Improvements in the Manufacture of certain kinds of Tubular Fork Sides for Cycle Construction.
Year: 1897

page_text: Improvements in the Manufacture of certain kinds of Tubular Fork
Sides for Cycle Construction.
I, HENRY WALTON LUDLOW, of the Firm of Fisher and Ludlow, of 83, Rea Street,
Birmingham, Manufacturer, do hereby declare the nature of this invention to be
as follows:-
This invention has reference to the D section and oval taper tubular fork sides
for the steering forks of bicycles and other velocipedes motor carriages and the
like.
By my invention I am enabled to reduce the cost of manufacture of the said
tubular fork sides and to make them light and very strong.
I will first describe my invention as applied to the manufacture of a D section
curved tubular fork side for the front fork of a safety bicycle.
In carrying out this invention I make the said curved tubular fork side from
two sheet metal blanks one of these blanks being of the size and shape to form the
rounded side of the D and the other blank being of the shape and size to form
the flat of the same, the said blanks being made wide enough so that their edges
can be overlapped and seamed and closed together. For instance the taper curved
sheet metal blank to form the rounded side of the D is by suitable dies worked in
a stamp or press and raised to the required trough section with a narrow flange
or rib along each edge. The other curved taper blank to form the flat side of the D
is by dies worked in a stamp or press or by other means so that its edges are
raised upwardly so as to form a channel in which the other blank will lie. The
two blanks are now placed together and the upwardly turned edges of the flat blank
are by dies worked in a stamp or press or other means closed over the edges of the
rounded blank thus forming a rib of three thicknesses of metal along
each of the curved sides of the tube, which ribs are
turned up
and closed flat against the sides of the tube thus securely fixing the two blanks
together and making a curved taper tube of D-section. A mandril made in one
or more pieces corresponding in shape with the interior of the tube is or may
be inserted therein during the process of seaming the edges together as above
described. For extra security the two edges may be soldered or brazed.
now
The above described methods of forming tubular fork sides of D-section apply
in the same way to the formation of tubular fork sides or oval or fish-back shape
in cross section."
My invention is similarly applied to making those tubular fork sides which are
of a straight taper form.

page_text: Improvements in the Manufacture of certain kinds of Tubular Fork
Sides for Cycle Construction.
I, HENRY WALTON LUDLOW, of the Firm of Fisher and Ludlow, of 83, Rea Street,
Birmingham, Manufacturer, do hereby declare the nature of this invention and in
what manner the same is to be performed, to be particularly described and ascer-
tained in and by the following statement:-
This invention has reference to the curved D-section and oval taper tubular fork
sides for the steering forks of bicycles and other velocipedes and the like.
By my invention I am enabled to reduce the cost of manufacture of the said
tubular fork sides and to make them light and very strong.
.
I will describe my invention by referring to the accompanying drawing on
which Fig. 1 is a side elevation of a curved D-section taper tubular fork side
constructed according to this invention; and Fig. 2 is a side view of same; Fig. 3 is a
cross section of the same on line xx of Figs. 1 and 2 and Fig. 3* is an enlarged
cross section of one of the side joints of the said tubular fork side;
Figs. 4 and 5 are respectively cross sections of the two sheet metal
stampings of which the D-section taper tubular side fork is formed;
Fig. 6 is
a cross section representing the two stampings shewn by
Figs. 4 and 5 in position ready to be secured together in the manner
represented in cross section by Fig. 7; Fig. 8 is a cross section of an oval section
taper tubular fork side constructed according to this invention for the steering
fork of a bicycle or other velocipede or motor carriage or the like; Fig. 8* is an
enlarged cross section of one of the side joints of the said oval taper tubular fork
side shewn by Fig. 8; Figs. 9 and 10 are respectively cross sections of the two sheet
metal stampings of which the oval taper tubular fork side represented by Fig. 8
is formed; Fig. 11 shews in cross section the two sheet metal stampings shewn
by Figs. 9 and 10 ready to be secured together in the manner represented in cross
section by Fig. 12..
The same letters of reference indicate the same or corresponding parts in all
the figures.
I will first refer to Figs. 1 to 7 both inclusive and describe how my invention
is applied to the manufacture of the curved tubular fork sides of D-section.
In carrying out my invention I make the said curved tubular fork side from two
sheet metal blanks one of these blanks being of the size and shape to form the
rounded side A of the D-section tube and the other blank being of the shape and
size to form the flat side B of the same, the said two blanks being made wide enough
for their edges to be overlapped and seamed and closed together in the manner
hereinafter described. The taper curved sheet metal blank to form the rounded
side A of the D-section tube is by suitable dies in a stamp or press raised to the
required trough section shewn by Fig. 4 with a narrow flange or rib a¹ a² along
each edge so that the cross section of this blank will now be as represented by Fig. 4.
The other curved taper blank to form the flat side B of the D-section tube has
its edges 61 62 raised upwardly by dies in a stamp or press or by other means so
that this blank will now have the shape in cross section represented by Fig. 5 form-
ing a channel in which the other blank A will lie. The two blanks A B are now
placed together as shewn in cross section by Fig. 6 the blank A.lying on the stamped
blank Band within the turned up edges 6 6% of the same. The upwardly turned
edges 61 62 of the flat blank B are now by dies in a stamp or press or by other
means closed over the flat edges a¹ aª of the rounded blank A thus forming a rib
of three thicknesses of metal along each of the curved sides of the tube as shewn

