CA2172418A1 - Method and device for deboning fish fillets - Google Patents

Abstract

A device for deboning fish fillets having a plurality of bones in flesh, said device comprising a generally stationary body having a surface upon which fish fillets may be placed; a fillet registering opening located in said surface; a bone puller located adjacent to said fillet registering opening, and being at least partially exposed through said fillet registering opening, said bone puller snagging bones located in a fillet when said fillet is pressed onto said bone puller; and a motor for moving said bone snagging device relative to said fillet registering opening to cause said snagged bones to be removed from the fillet while leaving behind substantially all of the flesh of the fillet, and wherein said fillets may be manipulated on said body to expose said plurality of bones to said bone snagging device.

Description

Title: A METHOD AND DEVICE FOR DEBONING FISH FILLETS

FIELD OF THE INVENTION
This invention relates to the food processing industry in general, and in particular relates to processing fresh and salt water fish 5 species for human consumption. More particularly, this invention relates to the removal of bones from fish fillets.

BACKGROUND OF THE INVENTION
Fresh and salt water fish species are well known as foods for human consumption. Fish processing operations typically involve a 10 number of steps including gutting the fish, removing the head and tail, removing scales, separating the fish fillets from the backbone, and washing and packaging the separated fillets. Many of these steps are automated, and are performed in large capacity machines. Although different fish species are processed in different manners, this invention is of particular 15 interest to those fish species which are processed in the form of fish fillets.
One of the drawbacks of fish fillets is the presence in the fillets of thin or fine fish bones, which are commonly referred to as pin bones. These bones are all that remain of the fish skeleton the bulk of which has been removed during typical fish meat processing as described 2 0 above. However, pin bones may be secured firmly in the fish fillet flesh, and thus when the backbone is separated from the fish fillet, remain in the flesh instead of being removed with the remainder of the backbone. The presence of these pin bones in the fish fillet makes the fillet more difficult and awkward to eat. During cooking, the flesh becomes easily separable 25 from the pin bones. However, the pin bones are typically very fine and may not be easily noticed by the person eating the fish. Thus, there is a tendency for the pin bones to be taken into the mouth, and swallowed.
This can lead to choking, or other discomfort in the event that the sharp pin bone is not removed prior to being placed in the mouth.

In the past, attempts have been made to remove pin bones by various mechanisms. For example, U.S. Patent 4,771,511 relates to a tool and a method for deboning fish. The tool in essence comprises a pair of tweezers for gripping and pulling a large number of pin bones from the 5 fish fillet simultaneously. However, the tool is manually operated and awkward to use. An attempt to automate the process was provided in U.S.
Patent 4,945,607 which relates to a gripping device which automatically extends, opens and closes the jaws for the purpose of gripping the ends of the pin bones to remove them from the fish fillet. However, each of these 1 0 devices require a precise positioning of the gripping jaws in order to have the desired effect of removing pin bones. Since fish fillets vary in size and since the pin bones may be located very close and even below the surface of the flesh of the fish fillet, these devices are not satisfactory.
Other devices have been proposed for the purpose of 1 5 providing machines for removing fish bones in an automatic process.
These include Canadian Patents 1,043,058, 1,329,684, 1,038,120 and 1,262,608.
However, none of the machines proposed by these devices is effective in removing pin bones quickly and easily.
Finally, there are devices such as shown in PCT Application 20 WO 91/07096 and corresponding U.S. Patent 5,232,396 which relate to a machine for removing fish, in particular what is left on the bones after filleting, from the bones. However, this is accomplished by means of gripping wheels which draw a fish bone over scrappers which are provided for the purpose and which scrape over the side bones and against 2 5 the main bone along the top and the bottom and the left and right of the main bone by means of which the fish is obtained in the form of strips from the original structure. In other words, this device removes the fish flesh from the bones rather than the bones from the fish fillet. This is not satisfactory for providing fish fillets in a form readily accepted by 3 0 consumers which have no pin bones.

