Abstract:
A linear guide device, comprising a guide rail; a guide carriage displaceable on the guide rail and having at least one rolling body circuit with a circulatory channel for rolling elements and including a running channel, a return channel and two turnaround channels. The guide carriage has a base unit and at least two circulatory assemblies with at least one rolling body circuit and configured to be separate and interconnected only via the base unit. The guide carriage also has at least four recesses with orthogonal end faces, with two end faces on each side of the guide rail pointing in opposite directions.

Description:
CROSS-REFERENCE TO A RELATED APPLIACTION 
       [0001]    The invention described and claimed hereinbelow is also described in German Patent Application DE 10 2006 007 067 filed on Feb. 15, 2006. This German Patent Application, whose subject matter is incorporated here by reference, provides the basis for a claim of priority of invention under 35 U.S.C. 119(a)-(d). 
       BACKGROUND OF THE INVENTION 
       [0002]    The present invention generally relates to a linear guide device with separate circulatory units. 
         [0003]    More particularly, the present invention relates to a linear guide device with a guide rail which extends in the guidance direction, and a guide carriage which is guided such that it is displaceable on the guide rail in the guidance direction using at least one rolling body circuit; the at least one rolling body circuit includes a circulatory channel and a large number of rolling elements which circulate in the circulatory channel; the circulatory channel includes a running channel which is bounded by a rolling body circuit formed in the guide rail and by a load-bearing wall section of the guide carriage, and it includes a return channel and two turnaround channels which connect the running channel with the return channel, in which the rolling elements are essentially load-free; the guide carriage includes a base unit and at least two circulatory assemblies. 
         [0004]    A linear guide device of this type is made known, e.g., in DE 102 37 278 A1. In this case, two circulatory assemblies designed as plastic injection-moulded parts are placed on the base unit of the guide carriage, and they are connected with each other at each end of the guide carriage using an end plate. The end plate contains turnaround inserts which, since the circulatory assemblies are manufactured via injection moulding, cannot be provided integrally with the circulatory assemblies. In addition, the circulatory assemblies are installed on the base unit of the guide carriage in a force-transmitting manner using the end plate. This known linear guide device has the disadvantage that, although the circulatory assemblies can be used “as is” for guide carriages having different widths, an end plate adapted to each width must be provided. 
         [0005]    It should be pointed out that reference is hereby expressly made to the contents of DE 102 37 278.0 and U.S. application, Ser. No. 10/638,756, which was submitted with claim to the priority of this German patent application, to supplement the disclosure of the current application, in particular with regard for the basic design of the guide carriage. 
         [0006]    An attempt is made to solve this problem using the linear guide devices made known on pages 166 through 169 of the catalog “Linearführungen, Profilschienenführungen, Laufrollenführungen, Wellenführungen” ( Linear Guides, Rail Guides, Cam Roller Guides, Shaft Guides ), publication LIF from the INA Company. The circulatory groups used there have the disadvantage, however, that, in order to provide a sufficiently stable guide, they are made of steel, and these steel circulatory groups are mounted on the base unit using screw bolts, which are difficult to install. 
       SUMMARY OF THE INVENTION 
       [0007]    Accordingly, it is an object of the present invention to provide a linear guide device with separate circulatory units, which is a further improvement of the existing linear guide devices. 
         [0008]    More particularly, it is an object of the present invention In contrast, the object of the present invention is to improve a generic linear guide device by ensuring that it can be easily adapted to guide carriages having different widths and lengths, but which are cost-favorable to manufacture and ensure easy installation of the circulatory groups and the guide carriage. 
         [0009]    This object is attained according to the present invention by a generic linear guide device, with which the two circulatory groups are designed separately and are connected with each other only via the base unit, and at least four recesses are provided in the guide carriage, each of which includes an end face which extends essentially orthogonally to the guidance direction, against which one of the circulatory assemblies bears in the guidance direction; the end faces of two recesses each located on one side of the guide rail point in opposite directions. 
         [0010]    By providing the recesses, the circulatory group of the inventive linear guide device can bear in the guidance direction against the end faces formed on the base unit, so that the force can be transferred between the circulatory group and the base unit preferably essentially entirely via this planar support. It is therefore not necessary to provide a mounting of the circulatory group on the base unit which is suitable for force transmission and which must therefore have a complex design. 
         [0011]    According to the descriptions provided above, compared with the related art, a “base unit” is understood—per the present invention—to refer to the guide carriage without circulatory groups and end plates on the end faces. Based on this fact, among others, the circulatory groups are mounted directly on the base unit. 
         [0012]    With an embodiment of the present invention, the recesses can be provided on both ends of the base unit; this ensures that the base unit will be particularly simple to manufacture. 
         [0013]    In addition or as an alternative thereto, at least one recess can be provided in an essentially central region of the base unit. Several circulatory groups located one behind the other in the guidance direction can be provided on the guide carriage, for example, so that the circulatory groups of the inventive linear guide device can also be used with guide carriages having different lengths. 