page_text: in Fig. 7 which ribs are marked 6s 6 and are now turned up and closed against
the sides of the tube as represented in Figs. 3 and 3* thus securely fixing the two
blanks A and B together and making a curved taper tube of D-section as repre-
sented in Figs. 1, 2 and 3.
If desired, a mandril corresponding in shape with the interior of the tube is
or may be inserted therein during the final process of turning up the edges 63 64
against the edges of the tube as represented by Fig. 3 and Fig. 3*, but I do not find
that any such mandril is necessary, such mandril if used will have to be made in
two or more parts to permit of its removal from the tube. After the edges of the
two blanks A and B have been secured together in the manner above described
the tube is brazed or soldered internally at c¹ 2 so as make the same perfectly
rigid.
The above described method of forming the tubular fork side of D-section
applies in the same way to the formation of a tubular fork side of oval or fish
back cross section as represented by Fig. 8 and which is formed of the two sheet
metal stamped blanks A¹ B. This will be clear by an examination of Figs. 9, 10, 11
and 12 where it will be seen that the oval or fish back section tubular fork side
represented in cross section by Figs. 8 and 8* is formed of two stamped sheet
metal blanks A¹ B¹ which are respectively made of the same taper curved shape
as are the two blanks A B but the blank B is made rather wider than the
blank B so as to allow of its being stamped to the semi-oval section represented
in Fig. 10. The blank A¹ has a narrow flange or rib a¹ a² along each side like
those on the blank A and the blank B₁ is also made with projecting side
flanges 63 b and turned up edges 61 62 to receive the top blank A¹ which fits
therein as represented by Fig. 11 and after the two parts A¹ B¹ have been placed
together as shewn in Fig. 11 the upwardly turned edges 61 62 of the blank B¹ are
closed down upon the flanges a¹ a² of the blank A¹ thus securing the two
blanks A B together as represented in Fig. 12 and forming the two projecting
side flanges b b which are afterwards turned upwardly against the sides of the
tube forming the two ribs 63 64 along the tube as represented in Figs. 8 and 8*.
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. A curved D-section taper tubular fork side for the steering forks of bicycles
and other velocipedes and the like consisting of the two sheet metal blanks B
formed and joined together at their edges in the manner substantially as herein-
before described and illustrated by Figs. 1 to 7 both inclusive of the accompany-
ing drawings.
2. A curved oval section taper tubular fork side for the steering forks of bicycles
and other velocipedes and the like consisting of the two sheet metal blanks A¹ B¹
formed and joined together at their edges in the manner substantially as herein-
before described and illustrated by Figs. 8 to 12 both inclusive of the accompany-
ing drawings.
Did th
Da 100%
CHARLES BOSWORTH KETLEY,
Agent for the Applicant.