CN2593292Y - Two-dimensional space-time tracing instrument - Google Patents
Two-dimensional space-time tracing instrument Download PDFInfo
- Publication number
- CN2593292Y CN2593292Y CN 02280127 CN02280127U CN2593292Y CN 2593292 Y CN2593292 Y CN 2593292Y CN 02280127 CN02280127 CN 02280127 CN 02280127 U CN02280127 U CN 02280127U CN 2593292 Y CN2593292 Y CN 2593292Y
- Authority
- CN
- China
- Prior art keywords
- movable body
- paper
- dimensional temporal
- utility
- model
- 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
Links
Images
Landscapes
- Toys (AREA)
Abstract
The utility model relates to a two-dimensional space-time tracing instrument, which belongs to the experimental instruments in high school physics. The utility model is provided with a box body which has steady structure barycenter, a spring gun, a projectile body, a pendant body, and a centripetal rolling body with various different quality, construction, and use, a rod pendulum, a paper reeling machine, etc. The utility model can be used for making various mechanics experiments. The front cover of the box body is conductive glass; the conductive glass and the vertical working surface of the box body, or the horizontal working surface, or the horizontal placing working surface are formed into a parallel plate electrode with very high accuracy; electric spark for discharge is generated by using an electric spark tracing power supply and by pressing one-way high voltage pulse; various kinetic traces are traced in the two-dimensional time space and are recorded in plain paper. The utility model has the advantages of clear and uniform size of a trace point between the points of trace diagrams, accurate position, high precision, compact structure, convenient operation, high safety, high cost performance, and teaching time saving.
Description
Technical field
The utility model is a kind of two-dimensional temporal-spatial trace instrument, belongs to the senior middle school physics teaching instrument.
Background technology
Known two-dimensional space-time hodoscope is that a kind of portable framework profile has, and its critical piece, part are all located and be stored on the framework back side, and complete machine " center of gravity " too concentrates on top, and stability of equilibrium is poor during experimental implementation, and is also dangerous.This instrument front shroud structure is to be composited by transparent insulation plate and wire netting simultaneously, making battery lead plate uses, its shortcoming is that wire netting " flatness " is poor, the gap that is compounded on the insulcrete is big, make whole front shroud and front plate " depth of parallelism " poor, arcing distance is not of uniform size when directly causing the movable body spray point to move between two battery lead plates that should be parallel, has influenced the quality of trace diagram.The front shroud that is combined into simultaneously is put in the complete machine front, and because of metal net shaped interference to sight line, the various tracks of electric spark clearly become unintelligible during experiment, complete machine " face " shortcoming aesthetic feeling.The movable body parts of known one time of two-dimensional space hodoscope are less, the Experiments of Machanics kind negligible amounts of being done.The movable body of many routines lacks tourelle, and is excessive because of frictional resistance when imitating and implementing a certain motion, causes a deviation, and the trace effect is influenced.
Summary of the invention
It is electro-conductive glass that the purpose of this utility model provides a kind of front shroud, and movable body installed the two-dimensional temporal-spatial trace instrument of the desk clock formula of tourelle additional.
The technical solution of the utility model is as follows:
A kind of two-dimensional temporal-spatial trace instrument comprises a portable casing with front plate workplace; A casing front shroud, an electric spark Tracing power supply, the one-way high-pressure Weak current pulse that can produce one or more fixed frequencies; Movable body with electrode is electrically connected with above-mentioned electric spark power supply; Be attached to ink powder paper and blank sheet of paper on the casing front plate workplace, when described movable body in when motion, electrode on it can discharge between described casing front shroud and front plate parallel electrode plate, and by ink powder paper and leave a trace on blank sheet of paper, wherein the casing front shroud adopts electro-conductive glass.
In the more excellent scheme: movable body has installed tourelle additional.
In the more excellent scheme: movable body has automatic ejection electrode.
In the more excellent scheme: portable casing is a seat kind formula.
In the more excellent scheme: increase the reel machine of output blank sheet of paper automatically, and place in the cabinet base box body.
In the more excellent scheme: also be provided with two spring guns of long track and short track, described movable body can be done the projectile motion of no rotation, and increase a tape guide respectively under the effect of long track and two spring guns of short track.
