DEVICE FOR AN AXIAL LOAD GAUGE
The invention relates to a device for investigating the statistical variability of an axial load gauge. The device is inserted into an axial load gauge and a load is gradually applied. At a preset load, a mechanism within the device controllably collapses and the applied load is safely transmitted through the structure of the device. A comparison of the load measured on the device load cell against that measured on the gauge load cell facilitates calculation of the repeatability and reproducibility of the axial load gauge. The test is non-destructible and highly repeatable; it permits comparison of load measurements made on different axial load gauge types and in different factories.
1 . A device for an axial load gauge comprising:
an interface for interfacing to the axial load gauge;
a collapsible mechanism;
a load cell;
whereby in use when a load is applied to the device, the applied load is transmitted through the device until a preset load value is reached, thereby activating collapse of the collapsible mechanism.
2 . A device as claimed in claim 1 , further comprising a chamber having an axially displaceable end wall.
3 . A device as claimed in claim 1 , wherein the collapsible mechanism includes a fluid bearing or a rolling element bearing.
4 . A device as claimed in claim 3 wherein the rolling element bearing is a plurality of ball bearings or rollers.
5 . A device as claimed in claim 1 , wherein the load cell is in communication with the collapsible mechanism.
6 . A device as claimed in claim 2 , wherein the load cell is contiguous with an external surface of the chamber.
7 . A device as claimed in claim 5 , wherein the device further comprises a compliant element interposed between the load cell and the collapsible mechanism.
8 . A device as claimed in claim 2 , wherein the chamber and axially displaceable end wall are made of metal.
9 . A device as claimed in claim 1 , wherein the device is adapted for insertion into the axial load gauge vertically or horizontally or both.
10 . A method of investigating the variability of an axial load gauge by use of a device as claimed in claim 1 , the method comprising the following steps:
i. inserting the device into the axial load gauge;
ii. applying a load onto the device until collapse at a preset load;
iii. measuring the load returned by the gauge when the device collapses;
iv. comparing the collapse loads returned by the gauge with the preset collapse load of the device; and
v. repeating steps ii-iv as required.
11 . The method of claim 10 , wherein the operator is the same person for steps i-v.
12 . The method of claim 10 , wherein the method is repeated by at least two different operators.
13 . (canceled)
14 . A device as claimed in claim 6 , wherein the device further comprises a compliant element interposed between the load cell and the collapsible mechanism.