Reg No: 4-8722 Rev1
Date: 2006-12-27. Sign: KN
Application Guidelines
Rubber Element with Flange
Type 52-05
Basic function
The basic function of the rubber element is to prevent side forces from affecting
load cell performance and at the same time, to keep the load carrier in position.
The rubber element is not to be seen as a vibration damper although is has a
limited damping effect.
It’s sandwich design makes it stiff in vertical direction while relatively weak in
horizontal direction.
No side force = centred Side force acting
A side force acting on the load carrier will push the load carrier to the side and the
rubber element deforms(shears) as shown on the figure. When the side force has
disappeared, the spring action of the rubber will pull the load carrier back to
centred position.
Side forces/movements are created by external or internal reasons. External might
be a cart braking on the weigh platform. Internal might be thermal expansions or
expansions due to deflection under load.
For high side forces, it is necessary to stop the side movement of the load carrier
by an external stop in order to protect the rubber element.
Installation
For best scale performance the rubber elements in a scale shall be installed
accurately centred to the loading holes of the load cells. Below a number of
alternative installation methods are shown
Rubber element mounted directly to
load carrier, which has large clearance
holes to allow centring, even if holes are
not in exact position. Through bolts with
large washers on top.
Figure 1
Figure 2.1 Figure 2.2
Welding plates can be accurately positioned in load carrier and foundation by
using Flintec welding fixtures (figure 2.1). After removal of fixture, the load cell,
base plate and rubber element can be installed (figure 2.2).
Figure 3.1 Figure 3.2
Examples where load cell is used as “welding fixture”. Base plate 52-00 welded
directly to foundation (figure 3.1). Make sure to ground welding machine in the
foundation plate. No current must flow through the load cell. Figure 3.2 shows the
same configuration but with a welding plate under the 52-00 base plate.
Figure 4
If big side forces, exceeding RF,
are expected, side movement
stops shall be arranged. For
example as shown in figure 4.
Dimensions and data
The table below shows maximum allowed lateral displacement for the
different capacities of rubber elements and the restoring force created by the
rubber at this displacement. The force is linearly proportional to the displacement.
If side forces exceeding RF are expected, external bumper stops must be
arranged.
Load Cell Type Capacity in kg L H1 H2 W1 W2
SB4/SB5-5/10/20 kN 510/1020/2039 180 63 12 80 58 M8 5 mm 1600 N
SB4/SB5-50 kN 5099 219 78 15 100 76 M10 5 mm 5000 N
SB6-200 N/500N/
1 kN/2 kN
SB14-500 lb 227 154 54 10 60 44 M6 6 mm 700 N
SB14-1/2.5/5 klb 454/1134/2268 164 60* 12 80 58 M8 5 mm 1600 N
SLB-200 lb/500 lb 91/227 154 55* 10 60 44 M6 6 mm 700 N
SLB-1/2.5/5 klb 454/1134/2268 164 59* 12 80 58 M8 5 mm 1600 N
* Including spacer.
** S
=maximum lateral displacement of load carrier.
max
*** RF =restoring force at S
All dimensions in mm. Dimensions and specifications are subject to change without notice.
CAD files for customer’s own applications drawings are available on request.
20.4/51/102/204 150 65* 10 60 44 M6 6 mm 700 N
.
max
Mounting
bolts D
S
max
**
RF***
at S
max
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