Improvements in Means for Connecting Crank Arms or Pedal Axle Arms to the Chain Wheels of Velocipedes.
Year: 1894

page_text: Date of Application, 22nd Mar., 1894
Complete Specification Left, 13th Nov., 1894-Accepted, 15th Dec., 1894
PROVISIONAL SPECIFICATION.
Improvements in Means for Connecting Crank Arms or Pedal Axle
Arms to the Chain Wheels of Velocipedes.
J, OLAF PIHLFELDT of 29 Golden Hillock Road, in the City of Birmingham,
Mechanical Engineer, do hereby declare the nature of this invention to be as
follows:-
My invention relates to improvements in means for directly connecting crank
arms or pedal axle arms to the chain wheels of velocipedes, and has for its object
primarily, simplifying the connection of the said parts.
In carrying out my invention, the head or boss of the crank is hollow or has an
axial and all through hole directed through its middle from back to front, and its
inner presented side or attachment part is provided with a small and narrow ring
flange or annular collar which has a neck of smaller diameter standing from its
face, and coming rearwards of and concentric with it.
Thus the inner presented face or connection side of the boss or head end of the
crank is collar-stepped which collar part is semi-circularly cross sunken at points
to form half key-ways for the reception of half parts of key studs employed for
preventing the rotation of the crank head upon the boss or nave of the chain wheel
when connected together as hereinafter described.
The middle of the front of the nave or boss of the chain wheel is sunken with an
annular recess equal in diameter and depth to the diameter and breadth of the
collar on the crank head and has a central hole within the sinking of a diameter
equal to the diameter of the neck and of a depth a little less than the depth of the
said neck, so as to admit of the metal at the outside edges of the neck being
slightly burred or expanded over the metal of the adjacent parts of the backside
of the nave of the wheel, so as to thereby prevent the lateral disconnection of the
said component parts.
Keyways are formed through the metal at the bottom of the sinking and within
the metal of the boundary walls surrounding it, so that the said boundary walls thus
have half or semi-circular key-ways whilst the metal at the bottom of the sinking
is pierced with full key ways, which keyways correspond with the half keyways
formed within the periphery of the collar of the crank head, so that when the
crank and chain wheel are put together, with the neck and flange of the one
respectively lying in the central piercing and annular sinking of the other, the
key-ways or half key-ways of both parts come together and intersect the joint or
seam at points, so that when studs or equivalents are passed in common through
and rivetted or otherwise secured therein the components thus united together are
prevented from rotating.
The connected-together components are secured to the crank axle by a cross
cottar pin or by an ordinary key in the usual way.
Dated this 21st day of March 1801

page_text: Improvements in Means for Connecting Crank Arms or Pedal Axle
Arms to the Chain Wheels of Velocipedes.
I, OLAF PIHLFELDT of 29 Golden Hillock Road, in the City of Birmingham,
Mechanical 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 :-
My invention relates to improvements in means for directly connecting crank
arms or pedal axle arms to the chain wheels of velocipedes, and has for its object
primarily, simplifying the connection of the said parts."
In carrying out my invention, the head or boss of the crank has an axial and all-
through hole directed through its middle from back to front, and its inner
presented side or attachment part is provided with a small and narrow ring flange
.or annular collar, which has a neck or annular extension, of small diameter, standing
from its face, and coming rearwards of and concentric with it.
Thus the inner presented face or connection side of the boss or head end of the
crank is collar-stepped, which collar part is semi-circularly cross sunken at points,
to form half key-ways for the reception of half parts of key studs or dowel pins
employed for preventing the rotation of the crank head upon the boss or nave of
the chain wheel when connected together as hereinafter described.
The middle of the front of the nave or boss of the chain wheel is sunken with an
annular recess, equal in diameter and depth to the diameter and breadth of the
collar on the crank head, and has a central hole within the sinking, of a diameter
equal to the diameter of the neck, and of a depth a little less than the depth of the
said neck, so as to admit of the metal at the outside edges of the neck being
burred or expanded over the metal of the adjacent parts of the backside, of the
nave of the wheel, so as to thereby prevent the lateral disconnection of the said
component parts.
Keyways are formed through the metal at the bottom of the sinking and within
the metal of the boundary walls surrounding it, so that the said boundary walls thus
have half or semi-circular key-ways whilst the metal at the bottom of the sinking
is pierced with full key ways, which keyways correspond with the half keyways
formed within the periphery of the collar of the crank head, so that when the crank
and chain wheel are put together, with the neck and flange of the oue respectively
lying in the central piercing and annular sinking of the other, the key-ways or half
key-ways of both parts come together and intersect the joint or seam at points, so
that when studs or equivalents are passed in common through and rivetted or
otherwise secured therein the components thus connected together are prevented
from rotating.
The connected-together components are secured to the crank axle by a cross
cottar pin or by an ordinary key in the usual way.
Figure 1 of the accompanying drawings represents a front elevation of a
detachable and combined crank and chain wheel, the parts of which are connected
together according to my invention.
Figure 2 represents a longitudinal vertical section of the same upon the dotted
lines - Figure 1.
Figure 3 represents a like vertical section as Figure 2, but before the
introduction of the dowel pins into the coincident key-ways of the respective
components.
Figure 4 represents a front elevation of the chain wheel separately, showing the
stepped sinking within the nave or boss, and the piercings through the said boss at
the junction of the sinking with the plain face.
Figure 5 represents front and side elevations of the crank or pedal axle arm.

page_text: Figure 6 represents a vertical section of the same upon the dotted line A, of one
of the views in Figure 5.
Figure 7 represents a vertical section of the chain wheel upon the dotted line B
Figure 4.
The same letters of reference indicate corresponding parts in the several figures
of the drawings.
a is a chain wheel, with the boss or nave a', having an annular and stepped
piercing a², as, for the reception of the ring flange or annular collar b', and neck or
extension 62, situated upon the inside part of the head or axle end 63, of the crank
or axle arm b. This said head or axle end of the crank has an axle hole or
piercing 6, through its middle, whilst the periphery of the flanged collar b', has
half key-ways or gaps 65, sunken within it in positions coming coincident with all-
through holes or key-ways a', situated at the junctions of the recessed part of the
boss with the face, through each of which coincident key-ways, a dowel pin or
rivet c, passes in common.
It will be observed that the collar flange b¹, is of the depth of the annular
sinking a², of the nave a', and that the neck or collar extension 62, is a little greater
than the depth of the contracted part a³, of the stepped piercing, so as to admit of
the end being expanded or turned over, as represented in the several figures.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
First. In detachable and combined cranks and chain wheels, securing or connecting
the one part to the other part by the means and in the way substantially as
described and set forth.
Secondly. In detachable and combined cranks and chain wheels, connecting a
crank, having a stepped inner part, to the boss or nave of a chain wheel, having a
she-stepped sinking and piercing, by dowel pins or rivets, and by spreading the
metal of the end of the neck part over the adjacent. edges of the other part,
substantially as described and set forth.
Dated this 12th day of November 1894.
OLAF PIHLFELDT,
By Henry Skerrett,
6, Livery Street, Birmingham, Agent for Applicant.