SUMMARY OF THE INVENTION
What is desired therefore is a way to remove pin bones from fish fillets. Preferably such a method would involve an easy to use piece of equipment which would not be expensive and yet would be effective in 5 removing pin bones. The method should not destroy the integrity of the fish fillet flesh, nor should it remove large amounts of flesh during the removal of the pin bones. Additionally, the method would be fast, and capable of being applied to a large number of fillets in a short period of time. Finally, the method should be comprehensive in that it should 10 remove substantially all of the pin bones from the fish fillets without missing any. Therefore, there is provided, according to the present invention a device for deboning fish fillets comprising a device for deboning fish fillets having a plurality of bones in flesh, said device comprising: a generally stationary body having a surface upon which fish 15 fillets may be placed; a fillet registering opening located in said surface; a bone puller located adjacent to said fillet registering opening, and being at least partially exposed through said fillet registering opening, said bone puller including means for snagging bones located in a fillet when said fillet is pressed onto said bone puller; and a means for moving said bone 20 snagging means relative to said fillet registering opening to cause said snagged bones to be removed from the fillet while leaving behind substantially all of the flesh of the fillet, and wherein said fillets may be manipulated on said body to expose said plurality of bones to said bone snagging means.

Reference will now be made to the attached drawings which depict, by way of example only, preferred embodiments of the invention and in which:
Fig. 1 shows a device for deboning fish fillets according to the 30 present invention;

Fig. 2 shows a closeup side view of a portion of the device of Fig. 1;
Fig. 3 shows an enlarged side view of a portion of the fish deboning device of Fig. 1 along line 3-3;
Fig. 3a show an enlarged view of the surface of a portion of the fish deboning device;
Fig. 4 shows a further enlarged side view having a fish fillet ready to start pin bone removal;
Fig. 5 shows the view of Fig. 4 with a pin bone engaging the 1 0 bone removing device; and Fig. 6 shows the view of Fig. 4 with the pin bone removed from the fillet and exiting the deboning device.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
According to the present invention, there is provided a 1 5 device for deboning fish fillets which is indicated generally in Fig. 1 as 10.
The fish fillet deboner 10 has a body 12 which includes an upper surface 14, a chain guard 16, a motor control 18, an on/off reverse switch 19 and a collection tray 20. In the most preferred form of the invention, the upper surface 14 is sloped, and is higher at the back. The collection tray 20 having 2 0 a chain 21 is formed around the perimeter of the base of the device and is explained in more detail below. Also shown are a vacuum attachment 22 and electrical connections 24.
The upper surface 14 of the fish fillet deboning device 10 includes first and second top plates 26 and 28 respectively, into which are 2 5 set a puller plate 32 and a guide plate 30. Each of the plates 26, 28, 30 and 32 include a plurality of counter sunk mounting openings 34, for fasteners 37.
Such mounting openings 34 in the puller plate 32 preferably include axial slots 34a, as explained below. The fasteners attach the plates to the main body 12. The guide plate 30 is preferably formed from food grade polyethylene, and machined to have a radius along one edge. The puller -plate 32 is preferably formed from food grade high density polyethylene and machined to have a double radius along one edge as described below.
The plates 30 and 32 are adjacent, but have a gap there between identified as 36. This will be referred to as the fillet registering 5 opening. Additionally, there is shown a bone puller at 38, which is at least partially exposed through the fillet registering opening 36. The bone puller 38 is described in more detail below.
Fig. 2 shows an electric motor 40 which is conveniently mounted within the body 12 of the fish fillet deboner 10. The electric 1 0 motor 40 includes a drive sprocket 42 which drives a toothed chain or drive belt 44. Good results have been obtained through use of a rubber drive belt 44. Drive belt 44 also goes around a slave sprocket 46 which is mounted on an axle 48. The bone puller 38 is also mounted on the axle 48 and the electric motor drives the drive sprocket 42 which in turn drives 1 5 the drive chain 44 which in turn drives the slave sprocket 46. The axle 48 is caused to rotate thereby rotating bone puller 38. The drive belt 44 is in turn covered by a chain guard 16. As a majority of people are right handed, it is preferred to mount the drive belt 44 and the chain guard 16 on the left of the device 10. However, it will be appreciated by those skilled in the art 2 0 that these could also be placed on the right hand side, if preferred.
The electric motor 40 is controlled by a pair of switches 18, 19 on the front of the device 10 (Fig. 1). Toggle switch 19 permits the motor to be run in a forward, stopped, or reverse mode, in case anything gets caught. Dial 18 permits the speed of rotation of the motor 40 to be finely 25 varied. The preferred motor is a low voltage direct current geared head motor by Dayton Corp.
Fig. 3 shows in close up the guide plate 30 and puller plate 32.
Also shown is a vacuum manifold 50 which ensures that the vacuum applied through vacuum connection 22 is placed across bone puller 38.
3 0 The vacuum is indicated by arrows 52. It will be appreciated that the bone puller 38, by reason of electric motor 40 is caused to rotate in a clockwise direction as shown in Fig. 3 and is indicated by arrows 54.

