NL1039605A

NL1039605A - Device and method for tensionable releasable thread coupling with lateral insertion of the thread.

Info

Publication number: NL1039605A
Application number: NL1039605A
Authority: NL
Inventors: Willem Hienekamp
Original assignee: Hienekamp
Priority date: 2012-05-15
Filing date: 2012-05-15
Publication date: 2013-11-18
Also published as: NL1040215A; NL1040215B1; NL1039605C2

Description

Device and method for tensionable releasable thread coupling with lateral insertion of the thread. SHORT DESCRIPTION OF THE INVENTION

The present invention relates to a coupling device for receiving and retaining a portion of a flexible body like a thread to connect it to other entities in a way that the connection can be reliably loaded by tensile force and can be tensioned, released and reconnected.

A common way of connecting material like thread is knotting. Knots have the advantage that no additional objects are needed, but knowledge and skill is required to knot in a reliable way, it's often time-consuming and there are more problems. Detaching knotted connections can be difficult or even impossible, especially after a heavy load. There are only a few kinds of knots offering tensioning of the thread after connecting. For a lot of knots it is necessary that the end of the thread is free, it is needed to put or draw the end through a hole or around another part, which is sometimes inconvenient. The invention aims to solve problems which occur when connecting flexible materials like thread or when attaching it to objects, with the intention of a variety of flexible materials, like for example rope, wire, twine, cord, strap and textile to be used.

This invention concerns couplings that are tensionable. Tensioning can be done by sliding the thread through the coupling device against the direction of the tensile load. Movement of the part of the thread which is located in the coupling device is blocked in one longitudinal direction, and is free to move in the other.

To achieve this, the coupling device comprises clamping parts that use a clamping principle that converts the tensile force of the thread to a force that pinches the thread. The thread follows a passageway that is running in curves around elements of the coupling device, wherein the thread exerts forces on some movable elements of the coupling device. These elements are in this way drawn together by the thread. The passageway of the thread bends around and between these elements, in this way the thread is clamped. The resulting friction force blocks the movement of the thread. The passageway is such that at a reverse pulling force of the thread the pinching force will be small.

It is an object of the present invention to solve problems of this kind of coupling devices found in prior art. To achieve this the passageway of the thread runs through the coupling device in a new way, offering advantages: The thread can be inserted into the coupling device by drawing a part chosen somewhere on the length of the thread in a lateral direction into the coupling device, the thread can be tensioned and released easily and quickly. The coupling device can be made of various materials like for example metal or plastic.

DETAILED DESCRIPTION OF THE INVENTION

The partnumbers in the description reference to the annexed drawings.

The invention concerns couplings in which a thread can be inserted into the coupling device in a lateral way by catching it behind one ore more oblong elements (11,12). These elements are positioned in a substantially vertical direction. The next step of insertion is a lateral sliding movement of the thread downwards along the backside of these elements, by pulling the free ends (15,16) of the thread. Alternating movements in the longitudinal direction of the thread are advantageous during this action. After this step a part of the thread is situated inside the coupling device, in a loop (10) around vertical element (12) and between this element (12) and connecting elements (27, 28, 29).

The shape of the guiding surface of vertical element (12) is beneficial to fetch the thread and pull the thread in a backward direction between the vertical connecting elements (27, 28, 29) when the thread is drawn downwards.

The inserted part of the thread is is referred to as the coupled part. The adjacent longitudinal parts of the thread are now sticking out of the coupling device at the bottom side. One of these parts is the active part of the thread that is to be loaded with the drawing force. It is called the pulling part (15). The other part is called the loose part (16) of the thread. By pulling this loose part (16) the thread is forced to slide through the coupling device, shortening and tensioning the pulling part (15).

