GB2447721A

GB2447721A - Apparatus and method for de-shelling crustaceans

Info

Publication number: GB2447721A
Application number: GB0800871A
Authority: GB
Inventors: Ian Mulgrave Penney
Original assignee: Individual
Current assignee: Individual
Priority date: 2007-03-21
Filing date: 2008-01-18
Publication date: 2008-09-24
Also published as: GB0705335D0; GB0800871D0; GB2447671A

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 uncooked (raw) 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.

It is known that cooking softens meat, fish and crustacean flesh and also weakens the connections between the flesh and bones I shells. Thus, cooked flesh is much more easily separated from bones / shells than when uncooked. US Patent No. 4 912 810 (Laughlin, et al.) teaches de-shelling cooked crustaceans by impaling the tail on a nozzle and blowing out the flesh with a single blast of air', compressed to at least 80 psig'. Fig. 5 shows that the nozzle discharges partly inside and partly outside the tail. Such aggressive treatment is clearly intended for speed of production but would almost certainly disrupt the soft flesh into a number of pieces.

US Patent No. 5 839 952 (Pollingue) teaches de-shelling cooked crustaceans via two needles inserted into the tail but again uses a single burst of air from a high pressure source. US Patent No. 3789460 (lngalls) and GB Patent No. 911 977 (Martin) do not state whether the crustaceans are cooked, or not, but again use a single strong jet or blast' and a single blast' of air respectively, via nozzles, to remove the flesh. All these methods are designed for speed of production and are acceptable where lumps of flesh are subsequently clumped together, coated in batter or breadcrumbs as Scampi', ready for cooking or have already been cooked.

One delicacy which Gourmet diners crave is complete langoustine tails and these have to be removed whole from the shells. None of the above arts would be suitable for this as the flesh must be gently eased' out of the shell, rather than blasted out. Hitherto, this de-shelling has been a dfficuIt, labour-intensive operation requiring careful handling to avoid damaging the soft, raw flesh inside. The high value of langoustines limits the work to skilled, highly trained personnel.

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 cufting the thorax from the abdomen. Unfortunately, the results are variable with relatively few coming out whole and a high proportion 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 apart to release the flesh. This works well if the scales are fully cut through but, if they are not, it is difficult to prise the 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 additional 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 experienced 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, one option is to freeze the langoustines, transport them to the Far East (where labour rates are lowest), partially thaw them, de-sheH, re-freeze and transport 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 mu!tiple freezing and thawing.

According to the invention, there is provided apparatus for de-shelling uncooked (raw) 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; charactensed 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 controlled 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 progressively ejected essentially ase tingle mass out of its shell by said fluid pressure and off the processing member into the produt 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 variation 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, 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.

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 upper (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 is 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 injected 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) 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 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 variation of the apparatus of the invention, the hollow needle is removed and reinserted between pulses.

According to a sixteenth variation of the apparatus 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 seventeenth variation of the apparatus of the invention, the number of the pulses, the duration of the pulses and I or the pressure of the fluid in the pulses are / is variable.

According to an eighteenth 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 so that no external contamination can reach the food items being processed therein.

According to a nineteenth 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 adjacent to said components are made of materials compatible with the appropriate hygiene requirements According to a twentieth 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 twenty first vanation 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-shelling uncooked (raw) 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 injecting a fluid, in a controlled manner, through said needle into said part so that the fleshy part of the abdomen is separated both from the tail and the shell and progressively ejected from the shell; vi) collecting as product the fleshy abdomen of the prawn, langoustine or the like essentially as a single mass; and vii) releasing the straightening means and the means retaining the shell of the prawn, langoustine or the like to the processing member, withdrawing the needle and discarding the empty shell.

According to a first variation of the method of the invention, the clamping of the tail centres the prawn, langoustine or the like axially in / on the processing member.

According to a second variation of the method of the invention, the straightening of the abdomen of the prawn, langoustine or the like aligns a specitic part of said abdomen with the line of action of the needle.

According to a third variation of the method of the invention, the fluid injected through the hollow needle distends the tail area of the prawn, langoustine or the like causing the shell scales to lie flat against the flesh forming a essentially gas-tight enclosure around the distended area.

According to a fourth variation of the method of the invention, the injection of fluid through the hollow needle is in a series of pulses.

According to a fifth variation of the method of the invention, the injection of the fluid either in a single pulse or in a series of pulses successively distends a greater volume of the abdomen so that the connections between the flesh and the tail and shell are progressively ruptured and the flesh is ejected from the shell.

