Needle assembly for a liquid applicator

Abstract

The present invention provides a needle assembly for a liquid application device, comprising a needle housing, a needle bundle and an elastic tubular member; the needle housing comprises a body portion, the body portion has a longitudinal channel, the longitudinal channel comprises an upper open end and a lower open end, the elastic tubular member comprises an elastic tubular portion connected to the upper end portion of the needle housing, connected to the lower end portion of the needle bundle, connecting the upper end portion and the lower end portion, and a spiral ridge extending on the outer surface of the elastic tubular portion, or the elastic tubular portion comprises a first portion and a second portion thinner than the first portion separated by a boundary, the boundary spirally extending from the upper end portion to the lower end portion on the outer surface of the elastic tubular portion, or two oblique ridges arranged oppositely and extending obliquely are provided on the outer surface of the elastic tubular portion. The elastic tubular member of the present invention has a simple outer surface feature so that small defects on the outer surface are easy to inspect, and the manufacturing method is simple, and the driving force provided by it is easier to adjust.

Description

Technical Field

[0001] The present invention relates to the field of devices for applying liquids to the skin, and in particular to a needle assembly for a liquid application device, such as a tattoo device or a device for permanent makeup. Background Art

[0002] Devices for applying liquids to the skin, such as tattoo devices, generally include a tattoo needle for applying ink to the skin, a tattoo machine having a needle driver, and a handle that connects the tattoo needle to the tattoo machine and can be conveniently held in the hand of an operator to manipulate the tattoo needle during use. During operation, a drive rod of the needle driver drives the tattoo needle to reciprocately extend and retract, thereby repeatedly piercing the skin of the tattooer. The tattoo needle can be arranged in a detachable needle assembly that can be attached to the handle. Tattoo devices include rotary tattoo devices and coil tattoo devices, and some needle assemblies include elastic biasing members for sealing and axially and laterally biasing the tattoo needle.

[0003] For example, Xiao Long's U.S. patent application with publication number US11052232 (application number US16 / 504066) published on July 6, 2021 discloses a needle assembly including an elastic biasing member for biasing a tattoo needle and forming a fluid seal.

[0004] A Chinese patent application with publication number CN106902452A published on June 30, 2017 discloses a tattoo device, including a housing, a needle and an elastic membrane, wherein the housing has a needle mouth for the needle to extend out, and the needle mouth extends forward to form an operating portion for contacting the tattooed body, and a connecting mechanism is provided on the needle, and the connecting mechanism firmly connects the needle and the elastic membrane. The elastic membrane has areas of different thicknesses for generating a force that causes the needle to move toward the operating portion. The elastic membrane includes an elastic rib that generates a force that causes the needle to move toward the operating portion, and the elastic rib is arranged along the direction in which the needle moves. Summary of the invention

[0005] The present invention aims to provide a needle assembly for a liquid application device, wherein the elastic tubular member has simple outer surface features so that small defects on the outer surface can be easily inspected, and the manufacturing method is simple, and the driving force provided by the elastic tubular member can be more easily adjusted.

[0006] The present invention relates to a needle assembly for a liquid application device, comprising a needle housing, a needle bundle and an elastic tubular member; the needle housing comprises a body portion, the body portion has a longitudinal channel, the longitudinal channel comprises an upper open end and a lower open end; the needle bundle is movably installed in the longitudinal channel, and the needle bundle can be driven by a driving rod to reciprocate between a retracted position and an extended position. The elastic tubular member comprises an upper end portion connected to the needle housing, a lower end portion connected to the needle bundle, and an elastic tubular portion connecting the upper end portion and the lower end portion, the elastic tubular portion is a column or truncated cone shape with an elastically retractable thin wall, and the stretched elastic tubular member longitudinally drives the needle bundle toward the retracted position.

[0007] In one aspect, the elastic tube has an extended spiral ridge on its outer surface, the spiral ridge is used to provide a longitudinal driving force and a transverse driving force, wherein the longitudinal driving force drives the needle bundle longitudinally to the retracted position and the transverse driving force biases the needle bundle toward the side wall of the longitudinal channel.

[0008] In different embodiments, the needle assembly may include one or more of the following features. The upper end and the lower end of the elastic tubular member may be sealingly connected to the needle housing and the needle bundle, respectively, to prevent fluid communication between the upper open end and the lower open end of the needle housing. The elastic tubular member may include a diaphragm. The spiral ridge may extend from the upper end of the elastic tubular member to the lower end. The number of the spiral ridges is two, and the two spiral ridges are symmetrically arranged relative to a plane passing through the longitudinal axis of the elastic tubular member. The spiral ridge may have a roughly polygonal or semicircular cross-section. The material of the elastic tubular member may be silicone, latex or rubber.

[0009] On the other hand, the elastic tube portion includes a first portion and a second portion thinner than the first portion separated by a boundary, wherein the boundary extends spirally from an upper end portion to a lower end portion on an outer surface of the elastic tube portion, so that when stretched, the elastic tubular member exerts a longitudinal driving force and a transverse driving force on the needle bundle, wherein the longitudinal driving force drives the needle bundle longitudinally to a retracted position and the transverse driving force biases the needle bundle toward a side wall of the longitudinal channel.

[0010] In various embodiments, the needle assembly may include one or more of the following features: The first portion and the second portion of the elastic tubular member may be separated by two helical boundaries that are symmetrically arranged relative to a plane passing through a longitudinal axis of the elastic tubular member.

[0011] On the other hand, two oblique ridges are arranged opposite to each other and extend obliquely on the outer surface of the elastic tube portion. The two oblique ridges are symmetrically arranged relative to a plane passing through the longitudinal axis of the elastic tubular member. The oblique ridges provide longitudinal driving force and transverse driving force. The longitudinal driving force drives the needle bundle to a retracted position in the longitudinal direction, and the transverse driving force biases the needle bundle toward the side wall of the longitudinal channel.

[0012] As can be appreciated, the helical ridges or helical borders on the resilient tubular member provide a driving force having both a longitudinal and a lateral component.

