1. Field of the Invention
The present invention relates to a wire harness-fixing clamp for holding a wire harness comprising wires or a cable, and more particularly to such a clamp suited for holding a self-supporting-type communication cable called xe2x80x9ca hanger gourd-shaped cablexe2x80x9d.
The present application is based on Japanese Patent Application No. Hei. 11-233535, which is incorporated herein by reference.
2. Description of the Related Art
FIG. 3 is a cross-sectional view showing a self-supporting-type cable 1 (called xe2x80x9ca hanger gourd-shaped cablexe2x80x9d) which is a kind of communication cable.
The self-supporting-type cable 1, having the illustrated configuration, includes a cable body portion 2, and a support wire portion 3 integrally formed with the cable body portion 2. Such self-supporting-type cables have various characteristics, and therefore have been extensively used in accordance with the purpose of use and a place where it is used. The cable body portion 2 comprises a conductor (cable core) 2a, an insulating layer 2b formed on the conductor 2a to cover the same, and a protective sheath 4 formed on the insulating layer 2b to cover the same. The support wire portion 3 comprises a support wire 3a, and the sheath 4 formed on the support wire 3a to cover the same, so that the support wire portion 3 is integrally connected to the cable body portion 2. The cable body portion 2 and the support wire portion 3 are interconnected by a sheath connection portion 4a at the boundary between the two portions 2 and 3.
In the installation of the self-supporting-type cable 1 of the above configuration, this cable is often fixed by clip-type clamps at suitable portions thereof spaced along the entire length thereof. One example of such clamps is a wire harness clamp disclosed in Unexamined Japanese Utility Model Publication No. Sho. 63-179717.
This clamp 5, shown in FIGS. 4A and 4B, includes a pair of left and right elastic holding portions 5a and 5b extending upwardly from a clamp body molded of a resin, and a holding recess 5c of an upwardly-open U-shape (in the drawings) is formed between the two elastic holding portions 5a and 5b. A retaining projection 5d is formed at an upper end of one of the elastic holding portions 5a, and bulges to be exposed to the holding recess 5c. 
When installing the self-supporting-type cable 1, this cable 1 is fixed to a mounting panel or the like at suitable portions thereof by the use of the clamps 5. More specifically, when the clamp 5 is mounted in an upwardly-directed posture as shown in FIG. 4A, the self-supporting-type cable 1 is usually fitted into the holding recess 5c, with the support wire portion 3 directed downwardly, so that the cable body portion 2 is disposed at a level above the support wire portion 3. The cable body portion 2, thus disposed at the higher level, is held between the left and right elastic holding portions 5a and 5b, and is retained by the elastic force of the resin, and the retaining projection 5d is press-contacted with the cable body portion 2 to prevent the same from withdrawal from the holding recess 5c. 
When the self-supporting-type cable 1 is set in an inverted posture in the related clip-type clamp 5 as shown in FIG. 4B, there is encountered the following disadvantage. More specifically, when the self-supporting-type cable 1 is attached to the clamp 5 in such a manner that the cable body portion 2 is directed downwardly, and is first fitted into the holding recess 5c, the support wire portion 3 projects outwardly from the clamp 5, so that the fixing of the cable is unstable. As a result, in use, the cable can flutter to produce noises, and in the worst case, the self-supporting-type cable is disengaged from the clamp 5.
It is therefore an object of the present invention to provide a wire harness-fixing clamp particularly best suited for holding a self-supporting-type communication cable (called xe2x80x9ca hanger gourd-shaped cable) among wire harnesses in a stable condition.
To achieve the above object, according to the first aspect of the present invention, there is provided a wire harness-fixing clamp which comprises a clamp body, a pair of elastic holding portions extending from the clamp body, the elastic holding portions being opposed to each other to form therebetween a holding recess, into which a wire is insertable, and which is operative to hold the wire, and a plurality of retaining projections formed respectively on the elastic holding portions to project into the holding recess, wherein when the wire is inserted into the holding recess, at least one of the retaining projections is operative to retain the wire in the holding recess. When the wire is held in the holding recess, the retaining projections are operative to engage the wire from such a direction as to prevent withdrawal of the wire from the holding recess. The retaining projections may be formed in a bulged manner respectively on inner surfaces of the elastic holding portions.
In the related art, the retaining projection is formed on only one of the elastic holding portions, and therefore there were occasions when the fixing of the wire harness was unstable. In the above construction of the present invention, however, the retaining projections are formed on the opposed elastic holding portions, respectively, and therefore even when the wire harness is set in any posture, the clamp can hold the wire harness in a stable manner.
According to the second aspect of the present invention, the wire may include a body portion, a connection portion, and a support wire portion connected to the body portion through the connection portion. In this case, when the wire is inserted into the holding recess so that the support wire portion is first introduced into the holding recess, the body portion is engaged with the retaining projections to be prevented from withdrawal from the holding recess. Further, when the wire is inserted into the holding recess so that the body portion is first introduced and pressed into the holding recess, the body portion is engaged with one of the retaining projections and a bottom of the holding recess. The wire may be a self-supporting-type cable having a hanger gourd-shape.
Accordingly, even when the wire is set in a proper posture or an inverted posture, with the support wire portion or the body portion first introduced into the holding recess, the body portion is positively held in a press-contacted manner, and therefore the self-supporting-type cable is positively held in a stable condition.
According to the third aspect of the present invention, it is preferable that the retaining projections are offset from each other in a longitudinal direction of the holding recess. More specifically, one of the retaining projections may be formed on an intermediate portion of one of the elastic holding portions, and the other one of the retaining projections may be formed on a distal end portion of the other one of the elastic holding portions. In this case, the retaining projections press-contact with the body portion of the wire, or the one of the retaining projections and the bottom of the holding recess press-contact with the body portion of the wire.
That is, the retaining projections are formed on the suitable portions of the opposed elastic holding portions, respectively. More specifically, the one retaining projection is formed on one of the two elastic holding portions intermediate the opposite ends thereof, whereas the other retaining projection is formed on the distal end portion of the other elastic holding portion. With this construction, the body portion is held between the two retaining projections, and are press-contacted with these retaining projections to be prevented from withdrawal from the holding recess. Alternatively, the body portion is held between the one retaining projection and the bottom of the holding recess in a press-contacted manner, and therefore is stably held against withdrawal from the holding recess.