Improvements in Tramway Points.
Year: 1889

page_text: Date of Application, 7th Feb., 1889
Complete Specification Left, 7th Nov., 1889-Accepted, 7th Dec., 1889
PROVISIONAL SPECIFICATION.
Improvements in Tramway Points.
1, THOMAS TWEDDELL of Hartlepool in the County of Durham, Manager of The
Hartlepool Steam Tramways Company Limited do hereby declare the nature of this
invention to be as follows:-
My invention is applicable to all tramways in which the flange of the wheel runs
in a sunk groove but is specially applicable to steam tramways on which there is
great danger, with the existing points, of the wheels taking the wrong grooves
or of taking opposite grooves thereby causing either serious trouble in loss of timo
or the more serious consequences resulting from straining or breaking wheels or
axles.
14
According to my invention I make both the groove and the flange of the "open"
point with a gradual depression commencing at the narrow end of the point aud
reaching its lowest point at, or about, the place where the two grooves diverge and
thence rising to the normal levels of the groove and flange of the rail. Thus tho
"tread" of the wheel of the locomotive or car, entering from the narrow end of the
point, follows the depression of the rail and the flange is imprisoned in the depressed
groove until the opposite wheel has taken the proper groove in the closed point.
Dated this 7th day of February 1889
T. J. DANSON,
Per L. W.
COMPLETE SPECIFICATION.
Improvements in Tramway Points.
I, THOMAS TWEDDELL, of Hartlepool, in the County of Durham, Manager of the
Hartlepools Steam Tramways Co. Limited do hereby declare the nature of said
invention and in what manner the same is to be performed to be particularly
described and ascertained in and by the following statement :-
My invention is applicable to all tramways in which the flange of the wheel runs in
a sunk groove but is specially applicable to steam tramways on which there is great
danger, with the existing points, of the wheels taking the wrong grooves or of taking
opposite grooves thereby causing, either serious trouble in loss of time or the more
sorious consequences resulting from straining or breaking wheels or axles.
According to my invention I make both the groove and the flange "or tread" of
the "open" point with a gradual depression commencing at the narrow end of the
point and reaching its lowest point at, or about, the place where the two two grooves
diverge and thence rising to the normal levels of the groove and flange or "tread" of
the rail. Thus the "tread" of the wheel of the locomotive or car, entering from the
narrow end of the point, follows the depression of the rail and the flange; and is
imprisioned in the depressed grooves until the opposite wheel has taken the proper
groove in the closed point.

page_text: Figs. 4 and 5 are diagrams of 2 forms of changing into sidings or passing places
the full and dotted arrows indicating the direction in which the cars are running. As
soon as the wheel of the car, travelling in the direction of the full arrows, reaclies the
point the flange enters into the inclined groove and the "trend" of the wheel upon the
inclined flange of the point the wheel flange being imprisioned until it reaches
the point where the groove and mail flange rise again to the normal level the opposite
wheel having meanwhile been compelled to take the proper groove in the opposite
point. Thus it is impossible either that both wheels can take the wrong groove or
one wheel the right and the other the wrong groove.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed declare that what I
claim is
The improvements in trainway points consisting in making the groove and the
rail flange at the narrow, or "taking on," end with a gradual depression reaching
the lowest point at or abont, the place where the two grooves diverge and thence
rising gradually to the normal level substantially as described and illnstrated with
the objects herein before stated.
T. J. DANSON, F. Inst. P. Agents,
2, St. Nicholas Buildings, Newcastle-upon-Tyne, Agent for Applicant.