Rotary grating device

A device is disclosed for efficiently grating and dispensing blocks of hand soap, comprising a housing and soap grating mechanism. The housing includes a tubular feed tower, a hollow cage and a funnel which collectively define a laterally enclosed passageway through which the soap travels. A grating disc is rotatably mounted in the housing, having an annular rim, a hub and a plurality of spokes connecting the hub and rim so as to define openings through which grated soap may pass. A long, thin, serrated metal band is mounted on the spokes in a continuous spiral between the hub and rim, forming a series of coils which define a planar cutting surface. The band is loosely wound, so that successive coils are spaced apart from each other a sufficient distance to easily permit soap shavings to drop through the space between adjacent coils. The rim of the grating disc comprises a cylindrical bearing surface and a plurality of radially extending gear teeth, which are seated in a stepped annular groove defined by the intersection of the cage and funnel. The feed tower has two rectangular paths into which correspondingly shaped bars of soap are placed, which hold the soap bars in contact with the cutting surface of the grating disc and off-center from its rotational axis. A rotator assembly, comprising a cog keyed to a crank and engaging the gear teeth at the periphery of the grating disc, turns the disc, causing soap shavings to fall through the disc and into the funnel which channels it into the user's hand.

This invention relates generally to the field of rotary devices for grating 
selected materials, especially fatty materials formed in solid blocks, 
such as cake soap, cheese and the like, which have a tendency to clog 
ordinary rotary graters. The invention is particularly well suited for use 
as a hand soap dispenser, as may be found in public washrooms where the 
grating and dispensing of measured amounts of soap is desired. 
BACKGROUND 
A wide assortment of rotary devices have been proposed for grating and 
dispensing measured amounts of hand soap and other fatty or waxy 
materials. For example, U.S. Pat. No. 969,204 (Shaver) discloses a soap 
dispensing machine having a cloverleaf shaped cutting blade axially 
mounted in an enclosure and coupled to a hand crank for rotating the blade 
while soap is pressed against its upper surface. U.S. Pat. No. 1,502,347 
(Nelson) describes a soap dispenser having a rotating conical cutting 
surface with curved blades projecting upwardly from the inner surface of 
the cone, which is peripherally seated on an annular ridge and rotated by 
a hand cranked beveled gear mounted at its periphery. U.S. Pat. No. 
673,662 (Schwechler) discloses yet another rotary design, in which a group 
of axially projecting serrated blades are mounted in a peripheral ring 
which is rotatably mounted at the output of a square, tubular enclosure. 
While such devices have experienced varying degrees of commercial success, 
a common problem continues to be the tendency of existing grating devices 
to clog and/or stall, depending on the design of the cutting mechanism and 
the consistency of the material being grated. Clogging occurs when the 
material being grated builds up in the teeth or projections of the cutting 
blade, causing the blade to slide past the opposing block of material 
without cutting into it. Stalling occurs when the blade digs so deeply 
into the material that it becomes difficult or impossible to turn any 
further. In either event, the cutting effectiveness of the blade is 
reduced or rendered useless until it is cleared. Moreover, episodes of 
clogging or stalling generally increase the mechanical loading on the 
cutting mechanism, resulting in higher material and manufacturing costs 
for devices designed to handle these loads. Accordingly, there exists a 
need for a rotary grating device which minimizes or eliminates clogging 
and stalling, is strong enough to withstand regular use and yet is simple 
and inexpensive to manufacture. 
It is therefore an object of the present invention to provide an improved 
rotary grating device which addresses these and other deficiencies in 
prior art designs. 
SUMMARY OF THE INVENTION 
In accordance with an illustrative embodiment of the present invention, an 
improved rotary device is disclosed which is designed for efficiently 
grating and dispensing a selected material, such as hand soap. In one form 
of the invention, a housing is provided which defines a laterally enclosed 
passageway having an input end and an output end, with a grating disc 
rotatably mounted in the housing. The grating disc has an annular rim, a 
hub and one or more spokes connecting the hub and rim so as to define an 
open space between the hub and rim through which grated material may pass, 
with a serrated band spirally mounted on the spoke. The housing and 
grating disc are mutually configured such that substantially all of the 
material passing from the input end to the output end of the passageway 
must pass through the grating disc before exiting, a rotator is coupled to 
the housing which engages the grating disc so as to selectively induce its 
rotation. 
