EP0709268A1

EP0709268A1 - Supporting guide for linear guideway handling system

Info

Publication number: EP0709268A1
Application number: EP95117134A
Authority: EP
Inventors: Vitaliano Russo; Antonio Marsilia
Original assignee: Alcatel Cavi SpA
Current assignee: Nexans Italia SpA
Priority date: 1994-10-31
Filing date: 1995-10-31
Publication date: 1996-05-01
Also published as: ITMI942218A1; ITMI942218A0; IT1276053B1

Abstract

There is disclosed a supporting guide for linear guideway handling systems of the type comprising a supporting profile (1) or matrix and at least one rolling or sliding track (3), designed to support cursors sliding on the guideway.

The invention provides for use of at least one high-strength steel stranded cable (3) of high hardness, set in the support (1) and forming the sliding track.

Description

The present invention relates to a supporting guide for linear guideway handling systems of the type including a guide body consisting in a structural shape and at least one slip track embedded therein and designed to slidably support the sliders running with kinetic or rolling friction along the guide itself.
Linear guideways of the above type, having one slip track (single guide) or two slip tracks (double guide), are available on the market nowadays.
They are constituted essentially by a support consisting of a structural shape generally made of aluminium material, variously shaped, embedded in which are one or two grinded bars made of hardened steel, designed to slidably support sliders running along them with low friction.
One of the problems encountered in using this type of guideway is the lubrication of the slip tracks. In fact the tracks, featuring very high hardness and resistance to wear, are formed from steel rounds or prismatic bars and suitably treated for hardening the slip surface and grinded in order to feature a low coefficient of friction, whereby the surfaces do not allow high adhesive power of meatuses of oil usually taken from a reserve located on the slider and delivered to the track as the sliding requires it or it is sprayed from the outside.
The problem of wettability of the track is sometimes solved having recourse to expensive conventional methods like scraping the track surface or drilling holes before the hardening heat treatment, and this creates dishomogeneity in cooling and therefore in hardening or after the heat treatment and this is still more difficult.
Moreover, the solid bars forming the tracks are not suitable to adapt the guides along curved paths when laying.
Lastly, the guides are produced in tranches whose maximum length is determined by the length of the transport vehicles whereby, when longer guideways are to be realized, a plurality of linear guide tranches must be disposed in series along the guideway path with consequent solutions of continuity in the slip track which is highly undesirable.
In this situation, it is an object of the present invention to eliminate the above-mentioned drawbacks by providing a supporting guide for linear guideway handling systems with slip track which besides having the required hardness and resistance to wear, is easily oilable and sufficiently flexible so as to be able to realize curved paths.
Another object of the present invention is to provide a guide of the above type which is easily connectable in alignment with guides of the same kind to form guideways without solutions of continuity in the slip track.
These and other objects which will become wore apparent in the description are achieved by a supporting guide for linear guideway handling systems which is characterized in that the slip track is realized by at least one stranded cable embedded in the guide body.
Thanks to this solution, a flexible slip track is obtained which is easily oilable since the slip surface, being constituted by the surface of the cable etched by the helical grooves formed by the borderlines between the wires, is able to hold up the lubricant necessary for the wettability of the surface itself. Further characteristics and advantages of the invention will become apparent to those skilled in the art from the following description of embodiments taken in conjunction with the attached drawings in which:

Fig. 1 represents schematically in a perspective sectional view a single supporting-guide in accordance with the invention;
Fig. 2 represents schematically, in a perspective sectional view, a double supporting-guide in accordance with the invention;
Fig. 3 represents schematically, in a perspective sectional view, a double supporting-guide suitable for heavy realizations, according to the invention;
Figs.4A and 4B represent a typical section respectively of a cable compacted by drawing and of a closed rope alternatively used, according to the needs, as a slip track in the supporting guide in accordance with the invention; and
Fig. 5 represents schematically respectively in a perspective view and in a side elevation view an embodiment of a section of a monotrack guideway in accordance with the invention.
Referring now to the figures in detail and bearing in mind that like reference numerals refer to like parts throughout the various figures, 1 stands for a guide body that can be of various configurations depending on the number of slip tracks embedded therein. At one (Fig. 1) or both ends (Fig. 2), the body is provided with a longitudinal seat having a substantially circular cross-section designed to house a high-hardness steel stranded cable 3 forming the slip track used for the rolling of the members supporting the slider running along it (or for the sliding of the guide blocks supporting the slider when the latter is of sliding friction type).

