CN207552473U - A kind of placing device for anodic oxidation aluminium - Google Patents

A kind of placing device for anodic oxidation aluminium Download PDF

Info

Publication number
CN207552473U
CN207552473U CN201721639118.4U CN201721639118U CN207552473U CN 207552473 U CN207552473 U CN 207552473U CN 201721639118 U CN201721639118 U CN 201721639118U CN 207552473 U CN207552473 U CN 207552473U
Authority
CN
China
Prior art keywords
aluminium
end engaging
slot
anodic oxidation
clamping section
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 - Fee Related
Application number
CN201721639118.4U
Other languages
Chinese (zh)
Inventor
施建军
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.)
Fujian Xuhui Aluminum Co Ltd
Original Assignee
Fujian Xuhui Aluminum 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 Fujian Xuhui Aluminum Co Ltd filed Critical Fujian Xuhui Aluminum Co Ltd
Priority to CN201721639118.4U priority Critical patent/CN207552473U/en
Application granted granted Critical
Publication of CN207552473U publication Critical patent/CN207552473U/en
Expired - Fee Related legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Abstract

The utility model belongs to anodic oxidation of aluminiun materials technique equipment technical field, more particularly to a kind of placing device for anodic oxidation aluminium, including U-shaped dispenser, it is arranged on the U-shaped dispenser bottom plate and mode is inserted vertically by aluminium lower end for carrying out the lower end engaging unit of snap fit clip to the aluminium and being socketed the upper end engaging unit being arranged on described two columns of U-shaped dispenser and for carrying out engaging compression to the aluminium upper end.The utility model reaches aluminium and effectively places fixed purpose by way of setting lower end engaging unit and upper end engaging unit on U-shaped dispenser.The utility model, which has, to be placed with the advantages of simple in structure effective, aluminium loading or unloading operation is convenient and places good fixing effect.

