CN106516837A - Automatic adjusting type tensioning device - Google Patents
Automatic adjusting type tensioning device Download PDFInfo
- Publication number
- CN106516837A CN106516837A CN201611023106.9A CN201611023106A CN106516837A CN 106516837 A CN106516837 A CN 106516837A CN 201611023106 A CN201611023106 A CN 201611023106A CN 106516837 A CN106516837 A CN 106516837A
- Authority
- CN
- China
- Prior art keywords
- cloth
- plane
- tensioning wheel
- fairlead
- live
- 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.)
- Withdrawn
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
- B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
- B65H23/00—Registering, tensioning, smoothing or guiding webs
- B65H23/04—Registering, tensioning, smoothing or guiding webs longitudinally
- B65H23/16—Registering, tensioning, smoothing or guiding webs longitudinally by weighted or spring-pressed movable bars or rollers
Abstract
The invention discloses an automatic adjusting type tensioning device. A slider of the automatic adjusting type tensioning device is provided with an oblique surface with an adjustable inclination angle. A guide part which extends out of a guide sleeve and walks on the oblique surface is arranged on a guide column, and the oblique surface forces the guide part to drive the guide column to vertically move and accordingly drive a tensioning wheel to move. The equivalent elastic coefficient of springs is changed by changing the inclination angle of the oblique surface, so that different tension ranges, namely a high range or a low range, are provided. By adjusting the inclination angle, the influence of spring invalidation on the elastic coefficient can be compensated. By adjusting tension variation caused by the variation of pressure between transmission rollers through an adjusting mechanism, tension is basically kept constant. Besides, by establishing a relationship between the tensioning wheel and the movement direction of the transmission rollers through a pressure sensor, a controller and a servo motor, a function of automatically adjusting the tensioning wheel is improved.
Description
Technical field
The present invention relates to textile technology field, more particularly to a kind of tensioner for automatically adjusting.
Background technology
In textile technology field, when cloth arranges rolling, cloth is transmitted typically on multipair spaced live-roller.
Specifically, cloth is clamped between a pair of live-rollers, so that certain frictional force between cloth and live-roller, is produced, so as to
Cloth is conveyed using live-roller.In order that cloth has some tension in course of conveying to make to have necessarily after cloth rolling
Consistency, generally, arranges a strainer between two pairs of live-rollers, and the strainer makes cloth produce some tension.
In prior art, the strainer for being tensioned cloth include one for the tensioning wheel that is resisted against on cloth and
For pushing against tensioning wheel so that tensioning wheel is resisted against the spring on cloth with certain pretightning force.This structure is actually spring and leads to
Crossing tensioning wheel and tension force being provided for cloth, the compression degree of spring is bigger, and the tension force of cloth is bigger, and the compression degree of spring is less,
The tension force of cloth is less.But due to the coefficient of elasticity of spring it is certain, the compression zone of spring be also it is certain, therefore, spring is only
A range of tension force can be provided for cloth.One more prominent shortcoming of this structure is, due to the Reusability of spring, spring
Fatigue failure can occur, so that its coefficient of elasticity reduces, finally enough tension force can not be provided for cloth, affect cloth rolling
Consistency afterwards.
Additionally, above-mentioned strainer can not provide stable tension for cloth, because being produced between cloth and live-roller
Raw frictional force is unstable（When the pressure between a pair of live-rollers increases, the frictional force produced by between cloth and live-roller
To increase, when the pressure reduction between a pair of live-rollers, or live-roller are worn serious, produced by between cloth and live-roller
Frictional force will reduce）, the size of frictional force can also affect the tension force of cloth, for example, when frictional force reduces so that cloth is opened
Begin lax, so that tensioning wheel starts movement towards cloth direction, spring-compressed degree diminishes, so that tension force diminishes；On the contrary,
When frictional force increases so that cloth starts to tense, so that tensioning wheel starts movement, spring-compressed journey towards away from cloth direction
Degree becomes increase, so that tension force becomes increase.Tension force is unstable also to produce impact to the consistency after cloth rolling.
