The present invention is directed to an elongated guide rail having a central axis and used with drilling, cutting, and grinding tools. One outwardly facing side of the guide rail has two first pairs of guide surfaces spaced laterally apart and extending in the direction of the central axis of the rail. The guide surfaces are V-shaped and the spacing between the surfaces increases in the outward direction.
It has been noted in manually guided drilling, cutting and grinding tools that a large material loss is experienced due to fracture and scrap when working on a base material, such as concrete, masonry, rock and the like, since an accurate and secure guidance of the tool is impossible manually. In addition, there is considerable danger for the person operating the tool if, for instance, the tool begins to rotate or if the tool is tilted.
Accordingly, a guidance device has been developed and is disclosed in DE-GM 9204693. This known guidance device has a guide rail clamped to a pedestal. The guide rail has two pairs of guide surfaces arranged in a V-shaped manner relative to one another and extending along the long axis of the rail and also located on an outwardly facing side of the guide rail located opposite the pedestal. The recesses formed by the guide surfaces and arranged in a V-shaped manner increase in width towards the outwardly facing side of the rail. A guide trolley, displaceable along the guide rail, engages with slide blocks shaped in a flat arrowhead-like roof-shaped manner and disposed next to each other in the two pairs of guide surfaces. A rock working tool can be attached to this known guide trolley. To prevent the guide trolley from lifting off the guide rail, backup rollers are arranged on the guide trolley protruding into guide recesses of the guide rail and bearing against abutment faces which extend essentially on the bottom side on the two pairs of guide surfaces.
In an arrangement of this known guide rail, extending essentially at right angles to the surface of a base material being worked, high forces are developed by a tool mounted on the guide trolley. These forces engage on one side of the guide rail. Distribution of such forces to the entire cross-section of the guide rail is not assured. A reversal of the of the guide trolley in the circumferential direction of the guide rail through 180.degree. is also not assured.
SUMMARY OF THE INVENTION
Therefore, the primary object of the present invention is to provide a guide rail on which different guide trolleys with different guide regions can be disposed and where a reversal of the guide rail through 180.degree. is assured and affords an adequate distribution of the forces generate across the cross-section.
In accordance with the present invention, two second pairs of guide surfaces arranged in a V-shaped manner are located basically symmetrically to the two first pairs of guide surfaces, and the second pairs of guide surfaces are located on an outer side of the guide rail and extend in the direction of the central axis of the rail.
Due to the inventive arrangement of the guide rail, a guide trolley can be used in an exposed arrangement with guide elements in the form of guide rollers corresponding to the arrangement of the guide surfaces provided in a V-shaped manner, so that the forces which are caused by a tilting movement and torque of a tool mounted on the guide trolley are transferred to the entire cross-section of the guide rail by means of the two outwardly facing sides disposed opposite to one another. Since the lateral spacing between the two first pairs and two second pairs of guide surfaces is substantially the same as the width of one side of the guide rail, a high degree of guidance stability of the guide trolley is assured. Forces arising parallel and basically at right angles to the direction of the central axis of the guide rail are subjected to a particularly good backup.
Preferably, so that the inventive guide rail can be used with different guide trolleys, a second axis of symmetry extends perpendicularly to a first axis of symmetry of the first and second pairs of guide surfaces, with at least one each additional pair of guide surfaces arranged on each side of the second axis of symmetry with these guide surfaces arranged inclined relative to one another and extending in the direction of the central axis of the guide rail. The additional pairs of guide surfaces can be arranged relative to one another in a flattened arrowhead-like roof-shaped manner or in an inwardly directed V-shaped manner. If the guide surfaces are oriented outwardly in a roof-shaped manner, the apex lines of the additional pairs of guide surfaces form the largest outside dimension of the guide rail.
For reasons of manufacturing and force engagement, the apex lines of the additional pairs of guide surfaces are preferably located in the same plane which extends perpendicularly to their axis of symmetry.
It is advantageous if the additional pairs of guide surfaces are located in the region of the two first pairs of guide surfaces, so that the guide regions of the guide trolley can be kept small as far as constructional size is concerned.
The guide rail can be a hollow section. This feature has weight advantages as well as manufacturing advantages.
The guide rail is suited for attachment of two guide trolleys shaped in different ways, whereby their guidance elements engage at two outwardly facing sides of the guide rail located opposite one another. Depending on the manner of its use, the guide rail must be positioned parallel to the surface of the base material, particularly when cutting or grinding, and it must be disposed basically perpendicularly to the surface of the base material when drilling.
If the guide rail is arranged horizontally, a guide trolley must be used which cooperates with the additional pairs of guide surfaces by means of guide elements. If the guide rail is used for drilling, a guide trolley is employed with guide elements which cooperate with the two first and second pairs of guide surfaces.
All the guide surfaces can be hardened, or provided with a hard coating or with hard platelets.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its use, reference should be had to the drawing and descriptive matter in which there is illustrated and described a preferred embodiment of the invention.