Improved Method of Removing Bones from Fish.
Year: 1897

page_text: Date of Application, 26th Apr., 1897-Accepted, 29th May, 1897
COMPLETE SPECIFICATION.
Improved Method of Removing Bones from Fish.
I, MARTIN EKENBERG, of 3, Agnegatan, Stockholm, in the Kingdom of
Sweden, Ph.D. and Chemical Engineer, do hereby declare the nature of this.
invention and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement :-
In the majority of fishes the skeleton is so loosely connected that a large number
of bones remain in the flesh when the back bone is removed. These remaining
bones must be picked out separately. To remove the bones from fish flesh,.
therefore usually involves a great expenditure of time and labour.
The present method has for its object to do away with this waste of labour, this.
being accomplished by placing the cleaned fish between coarse cloths made of flax,
hemp or the like, or wire netting, and pressing it afterwards. For fishes having
coarser skeletons perforated plates or cast gratings may be employed. As products
there are obtained press-cakes of fish-bone, with a slight quantity of adhering
flesh and fish-flesh free of bones, said flesh passing through the cloth or grating.
For soft loose fish finer cloths are to be employed and a comparatively low
pressure. For fish which is harder in the flesh more powerful pressures and coarser
press cloth must be used. Fish having very hard flesh is softened previously to
the pressing operation by subjecting it to a squeezing process between grooved
rollers, by pounding it or by similar procedure, or by dipping it into hot water or
heating it in some other way to a temperature not exceeding 100° C., the flesh
after said treatment forming a pliable mass that can be pressed to advantage.
The pressing operation may be performed by means of screw presses or hydraulic
presses of ordinary construction. The press plates resemble essentially those used
in oil- and stearine-candle works, with the difference that larger passages are used
for carrying away the flesh that is forced out through the press cloths etc.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, I declare that what I
claim is :-
1. The method of separating the bones and flesh of fish, consisting in pressing
the fish between cloths, netting, gratings or the like, causing the flesh to pass
through said cloths, netting or the like and leaving a residuum cake, composed of
fishbone together with a slight quantity of flesh between the cloths.
2. In combination with the method described in Claim 1, the method of softening
the fish previously to the pressing operation by subjecting it to pounding or
mechanical treatment between grooved rollers, for the purpose of producing a
pliable mass suitable for the pressing operation.
3. In carrying out the processes referred to in Claims 1 and 2, the method of
softening the fish previously to the pressing operation by heating it during a brief
period to a maximum temperature of 100° C., for the purpose of producing a
pliable mass suitable for the pressing operation.
Dated this 26th day of April 1897.
BOULT & WADE,
Agents for the Applicant.