         [0014]    According to a further refinement of the inventive object, the circulatory groups are made at least partially of plastic, preferably via injection-moulding. The circulatory group can include a load-bearing wall section—made of metal—of the running channel, which bears against the base unit of the guide carriage, so that, even though the circulatory group is manufactured as a plastic part, a stable design and support of the running channel can be provided. 
         [0015]    To ensure particularly simple mounting of the circulatory group on the base unit, it can be provided that each circulatory group includes several mounting segments which engage in openings of the base unit, and the end regions of which are deformable in order to rivet the circulatory group with the base unit. The mounting segments are preferably made of plastic. 
         [0016]    To simplify the manufacture of a circulatory group, e.g., using injection moulding, it can be provided that each circulatory group includes a main part and two turnaround inserts. 
         [0017]    Each of the turnaround inserts preferably bears in the guidance direction against the end face of the base unit and against a mounting segment, and/or a cover wall of the main part of the circulatory group, by way of which the turnaround inserts are fixed in position securely on the main part. 
         [0018]    The novel features which are considered as characteristic for the present invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0019]      FIG. 1  shows a perspective view of a guide carriage of a linear guide device according to a first embodiment of the present invention; 
           [0020]      FIG. 2  is an exploded view of the guide carriage in  FIG. 1 ; 
           [0021]      FIG. 3  is a front view of the linear guide device of the first embodiment of the present invention; 
           [0022]      FIG. 4  is a perspective view of the guide housing of the linear guide device in  FIGS. 1-3 ; 
           [0023]      FIG. 5  is a further perspective view of the guide carriage according to the first embodiment of the present invention; 
           [0024]      FIG. 6  shows a perspective view of a guide carriage according to a second embodiment of the present invention; and 
           [0025]      FIG. 7  is a sectional view of a linear guide device, which shows how the rolling element running channel rests on the base unit of the guide carriage in the manner according to the present invention. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0026]    The first embodiment of the present invention which is shown in  FIGS. 1 through 5  will be explained first. 
         [0027]    As shown in  FIG. 3 , a linear guide device  10  includes a guide housing  12 , in which two guide rails  14   a  and  14   b  are fixed in position by staking a dovetail segment of guide rails  14   a  and  14   b  in grooves  16   a  and  16   b  in guide housing  12 . A threaded spindle  20  is rotatably supported in guide housing  12  to drive a guide carriage  18  which is guided in guide housing  12  in a guidance direction. A counternut  22  fastened to guide carriage  18  is engaged with threaded spindle  20 . A cover plate  24  is also secured to guide housing  12 . 
         [0028]    Guide carriage  18  includes a base unit  26 , which is typically made, e.g., of aluminium, in particular an aluminium extruded profile section, which is provided with support sections  28  for securing an object to be moved by linear guide device  10 , and legs  30   a ,  30   a , each of which laterally encloses an associated guide rail  14   a ,  14   b  and is guided on this guide rail. 
         [0029]    Each of the legs  30   a ,  30   a  of guide carriage  18  includes a rolling element circulatory assembly  32   a ,  32   b . Each circulatory group  32   a ,  32   b  is riveted with base unit  26  using two mounting segments  34  (see  FIGS. 1 and 2 ) by guiding mounting segments  34  through openings  36  in base unit  26 , and then deforming the exposed end of mounting segments  34 . 
         [0030]    According to the present invention, guide carriage  18  and, in particular, circulatory groups  32   a ,  32   b , are designed such that circulatory groups  32   a ,  32   b  can be provided as preassembled units, by including the rolling elements (not shown in  FIGS. 1 through 5 ) which serve to guide guide carriage  12  on guide rail  14 . Each circulatory group  32   a ,  32   b  includes a main part  48 , which is preferably made as a plastic injection-moulded part, on which a trough-shaped element  42  is installed by being snapped into place, and two turnaround inserts  50  which are inserted in the main part such that they bear against a cover wall of main part  48  and mounting segment  34  which is integral with main part  48 . 
         [0031]    The rolling elements circulate in a rolling element circulatory channel  38  which is formed by a running channel  39 , a return channel, and two turnaround channels. Running channel  39  is formed between guide carriage  18  and guide rails  14   a ,  14   b , and is bounded by a running surface  40  on the side of guide rails  14   a ,  14   b , and by a load-bearing section of a trough-shaped element  42  on the side of guide carriage  18 . In return channel  44  which forms circulatory group  32   a ,  32   b , the rolling elements return, load-free, to the beginning of running channel  39 . Running channel  39  and return channel  44  are connected at both longitudinal ends in turnaround channels  46  formed in circulatory group  32   a ,  32   b.    
         [0032]    As shown in  FIG. 2  in particular, lower wall sections of return channel  44  and both turnaround channels  46  are formed on main part  48  of circulatory group  32   a ,  32   b . Together with a steel wire—which is indicated in  FIG. 2  using a dash-dotted line—the rolling elements are therefore enclosed by circulatory group  32   a ,  32   b  such that circulatory group  32   a ,  32   b  acts as a basket or shell, out of which the rolling elements do not fall. 