In the more excellent scheme: described motion physical efficiency is rotated around stationary shaft under the centripetal force effect, and spray point has constituted electrode on it.In the more excellent scheme: described movable body is a Metallic rod pendulum in a kind of external insulation, and the acusector of putting on it has constituted electrode.
In the more excellent scheme: described movable body is a falling body, discharges between casing front plate and front shroud parallel electrode plate at the gravity extension acusector.
In the more excellent scheme: the casing front shroud adopts tempering single face electro-conductive glass to make electrode, thickness L 〉=4mm, resistance≤30 Europe/cm
2With soft, hard double-deck low resistivity metal paper tinsel, conducting resinl is inlayed, and adds the plastic cement bound edge that insulate with inner conducting layer periphery.
In the more excellent scheme: top, machine top is provided with air-bubble level, is provided with rule on the movable barral of a gun of spring gun, tiltedly is being provided with bevel protractor on the throwing dress rifle ear, has increased the protection against electric shock lid on machine push rod pendulum electric connecting joint.
Advantage of the present utility model: it has a desk clock formula casing, structural focus is steady, also has spring gun, multiple different quality, structure, the projectile of purposes, falling body, the centripetal force rotor, the bar pendulum, parts such as reel machine, can do multiple Experiments of Machanics campaign, the casing front shroud is an electro-conductive glass, with the vertical workplace of casing, and horizontal operation face or horizontal positioned workplace, form the very high parallel-plate electrode of precision, and utilize the electric spark Tracing power supply, and apply the one-way high-pressure pulse, produce spark discharge, in two-dimension time-space, describe the track of various motions, and be recorded on the paper of plane, this instrument trace diagram between points, some mark size is clear evenly, fall the position accurately, the experimental precision height.The utility model structure is tightly played, and operates tube just, safety, and ratio of performance to price height is saved instructional blocks of time.
Description of drawings: figure one A, main frame front elevation
(1) base box body (6) is regulated horizontal screw bolt
(2) casing (7) is tiltedly thrown dress rifle ear and bevel protractor
(3) the flat dress rifle position of throwing of magnetic pressure bar (8)
(4) ink powder paper
(5) ballistic pendulum dress rifle position
B, host computer side view
(9) front shroud (13) centripetal force fixed rotating shaft axle sleeve
(10) front plate (14) surface bearing
(11) spring gun electrical socket switch (15) main frame horizontal positioned column
(12) spring gun electrical socket figure two A, main frame vertical view
(16) frequency adjustment (21) point is driven switch
(17) pilot lamp (22) bar pendulum electric connecting joint
(18) the some mark is regulated (23) air-bubble level
(19) cylinder (24) high-tension terminal on the reel machine
(20) reel machine power supply Tracing power supply switch (25) high-voltage plug
B, main frame base box body upward view
(26) electric spark Tracing power supply (27) reel machine power supply
(28) reel machine bottom roll (29) reel machine wheel box
(30) operation control panel (31) power lead hand-hole
(32) the high electricity bag of battery main switch (33) figure three A, main frame front shroud structural drawing
B, main frame back shroud figure figure four spring ejecting guns
A, spring gun structural drawing
(34) the fastening screw of track (35)
(36) emission barral of a gun (37) spring
(38) bore
B, long track spring gun
(39) long track
C, short track spring gun
(40) screw rod (41) wing nut
D, activity displacement barral of a gun
(42) rule (43) barral of a gun hook
(44) iron core (electromagnet) (45) coil
(46) spring gun plug
E, vernier figure five movable bodies
A, copper does flat the throwing and uses
(47) roller (48) spray point
B, the copper elastic collision of doing are used
(49) spring
C, make inelastic collision and use
D, make inelastic collision and use
(50) orienting sleeve
E, make elastic collision and use
(51) eject spray point figure six centripetal force rotors automatically
(52) elongated transverse axis (57) surface bearing
(53) rotary balance roller (58) roller ball
(54) rotating spindle (59) spray point
(55) rotate the transverse axis roller
(56) spring figure seven bars pendulum
(60) pendulum (63) electric connection screw
(61) spray point (64) adjustment screw
(62) fork (65) lever diagram eight falling bodies
(66) falling body suction nozzle (irony) (67) falling body main body (copper)
(68) spray point figure nine main frame inner packing foam box figure ten flat throwing application drawing figure 11 tiltedly throw application drawing figure 12 inelastic collision application drawing figure 13 elastic collision application drawing figure ten four-way mental and physical efforts application drawing figure 15 freely falling body application drawing figure 16 simple harmonic oscillation experimental implementation figure figure 17 bars pendulum experimental implementation figure figure 18 ballistic pendulum experimental implementation figure
Describe the utility model in detail below in conjunction with embodiment and description of drawings:
Embodiment
The utility model is produced a cover two-dimensional temporal-spatial trace instrument, adopt desk clock formula body structure to put the electric spark Tracing power supply, automatic paper winder power supply and critical part in base box body 1, other movable bodies, as spring gun, the centripetal force rotor, bar pendulum, freely falling body weight, common tool spiral shell cutter etc. is made annex and is stored in separately in accessory case and the inner packing foam box body, main frame is born a heavy burden alleviate greatly, " center of gravity " moves down, steady during experimental implementation, convenient, safety.
