Removable head rotary tool for food processors

A horizontal disc-like tool head is detachably mounted on an upper coupling portion of an elongated hub, while a lower coupling portion of the hub is adapted to be coupled to and rotated by the tool drive shaft of a food processor. The tool head has a receptacle underneath it for receiving the upper coupling portion of the hub, which has a flange-like configuration with spaced, projecting, peripheral teeth. The receptacle has a plurality of spaced, lip retainers which are adapted to receive and retain such teeth when the hub is inserted in an axial direction and then rotated about the tool axis for changing its angular orientation in the receptacle. The teeth and lip retainers have corresponding matching sizes, so that the hub properly fits into the receptacle in only one position, thus preventing incorrect insertion of the hub. A spring-loaded receptacle rod protrudes from the upper coupling member, and this retractable rod and its associated locking recess are offset from the axis of tool rotation for preventing removal of the hub from the receptacle, unless the rod is manually retracted by its release button. During manufacture, the receptacles in various tool heads may be provided with different size shims mounted between the receptacle and the lower surface of the tool head for producing slicing tool heads having different slicing thicknesses without changing hub length. Accordingly, one elongated hub can be used with several different tool heads.

FIELD OF THE INVENTION 
This invention relates to rotary food processing tools for food processors, 
and more particularly to such rotary food processing tools which are 
provided with removable heads, whereby the parameters and functions of the 
tool may be varied as desired by the user by positioning removable and 
interchangeable heads on an elongated hub without requiring the elongated 
tub or tool shank for each tool head. 
BACKGROUND OF THE INVENTION 
The present invention is applicable to food processors of the type having a 
working bowl with a motor driven tool drive means projecting upward into 
the bowl with which various selected rotary food processing tools can be 
engaged to be driven for performing various food processing operations in 
accordance with the desires of the user. A removable cover is secured over 
the top of the bowl during use. The cover includes a feed tube having a 
feed passageway which opens downwardly through the cover into the top of 
the bowl, and food items to be processed are placed in the feed tube and 
then pushed down through the feed tube into the bowl by means of a 
removable food pusher which is adapted to slide down in the manner of a 
plunger through the feed tube. The food items are sliced or otherwise 
processed by the rotating food processing tool in the top of the bowl. 
Additional information with respect to such food processors may be had by 
reference to U.S. Pat. Nos. 3,892,365--Verdun; 3,985,304--Sontheimer; 
4,198,887--Williams; 4,200,244--Sontheimer; 4,216,917--Clare & Sontheimer; 
4,213,570--Jones; 4,226,373--Williams; and 4,227,655--Williams. 
Of particular interest to the present invention are rotary food processing 
tools which are used for slicing, dicing, cutting, rasping, grating, and 
for making French fry slices or julienne slices and the like from food 
items, such as potatoes, onions, carrots, cucumbers, celery, cabbage, 
squash, etc. Such rotary food processing tools have a horizontal disc-like 
member formed of sheet metal, preferably of stainless steel, which is 
mounted on an elongated hub extending down in the bowl of the food 
processor and which is coupled near its lower end to motor-driven tool 
drive means. A horizontal cutting blade or other cutting or grating or 
rasping structure is associated with the horizontal disc-like member such 
that when items are cut they pass through one or more openings in the 
disc-like member into the bowl. The type of food processing which is 
performed by a rotary tool is determined by the type of cutting structure 
on the disc, the spacing and elevation of the cutting edges, the nature of 
the top surface of the disc, etc. 
In the prior art, in order to change the parameters or the particular 
cutting function of a rotary food processing tool, the entire tool is 
removed from the bowl and replaced by another entire tool. Accordingly, a 
multiplicity of separate tools each having an elongated hub and a flat 
horizontal disc-like member are kept on hand for performing different 
types of food processing operations. The elongated hub or shank projecting 
from each disc-like member of the respective rotary tools may cause a 
storage problem in crowded kitchens with little storage space, when there 
is a need for having on hand a multiplicity of individual rotary tools of 
different types. One solution to this problem is disclosed in copending 
application Ser. No. 274,719 which is assigned to the assignee of the 
present invention. This application is to another preferred embodiment. 
SUMMARY OF THE INVENTION 
Accordingly, it is an object of this invention to provide a new and 
improved rotary food processing tool in which the parameters and 
functioning of such tools can be varied without replacing the entire tool. 
