Crab processing machine

A machine for transporting cooked hard crabs to a plurality of successive stations at which the carapace pincers, walking legs, swimming legs and viscera are removed, and the remaining body is scrubbed and washed. An important feature is the provision of novel means for supporting each crab.

SUMMARY OF THE INVENTION 
A machine for removing the carapace, legs, claws and flippers from cooked 
Chesapeake Bay hard crabs has endless belt means on which individual crabs 
are placed to be successively moved through a first work station at which 
the crab body is sawed to separate the carapace into lateral parts, the 
legs, claws and flippers are removed by sawing, and the carapace is 
removed, and then to a second work station at which the crab body is 
cleaned by scrubbing brushes and water sprays. A further feature of the 
invention is the provision of a two-part articulated holder for each crab.

DESCRIPTION OF THE INVENTION 
The machine provided by the invention comprises means for individually 
moving cooked hard-shell Chesapeake Bay crabs to and through successive 
stations at which different operations are performed, resulting in the 
production of a crab body from which the carapace, claws, walking legs, 
swimming legs and viscera have been removed and which has been washed and 
scrubbed, leaving a body from which only the removal of the meat remains 
to be performed. 
The basic parts of the machine are an elongated supporting frame, a 
plurality of work stations spaced along the length of the frame, an 
endless chain or belt continuously traveling throughout the length of the 
frame to successive work stations A to D, a plurality of articulated crab 
holders carried by and spaced along the length of the endless traveling 
means, and operating means at each work station to perform one or more 
operations on the crab supported on each holder. 
The machine frame is shown generally at 2 in FIGS. 1 and 2 and may be of 
any size and configuration necessary to properly support the operating 
parts which form the invention. 
The transport part of the machine comprises an endless belt or chain 4 
which is trained over two spaced sprocket wheels 6, 8 which are supported 
at opposite ends of the machine frame and are driven by any suitable 
means. The upper reach of this belt passes from a loading station A at one 
end of the machine, through a plurality of work station B, C at which 
successive operations are performed, to a delivery station D at the other 
end of the machine from which the crab bodies pass for further processing 
by removal of the meat. 
The loading station A is located adjacent and on the downstream side of the 
sprocket wheel at the loading end of the machine. Empty crab holders 10 
carried by belt 4 arrive at this station and are filled, for example by 
workers, from trays on which cooked crabs are piled. Each holder carries 
one crab to the successive work stations, and each crab is mounted on a 
holder in the manner described herein in connection with the description 
of the holder itself. 
From the loading station each holder with the complete, uncut crab carried 
thereby is moved first to a station B where saws cut the carapace in half 
and simultaneously the claws, walking legs and swimming legs are removed 
from each end of the crab by a second set of saws, after which the 
carapace is removed. The crab body is then carried by its holder to a 
station C at which it is subjected to rotary brush means and water sprays 
to clean it and remove any trash and debris. After processing at this 
station the parts of the articulated crab supporting holder pass about the 
sprocket wheel at the delivery end of the machine and are automatically 
separated to release the crab body, after which the parts of the holder 
return to closed position for the reception of a new crab body at the 
loading station. 
The Articulated Crab Holder 
A plurality of articulated crab holders 10 are mounted on the endless chain 
4 and are suitably spaced along its length, each crab holder being 
constructed and intended to hold and support one crab throughout its 
passage through the successive work stations of the machine. Each crab 
holder comprises two separate parts 22, 24 which are separately connected 
to the chain 4 in downstream-upstream relation, part 22 being downstream 
from part 24 and separated from it. These parts are particularly 
illustrated in FIGS. 3, 4 and 5 and their co-operation in supporting a 
crab is illustrated in FIGS. 6 and 7. 
Crab holder part 22 has a flat end wall 26 which faces downstream of the 
conveyor chain and extends laterally beyond the sides of the chain, end 
walls 28, 30, upper surfaces 32, 34 which are separated by a centrally 
located open ended cut-out part 36, bottom 38, and an upstream-facing end 
wall 40 which, transversely of the chain 4, is curved on the arc of a 
circle the center of which is upstream, and which is also concave between 
the upper surfaces 32, 34 and bottom 38. The crab holder part 24 is 
right-triangular in cross sectional shape, having bottom 42, end wall 44 
at the upstream end of bottom 42, inclined surface 46 which faces 
downstream opposite the compound curved wall 40 of crab holder part 22, 
and side walls 48, 50. The surface 46 has formed in it a generally oval 
depression 52 which is centrally located in the surface. The positions, 
relations and sizes of the two crab holder parts, and the configurations 
of the surface 40 of part 22 and depression 52 of part 24, are such that 
they support a whole cooked Chesapeake Bay crab of legal size between 
them, as shown in FIGS. 6 and 7. In order to permit proper and intended 
operation of the machine apparatus at the successive work stations each 
crab is placed in the two-part holder with the carapace facing upwardly as 
shown in FIG. 6, and with the flippers, legs and claws outside the side 
walls 28, 30 and 48, 50 of the two parts of the holder as shown in FIG. 7. 
It will be understood that the parts of the crab holder will be made of 
such size that a legal size crab will be received and held in this 
relation of parts. 
It will be understood by those skilled in the art that with appropriate 
