US 3556407 A
Description (OCR text may contain errors)
United States Patent  Inventors lwajiro Niikura Hayama-machi, Miura-gun; Hiroshi Mikami, Yokohama, Japan  Appl. No. 773,733  Filed Nov. 6, 1968 [45} Patented Jan. 19, 1971  Assignee Niikura Kogyo Co., Ltd.
Tokyo, Japan a corporation of Japan  CLEANING DEVICE WELL ADAPTED FOR USE IN TANKS AND THE LIKE OF OIL TANKER 2 Claims, 4 Drawing Figs.
 US. Cl 239/227, 105/52  Int. Cl .l B05b 3/04  Field ofSearch 239/227, 228, 229; 74/128; 103/52, 159; 91/224, 321
 References Cited UNITED STATES PATENTS 3,079,900 3/1963 Hunnicutt 9 l/321X 3,141,384 7/1964 Hoffman 91/224X 3,170,378 2/1965 Rohde et al. 91/224 9/1966 Saad 239/227 Primary Examiner-Lloyd L. King Assistant E.raminer-Gene A. Church Atl0rneyGeorge B. Oujevolk ABSTRACT: A tank cleaning assembly of the type having upper and lower sections, the upper section including a flange with a fluid intake port defined above said flange while the lower section includes a pipe which is lowered into a tank and held to the tank upper deck by the flange, said pipe having nozzle means towards the end of the pipe lowered into said tank. This tank cleaning assembly comprises a hydraulic reciprocator in said upper section, including a piston therein, with a reciprocating piston ratchet shaft at an outer end thereof, and a conduit connected to said intake port which causes said piston to reciprocate by receiving pressure water through said conduit; a gear mechanism engaged by said ratchet shaft, upper and lower rotary shafts rotated and driven through said ratchet and gear mechanism, said rotary shafts being disposed in the pipe to lead pressurized cleaning fluid into said tank. A jet nozzle body with upper and lower ends fastened at its lower end to the lower end of the lower rotary shaft and is freely rotatable, a hollow and nonrotatable worm gear is concentrically mounted on the outside of said lower rotary shaft at least a part of which penetrates through said jet nozzle body outer wall and is exposed for engagement. A nozzle fitting shaft is mounted on the jet nozzle body in a transverse direction, a. nozzle holder with a cylindrical periphery is supported by said nozzle fitting shaft and said jet nozzle body in a freely rotatable manner. A worm wheel is fixed to the periphery of said nozzle holder and engaged with the worm gear to rotate the nozzle holder and nozzles fixed to said nozzle holder.
' Qs x llllllll% I a FWINTEU JAN 1 9 1971 SHEET 1 0F 3 MM E 7W INVENTOR) Ar /f /7/ CLEANING DEVICE WELL ADAPTED FOR USE IN TANKS AND THE LIKE OlF GIL TANKER This invention relates to a cleaning device well adapted for use in cleaning tanks of oil tankers, and it has for its object to rovide a strong, balanced and compact device wherein a liquid-pressure hydraulic-reciprocator is used without using the partial force of a jet discharged from nozzles, which has heretofore been used as a motive power of automatically converting the direction of nozzle, to carry out a slow direction conversion, and hence the entire jet emitted from the nozzle can be utilized for cleaning, and furthermore the nozzles are arranged symmetrically with each other.
Heretofore, some machines have been employed for cleaning tanks of tankers. With the recent tendency of enlargement in size of tankers, the development of a tank cleaning device which is stronger and easier to handle it has become necessa- When a tank cleaning device of a gigantic vessel is considered, it is necessary to consider the following:
A. Developing a strong injection nozzle having a long and large range;
B. Being easy to handle and responding to the demand of economizing labor;
C. A device which is simple, troubleless and cheap in maintenance costs.
The present inventors have contemplated that it is sufficient for obtaining a strong injection nozzle having a long and large range to obtain a rotary mechanism of an exceedingly low speed and strong rotating force without using jet reaction as motive power, and have exhaustively studied on the developrnent thereof. As a result, the present inventors have sucseeded in developing a liquid-pressure hydraulic-reciprocator.
