CN104637392A - Multifunctional four-bar mechanism demonstrator - Google Patents

Multifunctional four-bar mechanism demonstrator Download PDF

Info

Publication number
CN104637392A
CN104637392A CN201510099924.6A CN201510099924A CN104637392A CN 104637392 A CN104637392 A CN 104637392A CN 201510099924 A CN201510099924 A CN 201510099924A CN 104637392 A CN104637392 A CN 104637392A
Authority
CN
China
Prior art keywords
frame
slide block
bar
guide rail
bar mechanism
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.)
Granted
Application number
CN201510099924.6A
Other languages
Chinese (zh)
Other versions
CN104637392B (en
Inventor
罗红萍
陈道椿
卢海燕
陈遵平
任瑞如
魏小勇
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.)
Guangxi University of Science and Technology
Original Assignee
Guangxi University of Science and Technology
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 Guangxi University of Science and Technology filed Critical Guangxi University of Science and Technology
Priority to CN201510099924.6A priority Critical patent/CN104637392B/en
Publication of CN104637392A publication Critical patent/CN104637392A/en
Application granted granted Critical
Publication of CN104637392B publication Critical patent/CN104637392B/en
Expired - Fee Related legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09B—EDUCATIONAL OR DEMONSTRATION APPLIANCES; APPLIANCES FOR TEACHING, OR COMMUNICATING WITH, THE BLIND, DEAF OR MUTE; MODELS; PLANETARIA; GLOBES; MAPS; DIAGRAMS
    • G09B25/00—Models for purposes not provided for in G09B23/00, e.g. full-sized devices for demonstration purposes
    • G09B25/02—Models for purposes not provided for in G09B23/00, e.g. full-sized devices for demonstration purposes of industrial processes; of machinery

Landscapes

  • Engineering & Computer Science (AREA)
  • Business, Economics & Management (AREA)
  • Physics & Mathematics (AREA)
  • Educational Administration (AREA)
  • Educational Technology (AREA)
  • General Physics & Mathematics (AREA)
  • Theoretical Computer Science (AREA)
  • Toys (AREA)

Abstract

The invention discloses a multifunctional four-bar mechanism demonstrator, and relates to a teaching aid. The multifunctional four-bar mechanism demonstrator comprises a wooden box, a rack, a frame connecting rod, a telescopic connecting rod, a sliding block, a sliding block guide rail, a guide rail rotating bracket, a drawing board and a paintbrush, wherein the wooden box comprises a box body; the upper and lower halves of the box body are connected together through hinges; demonstration boards are arranged on the inner bottom surfaces of the upper and lower halves of the box body; magnetic strips for sucking the wooden box onto a blackboard are arranged on the demonstration boards; the rack is arranged on the demonstration boards, and is hinged to the telescopic connecting rod through the frame connecting rod; the sliding block is arranged on the telescopic connecting rod, and is matched with the sliding rod guide rail in a sliding manner; one end of the sliding block guide rail is a free end, and the other end of the sliding block guide rail is hinged to one end of the guide rail rotating bracket; the other end of the guide rail rotating bracket is hinged to the demonstration boards through dowels. The multifunctional four-bar mechanism demonstrator has the characteristics of convenience in carrying and operation, functional diversity, good demonstration effects and low cost, and is easy to popularize and use.

