Nutcracker

A nutcracker having two lever arms having first ends, a hinge pin connecting the two lever arms to each other, a press cup having an open top and substantially plane press surfaces, and press jaws, each of which is disposed at the first ends of the two levers and has stop surfaces to limit the travel of the two lever arms, with an opening angle which is constant in the initial position of the nutcracker regardless of nut size.

BACKGROUND OF THE INVENTION 
The present invention relates to a nutcracker. More particularly, it 
relates to a nutcracker utilizing a lever system or screw spindle to 
generate the force. 
Nutcrackers of the above mentioned general type are known in the art. 
In nutcrackers of the known type, force is transmitted by means of a lever 
system in the form of either one-armed or two-armed levers, although so 
called nut presses, in which a screw spindle is used to generate force, 
are also known. In each case, the nutcracker or nut press first has to be 
adjusted to the size of the nut to be borken open before the actual 
breaking open operation can be started. Both for adjustment and for 
breaking open, it is necessary or, in the latter case, advisable, to use 
both hands if the nutshells are to be prevented from flying around. Since, 
on the one hand, the handle lever travel constantly varies as a function 
of the nut size according to the initial position of the press jaws and, 
on the other hand, with an increasing handle-lever travel the amount of 
force exerted also increases because of a less favorable transmission 
ratio, force is generated in an uncontrolled manner during the 
breaking-open operation, especially where large nuts are concerned, thus, 
usually resulting in greater destruction of the nut kernel. In contrast to 
this, where small nuts are concerned, such as, for example hazelnuts, 
there is the possibility that they will not be grasped at all by the press 
jaws or that they can be broken open only under unfavorable conditions 
because of a shorter handle lever travel. 
SUMMARY OF THE INVENTION 
Accordingly, it is an object of the present invention to provide a 
nutcracker which avoids the disadvantages of the prior art. 
More particularly, it is an object of the present invention to provide a 
nutcracker whose handling is simple and safe. 
In keeping with these objects, and with others which will become apparent 
hereinafter, one feature of the present invention resides, briefly stated, 
in a nutcracker having two lever arms having first ends, a hinge pin 
connecting the two lever arms to each other, and a press cup having an 
open top and substantially plane press surfaces, wherein press jaws, each 
of which are disposed at the first ends of the two levers and have stop 
surfaces to limit the travel of the two lever arms and having an opening 
angle which is constant in the initial position of the nutcracker 
regardless of nut size. 
When the nutcracker is designed in accordance with the present invention 
the nutcracker is always ready for use, since the nut introduced into the 
press cup purely as a result of gravity assumes a position in which the 
actual breaking-open operation can be started immediately without further 
readjustment of the press jaws. The initial position of the handle ends of 
the lever arms remains unchanged for any size of nut and has a distance 
between the handle ends which is suitable for the user's hand, therefore 
making it substantially simpler to operate the nutcracker with only one 
hand. At the same time, the transmission ratio of the lever system and 
therefore the force to be exerted match the size of the nut. For example, 
where smaller nuts are involved the transmission increases and the 
relative amount of force exerted is reduced. Furthermore, the working 
stroke of the press jaws is directly related to the size of the nut which 
is to be broken open and the shell elasticity of which usually increases 
with increasing size, and thus a greater working stroke may be necessary 
to break open the nut. Finally, the nut introduced into the press cup sits 
securely between the press surfaces in such a way that force is usually 
exerted off-center, thus resulting in an improved breaking-open effect in 
comparison with a central exertion of force which is again the rule in 
known nutcrackers. 
In accordance with another feature of the present invention, the two lever 
arms have handles disposed at second ends which are disposed at opposite 
ends from the first ends of the two lever arms. 
Still another feature of the present invention is that the opening angle of 
the press jaws is at least 25.degree. in the initial position. 
A further feature of the present invention is that the opening angle of the 
press jaws is 30.degree. in the initial position. 
Yet another feature of the present invention is that the press jaws form an 
angle and have bottoms which are disposed from each other a distance in 
the range of 10 to 20 mm. 
Yet still another feature of the present invention is that the press jaws 
have a relative angular adjustability in the range of 10.degree. to 
20.degree.. 
Another feature of the present invention is that the press surfaces are 
roughened. 
Still another feature of the present invention is that the press surfaces 
are provided with a friction covering. 
Yet another object of the present invention is that the press jaws form an 
angle with the lever arms and the handle ends of the lever arms extend 
substantially horizontally. 
Another feature of the present invention is that the press cup forms a 
housing having side walls and a closed bottom and the side walls are made 
as one piece with one of the press jaws. 
Still another feature of the present invention is that the hinge pin of the 
lever arms is anchored in the side walls of the press cup housing. 
Finally, still a further feature of the present invention is that the lever 
arms are spring loaded and the press cup housing has a stop for the other 
one of the press jaws. 