When the jet reaction is used as motive power as heretofore, it is necessary to gear down the nozzle to obtain low speed. When the nozzle is geared down, dust and friction must be taken into consideration so that the nozzle cannot be geared down lower than a definite speed limit.
The aforementioned hydraulic reciprocator can freely select the rotational force and rotational speed by suitably selecting the diameter of the cylinder and that of the orifice and also can use cleaning water itself as the driving force and hence it is considered most suitable for the object of the present invention.
Accordingly, the inventors attained conviction that the present invention has been almost completed by the completion of said mechanism, so that the inventors set to work to develop the driving mechanism from the hydraulic reciprocator to nozzles. In designing said mechanism the following respects were considered:
D. Its construction is simple, troubleless and easily rotatable;
E. It assumes a construction having no bending and twisting operation caused by the reaction of the jet;
F. It assumes a construction having no propelling operation by liquid pressure.
The first feature of the cleaning device of the present invention adapted for tanks and the like of oil tankers as mentioned above, resides in using a hydraulic reciprocator provided separately from nozzles as will be described hereinbelow without using the jet emitted from the nozzle as a prime motive power for automatically converting the direction of nozzles, As a result, the emitted jet can be fully utilized for the cleaning operation and the dispersion distance of the jet is remarkable elongated, and if it is used for a tank cleaner, it is possible to clean wide spaces by only one cleaner.
The second feature of the present invention resides in using the combination of worm gear and a worm wheel as a nozzle rotation mechanism. As a result, in case where a worm gear is mounted on the rotary shaft in the core of a pressure water conductive pipe, a worm wheel shaft intersecting therewith can be in close proximity therewith, and the main body of the device can be formed into a shape easily encircling the worm gear and the worm wheel, and therefore a very compact design becomes possible, further the reduction gear ratio of the rotation of nozzle can be remarkably increased by the combination of the worm gear and worm wheel.
The third feature of the present invention resides in that a rotary shaft for rotating the nozzle is provided at the central portion ofa pressure water conductive pipe, a worm gear projected and secured at the end portion of said pressure water conductive pipe is made hollow and said rotary shaft is in serted in the inner part thereof in a freely rotatable manner. further a jet nozzle body which is secured to the end ofsaid rotary shaft and rotated therewith is provided at the end of said pressure water conductive pipe, still further a worm wheel and a nozzle holder engaging with said worm gear are mounted on the nozzle fitting shaft in a freely rotatable manner at said jet nozzle fitting body, and pressure water is introduced thereinto, whereby a very slow rotation (for example, I rotation in 45 minutes) and simultaneously a compact induction device for pressure water can be obtained.
The fourth feature of the present invention resides in that there are two nozzle holes formed symmetrically l apart (as circumstances require, three holes may be formed apart) so that the reaction force of the 'jet is fully eliminated and therefore the device can be operated lightly.
The fifth feature of the present invention relates to a hydraulic reciprocator employed as the motive power for antomatically converting the direction of the nozzle, wherein a piston is interposed in a very compact chambershape case and is reciprocated by the liquid pressure caused by the cleaning fluid. e.g., seawater, the rotary shaft within said pressure water conductive pipe is rotated by a ratchet mechanism provided at the end of the rod of said piston, further said chamber-shape case can be easily divided into both the main body portion and the cover portion; and since the main body of the prime mover is chamber-shaped and very compact, it is easy to provide and handle it, and moreover it uses only liquid pressure as a motive power and hence it can be utilized in vessels such as oil tankers, and since it can be easily divided into two parts, its inner part can be easily inspected for trouble.