Description

Multi-functional four-bar mechanism demonstrator
Technical field
The present invention relates to a kind of teaching aid, particularly a kind of multi-functional four-bar mechanism demonstrator.
Background technology
Along with the raising of people's living standard, people more and more focus on the quality of living.Learn no exception, pure theory teaching has seemed uninteresting, and academics and students expect to integrate theory with practice.In learning process, can find that students is when the relevant knowledge of study four-bar linkage, is not readily appreciated that.Particularly in time talking about " by two side links by predetermined correspondence position design four-bar mechanism ", they do not understand how reversal process operates.This just needs the assistant teaching aid adopting some directly can demonstrate on classroom.And current existing relevant teaching aid carries inconvenience, and complicated operation, function singleness.Ratio is if any four-bar linkage teaching appliance (patent announcement CN202075903U easy to carry ), this teaching appliance, when rod member rotates, needs to take frame with hand, paintbrush also cannot be adopted to draw movement locus simultaneously; Also certain operations four-bar linkage demonstrator (patent publication No. CN102034388A is easily had in addition ), but this demonstrator has an erecting frame, and floor area is large, and is not easy to carry, and paintbrush certainly also cannot be adopted to draw movement locus.
Summary of the invention
The technical problem to be solved in the present invention is: the multi-functional four-bar mechanism demonstrator providing a kind of easy to carry, easy and simple to handle, functional diversities, to solve prior art above shortcomings part.
The technical scheme solved the problems of the technologies described above is: a kind of multi-functional four-bar mechanism demonstrator, comprises tub, the frame laid respectively in tub, side link, extensible link, slide block, slide block guide rail, guide rail swinging mounting; Described tub comprises box body, and by gemel connection together, the inner bottom surface of the upper and lower two halves of box body is demonstration board to the two halves up and down of box body, and demonstration board is provided with the magnetic stripe for being adsorbed on by tub on blackboard; Described frame is arranged on demonstration board, this frame by described side link and extensible link hinged; Extensible link is provided with described slide block; Slide block and slide block guide rail are slidably matched, and this slide block guide rail one end is free end, the other end of slide block guide rail and one end of guide rail swinging mounting hinged, the other end of guide rail swinging mounting by pin-hinges on demonstration board.
Further technical scheme of the present invention is: described extensible link comprises con-rod only, and con-rod only is provided with chute, and described slide block is arranged on this chute.
Described side link comprises side link I and side link II, and one end of this side link I and side link II is hinged with the two ends of extensible link respectively.
Described frame comprises frame body, scalable frame bar, frame slide block, frame bar, gear, tooth bar; Described frame body is fixed on the demonstration board of tub, and scalable frame bar is arranged in frame body, and frame slide block is arranged on scalable frame bar; Described frame bar one end by securing member and frame slide block hinged, the other end of frame bar and the other end of side link I hinged; Described gear, tooth bar engage each other, the input shaft of gear and the other end of side link II hinged.
Described scalable frame bar comprises fixed length machine hack lever body, and this fixed length machine hack lever body is provided with guide-track groove, and described frame slide block is arranged on this guide-track groove.
Described tooth bar is also provided with screw.
This demonstrator also includes drawing board and paintbrush, and described drawing board is connected with the screw on tooth bar in use, be adsorbed on the magnetic stripe of tub when not using; Described paintbrush is arranged on slide block.
Also be provided with angle dial between described gear and demonstration board, slide block guide rail is also provided with length scale.
The two halves up and down of described tub are respectively equipped with snap close and handle.
Owing to adopting said structure, the multi-functional four-bar mechanism demonstrator of the present invention compared with prior art, has following beneficial effect:
1. easy to carry:
