CN213130100U

CN213130100U - Vaccination device

Info

Publication number: CN213130100U
Application number: CN202021588351.6U
Authority: CN
Inventors: 王肆玖; 杨文海; 何斌; 吴利军; 陈夏冰; 邵志勇; 陈洁; 金尔光; 周华; 童伟文
Original assignee: Wuhan Academy of Agricultural Sciences
Current assignee: Wuhan Academy of Agricultural Sciences
Priority date: 2020-08-04
Filing date: 2020-08-04
Publication date: 2021-05-07
Anticipated expiration: 2030-08-04

Abstract

The utility model discloses a vaccination device, which comprises a shell, a needle head and an action element, wherein one end of the shell is provided with a pushing injection cavity, the needle head is fixed on the outer wall of the pushing injection cavity and is communicated with the pushing injection cavity, a liquid inlet pipe is arranged inside the shell, one end of the liquid inlet pipe is provided with a first one-way structure and is used for controlling a vaccine to flow from the liquid inlet pipe to the pushing injection cavity, the pushing injection cavity is provided with a second one-way structure at a position close to the needle head and is used for controlling the vaccine to flow from the pushing injection cavity to the needle head, the other end of the liquid inlet pipe extends to a direction far away from the pushing injection cavity and is used for being communicated with a vaccine bag, one end of the; when pushing the intracavity pressure and reducing, the second one-way structure is closed, and first one-way structure is opened, and bacterin gets into through the feed liquor pipe and pushes the intracavity and inject the intracavity bacterin and flow out through the syringe needle on the contrary, and this vaccination device can control the vaccination dosage, and can effectively prevent that bacterin from being contaminated.

Description

Vaccination device

Technical Field

The utility model relates to the technical field of medical equipment, specifically relate to a vaccination device.

Background

"seed prick" is a form of vaccination, usually used in the vaccination process of chicken pox and other vaccines. When the vaccine is pricked, the skin under the chicken wings is pricked by a pricking needle to dip the vaccine, and then a trace amount of vaccine can be inoculated to the chicken body; the seed-pricking needle is an integral structure formed by a plastic handle with the length of 5-8 cm and two metal solid needles with the length of about 2 cm, and belongs to a disposable device.

The advantages of inoculating vaccine by the seed-pricking mode are that the operation is relatively simple and the cost of the seed-pricking needle is low. The disadvantage is that the chicken pox vaccine is contained in an open container, and the vaccine is easy to be polluted by other bacteria in the air when dipped; meanwhile, the inoculation dose is inaccurate due to the larger randomness when the vaccine is dipped; the inoculation needle is bigger than the injection needle, and the damage to the chicken is larger during the seed pricking.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing a vaccination device to solve the problem that above-mentioned prior art exists, make vaccination dose controllable, and can effectively prevent that the bacterin from being contaminated.

In order to achieve the above object, the utility model provides a following scheme:

the utility model provides a vaccination device, which comprises a shell, a needle head and an action element, wherein one end of the shell is provided with a push injection cavity, the needle head is fixed on the outer wall of the push injection cavity, the inside of the needle head is communicated with the inside of the push injection cavity, the inside of the shell is provided with a liquid inlet pipe, one end of the liquid inlet pipe is provided with a first one-way structure, the first one-way structure is used for controlling the one-way flow of a vaccine from the liquid inlet cavity to the push injection cavity, the position of the push injection cavity close to the needle head is provided with a second one-way structure, the second one-way structure is used for controlling the one-way flow of the vaccine from the push injection cavity to the needle head, the other end of the liquid inlet pipe extends towards the direction far away from the push injection cavity and is used for being communicated with a vaccine bag, one end of the action element extends, the pressure of the injection cavity can be changed by adjusting the length of the action element extending into the injection cavity;

when the action element controls the pressure of the injection cavity to be reduced, the second one-way structure is closed, the first one-way structure is opened, the vaccine in the vaccine bag enters the injection cavity through the liquid inlet pipe, when the action element controls the pressure of the injection cavity to be increased, the second one-way structure is opened, the first one-way structure is closed, and the vaccine in the injection cavity flows out through the needle head.