Also shown in Fig. 3 is a fish fillet 60 resting on the upper surface 14. The fish fillet 60 which includes a skin 62, a fleshy part 63 and a plurality of pin bones one of which is illustrated at 64.
The bone puller 38 is most preferably in the form of a 5 cylindrical drum which is caused to rotate by said electrical motor 40. The outer surface of the bone puller 38 has a plurality of holes formed in it as shown in Fig. 3a. These holes are referred to as bone registering openings 70. Most preferably, the bone registering openings 70 have a larger diameter at the outer perimeter, and a smaller diameter at the inner 1 0 perimeter (when the bone puller 38 is viewed in cross section) as shown in Fig. 3. Although satisfactory results have been achieved with a bell-shaped shoulder, as shown at 72 in Fig. 4, other shaped shoulders may also be appropriate. Preferably, the bone registering openings are between l/16 and l/2 inches in diameter and most preferably, the bone registering openings 1 5 70 at the outer perimeter are about 3/16 inches in diameter. The most preferred size of the bone registering openings 70 will vary depending upon the type of fish fillet being deboned. For fish fillets having larger pin bones, slightly larger bone registering openings 70 are preferred.
Conversely, for smaller fish fillets having smaller pin bones, smaller bone 20 registering openings 70 are preferred. For fresh water trout, the 3/16 inch diameter holes yield satisfactory results.
It will be noted that the bone registering openings 70 are formed with sharp corners 71 in cross-section, i.e. approximately 90 degree edges. These sharp edges are important for snagging the pin bones to drag 2 5 the pin bones out of the fish fillet 60 as described in more detail below. The most preferred material for the bone puller 38 is stainless steel, although other food grade non-corroding materials may also be used.
It will also be appreciated that the surface of the bone puller 38 is in the form of a myriad of perforations or bone registering openings 30 70. It is preferred, for the easy operation of the device 10, to have bone registering openings sweep over all of the fish fillet from which bones are to be removed. Therefore, it is most preferred to have the bone registering openings 70 in a staggered pattern across the outer surface of bone puller 38 in order to ensure that each portion of the fish fillet is swept by bone registering openings 70 as the bone puller 38 is rotated. This is shown in Fig. 3a.
As the bone puller 38 is rotated, the sharp corners 71 formed on the bone registering openings 70, act to snag the protruding ends. In some species the ends may be a bit thicker, but do not typically have enlarged heads. Once snagged in a bone registering opening 70, the bone puller 38 will rotate creating an axial force or pull on the pin bone 64.
1 0 Because the pull is generally aligned with the length of the pin bone 64, it has been found that the pin bone 64 easily and without any separation of flesh, pulls out of the fish fillet 62. With this method of bone removal there is very little flesh loss, in the order of .5% or less in typical use (mayvary according to flesh consistency). Further, the method has been found 1 5 suitable at almost any stage of rigor mortis.
An important aspect of the present invention is the use of the puller plate 32. In particular, it is most preferred if the puller plate 32 includes a rounded tip 31 with a flattened portion 31a. In addition, it will be noted that the plate 32 is separated from the bone puller 38 by a gap 2 0 shown as 80. It will be appreciated that gap 80 appropriately is importantfor the efficient operation of the device 10. The gap 80 must be sufficiently narrow to cause bones to remain snagged in the bone registering openings 70 as they are pulled past the rounded point 31. However, the gap 80 must be sufficiently wide to prevent the bones 64 from being broken off or 2 5 pulled out of the bone registering openings 70 as they pass the point 31.
The gap 80 is defined by a trailing surface 33 after the rounded tip 31. Good results have been achieved when the curve of trailing surface 33 is of about double to the curve of the outer circumference of bone puller 38. This causes the gap 80 to widen, the 3 0 farther away from rounded tip 31. This allows bones 64 to engage in the bone registering openings 70 to start out tightly engaged (by being pressed between the puller plate 32 and the bone puller 38), then to be more loosely snagged as the gap 80 widens.
Satisfactory results have been achieved by having the rounded tip closely adjacent to, or even resting upon, the bone puller 38.
5 In the most preferred embodiment, axial slots 34a (shown in Fig. 1) are provided in mounting openings 34, to provide for an easy adjustment and alignment of the puller plate rounded tip relative to the bone puller 38.
Also, a compression slot 34b is defined in the trailing surface 33 of the puller plate 32. The mounting openings 34 extend through the 1 0 compression slot 34b to allow the spacing of the slot 34b to be adjusted.
This allows the height of the rounded tip 31 of the puller plate 32 to be adjusted relative to the bone puller 38. It will be appreciated therefore that axial slots 34a and compression slot 34b facilitate 4-way adjustment of the position of the rounded tip 31 relative to the bone puller 38. A similar 1 5 compression slot 34c may be defined in guide plate 30 for adjusting the position of plate 30 to bone puller 38.
Turning now to Fig. 4, it can be seen how the fillet 60 with the pin bone 64 is to be positioned. In Fig. 5, the pin bone 64 is engaged in a particular bone registering opening shown as 100 and is snagged by sharp 2 0 corner 102 just past a head 104 of the pin bone 64. It can also be seen how the rounded tip 31 causes the pin bone to remain engaged or snagged in the bone registering opening 100 by being pressed against the edge of the opening 100 against the corner 102. It can also be seen that the axial path of the pin bone 64' as the bone puller rotates in accordance with arrow 54 2 5 causes it to be drawn out of the fish fillet 60.
Turning to Fig. 6 it can be seen that the pin bone 64 has moved along and is indicated by the numeral 64". As the bone puller 70 continues to rotate in the direction of arrow 54 the pin bone 64" is dragged along past the rounded tip 31 past the plate 32 and eventually will be free 3 0 beyond the end of the trailing edge 33 which is indicated at 35. At this point, the pin bone 64" will either fall away as shown in Fig. 6 or remain loosely attached to the bone puller 70. Attachment may occur because of moisture, wetness or other substances causing the pin bone 64" to remain stuck to the surface of the bone puller 38 (shown as 64"' in Fig. 5).
Therefore according to the present invention there is also preferably provided a scraper blade 110 which is used to scrape any such bones which 5 remain attached to the bone registering openings 70 of the bone puller 38 prior to the bone puller 38 making a full rotation back up to the fish fillet.
Although the scraper blade 110 is shown separated from plate 30, it is also capable of being positioned flush against the underside of plate 30. This may be preferred, in some cases, to prevent the blade 110 from riding up 1 0 and over caught bones. The pin bones are drawn away from the bone puller 38 by means of a vacuum or suction 52 facilitated by the vacuum manifold 50. It will be appreciated that the bones are shown going to the left of the bone puller 38 as shown in Fig. 6, but that they would preferably be piped to the rear of the device 10.
1 5 Of course, due to the nature of the application, all of the material from which the device 10 is made of should be made of food grade quality. This applies to the upper plates 26, 30, 32 and 28, as well as tothe body 12 with the tray 20. The bone puller 38 is preferably formed from stainless steel or other high quality metal which will not corrode. In 2 0 addition, the fibreglass body, stainless steel and nickel components should be easy to assemble and disassemble in order to adjust the spacing for different fish species and to make it easy to clean after for example a shift or the like.
The drive through the electric motor is preferably through an 2 5 DC motor which is wired to an AC/DC convertor. This allows the drive to be infinitely variable in terms of speed through speed control knob 18.
Again, different species of fish will be deboned most preferably at different speeds of rotation and the infinite variability is desirable to allow maximum control over tuning the equipment for an individual fish 30 species. It has been found that the preferred operating speed is usually from about 40 to 50 rpm for fresh water fish such as trout.

