CN201086082Y - Flushing mechanism of full-automatic turning bottle flushing device for wide neck container - Google Patents

Flushing mechanism of full-automatic turning bottle flushing device for wide neck container Download PDF

Info

Publication number
CN201086082Y
CN201086082Y CNU2007200557487U CN200720055748U CN201086082Y CN 201086082 Y CN201086082 Y CN 201086082Y CN U2007200557487 U CNU2007200557487 U CN U2007200557487U CN 200720055748 U CN200720055748 U CN 200720055748U CN 201086082 Y CN201086082 Y CN 201086082Y
Authority
CN
China
Prior art keywords
jet pipe
lead
wide
guide rail
rotating disk
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
CNU2007200557487U
Other languages
Chinese (zh)
Inventor
胡振中
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
WENZHOU JINOU LIGHT INDUSTRIAL MACHINERY Co Ltd
Original Assignee
WENZHOU JINOU LIGHT INDUSTRIAL MACHINERY Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by WENZHOU JINOU LIGHT INDUSTRIAL MACHINERY Co Ltd filed Critical WENZHOU JINOU LIGHT INDUSTRIAL MACHINERY Co Ltd
Priority to CNU2007200557487U priority Critical patent/CN201086082Y/en
Application granted granted Critical
Publication of CN201086082Y publication Critical patent/CN201086082Y/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Landscapes

  • Cleaning In General (AREA)

Abstract

The utility model relates to a washing mechanism used with a full-automatic rotary-type bottle washer for wide-mouth bottles, which utilizes a single guide column to drive and support spray pipes to move. With the structure, the spray pipes can be inserted into the bottle body to follow and wash the bottles. The utility model has the advantages of easy fabrication and assembly, reduced consumption of time and labor, no risk of locking the spray pipe, and simple structure. Additionally, the spray pipe is the interlined pipe, wherein the inner layer is gas pipe and the outer layer is liquid pipe, thereby allowing the bottle to be cleaned completely and ensuring good cleaning effect.