[0013] Beneficial effects of the present invention: The needle assembly for a liquid application device of the present invention comprises a needle housing, a needle bundle and an elastic tubular member; the needle housing comprises a body portion, the body portion has a longitudinal channel, the longitudinal channel comprises an upper open end and a lower open end; the needle bundle is movably mounted in the longitudinal channel, and the needle bundle can be driven by a driving rod to reciprocate between a retracted position and an extended position; the elastic tubular member comprises an elastic tubular portion connected to the upper end portion of the needle housing, connected to the lower end portion of the needle bundle, and connecting the upper end portion with the lower end portion, and a spiral ridge extending on the outer surface of the elastic tubular portion, or the elastic tubular portion comprises a first portion separated by a boundary and a second portion thinner than the first portion, the boundary spirally extending from the upper end portion to the lower end portion on the outer surface of the elastic tubular portion, or the outer surface of the elastic tubular portion is provided with two oblique ridges arranged oppositely and extending obliquely, and the two oblique ridges are symmetrically arranged relative to a plane passing through the longitudinal axis of the elastic tubular member. The elastic tubular member of the present invention has a simple outer surface feature so that small defects on the outer surface are easy to check, and the manufacturing method is simple, and it is easier to adjust the driving force provided by it.

[0014] Other aspects, features, and embodiments of the present invention will become apparent to those of ordinary skill in the art after reading the following description of specific embodiments in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to further understand the features and technical contents of the present invention, please refer to the following detailed description and drawings of the present invention. However, the drawings are only provided for reference and illustration and are not intended to limit the present invention.

[0016] In the accompanying drawings, the embodiments of the present invention are shown only as examples:

[0017] Figure 1 is a cross-sectional view of a needle assembly according to an embodiment of the present invention;

[0018] Figure 2 for Figure 1 A perspective view of a needle assembly;

[0019] Figure 3 and Figure 4 for Figure 2 An exploded view of the needle assembly;

[0020] Figure 5A and Figure 5B for Figure 1 A partial cross-sectional view of the needle assembly, Figure 5A The middle needle bundle is in the retracted position, Figure 5B The middle needle bundle is in the extended position;

[0021] Figure 6 To show that Figure 5B A schematic diagram of the driving force exerted by the elastic tubular member of the needle assembly and its longitudinal and lateral components;

[0022] Fig. 7A A front view of an elastic tubular member according to an embodiment of the present invention;

[0023] Figure 7B for Fig. 7A A bottom view of the elastic tubular member showing the plane of symmetry indicated by line BB;

[0024] Figure 7C for Fig. 7A A three-dimensional view of an elastic tubular member;

[0025] Fig.7D for Fig. 7A 7D-7D cross-sectional view of the elastic tubular member;

[0026] Fig. 8A for Fig. 7A A three-dimensional view of the elastic tubular member from another angle;

[0027] Figure 8B For along Fig. 8A The line 8B-8B in Fig. 7A A partial perspective view of an elastic tubular member;

[0028] FIG. 9A to FIG. 9G It is a front view of an elastic tubular member according to different embodiments of the present invention;

[0029] Figure 9H and Fig.9I A partially cut-away front view of an elastic tubular member according to a further embodiment of the present invention;

[0030] Fig. 10A is a three-dimensional view of an elastic tubular member according to another embodiment of the present invention;

[0031] Fig. 10B For along Fig. 10A The line 10B-10B in Fig. 10A A partial perspective view of an elastic tubular member;

[0032] Fig.11A For along Fig. 7A The line 11A-11A in Fig. 7A A cross-sectional view of a spiral ridge of an elastic tubular member;

[0033] FIG. 11B to FIG. 11F sectional views of spiral ridges according to different embodiments of the present invention. DETAILED DESCRIPTION

[0034] To further illustrate the technical means and effects of the present invention, the following is a detailed description in conjunction with the preferred embodiments of the present invention and the accompanying drawings.

[0035] One embodiment of the present invention is directed to a needle assembly of a liquid application device for applying liquid to skin.

[0036] The liquid application device may be an ink application device, such as a tattoo device described in U.S. Patent Application Nos. US11052232, US10806915 (Application No. US15 / 691125), or US2019 / 0217072 (Application No. US15 / 874597), the entire contents of which are incorporated herein by reference. Briefly, a suitable tattoo device (not shown) may include a needle assembly connected to a tattoo machine (not shown) via a handle (not shown). The needle assembly may be disposable, and the needle assembly and the handle may be configured to be removably coupled to each other.

[0037] In the embodiment disclosed in the present invention, the needle assembly can be as follows Figures 1 to 8B The needle assembly 10 shown may be configured for use in tattooing or for applying ink to the skin for permanent makeup, and the needle assembly 10 may be disposable.

[0038] like Figure 1 As shown, the needle assembly 10 includes a needle housing 40 and a reciprocating needle bundle 200 , wherein the needle bundle 200 has a puncture needle group 210 and is installed in the needle housing 40 . The puncture needle group 210 is used to puncture the skin and apply ink to the skin.

[0039] Although not shown in the figure, it should be understood that the needle assembly 10 can be connected and mounted to a tattoo machine (not shown), for example, through a handle (not shown) of the tattoo machine. The tattoo device (not shown) includes a needle driver (not shown) having a drive rod (not shown) for driving the needle bundle 200 to move downward through the needle shaft 220 of the needle assembly 10.

[0040] The structure of a suitable tattoo machine, including a handle and a tattoo machine body, is known in the art and may be similar to the corresponding devices and components disclosed in publication numbers US11052232, US10806915 or US2019 / 0217072. Therefore, these devices, components and their connection and interaction with the needle housing 40 and the needle shaft 220 are not described in detail in the present invention.

[0041] like Figures 1 to 5B As shown, the needle bundle 200 is movably installed in the needle housing 40 , and the needle housing 40 includes a tubular body portion 100 and a detachable cap portion 400 .

[0042] The body portion 100 has a tubular longitudinal passage 120 for accommodating the needle bundle 200. The longitudinal passage 120 extends from an upper open end 122 of the body portion 100 to a lower open end 124 and has a longitudinal central axis A. Figure 4 As shown (see also Figure 5A The body 100 has an opening 150 at the lower open end 124 to allow the needle group 210 of the needle bundle 200 to pass through. The needle guide wall 110 is provided at the lower open end 124 adjacent to the opening 150, which provides a guide (guiding and supporting) surface for guiding the movement of the needle group 210.

[0043] The opening 150 may be an integral part of the body portion 100. However, in other embodiments, the opening 150 may be attached to the body portion 100 as a separate part (not shown), and the opening may be constructed or provided according to known techniques, including those disclosed in the references incorporated herein.

[0044] The body portion 100 may also be provided with one or more protruding buckles 130 on the inner wall at the upper open end 122 for connecting and engaging with the cap portion 400 , as described below.