-To utilize the equipment, the operator places the fillet meat side down and skin side up on the body 12. Then, the fillet should be aligned to cause the pin bones to be located with the bone fillet registering opening 36 allowing them to contact the bone puller 38. In this position, 5 the fillet should have the belly edge toward the operator so that the pin bones can be removed on an angle approaching the angle they are found in naturally in the fish fillet as they are to minimize meat loss as indicated above. The operator is then required to apply gentle finger pressure on the skin side of the fish fillet (Fig. 5), to cause the bones to protrude slightly 10 from the flesh out of the other (bottom) side. It is most preferred to begin at the tail end. When the operator can feel the bones being snagged and pulled and removed, the operator can run their fingers along the upper surface of the fillet pushing out the bones to cause them to engage the bone puller 38 towards the front of the fillet. All of the bones should 1 5 typically be removed in one pass. If any of the bones tend to be snapped off, it is necessary to lower the speed of rotation of the bone puller to allow for a more gentle gripping and removal of the pin bones.
The most preferred technique allows the slight pressure applied by the operator to cause the pin bone to be snagged initially. Then 2 0 the slight pressure also squeezes the bone between the flesh and the bone puller 38 to keep the bones snagged, until the pin bone is dragged under the rounded point 31. Thereafter, the puller plate 32 causes the pin bone to remain snagged. It is most preferred, with precise positioning of the fish fillet by the operator relative to the puller plate 32, that the pin bones can 2 5 be snagged directly between the puller plate 32 and the bone registering openings 70.
It will now be appreciated that the upper surface is sloped to improve the ergonomics of the device, to assist the operator. Such a sloped upper surface is preferred, but not essential, as other configurations 30 may also be used to assist operators. Alternately, it may be that the fish fillets are aligned with the fillet registering opening automatically in which case an operator may not be required.