Preferably, the device further comprises a communicating pipe, one end of the communicating pipe is used for being connected and communicated with the vaccine bag, and the other end of the communicating pipe is connected and communicated with one end, far away from the pushing injection cavity, of the liquid inlet pipe.

Preferably, a communicating hole is formed in one end, opposite to the needle, of the shell, and is used for extending the liquid inlet pipe, and one end, extending out of the shell, of the liquid inlet pipe is detachably connected with the communicating pipe.

Preferably, communicating pipe includes puncture ware, hose and hasp, the puncture ware is fixed in the one end of hose for pierce the bacterin bag and with the leading-in hose to of bacterin bag internal bacterin, the hose is close to the one end of puncture ware is equipped with the breather pipe, the breather pipe be used for the intercommunication external with the hose, just breather pipe department is equipped with an air filter, still be equipped with a spacing ring on the hose, the spacing ring is fixed the puncture ware with between the breather pipe, be used for piercing the length of bacterin bag with bacterin bag liquid outlet cooperation control puncture ware, the hasp is located keep away from on the hose the one end periphery of puncture ware, be used for with the connection can be dismantled to the feed liquor pipe.

Preferably, a communicating groove is formed in the outer wall of the shell and is communicated with the inner cavity of the shell and the outside, and one end, far away from the pushing injection cavity, of the action element extends out of the outside through the communicating groove.

Preferably, the action element comprises an elastic rod, a connecting rod and a piston, an action hole is formed in one end, close to the elastic rod, of the pushing injection cavity, one end of the connecting rod extends into the pushing injection cavity through the action hole and is connected with the piston, the other end of the connecting rod is connected with one end of the elastic rod, the other end of the elastic rod extends out of the shell and is fixed on the outer side wall of the shell, the outer wall of the piston is attached to the inner wall of the pushing injection cavity, and the elastic rod can drive the connecting rod and the piston to reciprocate in the pushing injection cavity in the direction far away from or close to the needle head.

Preferably, the cross section of the elastic rod is arched, the middle part of the elastic rod protrudes in the direction away from the shell, and a pressing pad is further fixed at the middle part of the elastic rod and used for being pressed by an operator.

Preferably, the injection cavity is keeping away from the one end opening of syringe needle and being equipped with the internal thread, just the injection cavity is keeping away from an one end installation regulating block of syringe needle, be equipped with the external screw thread on the regulating block, the regulating block can stretch into inject the intracavity and with inject chamber threaded connection, just the regulating block stretches into the length of injecting the intracavity is adjustable, be equipped with spacing hole on the regulating block, just spacing hole is in link up in the length direction of regulating block the regulating block, the one end of connecting rod is passed through spacing hole stretches into inject the intracavity, just be close to on the elastic rod the diameter of the one end of connecting rod is greater than the internal diameter in spacing hole.

Preferably, the shell is provided with scale marks, and the outer edge of the adjusting block can always point to one scale mark for limiting the injection amount of the vaccine.

Preferably, the first one-way structure and the second one-way structure are both soft valves, and the soft valves can only be opened towards the direction close to the needle.

The utility model discloses for prior art gain following technological effect:

the utility model provides a vaccination device, which comprises a shell, a needle head and an action element, wherein one end of the shell is provided with an injection cavity, the injection cavity is used for storing a vaccine to be injected, the needle head is fixed on the outer wall of the injection cavity, the inside of the needle head is communicated with the inside of the injection cavity, the vaccine in the injection cavity can flow out through the needle head and be used for inoculating animals, a liquid inlet pipe is arranged inside the shell, one end of the liquid inlet pipe is provided with a first one-way structure, the first one-way structure is used for controlling the one-way flow of the vaccine from the liquid inlet cavity to the injection cavity, so that the vaccine in the liquid inlet pipe can enter the injection cavity, the vaccine in the injection cavity can not enter the liquid inlet pipe, the injection cavity is provided with a second one-way structure at a position close to the needle head, the second one-way structure is used for controlling the one-, the other end of the liquid inlet pipe extends in the direction far away from the injection cavity and is communicated with the vaccine bag, vaccines in the vaccine bag can enter the injection cavity through the liquid inlet pipe and are finally discharged through the needle head to complete the injection process, the whole process is completed in a closed container, the pollution of infectious microbes in the air to the vaccines can be reduced, one end of the action element extends out of the shell, the control of the action element is facilitated, the other end of the action element extends into the injection cavity, and the pressure intensity of the injection cavity can be changed by adjusting the length of the action element extending into the injection cavity so as to control the supplement of the vaccines and the injection of the vaccines; the chamber pressure reduces is injected in the action component control, the one-way structure of second closes, first one-way structure opens, the bacterin gets into through the feed liquor pipe and injects the chamber in the bacterin bag, the chamber pressure increase is injected in the action component control, the one-way structure of second opens, first one-way structure closes, inject intracavity bacterin and flow out through the syringe needle, inject the pressure in chamber through the action component control, thereby realize the replenishment and the injection of bacterin, can conveniently supplement dosage and injection dosage control to single bacterin, improve vaccination's accuracy.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