Front shroud 9 of the present utility model adopts tempering single face electro-conductive glass to make the electrode front shroud, thickness L 〉=4mm, resistance≤30 Europe/cm
2With soft, hard double-deck low resistivity metal paper tinsel, conducting resinl is inlayed, and adds the plastic cement bound edge that insulate with inner conducting layer periphery.So just can make fully and form the parallel-plate electrode that precision is very high between front plate 10 and the front shroud 9, when the spray point of movable body moves betwixt and two parallel electrode plates apart from equalization, make between the trace diagram point point, some mark size is clear evenly, fall the position accurately, the experimental precision height; Sound during experimental implementation, Xiang Bingmao, still the heart is pleasing, has both improved performance, has improved outward appearance again.
The utility model improves overall plan to the part of prior art two.First scheme is to have increased a long formula track spring gun, has increased the projectile of two special tectonics, has increased an automatic paper winder, has increased a falling body.Alternative plan is to transform to improve: all five projectiles " are slided " by original track under the spring gun effect be transformed into track " rolling ", installed centripetal force fixed rotating shaft axle sleeve 13 additional surface bearing 14, " slide block " on the elongated transverse axis slided, make " ball " into and roll.
One of the utility model improvement is the research collision experiment.Collision experiment comprises two kinds of perfect inelastic collision and elastic collisions, mainly is in order to checking kinetic energy conservation law.One time of the two-dimensional space hodoscope of present domestic use has been done statement respectively to these two experiments, and its greatest weakness has two; The one, do not consider in theory when the employed spring of spring gun is made projectile motion power because the instability of spring self adds that it is subjected to bore (figure four A) inwall in telescopic process, the friction force influence of barral of a gun outer wall, this " projectile power " is exactly one " variable ", emission each time, its " power " is different strictly speaking.The 2nd, in practice, do not solve of the influence of projectile rotation rolling kinetic energy to translational kinetic energy.
Perfect inelastic collision, according to prior art, trace is moved in inelastic collision experiment at twice, draw bump before and bump back two trace diagrams, displacement remains unchanged although it has emphasized twice action barral of a gun, but " power " repeatedly launched because of the above-mentioned spring gun that analyzes is " variable ", and this twice trace diagram that must cause this experiment is unscientific, and its data of surveying can't be used for accurately verifying the law of conservation of momentum.Say more specifically, do not carrying out under the situation of " collision " exactly, twice flat throwing trace before and after the barral of a gun displacement is done under the same position condition of equivalent, twice tracing point also can not overlap before and after it, the influence that Here it is " spring is used as power " " variable ", still more when launching for the second time, trace diagram is to have produced having taken place to collide under this state, therefore two trace diagrams of twice emitting gained can not be mentioned in the same breath before and after, do not have unitarity exactly.Its gained data have also just lost the meaning that can utilize calculating.Secondly, from practice, although existing hodoscope has been emphasized to be stained with plasticine on by the collision movement body, in case its rotation in spatial movement produces the influence of rolling kinetic energy to translational kinetic energy, but in fact this way can't solve this critical problem, the result of practice be active body with collided by kinetoplast this in a flash movable body fail to become a system in spatial movement, but promptly changed the plumbness with two parallel electrode plates the spray point wink of active body, make the trace failure.Trace diagram after the collision is unavailable.