A further object of this invention is to provide a new and improved rotary 
food processing tool which may provide a plurality of food processing 
functions by conveniently mounting a removable disc-like head on the 
elongated hub of the tool. 
Among the advantages of the present invention are those resulting from the 
fact that this invention provides a new and improved rotary food 
processing tool in which a plurality of removable disc-like heads are 
easily mounted upon or removed from the shank or hub of the rotary tool, 
thereby varying the parameters and functioning of the rotary food 
processing tool without requiring an individual shank for each tool. 
Still a further advantage of this invention is in the provision of a new 
and improved rotary food processing tool assembly for a food processor 
which enables the use of a single elongated hub or shank for different 
cutter heads, thereby providing a plurality of disc-like tool heads which 
may be stored relatively compactly. 
In carrying out this invention in one illustrative embodiment thereof, a 
removable head rotary food processing tool is provided for use in a food 
processor of the type having an upright working bowl in which the rotary 
tool is mounted for rotation therein by a motor drive means. There is a 
removable cover secured to the bowl for covering the bowl and the rotary 
tool, and a feed tube for feeding food items to the rotary tool in the 
bowl. The removable tool head has an elongated hub shank having an upper 
head coupling portion and a lower drive coupling portion adapted to be 
coupled to and rotated by the motor drive means. A horizontal disc-like 
tool head includes a disc-like member having a cutting structure thereon 
for processing food items applied thereto. The processed food items are 
directed through the cutting structure into the bowl. This disc-like tool 
head is removably mountable onto the upper coupling portion of said 
elongated hub, whereby other disc-like tool heads having different cutting 
structures for performing different food processing functions may be 
mounted on the same hub conveniently by changing heads without requiring a 
separate hub for each rotary tool. Manually releasable locking means are 
provided for preventing release of the tool head from the hub during 
operation. 
Among the many advantages of the present invention are those resulting from 
the fact that a single elongated hub or shank may be used for performing 
food processing operations simply by quickly and easily detachably 
mounting in locking engagement on the upper coupling portion of the hub 
various removable disc-like heads having different cutting structures. 
Since the horizontal disc-like tool heads, with the elongated hub 
detached, are relatively flat, they take up considerably less space, for 
example, when stored in a kitchen drawer, and are convenient to store in a 
stack one on top of another, rather than providing entire, separate rotary 
food processing tools for each operation to be performed at various times 
by the food processor. 
The tool head includes a socket receptacle on its underside, which 
comprises a plurality of spaced, lip retainers separated by a plurality of 
clearance notches. The upper coupling member has a plurality of spaced 
peripheral teeth extending therefrom which are adapted to fit into the 
notches between the lip retainers such that when the hub is axially 
inserted into the receptacle and then rotated relative to the tool head, 
the teeth become captured in the ledge retainers. A spring-loaded rod 
protruding from the hub and an associated locking recess in the receptacle 
are positioned off-center from the axis of rotation of the rotary tool for 
preventing removal of the hub from the tool head unless a release button 
attached to the rod is depressed for withdrawing the rod from its 
associated locking recess. By virtue of this receptacle, engagement 
between the tool head and the hub, they are securely and firmly attached 
for preventing or misalignment of the tool head as a result of stresses 
imposed during the processing of various food items.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Before describing in detail the removable head rotary tool, reference is 
first made to FIG. 5 which illustrates a portion of a food processor, 
indicated generally with the reference numeral 10. The food processor 10 
includes an upright working bowl 12 with a motor driven tool drive means 
14 in the form of a shaft extending up into the bowl. A removable cover 16 
having a feed tube 18 extending through the cover closes the bowl 12. At 
the same time, a cam surface 20 on the cover 16 depresses an actuator rod 
22 which closes a switch to enable operation of drive means (not shown) 
for driving the tool shaft 14. The feed tube 18 provides a feed passageway 
19 for introducing food to be processed into the working bowl 12. A 
removable pusher 21 is adapted to slide down into the feed tube 18 for 
pushing a food item 28 against the rotary processing tool. 
The rotary food processing tool, referred to generally with the reference 
numeral 25, includes a disc-like tool head 23 which is positioned near the 
cover 16 and has an elongated hub 24 with lower coupling means 26, for 
example such as a key or spline on the lower end of the elongated hub 
which is coupled to the motor-driven tool drive means 14 for rotating the 
tool 25. The upper end of the elongated hollow hub 24 carries a ledge-like 
upper coupling flange member 30 having a plurality of teeth 32 protruding 
from its periphery, which are separated by circumferential notches 34. The 
function of this upper head coupling member 30 will be described 
hereinafter. 
