Year: 1888

page_text: "ate of Application, 3rd Apr., 1888
Complete Specification Left, 29th Dec., 1888
Complete Specification Accepted, 29th Jan., 1889
ROBERT HOLBROOK of No. 1 St. Johns Road South Norwood in the County of Surrey,
Plumber, do hereby declare the nature of this invention to be as follows:-
A simple Oyster opening machine consisting of 9 parts ciz. :-(1) Bottom plate (with
jagged face) for fastening to table or stand by screws or otherwise in similar manner
to Coffee mill, to which on one side is affixed a hollow toothed plate with which to
break the fine part of the shell if necessary in order to show the division of top and
bottom shell (2) Two pillars which support (3) a lover with (4) moveable handie
attached and at pillar end this lever has a (5) projecting lever which on the handle
being raised depresses (6) two holders. These holders which if necessary can be
toothed to obtain a firmer grip on the oyster shell being inserted and held with one
hand have an equal prossure on the shell and are governed by (7) two springs placed
between the two pillars under the projecting lever. The lever with moveable handle
close beyond where it is halved (thereby enabling the handle to be moved in any
direction) has attached to it (8) the opening knife which by lifting the handle can be
inserted in the shell and by pressure forces it open. The hearing of the handle is
taken by (9) a spring which also holds the shell in its place during the insertion of
the knife and by its flexible nature permits any ordinary sized shell to be inserted.
For larger Oysters a larger Oyster opener can be made of similar construction.
Dated this 297th day of March 1888.
ROBERT HOLBROOK.
Charles Goble Champion.

page_text: I, ROBERT HOLBROOK of No. 1, St. Johns Road South Norwood in the County of
Surrey Plumber, 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:-
My invention relates to a new oyster opening machine which is constructed so that
the oyster is gripped by suitable gripping devices and held in position so that a knife
blade mounted on a pivotted and jointed lover can be inserted in the Oyster for the
purpose of opening it.
In order that my invention may be more readily understood I have hereunto
annexed the accompanying sheet of drawings.
Fig. 1 represents a side clevation of the apparatus embodying my invention.
Fig. 2 is a front elevation of the same.
Fig. 3 is a back clevation of the same.
Fig. 4 is a plan of the base of the sume.
Fig. 5 is a cross section of the same taken vertically through the machine on the
line which would cut the base between the points A. A. of fig. 4.
Fig. 6 is a detailed drawing of the arrangements of the joint and hinge in the long
arm of the lover of the same.
Figs. 7 & 8. aro detailed drawings of one of the holders or claws provided with
friction wheels.
Similar letters refer to similar parts in each of the drawings. B is the base plate,
is a jagged faced support fastened to the base plate a is a hollow toothed plate with
which to break the fine part of the shell if necessary, is a pillar supporting the knife
bearing lever, is the backwardly projecting lever which when the handle is raised
depresses the two grips or holders m, m. oo are the two springs governing the
movement of these two holders and allowing the holders to be opened sufficiently
wide to take in any ordinary sized shell and also serving to hold the shell in place
during the insertion of the knife in addition to which they take the bearing of the
handle through the medium of the lever v. and the upper portion of the grips or
holders m. m.
w. x. y is the lever which is jointed and pivotted thereby enabling the
handle to be moved in any direction and ok is the opening knife fixed to the lever.
The base plate A. may be cast wrought stainped or made in any suitable manner.
In the particular form shown in the drawings no means is indicated of fastening the
same to the table or bench but holes may be drilled in the base plate and screws
inserted to hold it firmly to the table or any convenient cramp or other suitable means
may be adopted for the same purpose for I do not claim as part of my invention any
particular means of fastening the apparatus to a bench or table. At a I have shewn
a slot with a toothed edge with which if necessary the shell at the mouth of the oyster
may be broken. As shown in the drawings this slot and toothed edge form part of
the base plate but if desired they could be formed separately and fastened to the plate
I may if desired in forming the base cast or otherwise form a portion of it with a

