SRH HINGE TEST RESULTS

TENSILE (extracts from lab tests)

"The TENSION test was carried out using a ‘J.J.Instruments’ testing machine to pull the hinge apart via the clamped plates. Hinge failure was at approximately 2,080 N, due to fractures at the strap to plate spot welds."

"The SHEAR test was carried out using a ‘Dartec’ testing machine to pull the two tubes apart along the length of the tubes. Hinge failure was at approximately 1,650 N, due to fractures at the strap to plate spot welds."

SENSITIVITY (extracts from lab tests)

"Each load receptor of the prototype weighing machine was loaded with 40kg and balanced as described previously. A load of 500mg was placed on one side, which caused the indicating needles to move by a viewable amount from their point of alignment. This can be equated to having a resolution of 1 part in 80,000 which for a mechanical assembly of this type compared to a weighing machine of similar design, is quite unique." 

"Owing to use of electronics in modern day weighing techniques, the hinge unit in its present form is impractible. However, where it could be advantageous in today’s weighing techniques is as a transfer mechanism from, for example, a weigh bridge bottom works to an electronic sensing device. In this instance only half the unit would be required with the need for only a single point transfer."

DURABILITY (lab test results)

Summary of SRH Door Hinge Reversal Tests
(Carried out in 1980s by Knight Strip Metals & Stirling Springs Ltd., Potters Bar, Hertfordshire, UK)

Strap Specs

Support Specs

Additional Specs

Degrees Rotation

Cycles per min

Reversals
000's

End Result

.004" 302 Stainless Steel

1.75" Dia Turned Steel

Single 1.5" Bolt 40Kg Tension

90

120

1,623

No Fail

.004" 302 Stainless Steel

1.75" Dia Steel

Single Bolt/3" 40Kg Tension

ditto

ditto

670

Edge Cracks X 2

.006" 302 Stainless Steel

2.5" Dia Raw Aluminium

ditto

ditto

ditto

2,250

No Fail

ditto

ditto + 25Kg Load

ditto

ditto

80

552

Edge Crack X 1

ditto

2.5" Dia Raw Aluminium

ditto

ditto

ditto

2,785

Centre Crack X 1

.008" 302 Stainless Steel

ditto

ditto

ditto

ditto

160

Centre Crack X 2

.006" 302 Stainless Steel

2.36" Dia Alu D-section

Self Tap Fixing Torqued 40Kg

ditto

100

362

General Cracks X 2

ditto

ditto

ditto + Increase Tension

ditto

ditto

---

Extrusion Distorted

ditto

2.36" Dia Alu Extrusion

ditto

60

ditto

201

General Cracks X 4

ditto

ditto + Strengthened

ditto

ditto

ditto

300

General Cracks X 2

ditto

ditto

Spring washers + Lower tension

ditto

ditto

2,500

No Fail

.005" 302 Stainless Steel

2.16" Dia Alu Extrusion

ditto + 50K Door

90

60

3,641

No Fail

(Final Result: 3,641,000 Maintainance-Free Reversals)