The upper end of the elongated hub 24 houses a spring-loaded rod 36 with a 
spring 38 which urges the rod upwardly, such that it protrudes out of the 
upper end of the hub 24. A manual release button 35 is attached to this 
rod which is adapted to retract the rod inward into the bore of the hub to 
release it from its locking engagement with the removable head in a manner 
to be described hereinafter. 
The rotary food processing tool 25 illustrated in FIGS. 1 and 5 has a 
removable head 23 including a slicing structure. The slicing structure is 
described merely for illustrating purposes but it will be appreciated that 
removable tool heads having other forms of cutting structures, such as 
graters, raspers, julienne and French fry cutters, etc., may be employed 
in practicing the present invention. 
As will be seen in FIGS. 1 and 5, the tool head 23 includes a horizontal 
disc-like member 40 of stainless steel having an opening 46 formed in its 
horizontal surface. This opening 46 extends from a region near the axis of 
rotation 74 out toward the depending peripheral skirt 42 on the disc-like 
member 40. The tool 25 rotates in a counterclockwise direction as shown by 
the arrow 47. The region behind the opening 46 is pressed upwardly to form 
an elevated platform 50 having a front lip 48. This lip 48 carries an 
arcuate hardened steel slicing blade 52 which is fastened in place by spot 
welding. The slicing blade 52, which is illustrated as having a slightly 
scalloped or serrated cutting edge projects forwardly partially over and 
above the arcuate opening 46. The elevated platform 50 has downwardly 
embossed strengthening ribs 54 and a gradually downwardly sloping rear 
shoulder 56 extending around behind the elevated platform 50. The 
configuration of the platform 50 is to facilitate the slicing of food 
items being processed by the food processor 10. As the items are sliced 
they will pass through the slot 46 into the bowl 22 with as little 
interference as possible from the sloping shoulder 56 of the platform 50, 
as described and claimed in the Sontheimer U.S. Pat. No. 4,200,244. 
As is indicated on the right hand portion of FIG. 5, the thickness H of the 
slice is determined by the vertical distance between the slicing blade 52 
and the horizontal member 40. 
Referring now to FIGS. 3-5, receptacle means, referred to generally with 
the reference character 60, is provided on the underside of horizontal 
member 40 of the removable head 23 which provides a means for detachably 
mounting the removable tool head 23 on the elongated hub 24. The 
receptacle 60 has a slightly larger than semi-circular base 62 with a 
plurality of spaced lip retainers 64 mounted thereon by rivets 66 attached 
to the horizontal member 40. Each lip retainer 64 is open at one end and 
has a stop 68 positioned on the opposite end for limiting the relative 
turning movement of the hub and for capturing the teeth 32 of the upper 
coupling member 30 in engagement with the lip retainers 64. The base 62 
also has a locking recess 70 which is adapted to capture and retain the 
end of the spring-biased retractable locking rod 36. 
It is to be noted that the lip retainers 64 are unevenly spaced; in other 
words, they are not symmetrically, circumferentially spaced, and that such 
spacing corresponds accurately with the circumferential spacing and size 
of the teeth 32 on the upper coupling member 30. This correspondence is 
very helpful to the user in that the upper coupling member 30 can 
consequently only be inserted into the receptacle means 60 in a single 
position, thus preventing the user from inadvertently attempting to mount 
the removable head 23 in an incorrect position on the hub 24. 
In use in order conveniently to mount the removable tool head 23 on the 
hub, the head is placed face down with the receptacle means 60 thereby 
being exposed. The flange-like upper coupling member, as shown in FIG. 2, 
is inverted and is inserted by the user into the receptacle means such 
that the teeth 32 are inserted into the clearance recesses separating the 
lip retainers 64. Since the spacing of the lip retainers and the spacing 
of the teeth 32 on the upper coupling member are each spaced unevenly in 
the same manner, proper alignment between the spaced teeth and the 
clearance recesses between the lips permits the insertion of the upper 
coupling member into the receptacle means 60 in only one position as is 
illustrated in FIG. 3. 