The novel features which are considered as characteristic for the invention 
are set forth in particular in the appended claims. The invention itself, 
however, both as to its construction and its method of operation, together 
with additional objects and advantages thereof, will be best understood 
from the following description of specific embodiments when read in 
connection with the accompanying drawing.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring now to FIG. 1, the nutcracker has two-armed levers 10 and 11 
which are connected to one another in the form of double lever pliers via 
a hinge pin 12 and which extend with handle ends 13, 14 substantially 
horizontally. Preferably formed substantially at right angles on the ends 
of the lever arms 10, 11 facing away from the handle ends 13, 14 are press 
jaws 15, 16, having press surfaces 17, 18 respectively. The press surfaces 
17, 18 are substantially plane and at the same time are part of a press 
cup 19 which is open at the top. The two press jaws 15, 16 form the front 
and rear end walls of the cup housing. Side walls 20, 21 and bottom 22 of 
the cup housing are preferably made in one piece with the front end wall 
(press jaw 15) and are therefore formed as with the lever arm 10 as one 
piece. The hinge pin 12 is anchored in the side walls 20, 21 near the 
bottom of the cup housing and it pivotably carries the press jaw 16 which 
is guided within the cup housing. The handle end 13 of the lever arm 10 
forms, in the region of the press cup 19, a cross member 23 which connects 
the side walls 20, 21 of the cup housing. The cross member 23 also serves 
as a stop for the press law 16 in the rest position. 
In the rest or initial position, the two press jaw 15, 16 form with their 
press surfaces 17, 18, respectively, an opening angle.alpha. of at least 
25.degree., preferably 30.degree., and form an angle vertex open at the 
bottom, because the hinge pin 12 is located at a distance of 10 to 20 mm 
from the opposite press surface 17. The lever arms 10, 11 are loaded in 
the direction of the intital position by a compression spring 24 which is 
located in the immediate vicinity of the press cup 19 between the lever 
arms. The abutment provided for this purpose on the lever arm 11 is 
designed at the same time as a stop projection 25 to limit the lever 
travel. The resulting relative angular adjustability of the press jaws at 
the same time determines their working stroke, the amount of which depends 
on the predetermined distance between the press surfaces in the region of 
the open angle vertex and on the degree of the opening angle and which is 
appropriately limited to a value of between 10.degree. and 20.degree.. 
Moreover, the press surfaces 17, 18 are roughened or are provided with an 
appropriate friction covering 26, to prevent the nut from slipping during 
the breaking-open operation, for example because force is exerted 
off-center. The coefficient of friction .mu. can be between 0.5 and more 
than one depending on the nature of the nutshells. 
So that the nutcracker can be placed on a plane base, a foot part 27 is 
formed on the end of the lever arm 11 on the same side as the handle, 
extends downward essentially at right angles and has a length that it 
forms, together with the bottom of the press cup 19, a resting surface. 
The nutcracker thus consists essentially of parts which can be produced, 
for example, by injection-molding. 
Depending on the size of the nut, the lever transmission ratio of the 
nutcracker described above is between 1:4 and 1:7, so that cracking forces 
of up to 100 kgf, for example for hazelnuts, can be generated. 
The same working principle can, of course, also be achieved for a 
nutcracker which is equipped merely with one-armed levers or in which the 
hinge pin is arranged in the lever plane and not offset to this. Finally, 
it will also be possible to replace the lever system by a screw spindle 
which moves one of the two press jaws. 
It has proved appropriate, regarding nuts obtainable in the trade, for the 
press jaws to form in the initial position an opening angle of at least 
25.degree., preferably 30.degree. and the press jaws can form an angle 
vertex open at the bottom with a distance between them of 10 to 20 mm. At 
the same time, the relative angular adjustability of the two press jaws 
can be between 10.degree. and 20.degree., so that the nut kernel remains 
substantially undamaged when the shell is broken open. 
To achieve an even more favorable transmission ratio with the same overall 
length, according to a further embodiment of the invention the press jaws 
can form an angle with the lever arms, the handle pieces of the lever arms 
preferably extending essentially horizontally. 
So that the shells do not fall down out of the press cup during the 
breaking-open operation, the press cup can form a housing which is closed 
at the bottom. The bottom and side walls of the housing can be made in one 
piece with one of the two press jaws for reasons of stength. The hinge pin 
of the lever arm can then appropriately be anchored in the side walls of 
the housing. 
So that the press jaws return automatically into their initial position 
after being actuated, the lever arms are spring-loaded in the direction of 
the initial position. The housing of the press cup is provided with a stop 
for the other press jaw. 
It will be understood that each of the elements described above, or two or 
more together, may also find a useful application in other types of 
constructions differing from the types described above. 
While the invention has been illustrated and described as embodied in a 
nutcracker, it is not intended to be limited to the details shown, since 
various modifications and structural changes may be made without departing 
in any way from the spirit of the present invention. 
Without further analysis, the foregoing will so fully reveal the gist of 
the present invention that others can, by applying current knowledge, 
readily adapt it for various applications, without omitting features that, 
from the standpoint of prior art, fairly constitute essential 
characteristics of the generic or specific aspects of this invention. 
What is claimed as new and desired to be protected by Letters Patent is set 
forth in the appended claims.