GB2341848A

GB2341848A - Blank feed for carton manufacturing machine

Info

Publication number: GB2341848A
Application number: GB9821049A
Authority: GB
Inventors: Robin Vincent Baker
Original assignee: Planet Fabrications Ltd
Current assignee: Planet Fabrications Ltd
Priority date: 1998-09-28
Filing date: 1998-09-28
Publication date: 2000-03-29
Anticipated expiration: 2018-09-28
Also published as: GB2341848B; GB9821049D0

Abstract

A mechanism for feed blanks to a carton manufacturing machine has a feed roller 1 and a gate mechanism 2 spaced from the roller to define a gap therebetween. The gate comprises two or more plungers 10 independently movable, eg pneumatically, between closed and open positions, so as to ensure that each blank is correctly fed whatever the shape of its trailing edge.

Description

IMPROVEMENTS IN OR RELATING TO CARTON MANUFACTURING MACHINERY This

invention relates to improvements in machines for manufacturing cartons from precut blanks, especially corrugated carton making machines known as folder gluers.

Automatic corrugated carton making machines such as folder gluers commonly use a feed mechanism of the type shown in Figure 1.

Essentially, the feed mechanism consists of a feed roller 1, above the axis of which is mounted a pair of substantially vertical gates 2 placed side is by side (only one of which is shown) which are adjustable in a vertical plane so as to permit a single product blank 3 to pass through the gap between the gates 2 and the feed roller 1. The gates 2 are adjustable in their lateral position and are normally located far enough apart to ensure that the front edge 4 of the blank 3 resting against them remains at right angles to the direction of feed.

A stack of corrugated carton blanks 3 is loaded into the machine with their forward edges 4 resting against the two gates 2 and rearward edges resting on a sloping support plate 6 or other support means. The forward edge 4 of the lowest of the blanks 3 rests on the feed roller 1.

As the feed roller 1 rotates the lowest blank 3 is drawn into the mechanism and is fed into a pair of nip rollers 7, or similar transport means, which draw it further into the machine. As the trailing ends of each blank 3 passes through the gates 2, the next blank 3 falls into its place and is fed into the machine in succession. By this means, a continuous stream of blanks 3 is fed into the machine.

Other versions of this arrangement may have feed belts instead of a feed roller 1, and may dispense with the support plate 6 so that the entire stack of blanks 3 rests on the feed belts. The essential principle, that each blank 3 falls into place and is fed immediately after its predecessor, remains unchanged.

It is inherent in this system that the gates 2 are always open to allow blanks 3 to pass through them in single file. However, from time to time it is necessary to stop new blanks 3 from being fed into the machine without stopping those already in the machine from being processed. Typically, this is accomplished is by means of a feed interrupter 8 consisting of a bar, or other device, which can be raised to lift the lowest blank 3 slightly above the level of the feed roller 1.

This system works very well with blanks that are essentially rectangular as shown in Figure 2 or those that have suitable pairs of parallel edges as shown in Figure 3.

A disadvantage with known machines is that some blanks 3 in common use, such as those shown in Figure 4 for example, do not meet this requirement. It is not possible to feed such blanks 3 in a conventional feed arrangement because, as each blank 3 passes through the feed gates 2, its trailing edge clears the gate 2 on one side of the machine before the other.

When this happens, one side of the following blank 3 can fall and be drawn into the gate 2 before an extended flap 9 on the previous blank 3 has cleared the gate 2 on the other side. This causes the blank 3 to slew out of line and produce a reject product.

Another problem associated with the known feed arrangements is that the feed interrupter 8 can be actuated at any time in the cycle and may, therefore, interrupt a blank 3 which is already part way through the gates 2. In such circumstances, a blank 3 may be damaged, but may still eventually be processed and supplied to a customer.

It is an object of the present invention to provide an improved feed mechanism to overcome these disadvantages and also make the feed arrangement more flexible for other applications.

The present invention therefore provides a feed mechanism for feeding blanks, comprising a main feed means and gate means in spaced relation to the main feed means to define an aperture therebetween through is which, in use, successive blanks may be fed, wherein the gate means comprises one or more members movable from a 'stop' state in which the aperture is closed, to prevent in use a blank being fed therethrough, to a go' state in which the aperture is open.

Preferably the gate means comprises two or more independently movable members.

