GB2176124A

GB2176124A - Model railway locomotive

Info

Publication number: GB2176124A
Application number: GB08514869A
Authority: GB
Inventors: Hugh Richard Lines
Original assignee: Hornby Hobbies Ltd
Current assignee: Hornby Hobbies Ltd
Priority date: 1985-06-12
Filing date: 1985-06-12
Publication date: 1986-12-17
Also published as: GB2176124B; GB8514869D0

Abstract

To improve the tractive effort of an electrically powered model railway locomotive having three pairs of coupled driving wheels, one of such pairs of wheels (10) is unsprung and has non-conductive rolling surfaces (8) made of high friction co-efficient material and the wheels (2) of at least one other such pair are spring loaded from the locomotive chassis frame into continuous conductive contact with the track. <IMAGE>

Description

SPECIFICATION Improvements in electrically powered model railway locomotives This invention relates to electrically powered model railway locomotives.

In the field of railway locomotives, the wheel configuration designated 0-6-0 (030 in some continental countries) indicates no front bogie wheels, 6 driving wheels coupled togetherand notrailing bogie wheels. Such a configuration is one ofthe most populartypes reproduced by model railway manufacturers as it is easyforyoungsters to place on the track, is atthelowerend ofthe cost/price range and isfully authentic.

In model railway the customary system of power is by electricity. This is introduced to an electric motor within the locomotive chassis by feeding positive cur rentthrough the running rail on one side whence it is picked up bythefrontand rear driving wheels on that side, led into the motor and returned to the other side running rail through the opposite driving wheels.

Such a system demands that the wheels are made of electrically conductive material and thatthere is insulation across the axles to prevent a short circuit condition arising. The centre pair of wheels have reduced flanges and run clear ofthe rails in orderthat the locomotive may negotiate curves of the nonscalertype as supplied in model train sets and also so that the locomotive may successfully run over a summit. This makes the model locomotive effectively a 4-wheeler.

This arrangement has been well-known over an extended period and has proved to be satisfactory to manufacturers but less so to users. The principal drawback is that the locomotives are prone to skid when trying to haul a heavy load and in particular when attempting to scale a gradient. The addition of substantial weights within the body helps to over come this drawback on level track but not significantlyon inclines and adds cost to the locomotive as well as requiring more elaborate and expensive packaging to protect it.

Magnets have been fitted within the chassis to ex ert a grip on steel running rails through the wheels but these are manifestly ineffective when running on commonly used nickel silver rails. Afurther objection has been that the centre driving wheels appear un realistic because they do not run on the rails.

The present invention provides a means whereby the limitation on hauling power is overcome without the use of weights or magnets, all driving wheels are on the rails and locomotives are able, on level or inclined track to haul trains of, at least, double previously known length.

In accordance with the invention there is proposed an electrically powered model railway locomotive with three pairs of coupled driving wheels characte rised in that the wheels of one of such pairs are un sprung relative to the locomotive chassis frame and have a non-conductive rolling surface made of high friction co-efficient material whereas the wheels of at least one other of such pairs are spring loaded from the locomotive chassis frame and are intended to make continuous conductive contact with the track.

In a locomotive with a 0-6-0 wheel configuration it is preferred that the wheels of the centre pair have rolling surfaces as aforesaid and that the leading andl ortrailing pairofwheels,which are independently coupled to the central pair of separate coupling rods, are spring loaded from the chassis as aforesaid.

The invention is hereafterfurtherexplained byre ference to the accompanying drawings in which: Figure lisa side elevation of the chassis and driving mechanism of a known electrically powered 0-6-0 model railway locomotive; Figure2 is a view similar to Figure 1 of a construction in accordance with the present invention; Figure 3 is an inverted plan view of the construction shown in Figure 2; Figure 4 is an enlarged scale cross-section on line IV-IV of Figure 2; and Figure 5is a cross-section on line V-V of Figure 4.

Referring now to the drawings, in the known construction illustrated in Figure 1 it isto be noted that each wheel 1 of the centre pair is of lesser diameter than each wheel 2,3 ofthetwo other pairs and in contrast to the latter does not make contact with the trackT. None of the wheel axles are sprung relative to the chassis frame 4 and a single rod 5 at each side of the chassis connects the primary drive wheels 3 to the centre wheels 1 and the secondary drive wheels 2.

The wheels 2 and 3 are electrically conductive and are electrically connected to a motor 6 through spring contacts 7 engaging their inward sides. The pair of wheels 3 are driven through a worm and worm wheel.

By contrast, in the construction shown in Figures 2 to 5 all thewheels 10,2 and 3 are of the same diameter and engagethetrack.

The centre pair of wheels 10 is driven from the motor6through aworm and worm wheel andthese wheels only are formed with a circumferential groove in which there is nested atyre8 made of rubber our other suitable high friction co-efficient material which will transmit the drive without slippage on the rails.

The other pairs of wheels 2,3 make metal to metal contactwiththe rails of the track.

As illustrated in Figures 4 and 5, and to ensure that the wheels 10 are always in contact with and have good adhesion with the rails, the pair of wheels 2 are springloaded from the chassis frame by means of a pair of vertically acting coil springs 9 which are sup- ported in sockets formed in the chassis frame 11 and bear against the axle 12 by which the wheels 2 are carried and which extends through a vertical slot 13 in the chassis frame 11. The spring loading must be neither too strong,which could cause lift-off ofthe driving wheels 10 nor too weak, which would cause the wheels 3, which pick-up the electric current and do not bear the weight of the locomotive, to bounce offthe track.

Because of the spring mounting of one of the wheel pairs, it is necessarythatthere should be separate coupling rods 15-aswith afull scale locomotive between each wheel pair. This arrangement permits the locomotiveto operate in a fully effective manner at the startand finish of gradient sections of track. The wheel and axle assembly of each wheel pair has an amount of lateral play ortolerance relative to the chassis frame to permitthe locomotive to travel around thesmallest radius section providedforthe track.

Thearrangementdescribed can be adapted for use with any type of6-coupled driving wheel locomotive e.g. 0-6-2(031), 4-6-0 (230), 4-6-2(231) and so forth.

Claims

1. An electrically powered model railway locomo tive with three pairs of coupled driving wheels, char- acterised in that the wheels of one ofsuch pairs are unsprung relativetothe iocomotive chassisframe and have a non-conductive rolling surface made of high friction co-efficient material whereasthewheels of at least one other such pairs, are spring loaded from the locomotive chassis frame and are intended to make continuous conductive contactwith the track.

2. An electrically powered model railway locomo tive according to Claim 1 in which the centre pair of coupled driving wheels is driven from a motor and has its rolling surface made of said high friction coefficient material and one end pair is spring loaded fromthe chassis frame.

3. An electrically powered model railway locomotive accordingto Claim 1 or Claim 2 in which a spring loaded pair of wheels is spring loaded by means of a -pair of springs mounted from the locomotive chassis frame and bearing upon an axle which carries the pair ofwheels and is vertically movable relative to the chassis frame.

4. An electrically powered model railway locomo tiveaccording to any of Claims 1 to 3 in which the non-conductive rolling surface is a tyre made of rub ber or like material nested in a circumferential groove in the wheel.

5. An electrically powered model railway locomotive constructed substantially as herein before describedwith reference to Figures 2to 5 ofthe accom panying drawings.