Description

A kind of placing device for anodic oxidation aluminium
Technical field
The utility model belongs to anodic oxidation of aluminiun materials technique equipment technical field more particularly to one kind for anodic oxidation The placing device of aluminium.
Background technology
Anodic oxidation aluminium refers to a kind of by anode oxidation process and in the advanced aluminium of aluminium material surface formation oxidation film Material.Anode oxidation process is under corresponding electrolyte and specific process conditions, by the effect of impressed current, in common aluminium Surface forms one layer of protective oxide layer, the defects of to overcome aluminum alloy surface hardness, wear resistance etc., expands using model It encloses, prolongs the service life.On the other hand, at present there is certain pick and place in existing anodic oxidation of aluminiun materials technique placing device Complicated and fixed the problem of being not sufficiently stable is operated, the problem of aluminium comes off from placing device occurs once in a while.
The Chinese utility model patent that patent announcement number is 205474048 U of CN, the day for announcing is 2016.08.17 discloses A kind of anodizing hanging device for placing aluminum bottle cover, including hanger, the multiple hanging rods being connected on hanger and is arranged on hanging rod On fixture, the fixture is the elastic piece to take the shape of the letter U, and the elastic piece includes the fixed plate being connected on hanging rod, both ends connection Head clamp in fixed plate, the guide plate being connected on head clamp, the guide plate described in both ends are between necking setting and minimum Away from the caliber less than bottle cap, the spacing of the head clamp is more than the caliber of bottle cap.
But there are fixed effect is poor and the problem of workpiece loading or unloading operation is complicated for the hanger in the utility model.
Utility model content
The purpose of this utility model is to provide a kind of placing device for anodic oxidation aluminium, can be by U-shaped peace The mode that lower end engaging unit and upper end engaging unit are set on frame is put, reaches aluminium and effectively places fixed purpose.This reality There is placement with the advantages of simple in structure effective, aluminium loading or unloading operation is convenient and places good fixing effect with novel.
The utility model solve the above problems the technical solution adopted is that:A kind of placement for anodic oxidation aluminium fills It puts, including U-shaped dispenser, is arranged on the U-shaped dispenser bottom plate and mode is inserted vertically into for right by aluminium lower end The aluminium carries out the lower end engaging unit of snap fit clip and socket is arranged on described two columns of U-shaped dispenser and is used in combination In the upper end engaging unit that engaging compression is carried out to the aluminium upper end.
Further preferred technical solution is:The lower end engaging unit includes the lower end card being arranged on the bottom plate Slot is closed, two limiting plates on the bottom plate and at the lower end engaging slot both sides setting is separately positioned on, is arranged on institute It states in the engaging slot of lower end and triggers the lower end engaging unit to the aluminium card by way of being retracted downwards The tight triggering block of co-clip is separately positioned in the lower end engaging slot and for carrying out the two of snap fit clip to the aluminium bottom end A first clamping section and be separately positioned in the lower end engaging slot and the limiting plate and for the aluminium lower end into Two the second clamping sections of row snap fit clip.
Further preferred technical solution is:The lower end engaging slot is dovetail groove, and section is described for trapezoidal shape Triggering block is arranged on by support spring on the slot bottom of the lower end engaging slot.
Further preferred technical solution is:Region of the aluminium across two limiting plates and to underthrust It taps into the lower end engaging slot, the limiting plate includes limiting plate body and for the second clamping section described in installation settings Lateral fluting.
Further preferred technical solution is:First clamping section includes the folder being arranged in the lower end engaging slot Tight portion's pedestal, the clamping slot being arranged on the clamping section pedestal and is arranged on by adjustable spring on the clamping slot First clamps bulb.
Further preferred technical solution is:Between two end side surfaces of the clamping section pedestal and the lower end engaging slot The side openings for the second clamping section described in installation settings are formed, the clamping section pedestal is engaged by pedestal mounting blocks to be set On the trough rim of the lower end engaging slot.
Further preferred technical solution is:Second clamping section includes the clamping section being arranged in the limiting plate Shaft, the swivel plate being arranged in the clamping section shaft and is arranged on the swivel plate lower end and by the triggering block The slide block that triggering mode carries out the aluminium for clamping column snap fit clip is stirred downwards, and the slide block is close to described Inclined-plane is used in stirring for the side of triggering block.
Further preferred technical solution is:The swivel plate lower end is equipped with different from the side of the setting slide block and uses In balancing the swivel plate to keep the balance weight of vertical state, the weight of the balance weight is more than the slide block.
Further preferred technical solution is:The distance between the slide block and first clamping section are less than described The distance between balance weight and the lower end engaging slot side.
Further preferred technical solution is:The upper end engaging unit includes upper end and engages plate body, is arranged on institute It states the column sleeve joint hole at the engaging plate body both sides position of upper end and is arranged in the middle part of the upper end engaging plate body and is used for Engaging downwards compresses the upper end engaging slot of the aluminium, and the upper end engaging slot extends out type groove body for the small shape of outer imperial palace.