Preferably the movable member(s) are further movable to a 'discrete feed state' in which, in use, the movable member(s) contact an upper surface of the blank being fed through the feed mechanism, the movable member(s) being biassed towards the 'stop' state such that as the blank moves out of alignment with the movable member(s) the movable member(s) independently move to the %stop' state.

The present invention also provides a method of regulating the operation of a feed mechanism for feeding successive blanks therethrough, the feed mechanism comprising a continuously operating main feed means and gate means in spaced relation to the main feed means comprising one or more members movable from a 'stop' state to a 'go' state comprising the cyclical steps of:

i) positioning the movable member(s) in the stop' state to prevent a first blank being fed through the gate means; ii) moving the movable member(s) to the 'go' state to open the gate means and allow the first blank to be fed therethrough; iii) moving the movable member(s) to a 'discrete feed state' in which the movable member(s) contact an upper surface of the first blank, the movable member(s) being biassed towards the 'stop' state such that as the first blank moves out of alignment with the movable member(s) the movable member(s) is independently move to the 'stop' state; and iv) maintaining the movable member(s) in the stop' state for a discrete time interval to allow a subsequent blank to be fed to the gate means.

Embodiments of the present invention will now be described, by way of example only, with reference to the following drawings, in which:

Figure 2 is a schematic view of a blank of a typical regular slotted case; Figure 3 is a schematic view of a blank of a typical regular die-cut case; Figure 4 is a schematic view of a blank of a typical die-cut case with trailing flap; Figure 5a is a schematic view of a feed mechanism according to the present invention with the gate in a closed position; and Figure 5b is a schematic view of the feed mechanism of Figure 5a with the gate in an open position.

A feed mechanism according to the present invention is shown in Figures Sa and 5b, and comprises a feed roller 1 above the axis of which is mounted a pair of substantially vertical gates 2 placed side by side (only one of which is shown). As in the prior device, the gates 2 are adjustable in a vertical plane to allow a single blank 3 to pass through the gap between the gates 2 and roller 1. In addition one or more plungers 10 are mounted directly behind (downstream of) each gate 2 which act as movable members, which can be used to close the gate aperture 11, together with a control system to enable the gates 2 to be opened and closed in response to a variety of signals.

is The plunger 10 is mounted directly on the rear surface 12 of the gate 2 and is constrained to slide vertically up or down relative to the gate 2. The upper end 13 of the plunger 10 is connected to a rod 14 of a pneumatic cylinder 15 and a body of the cylinder 15 is connected to a fixed part of a machine frame (not shown).

The stroke of the cylinder 15 needs to be slightly greater than the aperture 11 between the gate 2 and the feed roller 1 when the gate 2 is set at its highest working level. The cylinder mounting is adjustable in level and is set so that, when the cylinder rod 14 is fully extended, the plunger 10 is just clear of the top surface of the feed roller 1.

A source of compressed air is connected to a lower chamber of the cylinder 15 via a pneumatic valve. In an open position, in which blanks 3 may pass through the gate 2 as shown in Figure 5b, the valve connects the air to the cylinder 15. In a closed position, in which blanks 3 are prevented from passing through the gate 2 as shown in Figure 5a, the valve causes the air in the cylinder 15 to exhaust to atmosphere. In one embodiment, the valve is operated by an electric solenoid, which may be operated by a variety of electric control circuits.

When feeding blanks 3 of the form shown in Figure 4, the gate 2 is set to run on an automatic cycle, as follows:

1) a blank 3 is allowed to pass under the gates 2, by opening the valve to allow pressurised air to be supplied to the cylinders 15 on both gates 2. This raises both plungers 10 into the open position, thereby opening both gates 2 and enabling the blank 3 to pass through; 2) after a short preset time delay, the valve closes such that the air exhausts from the cylinders 15. Both plungers 10 fall under gravity into a discrete feed position' until they rest on top of a blank 3 as it passes under each gate 2 but does not prevent the passage of said blank 3; 3) as the rear 5 of the blank 3 clears each gate 2, each plunger 10 falls further under gravity into the closed position and so closing the gate 2 and stopping the next blank 3 from moving through the gate 2; 4) sensors (not shown) detect when both plungers 10 have fallen into the closed position, and after a short time interval (to allow the next blank 3 to pass from a face 16 of the gate 2 to a face 17 of the plunger 10), the valve opens, which causes the plungers 10 to lift, the gates 2 to open, and the next blank 3 starts to feed through. 5 This system ensures that neither gate 2 is opened until the face 4 of the next blank 3 is resting squarely against the plungers 10. It ensures therefore that each blank 3 will feed correctly whatever the shape of its trailing edge 5.

