Field of the Invention The present invention relates to devices for cutting, holding and sealing sheeting or film and for sealing items inside sheeting or bags, and in particular to a portable, hand-operated clamp for clamping and cutting to length the open end of a bag so that it may be sealed. Background

Devices are known for wrapping items in plastic film or for sealing them inside plastic bags, to prevent moisture damage or to protect them from damage from for example scuffing, insects, animals or from spoilage or mould. These devices are of various well known types, including for example vacuum sealing devices that partially evacuate plastic bags and then heat seal them closed; film wrapping devices that are known in a wide variety of sizes and configurations that present plastic film from a roll, and move the film relative to the item to achieve wrapping. Stretch film is often used.

Heat sealable bags and film are known that may be sealed together when pressed together and heated. Heat seal tools are known, typically comprising one or more electrically heated bars that are clamped orto the two layers of film held together, so melting the two layers into a seal. Small scale heat sealers are known, but typically only work with a given type of film, and with a limited thickness range, and are not adapted to seal longer lengths of film or to seal larger bags. Heat shrink bags or sleeving is known that shrink-wraps an item within it when the plastic bag is heated. Heat shrink bags are highly advantageous in that they fit the bagged item closely when the process is finished.

It is a general problem in small scale wrapping, for example in a domestic or mixed commercial setting, that a wide variety of items of irregular shapes need to be wrapped, and devices adapted to suit any one particular size or shape of item are not useful. Additionally, a wide variety of sizes and thicknesses of plastic bag, sheet or film may be used to wrap different items, and so a tool to assist wrapping needs to be adaptable to different film types and thickness, meaning that devices with built in heat sources adapted to suit a narrow range of film properties are disadvantageous.

A simple, manually operated device that will assist the closure of a heat shrink bag and capable of accommodating a wide range of items and film types is not available in the prior art and would have commercial and practical utility.

Prior Art Accordingly a number of patent applications have been filed in an attempt to resolve the problem or similar, including the following:

EP280300 discloses a clamp for clamping a web during stretch wrapping includes a first longitudinally extending clamp element for engaging the web, a second longitudinally extending clamp element extendable in a direction generally parallel to the longitudinal direction of the first clamp element for clamping the web between the second clamp element and the first clamp element as the second clamp element is longitudinally extended in a direction parallel to the longitudinal direction of the first clamp element.

This device is adapted to handle and clamp plastic film from a continuous roll while wrapping an item that is moved, for example rotated, past the clamp. The clamp extends longitudinally to hold the film ready for wrapping, then to allow it to move through the clamp while the item moves. The clamp comprises a cutter to cut the end of the film following wrapping. This device is adapted to be part of a wrapping machine and is not adapted for manual, for example domestic, use and is not adapted to present the wrapping film for heat sealing.

GB2211161 provides an apparatus for vacuum-packaging articles in flexible bags or envelopes, which comprises a supporting frame, two jaws one of which is pivoted on the other, actuating means for the or each pivoting jaw, a sealing gasket on an active face of one or both jaws a welding rod located on one or both jaws and spaced from the gasket, a fixed suction nozzle extending between the jaws beyond the sealing gasket when the jaws are closed together, a suction pump whose intake is in fluid communication with the nozzle, at least one wire or rod movably arranged in the nozzle and arranged to protrude out of it so as to extend between and beyond the jaws to enter a bag or envelope clamped by the jaws to the nozzle to be air- evacuated and to retract into the nozzle before the bag or envelope is sealed, and control means for operating the wire or rod, which functions to stop the bag blocking the suction nozzle during evacuation.

This device has sealing jaws movable together to clamp the bag ends, and includes heating bars to seal them. However, it is again a complex industrial device, adapted to suit a width of bag that fits wholly within the jaws, the jaws comprise heated bars that are moved together, and the system is not adapted for use in a domestic setting with range of materials and item sizes.

EP455907 discloses a vacuum sealer that has three wires that are heated to varying degrees. Two wires are used or dedicated to sealing plastic bags and one of the wires is used to cut the bags. The vacuum sealer is tapered downwardly, i.e. has a low profile, for a better air flow through a vacuum nozzle during the vacuuming step. A turbine with curved fins is used to increase the air flow and reduce the time to evacuate air from the bag. Also, the low profile of the unit, the increased size air ducts and the curved fins on the turbine, provide a more effective system for evacuating air from the plastic bag to be used.

This device again has heated jaws that close to heat seal a bag or film, and has a heated wire to act as a cutter. This limits the type of film that can be used to film that can be cut in this way. It is not suitable for heat shrink bags, where the material will move and pull away from the heated jaws, so created a poor or failed seal.