Another form of the present invention also provides a housing defining a 
laterally enclosed passageway having an input end and an output end, the 
housing having an annular groove with opposed groove surfaces encircling 
the passageway. A grating disc is rotatably mounted in the groove and 
engages the opposed groove surfaces so as to be restrained against 
movement in either axial direction. The disc comprises a cutting surface 
adapted for grating the selected material, the cutting surface having at 
least one opening through which grated material may pass. The housing and 
grating disc are mutually configured such that substantially all of the 
material passing from the input end to the output end of the passageway 
must pass through the grating disc before exiting, and a rotator is 
coupled to the housing which engages the grating disc so as to selectively 
induce its rotation. 
Yet another form of the present invention provides a housing defining a 
laterally enclosed passageway having an input end and an output end, the 
housing having a tubular feed tower, a cage and a funnel respectively 
defining an upper, middle and lower portion of the passageway. The cage 
includes a hollow shell having opposed input and output ports for passage 
of the selected material and a bearing surface about its inner periphery. 
The funnel defines an annular ridge encircling the passageway, and is 
detachably mounted to the cage at the output port. A grating disc is 
rotatably seated on the annular ridge, having a cutting surface adapted 
for grating the selected material and a peripheral bearing surface which 
faces the bearing surface of the cage and is laterally supported by it. A 
rotator is coupled to the housing, which engages the grating disc so as to 
selectively induce its rotation.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
The invention will be discussed with reference to a preferred embodiment 
which illustrates the inventive concepts in the context of a stationary, 
hand-operated device for dispensing grated soap, as may be found in public 
restrooms and the like. While this embodiment is used for illustrative 
purposes, it will be understood that the invention lies in the combination 
of various elements found in the device, and may be practiced in many 
forms, including but not limited to soap dispensers. 
Referring now to the drawings, FIG. 1 illustrates a grating device, or 
dispenser 101 according to the invention. Dispenser 101 is shown mounted 
to a wall 103 by screws 105, and is operated by rotating a hand crank 107 
to grate and dispense soap into the user's hand. 
FIG. 2 is a fragmented perspective view from the back of the dispenser, 
showing the soap grating mechanism 109 in more detail. Dispenser 101 
comprises a plastic enclosure 111, which supports the grating mechanism 
and protects the contents from contamination by dirt or fluids that may be 
present in the wash room environment. Enclosure 111 comprises a curved, 
vertical sheet 113 having a U-shaped cross section, as seen in FIG. 4, and 
a removable lid 114. The base of sheet 113 bends inwardly, forming a 
horizontal platform 115 which supports the soap grating mechanism 109, as 
seen in FIGS. 3 and 5. Vertical flanges 117 bend outwardly from the ends 
of the U-shaped vertical sheet 113, as seen in FIGS. 2 and 4, enabling the 
dispenser to be mounted to a wall 103 or other supporting surface by 
screws 105 or like fasteners. 
Funnel 119 is seated in the base of enclosure 111, and comprises a 
truncated plastic cone 121 having a wide, circular mouth 123 for 
collecting grated soap and a narrow opening 125 for dispensing the soap 
into the user's palm. A horizontal flange 127 extends outwardly from the 
rim of mouth 123, as seen in FIGS. 3 and 5, and rests on platform 115 with 
cone 121 extending down through a large circular opening 129 in the center 
of the platform. The transition from horizontal flange 127 to cone 121 
defines an annular ridge 130 which provides a bearing surface for soap 
grating mechanism 109, as discussed below. 
Soap grating mechanism 109 is seated on top of funnel 119 and attached to 
enclosure 111 with screws 131, which extend upwardly through horizontal 
platform 115 and flange 127 as seen in FIG. 5. Grating mechanism 109 
comprises a grating disc 133, cage 135, rotator assembly 137 and feed 
tower 139. Grating disc 133 is rotatably mounted between funnel 119 and 
cage 135, with its outer periphery resting on annular ridge 130 as seen in 
FIGS. 2 and 5 and described more fully below. Feed tower 139 is designed 
to hold two rectangular bars of soap 141 in contact with the upper face of 
the grating disc (FIG. 3). When rotated by rotator assembly 137, disc 133 
grates the soap into small shavings which drop through the disc and are 
funneled into the user's hand by cone 121. 
As seen in FIGS. 6 and 7, grating disc 133 comprises a molded plastic wheel 
143 with a serrated metal band 145 spirally mounted on its upper surface. 
