United States Patent 3834625

In an apparatus with rotary jets of the kind wherein the jet unit is rotatably carried by a support which rotates about an axis perpendicular to the axis of the said unit (as for instance, the axis of the jet unit being horizontal and the axis of the support vertical), the support drives the jet unit through a speed reducing gearing with perpendicular axes (as for instance a worm gearing) which receives its motion from a planet pinion carried by the support and in mesh with a fixed crown gear, the number of teeth on the pinion and on the crown gear being incommensurable so that the jet unit is at different angular positions after each full revolution of the support.

Application Number:
Publication Date:
Filing Date:
Primary Class:
Other Classes:
239/214, 239/264
International Classes:
B05B3/02; (IPC1-7): B05B3/00; B05B13/06
Field of Search:
View Patent Images:
US Patent References:
3544012PRESSURE JET TANK CLEANER1970-12-01McNally
3472451TANK WASHING APPARATUS1969-10-14Orem et al.
3255969Apparatus for cleaning tanks1966-06-14Saad
2947482Tank washing apparatus1960-08-02Lione
2917243Tank washing apparatus1959-12-15Lione
2714080Tank cleaning device and method1955-07-26Kennedy et al.

Primary Examiner:
Ward Jr., Robert S.
Attorney, Agent or Firm:
Dowell III, Arthur E.
I claim

1. A vat descaling apparatus of the type comprising:

2. In apparatus as set forth in claim 1, said driving means comprising a shaft housed within the hollow column; a drive motor for said shaft at the upper end of the column; reduction gearing disposed between the motor and shaft; a cylindrical hub carried by the lower end of said shaft, said hub having journaled therein the said worm.

3. In apparatus as set forth in claim 2, an annular flange fixed to the lower end of the hollow column; and a ring gear fixedly mounted on the lower end of said annular flange and forming said stationary annular gear.

4. In apparatus as set forth in claim 2, said shaft of the driving means being hollow below the motor and being connected to a supply of fluid under pressure, the lower end of said shaft communicating with a fluid duct extending downwardly into said hub; said hub having a cylindrical part in which the jet-carrying shaft is journaled in spaced relation to the walls thereof; an annular sleeve in said cylindrical part disposed around said jet-carrying shaft and communicating with the said duct of the hub for confining fluid from the said duct around said jet-carrying shaft; said jet-carrying shaft being hollow from said annular sleeve to the outer end of said shaft, and having ports therearound in way of the sleeve for conducting said fluid from said ports to the outer end of the jet-carrying shaft for spraying purposes.

The present invention relates to improvements to apparatus with rotary jets, used for descaling vats or the like.

It is known that apparatus of the type in question generally comprise a rotating shaft provided with a series of jets supplied with liquid or pressurised water, so as to sweep the whole of the interior wall of the vat to be cleaned. This jet-carrying shaft is mounted in a support, which is itself rotated about an axis perpendicular so that of the said shaft.

In known apparatus, the jets are so arranged that it is the reaction of the water which drives the jet-carrying shaft and the rotating support. It will be understood that, for correct operation, the water must be admitted to the apparatus at a very high pressure; now, such a pressure is not always available. Furthermore, braking means must be included in the apparatus to prevent accidental racing of the mobile organs; these means complicate the construction of the apparatus and increase its weight and price.

The improvements which form the object of the present invention are intended to permit construction of a simplified apparatus which, however, descales efficiently.

The apparatus in accordance with the invention is characterised in that the support of the jet-carrying shaft is rotated by a drive organ and drives the said shaft through a gearing-down mechanism with perpendicular axes, driven by a planet pinion which is mounted on this support and engages with a fixed, toothed ring-gear, the numbers of teeth on the planet pinion and on the ring-gear being incommensurable, so that the jet-carrying shaft has a different angular orientation after each revolution of the support.

It will be understood that such an apparatus does not require a very high water-pressure, as the mobile parts are driven not by the water, but by an independent drive organ. Any braking mechanism can obviously be dispensed with, and this simplifies construction and reduces the weight and cost of the assembly. Trials have shown that, due to the angular shift of the jet-carrying shaft after each revolution of the support, the efficiency of the apparatus was comparable to that of known apparatus.

The attached drawings, given by way of example, will lead to a better understanding of the invention:

FIG. 1 is an elevation of a descaling apparatus in accordance with the invention.

FIG. 2 is an axial section of the lower portion of this apparatus, to a larger scale.

FIGS. 3 and 4 are diagrammatic sections along the lines III--III (FIG. 2) and IV--IV (FIG. 3) respectively.

FIG. 5 shows the kinematic sequence of the mobile parts of the apparatus in accordance with FIGS. 1 to 4.