The content of the invention
For above-mentioned technical problem of the prior art, the invention discloses a kind of adjust automatically adjusting for cloth tension
Tensioner.
To solve above-mentioned technical problem, the technical solution used in the present invention is：
A kind of tensioner for automatically adjusting, which is used to provide tension force for the cloth between two pairs of live-rollers, including：
Mounting seat, which is used for installed in fixing equipment；
Fairlead, which is vertically arranged in the mounting seat；
Lead column, which is arranged in fairlead, and can be along the fairlead vertical shift；
Tensioning wheel, which is arranged in lead column, and for contacting with cloth；
Slide block, its level in the mounting seat slide with closer or far from the fairlead；
First spring, which is arranged in the fairlead, and is located at below the lead column for pushing against the lead column；
Second spring, which arranges to push against the cunning towards the fairlead direction with the direction moved perpendicular to the lead column
Block；
Governor motion, which includes the control that the pressure transducer being arranged on the tensioning wheel is electrically connected with the pressure transducer
Device processed, the servomotor and the servomotor that are arranged on below the live-roller and are electrically connected with the controller are connected
Screw that screw mandrel and the screw mandrel coordinate, it is fixed on the screw, and for pushing against the pallet of live-roller, wherein：
The pressure change of the cloth correspondence tensioning wheel that the controller is detected according to the pressure transducer controls the servo
Motor steering, so that when the pressure of cloth correspondence tensioning wheel becomes big, the servomotor drives screw mandrel to rotate and causes pallet court
Move away from the direction of live-roller, when the pressure of cloth correspondence tensioning wheel becomes hour, the servomotor is inverted and causes pallet court
The direction movement of live-roller.
On the slide block, the inclined-plane with an adjustable tilt angle, is provided with the lead column and stretches out the guiding
Set the guide part in inclined-plane walking, so that the inclined-plane forces the guide part to drive the lead column vertical shift.
Preferably, the guide part includes the installing arm for being fixed on the lead column and extending towards the inclined-plane and is articulated in
The installing arm free end the road wheel abutted with the inclined-plane.
Preferably, rotor is provided with the slide block, the rotor can be rotated relative to the slide block and fixed, institute
State inclined-plane to be formed on the rotor.
Preferably, the rotor is segmental rotor, and the inclined-plane is the planar section of the segmental rotor outer peripheral face.
Preferably, one end of the segmental rotor is fixed with bearing pin, and long arc-shaped holes, the bearing pin are offered on the slide block
Locked by nut after wearing the long arc-shaped holes.
Preferably, the first dovetail slideway is formed with the wire block, the first dovetail groove, institute are offered on the inclined-plane
State the first dovetail slideway to be arranged in first dovetail groove.
Preferably, the second dovetail slideway is formed with the slide block, on the upper mounting surface of the mounting seat, offers
Two dovetail grooves, second dovetail slideway are arranged in second dovetail groove.
Compared with prior art, the beneficial effect of the of the invention tensioner for automatically adjusting is：The present invention is by changing
The angle of inclination on inclined-plane is changing the equivalent coefficient of elasticity of spring, and then provides differential tension scope, i.e. higher range or relatively low
Scope, and by adjusting angle of inclination, spring can be made up and occur to fail and the impact to coefficient of elasticity；And pass through governor motion
To adjust due to the pressure change between live-roller and the change of caused tension force, it is held essentially constant tension force.
Description of the drawings
Fig. 1 is the tensioner for automatically adjusting of the present invention in the schematic diagram compared with small tension receiving coil state.
Fig. 2 is the schematic diagram of the tensioner for automatically adjusting in larger tension state of the present invention.
Specific embodiment
To make those skilled in the art be better understood from technical scheme, below in conjunction with the accompanying drawings and specific embodiment party
Formula elaborates to the present invention.