When the machine is running at high speed, it may be necessary to increase the speed of descent of the plungers 10 from the open position to the discrete feed position. To achieve this, air at a separately controlled adjustable pressure may be connected into the upper chamber of the cylinders 15 to act as an air spring, the force of which can be controlled by regulating the air pressure applied.

One of the advantages of this device is that for blanks 3 of the type illustrated in Figures 2 and 3, the plungers 10 are not required and can be maintained in their open position, by a manually operated switch; but whenever blanks 3 of the type illustrated in Figure 4 are to be run, the automatic system can be brought into operation by a changeover switch.

The plungers 10 can also be used to provide a feed interrupt. In this mode, an overriding switch or other means is used to close the air valve. This allows the plungers 10 to fall into and remain in the closed position closing the gates 2 at the next gap between blanks 3. With this form of interrupt no damage to blanks 3 will occur.

The gates 2 in their new form can also be used in applications requiring a timed feed. This is achieved either by providing the control circuit with an internal clock to regulate the cycle time, or by synchronising the gate opening cycle with an external signal generated by a previous or subsequent operation.

Although the embodiments of the invention described above refer to the plungers 10 being controlled by pneumatic cylinders, it is evident that other means, such as electric solenoids or mechanical actuators, could be used to operate them, and so open or close the gates 2. Also, the control circuit could be based on pneumatic switching and pneumatic logic.

The apparatus described above and in the following claims is equally suited for use in manufacturing cases other than corrugated cartons.

Claims

1. A feed mechanism for blanks comprising means for moving blanks, a gate mechanism in spaced relation to the blank moving means to define an aperture therebetween wherein the gate. mechanism comprises at least one member movable from a closed position in which the aperture is substantially closed to an open position in which the aperture is open and means for controlling the opening and closing of said gate mechanism.

2. A feed mechanism as claimed in claim 1 wherein the gate means comprises two or more independently is movable members.

3. A feed mechanism as claimed in claim 1 or claim 2 wherein the movable member(s) are further movable to a 'discrete feed position, in which the movable member(s) partially close by moving, in use, into contact an upper surface of the blank being fed through the feed mechanism, the movable member(s) further being biased towards the closed position such that as the blank moves out of contact with the movable member(s) the movable member(s) move to the closed position.

4. A feed mechanism as claimed in claim 3 in which the movable member (3) are allowed to fall under gravity to the discrete feed position.

5. A feed mechanism as claimed in claim 3 or claim 4 wherein the biassing of the movable member(s) is due to gravity.

6. A feed mechanism as claimed in claim 3 wherein the biassing of the movable member(s) is due to an air spring.

7. A feed mechanism as claimed in any preceding claim wherein the gate means comprises one or more pneumatic actuators to operate the movable member (s)

8. A feed mechanism as claimed in any preceding claim wherein the feed mechanism further comprises sensing means to detect when the or all of the movable member (s) are in the closed position.

9. A feed mechanism as claimed in any preceding claim wherein the blank moving means is a roller.

10. A feed mechanism as claimed in any of the preceding claims wherein the blank moving means is a feed roller.

11. A feed mechanism as claimed in any one of claims 1 to 8 wherein the blank moving means is a continuous belt.

12. A method of regulating the operation of a feed mechanism for feeding successive blanks through an aperture, the feed mechanism comprising a continuously operating blank moving means, a gate mechanism in spaced relation to the blank moving means to define an aperture therebetween, the gate mechanism comprising at least one members movable from a closed position in which the aperture is substantially closed to an open position in which the aperture is open to allow the passage of blanks comprising the cyclical steps of:

i) positioning the movable member(s) in the closed position to prevent blanks being fed through the aperture; ii) moving the movable member(s) to the open position to open the aperture and allow a blank to be fed therethrough; iii) moving the movable member(s) to a 'discrete feed position, in which the movable member(s) rest in contact with an upper surface of the blank, the movable member(s) being biassed towards the closed position such that as the blank moves out of contact with the movable member(s), the movable member(s) independently move to the closed position; and iv) maintaining the movable member(s) in the closed position for a discrete time interval to allow a subsequent blank to be fed to the gate means.

