Adjustable cutting mechanism

Details Adjustable cutting mechanism Adjustable cutting mechanism

2000-02-29

2001-11-13

Rosenbaum, Mark (Department: 3725)

Solid material comminution or disintegration

Apparatus

Comminuting elements

C029S700000, C425S311000, C425S313000

Reexamination Certificate

active

06315226

ABSTRACT:

BACKGROUND OF THE INVENTION
1. Technical Field
The present invention relates to an axially adjustable cutting mechanism and, in particular, to an extrudate cutting mechanism that incorporates blade holders that can be adjusted for uniform contact with an extruder die face.
2. Description of Related Art
Extruders used in the food processing industry commonly employ cutting devices that cut extrudate to a desired size as it exits the die face of the extruder. An example of prior art cutting mechanisms used with an extruder is shown in
FIGS. 1
,
2
, and
3
.
FIG. 1
shows a side view of a tube turn
110
, bell
112
, and die
114
assembly of an extruder. In operation, product, such as masa, is forced through the tube turn
110
into the bell
112
. It is then extruded through the die
114
. A shaft
116
extends through the turn
110
, bell
112
, and die
114
. Mounted on the end of the shaft
116
is a cutting mechanism. The cutting mechanism comprises a hub
130
, spokes
132
extending from the hub
130
, and blade holders
134
attached to the spokes. Each blade holders
134
in turn maintains a blade
136
in contact with the die
114
.
FIG. 2
shows a bottom view of the die face
115
. Corresponding reference numerals are used to represent corresponding elements on all figures unless otherwise indicated. The die face
115
will typically exhibit a number of channels or ports
120
that are cut through the die
114
, thus allowing communication of the product from the bell, through the die
114
, onto the die face
115
. As the product emerges from these ports, it is cut into relatively uniform pieces by the blades
136
as the entire cutting mechanism rotates about the shaft in the direction
102
illustrated in FIG.
2
. Such rotation
102
is typically in speeds ranging from sixty to one hundred fifty rpm, with approximately one hundred forty rpm generally used for cutting masa extrudate.
FIG. 3
shows a perspective view of a prior art cutting mechanism detached from the extruder. The side of the cutting mechanism presented is the same side that interfaces with the die face. Again shown is the hub
130
, the spokes
132
, the blade holders
134
, the blades
136
, and the direction
102
of intended rotation. The blade holders
134
on a prior art cutting mechanism are rigidly mounted to the spokes
132
, and thus static in relation to the cutting mechanism. Consequently, referring back to
FIG. 1
, the distance between the die face
115
and the blades
136
cannot be easily adjusted for each individual blade
136
. The overall distance of the cutting mechanism from the die face
115
is adjusted by using washers placed between the hub
130
and the die face
115
. The casting tolerance of the entire mechanism is relied upon to insure a consistent contact between each individual blade
136
and the die face
115
. However, if a spoke
132
or blade holder
134
becomes slightly bent or is otherwise out of tolerance, the blades
136
will not make consistent contact with the die face
115
. This can result in uneven cutting or smearing of the extrudate and misshapen product.
Exact tolerance between the blades
136
and the die face
115
is particularly important when the extrudate shape is complex, such as the race car shaped extrudate that would be generated by the die
114
shown in FIG.
2
. This race car pattern of the die ports
120
requires that the blades
136
remain consistently flush against the die face
115
and not deflect away from the die face
115
during cutting. Attempts to maintain consistent tolerance between the blades
136
and die face
115
in the past using prior art cutting mechanisms include physically bending the blade holders
134
or spokes
132
. This was not found to be an acceptable solution for the application shown in
FIG. 2
, however. Regardless of the minor adjustments made to the cutting mechanism, a consistent and clean cut, with no smearing of the extrudate pieces or misshapen product, could not be consistently achieved with the prior art cutting mechanism.
Consequently, a need exists for a cutting mechanism that is adjustable such that the fit between the cutting blades and the die face can be maintained consistently and adjusted as required. Such adjustable cutting mechanism should be adaptable to existing extruders and provide for clean cuts through extrudate even when the extrudate involves complex shapes.
SUMMARY OF THE INVENTION
The proposed invention comprises an adjustable cutting mechanism for use with an extruder and allows for individual adjustment of the interface between each cutting blade and the die face. An alternative embodiment also allows for adjustments of the angle of incidence between each blade and the die face.
The distance between each blade and the die face is adjustable axially by sliding a square stock blade holder through a channel in the end of each associated hub spoke. After the cutting mechanism is mounted on a drive shaft, each individual blade can be placed in direct contact with the die face. This position is then secured by tightening a set screw in the end of each spoke which applies pressure to a portion of the blade holder within the spoke channel. In one embodiment, the cutting blades themselves are shortened in order to reduce deflection of the cutting blades from the die face.
The above as well as additional features and advantages of the present invention will become apparent in the following written detailed description.


REFERENCES:
patent: 3981959 (1976-09-01), Cuff
patent: 4123207 (1978-10-01), Dudley

Affiliated with

Also associated with

Rating

Adjustable cutting mechanism does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Adjustable cutting mechanism, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Adjustable cutting mechanism will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2574588