Tramcars and other Vehicles.
Year: 1886

page_text: Tramcars and other Vehicles.
I, THOMAS MALLABAND, of Bamford, in the County of Derby, Engineer, do
hereby declare the nature of my invention for. IMPROVEMENTS IN THE CONSTRUCTION
OF METALLIC WHEELS FOR TRAMCARS AND OTHER VEHICLES and in what manner
the same is to be performed, to be particularly described and ascertained in and by
the following statement that is to say :-
My invention relates to a novel method of constructing metallic wheels suitable
for Tramcars and various other purposes, the object being to construct a wheel with
a removable tyre, in an economical and reliable manner, and that shall require no
fitting or machinery at the junction of the tyre and the arms.
The annexed sheet of explanatory drawings will enable my invention to be
clearly understood, and the same letters of reference will indicate the same or
similar parts in any of the figures in which they are found.
Fig. 1, represents a front elevation of a wheel made according to this invention.
Fig. 2, is a cross section of same.
Fig. 3, enlarged sectional view of the tyre and junction with the arm.
Fig. 4, cross section of same.
In constructing a wheel according to my invention, as shown in the drawings,
I cast the tyre A, of a suitable cross section for the desired purpose, and with any
number of lugs, in this case I have shown. eight, as being a very suitable number.
Four of the lugs are marked B, and the other four intermediate lugs are
marked C, their respective arms being marked B¹ and C¹.
The lugs are cast with recesses as clearly shown in the bottom lug in Fig. 1 (the
end of the arm being removed for that purpose), this recess I prefer to make slightly
tapering to the back, and the arms of wrot iron or steel are slightly tapered on
their edges so that they shall fit in their places without any play or slackness.
When the arms are all bolted into the lugs they project radially towards the
centre, and in this position the boss or hub D, is cast upon them, the method of
accomplishing this being well understood by any intelligent moulder; and when
this is done the bolts E are slackened to allow the arms to move, if drawn by the
contraction of the hub; for this purpose I also prefer to elongate the bolt hole in
the lug, a very little.

page_text: Either the hole in the lug or that in the arm should be square or oblong so as to
hold the bolt (which corresponds in shape) and prevents it from turning round
when the nut is being screwed upon it.
The four arms B¹ are held by the face of the lugs B, at a slight angle, and the
ends are therefore in the front part of the hub, but the increased angle of the
lugs C, throws back the arms C¹ so that their ends are embedded in the back part
of the hub as may be very clearly seen in Fig. 2; the arms C¹ therefore act as
struts, and their position gives great strength to the wheel.
I prefer to make one of the arms a little wider than the others, and to have one
of the lugs to match it, this will always enable the correct position of the arms in
the tyre, to be found without any trouble, but I do not confine myself to this
method as the same result may be attained by various means, such as altering the
shape of the end of one of the arms, so that it will only fitt into a correspondingly
shaped lug.
A lock nut may be used with advantage upon the bolt E.
Having now particularly described and ascertained the nature of my inven-
tion, and in what manner the same is to be performed I declare that what
I claim is:-
The construction of metallic wheels for tramcars and other vehicles, in the manner
substantially as herein before described and as illustrated.
In the manufacture of metallic wheels with removable tyres, the method of
constructing the central portion of the wheel so as to dispense with fitting or
machinery of the junction of the arms with the tyre, by first securing the arms in
their respective lugs and then casting the hub upon their jagged ends substantially
as described.