Owing to the present invention includes tub, the frame laid respectively in tub, side link, extensible link, slide block, slide block guide rail, guide rail swinging mounting; All be positioned at tub owing to all demonstrating rod member, and tub be upper and lower two halves by gemel connection folding structure together, therefore, all can be contained in all demonstrating rod member in box, then tub is closed, can withdraw, it carries very convenient.
2. easy and simple to handle:
Because tub of the present invention is provided with the magnetic stripe for being adsorbed on by tub on blackboard on demonstration board, therefore demonstrate time can like a cork by this demonstrator " stickup " on blackboard, without the need to taking frame with hand, its operation is easier, also save space, convenient for student viewing, rotate flexibly, easy to operate, mounting or dismounting are convenient.
3. functional diversities:
Due to this demonstrator comprise tub, the frame laid respectively in tub, side link, extensible link, slide block, slide block guide rail, guide rail swinging mounting, and frame comprises frame body, scalable frame bar, frame slide block, frame bar, gear, tooth bar; Therefore, the present invention can realize following functions:
(1) circumferential rotation type is done using side link II as crank, when can demonstrate crank and rocker mechanism;
(2) double-crank mechanism and double rocker mechanism can be demonstrated by adjuster bar length;
(3) slider-crank mechanism can be demonstrated by access slide block;
(4) can demonstrate by two side links by predetermined correspondence position design four-bar mechanism, and directly can draw track on drawing board;
(5) whether utilize the result of the differential seat angle of analytic calculation two instantaneous positions or displacement difference gained correct, and obtain required size by adjuster bar is long if can demonstrate real-time verification.
Therefore, the present invention not only can classroom use, and also can use when testing, its range of application is more extensive.
4. can draw movement locus, operating process is high-visible:
Because the present invention also includes drawing board and paintbrush, wherein paintbrush is arranged on slide block, and when slide block movement, paintbrush moves thereupon, thus can draw movement locus, make operating process high-visible, and track is also totally erasable.
5. good demonstration effect, student is by watching or operating, and impact is dark, easy to understand:
The present invention can demonstrate the principle of work of four-bar linkage, whether the demonstration fundamental type of four-bar linkage and evolution thereof, demonstration two side link utilize the result of the differential seat angle of analytic calculation two instantaneous positions or displacement difference gained correct by predetermined correspondence position design four-bar mechanism, real-time verification, good demonstration effect, student is by watching or operating, impact is dark, easy to understand, learning content can be made to change add enrich interesting, thus evoke the enthusiasm of attending class of classmates, create a positive interactive classroom atmosphere, make classroom become lighter.
6. each several part many employings standard component, cheap material, with low cost, is easy to promote the use of.
Below, in conjunction with the accompanying drawings and embodiments the technical characteristic of the multi-functional four-bar mechanism demonstrator of the present invention is further described.
Accompanying drawing explanation
Fig. 1: the structural representation of the multi-functional four-bar mechanism demonstrator of the present invention,
Fig. 2: the present invention demonstrates schematic diagram during centric slider-crank mechanism;
Fig. 3: the present invention draws the schematic diagram of slide block movement track;
Fig. 4: by the schematic diagram of connecting rod rest Position Design four-bar mechanism.
In above-mentioned accompanying drawing, each label declaration is as follows:
1-tub,
101-box body, 102-demonstration board, 103-magnetic stripe, 104-snap close, 105-handle,
2-frame,
201-frame body, the scalable frame bar of 202-, 2021-guide-track groove, 203-frame slide block, 204-frame bar,
205-gear, 206-tooth bar, 207-screw, 208-angle dial,
3-side link, 301-side link I, 302-side link II,
4-extensible link, 401-chute,
5-slide block, 6-slide block guide rail, 7-guide rail swinging mounting, 8-drawing board, 9-paintbrush.
Embodiment
Embodiment one:
A kind of multi-functional four-bar mechanism demonstrator, comprises tub 1, the frame 2 laid respectively in tub, side link 3, extensible link 4, slide block 5, slide block guide rail 6, guide rail swinging mounting 7, drawing board 8 and paintbrush 9; Wherein:
Described tub 1 comprises box body 101, the two halves up and down of box body 101 by gemel connection together, the inner bottom surface of box body about 101 two halves is demonstration board 102, demonstration board 102 is provided with the magnetic stripe 103 for being adsorbed on by tub on blackboard, and the two halves up and down of tub 1 are respectively equipped with snap close 104 and handle 105.
Described side link 3 comprises side link I 301 and side link II 302, and one end of this side link I 301 and side link II 302 is hinged with the two ends of extensible link 4 respectively.
Described frame 2 comprises frame body 201, scalable frame bar 202, frame slide block 203, frame bar 204, gear 205, tooth bar 206; Wherein frame body 201 is fixed on the demonstration board 102 of tub 1, scalable frame bar 202 is arranged in frame body 201, this scalable frame bar 202 comprises fixed length machine hack lever body, this fixed length machine hack lever body is provided with guide-track groove 2021, and described frame slide block 203 is arranged on this guide-track groove 2021; Described frame bar 204 one end by bolt, nut fastener and frame slide block 203 hinged, the other end of frame bar 204 and the other end of side link I 301 hinged; Described gear 205, tooth bar 206 engage each other, the input shaft of gear 205 and the other end of side link II 302 hinged, tooth bar 206 is also provided with screw 207, between gear 205 and demonstration board 102, is also provided with angle dial 208;
Described extensible link 4 comprises con-rod only, con-rod only is provided with chute 401, described slide block 5 is arranged on this chute 401, this slide block 5 is slidably matched with slide block guide rail 6, slide block guide rail 6 is provided with length scale, one end of slide block guide rail 6 is free end, the other end of slide block guide rail 6 and one end of guide rail swinging mounting 7 hinged, the other end of guide rail swinging mounting 7 by pin-hinges on demonstration board 102.
Described drawing board 8 is connected with the screw 207 on tooth bar in use, be adsorbed on the magnetic stripe 103 of tub when not using; Described paintbrush 9 is arranged on slide block 5.
Principle of work of the present invention:
(1) replace rocking bar with the slide block of diverse location, be convenient to demonstration centric slider-crank mechanism and offset slider-crank mechanism and quickreturn characteristics thereof, and then understand four-bar linkage.
(2) as shown in Figure 4, when extensible link occupies each precalculated position, two side links all correspondingly have corner α i, the φ i of a pair correspondence, or one group of correspondence position ABi and DCi.So by extensible link preposition design four-bar mechanism, and design the method for four-bar mechanism by the correspondence position that two side links are predetermined, can think in fact equally.Now give two positions of four-bar mechanism, corresponding corner α 1, the φ 1 of its two side link and α 2, φ 2.If imagined, whole mechanism is turned over (φ 1-φ 2) angle around the axle center D of component CD in the opposite direction by with turning of component CD.Obviously this does not affect each inter-agency relative motion.But now component CD has rotated back into DC1 by DC2 position, component AB has then moved to AB3 position by AB2.Through such conversion, can think that this mechanism has become with CD is frame, take AB as the four-bar mechanism of connecting rod, thus design the problem of four-bar mechanism by the correspondence position that two side links are predetermined, also just changed into the problem by connecting rod precalculated position design four-bar mechanism.
(3) by sticking scale paper with hinge centres as the center of circle in frame, and slide block guide rail sticking scale paper, realizing quantitatively demonstrating.
Using method of the present invention:
When 1. demonstrating crank and rocker mechanism, do circumferential rotation type using the shortest side link as crank;
When 2. demonstrating double-crank mechanism and double rocker mechanism, realize by adjuster bar is long;
When 3. demonstrating slider-crank mechanism, can connect and realize into slide block;
4., when demonstration designs four-bar mechanism by two side links by predetermined correspondence position, directly track can be drawn on drawing board;
5., when demonstration real-time verification utilizes the result of the differential seat angle of analytic calculation two instantaneous positions or displacement difference gained whether correct, required size is obtained by adjuster bar is long.