[0045] The removable cap 400 is disposed at the upper open end 122 of the body 100 and is connected to the upper open end 122 in a snap-on manner. The cap 400 has a central opening 450 for allowing the needle shaft 220 to pass through the central opening 450 and to reciprocate axially during operation. The cap 400 also has a downwardly extending tube 410, the outer wall of which has an annular flange 420 and an annular groove 430, which are configured to engage the upper end 320 of the elastic tubular member 300 to fix the upper end 320 to the needle housing 40, which will be further described below. The cap 400 also has an annular snap groove 440 for engaging the raised snap 130 of the body 100 so as to fix the cap 400 in place.

[0046] The body portion 100 and the cap portion 400 may be made of plastic material or any other suitable material.

[0047] like Figure 1 As shown in FIG. 5 , the needle bundle 200 has a needle group 210 attached to a needle shaft 220 .

[0048] In various embodiments, the needle group 210 of the needle bundle 200 may include one or more needles that may be welded together or otherwise combined. The needles may be formed of stainless steel or any other suitable material. A single needle may have any known suitable needle tip shape. The combined array of multiple needles of the needle bundle 200 may be bundled to form an overall profile that is generally cylindrical. Alternatively, the combined array of multiple needles may also be arranged side by side to form an overall profile that is generally rectangular, for example, a needle bundle may be stacked to form a single row or double row. Such different arrangements of tattoo needles are known in the art and may be referred to as "tightened round needles" or "sected round needles", "spread round needles", "single row straight needles" or "double row crossed needles", respectively. The needle group 210 may include 1-18 needles for "tightened round needles" and "spread round needles" of a circular array, or may include 4-27 needles for "single row straight needles" and "double row crossed needles".

[0049] It will be appreciated that the cross-sectional dimensions of the needle or needle bundle will affect the flow of ink. Generally, the smaller the needle size or the smaller the needle diameter, the thinner and more easily controlled the ink flow from each needle tip. Generally, the needles in the same needle bundle can have the same or similar sizes. The size of the needle can be selected by the operator or user based on the desired effect. Different sizes can be used for different reasons. Needles of standard sizes can be used. In some embodiments, the diameter of a single needle can be 0.25 mm, 0.30 mm, or 0.35 mm. The design of the needle can be selected and changed according to the desired tattoo pattern and the purpose to be applied, as known in the art.

[0050] The number of needles in the needle bundle 200 can vary from 1 to 27 or more as desired. For example, commercially available needle bundles in circular arrays typically have 1, 3, 5, 7, 8, 9, 11, 14, or 18 needles. It will also be appreciated that the overall profile of the needle bundle can vary depending on the number of needles in the needle bundle, the arrangement of the needles, the amount of solder material used by the needles, or other factors.

[0051] The needle assembly 210 is supported on the needle shaft 220. The axis of the needle shaft 220 can be aligned with the axis of the longitudinal channel 120 ( Figure 4 and Figure 5A The longitudinal center axis A shown in FIG. 2 is axially aligned with the axis of the needle group 210, but is offset from the axis of the needle group 210 (see FIG. Figure 3 , Figure 4 and Figure 5A ). The needle shaft 220 can be formed of a rigid plastic material or other suitable material. The material of the needle shaft 220 should have relatively high strength and hardness and be wear-resistant so as to support the needle group 210 to move smoothly during operation.

[0052] exist Figure 1In the illustrated embodiment, the needle group 210 is connected to the needle shaft 220 via a connecting rod 215 of the needle bundle 200. The connecting rod 215 may be made of steel, such as stainless steel. One end of the connecting rod 215 may be connected to the needle shaft 220 by an adhesive connected to the hole 222 of the needle shaft 220, and the needle group 210 may be connected to the other end of the connecting rod 215 by welding (soldering). The diameter of the connecting rod 215 is approximately 1.5 mm, and the hole 222 of the needle shaft 220 may have a corresponding diameter.

[0053] In other embodiments, the cylindrical array of needle groups 210 may have ends with cylindrical profiles that can be directly inserted into the holes 222 of the needle shaft 220 and connected to the needle shaft 220 by adhesive or the like. However, when the needle group 210 is connected to the needle shaft 220 by the connecting rod 215, the needle group 210 may have needles of different sizes or different numbers, and the needle group 210 does not need to have ends with cylindrical profiles that match the shape and size of the holes 222.

[0054] The needle bundle 200 can be Figure 5A Retracted position shown and Figure 5B The longitudinal reciprocating motion between the extended positions shown is along the longitudinal center axis A. The downward motion of the needle bundle 200 is driven by a needle driver of a tattoo machine to which the needle bundle 200 is connected.

[0055] In order to promote the reciprocating motion of the needle bundle 200, an elastic tubular member 300 made of an elastic material (e.g., silicone) is disposed in the needle housing 40 and is configured to pull the needle bundle 200 back upward after the needle bundle 200 is pushed downward by an excitation or driving mechanism (e.g., the needle driver of the above-mentioned tattoo device) in each motion cycle.

[0056] The resilient tubular member 300 is also configured to bias the needle group 210 of the needle bundle 200 toward a side wall of the longitudinal channel 120 , such as the needle guide wall 110 .

[0057] Furthermore, the elastic tubular member 300 is configured to provide a fluid seal between the lower open end 124 of the needle housing 40 and the central opening 450 of the cap 400 , and thus the elastic tubular member 300 can form a structure having a fluid seal function between the lower open end 124 and the central opening 450 .

[0058] Conveniently, when fluid (e.g., ink, blood, or other body fluid) enters the needle housing 40 through the opening 150, the sealing function provided by the elastic tubular member 300 will prevent the fluid from escaping through the central opening 450 and prevent the fluid from contaminating the components above the needle housing 40. Therefore, the fluid is contained in the needle housing 40, and other components of the tattoo device connected to the needle assembly 10 can be prevented from being contaminated. When the needle assembly 10 is discarded after use, the fluid in the needle housing 40 can be disposed of together with the needle assembly 10. For other tattooers who want to tattoo, a new needle assembly 10 can be used and connected to the tattoo device to prevent cross infection caused by the needle assembly 10.

[0059] like FIG. 7B to FIG. 7D and Fig. 8A As shown, the elastic tubular member 300 includes a lower end portion 310, an upper end portion 320, and an elastically stretchable (thin-walled) tubular elastic tube portion 330 connecting the upper end portion 320 and the lower end portion 310. The elastic tubular member 300 is made of an elastic material.

[0060] The upper end 320 of the elastic tubular member 300 is sized and shaped to fit tightly against the inner wall of the body 100. The upper end 320 has an annular rib 322 extending circumferentially along the outer wall of the upper end 320 to provide a fluid seal and friction fit with the inner wall of the body 100.

[0061] As previously described, the cap 400 is configured to engage the upper end 320 of the elastic tubular member 300. In particular, the upper end 320 is firmly fixed between the annular groove 430 of the cap 400 and the body 100 by the annular flange 420, and is thus sealingly fixed to the needle housing 40.

[0062] The lower end portion 310 of the elastic tubular member 300 is configured to sealingly engage the needle shaft 220 of the needle bundle 200. Fig. 8A As shown, the lower end 310 of the elastic tubular member 300 may include an opening 312 for allowing the needle shaft 220 to pass therethrough and frictionally engage (clamp) the needle shaft 220 in a fluid-tight manner.

[0063] The elastic tube portion 330 is tubular and includes a spiral ridge 340, or wall segments of different thicknesses separated by a spiral boundary, as will be further described below.

[0064] It is worth noting that the structure of the elastic tubular member 300 in the embodiment shown in the accompanying drawings disclosed in the present invention is different from the elastic biasing member disclosed in US11052232 or the driving member disclosed in US2019 / 0217072.

[0065] Specifically, if Figure 3 To Figure 5 and FIG. 5A to FIG. 8BAs shown, the elastic tubular member 300 in this embodiment includes two spiral ridges 340 extending on the outer surface of its elastic tubular portion 330. The two spiral ridges 340 are symmetrically arranged relative to a plane passing through the axis of the elastic tubular member 300, which is aligned with the longitudinal center axis A, as shown in FIG. Figure 4 and Figure 5A As shown. Figure 7B As shown, the symmetry plane is indicated by line BB and will be referred to as symmetry plane B hereinafter. Conveniently, the stretched helical spine 340 provides a driving force that can be decomposed into a longitudinal driving force (longitudinal force, longitudinal component) and a transverse driving force (transverse force, transverse component). The longitudinal driving force longitudinally biases the needle bundle 200 back upward, and the transverse driving force laterally biases the needle bundle 200 toward the side wall of the longitudinal channel 120.

[0066] In the present invention, "spiral ridge" refers to a ridge extending obliquely along the warp and weft (longitudinal and transverse) of the cylindrical or truncated cone outer surface, and the projection line formed by the projection of the ridge to the symmetry plane B is not parallel to the longitudinal center axis A and forms an oblique intersection. The three-dimensional (3D) profile of the spiral ridge can roughly form a geometric spiral or helical shape. The so-called spiral here refers to the protruding ridge extending along the warp and weft directions (longitudinal and transverse) of the cylindrical or truncated cone outer surface of the elastic tube portion 330 of the elastic tubular member 300, which can also be referred to as oblique extension or oblique extension. In different embodiments, the spiral ridge can have other curved or straight-edge shapes that do not form a perfect spiral. For example, the spiral ridge can have a shape similar to the helical tooth track on the helical gear. In a specific embodiment, for example, the outer surface of the elastic tube portion 330 of the elastic tubular member 300 has a hexagonal pyramid (hexagonal pyramid), a quadrangular pyramid (quadrangular pyramid) shape or other special shapes, and the outer surface can be a plane. The path of the spiral ridge 340 extending obliquely on the outer surface of the hexagonal pyramid or the quadrangular pyramid is not a strict spiral, but evolves into an oblique line segment extending in both the warp and weft directions. That is, in this particular embodiment, two (a pair of) oblique ridges 340 arranged oppositely and extending obliquely are provided on the outer surface of the elastic tube portion 330, and the two oblique ridges (the pair of oblique ridges) 340 are arranged symmetrically relative to the plane passing through the longitudinal axis of the elastic tubular member 300, and the oblique ridges 340 provide a longitudinal driving force and a transverse driving force, the longitudinal driving force drives the needle bundle 200 to the retracted position in the longitudinal direction, and the transverse driving force biases the needle bundle 200 toward the side wall of the longitudinal channel 120. "Spiral boundary" refers to a boundary line extending obliquely along the warp and weft directions (longitudinal and transverse) on the outer surface of a cylindrical or truncated cone. The projection line formed by projecting the boundary onto the symmetry plane B is not parallel to the longitudinal center axis A and forms an oblique intersection. In this embodiment, "helix" refers to a line extending in three-dimensional space, which is not parallel to any straight line and is not in any single plane. However, in other embodiments, the spiral boundary is not necessarily a perfect standard spiral shape.

[0067] The upper end (first end) and the lower end (second end) of the elastic tubular member are respectively connected to the needle housing and the needle bundle in a sealing manner to prevent fluid communication between the lower open end and the upper open end of the needle housing. Therefore, the elastic tubular member 300 also serves as a seal, and for this purpose, the elastic tubular member 300 may include a diaphragm for sealing.

[0068] exist Figures 1 to 8B In the illustrated embodiment, the spiral ridge 340 extends obliquely from the upper end to the lower end of the elastic tubular member 300. However, in different embodiments, one or more shorter spiral ridges, or a plurality of spaced apart ridges arranged in a spiral pattern, may be provided on the elastic tubular member 300 to provide the urging force.

[0069] like Figure 5A , Figure 5B and Fig. 7A As shown, when viewed from the side, the spiral ridge 340 includes a generally straight outer edge. However, in different embodiments, the side edge of the spiral ridge 340 can have a different shape or profile, which will be described in more detail below.

[0070] The elastic tubular portion 330 of the elastic tubular member 300 can also be considered to include a thicker portion (first portion) and a thinner portion (second portion), the thicker portion and the thinner portion being separated by a spiral boundary that extends spirally between the upper end and the lower end of the elastic tubular member 300. For example, in the case of FIG. 5A to FIG. 8B and 9A to 9D In the various embodiments of the elastic tubular member 300 shown, the spiral ridge 340 is a thicker portion, the area between two symmetrical spiral ridges 340 is a thinner portion, and the boundary is located at the bottom edge of the spiral ridge 340.

[0071] In some embodiments, the elastic tubular member 300 may include only two portions, a thicker portion and a thinner portion, such as Fig.9E The two parts are separated by two spiral boundaries 345, which can be arranged symmetrically with respect to a plane (symmetry plane B) passing through the longitudinal axis of the elastic tubular member 300. A curved side wall can be formed at the boundary between the thinner part and the thicker part.

