Improvements in Knives for Meat-cutting and similar Machines.
Year: 1890

page_text: Date of Application (in United Kingdom), 29th July, 1890
Complete Specification Left, 29th July, 1890-Accepted, 22nd Nov., 1890
COMPLETE SPECIFICATION.
Improvements in Knives for Meat-cutting and similar Machines.
I, CHARLES F. LEOPOLD, of Philadelphia, Pennsylvania, United States of America,
Machinist 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 the construction of the knives used in machine for cutting
up plastic substances, and of the general character of the machine shewn and described
in the Specification of United States Patent No. 348,132, of August 24, 1886. The
leading feature of such machine is a casing having a hopper at one end to receive the
meat or other substance to be cut up, and an opening at the delivery end, a perforated
terminal plate at the delivery end of the cylinder or casing, a knife working on the
inside of and against the terminal plate to cut up the meat or other substance, and a
feed-screw working in the casing to force the substance under treatment against and
through the plate. Generally, as in the Patent referred to, the plate is stationary
and the knife revolves with the screw; but in some machines the plate is revolved
and the knife remains stationary.
As heretofore constructed the knives used with machines of the above-noted
character have been so formed that they acted like wedges in forcing back the meat
not cut off by them against the feed-screw, thus interfering with the continuous
feeding of the meat and consuming power uselessly. This is a defect which my
present invention aims to overcome. The said knives have also been so constructed
that they require to be placed in the machine in a certain position, and another object
of my invention is to construct them so that they will be reversible, thus at the same
time ensuring that the most unskilful will place them in correct position, and providing
a double set of cutting-edges, which doubles the effective life of the knife.
In connection with my preferred construction of machine, viz., that shewn in Patent
before referred to, my improved knife has other and very marked advantages, to which
attention will be hereinafter called.
--
To enable my invention to be fully understood I will describe how it can be carried
into practice by reference to the accompanying drawings, in which
Figure 1 is a perspective view of my improved knife in the preferred form :
Figure 2 is a section; and,
Figure 3 is an end view of one arm of the knife drawn to an enlarged scale.
Figure 4 is a longitudinal section through my meat-cutting machine, shewing the
improved knife in position.
a is the cylinder or casing of the machine; a¹ its hopper; a² a journal in its back
end for the end of the feed-screw; and a³ its open delivery end. b is the feed-screw
having a rear extension b', to which the handle (not shewn) is connected, and a front
extension 6, which, as shewn is required to pass through and engage the knives.
c is a plate with perforations formed through it which fits against a shoulder a* of

page_text: the casing, and d is a perforated plate screwing in the end of the casing, while fis
the knife which, as shewn, is clamped between the plates c and d.
The lug a³ and catch e are devices described in the said former Patent and need not
be further noted..
Referring now to the construction of my new knife, g is its hub which is formed with
a socket to receive the end of the screw, and from which extend a number of radial
arms h, h, the upper and lower faces of which have cutting edges formed thercon in
parallel planes and in such a way as to make the knife reversible. When iny knife
is to be used between plates, as c and d, its arms are made of a general quadrangular
section, as shewn in Figure 1, and cutting-edges 1, 2, 3 and are formed at each
corner. When the knife is intended for use in connection with but one perforated
plate it is sufficient to form cutting-edges only on the diagonally opposite corners /
and . The front and rear faces i, i of the arms h, h are formed, as shewn, with
longitudinal grooves in them extending close to the cutting-edges, so that only a
narrow strip of the arm inside the cutting-edge or edges comes in contact with the
plates c, d. The faces j, j of the arms are, as shewn, formed so that at the top and
bottom they will lie in, or substantially in, planes parallel with a plane passing through
the axis of the hub. These faces are preferably hollow ground or concave, as shewn,
so as to give the cutting-edge a sharper angle. This feature of the construction of
the faces of the cutter-arms avoids the tendency heretofore existing in the knife-
arms to force or wedge the meat away from the plate, and ensures its being carried
around in front of the cutting-edges until the pressure behind it forces it into the
perforations of the plate, when, of course, it is cut off.
This feature of construction is obviously applicable to non-reversible knives, as well
as reversible ones, and to obtain its full advantage it is desirable to make knives which
cut only against one plate, but are reversible, of the substantially quadrangular form
shewn.
A great advantage of my knife, as used with the double plates c and d is that the
two cutting edges not in use are sharpening themselves against the plates, while the
other two edges are cutting, so that sharp edges can always be secured by reversing
the knife after it has been in use for a short time.
Preferably the hub g should be of less thickness than the arms, as shown in Figure 2.
This would be practically essential were the plates not slightly recessed where the hub
comes adjacent to them, and is in any case desirable, so that the knives can be ground
readily and accurately, and this grinding is also facilitated by grooving the faces i, i
of the arms.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, I declare that what 1
claim is:
1. A reversible knife for meat-cutting and similar machines, consisting of a central
hub having a socket formed in it to receive the end of the feed-screw, arms of
substantially quadrangular section extending from the said socket, cutting-edges h³, 12
and h³, formed at each angle and on parallel planes, and longitudinal grooves
formed on the front and rear faces i, i of the arms and extending close to the edges
thereof, all substantially as, and for the purpose, specified.
2. A reversible knife for meat-cutting and similar machines, consisting of a central
hub having a socket formed in it to receive the end of the feed-screw, arms of
substantially quadrangular section extending from said socket cutting edges 1, 2 and
3, formed at each angle and on parallel planes, longitudinal grooves formed in the
front and rear faces i, i of the arms and extending close to the cutting-edges thereof
and concave grooves extending from face to face of the arms, all substantially as, and
for the purpose, specified.
3. A reversible knife for meat-cutting and similar machines, consisting of a central
hub having a socket formed in it to receive the end of the feed-screw, arms of greater
thickness than the hub and of substantially quadrangular section extending from said
socket, cutting-edges lª³, h² and h³, 1 formed at each angle and on parallel planes,

page_text: longitudinal grooves formed in the front and rear faces i, i of the arms and extending
close to the cutting-edges thereof, and concave grooves extending from face to face of
the arms, all substantially as, and for the purpose, specified.
Dated the 29th day of July 1890
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.