Device and method for extracting a mussel foot from a mussel and a mussel cutting device
[0001 ] The present invention relates generally to a device and method for extracting a mussel foot from a mussel.
 It is known that Mussel Adhesive Protein (MAP) is formed in a gland in the foot of byssus forming mussels, such as the common blue mussel (Mytilus edulis). US 5,015,677 as well as US 4,585,585 disclose that MAP has very strong adhesive properties after oxidation and polymerization, e.g. by the activity of the enzyme tyrosinase, or after treatment with bifunctional reagents.
 J. H. Waite et al in The Journal of Adhesion, vol. 81 , 2005, pp 297-31 7 reviews adhesive proteins from mussels.'
 To the present date, devices an methods relating to the extraction of mussel feet from mussels involves a manual operation with various kind of hand tools. For instance it is known, by applying well known tools and knowledge of their effect upon usage, to open a mussel with a knife, lift the mussel feet by hand or by some kind of gripping device and cut the mussel feet from the mussel by means of a cutting tool such as a knife or a pair of scissors.
Summary of invention
 An object of the present invention is to alleviate some of the disadvantages of the prior art and to provide an improved device and method for extracting a mussel foot from a mussel.
 According to a first aspect of the present invention, a device for extracting a mussel foot from a mussel comprises a suction device adapted to create a suction pressure, the suction device having an end aperture arranged at a first end thereof, and a cutting device, the device being characterized in that the suction pressure of the suction device during operation erects the mussel foot from a mussel adjacent to the end aperture and sucks the mussel foot through the end aperture of the suction device, wherein the cutting device is arranged adjacent to the end aperture of the suction device.
 According to one embodiment the cutting device is movable in a direction perpendicular to the end aperture, ensuring an appropriate cut for dividing the mussel foot from the rest of the mussel.
 According to one embodiment said cutting device comprises a hole with an edge and is slidingly arranged adjacent the end aperture of the suction device, wherein the cutting device is movable from a first position wherein the hole is essentially aligned with the end aperture of the suction device for orienting the mussel foot through the end aperture and the hole, to a second position wherein the hole is non-overlapping with the end aperture.
 According to one embodiment the cutting device and the first end of the suction device function as a pair of scissors.
[001 0] According to one embodiment the first end of the suction device is a nozzle.
[001 1 ] According to one embodiment said first end of the suction device is connected to a first end of a first tube, wherein a second end of the first tube is connected to a container for containing extracted mussel feet. Thereby, extracted mussel feet can be easily collected and stored for further preparation.
[001 2] According to one embodiment the first end of a second tube is connected to the container and a second end of the second tube is connected to a suction pressure generating device, facilitating suction of extracted mussel feet into the container.
[001 3] According to one embodiment the device comprises a cooling device for cooling the interior of the container during operation of the device, ensuring that extracted mussel feet are maintained in good condition.
[001 4] According to one embodiment the device comprises a holding device to which the container is detachably arranged. Advantages of the invention include that the device enables a fast and efficient means of extracting feet from mussels in that only the entire protein containing foot is extracted from the mussel, excluding any other part of the mussel such as e.g. muscles or gills that does not contain any useful protein.
[001 5] According to a second aspect of the present invention, a method for extracting a mussel foot from a mussel is characterized by the steps of opening the mussel to expose the interior thereof, erecting the mussel foot by means of suction force, and when erected by means of suction force, cutting the mussel foot.
Brief description of drawings
[001 6] The invention is now described, by way of example, with reference to the accompanying drawings, in which:
[001 7] Fig. 1 shows a cut open mussel disclosing the inside of the mussel
[001 8] Fig. 2 shows a perspective view of a device for extracting a mussel foot from a mussel according to the invention comprising a suction device.
[001 9] Fig. 3 shows a side view of part of the device of fig. 2, comprising the suction device end aperture and the mussel foot cutting device.
 Fig. 4α shows a section of a device according to the invention prior to operation of the mussel foot cutting device.
[0021 ] Fig. 4b shows a cross-section of the device of fig. 4a after operation of the mussel foot cutting device.
 Fig. 5 shows a mussel cutting device according to the invention comprising the mussel feeding section.
 Fig. ό shows a mussel holding device comprised in the device of fig. 5. Description of embodiments
 In the following, a detailed description of the invention will be given. In the drawing figures, like reference numerals designate identical or corresponding elements throughout the several figures. It will be appreciated that these figures are for illustration only and are not in any way restricting the scope of the invention.