Further, the sixth feature of the present invention relates to the internal structure of the aforementioned hydraulic reciprocator in which holes for passing liquid are formed on the piston, a pilot valve is disposed so as to close said holes from the side to which liquid pressure is applied, a valve pushup spring accelerates the full opening of the pilot valve and a valve pushdown spring which ascertains its restoration are attached. Also a valve opening promoting member for accelerating the opening by imparting a force acting in the direction of promoting the opening at the time of opening said pilot valve is provided under pressure of a valve opening promoting spring. By these mechanisms it is possible to guarantee precise operations of the reciprocator caused by the liquid pressure.
Further features and advantages will be apparent from the following description taken in connection with the accompanying drawings showing one preferred embodiment of the present invention in which:
FIG. I is an oblique view, partly broken away, showing a device according to the present invention;
FIG. 2 is a vertical sectional view showing a liquid-pressure reciprocator at the state prior to the operation of piston;
FIG. 3 is a vertical sectional view showing the pilot valve at the state prior to the operation thereof while the piston is in motion; and
FIG. 4 is a sectional view showing the pilot valve at the state immediately after the operation thereof In FIG. 1, reference numeral 15 designates a flange which is provided on an upper deck UDF. At the upper part of said flange 15 a fitting joint 17 of hydraulic reciprocator 2. is provided through an L-shaped joint 16 for introducing cleaning water and at the lower part thereof there is ajet nozzle body 7 mounted at the end portion having a pipe 18 for leading pressure water, integrally welded with said flange and a joint piece 19. Jet nozzle member 7 is mounted on the joint piece I9 through a radial bearing 20 in a freely rotatable manner.
Reference numeral 1 designates a driving water intake port in a L-shape joint 16, the driving water is led into the hydraulic reciprocator 2 through a conduct pipe 21 and a strainer 14. The detailed construction of the hydraulic reeiprocator 2 will be mentioned hereinbelow. A gear 4 is rotated in the direction shown by the arrow through a ratchet 3 provided at one end thereof by the reciprocating motion of the piston. Reference numeral designates an upper driving shaft secured to the gear 4 and is rotated by the gear 4 in the direction shown by the arrow. The upper driving shaft 5 passes through seawater induction portion below the L-shape joint 16 by way of a packing 22, and its lower end is connected to a lower driving shaft 5 having a coupling ring 23 in a freely attachable and detachable manner. Accordingly, the lower driving shaft 5 is also rotated in the direction shown by arrow, The lower driving shaft 5 is connected to the lower part of jet nozzle body 7 through a key 6, and hence the jet nozzle member 7 is also rotated in the direction shown by arrow. Reference numeral 8 is a worm gear which is hollow and houses the lower driving shaft 5' within the inner part thereof in a freely rotatable manner, and its upper end is fixedly screwed to said joint piece 19. The central portion penetrates through the outer wall of jet nozzle member 7, the lower end is screwed fixedly to a balance piston 13 incorporated at the lower part of jet nozzle member 7 in a freely slidable manner. Accordingly, the worm gear 8 is fixed and does not rotate, the lower driving shaft 5 rotates in the inner part thereof and the jet nozzle body 7 does in the outer part thereof. The balance piston 13 is provided for eliminating thrust produced in jet nozzle body 7.
Reference numeral 24 designates a nozzle fitting fixed shaft, mounted on the jet nozzle body 7 in a transverse direction and provided with a nozzle holder 11 through a balance piston 25. The nozzle holder 11 is connected to the worm wheel 9 through a key 10, said worm wheel 9 being in engagement with said worm gear 8. As to the nozzle holder there are attached two nozzles 12 and 12 symmetrically separated by 180 in the same plane. Accordingly, when on the periphery of the fixed worm gear 8 the worm wheel 9 rotates integrally with the jet nozzle body 7, the nozzles 12 and 12 rotate in a direction shown by arrow by being driven by the worm gear 8 through worm wheel 9 and hence nozzle holder 11 rotates. As for the device in the drawing, the nozzles 12 and 12 make 1/45 of a rotation while the jet nozzle body 7 makes one rotation. Assumed that it takes approximately a minute for the jet nozzle body 7 to make one revolution, it takes approximately 45 minutes for the nozzles 12 and 12 to make one revolution and hence it requires 45 minutes to complete cleaning operation.