The utility model is reached by way of setting lower end engaging unit and upper end engaging unit on U-shaped dispenser Fixed purpose is effectively placed to aluminium.The utility model have place with it is simple in structure effectively, aluminium loading or unloading operation facilitate with And the advantages of placing good fixing effect.
Description of the drawings
Fig. 1 is the structure diagram of the utility model.
Fig. 2 is the positional structure schematic diagram of lower end engaging unit in the utility model.
Fig. 3 is the structure diagram of upper end engaging unit in the utility model.
Fig. 4 is the schematic view of the mounting position of the first clamping section in the utility model.
Fig. 5 uses schematic diagram for the utility model.
Specific embodiment
As described below is only the preferred embodiment of the utility model, and not the scope of the utility model is defined.
Embodiment:As shown in attached drawing 1,2,3,4 and attached drawing 5, a kind of placing device for anodic oxidation aluminium, including U-shaped dispenser 1 is arranged on 1 bottom plate of U-shaped dispenser and is inserted vertically into mode by 4 lower end of aluminium for described Aluminium 4 carries out the lower end engaging unit 2 of snap fit clip and socket is arranged on described 1 two columns of U-shaped dispenser and is used for The upper end engaging unit 3 of engaging compression is carried out to 4 upper end of aluminium.
In the present embodiment, the aluminium 4 is arranged in the U-shaped framework of the U-shaped dispenser 1, and the lower end engaging is single Member 2 and upper end engaging unit 3 fix the aluminium 4 from the lower part of the aluminium 4 and top respectively, ensure the aluminium 4 It will not be fallen from the U-shaped dispenser 1 easily so that anode oxidation process is smooth.
The lower end engaging unit 2 includes the lower end engaging slot 201 being arranged on the bottom plate, is separately positioned on the bottom Two limiting plates 202 on plate and at the 201 both sides setting of lower end engaging slot, are arranged on the lower end engaging slot 201 It is interior and snap fit clip is carried out to the aluminium 4 for triggering the lower end engaging unit 2 by way of being retracted downwards touch Block 203 is sent out, is separately positioned in the lower end engaging slot 201 and for carrying out two of snap fit clip to 4 bottom end of aluminium It first clamping section 204 and is separately positioned in the lower end engaging slot 201 and the limiting plate 202 and for the aluminium 4 lower end of material carries out two the second clamping sections 205 of snap fit clip.
In the present embodiment, space and the entrance lower end card of the aluminium 4 across two limiting plates 202 It closes in slot 201, and triggering 204 and second clamping section 205 of the first clamping section is stirred by the triggering block 203 so that The bottom end and lower end of the aluminium 4 are acted on by effective snap fit clip, avoid the problem that comes off of the aluminium 4.
The lower end engaging slot 201 is dovetail groove, and section passes through support spring for the triggering block 203 of trapezoidal shape 206 are arranged on the slot bottom of the lower end engaging slot 201.
Simultaneously grafting downwards enters the lower end engaging slot in region of the aluminium 4 across two limiting plates 202 201, the limiting plate 202 includes limiting plate body 202a and is opened for the lateral of the second clamping section 205 described in installation settings Slot 202b.
First clamping section 204 includes the clamping section pedestal 204a being arranged in the lower end engaging slot 201, is arranged on Clamping slot 204b on the clamping section pedestal 204a and be arranged on by adjustable spring on the clamping slot 204b first Clamp bulb 204c.
In the present embodiment, the both sides of the triggering block 203 are inclined ramp, in the triggering block 203 by the aluminium 4 Before pushing is stirred, the triggering block 203 is concordant with the notch of the lower end engaging slot 201, and described first clamps bulb 204c tops On the inclined side of the triggering block 203 and keep state to be triggered.
Then, the triggering block 203 is stirred in the pushing of aluminium 4, and the triggering block 203 declines, first clamping balls Head 204c slips over the inclined side of the triggering block 203 and rests on the aluminium 4 under the jack-up effect of the adjustable spring Side on, pairs of described first, which clamps bulb 204c, completes bottom snap fit clip operation to the aluminium 4, wherein described Triggering block 203 can falling head be 2-5cm, ensure it is described first clamp bulb 204c at the 3-4cm height of the aluminium 4 into The effective snap fit clip operation of row.
It is formed between two end side surfaces of the clamping section pedestal 204a and the lower end engaging slot 201 for installation settings institute The side openings of the second clamping section 205 are stated, the clamping section pedestal 204a is arranged on described by pedestal mounting blocks 204d engagings On the trough rim of lower end engaging slot 201.
In the present embodiment, the triggering block 203, the first clamping section 204 and the second clamping section 205 are all or part of It is arranged in the lower end engaging slot 201, wherein the lower end engaging slot 201 inside contracts shape as opening, is unfavorable for inwardly pacifying Dress other structures component, and the engaging inserting mode of the clamping section pedestal 204a so that the lower end engaging slot 201 is opened It is open, to facilitate the installation placement operation of 203 and second clamping section 205 of triggering block.
On the other hand, it is described in first installation toward erection sequence in the lower end engaging slot 201 in the lower end engaging unit 2 203 and second clamping section 205 of triggering block, then engage installation first clamping section 204, at this time the lower end engaging slot 201 It is " closed ", the entire lower end engaging unit 2 installs, and 204 and second clamping section 205 of the first clamping section is located In effective state to be stirred.