Fig. 1 is a schematic structural diagram of a vaccination device provided by the present invention;

FIG. 2 is a schematic structural view of a communicating tube in the vaccination device provided by the present invention;

FIG. 3 is a schematic structural view of a vaccine bag in the vaccination device provided by the present invention;

in the figure: 1-shell, 2-needle, 3-pushing injection cavity, 4-liquid inlet pipe, 5-communicating hole, 6-elastic rod, 7-pressing pad, 8-connecting rod, 9-piston, 10-adjusting block, 11-first one-way structure, 12-second one-way structure, 13-scale mark, 14-puncture outfit, 15-vent pipe, 16-air filter cover, 17-limit ring, 18-hose, 19-lock catch and 20-vaccine bag.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

The utility model aims at providing a vaccination device to dose is uncontrollable when solving vaccination, and pollutes the technical problem of bacterin easily.

In order to make the above objects, features and advantages of the present invention more comprehensible, the present invention is described in detail with reference to the accompanying drawings and the detailed description.

As shown in fig. 1-3, the utility model provides a vaccination device, which comprises a housing 1, a needle 2 and an action element, wherein one end of the housing 1 is provided with a push injection cavity 3, the push injection cavity 3 is used for storing a vaccine to be injected, the needle 2 is fixed on the outer wall of the push injection cavity 3, the inside of the needle 2 is communicated with the inside of the push injection cavity 3, the vaccine in the push injection cavity 3 can flow out through the needle 2 and is used for inoculating animals, a liquid inlet pipe 4 is arranged inside the housing 1, one end of the liquid inlet pipe 4 is provided with a first unidirectional structure 11, the first unidirectional structure 11 is used for controlling the unidirectional flow of the vaccine from the liquid inlet pipe 4 to the push injection cavity 3, the vaccine in the liquid inlet pipe 4 can enter the push injection cavity 3, the vaccine in the push injection cavity 3 can not enter the liquid inlet pipe 4, the position of the push injection cavity 3 close to the needle 2 is provided with a second unidirectional structure 12, the second unidirectional structure 12 is used for controlling, the vaccine in the injection cavity 3 can enter the needle head 2, the vaccine in the needle head 2 can not enter the injection cavity 3, the other end of the liquid inlet pipe 4 extends in the direction far away from the injection cavity 3 and is communicated with the vaccine bag 20, the vaccine in the vaccine bag 20 can enter the injection cavity 3 through the liquid inlet pipe 4 and is finally discharged through the needle head 2, the injection process is completed, the whole process is completed in a closed container, the pollution of infectious microbes in the air to the vaccine can be reduced, one end of the action element extends out of the shell 1, the control of the action element is facilitated, the other end of the action element extends into the injection cavity 3, and the length of the action element extending into the injection cavity 3 is adjusted, so that the pressure of the injection cavity 3 can be changed, and the vaccine supplement and injection can be controlled;

when the action element controls the pressure of the injection cavity 3 to be reduced, the second one-way structure 12 is closed, the first one-way structure 11 is opened, the vaccine in the vaccine bag 20 enters the injection cavity 3 through the liquid inlet pipe 4, when the action element controls the pressure of the injection cavity 3 to be increased, the second one-way structure 12 is opened, the first one-way structure 11 is closed, the vaccine in the injection cavity 3 flows out through the needle head 2, and the pressure of the injection cavity 3 is controlled through the action element, so that the supplement and injection of the vaccine are realized, the supplement dosage and the injection dosage control of the single vaccine can be conveniently realized, and the accuracy of vaccination is improved;

it is worth to say that, the vaccination device that the utility model provides except can be used to sting, still can be used to the hypodermic of poultry bacterin, intramuscular injection and drip nose etc to can remove the inoculation, be particularly useful for kind of chicken farm and commodity laying hen farm.