Description

A kind of flushing machine of wide-mouth bottle full automatic rotary type bottle cleaning machine
Technical field
The utility model relates to a kind of flushing machine of wide-mouth bottle full automatic rotary type bottle cleaning machine.
Background technology
Existing full-automatic bottle cleaning machine mainly comprises the flat-top chain transfer mechanism, transmission mechanism, the bottle cleaning machine structure, frame, parts such as electrical equipment, transmission mechanism is by reductor, gear, compositions such as main shaft, reductor is positioned at frame, reductor is by the gear driven spindle operation, the bottle cleaning machine structure comprises the water feeding machine structure, conduit, distributor, bottle gripper, nozzle, the rotating disk of support nozzle mechanism and bottle gripper, coupling block, turn over bottle guide rail etc., rotating disk by coupling block by the main shaft driven rotary, a plurality of nozzles and bottle gripper are evenly distributed on the rotating disk along circumference, distributor is positioned at rotating disk top and corresponding with each nozzle location, and the water feeding machine structure supplies water to distributor by conduit.Initial bottle bottleneck upwards, when bottle along turn over bottle guide rail rotate turn over turnback after, bottleneck down, nozzle washes by the design station, after flushing finished, bottle turned over turnback and resets along turning over a bottle guide rail again.Existing nozzle mechanism is generally the jet pipe that fixedly installs, and during flushing, jet pipe is positioned at the downside of handstand bottle body and bottleneck, and this structure developing result is relatively poor.General in addition jet pipe or be single liquid wash, adopt the jet pipe of gas-liquid one to wash and dry up, the delay moisture content that the former washes in the bottle of back is difficult for empty doing, the latter is owing to adopt the jet pipe of one to realize washing and drying up, therefore washing when drying up, the moisture content that is trapped in the jet pipe is directed onto in the bottle again, so still has delay moisture content in the bottle, can't guarantee rinsing quality.The applicant proposes the utility application that name is called a kind of nozzle mechanism of full automatic rotary type bottle cleaning machine to State Intellectual Property Office personally on August 16th, 2006, this structure has realized that jet pipe can stretch into interior tracking of bottle and dash bottle, its flushing is more thorough, can effectively guarantee rinsing quality, but because its structure that adopts two leads and slider support and drive the jet pipe motion, the precision that needs when processing and assembling is higher, the stuck phenomenon of jet pipe takes place easily, its structure more complicated relatively wastes time and energy at fit in addition.
The utility model content
The utility model is intended to overcome above-mentioned the deficiencies in the prior art, provides a kind of jet pipe to stretch into to follow the tracks of in the bottle to dash bottle, process and assemble the flushing machine that simple and time saving and energy saving, jet pipe is difficult for taking place stuck phenomenon, wide-mouth bottle full automatic rotary type bottle cleaning machine simple in structure.
Another purpose of the present utility model is, provides that a kind of cleaning is more thorough, the flushing machine of the wide-mouth bottle full automatic rotary type bottle cleaning machine that can effectively guarantee developing result.
The flushing machine of a kind of wide-mouth bottle full automatic rotary type bottle cleaning machine that provides according to the utility model, comprise framework platform and be arranged on this framework platform top and drive the rotating disk that rotates by main shaft, the edge circumferentially evenly is provided with a plurality of jet pipes moving up and down between described rotating disk and the framework platform, corresponding described jet pipe is correspondingly configured on the described rotating disk a plurality of through holes, the top of each described jet pipe is passed corresponding through hole and can be extend in the wide-mouth bottleneck of being inverted side disposed thereon, the other end of described jet pipe communicates with water inlet and/or airway, be provided with a plurality of positioning and guiding covers along circumferential corresponding described through hole between described rotating disk and the framework platform, the inner chamber of each positioning and guiding cover communicates with corresponding described through hole, the upper end of each positioning and guiding cover is fixed on the rotating disk, each positioning sleeve inside is provided with a lead that can slide up and down along its inner chamber, this lead upper end is formed with downwards on the bar shaped shrinkage pool that allows the insertion of jet pipe the latter half, described jet pipe is fixed in this shrinkage pool, this shrinkage pool bottom is provided with the intercommunicating pore that jet pipe communicates with conduit, opened strip gab vertically on the described positioning and guiding cover sidewall, described conduit passes described strip gab and described intercommunicating pore is communicated with described jet pipe, the distance that described jet pipe moves up and down is less than the axial distance of described strip gab, described lead stretches out described positioning sleeve and is provided with roller in its bottom, described framework platform is along circumferentially being provided with the guide rail with particular track, this guide rail is in order to control moving up and down of described jet pipe, this guide rail is positioned at the downside of described roller, its upper end has a guide pass, and described roller rolls on this guide pass.
The utility model also has following additional technical feature:
Described guide rail upper surface comprises tilting that ascent stage guide pass, level keep section guide pass and inclination descending branch guide pass.
Each described jet pipe is the interlayer pipe, pipe is gas pipeline in it, outer tube is a fluid pipeline, and described lead shrinkage pool bottom is respectively equipped with the intercommunicating pore that two jet pipes communicate with conduit, and described two conduits pass described strip gab respectively and corresponding intercommunicating pore communicates with jet pipe.
Each described positioning and guiding put the end have one greatly the end, described positioning and guiding cover is passed down through described through hole, its big end leans the upper surface at rotating disk, and the periphery of described big end is provided with half through hole vertically, and a screw passes this half through hole and makes described big end and rotating disk Joint.
Described lead upper end has is with externally threaded projection, a downward cavity is opened in the upper end of this projection, the corresponding position of described jet pipe periphery wall is formed with the boss that is contained in the cavity, and a thread cap with internal thread is fixed together described lead and described jet pipe.
Corresponding two the intercommunicating pore places of the outer wall of described lead are provided with the depression that a bottom surface is the plane, are provided with a cover plate in this depression, and this cover plate is affixed by screw and described lead, opens two holes that allow two conduits to pass respectively on the described cover plate.
U-lag has been opened in described lead lower end, and described roller portion is contained in this U-lag, links together by a bearing pin and described lead.
Described bearing pin has and stretches out described lead one external part, this external part is provided with another roller, corresponding described inclination descending branch guide pass place is provided with another guide rail on the described framework platform, the lower surface of this another guide rail has an inclination decline guide pass, the inclination angle of this inclination decline guide pass and length are identical with the inclination angle and the length of described inclination descending branch guide pass, and the inclination decline guide pass of described another guide rail is positioned at the top of described another roller.
The utility model compared with prior art, have following advantage: the utility model adopts single lead to drive to support jet pipe motion, this structure not only to make jet pipe to stretch into to follow the tracks of in the bottle to dash bottle but also processing and assemble simple and time saving and energy saving, jet pipe and is difficult for taking place stuck phenomenon, simple in structure.Described in addition jet pipe is the interlayer pipe, and pipe is gas pipeline in it, and outer tube is a fluid pipeline, and this structure makes that cleaning is more thorough, can effectively guarantee developing result.
Description of drawings
Embodiment below in conjunction with accompanying drawing provides describes the utility model in detail, wherein:
Fig. 1 is the structural representation of a kind of preferred embodiment of flushing machine of a kind of wide-mouth bottle full automatic rotary type of the utility model bottle cleaning machine;
Fig. 2 is a schematic top plan view of the present utility model;
Fig. 3 is the fit structure schematic diagram of Fig. 1 turntable, jet pipe, lead, fairlead, guide rail, conduit and another guide rail;
Fig. 4 is the front elevational schematic of the cooperation of jet pipe, lead, fairlead, guide rail, conduit and another guide rail among Fig. 3;
Fig. 5 is the fit structure schematic diagram of jet pipe, lead, fairlead and conduit among Fig. 3;
Fig. 6 is the schematic top plan view of Fig. 2 middle guide and another guide rail.
The specific embodiment
Referring to Fig. 1 to Fig. 6, a kind of preferred embodiment of flushing machine of a kind of wide-mouth bottle full automatic rotary type bottle cleaning machine of the present utility model is shown, comprise framework platform 1 and be arranged on this framework platform top and drive the rotating disk 2 that rotates by main shaft 3, the edge circumferentially evenly is provided with a plurality of jet pipes moving up and down 4 between described rotating disk and the framework platform, corresponding described jet pipe is correspondingly configured on the described rotating disk a plurality of through holes 20, the top of each described jet pipe is passed corresponding through hole 20 and can be extend in the wide-mouth bottleneck of being inverted side disposed thereon, the other end of described jet pipe communicates with water inlet and/or airway 5, be provided with a plurality of positioning and guidings covers 6 along circumferential corresponding described through hole 20 between described rotating disk 2 and the framework platform 1, the inner chamber of each positioning and guiding cover 6 communicates with corresponding described through hole, the upper end of each positioning and guiding cover 6 is fixed on the rotating disk, each positioning sleeve inside is provided with a lead 7 that can slide up and down along its inner chamber, this lead upper end is formed with downwards on the bar shaped shrinkage pool 70 that allows the insertion of jet pipe the latter half, described jet pipe 4 is fixed in this shrinkage pool, this shrinkage pool bottom is provided with the intercommunicating pore 71 that jet pipe 4 communicates with conduit 5, described positioning and guiding overlaps has opened strip gab 60 vertically on 6 sidewalls, described conduit passes described strip gab and described intercommunicating pore 71 is communicated with described jet pipe, the distance that described jet pipe moves up and down is less than the axial distance of described strip gab, described jet pipe moves up and down and is limited in the strip gab, described lead 7 stretches out described positioning sleeve and is provided with roller 8 in its bottom, described framework platform 1 is along circumferentially being provided with the guide rail 9 with particular track, this guide rail is in order to control moving up and down of described jet pipe 4, this guide rail is positioned at the downside of described roller, its upper end has a guide pass 93, described roller rolls on this guide pass, owing to adopt single lead 7 to drive also to support jet pipe 4 motions, this structure not only makes jet pipe 4 to stretch into to follow the tracks of in the bottle dashes bottle but also processing and assembles simple and time saving and energy saving, jet pipe is difficult for taking place stuck phenomenon, simple in structure.