Second clamping section 205 includes the clamping section shaft 205a being arranged in the limiting plate 202, is arranged on described Swivel plate 205b on the shaft 205a of clamping section and it is arranged on the swivel plate 205b lower ends and by the triggering block 203 The slide block 205d that triggering mode carries out the aluminium 4 for clamping column 205c snap fit clip is stirred downwards, it is described to stir Block 205d uses inclined-plane close to the stirring for side of the triggering block 203.
In the present embodiment, 205 lower part of the second clamping section is located in the lower end engaging slot 201, by the triggering Block 203 is stirred downwards and triggers rotation, and 205 top of the second clamping section is located in the lateral fluting 202b, is used for Snap fit clip operation is carried out to the lower end side of the aluminium 4 after outside Unscrew, in addition two clamping column 205c it Between be open by proximal end distance with the lower end engaging slot 201 and the bottom plate of the aluminium 4 is consistent to width, ensure first The aluminium 4 smoothly enters the lower end engaging slot 201 after being inserted into, secondly so that clamping column 205c progress is a degree of After outside Unscrew, you can carry out effective snap fit clip operation to the aluminium 4.
In the present embodiment, the clamping column 205c is at the 8-12cm of the aluminium 4, i.e., at " lower end " position, carries out Snap fit clip operates, and the realization step of snap fit clip operation is as follows:
First, the lower end seamed edge of the triggering block 203, which is stirred downwards and withstands on the described of the slide block 205d, stirs use On inclined-plane, the slide block 205d carries out rotation process around the clamping section shaft 205a;
Second, the slide block 205d drives swivel plate 205b and clamping column 205c progress Unscrew, two The clamping column 205c comes closer, and completes the snap fit clip operation to the aluminium 4, the placement fixed operation of the aluminium 4 It completes;
Third, the aluminium 4 complete anodic oxidation operation, and the aluminium 4 is raised, described first clamp bulb 204c according to The inclined surface of the secondary side and triggering block 203 for slipping over the aluminium 4, and the clamping is inwardly pushed back by the triggering block 203 In slot 204b, second clamping section 205 also rotates return, is embodied in the clamping column 205c and turns round outward, described group Motion block 205d is rotated up, and trigger action is stirred next time with treat the aluminium 4.
In addition, the support spring 206 is arranged in spring spool, the upper end level of the spring spool is dialled higher than described The height of motion block 205d lower faces horizontality enters the slide block 205d to avoid the 203 lower end seamed edge of triggering block Lower section avoids the slide block 205d that stuck phenomenon occurs with the triggering block 203.
The swivel plate 205b lower ends are equipped with to balance the swivel plate different from the side of the setting slide block 205d 205b with keep the weight of the balance weight 205e, the balance weight 205e of vertical state be more than the slide block 205d.
In the present embodiment, the balance weight 205e is used to balance the weight of the slide block 205d and clamping column 205c Amount, ensures the vertical state of the swivel plate 205b, ensures that stirring for the slide block 205d is located at the triggering block with inclined-plane Effectively stirring at position below 203 lower end seamed edges.
The distance between the slide block 205d and first clamping section 204 be less than the balance weight 205e with it is described under Hold the distance between 201 side of engaging slot.
In the present embodiment, in order to enable the structure of the placing device is compacter so that equally length is described U-shaped More aluminiums 4 can be placed on dispenser 1, the slide block 205d only sets rotation space in rotation side outward, Space between first clamping section 204 is opposite to the direction of rotation, so without setting, to ensure that the lower end engages The space of slot 201 is able to save and utilize.
The upper end engaging unit 3 includes upper end and engages plate body 301, is arranged on 301 liang of the plate body of upper end engaging It column sleeve joint hole 302 at side position and is arranged on 301 middle part of upper end engaging plate body and is compressed for engaging downwards The upper end engaging slot 303 of the aluminium 4, the upper end engaging slot 303 extend out type groove body for the small shape of outer imperial palace.
In the present embodiment, when the aluminium 4 is inserted into the lower end engaging slot 201, the engaging of the lower end engaging unit 2 Clamp operation has just realized that the upper end engaging unit 3 compresses the aluminium 4 again, completes entire aluminium placement operation.
On the other hand, the external opening of upper end engaging slot 303 is more than the width of the aluminium 4, and interior groove Bottom width degree is then less than the width of the aluminium 4 so that the upper end engaging slot 303 is when engaging compresses the aluminium 4, the aluminium Two lateral edges of upper end of material 4 can be effectively withstood in the outer inclined-plane of the upper end engaging slot 303, ensure that top engaging compresses behaviour Make, wherein the pressure result compressed is realized by its own gravity of upper end engaging plate body 301.On the other hand, the upper end Engage plate body 301 first to retract upwards, the aluminium 4 is extracted upwards out of described lower end engaging slot 201 again, you can complete entire Aluminium takes out operation, has the advantages that convenient and efficient.
The embodiment of the utility model is explained in detail above in conjunction with attached drawing, but the utility model is not limited to Embodiment is stated, in the knowledge having in the technical field those of ordinary skill, this practicality can also not departed from Various modifications are made under the premise of novel objective.These are all without creative modification, as long as in the power of the utility model It is all protected in sharp claimed range by Patent Law.

