Improvements in Cycle Fork Crowns.
Year: 1899

page_text: Improvements in Cycle Fork Crowns.
I, THOMAS WILLIAM BLUMFIELD, of 157, Victoria Road, Aston, in the County..
of Warwick, Engineer, do hereby declare the nature of this invention to be as
follows:
This invention consists of improvements in fork crowns for cycles, my object
being to provide in a ready and convenient manner strong and durable crowns
of the box type or pattern and to neatly and rigidly secure the same with the D
or other shaped steering forks
I produce a box crown shell in accordance with my invention from a solid
piece of steel or other metal the centre of which is bored right through for the
reception of the lower end of the steering tube, and on each side of such central
clear way aperture I bore out the metal to form sockets for the upper ends of
the forks. Such fork sockets or apertures do not pass right through the clown
shell as with the central aperture, but terminate sufficiently short of its upper
side to leave sufficient metal to serve as end covers. The outer surfaces of the
bar or piece of metal are suitably machined to the desired shape and I thus pro-
duce from the solid metal a light, neat, and durable fork crown shell.
I sometimes make my shells from castings, and also from sheet metal by sub-
jecting such metal to ordinary piercing, pressing, or drawing through processes.
For the purpose of adapting the end or outer circular apertures or sockets
in fhe crown for the reception of D shaped tubular forks, and for closing or
covering the lower side of the central or steering tube aperture, I employ a cover
plate shaped to suit the outer configuration of the crown and having its ends
suitably formed and bent to enter the fork apertures therein. A portion of each
fork aperture is thus closed and an open portion of D section is provided for the
reception of the fork end, whilst at the same time the lower end of the central
aperture is sealed or closed On the brazing of the fork ends the crown and its
cover plate are very effectually and rigidly secured therewith.
In order that the outer face of the cover plate shall finish flush or level with
the lower edges of the fork crown, I cut away the central portion of such edges
for a depth equal to the thickness of the cover plate to form recesses for the
reception of the said plate.
As an alternative method of constructing my box crown I take a piece of steel
or other metal and make all three of the bored holes to receive the end of the
steering tube and the ends of the forks, terminate sufficiently short of the under
side of the crown as to leave no through aperture for the fork stem. I then cut
away portions of the bottoms of the side apertures of suitable shape to allow
the forks of D or other section to pass through. The cover plate for the top
of the crown shell has a central aperture to pass over the steering tube and
suitable projections on its under side to engage with the upper end of the forks

page_text: inside the crown shell. On the brazing of the forks they are united firmly and
securely with the crown shell and top cover plate, making a strong and rigid
construction without any aperture.
A
L
1900
MARKS & CLERK,
18, Southampton Buildings, London, WC.,
13, Temple Street, Birmingham, & 25, Cross Street, Manchester,
Agents for the Applicant.
I, THOMAS WILLIAM BLUMFIELD, of 157, Victoria Road, Aston, in the County
of Warwick, Engineer, do hereby declare the nature of this invention and in what
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement:-
This invention consists of improvements in fork crowns for cycles, my object
being to provide in a ready and convenient manner strong and durable crowns
of the box type or pattern having the D or other shaped steering forks neatly and
rigidly secured thereto.
Such fork
I produce my box crown shell preferably from a solid piece of steel or other
metal the centre of which is bored right through for the reception of the lower
end of the steering tube, whilst on each side of such central clear way aperture
I bore out the metal to form sockets for the upper ends of the forks
sockets or apertures do not pass right through the crown shell as with the central
aperture, but terminate sufficiently short of its upper side to leave enough metal
to serve as end covers. The outer surfaces of the bar or piece of metal are suit-
ably machined to the desired shape.
I sometimes make my shells from castings, and also from sheet metal by sub-
jecting such metal to ordinary piercing, piessing, or drawing through processes.
For the purpose of adapting the end or outer circular apertures or sockets
in the crown for the reception of D shaped tubular forks, and for closing or
covering the lower side of the central or steering tube aperture, I employ a cover
plate shaped to suit the outer configuration of the crown and having its ends
suitably formed and bent to enter the fork apertures therein. A portion of each
fork aperture is thus closed and an open portion of D section is provided for the
reception of the fork end, whilst at the same time the lower end of the central
aperture is sealed or closed. On the brazing of the fork end the crown and its
cover plate are very effectually and rigidly secured therewith
In order that the outer face of the cover plate shall finish flush or level with
the lower edges of the fork crown, I cut away the central portion of such edges
for a depth equal to the thickness of the cover plate to form recesses for the
reception of the said plate.
As an alternative method of constructing my box crown I take a piece of steel
or other metal and make all three of the bored holes to receive the end of the
steering tube and the ends of the forks, terminate sufficiently short of the under-
side of the crown as to leave no through aperture for the fork stem. I then cut
away portions of the bottoms of the side apertures, of suitable shape to allow
the forks of D or other section to pass through. The cover plate for the top
of the crown shell has a central aperture to pass over the steering tube and
suitable projections on its under side to engage with or abut against the upper

page_text: end of the forks inside the crown shell. On the brazing of the forks they are
united firmly and securely with the crown shell and top cover plate, making a
strong and rigid construction without any aperture.
On the accompanying sheet of explanatory drawings to be hereinafter referred
to.-
Figure 1 is an elevation and Figure 2 a plan of the top or upper side of my
box crown shell, whilst Figure 3 is a sectional elevation and Figure 4 a plan
of the bottom or lower side of the same.
Figure 5 is an elevation and Figure 6 a plan of the cover plate for the bottom
or lower side of the crown.
Figure 7 is a sectional elevation and Figure 8 a plan showing the crown shell
with the cover plate in position.
The same reference letters in the different views indicate the same parts.-
The shell A is formed from a block of solid metal by drilling or boring aper-
tures as a a¹ and a therein the central aperture a (for the reception of the
steering tube) extends right through the block, but the side apertures a¹ and a
do not pass right through the block but from sockets as shown for the reception
of the upper ends of the forks. The said sockets are adapted to correspond with
the Dor like shape fork ends which are inserted therein, by the employment
of a cover plate B having its ends turned back and in as shown. Small recesses
as c are formed in the metal of the crown or block A in order that the outer
surface of the plate B shall lie flush with the lower edges of the crown.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is:-
1. In cycle fork crowns, the combination with a hollow shell as A having
a central aperture for the reception of the steering tube and a pair of side sockets
for the reception of the upper ends of the steering forks, of a cover plate as B
having ends turned back and in and arranged to fit within the said side sockets,
substantially as and for the purposes described and as illustrated.
2-The arrangement and combination of cycle fork crown shells with cover
plates having projections which enter the said shells and engage or abut against
the upper ends of the steering forks fitted therein, substantially as described.
Dated this 10th day of November 1800.
MARKS & CLERK,
18, Southampton Buildings, London, WC.,
25, Cross Street, Manchester, & 13. Temple Street, Birmingham,
Agents for the Applicant.