Patent Application
20060213375
None
The present invention relates generally to fruit and vegetable juicers. A fully electrically powered juicer which requires no manual manipulation of the fruit or vegetables to be juiced is disclosed in my prior U.S. Pat. No. 6,050,180 issued Apr. 18, 2000.
The juicer of the present invention is electrically powered but has a top with an upwardly extending head of generally rounded conical shape with protrusions against which a fruit or vegetable to be juiced may be held manually and rotated manually while the head is also rotated under power supplied by an electric motor. The motor may be provided in a lower housing to which a separate juicer attachment may be attached when desired or the motor housing and juicer may be permanently attached together.
A cross sectional view of a juicer attachment of the prior art is shown in
It has been found that heat buildup and bearing failure is a substantial problem in the prior art juicers discussed above because the motor is frequently left on for long periods of time, particularly in commercial establishments such as restaurants and because the motor is always attached in driving relationship to the jrotary straining and juicing basket.
An improved juicer or juicer attachment in which heat build up and wear induced by operation of the motor for protracted periods of time is significantly reduced and which is suitably quiet in operation is therefore desired.
Disclosed herein is an electrically powered juicer which includes a motor housing, a gear cover and a rotary straining and juicing basket having a protruding juicer head for engaging fruit or vegetables to be juiced. The gear cover is preferably latched to the motor housing but may be affixed by other means to the motor housing.
More particularly, a separate juicer attachment is disclosed for mounting on a housing containing a motor having a rotary drive shaft. The attachment comprises:
a) an upper cover having a side wall and a bottom wall having an aperture for receiving a drive shaft;
b) a lower cover having an aperture for receiving a drive shaft, the lower cover being attached to the upper cover, the upper and lower covers defining a gear chamber;
c) an upper drive shaft slidably mounted in the aperture in the upper cover;
d) a rotary straining and juicing basket supported on the upper drive shaft in the upper cover;
e) a lower drive shaft telescopically engaged with and rotatable relative to the upper drive shaft, the lower drive shaft having a drive coupling thereon for engaging a drive coupling s driven by a motor;
f) gears in the gear chamber for transferring power from the lower drive shaft to the upper drive shaft; and
g) at least one spring biasing at least one of the upper and lower drive shafts upwardly relative to the covers to normally disengage at least two gears in the chamber.
As best seen in
The attachment 20 further includes a lower cover 50, also preferably formed of molded plastic, having a top wall 52 with a peripheral groove 54 forming a seat for receiving the lower end of the cylindrical wall 38 of the upper cover 30 such that the covers 30, 50 may be connected together, by screws or in any other suitable manner, to form a gear chamber 56. The top wall 52 also includes a central aperture 58 which provides a seat for a lower mounting bushing 60 for the drive shaft. The lower mounting bushing 60 preferably comprises an integrally formed sleeve and collar 62 of lubricious material such as PEEK and a washer 64 preferably formed of nylon seated on the upper surface of the collar 62.
A rotary straining and juicing basket 70 is supported on the upper end of an upper drive shaft and includes a side wall 72, a bottom wall 74 having perforations preferably formed as slots 75, an upwardly extending juicer portion 76 in the form of a rounded cone having projections for engaging fruit to be juiced and a downwardly extending drive sleeve 78 having inwardly facing one way drive cam surfaces 80.
The rotary straining and juicing basket 70 is rotated by an upper drive shaft 9010 having a downwardly extending sleeve 92 slidably mounted in the upper mounting bushing 44 in the central aperture 40 in bottom wall 34 of the upper cover 30. The upper end of the upper drive shaft 90 is received in the downwardly extending drive sleeve 78 of the juicer basket 70. One way drive cam surfaces 94 (
The upper drive shaft 90 is telescopically connected to a lower drive shaft 100 having a lower end extending through the lower mounting bushing 60 and washer 64. A drive coupling 102 is affixed to or formed on the lower end of the lower drive shaft 100. In the embodiment shown, the drive coupling 102 is in the form of a disc having a lower face, preferably of rubber or synthetic material which provides a friction surface for engagement with similar friction surface on an upwardly facing end of a drive coupling on the upper end of a drive shaft (not shown) of an electric motor contained in a lower housing 140 which includes a n upwardly facing receptacle 142 with a spout 144, shown in
A gear train is enclosed in the gear chamber 56 for reducing the rotary speed imparted to the lower drive shaft 100 by the motor drive shaft, typically about 3600 RPM, to rotate the upper drive shaft 90 and attached rotary straining and juicing basket 70 at a speed of about 200 RPM—i.e., a reduction ratio of 18:1 in the preferred embodiment. The gear train may take any suitable configuration and include any suitable number of gears for establishing a speed reduction ratio of choice. In the arrangement shown, the gear train is comprised of a pinion gear 120 non-rotatably affixed to the lower drive shaft 100, a speed reduction gear 122 having outer teeth and inner teeth, and an output gear 124. The speed reduction gear 122 is mounted on a shaft s 123 extending between seats formed in the upper and lower covers 30, 50. The outer teeth of the speed reduction gear 122 are normally disengaged from the teeth of the pinion gear 120 due to the upward bias of spring 98 on the upper drive shaft 90 and the inner teeth of the speed reduction gear 122 are continuously engaged with the teeth of the output gear 124 which is non-rotatably affixed to the sleeve 92 of the upper drive shaft 90. The teeth of the pinion gear 120 are engaged 10 when desired with the outer teeth of the speed reduction gear 122 by pushing a fruit or vegetable to be juiced downwardly onto the juicer cone 76 against the bias of spring 98. The rotary straining and juicing basket 70 then pushes the upper drive shaft 90 and the lower drive shaft 100 therein downwardly against the bias of the spring 98 and against the bias of another coil compression spring 130 mounted on the lower drive shaft 100 and seated between the lower face is of the pinion gear 120 and the washer 64 on the lower mounting bushing 60 to bring the teeth of the pinion gear 120 into horizontal alignment with the outer teeth of the speed reduction gear 122. The springs 98 and 130 thus function to normally disengage at least two gears in the gear chamber 62. Those skilled in the art will understand other configurations of springs which do not encircle the lower drive shaft may be substituted.
In the arrangement described, the spaced bushings 110, 112 between the upper drive shaft 90 and the lower drive shaft 100 ensure concentric alignment of the two shafts while the air space between the bushings efficiently dissipates heat. By using one or more springs 98, 130 to normally disengage gears in the gear train, the motor may be allowed to run continuously s for protracted periods of time without causing rotation of the lower or upper drive shafts, gears or the rotary straining and juicing basket while the rotary parts of the juicer attachment remain stationary. The associated heat build up and wear of all of the bushings 44, 60, 110, 112 is thereby significantly reduced as compared with prior designs.
The disclosed co-axial arrangement of the telescopically engaged lower and upper drive shafts and gears which effectuate an 18:1 speed reduction from the speed of an exemplary electric motor output shaft aligned with the lower and upper drive shafts significantly reduces heat, noise and wear and of course the specific arrangement disclosed is by way of example rather than limitation.
Persons skilled in the art will readily appreciate that various additional modifications can be made from the presently preferred embodiment thus the scope of protection is intended to be defined only by the appended claims.