         [0033]    Trough-shaped element  42  is preferably made of steel, so that it can easily withstand the stresses placed on its load-bearing wall. In the state in which it is joined with base unit  26 , trough-shaped element  42  bears with its back side directly against base unit  26 . In this manner, the forces of the load-bearing running channel  39  to be absorbed can be transferred directly to base unit  26 . 
         [0034]    Four recesses  52  are formed in the ends of base unit  26 , the end faces  54  of which extend essentially orthogonally to the guidance direction. As shown in  FIGS. 1 and 2  in particular, circulatory groups  32   a ,  32   b  bear via their turnaround inserts  50  against end faces  54  such that forces acting in the guidance direction or against the guidance direction can be transferred via this planar support directly from circulatory groups  32   a ,  32   b  to base unit  26 . 
         [0035]    This design makes it possible, with inventive linear guide device  10 , to install circulatory groups  32   a ,  32   b —at least part of which are manufactured as a plastic injection-moulded part—directly on base unit  26  of guide carriage  18  without installing an end plate in-between, since, given that circulatory groups  32   a ,  32   b  bear against end faces  54  of recesses  52 , a stable transfer of force between circulatory groups  32   a ,  32   b  and base unit  26  is attained without placing stress on the attachment of circulatory groups  32   a ,  32   b  on base unit  26  via mounting segments  34 . 
         [0036]    It is therefore possible, with the linear guide device according to the present invention, to use the same injection-moulded main parts  48  and trough-shaped elements  42  of circulatory assemblies  32   a ,  32   b , which are already used, e.g., for linear guide deices made known in DE 102 37 278 A1. It is only necessary to change turnaround inserts  50  of inventive circulatory groups  32   a ,  32   b  as compared with the circulatory groups made known in DE 102 37 278 A1, in which case they are connected with each other via an end plate with integrated turnaround inserts. As a result, the manufacturing cost for inventive circulatory groups  32   a ,  32   b  is minimized. 
         [0037]    In addition, a preload-adjustment device  56  is assigned to a leg  30   a  of guide carriage  18  ( FIG. 5 ). This preload-adjustment device  56  includes several knee joints  58  which are integral with base unit  26  of guide carriage  18 . A not-shown adjustment screw bears against base unit  26  of guide carriage  18  and engages in a thread in an engagement part  60  of knee joint  58 , so that the preload of legs  30   a ,  30   a  against guide rails  14   a ,  14   b  can be adjusted by rotating the adjustment screw. 
         [0038]    As shown in  FIG. 5 , two bores  62  are formed on the end face of counternut  22 , in which a matching tool can engage in order to screw counternut  22  via its (not shown) outer thread into the (not shown) thread of base unit  26 . 
         [0039]      FIG. 6  shows a second embodiment of the present invention, in which two circulatory groups  32   a   1 ′,  32   a   2 ′,  32   b   1 ′  32   b   2 ′ are provided on either side of base unit  26 ′ and extend in the guidance direction. In order to support circulatory groups  32   a   1 ′,  32   a   2 ′  32   b   1 ′,  32   b   2 ′ in the guidance direction and in the direction opposite thereto, an additional, central recess  62 ′ with two end faces  64   a ′,  64   b ′ is provided on both sides of base unit  26 ′. Each circulatory group  32   a   1 ′,  32   a   2 ′  32   b   1 ′,  32   b   2 ′ therefore bears, via one side, against an end face  54 ′ of recess  52 ′ located on one end of guide carriage  18 ′, and via its other side against an end face  64   a ′,  64   b ′ of center recess  62 ′. As a result, circulatory groups  32   a   1 ′,  32   a   2 ′  32   b   1 ′,  32   b   2 ′ can be used with guide carriages  18 ,  18 ′ having different lengths or widths. 
         [0040]      FIG. 6  also shows a retaining bracket  66 ′ which is mounted on a main part  48 ′ of circulatory groups  32   a   1 ′,  32   a   2 ′  32   b   1 ′,  32   b   2 ′, which prevents rolling elements  68 ′ from falling out of the running channel when guide carriage  18 ′ is not installed on a guide rail. Instead of this retaining bracket, it is can be provided that the load-bearing wall section of the running channel formed in each circulatory group encloses the rolling elements around more than half of their circumference. 
         [0041]      FIG. 7  shows a cross section through a linear guide device  10 ″, with which, instead of the guide rail, an arm element  14 ″ is enclosed by guide carriage  18 ″ and serves to illustrate how element  42 ″—which forms a wall of load-bearing running channel  39 ″—of circulatory groups  32   a ″,  32   b ″ bears against base unit  26 ″ of guide carriage  18 ″. As a result, the forces transferred via the running channel between guide carriage  18 ″ and guide rail  14 ″ are absorbed by base unit  26 ″ without the intermediate installation of main part  48 ″ of circulatory group  32   a ″,  32   b ″, so that, despite the fact that main part  48 ″of circulatory groups  32   a ″,  32   b ″ is designed as a plastic part, it is ensured that the guidance of guide carriage  18 ″ on guide rail  14 ″ is adequately stable. 
         [0042]    It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of constructions differing from the type described above. 
         [0043]    While the invention has been illustrated and described as embodied in a linear guide device with separate circulatory units, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention. 
         [0044]    Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention.