US20240044607A1 - Archery cushion plunger - Google Patents

Abstract

The present disclosure relates to an archery cushion plunger in which a structure is changed so that a plunger shaft in contact with an arrow shaft passes through a center of an elastic member, the plunger shaft stably grips the center of the elastic member, and thus deformation of the elastic member may be fundamentally prevented even when a pressure is applied to front and rear sides of the elastic member during adjustment of a tensile force. Therefore, a tip portion of the plunger in contact with the arrow shaft is always in horizontal contact with the arrow shaft to stably compensate for horizontal vibration, stable flight of an arrow is induced, and thus a hit rate of the arrow can be improved.

Description

CROSS-REFERENCE TO RELATED APPLICATION
• This application claims priority to and the benefit of Korean Patent Application No. 10-2022-0096982 filed on Aug. 3, 2022, the disclosure of which is incorporated herein by reference in its entirety.
BACKGROUND 1. Field of the Invention
• The present disclosure relates to an archery cushion plunger, and more particularly, to a cushion plunger that adjusts a strength of a pressure point, compensates for horizontal vibrations that occur in an arrow shaft when an arrow is fired from a bowstring and is accelerated, and thus induces right flight of the arrow.
2. Discussion of Related Art
• In general, in archery that is a Western-style bow, a stabilizer, a cushion plunger, or the like are used as an auxiliary device that helps an arrow fired from a bowstring of a body that shoots the arrow by hanging the arrow on the bowstring to fly correctly in addition to the body.
• Among them, the cushion plunger, which is a device that adjusts a strength of a pressure point, compensates for a horizontal vibration that occurs in an arrow shaft when an arrow is fired from a bowstring and is accelerated, minimizes a paradox phenomenon in which the arrow that leaves the bowstring flies while shaking in a left-right direction like a fish, and thus serves to help the arrow fly correctly.
• Various examples of this cushion plunger have been proposed in a number of related documents including Korean Patent Publication No. 10-2017-0121592, Korean Patent Publication No. 10-2016-0063828, U.S. Pat. Nos. 4,697,323, 5,081,980, 5,359,984, and 5,375,584, Japanese Utility Model Registration No. 20-3175621, and the like.
• The cushion plunger according to the relate art including the related documents compensates for the horizontal vibration of the arrow shaft by adjusting a tensile force and pressure of a spring provided inside the body through a screw. That is, by adjusting the tensile force of the plunger by rotating the screw in a tightening direction with respect to a housing to increase the tensile force of the spring or rotating the screw in an untightening direction to decrease the tensile force of the spring, the arrow leaving the arrow shaft can fly stably.
• FIG. 1 is a schematic cross-sectional view illustrating an example of a cushion plunger according to the related art.
• Referring to FIG. 1 , the cushion plunger 10 according to the related art includes a sleeve 11, a plunger 12 embedded in the sleeve 11 and having a tip portion 12 a that protrudes and retracts to buffer a lateral pressure of an arrow shaft 1 (see FIG. 2 ), a spring 13 that is embedded in the sleeve 11 and applies a pressure to the plunger 12, a tensile force adjustment bar 14 that adjusts a tensile force of the spring 13, and a tensile force adjustment housing 15 that adjusts the tensile force of the spring 13 by linearly moving the tensile force adjustment bar 14.
• Operating characteristics of the cushion plunger 10 having this structure according to the related art will be described.
• When the tensile force adjustment housing 15 rotates about the sleeve 11, the tensile force adjustment bar 14 moves along the sleeve 11 in conjunction with the rotation. In this process, the tensile force of the spring 13 is adjusted to compensate for a horizontal vibration of the arrow shaft so that an arrow can fly stably.
• However, the cushion plunger 10 according to the related art has the following problems, which will be described in conjunction with FIG. 2 . FIG. 2A is a view illustrating a normal state, and FIGS. 2B and 2C are views illustrating a state in which a spring is deformed in an up-down direction with respect to a center line CL.
• As illustrated in FIG. 2A, only when a tip portion of the plunger 12 is in horizontal contact with the virtual center line CL, the arrow shaft 1 can stably fly, and a hit rate can be improved. However, in the cushion plunger 10 according to the related art, in a process of adjusting the tensile force, as illustrated in FIGS. 2B and 2C, the spring 13 is twisted to one side with respect to the center line CL due to a gap g (see a portion “A” of FIG. 1 ) present between the spring 13 and the sleeve 11 for connecting the tensile force adjustment bar 14 and the plunger 12. Accordingly, a lateral pressure applied to the arrow shaft 1 is twisted, making stable shooting difficult and reducing a hit rate of the arrow.
RELATED ART DOCUMENT Patent Document
• KR 10-2017-0121592 A, 2017 Nov. 2.
• KR 10-2016-0063828 A, 2016 Jun. 7.
• KR 10-2020-0113157 A, 2020 Oct. 6.
• U.S. Pat. No. 5,375,584 B1, 1994 Dec. 27
SUMMARY OF THE INVENTION
• Thus, the present disclosure proposes an objective for solving the above-described problem of the related art.
• The present disclosure is directed to providing an archery cushion plunger in which a tip portion of a plunger in contact with an arrow shaft is always in horizontal contact with the arrow shaft to stably compensate for horizontal vibration, stable flight of an arrow is induced, and thus a hit rate of the arrow can be improved.
• Further, the present disclosure is not limited to the above-described objective, and in addition, various objectives may be additionally provided through technologies described through the following embodiments and the appended claims.
• An archery cushion plunger includes a sleeve, a plunger shaft that buffers a lateral pressure of an arrow shaft through a tip portion exposed to one end of the sleeve, an elastic member which is embedded in the sleeve and has a front surface horizontally stopped and supported on the plunger shaft in a direction of the arrow shaft and through which the plunger shaft is coupled at a center thereof, a tensile force adjustment cylinder into which a rear part of the plunger shaft is slidably inserted and of which a front surface is in contact with a rear surface of the elastic member so that the tensile force adjustment cylinder is horizontally stopped and supported, and a tensile force adjustment housing that is screw-coupled to an outer surface of the sleeve to rotate about the sleeve and adjusts a tensile force of the elastic member by linearly moving the tensile force adjustment cylinder along the plunger shaft while linearly moving along the sleeve in a rotational direction.
• The archery cushion plunger may further include a ball plunger that moves into a hollow of the tensile force adjustment housing through a fastening hole formed in the tensile force adjustment housing and is vertically coupled to a tensile force adjustment groove formed in a rear part of the sleeve inserted into the tensile force adjustment housing.
• An alignment key groove may be formed in the outer surface of the sleeve in a horizontal cut surface structure such that the alignment key groove is horizontally parallel to a first tensile force adjustment groove among the tensile force adjustment grooves formed in the sleeve.
• The tensile force adjustment cylinder may include an outer ring, an inner ring inserted into the outer ring, and a ball installed between the outer ring and the inner ring.
• The plunger shaft may include a front part having the tip portion, a rear part connected to a rear end of the front part and inserted into the tensile force adjustment cylinder, and a step part that is formed at a boundary between the front part and the rear part, protrudes outer surfaces of the front part and the rear part, and is in contact with the front surface of the elastic member to be stopped and supported.
• A separation prevention step by which a step part of the plunger shaft supported by the front surface of the elastic member in the direction of the arrow shaft is stopped may be formed inside the sleeve.
• The archery cushion plunger may further include a fixing nut screw-coupled to the outer surface of the sleeve.
• When viewed in the direction of the arrow shaft, the tensile force adjustment housing may be formed in a polygonal structure.
• The front surface of the rear force of the elastic member may be polished to have a surface step of 0.3 mm or less.
BRIEF DESCRIPTION OF THE DRAWINGS
• The above and other objects, features and advantages of the present disclosure will become more apparent to those of ordinary skill in the art by describing exemplary embodiments thereof in detail with reference to the accompanying drawings, in which:
• FIG. 1 is a cross-sectional view illustrating an example of a cushion plunger according to the related art;
• FIG. 2 is a view illustrating deformation of a spring of the cushion plunger having the structure of FIG. 1 ;
• FIG. 3 is an assembly perspective view illustrating an archery cushion plunger according to an embodiment of the present disclosure;
• FIG. 4 is an exploded perspective view of the archery cushion plunger illustrated in FIG. 3 ;
• FIG. 5 is an assembly cross-sectional view of the archery cushion plunger illustrated in FIG. 3 ; and
• FIG. 6 is a front view illustrating an elastic member illustrated in FIG. 4 .
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
• Advantages and features of the prevent disclosure and methods of achieving the advantages and the features will become apparent with reference to embodiments which will be described below in detail together with the accompanying drawings. However, the present disclosure is not limited to embodiments disclosed below and may be implemented in various different forms.
• In the present specification, the present embodiment is provided to complete the disclosure of the present disclosure and to completely inform the scope of the present disclosure to those skilled in the art to which the present disclosure pertains. Further, the present disclosure is merely defined by the scope of the appended claims. Thus, in some embodiments, well-known components, well-known operations, and well-known technologies are not described in detail in order to avoid an ambiguous interpretation of the present disclosure.
• Further, throughout the specification, the same reference numerals refer to the same components. Further, terms used (mentioned) in the present specification are intended to describe the embodiments and are not intended to limit the present disclosure. In the present specification, a singular form also includes a plural form unless specifically mentioned in a phrase. Further, components and operations mentioned as “include (or be provided with)” do not exclude the presence or addition of one or more other components and operations.
• Unless otherwise defined, all the terms (including technical and scientific terms) used herein may be used as meanings that may be commonly understood by those skilled in the art to which the present disclosure pertains. Further, terms defined in commonly used dictionaries are not interpreted ideally or excessively unless the terms are defined.
• Hereinafter, embodiments of the present disclosure will be described in detail using the accompanying drawings.
• FIG. 3 is a schematic assembly perspective view for describing an archery cushion plunger according to an embodiment of the present disclosure, FIG. 4 is an exploded perspective view, and FIG. 5 is an assembly cross-sectional view.
• Referring to FIGS. 3 to 5 , an archery cushion plunger 20 according to the embodiment of the present disclosure may be provided such that a tip portion 221 a of a plunger shaft 22 is not twisted about a virtual center line and is always in contact with an arrow shaft 1 in a horizontal direction. Thus, a horizontal vibration of the arrow shaft 1 is always stably compensated for, so that an arrow can fly stably.
• As illustrated in FIG. 2A, in the archery cushion plunger 20 according to the embodiment of the present disclosure, two methods are proposed as a method in which the tip portion 221 a of the plunger shaft 22 is always in horizontal contact with the arrow shaft 1. First, the plunger shaft 22 is coupled to pass through an elastic member 23. Second, contact surfaces of both ends of the elastic member 23 that is in direct contact with the plunger shaft 22 and a tensile force adjustment cylinder 24 are precisely polished, thereby improving surface flatness.
• As illustrated in FIGS. 2B and 2C, in the related art having a structure in which a spring 13 connects a plunger 12 and a tensile force adjustment bar 14, when a force is applied in a direction from the tensile force adjustment bar 14 to the plunger 12 to adjust a tensile force due to characteristics of the spring 13, the spring 13 is contracted, and in this process, is twisted away from the center line CL.
• In order to solve this problem, as illustrated in FIG. 5 , in the archery cushion plunger 20 according to the embodiment of the present disclosure, a rear part 222 of the plunger shaft 22 passes through the elastic member 23 made of a compression spring (coil spring) and is inserted into and coupled to the tensile force adjustment cylinder 24.
• In this structure in which the plunger shaft 22 is coupled through the elastic member 23, the plunger shaft 22 serves to grip deformation of the elastic member 23. That is, when a pressure is applied to the elastic member 23 between the plunger shaft 22 and the tensile force adjustment cylinder 24 and thus the elastic member 23 is about to be deformed by a pressing force, the plunger shaft 22 is centered so that the elastic member 23 is not deformed, and thus twisting deformation of the elastic member 23 is prevented.
• In contrast, in the related art, as illustrated in FIG. 1 , since a central axis is not present in the spring 13, when a pressure is applied to the spring 13 between the plunger 12 and the tensile force adjustment bar 14, twisting deformation may occur in a space formed due to a gap g by the pressing force applied to the spring 13. However, in the embodiments of the present disclosure, this deformation does not occur.
• Meanwhile, in the present disclosure, in order to maintain the plunger shaft 22 horizontal, a sleeve 21 and the tensile force adjustment cylinder 24 are assembled and installed in a horizontally aligned state. That is, a front part 221 of the plunger shaft 22 is closely coupled through an inside of the sleeve 21, and the rear part 222 is closely inserted into and coupled to an inside of the tensile force adjustment cylinder 24. In this case, as the sleeve 21 and the tensile force adjustment cylinder 24 are assembled and installed in a horizontally aligned state, the plunger shaft 22 may be horizontally maintained between the sleeve 21 and the tensile force adjustment cylinder 24.
• FIG. 6 is a front view illustrating an elastic member illustrated in FIG. 4 .
• As illustrated in FIGS. 5 and 6 , the elastic member 23 according to the present disclosure, which is a compression spring, is installed between a step part 223 of the plunger shaft 22 and a front surface 24 a of the tensile force adjustment cylinder 24.
• A front surface 23 a of the elastic member 23 is in close contact with a rear surface of the step part 223 of the plunger shaft 22, and a rear surface 23 b thereof is in close contact with the front surface 24 a of the tensile force adjustment cylinder 24. In this case, when the elastic member 23 is pressed, the entire front surface 23 a may be in close contact with the step part 223 of the plunger shaft 22, and the entire rear surface 23 b may be uniformly in close contact with the front surface 24 a of the tensile force adjustment cylinder 24.
• To this end, in the elastic member 23, the front surface 23 a is precisely polished so that the front surface 23 a is horizontally in close contact with the step 223 of the shaft 22, and the rear surface 23 b is also precisely polished so that the rear surface 23 b is not twisted when in close contact with the front surface 24 a of the tensile force adjustment cylinder 24.
• The front surface 23 a and the rear surface 23 b of the elastic member 23 may be polished so that a surface step therebetween is 0.3 mm or less, preferably 0.2 mm, and more preferably 0.1 mm.
• As illustrated in FIG. 4 , the plunger shaft 22 according to the embodiment of the present disclosure can increase the degree of adhesion between the sleeve 21 and the elastic member 23 to prevent shaking during a horizontal (left-right) linear reciprocating movement.
• The plunger shaft 22 may be made of stainless steel that is resistant to corrosion and oxidation. For example, the plunger shaft 22 includes a front part 221 and a rear part 222 formed of a round bar. Further, the step part 223 formed in a circular ring shape protrudes from outer surfaces of the front part 221 and the rear part 222 at a boundary between the front part 221 and the rear part 222.
• The front part 221 and the rear part 222 may be integrally formed as a round bar. The step part 223 may be formed by fastening a separately manufactured circular ring to the front part 221 and the rear part 222. Further, the front part 221 may be formed to have a greater outer diameter than that of the rear part 222.
• As illustrated in FIGS. 4 and 5 , in the tensile force adjustment cylinder 24 according to the embodiment of the present disclosure, the front surface 24 a with which the rear surface 23 b of the elastic member 23 is in close contact has a flat surface having uniform flatness without a surface step, is in close contact with the rear surface 23 b of the elastic member 23 without a step, and thus guides the elastic member 23 so that the elastic member 23 may be horizontally contracted and extended without being twisted.
• As illustrated in FIG. 5 , the rear part 222 of the plunger shaft 22 is inserted into and coupled to the tensile force adjustment cylinder 24 to slidably move in a lengthwise direction of the tensile force adjustment cylinder 24. In this way, as the rear part 222 is inserted into and coupled to the tensile force adjustment cylinder 24, the plunger shaft 22 may linearly and horizontally move through the tensile force adjustment cylinder 24 without shaking.
• For example, the tensile force adjustment cylinder 24 may have a ball bearing including an outer ring 241, an inner ring 242, and a ball 243 installed between the outer ring 241 and the inner ring 242. In this case, a contact surface between the outer ring 241 and the inner ring 242 in contact with the rear surface 23 b of the elastic member 23 is formed in a flat surface without a surface step to prevent the twisting of the elastic member 23 as described above.
• Further, the outer ring 241 may be formed of stainless steel that is resistant to corrosion and oxidation, and the inner ring 242 may be formed of a synthetic resin material that is resistant to corrosion. Therefore, a supporting force can be provided, and smooth movement can be provided when the plunger shaft 22 slidably moves.
• Meanwhile, a ball bearing having a structure in which a part of a ball passes through the inner ring and protrudes to the hollow of the tensile force adjustment cylinder 24 may be used as the tensile force adjustment cylinder 24. In this case, when slidably moving along the hollow of the tensile force adjustment cylinder 24, the plunger shaft 22 slidably inserted into the hollow of the tensile force adjustment cylinder 24 is in direct contact with the ball passing through the inner ring and protruding, and thus can move more smoothly due to a rolling movement of the ball.
• As illustrated in FIG. 3 , the sleeve 21 according to the embodiment of the present disclosure, which is a screw-type sleeve having a thread formed on an outer surface thereof, includes a front part 211 and a rear part 212 having different outer diameters.
• As illustrated in FIG. 4 , threads are formed on outer surfaces of the front part 211 and the rear part 212. Further, an alignment key groove 212 a formed in a horizontal cut surface so that a tensile force adjustment position of the archery cushion plunger 20 is easily identified may be formed on one side of the outer surface of the rear part 212.
• A thread to which a tensile force adjustment housing 25 is screw-coupled is formed in the outer surface of the rear part 212 of the sleeve 21. Further, when a tensile force is adjusted using a dial manner through the tensile force adjustment housing 25, tensile force adjustment grooves 212 b are formed on the rear part 212 at regular intervals so that the tensile force adjustment grooves 212 b are perpendicular to a rotational direction of the thread formed in the rear part 212 to uniformly adjust a tensile force adjustment value.
• A plurality of tensile force adjustment grooves 212 b are formed in a rotational direction of the sleeve 21 at regular intervals. A tensile force of the elastic member 23 may be determined based on a position of the tensile force adjustment groove 212 b to which a ball 26 a of a ball plunger 26 is coupled, and thus a strength of a pressure point of the arrow can be finely adjusted.
• Meanwhile, the first tensile force adjustment groove among the tensile force adjustment grooves 212 b may be formed in parallel to the alignment key groove 212 a of the sleeve 21 so that an archer may easily recognize the strength of the adjusted tensile force. Alternatively, a zero point (scale) may be displayed to correspond to the firsts tensile force adjustment groove. Based on this, the archer may easily recognize the strength of the pressure point of the currently adjusted arrow to correspond to the tensile force adjustment groove located in a clockwise direction or a counterclockwise direction.
• As illustrated in FIGS. 3 and 4 , the tensile force adjustment housing 25 has a hollow 25 a to which the sleeve 21 is coupled. Further, a thread to be screw-coupled to the thread formed in the rear part 212 of the sleeve 21 is formed in an inner circumferential surface of the hollow 25 a. Thus, the tensile force adjustment housing 25 may linearly reciprocate along the sleeve 21 in a rotational direction through screw coupling with the sleeve 21. For example, when rotating in a tightening direction, the tensile force adjustment housing 25 moves leftward along the sleeve in FIG. 5 , and when rotating in an untightening direction, the tensile force adjustment housing 25 moves rightward in FIG. 5 .
• As illustrated in FIG. 5 , a rear end of the tensile force adjustment housing 25 may be sealed. This is for preventing foreign substances from being introduced into the tensile force adjustment housing 25. Further, the tensile force adjustment cylinder 24 inserted into the hollow 25 a of the tensile force adjustment housing 25 has a rear surface 24 b that is supported on an inner surface of the sealed rear end of the tensile force adjustment housing 25 in a right direction in FIG. 5 . Thus, as the tensile force adjustment housing 25 moves, the tensile force adjustment cylinder 24 inserted and coupled thereinto also moves horizontally in conjunction with the movement of the tensile force adjustment housing 25.
• As illustrated in FIG. 4 , a fastening hole 25 b into which the ball plunger 26 for fixing the tensile force adjustment housing 25 to the sleeve 21 is inserted and fastened is formed above the tensile force adjustment housing 25.
• The ball plunger 26 may be fixedly fastened to the fastening hole 25 b through a nut N and a washer W.
• As illustrated in FIG. 5 , the fastening hole 25 b is formed to communicate with the hollow 25 a of the tensile force adjustment housing 25. The ball plunger 26 coupled to the fastening hole 25 b has a ball 26 a installed at a lower end thereof, and thus when the tensile force is adjusted, the ball 26 a may be more smoothly caught by the tensile force adjustment groove 212 b.
• Meanwhile, as illustrated in FIG. 3 , a fixing nut 27 for mounting the cushion plunger 20 to a bow may be installed in the sleeve 21. For example, the fixing nut 27 may be formed through an aluminum anodizing process. Further, as illustrated in FIGS. 4 and 5 , a thread is formed on an inner circumferential surface of the hollow 27 a to be screw-coupled to the thread formed on an outer surface of the sleeve 21 and moves leftward and rightward along the sleeve 21 in the rotational direction. Further, a fastening hole 27 b to which a locking screw (not illustrated) is fastened is formed on an upper side to be fixed to the sleeve 21 at a predetermined position.
