Abstract:
An apparatus ( 10 ) is provided for automatically cutting strip materials ( 22 ) into slats ( 20 ) for a venetian blind. The apparatus ( 10 ) has a feeding station ( 12 ), a cutting station ( 14 ), a punching station ( 16 ) and a laddering station ( 18 ). Strip materials ( 22 ) for the slats ( 20 ) are stored in a magazine ( 24 ) of the station ( 12 ) and they are fed one at a time to the cutting station ( 14 ) for cutting into slats ( 20 ) of preset length after slots ( 46 ) have been punched. The slats ( 20 ) are then fed to the laddering station ( 18 ) for assembling into blinds. A sensor ( 56,58 ) is positioned to sense remnants of the strip material ( 22 ) and the remnants are automatically moved back to the feeding station ( 12 ) where they are lifted off the feeding path for ejection by a following strip ( 12 ).

Description:
TECHNICAL FIELD OF THE INVENTION 
     THIS INVENTION relates to an apparatus for manufacturing slats and in particular but not limited to an apparatus for manufacturing venetian blinds automatically. 
     BACKGROUND OF THE INVENTION 
     Prior apparatuses for manufacturing slats for venetian blinds involve two discrete stages. One stage is for cutting slats to length and then the cut slates are manually positioned in the other stage for punching slots in each said cut slats and laddering the punched slats. 
     Both stages of the prior art require proper setting for slats of particular blinds. In general the cutting stage requires setting a cutter to a position for cutting the slats to a desired length and the punching operation requires fixing punches for punching desired slot shape and setting the punches for punching in desired positions in the slats. As up to five punches may be involved in the punching operation the time for setting are relatively long. 
     The existing apparatuses are not flexible as they can only be used to manufacture slats selected from two different widths. 
     As two stages are involved, storage of cut or punched slats is required depending on whether the cutting or punching operation is carried out first. 
     These apparatuses cannot be fully automated as the cutting stage requires manual positioning of strip materials for cutting. 
     The existing apparatuses are therefore highly labour intensive and the slats are costly to manufacture. For timber slats, the existing apparatuses do not give a clean cut and chippings occur at ends of the cut slats. 
     OBJECT OF THE INVENTION 
     An object of the present invention is to alleviate or to reduce to a certain degree one or more of the prior art disadvantages. 
     SUMMARY OF THE INVENTION 
     In one aspect therefor the present invention resides in an apparatus for manufacturing slats. The apparatus comprises a strip material feeding station and a cutting station positioned downstream of the feeding station. The feeding station is adapted to feed a strip material into the cutting station for cutting into one or more slats of a preset length, and includes means for ejecting the strip material when the length of the strip material or remnant of the cut strip material is shorter than said preset length. 
     The ejection means may be arranged to eject the strip material or the remnant at the feeding station or downstream thereof. 
     Preferably the feeding station includes a receiving section for receiving the strip material to be cut and controllable drive means arranged for feeding the strip material into the cutting station. More preferably the drive means is positioned adjacent to the cutting station. 
     Desirably the drive means is reversible and the strip material for ejection or the remnant is driven back to the receiving section for ejection. 
     Preferably the apparatus has a collection section for collecting any of the ejected strip material and the remnants. 
     The feeding station may also include a magazine section in which a plurality of strip materials are stored and an inserting means for inserting one of the strip materials in the magazine section. 
     The magazine section desirably includes a guide arrangement for guiding the strip materials in said magazine section. Advantageously the guide arrangement is adjustable for different width of the strip material. 
     The ejection means may include a sensing device arrange to produce an ejection signal when the strip material or remnant is shorter than the preset length. Typically said sensing means is an optical detector arranged so that it receives an optical signal when the strip material or the remnant is shorter than said preset length. 
     Preferably the cutting stations include a cutting device positioned in close proximity to the feeding station and in particular to the drive means. This positioning allows a maximum number of slats to be cut from the strip material and remnant size is reduced to a minium. 
     In preference a vibration damping arrangement is provided for reducing chippings when cutting. 
     Desirably the cutting device has a saw blade and an anvil for the blade, and the damping arrangement includes employing a vibration damping material for certain parts close to the saw blade and contactable with the strip material during cutting. Said parts typically include a support for supporting the strip material, a clamp for clamping the strip material and the anvil. 
     The apparatus may have a punching station arranged downstream of the cutting station. The punching station includes a punch head having at least one punch controllably movable for punching apertures in the strip material. 
     The punch head preferably having a plurality of different punches selectable for a punching operation. 
     Typically the punch head has an elongate punch fixing member to which the punches are spacedly fixed and the fixing member is movable to select one of the punches for the punching operation. 
     The punching station is advantageously provided with a punch selection arrangement having a movable selection member with markings indicating positions for the punches and the selection member is connected to the punch head so that a punch can be selected by simply moving the selection member to the corresponding marking. 
