Method and apparatus for extracting meat from crab claws

This invention is a means and method for mechanically removing the meat from crab claw pincers and their attached claw arms. This is accomplished by placing the claws on a conveyor and holding the same in position prior to and during cutting of the claw pincer jaw ends and attached claw arm body joint ends. The cut claws are placed in paired diverging openings in pads with the cut ends disposed downwardly. The pads are then conveyed into a vibratory meat extracter where the meat within the cut claws is extracted therefrom prior to removing the remains of the claws from the pad and returning such pad for reloading.

FIELD OF INVENTION 
This invention relates to seafood processing and more particularly to the 
extraction of meat from crab claws. 
BACKGROUND OF INVENTION 
The removal of meat from the bodies and appendages of crustaceans such as 
crabs have historically been accomplished by hand. This is particularly 
true in removing the meat from blue crabs found on the eastern seaboard of 
the United States which are considerably smaller than dungeness and snow 
crab found on the West Coast of the country. 
Skilled workers, commonly referred to as crab pickers, work in crab houses 
picking the cooked crab meat from the bodies of the crabs. Machines and 
apparatuses have been developed to separate edible crab meat from 
nonedible portions of the crab body but almost invariably more fragments 
of crab shells are found in the meat following this process than is found 
in crab meat hand picked by crab pickers. 
There is a considerable amount of meat in the bodies of East Coast blue 
crabs and is relatively easy to extract by hand. The claws of these crabs, 
however, are relatively small, certainly as compared to the claws of 
dungeness and snow crabs, and are hard and difficult to crack. For this 
reason, blue crab claws are quite often frozen and sold separately as hors 
d'oeuvres or the like due to the difficulty of extracting meat therefrom. 
A number of machines and apparatuses have been developed for extracting 
meat from the appendages of crustaceans but a majority of these have been 
for removing the meat from the legs and claws of the large dungeness, snow 
and king crab, rather the much smaller pincer claws of the eastern blue 
crab. These various crab claw meat extracting apparatuses cut the shell or 
the entire claw to expose the meat in the interior of such claw. This 
cutting process is usually circumventially around the claw to separate one 
end from the other end or a transverse cut through the entire claw. In 
either case, rather large areas of claw shell are cut which greatly 
increases the chance of splintered shell or shell dust from contaminating 
the claw meat being extracted. 
CONCISE EXPLANATION OF PRIOR ART 
U.S. Pat. No. 4,785,502 to Howard discloses an apparatus for extracting the 
meat from crustacean appendages including the utilization of pressurized 
air injected into the appendage to expel the meat therefrom. 
U.S. Pat. No. 4,021,886 to Crepeau discloses an apparatus for scoring crab 
claws circumventially so that one end of the shell can be separated from 
the other end. See particularly FIG. 5. 
U.S. Pat. No. 3,135,992 to Fredrickson discloses a method of producing 
shelled crab claws including bisecting the shell of the bulb portion of a 
king crab claw longitudinally to expose the meat within the claw. See 
particularly FIG. 11. 
U.S. Pat. No. 4,316,306 to Huebotter discloses a method and apparatus for 
holding the pincer carrying leg of a crab for splitting the leg and pincer 
longitudinally to expose the meat therein. See particularly FIG. 5. 
U.S. Pat. No. 4,003,103 to Wenstrom et al discloses an apparatus for 
separating edible crab meat from nonedible body portions of cooked crabs 
after the top shell has been removed therefrom. 
U.S. Pat. No. 4,124,920 discloses a method of separating edible crab meat 
from nonedible body portions of cooked crabs which is a division of U.S. 
Pat. No. 4,003,103 and is based on a continuation-in-part thereof. 
U.S. Pat. No. 4,535,507 is a method and apparatus for removing lump meat 
from blue crabs including cutting the crabs so that they can be hand 
picked with a special tool. 
U.S. Pat. No. 3,022,175 is a method of preparing king crab legs including 
freezing of the same and enclosing such legs in a moisture impervious 
sheet. 
U.S. Pat. No. 2,784,447 is a crab cleaning machine for removing the top 
shells and gills of crabs and washing the same in an automatic operation. 
U.S. Pat. No. 3,750,234 to Rodgers et al discloses a crab picking machine 
wherein cooked crabs are elevated and allowed to fall on a shaker screen 
wherein the fall impact breaks up the crabs allowing the parts to be 
separated. 