page_text: I
jagged face against which the oyster may rest and be held whilst being opened but in
practice and in order to render the same adjustable for different sized oysters I find it
more convenient to make this portion of my apparatus separately. At 6 I have
indicated one form in which the oyster rest may be made it consists of a ring of metal
or other suitable substance supported on two pillars and at its lever end provided with
a projection upon which a screw is cut I find it best that the face of the ring should
be suitably toothed or jagged to prevent any slip when the oyster is placed upon it.
The Pillars and the projecting screw rest in suitable slots d. d. d cut in the base plate.
The oyster rest may be fixed in position by means of a thumb screw c below the plate.
It is of course apparent that the form of this rest and the manner of its attachment to
the base may be greatly varied without departing from the spirit of my invention.
I find the best results are obtained when the oyster rest is placed at such an angle with
the base plate that when the oyster is placed upon the rest as shewn in Fig. 5 the
knife will pass along the inner surface of the oyster shell which is nearest to the rest
may also form in the base plate an opening e in which the end of the oyster will rest
as shewn in Fig. 5. Though it is not necessary to the working of my machine that
I should have this opening. At the end of the base plate opposite to the oyster rest I
erect a pillar which I securoly fasten to the base plate I have in the drawings shewn
this pillar bolted through a slot k in the base plate by the nut 1. The illar is divided
into two at the top and with the pink forms the bearing upon which the lever
carrying the opening knife works upon each side of the pillar f I place the claws
or holders m m. They are secured to the pillar by the screws n n upon which
they take their bearings and round which they are free to revolve. I also fusten to the
pillar the two springs oo which I secure into position by the screw pand the block v.
The springs severally engage either with each of the claws or holders m m or with the
friction wheels s. s. which are fastened to them. These friction wheels are so
arranged upon the claws or holders that the springs oo will tend to keep the claws in
the position indicated by figure 1. In addition to the friction wheels ss 1 may also
place upon the claws or holders the friction wheels which I place at the end of
the claws remote from the toothed edges. In figs. 7 & 8 I have shown one of the
claws or holders they may be stamped or cut out of metal or any suitable substance.
It will be observed that the curved and toothed edge does not form part of an are
of a circle struck from the bearing as a contre but that the distance of the teeth
from the bearing a increases gradually from the lower to the upper teeth it will thus
be seen that when the oyster is in position between the oyster rest band the claws mm
the greater the pressure that is put by the knife upon the mouth of the oyster the
more tightly will the oyster be held. It will be seen from the drawings that when the
handle of the lever carrying the opening knife is raised the portion of the lever
projecting behind the pillar will engage with the friction wheels tt and it will cause
the toothed edges of the claws or holders to rise and an oyster may then be inserted.
It will of course be apparent that the pillar may be made in one single piece or may
consist of two separato portions in which case it would be more properly described as
two pillars and it can also be readily seen that the springs governing the grips or holders
could readily be applied in many different ways without departing from the spirit of
my invention. I find that the friction wheels ss and trender the working of my
machine easier by reducing the friction but I do not wish to limit my claim to the
use of the holding claws provided with these wheels for I find that without any of
these friction wheels my machine will work very well. As will be seen from the
drawings the knife bearing lever works upon a pink situate at the top of the Pillar f
and consists of three parts way and the handle.
Fig. 6 shows in detail the parts way of the lever and the manner in which the
connections are made between the different parts, it will however be observed that in
the parts marked ww in Fig. 6 the backward prolongation of the lever as shown in
figs. 1 and 5 which 1 generally form in one piece with the part w of the lever is
omitted. This portion I may form with a circular plate or any flat surface so that
if desired the hand of the operator may be rested upon it for the purpose of raising
the lever or of steadying the hand of the operator. It will be seen that the piece v is