After insertion the thread follows a passageway that is running in curves around elements of the coupling device, wherein the bends in the thread exert forces on these elements. Mutually movable and substantially parallel elements (35, 36) are connected to one or two vertical elements (11,12) and are in this way drawn together by a tensioned part (19) of the thread and are functioning as clamping elements (35, 36), pinching the thread. If these clamping elements (35, 36) are drawn together, and the thread is located between these elements (35, 36), the thread is clamped. In this situation, by connection with the main clamping elements (35, 36) the vertical elements (11,12) and the connecting elements (27, 28, 29) can exert additional pinching force. If the sum of the friction force generated by the pinching force of the clamping elements (35, 36) and the frictional force generated by the other elements along which the thread runs together are greater than the tension in the thread at the point of entry, the thread will be clamped and the motion will be blocked. This will continue at increasing force. The frictional force increases together with an increasing tensile force as long as the coupling device can maintain its shape.

To facilitate a start of this clamping process a small clamping force should exist when the coupling device is unloaded. This is achieved by the force of elastic deformation of the connecting elements (27, 28, 29) or other elastic elements that keep the clamping elements (35, 36) pressed against the thread and by an amount of force exerted on the thread as result of friction when the thread slides along statical elements of the coupling device. The connecting elements (27, 28, 29) connect clamping elements (35, 36) to an attachement part (14) that is situated at the top of the coupling device and that facilitates attaching the coupling device to other entities and exercise of force. Some of the connecting elements (27, 29, 28) are flexible to connect the clamping elements (35, 36) in a pivotable way.

When the loose part (16) is pulled instead of the pulling part (15) the pinching force of the clamping elements (35, 36) is small because the lateral forces exerted by the thread on the elements of the coupling device have been changed. The force in the tensioned part (19) is reduced. This allows sliding of the thread in the reverse of the blocking direction. When both parts (15) and (16) are pulled a balance of forces arises between the friction forces generated by the pinching force of the clamping elements (35, 36) and other frictions and the logitudinal pulling forces. This forms a state of transition between blocking or sliding movement of the thread. An advantage of the invention is that only a small movement of the thread occurs during this transition. When using knots the transition is a difficult part of making the connection. The knot can slip back, with the effect of loss of tension.

Decreasing the pulling force of pulling part (15) that is exerted on the coupling device by pulling the part (15) by external force when tensioning by pulling the loose part (16) of the thread decreases the needed pulling force by shifting the balance. Some coupling devices found in prior art will only function in this way. Using the invention with no external force on pulling part (15) when tensioning at full load of the thread is possible. The device is than working like a one way pulley, more than twice the pulling force on the loose part (16) of the thread will be exerted by the thread on the coupling device in the passageway. To facilitate this at high loads a strong coupling device with a smooth passageway is to be applied.

Other clamping systems known from prior art are in a similar way using a curve formed by the thread around two parallel elements that are relative movable, wherein the thread also follows a path between the elements and wherein the tensile force of the thread exerts forces on these elements that pull the elements towards each other, and using this force as a pinching force to clamp the thread. This principle is common and found as prior art in various ways, for instance at pat. GB2085060. The invention uses a similar principle, in combination with other principles and art

The coupling device according to the invention differs from the prior art in which the thread is being rigidly coupled, in which only tensioning can be achieved by fully or partially decoupling the connection. After tensioning recoupling is needed. Examples are JPH0728998 and US20050061905A1. The coupling device according to the invention can be tensioned without removing the thread from the coupling device. Quick locking and in this way fixing of the tensioned state in one action after the tensioning is an important object of the invention.

This coupling device also differs from the prior art in which the end of the thread is to be punched through an opening, eyelet or ring before being able to reach a state of connection. Technically such a coupling device is simpler because a ring is strong, and because it encloses the thread. The disadvantage is that by stabbing various problems arise when one uses the coupling: The end of the thread must be a free end, easily accessible and it should not thickened or split. Thereby it can be necessary to draw a long length of the thread through the coupling device.