-It is further preferred to have a water supply near by to clean the working surface and the bone puller periodically. Water and other wastes are then caught in the drip tray 20 which is preferably molded right into the body 12. Then, the drain 21 can be used to ensure that an overflow 5 does not occur.
It is also preferred to provide an on/off/reverse switch which should be located on the front of the device so that the operator may shut down the machine or reverse the bone puller 38 in case of a sudden jamming.
It will be appreciated by those skilled in the art that while the foregoing makes reference to certain specific embodiments of the invention, many variations and adaptations are possible within the broad scope of the invention. Some of these have been discussed above and others will be apparent to those skilled in the art. However, the scope of 15 the invention is to be considered as defined by the appended claims.

Claims (30)

1. A device for deboning fish fillets having a plurality of bones in flesh, said device comprising:
a generally stationary body having a surface upon which fish fillets may be placed;
a fillet registering opening located in said surface;
a bone puller located adjacent to said fillet registering opening, and being at least partially exposed through said fillet registering opening, said bone puller including means for snagging bones located in a fillet when said fillet is pressed onto said bone puller;
and a means for moving said bone snagging means relative to said fillet registering opening to cause said snagged bones to be removed from the fillet while leaving behind substantially all of the flesh of the fillet, wherein said fillets may be manipulated on said body to expose said plurality of bones to said bone snagging means.

2. A device as claimed in claim 1 wherein said bone snagging means is in the form of a non-abrasive surface which has a plurality of bone registering openings, each of said bone registering openings being capable of snagging fish bones protruding from a fish fillet.

3. A device as claimed in claim 2 wherein said bone snagging means is in the form of a drum rotatably mounted to said body and wherein said means for moving said bone snagging means is a motor which rotates said drum to cause said non-abrasive surface and said plurality of bone registering openings to move past said fillet registering opening.

4. A device as claimed in claim 3 wherein said surface includes an edge, said edge defining a rounded tip adjacent to said fillet registering opening and sufficiently close to said bone snagging means to facilitate bones being snagged by said bone snagging means and wherein said bone puller comprises in combination said edge and said bone snagging means.

5. A device as claimed in claim 4 wherein said rounded tip is sufficiently close to said bone snagging means to cause said bones to remain snagged in said bone registering openings as said bone snagging means moves relative to said fillet registering opening.

6. A device as claimed in claim 5 wherein said rounded tip further includes a trailing surface, said trailing surface being sufficiently close to said bone snagging means to cause said bones to remain snagged in said bone registering openings as said bone snagging means moves relative to said fillet registering opening.

