GB2447671A

GB2447671A - Apparatus and method for de-shelling crustaceans

Info

Publication number: GB2447671A
Application number: GB0705335A
Authority: GB
Inventors: Ian Mulgrave Penney
Original assignee: Individual
Current assignee: Individual
Priority date: 2007-03-21
Filing date: 2007-03-21
Publication date: 2008-09-24
Also published as: GB2447721A; GB0800871D0; GB0705335D0

Abstract

An apparatus for de-shelling prawns, langoustines or the like comprises means to orientate (8B, Fig 2) and secure 24 the fleshy abdomen 20, in its shell 22 and 23, and the tail 21 of a langoustine to a processing member 8 and straightening 27 the abdomen so that it lies along the processing member. In this orientation a hollow needle 29 is inserted, between the scales, into the abdomen, adjacent to the tail, and a pulse(s) of fluid, preferably compressed air, is injected to create a pressure inside the shell. This pressure severs the flesh where the abdomen joins the tail and also severs connections between the abdomen and the shell, so that the fleshy abdomen is ejected, as a single entity, out of its shell and off the processing member into a product collector (16, Fig 2). The method of using the apparatus is also disclosed, as is a means to automate the process, so that a skilled operator could de-shell thousands of langoustines per hour.

Description

APPARATUS AND METHOD FOR DE-SHELLING

CRUSTACEANS

This specification relates to de-shelling crustaceans. particularly prawns. langoustineS and the like, but the principle is equally applicable to other types of crustacean or parts of crustaceans. such as cray fish tails or lobster tails Prawns are usually cooked before de-shelling, this softens the shell and makes de-shelling relatively easy In contrast, langoustines are larger. have tougher shells with more appendages on the underside of the shell and have to be de-shelled before cooking Thus.

de-shelling is a difficult, labour-intensive operation requiring careful handling to avoid damaging the soft flesh inside The high value of langoustines limits the work to skilled, highly trained personnel Scampi' is the term for langoustines. which have been de-shelled. coated in batter or breadcrumbs ready for cooking or already cooked The most commonly used method of de-shelling is for an operator to place the langoustines, tail first on a belt feeding into the angle of nip between a pair of water-flooded rollers so that the flesh is squeezed out through the aperture created by cutting the thorax from the abdomen Unfortunately. the results are variable with relatively few coming out whole and a high proDortion appearing as squashed flesh. There is also a significant amount of flesh left in the shells, which has to be removed by hand As the tails tend naturally to curl up into a crescent, they have to be straightened before placing on the belt and many tend to re-curl before they enter the angle of nip. Thus this method has significant disadvantages Another method of de-shelling is to cut the scales on the underside with a circular saw and bend the two sides aoart to release the flesh This works well if the scales are fully cut through but, if they are not, it is difficult to prise sides apart Thus, the operator will try to ensure that the scales are cut completely through and, frequently. will inadvertently allow the circular saw to cut into the flesh This is not serious for the low value scampi, which are usually sold breadcrumbed or battered, ready for deep frying. However flesh with saw cuts is not acceptable to Gourmets. who often eat langoustines without any covering For Gourmet consumption. only the best langoustines are used If inexperienced operators are used to de-shell them, wastage rates can be high (often over 50%), so that only the most expenenced operators are used In either case. this makes the unit cost per langoustine high, especially as each one must be inspected after de-shelling. In an effort to reduce costs, a number of organizations have resorted to freezing the langoustines.

transporting them to the Far East (where labour rates are lowest), thawing them.

de-shelling re-freezing and transporting them back to the UK While this might be economically advantageous, the cost to the environment in food miles' is considerable Furthermore, the repeated freezing, thawing and re-freezing affects the quality of the flesh and also bears on quality control and hygiene Thus, there is a clear need for a reliable and economic means of de-shelling langoustines.

without damaging the flesh or without multiple freezing and thawing According to the invention, there is provided apparatus for de-shelling prawns, langoustines or the like, comprising -i) providing a prawn. langoustine or the like, the head and thorax of which have been removed leaving only the fleshy abdomen in its shell and the tail, ii) providing a processing member for the prawn. langoustine or the like on which said prawn, langoustine or the like can be placed: iii) providing a means to clamp the tail of the prawn, langoustirie or the like on the processing member to said processing member, iv) providing a means to straighten the abdomen of the prawn, langoustine or the like so that it lies along the processing member v) providing a means of injecting a fluid into a selected part of the abdomen of the prawn, langoustine or the like, vi) providing a means to collect as product the fleshy abdomen of the prawn.

langoustine or the like, and vii) releasing the straightening means from the abdomen and the clamping means from the tail of the prawn, langoustine or the like and providing a means to remove the emoty shell from the processing member and discharging it into a waste collector and returning the injection means to its rest position.

characterised in that the selected part of the abdomen is the area adjacent to the clamped tail so that the injection of the fluid into this area creates a pressure within said area and inside the shell, severing the flesh where the abdomen joins the tail and also severing connections between the abdomen and the shell so that the fleshy abdomen is ejected out of its shell by said fluid pressure and off the processing member into the product collection means According to a first variation of the apparatus of the invention, the processing member is a flat surface According to a second variation of the apparatus of the invention, the processing member has a longitudinal depression in the surface According to a third variation of the apparatus of the invention, the longitudinal depression in the surface of the processing member is a V-shaped groove.

According to a fourth vanation of the apparatus of the invention, the means to clamp the tail of the prawn, langoustine or the like to the processing member is a member which is movable downwardly to clamp said tail between said member and the processing member According to a fifth variation of the apparatus of the invention, the means to straighten the abdomen of the prawn. angoustine or the like is a weight movable downwardly onto the curved abdomen causing it to straighten and lie essentially on and parallel to the surface of the processing member According to a sixth variation of the apparatus of the invention, the straightened abdomen lies in the V-shaped groove in the processing member.

According to a seventh variation of the apparatus of the invention, the abdomen is orientated so that the up er (dorsal) part of the shell is downward in the bottom of the V-shaped groove According to an eighth variation of the apparatus of the invention, the means of injecting the fluid into the abdomen of the prawn. langoustine or the like is a hollow needle According to a ninth variation of the apparatus of the invention, the fluid ts a compressed gas According to a tenth variation of the apparatus of the invention, the gas is oil-free filtered.

compressed air According to an eleventh variation of the apparatus of the invention, the fluid is infected in a plurality of pulses According to a twelfth variation of the apparatus of the invention, the fluid pulses are sequentially timed and of predetermined durations.

According to a thirteenth variation of the apparatus of the invention, the first pulse(s) ts(are) of a predetermined duration(s) to sever gently the connections between the abdominal flesh and the tail and between the abdominal flesh and the shell and also to urge, or commence urging, said flesh out of the shell.

According to a fourteenth variation of the apparatus of the invention, the subsequent pulse(s) is(are) of a predetermined duration(s) to eject the flesh, or any flesh remaining after the first pulse(s). completely from the shell and to blow it off the processing member so that it enters a product collector According to a fifteenth vanation of the arnaratus of the invention, an additional pulse is used to blow the empty shell off the processing member and into the waste collector According to a sixteenth variation of the apparatus of the invention, the number of the pulses, the duration of the pulses and / or the pressure of the fluid in the pulses are / is variable According to a seventeenth variation of the apparatus of the invention, the operations to eject the flesh from the shell and into the product collector and to discharge the shell into the waste collector are performed within an enclosure so that any airborne particles created during the operations are retained therein and also that no external contamination can reach the food items being Drocessed therein According to an eighteenth variation of the apparatus of-the invention, all materials of construction of components, which will come into contact with the items of food being processed and all other members in areas ad;acent to said components are made of materials compatible with the appropriate hygiene requirements According to a nineteenth variation of the apparatus of the invention, all electrical and / or pneumatic and I or hydraulic apparatus and the power connections thereto are compatible with performing operations on damp, potentially-saline food items According to a twentieth variation of the apparatus of the invention, the processing member is cleaned before re-use.

According to the invention, there is provided a method for de-shelUng prawns, langoustines or the like, comprising the steps of -I) taking a prawn, langoustine or the like, the head and thorax of which have been removed leaving only the fleshy abdomen in its shell and the tail: ii) placing the prawn, langoustine or the like on a processing member; iii) clamping the tail of the prawn, langoustine or the like on the processing member to said processing member: iv) straightening the naturally curved abdomen of the prawn. langoustine or the like so that it lies along the processing member: v) inserting a hollow needle into a selected part of the abdomen of the prawn, langoustine or the like and in,ecting a fluid through said needle into said part so that the fleshy part of the abdomen is separated both from the tail and the shell and ejected from the shell.

vi) collecting as product the fleshy abdomen of the prawn, langoustine or the like; and vii) releasing the straightening means and the means retaining the shell of the prawn.

langoustine or the like to the processing member and discarding the empty shell According to a first variation of the method of the invention, the fluid injected through the hollow needle is a compressed gas According to a second variation of the method of the invention, the fluid injected through the hollow needle is a liquid According to a third variation of the method of the invention, the fluid is injected in a series of successive pulses According to a fourth variation of the method of the invention, the parts of the apparatus which come into contact with the prawn. langoustine or the like during the de-shelling process are cleaned prior to de-shelling each prawn, langoustine or the like According to a fifth variation of the method of the invention the cleaning orocess involves sorayina surfaces, which come into contact with the prawn, langoustine or the like with clean water In a preferred application of the apparatus and method of the invention, a langoustine, with the head and thorax removed, is placed on a processina surface The abdomen of a langoustine is covered with a segmented shell so that it can flex between a curved and straight form. For this application, the abdomen is required in a straight form and. ideally.

this is achieved by placing the langoustine with its back (dorsal) side downwards into a groove on the orocessing surface, clamping the tail to the processing surface and applying a weight to the abdomen to cause it to become straight and rest centrally in the groove The next operation is to insert a hollow needle into the base of the underside of the abdomen, Just above the point where the shell merges into the tail, and inject a pulse of air This will create a pressure inside the shell, so that the flesh joining the abdomen to the tail is severed Additionally, the flesh in the abdomen will be pushed away from the tail.

severing the connections with the shell and ejecting the flesh, as a single mass, out of the shell. If the air pulse is sufficient, the flesh can be blown off the processing surface and into a product collection bin In the preferred application, the weight and clamping means are then removed and a further pulse of air is used to blow the empty shell off the processing surface into a waste bin An advantage of straightening out the abdomen is that it is easier to eject the flesh from the shell when the shell is essentially in the form of a right truncated cone or parallel-sided tube as opposed to having to pass out through a curved, part-involute oassage Another advantage of straightening the shell of the abdomen is that the scales of the shell lie flat against each other and form a better seal to retain the injected air Ideally, the air is iniected in a number of discrete pulses. for example a first pulse to create a gentle oressure to commence severing the fleshy connections and to start the flesh mass moving out of the shell, followed by a further pulse(s) to complete the separation of flesh from the shell and to blow the freed flesh out of the shell and into the collection bin If a single large pulse was to be used instead, there could be a risk of rupturing the shell and the air escaping The pressure of the gas may also be varied to suit the particular characteristics of different crustaceans.

Ideally, the apparatus is automated so that a plurality of processing surfaces sequentially pass the various stations where the de-shelling operations are performed If required, part of the automation would involve spraying the surfaces, which come into contact with the prawns, langoustines or the like, with clean water to remove debris and clean the apparatus after each prawn. langoustine or the like has been de-shelled. as part of the hygiene procedure of the de-shelling process For a clearer understanding of the invention and to show how it may be carned into effect, reference will now be made, by way of example only, to the accompanying drawings in which:-Figure 1 is a plan view of the apparatus of the invention, Figure 2 is a plan view of one possible detail of the processing station of the apparatus of the invention shown in Fig 1, Figure 3 is a side elevation of a langoustine. placed on a handling tray ready for processing by the apparatus of the invention, Figure 4 is a side elevation of the langoustine, shown in Fig 3, after clamping to the anvil Figure 5 is a side elevation of the langoustine shown in Fig 4 after the application of a weight to straighten the body.

Figure 6 is a side elevation of the langoustine, shown in Fig. 5, after the insertion of a hollow needle into the abdomen of the angoustine Figure 7 is a side elevation of the shell of the langoustine. shown in Fig 6, after the ejection of the flesh and ready for the removal of the shell from the handling tray following removal of the weight and freeing from the tail I anvil clamp, Figure 8 is an end elevation showing the forms of the handling tray and the tail I anvil clamp.

Figure 9 is a side elevation of the langoustine, shown in Figs 3 and 4, when its abdomen is curved and the shell scales are deflected away from the body, and Figure 10 is a side elevation of the langoustine, shown in Figs 5 and 6. when the abdomen is straightened out and the scales lie flat against each other In the following description, the same reference numeral is used for the same part in different figures. or for different oarts fulfilling an identical function The descnption is written with reference to langoustine but the orincirle aDplies equally to orawns, langoustines and other types of crustacean, such as cray fish tails or lobster tails, etc It will be understood that the size of the whole apparatus. or parts thereof, would be scaled appropriately so that the dimensions fitted the particular crustacean to be handled Fig I shows a plan view of the apparatus 1 of the invention. it consists of two horizontal wheels, a processing wheel 3 and an idling wheel 4. A roller chain 5 passes circumferentially round part of each wheel 3 and 4 and co-tangentially between them. The clockwise rotation of wheels 3 and 4 is shown 6 and the linear motion of chain 5 between wheels 3 and 4 is shown 7 Roller chain 5 consists of a series of links 5. joined end-to-end by rollers 18 Fast with, and built into each roller 18, is an anvil 19 having a head 9 Fast with each anvil 19 of chain 5 are processing trays 8 extending essentially perpendicularly outwards from chain 5. A filling station G is Drovided where an operator will Diace one langoustine on each tray 8 as that tray passes 7 station G Fig. 2 shows a detail of the processing station 2 of apparatus 1 This consists of a rotating nrocessing wheel 3 on which a plurality of processing heads 12. aligned radially outwards from centre 14 of wheel 3, is provided. One processing head 12A is shown curtailed to indicate roller chain engagement sprocket 10 in wheel 3 As wheel 3 rotates 6. an engagement sprocket 10, aligned with each processing head 12, engages, in turn, with each roller 18 (Fig 3) of roller chain 5 As shown, this indexing arrangement sequentially aligns each processing head 12 with an anvil head 9 and a tray 8 Symbols 8A indicate that only a part of trays 8 are shown in Fig 2 At filling station G (Fig 1). an operator places a langoustine 20 on each tray 8 as it passes This is shown in Fig 3 arid langoustine 20 is placed with its curved (dorsal) back 22 downwards into the V-shaped groove 88 of tray 8 (Fig 8) and with its tail 21 on anvil surface 9 Fig 3 also shows how the C-shape of anvil member 19 encompasses links 5 and rollers 18 Sprocket 10 of wheel 3 is shown engaging with roller 18 An axial shaft (not shown) through roller 18 allows roller 18 to rotate and links 5 to flex relative to anvil member 19 Tray 8 is fast with anvil member 19. Fig 4 shows how compression member 24 is moved downwards 25A onto tail 21 of langoustine 20. As the tail 2lis at right angles to the axial line through the body of lanooustine 20 the descent 25A of member 24 aligns body 20 over tray 8 so that the dorsal (convex) side 22 is downwards and the upper (concave) side 23 is uppermost.

Fig 5 shows weight 27 placed 28A onto langoustine body 20 The load of the weight presses the back 22 into groove 8B and straightens the curve in body 20 (Figs 3 and 4) so that sides 22 and 23 are effectively either parallel to each other or form a right truncated cone towards tail 21 The mass of weight 27 and the distance 28A, through which it is allowed to descend, are carefully designed for a range of langoustine so that dorsal side 22 is fully pressed into groove 8B but that underside 23 is not so squashed onto the rest of body 20 that the shell 22 and 23 is deformed to an extent that it will not allow flesh 20 to be extruded therefrom The placing of langoustine 20 in groove 8B, with its dorsal side downwards and its tail 21 adiacent to anvil 19 (Fig 3) is critical to the subsequent operations because the clamping 24 25A (Fig 5) of tail 21 to anvil head 9 orientates the body 20 normally in and along groove 8B Thus, application of weight 27, together with the centring effect of the V-shaped sides of groove 8B combine to align each langoustine in an essentially identical manner to facilitate the subsequent de-shellina operations.

Fig 6 shows the insertion 32A of hollow needle 29 into the base 30 of body 20. i e the portion adjacent to tail 21. A slot 26 is provided in the face 24A of compression member 24 (Fig. 8) to allow free passage of needle 29, irrespective of the size of tail 21 or even when no langoustine 20 is present in tray 8, I e no tail 21 is present on anvil surface 9 Needle 29 is aligned at a predetermined angle to the surface of anvil 9 so that it will slide easily between shell scales 23A (Fig 10) and into area 30 of the body of langoustine 20 When needle 29 is in position (Fig 6) a predetermined quantity(ies) of fluid is(are) injected 31 through the bore of needle 29 and into the tail area 30 of body 20 ComDressed air is preferred but water is also applicable Ideally, the air is added in a plurality of pulses For example, the first pulse creates an area of raised pressure 30 between the body 20 and the tail 21 which severs the body flesh 20 from that in the tail 21 and starts to move the flesh 20. in a single mass, to the left, breaking the linkages between flesh 20 and shell 22 and 23.

After a predetermined time, a second pulse (or further pulses) 31 is(are) a repeat of the first and intended to eject any flesh not removed by the first pulse, and blown 33 out of shell 22 and 23 and off tray 8 and into product collection box 16 (Fig 2) Ortionallv. needle 29 may be removed and re-inserted before a further pulse of air is applied.

As stated, compressed air is preferred as the working fluid as it will continue to expand down to atmospheric pressure and, thus, blow flesh 20 out of shell 22, 23 and off tray 8 into box 16. Water would not do this, unless supplied as a continuous Jet A further disadvantage of water is that is can remove some of the natural flavours and nutrients There are several advantages of using a number of air pulses. One is progressively to increase the pressure in area 30 and so ease 33 flesh 20 away from its connections with tail 21 and shell 22. 23. If all the air was applied at once, the pressure 30 might burst the shell 22 23 Different combinations of pulse duration, pressure and the intervals between pulses can be otimised for each particular crustacean Then, weight 27 and compression member 24 are raised 28B and 25B respectively (Fig 7) and a third air shot 3lis applied to needle 29. which is simultaneously withdrawn 32B. The result is to blow shell 22 and 23 along tray 8 and allow it to fall into waste container 17 (Fig. 2) Tray 8 is now empty and will continue 6 past a washing station 12F and thence onwards 7, as part of chain 5 along the co-tangent, round idler wheel 4 back to filling station G for re-filling with another langoustine 20 Fig 2 shows wheel 3 with processing heads 12 rotating around fixed central core 13 As shown there are twelve processing heads 12. aligned radially from axis 14, which. via sprockets 10, successively align with anvils 9 and trays 8 A langoustine is placed in a tray 8 (Fig 3) at filling station G (not shown on Fig 2) and chain 5 moves 7 tray B on to station A for clamping (Fig 4) In At station B, weight 27 is applied, needle 29 is inserted and the first air pulse 3lis delivered Product container 16 is in line with tray 8 at station B. in case flesh 20 is eJected from shell 22. 23 at this point A further air pulse(s) 3lis delivered at station C and the flesh 20. or any additional flesh 20, falls off tray 8 into container 16. At station D. weight 27 and compression member 24 are lifted (28B and 25B respectively) At station E, a third air pulse 3lis applied, which blows shell 22, 23 off tray 8 into container 17, and needle 29 is withdrawn 32B (fig 7) If required at a station F, water sprays (not shown) wash down tray 8 and the other parts of processing head 12 which come into contact with the langoustine The actwation of all the individual operations at stations A to F may be performed in a number of ways but one method which is particularly reliable and suitable for this application is via a system of cams 15 and cam followers 11 Cams 15 are fast with static central core 13 (Fig. 2) Cam followers 11 engage with cams 15 and consist of a contact member 11' and an activating rod 11" Member 11' could be a hardened sliding contact or a rolling head As wheel 3 rotates 6 around core 13. members 11' move round core 13 and up and over cams 15 Cams 15 have gentle chamfers up and down over which members 11' slide or roll Low friction materials or food quality lubrication is used to promote smooth operation of cam followers 11 Fig. 2 is a plan view of processing wheel 3 and the apparatus thereon. A plurality of cams 15 is arranged in separate layers around core 13. each layer being at a diffenng height above the plane of wheel 3 and in a plane parallel to the plane of wheel 3 An equal number of cam followers 11 on each processing head 12 is located one at the height of each of the separate cam layers 15 so that one cam follower 11 engages with each one of the plurality of cam layers 15 The arrangement is such that. as wheel 3 rotates, each cam follower 11 bears on core 13 at its respective height above the plane of wheel 3 and engages with its cam or cams 15 as it rotates around core 13 When a contact member 11' rides over a cam 15, it forces rod 11" into head 12. activating the means to undertake one of the de-shelling operations. In Fig 2, all cams 15 are shown, irrespective of their heights above the plane of wheel 3 Where a cam follower 11 is engaging a cam 15, that cam follower 11 is shown, even though (technically) it might be obscured by an in-active cam follower 11 in a higher plane above wheel 3 The movement of rods 1 lA-F into / out of heads 12 activates / deactivates one or more of either a mechanical connection, or opening I closing a valve, or making I breaking an electrical connection to perform the necessary operations. as follows. -Station A Clamping 24 of langoustine to tray 8, Station B Application of weight 27, insertion of needle 29, first air pulse (freeing flesh 20 from shell and blowing into bin 16): Station C Further air pulse(s) (more flesh 20 may be blown into bin 16).

Station D Weight 27 and clamp 24 both removed.

Station E Air pulse (to blow shell 22, 23 into bin 17), Station F Washing of apparatus. and Station C (G') Operator placing a further langoustine on tray 8 (There are six stations (A to F) where operations on heads 12 occur so there could be up to six layers of cam followers 11, engaging respectively with up to six tiers of cams 15 In Fig. 2, for clarity, only the active cam follower is shown The washing at station F may be activated independently by a further cam 15.) The sources of compressed air, pneumatic or hydraulic power, etc would preferably be from below wheel 3 and are not shown Electrically operated means are not preferred to effect the operations at stations A to F, due to the presence of water and salt (in the Jangoustines) However, there would be a solenoid-controlled valve to dump the compressed air if the Emergency Stop (not shown) was activated or if any of the Safety Guards (not shown) were opened Appropriate safety devices, such as slot 26 in member 24 (Fig 8) to avoid damage to needle 29 if the operator at C misses placing a langoustine in a tray 8, are provided to protect the apparatus and the langoustine being processed As shown, langoustine 20 have their heads and abdomens cut off before the operator (not shown) places them in trays 8, i e it is just the tail section 20 of the whole crustacean which is the subject of this disclosure With the apparatus and method of the invention, a skilled operator could place between 60 -80 langoustines on trays 8 per minute Ideally, the operator would have a speed control to adjust the speed 6. 7 of chain 5 to suit their skill level and any peculiarities of the langoustines being handled.

If required, idler wheel 4 could be provided with the components on processing wheel 3 and a second filling station orovided at G' However, this would require two operators of equal skill levels to work at the same speed. Alternatively, two operators could work side-by-side at the same filling station A key aspects of the invention are the clamping of the tail 21 (Fig 4) and the apPlication 28A of weight 27 (Figs 5 and 6) This causes larigoustine 20 to be aligned in and along groove 8B, with the dorsal side downwards This has three synergetic effects Firstly, it causes body 20 to become essentially straight, e g a parallel-sided or a truncated cone, as opposed to being curved (Fig 4) Clearly, it will be more difficult for the injection of air 31 into area 30 to expel flesh 20 from a curved shell (Fig 4) than from a parallel-sided one (Fig 6) As shown, the shell 22. 23 around area 30. where the air 31 is injected 29. is essentially in the form of a right truncated cone The expansion of this air 30 in this cone naturally tends to force flesh 20 to the left 33 The second aspect is that when and as tail 21 is being clamped, body 20. 22 and 23 is rotated in the V-section 8B, so that it lies in a central position, thereby causing needle 29 to enter 32A centrally into tail 21 at the point where it ioins the body 22. 23 The third aspect is shown in Figs9 and 10. When abdomen 20 is curved (Fig 9), the scales 22A and 23A on sides 22 and 23 respectively flex relative to each other However.

when the abdomen 20 is straightened (Fig 10). scales 22,4 and 23A lie flat one-on-top-of-the-next forming a more, effective seal around flesh 20 so that air 35 inected 31 into area 30 has no easy escape route Clearly, scales 22A, 23A will not make a perfect seal but. if air 3lis not injected too rapidly, most of the injected air 35 will be contained to provide the reaction to the force (pressure) needed to sever flesh 20 from tail 21 and separate the bonds between flesh 20 and shell 22 and 23.