As depicted in figs. 1 and 2, embodiment of the invention discloses that a kind of tensioner for automatically adjusting, this automatically adjusts
Tensioner be used to provide tension force for the cloth 15 between two pairs of live-rollers 14.The tensioner for automatically adjusting specifically is wrapped
Include：Mounting seat 1, fairlead 2, lead column 3, tensioning wheel 4, slide block 5, the first spring 19, second spring 6 and governor motion.Peace
Dress seat 1 is fixed on for transmitting the integral device of cloth 15, and between two pairs of live-rollers 14 cloth 15 lower section；It is oriented to
Cover 2 it is vertical be fixed in mounting seat 1, and vertical slots are opened up on jacket wall along the axial direction of fairlead 2；Lead column 3 is arranged on
In fairlead 2, and fairlead 2 and lead column 3 have and cooperate and gathering sill that vertical direction extends and guide rail, to be oriented to
Post 3 can be vertically moved freely set 2 is oppositely oriented, and rotated without being oppositely oriented set 2；Tensioning wheel 4 is fixed on guiding
The upper end of post 3, which is connected to the lower surface of cloth 15 so that cloth 15 produces some tension；Slide block 5 is capable of leaning on for level slip
Close or remote from fairlead 2；Slide block 5 fixes a baffle plate 13 away from the side of fairlead 2, and second spring 6 is arranged on baffle plate 13 and slides
With towards 2 direction of fairlead pushing and pressing slide block 5 between block 5；First spring 19 is arranged in the fairlead 2, and is located at the guiding
It is used for pushing against the lead column 3 below post 3.The present invention's it is critical only that：One is arranged on slide block 5 and can adjust angle of inclination
Inclined-plane 8, a guide part is set in lead column 3, the guide part stretched out outside fairlead 2 by vertical slots, stretches to slide block 5 simultaneously
Contact with the inclined-plane 8 of slide block 5, so that inclined-plane 8 pushes against lead column 3 by guide part so that tensioning wheel 4 is moved to 15 direction of cloth
It is dynamic, or tensioning wheel 4 drives guide part by lead column 3, slide block 5 is pushed against to the direction away from fairlead 2 by inclined-plane 8 so that
Second spring 6 is compressed, and tensioning wheel 4 is the tension force of the offer of cloth 15 by the first spring 19 being vertically arranged and is horizontally disposed with
Second spring 6 common provide generation.The key of the present invention is also resided in：Governor motion is according to the mobile regulation of tensioning wheel 4
Extruding force between live-roller 14, due to the tension force of cloth 15 it is not only relevant with the pretightning force provided by tensioning wheel 4, also with transmission
Pressure between roller 14 is relevant, and when the pressure between live-roller 14 increases, tension force can become big pressure between live-roller 14
During reduction, tension force can diminish.In order that live-roller 14 pressure keep relative constancy so that tension force keep it is constant, by adjust machine
Structure, reduces the pressure between live-roller 14 when tension force increases, and increases the pressure between live-roller 14 when strain is relieved.
Said structure can expand range of accommodation of the tensioning wheel 4 to the tension force of cloth 15, and its reason is：Cloth 15 is produced
Raw tension force is mainly provided to the pretightning force of cloth 15 by tensioning wheel 4, and the pretightning force is directly provided by the elastic force of the first spring 19
And the elastic force of second spring 6 is provided indirectly（Both are common to provide）, do not considering 3 gravity of lead column and other moving parts
Frictional force in the case of（Even if actually considering gravity and frictional force, effect is also identical）, it is pre- that second spring 6 is provided
Clamp force F1 with the elastic force F2 relations of second spring 6 is：F1=F2/tga, wherein：A is the inclination angle with respect to the horizontal plane of inclined-plane 8
Degree, due to the coefficient of elasticity of second spring 6 it is constant, when spring produces the pushing force of a certain numerical value, its compression degree（Here is interchangeable
Calculate as horizontal displacement）Be it is certain, and pretightning force can pass through change inclined-plane 8 angle of inclination can have various numerical value.Namely
Say, under different angles of inclination, in the case where 6 compression degree of second spring is constant, tensioning wheel 4 can provide different pretensions
Power, if assume that second spring 6 is identical with the first spring 19 being also set directly at below lead column 3 in the way of vertical, by tune
Section angle of inclination, under a certain pretightning force, tensioning wheel 4 can have different vertical positions, and spring has different compression degrees,
Different equivalent coefficient of elasticity are formed.