Claims (10)

1. a kind of placing device for anodic oxidation aluminium, it is characterised in that:Including U-shaped dispenser(1), it is arranged on the U Type dispenser(1)Mode is inserted vertically into for carrying out the lower end of snap fit clip to the aluminium on bottom plate and by aluminium lower end Engaging unit(2)And socket is arranged on the U-shaped dispenser(1)On two columns and for being carried out to the aluminium upper end Engage the upper end engaging unit compressed(3).
2. a kind of placing device for anodic oxidation aluminium according to claim 1, it is characterised in that:The lower end card Close unit(2)Including the lower end engaging slot being arranged on the bottom plate(201), it is separately positioned on the bottom plate and positioned at described Lower end engaging slot(201)Two limiting plates at the setting of both sides(202), it is arranged on the lower end engaging slot(201)It is interior and pass through The mode being retracted downwards is for the triggering lower end engaging unit(2)The triggering block of snap fit clip is carried out to the aluminium (203), it is separately positioned on the lower end engaging slot(201)It is interior and for carrying out two of snap fit clip the to the aluminium bottom end One clamping section(204)And it is separately positioned on the lower end engaging slot(201)With the limiting plate(202)It is interior and for institute State two the second clamping sections that aluminium lower end carries out snap fit clip(205).
3. a kind of placing device for anodic oxidation aluminium according to claim 2, it is characterised in that:The lower end card Close slot(201)For dovetail groove, section is the triggering block of trapezoidal shape(203)Pass through support spring(206)It is arranged on described Lower end engaging slot(201)Slot bottom on.
4. a kind of placing device for anodic oxidation aluminium according to claim 2, it is characterised in that:The aluminium is worn Cross two limiting plates(202)Between region and downwards grafting enter the lower end engaging slot(201), the limiting plate (202)Including limiting plate body(202a)And for the second clamping section described in installation settings(205)Lateral fluting (202b).
5. a kind of placing device for anodic oxidation aluminium according to claim 2, it is characterised in that:First folder Tight portion(204)Including being arranged on the lower end engaging slot(201)Interior clamping section pedestal(204a), it is arranged on the clamping section base Seat(204a)On clamping slot(204b)And the clamping slot is arranged on by adjustable spring(204b)On the first clamping balls Head(204c).
6. a kind of placing device for anodic oxidation aluminium according to claim 5, it is characterised in that:The clamping section Pedestal(204a)With the lower end engaging slot(201)Two end side surfaces between formed for the second clamping section described in installation settings (205)Side openings, the clamping section pedestal(204a)Pass through pedestal mounting blocks(204d)Engaging is arranged on the lower end card Close slot(201)Trough rim on.
7. a kind of placing device for anodic oxidation aluminium according to claim 2, it is characterised in that:Second folder Tight portion(205)Including being arranged on the limiting plate(202)Interior clamping section shaft(205a), it is arranged on the clamping section shaft (205a)On swivel plate(205b)And it is arranged on the swivel plate(205b)Lower end simultaneously passes through the triggering block(203)To Under stir triggering mode for clamping column(205c)The slide block of snap fit clip is carried out to the aluminium(205d), it is described to stir Block(205d)Close to the triggering block(203)Stirring for side use inclined-plane.
8. a kind of placing device for anodic oxidation aluminium according to claim 7, it is characterised in that:The swivel plate (205b)Lower end is different from the setting slide block(205d)Side be equipped with for balancing the swivel plate(205b)To keep perpendicular The balance weight of straight state(205e), the balance weight(205e)Weight be more than the slide block(205d).
9. a kind of placing device for anodic oxidation aluminium according to claim 8, it is characterised in that:The slide block (205d)With first clamping section(204)The distance between be less than the balance weight(205e)With the lower end engaging slot (201)The distance between side.
10. a kind of placing device for anodic oxidation aluminium according to claim 1, it is characterised in that:The upper end Engaging unit(3)Engage plate body including upper end(301), it is arranged on the upper end engaging plate body(301)At two side positions Column sleeve joint hole(302)And it is arranged on the upper end engaging plate body(301)Middle part simultaneously compresses the aluminium for engaging downwards The upper end engaging slot of material(303), the upper end engaging slot(303)Type groove body is extended out for the small shape of outer imperial palace.
CN201721639118.4U 2017-11-30 2017-11-30 A kind of placing device for anodic oxidation aluminium Expired - Fee Related CN207552473U (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201721639118.4U CN207552473U (en) 2017-11-30 2017-11-30 A kind of placing device for anodic oxidation aluminium

