GB2044732A - Dispensing continuous sheet material - Google Patents

Abstract

For the dispensing of continuous sheet material (10) step by step, the material has transverse lines of perforations (11) to allow the material to be manually divided into discrete lengths and an identification area (6) at a predetermined distance longitudinally of the material from the leading edge of each length in the dispensing direction. Such material may be dispensed by successively causing a portion of the material to move longitudinally in the dispensing direction from a holder past a tear-off device, stopping the material when the line of perforations defining the trailing edge of the leading length is aligned with the tear-off device, and manually tearing off the leading length. The step of stopping the material is actuated by sensing the identification area on a succeeding length. The invention provides apparatus for dispensing continuous sheet material and is particularly intended for dispensing a roll of bags of high density polyethylene. <IMAGE>

Description

SPECIFICATION Method and apparatus for dispensing continuous sheet material step by step This invention relates to a method and apparatus for dispensing continuous sheet material step by step.

According to the invention there is provided a method of dispensing continuous sheet material step by step, the material having transverse lines of perforations to allow the material to be manually divided into discrete lengths and there being provided an identification area at a predetermined distance longitudinally of the material from the leading edge of each length in the dispensing direction, the method comprising successively causing a portion of the material to move longitudinally in the dispensing direction from a holder past a tear-off device, stopping the material when the line of perforations defining the trailing edge of the leading length is aligned with the tear-off device, said step of stopping the material being actuated by sensing said identification area on a succeeding length, and manually tearing off the leading length.

Preferably each length of the material is a bag, and preferably the material is high density polyethylene.

It is also preferred that said identification area on each bag is a marking at or adjacent one longitudinal edge of the bag.

The invention also provides apparatus for dispensing continuous sheet material step by step, the material having transverse lines of perforations to allow the material to be manually divided into discrete lengths and there being an identification area at a predetermined distance longitudinally of the material from the leading edge of each length in the dispensing direction, the apparatus comprising a holder for the material, drive means for moving a portion of the material longitudinally in the dispensing direction from the holder past a tear-off device and means for stopping the material when the line of perforations defining the trailing edge of the leading length is aligned with the tear-off device, said stopping means being actuated by sensing means which sense said identification area on a succeeding length.

Preferably the holder is adapted to hold a roll of material, the holder having opposed end walls, one being fixed and the other being movable towards the fixed end wall whereby the holder is suitable for holding rolls of different widths.

The drive means may be a pair of rollers, one of which is driven intermittently by an electric motor.

In one embodiment of the invention the electric motor is controlled by two switches alternately, the first switch being activated when the apparatus is set for dispensing material, the material being stopped by the sensing means, and the tear-off device is a hinged plate which is pivoted when a length is torn off to activate the second switch to operate the motor for a relatively short period of time to move said identification area on a succeeding length clear of the sensing means.

The sensing means may be an infrared light emitting diode and receiver aligned to sense the identification area of each length in turn.

By way of example, a specific embodiment in accordance with the invention will be described with reference to the accompanying drawings in which: Figure 1 is a perspective view of apparatus for dispensing continuous sheet material step by step, the lid of the apparatus being open and partly cutaway; Figure 2 is a transverse section through the apparatus of Figure 1, the lid being closed; and Figure 3 is a diagrammatic representation of the control circuit for the electric motor of the apparatus of Figure 1.

Referring to the drawings, there is shown an apparatus for dispensing continuous sheet material step by step. In this embodiment the material is a roll 12 of bags 10 of high density polyethylene. The bags are initially joined by lines of perforations 11 and the purpose of the apparatus is to allow a bag to be torn from the roll when required, the apparatus then dispensing the next bag into the position shown in Figure 1. For this purpose each bag 10 carries an identification area comprising an opaque stripe 6 capable of being sensed by a photocell. In this embodiment, the photocell is an infrared light emitting diode 7 and a receiver 8.

The roll 12 of the bags 10 is placed in a wiremesh holder 1 3 housed within a container 14, having opposed end plates, the end plate 1 5 being adjustable along slots 1 6 extending longitudinally of the holder to accommodate rolls of different widths, i.e. to ensure that the edge of the roll remote from the end plate 1 5 is always in the same position relative to the photocell irrespective of the width of the roll. The leading end of the roll passes over a guide roller 1 7 and the receiver 8 of the photocell, and then downwardly between a drive roller 18 and a pressure roller 1 9 which is urged towards the drive roller by springs 20.

The container 14 has a hinged lid 21. Within the lid is fixed an L-shaped frame 22 from which the pressure roller 1 9 is suspended by two arms 23 pivotally attached to the frame. Pivotal movement of the arms 23 under the action of the springs 20 is limited by the engagement of stops 24 on the arms against the fixed frame 22.

Also pivotaliy attached to the frame 22 is a tear-off plate 25 which extends parallel to the pressure roller in edge contact with the portion of the material hanging beneath the rollers 18, 1 9.

Thereby when a line of perforations 11 is aligned with the lower edge of the plate 25, the bag 10 hanging freely beneath the plate 25 may readily torn off. Such action effects pivotal action of the plate in a clockwise direction as viewed in Figure 2 and activates a cycle of operation to dispense the next bag. The frame 22 further carries the diode 7 of the photocell whereby when the lid 21 is raised the threading of the material through the dispensing apparatus to load the apparatus is made easy.

The drive roller 1 8 is driven by an electric motor 26 through a gear box 27. The main control means for the motor 26 are two switches 28, 29 and the photocell. The first switch 28 is mounted on the frame 22 fixed within the lid 21 and is switched on by closing the lid, a projection 30 from the switch 28 being depressed by the adjacent bracket 31 on which that end of the frame 22 rests when the lid 21 is closed.