In sum, by the angle of inclination on change inclined-plane 8 so that spring has different equivalent coefficients, when cloth 15
When needing with larger tension range, as shown in Fig. 2 reducing the angle of inclination on inclined-plane 8, i.e. the numerical value of a reduces, then equivalent system
Number increase, so that the pretightning force increase of tensioning wheel 4, finally increases the tension adjustment range of cloth 15.In the same manner, work as cloth
When 15 needs are with compared with small tension receiving coil scope, as shown in figure 1, increasing the angle of inclination on inclined-plane 8, i.e. the numerical value of a increases, then equivalent
Coefficient is less, so that the pretightning force of tensioning wheel 4 reduces, finally reduces the tension adjustment range of cloth 15.
The present invention changes the equivalent coefficient of elasticity of spring by the angle of inclination on change inclined-plane 8, and then provides different
Power scope, i.e. higher range or relatively low scope, and pass through to adjust angle of inclination, spring can be made up and failure is occurred and to elasticity is
Several impacts.
Governor motion includes pressure transducer 16, controller 17, servomotor 21, screw mandrel 20, screw 18 and pallet；Pressure
Force transducer 16 is used to check pressure of the cloth to tensioning wheel 4；Controller 17 respectively with servomotor 21 and pressure transducer 16
Electrical connection；Servomotor 21 is arranged on below live-roller 14, and screw mandrel 20 is connected with servomotor 21, and screw 18 is coordinated with screw mandrel 20
Coordinate, pallet is fixed on screw 18 live-roller 14 for being used for that the live-roller 14 for pushing against lower section to extrude top with certain pressure.Its
In, the tension force increase of cloth when the cloth that pressure transducer 16 is detected becomes big to the pressure of tensioning wheel 4, is illustrated, and then is said
Extruding force increase between bright live-roller 14, now, controller 17 controls servo according to the pressure signal that position pressure sensor 16 is transmitted
Motor is rotated, and servomotor drive screw is rotated, and by coordinating with screw, makes screw drive pallet towards away from 14 direction of live-roller
It is mobile, so that the extruding between two live-rollers 14 reduces, so that the tension force of the increase of cloth returns to former state；When
When the cloth that pressure transducer 16 is detected reduces to the pressure of tensioning wheel 4, illustrate that the tension force of cloth reduces, further relate to transmission
Between roller 14, extruding force reduces, and now, controller 17 controls servomotor 21 according to the pressure signal that pressure transducer 16 is transmitted
Rotate backward, 21 drive screw 20 of servomotor is rotated, by coordinating with screw 18, make screw 18 pallet be driven towards live-roller 14
Direction is moved, so that the extruding increase between two live-rollers 14, so that the tension force of the reduction of cloth returns to former shape
State.
In a preferred embodiment of the invention, guide part includes the installation for being fixed on lead column 3 and extending towards inclined-plane 8
Arm 9 and the road wheel 10 for being articulated in 9 free end of installing arm and abutting with inclined-plane 8.Road wheel 10 is walked on inclined-plane 8.
As a kind of selection, on slide block 5, be provided with rotor 7, rotor 7 can opposing slider 5 rotate and fix, inclined-plane
8 are formed on rotor 7.
Used as a kind of selection, rotor 7 is segmental rotor, and inclined-plane 8 is the planar section of segmental rotor outer peripheral face.
For inclined-plane 8 can be made fixed after the regulation of angle of inclination, bearing pin 12, slide block 5 are fixed with one end of segmental rotor
On offer long arc-shaped holes 11, bearing pin 12 is locked by nut after wearing long arc-shaped holes 11.When needing to adjust angle, nut is sent in rotation,
Tightening nut is again adjusted after angle.
To prevent guide pad from departing from inclined-plane 8, the first dovetail slideway is formed with wire block, on inclined-plane 8, first is offered
Dovetail groove, the first dovetail slideway are arranged in the first dovetail groove, and guide pad slides along the first dovetail groove.
