A cable force measuring device

Abstract

A cable force measuring device (1) comprising a base (2), a cable guiding mechanism (3) for a cable (4), and a sensor (5) for measuring force or pressure, wherein the cable guiding mechanism (3) comprises three rollers (6, 7, 8) for guiding the cable (4) through the device (1), wherein the base (2) supports two rollers (6, 8) that are provided on opposite sides of a middle roller (7), which middle roller (7) is supported by an arm (9) that is connected with a hinge (10) to the base (2) so as to arrange that the middle roller (7) is movable back-and-forth and / or up-and-down between the two rollers (6, 8) that are on opposite sides of the middle roller (7), and that distant from said hinge (10) rotatably connecting the arm (9) with the base (2) and at a side of the hinge (10) that is opposite to the cable guiding mechanism (3), the arm (9) supporting the middle roller (7) is provided with a first pressing element (11), and the base (2) supporting the rollers (6, 8) that are on opposite sides of the middle roller (7) is provided with a second pressing element (12), wherein the first pressing element (11) and the second pressing element (12) are opposite to each other and that between said first pressing element (11) and said second pressing element (12) the sensor (5) is provided.

Description

[0001] A cable force measuring device

[0002] The invention relates to a cable force measuring device comprising a base, a cable guiding mechanism for the cable, and a sensor for measuring force or pressure, wherein the cable guiding mechanism comprises three rollers for guiding the cable through the device.

[0003] CN 216746530 U discloses such a cable force measuring device, wherein in the center of the measuring device the sensor is provided on the middle roller. The complete cable guiding mechanism is movable with reference to the base, which makes that the cable force measuring device according to this prior art document responds fairly slowly to variations in the forces to which the cable is subjected. This known cable force measuring device is also sensitive to wear and tear and may be inaccurate when the forces acting on the cable guiding mechanism are unevenly distributed.

[0004] It is an object of the invention to provide a cable force measuring device alleviating at least some of the problems that are associated with the prior art cable force measuring device .

[0005] According to the invention a cable force measuring device is proposed having the features of one or more of the appended claims.

[0006] In a first aspect of the invention the base directly supports two rollers that are provided on opposite sides of a middle roller, which middle roller is indirectly supported by the base and directly supported by an arm that is connected with a hinge to the base so as to arrange that the middle roller is movable back-and-forth and / or up-and-down between the two rollers that are on opposite sides of the middle roller, and that distant from said hinge rotatably connecting the arm with the base and at a side of the hinge that is opposite to the cable guiding mechanism, the arm directly supporting the middle roller is provided with a first pressing element, and the base directly supporting the rollers that are on opposite sides of the middle roller is provided with a second pressing element, wherein the first pressing element and the second pressing element are opposite to each other and that between said first pressing element and said second pressing element the sensor is provided. The said back-and-forth and / or up-and-down between the two rollers that are on opposite sides of the middle roller means that this may include the possibility that the middle roller can rotate around the hinge connecting the arm with the base .

[0007] According to the invention the part of the cable force measuring device that has to execute a motion is only the arm that directly supports the middle roller, which can be restricted in weight. Accordingly the response time of the cable force measuring device of the invention can be relatively limited, also because by a proper choice of dimensions of the arm on opposite sides of the hinge connecting the arm to the base, the required amount of motion of the middle roller can be restricted. Also the cable force measuring device of the invention does not suffer from sensitivity in terms of an uneven distribution of loads applied to the device. Accordingly the accuracy and reliability of the cable force measuring device of the invention is at a higher standard than with the prior art solution, also because wear and tear does not have a notable influence on the operation of the device according to the invention .

[0008] It is preferred that the first pressing element that is provided on the arm supporting the middle roller is rotatably placed on the arm to enable that independent from the back-and- forth and / or up-and-down movement of the middle roller, the first pressing element and the second pressing element are enabled to maintain a level orientation with respect to each other. This also contributes to the accuracy and reliability of the device according to the invention. There are notable advantages in using the cable force measuring device of the invention, particularly by applying the device in a robotic application. The cable may then be used to actuate a part of the robot, particularly a hinge of the robot.

[0009] Suitably the robotic application is one selected from the group comprising a robot hand, a robot gripper, an exoskeleton finger.

[0010] The accompanying drawing, which is incorporated into and forms a part of the specification, illustrates one or more embodiments of the present invention and, together with the description, serves to explain the principles of the invention. The drawing is only for the purpose of illustrating one or more embodiments of the invention and is not to be construed as limiting the invention.

[0011] In the drawing:

[0012] -figure 1 depicts the cable force measuring device of the invention with part of the construction being omitted for clarity;

[0013] -figure 2 provides the cable force measuring device of figure 1 without omitted parts;

[0014] -figure 3 shows a finger forming part of the robot hand of figure 4, as provided with the cable force measuring device of figure 1;

[0015] -figure 4 shows the robot hand;

[0016] -figure 5 shows the cable force measuring device of figure 1 as used in combination with a robot gripper; and

[0017] -figure 6 shows the cable force measuring device of figure 1 is used in combination with an exoskeleton finger.

[0018] Whenever in the figures the same reference numerals are applied, these numerals refer to the same parts.

[0019] With reference to figure 1 and figure 2 a cable force measuring device 1 is shown comprising a base 2, a cable guiding mechanism 3 for the cable 4, and a sensor 5 for measuring force or pressure, wherein the cable guiding mechanism 3 comprises three rollers 6, 7, 8 for guiding the cable 4 through the device

[0020] 1.

[0021] The base 2 directly supports two rollers 6, 8 that are provided on opposite sides of a middle roller 7, which middle roller 7 is indirectly supported by the base 2 and directly supported by at least one arm 9. Preferably there are two arms 9 on opposite sides of the middle roller 7 as shown in figure 2. The arm or arms 9 are connected with a hinge 10 to the base 2 so as to arrange that the middle roller 7 is movable back- and-forth and / or up-and-down between the two rollers 6, 8 that are on opposite sides of the middle roller 7. The said back- and-forth and / or up-and-down of the middle roller 7 between the two rollers 6, 8 that are on opposite sides of the middle roller 7 means that this may include the possibility that the middle roller 7 can rotate around the hinge 10 connecting the arm or arms 9 with the base 2.

[0022] Distant from the hinge 10 which rotatably connects the arm or arms 9 with the base 2 and at a side of the hinge 10 that is opposite to the cable guiding mechanism 3, the arm or arms 9 that are supporting the middle roller 7 are provided with a first pressing element 11. The first pressing element 11 is through a hinge or hinges 17 rotatably connected to the arm or arms 9.

[0023] The base 2 directly supporting the rollers 6, 8 that are on opposite sides of the middle roller 7 is provided with a second pressing element 12, wherein the first pressing element 11 and the second pressing element 12 are in-line opposite to each other. Further between said first pressing element 11 and said second pressing element 12 the sensor 5 is provided.

[0024] By the feature that the first pressing element 11 is rotatably mounted on the arm or arms 9 it is possible that the first pressing element 11 and the second pressing element 12 maintain a level orientation with respect to each other, independent from the back-and-forth and / or up-and-down movement of the middle roller 7 which is caused by the force of the cable 4 acting on it, and which force is to be measured with the device 1 of the invention.

[0025] The device 1 of the invention is suitably comprised in a robotic application, such as one selected from the group comprising a finger 13 (see fig. 3) of a robot hand 14 as shown in fig. 4, a robot gripper 15 as shown in fig. 5, or an exoskeleton finger 16 as shown in fig. 6. The roller 8 of the device 1 of the invention then operates as a pulley guiding the cable 4 that connects to a motor drive 17 of the robot hand 14, robot gripper 15, or exoskeleton finger 16.

[0026] Although the invention has been discussed in the foregoing with reference to an exemplary embodiment of the invention, the invention is not restricted to this particular embodiment which can be varied in many ways without departing from the invention. The discussed exemplary embodiment shall therefore not be used to construe the appended claims strictly in accordance therewith. On the contrary the embodiment is merely intended to explain the wording of the appended claims without intent to limit the claim to this exemplary embodiment. The scope of protection of the invention shall therefore be construed in accordance with the appended claims only, wherein a possible ambiguity in the wording of the claims shall be resolved using this exemplary embodiment.

[0027] Variations and modifications of the present invention will be obvious to those skilled in the art and it is intended to cover in the appended claims all such modifications and equivalents. The entire disclosures of all references, applications, patents, and publications cited above are hereby incorporated by reference. Unless specifically stated as being "essential" above, none of the various components or the interrelationship thereof are essential to the operation of the invention. Rather, desirable results can be achieved by substituting various components and / or reconfiguration of their relationships with one another.

Claims

CLAIMS1. A cable force measuring device (1) comprising a base (2) , a cable guiding mechanism (3) for a cable (4) , and a sensor (5) for measuring force or pressure, wherein the cable guiding mechanism (3) comprises three rollers (6, 7, 8) for guiding the cable (4) through the device (1) , characterized in that the base (2) directly supports two rollers (6, 8) that are provided on opposite sides of a middle roller (7) , which middle roller (7) is indirectly supported by the base (2) and directly supported by at least one arm (9) that is connected with a hinge (10) to the base (2) so as to arrange that the middle roller (7) is movable back-and-forth and / or up-and-down between the two rollers (6, 8) that are on opposite sides of the middle roller (7) , and that distant from said hinge (10) rotatably connecting the at least one arm (9) with the base(2) and at a side of the hinge (10) that is opposite to the cable guiding mechanism (3) , the at least one arm (9) directly supporting the middle roller (7) is provided with a first pressing element (11) , and the base (2) directly supporting the rollers (6, 8) that are on opposite sides of the middle roller (7) is provided with a second pressing element (12) , wherein the first pressing element (11) and the second pressing element (12) are opposite to each other and that between said first pressing element (11) and said second pressing element (12) the sensor (5) is provided.

2. The cable force measuring device according to claim 1, characterized in that the first pressing element (11) that is provided on the at least one arm (9) supporting the middle roller (7) is with a hinge (17) rotatably placed on the arm (9) to enable that independent from the back-and-forth and / or up-and-down movement of the middle roller (7) , the first pressing element (11) and the second pressing element(12) are enabled to maintain a level orientation with respect to each other.

3. The cable force measuring device according to claim 1 or 2, characterized in that the device (1) is comprised in a robotic application (13, 14, 15, 16) .

4. The cable force measuring device according to claim 3, characterized in that the robotic application is one selected from the group comprising a robot finger (13) , a robot hand (14) , a robot gripper (15) , an exoskeleton finger

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