The above devices are typical of devices in the prior art, shortcomings of which the present invention aims to overcome.

Summary of the Invention

According the present invention a cutting device includes a clamp for clamping together and cutting one or more sheets comprises: first and second arms, the first arm being moveable with respect to the second arm, the arms having clamping faces; a clamping means is adapted to clamp the arms in a closed position with clamping faces together; and a cutter that is mounted on at least one of the arms and is movable along the length of the said arm and has a blade to cut portions of the sheet(s) protruding from the clamped faces.

Preferably the cutting device is portable.

In preferred embodiments the device is adapted for use in clamping the plastic sheet portions together in order to heat seal them together. In contrast with devices of the prior art, it is advantageous to provide the heat sealing means separately from the clamping and cutting means, in order to make a simple device capable of low cost production and for it to be adaptable to be used with a variety of types and thicknesses of plastic. The device may in preferred embodiments be made heat resistant and so may be used with a conventional heat gun as known in the art to effect sealing of the plastic sheet clamped and cut to shape for sealing by the device. It will be understood that the terms 'stationary arm' and 'moving arm" are intended to indicate relative movement. According to the embodiment, both arms may be moveable one with respect to the other. In some embodiments the stationary arm may be adapted to remain stationary, for example to be mounted on a surface or attached to a further surface or component, or may be heavy for example to assist keeping it in position for example on a table, the moving arm then being moved with respect to it. In other embodiments both arms are adapted to be held manually and to be moved towards and away from each other.

It will be understood that by a first and a second portion of plastic sheet may be meant two regions of the plastic bag, for example the entire circumference of the open end of the bag when folded flat, or two separate portions of plastic sheet that have no connection elsewhere.

In this way in use the open end of a plastic bag may be placed between the moving arm and the stationary in the open position, and the device may then be closed, bringing the first and second clamping face into contact with the bag and clamping the two sheets of the bag opening in tight contact along the length of the opening.

The clamping means then holds the two arms together, clamping the bag in position.

The cutter is then run along the length of an arm, moving the blade substantially perpendicularly to the clamping face and so cutting through the plastic sheeting outside the clamping area. This removes excess sheeting and reveals a short length of sheeting outside the clamping faces, the length being determined by the spacing of the cutter blade from the extremity of the clamping faces. A heat gun or hot wire may then be run along the cut ends of the plastic, fusing them together along the length of the bag opening. The device may then be opened and the bag released. If the bag comprises heat shrink film the bag may then be shrunk to fit the item within.

Preferably the clamping surfaces of clamping faces are: serrated and/or grooved and/or flat and/or profiled. Advantageously sheets which are particularly slippery are better clamped by serrated or grooved clamping faces, and sheets which are particularly fragile are better gripped by a flat or gently profiled clamping face.

In preferred embodiments the cutter is adapted to slide along one or both of the stationary and the moving arms and to be retained on the aim(s). Preferably the cutter is adapted to be guided by one or both arms and to be movable substantially only parallel to one or both, or more particularly in reference to the stationary arm, wherein the arms are closed during movement.

The cutter may be detachable at least in part from one or both of the arms. In a preferred embodiment the cutter is adapted to mount over both arms while in the closed position and to move along the length of the device. Preferably the cutter comprises a housing that wraps around the outside surfaces of the arms, and is retained on the arms by its shape. In a preferred embodiment the device comprises a region of the stationary arm between the pivot and the proximal end of the arm over which the cutter may sit.

In a preferred embodiment the cutter comprises a blade having a variable height above the arms. Preferably the blade height is adjustable by a user and the cutter comprises means to control the blade height, so controlling the length of plastic that protrudes from the clamp for heat welding.

In preferred embodiments one or both clamping faces comprise a cutaway portion at the edge facing away from the bag in use. Preferably the cutaway portion is bevelled or stepped. In this way a known length of plastic film is revealed between the outside edge of the clamp faces on the opposite side from the bag and the cutter blade path, so allowing a known amount of plastic to be left when the cutter is run along adjacent to the clamping faces. This gives improved control of the melt sealing process.

Preferably the clamping means comprises the cutter positioned at the distal end of the arms. Preferably one or both arms comprise a stop means that prevents the cutter from sliding off the end of the arms in use.

In an alternative embodiment the clamping means is provided at the distal ends of the arms. In an alternative embodiment the clamping means is provided at or adjacent to the pivot, acting in use to limit, hinder or prevent pivoting.