The utility model takes to increase a long track spring rifle, the movable body that increases a tape guide band tourelle is seen instrument layout figure 12, the rolling active body is placed on spring gun emission masthead end, the movable body of tape guide band tourelle is placed on 10mm place in the long track rifle right-hand member track right endpoint, the displacement of adjusting activity barral of a gun makes it at the 12mm place, and checks the distance of adjusting between active body spray point and two parallel electrode plates, about 2mm, synchronized transmissions trace see figure 12 right sides.The left lateral branch of figure is rare and few as can be known from the design sketch, the right point honey of figure and many, and clearly the left side is to bump preceding trace, the right is to bump trace afterwards.A trace diagram, i.e. once emission has been write down before bumping and has been bumped the space time information of the system that latter two movable body forms.Fundamentally solved this key issue of spring gun twice emitting " dynamical variable ", because guide piece is arranged, make the two movable bodies collision adhesion of promptly leading a flash become a system, the movable body spray point still keeps bumping plumbnesss preceding and two parallel electrode plates, also fundamentally solved of the influence of rolling kinetic energy to translational kinetic energy, make this experiment finish to such an extent that science is smooth, computational accuracy improves greatly.
Elastic collision: the utility model is to finish this experiment like this, sees instrument layout figure 13.The copper active body that has spring is placed on ejecting gun masthead end, being housed, automatic ejection spray point is placed on long track rifle track 39 right-hand member edges by kinetoplast, be arranged on by kinetoplast in by the kinetoplast spray point this moment, check the distance of adjusting between active body spray point and two parallel electrode plates, about 2mm, the synchronized transmissions trace, obtained a complete trace diagram, from the design sketch as can be known, the left end point of figure is rare and few, this is that active body bumps preceding trace, and the right endpoint of figure is rarer and many, and this is after bumping, collided the automatic spray point trace under the speed that active body transmitted that ejects at a flash by kinetoplast, simultaneously active body collide by kinetoplast during a flash speed reduce at once, becomes one and leaves body rapidly, the below of trace diagram is exactly the trace of active body collision back one-tenth projectile.Like this on a trace diagram, i.e. the spatiotemporal motion information of the elastic collision of two movable bodies of this experiment has just been write down in once emission, and experiment is convenient, to survey data accurate.In a word, whole collision experiment comprises two kinds of non-perfect elasticity and elasticity, suffered influence such as friction force " variable " when fundamentally having overcome the instability of spring self and its work.Comparatively speaking relatively the solution of science this problem experiment of high school physics collision experiment.
Two of the utility model improvement is research vibrational images.Experiment was after connecting Tracing power supply in the past, pull out the blank sheet of paper bar rapidly with hand, teaching material also is that the motion of requirement paper tape should be at the uniform velocity, but the student will control the Tracing power supply switch on the other hand in the practice, will at the uniform velocity pull out paper slip on the other hand, and its action is difficult to coordinate, it is unpractical particularly using hand " at the uniform velocity " to pull out the blank sheet of paper bar, even two student's co-operatings, it also is impossible reaching " at the uniform velocity " pulling blank sheet of paper bar, still more trace and go out paper slip and also be difficult to reach synchronous.