[0072] The thinner portion of the elastic tubular member 300 may include one or more bellows portions. Figure 9H As shown, the elastic tubular member 300 may be provided with a bellows portion 332 on one side, or as shown in FIG. Fig.9I As shown, the elastic tubular member 300 may provide two bellows portions 332 on opposite sides.

[0073] The elastic tubular member 300 may be formed of a silicone material or other elastic material (e.g., latex, rubber). The elastic material may be selected so that it has sufficient elasticity to extend to the desired extended position under stress to expose the needle tips of the needle group, but also has sufficient elasticity to provide the required driving force to return the needle bundle 200 from the extended position to the retracted position. In one embodiment, the elastic tubular member 300 may be formed of a silicone material having a Shore hardness of about 30A to about 50A.

[0074] During use, the needle assembly 10 is connected to the handle of the tattoo device, and the needle bundle is driven by the needle driver of the tattoo device to move downward, so that the needle bundle 200 will move to the extended position, and the needle tip of the needle group 210 extends to the outside of the opening 150 of the needle housing 40. After the needle bundle 200 has been pushed downward by the needle driver, the stretched elastic tubular member 300 pulls the needle bundle 200 upward during each movement cycle, and the elastic tubular member further promotes the reciprocating movement of the needle bundle 200. During the downward movement of the needle bundle 200, as the elastic tubular member 300 having elasticity is stretched to a greater extent, the driving force gradually increases.

[0075] In addition, the spiral ridge 340 is a convex ridge extending obliquely (extending in both the warp and weft directions) along the outer surface of the elastic tube portion 330 of the elastic tubular member 300, and the projection line formed by projecting the convex ridge onto the symmetry plane B is not parallel to the longitudinal central axis A but forms an oblique intersection. In this embodiment, due to the spiral profile (or spiral boundary) of the spiral ridge 340, after the elastic tubular member 300 is stretched, the elastic tubular member 300 also biases the needle group 210 of the needle bundle 200 toward the side wall of the longitudinal channel 120, for example, toward the needle guide wall 110 near the opening 150. This lateral bias of the needle group 210 toward or against the needle guide wall 110 can stabilize the needle bundle 200 and maintain stable contact between the needle bundle 200 and the needle guide wall 110, thereby avoiding or reducing the shaking of the needle tip during the tattooing process.

[0076] Additionally, the resilient tubular member 300 may conveniently provide a fluid seal between the lower open end 150 and the upper open end 450 of the needle housing 40 .

[0077] The upper end portion 320 of the elastic tubular member 300 is used to engage the inner wall of the body portion 100 and the cap portion 400. Fig. 7A As shown in , the upper end portion 320 of the elastic tubular member 300 may include a plurality of annular ribs 322, which are sized and shaped to closely fit with the inner wall of the body portion 100. In the depicted embodiment, the upper end portion 320 has four annular ribs 322 extending along the circumference of the outer wall of the upper end portion 320. The inner wall of the upper end portion 320 defines an opening that allows the needle shaft 220 of the needle bundle 200 to pass therethrough and is used to engage the cap portion 400.

[0078] After assembly, the upper end portion 320 is firmly fixed between the cap portion 400 and the body portion 100, and is sealed with the needle housing 40. Because the upper end portion 320 of the elastic tubular member 300 is not attached to the needle bundle 200, and when the needle bundle 200 moves up and down, the upper end portion 320 does not move. Therefore, during operation, the position of the upper end portion 320 of the elastic tubular member 300 relative to the needle housing 40 is fixed.

[0079] The lower end 310 of the resilient tubular member 300 is configured to sealingly engage the needle shaft 220 of the needle bundle 200. The lower end 310 has an opening 312, and the size and shape of the opening 312 are configured so that the needle shaft 220 forms a tight fit with the lower end 310 at the opening 312, thereby forming a fluid seal between the resilient tubular member 300 and the needle bundle 200, while allowing the needle shaft 220 to move axially up and down during operation without breaking the seal.

[0080] For example, from Figure 1 and Figure 4 As can be better seen in the figure, the lower end portion 310 has a thickened portion with an upwardly facing surface, and the needle shaft 220 may have an expanded portion, i.e., a shoulder 230, which engages the upwardly facing surface of the lower end portion 310 of the elastic tubular member 300. The size and shape of the thickened portion of the lower end portion 310 are configured to be tightly coupled with the shoulder 230, so that the shoulder 230 exerts a downward force on the thickened portion of the lower end portion 310 to pull the lower end portion 310 downward when the needle bundle 200 is driven by the needle driver to move toward the extended position. As the lower end portion 310 is pulled downward, the elastic tubular member 300 is stretched and the length of the elastic tubular member 300 increases. Therefore, the elastic tubular member 300 generates a driving force to drive the needle bundle 200 upward. After the needle driver stops driving the needle bundle 200 downward and the needle bundle 200 reaches the final extended position, the driving force applied by the elastic tubular member 300 pulls the needle bundle 200 back to the retracted position.

[0081] In order to further limit the relative movement between the lower end 310 of the elastic tubular member 300 and the needle bundle 200, the needle bundle 200 may include a collar 232 spaced apart from the shoulder 230 by a neck 234, so that the lower end 310 of the elastic tubular member 300 can be received in a groove formed by the shoulder 230, the collar 232 and the neck 234, thereby attaching the lower end 310 to the needle bundle 200. Therefore, the movement of the lower end 310 relative to the needle bundle 200 is limited by the shoulder 230 and the collar 232.

[0082] In various embodiments, the resilient tubular member 300 may be formed of an elastic material that is sufficiently resilient under stress to extend to a desired extended position to expose the needle group, and is also sufficiently resilient to provide a desired driving force for returning the needle bundle 200 from the extended position to the retracted position, and to apply a sufficient lateral biasing force to press the needle group 210 of the needle bundle 200 against a predetermined side wall of the longitudinal channel 120 in the needle housing 40, for example. Figure 3 The needle guide wall 110 is shown. In some embodiments, the elastic material can be a silicone material with a Shore hardness of about 25A to 50A.

[0083] In the embodiment shown in the drawings, the wall thickness of the upper end portion 320 and the lower end portion 310 are both greater than the wall thickness of the elastic tube portion 330. The upper end portion 320 and the lower end portion 310 may be more rigid and less elastic than the elastic tube portion 330.