Specifically, still include a communicating pipe, the one end of communicating pipe is used for connecting and communicating the vaccine bag 20, and the other end is connected and is communicated with the one end of keeping away from pushing injection chamber 3 on feed liquor pipe 4, regard communicating pipe as the intermediate element who connects vaccine bag 20 and feed liquor pipe 4, realize the stability of connecting, prevent that the vaccination in-process, direct removal vaccine bag 20 causes the interference to supplementary or injection dose.

One end relative with syringe needle 2 on the casing 1 is equipped with the intercommunicating pore 5, and intercommunicating pore 5 is used for feed liquor pipe 4 to stretch out, and the one end that feed liquor pipe 4 stretches out casing 1 can be dismantled with communicating pipe and be connected, guarantees the stability of connecting, prevents to remove in-process feed liquor pipe 4 and communicating pipe between the separation, leads to the bacterin to flow out the external world directly.

The communicating pipe comprises a puncture outfit 14, a hose 18 and a lock catch 19, wherein the puncture outfit 14 is fixed at one end of the hose 18 and is used for puncturing the vaccine bag 20 and guiding the vaccine in the vaccine bag 20 into the hose 18, one end of the hose 18 close to the puncture outfit 14 is provided with a vent pipe 15, the vent pipe 15 is used for communicating the outside with the hose 18, an air filter 16 is arranged at the vent pipe 15, the hose 18 is also provided with a limiting ring 17, the limiting ring 17 is fixed between the puncture outfit 14 and the vent pipe 15 and is used for matching with the liquid outlet of the vaccine bag 20 to control the length of the puncture outfit 14 puncturing the vaccine bag 20, meanwhile, the limiting ring 17 can seal the liquid outlet of the vaccine bag 20 and prevent the vaccine from flowing out through a gap between the liquid outlet of the vaccine bag 20 and the puncture outfit 14 in the using process, the lock catch 19 is arranged at the periphery of one end of the hose 18 far away from the, the stability of connecting is guaranteed, improves this vaccination device's wholeness, and communicating pipe can prevent that the bacterin from getting into the in-process of feed liquor pipe 4 from bacterin bag 20 by the pollution, and the structure of communicating pipe is similar with the disposable transfusion system structure of common use in medical science, the difference is the utility model provides an among the vaccination device need not pass through communicating pipe control liquid flow rate, and need not set up syringe needle 2 on communicating pipe.

Be equipped with the intercommunication groove on the 1 outer wall of casing, intercommunication groove intercommunication 1 inner chamber of casing and external, the action component is kept away from the one end of pushing injection chamber 3 and is stretched out the external world through the intercommunication groove, can make things convenient for operating personnel to the control of action component.

The action element comprises an elastic rod 6, a connecting rod 8 and a piston 9, the connecting rod 8, the piston 9 and the injection cavity 3 jointly form a piston-connecting rod mechanism, one end of the injection cavity 3, which is close to the elastic rod 6, is provided with an action hole, one end of the connecting rod 8 extends into the injection cavity 3 through the action hole and is connected with the piston 9, the reciprocating movement of the piston 9 can be controlled through the movement of the connecting rod 8, the other end of the connecting rod 8 is connected with one end of the elastic rod 6, the other end of the elastic rod 6 extends out of the shell 1 and is fixed on the outer side wall of the shell 1, the stability of the whole structure is ensured, when acting force is applied to the elastic rod 6, the connecting rod 8 and the piston 9 can be driven to move towards the direction close to or far away from the needle head 2, the change of the volume of the cavity at one side, which is far away from the connecting rod, the outer wall of piston 9 and the laminating of the inner wall of pushing injection chamber 3 guarantee piston 9's leakproofness, and elastic rod 6 can drive connecting rod 8 and piston 9 along keeping away from or being close to the direction reciprocating motion of syringe needle 2 in pushing injection chamber 3.

