CN201041799Y

CN201041799Y - Falling fuser

Info

Publication number: CN201041799Y
Application number: CNU2007200902951U
Authority: CN
Inventors: 王保全; 郭留柱
Original assignee: Individual
Current assignee: Individual
Priority date: 2007-05-10
Filing date: 2007-05-10
Publication date: 2008-03-26
Anticipated expiration: 2017-05-10

Abstract

The utility model provides a falling type fuse, which includes a fuse tube 4 and an insulated ceramic piece 17. A conductor upper contact head 6 and a conductor lower contact head 5 are respectively arranged on the upper end and the lower end of an insulated rod in the middle of the fuse tube 4. A conductor fuse fixing tongue 14 is arranged on the upper part of the upper contact head 6 and fixed by a protecting cap. The fuse passes through inside the fuse tube 4 and electrically connect with a lower active contact head 8 on the lower contact head. A conductor upper upward press mouth 21 and a positioning block 33 are arranged on the upper part of the insulated ceramic piece 17. The lower active contact head 8 at the lower part of the fuse tube 4 is connected with the lower contact head 5 movably, a main force arm 13 is movably connected on the lower active contact head 8, and a fixing device for fixing the fuse lines is arranged on the main force arm 13. An upward press spring leaf 20 which presses down the upper active contact head 8 on the fuse tube is arranged on the upper part of the upward press mouth 21 of the insulated ceramic piece 17, and the fuse tube is caused to fall quickly when the fuse is broken.

Description

Fuse switch

Technical field

The utility model relates to the power supply protection equipment in the electric power system, relates in particular to a kind of fuse switch.

Background technology

Present fuse switch as shown in Figure 1, it comprises insulating porcelain piece 17 and fusion tube 4, insulating porcelain piece 17 tops are provided with upper press nozzle 21, upper press nozzle 21 is oppositely arranged by two, the spring leaf that is clamp position constitutes, on the insulating porcelain piece 17, also be provided with a locating piece 33 that is used to locate moving contact 2 on the fusion tube 4 between 21 liang of spring leaf installation sites of upper press nozzle, insulating porcelain piece 17 bottoms are provided with down fixed contact 16, following fixed contact 16 is the half opening shape hollow box of no leading flank and bottom surface, one bolt 30 passes behind the bolt hole on the spring leaf 31 bolt hole that passes on its back sidewall from the inside of fixed contact 16 down again and will descend fixed contact 16 to be fixed on the clips 32 of insulating porcelain piece 17 bottoms, simultaneously spring leaf 31 is fixed on down on the side, back in the fixed contact 16, spring leaf 31 free ends up, be the arc that upwards arches upward; What be respectively equipped with a correspondence on the left and right sides wall of following fixed contact 16 articulates gib head 29.

Fusion tube 4 is the tubulose upper binding heads 6 that are socketed with hollow on the top of insulated tube, and the insulated tube bottom is socketed with lower union joint 5; The lateral surface radial symmetric position of upper binding head 6 is installed with an outwards flat side arm 22 and an one handle 24 of stretching respectively, and the head of side arm 22 is fixed with moving contact 2; Upper binding head 6 top outer walls are provided with thread segment, and a head protector 1 can cooperate and is screwed onto on the described thread segment, and head protector 1 inside also is provided with a circle and presents a theatrical performance as the last item on a programme, and are used for fixing the fixing tongue piece 14 of fuse that connects the fuse backguy; Existing head protector is both ends open, is that rainproof water flows into, and presses in the head protector that has to be provided with rainproof that a slice circle, middle part slightly arch upward; The lateral surface of fusion tube 4 bottom lower union joints 5 is installed with an outwardly directed linking arm 7, first spool 27 front end that be fixed on linking arm 7 of lower moving contact 8 by being provided with on the one end, lower moving contact 8 is D shape, connect and compose by an arc limit of outwards arching upward and a straight flange two ends correspondence, the arc limit is being descended at last, straight flange, first 27 rearward end that is located at its straight flange, second 26 middle part that is located at straight flange, a spring pressuring plate 32 is by second 26 bottom that is fixed on lower moving contact 8 straight flanges; The leading section bilateral symmetry of described straight flange is respectively protruded fixed axis 25, one set bolts 9 that a cross section is fan-shaped, semicircle, circle or D shape and is arranged on the lower moving contact 8 front end lateral surfaces; Fuse 28 two ends respectively connect a metal backguy, be through in the fusion tube 4, one end backguy is fixed on fuse, and fixedly on the tongue piece 14 (fuse fixedly tongue piece 14 is vertical straight tubes that connect of downside at a disk, be wire nail shape, the fuse backguy is at nail pipe internal fixation, nail pipe inserts in the upper binding head 6 and the disk on top is covered at upper binding head 6 top open parts), fuse 28 other end backguys were pressed to tighten behind the spring pressuring plate 32 of lower moving contact 8 bottoms and were fixed on the set bolt 9, and the straight flange of lower moving contact 8 is pressed to spring pressuring plate 32 in backguy.

