This invention relates to cutting apparatus for cutting sheet material and in particular, but not exclusively, to such arrangements for cutting plastics sheet material such as cling film and other thin plastics sheet or films as well as metal foils such as aluminium foil, and other materials such as siliconised baking paper or baking parchment. The invention also extends to dispensers for sheet material that incorporate such cutting apparatus.

It is well known to provide cling film or foil dispensers in the home, catering establishments, food stores etc, from which sheet material on a roll may be dispensed and cut to length as required using a cutter device in the dispenser. Such devices may be used hundreds of times a day in commercial establishments and it is important that they provide a reliable, consistent cutting action time after time. Examples of typical devices are described in a number of different earlier documents, for example US3311278, US4417495, US5107732. In such devices, an elongate cutter blade is disposed next to a first jaw member which provides jaw surfaces spaced to either side of the elongate cutting edge, and the first jaw member being movable relative to the cutting edge between a position in which the blade is at least partially shielded and a cutting position in which the blade projects beyond the jaw members. A second jaw member is movable relatively into engagement with the first jaw member to grip a portion of the sheet material and then to pass the gripped portion of sheet material over the blade to sever it. In these arrangements there is a first jaw assembly which is mounted for mechanical pivoting or linear movement relative to the blade and a separate spring arrangement to bias the assembly into a position in which it shields the blade. These types of arrangements have several disadvantages; they tend to rely on a metal spring to provide the resilience which, given the large number of cycles of operation can fail due to fatigue. The mountings necessary to constrain the movement the first jaw member relative to the blade require radius arms or linear mounting mechanisms which add to the component count and the complexity of the assembly. Furthermore, particularly where these are used in the food industry, the complexity of the assembly means that they are difficult to clean.

US3311278 discloses an arrangement in which a hollow section seal strip is used to line the upper jaw members, but movement of the gripped sheet material requires an inner clamp plate pivoted to the casing of the device and biased by a resilient strip. Therefore, we have designed an improved cutter apparatus preferred embodiments of which obviate the need for mechanical pivotal or linear support mechanisms for the jaw member associated with the cutting blade and in which separate springs are not required.

Accordingly, in one aspect, this invention provides a cutting apparatus for cutting sheet material, said cutting apparatus comprising: a cutter member having an elongate cutting edge; a first jaw arrangement providing elongate jaw surfaces spaced to either side of said elongate cutting edge and movable with respect thereto, and a second jaw arrangement having complementary jaw surfaces spaced to either side of the plane of said blade for being relatively moved in a given sense into engagement with said first jaw arrangement initially to grip a portion of the sheet material in use at positions to either side of said cutter member and on further movement to move said gripped portion relative to the cutter member to cut said sheet material, wherein said first jaw arrangement comprises two compressible jaw elements of resiliently compressible hollow section adapted to be resiliently compressed by engagement with said second jaw member from a rest position in which said cutter element is at least partially shielded between said compressible jaw elements, to a compressed position in which said cutter edge projects beyond said compressible jaw elements to cut the sheet material in use.

In this construction, the compressible jaw elements provide the required movement of the first jaw arrangement without needing a radius arm or other support mechanism. Furthermore, the resiliently compressible nature of the hollow section means that the element itself provides the necessary resilience to return to its initial position. In this manner, assembly and cleaning of the device are considerably simplified.

Each compressible jaw element is preferably of substantially uniform cross-section, formed for example by extrusion. The jaw elements are conveniently of extruded plastics material.

Each jaw element is preferably a four-sided section comprising a base wall, an inner side wall that faces the cutter member, an outer side wall, and a jaw surface wall that faces said second jaw member in use. The base wall may conveniently be designed to be anchored to a further component. For this purpose it may have attachment or plug features such as a serrated edge.

Conveniently, the jaw surface wall is adapted to flex about its merger with the outer side wall to allow the jaw element to move to its compressed position. Conveniently, the inner side wall is designed as a flexural spring which buckles inwardly of the section (i.e. towards the outer side wall) as said jaw surface wall flexes. This arrangement provides a robust resilience which enables the section to be cycled between its rest and compressed positions many times before failure of the section. Preferably, said cutter member comprises a cutter blade anchored in an elongate assembly having elongate channels to each side of the blade, each channel receiving one of said jaw elements. In this manner, the blade and the jaw elements may form a removable cartridge that may be removed from the device for cleaning simply by lifting out of the channels with the jaw elements still shrouding the blade for safety. The removable cartridge can be placed in a dishwasher for cleaning, and has drainage holes.

The cutter member may comprise a straight cutting blade or it may be serrated, scalloped or otherwise shaped according to the sheet material to be cut. The cutter member may comprise a single cutter blade or a number of cutting components.

In the illustrated embodiment of the cutting apparatus of this invention, the first jaw arrangement, in addition to cooperating with the second jaw arrangement to grip the sheet and cut it, also performs the function of acting as a retractable shield which shields the cutter member other than when performing a cutting action.

