U.S. patent number 3,784,118 [Application Number 05/224,111] was granted by the patent office on 1974-01-08 for mixing and comminuting apparatus.
Invention is credited to Mathew Hurwitz.
United States Patent |
3,784,118 |
Hurwitz |
January 8, 1974 |
MIXING AND COMMINUTING APPARATUS
Abstract
An agitator and cutter assembly for a food blender and the like
having cutter blades arranged so that they may be tilted from a
vertical axis to change the pitch of the blades.
Inventors: |
Hurwitz; Mathew (Auburndale,
MA) |
Family
ID: |
22839320 |
Appl.
No.: |
05/224,111 |
Filed: |
February 7, 1972 |
Current U.S.
Class: |
241/282.1;
366/205; 366/330.3; 366/330.5 |
Current CPC
Class: |
B02C
18/12 (20130101); A47J 43/046 (20130101) |
Current International
Class: |
A47J
43/04 (20060101); A47J 43/046 (20060101); B02C
18/12 (20060101); B02C 18/06 (20060101); B02c
018/12 () |
Field of
Search: |
;241/199.12,277,282.1,282.2,46.17 ;259/107,108,DIG.25,DIG.26
;209/169 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Custer, Jr.; Granville Y.
Assistant Examiner: Goldberg; Howard N.
Attorney, Agent or Firm: Kraus; Nathan N. Marcus; Joseph R.
Schur; Gerald S.
Claims
I claim:
1. In an agitator and cutter assembly for a blending and
comminuting apparatus a one piece rotary cutter including a hub
portion and extending blades having a fixed angular relationship to
each other and means for tilting said cutter at an angle relative
to its axis of rotation for varying the attitude of said
blades.
2. In an agitator and cutter assembly for a blending and
comminuting apparatus, a drive shaft, a cutter having extending
blades and keyed to said shaft for rotation therewith but being
tiltably movable axially thereof, and cam means rotatably movable
relative to said shaft and engageable with said cutter to vary the
angular disposition of said cutter thereby to vary the pitch of
said blades.
3. An agitator and cutter assembly for a blending and comminuting
apparatus comprising a drive coupling arranged to be connected to
power drive means, a drive shaft fixed to said coupling, a cutter
having extending blades and keyed to said drive shaft for rotation
therewith but being tiltably movable relative to the axis thereof,
a hollow shaft concentric with said drive shaft and rotatably
receiving said drive shaft, a wedge shaped member fixed to the
upper end of said upper shaft, the upper face of said member being
disposed in a plane angular to a plane normal to the axis of said
drive shaft, said cutter resting on said upper face of said member,
an adjuster member rigid with the lower end of said hollow shaft
and having a surface in abutment with a confronting surface of said
drive coupling, the adjuster member being rotatable relative to
said drive coupling, and resilient means urging said cutter into
engagement with said upper face, said cutter being rotatably
movable relative to said upper face whereby to vary the angular
disposition of said blades relative to their axis of rotation
thereby to vary the pitch of said blades.
4. The invention as defined in claim 3 including a second cutter
fixed to said hollow shaft.
5. The invention as defined in claim 3 in which the resilient means
comprises an elastomeric washer.
6. The invention as defined in claim 3 in which the abutting
surfaces of said adjuster member and said drive coupling are
provided with interengaging shoulders to effect a driving
connection therebetween.
7. The invention as defined in claim 3 including braking means for
arresting movement of said adjuster member while manually rotating
said drive coupling to move said cutter relative to said wedge
shaped member.
8. The invention as defined in claim 3 including braking means for
arresting movement of said adjuster member while the drive coupling
is being rotated to move said cutter relative to said adjuster
member thereby to adjust the position of the cutter relative to the
wedge shaped member.
9. The invention as defined in claim 3 including braking means
comprising a deformable elastomeric ring concentric with said
adjuster member.
10. The invention as defined in claim 3 in which the root line of
each of the blades is disposed at an angle substantially similar to
the angle of the wedge shaped member.
11. The invention as defined in claim 3 in which the abutting
surfaces of the adjuster member and the drive coupling include
cooperating ratchet elements to afford relative movement between
the adjuster member and the drive coupling in one direction of
rotation.
12. In an agitator and cutter assembly for a blending and
comminuting apparatus, a drive shaft, a cutter having a hub portion
having a central slot and extending blades and being keyed to said
shaft for rotation therewith but being tiltably movable relative to
the axis of the shaft, each of said blades being compoundly bent in
angular relation to the plane of said hub portion and being
connected to said hub portion by an intermediate portion
substantially normal to the plane of the hub portion, the root line
of each of said blades at the juncture of said intermediate portion
and the base of the blade being disposed in angular relation to the
plane of said hub portion.