The both sides that two fixed axis, 25 correspondences on the fusion tube 4 bottom lower moving contacts 8 are hung on 17 times subordinate's fixed contacts 16 of insulating porcelain piece articulate on the gib head 29, fusion tube 4 is upwards rotated, lower moving contact 8 is pushed down in the box body of fixed contact 16, be pressed on the spring leaf 31, simultaneously, the last moving contact 2 and the side arm 22 on fusion tube 4 tops are snapped between 21 liang of spring leafs of upper press nozzle on insulation ceramics 17 tops, and last moving contact 2 only leans against location on the locating piece 33.

This fuse switch is after fuse is fused, the spring pressuring plate 32 of fusion tube 4 bottoms flicks, utilize the reaction force of this elastic force to lower moving contact 8, weight in conjunction with the elastic force of the 31 pairs of lower moving contacts 8 of spring leaf in the following fixed contact 16 and fusion tube 4 self flicks fusion tube 4 again, moving contact 2 and side arm 22 are broken away from from the upper press nozzle 21 on insulation ceramics 17 tops, and fusion tube 4 promptly falls around fixed axis 25 rotations of its underpart.

This fuse switch in actual applications, because the autoxidation of upper press nozzle 21 spring leafs and rainwater are to its corrosion, with last moving contact 2, frictional force between the side arm 22 increases, behind fuse opening, be difficult for falling, therefore cause its protectiveness poor, temperature raises and burns out fusion tube, cut-off problems such as narrow range, simultaneously, the fuse backguy is fixedly fixing in the nail pipe of tongue piece 14 at fuse, change fuse and need change tongue piece and fuse black box, cost is higher, and the fuse backguy is tight in fusion tube 4, when external shock surpasses the strength tolerance range of backguy, the backguy fracture causes improper falling, thereby causes extra line upkeep work; The insulated tube outer wall at fusion tube middle part is soaked with rain in addition, and the back is easy conducts electricity, and has potential safety hazard, may operating personnel's personal safety be threatened when the bad weather maintenance line.

The utility model content

The purpose of this utility model provides a kind of novel fuse switch; the backguy that present fuse switch exists easily breaks to solve, problem such as poor, the easy burn-out fusion tube of protectiveness such as fusion tube is difficult for falling behind the fuse opening, and the insulated tube at fusion tube middle part be soaked with rain back easy conductive, fuse and the fixedly fixing difficult replacing of tongue piece one of fuse, cut-off problem such as narrow range.

The utility model adopts following technical scheme to realize:

A kind of fuse switch, comprise fusion tube 4 and insulating porcelain piece 17, wherein, the insulating bar upper and lower side at described fusion tube 4 middle parts is respectively arranged with electric conductor upper binding head 6, lower union joint 5, upper binding head 6 tops are provided with fixedly tongue piece 14 of electric conductor fuse, are fixed by head protector; The fuse two ends are provided with the electric conductor backguy, pass in fusion tube 4, and the upper end is fixed on fuse fixedly on the tongue piece 14, and the lower end is electrically connected with lower moving contact 8 on the lower union joint 5; Lower moving contact 8 both sides convex with fixed axis 25; The top of described insulating porcelain piece 17 is provided with electric conductor upper press nozzle 21 and locating piece 33, and the bottom is provided with down fixed contact 16, following fixed contact 16 two sides be provided with fixed axis coupling articulate gib head 29; Fixed axis 25 correspondences are articulated in and articulate on the gib head 29, upwards rotate fusion tube 4 lower moving contact 8 is pushed down in the fixed contact 16, and the last moving contact 2 and the side arm 22 on fusion tube 4 tops snap in insulating porcelain piece 17 upper press nozzles simultaneously, and last moving contact 2 only leans against location on the locating piece 33; Wherein: fusion tube 4 bottom lower moving contacts, 8 one ends and lower union joint 5 flexibly connect, and main force's arm 13 is articulated on the lower moving contact 8; Main force's arm 13 is provided with fixture 12, and lower end fuse backguy is strained and fixed on fixture 12, and main force's arm 13, lower moving contact 8 are fixed with lower union joint 5; Upper press nozzle 21 tops of insulation ceramics 17 are provided with one to pressing down the last pressing spring sheet 20 that touches moving contact 8 on the fusion tube 4.