Although the opposite configuration is of course possible, it is preferred for the cutter member to remain substantially stationary during operation of the apparatus with a cutting operation being effected by manually moving the second jaw arrangement to contact the first jaw arrangement to grip the sheet material, with further manual movement of the second jaw arrangement moving the first and second jaw members past the cutter member to effect the cut.

The invention extends to a compressible jaw element of resiliently compressible elongate hollow section as described above, for use in a cutter apparatus, and to an assembly comprising a cutter member and two such compressible jaw elements provided one to either side of the cutter member. The invention also extends to a dispenser for sheet material including a cutting apparatus as set out above. Whilst the invention has been described above, it extends to any inventive combination or sub-combination of the features set out above, or in the remainder of the specification.

The invention may be performed in various ways and, by way of example only, a specific embodiment thereof will now be described in detail, reference being made to the accompanying drawings in which:

Figure 1 is a schematic cross-section view through a sheet material dispenser having a cutter apparatus of this invention;

Figure 2 is a cross-section view through the cutter apparatus of Figure 1 immediately prior to a cutting operation, and Figure 3 is a view similar to Figure 2 but showing the apparatus with the components at the bottom of a cutting stroke.

Referring initially to Figure 1 , the dispenser comprises a container having a base 10 of rectangular trough form which receives a roll 12 of sheet material and the lower components of a cutter apparatus indicated generally at 14. The roll 12 is supported by suitable fittings at each end to allow the roll to rotate as sheet material is paid off the roll. From the roll 12, the material passes around a feed roller 16, through upper and lower spreader plates 18 ¹ 18 ¹¹ to pass to the cutter apparatus 14. Hinged at 18 to the base 10 is a lid 20 which, on the front edge thereof carries the upper components of the cutter assembly 14. The lid 20 is movable downwardly against a resilient bias afforded by the lower components of the cutter apparatus to cut a length 22 of sheet material.

Turning now to Figures 2 and 3, the cutter apparatus 14 comprises a lower footing channel 24 of elongate form, from the centre of which upstands a cutter blade 26 of serrated form. To either side of the cutter blade respective inner and outer jaw support channels 28, 30 are provided. Within each jaw support channel is mounted a resiliently compressible hollow section jaw element 32, 34 respectively. Each hollow section jaw element comprises a base wall 38 of thicker section and having outwardly directed serrations 40 to either side to engage the walls of the respective support channel 28, 30. An outer wall

42 extends from the base 38, against the wall 43 of the jaw support channel remote from the blade 26. Integral with the top end of the outer wall 42 is an upper wall 44 with there being a hinge region 46 at the merger between the outer wall and the upper wall. The upper wall 44 has longitudinal grooves 47 formed in it to assist flexing, and an upwardly facing U-shaped trough 48 for cooperating with an aligned one of the upper jaw members 50. The inner side wall 49 is bowed inwardly and connects the upper wall 44 to the base wall 38. The other jaw member 34 is of identical section but in mirror image to provide a symmetrical arrangement. The jaw members may conveniently be formed by extruding a suitable plastics material. The other jaw member 34 cooperates with the upper jaw member 52. The blade 26, jaw members 32 and 34 (hereinafter referred to as the first jaw members) and the second jaw members 50, 52 extend for the length of the roll 12. In use, sheet material 22 from the roll 10 is fed through the cutter apparatus to lie between the upper and lower jaws. To cut a section of the sheet material, the upper jaw is pushed downwardly so the jaw members 50, 52 engage the sheet material 22 and trap it against the troughs 48 in the respective lower jaw members 32, 34. Continued downward pressure on the upper jaw members 50, 52 causes lower jaw members 32 and 34 to collapse downwardly so that the sheet material 22 held tautly to either side of the blade is severed by the blade as the lower jaw members pass the blade. As seen from a comparison of Figures 2 and 3, each jaw surface wall 44 pivots about the hinge region 46. Thus as the film is trapped and dragged downwards due to the jaw movement, the jaw surface walls 44 pivot so that the jaw gripping troughs 48 follow an arc centred on the hinge regions to pull away from the blade to stretch the film across the blade during the cutting action.

As will be seen in Figure 3, the hollow section of the jaw members is designed so as to fulfil a number of different functions. Firstly, on initial contact the lower jaw members grip the film firmly with the upper jaw members. Then, as further pressure is applied, the inner walls flex away from the blade into the section, to allow the upper walls 44 to flex about the hinge 46, with the inner walls providing a resilient restoring force when pressure is removed so that they return to the configuration of Figure 2.

The use of a hollow section resiliently compressible jaw member means that the section itself provides the cutting stroke of movement and also the resilient return. Thus, no separate spring bias is required and furthermore, no separate radius arm or linear support mechanism is required. Furthermore, for cleaning and or replacement, one or more of the components in the lower half of the cutter assembly, for example the jaw members and the blade, may form a replaceable cartridge that can be pulled out and replaced relatively easily and also allowing access to the blade if required. This is important from a point of view of hygiene and servicing. It will of course be appreciated many variations of the above example are possible; for example the components may be inverted so that the jaw members 50 and 52 are the lower jaw members and mounted in the base 10 with the blade and resiliently compressible jaw members 32 and 34 mounted on the lid 20.