After cleaning water is introduced into the L-shape joint 16, it flows as shown by dotted line of the arrow, and at last is emitted from nozzle 12 and 12. The balance piston is arranged for eliminating thrust produced at the nozzle portion.
In the hydraulic reeiprocator shown in FIGS. 2 to 4, reference numeral 2 designates the entire device and 14 designates a strainer. Reference numeral 31 designates a case and 32 designates a cover. A piston 33 in case 31 is constantly under compression of a return spring 34. At the center of the piston 33 there is a liquid passing hole 35, a pilot valve 36 being led in a first guide 37 fastened to the piston 33 and fitted therein so as to close said liquid passing hole from the side to which liquid pressure is applied. A nut 38 is screwed fixedly at one end of the pilot valve 36. A valve pushup spring 39 is disposed between said nut 38 and first guide 37. Reference numeral 4 designates a second guide which is fastened to the case 31 by the cover 32. A ring-shape valve opening promoting member 41 is incorporated in the second guide in a freely slidable manner, and further a spring bracket 42 is screwed fixedly therein. Reference numeral 43 designates a valve initial pushup spring inserted between nut 38 and spring bracket 42, 44 designates a valve final-stage pushup spring inserted between valve opening promoting member 41 and second guide 40, 45 designates a bushing which receivesthe end portion of pilot valve 36, 46 designates a screen of strainer, 47 designates a compression spring for said screen, 48 designates a driving water intake port, and 49 designates a hole passing water.
Four springs 34, 39, 43, and 44 contained in said construction. The action of those springs will be shown hereinbelow.
Return spring 34: Used for returning the'piston 33.
Valve pushup spring 39: Pushing up pilot valve 36.
5 Valve initial pushdown spring 43: Pushing down pilot valve 36 at the initial stage of operation of piston. This is necessary in the period of time where internal pressure of cylinder is low.
Valve final-stage pushup spring 44: Pushing up the pilot valve 36 in the final period of operation of piston, i.e., while pilot valve 36 is in operation.
FIG. 2 indicates the state of the piston prior to the commencement of operation. The return spring 34 is loosely compressed, and valve pushup spring 39 is also compressed. and valve initial pushdown spring 43 is compressed but valve finalstage pushup spring 44 is elongated. The pilot valve 36 is closed. At this state, when driving water having pressure is supplied from an intake port 48. the driving water passes through a screen 46 of the strainer, and is introduced in the cylinder portion of case 31 through the hole 49 for passing water, and presses the right side of piston 33 inresistanceto the return spring 34.
FIG. 3 illustrates the state of pilot valve prior to the commencement of operation while piston is in motion. At this state, piston 33 is transferred to the left and return spring 34 is compressed, valve pushup spring 39 is also compressed, but valve initial pushdown spring 43 is elongated, and valve finalstage pushup spring 44 is compressed.
At this state, pilot valve 36 is still closed and piston 33 continues to shift to the left. The valve opening promoting member 41 pressed by the nut 38 on the pilot valve 36 which is shifted to the left together with piston 33 comes into contact with the stage portion of second guide 40. Thus, the pilot valve 36 is restricted in transference by valve opening promoting member 41. When the piston 33 still continues to shift to the left, the pilot valve 36 is separated from the piston 33 and pressure of driving water acts upon the end surface of pilot valve 36 whereby pilot valve 36 operates. More particularly, 40 the compressive force of two springs 39 and 44 in combination rapidly open pilot valve 36. i
. FIG. 4 illustrates the state of pilot valve immediately after the commencement of operation thereof, i.e., the state where pilot valve is opened and piston 33 commences to return. At this state, the return spring 34 is compressed, the valve pushup spring 39 is loosely compressed, but the valve initial pushdown spring 43 is elongated, and the valve final-stage pushup spring 44 is loosely compressed. At this state, the central hole of piston 33 is opened and pressure water of cylinder portion of case 31 passes through this central hole and flows to another side of piston 33, and hence the piston 33 rapidly shifts to the right by the compressive force of return spring 34, and
becomes to assume the state of FIG. 2. j
The reciprocating motion of piston 33 is continued by repeating the state as shown in FIGS. 2, 3 and 4 in cycle.