Described fuse switch, wherein: described top of going up pressing spring sheet 20 also is provided with and presses solidly stator 18 on one, presses between the two to be provided with holddown spring 19 on.

Described fuse switch, wherein: main force's arm 13 flexibly connects by a link and lower moving contact 8, link comprises two connecting plates 32,32 ' and one base plate 33, two connecting plates, 32,32 ' bottom symmetry is movably arranged on base plate 33 both sides, and two connecting plates, 32,32 ' upper end symmetry is movably arranged on lower moving contact 8 both sides; It is fixing with main force's arm 13 with base plate 33 that base plate 33 is provided with the link fixing hole that a chute 38, one bolts 11 pass on this chute and the main force's arm 13.

Described fuse switch, wherein: have two recesses 23 on the described upper binding head 6 top sidewalls, described fuse fixedly tongue piece 14 is " protruding " font, size and upper binding head 6 open tops coupling, and with head protector in the compression fit of presenting a theatrical performance as the last item on a programme; The fuse fixedly side of tongue piece 14 is provided with the fixing fixture of fuse.

Described fuse switch, wherein: insulation ceramics 17 tops also are provided with the protective cover 15 that front side and bottom side openings are communicated with, will on press solidly stator 18, go up pressing spring sheet 20 and locating piece 33, upper press nozzle 21 covers in it.

Described fuse switch, wherein: the outer wall upper sleeve through of described fusion tube 4 insulating bars has the rain cover 3 of hollow tube-shape, seals at the bottom of the tube of rain cover two ends and between the outer wall of insulating bar.

Described fuse switch, wherein: be made as the vertex of a cone at the bottom of the upper end tube of described rain cover, the top center of the vertex of a cone has the hole of passing for insulating bar.

Described fuse switch, wherein: described head protector upper end is closed, the lower end inwall is provided with and the thread segment of the screw thread on upper binding head 6 tops coupling.

The utility model adopts technique scheme will reach following technique effect:

Fuse switch of the present utility model, flexibly connect between the lower moving contact of fusion tube bottom and the lower union joint, one main force's arm is articulated on the lower moving contact, also be provided with the fixedly fixture of fuse backguy on main force's arm, the fuse two ends are strained and fixed at the fuse at fusion tube upper binding head top fixedly between tongue piece and the fusion tube bottom main force arm, fuse is with main force's arm, lower moving contact and fusion tube fuse, stiff each other, when fuse is fused, main force's arm, promptly unclamp between lower moving contact and the fusion tube, because of flexibly connecting each other, do not fall so can not hinder fusion tube; In addition, the last pressing spring sheet that the top of insulating porcelain piece top upper press nozzle is provided with is to pressing down the last moving contact that touches fusion tube, press solidly on the upper side of last pressing spring sheet and its top one also to press between the stator and be provided with holddown spring on, last pressing spring sheet and last holddown spring have a downward thrust to fusion tube, gravity in conjunction with fusion tube self when fuse failure promotes fusion tube disengaging upper press nozzle, falls fast; In addition, fuse switch of the present utility model is sheathed rain cover on the insulating bar outer wall of fusion tube, guarantees the insulation of rainy weather insulating bar; Insulation ceramics top is provided with protective cover, rainproof, dustproof, effectively delay upper press nozzle, go up the pressing spring sheet, go up the aging of each parts such as holddown spring; The head protector upper end is closed to be provided with, and prevents that rainwater from flowing into the erosion fuse.