13. The invention as defined in claim 12 including means for
tilting said cutter to vary the pitch of said blades relative to
their axis of rotation.
14. A blending and comminuting apparatus comprising in combination
an agitator cutter assembly having a drive shaft, a cutter having
extending blades and keyed to said shaft for rotation therewith but
being tiltably movable axially thereof, cam means rotatably movable
relative to said shaft and engageable with said cutter to vary the
tilt of said cutter thereby to vary the pitch of said blades, a
reversible motor for driving said shaft, and means for changing the
direction of rotation of said motor to effect relative movement
between said shaft and said cam means thereby to adjust the pitch
of said blades.
15. The invention as defined in claim 14 including coupling means
interposed between said shaft and said cam means and permitting
substantially 180.degree. relative rotation in either direction
between said shaft and said cam means.
16. The invention as defined in claim 2 in which the cam means
comprises a wedge shaped disc.
Description
FIELD OF THE INVENTION
The present invention relates to an apparatus for blending and/or
comminuting food materials and the like, and more particularly, to
such a device having agitator and cutter blades which are
adjustable to change their pitch of operation.
BACKGROUND OF THE INVENTION
A common objectionable condition found in many prior art blenders
is the tendency of certain kinds of foods being processed to
"bridge" over the agitator blades because of self-impeded
circulation which hinders the desired vortex-like flow of unchopped
food to the blades and of chopped food away from the blades. The
result is that a small portion of the food being processed may
become overblended, mushy or too finely comminuted with the major
portion of the food remaining substantially unprocessed. In order
to alleviate this condition common expedients are to vary the
blender speed, to switch the blender on and off periodically, or to
use a spatula or like implement manually to stir or force food
towards the agitator blades. Also, some improved blade
configurations have somewhat remedied the problem with certain
foods but, for the most part, the improvements seen with some foods
are paid for at the expense of either a degradation in performance
with other foods or a gross overloading of the blender motor when
highly viscous foods or other materials are processed. In
particular, it is well known that few food blenders are capable of
producing consistently acceptable coarse chopped foods, such as
cole slaw, egg salad, grated cheese, celery, nuts, graham cracker
crumbs, carrots, and the like. Most blenders commonly produce a
puree of too finely comminuted food or a paste when what was
desired was a coarse chopped consistency similar to what might be
obtained using a food grater or meat grinder. In many cases, the
user becomes disillusioned and abandons any further attempt at
using the blender for such foods. Thus, too many blenders become
relegated to the trivial operation of mixing only liquids.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an improved
agitator-cutter assembly having means by which the user may
conveniently adjust the angular disposition or pitch of the
agitator blades relative to their axis of rotation to produce
varying degrees of dynamic coupling between the blades and the
food, as may be required by the various foods.
Another object of this invention is the provision of means for
safely and conveniently adjusting blade pitch with the agitator and
blender jar assembled but removed from the blender motor base.
Still another object of this invention is the provision of agitator
blades having a novel configuration which may be utilized in fixed
or adjustable pitch modes. These blades have been found to afford
significant improvements in performance even when operated with
conventional blender agitators which lack any adjustable pitch
feature.
A further object of this invention is the provision of an improved
agitator-cutter assembly and cooperative means by which the user
may safely and conveniently adjust the pitch of the blades while
the agitator and blender jar remain mounted on the blender motor
base.
Still a further object of this invention is the provision of an
apparatus of the foregoing type which may be produced competitively
with certain costly multi-speed blenders available on the market,
since the use of adjustable pitch blades, in accordance with my
invention, will enable a blender having one or two or at the most
three speeds, to outperform a multi-speed apparatus of
corresponding power.
Other and further objects and advantages of my invention will
become apparent as the following description of preferred
embodiments proceeds and the features of novelty which characterize
the invention will be pointed out with particularity in the
appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a vertical cross-sectional view of an agitator-cutter
assembly having a single cutter blade, in accordance with my
invention.
FIG. 2 is a similar view of a modified embodiment provided with two
cutter blades.
FIG. 3 is a perspective view of one embodiment of an
agitator-cutter blade unit, in accordance with my invention.
FIG. 4 is a similar view of another embodiment of an
agitator-cutter blade unit.
FIG. 5 is a top plan view of a coupling element, on an enlarged
scale.
FIG. 5a is a cross-sectional view taken substantially on line
5a--5a of FIG. 5.
FIG. 6 is a plan view of a modified embodiment of the coupling
element shown in FIG. 5.
FIG. 6a is a cross-sectional view taken substantially on line
6a--6a of FIG. 6.
