of slat material, interrupting means for interrupting feeding of said strip of slat material, cut-off means for cutting said strip of slat material into first and second sections, rejection means for rejecting second cut sections, passing means for passing first cut sections to a venetian blind assembly machine, control means connected to said interrupting means, said cut-off means, said passing means and said rejection means, said control means being effective to control said interrupting means, said cut-off means, said passing means and said rejection means so as to cut first sections of a first predetermined length from said strip of slat material and pass said first sections to said venetian blind assembly machine, and to cut said second sections from said strip of slat material and reject said second sections.

The second cut sections may have a predetermined fixed length, or have a variable or random length; and a variable, random or predetermined number of such second sections may be cut betweeen adjacent first sections. If it is desired to eliminate any secondary pattern in the assembled blind, the second sections are cut with random length, or a random number are cut, or possibly both. If a particular secondary pattern is desired the length and number of the second sections cut may be fixed or may vary according to a predetermined formula.

The rejected second sections may either be scrapped or may in some cases be recycled into the production of the continuous strip or might alternatively be used as samples for promotional purposes.

In order that the present invention may more readily be understood, the following description is given, by way of example only, with reference to the accompanying drawings in which: Figure 1 is a schematic view showing how slats are cut from a continuous strip of slat material in a conventional venetian blind assembly apparatus.

Figure 2 is a front elevation of a conventional venetian blind assembly apparatus.

Figure 3 is a front elevation of a first embodiment of the present invention, using a modified disc section of a conventional apparatus.

Figure 4 is a front elevation of a second embodiment of the present invention.

Figure 5 is a side elevation of a cut off die modified according to the first or second embodiment of the present invention.

Figure 6 is a partly cross-sectioned side view of a left punch die of the first embodiment of the present invention.

Figure 7 is a front view of an alternative type of assembly apparatus incorporating a third embodiment of the present invention.

Figure 8 is a front view of a cut off die of the third embodiment of the present invention.

Figure 9 is a schematic diagram showing how slats are cut from a continuous strip of slat material in one form of venetian blind assembly machine according to the present invention.

Figure 10 is an enlarged cross-section along line X-X of figure 5.

Referring to figure 2, a conventional venetian blind assembly machine includes a strip supply section 7, a forming section 8, a die section 9 and a lacing section 10. The die section 9 includes a left punch die 12, a cut off die 13 and a right punch die 14.

The normal operation of a conventional venetian blind assembly will be described with reference to figures 1 and 2.

It can be seen that the left-hand punch die 12, the cut-off die 13 and the right-hand punch die 14 are all activated simultaneously to cut off a slat 1 while punching the left-end hole 4 of slat 1 and the right-end hole 5 of the next slat 2.

The slat feed roller is stopped and the cut-off slat is fed out of the dies by a feed-out motor and fed to the lacing section, which comprises a number of appropriately activated lacing stations. The feed roller is then restarted and the continuous strip of slat material fed until it reaches a first stop. The right-hand punch die 14 is then activated separately to punch an intermediate hole 6 in the slat. This procedure is repeated until the appropriate number of intermediate holes for the length of slat desired have been punched. When the continuous strip material has been fed a length equivalent to one slat, all three dies are activated simultaneously to cut off slat 2 and punch the left-end hole 4 of this slat and the right-end hole 5 of the slat 3, the process now repeats. In this conventional venetian blind assembly machine, the two punch dies 12, 14 and the cut-off die 13 are all activated by a single camshaft similar to camshaft 18 of Figure 3.

In a first embodiment of the present invention as generally illustrated in figure 3, the following modifications are made to a conventional apparatus: punch die 12a is provided with a solenoid activated mechanism 17, see Figure 6; cut-off die 13a is milled at its lower die part 27, as indicated at 28, to facilitate the drop-out of short pieces of slat material and is provided with a solenoid activated stop mechanism 21, see Figures 5 and 10; The control system for this machine is also modified.

In the first embodiment, the second sections are of a fixed predetermined length, equal to the distance 22, between the cut-off nipple 26 and the stop mechanism 21 in Figure 10, and the control mechanism is adapted to cut a variable or random number of second section between adjacent first sections which form the slats.

The operation of this apparatus in a random pattern mode will be described with reference to Figure 9. At the end of slat 32 and beginning of slat 33, all three dies are activated simultaneously to punch the right end hole 4 of slat 32, the left-end hole of slat 5 and to cut off slat 32. As the strip material is fed, punch die 14 is activated twice at appropriate locations to punch the intermediate holes of slat 33. The dies 12a, 13a are then disengaged from the camshaft device by a clutch 16. At the end of slat 33, cut-off die 13a and punch die 14 are activated to punch the end hole of slat 33 and cut it off. Cut-off die 13a and the stop mechanism 21, are activated to cut-off a single short piece of slat material 31.

Punch die 12a, cut-off die 13a and the stop mechanism 21 are then activated together to cut off a further short piece 31 and to punch the end hole of slat 34. Punch die 14 is then activated twice again at appropriate points to cut the intermediate holes of slat 34. At the end of slat 34, cut-off die 13a and punch die 14 are activated to cut the end hole 4 of slat 34, and to cut slat 34 off the continuous strip of slat material. Cut-off die 13a and the stop mechanism 21 are then activated four times to cut off four short pieces of slat material 31. Next punch die 12a, cut-off die 13a, and the stop mechanism 21 are activated to cut off a fifth short piece of strip material and punch the left-end hole of slat 35.