Instrument layout figure 16 of the present utility model has taked to increase electronic automatic paper winder, and method is to utilize the toy for children motor to go change from two aspects.The one, utilize reel machine of electronic original part assembly unit to rotate power supply, children's motor is made into as power supply with dry cell and make power supply and synchronous with the electric spark Tracing power supply with alternating current.Become toy reel machine power supply.The 2nd, utilize mechanic gear, a kind of motor of the thousands of commentaries on classics up to ten thousand of per minute of high speed is formed a speed-changing gear box by various gears, rotating speed is dropped to 80 to be changeed minute.The bottom roll of reel machine is connected and all places the last cylinder 19 of base box body 1 inner wrap paper machine with the reel machine power supply by change speed gear box, promptly driven cylinder places on the base box body 1, hangs up properly bar and shakes, and adjuster bar is accommodated the distance of end spray point and arc-shaped electrode plate.Whole bar pendulum is parallel with front plate, sees figure instrument layout figure 16.The blank sheet of paper of 350mm * 130mm is put in from main frame back shroud indentation, there; pass under the main frame front plate and from the arc-shaped electrode plate the pendulum spray point descended cylinder 19 on the reel machine; use cylinder 19 by the power of little spring folder between the reel machine up-down roller; open trace, reel machine electric switch; blank sheet of paper is at the uniform velocity mobile, and the trace spark occurs.Treat all off switch more after rolling of blank sheet of paper.The sinusoidal curve figure of one Zhang Zhen's cardon elephant is high-visible.Simple, convenient, because of reel machine places in the base box body, also increased aesthetic feeling to complete machine.
Three of the utility model improvement is the centripetal force that the research object is made circular motion.See instrument layout figure 14, be in the fixed rotating shaft axle sleeve 13 and the main shaft of fixed rotating shaft on, increased surface bearing 57, rotate flexibly steadily when making the rotor experiment.Again the right cylinder " slide block " on the elongated transverse axis 52 is made into simultaneously to have reduced the influence of friction force when " roller " (figure six) make experiment, improved the quality (figure 14 upper left, bottom rights) and the computational accuracy of trace diagram centripetal force.
The utility model has increased a research freedom falling, and instrument layout figure 15.The movable barral of a gun 36 of ejecting gun is turned on wing nut 41 to be unloaded from spring gun, be placed on the roof box, the power plug wire that is fixed in electromagnet on the back shroud column inserts in the little spring hole scoket interior 12 of casing left plate, opening the socket electricity connects switch 11 perpendicular the keeping flat of the trace recording chart of 350mm * 100mm is affixed on the front plate, and with two magnetic stripes paper is entirely inhaled and to be overlayed the jail, during experiment the falling bodies weight is inhaled in the electromagnet below, cover the front shroud inspection adjust on the weight spray point and two parallel pole distances between plates from, determine the Frequency point mark, point is driven Tracing power supply switch 20, weight vertically falls, and wink is that the off switch trace diagram obtains synchronously.
The utility model has also increased air-bubble level 23 on top, machine top, cancelled original way with the vertical line level-off, on the movable barral of a gun 36 of spring gun, increased rule 42, tiltedly increasing bevel protractor 7 on the throwing dress rifle ear, (figure one A) increased protection against electric shock lid etc. on machine push rod pendulum electric connecting joint, these improve in the time of all can making experimental implementation, assurance level is rapidly transferred machine, hold rapidly displacement, the angle, both convenient of spring gun, again safely, make the total quality level of whole instrument that a bigger raising arranged.
Claims (9)
1, a kind of two-dimensional temporal-spatial trace instrument comprises a portable casing with front plate workplace; A casing front shroud, an electric spark Tracing power supply, a movable body with electrode, the electric spark power supply is electrically connected; Be attached to ink powder paper and blank sheet of paper on the casing front plate workplace, it is characterized in that: the casing front shroud adopts electro-conductive glass, and movable body has installed tourelle additional.
2, two-dimensional temporal-spatial trace instrument according to claim 1, it is characterized in that: movable body has automatic ejection electrode.
3, two-dimensional temporal-spatial trace instrument as claimed in claim 1 or 2 is characterized in that: portable casing is a seat kind formula.
4, two-dimensional temporal-spatial trace instrument as claimed in claim 1 or 2 is characterized in that: increase the reel machine of output blank sheet of paper automatically, and place in the cabinet base box body.
5, two-dimensional temporal-spatial trace instrument as claimed in claim 1 or 2 is characterized in that: also be provided with two spring guns of long track and short track, movable body increases a tape guide.
6, two-dimensional temporal-spatial trace instrument as claimed in claim 1 or 2 is characterized in that: movable body rotates around stationary shaft under the centripetal force effect, and spray point has constituted electrode on it.
7, two-dimensional temporal-spatial trace instrument as claimed in claim 1 or 2 is characterized in that: movable body is a Metallic rod pendulum in a kind of external insulation, and the acusector of putting on it has constituted electrode.