Described guide rail 9 upper surfaces comprise tilting ascent stage guide pass 90, level keeps section guide pass 91 and inclination descending branch guide pass 92, the full automatic rotary type bottle washing machine generally comprises three phases, the one, bottleneck put up turn over turnback in the bottle gripper then and make the bottleneck stage down, the 2nd, the rinse stage of carrying out according to rinsing requirement, the 3rd, turn over turnback after flushing finishes and recover the bottleneck stage up, three guide pass of described guide rail 9 are corresponding with above-mentioned three phases respectively, described roller 8 rolls on this guide pass, rises gradually and enters in the bottleneck thereby form to drive nozzle, in bottleneck, keep washing and descend gradually and withdraw from the bottleneck three phases.
Each described jet pipe 4 is the interlayer pipe, pipe 40 is a gas pipeline in it, outer tube 41 is a fluid pipeline, described lead shrinkage pool 70 bottoms are respectively equipped with the intercommunicating pore 71 that two jet pipes communicate with conduit, described two conduits pass described strip gab 60 respectively and corresponding intercommunicating pore communicates with jet pipe, liquid is generally warm water or hot water (being sterilization water during plastic bottle) herein, realized gas-liquid separation, therefore dry up the delay moisture content in the bottle more up hill and dale, make that cleaning is more thorough, can effectively guarantee developing result.
Each described positioning and guiding overlaps 6 upper ends and has a big end 61, described positioning and guiding cover 6 is passed down through described through hole 20, its big end 61 leans the upper surface at rotating disk 2, the periphery of described big end 61 is provided with half through hole 62 vertically, one screw 63 passes this half through hole and makes described big end and rotating disk Joint, it is fastening fixing that this structure makes that fairlead 6 obtains, in the course of the work can the occurrence positions skew.
U-lag 78 has been opened in described lead lower end, described roller 8 parts are contained in this U-lag 78, link together with described lead 7 by a bearing pin 79, roller and bearing pin are hinged, thereby guarantee that roller is rotatable, this structure greatly reduces the friction between guide pass and the roller, has prolonged the life-span of guide pass, thereby guarantees the normal operation of bottle washing machine.
Described lead 7 upper ends have is with externally threaded projection 72, a downward cavity 73 is opened in the upper end of this projection 72, the corresponding position of described jet pipe periphery wall is formed with the boss 42 that is contained in the cavity 73, one thread cap 43 with internal thread is fixed together described lead 7 with described jet pipe, this structure makes jet pipe 4 can be fastened on the lead, can not be offset in the course of the work, make lead in the process of sliding up and down, stuck phenomenon can not take place.
Corresponding two intercommunicating pore 71 places of the outer wall of described lead 7 are provided with the depression 74 that a bottom surface is the plane, be provided with a cover plate 75 in this depression 74, this cover plate is affixed by screw 76 and described lead, opens two holes 77 that allow two conduits to pass respectively on the described cover plate 75.
Described bearing pin 79 has and stretches out described lead 7 one external parts 80, this external part is provided with another roller 81, corresponding described inclination descending branch guide pass 92 places are provided with another guide rail 10 on the described framework platform 1, the lower surface of this another guide rail has an inclination decline guide pass, the inclination angle of this inclination decline guide pass and length are identical with the inclination angle and the length of described inclination descending branch guide pass 92, the inclination decline guide pass of described another guide rail 10 is positioned at the top of described another roller 81, this structure makes when jet pipe when wash bottle finishes can not stretch out in bottleneck just in case stuck phenomenon takes place, the inclination decline guide pass of described another guide rail is pushed down described another roller 81, force the inclination decline guide pass motion of described another guide rail 10, thereby thereby force to stretch out in jet pipe 4 bottlenecks, form the anti-jamming guarantee in second road.
The foregoing description is only for the usefulness that the utility model is described; and be not to be to restriction of the present utility model; the those of ordinary skill in relevant technologies field; under the situation that does not break away from spirit and scope of the present utility model; can also make various variations and modification; therefore all technical schemes that are equal to also should belong to category of the present utility model, and scope of patent protection of the present utility model should be limited by each claim.

