Improvements in or connected with Velocipedes.
Year: 1891

page_text: Date of Application, 18th Nov., 1891
Complete Specification Left, 18th Aug., 1892-Accepted, 24th Sept., 1892
PROVISIONAL SPECIFICATION.
Improvements in or connected with Velocipedes.
I, ROBERT WALKER SMITH, of the Butts, Coventry, in the County of
Warwick, Machinist, do hereby declare the nature of this invention to be as
follows
This invention has for its object a novel and simple method of attaching and
detaching the chain wheels of velocipedes to and from the crank axle. I take the
crank axle of a machine and braze or key thereon a boss which is turned to fit
chain wheel, the said chain wheel has a hole bored sufficiently large to pass over
the crank without removing the same, and also has two lugs upon its boss which fit
into two suitably machined spaces upon the aforesaid boss of the crank axle. The
chain wheel is also further secured by means of a nut screwed upon the boss which
nut clamps the wheel and boss together. Other suitable methods may be used
embodying the same principles.
For example, I sometimes prefer, instead of using two lugs left in boss of the
chain wheel, to insert a key in the wheel and boss of the crank axle.
Dated this 10th dor of Navarchar 1901
VAUGHAN & SON,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in or connected with Velocipedes.
I, ROBERT WALKER SMITH, of the Butts, Coventry, in the County of
Warwick, Machinist, 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 said invention has for its object a novel and simple method of attaching and
detaching the chain wheels of velocipedes to and from the crank axle. I take the
crank axle of a machine and braze or key thereon, a boss which is turned to fit
chain wheel, the said chain wheel has a hole bored sufficiently large to pass over
the crank without removing the same and also has two lugs upon its boss which fit
into two suitably machined spaces upon the aforesaid boss of the crank axle. The
chain wheel is also further secured by means of a nut screwed upon the boss which
nut clamps the wheel and boss together. Other suitable methods may be used
embodying the same principles.
For example, I sometimes prefer, instead of using two lugs left in boss of the
chain wheel, to insert a key in the wheel and boss of the crank axle.
And in order that the said invention may be more clearly understood and readily
carried into effect I will proceed aided by the accompanying drawings more fully
to describe the same.
DESCRIPTION OF THE DRAWINGS.
Figure 1. is a vertical longitudinal section of a portion of the crank axle of a
velocipede and connected parts having my invention applied thereto.

page_text: Figure 7. is a face view of the nut employed to secure the chain wheel in
position.
Figure 8. is an edge view thereof.
Figure 9. is a face view of the key employed to turn the nut.
Figure 10. is a similar view to Figure 1. but illustrating a slight modification,
and,
Figure 11. is an end view thereof.
in the several figures like parts are indicated by similar letters of reference.
Referring to Figures 1. to 9. a. represents the crank axle, b. represents the crank,
and c. represents the chain wheels.
Upon a reduced part a¹ of the crank axle a. is fixed, by means of a key c²,
a boss c¹ the same being previously shrunk on to the axle, or, in lieu of keying it
thereon, it might be shrunk on and brazed, as will be readily understood.
Upon the boss c is formed a flange c³ and in this flange c³ are formed slots or
recesses for the purpose hereinafter described.
The chain wheel c. is formed with a central aperture c* of a size to pass easily
over the crank b. without the necessity for removing the latter, and the boss c¹ is
turned to fit the central aperture of the chain wheel c.
The chain wheel c. is formed with two lugs or projections c*1 which, when the
chain wheel c. is placed in position upon the boss c', fit into the slots or recesses c
in the flange thereof, and thus securely lock the chain wheel c. and boss e¹
together, whilst, in order to hold the chain wheel c. in place, the boss c¹ is formed
with a left hand thread, and a nut correspondingly threaded is screwed thereon
with the aid of a key d. which is formed with a lug or projection d to fit a corre-
sponding notch c* in the nut c.
It will be understood that the chain wheel c. may be fixed to the boss c¹, by any
suitable means, other than those hereinbefore described, and, such, for example as
those represented at Figures 10. and 11.
.*1
In this example, the slots or recesses in the flange and the corresponding
lugs c upon the chain wheel c. are dispensed with, and in lieu thereof key-ways
are formed partly in the boss c' and flange and partly in the chain wheel c. to
receive loose keys which key the chain wheel c. and boss c¹ securely together,
the nut securing the keys e* against accidental displacement.
By the arrange of parts herein before described, I obtain a simple means of
readily mounting or dismounting the chain wheel without the necessity for detaching
the crank or other parts.
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 1
claim is :-
1. In a velocipede, the combination of a chain wheel formed with a large central
aperture, a boss fixed upon the crank axle and fitting the central aperture of the
chain wheel and means for fixing the boss with the axle and holding the same in
position, substantially as herein shown and described and for the purpose stated.
2. In a velocipede, the combination of a chain wheel formed with a large central
aperture, a boss fixed upon the crank axle and fitting the central aperture of the
chain wheel, slots or recesses in the boss, corresponding lugs or projections upon
the chain wheel, a screw thread upon the boss, and a nut screwing thereon,
substantially as herein shown and described and for the purpose stated.
Dated this 18th day of August 1805
VAUGHAN & SON,
Agents for the Applicant.