8, two-dimensional temporal-spatial trace instrument according to claim 1, it is characterized in that: described movable body is a falling body.
9, two-dimensional temporal-spatial trace instrument as claimed in claim 1 or 2 is characterized in that: the casing front shroud adopts tempering single face electro-conductive glass to make electrode, thickness L 〉=4mm, resistance≤30 Europe/cm
2With the inner conducting layer periphery is soft, hard double-deck low resistivity metal paper tinsel, and conducting resinl is inlayed, and adds insulation plastic cement bound edge; Top, machine top is provided with air-bubble level, is provided with rule on the movable barral of a gun of spring gun, tiltedly is being provided with bevel protractor on the throwing dress rifle ear, has increased the protection against electric shock lid on machine push rod pendulum electric connecting joint.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 02280127 CN2593292Y (en) | 2002-11-28 | 2002-11-28 | Two-dimensional space-time tracing instrument |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 02280127 CN2593292Y (en) | 2002-11-28 | 2002-11-28 | Two-dimensional space-time tracing instrument |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN2593292Y true CN2593292Y (en) | 2003-12-17 |
Family
ID=33742982
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 02280127 Expired - Fee Related CN2593292Y (en) | 2002-11-28 | 2002-11-28 | Two-dimensional space-time tracing instrument |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN2593292Y (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104575187A (en) * | 2015-01-30 | 2015-04-29 | 王振环 | Kinetics study apparatus of vertical plane |
| CN107369365A (en) * | 2017-09-11 | 2017-11-21 | 柯胜 | A kind of new electric spark flat throws track record instrument apparatus |
-
2002
- 2002-11-28 CN CN 02280127 patent/CN2593292Y/en not_active Expired - Fee Related
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104575187A (en) * | 2015-01-30 | 2015-04-29 | 王振环 | Kinetics study apparatus of vertical plane |
| CN104575187B (en) * | 2015-01-30 | 2017-02-22 | 青岛农业大学 | Kinetics study apparatus of vertical plane |
| CN107369365A (en) * | 2017-09-11 | 2017-11-21 | 柯胜 | A kind of new electric spark flat throws track record instrument apparatus |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN1174786C (en) | Lightening toy | |
| CN103240585B (en) | A kind of device and method of connector assembling nut | |
| CN2593292Y (en) | Two-dimensional space-time tracing instrument | |
| CN107695812A (en) | A kind of equipment for grinding for spring manufacture | |
| CN103230176A (en) | Vehicle-mounted three-dimensional self-generating seat | |
| CN209541540U (en) | One kind is travelled pistol | |
| CN203719544U (en) | Equipment imitating spraying effect | |
| CN216790975U (en) | Gunshot simulation continuous firing device | |
| CN210689395U (en) | Police shooting training target frame | |
| CN214200563U (en) | Head protector test device for fire fighting | |
| CN215615342U (en) | Novel high-efficiency combined drill bit | |
| CN215895764U (en) | University's mathematics teaching parabola demonstration teaching aid | |
| CN204555806U (en) | Novel Light Electrical Multi-functional analog checker for shooting training | |
| CN208557279U (en) | Lower bracket fixing device of shock absorber | |
| CN209108583U (en) | A kind of flight pterosaur VR immersion experience apparatus | |
| CN113706975A (en) | Case display device for law teaching | |
| CN207280289U (en) | Popular edition high precision photoelectric magnetic simulates Pistol for military police transmitter | |
| CN207977020U (en) | A kind of adjustable flight simulator | |
| CN205627002U (en) | Energy -saving intelligent baseball service robot | |
| CN109779856A (en) | A kind of portable inertial energy recyclable device | |
| CN215360997U (en) | New forms of energy fill electric pile aluminum product device convenient to remove | |
| CN211215324U (en) | A training ware of catching ball for football training | |
| CN203561750U (en) | Light electromagnetic seismic wave source | |
| CN211866450U (en) | High-speed steel wire unloader | |
| CN203910103U (en) | Horizontal projectile motion demonstrator |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C19 | Lapse of patent right due to non-payment of the annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |