Abstract:
The invention relates to a device for provisionally connecting a fastening strap, specially a wheel chair strap, to a fixing rail ( 12 ) with a longitudinal groove. A securable and removable locking member of the fastening strap can be inserted into said longitudinal groove. A pivoting point for the fastening strap is arranged above a connecting member which can be anchored in the fixing rail ( 12 ) adjacent to the latter. A ball-and-socket joint ( 51 ) can be mounted on the connecting member. The joint can be connected to the connecting member and the fastening strap.

Description:
BACKGROUND 
     1. Field of the Invention 
     The invention concerns a device for temporarily connecting a fastening strap—in particular a strap on a wheelchair—to an anchor point. 
     2. Description of the Prior Art 
     Various configurations of carriage or wagon body structures suitable for wheelchairs are known, in which the wheelchair—which is introduced by way of access ramps or rails—is secured with fastening or lashing straps to point anchorages or in hold rails. The fastening straps in that respect are provided adjacent the wheelchair with so-called retractors which are connected to the retaining bodies by way of comparatively long cable lines. It has been found that this entails the disadvantage that the cable lines connected to the excessively heavy retractors, due to being frequently turned, become undesirably twisted and become easily breakable. 
     FR-A-1161214 discloses a fixing pairing comprising a channel-like holding rail with laterally protruding channel edges and pairs of slots formed therein for a transverse plate which is displaceable thereon and whose side regions which are curved downwardly in cross-section embrace the channel edges in holding relationship with play. Held on the transverse plate is a longitudinal plate which is movable relative thereto and which is of U-shaped longitudinal section and which can engage with its free limbs into the pairs of slots. Passing through both plates is a substantially concentric pin which is embraced by a coil spring that bears against the longitudinal plate, while an eye is pivotably connected to the pin. 
     In accordance with U.S. Pat. No. 3,765,637 lateral pin portions which arc disposed on a common axis, of an eye plate which is mounted rotatably by same engage on both sides in openings of a cap which is rotatably supported on a thrust body of a holding rail. The thrust body engages with plate-like shaped portions provided on both sides into the longitudinal groove in a holding rail, the shaped portions engaging in a retaining position under regions of the holding rail, which are of an undercut configuration. 
     Finally it is known per se from WO-A 9809588 for a coupling element for a fastening strap of a wheelchair to be associated with a tightening housing. 
     Therefore the object of the present invention is to improve the connection of a wheelchair to an anchor point or a holding rail; in particular the invention seeks to ensure non-twistability and long service lives. 
     SUMMARY OF THE INVENTION 
     In accordance with the invention, the pivot point for the fastening strap, which is above the connecting body that can be anchored in the holding rail and adjacent to the connecting body is arranged at a very short spacing relative to the holding rail; a ball joint which is arranged on the connecting body and which has the pivot point is connected on the one hand to the connecting body and on the other hand to the fastening strap. In addition the ball joint is to have a mounting ball portion which is towards the strap and which is rotatable in a mounting casing of the connecting body. 
     In accordance with a further preferred feature of the invention, the substantially cylindrical mounting casing of the ball joint, in which the mounting ball portion associated with the fastening strap is rotatably disposed projects up from the connecting body; the edge of the mounting casing which is arranged at the mounting ball portion and which surrounds the mouth opening of the mounting casing is also to be curved inwardly in cross-section in order to engage over the mounting ball portion in holding relationship. 
     In a device with a cable line extending between the fastening strap and the holding rail, in accordance with an embodiment of the invention formed on the mounting ball portion is a connecting sleeve for a short tensile cable portion which at the other end is connected to a tightening or tensioning housing or to a pivot member. This tensile cable portion which is preferably protected by a casing member terminates at the tightening housing in a sleeve-like shaped portion on a mounting plate and is connected with same by an axis pin to mounting bars of the tightening housing; the mounting plate and the mounting bars are advantageously rigidly connected by the axis pin. 
     To enhance the safeguard against twisting in addition the spacing between the axis pin and the mounting ball portion should correspond to approximately four times the spacing of the plane of rotation of the mounting ball portion from the underneath surface of the connected holding rail, which in turn approximately corresponds to four times the height of the connected holding rail which preferably measures about 10 mm. The spacings are therefore in the region of a few centimeters. 
     It has also proven to be advantageous for the unit consisting of the mounting ball portion and the connecting sleeve to be provided with a protective collar or muff which fits with a portion that enlarges towards the end of the edge of the mounting casing and covers over—in protecting relationship therewith—the casing mouth opening which accommodates the mounting ball portion. 
     The invention provides that at the end mounted movably on the connecting body which is connected to the mounting sleeve by a rivet pin is a locking pin which is connected to the mounting sleeve by a rivet pin is a locking pin which can be withdrawn from a retaining opening in the holding rail against a force-storage device. The locking pin is securely guided at a right angle to the holding rail in a nose portion formed on the connecting portion. 
     The following advantages in particular are enjoyed in comparison with known lashing systems for wheelchairs: 
     a pivot point at a lower level, combined with minimum lever forces which are applied to the floor anchorage; 
     uniform application of force to the connecting body by way of the mounting casing of the ball joint in different lashing positions for the wheelchair in the transportation means; 
     advantageous rotatability and pivotability by way of the ball joint, the short tensile cable portion is protected in the best possible fashion from loadings such as torsion and bending; 
     the mounting casing is accommodated in positively locking relationship in the connecting body; and 
     the ball joint is protected from fouling by the cuff or collar or a plastic cap. 
     The device according to the invention may also be used to advantage in connection with other loads requiring lashing. 
     Further advantages, features and details of the invention will be apparent from the description hereinafter of preferred embodiments and with reference to the drawings: 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of a wheelchair which is connected by lashing elements to lateral holding rails of a loading surface. 
     FIG. 2 is a side view of a wheelchair with a retaining system according to the invention. 
     FIG. 3 is a plan view of a holding rail from FIG.  2 . 
     FIG. 4 is a view on an enlarged scale in cross-section through the holding rail of FIG. 3 taken along line IV—IV therein. 
     FIG. 5 is a side view of a lashing element on an enlarged scale in comparison with FIG.  2 . 
     FIG. 6 is a front view of the lashing element with tightening housing. 
     FIG. 7 is a view in section on an enlarged scale through a coupling unit which can be seen in FIGS. 5 and 6. 
     FIG. 8 is a view on an enlarged scale through FIG. 6 taken along line VIII—VIII therein. 
     FIG. 9 is a side view on an enlarged scale in comparison with FIG. 2 of a lashing element with coupling unit. 
     FIG. 10 is a front view of a tightening housing, and 
     FIGS. 11 and 12 are views on an enlarged scale of the coupling unit of FIGS. 9 and 10 in different positions. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Fitted on to the loading surface  10  of a transportation vehicle which is not shown in further detail at a spacing a from each other are parallel holding rails  12 —of a width b of for example 34 mm with a height e of about 12 mm—, being mounted by means of their lower mounting surface  13 , for the purposes of temporarily fixing a wheelchair  14  by means of two front straps  16  and two rear tightening straps  16   a —with associated lap belt  17  thereabove. For tightening and loosening the front strap  16 , mounted thereto in FIG. 1 at a spacing relative to the holding rail  12  is a so-called retractor  18  connected by a relatively long cable to a retaining body  19  which sits in one of the holding rails  12 . 
     In the embodiment shown in FIGS. 2 through 8 the straps  16 ,  16   a ,  17  are releasably fixed in the holding rail  12  by means of fittings or turnbuckles  20 —connected to the straps at their ends—, by virtue of a longitudinal groove  22  of undercut configuration, of a depth e 1  of about 8 mm; in that way the wheelchair  14  is braced in a shake-free manner by the two variable-length pairs of straps  16 ,  1   6a  as those straps, with the lap strap  17 , carry the forces which occur. 
     The two groove edges  24 —which laterally define the slot-like region of the longitudinal groove  22  which is in the rail surface  11 —at the spacing f of  12  mm are of a wave-like configuration in FIGS. 3 and 4 by virtue of contours  26  which are part-circular in plan view, the contours  26  being of a diameter d of  22  mm in this case. Holding rails  12  of that kind are used as so-called airline systems, in particular in the form of lashing rails in aircraft. 
     In particular as shown in FIGS. 5,  6  and  9 ,  10 , the turnbuckle  20  according to the invention—for example as part of the front strap  16 —has a tensioning or tightening housing  28  with lateral rotary handle  30  for a tensioning or tightening device (not shown) disposed therein, for the front strap  16 , which can be releasably attached to the housing  28  by a coupling tongue  21  of a belt loop  29 . A radial release lever  32  projects from the housing  28  at the front side. 
     Two parallel mounting bars  34  of the housing  28  are connected by an axis pin  36  to a mounting plate  38  which in turn—in FIGS.  5  through  8 —is connected with a sleeve-like shaped portion  40  thereon to a comparatively stiff and short tensile cable portion  42 . The end, towards the rail, of the cable portion  42  which is overall surrounded by an enclosing tube  44  and which represents a flexible whip handle-like unit  42 / 44  is carried—as can be seen from FIGS.  7  and  8 —in a connecting sleeve  46  which is formed on a mounting ball portion  48 . 