In preferred embodiments the stationary and the moving arm comprise an extended rod having a clamping face and a second face forming a right angle to the clamping face, the cutter running along the arms in use so as to present the blade substantially parallel to the second faces. Preferably the blade is spaced at a distance from the second faces. Preferably the device comprises means to set the distance of the blade from the second faces.

In some embodiments the clamping face is narrower than the second face and the two arms are pivoted together as known in the art, and in some embodiments may have a motion like that of a pair of scissors or a clapper board as known in film making. In other embodiments the clamping face is approximately as wide or is wider than the second face, and the pivot comprises a hinge, in some embodiments the closing action being like that of clamshell. In each case the axis of the pivot or hinge is parallel to the clamping face.

Preferably one or both clamping faces comprise a compliant grip material. Preferably the grip material comprises a heat resistart elastomer. Preferably the grip material stops short of the edge at which heat will be applied.

Preferably the cutter is removable from an arm or from both arms, according to the embodiment, in order to change the blade. Preferably the device is adapted to allow the cutter to be slid off from an arm or from both arms, according to the embodiment, the device comprising a cutter retaining means that retains the cutter on the arm or arms and operable to allow the cutter to be slid off. Preferably in embodiments having a region of the stationary arm between the pivot and the proximal end of the arm as described above the cutter arm is removable from that region by sliding it off the end of the stationary arm. In such embodiments the stationary arm preferably further comprises a cutter retaining means at or adjacent to the proximal end of the arm adapted to prevent the cutter from being slid off the arm. In a preferred embodiment the cutter retaining means comprises a stop member that projects from the profile of the arm under the action of a spring, so preventing the cutter from being slid past it, such that when the stop member is pressed down against the spring the cutter may then be slid over it and off the end of the arm. In a preferred embodiment the stop member projects from the second face of the arm.

In a preferred embodiment in which the cutter wraps partially around the arms, the cutter retaining means comprises a rod that moves within a hole extending through the stationary arm from the second face, and spring loaded such that it tends to project from the second face, over which the cutter slides. On being pressed down by a user, the rod moves through the hole so as to project instead from the face opposite to the second face, in a region where the cutter does not lie close to the said opposite face. In this way, when the rod is in its rest position the cutter is retained on the stationary arm and when it is pressed down the cutter may be slid off the end of the stationary arm.

The device is not limited as to size, and according to the embodiment the arms may be short or long. In a preferred embodinent the arms may be up to 2m, more preferably up to 1 m, more preferably between 20cm and 1 m long according to the size of bag to be sealed.

According to a further aspect of the invention there is provided a kit for heat sealing a plastic bag comprising a device as described herein and a heat seal gun adapted to melt plastic film clamped in the device. According to a further aspect of the invention there is provided a method for heat sealing a plastic bag comprising the steps of

providing a device as described herein,

placing the open end of the bag between the arms of the device and closing the arms,

moving the cutter along the device so as to cut the plastic,

and melting the cut protruding ends of the plastic to form a seal. In a preferred embodiment the method comprises the further step of using a clamping means to clamp the arms in the closed position. It will be understood that where reference herein is made to sealing a plastic bag, is meant sealing together of two sheets of plastic even if not joined in the form of a bag.

The invention has been described by way of examples only and it will be appreciated that variation may be made to the above-mentioned embodiments without departing from the scope of invention.

With respect to the above description then, it is to be realised that the optimum dimensional relationships for the parts of the invention, to include variations in size, materials, shape, form, function and manner of operation, assembly and use, are deemed readily apparent and obvious to one skilled in the art, and all equivalent relationships to those illustrated in the drawings and described in the specification are intended to be encompassed by the present invention.

Therefore, the foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention. Brief Description of Figures

Figure 1 shows a top view of an embodiment of the invention with the arms open;

Figure 2 shows a side view of the embodiment shown in figure 1 with arms closed;

Figure 3 shows an end view of the embodiment in figure 1 ;

Figure 4 shows an isometric view of the embodiment in figure 1 ; Figure 5 shows an isometric view of the embodiment shown in figure 1 with arms closed; and Figure 6 shows an isometric view of an alternative embodiment of the invention with arms open. Detailed Description of Figures

Figure 1 shows a top view of an embodiment of the device for clamping and cutting 100 with the arms 1 , 2 open. The stationary arm 1 is to the right and the moving arm 2 to the left, mounted and pivoted on the stationary arm 1. In this embodiment the arms have a first clamping face 4 that is narrower than the second face 3, which second face 3 faces out in figure 1. ^'

The device is suitable for clamping a first portion of a sheet to a second portion, whether the sheet is paper, polymer, synthetic plastic material, cloth, or textile. The stationary arm has a first clamping face 4. And the moving arm 2 has a second clamping face 4.

