EP0935688A1

EP0935688A1 - Clamping device and production process

Info

Publication number: EP0935688A1
Application number: EP97950038A
Authority: EP
Inventors: Christoph Heiland
Original assignee: Individual
Current assignee: Individual
Priority date: 1996-10-29
Filing date: 1997-10-29
Publication date: 1999-08-18
Anticipated expiration: 2017-10-29
Also published as: DE19644822A1; WO1998018991A1; EP0935688B1; DE59703972D1; ATE202808T1

Abstract

The present invention relates to a clamping device (3) comprising two or more grip jaws (4), both extending to a pincer portion (6) and being linked to each other in the transition area (5) by a crosspiece (7). For a low cost manufacturing, the invention suggests that the clamping device (3) or its external half-profile (3') be made of one single plastic piece with a plurality a hollow profiles (P). The preferred extrusion process enables a plastic monofilament with such hollow profiles (P) to be obtained and the pincers to be severed to the desired width. Thus, clips and clamps of varying widths can be manufactured at a low cost using a simple forming tool.

Description

description

Clamping device and method for its manufacture

The invention relates to a clamping device with two clamping jaws, each of which merges into a grip section and is connected to one another in the transition region by a crossbar. This clamping device can be a clamp in which, in the non-actuated state, the clamping jaws are preferably in contact with one another under a pretension, while the handle sections are spread apart, or a clamp in which the clamping jaws are opened or not in the actuated state are spaced. The invention further relates to a method for producing such clamping devices.

The present invention has for its object to provide clamping devices of the type under consideration, which can be produced at low cost.

This object is achieved by the features of claims 1 and 10. Advantageous embodiments of the invention are characterized in the dependent claims.

According to the present invention, the clamping device or its half profiles is made in one piece from plastic, for example PVC, POM, PC or PP, the handle sections being designed as hollow chamber profiles. As a result, the material consumption is considerably reduced, and despite the thin wall thicknesses, a high degree of rigidity of the handle sections and / or clamping jaws can be achieved. Accordingly, it is also proposed that the clamping jaws are also designed as hollow chambers.

If the clamping jaws of the clamping device abut one another in their unactuated state and the handle sections are spaced apart from one another, preferably spread apart at an angle, the clamping device is a clip, the clamping jaws of which are opened against spring force by the fact that the handle sections

CONFIRMATION COPY towards each other. Here are the

Connection areas of the clamping jaws on both sides with their adjoining grip sections, which are preferably symmetrical to the longitudinal axis of the clamping device, are connected to one another with a crosspiece shaped and dimensioned in such a way that the elasticity of the opened clamping jaws brings them back into the closed state when the grip sections are released .

However, it can also be provided that the handle sections are forced apart by a spring device, for which purpose, for example, a metal clip or a plastic clip can be arranged between the handle sections in the tensioned state. Advantageously, however, it can also be provided that the spring device is formed by extensions which are formed on the ends of the handle sections and bent inwards, which extend at an angle to one another and preferably rest against one another with their free ends. However, they can also be connected to one another at the ends.

The inwardly bent extensions preferably enclose an angle of 60 to 90 ° between them and are pressed against each other when the jaws are opened so that they finally abut against one another along their straight ends, with this elastic deformation resulting in a considerable restoring force which the jaws strongly press against each other when the handle sections are released.

The jaws of the clamping device according to the invention can, however, also be opened in their non-actuated state, preferably spread apart, so that they form approximately an X-shape together with the likewise spread apart grip sections, in which the leg length of the clamping jaws is, however, preferably smaller than that of the grip sections. In this embodiment, the clamping device forms a clamp, the clamping jaws of which are pressed apart by the handle sections are pressed against each other, for example, to seal a hose or bag in this state.

It is further provided that the handle sections are connected to a spreading device which not only presses the handle sections apart to close the jaws, but preferably can maintain the closed state of the jaws. It is particularly advantageous that the spreader device has two webs connected to the ends of the handle pieces via weakened sections or film hinges, which are connected to one another by at least one further weakened section or film hinge, the two webs having an overall length in an aligned arrangement , which is slightly larger than the distance between the free ends of the handles when closed.

In this embodiment of the invention, the film hinges have such a large restoring force that the webs in the over-dead center position, which is pressed inward, exert such a spreading force on the handle sections that the clamping jaws remain closed under pretension. The film hinges therefore do not allow the webs to move freely with respect to one another and with respect to the handle sections, but instead, after being displaced beyond the dead center, assume a fixed position in which they push the handle sections apart. This position can also be defined by stops on the handle sections and the webs.

It is further proposed that a handle is arranged in the connecting area of the two webs, which is connected on both sides to the ends of the webs by a film hinge or a weakened section. This grip protrudes outwards and can be designed as a hollow body.

The spreading device thus consists of the sequence film hinge-web hinge-grip piece-film hinge-web hinge-film hinge and facilitates the opening of the clamp by the webs on the Pull the handle beyond the dead center position into the release position. It goes without saying that the clamp does not necessarily have to be equipped with such a handle, rather the dead center position of the webs can also be released in that the handle sections are compressed laterally if the dimensions of the handle sections and webs are selected accordingly.

According to the invention it is also proposed to produce the clamping devices or their half profiles in the plastic extrusion process. Although it is also possible to manufacture the clamp individually or in several pieces in a coherent injection molding process, the plastic extrusion process is particularly advantageous because in this way a plastic strand of any length can be extruded with the (half) profile of the clamping device, from which after cooling, the clamping devices are cut off in the desired widths or broken off at predetermined breaking points and, if necessary, connected to one another. The clamping devices according to the invention can thus be manufactured particularly inexpensively, since a separate tool is not required in each case for the different widths.

In addition, this method offers the possibility of creating a prestress in the profile after the extrusion, with which the clamping jaws abut one another. This bias can be in a calibration zone, e.g. a water bath in which the e.g. already partially hardened handle sections spread or pressed towards each other between rollers.

The invention accordingly provides universal clamps and universal clamps which can be produced in different widths with one and the same tool if the particularly preferred extrusion process is used. Different biases of the clips can be created in a calibration process after extrusion, so that the clips are used both to hold thin objects (such as a sheet of paper) can also serve relatively thick objects (such as a stack of paper). In addition, a softer material can be co-extruded at the holding or clamping points in order to increase the slip resistance. In addition, the clamp according to the invention can thus be operated comfortably with one hand.

Some embodiments of the invention are described below with reference to the drawing. Show:

1A to IC a first embodiment of a clip according to the invention in a perspective view and an end view in the closed and in the open state;

2A to 2C show a second embodiment of a clip in a perspective view and an end view in the closed and in the open state;

3A to 3C show a third embodiment of a clip in a perspective view and an end view in the closed and in the open state;

4A to 4C a clamp according to the invention in a perspective view and an end view in the open and closed state;

Fig. 5 is a bracket, the halves of which are mirror images in

Plastic extrusion processes are produced and then connected to a one-piece component by welding;

Fig. 6 shows a modified embodiment, one

Spring device is molded or used;

FIGS. 7A and 7B show a further modified embodiment of the clamp, the preferred co-extrusion process being illustrated in the left half, while a snap connection of the transition region is shown in the left half; and Fig. 8 shows a further modified embodiment of the

Clamping device, wherein an identical, extruded base part is connected to form a multiple clamp.

1A shows a first clamp profile extruded as a strand. The lines 1 in the figure indicate that, for example, a large number of staples can be cut off from the strand in the width given by the spacing of the lines 1 or broken off at embossed predetermined breaking points, but the staple can also have the entire width shown. In this case, the hole 2 is provided, with which the clip can be hung on a hook, for example.

The first embodiment of a clip according to the invention, designated overall by reference number 3, contains two clamping jaws 4, which are designed as hollow body profiles with a small wall thickness and have approximately the shape of a flat segment of a circle. At their upper end section in the figure, the clamping jaws 4 merge into a handle section 6 in a transition region 5, which is also designed as a hollow chamber profile with a thin wall thickness. In the transition area 5, the two clamping jaws 4 are connected to one another with their molded-on grip sections 6 by a cross piece 7.

The bracket 3 is formed symmetrically to its longitudinal central axis 8, which also applies to the other embodiments. However, the invention is not limited to this, but the clamping jaws 4 can, for example, have different profiles on the inside or outside. Depending on the application, the inside of the jaws can have tooth profiles, smooth profiles, round or, for example, serrated recesses, as well as special additional recesses for certain holders. FIG. 1B shows the non-actuated state of the clamp 3, in which the two clamping jaws 4 bear against one another with a pretension caused by the elasticity of the transverse webs 7. The clamping jaws 4 are opened in that the grip sections 6, which in the initial state diverge at an acute angle, are pressed towards one another. As a result, the crossbar 7 is elastically deformed, which causes a corresponding restoring force.

During a calibration process, pressure can be exerted on the inner sides of the handle sections 6, for example by roller pressure, in order to generate a pretension with which the clamping jaws 4 bear against one another in the non-actuated state of the clamp 3 shown in FIG. 1B.

The clip according to FIGS. 2A to 2C differs mainly from the first embodiment in that the closing force of the clip in the state of FIG. 2B is increased by a spring clip 9, which forces the handle sections 10 apart. The spring clip 9 is expediently made of metal, but it can also be a plastic clip. Of course, other types of leaf springs or a coil spring can also be used.

In the area adjacent to the clamping jaws 4, the grip sections 10 have a hollow chamber profile P and hook-shaped inwardly bent ends 11, which serve to hold the spring clip 9.

Figure 2C shows the compressed state of the two handle sections 10, which opens the jaws 4 and compresses the spring clip 9, so that it develops a large restoring force.

In the third embodiment of the clip according to the invention shown in FIGS. 3A to 3C, the handle sections 10 are connected in one piece to a spring device, which is formed by extensions 12 which are bent inwards Handle sections 10 are formed. The free ends of the extensions 12 abut against one another (reference number 13), which can be accomplished by initially extruding the extensions 12 continuously, ie connected to one another, and cutting them open in a later step.

However, it is within the scope of the invention that the extensions 12 can remain connected to one another. The desired restoring force of this spring device can be set by a suitable choice of the wall thickness of the extensions 12 and of the transition region 14. In the embodiment shown, the extensions 12 form an angle of approximately 60 ° with one another, without the invention being restricted to this.

FIGS. 4A to 4C show a clamp in which, in contrast to the clamps described above, the clamping jaws designated here 15 are opened in the non-actuated state of the clamp according to FIG. 4B, i.e. are spread apart. The clamp 16 can be handled and closed with one hand by pushing a handle 17 outward from the starting position shown in FIG. 4B, with the handle sections 10 spreading, the handle sections 18 additionally being bent outwards when the clamping jaws 15 abut one another, before the ends Snap the molded webs 19 into the over-center position shown in FIG. 4C. As a result, the closed state of the jaws 15 is reliably maintained.

The webs 19 are connected via film hinges 20 to the upper ends of the handle sections 18, although these film hinges allow the webs 19 to pivot from the position shown in FIG. 4B into the locking position of FIG. 4C, but no further due to their remaining wall thickness and thus rigidity Allow pivoting inwards, which would otherwise open the jaws 18. This means that the film hinges are formed by areas of reduced wall thickness, but still one have such rigidity that the state of FIG. 4C is maintained.

This could also be accomplished in that, in the angular position of the webs 19 shown in FIG. 4A, the webs, for example with their inner surface, strike corresponding inner surfaces of the handle sections 18, thereby preventing further pivoting. The handle 17, which has a hollow profile, is connected on both sides to the webs 19 by means of film hinges, so that the required possibility of movement is also ensured here.

The closed state of the clamp according to FIG. 4C can be released by pulling the handle 17 upwards in the figure, or lateral pressure can be exerted on the handle sections 18, whereby the webs 19 with the additional additional spreading of the handle sections 18 upwards be relocated.

In all embodiments of the clamping device according to the invention, the clamping jaws 4 and 15 are designed such that they come into contact with one another with a short clamping surface 22. The invention is of course not limited to this, rather the inner and outer surfaces of the clamping jaws can have all appropriate contours. In particular, reference is made here to the embodiment according to FIG. 7A, on which the clamping surface 22 is produced by co-extrusion with a softer plastic 23. As a result, the holding force of the clamping device 3 is significantly increased. To improve the grip of the clamping device, a softer surface 23 'can also be co-extruded in the upper, outer area of the handle sections 18, likewise in the connecting area 5 for forming the crossbar 7 or also the spring device 9 or 12.

5 and 6 a particularly preferred embodiment of the extruded plastic clamping device 3 is shown. First, the two half-profiles 3 'of the clamping device 3, which are symmetrical along the center line 8 Extrusion process with hollow chamber profiles P, which run in the direction of extrusion (see also FIG. 4A), produced and then, as shown in each case on the right half, connected to one another by welding in the transition region 5, preferably in the immediate continuation of the extrusion process by so-called wedge welding, wherein the two half-profile strands 3 'are pressed together. The design of the hollow chamber profiles P with webs 18 'running transversely to the direction of actuation is also important here, since in this way a particularly high rigidity of the handle sections or the clamping jaws is achieved despite the very thin wall thicknesses of the boundary walls and correspondingly reduced material consumption. In addition, a defined pretension can be achieved by welding the two half profiles 3 'of the clamping device.

6 shows a modified embodiment in which a spring device 12, similar to that in FIG. 3, is also molded on. The spring device 12 can consist of two individual spring legs or a continuous leg arch. However, a separate bow spring 9, as in FIG. 2C, can also be used to increase the pretensioning force.

A further embodiment of the clamping device is shown in FIG. 7B, since the two half profiles 3 ′ of the clamping device 3, which are integrally joined in the transition area, are likewise identical and can be joined together by a snap connection 30. The walls running in the direction of extrusion in the transition area 5 are compressed on the one hand in the inner part of the snap connection 30, while the identical, encompassing part is forced apart. As a result, a considerable preload is applied to the clamping device 3. In particular, it should be pointed out that the two half-profiles 3 'joined together to form the one-piece clamping device 3, which in turn are preferably produced by the extrusion process, are mirror images of one another and thus a rigid, in Cross-section of a diamond-shaped joint or, in the case of a cylindrical cross-section, a ball-head joint.

FIG. 8 shows a variation of the clamping device 3, the clamping device 3 equipped with hollow chamber profiles P for reducing the material consumption being combined to form a multiple clamp and thereby being able to be expanded as desired. This allows multiple bags or stacks of paper to be clamped together. Of course, more than three such jaws can also be provided, in the illustration on the right with three jaws, for example, the middle jaw can also be arranged “over head”, so that this means that clamping can also be carried out not only in the area below, but also in the upper area. As a result, the handle portion is also used as a clamping jaw. This double use offers further possible uses, for example by clamping the upper area to a clothes line, while in the two lower clamping areas two socks or similar items of laundry can be clamped in pairs but separately from one another.

Finally, it should be pointed out that for the production of the half profiles of the clamping device 3, which are made in one piece from plastic, the halves shown in FIGS. 5 to 8 can also be connected to one another by gluing, in particular in a continuous process, even if the wedge welding is carried out directly after the extrusion is preferred. In all of these manufacturing processes, a clamping device 3 is thus achieved with a minimal expenditure of material, which ensures high rigidity and clamping force despite the thin walls. The respective pretensioning force can easily be varied for the various purposes, for example by the amount of the connecting force in the transition area 5 or by the inclination of the connection point 5 'in the transition area 5, as shown in the second position from the left in FIG. 5.

Claims

claims

1. Clamping device with two or more clamping jaws, each of which merges into a handle section and is connected to one another in the transition area by a crosspiece, characterized in that the clamping device (3) or its half-profiles (3 ') is made in one piece from plastic and the handle sections ( 6, 10, 18) are designed as hollow chamber profiles (P).

2. Clamping device according to claim 1, characterized in that the clamping jaws (4, 15) are also designed as hollow chamber profiles (P).

3. Clamping device according to claim 1 or 2, characterized in that in the non-actuated state the clamping jaws (4) bear against one another under pretension and the handle sections (6, 10) are spaced apart.

4. Clamping device according to one of claims 1 to 3, characterized in that in the hollow chamber profiles (P) of the handle sections (6, 10, 18) and / or the clamping jaws (4, 15) at least one web extending transversely to their direction of actuation (18 ') is formed in one piece with the boundary walls of the hollow chamber profiles (P).

5. Clamping device according to one of claims 1 to 4, characterized in that a spring device (9, 12) forces the handle sections (10) apart.

6. Clamping device according to claim 5, characterized in that the spring device (12) is formed in that the handle sections (10) have integrally formed, inwardly bent extensions (12) at their ends, which abut one another at an angle and with their ends.

7. Clamping device according to claim 1 or 2, characterized in that the handle sections (18) are connected to a spreading device (20, 19, 21), the webs (19) connected to the ends of the handle sections (18) via weakened sections (20) ) which are connected to one another by at least one further weakened section (21), the two webs (19) having an overall length which is somewhat greater than the distance between the free ends of the handle pieces (18) when the clamping jaws (15) are in contact with one another .

8. Clamping device according to claim 7, characterized in that a handle (17) is connected on both sides to the ends of the webs (19) via weakened sections.

9. Clamping device according to one of claims 1 to 8, characterized in that the clamping devices (3) or their half profiles (3 ') are made in the plastic extrusion process, in particular with co-extruded grip, clamping and / or connecting points (23rd , 23 ').

10. A method for producing clamping devices, characterized in that a plastic strand with hollow chamber profiles (P) is extruded to form a plurality of clamping devices (3), and that the clamping devices (3) are cut off from the strand in the desired widths.

11. The method according to claim 10, characterized in that a prestress is generated after the extrusion, with which the clamping jaws (4, 15) of the clamping devices (3) abut each other.

12. The method according to claim 11, characterized in that the bias voltage is generated in a calibration zone in which the handle portions (6, 10) of the clamping devices (3) are spread.

13. The method according to claim 11, characterized in that the bias voltage is generated in a calibration zone in which the half profiles (3 ') of the clamping devices (3) are pressed towards each other, in particular with welding in the transition region (5).

14. The method according to any one of claims 10 to 13, characterized in that predetermined breaking points are impressed in the extruded plastic strand.

15. The method according to any one of claims 10 to 14, characterized in that to form a snap connection (30) between the half profiles (3 ') in the transition region (5) interlocking snap profiles are extruded.