Although but one 17, of the invention, has been 16 and described in detail, it 2, be understood that 4 embodiments are possible and that 3, changes may be made in the design and ar- 0 rangement of the parts without departing from the spirit of the invention.
1. A tank cleaning assembly of the type having upper and lower sections, said upper section including a flange 15 with a fluid intake port 1 defined above said flange 15, said lower section including a pipe 18 which is lowered into a tank and held to the tank upper deck by said flange, said pipe 18 having nozzle means 12 towards the end of the pipe 18 lowered into said tank, said assembly comprising in combination:
a. a hydraulic reeiprocator 2 in said upper section, including a piston 33 therein, with a piston ratchet shaft 3 at an outer end thereof, and a conduit 21 connected to said in take port 1 which causes said piston 33 ro reciprocate by receiving pressure water through said conduit 21, said intake port 1 forming part of an L-shaped joint 16;
b. ajoint l7 fixed to said L-shaped joint 16 connected with the hydraulic reciprocator 2, a gear mechanism 4 engaged 3, said ratchet shaft (3), upper and lower rotary shafts 5, 5 rotated and driven through said ratchet and gear mechanism 3, 4 said rotary shafts 5,5 5' being disposed in said pipe 18, said pipe 18 being fixed to said L-shaped joint 16 and disposed to lead pressurized cleaning fluid into said tank. a joint piece 19 attached to the lower end of said pipe 18;
c. a jet nozzle body 7 with upper and lower ends and an outer wall which is fastened at its lower end to the lower end of said lower rotary shaft 5' and the upper end thereof is supported by said joint piece 19 in a freely rotatable manner. a hollow and nonrotatable worm gear 8 concentrically mounted on the outside of said lower rotary shaft 5' and fixed to said joint piece 19. at least a part of which penetrates through said jet nozzle body outer wall and is exposed for engagement; and,
d. a nozzle fitting shaft 24 mounted on said jet nozzle body 7 in a transverse direction, a nozzle holder 11 with a cylindrical periphery supported by said nozzle fitting shaft 24 and said jet nozzle body 7 in a freely rotatable manner, a worm wheel 9 fixed to the periphery of said nozzle holder 11 and engaged with said worm gear 8 to rotate said nozzle holder 11 and nozzles 12 fixed to said nozzle holder 2. A cleaning assembly as set forth in claim 1, said hydraulic reciprocator 2 comprising a casing 31 with a hole 49 for passing driving pressure water, said piston 33 being freely moveable in said casing 31 and having an opening 35 at the center of the piston, a pilot valve 36 arranged so as to open and close said opening 35 at one side of said piston 33 to which pressure is applied, a return spring 34 at the opposite side of said piston 33, a first guide 37 secured to said piston 33. a second guide 40 secured to said casing 31 in a freely moveable manner with said first guide 37, a fixing member 38 fastened to said plot valve 36, a valve opening promoting member 41 disposed in said second guide 40 in a freely moveable manner at a predetermined distance. a valve pushup spring 39 which constantly pushes up said pilot valve 36 interposed between said first guide 37 and said fixing member 38, a valve initial-stage pushdown spring 43 which pushes down said pilot valve 36 at the initial stage of the operation of the piston interposed between said second guide 40 and said fixing member 38, and a valve final-stage pushup spring 44 which pushes up said pilot valve 36 at the final stage of the operation of piston disposed between said second guide 40 and said valve opening promoting member 41.