CLOSURE DEVICE
The present invention relates to closing devices of the type on the center, particularly for closing housings, especially the cable connection closure housings, either as part of the housing itself or as part of a clamp for securing the first one together and second parts of the accommodation. EP 0 094 848B (Raychem) describes an enclosure for protecting cable junctions from the environment. The enclosure comprises two parts, for example a closure and a base. The two parts are held together by a clamping ring that forces the tabs on the two parts together. No details of the clamping ring are given. US 5 059 748 (Raychem) discloses a butt joint cable connecting enclosure comprising a dome and a base held together by a clamping ring. The ring is in two parts, which are hinged together at their ends opposite the hinge by means of a threaded bolt that acts in threaded portions that join the ends of the parts of the rings. GB 2 193 605A discloses a cable joint comprising a two-part hollow sleeve and two end caps which can be held together by a retaining ring at each end. The clamping ring is in two hinged parts together with the ends away from the hinge which is provided with threaded portions that allow them to be joined by means of a bolt.
Cable tie fasteners are commercially available, for example for fiber optic cables, in which a base and a cover are held together by means of a clamp, for example a split ring clamp, which is closed in its position by means of a closing device on the center. A problem with conventional clamps is that it is often difficult for a technician in the field to close a clamp around a cable tie closure housing, particularly when the clamp and / or housing is / are new. Frequently the technician has to resort to hitting the clamp with a hammer or mallet (which can damage the housing and / or the cables and, in general, makes installation difficult) to close it sufficiently for the lever of the device of closure on the center of the clamp can be operated to close the clamp completely. It would be desirable, therefore, to make the initial step of closing the clamp easier. It is often necessary to reopen the cable tie closure housings to access the cable joints. Conventional cable tie closure clamps often suffer from the problem that they are difficult to remove from the closure housing once they have been closed, particularly when they have been closed for some time. At present, the technician who opens a housing often has to use a separate tool (which, at least in some cases is a specially designed tool) to help him open the clamp and remove it from the housing. It would be desirable to eliminate the need for the use of such tools. According to a first aspect of the present invention, a closure device is provided on the center for closing the first and second parts of an article, comprising a lever pivotally attached to an arm that is pivotally mounted to the first part of the article. , the lever having a coupling surface engaging the second part of the article and holding the two parts of the article together when the lever is in position over the center in use, wherein the lever has an extension extending beyond the coupling surface and which can cooperate with the second part of the article to provide the initial closing lever arm during an initial stage of closure of the article and which allows the coupling surface to make contact with the second part of the article to provide the final closing lever arm during a final stage of closure of the article. The first aspect of the invention has the advantage that because the lever has an extension that can cooperate with the second part of the article (the article can, for example, comprising a clamp or, a housing) to provide the initial closing lever arm during an initial stage of closure of the article, this initial stage of closing the article is made easier and usually avoids the need to hit the clamp , thus solving the first problem mentioned above. According to a second aspect of the invention, a closing device is provided on the center to close together the first and second parts of an article, comprising a lever pivotally attached to an arm that is pivotally mounted towards the first part of the article , the lever having a coupling surface engaging the second part of the article and holding the two parts of the article together when the lever is in its position on the center in use, wherein the lever has an extension extending beyond the coupling surface and which can cooperate with the second part of the article to provide an initial opening lever arm during an initial stage of opening the article. The second aspect of the invention has the advantage that because the lever has an extension extending beyond the coupling surface and that it can cooperate with the second part of the article to provide an initial opening lever arm during a The initial stage of opening the article avoids the need to use a separate tool to facilitate the opening of the clamp, thus solving the second problem mentioned above. Advantageously, the lever arm provided by the closure device of the invention provides at least the radially outward movement of the clamp, for example radially away from a housing around which it is placed. This usually increases the ease with which the clamp can be opened and removed and is particularly difficult to achieve without