FIG. 7 is a perspective view of a well known blender apparatus
embodying one form of my invention.
FIG. 8 is a similar view of another embodiment of my invention
which permits manual adjustment of the pitch of the agitator
blades, while the blender jar is on the base.
FIG. 9 is a similar view of another modified embodiment wherein
adjustment of the pitch of the agitator blades is effected by
reversing the direction of rotation of the blender motor.
FIG. 10 is a bottom plan view, partly in cross section and on a
reduced scale, of the agitator and jar nut illustrated in FIGS. 1
and 2.
FIG. 11 is a bottom plan view of a detail illustrated in FIG. 1
FIG. 12 is a bottom plan view of a modified embodiment of the
detail illustrated in FIG. 11.
FIG. 13 is a top plan view of a blank of one embodiment of a cutter
blade shown in FIG. 4.
FIG. 14 is a side elevational view thereof showing in broken lines
the final configuration of the cutter blade.
FIG. 15 is an end elevational view of the cutter blade illustrated
in FIGS. 13 and 14 in its final configuration.
FIG. 16 is a view similar to FIG. 13 of a modified embodiment of
cutter blade.
FIG. 17 is a view similar to FIG. 14 of the modified embodiment
illustrated in FIG. 16, and,
FIG. 18 is a view similar to FIG. 15 of the modified embodiment
illustrated in FIG. 16.
BRIEF DESCRIPTION OF A PREFERRED EMBODIMENT
Referring particularly to FIG. 1 of the drawings, the numeral 20
indicates generally an agitator-cutter and jar nut assembly which
is arranged to be threaded to the lower end of a container 200 in a
conventional manner. The jar nut 21 basically is an annular member
formed preferably of molded plastic having vertical ribs 25 to
facilitate handling and provided with internal threads 23 and an
inwardly directed integral flange 24. Rested on the flange 24 is a
support disc 26 having an annular offset portion and provided with
a central aperture in which is received a generally tubular shaft
housing 27, the housing being secured to the disc 26 as by swaging
or welding. The offset portion supports a gasket 201 which seals
the assembly 20 to the blender jar 200. A hollow shaft 28 is
rotatable in a bushing 29 press fitted in the housing 27. An
annular wedge shaped disc 31 having a lower face normal to the axis
of the disc and an upper face in non-parallel relationship to the
lower face, preferably at an acute angle .alpha. of approximately
8-12.degree. to the plane of the lower face, is suitably secured as
by swaging or welding to the upper end of the shaft 28. A thrust
washer/slinger 32, cup-shaped, substantially as illustrated in FIG.
1, rests on top of the bushing 29. Compressed between the disc 31
and slinger 32 is a ring 30 of elastomeric material which functions
both as a seal to prevent the ingress of any fluid or solid
material into the clearance space between the shaft 28 and bushing
29 and as a spring to provide a desired preloading on the washer
32. Suitably secured to the lower end of the shaft 28 is an
adjuster disc 33, shaped substantially as illustrated. Said disc
may be provided with knurls 34 on its periphery (FIGS. 10 and 11).
A pair of diametrically opposed drive dogs 36 (FIG. 11) are
integral with the under surface of the adjuster disc 33 and
function, as will be hereinafter explained. It will be noted that
the adjuster disc 33, shaft 28 and disc 31 are in fixed
relationship and rotate as a unit.
A drive shaft 37 is rotatably supported within the shaft 28 and has
an enlarged lower end which is pressed into the metal core 39 of a
drive coupling, indicated generally by the numeral 38, (FIGS. 5 and
5a), said metal core having on its upper surface opposed shoulders
41 adjacent to respective ratchet ramps 42 (FIGS. 5 and 5a). The
dogs 36 of the adjuster disc 33 (FIG. 11) cooperate with the
shoulders 41, as will be hereinafter explained. Fixed to the
underside of the core 39 may be a rubber coupling element 44a (FIG.
10) of conventional construction which comprises a plurality of
depending fingers arranged to interengage with similar fingers of a
cooperating coupling element carried on the motor drive shaft of
the blender base. Alternatively, an eight pointed star shaped
socket 44b may be provided in the enlarged end of shaft 37 (FIG.
10) to enable the shaft to couple to blenders having square drive
couplings. The upper end of the shaft 37 is provided with a pair of
diametrically opposed milled flats 46. An agitator-cutter blade
indicated generally by the numeral 48 and hereinafter to be
described in greater detail, is rested on the wedge disc 31 and is
surmounted by an elastomeric washer 49 and a flat washer 51, all
secured by upsetting the reduced end portion of shaft 37 as at 47.