 Fig. 1 shows a cut open mussel 2 disclosing the mussel shell parts 2a, 2b, as well as the inside of the mussel. Reference number 4 represents the mussel foot, which is the major part of relevance to this invention. The mussel foot is an organ of the mussel facilitating movement and helping the mussel stay stationary essentially having the function of an anchor. The mussel foot can be used to extract Mussel Adhesive Protein (MAP).
 Fig. 2 shows an overview of a device 1 0 according to the invention for extracting a mussel foot from a mussel. The device 1 0 comprises a suction device 1 2, adapted to create a suction pressure by means of a suction generating device 14, such as a fan. In the figure, the device 1 0 is placed on a desk structure 1 6 but this structure can have other alternative forms.
 As seen in fig. 3, a holding device 1 8 is placed on the desk structure 1 6 onto which a first end, i.e. a nozzle 20 of the suction device is arranged. The
nozzle 20 is movable vertically relative to the holding device along rails 1 8a on the holding device and can be locked in position by means of a locking device 1 8b, enabling an adjustment of the height of the first end of the suction device in order to accommodate for different heights, i.e., working positions of a person operating the device. An end aperture 20a is arranged on the end surface of the nozzle 20. Further, a cutting device 22 is arranged adjacent the end aperture 20a of the suction device. The cutting device 22 is pivotally arranged on the nozzle of the suction device, and has a first, upper part 22a adapted to function as a handle for an operator and a second, lower part 22b adapted to slidingly fit into and extend through an opening 20b in the nozzle perpendicular to the end aperture 20a as seen in fig. 4a. As is evident from fig.3, the first part 22a of the cutting device is provided with a pivot point wherein the first part 22a is journalled about a pin 22c. The first part also comprises a cam surface made up of the edges of a hole 22d . The second part 22b slidingly fits into the opening 20b and has a pin 22e that engages with the cam surface in the form of the hole 22d to translate rotational movement of the first part 22a, i.e., the handle, to a linear movement of the second part 22b of the cutting device. As can further be seen in fig. 3, a number of apertures 20c arranged with an essentially longitudinal extension in the nozzle direction are placed above the opening 20a and circumferentially around the nozzle 20 with the purpose to allow sufficient air to flow through the nozzle, also when the end aperture 22a is closed by mussel parts held in front of the aperture during operation. Hereby, a suction pressure through the suction device, and thereby transportation of mussel feet is enabled at all times.
 As seen in fig. 4a, the second, lower end part 22b of the cutting device 22 has a hole 22f with an edge 22g functioning as a cutting edge that preferably has a sharp or inclined surface. Due to the pivotal arrangement of the cutting device, and the two parts 22a, 22b of the cutting device 22 as explained above, the second, lower part 22b is movable in a direction perpendicular to the end
aperture 20a through the opening 20b. The second, lower part 22b of the cutting device 22 is movable from a first position, see fig. 4a, wherein the hole 22f is essentially aligned with the end aperture 20a of the nozzle 20 to a second position, see fig. 4b, wherein the hole 22f is non-overlapping with the end aperture 20a.
 Fig. 3 further discloses a first tube 24, having a first end connected to the nozzle 20 and a second end connected to a container 26, which is detachably arranged on an arm 28, extending from the holding device 1 8. A cooling device (not shown), can be placed in the proximity of the container for cooling the container. In one alternative embodiment, such cooling device could comprise a bucket of ice placed below and encompassing the container 26. A second tube 30 has a first end connected to the container 26, and a second end connected to the suction generating device 1 4 shown in fig. 2.
 Operation of the device will be further explained with reference to figs. 4a and 4b. In fig. 4a a cut open mussel with a mussel foot inside is placed adjacent the aperture 20a. The cutting device 22 is now in a first position wherein the hole 22f of the cutting device is essentially aligned with the aperture 20a of the suction device. A suction pressure is present in the proximity of the aperture of the suction device which erects the mussel foot from the mussel and sucks the mussel foot through the end aperture 20a as well as through the hole 22f of the cutting device. In fig. 4b, the cutting device handle has been operated by an operator such that the second, lower part 22b of the cutting device has been moved slidlingly through the opening 20b from left to right in the figure. The relative movement of the second, lower part 22b of the cutting device and nozzle 20 of the suction device resembles the function of a pair of scissors, cutting the mussel foot from the mussel at the base of the mussel foot. The scissor or cutting function is enhanced, but not enabled, by the sharp cutting edge 22g of the second part of the cutting device.