Claims (9)

1. a multi-functional four-bar mechanism demonstrator, is characterized in that: comprise tub (1), the frame (2) laid respectively in tub, side link (3), extensible link (4), slide block (5), slide block guide rail (6), guide rail swinging mounting (7); Described tub (1) comprises box body (101), the two halves up and down of box body (101) by gemel connection together, the inner bottom surface of the upper and lower two halves of box body (101) is demonstration board (102), and demonstration board (102) is provided with the magnetic stripe (103) for being adsorbed on by tub on blackboard; Described frame (2) is arranged on demonstration board (102), and this frame (2) is hinged by described side link (3) and extensible link (4); Extensible link (4) is provided with described slide block (5); Slide block (5) and slide block guide rail (6) are slidably matched, this slide block guide rail (6) one end is free end, the other end of slide block guide rail (6) and one end of guide rail swinging mounting (7) hinged, the other end of guide rail swinging mounting (7) by pin-hinges on demonstration board (102).
2. multi-functional four-bar mechanism demonstrator according to claim 1, is characterized in that: described extensible link (4) comprises con-rod only, and con-rod only is provided with chute (401), and described slide block (5) is arranged on this chute (401).
3. multi-functional four-bar mechanism demonstrator according to claim 1, it is characterized in that: described side link (3) comprises side link I (301) and side link II (302), one end of this side link I (301) and side link II (302) is hinged with the two ends of extensible link (4) respectively.
4. multi-functional four-bar mechanism demonstrator according to claim 3, is characterized in that: described frame (2) comprises frame body (201), scalable frame bar (202), frame slide block (203), frame bar (204), gear (205), tooth bar (206); Described frame body (201) is fixed on the demonstration board (102) of tub (1), and scalable frame bar (202) is arranged in frame body (201), and frame slide block (203) is arranged on scalable frame bar (202); Described frame bar (204) one end by securing member and frame slide block (203) hinged, the other end of frame bar (204) and the other end of side link I (301) hinged; Described gear (205), tooth bar (206) engage each other, the input shaft of gear (205) and the other end of side link II (302) hinged.
5. multi-functional four-bar mechanism demonstrator according to claim 4, it is characterized in that: described scalable frame bar (202) comprises fixed length machine hack lever body, this fixed length machine hack lever body is provided with guide-track groove (2021), and described frame slide block (203) is arranged on this guide-track groove (2021).
6. multi-functional four-bar mechanism demonstrator according to claim 4, is characterized in that: described tooth bar (206) is also provided with screw (207).
7. multi-functional four-bar mechanism demonstrator according to claim 6, it is characterized in that: this demonstrator also includes drawing board (8) and paintbrush (9), described drawing board (8) is connected with the screw (207) on tooth bar in use, being adsorbed on when not using on the magnetic stripe (103) of tub; Described paintbrush (9) is arranged on slide block (5).
8. multi-functional four-bar mechanism demonstrator according to claim 7, is characterized in that: be also provided with angle dial (208) between described gear (205) and demonstration board (102), slide block guide rail (6) is also provided with length scale.
9. the multi-functional four-bar mechanism demonstrator according to the arbitrary claim of claim 1 to 8, is characterized in that: the two halves up and down of described tub (1) are respectively equipped with snap close (104) and handle (105).
CN201510099924.6A 2015-03-06 2015-03-06 Multi-functional four-bar mechanism demonstrator Expired - Fee Related CN104637392B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201510099924.6A CN104637392B (en) 2015-03-06 2015-03-06 Multi-functional four-bar mechanism demonstrator

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201510099924.6A CN104637392B (en) 2015-03-06 2015-03-06 Multi-functional four-bar mechanism demonstrator

Publications (2)

Publication Number Publication Date
CN104637392A true CN104637392A (en) 2015-05-20
CN104637392B CN104637392B (en) 2017-05-31

Family

ID=53216084

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201510099924.6A Expired - Fee Related CN104637392B (en) 2015-03-06 2015-03-06 Multi-functional four-bar mechanism demonstrator

Country Status (1)

Country Link
CN (1) CN104637392B (en)

Citations (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH10216288A (en) * 1997-02-06 1998-08-18 Mizuno Corp Gliding device continuously turning on slope while gliding
EP1348473A2 (en) * 2002-07-15 2003-10-01 Plast Wood s.r.l. Set of elements for assembling structures
CN201444378U (en) * 2009-07-11 2010-04-28 山东科技职业学院 Four-bar linkage demonstration instrument
CN201498138U (en) * 2009-10-16 2010-06-02 李正峰 Hinged four-lever mechanism demonstrator
CN201886690U (en) * 2010-12-17 2011-06-29 魏秀军 Hinged four-bar linkage type demonstration device
CN202075903U (en) * 2011-05-10 2011-12-14 湖州师范学院 Hinge four-bar mechanism teaching instrument
US20120052477A1 (en) * 2010-08-24 2012-03-01 Zike, Llc Four bar drive link system simulator
CN103886803A (en) * 2014-04-17 2014-06-25 重庆交通大学 Integrated mechanical teaching aid
CN104036684A (en) * 2014-05-22 2014-09-10 杭州电子科技大学 Typical transmission mechanism comprehensive demonstration teaching aid
CN203838957U (en) * 2014-05-12 2014-09-17 长春理工大学 Portable multi-mechanism combined demonstration box
CN203910156U (en) * 2014-05-22 2014-10-29 杭州电子科技大学 Teaching aid of cam and rod mechanisms
CN203931316U (en) * 2014-03-20 2014-11-05 青岛理工大学琴岛学院 A kind of new hinges four-bar mechanism teaching aid
CN203941653U (en) * 2014-05-05 2014-11-12 浙江工业大学 Three-dimensional mechanical book
CN203966436U (en) * 2014-04-29 2014-11-26 江汉大学 A kind of four-bar linkage apparatus for demonstrating
CN204463677U (en) * 2015-03-06 2015-07-08 广西科技大学 Multi-functional four-bar mechanism demonstrator