In a preferred embodiment the cable 3 having high hardness and high strength (each wire should preferably have a tensile strength of at least 100 kg./sq.mm.) is compacted by drawing. When technical needs require it, a "closed" rope can be used (see Fig. 4B).
The cable is embedded in its longitudinal seat of the guide body 1 eventually with the interposition of suitable adhesive material 5 (Fig. 3), for instance, a reinforced epoxy resin capable of seaking between the wires of the cable in order to obtain adhesion between the surface of the guide body in the contact area and the surface of the cable itself, adhesion that can be improved by roughening the jointing surface of the guide body.
Such adhesive material must be porous enough otherwise it has to be provided with holes to allow the lubricant to pass.
The jointing is eventually improved also by the vice action exerted by screws inserted into holes 2,4 drilled transversely in the guide body which is provided with suitable slots 8 transverse to holes 2,4 and extending from the jointing surface towards the inside of the body (Figs. 1 and 2).
The guide body 1, which inter alia performs the function of supporting, holding up and positioning the track in the space, is formed by a soft material matrix, preferably aluminium.
The lubrication of the slip track can be carried out in several ways. The lubricant (grease) can be incorporated conventionally in the cable, or the oil can be forwarded to the track by gravity or forced by suitable known pumping systems.
In Fig. 3 there is represented an embodiment particularly suitable for the realization of guideways of the heavy series.
Therein the cables are not disposed in opposite positions like in Fig. 2, but they are disposed on the same side of the guide body. Therein the possibility of making the lubricant flow from an external source to the rolling surfaces through suitable channels 6,7 is emphasized.
The cable being formed by several wires, even if compacted by drawing, features longitudinal microcavities extending helically and formed by the gaps existing between wires. The lubricant forwarded to the tracks through channels 6,7 can be passed through these natural gaps in the cable. By closing e.g. the channel 7 (in Fig. 3), channel 6 being open, the lubricant can be caused to flow to the contact area between cable and sliders through the contact area between cable and guide body.
The surplus of lubricant laid down on the guideway in the vicinity of the track can be sucked up if leakage towards the outside is undesired.
The lubrication system described in connection with Fig. 3 can be used with both guideways mounting a sole (Fig. 1) or two (Fig. 2) tracks.
Fig. 4A shows a cross-section of a cable compacted-by-drawing, very flexible and hard, used as a slip track in the supporting guide in a preferred embodiment of the invention, while Fig. 4B shows a closed rope that can be used as an alternative to the drawn cable.
Fig. 5 shows a section of a monotrack guideway according to an advantageous embodiment of the invention, formed with a plurality of tranches 1 of guide support, which can be also spaced apart, and by applying on the field a steel cable 3 or a rope, whereby there is no solution of continuity in the slip track.
Thus the invention achieves all the intended objects. In fact there is provided a supporting guide for linear guideway handling systems with a slip track which is hard, easily lubricable and sufficiently flexible. The hardness is the intrinsic hardness of the high-hardness, steel stranded cables, without the need of further hardening treatment.
The lubricability is due to the conformation of the slip surface which, being the surface of the cable, allows the achievement of a surface easy to wet, capable of holding up the amount of lubricant necessary to maintain it moistened, thanks to the permeability of the cable to the lubricant due to gaps between wires that are helicoidal and transverse to the direction of slider motion, even if in some circumstances said gaps can be very narrow.
Moreover, by suitably choosing the diameter and number of wires forming the cable, along with the use of a soft material for the guide body, a flexible guideway is obtained such as to be able to adapt also to curved paths.
Lastly, the cable or rope forming the slip track of a long route guideway, being transportable wounded on take-up reels thanks to its flexibility may be of length equal to the overall length of many pieces of guide body and, being mounted after the lay down of the pieces of guide body necessary to reach the desired path length, it allows the advantageous elimination of the discontinuities between the guide body pieces.
By using supporting guides in accordance with the invention linear guideway systems can be realized with the same precision and motion accuracy but at lower costs than the conventional systems.
Further, the supporting guide according to the invention allows the use of guideways to be extended to fields in which the costs of conventional sytems makes the access to automation prohibitive, such as, e.g., the logistic of poor products and goods.
Naturally the materials, the dimensions and manufacturing details can be varied depending on the type of supporting guide for linear guideway handling systems and depending on needs of production and use, still observing the features illustrated, described and claimed hereinafter.

Claims

Supporting guide for linear guideway handling systems of the type including a guide body consisting in a profile and at least one slip track embedded in said profile and designed to support sliders running along the guideway, said supporting guide being characterized in that said at least one slip track consists of at least one stranded cable.
Supporting guide according to claim 1, characterized in that said stranded cable consists of a multiplicity of steel wires each having a tensile strength greater than 100 kg./sq.mm.
Supporting guide according to claim 1, characterized in that said stranded cable is of the type compacted and drawn.
Supporting guide according to claim 1, characterized in that said stranded cable is a so called "closed rope".
Supporting guide according to any of the preceding claims characterized in that said body is made of soft material and said stranded cable is flexible.
Supporting guide according to claim 1, characterized in that an adhesive material is incorporated between said guide body and said stranded cable and in that the jointing surface of said body is roughened to improve the adhesion between body and cable.
Supporting guide according to claim 6, characterized in that said adhesive material is a reinforced epoxy resin and is permeable to the lubricant.
Supporting guide according to claim 1, characterized in that said stranded cable englobes lubricating material.
Supporting guide according to claim 1, characterized in that a lubrication channelling is provided in said body, through which the lubricant is caused to flow to the contact surface and from here to the slip surface through the gaps between wires.
Guideway for linear handling of the type comprising a plurality of guide body sections disposed in series along the path of the guideway and at least one slip track embedded in at least one side of said sections, characterized in that said slip track is realized by a steel stranded cable applied without solution of continuity to said plurality of guide body sections.