U.S. Pat. No. 3,455,668 to Wenstrom discloses an apparatus for separating 
edible crab meat from nonedible portions from cooked crab bodies including 
violently impacting such crabs against a chamber wall. 
Finally, U.S. Pat. No. 4,321,730 to Tolley et al discloses a core box 
supporting means for vibratory type processing machines where meat is 
removed from the body of crabs. 
BRIEF DESCRIPTION OF INVENTION 
After much research and study into the above-mentioned problems, the 
present invention has been developed to extract meat from crab claws in a 
highly-efficient manner while reducing to an absolute minimum the chance 
of pieces of shell contaminating such meat. 
The above is accomplished by sizing the crab claws from which the meat is 
to be extracted, cutting the pincer end of the claws and the body joint 
end of the attached claw arm so that the interior of the claws and claw 
arms communicate with the exterior thereof, moving the thus prepared claws 
to an endless conveyor with inverted V-shape openings therein, holding the 
claws and attached arms on said conveyor and rapidly vibrating the same to 
remove the crab meat from the interior thereof, and discharging the empty 
shells from said conveyor. 
The above is accomplished with a minimum of labor while removing larger 
amounts of meat than can ordinarily be removed by hand, with few or no 
pieces of shell contaminating the meat, in much less time than such 
process can be accomplished manually. 
In view of the above, it is an object of the present invention to provide a 
highly-efficient means and method of extracting meat from crab claws. 
Another object of the present invention is to provide a means and method of 
extracting meat from crab claws with a minimum amount of cutting of the 
claw shell. 
Another object of the present invention is to provide a means and method of 
extracting meat from crab claws including cutting of the ends of the 
pincers of the claw and the end of the claw arm adjacent the body joint 
followed by placing the joined crab claw and arm in an inverted V holder 
and vibrating the same to remove the claw meat therefrom. 
Another object of the present invention is to place a joined crab claw and 
arm on an inverted V in cross section holder with the knuckle joint 
therebetween being at the apex of the V and cutting the pincer end of the 
claw and the body joint end of the arm prior to vibrationally removing the 
meat from said claw and arm. 
Other objects and advantages of the present invention will become apparent 
and obvious from a study of the following description and accompanying 
drawings which are merely illustrative of such invention.

DETAILED DESCRIPTION OF INVENTION 
With further reference to the drawings, the crab claw meat extractor of the 
present invention, indicated generally at 10, includes a crab claw cutting 
portion, indicated generally at 11 and a meat extraction portion, 
indicated generally at 12. 
The crab cutting portion 11 includes work tables 13 on opposite sides 
thereof with a crab claw conveyor 14 therebetween. 
The worktables 13 are provided at a convenient height that workers can take 
crab claws from the worktables 13 and place the same on the crab claw 
conveyor 14 as will hereinafter be described in greater detail. 
The crab claw conveyor 14 includes a carrier chain 15 that is trained over 
sprockets 16 and 17, idler sprocket 18 and drive sprocket 19. Drive 
sprocket 19 is operatively attached to drive motor 20 in the normal 
manner. Since the operation of drive chains, sprockets and drive motors 
are well known to those skilled in the art, further detailed discussion of 
the same is not deemed necessary. 
A plurality of crab claw carriers 21 are provided and are operatively 
mounted on drive chain 15. These crab claw carriers are inverted V-shaped 
in cross section with sloping sides 22 with a peak 23. 
The rear of each of the crab claw carriers has an end wall 24 with 
forwardly rolled flanges 25 as can clearly be seen in FIG. 4. 
The crab claw cutting portion 10 of the present invention includes a 
conveyor loading station 26, a claw cutting station 27 and a claw from 
waste separating station 28. 
The meat extraction portion 12 includes a carrier belt loading station 29, 
a meat from shell separating station 30 and a claw shell waste removal 
station 31. 
Disposed between conveyor chain sprockets 16 and 17 is a chain bar 32 which 
supports the conveyor chain 15. The conveyor chain 15 is adapted to move 
in the direction shown by arrow 33 in FIG. 2. 
Near the end of the direction of travel of the conveyor chain 15, and in 
the area adjacent sprocket 17 which reverses the direction of travel of 
said chain, are a pair of cutting motors 34 and 35. Each of these motors 
has a drive shaft 34' and 35', respectively, with circularly cutting 
blades 36 and 37 operatively mounted thereon. 