The cross section of the elastic rod 6 is arched, the middle part of the elastic rod 6 protrudes in the direction away from the shell 1, the elastic rod 6 is made of high polymer materials with good elasticity and certain hardness, the deformation and the reset of the elastic rod 6 can be guaranteed, the middle part of the elastic rod 6 is also fixed with a pressing pad 7, the pressing pad 7 is used for being pressed by an operator, when vaccines need to be injected, the pressing pad 7 is pressed by fingers, one end of the elastic rod 6 connected with a connecting rod 8 drives the connecting rod 8 to move in the direction close to the needle head 2, meanwhile, a piston 9 moves in the direction close to the needle head 2 in a pushing cavity 3, the volume of the pushing cavity 3 between the piston 9 and the needle head 2 is reduced, the pressure is increased, a second one-way structure 12 is driven to be opened, meanwhile, a first one-way structure 11 is closed, the vaccines in the pushing cavity 3 flow out from the needle head 2, when the injection is completed, and drive connecting rod 8 and piston 9 and to the direction removal of keeping away from syringe needle 2, the 3 volumetric increases in the injection chamber between piston 9 and the syringe needle 2, the pressure reduces, drive second one-way structure 12 and close, first one-way structure 11 is opened, inject chamber 3, feed liquor pipe 4, communicating pipe and bacterin bag 20 communicate in proper order, the bacterin enters into and injects chamber 3, realize the replenishment process, press and loosen the operation of pressing pad 7 through the aforesaid, can realize the replenishment and the injection circulation of bacterin, and convenient operation.

The opening of one end of the injection cavity 3 far away from the needle head 2 is provided with an internal thread, the adjusting block 10 is arranged at one end of the injection cavity 3 far away from the needle head 2, the adjusting block 10 is provided with an external thread, the adjusting block 10 can extend into the injection cavity 3 and is in threaded connection with the injection cavity 3, the length of the adjusting block 10 extending into the injection cavity 3 is adjustable, the adjusting block 10 is provided with a limit hole which is communicated with the adjusting block 10 in the length direction of the adjusting block 10, one end of the connecting rod 8 extends into the injection cavity 3 through the limit hole, the diameter of one end of the elastic rod 6 close to the connecting rod 8 is larger than the inner diameter of the limit hole, the change of the extending length of the adjusting block 10 into the injection cavity 3 is realized by rotating the adjusting block 10, meanwhile, the outer edge of the limit hole can limit the elastic rod 6, the elastic rod 6 is prevented from extending into the injection cavity 3, and the single vaccine supplement dosage is accurately, and the supplementary dose is adjustable, so that the injection dose of the vaccine is controlled, and the method is simple and reliable.

Be equipped with scale mark 13 on casing 1, the outer fringe of regulating block 10 can point to a scale all the time for the injection volume of injecing bacterin, according to the scale of regulating block 10 position, can obtain when elastic rod 6 removes the terminal surface contact with regulating block 10, inject the bacterin dose of supplementing in the chamber 3, thereby realize the accurate control of bacterin injection dose.

First one-way structure 11 and second one-way structure 12 are soft valve, and soft valve all can only be opened to the direction towards syringe needle 2, and the one end of soft valve is the stiff end and fixes the inner wall at injecting chamber 3 promptly, and the other end is the expansion end, can rotate around the stiff end, and can only rotate to the direction towards syringe needle 2 to realize the switching function, nevertheless the utility model provides an among the vaccinator device first one-way structure 11 and second one-way structure 12 all do not are not limited to soft valve, also can realize one-way closure for marble or other, and can open and the structure of closing.

The principle and the implementation mode of the present invention are explained by applying specific examples in the present specification, and the above descriptions of the examples are only used to help understanding the method and the core idea of the present invention; meanwhile, for the general technical personnel in the field, according to the idea of the present invention, there are changes in the concrete implementation and the application scope. In summary, the content of the present specification should not be construed as a limitation of the present invention.