The elastomeric washer 49 functions both as a seal to prevent
foreign matter from entering into the clearance area between the
shafts 37 and 28 and as a spring for providing an axial preload so
that the cooperating drive elements of the adjuster disc 33 and
coupling 38 are maintained in interengagement.
The cutter 48 (FIGS. 4, 13-15) includes a central hub portion 50
and oppositely disposed integral blades 51. The hub portion 50 is
provided with a centrally located rectangular slot 53 in which is
received the milled portion of the shaft 37. Thus, the cutter 48 is
keyed to rotate with the shaft 37 but because the slot is oversized
it is capable of being tilted angularly relative to the shaft axis,
as will be hereinafter made clear. The blades 51 are generally
triangular in form and connected by intermediate portions 51a to
the hub portion 50. One blade 51 extends upwardly in a plane
disposed typically at an angle of 45.degree. to the plane of the
hub portion 50. The other blade 51 extends downwardly in a plane
disposed typically at an angle of 60.degree. in relation to the
plane of the hub portion 50. Each of the blades 51 includes
compound bends (FIGS. 4, 13-15). The upwardly directed blade is
first bent along line a at an angle of substantially 90.degree. and
then is bent outwardly along line b at an angle of substantially
45.degree.. The two bend lines a and b are at an angle .beta.
relative to each other, said angle typically having a value of
approximately 8-12.degree.. Similarly, the downwardly directed
blade is bent down 90.degree. along line a' and outwardly
approximately 30.degree. along line b'.
In accordance with my invention, the cutter 48 may be operated in
two distinct attitudes or positions relative to the axis of
rotation in order to effect a change in the pitch of the blades in
relation to the axis of rotation. For example, in a first position
of the cutter 48, the angle .beta. is added to the wedge angle
.alpha. of the disc 31 with the result that the blades 51 assume a
first angular relationship with the axis of rotation based on the
sum of angles .alpha. and .beta.. In a second position, wherein the
position of the cutter 48 is rotated 180.degree., the angle .alpha.
is subtracted from angle .beta. of the wedge disc 31 with the
result that the blades 51 assume a second angular relationship with
the axis of rotation based on the difference between angles .alpha.
and .beta.. Thus, in accordance with my invention the pitch of the
blades may be changed to achieve different operational effects.
It will be understood that relative movement in the direction
counter to powered rotation between shaft 37 and hollow shaft 28 is
permitted. In powered operation the dogs 36 of adjuster disc 33
engage against the shoulders 41 of core 39 and effect simultaneous
rotation of these two parts so that disc 31 and shaft 37 rotate
together. In order to effect a change in the pitch of the blades
51, the drive coupling 38 is manually or otherwise rotated
180.degree. in a reverse direction while the adjuster disc 33 is
held stationary, as will be presently described. It will be
apparent that in such reverse rotation the dogs 36 will disengage
from the shoulders 41, ride over the ratchet ramps 42 and the
adjacent surfaces 39a of the coupling core 39 and snap into
engagement with opposed ratchet ramps 42 so that when the coupling
element 38 is again driven in a forward direction the dogs 36 will
engage with opposite shoulders 41. The blades 51 are now in a
different angular relation to the axis of shaft 37 and in rotation
they will produce an effect on the materials being processed in the
blender apparatus different from that produced when the blades are
disposed in the position first described. This results in a
significant improvement in performance and extends the usefulness
of the blender apparatus by enabling it to perform operations
heretofore either not possible or impracticable. Specifically, in
the higher pitch mode the blades are particularly well disposed for
coarse chopping whereas in the lower pitch mode the blades are
appropriately disposed for blending viscous fluids without
overloading the blender motor.
Although, as was hereinabove explained, the adjuster disc 33 may be
manually grasped at the knurls 34 and held in a stationary position
while the drive coupling 38 is being rotated, I have provided means
associated with the jar nut 21 to facilitate the foregoing
adjustment. Referring to FIG. 1 an elastomeric brake ring 56 is
disposed in the lower part of the jar nut 21 concentric with the
adjuster disc 33 and substantially in horizontal registration with
the knurls 34, the brake ring 56 being retained in position by a
snap ring 57. The brake ring 56 is provided with a plurality of
buttons 58 which project radially outwardly through openings in the
wall of the jar nut 21. Adequate clearance is provided between the
brake ring 56 and adjuster disc 33 so that the disc will not rub
against the ring in normal operation. In order to hold the adjuster
disc 33 stationary the operator is required merely to press against
a button 58 which effects deformation of the brake ring 56 and
causes an inner portion thereof to engage against the knurls 34,
thereby holding the adjuster disc stationary so that the drive
coupling 38 may be manually rotated 180.degree. to effect a change
in the pitch of the blades.