Claims (8)

1. the flushing machine of a wide-mouth bottle full automatic rotary type bottle cleaning machine, comprise framework platform (1) and be arranged on this framework platform top and drive the rotating disk (2) that rotates by main shaft (3), the edge circumferentially evenly is provided with a plurality of jet pipes moving up and down (4) between described rotating disk and the framework platform, corresponding described jet pipe is correspondingly configured on the described rotating disk a plurality of through holes (20), the top of each described jet pipe is passed corresponding through hole and can be extend in the wide-mouth bottleneck of being inverted side disposed thereon, the other end of described jet pipe (4) communicates with water inlet and/or airway (5), it is characterized in that being provided with a plurality of positioning and guiding covers (6) along circumferential corresponding described through hole (20) between described rotating disk (2) and the framework platform (1), the inner chamber of each positioning and guiding cover (6) communicates with corresponding described through hole, the upper end of each positioning and guiding cover (6) is fixed on the rotating disk, each positioning sleeve inside is provided with a lead (7) that can slide up and down along its inner chamber, this lead upper end is formed with downwards on the bar shaped shrinkage pool (70) that allows the insertion of jet pipe (4) the latter half, described jet pipe is fixed in this shrinkage pool, this shrinkage pool bottom is provided with the intercommunicating pore (71) that jet pipe (4) communicates with conduit (5), opened strip gab (60) vertically on described positioning and guiding cover (6) sidewall, described conduit (5) passes described strip gab (60) and described intercommunicating pore (71) is communicated with described jet pipe (4), the distance that described jet pipe moves up and down is less than the axial distance of described strip gab, described lead (7) stretches out described positioning sleeve and is provided with roller (8) in its bottom, described framework platform (1) is along circumferentially being provided with the guide rail (9) with particular track, this guide rail is in order to control moving up and down of described jet pipe, this guide rail is positioned at the downside of described roller, its upper end has a guide pass (93), and described roller rolls on this guide pass.
2. the flushing machine of wide-mouth bottle full automatic rotary type bottle cleaning machine according to claim 1 is characterized in that described guide rail (9) upper surface comprises tilting that ascent stage guide pass (90), level keep section guide pass (91) and inclination descending branch guide pass (92).
3. the flushing machine of wide-mouth bottle full automatic rotary type bottle cleaning machine according to claim 1, it is characterized in that each described jet pipe (4) is the interlayer pipe, pipe (40) is a gas pipeline in it, outer tube (41) is a fluid pipeline, described lead shrinkage pool (70) bottom is respectively equipped with the intercommunicating pore (71) that two jet pipes communicate with conduit (5), and described two conduits pass described strip gab (60) respectively and corresponding intercommunicating pore communicates with jet pipe.
4. the flushing machine of wide-mouth bottle full automatic rotary type bottle cleaning machine according to claim 1 and 2, it is characterized in that each described positioning and guiding cover (6) upper end has one and holds (61) greatly, described positioning and guiding cover (6) is passed down through described through hole (20), its big end (61) leans the upper surface in rotating disk (2), the periphery of described big end (61) is provided with half through hole (62) vertically, and a screw (63) passes this half through hole and makes described big end and rotating disk Joint.
5. according to the flushing machine of claim 1 or 3 described wide-mouth bottle full automatic rotary type bottle cleaning machines, it is characterized in that described lead (7) upper end has is with externally threaded projection (72), a downward cavity (73) is opened in the upper end of this projection (72), the corresponding position of described jet pipe periphery wall is formed with the boss (42) that is contained in the cavity (73), and a thread cap (43) with internal thread is fixed together described lead (7) and described jet pipe (4).
6. the flushing machine of wide-mouth bottle full automatic rotary type bottle cleaning machine according to claim 3, corresponding two intercommunicating pores of outer wall (71) that it is characterized in that described lead (7) locate to be provided with the depression that a bottom surface is the plane (74), be provided with a cover plate (75) in this depression (74), this cover plate is affixed by screw (76) and described lead, opens two holes (77) that allow two conduits (5) to pass respectively on the described cover plate.
7. the flushing machine of wide-mouth bottle full automatic rotary type bottle cleaning machine according to claim 2, it is characterized in that described lead (7) lower end opened U-lag (78), described roller (8) part is contained in this U-lag (78), links together by a bearing pin (79) and described lead.
8. the flushing machine of wide-mouth bottle full automatic rotary type bottle cleaning machine according to claim 7, it is characterized in that described bearing pin (79) has stretches out described lead (7) one external parts (80), this external part is provided with another roller (81), described framework platform (1) is gone up corresponding described inclination descending branch guide pass (92) and is located to be provided with another guide rail (10), the lower surface of this another guide rail has an inclination decline guide pass, the inclination angle of this inclination decline guide pass and length are identical with the inclination angle and the length of described inclination descending branch guide pass (92), and the inclination decline guide pass of described another guide rail (10) is positioned at the top of described another roller (81).
CNU2007200557487U 2007-08-20 2007-08-20 Flushing mechanism of full-automatic turning bottle flushing device for wide neck container Expired - Lifetime CN201086082Y (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CNU2007200557487U CN201086082Y (en) 2007-08-20 2007-08-20 Flushing mechanism of full-automatic turning bottle flushing device for wide neck container