Wheel 143 comprises an annular rim 147, a central hub 149 with an axially 
disposed access hole 150, and eight radially oriented spokes 151 
connecting the hub to the rim and defining seven pie-slice shaped openings 
153 which enable grated soap shavings to pass through disc 133 and into 
cone 121. The periphery of rim 147 is formed with a plurality of gear 
teeth 154 extending radially outwardly, enabling the grating disc to be 
rotated by rotator assembly 137, as described more fully below. A vertical 
flange 155 with a cylindrical outer surface extends upwardly from rim 147, 
forming a continuous bearing surface about the periphery of wheel 143 
which centers and supports it during rotation. 
Band 145 comprises a long, thin flexback bandsaw blade of hardened chrome 
plated spring steel, with serrated cutting teeth 156 of a hookback design 
along its upwardly facing edge. It is wound in a continuous spiral from 
hub 149 to annular rim 147, supported by each of the spokes at a plurality 
of intersections 157 between the hub and the rim. The band is loosely 
wound, so that successive coils of the band are spaced apart from each 
other a sufficient distance to easily permit soap shavings to drop through 
the space between any two adjacent coils. In the preferred embodiment, 
which is designed for use with Cra-Z Soap.TM. or other soaps of similar 
consistency, grating disc 145 has an outer diameter of 5.112", the height 
and thickness of the band are 0.25" and 0.03", respectively, cutting teeth 
156 are 0.06" high and spaced 6 teeth per inch, the distance between 
adjacent coils of the band is typically 0.56", and the band spirals 
through 1,350 degrees of rotation, or 33/4 complete coils. Variations may 
be made from these dimensions depending on the consistency of the material 
being grated and the desired size of the shavings, as is well known in the 
art. 
Each of spokes 151 is formed with several pairs of closely spaced, 
vertically oriented cylindrical posts 158 on its upper surface 159. Band 
145 is mounted to the spokes by press fitting it between the pair of posts 
at each of intersections 157, as seen in FIG. 7, with the lower edge of 
the band resting against upper surface 159, thus maintaining the cutting 
teeth in a substantially planar array across the upper face of grating 
disc 133 so as to form a flat grating surface. The height of the posts is 
less than the distance from the lower edge of the band to the base of the 
cutting teeth, so the posts do not interfere with the cutting action of 
the teeth. 
The diameter of grating disc 133 is slightly greater than the inner 
diameter of annular ridge 130, as seen in FIG. 5, so that at least the 
outer portion of annular rim 147 rests on and is vertically supported by 
the ridge, which provides a bearing surface for the rotation of wheel 143. 
The compositions of flange 127 and annular rim 147 are selected to provide 
a low friction interface between the two, enabling the grating disc to be 
easily rotated. The disc rotates freely within cage 135, which traps the 
wheel between its inner surface 161 and flange 127, restraining the wheel 
from moving laterally or upwardly. 
Cage 135 comprises a hollow, circular plastic shell with opposed input and 
output ports 162, 164 leading, respectively, to the interiors of feed 
tower 139 and funnel 119. Cage 135 comprises a peripheral rim with a 
stepped cross-section, as seen in FIGS. 4 and 5. The lower step 163 of the 
shell encloses the gear teeth 154 of annular rim 147 between its inner 
surface 161 and flange 127, while the upper step 165 has a vertical 
cylindrical inner surface 167 which opposes and fits closely about the 
outer periphery of vertical flange 155, providing a lateral bearing 
surface for wheel 143. The intersection of annular ridge 130 with inner 
surface 161 thus defines a two-step annular groove 168 encircling the 
passageway defined by feed tower 139, cage 135 and funnel 119. Annular rim 
147 is seated in this groove such that the grating disc is fully supported 
and suspended thereby in the portion of the passageway between feed tower 
139 and cone 121. The opposed surfaces of annular groove 168, defined by 
the upwardly facing horizontal surface of annular ridge 130 and the 
downwardly facing portions of inner surface 161, support grating disc 133 
and restrain it from movement in either axial direction, and the 
cylindrical inner surface 167 of the annular groove supports the disc and 
restrains it from lateral movement. 
Cage 135 further comprises a square frame 169 which projects upwardly from 
the top surface of upper step 165, surrounding a narrow ledge 171 and 
support strut 173 on which feed tower 139 rests. Frame 169 provides 
lateral support to the feed tower, which is connected to the cage at 
support strut 173 by screw 175. 