[0031 ] It should also be noted that the second part 22b of the cutting device is adapted to be easily replaceable so that a dull cutting edge 22g after continuous use can be replaced by a new and sharp edge. Further, an operator hereby has the means to replace the second part of the cutting device with a version having a hole 22f with a sized adapted to the size of the mussel foot. It is then preferred that mussels to be processed are divided into batches of mussels having essentially the same size and to process the mussels of each batch with a cutting device adapted to the respective size. For example, if a batch of large mussels, typically having a larger type of mussel feet to be extracted, then a cutting device 22 having a large hole 22f is used, such as a hole with a diameter of 1 0 millimeters. Cutting devices 22 with smaller holes 22, such as holes with a diameter of 8 or ό millimeters, can be used for smaller mussels. Alternatively, as can be seen in fig. 3 an adjustment device 51 a in the form of a screw, is arranged on the second part 22b of the cutting device and directed through an opening of a bracket portion 52 fixedly attached to the holding device 1 8 to enable the adjustment of an initial size of the hole 22f, thereby adapting the hole size 22f to the mussel foot size.. A screw nut 51 b is screwed on to the adjustment device 51 a on the opposite side of the bracket piece in relation to the second part 22b. By screwing the screw nut 51 b, the second part 22b will be moved in a horizontal direction through the opening 22b thereby adjusting the initial size of the hole 22f.
 The suction pressure in the first end of the suction device generated by the suction generating device causes the extracted mussel foot to be sucked to the cooled container 26. An air permeable filter 30a at the connection of the second tube 30 to the container 26 prevents the extracted mussel foot to be further sucked through the second tube 30 and into the suction generation device 14.
 Fig. 5 discloses a mussel cutting device 40 arranged on a desk structure 42 and including a conveyor belt 44 movable in a first direction, as indicated by
the arrow, and at least one but preferably a plurality of mussel holding devices 46. The mussel cutting device 40 further comprises a sawing device 48, such as for instance a rotating saw blade, a band saw, a water jet cutter or any other cutting means, arranged adjacent the conveyor belt. The sawing device is provided with a cover 48a.
 Behind the sawing device 48 in the first direction, a separator 50, consisting of a thin metal screen is arranged in line with the saw blade.
 Each mussel holding device 46 comprises a first section 46a and a second section 46b extending in a second direction perpendicular to the first direction with a spacing between the sections in the first direction as seen in fig. 6. The first section 46a preferably has a length that is approximately one half of the length of the second section 46b. Each section of the mussel holding device 46 further comprises a two part brush device, arranged on each side of a mussel to be processed for holding the mussel in place.
 The sawing device 48 and the separator 50 have a width so that they fit in the spacing between the two sections 46a, 46b of the mussel holding device 46, whereby the first and second sections during operation of the conveyor belt 44pass on each side of the saw blade when the mussel holding device passes the moving saw blade upon operation of the mussel cutting device 40.
 An arrangement for industrial use for extracting a mussel foot from a mussel thus contains a device 1 0 for extracting a mussel foot from a mussel and a mussel cutting device 40. An operator operating the arrangement places a mussel in the mussel holding device on the conveyor belt, so that approximately 1 /3 of the mussel, measured from the end of the mussel part containing the closing muscle, is located on the first section 46a of the mussel holding device, i.e., to the right in fig. 6, and so that approximately 2/3 of the mussel, measured from the hinge end, i.e.
the end of the part containing the mussel foot is located on the second section 46b of the mussel holding device, i.e., to the left in fig. 6. This enables an optimized cutting location of the mussel for removing the muscle that holds the two shell parts together and for uncovering the mussel foot. The conveyor belt 44 moves the mussel holding device and thus the mussel towards and beyond the cutting saw blade such that the mussel is cut in two parts, see fig. 6. During passage of the saw blade, the first section 46a of the mussel holding device passes on one side of the saw blade and the second section 46b passes on the other side of the saw blade since the saw blade is allowed to pass through the spacing between the sections. The mussel parts are then transported in the mussel holding device on each side of the separator 50 for facilitating the next step in the operation whereby the operator manually picks the mussel part containing the mussel foot and turns to the mussel extraction device for operation according to the method as described with reference to figs. 4a and 4b.
 A preferred embodiment of a device and method for extracting a mussel foot from a mussel has been described. It will be appreciated that this can be varied within the scope of the appended claims without departing from the inventive ides. Thus, the invention is not limited to a hand operated cutting device using a handle. For instance a foot pedal and a mechanical linkage between the foot pedal and the cutting device to enable a user to operate the cutting device by his foot is one example of such alternative embodiment.