According to a sixth variation of the method of the invention, the hollow needle is withdrawn and re-inserted between successive pulses.

According to a seventh 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 an eighth variation of the method of the invention, the cleaning process involves spraying surfaces, which come into contact with the prawn, langoustine or the like with clean water.

According to a ninth variation of the method of the invention, the cleaning process involves blowing air onto I across surfaces, which come into contact with the prawn, langoustine or the like.

In a preferred application of the apparatus and method of the invention, a langoustine, with the head and thorax removed, is placed on a processing 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 processing 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 on the processing surface.

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 this specification and in the description following, the term pulse' is used to mean a predetermined quantity of fluid (pressure and volume), which is injected, in a controlled manner, into the inside of the shell of the prawn, langoustine or the like, to create a pressure therein which will sever connections between the flesh and the shell but not burst open the shell. Thus, a pulse' is a controlled administration of a small quantity of compressed fluid, as opposed to an essentially uncontrolled blast'.

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 and simultaneously clean the surface by blowing off any other debris into the 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 passage. Another advantage of straightening the shell of the abdomen is that it is easier to insert the needle between adjacent scales and that, when air is injected and there is pressure inside the tail, the scales of the underside of the shell tend to lie flat against each other and form a better seal to retain the injected air.

Ideally, the air is injected in a number of discrete pulses. For example, a first pulse will create a gentle pressure to commence severing the fleshy connections and to start the fleshy 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, i.e. a blast of air, was to be used instead, there would be a risk of rupturing the shell and the air escaping and I or the flesh being ruptured in to a number of pieces. 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 passes 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 carried 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 langoustine; 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 / 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; 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; Figure 11 is a side elevation of the handling tray, anvil, and tail clamp, straightening weight and needle assembly; Figure 12 is a side elevation of the tip of the needle shown in Fig. 11; Figure 13 is a part sectional side elevation of a crustacean in position in the handling tray; Figure 14 is a part sectional elevation of the crustacean shown in Fig. 13 after the tail has been clamped, the body straightened and with the needle inserted; Figure 15 is a part sectional elevation of the crustacean shown in Fig. 14 after compressed air has been injected; and Figure 16 is a part sectional elevation of the crustacean shown in Fig. 16 after the compressed air has started to force the flesh out of the tail shell.

In the following description, the same reference numeral is used for the same part in different figures, or for different parts fulfilling an identical function. The description is written with reference to langoustine but the principle applies equally to prawns, Iangoustines 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. 1 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 provided where an operator will place 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 processing 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 continuously-moving, 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 and langoustine 20 is placed with its curved (dorsal) back 22 downwards into the V-shaped groove 8B 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 21 is at right angles to the axial line through the body of langoustine 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. Unless the tail and abdomen are distorted relative to each other (in which case the operator would have rejected the crustacean), the descent 25A of member 25 onto tail 21 swivels, moves and I or aligns the body of langoustine 20 axially within V-shaped groove 8B so that the dorsal side 22 is aligned essentially symmetrically downwards in groove 8B.

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, symmetrically in groove 8B (Figs. 3, 4 and 8) 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 88 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 clamped 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 onentates 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-shelling 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. As shown in Fig. 11, needle 29 is aligned at a predetermined angIe 38 to the surface of anvil 9 so that it will slide easily between shell scales 23B (Figs. 10 and 14) and into area 30 of the body of langoustine 20.

When needle 29 is in position (Figs. 6, 14), a predetermined quantily(ies) of fluid is(are) injected 31 through the bore of needle 29 and into the tail area 30 of body 20. Compressed 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 accelerate the movement of the flesh, commenced by the first pulse, and blow it 33 out of shell 22 and 23 and off tray 8 and into product collection box 16 (Fig. 2).

Optionally, needle 29 may be removed and re-inserted before a further pulse of air is applied. The advantage of this is that any air leakage, caused by tearing of the skin due to the insertion of the needle will be minimised as the internal pressure of the air 36 forces the skin against the underside of the scales 23C (Fig. 15).

As stated, compressed air is preferred as the working fluid as it will continue to expand down to atmospheric pressure and, thus, progressively break the connections with tail and shell, start flesh 20 moving and blow it out of shell 22, 23 and off tray 8 into box 16. The air may be supplied either as a single large pulse or, preferably, as a number of smaller ones in succession. 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 optimised for each particular crustacean.

When flesh 201s in box 16, weight 27 and compression member 24 are raised 28B and 25B respectively (Fig. 7) and a further air pulse 31 is applied via needle 29, which is simultaneously withdrawn 326. The result is both to blow shell 22 and 23 along tray 8 and off into waste container 17 (Fig. 2) as well as to clean tray 8 and groove 8B of any other debris, which might be there. Tray 8 is now empty and will continue 6 past an (optional) 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 8 on to station A for clamping (Fig. 4).

At station B, weight 27 is applied, needle 29 is inserted and a first air pulse 31 is 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) 31 is 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 31 is applied, which blows shell 22, 23, and any otherdebris, 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 activation 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 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 fnction 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 differing 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 at least 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 I lA-F into I out of heads 12 activates / deactivates one or more of either a mechanical connection, or opening / closing a valve, or making / 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) (blowing flesh 20/ more flesh 20 into bin 16); Station 0 Weight 27 and clamp 24 both removed; Station E Air pulse (to blow shell 22, 23 and debris into bin 17); Station F Optional washing of apparatus; and Station G (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 langoustines). However, there could 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 G misses placing a langoustine in a tray 8, are provided to protect the apparatus and the langoustine being processed.

As shown, langoustines 20 have their heads and abdomens cut off before the operator (not shown) places them in trays 8. i.e. it is just the abdomen / tail section 20, 21 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 provided 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.

Key aspects of the invention are the damping of the tail 21 (Fig. 4) and the application 28A of weight 27 (Figs. 5 and 6). This causes body 20 of the langoustine to be aligned paraHel in and along groove 86, with the dorsal side downwards. This has three synergetic effects.

Firstly, it causes body 20 to become essentially straight, e.g. as 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 this air 36 (Fig. 15) 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 (Fig. 16).

The second aspect is that, 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 joins the body 22. 23.

The third aspect is shown in Figs 9-10 and 13-16. When abdomen 20 is curved (Figs. 9 and 13), 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 22B on the convex dorsal side lie flat, le. one-on-top-of-the-next forming an effective seal around flesh 20 so that air 35 injected 31 into area 30 has no easy escape route. In contrast, scales 238 on the concave underside tend to be slightly clear of the next one. This allows needle 29 free access between adjacent scales into flesh 20 (Fig 14).

The initial injection of air 31 forms a bubble 36 (Fig. 15), which inflates tail area 30, causing scales 23C to lie flat over the skin which retains flesh 20. Clearly, scales 22B, 23C will not make a perfect seal but, if air 31 is not injected too rapidly, most of the injected air 36 will be contained to provide the reaction to the force (pressure 35) needed to sever flesh 20 from tail 21 and separate the bonds between flesh 20 and shell 22 and 23. As bubble 36 expands 36A (Fig. 16) (either because flesh 20 starts to move 33 or because a further pulse has been injected), the gentle urging 35 continues, causing flesh 20 to move 33 to the left out of shell 22, 23, off tray 8 and into container 16.

Injecting air 31 in pulses is preferred (Figs. 6, 14) as it provides a gentle pressure build up to free flesh 20 and blow it 33, as a single mass, out of shell 22, 23, off tray 8 and into container 16. A single, large pulse, or blast' or air, would risk bursting 34 (Fig. 9) through shell 22 or 23, losing air 36 and obtaining only a part of the flesh 20, or perhaps no flesh at all. It is a feature of the apparatus of the invention and the method of its use that flesh 20 is handled in a controlled, gentle manner and ejected as a single mass, usually without the so-called mud vein, which remains attached to the shell.

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 residua' 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 the vein (not shown) along the underside 23 is usually separated 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.

A slot 26 is provided in member 24 to accept the passage of needle 29. The insertion 32A of needle 29 into area 30 of body 20 (Figs. 6 and 7) is at a predetermined angle 38 to anvil surface 9 and the surface of tray 8. Fig. 11 shows a developed arrangement of the needle insertion. Insertion angle 38 and the angle of 37 of the needle point are such that the scarfed end 29C of needle 29 enters 32 flesh 20 essentially parallel to scales 23B so that point 298 passed between adjacent scales 23B and not through a scale. The design (Fig. 11) of the apparatus and its use, as described, enables needle 29 to be inserted essentially into the anus (not shown) of the langoustine and this is reproducible on langoustine after langoustine with a consistent accuracy of a fraction of a millimeter. This level of accuracy is needed with a high value product, such as this. The anus is the ideal position for the insertion of needle 29, as it is located at the junction of the tail 21 and abdomen 20.

One option is to retract needle 29 between consecutive air pulses 31. As taught, the insertion of needle 29 is between, not through, scales 238, so that the essential air-tightness of the abdomen is not jeopardized. However, minor tearing of the skin adjacent to the needle will occur, leading to some loss of air. By removing needle 29, the scales 23C will be caused to lie flat against the flesh 20, due to the internal pressure 35, thus, essentially sealing the injection hole (not shown). By retaining this pressurized air 35 for a short time (a few milliseconds), the process of severing the flesh between tail 21 and abdomen 20 and between shell 22, 23 and abdomen 20 and the freeing of the mud vein can all be fully completed and flesh 20 will start to move 33 to the left, out of shell 22, 23.

When needle 29 is reinserted, a further pulse 31, through bore 29A, will accelerate the movement 33 of flesh 20 out of shell 22, 23 and into container 16.

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 daws, etc. All such adaptations fall within the scope of the invention.

Claims

Claims:- 1 Apparatus for de-shelhng 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 controlled 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 essentially as a single mass 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-shefling 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-sheHing 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 niember.

8 Apparatus for de-shelling prawns, langoustines 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-sheilirig prawns, langoustines or the like, as claimed in claim 1, wherein the means of injecting the fluid into the abdomen of the prawn, langoustine 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 compressed gas.

11 Apparatus 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 pulses.

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.

Apparatus for de-shelling prawns, langoustines 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 claims 12-15 wherein the hollow needle is removed and reinserted between pulses.

17 Apparatus for de-shelling prawns, langoustines or the like, as claimed in claims 12-15, wherein an additional pulse is used to blow the empty shell off the processing member and into the waste collector.

18 Apparatus for de-shelling prawns, langoustines or the like, as claimed in claims 12-17, wherein the number of the pulses and! or the duration of the pulses and I or the pressure of the fluid in the pulses are / is variable.

19 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 so that no external contamination can reach the food items being processed therein.

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 21 Apparatus for de-shelling prawns, langoustines or the like, as claimed in any preceding claim, wherein all electrical and I or pneumatic and / or hydraulic apparatus and the power connections thereto are compatible with performing operations on damp, potentially-saline food items.

22 Apparatus for de-shelling prawns, langoustines or the like, as claimed in any preceding claim, wherein the processing member is cleaned before re-use.

23 A method for de-shelling uncooked (raw) 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 injecting a fluid through said needle, in a controlled manner, into said part so that the fleshy part of the abdomen is separated both from the tail and the shell and ejected progressively from the shell; vi) collecting as product the fleshy abdomen of the prawn, langoustine or the like essentially as a single mass; and vii) releasing the straightening means and the means retaining the shell of the prawn, langoustine or the like to the processing member, withdrawing the needle and discarding the empty shell.

24 A method for de-shelling prawns, langoustines or the like, as claimed in claim 23, wherein the clamping of the tail centres the prawn, langoustine or the like axially in I on the processing member.

25 A method for de-shelling prawns, langoustines or the like, as claimed in claim 24, wherein the straightening of the abdomen of the prawn, langoustine or the like aligns a specific part of said abdomen with the line of action of the needle.

26 A method for de-shelling prawns, langoustines or the like, as claimed in claims 24 and 25, wherein the fluid injected through the hollow needle distends the tail area of the prawn, langoustine or the like causing the shell scales to lie flat against the flesh forming a essentially gas-tight enclosure around the distended area.

27 A method for de-shelling prawns, langoustines or the like, as daimed in claim 26, wherein the injection of fluid through the hollow needle is in a series of pulses.

28 A method for de-shelling prawns, langoustines or the like, as claimed in claims 26 or 27, wherein the injection of the fluid, either in a single pulse or in a series of pulses successively distends a greater volume of the abdomen so that the connections between the flesh and the tail and shell are progressively ruptured and the flesh is ejected from the shell.

29 A method for de-shelling prawns, langoustines or the like, as claimed in claims 23-28, wherein the hollow needle is withdrawn and re-inserted between successive pulses.

A method for de-shelling prawns, langoustines or the like, as claimed in claims 23-29, wherein the parts of the apparatus which come into contact with the prawn, langoustine or the like dunng the de- shelling process are cleaned prior to de-shelling each prawn, langoustine or the like.

31 A method for de-shelling prawns, langoustines or the like, as claimed in claim 30, wherein the cleaning process involves spraying surfaces, which come into contact with the prawn, langoustine or the like with dean water.

32 A method for de-shelling prawns, langoustines or the like, as claimed in claim 30, wherein the cleaning process involves blowing air onto / across surfaces, which come into contact with the prawn, langoustine or the like.

33 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.