[0084] Figure 5A and Figure 5B The needle assembly 10 is shown with the needle bundle 200 in a retracted position ( Figure 5A ) and extended position ( Figure 5B ).like Figure 5A As shown, even in the retracted position, the elastic tubular member 300 may still be stretched and exert a lateral biasing force to press the needle shaft 220 , so that the puncture needle group 210 of the needle bundle 200 is pushed toward or against the side wall of the needle housing 40 .

[0085] like Figure 5B As shown, the elastic tube portion 330 of the elastic tubular member 300 is stretched by a distance X in the extended position, and thus generates a relatively large driving force. Figure 5B As shown, the driving force generated by the spiral ridge 340 when stretched is Driving force It can be decomposed into the longitudinal force along the longitudinal center axis A of the longitudinal channel 120 and the needle shaft 220 and the lateral force (lateral force, lateral offset force) perpendicular to the longitudinal center axis A like Figure 6 As shown, Longitudinal force Pull the needle bundle 200 toward the retracted position, the lateral force The puncture needle group 210 of the needle bundle 200 is pressed against the needle guide wall 110 .

[0086] For a typical tattoo machine, the distance X when the needle bundle 200 moves between the retracted position and the extended position may be approximately 2 mm to 5 mm, and the drive rod of the needle driver in a typical tattoo machine may move the same distance in each movement cycle.

[0087] Understandably, in Figure 5AIn the retracted position shown, the elastic tubular member 300 can still be tensioned. For example, when the needle assembly 10 is not connected to the handle of the tattoo machine (not shown), the elastic tubular member 300 can be tensionless and in a relaxed state. However, when the needle housing 40 of the needle assembly 10 is installed and coupled to the handle of the tattoo machine, the needle shaft 220 has moved downward relative to the body portion 100, for example, by about 2mm to 4mm. Even if the needle bundle 200 is initially still in the retracted position, this downward displacement of the needle shaft 220 will stretch the elastic tubular member 300. During operation, the needle shaft 220 and the needle bundle 200 can be pushed to further reciprocate downward by about 2mm to 5mm.

[0088] As described above, the annular flange 420 and the annular groove 430 of the cap 400 are engaged with the upper end portion 320 of the elastic tubular member 300, and the upper end portion 320 is fixed in an appropriate position between the cap 400 and the inner wall of the upper end of the longitudinal channel 120, so that during operation, when the needle bundle 200 reciprocates up and down relative to the body portion 100, the upper end portion 320 cannot move relative to the body portion 100 in the longitudinal direction (along the longitudinal center axis A). The upper end portion 320 of the elastic tubular member 300 is also configured to elastically and tightly engage the inner wall of the body portion 100 and provide a seal between the upper end portion 320 and the body portion 100.

[0089] like Figure 7B , Figure 7C , Fig. 8A and Figure 8B As shown, two symmetrically arranged spiral ridges 340 may be provided. Each spiral ridge 340 may be rib-shaped.

[0090] The opening 150 of the needle housing 40 can have different shapes and sizes. For example, if the needle bundle 200 of the needle assembly 10 is as shown in FIG. Figure 2 , Figure 3 and Figure 4 If the flat needle bundle has a row of needles as shown, the opening 150 can have a corresponding rectangular outline. Figure 3 and Figure 4 As shown, the needle guide wall 110 may have a corresponding flat inner surface. Figure 7B In the illustrated embodiment, the symmetry plane B passes through and is parallel to the longitudinal center axis A, and is perpendicular to the needle guide wall 110 of the body portion 100. The two spiral ridges 340 are symmetrically arranged relative to the symmetry plane B.

[0091] In various embodiments, the needle assembly 210 of the needle bundle 200 may have a generally cylindrical overall profile, in which case the opening 150 of the needle housing 40 may be circular. The inner wall of the needle guide wall 110 may also be curved in an arc shape. The needle bundle 200 may contact the needle guide wall 110 along a longitudinal line (herein referred to as a needle guide line). In this case, the symmetry plane B may contain the longitudinal center axis A and the needle guide line.

[0092] As previously mentioned, in different embodiments, the helical ridges 340 of the elastic tubular member 300 can have different shapes and configurations.

[0093] For example, in some embodiments, Fig. 9A As shown, when viewed from the side, the spiral ridge 340 may have a curved outer edge. In other words, in some embodiments, when the observer directly faces the spiral ridge 340, the outer edge of the spiral ridge 340 may be curved in the front view (the projection line formed by the projection of the spiral ridge 340 onto the symmetry plane B may be a curved line).

[0094] In some embodiments, the spiral ridge 340 may have a Fig. 7A 9A and 9B may have substantially parallel outer edges as shown, or may have non-parallel outer edges as shown in 9A.

[0095] In some embodiments, Fig. 9B As shown, the spiral ridge 340 may have a stepped outer edge arranged in a spiral shape. That is, in some embodiments, the outer edge of the spiral ridge 340 may be stepped or sawtooth-shaped in a front view.

[0096] like Fig. 9C As shown, two or more spiral ridges 340 can also be arranged side by side and generally parallel to each other. Two or more spiral ridges 340 can be located on one side of the elastic tubular member 300.

[0097] like Fig. 7A and Fig.9D As shown, in different embodiments, the spiral ridge 340 can have different widths. In different embodiments, the spiral ridge 340 can also have different heights. It is understood that a wider or taller spiral ridge 340 can provide greater driving force.

[0098] Fig.9D , Fig.9E and Fig.9F It is shown that the spiral ridge 340 can have different widths in different embodiments, and the spiral ridge 340 can be located at different positions. Fig.9D As shown, the spiral ridge 340 has a relatively large width, and the area of ​​the thin-walled region 332 is much larger than the area of ​​the thin-walled region 334. Fig.9EIn the embodiment of the present invention, the elastic tubular portion 330 of the elastic tubular member 300 has only different regions: a thin wall region 332 and a thicker spiral ridge 340 (the thin wall region 334 has zero area), which are separated by the boundary 345 of the spiral. Fig.9F and Fig.9E In comparison, the thin-walled region 332 has a larger area, and the spiral ridge 340 has a correspondingly smaller area. Fig. 10A and Fig. 10B They are shown respectively Fig.9E and Fig.9F A perspective view of the elastic tubular member 300 is shown in FIG.