Description of drawings

Fig. 1 is the fusion tube structure chart of existing fuse switch;

Fig. 2 is the insulating porcelain piece structure chart of existing fuse switch;

Fig. 3 is the fusion tube structure chart of fuse switch of the present invention;

Fig. 4 is the insulating porcelain piece structure chart of fuse switch of the present invention;

Fig. 5 is the fixing tongue piece schematic diagram of the fuse of fuse switch of the present invention;

Fig. 6 is the fixing tongue piece schematic diagram of the another kind of fuse of fuse switch of the present invention;

Fig. 7 is the enlarged drawing of looking up of base plate.

Embodiment

Embodiment:

A kind of fuse switch, comprise fusion tube 4 and insulating porcelain piece 17, Fig. 3 is the fusion tube structure chart of fuse switch of the present invention, as shown in Figure 3, the insulating bar upper and lower side at fusion tube 4 middle parts is respectively arranged with electric conductor upper binding head 6, lower union joint 5, the top exterior walls of upper binding head 6 is provided with thread segment, be spirally connected with the thread segment coupling on the head protector 1 lower end inwall, the top of head protector 1 internal thread segment also is provided with a circle and presents a theatrical performance as the last item on a programme, and is used for being fixed when being spirally connected with upper binding head fixedly tongue piece of the fuse that is provided with in the upper binding head open top.

The lateral surface radial symmetric of upper binding head 6 is installed with side arm 22 and the ring-shaped handle 24 that side is stretched, and the head of side arm 22 is provided with moving contact 2; Be installed with the linking arm 7 that side is stretched on the lateral wall of fusion tube 4 bottom lower union joints 5, the rearward end of the front end of linking arm 7 and lower moving contact 8 flexibly connects; Wherein, linking arm 7 and side arm 22 are towards identical.

The front end of the rear portion of lower moving contact 8 and linking arm 7 runs through flexible connection by first connecting axle 27; One main force's arm 13 is articulated on second connecting axle 26 of lower moving contact 8 by a link; Described link comprises two connecting plates 32,32 ' and one base plate 33, base plate 33 vertical both sides are provided with the lower edge, wherein, the symmetric position that is arranged on the lower edge, base plate 33 both sides is run through by a movable axis 39 in two connecting plates 32,32 ' bottom, and two connecting plates 32,32 ' upper end are run through by second connecting axle 26 and be movably connected in bilateral symmetry position on the lower moving contact 8; Base plate 33 is provided with a chute 38, Fig. 7 is the enlarged drawing of looking up of base plate 33, bolt 11 passes link fixing hole on this chute 38 and the main force's arm 13 and base plate 33 is fixed on the downside of main force's arm 13 (bolt 11 can move forward and backward in chute 38 and be fixed on diverse location, regulating the stressed arm of force length of main force's arm, thereby be convenient to control the stressed size of fuse backguy); In addition, the rearward end of main force's arm 13 is provided with the fixing bolt 12 of fuse backguy, and the leading section upper side is welded with a connection piece 37, and the upper end of connector 37 is movably connected in the front end downside of linking arm 7; When the fuse backguy was strained and fixed on main force's arm 13 by bolt 12, according to the triangle stability principle, lower moving contact 8, main force's arm 13 and linking arm 7 were tightly fixing, stiff each other, and when the fuse backguy disconnected, above-mentioned three was all movable between any two, can not hinder fusion tube.

The front end bilateral symmetry of described lower moving contact 8 is provided with the D shape fixed axis 25 of protrusion, be used for 17 times subordinate's fixed contact 16 two sides of insulating porcelain piece on articulate gib head 29 corresponding articulating; Also be provided with connecting bolt 9 on the lower moving contact 8, be used for being electrically connected with the fuse backguy.

One electric conductor fuse fixedly tongue piece 14 is arranged on the opening at upper binding head 6 tops; Fuse fixedly tongue piece 14 can be circle, as shown in Figure 5, one electric conductor disk is provided with a through hole 34 and a set bolt 35, the fuse backguy is fixed on the bolt 35 after passing through hole 34, tongue piece 14 horizontal are erected in upper binding head 6 open tops, are spun on fixing getting final product on the upper binding head 6 with head protector 1; In addition, present embodiment also provides fixedly tongue piece of another fuse, as shown in Figure 6, sheet, be " protruding " font, the tongue piece side is provided with the fixing bolt 36 of fuse backguy, to open two recesses 23,23 ' on the fusion tube 4 upper binding heads 6 top open part circumference, with fuse shown in Figure 6 fixedly tongue piece little head-up, be inserted in two recesses greatly upside down, be erected at upper binding head 6 tops, be spun on the upper binding head 6 fixing get final product with head protector, head protector is interior presenting a theatrical performance as the last item on a programme can be pressed on the step between tongue piece microcephaly and the major part it is fixed.Present embodiment also provides a kind of novel head protector, and its upper end closed, lower ending opening inwall are provided with the thread segment that is spirally connected with upper binding head 6 screw top couplings, and upper end closed can prevent dust, rainproof, slows down the aging of fusion tube and fuse.

