How does a hand operated point lever work?

[Happy Hippo]

On my outdoor layout, I use two types of levers to move the switch rails. The first is a counterbalanced 'Heywood' lever, and the other is the traditional 'ground throw'. Both types simple move the switch blades into the appropriate position through a straight pull of the operating bar and the weight on the top of the lever ensures they do not move once set in position. ( I also have a model of a lift/move/drop'lock US style switch stand).

 

Next year I am looking to rebuild the railway and this would include getting rid of the existing multitude of ground throws in favour of a centralised lever frame with just a couple of vertical hand levers in the yard. These levers appear to work on a spring and cam system: As you pull the lever to set the road and then return the lever to it's original position (Or it should fall back if properly balanced). To change direction you pull the lever again and it will change the route back to the original.

 

To date I have been unsuccessful in finding out much about these levers and thought I'd ask here before, trekking to the local preserved railway sites etc.

 

Can any one point me in the right direction as to where I can get this information? Perhaps a diagram or a couple of relevant pictures. I did get one very good picture of a stub switch at Dinorwic which showed tantalizing glimpses of the mechanism, but the top cover was in place, so I couldn't quite see the important bit.

 

One thing this has proved is that my railway library is sadly lacking in information regarding the track and it's associated fixings!

 

Regards

 

Richard

[Grovenor]

These are known as "Williams Levers", essentially position is held by a spring with an over centre mechanism, in principle similar to a Peco point. Pulling the lever compresses the spring and moves the point over so that releasing the spring holds them the other way.

Google brings up these http://www.miniaturerailwaysupply.com/pointlevers/llewellyn.htm, http://www.scalewaysignals.com/products/pointlever/Williamspatterns.htm

Regards

Keith

[The Stationmaster]

Richard,

 

I have tried what I hoped would be a likely source in the shape of Henry Williams Ltd's website but they don't show them (to my surprise as they were the most common source of two-way levers in recent years) but it might be worth contacting them to see if they can help,

 

Hand point levers used to come in two varieties, viz one way levers and two way levers although those terms might be a little confusing when applied to what they meant in practice With a one way lever, usually the prototype equivalent of the old S&B hand lever or this sort of thing in a current larger scale version http://www.miniature...leverthumbs.htm the lever operates by turning from one side of the centre pivot to the other (as you will obviously know) so either movement of the lever can only turn the switches one way.

 

In contrast with a two way lever http://www.miniature...s/llewellyn.htm the lever is always pulled in the same direction and it will move the switches to their opposite position, ie. it can operate the switches two ways. The lever box contains a spring and the action of the lever drives a 'V' shaped plate (possibly a casting?) from which the drive to the point is derived. The model mechanism in the link looks to have a basic similarity to the real thing, and presumably woks in a similar manner?

 

Alas the one thing I have not got is a picture of the mechanism underneath the mounting plate because my photography has tended to concentrate on points and rodding connected to signalboxes and ground frames. The pic below is the (very poor) best that I can manage. I would suggest that you best options are to try Henry Williams and or establish contact with a preserved railway if you happen to be enar one in the hope that they might have one lying in their spare parts heap. I will try a pal of mine to see if his mate's containers happen to have one amongst the lever frames and sundry other signalling kit or if he has come across one during our dealings with the various railways we speak to.

[Happy Hippo]

Keith and Mike,

 

Thanks quick replies and for the links.

 

If those mechanisms are quite small I'll get one and have a look. I can always try to scale it down and make a smaller version (but not scaling down to P4!!)

 

I thought it would be something along those lines, but sometimes it is hard to visualise.

 

I can see a trek to the SVR/TSR/W&LLR on the cards (which will be a terrible hardship!!)

 

Regards

 

Richard

 

(Edited to include both Grovenor & The Stationmaster)

[Happy Hippo]

Just a resurrection of this topic!

 

I found the following information lurking on the beloved interweb:

 

http://www.valleysignals.org.nz/track/springpoints.html

 

The two diagrams and description makes it all so clear.

 

I understood the principle of the overspring unit, but couldn't work out how the cam worked.

 

Now I understand

 

Regards

 

Richard

[Dave777]

Sorry to top an old thread for the second time, but which way round should the lever go? So in Mike's photo above, taking into account the S bend at the bottom of the white section, is the point off to the left or right of the photo? Or is there no set way and they were placed any old how?

 

Thanks.

 

 

Edit: I think a photo on Richard's link shows the lever S-bending towards the point...?

 

Crude 3D diagram:

 

Are they always like the red one or like the blue one... or no set rules?

 

[avonside1563]

Here's a lie flat one found on a footpath which is an ex-GW branch at Gloucester that led to a small power station near the docks. It's slap in the middle of a bridge so I assume it would have been for a trap point although research has, so far, not turned up any details.

[The Stationmaster]

Dave - normally the levers would be as per your red one - that way round they were easier for the Shunters to work as they walked towards the toe of the point; and they should all be the same way round in a yard. it's a right b*gger if they aren't. But you could see them installed the wrong way round and in more recent years some contractors got far too good at doing that.

 

The 'lie flat' levers were used where capstans were in use or where there were flat/paved working areas such as in some parts of goods yards or where there was no option but to put them in a walkway.

[Dave777]

Great, I can place mine now - many thanks