As can be readily seen, the number of short pieces of strip material cut off between adjacent slats may be easily varied in a random manner so as to eliminate any secondary patterns in the assembled blind.

In the second embodiment of the present invention, of Figure 4, the cut-off die 13a is milled and provided with a solenoid activated stop mechanism 21 as before, see figures 5 and 10. However, the camshaft is provided with two solenoid activated clutches 19, 20 placed either side of the cut-off die 13a. This embodiment then operates as described above. The left hand punch die 12 can remain substantially unmodified.

The third embodiment of the present invention, shown in Figure 7 in which previously used numerals denote like parts, has an electrically activated cut-off die 23, which is controlled seperately from the punch dies 24, which are driven by a camshaft 25, it is therefore only necessary to mill the cut-off die 23 and add a stop mechanism comparable to the mechanism of the previous embodiments. The cut-off die 23, shown in Figure 8, includes a cut-off nipple 26a, a lower die part 27a from which a section 28a is milled out. To this is added a swivelling end stop 29 activated by a solenoid 30. This embodiment may then cut off short portions of slat material of length equal to the distance 22a, and to adapt the control system in order for this apparatus to function according to the present invention.

The end stop shown, is merely one example of the many varieties of end stops that might be employed in an embodiment of the invention; it would also be possible to position the end stop at any position between the cut-off die and the first lacing station, or to employ several end stops, or even an end stop of variable position. The end stop might also be hydraulically or pneumatically controlled rather than electrically operated.

Claims

1. A method for the automatic manufacture of venetian blind slats from a preferably continuous strip of slat material, said method comprising the steps of: feeding said strip of slat material to a cutting unit; cutting first sections, each of a given length, from said strip of slat material; punching holes in said first sections; cutting second sections from parts of said strip of slat material immediately following said cut-off first sections; rejecting said second sections, and passing said first sections to a lacing station for assembly into a venetian blind.

2. A method according to claim 1, wherein said second sections are of variable length.

3. A method according to claim 1, wherein said second sections are of a second predetermined length.

4. A method according to claim 1, wherein said second sections are of random length.

5. A method according to any preceeding claim, wherein said second sections comprise a number of portions, each portion being cut separately from the strip of slat material.

6. A venetian blind slat cutting apparatus, wherein sections are cut from a preferably continuous strip of slat material, and passed to a lacing station for assembly into a venetian blind, said apparatus comprising: feed means for feeding said strip of slat material, interrupting means for interrupting feeding of said strip of slat material, cut-off means for cutting said strip of slat material into first and second cut sections, rejection means for rejecting said second cut sections, passing means for passing first cut sections to a Venetian Blind assembly machine, control means connected to said interrupting means, said cut-off means, said passing means and said rejection means said control means being effective to control said interrupting means, said cut-off means, said passing means and said rejection means so as to cut first sections of a first predetermined length from said strip of slat material and pass said first sections to said venetian blind assembly machine, and to cut said second sections from said strip of slat material and reject said second sections.

7. An apparatus according to claim 6, wherein said control means are further effective to control said feed means, said interrupting means and said cut-off means to cut said second sections of a second predetermined length.

8. An apparatus according to claim 6, wherein said control means are further effective to control said feed means, said interrupting means and said cut-off means to cut said second sections of variable length.

9. An apparatus according to claim 6, wherein said control means are further effective to control said feed means, said interrupting means and said cut-off means to cut second sections of a random length.

10. An apparatus according to any of claims 6 to 9, wherein said control means are further effective to control said at least one feed means, said interrupting means and said cut-off means, so as to cut a number of portions which comprise said second sections.

11. An apparatus according to any of claims 6 to 10, wherein said interrupting means comprises at least one retractable stop mounted downstream of said cut-off means.

12. An apparatus according to any of claims 6 to 11, further comprising a plurality of punch-dies used so as to punch holes in said continuous strip of slat material.

And wherein said control means is further connected to said plurality of punch dies and is further adapted to control each said punch die to punch holes in said first sections.

13. An apparatus according to claim 12, wherein said punch dies are activated by a camshaft which is connected to said control means.

14. An apparatus according to claim 13, wherein a cut-off die forming said cut-off means is also connected to said camshaft, and said plurality of punch dies are controllably disengagable from said camshaft under the control of said control means.

15. An apparatus according to any of claims 12, 13 or 14, wherein all of said punch dies are upstream relative to the direction of feed of said strip material of said cut-off means.

16. An apparatus according to any of claims 12, 13 or 14, wherein one of said plurality of punch dies is downstream of said cut-off means, and the remainder of said plurality of punch dies are upstream of said cut-off means.

17. A venetian blind slat cutting apparatus substantially as hereinbefore described with reference to and as illustrated in the accompanying figures.

18. A venetian blind fabrication machine including an apparatus according to any of claims 6 to 17.

19 . A method of cutting venetian blind slats, said method being substantially as hereinbefore described reference to and as illustrated in the accompanying drawings.