Traction limiting device

Abstract

A tensile force limiting device (10) is provided, comprising a first receptacle (12) and a second receptacle (13), and a tensile force determination unit (29) for determining the value of a tensile force applied between the first receptacle (12) and the second receptacle (13). According to the invention, the tensile force limiting device (10) is configured to interrupt the tensile force at a predefined value.

Description

[0001] The present invention relates to a traction force limiting device according to the preamble of claim 1.

[0002] In the prior art, DE 3708748 C1 discloses a device for measuring a tensile force during cable laying using a tensile force sensor arranged between the cable and a steel pull rope, the latter comprising a force sensor, e.g. strain gauge, and a measuring circuit that amplifies the signals received from the force sensor and converts them into frequency-modulated, tensile force-proportional measurement signals, which are directed to a measurement receiver typically located in the area of ​​a winch, wherein a first line to the measurement receiver incorporates the pull rope and a second line the earth, wherein the output of the measuring circuit, which is connected to the line running through the earth, transmits the measurement signals via the earth to the measurement receiver with a capacitive coupling that is galvanically isolated from the earth.

[0003] The invention is based on the objective of avoiding excessive tensile forces during cable laying.

[0004] This problem is solved with a tensile force limiting device. Advantageous further developments of the invention are specified in the dependent claims.

[0005] The tensile force limiting device according to the invention comprises a first receptacle and a second receptacle and a tensile force determination unit for determining the value of a tensile force applied between the first receptacle and the second receptacle. According to the invention, the tensile force limiting device is designed to interrupt the tensile force at a predefined value.

[0006] This makes it advantageous, particularly when laying a cable, to prevent tensile forces exceeding a predetermined value. This protects the cable from damage.

[0007] In an advantageous embodiment of the tensile force limiting device according to the invention, the tensile force limiting device comprises a coupling device, a hollow tube which is force-transmittingly connected to the first receptacle, and a rod with a recess which is force-transmittingly connected to the second receptacle. The coupling device is designed to couple the hollow tube and the rod to each other in a second state and to release this coupling in a first state.

[0008] The coupling can be released if necessary, allowing for non-destructive decoupling and easy reuse of the tensile force limiting device.

[0009] In a further advantageous embodiment of the traction force limiting device according to the invention, the coupling device has a drive and a control unit, wherein the drive is configured to set the first state and the second state in the coupling device, and the control unit is connected to the traction force determination unit in a way that transmits information and is configured to control the drive.

[0010] This ensures a very precise and rapid decoupling compared to a purely mechanical system.

[0011] In a further advantageous embodiment of the tensile force limiting device according to the invention, the coupling device comprises balls which can be fixed projecting into the recess of the rod.

[0012] The shape of the spheres allows for easy insertion and removal of the rod, with the recessed area forming the sphere. Simultaneously, the rod can be rotated around its longitudinal axis within the hollow tube. This effectively prevents torsional stresses between the rod and the hollow tube.

[0013] In a further advantageous embodiment of the tensile force limiting device according to the invention, the tensile force determination unit is designed to record determined tensile force values.

[0014] This makes it possible to collect and document the determined tensile force values ​​over a specific period of time.

[0015] Further advantages of the present invention will become apparent from the detailed description and the illustrations. The invention is explained in more detail with reference to the illustrations and the following description. It shows: Fig. 1 a tensile force limiting device according to the invention in an exemplary embodiment.

[0016] In the Fig. Figure 1 schematically illustrates an exemplary embodiment of the tensile force limiting device 10 according to the invention. The tensile force limiting device 10 is designed to transmit a tensile force up to a predefined maximum value. For this purpose, the tensile force limiting device 10 has a first receptacle 12 and a second receptacle 13. The receptacles 12 and 13 serve, for example, to attach a pulling sleeve for pulling a cable. The tensile force limiting device 10 is designed such that the receptacles 12 and 13 can be coupled to each other to transmit force.

[0017] The tensile force limiting device 10 comprises, in particular, a housing 11. The tensile force limiting device 10 also preferably includes a hollow tube 14. The hollow tube 14 is preferably arranged in the housing 11. The first receptacle 12 is force-transmittingly connected to the hollow tube 14. The tensile force limiting device 10 also comprises a rod 19. The second receptacle 13 is force-transmittingly connected to the rod 19. The rod 19 is dimensioned such that it is slidably arranged in the hollow tube 14 on a longitudinal axis 27. The rod 19 has a recess 25 at the end opposite the second receptacle 13, preferably an annular recess 25.

[0018] According to the invention, the tensile force limiting device 10 has a coupling device 26. The coupling device 26 is designed to couple and decouple the rod 19 and the hollow tube 14. The coupling device 26 comprises, in particular, a ball holding device 20 with, in particular, five balls 23, a drive 21, and a control unit 22. Fig. Figure 1 shows the rod 19 and the hollow tube 14 in an uncoupled situation.

[0019] The ball holding device 20 is fixedly connected to the hollow tube 14. The ball holding device 20 houses the balls 23, in particular in a ball cage. The balls 23 are preferably arranged uniformly around the longitudinal axis 27. With five balls 23, this means they are spaced at intervals of 72°. The balls 23 have a dimension corresponding to the recess 25 of the rod 19. Thus, the radius of the recess 25 is slightly larger than the radius of the balls 23. The ball holding device 20 can have at least two states, a first state and a second state. In the first state, the balls 23 are movable, in particular, the balls 23 are movable in the radial direction from the longitudinal axis 27. In the second state, the balls 23 are immobile, in particular, the balls 23 are blocked in the radial direction from the longitudinal axis 27. In a coupled situation, the rod 19 with its depression 25 is located at the same position on the longitudinal axis 27 as the balls 23.Furthermore, the balls 23 with the recess 25 form a positive fit along the longitudinal axis 27. And the ball holding device 20 is in the second state.

[0020] The ball holding device 20 preferably comprises a ring having a recess or a projection for each ball 23. The ring is preferably rotatably arranged over the balls 23 about the longitudinal axis 27. When the ring is in a position where the recesses or projections are positioned over the balls 23, the balls 23 are movable in a radial direction from the longitudinal axis 27. In this state, the rod 19 can be pulled out of or pushed into the ball holding device 20. The ball holding device 20 is thus in the first state. Fixing the balls 23 in the second state of the ball holding device 20 is achieved by rotating the ring into a position where the recesses or projections are positioned between the balls 23. In the second state, the ring blocks the balls 23, particularly in a radial direction from the longitudinal axis 27.

[0021] To change the state of the ball holding device 20, the coupling device 26 includes the drive 21. The drive 21 preferably consists of an electric motor and a connection to the ball holding device 20. The ring or ball cage is preferably rotatable by the drive 21. The drive 21 is controlled by the control unit 22.

[0022] The tensile force limiting device 10 preferably comprises a tensile force determination unit 29 with a measuring element 15 and a measuring device 28 connected to the measuring element 15. In the Fig.Figure 15 is an example of a measuring element, a measuring tab which is connected to the first receptacle by means of a first bolt 16 and to the hollow tube 14 by means of a second bolt 17. The tensile force determination unit 29 is designed to determine the applied tensile force, thus ascertaining a value of the tensile force. The tensile force determination unit 29 is preferably designed to record the determined tensile force values. The measuring device 28 of the tensile force determination unit 29 is also designed to transmit the determined value to the control unit 22.

[0023] The coupling device 26 is designed to move the ball holding device 20 from the second state to the first state when a predefined, in particular adjustable, maximum value is reached. The tensile force applied to the rod 19 then pulls it out of the ball holding device 20. The tensile force is then interrupted.

[0024] The tensile force limiting device 10 preferably comprises two pushbuttons 24 with which the two states of the ball holding device 20 can be manually selected. Furthermore, the tensile force limiting device 10 preferably includes its own battery 18 for supplying the tensile force limiting device 10 with electrical energy. Reference symbol list: 10 Traction force limiting device 11 cases 12 First recording 13 Second recording 14 hollow tubes 15 measuring element 16 First bolt 17 Second bolt 18 Battery 19 Staff 20 Ball holding device 21 Drive 22 Control unit 23 balls 24 buttons 25 In-depth study 26 Coupling device 27 Longitudinal axis 28 measuring device 29 Traction force determination unit QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] DE 3708748 C1

[0002]

Claims

[1] Tensile force limiting device (10) with a first receptacle (12) and a second receptacle (13) and a tensile force determination unit (29) for determining a value of a tensile force applied between the first receptacle (12) and the second receptacle (13), characterized by , that the tensile force limiting device (10) is designed to interrupt the tensile force at a predefined value. [2] Traction force limiting device (10) according to claim 1, characterized by , that the tensile force limiting device (10) has a coupling device (26), a hollow tube (14) which is force-transmittingly connected to the first receptacle (12), and a rod (19) with a recess (25) which is force-transmittingly connected to the second receptacle (13), and the coupling device (26) is designed to couple the hollow tube (14) and the rod (19) together in a second state and to release this coupling in a first state. [3] Traction force limiting device (10) according to claim 2, characterized by , that the coupling device (26) has a drive (21) and a control unit (22), wherein the drive (21) is configured to set the first state and the second state in the coupling device (26), and the control unit (22) is connected to the traction force determination unit (29) in a way that transmits information and is configured to control the drive (21). [4] Traction force limiting device (10) according to claim 2 or 3, characterized by , that the coupling device (26) comprises balls (23) which can be fixed projecting into the recess (25) of the rod. [5] Traction force limiting device (10) according to one of the preceding claims, characterized by , that the traction force determination unit (29) is designed to record determined traction force values.

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