[0099] exist Figure 9G In the embodiment of the elastic tubular member 300 shown, the wall thickness of the thin-walled regions 332 and 334 is different. For example, the thin-walled region 332 can be thinner than the thin-walled region 334. In this case, when the elastic tubular member 300 is stretched, the thin-walled region 332 and the thin-walled region 334 generate different biasing forces, and the biasing force generated by the thin-walled region 334 is greater than the biasing force generated by the thin-walled region 332. In addition to the effect generated by the spiral ridge 340, this difference in biasing force also affects the total lateral force.

[0100] Figure 9H An embodiment of the elastic tubular member 300 is shown, in which the thin-walled region 332 of the elastic tubular portion 330 is corrugated, and the thin-walled region 334 is not corrugated. Fig.9I Another embodiment of the resilient tubular member 300 is shown wherein both the thin-walled region 332 and the thin-walled region 334 are corrugated.

[0101] It is understood that when one or more regions of the elastic tube 330 have curved or corrugated walls, the walls of different regions may have different rectified lengths, which are longer than straight walls. For a curve, its corrected length refers to the length of the corrected curve. After correction, the curve will give a straight line segment with the same length as the arc length of the curve. For a straight line, its corrected length is the same as the length of the straight line.

[0102] exist Figure 9H In the illustrated embodiment, the thin-walled region 334 has a shorter modified length than the thin-walled region 332 , so that when the elastic tube 330 is stretched due to the downward movement of the needle bundle 200 , the thin-walled region 334 is more tightly stretched than the thin-walled region 332 .

[0103] Understandably, Figure 9H In the embodiment of the present invention, when the elastic tubular member 300 is stretched, the tension of the corrugated thin-walled area 332 is less than the tension of the non-corrugated thin-walled area 334. Therefore, the longitudinal force generated by the thin-walled areas 332 and 334 is unbalanced, thereby generating additional lateral force.

[0104] The spiral ridge 340 may have any number of cross-sectional shapes or profiles, some of which may be FIG. 11A to FIG. 11F For example, the cross-sectional shape of the spiral ridge 340 may be roughly polygonal or semicircular. Fig.11A As shown, the cross-section of the spiral ridge 340 can be square. Fig. 11B As shown, the cross-section of the spiral ridge 340 can be trapezoidal. Fig.11D As shown, the cross-section of the spiral ridge 340 can be triangular. Fig.11E and Fig.11F As shown, the cross-section of the spiral ridge 340 can be rectangular. The cross-section of the spiral ridge 340 can also include Fig. 11C The outer edge of the semicircle shown.

[0105] exist FIG. 11A to FIG. 11E In the embodiment, the thin-walled area 332 and the thin-walled area 334 have the same wall thickness. Fig.11F In the embodiment of the present invention, thin-walled region 334 is thicker than thin-walled region 332. In any case, the wall thickness at spiral ridge 340 is greater than the wall thickness at thin-walled region 334 and thin-walled region 332.

[0106] exist Fig.11E and Fig.11F In the embodiment, the spiral ridge 340 has a substantially rectangular cross-sectional profile, but the top edge can be curved or arched. For example, the top edge of the spiral ridge 340 can be concentric with the thin-walled area 334 and the thin-walled area 332.

[0107] Conveniently, the helical ridge 340 or different portions having a helical border and different thicknesses may provide an urging force that biases the needle bundle longitudinally to the retracted position and laterally to the sidewalls of the longitudinal channel 120 when stretched.

[0108] The resilient tubular member 300 also conveniently provides a fluid seal between the upper and lower open ends of the longitudinal passage 120 .

[0109] Compared with the elastic biasing member disclosed in US11052232 or the elastic membrane disclosed in CN106902452A, the elastic tubular member of the present invention provides many beneficial effects or advantages.

[0110] For example, the elastic tubular member with one or more spiral ridges according to the present invention is easier to manufacture than a driving member with different modified lengths and corrugated walls on both sides. Fig. 7A , Figure 7C and Fig.7DThe internal shape of the mold of the elastic tubular member 300 shown is not as complicated as the mold used to manufacture elastic tubular members with different modified lengths and corrugated tube walls. Therefore, production efficiency and product output can be improved. In addition, it is easier to inspect small defects on the outer surface of the product with simpler outer surface features.

[0111] The elastic membrane disclosed in CN106902452A has regions of different thicknesses, and the boundaries between the different regions extend in the axial direction (longitudinal direction). CN106902452A may have elastic tendons extending along the needle movement direction on one side of the elastic membrane. The disadvantage of the elastic membrane disclosed in CN106902452A is that it is difficult to adjust the amount or proportion of forces generated in different directions. For example, although the thickness of different parts of the elastic membrane can be adjusted to generate forces of different proportions, the adjustable range of this proportion is limited, and it is difficult to generate a sufficiently large lateral force.

[0112] Compared to the borders or elastic ribs between regions extending linearly along the axial direction of the needle, the spiral ridges or borders of the present invention can provide additional lateral forces, which are relatively stronger, and these lateral forces can be more easily adjusted by changing the spiral direction without changing the thickness of any part of the spiral ridges or elastic tubular member. For example, without changing the thickness of the elastic tubular member, a higher ratio of lateral force to longitudinal force can be achieved using the spiral ridges or borders.

[0113] The needle assembly 10 may be disposable and may be used directly after opening the needle assembly package without further cleaning, disinfection or sterilization, or may be discarded after a single use without cleaning or any other treatment.

[0114] For the sake of clarity, it is noted that "single use" may refer to the use of a tattoo needle or needle assembly on a single subject for one complete session. During this session, the operator may alternate between using needle assemblies of different sizes to apply different colors of ink or for other reasons. For example, typically two or five different tattoo needle assemblies may be used on the same subject during one tattoo session, depending on the complexity of the tattooed design.

[0115] It will be appreciated that the configuration of the elastic tubular member 300 with helical ridges or helical boundaries can provide both longitudinal and lateral (radial) forces to drive the needle bundle 200 .

[0116] During operation, the elastic tubular member 300 also separates the lower open end of the body portion 100 from the upper open end of the body portion 100 and provides a fluid seal in the longitudinal channel 120 of the needle housing 40, thereby preventing body fluids discharged from the skin punctured by the operated subject from flowing from the puncture needle group 210 through the longitudinal channel 120 to the upper open end of the needle housing. The elastic tubular member 300 can act as a seal and can also prevent ink from entering and passing through the upper open end of the needle housing 40, thereby conveniently preventing the body fluids and ink of the operated subject from contacting the handle (not shown) connected to the needle assembly 10 or the parts of the tattoo machine (not shown). Conveniently, the tattoo machine and the handle can be reused after each treatment or after the needle assembly is replaced without the need to re-sterilize any part of the tattoo machine. In some cases, the handle can also be disposable.

