Roller clamp

Abstract

To provide a roller clamp that is capable of ensuring a better controlled and precise operation and thus a more efficient operation.SOLUTION: A roller clamp for regulating a flow of a fluid through an elastically deformable tube includes a generally channel-shaped body 2 whose bottom wall 4 has a clamping surface 6a, 6b with a longitudinal groove 7 with a cross-section decreasingly varying from an initial end towards a terminal end. The longitudinal groove 7 is arranged asymmetrically with respect to lateral walls 5a, 5b of the body 2.SELECTED DRAWING: Figure 7

Description

Technical Field

[0001] The present invention relates to a roller clamp particularly used in the medical industry, for example, a roller clamp for adjusting the flow of fluid flowing through an elastically deformable tube in an infusion device / infusion set.

[0002] More specifically, the present invention relates to a type of roller clamp having a substantially channel-shaped body with two side walls and a bottom wall. The bottom wall defines a clamping surface along at least a portion where a longitudinal groove is formed. The longitudinal groove has a start end and an end end, and has a cross section that gradually reduces and deforms from the start end towards the end end. A roller is rotatably supported on the side wall of the body. In order to gradually clamp an elastically deformable tube inserted into the body in use between the bottom wall and the roller, the roller is guided on the body so as to be substantially parallel to the clamping surface of the bottom wall and is movable in the longitudinal direction.

Background Art

[0003] A roller clamp of the type characterized as above is known, for example, from U.S. Patent No. 5,014,962 and U.S. Patent No. 6,129,330 by the applicant. In these documents, the longitudinal groove formed along the clamping surface of the body of the clamp has a substantially V-shaped or substantially isosceles triangular shape in its cross section, and the side walls branch while inclining from the bottom wall.

[0004] By using a roller clamp manufactured in this manner, the flow of fluid through an elastically deformable tube is regulated by gradually changing the longitudinal position of the roller along the clamp surface of the bottom wall of the main body. The flow is minimal or zero when the roller is positioned at the end of the longitudinal groove formed along the clamp surface of the bottom wall, and the flow is maximum when the roller is positioned at the beginning of the longitudinal groove. Clearly, this is due to the following: the clamp surface of the bottom wall of the main body is provided between the central longitudinal groove and the side wall of the main body, and the cross section of the tube is clamped and compressed between the roller and a portion of this clamp surface. This compressed cross section of the tube forms a narrow flow path or lumen for the fluid, the width of which depends on the depth of the central longitudinal groove. The smaller the cross section of the longitudinal groove, the smaller the cross section of the lumen, and vice versa. In other words, as the roller's position gradually moves toward the end of the longitudinal groove, the degree of clamping of the tube gradually narrows in response, and as a result, the elastic deformation of the tube gradually increases.

[0005] In the roller clamps known from the above-mentioned literature, the longitudinal grooves extend along the central region of the body, which is closer to the center with respect to the clamping surface. Therefore, when a flexible tube is clamped by the rollers in use, the space inside the tube is located in the center between the two sides of the flexible tube. The two sides stretch equally, although they cannot be compressed completely homogeneously. As a result, there is a slight but undesirable risk of flow occurring in some areas. For this reason, there are limitations to the accuracy of flow adjustment performed by roller clamps.

[0006] U.S. Patents 3,918,675 and 4,869,721 propose asymmetrically positioning longitudinal grooves relative to the side walls of the body to improve the precision of the clamping action. This allows for better control of the clamping of the tube inserted into the body when in use. In the solutions of both documents, the grooves have a U-shaped cross-section with side walls perpendicular to the bottom wall.

[0007] Even this solution does not demonstrate that it is more effective in terms of the precision with which flow is regulated through the tube. [Overview of the project]

[0008] The present invention aims to provide a roller clamp of the type specified above that can ensure better controlled and precise operation, thereby ensuring more efficient operation.

[0009] According to the present invention, this problem is primarily achieved by the features specified in claim 1, and secondarily by the features specified in subsequent claims.

[0010] Therefore, the clamping surface of the clamp body is asymmetrical. The clamping surface comprises a large section along one side of the longitudinal groove (the side farther from the corresponding sidewall of the body) and a smaller section along the other side of the longitudinal groove (the side closer to the corresponding sidewall of the body). In the operation of the clamp, the crushing of the tube by the roller occurs asymmetrically, unlike conventional roller clamps. The main part of the flexible tube (the side corresponding to the large clamping surface) is crushed more completely and safely, and stretched more. The internal space through which the medical fluid flows is formed in the remaining portion of the flexible tube where the stretching is less. Therefore, the adjustment accuracy is greatly improved. Such adjustment accuracy is achieved because the two transition sections connecting the longitudinal groove and the clamping surface have unique and distinct configurations. On one side (the side with the larger radius of curvature), deformation for sliding of the flexible tube wall occurs easily, while on the other side (the side with the smaller radius of curvature), complete occlusion by crushing the tube occurs easily.