• When viewed from the tip portion 221 a of the plunger shaft 22, the tensile force adjustment housing 25 may have a polygonal shape (for example, a triangular shape) so that a gripping sense of a finger is improved and the finger does not slide when the tensile force is adjusted. The fixing nut 27 may also have a triangular structure in consideration of a gripping sense or the like.
• Hereinafter, operation characteristics of the archery cushion plunger 20 according to the embodiment of the present disclosure will be described.
• As illustrated in FIG. 5 , in order to adjust the strength of the pressure point of the arrow, when the tensile force adjustment housing 25 rotates about the sleeve 21 in the tightening direction (clockwise direction), the tensile force adjustment housing 25 moves in a leftward direction along the sleeve 21. The tensile force adjustment cylinder 24 moves by being guided by the tensile force adjustment housing 25 in conjunction with the tensile force adjustment housing 25. As the tensile force adjustment cylinder 24 moves, a rear part of the elastic member 23 is pressed to increase the tensile force. The strength of the pressure point of the arrow increases to correspond to the increase in the tensile force of the elastic member 23.
• In contrast, when the tensile force adjustment housing 25 rotates in the untightening direction (counterclockwise direction), the tensile force adjustment housing 25 moves in a rightward direction. Further, the tensile force adjustment cylinder 24 is pushed to the right side by an elastic restoring force of the elastic member 23 in conjunction with the rightward movement of the tensile force adjustment housing 25. Accordingly, a pressing force applied to the elastic member 23 is reduced or eliminated, and thus the tensile force is reduced. The strength of the pressure point of the arrow is reduced to correspond to the reduction in the tensile force of the elastic member 23.
• As described above, according to an archery cushion plunger according to the present disclosure, a structure is changed so that a plunger shaft in contact with an arrow shaft passes through a center of an elastic member, the plunger shaft stably grips the center of the elastic member, and thus deformation of the elastic member can be fundamentally prevented even when a pressure is applied to front and rear sides of the elastic member during adjustment of a tensile force.
• Further, according to the archery cushion plunger according to the present disclosure, a front surface and a rear surface of the elastic member installed between the plunger shaft and a tensile force adjustment cylinder are precisely polished so that the front surface and the rear surface are in close contact with a contact surface between the plunger shaft and the tensile force adjustment cylinder without a surface step. Therefore, a pressing force applied from the tensile force adjustment cylinder to the elastic member and from the elastic member to the plunger shaft is horizontally and stably transmitted, a tip portion of the plunger shaft is always in horizontal contact with the arrow shaft, and thus horizontal vibration can be stably compensated for.
• Thus, according to the archery cushion plunger according to the present disclosure, the tip portion of the plunger in contact with the arrow shaft is always in horizontal contact with the arrow shaft to stably compensate for horizontal vibration, stable flight of an arrow is induced, and thus a hit rate of the arrow can be improved.
• Further, according to the archery cushion plunger according to the present disclosure, the tensile force adjustment cylinder into which a rear part of the plunger shaft passing through the elastic member is inserted and coupled and which interlocks with a tension adjustment housing that rotates in a dial manner to adjust a tensile force of the plunger shaft is formed in a ball bearing structure, and thus, when the tensile force is adjusted, the plunger shaft can move more smoothly than when the plunger shaft moves horizontally and linearly in a sliding manner inside the tensile force adjustment cylinder.
• Further, according to the archery cushion plunger according to the present disclosure, tensile force adjustment grooves are formed in an outer surface of a sleeve at regular intervals, an adjusted tensile force is fixedly locked using a ball plunger coupled to the tensile force adjustment housing after the tensile force is adjusted by rotating the tensile force adjustment housing in a dial manner, and thus a tensile force adjustment operation can be more smoothly performed.
• As above, embodiments of the present disclosure have been described and illustrated using specific terms, but these terms are only intended to clearly describe the present disclosure. Further, it is obvious that the embodiments and the described terms of the present disclosure may be variously changed and modified without departing from technical spirit and scope of the appended claims. The modified embodiments should not be individually understood from the spirit and scope of the present disclosure and should belong to the appended claims of the present disclosure.