In use a sheet protrudes from between the clamped arms and is perpendicular to the second face 3.

The device is particularly suited for holding and sealing plastic sheeting or plastic film and for sealing items inside plastic sheeting or bags, and in particular to a portable, hand-operated clamp for clamping and cutting to length the open end of a plastic bag so that it may be sealed.

The stationary arm is joined to the stationary arm by a pivot 5 at a point near a proximal end 6 of the stationary and the moving arms. The moving arm 2 is movable with respect to the stationary arm 1 between a closed position in which the first and the second clamping faces 4 are parallel and in contact and an open position in which the first and second clamping faces are moved apart from each other.

The cutter 7 comprises a blade 9 oriented at right angles to the clamping faces and adapted to cut the sheets protruding from between the clamping faces. The cutter 7 is adapted to slide along and be retained by at least one of the arms 1 , 2. The cutter is adapted to engage with both arms while in the closed position and to move along the length of the arms. In the embodiment shown in Figures 1 to 5, the cutter 7 is mounted on the stationary arm 1 and the moving arm 2 and resting near the proximal end 6. The cutter is movable along the arms 1, 2. The arms 1 , 2 must be in the closed position shown in Figure 5 for the cutter to move along both arms 1 , 2.

In an alternative embodiment shown in Figure 6, the cutter 7 is mounted on the moving arm 2 and arranged to slide from near the pivot 5 to the distal end. With the arms 1 , 2 open the cutter is movable along the moving arm 2. With the arms 1 , 2 closed, the cutter is movable along both arms 1 , 2.

In the alternative embodiment shown in Figure 6, the arms have a first clamping face 4 that is about the same width as the second face which in use is perpendicular to the sheet which protrudes from between the clamped arms.

The clamping means is adapted to hold the moving and stationary arms in the closed position. In the embodiments shown in Figures 1 to 6 the clamping means is integral with the cutter 7. This has an advantage that the cutter acts to draw the clamping faces together so as to clamp the sheets tightly. The cutter slides from the proximal end to the distal end. As it slides, the cutter simultaneously cuts sheets clamped between the arms 1 , 2 and clamps the arms 1 , 2 together.

In an alternative embodiment, not shown, the clamping means may be separate from the cutter. The pivot 5 comprises an axle having an axis parallel to the clamping faces. The arms 1 , 2 in figure 1 are pivoted at a distance from the proximal end 6. The cutter 7 is shown as fitting over the arms 1 , 2 of the device in such a way that when the arms are in the closed position the cutter 7 may slide along the length of the arms 1, 2 over both of them together. The cutter 7 may be located in a resting position on the far side of the pivot 5 from the arms 1 , 2 in order to open the arms 1 , 2.

The cutter 7 comprises a blade 9 that slides along an adjustable distance above the second face 3. The clamped sheet protrudes above the second face and the blade 9 slices through the sheet as the cutter slides along. Moving the cutter 7 also moves the blade 9 so as to cut a clamped sheet or bag. The cutter 7 comprises a means 8 for varying the distance between a blade tip and the second face 3. The means for varying the distance is a height adjusting knob 8 on the top of a housing that houses blade tip protecting users from accidental self harm. . The clamping edges 9 are provided with a compliant grip. A stop means 10 is provided at the ends of the arms 1 , 2 in the form of a raised ridge that stops the cutter 7 from moving off the ends of the arms 1 , 2.

Figure 2 shows a side view of the embodiment in figure 1. The cutter 7 is visible in the resting position at the proximal end of the device. The raised stop means 10 at the distal end of the arms is visible.

Figure 3 shows an end view of the embodiment in figure 1 , showing details of the cutter. The cutter 7 comprises a housing mounted over the device and having returns 11 on the underside of the device to retain the cutter 7 on the device, allowing it to slide along the device past the pivot 5 when the arms 1 , 2 are in the closed position. The blade 9 is visible as a narrow horizontal line above the upper surface 4 of the device, at the base of the screw thread height adjusting means. The screw thread may be turned by the height adjusting knob 8 projecting on the top of the cutter 7 to move the blade 9 upwards and downwards with respect to the second surface 4 so adjusting the length of the protruding plastic sheet to be sealed. Preferably the cutter 7 comprises a spring means that raises the blade 9 above the second surface 4 and keeps it steady in position pressed upwards against the screw thread height adjusting means blade 9, allowing the spring to move the blade 9 upwards when the screw thread is wound upwards. In a preferred embodiment the spring means comprises a spring steel strip bearing on the second surface 4 of the device. Preferably the cutter 7 comprises a blade 9 secured in a plastic housing with a minimal amount of blade 9 protruding for safety.