Each of the cutting motors 34 and 35 are mounted on support means 38 and 39 
that are pivoted as indicated at 38' and 39'. The end of each of the 
support means 38 and 39, opposite their respective pivots 38' and 39', are 
connected to threaded jack shafts 40 and 41, respectively. When the 
handles 40' and 41' of the respective jack shafts 40 and 41 are 
manipulated, the motors 34 and 35 can be raised or lowered as can clearly 
be seen in FIG. 3. 
An inverted V-shaped-in-cross-section crab claw hold-down bar 42 is 
provided above the conveyor chain 15 and its associated crab claw carriers 
21 in the claw cutting station 27. This hold-down bar 42 is mounted on 
downwardly biased springs 43 on hold-down bar frame 44. This arrangement 
allows the hold-down bar to hold the claws in place during the cutting 
operation due to the bias of springs 43 while at the same time allowing 
said bar to floatingly ride thereon to automatically adjust to slight 
changes in the size of the claws passing thereunder as will hereinafter be 
described in greater detail. 
The common blue crab that is commercially harvested from the Gulf and 
Atlantic Coasts has five pairs of legs. The front pair of legs, commonly 
referred to as crab claws, indicated generally at 64, are pincer carrying 
and include a crab claw arm 45 that has a body joint end 46 with the other 
end connected to knuckle joint 47. The opposite side of this joint is 
connected to the pincer 48. The pincer includes a stationary jaw 49 and a 
movable jaw 50. 
When the body joint 46 of the claw arm 45 and at least a portion of the 
jaws 49 and 50 are cut from the crab claw 64, the waste is ejected through 
chute 51 in the bottom of cutting station 27 into either a receptacle (not 
shown) or onto a cross conveyor 51' for removal. The thus cut crab arm 45 
and pincer 48 with the connecting joint 47 are then dropped off the end of 
conveyor 14 adjacent sprocket 17 and pass out slide chute 52 onto the side 
trays 29' of the carrier belt loading station 29. 
A relatively wide conveyor belt 53 is operatively mounted on support 
rollers 54 and 55. Since conveyor belts and support rollers are well known 
to those skilled in the art, further detailed discussion of this part of 
the present invention are not deemed necessary. 
Spaced along and supported by conveyor belt 53 are a plurality of claw 
receiving pads 55. These pads can either be mounted on the conveyor belt 
53 or they can be part of said belt. These pads are preferably made from 
neoprene or similar material and have a plurality of paired openings 
extending outwardly from each other at an angle that will allow the arm 45 
and pincer 48 of the crab claw 64 to be inserted thereinto with the 
knuckle joint 47 at the apex of the openings. 
The claw receiving pads of areas 55 are preferably rectangular in shape and 
are so sized that they fit within the shaker box 57 operatively mounted 
within the meat separating station 30. 
Inside the shaker box 57 and above the claw receiving pads 55 is a 
hold-down means 59. This hold-down means can be a neoprene pad or the like 
that can be either inflated or lowered into contact with the crab claws 64 
disposed in the slanted, paired openings 56. 
A shaker means 62 is operatively attached to shaker box 57 to vibrate the 
same between 1,500 and 5,000 vibrations per minute to shake the crab meat 
from the claw arm and pincer. One method of vibrating the crab meat from 
the connected arm and pincer would be the vibratory apparatus disclosed in 
U.S. Pat. Number 4,003,103 (now expired). Other vibratory means could, of 
course, be used to obtain the same results. 
A lateral or cross conveyor 58 can be provided under the shaker box 57 to 
remove the extracted crab meat to an area for packing or further 
processing. Cross conveyors of this type are well known to those skilled 
in the art and further detailed discussion of the same is not deemed 
necessary. 
The process of removing the crab meat from the claw arm and pincer is an 
incremental process with the pad 55 moving in place within shaker box 57, 
the hold-down means 59 moving against the pad 55, the pad 55 being 
vibrated to remove the crab meat from the pincer and arm, and then the 
hold-down cushion moving out of contact with such pad and the same moving 
from the shaker box and the next pad moving thereinto. As this process 
continues each pad will move around the end support roller 54 and will be 
inverted as can clearly be seen on the right hand side of the sectional 
schematic of FIG. 9. A means is then used to remove the arm and pincer 
shells of the crab claws 64 from each of the pads. This can be 
accomplished through the use of high pressure fluids such as air or water 
nozzles 60 which are aimed down the bore of each of the openings 56 in pad 
55. These shells will fall into chute 61 and from there onto cross 
conveyor 62 for removal and disposal. 