To make slide block 5 slide towards fairlead 2, the second dovetail slideway, the upper installation of mounting seat 1 on slide block 5, are formed with
Second dovetail groove for extending is offered towards fairlead 2 on face, and the second dovetail slideway is arranged in the second dovetail groove, slide block 5
Slide along the second dovetail groove.
Above example is only the exemplary embodiment of the present invention, is not used in the restriction present invention, protection scope of the present invention
It is defined by the claims.Those skilled in the art can be made respectively to the present invention in the essence and protection domain of the present invention
Modification or equivalent are planted, this modification or equivalent also should be regarded as being within the scope of the present invention.
Claims (7)
1. a kind of tensioner for automatically adjusting, which is used to provide tension force for the cloth between two pairs of live-rollers, it is characterised in that
Including：
Mounting seat, which is used for installed in fixing equipment；
Fairlead, which is vertically arranged in the mounting seat；
Lead column, which is arranged in fairlead, and can be along the fairlead vertical shift；
Tensioning wheel, which is arranged in lead column, and for contacting with cloth；
Slide block, its level in the mounting seat slide with closer or far from the fairlead；
First spring, which is arranged in the fairlead, and is located at below the lead column for pushing against the lead column；
Second spring, which arranges to push against the cunning towards the fairlead direction with the direction moved perpendicular to the lead column
Block；
Governor motion, which includes the control that the pressure transducer being arranged on the tensioning wheel is electrically connected with the pressure transducer
Device processed, the servomotor and the servomotor that are arranged on below the live-roller and are electrically connected with the controller are connected
Screw that screw mandrel and the screw mandrel coordinate, it is fixed on the screw, and for pushing against the pallet of live-roller, wherein：
The pressure change of the cloth correspondence tensioning wheel that the controller is detected according to the pressure transducer controls the servo
Motor steering, so that when the pressure of cloth correspondence tensioning wheel becomes big, the servomotor drives screw mandrel to rotate and causes pallet court
Move away from the direction of live-roller, when the pressure of cloth correspondence tensioning wheel becomes hour, the servomotor is inverted and causes pallet court
The direction movement of live-roller；
On the slide block, the inclined-plane with an adjustable tilt angle, is provided with the lead column and stretches out the fairlead simultaneously
In the guide part of inclined-plane walking, so that the inclined-plane forces the guide part to drive the lead column vertical shift.
2. the tensioner for automatically adjusting according to claim 1, it is characterised in that the guide part includes being fixed on institute
The installing arm stated lead column and extend towards the inclined-plane and the row for being articulated in the installing arm free end and abutting with the inclined-plane
Walk wheel.
3. the tensioner for automatically adjusting according to claim 2, it is characterised in that rotation is provided with the slide block
Body, the rotor can be rotated relative to the slide block and fixed, and the inclined-plane is formed on the rotor.
4. the tensioner for automatically adjusting according to claim 3, it is characterised in that the rotor is segmental rotor,
The inclined-plane is the planar section of the segmental rotor outer peripheral face.
5. the tensioner for automatically adjusting according to claim 4, it is characterised in that one end of the segmental rotor is fixed
There is bearing pin, on the slide block, offer long arc-shaped holes, the bearing pin is locked by nut after wearing the long arc-shaped holes.
6. the tensioner for automatically adjusting according to claim 5, it is characterised in that be formed with first on the wire block
Dovetail slideway, offers the first dovetail groove on the inclined-plane, first dovetail slideway is arranged on first dovetail groove
In.
