| |
Harry F Rochat
Ltd - Heritage Engineering Works
The engineers at Harry F Rochat Ltd not only are capable of fully manufacturing
our own machinery but take pleasure in manufacturing bespoke heritage items and
enjoy the challenges they present.
We have undertaken many projects over the years from extrusion rolls for the
plastics industry to smaller heritage items such as the objects below. Below
/ side, are images of the Gudgeon pin assembly made specifically for a local
railway society, who are painstakingly rebuilding GWR 7200. The original assembly
was incomplete and heavily worn, so there were no pattern parts to copy. These
items were remade by measuring the existing body of the crossheads, which were
heavily worn, along with the bores, which were no longer round due to extensive
use on the train during it’s working life and then working out what was
required from a selection of old parts and drawings, none of which were accurate
or consistent.
Each part was reviewed on paper before machining started to ensure all the
parts would fit together into the crosshead to the tight tolerances and tapers
called for. Jigs had to be made for the crossheads to enable the bores to be
lapped by hand, until the bores were in line and as round as possible. Specific
specialist material was then chosen for each part and machining commenced. Once
the parts were made, they were sent off to the hardeners for hardening and then
the parts were machined in our works to size, using specialist CBN tooling. Castle
nuts were made and the parts were then fitted to the crosshead bodies in our
works. These parts have now been collected from our works and are waiting to
be fitted to the train. Further details of this restoration project can be found
on the Trust’s
web site www.7200trust.org.uk

The following are some of the other made to order parts we have manufactured.
|
|
30 cm (12”) long Jacking Screw for industrial usage |
Hardened and tempered punches for the construction of wall sockets |
| |
|
|
|
A variable speed pulley made in our works for a clients particular
machine |
| |
|
|
Traditional styled gears can be cast at our
foundry and then cut to your specific requriements. This particular gear is held
in place with an individually fitted ¾” Gibb head key, which is shown ready to
be driven. The diameter of the gear shown is 24” and cast in Iron. |
| |
|
Thread Profiles Available
| Metric 60º |
MJ 60º |
| UN 60º |
NPTF 60º |
| Whitworth 55º |
Butress |
| NPT 60º |
VAM |
| Round 30º |
New VAM |
| BSPT 55º |
API Rd 60º |
| Trapezoidal 30º |
V-0.038R |
| ACME 29º |
V-0.040 |
| Sub-ACME 29º |
V-0.050 |
| UNJ 60º |
|
|
|