Claims (9)

What is claimed is:

1. An archery cushion plunger comprising:

a sleeve;

a plunger shaft that buffers a lateral pressure of an arrow shaft through a tip portion exposed to one end of the sleeve;

an elastic member which is embedded in the sleeve and has a front surface horizontally stopped and supported on the plunger shaft in a direction of the arrow shaft and through which the plunger shaft is coupled at a center thereof;

a tensile force adjustment cylinder into which a rear part of the plunger shaft is slidably inserted and of which a front surface is in contact with a rear surface of the elastic member such that the tensile force adjustment cylinder is horizontally stopped and supported; and

a tensile force adjustment housing that is screw-coupled to an outer surface of the sleeve to rotate about the sleeve and adjusts a tensile force of the elastic member by linearly moving the tensile force adjustment cylinder along the plunger shaft while linearly moving along the sleeve in a rotational direction.

2. The archery cushion plunger of claim 1, further comprising a ball plunger that moves into a hollow of the tensile force adjustment housing through a fastening hole formed in the tensile force adjustment housing and is vertically coupled to a tensile force adjustment groove formed in a rear part of the sleeve inserted into the tensile force adjustment housing.

3. The archery cushion plunger of claim 2, wherein an alignment key groove is formed in the outer surface of the sleeve in a horizontal cut surface structure so that the alignment key groove is horizontally parallel to a first tensile force adjustment groove among the tensile force adjustment grooves formed in the sleeve.

4. The archery cushion plunger of claim 1, wherein the tensile force adjustment cylinder includes:

an outer ring;

an inner ring inserted into the outer ring; and

a ball installed between the outer ring and the inner ring.

5. The archery cushion plunger of claim 1, wherein the plunger shaft includes:

a front part having the tip portion;

a rear part connected to a rear end of the front part and inserted into the tensile force adjustment cylinder; and

a step part that is formed at a boundary between the front part and the rear part, protrudes outer surfaces of the front part and the rear part, and is in contact with the front surface of the elastic member to be stopped and supported.

6. The archery cushion plunger of claim 1, wherein a separation prevention step by which a step part of the plunger shaft supported by the front surface of the elastic member in the direction of the arrow shaft is stopped is formed inside the sleeve.

7. The archery cushion plunger of claim 1, further comprising a fixing nut screw-coupled to the outer surface of the sleeve.

8. The archery cushion plunger of claim 1, wherein when viewed in the direction of the arrow shaft, the tensile force adjustment housing is formed in a polygonal structure.

9. The archery cushion plunger of claim 1, wherein the front surface of the rear force of the elastic member are polished to have a surface step of 0.3 mm or less.

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