tensioning device

Abstract

The present invention relates to a tensioning device for tensioning a chain, belt, rope or similar tensioning member (1), the tensioning device having at least one tubular tensioning nut (2) and at least one bolt (3) recessed into and interacting with the tensioning nut (2), wherein the bolt (3) is equipped with at least one end-side screw-out safety device (9; 10a, 10b, 11), and wherein the bolt (3) is provided at the end-side with a threadless region (9) and a stop (10a, 10b, 11) connected to the threadless region as a screw-out safety device (9; 10a, 10b, 11).

Description

Technical Field

[0001] The present invention relates to a tensioning device for tensioning a chain, belt, rope or similar tensioning member, the tensioning device having at least one tubular tensioning nut and at least one bolt recessed into and interacting with the tensioning nut, wherein the bolt is equipped with at least one end-side unscrew stop. Background Technology

[0002] This type of tensioning device is commonly used in lifting and transportation technologies, or in general, in the field of logistics. The tensioning member used in this way is not limited to chains, belts, ropes, etc. With the aid of this tensioning member, for example, goods can be locked to the transport surface of a transport vehicle. Envisioned transport vehicles include LKW semi-trailers, trailers, train trailers, etc., but loading platforms used for ships, containers, etc., are also used.

[0003] Due to the application areas described, it is often necessary to apply high tension to the tensioning member using a tensioning device. For this purpose, tensioning nuts are typically equipped with ratchet mechanisms, as detailed in, for example, in DE202020103769U1 of this applicant. Furthermore, the tensioning device can be connected to the tensioning member on one side and engage with a hole on the loading surface or another fixing point via a movable end on the bolt. However, it is also possible to connect the tensioning device to the tensioning member on both sides to provide the necessary binding force, for example, to lock the cargo to the transport surface.

[0004] For example, the tensioning device with the structure described at the beginning is illustrated in US4130269. Here, two bolts, each a tubular tensioning nut recessed at the center on both sides, are implemented. These bolts have screws screwed into them at their ends, which drive towards a stop when the maximum bolt unscrewed length is reached. This provides the desired unscrew safety device.

[0005] However, a problem with this type of tensioning device is that the screw can be sheared or damaged when a large tensioning force is applied. Consequently, the safety catch can no longer function as intended. Furthermore, the tensioning device is often irreparably damaged or requires costly repairs.

[0006] In practice, this phenomenon is increasingly observed because, on the one hand, the applied tension force is increasing, and on the other hand, the tensioning stroke is becoming larger. This can be attributed in particular to the fact that, by means of the tensioning devices described, not only steel chains with forged chain elements are tensioned, but also an increasing number of so-called fabric chains equipped with the required binding force. Such fabric chains are described, for example, in DE202018105723U1 of this applicant. The outstanding feature of this fabric chain is its light weight and high strength, but it is susceptible to significant torsion before the required tension force can be applied. As a result, a large tensioning length is required for the bolt, which causes the associated bolt to travel toward the unscrewed safety device.

[0007] The tensioning device described in WO2018 / 073098A1 of the same type also faces similar problems. In practice, a terminal stop is provided at the end of the screw. This involves a locking ring or end cap. Due to the disc-shaped or annular feature of this terminal stop, although better force introduction is observed compared to the screw described according to US4130269, damage can still occur in this case. Furthermore, the prior art to date has not provided a solution for providing feedback to the operator regarding the arrival at the terminal stop to prevent such damage. Therefore, the present invention aims to provide a remedy. Summary of the Invention

[0008] The technical problem addressed by this invention is to improve this type of tensioning device for tensioning chains, belts, ropes, etc., so as to minimize damage and notify the operator of reaching the end stop.

[0009] To solve this technical problem, this type of tensioning device within the scope of the present invention is characterized in that the bolt is provided with a threadless area on the end side and a stop connected to the threadless area as a screw-out safety device.

[0010] Therefore, the present invention still utilizes a stop element, but combines the stop element with a threadless region. The key feature of the threadless region is that the necessary threads provided around the bolt circumference are interrupted or removed in this region. Thus, the bolt cannot transmit force in the threadless region.

[0011] In detail, a tensioning nut has at least one threaded section inside, into which the bolt is driven. Now, if the bolt reaches the threaded section inside the tensioning nut with its unthreaded portion, it cannot be unscrewed further. A typical design for this purpose is that the unthreaded portion of the bolt has an axial length that is substantially equal to the thread length of the bolt's threaded section inside the tensioning nut. As a result, once the unthreaded portion of the bolt reaches the threaded section inside the tensioning nut, the bolt slips.

[0012] Simultaneously, during this process, a stop connected to the unthreaded region in the direction toward the bolt end ensures that the bolt remains inside the tension nut. Typically, the stop is located at the rear end of the bolt or in this region in the bolt's unscrewing direction. Conversely, if the bolt's thread ends beforehand, transitioning into the unthreaded region, the stop is connected to this unthreaded region in the axial direction.

[0013] In any case, by means of this method and by equipping the bolt with a threadless area, not only is an effective unscrewing safety device provided, but the operator is also notified of reaching the stop, or more precisely, the terminal stop. Because when the threadless area of ​​the bolt reaches the threaded line inside the tension nut, the operator notices that the bolt actually "slips" and cannot continue to be unscrewed, but instead travels axially towards the stop. Thus, an effective unscrewing safety device is achieved, which also has the additional possibility of notifying the operator of reaching the stop, or more precisely, the terminal stop. A significant advantage is obtained from this.

[0014] According to a favorable design, the unthreaded region is constructed as a relief groove introduced into the thread of the bolt. By definition, this relief groove is removed at the rotationally symmetrical thread in a predetermined manner and with predetermined dimensions. In practice, for example, the relief groove can be introduced into the thread of the bolt so that the thread is simply and clearly removed to such an extent in the unthreaded region that the bolt engages without (no longer) transmitting force and can engage with the thread inside the tensioner nut. This explains the freewheeling or "slippage" of the bolt relative to the tensioner nut in the unthreaded region discussed above.

[0015] Advantageously, the stop is a ring-shaped stop. Furthermore, the most common design is that the stop is equipped with a spring. Here, the spring can advantageously be made from a spring body. This makes the spring construction particularly simple and cost-effective. It has proven advantageous here that the spring is constructed as a spring ring. Therefore, in the simplest case, the spring ring is an elastomeric ring, which can be easily manufactured and supplied in large quantities and therefore cost-effectively.

[0016] Furthermore, it has proven advantageous that the stop is constructed as a two-piece unit, comprising a fixed stop and a movable stop. Typically, the stop is constructed as a ring, or more precisely, as a circular stop, as explained above. Thus, the fixed stop is a fixed stop ring, and the movable stop is a movable stop ring. Here, the spring is advantageously arranged between the fixed stop and the movable stop, or between the fixed stop ring and the movable stop ring. In most commonly adopted designs, the spring, or more precisely, the spring ring, along with the fixed stop ring and the movable stop ring, are arranged concentrically with each other and share a common axis as their respective centers.

[0017] Generally, a fixed stop ring is connected to a bolt and therefore cannot move axially relative to the bolt. In contrast, a movable stop ring is connected to the bolt in a way that allows axial movement. It has proven advantageous here that the movable stop ring (and the fixed stop ring) are received within a recess in the bolt. Within this recess, the movable stop ring can move axially. According to the invention, axial movement of the movable stop ring is obviously permitted because a spring ring made of an elastomer is arranged between the movable and fixed stop rings, thus elastically accommodating the axial movement of the movable stop ring relative to the fixed stop ring.

[0018] Each of the two stop rings is typically equipped with its own safety ring. Furthermore, both stop rings are mostly L-shaped in cross-section. A further design approach is to overlap the corresponding safety ring with its two short L-shaped sides. As a result, the two short L-shaped sides of the respective stop rings point opposite to each other and define a receiving groove therebetween for a spring ring made of a spring body.

[0019] The result provides a tensioning device equipped with a particularly effective and especially damage-free unscrewing safety device. Its core can be summarized as a threadless region located on the bolt end side, together with a stop connected to this threadless region, acting as an unscrewing safety device. Once the bolt reaches the threadless region during the unscrewing process, the bolt "slips" relative to the threaded line that houses it within the tensioning nut. Here, the stop ensures that the bolt cannot "fall out" of the threaded line.

[0020] By strategically placing a stop at this location, along with the design of a spring made of a spring body, it is further achieved that when the bolt is unscrewed from the threads inside the tension nut, the corresponding last thread of the bolt disengages accordingly, and further rotational movement results in a "click" sound, because the spring fitted to the stop always presses the bolt—simply—back into the threads inside the tension nut. The advantage of this process is that not only is the unscrewing of the safety device tactilely perceived by the operator, i.e., by the bolt "slipping" relative to the tension nut as discussed above, but the repetitive "click noise" also acoustically aids the process.

[0021] Ultimately, this special design ensures that when the safety catch is unscrewed, the bolt can easily re-enter the threads inside the tension nut in the opposite direction, because the bolt is essentially pulled or guided into the threads inside the tension nut by the (small) spring force acting in that direction. This effectively eliminates the possibility of the bolt being misaligned relative to the threads inside the tension nut when it is screwed back into the tension nut.

[0022] As a result, the invention eliminates the possibility of damage to the bolt and the unscrew stop, and also notifies the operator, not only tactilely but also acoustically, of the arrival of the unscrew stop. This, combined with the orientation of the bolt relative to the thread inside the tension nut, achieved simultaneously by the spring at the stop, ensures that the bolt, upon re-screwing, reaches the tension nut without problems. All of this results in overall, damage-free and therefore continuous operation with a long service life, which is unprecedented in the prior art. Attached Figure Description

[0023] The invention will now be explained in detail with reference to the accompanying drawings, which only illustrate embodiments of the invention. Wherein:

[0024] Figure 1 The tensioning device according to the invention is illustrated in part by cross-sectional view in a generalized manner, and

[0025] Figure 2 The bolt with the screw-out safety device is also shown in detail in part in cross-sectional views. Detailed Implementation

[0026] The tensioning device is shown in the figure. This tensioning device can be used to tension chains, belts, ropes, or similar tensioning members 1. Figure 1 The image is only shown schematically. Here, the corresponding tensioning member 1 can be connected to the tensioning device on both sides. However, in principle, the tensioning member 1 can also be connected to the tensioning device only on one side. Thus, the tensioning device is connected, for example, to the loading surface or another fixing point via its other end. This is not shown in detail.

[0027] The tensioning device, in its basic structure, first has at least one tubular tensioning nut 2, which, according to this embodiment, is constructed as a tensioning sleeve extending elongated in the longitudinal direction L, or axial direction. According to this embodiment, bolts 3 are recessed into the tensioning nut 2 on both sides. The corresponding bolts 3 interact with the tensioning nut 2. For this purpose, the tensioning nut 2 has opposing threads 4 on its end sides, and the corresponding bolts 3 engage with these threads 4 using the threads 5 on their outer circumference. However, in principle and preferably, the tensioning nut 2 may also be equipped with only one (single) bolt 3.

[0028] In this way, the rotation of the tension nut 2 in the rotational direction causes both bolts 3 or the single bolt 3 to sink into or out of the tension nut 2 uniformly, more precisely, axially or longitudinally L. During this process, the corresponding tensioning member 1 is loosened or tightened. For this purpose, the relevant bolt 3 is equipped with a hole 6 on its end side, which can be connected to the tensioning member 1 or also to a fixed point at the loading surface. The rotational movement of the tension nut 2 for tensioning the tensioning member 1, as discussed above, is transmitted to the tension nut 2 by means of ratchet mechanisms 7, 8. The ratchet mechanisms 7, 8 have a tension lever 7, which has a tension pawl that interacts with a toothed ring 8 connected to the tension nut 2 in a known manner.

[0029] Regardless, the tension nut 2 can be loaded counterclockwise and clockwise by means of ratchet mechanisms 7 and 8. According to the design of the threads 4 and 5, this causes the two bolts 3 to either sink into or emerge from the tension nut 2, more precisely, in the axial direction or longitudinal direction L. The result is the tensioning or loosening of one or more tensioning members 1.

[0030] To prevent the bolt 3 located on the left side in this embodiment from rotating out of the tension nut 2 due to the unscrewing movement relative to the thread 4 inside the tension nut 2, the bolt 3 is equipped with end-side unscrewing safety devices 9, 10a, 10b, and 11. For this purpose, the bolt 3 has a threadless region 9 on its end side and stops 10a, 10b, and 11 connected to the threadless region, which are collectively configured and function as unscrewing safety devices 9, 10a, 10b, and 11.

[0031] In this regard, the unthreaded region 9 has an axial length A, which is substantially equal to the length of the thread 4, or thread length, of the associated bolt 3 housed within the tension nut 2. This is in comparison Figure 1 and 2 It becomes obvious over time.

[0032] The unthreaded region 9 is a relief groove introduced into the thread 5 of the associated bolt 3, that is, the thread 5 is removed in this region. This can be achieved and accomplished, for example, by correspondingly cutting away the thread 5 in the unthreaded region 9.

[0033] Stops 10a, 10b, and 11 are integrally formed as annular stops. In fact, stops 10a, 10b, and 11 have an annular shape, more precisely, an annular shape relative to the common axis of rotation R with bolt 3. Furthermore, stops 10a, 10b, and 11 are equipped with springs 11, which are made of an elastomer. In fact, spring 11 is a spring ring made of elastomeric plastic.

[0034] In addition to the spring 11, the stops 10a, 10b, and 11 are designed as two-piece units, comprising a fixed stop 10a and a movable stop 10b. Since the stops 10a, 10b, and 11 are constructed as a single ring, the fixed stop 10a is a fixed stop ring 10a, and the movable stop 10b is a movable stop ring 10b. Here, the spring 11 is arranged between the fixed stop ring 10a and the movable stop ring 10b. For this purpose, the spring 11 is accommodated in a recess or receiving groove 12 between the two stop rings 10a and 10b.

[0035] according to Figure 2 As can be seen in the detailed drawing, the fixed stop ring 10a is connected to the bolt 3. Conversely, the movable stop ring 10b can move axially along the longitudinal direction L. For this purpose, the movable stop ring 10b is guided axially on the bolt 3. For this purpose, the movable stop ring 10b is received in the recess 15 of the bolt 3. The same applies to the fixed stop ring 10a.

[0036] The two stop rings 10a and 10b are respectively equipped with safety rings 13 and 14. Safety ring 13 is a fixed stop ring 10a, while safety ring 14 interacts with the movable stop ring 10b. In addition, the two stop rings 10a and 10b are designed in an L-shape in cross-section.

[0037] In fact, the two stop rings 10a and 10b each have short L-shaped sides, and each side overlaps with its respective safety ring 13 and 14. Since the two stop rings 10a and 10b also have substantially the same outer diameter, a receiving groove 12, as discussed above, is formed between the two stop rings 10a and 10b, into which a spring made of elastomeric plastic, or more precisely a spring ring 11, engages.

[0038] The safety ring 13, which is provided for the fixed stop ring 10a, engages in a groove on the outer circumference of the bolt 3 and is thereby axially locked. The same applies to the fixed stop ring 10a. Conversely, the safety ring 14 associated with the movable stop ring 10b is arranged axially movable in the recess 15 of the bolt 3.

[0039] Therefore, once the bolt 3 is unscrewed from the tension nut 2 until the safety devices 9, 10a, 10b, and 11 are unscrewed in this way, the movable stop ring 10b moves inward toward the thread 4 inside the tension nut 2. At the same time, the unthreaded region 9 is completely submerged in the thread 4, because the axial length of the thread 4 is equal to the axial length A of the unthreaded region 9.

[0040] Now, as a result of the incremental unscrewing motion of bolt 3, spring 11 is compressed between the two stop rings 10a and 10b, because the movable stop ring 10b abuts against the stop inside the tension nut 2, and can move toward spring 11 within the recess 15 together with the safety ring 14 via the axially movable support of the movable stop ring and (slightly) compress the spring.

[0041] Thus, inside the tension nut 2, on the opposite side of the thread 4, the end of the thread 5 of the bolt 3 leaves the thread 4, but is subsequently pulled back into the thread 4 by the slightly relaxed spring 11. This results not only in the bolt 3 "slipping" in this area, but also in a "clicking noise" observed each time the end of the thread 5 emerges from the thread 4 inside the tension nut 2 and is re-engaged into the thread 4 by the relaxed spring. Simultaneously, the spring force applied by the spring 11 ensures that the thread 5 of the bolt 3 is unobstructed—again—introduced into the thread 4 in the opposite direction to the bolt 3's unscrewing movement, and therefore no misalignment is observed between the bolt 3 and the tension nut 2.

Claims

1. A tensioning device for tensioning a tensioning member (1), the tensioning device having at least one tubular tensioning nut (2) and at least one bolt (3) recessed into and interacting with the tensioning nut (2), wherein, The bolt (3) is equipped with at least one end-side screw-out safety device, characterized in that the bolt (3) is provided with a threadless region (9) on the end-side and a stop connected to the threadless region as a screw-out safety device, and the stop is configured as a two-piece having a fixed stop (10a) and a movable stop (10b) and a spring (11) arranged between the fixed stop and the movable stop.

2. The tensioning device as described in claim 1, characterized in that, The unthreaded region (9) has an axial length (A) that is substantially equal to the thread length of the thread (4) of the receiving bolt (3) inside the tension nut (2).

3. The tensioning device as described in claim 1 or 2, characterized in that, The unthreaded region (9) is configured as a relief groove introduced into the thread (5) of the bolt (3).

4. The tensioning device as described in claim 1 or 2, characterized in that, The stop is configured as a ring-shaped stop.

5. The tensioning device as described in claim 1 or 2, characterized in that, The spring (11) is made of an elastomer.

6. The tensioning device as described in claim 1 or 2, characterized in that, The spring (11) is configured as a spring ring.

7. The tensioning device as described in claim 1 or 2, characterized in that, The fixed stop (10a) is configured as a fixed stop ring, and the movable stop (10b) is configured as a movable stop ring.

8. The tensioning device as described in claim 7, characterized in that, The fixed stop ring is connected to the bolt (3).

9. The tensioning device as described in claim 7, characterized in that, The movable stop ring is axially movable and supported on the bolt (3).

10. The tensioning device as claimed in claim 7, characterized in that, The fixed stop ring and the movable stop ring are accommodated in the recess (15) of the bolt (3).

11. The tensioning device as claimed in claim 7, characterized in that, The fixed stop ring and the movable stop ring are each equipped with a safety ring (13, 14).

12. The tensioning device as claimed in claim 7, characterized in that, The fixed stop ring and the movable stop ring are configured in an L-shape in cross-section.

13. The tensioning device as claimed in claim 1, characterized in that, The tensioning member (1) is a chain, belt or rope.

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