The second switch 29 is also mounted on the frame 22 and is activated by a flexible lever 32 each time the tear-off plate 25 is pivoted away from its normal position during the removal of each bag. The purpose of this second switch is to operate the motor 26 for a short period of time so that the particular identification area 6 located between the diode 7 and receiver 8 of the photocell is moved past the photocell.

Figure 3 shows the electric circuit linking the motor 26 and the switches 28, 29 and the photoceil. The first switch 28 is connected to a power source via a transformer 32, and is connected to the motor 26 via the diode 7 and the receiver 8 of the photocell and a relay 33. The second switch 29 is connected to the motor via a timer 34 and a relay 35, in parallel with the photocell so that activation of the second switch will bypass the photocell and operate the motor for the relatively short time period determined by the timer 34. In this embodiment the circuit is such that the first switch 28 cannot operate the motor 26 whilst the second switch 29 is itself activated by the tear-off plate.However, as soon as the second switch is no longer activated the motor will be operated to dispense further material until the next identification area 6 is located between the diode and the receiver of the photocell.

The apparatus may be loaded simply by raising the lid 21 and dropping a roll 12 of bags 10 into the holder 1 3 with the loading bag extending over the guide roller 17, the receiver 8 of the photocell and the drive roller 1 8. The lid is then closed thereby lowering the pressure roller 19 and the tear-off plate 25 into contact with the leading bag.

As will be seen from Figure 2, the bag 10 is pushed inwardly by the bottom edge of the tearoff plate to assist the tearing-off action of each bag in turn should the bag be pulled downwardly rather than against the tear-off plate. Assuming an identification area 6 is not present between the diode and receiver of the photocell, closure of the lid 21 will activate the first switch 28 to operate the motor 26 until the first bag is dispensed and the identification area of the second bag is aligned with the photocell. The motor will then be stopped with the line of perforations 11 separating the first two bags adjacent the bottom edge of the tear-off plate 25. The apparatus is then set for use.

When the first bag is torn off, the tear-off plate 25 will be pivoted to activate the second switch 29. The motor will then be operated for the relatively short time period determined by the timer to move the identification area 6 aligned with the photocell past the photoceil. When the plate 25 returns to its initial position, the motor 26 will be operated continuously to dispense the second bag, the motor being stopped when the identification area 6 of the third bag is aligned with the photocell. The cycle of operation may then be repeated for each bag in turn.

The invention is not restricted to the specific details of the embodiment described above. For example, the material to be dispensed may be any continuous sheet material and not necessarily bags of high density polyethylene. For example the sheet material may be paper towelling, and the material may be stored in the apparatus in zig-zag form.

Also, instead of a photocell to stop the dispensing process when the desired length of material has been dispensed, any form of switching device may be employed, e.g. a proximity switch which detects a sensitized marking on the material being dispensed.

The identification area on each length of material may be of any desired form and is not necessarily positioned adjacent the edge of the material. If desired, the identification area may comprise part of any printed matter on the material, providing that the identification area on each bag is the same distance longitudinally of the material from the preceding line of perforations.

In the embodiment desc;-ibed above, the action of tearing off a bag automatically effects the dispensing of the next bag. If desired the control means may be changed so that a button must be pressed to dispense a bag which can then be tornoff, or a coin must be inserted into the apparatus to dispense a bag.

Claims (11)

1. A method of dispensing continuous sheet material step by step, the material having transverse lines of perforations to allow the material to be manually divided into discrete lengths and there being provided in identification area at a predetermined distance longitudinally of the material from the leading edge of each length in the dispensing direction, the method comprising successively causing a portion of the material to move longitudinally in the dispensing direction from a holder past a tear-off device, stopping the material when the line of perforations defining the trailing edge of the leading length is aligned with the tear-off device, said step of stopping the material being activated by sensing said identification area on a succeeding length, and manually tearing off the leading length.

2. A method as claimed in claim 1, wherein each length of the material is a bag.

3. A method as claimed in claim 2, wherein the material is high density polyethylene.

4. A method as claimed in claim 2 or claim 3, wherein said identification area on each bag is a marking at or adjacent one longitudinal edge of the bag.

5. Apparatus for dispensing continuous sheet material step by step, the material having transverse lines of perforations to allow the material to be manually divided into discrete lengths and there being an identification area at a predetermined distance longitudinally of the material from the leading edge of each length in the dispensing direction, the apparatus comprising a holder for the material, drive means for moving a portion of the material longitudinally in the dispensing direction from the holder past a tearoff device and means for stopping the material when the line of perforations defining the trailing edge of the leading length is aligned with the tearoff device, said stopping means being activated by sensing means which sense said identification area on a succeeding length.

6. Apparatus as claimed in claim 5, wherein the holder is adapted to hold a roll of material, the holder having opposed end walls, one being fixed and the other being movable towards the fixed end wall whereby the holder is suitable for holding rolls of different widths.

7. Apparatus as claimed in claim 5 or claim 6, wherein the drive means are a pair of rollers, one of which is driven intermittently by an electric motor.

8. Apparatus as claimed in claim 7, wherein the electric motor is controlled by two switches alternately, the first switch being activated when the apparatus is set for dispensing material, the material being stopped by the sensing means, and the tear-off device is a hinged plate which is pivoted when a length is torn off to activate the second switch to operate the motor for a relatively short period of time to move said identification area on a succeeding length clear of the sensing means.

9. Apparatus as claimed in any one of claims 5 to 8, wherein the sensing means is an infrared light emitting diode and receiver aligned to sense the identification area of each length in turn.

10. A method of dispensing continuous sheet material step by step substantially as hereinbefore described with reference to the accompanying drawings.

11. Apparatus for dispensing continuous sheet material step by step substantially as hereinbefore described with reference to and as shown in the accompanying drawings.