TECHNICAL FIELD

The present invention relates to a body having a surface or surfaces subjected to friction when the body is put to practical use at a work¬ place or site of use, which surfaces are coated with a lubricant already on production in the factory and delivered coated with lubricant.

BACKGROUND ART

At the site of use, the lubricant has so far been, applied with some suit¬ able lubricating tool, e g it has been injected into the hole wherein the detail or body in question is to be inserted, which signifies an extra work operation and a messy job in many cases as well.

One way of supplying lubricant-coated bodies would be to have them placed in a plastic envelope, for example. A disadvantage here is, however, that a large part of the lubricant w ll remain in the envelope when it is re¬ moved, and furthermore handling will quite often be messy. Attempts have been made to put a thin plastic foil outside the lubricant, this film being allowed to remain on applying the body. The intention here has been that the foil will rupture and let out the underlying lubricant. However, it has been found that the desired effect has not been obtained, inter alia due to the pLastics ^* in itself being tough and having poor lubricat¬ ing effect-, and even in the cases where the plastic foil has ruptured as intended, it has often been found that this occurs at one place only, with poor distribution of the lubricant as a result. The plastic foil furthermore accompanies the body" and this also causes the desired lu¬ bricating effect to be unobtained.

DISCLOSURE OF INVENTION

The object of the present invention is to provide bodies or details with a prefabricated, lubricant-coated surface, the above-ment oned work op- erations at the site of use being eliminated, a messy lubricant surface substantially being avoided and the intended achievement of lubricating effect guaranteed.

OMPI

The invention is characterized in that the lubricant-coated surface out¬ side the lubricant is provided with a protective coating of such a ma¬ terial which has -a certain lubricating effect and which breaks already at the beginning of the insertion in the material or hole, so that the underlying lubricant comes out.

In accordance with the invention, the protective layer preferably com¬ prises paraffin or stearin, said materials being lubricanting per se, and eas ly break already at moderate loading..Such a protective layer can also be simply produced by dipping in a melt having a correctly ad- justed temperature.

In an advantageous application of the invention, the body constitutes a conical driving tip for perforating a fire-sealing lead-through compris¬ ing an elastomeric fire-resistant foamed material.

BRIEF DESCRIPTION OF DRAWINGS

Figure 1 illustrates making a hole through a fire-sealing body.

Figure 2 is a section to_a larger scale along the line II—II in Figure 1.

MODES FOR CARRYING OUT THE INVENTION

Figure 1 illustrates a fire-sealing body 1 inserted, e g moulded-in, in a wall 2. The fire-sealing body comprises a foamed material 3, suitably a silicon foam, which expands inside a surrounding casing 4 and assumes a foamrubbei—like consistency in the production of the fire seal. The foamed material is kept compressed by the casing transverse the longi¬ tudinal axis of the casing. For passing a conduit through the fire-seal¬ ing body in the example shown in Figure 1 there is used a perforating tool, which here comprises three parts, namely a conical tip 5, sleeve 6 and a handle 7 with a head S.

As illustrated in Figure 1, the tip 5 is-at first suitably pressed by itself into the foamed material 3. The forward end 9 of the sleeve is

inserted in the tip, and with the aid of the handle the tip and sleeve are pressed through the foamed material, and when the tip has passed through the material -it falls off by itself. For this through penetra¬ tion the handle 7 may press against the back end 10 of the sleeve, there being an annular bottoming groove made in the head 8 of the handle for insertion of the sleeve end during the through penetration. By special forming of the head 8 with a recess 11 for hooking onto two of four abut¬ ments 12, uniformly distributed round the circumference of the sleeve 6, and situated in the vicinity of the back end of the sleeve, through pen- etration of the tip 5 and sleeve 6 can take place, after such a hooking- on, alternatively with a position for the handle 7 which is oblique rel¬ ative the sleeve, and this can be valuable in more inaccessable places.

After the sleeve 6 has been urged through the fire-sealing body 3 and a conduit has been passed through the sleeve, the sleeve is withdrawn with the aid of the handle 7.

To reduce the penetration force, and the withdrawing force also, it is suitable to lubricate the tip 5 with a suitable lubricant. This can nat¬ urally be done at the site of use, but an extra operation is then re¬ quired with the -use of a suitable lubricating tool. By means of the pres- ent invention this operation has been eliminated, and in the case exem- . plified the tip 5 is delivered to the site of use with lubricant applied to the tip-during production of the latter, and without messy handling of the tip because of the lubricant.

As will be seen from Figure 2, the tip 5 is provided with a coating of lubricant 13 and outside this coating a protective layer 14. It is es¬ sential that the protective layer 14 has a lubricating effect without being messy to handle, and that it breaks up at the mechanical loading to which the tip 5 is subjected at the beginning of penetration, so that the lubricant comes out and spreads round the tip. A suitable material for the protective layer has been found to be paraffin or stearin. Apart from the above-mentioned properties, there is obtained with such mate¬ rial the advantage of simple production by dipping the tips 5 in a melt at a correctly adjusted temperature.

With a lubricant coating 13 and a protective layer 14, as described above, it has been found that the penetration and withdrawal force was reduced to 1/2 - 1/3 of the force required without these layers.

A special applications of the present invention has been described above as an example while referring to Figures 1 and 2. However, there are a plurality of other fields of use, where a body or detail with a prefab¬ ricated lubricant-coated surface with an exterior protective layer of suitable material, e g paraffin or stearin, can.be used to advantage.

OMPI