Figure 4 shows an isometric view of the embodiment in figure 1 , showing the cutter 7 at the resting position, with the edge of the blade 9 showing at the front of the cutter 7; the moving arm 2 pivoted in an open pos tion to allow a plastic bag open end to be placed between it and the stationary arm 1 ; the elastomer grip along the clamping edges 12, and a bevel on the second surface 13 that provides an extended region of plastic film to be heat sealed. In use, the plastic bag (not shown) is placed in the device with the open end facing out of the paper in figure 4, the arms 1 , 2 are closed together and the cutter 7 is moved upwards along the arms 1 , 2 to the other end. In so doing the cutter clamps the arms 1 , 2 in the closed position, the elastomeric grip 12 being compressed to grip the plastic. The cutter 7 cuts off the excess plastic from the end of the bag and leaves a controlled amount protruding from the clamping edges 12. A heat gun is then run along the plastic edge causing it to seal. The device is then removed by sliding the cutter 7 back into the resting position and opening the arms 1 , 2. If the plastic bag comprises heat shrink material it may then be shrunk around an item using the heat gun.

The device is preferably formed from heat resistant materials to prevent melting or release of fumes. The arms 1 , 2, cutter 7 and blade 9 housing, pivot 5 axle, and thumb screw 8 may be formed from a heat resistant rigid polymer; the grip from a heat resistant elastomer or rubber; the blade 9 may be a stainless steel razor blade and the spring means may comprise a sprirg or a curved strip of spring steel.

As is evident particularly from Figure 3, the cutter 7 comprises a housing mounted over the device and having returns 11 on the underside of the device to retain the cutter 7 on the device, allowing it to slide along the device past the pivot 5 when the arms 1, 2 are in the closed position. Thus the cutter 7 is moveable from the proximal end 6 of the arms to the distal end when the arms are closed.

The stationary arm 1 and the movable arm 2 are shown in the closed position in Figure 5. The cutter 7 clamps the stationary arm 1 and the movable arm 2 together. The location of the clamp is the same as the location of the cutter. As the cutter 7 is moved from the proximal end 6 to the distal end the clamp remains co-located with the blade 9 since the cutter 7 comprises the blade. An advantage of the clamp and blade being collocated is that a bag clamped between the stationary and moving arms is held most securely close to where it is cut by the blade. Straight cuts are therefore reliably obtained. Another advantage of the clamp being integrated with the cutter it enables a one piece cutter and clamp.

Figure 6 shows second embodiment of an embodiment of the device for clamping and cutting 100. As the previous embodiment there is a stationary arm 1 , a movable arm 2, and a cutter 7. The cutter 7 of the second embodiment is retained by a long slot 16 through the movable arm 2 and the cutter 7 is slidable in the long slot 16 along the movable arm 1 from the proximal end 6 to the distal end. The cutter 7 is slidable from proximal end to distal end when the arms 1 , 2 are apart and when the arms 1 , 2. Thus the cutter 7 of the second embodiment differs from that of first embodiment which is only slidable from the proximal end the first end when the arms 1 , 2 are closed together.

As shown in Figure 6 the cutter 7 of the second embodiment comprises a return 14 which moves along the clamping face 4 of the moveable arm when the arms 1 ,2 are apart.

The return 14 forms a portion of the clamp that holds the moveable and stationary arms 1 , 2 together in the closed position.

The stationary arm 1 comprises an aperture 15 near the proximal end. The aperture 15 is sized larger than the return 14 on the cutter. To clamp the arms together and cut a sheet or bag, the cutter is moved to tne proximal end 6 so that the return 14 is in a matching position with the aperture. Closing the arms 1. 2 inserts the return 14 through the aperture 15. Clamping the moveable arm 2 and the stationary arm 1 together is accomplished by closing the arms together and sliding the cutter 7 from the proximal end 6 to the distal end. The return 14 slides against the fixed arm so that the cutter 7 drawing the clamping face 4 of the movable arm 2 against the clamping face 4 of the fixed arm 1. Thus sliding the cutter 7 along the arms 1 , 2 both cuts a sheet clamped between the clamping face and draws the arms together so as to clamp the sheet between the clamping faces 4 of the arms 1 , 2.