     The structural center point of the mounting ball portion  48  is identified by Q for the sake of enhanced clarity of the drawing and defines a rotational plane E for a ball joint  51  which comprises the mounting ball portion  48  and a cylindrical mounting casing  50  which accommodates it. For the purposes of determining the position of the mounting ball portion  48 , the casing edge  54  which surrounds the mouth opening  52  of the casing is curved inwardly in a part-spherical configuration towards the longitudinal axis A. By virtue of that mounting arrangement the mounting ball portion  48 —and therewith the whip handle unit  42 / 44 —is pivotable about the structural center point Q shown in FIG. 5 through a pivot angle w of about 60°. Moreover the spacing n between the structural center point Q and the axis B of the eye hole in the mounting plates  38 , through which the pin  36  passes, is here about 90 mm. 
     The axis pin  36  and the rotational plane E of the mounting ball portion  48  are spaced apart from one another a distance ranging from approximately twice to five times the distance which the rotational plane E is spaced from an underneath surface of the holding rail  12 . The distance which the rotational plane E is spaced from the underneath surface of the holding rail  12  is approximately double the height of the holding rail  12 . This distance separating the rotational plane E from the underneath surface of the holding rail  12  is preferably about 11 mm. The overall spacing between the axis pin  36  and the underneath surface of the holding rail  12  is in a range from about 60 mm to about 110 mm. 
     Bearing against the edge  54  is the free end of a protective collar or cuff  56  of flexible material which enlarges in a downward direction and embraces the connecting sleeve  46  and covers the mouth opening  52  of the casing, being defined by the edge  54 . 
     A rivet pin  58  which passes on the one hand through the substantially cylindrical mounting casing  50  and on the other hand through a cuboidal connecting body  60  which can be fitted into the holding rail  12  and which is supported in the mounting casing  50  defines a pin axis M whose spacing i from the holding rail  12  approximately corresponds to the height e thereof. The spacing h of the underneath surface  59  of the connecting body  60  relative to the structural center point Q measures in this case 21 mm. 
     The connecting body  60  is at a gap spacing  61  relative to the base plane  49  of the mounting ball portion  48  and is provided in its lower region on both sides with two respective plate-like shaped portions  62  which project with regions that are part-circular in plan view from the longitudinal surfaces  64  of the connecting body  60 ; the diameter d 1 , of the portions  62 —as can be clearly seen from FIG.  8 —is slightly shorter than the diameter d of the circular contour  26  of the longitudinal groove  22 ; two respective adjacent circular contours  26  can receive the two plate-like shaped portions of the connecting body  60 ; the latter is displaceable after being moved downwardly into the shaped portions  62  in the longitudinal groove  22 . 
     As can be seen from FIGS. 6 and 7, mounted to the connecting body  60  of the turnbuckle  20  is a locking pin  66  of a diameter d 1 , which co-operates with the holding rail  12  and which in the locking position engages into one of the circular contours  26  of the holding rail  12  and which in the looking position engages into one of the circular contours  26  of the holding rail  12  and is unlocked by pulling on a handle bar  68  in the direction indicated by the arrow x; in that situation the locking pin  66  is lifted axially against the force of a coil spring  70  as a force-storage means out of its retaining mounting which is formed by the circular contour  26  of the holding rail  12 , whereupon the shaped portions  62  in turn can be removed from their seats which are then respectively in the narrow regions between two circular contours  26 , by being displaced in the longitudinal groove  22 . The locking pin  66  has a diametral slot (not shown) which is guided at a fin-like central wall  72  of a nose portion  74  which is formed on the connecting body  60 . 
     In the embodiment shown in FIGS. 9 through 12, instead of a tensile cable portion  42  formed on the mounting wall portion  48  is a neck  76  provided with a shoulder-like annular step  78  against which the upper edge  57  of the collar or cuff  56  bears. The neck  76  blends integrally into the mounting plate  38  which is in the form of an eye; the spacing n of the axis B of the eye hole  39  of the mounting plate  38  relative to the rotational plane E measures 44 mm here and its spacing h relative to the underneath surface  59  of the connecting body  60  is about 21 mm while the pivotal angle w is 70° or 90°. It will be clear that here there is a considerably narrower overall spacing q of 65 mm in respect of the axis B relative to the underneath surface  59 , in comparison with an overall spacing q of 110 mm in the embodiment with the cable portion  42 .