13. A method as claimed in claim 12 wherein the movable member(s) is/(are) moved from the closed position to the open position by means of compressed air.

14. A method as claimed in claim 12 or claim 13 wherein the movable member(s) position is/(are) moved from the open position to the 'discrete feed state' by means of compressed air.

15. A method as claimed in claim 12 or claim 13 wherein the movable member(s) are moved from the open position to the discrete feed position' by means of gravity.

16. A method as claimed in any one of claims 12 to 15 wherein the movable member(s) may be optionally maintained in the closed position to interrupt feeding of blanks without stopping the blank moving means.

17. A method as claimed in any of claims 12 to 16 wherein operation of the gate mechanism is controlled by a time signal.

18. A method of regulating the operation of a feed mechanism substantially as hereinbefore described with reference to and as shown in Figures Sa and 5b.

18. A feed mechanism substantially as hereinbefore described with reference to and as shown in Figures Sa and 5b. 10

19. A method of regulating the operation of a feed mechanism substantially as hereinbefore described with reference to and as shown in Figures 5a and 5b.

AmerKknents; to the clakna have been fNed as fodows CIAIMS: - A feed mechanism for blanks comprising means for moving blanks, a gate mechanism in spaced relation to the blank moving means to define an aperture therebetween wherein the gate mechanism comprises two or more members independently movable from a closed position in which the aperture is substantially closed to an open position in which the aperture is open and means for controlling the opening and closing of said gate mechanism.

2. A feed mechanism as claimed in claim 1, wherein the movable members are further movable to a 'discrete feed position' in which the movable members partially close by moving, in use, into contact with an upper surface of the blank being fed through the feed mechanism, the movable members further being biased towards the closed position such that as the blank moves out of contact with the movable members the movable members move to the closed position.

3. A feed mechanism as claimed in claim 2, in which the movable members are allowed to fall under gravity to the discrete feed position.

4. A feed mechanism as claimed in claim 2 or claim 3, wherein the biassing of the movable members is due to gravity.

5. A feed mechanism as claimed in claim 2, wherein the biassing of the movable members is due to an air spring.

6. A feed mechanism as claimed in any preceding - 11+ - claim, wherein the gate means comprises one or more pneumatic actuators to operate the movable members.

7. A feed mechanism as claimed in any preceding claim, wherein the feed mechanism further comprises sensing means to detect when all of the movable members are in the closed position.

8. A feed mechanism as claimed in any preceding claim, wherein the blank moving means is a roller.

9. A feed mechanism as claimed in any of the preceding claims, wherein the blank moving means is a feed roller.

10. A feed mechanism as claimed in any one of claims 1 to 7, wherein the blank moving means is a continuous belt.

11. A method of regulating the operation of a feed mechanism for feeding successive blanks through an aperture, the feed mechanism comprising a continuously operating blank moving means, a gate mechanism in spaced relation to the blank moving means to define an aperture therebetween, the gate mechanism comprising two or more members independently movable from a closed position in which the aperture is substantially closed to an open position in which the aperture is open to allow the passage of blanks comprising the cyclical steps of:

i) positioning the movable members in the closed position to prevent blanks being fed through the aperture; ii) moving the movable members to the open - Is-- position to open the aperture and allow a blank to be fed therethrough; iii) moving the movable members to a %discrete feed position, in which the movable members rest in contact with an upper surface of the blank, the movable members being biassed towards the closed position such that as the blank moves out of contact with the movable members, the movable members independently move to the closed position; and iv) maintaining the movable members in the closed position for a discrete time interval to allow a subsequent blank to be fed to the gate means.

12. A method as claimed in claim 11, wherein the is movable members are moved from the closed position to the open position by means of compressed air.

13. A method as claimed in claim 11 or claim 12, wherein the movable members are moved from the open position to the 'discrete feed state, by means of compressed air.

14. A method as claimed in claim 11 or claim 12, wherein the movable members are moved from the open position to the 'discrete feed position, by means of gravity.

15. A method as claimed in any one of claims 11 to 14, wherein the movable members may be optionally maintained in the closed position to interrupt feeding of blanks without stopping the blank moving means.

16. A method as claimed in any of claims 11 to 15, wherein operation of the gate mechanism is controlled by a time signal.

- V - 17. A feed mechanism substantially as hereinbefore described with reference to and as shown in Figures 5a and 5b.