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CNU2007200557487U CN201086082Y (en) 2007-08-20 2007-08-20 Flushing mechanism of full-automatic turning bottle flushing device for wide neck container

Publications (1)

Publication Number Publication Date
CN201086082Y true CN201086082Y (en) 2008-07-16

Family

ID=39633671

Family Applications (1)

Application Number Title Priority Date Filing Date
CNU2007200557487U Expired - Lifetime CN201086082Y (en) 2007-08-20 2007-08-20 Flushing mechanism of full-automatic turning bottle flushing device for wide neck container

Country Status (1)

Country Link
CN (1) CN201086082Y (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110605288A (en) * 2019-10-12 2019-12-24 广州达意隆包装机械股份有限公司 Distributor and bottle washing machine

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110605288A (en) * 2019-10-12 2019-12-24 广州达意隆包装机械股份有限公司 Distributor and bottle washing machine

Similar Documents

Publication Publication Date Title
CN100584471C (en) A kind of flushing machine of wide-mouth bottle full automatic rotary type bottle cleaning machine
CN101474628A (en) Full automatic machine for washing bottle mouth of wide neck container
CN201135988Y (en) Automatic wide neck container bottle mouth rinsing machine
CN106111646A (en) Full-automatic chemiluminescence reagent bottle cleaning machine
CN107790453A (en) A kind of sample injection bottle automatic flushing device
CN107571382B (en) Glazing assembly line and glazing method
CN201086084Y (en) Bottle claming mechanism of full-automatic turning bottle flushing device for wide neck container
CN101372011B (en) Bottle-clamping mechanism of wide neck container full automatic rotary type bottle-washing machine
CN202845396U (en) Linear type full-automatic bottle flushing machine
CN201086082Y (en) Flushing mechanism of full-automatic turning bottle flushing device for wide neck container
CN201172052Y (en) Full-automatic recovery-bottle cleaning line device
CN2936465Y (en) Jet nozzle mechanism of full automatic rotary bottle washing machine
CN2926182Y (en) Ejector of bottle punch
CN202933907U (en) Vertical bottle washer
CN106111644A (en) The main drive of cleaning machine and reagent bottle clean device
KR20050116956A (en) A pail of spring water washing apparatus
CN204417091U (en) Full-automatic beer bucket cleaning and filling machine
CN209476878U (en) A kind of mineral water external wall cleaning machine
CN209363214U (en) Flusher in synchronization lifting formula bottle
CN102151677A (en) Three-wash bottle washing machine for wild-mouth bottles
CN106583384A (en) Inner washing machine capable of rotationally spraying and washing
CN109530369B (en) Synchronous lifting type in-bottle flushing device
CN203711445U (en) Lifting mechanism of bottle flushing machine nozzle
CN103691720B (en) A kind of elevating mechanism of bottle cleaning machine nozzle
KR200360046Y1 (en) A pail of spring water washing apparatus

Legal Events

Date Code Title Description
C14 Grant of patent or utility model
GR01 Patent grant
AV01 Patent right actively abandoned

Effective date of abandoning: 20070820

C25 Abandonment of patent right or utility model to avoid double patenting