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14. Maintenance
When mounting and demounting the system joint too often, the bars of the cover plate can deform due to the
elasticity of the material and thus cause lateral play in the system joint. In this case, the acting force of the spring
units can increase the play. Consequently, the bars of the cover plate can become progressively smaller and the
clearance larger. To prevent the screws for the cover plate from loosening, we recommend to use LOCTITE® 243
for the screw retention as well as LOCTITE® 638 to adhere the cover plate to the joint's upper part.
In order to avoid noise (loud creaking) caused by play between screw and cover plate, we generally recommend
to re-adhere the cover plate at every maintenance. This is explicitly valid for 16 and 20mm system joints.
In case of repeated maintenance of already adhered system joints, make sure that all adhesive residues are
removed from the bars of the cover plate and the grooves of the joint's upper part before reassembling the
system joint and fixing the cover plate with LOCTITE®638. For this purpose, heat the affected parts locally to
about 250°C or use a suitable solvent. Remove the residues with a pointed tool such as an awl. Continue the
assembly as described in paragraph 11.
We recommend checking the system joint’s functionality and wear every 6 months.
Note and respect in particular if the alignment of the orthosis, the range of motion and the spring force still
correspond to the required adjustments. If you notice any changes in adjustment, check the joint components
listed below, and, if necessary, carry out the following measures.
Joint Part Problem Measure
spring unit
breakage of springs replacing
radial move of disc springs (fig. 33)
aligning with pliers
squeaking of pressure springs
greasing with orthosis joint grease
O-rings wear replacing
bore for bearing nut of
system stirrup oversize inserting repair bushing,
see paragraph 14.1
sliding washers wear replacing, see paragraph14.2
bearing nut wear replacing
During maintenance, check the disc springs in detail, for
example for any breaking points (fig. 32). If you notice
a breakage, it is absolutely necessary to exchange the
spring units. A radial move of the disc springs is quite
normal (fig.33). To increase the service life of the spring
units, realign the displaced disc springs with pliers. If
the pressure springs are damaged, you must replace
the spring units.
14.1 Repairing the Bearing Nut Bore
If the bore for the bearing nut is worn out at the system stirrup, bore (fig.34) and ream (fig.35) it with a reamer
(see product catalogue System Joints and Articulated System Side Bars) in order to insert a repair bushing
(boring and reaming measurements see table). For a centred boring and reaming, clamp the system stirrup
firmly. After inserting the repair bushing (fig. 36), the bore has the specified size again. The joint system is now
free of play (fig.37).
fig. 32 fig. 33
fig. 37fig. 36fig. 35fig. 34