When any given pad 55 moves back in place adjacent the side trays 29' of 
station 29, the same is ready for reloading with the trimmed crab claws 
64. 
The means or method of using the crab claw meat extractor of the present 
invention includes taking a plurality of crab claws 64, including pincers 
and attached arms, that have been graded to the same size and placing such 
graded claws on the work tables 13 of the conveyor loading station 26. 
Workers standing on either side thereof can then place multiple crab claws 
64 on the crab claw carrier 21 mounted on the conveyor drive chain 15. 
When one of the crab claw carriers 21 is full then the next one is filled, 
etc. The crab claw conveyor 14 moves steadily in the direction of the 
arrow 23 and each of the claw carriers 21 passes under spring-biased 
hold-down bar 42 when it enters the claw cutting station 27. 
The handles 40' and 41' of the respective threaded jack shafts 40 and 41 
are adjusted to set the position of the respective cutting motors 34 and 
35 and their associated blades 36 and 37 to the correct height for the 
size crab claws 64 being processed at the time. 
As the claws pass through the cutting station 27, the cutting blade 36 will 
sever the pincer jaws 49 and 50 at the preset location and blade 37 will 
sever the body joint end 46 of the crab claw arm 45 opposite knuckle joint 
47. The cut or waste jaws 49 and 50 and arm end 46 will drop through chute 
51 and either into a receptacle (not shown) or onto a lateral conveyor 51' 
to remove the same for disposal. 
As the crab claw carrier 21 with its associated trimmed crab claws 64 
passes around sprocket 17, which is past hold-down bar 42, such crab claws 
will fall into slide chute 52 and be deposited on the trays 29' at the 
belt loading station 29. 
Workers standing on either side of the side trays 29' can take the crab 
claws 64 and insert the claw arm in one of the paired holes 56 and the 
pincer in the other with the knuckle joint 47 at the top. 
Once each of the pads 55 has been filled, it can be moved by conveyer 53 
until it enters the meat-from-shell separating station 30. At that point 
the hold-down cushion 59 presses down against the pad 55 and its inserted 
crab claws. With the cushion in place to hold the crab claws in the holes 
56 of pad 57, the shaker box is vibrated in the range of 1,500 to 5,000 
vibrations per minute for a predetermined period of time until the meat 
within the crab claw pincer and arm has vibrated therefrom and has fallen 
onto lateral conveyor 58. The hold-down cushion 59 is then raised and the 
pad thereunder moved in the direction shown by arrow 33' a distance equal 
to the length of the pad so that the next pad is disposed beneath the 
hold-down cushion 59. The shaking process is then repeated. 
As the pads 55 with their associated de-meated pincer and arm shells moves 
above disposal chute 61, fluid jets 60 of water, air or the like are 
directed down the bore of each of the angled holes 56 to remove such 
shells therefrom. Once the holes have been emptied, the pad above the 
chute will move therefrom as the shaker process is completed for 
subsequent pads. The cross or lateral conveyor 56 can be used to remove 
the empty shells for disposal. 
As the empty pads 55 move around roller 54 and are again adjacent to the 
side trays 29' of the belt loading station 29, the workers (not shown) can 
again fill such pads so that the vibratory crab claw meat removal process 
can sequentially be continued until all the crab claws 64 have had the 
meat extracted therefrom. 
From the above it can be seen that the present invention provides a highly 
efficient method of extracting the meat from crab claws including the 
pincer portions and arm portions thereof. The apparatus for accomplishing 
this operates in an endless cycle and is simple and yet highly efficient. 
The present invention provides a means for extracting the meat from crab 
claws with very little if any contamination of shells with the meat during 
such process. 
The present invention can, of course, be carried out in other ways than 
those herein set forth without departing from the spirit and essential 
characteristics of such invention. The present embodiments are, therefore, 
to be considered in all respects as illustrative and not restrictive, and 
all changes coming within the meaning and equivalency range of the 
appended claims are intended to be embraced therein.