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201721639118.4U CN207552473U (en) 2017-11-30 2017-11-30 A kind of placing device for anodic oxidation aluminium

Publications (1)

Publication Number Publication Date
CN207552473U true CN207552473U (en) 2018-06-29

Family

ID=62678305

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201721639118.4U Expired - Fee Related CN207552473U (en) 2017-11-30 2017-11-30 A kind of placing device for anodic oxidation aluminium

Country Status (1)

Country Link
CN (1) CN207552473U (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107747114A (en) * 2017-11-30 2018-03-02 福建旭晖铝业有限公司 A kind of placing device for anodic oxidation aluminium

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107747114A (en) * 2017-11-30 2018-03-02 福建旭晖铝业有限公司 A kind of placing device for anodic oxidation aluminium

Similar Documents

Publication Publication Date Title
CN202688493U (en) Electroplating device with overturning mechanism
CN205474048U (en) Anodic oxidation hanger of aluminium system of placing bottle lid
CN207552473U (en) A kind of placing device for anodic oxidation aluminium
CN107747114A (en) A kind of placing device for anodic oxidation aluminium
CN107723772A (en) A kind of oxidation aluminium material clamp
CN207552474U (en) A kind of oxidation aluminium material clamp
CN106786027B (en) A kind of power equipment case support base
CN218617878U (en) Kit for detecting squamous cell carcinoma antigen
CN216287437U (en) Moral education propaganda platform
CN207738406U (en) One kind disposes waste liquid is lifted cleaning mechanism with electrode plate
CN209761276U (en) Adjustable landscape door and window flowerpot placing frame
CN206762402U (en) A kind of root of kudzu vine slurries centrifugal filter device
CN208550306U (en) A kind of writing brush storage box of the drills to improve one's handwriting convenient for assembling
CN206770381U (en) A kind of vacuum cup
CN217549048U (en) Cholesterol extraction tank
CN208071838U (en) A kind of copper ball feeding device for electroplating bath
CN207683898U (en) Automatic material connection sack-filling device
CN206799754U (en) Cupric dangerous waste processing electrolytic cell
CN212833961U (en) Aluminum alloy heat treatment equipment
CN214912998U (en) A portable goat apparatus for Thomas training
CN116988132B (en) Gantry barrel plating device
CN213038238U (en) Warning device for construction that warning effect is good
CN215404627U (en) Anodic oxidation electrode support
CN216735816U (en) Household garbage can
CN211099911U (en) Sunroof guide rail spout oiling station

Legal Events

Date Code Title Description
GR01 Patent grant
GR01 Patent grant
CF01 Termination of patent right due to non-payment of annual fee

Granted publication date: 20180629

Termination date: 20181130

CF01 Termination of patent right due to non-payment of annual fee