The modified embodiment of my invention illustrated in FIG. 2
utilizes a pair of cutters instead of the single cutter of the
embodiment of FIG. 1. For purposes of simplification the parts
which are common to both embodiments will be identified by
corresponding numerals.
A lower cutter 93, of generally conventional construction, and
wedge disc 31 are fixed to the hollow shaft 28 as by pressing
swaging or welding to form an integrated unit. The upper cutter
105, formed substantially as illustrated in FIG. 3, includes a hub
portion 108 having a rectangular drive slot 109 and upwardly
directed integral blades 111, presently to be described. The upper
cutter 105 includes compound bends substantially similar to those
of cutter 48, hereinabove described. Specifically, the cutter 105
is formed of a blank 107 (FIG. 16). The blades 111 are first bent
upwardly along lines c relative to the plane of hub portion 108 and
then outwardly along lines d at an angle of substantially
45.degree. relative to the axis of rotation (FIG. 17). Similarly,
as in the blade 48 the bend lines c and d are disposed at an angle
.beta. (FIG. 18) relative to each other. It will be apparent that
the wedge disc 31 and cutter 105 cooperate in the same manner,
hereinbefore described, to vary the pitch of the blades 111. The
blades 111 may be alternately tilted or pitched relative to the
axis of rotation to either of two positions, one position being
determined by the sum of the angles .alpha. and .beta. and the
other by the difference of the two angles, depending upon the
relative positions of the drive elements on the adjuster disc 33
and drive core 39.
My invention contemplates the use of suitable mechanical means for
effecting a change in pitch of the blades while the apparatus is in
use. FIG. 7 illustrates one embodiment, probably the most simple
form hereinabove referred to, whereby the jar 200 and agitator
assembly 20 are removed from the base 121 when it is desired to
change the pitch of the blades. Adjustment is manual, the same
being effected by the user pressing against one or more of the
brake ring buttons 58 with one hand while reversely rotating the
drive coupling 38 with the other hand.
In FIG. 8 there is shown an embodiment incorporating the features
of the invention in which the base 121 of the apparatus includes a
pair of levers 122 and 123 which project outwardly of a slot 124,
the said slot extending substantially half-way around the
circumference of the base 121 and terminating substantially at
diametrically opposite points. Levers 122 and 123 may be connected,
by appropriate means, not shown, to respectively engage the
adjuster disc 33 and drive coupling 38 to secure either one of said
parts against rotation while effecting rotation of the cooperating
part approximately one-half turn so as to dispose the blades in a
different relation, thereby to effect a change in the pitch of the
blades. It is considered that the means available for accomplishing
the foregoing result are clearly within the scope of one skilled in
the art and would not require the exercise of invention to
construct such mechanism. It will be understood that in this
embodiment either of the combinations of the cores and adjuster
discs, hereinabove described, could be employed.
FIG. 9 illustrates another embodiment in which the blender base
121a utilizes a motor which may be operated in two directions,
forward and reverse, the motor being controlled by button operated
switches 126 and 127. In this embodiment the agitator cutter blades
are sharpened along both edges so that they are operative in either
direction of rotation. This embodiment requires a modified coupling
core 101 (FIGS. 6 and 6a) and adjuster disc 33a (FIG. 12). The core
101 includes a pair of diametrically disposed radial drive dogs
116a and 116b which engage with similar drive dogs 36a and 36b on
the underside of adjuster disc 33a. This arrangement provides
nearly 180.degree. of backlash between the coupling core 101 and
the adjuster disc 33a. An annular shoulder 117 on core 101 affords
a bearing surface in engagement with the underside of adjuster disc
33a. Accordingly, when the blender motor is driven in a forward
direction the dogs 116a and 116b engage dogs 36a and 36b
respectively. When the motor is driven in a reverse direction the
dogs 116a and 116b are caused to engage dogs 36b and 36a
respectively, and shaft 37 moves about 180.degree. relative to
shaft 28. Accordingly, during forward rotation of the motor the
blades 51 or 111 will be pitched at one angle relative to the axis
of rotation and during reverse rotation, the blades will be
automatically adjusted to a second pitch angle different from the
first described position.
It will also be understood that my invention contemplates various
combinations utilizing the different cutter arrangements,
hereinabove described, with the different means for effecting a
change in blade pitch.
Various changes coming within the spirit of my invention may
suggest themselves to those skilled in the art; hence, I do not
wish to be limited to the specific embodiments shown and described
or uses mentioned, but intend the same to be merely exemplary, the
scope of my invention being limited only by the appended
claims.
* * * * *