Once this had been done, the pressurised air 35 will start to expand, moving 33 flesh 20 to the left out of shell 22, 23. off tray 8 and into container 16 Injecting air 31 in pulses is preferred (Fig 6) as it provides gentle pressure build up 35 to free flesh 20 and blow it 33 out of shell 22. 23, off tray 8 and into container 16 A single. large pulse could risk bursting through shell 22 or 23, losing air 35 and obtaining no flesh 20 A further point to note is that the shell 22. 23 around area 30 is in the form of a truncated cone so that the pressure of the air in area 30 naturally forces flesh 20 to the left 33 The second pulse 31 may also clear any residual flesh 20, still remaining in shell 22 23. It may also help to blow flesh 20 off tray 8 into container 16 The efficacy of this two-stage process is shown by the fact that a vein (not shown) along the underside 23 is usually removed cleanly from flesh 20 If air was injected 31 into a curved body (Fig. 9), either as a single or double pulse, it could well burst out 34 between scales 22A or 23A and only free a small part of flesh 20 The result would be a mangled. partial extraction of flesh 20. if any was extracted at all The insertion 32A of needle 29 into area 30 of body 20 (Figs. 6 and 7) is at a predetermined angle to anvil surface 9 and the surface of tray 8. Slot 26 is sized to accept the passage of needle 29 This angle is chosen to place the tip of needle 29 into flesh 20 as close as practicable to the point where flesh 20 merges into tail 21. Comparing these Figures (6 and 7) to Fig 10, it will be noted that needle 29 will easily slide between two adjacent scales 23A on the underside of shell 23 and into area 30 The importance of this is that it will not cause a significant disruption to surface 23 of the shell and so should not create a weak point in shell 23 through which air 31 could escape 34 (Fig. 9) after injection. ie all the air 31 will be retained 35 (Fig 10) to work effectively freeing flesh 20. The nearer to tail 21 that the air injection 31 occurs, the more effective it will be, as the size of the shell cone 22, 23 decreases towards tail 21 so that the leftward force 33. generated by the expansion of air 31, will be maximised The skilled man will appreciate the synergy of the various steps which form the invention and will understand how it may be adapted. e.g by changing the dimensions of appropriate parts, to handle other crustaceans. e g. cray fish tails, lobster tails, lobster or crab claws, etc All such adaptations fall within the scope of the invention

Claims

Claims - 1 Apparatus for de-shelling prawns. langoustines or the like,

comprising -i) providing a prawn, langoustine or the like, the head and thorax of which have been removed leaving only the fleshy abdomen in its shell and the tail: ii) providing a processing member for the prawn, langoustine or the like on which said prawn. langoustine or the like can be placed: iii) providing a means to clamp the tail of the prawn, langoustine or the like on the processing member to said processing member iv) providing a means to straighten the abdomen of the prawn. langoustine or the like so that it lies along the processing member: v) providing a means of injecting a fluid into a selected part of the abdomen of the prawn, langoustine or the like: vi) providing a means to collect as product the fleshy abdomen of the prawn.

langoustine or the like: and vii) releasing the straightening means from the abdomen and the clamping means from the tail of the prawn, langoustine or the like and providing a means to remove the empty shell from the processing member and discharging it into a waste collector and returning the injection means to its rest position; characterised in that the selected part of the abdomen is the area adjacent to the clamped tail so that the inJection of the fluid into this area creates a pressure within said area and inside the shell, severing the flesh where the abdomen joins the tail and also severing connections between the abdomen and the shell so that the fleshy abdomen is ejected out of its shell by said fluid pressure and off the processing member into the product collection means.

2 Apparatus for de-shelling prawns. langoustines or the like, as claimed in claim 1, wherein the processing member is a flat surface.

3 Apparatus for de-shelling prawns. langoustines or the like, as claimed in claim 2.

wherein the processing member has a longitudinal depression in the surface 4 Apparatus for de-shelling prawns. langoustines or the like, as claimed in claim 3.

wherein the longitudinal depression in the surface of the processing member is a V-shaped groove 5 Apparatus for de-shelling prawns, langoustines or the like, as claimed in claim 1, wherein the means to clamp the tail of the prawn, langoustine or the like to the processing member is a member which is movable downwardly to clamp said tail between said member and the processing member 6 Apparatus for de-shelling prawns, langoustines or the like, as claimed in claim 1, wherein the means to straighten the abdomen of the prawn, langoustine or the like is a weight movable downwardly onto the curved abdomen causing it to straighten and lie essentially on and parallel to the surface of the processing member 7 Apparatus for de-shelling prawns, langoustines or the like, as claimed in claims 4 and 6. wherein the straightened abdomen lies in the V-shaped groove in the processing member 8 Apparatus for de-shelling prawns, langoustiries or the like, as claimed in claim 7, wherein the abdomen is orientated so that the upper (dorsal) part of the shell is downward in the bottom of the V-shaped groove.

9 Apparatus for de-shelling prawns, langoustines or the like, as claimed in claim 1.

wherein the means of injecting the fluid into the abdomen of the prawn, angoustine or the like is a hollow needle.

Apparatus for de-shelling prawns. langoustines or the like, as claimed in claim 9.

wherein the fluid is a comrressed gas 11 Apraratus for de-shelling prawns. langoustines or the like, as claimed in claim 10.

wherein the gas is oil-free, filtered, compressed air 12 Apparatus for de-shelling prawns. langoustines or the like, as claimed in claims 10 or 11, wherein the fluid is injected in a plurality of oulses 13 Apparatus for de-shelling prawns, langoustines or the like, as claimed in claim 12, wherein the fluid pulses are sequentially timed and of predetermined durations 14 Apparatus for de-shelling prawns. langoustines or the like, as claimed in claim 13.

wherein the first pulse(s) is(are) of a predetermined duration(s) to sever gently the connections between the abdominal flesh and the tail and between the abdominal flesh and the shell and also to urge, or commence urging, said flesh out of the shell 15 Apparatus for de-shelling prawns. lanaoustines or the like, as claimed in claim 14.

wherein the subsequent pulse(s) is(are) of a predetermined duration(s) to eJect the flesh, or any flesh remaining after the first pulse(s), completely from the shell and to blow it off the processing member so that it enters a product collector 16 Apparatus for de-shelling prawns. langoustines or the like, as claimed in claim 15.

wherein an additional pulse is used to blow the empty shell off the processing member and into the waste collector 17 Apparatus for de-shelling prawns. langoustines or the like, as claimed in claims 12 -16. wherein the number of the pulses. the duration of the pulses and / or the pressure of the fluid in the pulses are / is variable.

18 Apparatus for de-shelling prawns, langoustines or the like, as claimed in any preceding claim wherein the operations to eject the flesh from the shell and into the product collector and to discharge the shell into the waste collector are performed within an enclosure so that any airborne particles created during the operations are retained therein and also that no external contamination can reach the food items being processed therein 19 Apparatus for de-shelling prawns. langoustines or the like, as claimed in any preceding claim, wherein all materials of construction of components, which will come into contact with the items of food being processed and all other members in areas adjacent to said components are made of materials compatible with the appropriate hygiene requirements -17 Apparatus for de-shelling prawns. langoustines or the like, as claimed in any preceding claim, wherein all electrical and / or pneumatic and / or hydraulic apparatus and the power connections thereto are compatible with performing operations on damp.

potentially-saline food items 21 Apparatus for de-shelling prawns, langoustines or the like, as claimed in any preceding claim, wherein the processing member is cleaned before re-use 22 A method for de-shelling prawns, langoustines or the like comprising the steps of -i) taking a prawn. langoustine or the like the head and thorax of which have been removed leaving only the fleshy abdomen in its shell and the tail, ii) placing the prawn. langoustine or the like on a processing member.

iii) clamping the tail of the prawn, larigoustine or the like on the processing member to said processing member.

iv) straightening the naturally curved abdomen of the prawn, langoustine or the like so that it lies along the processing member: v) inserting a hollow needle into a selected part of the abdomen of the prawn.

fangoustine or the like and injecting a fluid through said needle into said part so that the fleshy part of the abdomen is separated both from the tail and the shell and ejected from the shell.

vi) collecting as product the fleshy abdomen of the prawn, tangoustine or the like: and vii) releasing the straightening means and the means retaining the shell of the prawn.

langoustine or the like to the processing member and discarding the empty shell 23 A method for de-shelling prawns. langoustines or the like, as claimed in claim 22, wherein the fluid injected through the hollow needle is a compressed gas 24 A method for de-shelling prawns. langoustines or the like, as claimed in claim 22, wherein the fluid injected through the hollow needle is a liquid A method for de-shelling prawns langoustines or the like, as claimed in claims 23 or 24. wherein the fluid is injected in a series of successive pulses.

26 A method for de-sheHing prawns. langoustines or the like, as claimed in claim 22.

wherein the parts of the apparatus which come into contact with the prawn. langoustine or the like during the de-shelling process are cleaned prior to de-shelling each prawn.

langoustine or the like 27 A method for de-shelling prawns, langoustines or the like, as claimed in claim 26, wherein the cleaning process involves spraying surfaces which come into contact with the prawn, langoustine or the like with clean water 28 Apparatus and method for de-shelling prawns. langoustines or the like, as described in and by the above statement, with reference to the accompanying drawings