     The apparatus may have a shaping station positioned between the cutting station and the punching station. The shaping station includes a shaping device arranged for shaping cut ends of the strip material. 
     The shaping device can be arranged to shape adjacent ends of two separate slats simultaneously or in sequence. 
     The shaping device may be selectable from devices for different shapes. 
     The shaping device can be arranged to follow a contoured path to product shapes including radiused corners to said ends, and/or bevelled edges. 
     The apparatus may include one or more laddering stations positioned for receiving the cut and punched slats. 
     Each said laddering stations may have relatively adjustable side members for selectively setting slat width. 
     The laddering stations may also have a mechanism for alternating the amplitude of movement of a string oscillating device as the width setting is change. The string oscillating device provides a zig-zag shaped ladder for the slats. The mechanism may comprise a tapered element acting as a stop for either direction of movement to limit the travel according to that required for each width. 
     The apparatus may have a controller for controlling operations of any of the stations. 
     The controller may be set for controlling the drive means to feed the strip material a preset length from a plurality of settable lengths. It may also be set to control the slot positions. 
     The controller settings may be preprogrammed and can then be selected to simply selecting the program for the settings. The programs are preferably bar coded and a bar code reader is used to select the desired program. 
     The controller may also be set to produce a fixed member of slats. 
     The controller may also be set to control one or more of the operations. 
     The strip material may be wood, plastic, metal including aluminium. 
     Strip materials with widths from 10 to 100 mm can be accommodated by the apparatus. 
     In order that the present invention can be more readily understood and be put into practical effect the description will now be described with reference to the accompanying drawings which illustrate non-limiting embodiments of the present invention, and wherein: 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a schematic diagram of a plan view of the apparatus for manufacturing wood venetian blinds according to the present invention. 
     FIG. 2 is a side view of the apparatus shown in FIG. 1; 
     FIG. 3 is an end cross-section view at A—A of the apparatus shown in FIG. 1; 
     FIG. 4 is an end cross-section view along B—B of the apparatus shown in FIG. 1; 
     FIGS. 5A to  5 D are schematic diagrams showing operational steps of the apparatus of FIG. 1 from feeding a strip of wood for cutting to slat lengths to positioning a cut and punched slat for laddering; 
     FIGS. 6A to  6 D are schematic diagrams showing stages in a remnant ejection process of the apparatus of FIG. 1; 
     FIG. 7 is a schematic diagram showing a partial cross sectional side view of the cutting station of the apparatus of FIG. 1; 
     FIG. 8 is a schematic diagram showing a partial cross sectional end view of the cutting station of the apparatus of FIG. 1; 
     FIG. 9 is a schematic diagram showing a partial perspective view of the punching station of the apparatus of FIG. 1; and 
     FIGS. 10A to  10 C are schematic diagrams showing steps in a shaping station for the apparatus of FIG.  1 . 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring initially to FIG. 1 there is shown a plan schematic view of the apparatus  10  for manufacturing timber venetian blinds according to the present invention. 
     The apparatus  10  as shown comprises a feeding station  12 , a sawing station  14 , a punching station  16  and a laddering station  18  where slats  20  cut from timber strips  22  are assembled into a venetian blind. 
     The feeding station  12  has a magazine section  24  which is shown more clearly in FIGS. 3 and 4. As can be seen a stack of timber strips  22  for cutting into the slats  28  of preset lengths is stored in the section  24 . 
     The section  24  has a number (three in this embodiment) of paired arms  26 ,  28 . The arms  28  are linked and are adjustably movable in unison relative to the arms  26  for accommodating timber strips  22  of various widths in the magazine section  24 . Typically the space between the arms  26  and  28  can be adjusted to accommodate strips  22  with 10 to 100 mm width. 
     The feeding station  12  has a base or track  30  adjacent to one side of which the magazine section  24  is positioned. Each of the arms  26  is spaced from the base or track  30  by a plate  32  which is fixed to a block  34  arranged on the base or track  30 . As shown in FIG. 3 this arrangement provides a gap under each arm  26  for receiving a timber strip  22  fed from the bottom of the stack in the magazine  24 . The block  23  and the plate  32  cooperate to confine the strip  22  within the gaps. 
     Returning to FIG. 1, a controllably moveable element (not shown) is employed to push the bottom strip  22  in the magazine section  24  in the gap when the apparatus  10  is in operation. 
     A pair of driving rollers  40 ,  42  are located in close proximity to the sawing station  14  for maximising the number of slats  20  that can be cut from the timber strips  22 . The roller  42  is in this case is a feed roller. 
     As shown in FIG. 4 the roller  40  is controllably movable in a certain direction. The roller  40  is controlled to move away from the roller  22  when a timber strip is to be delivered in to the gaps. 