Feed tower 139 acts as a guide member for feeding soap into the grating 
disc. It comprises a square plastic tube 177 with a longitudinal divider 
179 extending down the center of the tube and defining two identical 
tubular paths 181 with rectangular cross-sections, as seen in FIG. 4. The 
upper and lower ends of the feed tower are open, enabling soap bars 141 to 
be inserted in the upper end and laterally supported by the walls of the 
tower while resting against the cutting teeth 156 of grating disc 133, as 
seen in FIGS. 3 and 5. The non-circular cross sectional shape of tubular 
paths 181 prevents the correspondingly shaped soap bars from spinning 
inside the feed tower as the grating disc turns. Additionally, the 
positioning of paths 181 relative to the grating disc is such that each of 
the soap bars contacts the upper face of the disc off-center from its 
rotational axis, minimizing the tendency of the rotating grating disc to 
make the soap bars spin inside the feed tower and maximizing the grating 
action of the disc. 
Rotator assembly 137 comprises crank 107, cog 183, inner and outer support 
plates 185 and 186, and circlip 187. Cog 183 is positioned perpendicular 
to and on the periphery of grating disc 133, with its teeth 189 engaging 
gear teeth 154 of the disc. The cog is keyed to shaft 191 of crank 107, so 
as to rotate when the crank is turned. Shaft 191 passes through a hole 193 
in enclosure 111 and is journaled in inner support plate 185 on one side 
of the cog and outer support plate 186 on the other side. Inner support 
plate 185 is formed as part of cage 135, projecting vertically upwardly 
from the top surface thereof. Outer support plate 186 is fixed to the 
inner surface of vertical sheet 113, as by glue or the like. 
In operation, dispenser 101 is loaded by removing lid 114 and placing a 
soap bar 141 into each of the paths 181 in feed tower 139. When crank 107 
is turned, cog 183 rotates, causing grating disc 133 to rotate inside cage 
135. Serrated band 145 rotates with the disc, causing cutting teeth 156 to 
scrape across the bottom surfaces of soap bars 141, grating the soap into 
fine shavings. The spiral mounting of band 145 prevents teeth 156 from 
digging concentric grooves in the soap bars, thus avoiding the clogging 
problem commonly found with other rotary grating mechanisms. The soap 
shavings fall from the spiral band through the pie-slice shaped openings 
153 of wheel 143, and into cone 121, which funnels them through cone 
opening 125 into the user's hand. 
Having thus described the structure and operation of the preferred 
embodiment in detail, it will be seen that dispenser 101 is a device for 
grating a selected material, such as Cra-Z Soap.TM.. The feed tower 139, 
cage 135 and funnel 119 form a housing which defines a laterally enclosed 
passageway having an input end at the top of feed tower 139 and an output 
end at the opening 125 of the funnel. Grating disc 133 is rotatably 
mounted in this housing, and comprises an annular rim 147, a hub 149 and 
spokes 151 connecting the hub and rim so as to define openings 153 between 
the hub and rim through which grated soap may pass, and a serrated band 
145 spirally mounted on the spokes. The housing and grating disc are 
mutually configured such that all or substantially all of the soap passing 
from the input end to the output end must pass through the grating disc 
before exiting the enclosed passageway. Rotator assembly 137 is coupled to 
the housing and engages the grating disc so as to selectively induce 
rotation of the disc when crank 107 is turned. 
From the foregoing description it will be apparent that variations may be 
made in the disclosed device without departing from the basic principles 
of the various aspects of this invention. For example, while the preferred 
embodiment is designed for stationary operation as a soap dispenser, the 
invention works equally well for grating other materials, especially fatty 
or waxy materials having a consistency similar to that of cake soap, which 
have a tendency to clog ordinary rotary graters. One such use would be for 
grating cheese, in which case the dispenser may be designed for hand held 
use rather than wall mounting. Similarly, the dispenser could incorporate 
other mechanisms for rotating the grating disc, including electrically 
powered rotary mechanisms, as are well known in the art. Other variations 
may be made in the size and shape of the dispenser, to suit the type of 
grating operation for which it will be used. Likewise, grating devices 
according to the invention may be made from other materials than those 
described above, using other manufacturing methods as are well known in 
the art. 
Many other modifications to the invention disclosed above will be apparent 
to those skilled in the art, and it should be understood that this 
invention includes all modifications falling within the scope of the 
following claims.