[0011] Further features and advantages of the present invention will be made more apparent from the following description with reference to embodiments shown in the accompanying drawings, which are provided for illustrative purposes only and are not intended to limit. [Brief explanation of the drawing]

[0012] [Figure 1]A schematic perspective view showing a medical roller clamp, which is an embodiment of the present invention, as seen from the front. [Figure 2] A perspective view showing the main body of the roller clamp as seen from the rear. [Figure 3] Side elevation view of the roller clamp body. [Figure 4] Top view of the roller clamp body. [Figure 5] Bottom view of the roller clamp body. [Figure 6] Front elevation view of the roller clamp body. [Figure 7] Front view of the roller clamp body. [Figure 8] A cross-sectional view shown along the DD line in Figure 3. [Figure 9] A cross-sectional view along the CC line in Figure 3. [Figure 10] A cross-sectional view shown along line BB in Figure 3. [Figure 11] Figure 3 is an enlarged cross-sectional view along line AA, showing a roller or clamp and a flexible tube. [Modes for carrying out the invention]

[0013] Referring to the drawings, the part indicated by reference numeral 2 is the body of the roller clamp according to the present invention. As shown in its entirety in Figure 11, the roller clamp 1 is used particularly in the medical field and is configured to regulate the flow of injection fluid, transport fluid, etc., through an elastically deformable tube.

[0014] The clamp 1 has a roller 3 or a wheel adjacent to the main body 2. Both are easily manufactured by molding synthetic resin material.

[0015] The main body 2 has a substantially channel shape, comprising a bottom wall 4 and two side walls 5a and 5b. The lower tubular appendage 11, whose function is well known, protrudes from the bottom wall 4.

[0016] The inner surface of the bottom wall 4 faces the inside of the main body 2 and has a substantially flat surface. Hereinafter, this will be referred to as the clamping surface of the roller clamp 1. Similar to many such clamping surfaces, a longitudinal groove 7 is formed in the clamping surface. The longitudinal groove 7 forms a flow adjustment region along the main body 2 of the clamp 1 and also divides the clamping surface into two clamping surface portions 6a, 6b extending in the longitudinal direction. One of them is adjacent to the side wall 5a and the other is adjacent to the side wall 5b.

[0017] The longitudinal groove 7 formed along the clamping surface of the main body 2 of the clamp has a substantially V-shaped or substantially isosceles triangular shape in its cross section and includes side walls 7h, 7k that incline and branch from the bottom wall 7j.

[0018] The longitudinal groove 7 does not extend at the center and extends asymmetrically along the main body 2. More specifically, the longitudinal groove 7 is closer to the side wall 5b and is thus farther from the side wall 5a. As a result, the clamping surface portion 6a adjacent to the side wall 5a is wider than the clamping surface portion 6b adjacent to the side wall 5b.

[0019] The longitudinal groove 7 has a start end 7a and an end end 7b, and its cross section can be reduced and deformed from the start end 7a toward the end end 7b. As described above, the cross section of such a groove 7 has a substantially isosceles trapezoidal shape including a short base arranged on the bottom surface and defining the bottom wall 7j of the longitudinal groove 7 and a long base directed upward and opened.

[0020] The pair of edges extending in the longitudinal direction of the longitudinal groove 7 are connected to the clamping surface portions 6a, 6b via a pair of curved edges 7c, 7d respectively. More specifically, such curved edges 7c, 7d are convex and have different radii of curvature from each other. The radius of curvature of the curved surface 7c connecting the side wall 7h to the standard surface portion 6a is larger than the radius of curvature of the curved surface 7d connecting the side wall 7k to the standard surface portion 6b. For example, the radius of curvature of the curved surface 7c is about 0.3 mm, and the radius of curvature of the curved surface 7d is about 0.05 mm. Therefore, the curved surface 7d is generally sharp.

[0021] In the front part of the starting end 7a of the longitudinal groove 7, inclined surfaces 7e, 7f directed toward the center are formed, facilitating the insertion of the flexible tube T into the main body 2 of the clamp 1.

[0022] The two clamp faces 6a, 6b have ribs 8. The ribs 8 are narrow grooves and, as better shown in FIG. 4, extend longitudinally adjacent to the longitudinal groove 7 and are arranged asymmetrically and subdivided.

[0023] Along the flow control region, the side walls 5a, 5b each have an inner groove 9 extending substantially parallel to the clamp faces 6a, 6b at their upper parts. The two grooves 9 each form a longitudinal guide in which two shaft pins 10 (FIG. 11) protruding from the side surfaces of the roller 3 are rotatably and slidably engaged.

[0024] Thereby, the roller 3 is slidable and rotatable longitudinally along the guide 9, and the guide 9, together with the central longitudinal groove 7 and the clamp faces 6a, 6b, defines the flow control region described above.

[0025] When using an elastically deformable tube T typically manufactured from thermoplastic material, the tube T is inserted into the body 2 via the front end of the body 2 corresponding to the starting end 7a of the groove 7, and also inserted between the clamp surfaces 6a, 6b and the roller 3. The roller 3 should be positioned in the region ahead of the starting end 7a of the longitudinal groove 7, as shown in Figure 7, in which case the tube T will hardly deform and the flow of liquid inside the tube T will not be adjusted. In order to adjust the flow, the roller 3 must move at the starting end 7a, thereby gradually moving towards the end 7b through the regions shown in Figures 8 to 11. As a result, the tube T is gradually deformed until it becomes substantially flat between the roller 3 and the clamp surfaces 6a, 6b. For example, in the state shown in Figure 11, a narrow passage or internal space P having a width directly proportional to the cross-sectional area of ​​the longitudinal groove 7 remains open. In other words, when roller 3 is positioned at or near the starting end 7a of the central longitudinal groove 7, the size of the space P inside the tube, and consequently the flow rate of the liquid through tube T, becomes larger. As roller 3 approaches the end 7b, the size of the space P inside the tube gradually decreases. Roller 3 should be moved further beyond the end 7b of the longitudinal groove 7, at which point tube T is flattened completely, thereby stopping the flow of liquid.

[0026] The provision of ribs 8 along the clamp surfaces 6a and 6b prevents the tube T from moving laterally while elastic deformation occurs in the tube T due to the movement of the roller 3, thus ensuring more stable adjustment.

[0027] According to the features of the present invention, the asymmetrically arranged grooves 7 have the aforementioned substantially V-shaped cross-section and are connected to the standard surfaces 6a and 6b via curved surfaces 7c and 7d with different curvatures. As a result, the tube T is crushed by the roller 3 in an asymmetrical and differential manner with respect to the clamp surfaces 6a and 6b, as illustrated in Figure 11. The portion corresponding to the clamp surface 6a is the main portion which is stretched more significantly. The internal space P of the tube is located in the portion of the tube T that is stretched less in relation to the clamp surface 6b, while the main portion of the tube T is clamped safely and reliably and completely closed. As the tube T undergoes elastic deformation, the portion corresponding to the curved connection 7d with a smaller curvature is bent and clamped on the standard surface portion 6b, while the main portion of the tube T corresponding to the curved connection 7c with a larger curvature is easily crushed while sliding on the standard surface portion 6a. This ensures a significant improvement in the accuracy of flow control through the tube T.

[0028] It goes without saying that the details of the configuration and embodiments may be broadly modified from those described above and illustrated, without departing from the scope of protection of the present invention as defined in the claims.

Claims

1. A roller clamp (1) for regulating the flow of a fluid through an elastically deformable tube, comprising: a generally channel-shaped body (2) having two side walls (5a, 5b) and a bottom wall (4); a roller (3) rotatably supported on the side walls (5a, 5b) of the main body (2); the bottom wall (4) defines clamping surfaces (6a, 6b) at least along a portion where the longitudinal groove (7) is formed, the longitudinal groove (7) having a bottom wall (7j), side walls (7h, 7k), a starting end (7a) and a terminal end (7b) and having a cross section that can be reduced and deformed from the starting end (7a) to the terminal end (7b); the rollers (3) are guided in the body (2) so as to be substantially parallel to the clamping surfaces (6a, 6b) and are movable vertically in order to clamp an elastically deformable tube (T) inserted in the body (2) between the bottom wall (4) and the rollers (3) in a use state; A roller clamp (1), wherein the longitudinal grooves (7) are asymmetrically disposed with respect to the side walls (5a, 5b) of the body (2), The side walls (7h, 7k) of the longitudinal groove (7) are inclined and branched off from the bottom wall, The flute (7) is connected to the clamping surfaces (6a, 6b) via two curved surfaces (7c, 7d) having different radii of curvature, the radius of curvature of the curved surface (7d) of the longitudinal groove (7) located closer to the side wall (5b) of the main body (2) is smaller than the radius of curvature of the curved surface (7c) located farther from the other side wall (5a) of the main body (2); A roller clamp (1).

2. the clamping surfaces (6a, 6b) have a plurality of longitudinally extending ribs (8) adjacent the longitudinal grooves (7); A roller clamp (1) according to claim 1, characterised in that

3. The plurality of ribs (8) are asymmetric; A roller clamp (1) according to claim 2, characterised in that

4. The start end (7a) of the longitudinal groove (7) is formed to have inclined surfaces (7e, 7f) toward the center for inserting the elastically deformable tube into the main body (2). A roller clamp (1) according to any one of claims 1 to 3, characterised in that

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