adjustment for size of the parts of the holders, and any other necessary 
adjustments, the machine will process crabs other than Chesapeake Bay hard 
crabs such, for example, as tanner, jonah rock, stone, red, dunganess and 
other hard crabs. 
Operations at Station B 
Means are provided by the invention for holding each crab body firmly on 
its crab holder, cutting the carapace in half longitudinally of the body, 
cutting off the flippers, legs and claw at each side of the body of the 
crab, preliminarily cleaning the visceral cavity, and removing the two 
halves of the carapace. These means are provided at Station B as shown 
generally in FIGS. 1 and 2 and, more particularly, in FIGS. 8 to 15, and 
comprise, first, an elongated plate or sled 60 which is positioned above 
and parallel to the belt 4 and is supported on the machine frame at 62 by 
bolts 64 each of which is surrounded by a compression spring 66 which 
bears downwardly on the sled 60. At its upstream end the sled is upwardly 
curved as shown at 68 in order to freely admit and accommodate the crab 
body entering Station B on a crab holder. Downstream of the upwardly 
curved entering part 68 the sled is provided with a level part 70 which is 
positioned vertically above the upper surface of the belt by such a 
distance that the sled is forced downwardly on the crab body by springs 
66, thus maintaining the crab body in position on the holder while the 
operations at Station B are performed. 
Between the ends of the sled 60 and between its side edges the machine is 
provided with two parallel vertical circular saws 72, 74 which are mounted 
on and rotated by a horizontal shaft 76 which, as shown in FIG. 2, is 
rotated by a motor 78 through belt connection 80. These two saws are 
positioned closely adjacent each other above the longitudinal center line 
of the belt 4, the sled 60 and the crab holder so that as the crab and its 
holder approach and pass the two saws the saws will cut the carapace 
longitudinally of the crab body, and in so doing the lower parts of the 
saws will extend into the visceral cavity, partially cleaning the same. It 
will be seen that the cut out part 36 of part 22 of the crab holder 
accommodates the rotating saws. 
Also mounted on shaft 76 for rotation thereby are two additional circular 
saws 82, 84 which are positioned externally of the side edges of the 
endless belt and are so positioned that they will cut off the legs, 
flippers and claw at each side of the crab body, as shown in FIGS. 11 and 
12. 
After the crab passes from the saws 72, 74, 82, 84 it is held on the crab 
holder by downward pressure maintained on the crab body by a vertically 
floating hold down rod 90 which extends from the lower surface of sled 60 
in the direction of belt movement and which is positioned to extend 
through the central saw cut in the carapace into the visceral cavity. The 
floating rod is provided adjacent, but spaced from, its free downstream 
end with a part 91 known as the plow, which comprises two prongs which 
respectively extend outwardly from the side edges of the floating rod in 
the downstream direction and which have the functions of forcing the 
undesired visceral material from the central cavity of the crab body and 
loosening the carapace. The means provided at Station B for removing the 
carapace are located downstream from the four saws and comprise two 
elongated arms 92, 94 which are arranged in side-by-side relation above 
belt 4 and which extend in the direction of belt travel from pivotal 
supports 96, 98 on the downstream end of sled 60 so that they have 
floating vertical movement. At its downstream end each of these arms is 
turned downwardly and rearwardly to provide a hook 100. It will be 
apparent that as each crab holder moves from beneath sled 60 the edges of 
the two halves of the cut carapace will engage the hooks and on further 
movement of the holder the two halves will be torn off and removed from 
the body, and then discharged from the machine by gravity. As the hook 
members float vertically on their pivotal supports they adjust 
automatically to the height of the crab body and therefore always grasp 
the leading edge of the carapace of each crab. 
Operation at Station C 
The apparatus at this station is disclosed generally in FIGS. 1 and 2 and, 
more particularly, in FIGS. 16, 17 and 18 and comprise a rotary brush 110 
which is mounted on shaft 112 which extends transversely of the machine 
and is rotated by electric motor 114 through any suitable means such as 
belt 116. This brush is positioned centrally of the belt 4 and at such a 
height that it will enter into the visceral cavity of the crab body held 
on a holder and remove viscera and trash therefrom, and will also 
preferably be sufficiently wide that it will scrub the side and other 
parts of the crab body. 
Each crab body is held firmly on its holder during the brushing and 
cleaning operation by the downward pressure of a hold down bar or sled 120 
which extends in the direction of belt movement. This bar is positioned 
centrally of the belt and is so positioned above the belt and the crab 
holders that it enters the visceral cavity of each crab body and is of 
such length that it engages the crab body until it is finally discharged 
from the machine, as shown in FIG. 1. 
Streams and sprays of water are directed toward the various stations of the 
machine from the pipes 130 and serve to flush waste matter downwardly to 
be removed as trash. In a preferred form, the hold down bar is provided 
with an elongated opening 121 through which water is sprayed into the 
visceral cavity. 
Discharge Station D 
As described above each crab holder 20 comprises two parts 22, 24 which are 
spaced longitudinally of the belt 4 and are of such size, configuration 
and relation to snugly hold a crab, and the crab body after passage from 
Station C. Because of this crab holder structure and relation to the 
endless belt 4 the two parts of each crab holder will separate as the 
holder passes over the sprocket wheel 6 at the discharge end of the 
machine, this separation being illustrated in FIGS. 1 and 18, thus 
automatically discharging the crab body from the machine.