page_text: not in a straight line with the rest of the knife-bearing lover 1 make the piece at
such an angle with the rest of the lover that when the toothed edges of the claws have
engaged with the oyster shell the upper end of the claws or the friction wheels t t will
have ceased to be in contact with the piece before the point of the knife has
commenced to enter between the shells of the oyster. In the end of the piece
remote from I cut a screw thread and I provided the piece with a screwed end
which will screw into and engage with the screwed hole in the piece w I so form the
other end of the piece a that with one end of the piece y and with a pin passed through
the joint it will form a halved joint as shown in the Drawings at the other end of the
piece y I provide a handle z.
To the piece y 1 secure the opening knife ok. The knife I make of steel or other
suitable material and of such length that it will readily pass to the bottom of any
ordinary oyster shell I find that the best results are obtained when I bend this knife
in a curve I find in practice that when the knife is curved so as to form part of an arc
of a circle having a radius rather smaller than the distance between the pink and the
point of attachment of the knife to the piece I get the best results. I do not wish to
he understood as limiting my claim to the particular curve of blade which I have
indicated for 1 get very good results when the blade is not curved exactly in theso
proportions but I find that the curve I have indicated gives the best results.
1 attach the knife ok to the piece y in any secure manner. In the Drawings
I have shown the piece y slightly recessed to receive the head of the knife to
prevent any side movement and I have also shewn a hole drilled through the piece »
a portion of the head of the knife being turned down and screw throuded and the
knife held in position against the piece y by a thumb screw.
I find that the best position in which to place the knife ok is such that if the pin
forming the joint between the pieces and y as shown in Fig. 1 were produced down
towards the base plate of the machine it would meet the knife at its point.
In practice I do not screw up the pieces and a closely together so that when the
machine is in operation the knife is capable of three movements, a vertical movement
about the pink a circular movement by means of the joint between the pieces and e
and a movement round the pin joining the pieces .e and y. It will be seen that in case
the size of the oyster should render it necessary to move the oyster rest the screwed
joint between the pieces to and renders it easy to increase or decrease the length of
the lever and so to bring the point of the oyster knife over the opening between the
shells. It will also be seen that there are many other ways in which the joint between
the pieces and can be formed other than the one I have indicated for instance I
may drill in the end of the piece simply a cylindrical hole and I may turn down the
end of the piece y to a cylindrical form to pass within the hole, I may turn on the
cylinder one or more grooves and I may provide a pin or Thumbscrew passing
through the pieco w which will engage with the grooves on the piece e and will
permit to revolve within w but will prevent the separation of the two pieces until
the pin is withdrawn or the Thumbscrew unfastened.
The threefold movement which I have above indiented I find to give the best results
but I find that I can get very good results by doing away altogether with the piece
and by turning down the end of the piece y to a screw or a cylinder and inserting it
and securing it within the piece w in the manner I have above indicated. By this
arrangement it will of course he seen that the knife is only capable of two movements
aud in this arrangement I fix the knife in such a position that the point of the knife
would be opposite the joint between the pieces y and w. It will be readily seen that
when the handle is raised and the holding end of the claws are also raised an oyster
can be inserted between the jagged face of the oyster rest and the claws or holders.
The oyster will be placed so that the point of the knife will be opposite the Division
between the shells which if necessary have had their edges broken against the jagged
edges of the slot in order to show the division between the shells. The oyster rest
will be fixed in such a position that when the oyster is placed against it, the flat
shell being against the rest the point of the knife as it descends will travel along the
surface of the shell without damaging the oyster.

page_text: On leaving the handle the claws or holders will be forced by their springs against
the shell of the oyster and will hold it securely or if found necessary the haud may be
placed upon the top of the claws to aid the action of the springs. The handle should
now be pressed straight down and the knife will pass between the shells until it
reaches the bottom of the shells. The flexible nature of the lever will now enable the
knife to be moved within the shells severing the muscles without injuring the oyster
and on raising the handle the knife will be withdrawn and the claws or holders will be
lifted from the shell and the oyster may be removed.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what
I claim is :-
1. A new kind of machine for opening oysters such as is herein before described
consisting essentially of a gripping device for holding the oyster shell and a knife
blade suitably mounted for the purpose of opening the shells.
2. An oyster opening machine arranged and operating substantially as herein before
described and illustrated.
3. An adjustable device for gripping an oyster whilst it is being opened substantially
as hereinbefore described.
4. In an oyster opening machine a knife and knife carrying lever arranged and
operated substantially as and for the purposes herein before described.
5. In an oyster opening machine the combination of the knife lever with pivotted
claws or grips substantially as hereinbefore described.
Dated this 29th day of December 1888.
CHARLES GOBLE CHAMPION,
Agent for the said Robert Holbrook.