     When the timber strip  22  within the gaps are to be fed for a subsequent operation the roller  40  is controlled to move towards the roller  42  and the roller  40  is then driven to feed the timber strip  22  towards the sawing station  14  (See FIG.  2 ). 
     In this embodiment the roller  40  is a rotary encoder serving as a measuring device for providing feedback signals to a controller which controls operations of the apparatus  10 . By using the feedback signals the controller can accurately position the strip  22  for sawing the strip  22  into preset lengths and punching slots. 
     FIG. 5A shows that the strip  22  is driven by the rollers  40 ,  42  a small distance past a saw  44  in the sawing station  14  for trimming one end thereof. The saw  44  is controlled to reciprocate in the direction shown by the double ended arrow for sawing and retracting from the strip  22 . 
     The trimmed end piece then drops in the collection bin (not shown) as illustrated in FIG.  5 . The strip  22  is again fed into positions (2 in this embodiment) for punching slots  46  by a selected one of the punches  48 ,  50 ,  52  fixed to a punch head  47  which is controllably movable between an up position for allowing the strip  22  to more through the punching station  16  and a down position for punching a slot  46 . 
     The punch head  47  is adjustably movable to position one of the punches  48 ,  50 ,  52  for the punching operation. An indexed shaft is used to more the head  47  and is colour coded for the positions of the punch heads so that a user simply moves to lock the shaft into the colour coded index for the punch ( 48 ,  50  or  52 ) to the used. 
     After the second slot  46  is punched the strip  2  is controlled to move to a position as shown in FIG. 5C to be sewn into a slat  20  of the preset length. 
     The strip  22  is fed to positions for the operations as shown in FIGS. 5A to  5 C except for the initial end trimming operation. At the same time the slat  20  previously cut is pushed by the strip  20  in between rungs of a pair of ladders  54  of the blind to be assembled in the laddering station  18 . 
     As strips  22  are not usually of equal length and the cut slats  20  are not usually multiples of the strips  22  there are remnants having a length shorter than the slat length. These remnants must be cleared from the feeding path of the strips  22  if full automation of venetian blind manufacturing is to be realised. 
     FIGS. 6A to  6 D show an example of how the remnants are ejected from the feeding path. Turning to FIG. 6A there is shown a sensor means having a light emitting device  56  and a light receiving detector  58  positioned on opposite sides of the strip  22  when placed in the gaps. The detector  58  is arranged to produce an output signal when it detects the light from the device  56 . 
     In operation when the far end of the strip  22  moves past the device  56  as shown in FIG. 6A the strip  22  is now shorter than the length of the slats  20  and the detector  58  sends a signal to the controller to begin an ejection operation. 
     If any part of the strip  22  is under the plate  32  close to the roller  40  the roller  42  is controlled to feed the strip  22  forward to clear the plate  32 . 
     When the far end of the strip  22  is positioned past the block  32  as shown in FIG. 6B, lifting elements  36  and  38  are operated to lift the strip  22  and the feed roller  42  is controlled to reverse the feed direction. The strip  22  now rests on the plate  32  waiting for a following strip  22  from the magazine section  24  to move in a direction toward the gap. At the same time the strip  22  is lifted to rest on the plate  32  as shown in FIG.  6 D. 
     FIGS. 7 and 8 show in some detail the arrangement of the saw  44  and its anvil  60  at the saw station  14 . The strip  22  to be cut is clamped by a pair of clamps  62 , 64  arranged on opposite sides of the saw  44 . Both the anvil  60  and the clamps  62 , 64  are made of vibration damping material including rubber compound. This reduces vibration when the strip  22  is being sawn. The damping material also reduces noise. 
     FIG. 9 shows in detail the punch head  47  and the punches  48 ,  50 ,  52  described earlier with reference to FIGS. 5A to  5 D. 
     The head  47  has a cross arm  66  and the two side arms  68 , 70 . All of the punches  48  to  52  are fixed on the cross arm  66 . Each said side arms  68 , 70  have an aperture movably positionable along rods  72 ,  74 . The rods  72 , 74  are fixed to a beam  76  having slots  78 , 80 , 82  shaped to receive the punches  48  to  52 . 
     FIGS. 10A to  10 C show arrangement of a shaping station that can be positioned between the cutting station  14  and the punching station  16 . 
     Referring to FIG. 10A, after sawing through the strip  22  the roller  42  is reversed to an extent to allow a shaping tool to controllably movable between adjacent ends of the slat  20  and the strip  22 . The shaping tool  78  is adapted to round corners at the ends of the strip  22  and the slot. The shaping may also be arranged to bevel the top and bottom of the ends. Whereby the ends of the slats  20  can be contoured to a predetermined shape.