Fuse from top to bottom passes in fusion tube 4, and the lower end backguy is strained and fixed on the set bolt 12 of main force's arm 13 (outside this section backguy can sheathed one section insulating sleeve, with main force's arm 13 insulation) be electrically connected on the bolt 9 of lower moving contact 8 again.

Fig. 4 is the insulating porcelain piece structure chart of fuse switch of the present invention, the top of described insulating porcelain piece 17 is provided with electric conductor upper press nozzle 21 and locating piece 33, the top of upper press nozzle 21 also be provided with an elastic force downward press down spring leaf 20, the top that presses down spring leaf 20 is provided with and presses solidly stator 18 on one, on press solidly stator 18 and press down between the spring leaf 20 to press and be provided with holddown spring 19.Insulating porcelain piece 17 tops also are provided with the box-like protective cover of a hollow 15, its back fixation is on insulating porcelain piece 17, do not establish leading flank and bottom surface, downwards will on press solidly stator 18, go up holddown spring 19, press down spring leaf 20 and locating piece (33), in upper press nozzle (21) is located at, dustproof, rainproof, delay the aging of above-mentioned each parts; Insulating porcelain piece 17 bottoms are provided with fixed contact 16 under the electric conductor, are symmetrically arranged with on following fixed contact 16 two sides and articulate gib head 29, and the following fixed contact 16 inner back sides are provided with the downward spring leaf of elastic force 31.

Two fixed axis, 25 correspondences on the fusion tube 4 bottom lower moving contacts 8 are articulated in articulating on the gib head 29 on 17 times subordinate's fixed contact 16 two sides of insulating porcelain piece, upwards rotate fusion tube 4, lower moving contact 8 is pushed down in the fixed contact 16, be pressed on the spring leaf 31, moving contact 2 and side arm 22 snap between 21 liang of spring leafs of insulating porcelain piece 17 top upper press nozzles on the fusion tube 4 simultaneously, last moving contact 2 leans against location on the locating

piece

33, and 20 pairs of last holddown spring 19 and last pressing spring sheets are gone up moving contact 2 a downward pressure.

When fuse disconnects, can be movable mutually between lower moving contact 8, main force's arm 13 and the linking arm 7, last pressing spring sheet 20 and last holddown spring 19 will be gone up moving contact 2 and promote downwards, gravity in conjunction with fusion tube self, impel fusion tube to withdraw between upper press nozzle two spring leafs, fusion tube 4 is articulated in insulating porcelain piece 17 and articulates fixed axis 25 on the gib head 29 and rotate and fall around the bottom; Because of can be movable mutually between lower moving contact 8, main force's arm 13 and the linking arm 7 of fusion tube 4 bottoms, do not exist and hinder the resistance that the rotation of fusion tube 4 bodies is fallen, so fusion tube 4 can easily fall.

Therefore, because of the tension degree of fuse in hold-down bolt 12 on the bottom main force arm 13 and the 38 scalable fusion tubes of the chute on the base plate 33, can prevent that it is subjected to vibration and snaps, thereby avoid causing abnormal falling; The fuse on fusion tube top fixedly tongue piece can be installed the fuse of different model, and it is wideer that therefore fuse of the present utility model cut-offs scope; Flexible connection design between last pressing spring sheet that insulating porcelain piece top installs additional and last holddown spring and fusion tube bottom lower moving contact, main force's arm and the linking arm; fusion tube is easily fallen; and the protective cover on insulating porcelain piece top has more delayed the aging of each parts of top, makes the protective value of the utility model fuse be better than fuse switch of the prior art.