the extension of the lever according to the invention. Preferably the first and second aspects of the invention are combined in a closing device on the center. Preferably the second part of the article has a projection and the cooperation of the extension of the lever with the second part of the article comprises the contact between the extension and the projection. Advantageously, the extension may have a hook-like part which engages the projection during the cooperation of the extension with the projection. The article may comprise a housing, preferably a cable tie closure housing. Preferably, however, the article comprises a clamp, especially a clamp in the form of a split ring. The fractional ring may not be circular, for example oval or angular, although it will normally be substantially circular when closed. The split ring is preferably hinged to allow it to be opened, placed around a housing etc., and closed in place. The invention can consequently provide a clamp for securing together the first and second parts of a housing, comprising a split ring and a closing device on the center according to the invention, the fractionated ring comprising the article and the closing device on the center that closes the split ring in a clamping position in use. The housing preferably comprises a cable joining closure housing. The clamp preferably holds the peripheral flanges on the first and second housing parts. The clamp is preferably provided with means, for example angled portions, which cooperate with the corresponding portions, for example tabs, on the parts to be clamped so that the closure of the clamp unites the parts. Preferably a pair of extensions is provided on the lever, each of which cooperates preferably with a projection on the second part of the article (for example the clamp). The invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a perspective view of a clamp in accordance with the invention before the initial stage of closure. Figure 2 is a perspective view of the clamp of Figure 1 in the closed position before the initial opening stage. Figure 3 is an enlarged view of the clamp of the Figure
2, which shows the closing device in detail. Figure 4 is an elongated view of the clamp of Figures 1 to 3 subsequent to the initial opening stage. Figure 1 is a perspective view of part of the clamp 1 according to the invention. The clamp comprises a split ring (for example to close around the peripheral flanges of a cable tie closure housing) having a first part 2 and a second part 3 (the complete clamp is shown in Figure 2). The closing device 6 of the clamp 1 comprises a lever 1 1 pivotally connected at 12 to an arm 9 which is pivotally mounted at 20 to the first part 2 of the clamp. The lever 1 1 has a coupling surface 21 which engages the second part 3 of the clamp 8 and holds the two parts 2, 3 of the clamp together when the blade is in its position on the center in use (which is shows in dotted lines in Figure 2). The lever has two extensions 1 5 which extend beyond the coupling surface 8 and which, as shown in Fig. 1, can cooperate with the second part 3 of the clamp when making contact with the projections 17 (which they are preferably in the form of pins) to provide the initial closing lever arm during an initial stage of closure of the clamp. In this mode of operation, therefore, the extensions 15 i increase the stroke of the lever 1 1 in comparison with the conventional levers without such extensions. However, in this mode of operation, the amount of lever arm provided by the lever is networked due to the use of the extensions, is normally sufficient for this initial stage of closing the clamp. In conventional closure devices, this assistance during the initial stage of closing the clamp is not provided due to the absence of such extensions and, consequently, it may be difficult to close the clamp sufficiently to allow the closure device to completely close the clamp Figure 2 shows the clamp 1 of the Figure in its closed position. The entire clamp is shown and a hinge 4 is illustrated between parts 2 and 3. The position on the end center of lever 1 1 is shown in dashed lines and the all-extra lever is shown before use as an arm. Initial opening lever during an initial stage of opening the clamp. The closure device 6, which includes the lever 1 1, is shown in greater detail in Figure 3. The hook-like portions 16 on the end of the extensions 1 5 are shown coupled with the projections 17. In Figure 4, the lever 1 1 has been used to provide an initial opening lever arm for opening the split ring clamp, by means of the engagement of the extensions 15 with the projections 17. Preferably this lever arm imparts at least some force radially outward towards the clamp which helps to free it from the housing. Therefore, Figures 2 to 4 illustrate the second advantageous feature of the invention, ie, making the clamp opening and removal easier than in the case of conventional clamps. Conventionally, a separate tool is normally needed to be able to open the clamp. The invention eliminates the need for this separate tool and provides a simple and effective mechanism for opening the clamp. The clamp and, particularly the closure device, shown in Figures 1 to 4 illustrate how both advantageous features of the invention (ie the case of clamp closure and the ease of opening the clamp) can be combined in a single embodiment .