Claims

1. A vaccination device, characterized by: the injection device comprises a shell, a needle and an action element, wherein one end of the shell is provided with an injection cavity, the needle is fixed on the outer wall of the injection cavity, the inside of the needle is communicated with the inside of the injection cavity, a liquid inlet pipe is arranged inside the shell, one end of the liquid inlet pipe is provided with a first one-way structure, the first one-way structure is used for controlling the one-way flow of a vaccine from the liquid inlet cavity to the injection cavity, the injection cavity is provided with a second one-way structure at a position close to the needle, the second one-way structure is used for controlling the one-way flow of the vaccine from the injection cavity to the needle, the other end of the liquid inlet pipe extends in a direction far away from the injection cavity and is communicated with a vaccine bag, one end of the action element extends out of the shell, the other end of the action element extends into the injection cavity, and the length of the action element extending into, is capable of changing the pressure of the bolus chamber;

2. The vaccination device of claim 1, wherein: still include a communicating pipe, the one end of communicating pipe is used for connecting and communicates the vaccine bag, the other end with keep away from on the feed liquor pipe the one end of pushing the intracavity is connected and is communicated.

3. The vaccination device of claim 2, wherein: the one end opposite with the syringe needle on the casing is equipped with the intercommunicating pore, the intercommunicating pore is used for the feed liquor pipe stretches out, the feed liquor pipe stretch out the one end of casing with communicating pipe can dismantle and be connected.

4. The vaccination device of claim 3, wherein: communicating pipe includes puncture ware, hose and hasp, the puncture ware is fixed in the one end of hose for pierce the bacterin bag and with the leading-in hose to of bacterin bag internal bacterin, the hose is close to the one end of puncture ware is equipped with the breather pipe, the breather pipe be used for the intercommunication external with the hose, just breather pipe department is equipped with an air filter, still be equipped with a spacing ring on the hose, the spacing ring is fixed the puncture ware with between the breather pipe for pierce the length of bacterin bag with bacterin bag liquid outlet cooperation control puncture ware, the hasp is located keep away from on the hose the one end periphery of puncture ware, be used for with the connection can be dismantled to the feed liquor pipe.

5. The vaccination device of claim 1, wherein: the outer wall of the shell is provided with a communicating groove, the communicating groove is communicated with the inner cavity of the shell and the outside, and one end, far away from the pushing injection cavity, of the action element extends out of the outside through the communicating groove.

6. The vaccination device of claim 5, wherein: the action element comprises an elastic rod, a connecting rod and a piston, wherein an action hole is formed in one end, close to the elastic rod, of the injection cavity, one end of the connecting rod extends into the injection cavity through the action hole and is connected with the piston, the other end of the connecting rod is connected with one end of the elastic rod, the other end of the elastic rod extends out of the shell and is fixed on the outer side wall of the shell, the outer wall of the piston is attached to the inner wall of the injection cavity, and the elastic rod can drive the connecting rod and the piston to reciprocate in the injection cavity along the direction far away from or close to the needle head.

7. The vaccination device of claim 6, wherein: the cross section of the elastic rod is arched, the middle of the elastic rod protrudes in the direction away from the shell, and the middle of the elastic rod is further fixedly provided with a pressing pad which is used for being pressed by an operator.

8. The vaccination device of claim 7, wherein: the injection cavity is keeping away from the one end opening of syringe needle is equipped with the internal thread, just the injection cavity is keeping away from an one end installation regulating block of syringe needle, be equipped with the external screw thread on the regulating block, the regulating block can stretch into to inject the intracavity and with inject chamber threaded connection, just the regulating block stretches into inject the adjustable length of intracavity, be equipped with spacing hole on the regulating block, just spacing hole is in link up in the length direction of regulating block the regulating block, the one end of connecting rod is passed through spacing hole stretch into to inject the intracavity, just be close to on the elastic rod the diameter of the one end of connecting rod is greater than the internal diameter in spacing hole.

9. The vaccination device of claim 8, wherein: the shell is provided with scale marks, and the outer edge of the adjusting block can always point to one scale for limiting the injection amount of the vaccine.

10. The vaccination device of claim 1, wherein: the first one-way structure and the second one-way structure are both soft valves, and the soft valves can only be opened towards the direction close to the needle head.