The apparatus shown in FIG. 1 comprises a base 1, so shaped as to bear against the edge of the openings in the vats to be descaled. This base 1 carries an electric, pneumatic or hydraulic drive motor 2, the said motor being associated with reduction gearing 3. On the side opposite to assembly 2-3, base 1 is rigidly attached to a vertical column 4, forming a housing for the output shaft of reduction gearing 3; this shaft 5 is in tubular form, its interior space communicating through a swivel joint with a fixed pipe 6, to which is connected a feed channel 7.

As shown in FIG. 2, the lower end of fixed column 4 is provided with an annular flange 8, forming a support for a toothed ring-gear 9, the axis of which coincides with that of the said column 4 and of drive shaft 5. In the same way, the base of shaft 5 is rigidly connected to a cylindrical hub 10, centered inside column 4 by a bearing 11. This hub 10 is hollow to form a crooked channel 10a, the upper opening of which communicates with the interior space of shaft 5.

A cylindrical part 13 is fixed against the lower, suitably shaped face of hub 10, by a series of screws 12, and is thus rotated simultaneously with hub 10 and shaft 5; a packing 14, associated with a stop 15 rigidly attached to the base of toothed ring-gear 9, ensures the tightness of the rotation of the assembly or support 10-13 relative to the said ring-gear 9. Piece 13 has a transversal bore at 13a to form a housing for a sleeve 16, inside which a horizontal, tubular shaft 17 is mounted in cantilever; the interior space 17a of this shaft 17 is connected by borings 17b and an annular port 18, to a channel 13b, formed in part 13 so as to open opposite the lower end of the above-mentioned crooked channel 10a.

The end of shaft 17 which projects laterally beyond piece 13, carries a head 19, which is radially threaded to receive two arms 20, provided with a nozzle or jet 20a with a calibrated insert. Between this head 19 and one of the two bearings 21 which support it in part 13, this shaft 17 is provided with a hollow toothed wheel 22, suitably keyed on the periphery of the said shaft; this wheel 22 engages with a worm 23 (FIGS. 4 and 5) rigidly attached to a stub shaft 24, mounted in bearings 25 introduced into a vertical bore 13c in part 13. The top of stub shaft 24 receives a pinion 26, which co-operates with the teeth of ring-gear 9 in the manner or a planet-wheel.

It should be noted that the numbers of teeth on ring-gear 9 and on planet pinion 26 are incommensurable. To crystallize these ideas in a precise example which, however, is in no way of a limiting nature, it may be supposed that ring-gear 9 has 59 teeth, while pinion 26 has 15. The reduction ratio between this pinion 26 and the hollow wheel 22 which co-operates with worm 23 is variable, the said wheel having thirty teeth in the example in question.

The operation and use of the apparatus described above will be easily understood. Column 4 is inserted into the vat to be descaled, base 1 resting against the edge of the opening in the latter. Motor 2 is started simultaneously as channel 7 is connected to a supply of pressurised liquid or water.

Assembly or support 10-13 is thus rotated continuously relative to ring-gear 9, which is held angularly fixed by column 4. Planet wheel 26 carried by the above-mentioned assembly engages with ring-gear 9, so that stub shaft 24 is rotated, this movement being communicated to jet-carrying shaft 17 by reduction worm-gear mechanism 23-22. Jet-carrying arms 20 therefore spin about the axis of this shaft 17, simultaneously as support 10-13 moves angularly about the axis of drive shaft 5. The water which enters this shaft 5 passes through channels 10a and 13b, is admitted to shaft 17 through port 18 and borings 17b and is projected through jets 20a against the interior wall of the vat to be cleaned.

It will be appreciated that the apparatus can operate with absolutely any liquid pressure. Of course, this liquid can be heated to improve descaling, or a detergent or solvent may be added to it. Moreover, and principally, the way in which jet-carrying shaft 17 is driven by pinion 26 and ring-gear 9 ensures continuous sweeping of the vat wall, with the introduction of a jet shift effect at each rotation. Returning to the numerated example given above, it will be understood that, taking into account the two jets of the apparatus, at the end of thirty revolutions of drive-shaft 5, the said jets will have adopted 60 different positions, so that there is in effect an impact point every 6. After this first cycle, support 10-13 commences a second cycle of 30 revolutions, during which the jets will adopt 60 new angular positions, staggered relative to the first ones by 0.8 of angle. In short, for jet-carrying shaft 17 to return to its initial angular position, it must effect seven and one half cycles, or in all 225 revolutions of shaft 5. If it is supposed that this shaft rotates at 15 revolutions per minute, the operations as a whole will last 15 minutes, with a very concentrated sweep (an impact every 0.8 of angle).

It is self-evident that the user can decrease the number of cycles, depending upon the nature of the work to be carried out, e.g., if the vat in question only requires washing. It will be noted that shaft 17 can carry any number of jets; in certain cases a single jet will be sufficient, which is obviously impossible with conventional descaling apparatus, in which drive is provided by the reaction of the projected water. The apparatus can be used in the horizontal position as in the vertical; it can even be positioned with base 1 turned downwards, provided of course that assembly 2-3 lends itself to such a position.