A resiliometer

Abstract

The present application relates to a rebound hammer, the rebound hammer shell includes the lower shell section and the telescopic shell section arranged on the upper end of the lower shell section, the impact lever guide moves the assembly on the lower end of the lower shell section, the telescopic shell section includes at least two telescopic sleeves telescopic cooperation in sequence along the up-down direction, wherein the uppermost telescopic sleeve is the fixed sleeve fixed on the upper end of the lower shell section, the guide flange is fixed in the inner hole of the lowermost telescopic sleeve, the top of the fixed sleeve is provided with the end cover, the unhooking screw is arranged on the lower end of the end cover, the fixed sleeve is provided with the locking button for limiting cooperation with the lowermost telescopic sleeve, the top of the lower shell section is provided with the impact spring located on the periphery of the telescopic shell section, and the lower end of the impact spring is used to contact and push the upper end of the impact hammer when the impact hammer moves up. The present application solves the technical problems that the impact spring is prone to failure in the prior art.

Description

Technical Field

[0001] This invention relates to concrete strength measuring equipment, and more particularly to a rebound hammer. Background Technology

[0002] A concrete rebound hammer is a testing device used to detect the strength of concrete. It is widely used in the field of concrete strength testing. Its structure is illustrated in the "Automatic Reset Rebound Hammer" disclosed in Chinese Patent CN111238977A. The specification details the structure of a typical existing rebound hammer. Figure 1 As shown, it includes a housing 1, a striking rod 2, a striking hammer 4, a striking spring 3, and a central guide rod 5. The striking rod 2 is located at the lower end of the central guide rod and is guided and moved in conjunction with the housing. The striking hammer 4 is guided and fitted onto the central guide rod. The striking spring 3 is a tension spring connected to the lower end of the striking hammer.

[0003] The upper end of the impact hammer is provided with an annular groove 8. A guide flange 11 is mounted on the housing for guiding movement. A return spring 6 is provided between the guide flange 11 and the top of the housing. A hook 7 is provided on the guide flange for engaging with the annular groove at the upper end of the impact hammer. A release screw 9 is provided on the top of the housing for contacting the hook to release the impact hammer. A locking button 10 is provided on the housing for limiting the movement of the guide flange. By pressing the locking button, the inner end of the locking button can extend to stop the guide flange, thereby restricting the movement of the guide flange. Pressing the locking button again will retract the inner end of the locking button, thereby releasing the restriction on the guide flange.

[0004] In use, the end of the impact rod is brought into contact with the concrete surface to be tested. Initially, the locking button is released, and the impact rod extends a considerable length out of the housing under the action of the reset spring. The hook engages with the annular groove at the upper end of the impact hammer. Then, the housing is pressed down. During this process, the housing moves relative to the impact rod toward the concrete surface, and the impact spring stretches and stores energy. As the pressing continues, the guide flange gradually moves toward the release screw. When the release screw touches the hook on the guide flange, the hook releases its grip on the impact hammer, the impact spring releases its energy, and the impact hammer moves toward the impact rod and strikes it. The impact rod strikes the concrete surface, and the concrete surface generates a reaction force on the impact rod, causing the impact hammer to rebound. The strength of the concrete surface is judged based on the rebound height of the impact hammer. Generally speaking, the harder the concrete surface, the higher the strength, the less energy loss during impact, and the higher the rebound height of the impact hammer.

[0005] When not in use, the reset spring can be locked in the energy storage state via the locking button. At this time, most of the impact rod retracts into the housing, resulting in a shorter overall product length for easy carrying and transportation. The existing rebound hammers have the following problems: 1. The impact spring is a tension spring, using the energy released after the tension spring is stretched and deformed to achieve the impact of the hammer on the impact rod. The manufacturing and processing cost of a tension spring is higher than that of a compression spring, and its lifespan is shorter and more prone to failure during use. 2. Furthermore, theoretically, at the moment the hammer strikes the impact rod, the tension spring should be in a zero potential energy position. Only when the tension spring is in a zero potential energy position can the complete conversion between the tension spring's potential energy and the hammer's kinetic energy be achieved, allowing the hammer to output the target impact energy. Each rebound hammer is marked with a fixed energy output value. However, after a period of use, the tension spring cannot be effectively reset. This will cause the tension spring to be in a non-zero potential energy position when the hammer strikes the hammer rod, and the potential energy of the hammer spring cannot be completely converted into the kinetic energy of the hammer. Therefore, the hammer cannot impact the outside with the set energy value, and the rebound value of the impact will also be deviated, which is not conducive to the accurate measurement of the concrete surface strength. Summary of the Invention

[0006] The purpose of this invention is to provide a rebound device that can use a compression spring as an impact spring, so as to solve the technical problem that the impact spring in the prior art is prone to failure due to the use of a tension spring.

[0007] To solve the above-mentioned technical problems, the technical solution of the rebound hammer in this invention is as follows: A rebound hammer includes a rebound hammer housing. A striking rod is guided and movable at the lower end of the rebound hammer housing. A central guide rod is provided at the upper end of the striking rod. A striking hammer is guided and movable on the central guide rod. A guide flange is provided at the upper end of the central guide rod. A hook for engaging with the upper end of the striking hammer is provided on the guide flange. A release screw is provided at the top of the rebound hammer housing for pushing the hook to release the striking hammer when the guide flange moves upward. A return spring is provided between the top of the rebound hammer housing and the guide flange. The rebound hammer housing includes a lower housing section and a telescopic housing section located at the upper end of the lower housing section. The striking rod guide and movable assembly... The telescopic housing section includes at least two telescopic sleeves that extend and retract sequentially in the vertical direction. The uppermost telescopic sleeve is a fixed sleeve fixed to the upper end of the lower housing section. A guide flange is fixed in the inner hole of the lowermost telescopic sleeve. An end cap is provided on the top of the fixed sleeve, and a release screw is provided at the lower end of the end cap. A locking button is provided on the fixed sleeve for limiting the engagement with the lowermost telescopic sleeve. A spring is provided on the top of the lower housing section, located on the periphery of the telescopic housing section. The lower end of the spring is used to contact and push against the upper end of the spring hammer when the spring hammer moves upward.

[0008] Furthermore, the striking hammer includes a striking hammer body that moves in coordination with the central guide rod, and an annular retaining edge is fixed at the upper end of the striking hammer body to achieve contact and push engagement with the lower end of the striking spring.

[0009] Furthermore, the telescopic sleeve has three sections. In the vertical direction, the lower telescopic sleeve is guided and moved to fit into the inner hole of the upper telescopic sleeve.

[0010] Furthermore, the two lower telescopic sleeves are referred to as the second telescopic sleeve and the third telescopic sleeve, respectively. The second telescopic sleeve has a sleeve through hole along the radial direction for the locking button to pass through.

[0011] Furthermore, when the hammer strikes the impact rod downwards, the upper end of the hammer is spaced apart from the impact spring in its free state.

[0012] Furthermore, the upper end of the spring is fixed to the spring seat, and a height adjustment structure for adjusting the height of the spring seat is provided on the top of the lower housing section.

[0013] Furthermore, the lower housing section has a housing section top plate at its top, and the height adjustment structure includes an adjusting screw whose axis extends in the vertical direction and is threaded into the housing section top plate. There are at least three adjusting screws, and each adjusting screw is circumferentially spaced around the fixed sleeve. The lower end of each adjusting screw is rotatably engaged with the spring seat.

[0014] The beneficial effects of this invention are as follows: This invention improves upon the existing spring-loaded impact spring by replacing it with a spring-loaded compression spring, which is positioned on the upper side of the impact hammer. The key innovation of this invention lies in ensuring effective guidance of the rebound hammer housing to the guide flange after placing the spring-loaded compression spring on the upper side of the impact hammer. Therefore, this invention uses a telescopic housing section composed of multiple telescopic sleeves. This ensures effective guidance of the guide flange and avoids obstructing the upward movement of the impact hammer when it presses against the rebound hammer compression spring. Using a spring-loaded compression spring as the elastic element for releasing the impact energy of the impact hammer is less prone to failure, has a longer service life, and reduces manufacturing costs compared to the existing spring. Attached Figure Description

[0015] The above and other objects, features, and advantages of this disclosure will become readily apparent from the following detailed description of exemplary embodiments with reference to the accompanying drawings. In the drawings, several embodiments of this disclosure are illustrated by way of example and not limitation, and like or corresponding reference numerals denote like or corresponding portions, wherein: Figure 1 This is a schematic diagram of the structure of the prior art rebound hammer of this invention; Figure 2 This is a schematic diagram of one embodiment of a rebound hammer according to the present invention; Figure 3 yes Figure 2 A schematic diagram showing the state after the middle locking button is released from limiting the bottommost telescopic sleeve; Figure 4 yes Figure 2 Schematic diagram of the fit between the telescopic shell section and the guide flange; Figure 5 yes Figure 3 Schematic diagram of the fit between the telescopic shell section and the guide flange; Figure 6 yes Figure 2 Enlarged view of point A in the image; Explanation of reference numerals in the attached drawings: 1. Housing; 2. Impact rod; 3. Impact spring; 4. Impact hammer; 5. Central guide rod; 6. Return spring; 7. Hook; 8. Annular groove; 9. Release screw; 10. Locking button; 11. Guide flange; 12. Surface of concrete to be tested; 13. Impact hammer body; 14. Annular flange; 15. Lower housing section; 16. Impact spring; 17. Telescopic housing section; 18. End cap; 19. Guide sleeve; 20. Adjusting screw; 21. Top plate of housing section; 22. Second telescopic sleeve; 23. Third telescopic sleeve; 24. Fixed sleeve; 25. Spring seat. Detailed Implementation

[0016] To facilitate understanding of the present invention, a more detailed description is provided below with reference to the accompanying drawings and specific embodiments. Preferred embodiments of the invention are shown in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the invention.

[0017] It should be noted that, unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention.

[0018] An embodiment of a rebound hammer in this invention is as follows: Figures 2-6 As shown: The rebounder housing includes a lower housing section 15 and a telescopic housing section 17 located at the upper end of the lower housing section. Specifically, the lower housing section has a housing section top plate 21 at its top. The telescopic housing section includes three telescopic sleeves that are sequentially telescopically connected in the vertical direction. The uppermost telescopic sleeve is a fixed sleeve 24 fixed to the housing section top plate. The two lower telescopic sleeves are referred to as the second telescopic sleeve 22 and the third telescopic sleeve 23, respectively. The lower telescopic sleeve is guided and moved into the inner hole of the upper telescopic sleeve.

[0019] An end cap 18 is fixed to the top of the fixed sleeve. A spring rod 2 is guided and moved along the bottom of the lower housing section. A central guide rod 5 is provided at the upper end of the spring rod 2. A spring hammer 4 is guided and moved along the central guide rod 5. A guide flange 11 is fixed to the upper end of the central guide rod 5. An annular groove 8 is provided at the upper end of the spring hammer. A hook 7 is provided on the guide flange 11 for hooking and connecting with the annular groove at the upper end of the spring hammer. A release screw 9 is provided at the lower end of the end cap for pushing the hook to release the spring hammer when the guide flange moves upward. A return spring 6 with its axis extending along the vertical direction is provided between the end cap 18 and the guide flange 11. The spring rod, central guide rod, guide flange, return spring, hook, release screw, and their cooperation with the spring hammer are all prior art and will not be described in detail here.

[0020] The guide flange 11 is fixed in the inner hole of the lowest telescopic sleeve, namely the third telescopic sleeve 23. The fixed sleeve 24 is provided with a locking button 10 for engaging with the lower end of the third telescopic sleeve. The second telescopic sleeve has a sleeve through hole along the radial direction for the locking button to pass through. The structure of the locking button 10 itself is also existing technology. By pressing the locking button, the inner end of the locking button can extend to the lower end of the third telescopic sleeve, thereby blocking the third telescopic sleeve and the guide flange, thus restricting the movement of the guide flange and also restricting the movement of the second telescopic sleeve. Pressing the locking button again will retract the inner end of the locking button, thereby releasing the restriction on the third telescopic sleeve and the guide flange, and also releasing the restriction on the second telescopic sleeve.

[0021] A spring 16 is provided on the top of the lower housing section 15, located around the periphery of the telescopic housing section. The lower end of the spring 16 is used to contact and push against the upper end of the impact hammer when it moves upward. The impact hammer includes an impact hammer body 13 that moves in a guiding manner with the central guide rod. An annular retaining flange 14 is fixed to the upper end of the impact hammer body 13 to achieve contact and push against the lower end of the spring 16. When the impact hammer strikes the impact rod downward, the upper end of the impact hammer is spaced apart from the spring 16 in its free state.

[0022] The upper end of the spring is fixed to the spring seat 25, and a guide sleeve 19 is fixed to the inner wall of the lower housing section. The spring seat 25 and the inner hole of the guide sleeve 19 are guided and moved together. A height adjustment structure for adjusting the height of the spring seat is provided at the top of the lower housing section. The height adjustment structure includes three adjusting screws 20 whose axes extend vertically and are threaded into the top plate of the housing section. Each adjusting screw 20 is circumferentially spaced around the fixed sleeve 24. The lower end of each adjusting screw is rotatably engaged with the spring seat 25, and the adjusting screw and the spring seat are anti-disengaged in the vertical direction. By turning the adjusting screws, the height of the spring seat can be adjusted, thereby adjusting the compression amount of the spring when it is pushed back by the impact hammer, and thus adjusting the output kinetic energy of the impact hammer.

[0023] In this invention, "up" and "down" are merely to define a direction for ease of explanation of the rebound hammer's structure, and do not restrict its usage. During use, to avoid the influence of gravity on the output kinetic energy of the rebound hammer, it is typically used horizontally. Specifically, the impact rod of the rebound hammer is lightly pressed against the surface of the concrete being tested, such as... Figure 2 As shown, press the locking button, which moves radially outward, releasing the limits on the third and second telescopic sleeves. The operator releases their grip on the rebound spring housing, and the reset spring 6 releases its energy. Under the action of the reset spring, the guide flange, along with the central guide rod and the impact rod, moves downward. Each telescopic sleeve section of the telescopic housing unfolds sequentially, ensuring a long guiding distance for the guide flange. Figure 2 As shown, the impact hammer remains in place due to inertia. Hook 7 hooks the upper end of the impact hammer. Then, the operator holds the lower shell section and presses it against the concrete surface to be tested. During the pressing process, the return spring is compressed and stores energy. The telescopic sleeves of the telescopic shell section retract sequentially. When the annular flange of the impact hammer touches the lower end of the impact spring, the impact spring also begins to be compressed and stores energy. With the continuous pressing of the lower shell section, the hook touches the release screw, the hook rotates, and the hook rotates out of the annular groove at the upper end of the impact hammer, releasing the connection between the hook and the impact hammer. The impact spring releases energy, and the impact hammer moves towards the impact rod. When the impact spring is in a free state, the impact hammer disengages from the impact spring. After the impact hammer disengages from the impact spring, it strikes the impact rod, which in turn strikes the concrete surface to be tested. The impact rod transfers the rebound energy to the impact hammer. The strength of the concrete surface to be tested is judged by the rebound distance of the impact hammer. In other words, the operation process of the rebound hammer in this invention is the same as that of the rebound hammer in the prior art.

[0024] In other words, in this embodiment, the impact hammer only strikes the impact rod after disengaging from the impact spring. At the moment of impact, the impact spring does not act on the hammer, as it has already transferred all its potential energy to the hammer, ensuring the rebound hammer accurately outputs impact energy. The use of telescopic sleeves allows for adjustment of the guide flange's guide length as needed. During the process of hooking the impact hammer, the guide flange has a longer guide distance. Furthermore, during the rebound hammer's application of pressure to the impact spring, each section of the telescopic sleeve in the telescopic housing retracts sequentially, preventing any impact on the hammer's movement.

[0025] In the foregoing description of this specification, unless otherwise expressly specified and limited, the terms "fixed," "installed," "connected," or "linked" should be interpreted broadly. For example, the term "linked" can refer to a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; or it can refer to the internal communication of two components or the interaction between two components. Therefore, unless otherwise expressly limited in this specification, those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0026] Based on the above description in this specification, those skilled in the art will also understand that terms used, such as "upper," "lower," "front," "rear," "left," "right," "length," "width," "thickness," "vertical," "horizontal," "top," "bottom," "inner," "outer," "axial," "radial," "circumferential," "center," "longitudinal," "transverse," "clockwise," or "counterclockwise," are terms indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings of this specification. They are only for the purpose of facilitating the explanation of the present invention and simplifying the description, and do not imply that the devices or elements involved must have the specific orientation, or be constructed and operated in a specific orientation. Therefore, the above-mentioned orientation or positional relationship terms should not be understood or interpreted as limitations on the present invention.

[0027] Furthermore, the terms "first" or "second," etc., used in this specification to refer to numbers or ordinal numbers are for descriptive purposes only and should not be construed as indicating, explicitly or implicitly, relative importance or specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this specification, "a plurality of" means at least two, such as two, three, or more, unless otherwise explicitly specified.

[0028] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A rebound hammer, comprising a rebound hammer housing, a striking rod being guided and movably mounted on the lower end of the rebound hammer housing, a central guide rod being provided at the upper end of the striking rod, a striking hammer being guided and movably mounted on the central guide rod, a guide flange being provided at the upper end of the central guide rod, a hook being provided on the guide flange for hooking and connecting with the upper end of the striking hammer, a release screw being provided at the top of the rebound hammer housing for pushing the hook to release the striking hammer when the guide flange moves upward, and a return spring being provided between the top of the rebound hammer housing and the guide flange, characterized in that: The rebound hammer housing includes a lower housing section and a telescopic housing section located at the upper end of the lower housing section. A guide rod is mounted on the lower end of the lower housing section. The telescopic housing section includes at least two telescopic sleeves that extend and retract sequentially in a vertical direction. The uppermost telescopic sleeve is a fixed sleeve fixed to the upper end of the lower housing section. A guide flange is fixed in the inner hole of the lowermost telescopic sleeve. An end cap is provided on the top of the fixed sleeve, and a release screw is located at the lower end of the end cap. A locking button is provided on the fixed sleeve for limiting engagement with the lowermost telescopic sleeve. A spring is located on the top of the lower housing section, surrounding the telescopic housing section. The lower end of the spring is used to contact and push against the upper end of the spring when the spring moves upward. The telescopic sleeve has three sections. Along the vertical direction, the lower telescopic sleeve is guided and fitted into the inner hole of the upper telescopic sleeve. The telescopic sleeve is located inside the spring. During use, the operator releases their grip on the rebound hammer housing, releasing the energy of the return spring. Under the action of the return spring, the guide flange, along with the central guide rod and the impact rod, moves downwards. The telescopic sleeves of the telescopic housing section unfold sequentially, ensuring a long guiding distance for the guide flange. At this point, the guide flange is located below the impact spring, and the impact hammer remains in place due to inertia. The hook engages the upper end of the impact hammer. The operator then holds the lower housing section and presses it against the concrete surface being tested. During this pressing process, the return spring compresses. Yes, the telescopic sleeves of the telescopic housing section retract sequentially. When the annular flange of the impact hammer touches the lower end of the impact spring, the impact spring is also pressed to store energy. With the continuous pressing of the lower housing section, the hook touches the release screw, the hook rotates, and the hook rotates out of the annular groove at the upper end of the impact hammer, releasing the connection between the hook and the impact hammer. The impact spring releases energy, and the impact hammer moves toward the impact rod. When the impact spring is in a free state, the impact hammer disengages from the impact spring. After the impact hammer disengages from the impact spring, it strikes the impact rod.

2. The rebound hammer according to claim 1, characterized in that: The impact hammer includes an impact hammer body that moves in coordination with the central guide rod, and an annular retaining edge is fixed at the upper end of the impact hammer body to achieve contact and push engagement with the lower end of the impact spring.

3. The rebound hammer according to claim 1, characterized in that: The two lower telescopic sleeves are called the second telescopic sleeve and the third telescopic sleeve, respectively. The second telescopic sleeve has a sleeve through hole along the radial direction for the locking button to pass through.

4. The rebound hammer according to claim 1, characterized in that: When the hammer strikes the impact rod downwards, the upper end of the hammer is spaced apart from the impact spring in its free state.

5. The rebound hammer according to any one of claims 1 to 4, characterized in that: The upper end of the spring is fixed to the spring seat, and the top of the lower housing section is provided with a height adjustment structure to adjust the height of the spring seat.

6. The rebound hammer according to claim 5, characterized in that: The lower housing section has a housing section top plate at its top. The height adjustment structure includes an adjusting screw whose axis extends vertically and is threaded into the housing section top plate. There are at least three adjusting screws, each of which is spaced circumferentially around the fixed sleeve. The lower end of each adjusting screw is rotatably engaged with the spring seat.

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