Patent Citations (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH10216288A (en) * 1997-02-06 1998-08-18 Mizuno Corp Gliding device continuously turning on slope while gliding
EP1348473A2 (en) * 2002-07-15 2003-10-01 Plast Wood s.r.l. Set of elements for assembling structures
CN201444378U (en) * 2009-07-11 2010-04-28 山东科技职业学院 Four-bar linkage demonstration instrument
CN201498138U (en) * 2009-10-16 2010-06-02 李正峰 Hinged four-lever mechanism demonstrator
US20120052477A1 (en) * 2010-08-24 2012-03-01 Zike, Llc Four bar drive link system simulator
CN201886690U (en) * 2010-12-17 2011-06-29 魏秀军 Hinged four-bar linkage type demonstration device
CN202075903U (en) * 2011-05-10 2011-12-14 湖州师范学院 Hinge four-bar mechanism teaching instrument
CN203931316U (en) * 2014-03-20 2014-11-05 青岛理工大学琴岛学院 A kind of new hinges four-bar mechanism teaching aid
CN103886803A (en) * 2014-04-17 2014-06-25 重庆交通大学 Integrated mechanical teaching aid
CN203966436U (en) * 2014-04-29 2014-11-26 江汉大学 A kind of four-bar linkage apparatus for demonstrating
CN203941653U (en) * 2014-05-05 2014-11-12 浙江工业大学 Three-dimensional mechanical book
CN203838957U (en) * 2014-05-12 2014-09-17 长春理工大学 Portable multi-mechanism combined demonstration box
CN104036684A (en) * 2014-05-22 2014-09-10 杭州电子科技大学 Typical transmission mechanism comprehensive demonstration teaching aid
CN203910156U (en) * 2014-05-22 2014-10-29 杭州电子科技大学 Teaching aid of cam and rod mechanisms
CN204463677U (en) * 2015-03-06 2015-07-08 广西科技大学 Multi-functional four-bar mechanism demonstrator

Also Published As

Publication number Publication date
CN104637392B (en) 2017-05-31

Similar Documents

Publication Publication Date Title
CN203910156U (en) Teaching aid of cam and rod mechanisms
CN206400796U (en) The exhibiting device that financial Teaching reform is used
CN204463677U (en) Multi-functional four-bar mechanism demonstrator
CN207777933U (en) A kind of computer with integrated facilitating transformation displaying direction
CN207624215U (en) A kind of Teaching of Economics display platform
CN204117376U (en) One moves freely instructional terminal screen height regulating device
CN204759791U (en) Portable teaching equipment
CN202748962U (en) Ancient poem learning machine with shutter
CN205428354U (en) Multi -functional plane link mechanism teaching mode
CN104637392A (en) Multifunctional four-bar mechanism demonstrator
CN209447375U (en) It is a kind of for assisting the display device of German teaching
CN205306398U (en) Combination book case that suitable ideological and political theory teaching used
CN205285722U (en) Novel desktop upset pneumatic adjustment kid table
CN206505603U (en) A kind of English teaching board
CN208324674U (en) A kind of human resource management instructional device
CN203149865U (en) Spelling teaching aid for pupils
CN206893143U (en) A kind of teaching through activities plate for being used to demonstrate English tense
CN107103831A (en) A kind of mechanical principle teaching experimental provision
CN206236290U (en) A kind of structure improved art design teaching plate
CN206576546U (en) A kind of lift is easy to place the single desk of books
CN206379050U (en) A kind of intelligent mathematical parses showing stand with applied mathematics problem
CN204010371U (en) A kind of multimedia teaching information platform
CN109662460A (en) A kind of mathematical education table that stability is good
CN211015956U (en) Internet medical science teaching remote video teaching device
CN104036685A (en) Three-dimensional mechanism book

Legal Events

Date Code Title Description
C06 Publication
PB01 Publication
C10 Entry into substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant
CF01 Termination of patent right due to non-payment of annual fee
CF01 Termination of patent right due to non-payment of annual fee

Granted publication date: 20170531

Termination date: 20180306