7. the tensioner for automatically adjusting according to claim 6, it is characterised in that the second swallow is formed with the slide block
Tail shape guide rail, offers the second dovetail groove on the upper mounting surface of the mounting seat, second dovetail slideway is arranged on described
In second dovetail groove.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201611023106.9A CN106516837A (en) | 2016-11-19 | 2016-11-19 | Automatic adjusting type tensioning device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201611023106.9A CN106516837A (en) | 2016-11-19 | 2016-11-19 | Automatic adjusting type tensioning device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN106516837A true CN106516837A (en) | 2017-03-22 |
Family
ID=58352494
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201611023106.9A Withdrawn CN106516837A (en) | 2016-11-19 | 2016-11-19 | Automatic adjusting type tensioning device |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN106516837A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107539816A (en) * | 2017-07-04 | 2018-01-05 | 芜湖市亿仑电子有限公司 | A kind of metallized film automatic transport clamping device |
| CN109230740A (en) * | 2018-08-01 | 2019-01-18 | 北京龙马负图科技有限公司 | A kind of Manual pressure bandage tension adjustment instruction device |
| CN110193504A (en) * | 2019-05-09 | 2019-09-03 | 中国长城葡萄酒有限公司 | Cylinder of steel cleaning device for outer walls |
| CN110950142A (en) * | 2019-12-13 | 2020-04-03 | 含山县金中环装饰材料有限公司 | Coiling mechanism is used in production of BOPP membrane |
-
2016
- 2016-11-19 CN CN201611023106.9A patent/CN106516837A/en not_active Withdrawn
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107539816A (en) * | 2017-07-04 | 2018-01-05 | 芜湖市亿仑电子有限公司 | A kind of metallized film automatic transport clamping device |
| CN109230740A (en) * | 2018-08-01 | 2019-01-18 | 北京龙马负图科技有限公司 | A kind of Manual pressure bandage tension adjustment instruction device |
| CN110193504A (en) * | 2019-05-09 | 2019-09-03 | 中国长城葡萄酒有限公司 | Cylinder of steel cleaning device for outer walls |
| CN110193504B (en) * | 2019-05-09 | 2024-03-26 | 中国长城葡萄酒有限公司 | Steel tank outer wall cleaning device |
| CN110950142A (en) * | 2019-12-13 | 2020-04-03 | 含山县金中环装饰材料有限公司 | Coiling mechanism is used in production of BOPP membrane |
| CN110950142B (en) * | 2019-12-13 | 2021-12-14 | 义乌伟岸塑业有限公司 | Coiling mechanism is used in production of BOPP membrane |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN106516837A (en) | Automatic adjusting type tensioning device | |
| CN106516838A (en) | Tensioning device capable of achieving automatic adjustment | |
| CN106516839A (en) | Self-adjusting tensioning gear | |
| CN106516836A (en) | Tension device capable of achieving automatic adjustment | |
| CN1618654A (en) | Vehicle seat with automatic height adjustment and method therefore | |
| CN106743892A (en) | Tension-adjusting gear | |
| CN208189698U (en) | Tab flattening device and up- coiler | |
| CN105606302A (en) | Belt tension meter calibration device | |
| CN106516835A (en) | Tension device capable of achieving automatic adjustment | |
| CN211418557U (en) | Adjustable conveyor belt tensioning device | |
| CN106494926A (en) | A kind of tensioner | |
| CN203600408U (en) | Concrete precast member production system and molding bench rolling wheel thereof | |
| CN112265562B (en) | Adjustable elastic pressing guide wheel device | |
| US20120037785A1 (en) | Spring arm device | |
| CN212862881U (en) | Deviation correcting device for belt conveyor | |
| CN101903597A (en) | Vibration plate having belt drive having multiple deflection | |
| US1433958A (en) | Power-transmission belt gearing | |
| CN106743893A (en) | Tensioning apparatus | |
| CN205426417U (en) | Belt tension counts calibrating device | |
| CN205371494U (en) | Belt tensioner adjustment mechanism | |
| CN104369640B (en) | Automobile and turning-angle-related rigidity-variable transverse stabilizing device of automobile | |
| US1057648A (en) | Dash-pot. | |
| CN203050193U (en) | Loading board lifting structure used for one-arm double-layer parking device | |
| CN209480887U (en) | A kind of film dividing equipment guide roller mechanism | |
| CN205973263U (en) | Tube -shape yarn tension ware |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| WW01 | Invention patent application withdrawn after publication |
Application publication date: 20170322 |
|
| WW01 | Invention patent application withdrawn after publication |