The hub 24 is then rotated in the direction shown by the arrow 72 on FIG. 4 
thereby turning the teeth into engagement with the spaced lip retainers 64 
until the respective teeth contact the stops 68. At this angular position 
of the hub relative to the tool head, the spring-loaded rod 36 comes into 
alignment with and projects into and is held in the locking recess 70 in 
the base 62. It is to be noted that the rod 36 is located in the bore of 
the upper portion of the elongated hub but this rod 36 is not in the axis 
of rotation 74 of the tool 25. Accordingly, once the rod 36 is in 
alignment with and enters the locking recess 70 in the base of the 
receptacle means 60, the removable tool head 23 can no longer be removed 
from the hub 24 unless the rod 36 is manually released. 
Therefore, the release button 35 must be actuated by the user to retract 
the rod 36 from the locking recess 70 in the base 62 in order to remove 
the tool head 23 from the hub 24. Thus, the combination of the 
non-symmetrical spacing of the lip retainers and the teeth 32 along with 
the operation of the locking rod 36 provides a positive, fail-safe 
alignment and locking relationship between the removable head 23 and the 
hub 24. 
As is illustrated in FIG. 5, the removable tool head 23 is detachably 
mounted on a dog-leg shank of the hub 24 such that the axis of the 
rotation 74 of the rotary tool 25 is offset from the region where the 
removable tool head 23 is joined or mounted on the hub 24. This is a 
preferred form of tool construction for the reasons described in U.S. Pat. 
No. 4,227,655 referred to above. However, the present invention is not 
limited to the offset hub, but is equally applicable to rotary tools with 
a hub which is aligned with the axis of rotation of the tool in the food 
processor 10. However, in such an embodiment in order to achieve the 
locking benefits of the rod 36, this rod is positioned off axis on the 
upper end of the hub 24. 
The periphery of the flange-like coupling member 30, including its 
circumferentially spaced teeth 32, is concentric with the axis of rotation 
74. Thus, the receptacle means 60 is concentrically mounted on the 
horizontal member 40 of the tool head 23. Consequently, when the coupling 
member is rotated into its fully engaged position in the receptacle, it is 
turned about the axis of rotation, but the locking rod 36 and recess 70 
are offset from this axis of rotation for locking the hub 24 against 
rotation relative to the tool head 23. The stops 68 are located to receive 
the thrust of the teeth 32 resulting from the torque applied to the hub 24 
by the tool drive means 14. 
As mentioned further above, the base 62 extends around the axis of rotation 
more than a semi-circle. In this embodiment, the angular extent of the 
receptacle base 62 is 225.degree., and the angular extent of the 
flange-like member 30 on the upper end of the hub is correspondingly 
225.degree., including three teeth 32 and two circumferential notches 34 
between neighboring teeth. 
In accordance with the present invention, a plurality of removable heads 23 
each having receptacle means 60 thereon will be provided, each of which 
has a different cutting structure for performing different food processing 
operations. Thus, a single hub may be utilized with a plurality of rather 
flat removable heads instead of having to provide each head with its own 
shank. 
In FIG. 5 the distance H representing the thickness of a slice is 
determined by the vertical spacing of the blade 52 from the horizontal 
member 40. In FIG. 6 the distance between the blade 52 and the horizontal 
member 40 is represented by H.sub.1, which is smaller than H thereby 
providing a thinner slice. This result is accomplished in FIG. 6 by 
inserting a shim 76 between the base 62 of the receptacle means 60 and the 
bottom of the horizontal member 40. 
In a similar fashion in FIG. 7 the distance H.sub.2 is achieved, 
representing yet a thinner slice, by providing a thicker shim 76 between 
the base 62 and the underside of the member 40. In other words, the 
removable heads 40 may be readily manufactured to perform different 
slicing functions, for example, thinner or thicker slices, simply by 
varying the thickness of a shim inserted between the base of a receptacle 
means and the underside of the member 40 without changing the length of 
the hub 24. 
As further assurance against the user attempting incorrect insertion of the 
hub into the receptacle, the last tooth 32' may have a slightly greater 
radial length than the others, and the region of the receptacle which 
receives the tooth 32' has a slightly greater radial clearance for such a 
longer tooth. 
Among the advantages of this removable head tool is the convenience in 
storing the removable tool heads each of which has a generally flat 
disc-like overall configuration. The rather flat overall configuration of 
the removable heads permits the various removable heads to be stored 
compactly and requires only one elongated hub 14 for all of the tool 
heads. 
Since other changes and modifications varied to fit particular operating 
requirements and environments will be apparent to those skilled in the 
art, the invention is not considered limited to the examples chosen for 
purposes of illustration, and includes all changes and modifications which 
do not constitute a departure from the true spirit and scope of this 
invention as claimed in the following claims and equivalents thereto.