[0117] It can be understood that different embodiments or variations of the elastic tubular member 300 can also achieve the above-mentioned convenient effects.

[0118] It is understood that the needle assembly described in the present invention can be used or adapted to apply other types of liquids to the skin. For example, the applied liquid may include a colored liquid or pigment, or may include a medical or therapeutic agent, collagen, or other similar or similar substances. The needle assembly can be used in a liquid application device to apply the selected liquid.

[0119] Those skilled in the art will be able to understand other features, modifications and applications of the embodiments described herein based on the disclosure of the invention herein.

[0120] It will be understood that any range of values ​​disclosed herein is intended to specifically include any intermediate values ​​or sub-ranges within a given range, and all such intermediate values ​​and sub-ranges are disclosed individually and specifically. It will also be understood that the words "one" or "an" are intended to mean "one or more" or "at least one", and any singular form is meant to include the plural form herein. It will be further understood that the term "comprising", including any variation thereof, is intended to be an open-ended expression, meaning "including but not limited to", unless otherwise expressly stated to the contrary. When a list of items with an "or" before the last item is given herein, any one of the listed items may be selected and used or any appropriate two or more listed items may be combined.

[0121] It will be appreciated that various modifications may be made to the example arrangements depicted in the drawings.

[0122] Of course, the embodiments of the present invention described above are intended to illustrate rather than limit the present invention. The form, arrangement of parts, details and sequence of operations of the described embodiments are susceptible to various modifications. It is the object of the present invention to include all such modifications within the scope of the claims as defined.

[0123] As described above, for ordinary technicians in this field, various other corresponding changes and modifications can be made based on the technical solutions and technical concepts of the present invention, and all these changes and modifications should fall within the protection scope of the appended claims of the present invention.

Claims

1. A needle assembly for a liquid application device, characterized in that It includes a needle housing, a needle bundle and an elastic tubular component; The needle housing includes a body portion having a longitudinal passage, the longitudinal passage including an upper open end and a lower open end; The needle bundle is movably mounted in the longitudinal channel, and the needle bundle can be driven by a drive rod to reciprocate between a retracted position and an extended position; The elastic tubular member includes an upper end portion connected to the needle housing, a lower end portion connected to the needle bundle, an elastic tube portion connecting the upper end portion and the lower end portion, and a spiral ridge extending on the outer surface of the elastic tube portion. The elastic tubular member is made of elastic material. When the needle bundle moves from a retracted position to an extended position, the elastic tube portion is stretched and elastically deformed. The spiral ridge is stretched and elongated, and stress is generated inside the material, thereby providing a longitudinal driving force and a transverse driving force for the needle bundle. The longitudinal driving force drives the needle bundle longitudinally to the retracted position, and the transverse driving force biases the needle bundle toward the side wall of the longitudinal channel.

2. The needle assembly for a liquid application device according to claim 1, characterized in that The upper end is sealingly connected to the needle housing, and the lower end is sealingly connected to the needle bundle to prevent fluid communication between the upper open end and the lower open end of the needle housing.

3. The needle assembly for a liquid application device according to claim 1, characterized in that The resilient tubular member includes a diaphragm.

4. The needle assembly for a liquid application device according to claim 1, characterized in that The helical ridge extends from an upper end to a lower end of the elastic tubular member.

5. The needle assembly for a liquid application device according to claim 1, characterized in that The number of the spiral ridges is two, and the two spiral ridges are symmetrically arranged with respect to a plane passing through the longitudinal axis of the elastic tubular member.

6. The needle assembly for a liquid application device according to claim 1, characterized in that The spiral ridge has a polygonal or semicircular cross section.

7. The needle assembly for a liquid application device according to claim 1, characterized in that The elastic tubular component is made of silicone, latex or rubber.

8. A needle assembly for a liquid application device, characterized in that It includes a needle housing, a needle bundle and an elastic tubular component; The needle housing includes a body portion having a longitudinal passage, the longitudinal passage including an upper open end and a lower open end; The needle bundle is movably mounted in the longitudinal channel, and the needle bundle can be driven by a drive rod to reciprocate between a retracted position and an extended position; The elastic tubular member includes an upper end connected to the needle housing, a lower end connected to the needle bundle, and an elastic tube portion connecting the upper end and the lower end, the elastic tube portion includes a first portion separated by a boundary and a second portion thinner than the first portion, the boundary extending spirally from the upper end to the lower end on the outer surface of the elastic tube portion, the elastic tubular member is made of elastic material, when the needle bundle moves from the retracted position to the extended position, the elastic tube portion is stretched and elastically deformed, so that when stretched, the elastic tubular member applies a longitudinal driving force and a transverse driving force on the needle bundle, the longitudinal driving force drives the needle bundle longitudinally to the retracted position, and the transverse driving force biases the needle bundle toward the side wall of the longitudinal channel.

9. The needle assembly for a liquid application device according to claim 8, characterized in that The first portion and the second portion are separated by two helical boundaries that are arranged symmetrically with respect to a plane passing through a longitudinal axis of the elastic tubular member.

10. A needle assembly for a liquid application device, characterized in that It includes a needle housing, a needle bundle and an elastic tubular component; The needle housing includes a body portion having a longitudinal passage, the longitudinal passage including an upper open end and a lower open end; The needle bundle is movably mounted in the longitudinal channel, and the needle bundle can be driven by a drive rod to reciprocate between a retracted position and an extended position; The elastic tubular member includes an upper end connected to the needle housing, a lower end connected to the needle bundle, and an elastic tube portion connecting the upper end and the lower end. Two oblique ridges arranged opposite to each other and extending obliquely are provided on the outer surface of the elastic tube portion. The two oblique ridges are symmetrically arranged relative to a plane passing through the longitudinal axis of the elastic tubular member. The elastic tubular member is made of elastic material. When the needle bundle moves from a retracted position to an extended position, the elastic tube portion is stretched and elastically deformed. When stretched, the oblique ridges provide a longitudinal driving force and a transverse driving force. The longitudinal driving force drives the needle bundle longitudinally to the retracted position, and the transverse driving force biases the needle bundle toward the side wall of the longitudinal channel.

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