An example of a coupling device in the prior art in which the end of the thread has to be punched, is the coupling device according to Pat. US5402555A. The thread has to be inserted two times; through two abutting parallel rings, then between the mounting arms of the rings. A comparable coupling device is formed by the well-known operating principle of two superposed rings in which a thread is first stabbed through the two rings, followed by bringing back the end from the outside in between the rings and than back to the side where the thread is entering the rings.

The invention described herein provides a solution to the problems of the punching of the thread through a hole or ring. It is avoided by application of a method of coupling in which the thread can be inserted sideways, with a lateral movement, into the coupling device. This distinguishes the invention from known couplings such as US20050061905A1 and US5402555A.

The described clamping of the thread by converting tensile force into the clamping force can be reached by various techniques. A widely applied method uses just a loop around a static element that clamps itself like US2006000063A1 and CA1093285. This is known of plastic buckles for straps for bags, clothing and the like. Because of the difficult way of detaching the clamping system, these are often combinated with a quicklock coupling.

In the above-mentioned prior art known from Pat. JPH0728998 a similar technique is used.

The clamping elements are open hooks so that stabbing is not required. But this art differs strongly from the invention. A problem which may occur with the technique is that the hooks may slide next to each other so that the clamping will not be secured. Multi-turning of the thread around the hook is applied to prevent this. The most important difference is that the clamping of the thread takes place afterwards, having the effect of making tensioning of the clamped thread impossible. Pulling the loose end of the coupling will only tighten the clamp with extra force. It is therefore a quick fixing connection, not a tensionable coupling device, like mentioned before.

A half solution to the problems of the punching of the thread through a hole, found in prior art, is to fold the thread double and use the double thread which is obtained as if it has one end. It still has to be punched but it is advantageous that one is able to couple a part somewhere in the middle of the thread. At clamping in a coupling device this method can cause problems of reduction of the clamping action in that the double thread can twist, it is twice as thick and in that the clamping force has to be distributed over a parallel clamped pair of an unloaded and loaded thread which can give disruption of the clamping action.

An example found in the prior art using this way of connecting and which could be compared with the invention is Pat. US2005217079A1. It differs from the invention in that it needs stabbing through a hole. In this case of a loop as mentioned above. After insertion this loop is to be bent in a separate operation back to the front, the loop is to be opened and pushed over an extension. As a second difference compared with the invention is that the active tensioned part of the thread is found running between the clamping elements together with the part of the thread that is to be clamped. This causes the clamping force of the clamping elements exerted on the thread to be disturbed by the tension in the active part, because this tensioned part will be a stiff straight thread that pushes the clamping elements apart. The present invention offers a different way of bending of the thread through the coupling device, in which the active pulling part (15) and the clamped part are separated.

The position of the spot (18) between the clamping elements (35, 36) where the clamping of the thread occurs is important. The force that is generated by the bends of the tensioned part (19) of the thread is directed along an imaginary thread force line of pinching force that connects the effective centers of the pressure exerted by the thread on the clamping elements (35, 36) and the attached vertical elements (11,12). In a similar manner there is a short imaginary clamping line which connects the effective centers of the force exerted by the pinching clamping elements (35, 36) ,and possibly to some extent by the connected vertical elements (11,12) and connecting elements (27, 28, 29) on the outer side of the clamped thread at the place of the clamping. In various optimized embodiments, for example by choices of the manufacturing methods, and the applied materials such as plastic or metal, the placement relative to each other of the thread force line and the clamping force line differences.

Especially with the use of weak or resilient materials such as plastics, it is important that the thread force line is located very close to the clamping line. In this way, the occurrence of bending and torsion stresses which are high at large loads and can cause distortion, is greatly reduced. A rigid guiding of the movement of the clamping elements (35, 36) by strong pivots and connecting elements (27, 29, 28) increases the loadability. Use of hard pivots or sliding guides instead of elastic pivoting can be beneficial.

Additional guiding elements (23,24, 25) for guiding of the passageway of the thread to an optimal position between the pinching elements, for example in a horizontal direction between the clamping elements (35, 36), may be present. In embodiments that have been manufactured from rigid and strong material, location of the thread force line and the clamping force line at some distance from each other is possible, offering somewhat simpler shapes.

FIGURES WITH EXPLANATION

The same reference numerals refer to the same parts throughout the various figures.

FIGURE 1 is showing a sideview of the the preferred embodiment (1) of the coupling device from the left side. A thread is inserted. Without an inserted thread only a narrow gap would have been existing between the clamping elements (35) and (36), where a clamping spot (18) can be seen, at the start of the loose part (16) of the thread.

Visible is the pulling part (15) of the thread and the starting point of the first bend of the thread around the frontal top edge of the clamping element (35). Here a force component in the backward direction pushes the clamping element (35) in the direction of the clamping element (36) when a pulling force is exerted on the pulling part (15).

At the front are horizontal clamping element (35), vertical element (11) and connection element (28) attached to each other and forming a group of elements. At the back side of the coupling device horizontal clamping element (36), vertical element (12) and connection element (29) are attached to each other and forming a group of elements in the same way.

Parts of these groups are pinching the thread on the clamping spot (18). The needed pulling force is powered by pulling segment (19) of the thread, where it crosses a virtual face between the elements (35) and (36) at the place of the visible aperture. The clamping element (36) is pushed to the front by vertical element (12) that is connected to it. This element (12) is receiving a force to the front by segment (19) and loop (10) of the thread around it.

The pinching faces of the elements (35) and (36) on the clamping spot (18) are to a great extent vertical situated in this embodiment (1). In other embodiments these may have a position rotated in a counterclockwise direction of maximal 60 degrees, around the present line of view, relative to the vertical direction. At the front are visible the connection element (28) that connects element (35) and connection element (29) that connects element (36) to the attachment part (14).

FIGURE 2 is showing a frontal view of embodiment (1) of the coupling device. It shows the connection element (27) that is connecting element (36) to the attachment part (14).

Vertical element (11) is connected at the end of element (35). It can be seen that the pulling part (15) is situated to a great extent in front of the loose part (16), under pulling segment (19), and is in that way able to exert a direct pushing force on the clamped part of the thread, in a direction in a horizontal plane perpendicular to the direction of the pincing faces of the elements (35) and (36). The mentioned thread force line and clamping force line are situated near to each other.

FIGURE 3 is showing a top view of embodiment (1) of the coupling device.

Vertical element (12) is connected at the bottom to element (36). After loop (10) of the thread around element (12) the passageway of the thread is guided along a guiding element (22) towards the position under pulling segment (19). There the passageway of the thread runs between the pinching faces of the clamping elements (35) and (36), after which the thread exits the coupling device as loose part (16).

FIGURE 4 is showing a sideview of embodiment (1) of the coupling device from the right side.

From this side the opening can be seen through which the thread is inserted between the clamping elements (35) and (36) after the catching of the thread behind elements (11,12) and the sliding movement of the thread downwards along the backside of element (12). When it is inserted it ends after clamping spot (18) as loose part (16) of the thread.

FIGURE 5 is showing a topview from the backside of an embodiment (2) of the coupling device. This embodiment (2) comprises a guiding element (23) attached to an end of clamping element (36) .

After the loop (10) around vertical element (12) the thread runs below pulling segment (19) of the thread along the guiding element (23). This offers a very small distance between the mentioned thread force line and clamping force line. In the case of this embodiment (2) the clamping element (36) is only connected to attachment part (14) by connection element (29), leaving the other end free. The vertical elements (12) and (11) (not visible) can be connected at the top like shown at figure 8, to get a stronger connection between the elements (35) and (36).

FIGURE 6 shows a topview from the backside of an embodiment (3) of the coupling device. This embodiment (3) comprises a guiding element (24) attached to an end of clamping element (35).

In the case of this embodiment (3) the other clamping element (36) is only connected to attachment part (14) by connection element (29), leaving the other end free.

The vertical elements (12) and (11) (not visible) can be connected at the top like shown at figure 8, to get a stronger connection between the clamping elements (35) and (36).

FIGURE 7 is showing a view from the left side of an embodiment (4) of the coupling device. Embodiment (4) comprises a guiding element (25) attached to an end of clamping element (36). In this embodiment (4) the guiding element (25) is attached at the front side of element (36). After the loop (10) around vertical element (12) the thread runs in a straight line just below pulling segment (19) to the guiding element (25).The clamping element (36) is connected to attachment part (14) at both ends by connection elements (28) and (29) for a stronger coupling device.

FIGURE 8 is showing a frontview of embodiment (4) of the coupling device. The vertical elements (11) and (12) are connected at the top to each other by a bridge (17). This is beneficial for the strength and clamping performance of the coupling device (4) and it prevents errors when inserting the thread. The embodiments (1), (2) and (3) can be provided of a similar bridge.

Connecting element (27), bridge (17) and vertical elements (11,12) are offering by their flexibility a guided movability to the clamping elements (35, 36).

FIGURE 9 is showing a frontview of an embodiment (5) of the coupling device. This coupling device is made of bended wire materiaal. The attachment part (14) consists of the two meeting ends of the wire, bended as two parallel hooks. The functional elements shown here can also be found in a different form in the other embodiments.

FIGURE 10 is showing a frontview of embodiment (5) of the coupling device, with an inserted thread. In the same way as can be seen in figures 1 to 4, the pulling part (15) of the thread pulls the clamping elements (35) and (36) and the attached vertical elements (11,12) together, between these elements the thread is pinched at clamping spot (18).

The coupling device can be rigid caused by the applied connection (17) between the vertical elements (11) and (12) and the material and size of the wire. This allows a distance between the clamping spot (18) and the pulling segment (19) of the thread.

FIGURE 11 shows a view from the right side of embodiment (5) of the coupling device.

FIGURES 12 and 13 are showing a frontview and a sideview of an embodiment (6) of the coupling device. This embodiment comprises two devices, with a clamping part identical to embodiment (5) connected to each other. The ends of the wire are welded together at the connection elements (27). This embodiment is aimed at connecting thread to thread.

FIGURE 14 shows a view from the right side of an embodiment (7) of the coupling device. This embodiment comprises also two connected identical coupling devices. It differs from the embodiment (6) by being made of one piece of wire without welding. It shows an example. The ends of the wire are bended together with other elements to position them a safely.

An extra small bend (20) is made in element (12) to obtain a narrow passage together with connection element (28) to keep pulling part (16) of the thread on its place when it is untensioned.

Claims

An engaging device (1-7) comprising an attachment member (14) located on the upper side of the engaging device (1-7), connecting members (27, 28, 29) and elements for engaging a longitudinal member, referred to as the coupled part, of an elongated flexible body, such as, for example, a wire, to block movement thereof in the longitudinal direction when a tensile force is exerted in a longitudinal direction of an end of the wire, referred to as the pulling end (15), and movement in the direction from the other end of the coupled part, referred to as the loose end (16), to allow when a tensile force is exerted in that direction, whereby a passage can be distinguished in the engaging device (1-7) intended for the inserted longitudinal part of the wire, which begins at an entry site located on a vertical side of the engaging device (1-7), referred to as the front face of the engaging pin hting (1-7), where the passage path of the wire starts with a bend, starting from a vertical direction from below, around an element (35) and then continuing in turns around other elements that are movable with respect to the first element (35), after which the passage path runs between the movable elements, through which the wire can be pinched by narrowing the passage path, and thereafter ends upon leaving the engaging device (1-7), characterized in that, the engaging device (1) -7) comprises two movable element groups which are movable relative to each other and which are attached to the attachment part (14), being a front element group consisting of a horizontal element (35) and a connecting part (28) connected thereto for connection to the attachment part (14) and a rear element group consisting of a horizontal element (36), a vertical element (12) connected to the horizontal element (36) and viewed from the point of connection substantially protrude in the vertical direction, and one or more vertical connecting parts (27, 29) for connection to the attachment part (14), wherein it holds that the front element group and the rear element group are movably mounted relative to each other by connecting parts (27, 28) 29) that the horizontal elements (35, 36) are substantially parallel to each other and to the front of the engaging device (1-7) and that they are at approximately the same height, the vertical element (12 ) of the rear element group is arranged to provide the wire guide when it is inserted in the engagement device (1-7) by guiding it laterally downwards in a vertical direction downwards along this vertical element (12), until it approaches the passage path reaches the horizontal element (36) of the rear element group, and wherein the passage path can be indicated as starting at the said input location of the pulling part (1) 5) with a bend of 70 to 110 degrees around the horizontal element (35) of the front element group, after which the passage path crosses an imaginary transition plane between the two movable element groups in a direction that is substantially perpendicular to the front surface, after which the passage path forms a loop (10) of at least 170 degrees around the vertical element (12) near the place where the vertical element (12) is connected to the horizontal element (36) of the rear element group, after which the passage path between the front element group and the rear element group runs and then ends on the outside of the engaging device (1-7) at the transition to the loose end (16).

An engaging device (1-7) according to claim 1, characterized in that a vertical element (11) attached to the horizontal element (35) is part of the front element group, said vertical element (11) being located near the vertical element (12) of the posterior element group and it is substantially parallel to it.

An engaging device (2-7) according to claim 2, characterized in that the high end of the vertical element (11) of the front element group is connected to the high end of the vertical element (12) of the rear element group.

An engaging device (2, 3, 5-7) as claimed in claim 1, 2 or 3, characterized in that no more than one of two horizontally opposite ends of the horizontal element (36) of the rear element group, being the end that is furthest away from the entrance location of the towing member (15) is attached to the attachment member (14).

An engaging device (1-4) as claimed in any of the claims 1-4, characterized in that guide parts (22, 23, 24, 25) are attached to the horizontal elements (35, 36) or the connecting parts (27, 28, 29), wherein these guide parts (22, 23, 24, 25) guide the passageway after passing through the bend (10) and before the passageway ends on the outside of the gripping device (1-4) at the transition to the loose end (16).

An engaging device (2, 3, 4) as claimed in claim 5, characterized in that guide parts (23, 24, 25) guide the passage path, which runs between elements belonging to said two movable element groups and along the bottom where the passage path is located another location of its length intersects the imaginary transition surface between the two movable element groups.

An engaging device (2, 3, 4) according to claim 6, characterized in that the guide through the guide parts (23, 24, 25) relates to a passage path which takes place to a large extent in a horizontal direction in the section between passing through the bend (10) and the outer end of the engaging device (1-4) at the transition to the loose end (16).

An engaging device (3) according to claim 5, 6 or 7, characterized in that it comprises a single guide part (24), wherein it is attached to an element that is part of the front element group.

An engaging device (2,4) as claimed in claim 5, 6 or 7, characterized in that it comprises a single guide part (23) or (25), wherein it is attached to an element which is part of the rear element group.

An engaging device (1-4) according to any of claims 1-9, characterized in that the engaging device (1-4) is made of plastic.

An engaging device (5,7) as claimed in any one of claims 1-10, characterized in that at least one element of the engaging device (5,7) consists of a plurality of elongated parts.

An engaging device (6, 7) according to any of claims 1 to 11, characterized in that the attachment part (14) of the engaging device (6, 7) consists of an engaging device.

A method for introducing an elongated flexible body into an engaging device (1-7) according to any one of claims 1-12, along a part of the length of the wire in a vertical direction downwards in a vertical direction downwards move the vertical element (12) and bring it into said passage path.

A method of sliding a longitudinal portion of an elongated flexible body disposed in the passageway of an engaging device (1-7) according to any of claims 1-12, through the passageway.