In addition, become conductor for preventing that the fusion tube outer wall from being drenched in the rainy day, the rain cover 3 at outer wall upper sleeve through one hollow cylindrical of fusion tube 4 insulating bars seals between the perforate at the bottom of the tube of rain cover two ends and the outer wall of insulating bar; Be designed to the vertex of a cone at the bottom of the upper end tube of present embodiment rain cover, the top center of the vertex of a cone has the hole of passing for insulating bar, and the vertex of a cone is set on the insulating bar up.

Claims

1. fuse switch, comprise fusion tube (4) and insulating porcelain piece (17), wherein, the insulating bar upper and lower side at described fusion tube (4) middle part is respectively arranged with electric conductor upper binding head (6), lower union joint (5), upper binding head (6) top is provided with fixedly tongue piece (14) of electric conductor fuse, is fixed by head protector; The fuse two ends are provided with the electric conductor backguy, pass in fusion tube (4), and the upper end is fixed on fuse fixedly on the tongue piece (14), and the lower end is electrically connected with lower moving contact (8) on the lower union joint (5); Lower moving contact (8) both sides convex with fixed axis (25); The top of described insulating porcelain piece (17) is provided with electric conductor upper press nozzle (21) and locating piece (33), and the bottom is provided with down fixed contact (16), following fixed contact (16) two side be provided with fixed axis coupling articulate gib head (29); Fixed axis (25) correspondence is articulated in and articulates on the gib head (29), upwards rotating fusion tube (4) pushes down lower moving contact (8) in the fixed contact (16), the last moving contact (2) and the side arm (22) on fusion tube (4) top snap in insulating porcelain piece (17) upper press nozzle simultaneously, and last moving contact (2) only leans against locating piece (33) and goes up the location; It is characterized in that: lower moving contact (8) one ends, fusion tube (4) bottom and lower union joint (5) flexibly connect, and main force's arm (13) is articulated on the lower moving contact (8); Main force's arm (13) is provided with fixture (12), and lower end fuse backguy is strained and fixed on fixture (12), and main force's arm (13), lower moving contact (8) are fixed with lower union joint (5); Upper press nozzle (21) top of insulation ceramics (17) is provided with one to pressing down the last pressing spring sheet (20) that touches the last moving contact (8) of fusion tube (4).

2. fuse switch as claimed in claim 1 is characterized in that: described top of going up pressing spring sheet (20) also is provided with and presses solidly stator (18) on one, presses between the two to be provided with holddown spring on (19).

3. fuse switch as claimed in claim 1 or 2, it is characterized in that: main force's arm (13) flexibly connects by a link and lower moving contact (8), link comprises two connecting plates (32,32 ') and a base plate (33), two connecting plates (32,32 ') bottom symmetry is movably arranged on base plate (33) both sides, and two connecting plates (32,32 ') upper end symmetry is movably arranged on lower moving contact (8) both sides; Base plate (33) is provided with a chute (38), and the link fixing hole that a bolt (11) passes on this chute and the main force's arm (13) is fixing with base plate (33) and main force's arm (13).

4. fuse switch as claimed in claim 3, it is characterized in that: have two recesses (23) on the sidewall of described upper binding head (6) top, described fuse fixedly tongue piece (14) is " protruding " font, size and upper binding head (6) open top coupling, and with head protector in the compression fit of presenting a theatrical performance as the last item on a programme; The fuse fixedly side of tongue piece (14) is provided with the fixing fixture of fuse.

5. fuse switch as claimed in claim 4, it is characterized in that: insulation ceramics (17) top also is provided with the protective cover (15) that front side and bottom side openings are communicated with, will on press solidly stator (18), go up pressing spring sheet (20) and locating piece (33), upper press nozzle (21) covers in it.

6. fuse switch as claimed in claim 5 is characterized in that: the outer wall upper sleeve through of described fusion tube (4) insulating bar has the rain cover (3) of hollow tube-shape, seals at the bottom of the tube of rain cover two ends and between the outer wall of insulating bar.

7. fuse switch as claimed in claim 6 is characterized in that: be made as the vertex of a cone at the bottom of the upper end tube of described rain cover, the top center of the vertex of a cone has the hole of passing for insulating bar.

8. fuse switch as claimed in claim 7 is characterized in that: described head protector upper end is closed, the lower end inwall is provided with and the thread segment of the screw thread on upper binding head (6) top coupling.