7. A device as claimed in claim 6 wherein said trailing surface is generally parallel to said nonabrasive surface of said bone snagging means.

8. A device as claimed in claim 7 wherein said trailing surface of said device ends and said device further includes a bone receptacle for catching bones released from said bone snagging means past the end of said trailing surface.

9. A device as claimed in claim 8 wherein said device further includes a means for applying a suction across said bone snagging means to facilitate removing bones from said bone snagging means past the end of said trailing surface.

10. A device as claimed in claim 9 wherein said bone registering openings on said bone snagging means are formed with a corner which is sufficiently sharp to catch and drag a bone out of said fillet without breaking said bone.

11. A device as claimed in claim 3 wherein said motor is a variable speed motor to adjust the speed of the bone snagging means past the fillet registering opening.

12. A device as claimed in claim 11 wherein said drum rotates at between 10 and 90 rpm.

13. A device as claimed in claim 11 wherein said drum rotates at between 30 and 55 rpm.

14. A device as claimed in claim 4 wherein said drum is formed from stainless steel and said plurality of bone registering openings are generally circular.

15. A device as claimed in claim 14 wherein said bone registering openings are between 1/16 and 1/2 inches in diameter.

16. A device as claimed in claim 14 wherein said bone registering openings are about 3/16 inches in diameter.

17. A device as claimed in claim 5 wherein said space between said rounded tip and said drum averages 3/16 inches.

18. A device as claimed in claim 17 wherein said space between said trailing edge and said drum is between 1/16 and 1/2 inches.

19. A device as claimed in claim 4 wherein said drum is of a length which is at least greater than the average length of a fillet.

20. A device as claimed in claim 3 wherein said bone registering openings are formed in an overlapping pattern and as the bone snagging means is moved past the fillet registering opening, at least one bone registering opening is drawn past each point along the fillet registering opening.

21. A device as claimed in claim 4 wherein said device further includes a means for scraping said drum prior to said nonabrasive surface of said drum being rotated past said fillet registering opening.

22. A method of deboning fish fillets comprising:
providing a fish fillet deboning device having a fillet registering opening through which a bone puller is exposed, wherein the bone puller includes a surface having a plurality of bone snagging openings;
placing a fish fillet onto said device, whereby any bones in said fish fillet are presented at one end to said bone pulling device;
moving one of said surface of said bone puller and said fish fillet relative to the other to cause said plurality of bone snagging openings to move relative to any of said bones;
pressing said fish fillet to cause at least an end of any of said bones to stand proud of said fish fillet; and snagging said bones in said bone snagging openings and drawing said bones out of said fish fillet, while leaving substantially all of the fillet behind.

23. The method of deboning fish fillets as claimed in claim 22 wherein said step of moving one of said surface of said bone puller and said fish fillet relative to the other to cause said plurality of bone snagging openings to move relative to any of said bones comprises moving said bone puller relative to said fish fillet.

24. The method of deboning fish fillets as claimed in claim 23 wherein said bone puller is in the form of a drum and said step of moving said bone puller comprises rotating said drum.

25. The method of deboning fish fillets as claimed in claim 22 wherein said step of providing a fillet registering opening further comprises providing a puller plate adjacent to the fillet registering opening for facilitating any bones being removed from said fish fillet from unsnagging from said bone puller.

26. The method of deboning fish fillets as claimed in claim 25 wherein said step of providing a puller plate further comprises providing a rounded point and a trailing edge.

27. The method of deboning fish fillets as claimed in claim 22 further including the step of applying a vacuum across said bone puller to help remove bones from said bone puller after the bones have been remove from said fish fillet.

28. The method of deboning fish fillets as claimed in claim 22 further including the step of scraping said bone puller to remove any bones which may be stuck to said bone puller.

29. The method of deboning fish fillets as claimed in claim 22 further including the step of adjusting a speed of movement between said fish fillet and said bone puller to allow said bone puller to pull substantially all of said bone without breaking any of said bones.

30. The method of deboning fish fillets as claimed in claim 22 wherein said bone puller is driven by an electric motor and is in the form of a drum, and said step of adjusting said speed of movement of said bone puller comprises adjusting the speed of the motor.