Year: 1897

page_text: I, THOMAS WILLIAM BLUMFIELD, of 11, Wren Street, Coventry, in the County of
Warwick, Engineer, do hereby declare the nature of this invention to be as follows:-
This invention consists of improvements relating to cycles and other vehicles having
chain driving gear, my object being to so construct and arrange the framing of such
vehicles that the compression tubes on the driving side forming an integral part of
the framing, shall serve also as chain guards or as a gear case.
In the application of my invention to cycles I form a disc like projection at the
chain wheel side of the bottom bracket of the cycle frame, such projection having its
circular edge turned at right angles in an outward direction for the purpose of
enclosing the wheel. Upon the side of such bottom bracket disc nearest to the rear
end of the frame I provide a pair of lugs or projections each having an eye or aperture
extending through it to permit of the passage of the chain. Within such lugs I
braze or otherwise secure one end of the stay tubes which have their opposite ends
secured to similar lugs formed with the fork end adjacent to the driven chain wheel.
The endless chain connecting the driving and driven chain wheels in the ordinary
manner is caused to pass through the said tubes which form a rigid connection
between the bottom bracket and the fork end, and thus stiffen or strengthen the
framing.
To provide ample freedom for the chain when in motion I preferably make the
connecting tubes hereinbefore described of a parabolical or other configuration that
will give a maximum space for the chain about mid-way between the wheels.
I do not limit the application of my invention to cycles of any one form or pattern
but adapt the same with such modifications as may be necessary to such machines of
varying types, and to mechanically propelled carriages of any description where the
power is transmitted by means of pitch chains and chain wheels.
In order to minimise or avoid rattle caused by the chain swaying and striking the
inside of the tubes, I sometimes line the insides of the two tubes with any suitable
fabric, such as flannel or canvas; or I apply a coating to form a silencing cushion in
the form of a solution or paint such as finely ground cork, rubber, or any suitable
material that will resist the action of oil.
MARKS & CLERK,
18, Southampton Buildings, London, W.C., and
13, Temple Street, Birmingham, Agents for the Applicant.

page_text: I, THOMAS WILLIAM BLUMFIELD, of 11, Wren Street, Coventry, 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 relating to cycles and other vehicles
having chain driving gear, my object being to construct and arrange the framing of
such vehicles that the compression tubes on the driving side forming an integral
part of the framing shall serve also as chain guards or as a gear case.
In the accompanying sheets of explanatory drawings to be hereinafter referred
to:
'
Figure 1 is an elevation, Figure 2 a part sectional plan, and Figure 3 a sectional
end view of my improved cycle chain guard or gear case.
The same reference letters in the different views indicate the same parts.
In the application of my invention to cycles I form or attach a disc like projec-
tion as A at the chain wheel side of the bottom bracket B of the cycle frame, such
projection having its circular edge turned at right angles in an outward direction
for the purpose of enclosing the wheel C. Upon the side of such bottom bracket
disc A nearest to the rear end of the frame I provide a pair of lugs or projec-
tions A¹ A² each having an eye or aperture extending through it to permit of the
passage of the chain D. Within such lugs I braze or otherwise secure one end of
the stay tubes E E¹ which have their opposite ends secured to the similar lugs formed
with the forked end or the two part hinged rear disc F adjacent to the driven chain
wheel G. The rear disc F is connected to the cycle-frame by means of the hollow
lug or projection F¹ into which the lower end of one of the back stay tubes (as H)
of the frame is brazed or otherwise secured.
The endless chain D connecting the driving and driven chain wheels in the ordinary
manner is caused to pass through the said tubes E E¹ which form a rigid connection
between the bottom bracket and the fork end, and thus stiffen or strengthen the
framing.
To provide ample freedom for the chain when in motion I preferably make the
connecting tubes E E¹ of a parabolical or other configuration that will give a
maximum space for the chain about mid-way between the wheels. The cross
stay H increases the rigidity or stiffness of the combined stay tubes and the chain
guards E E¹.
In order to minimise or avoid rattle caused by the chain swaying and striking the
inside of the tubes, I sometimes line the insides of the two tubes with any suitable
fabric, such as flannel, leather, or canvas, or thin wood; or I apply a coating to form
a silencing cushion in the form of a solution or paint such as finely ground cork
rubber, or any suitable material that will resist the action of oil.
I sometimes make the disc A from two parts hinged together after the manner of
the rear disc F, instead of in one piece as illustrated. To permit of inspection of
the chain I provide sight apertures in one of the tubes E or E¹ and close the
same with spring or clip like cover pieces such as indicated by the dotted lines J J¹
(Figure 1).
I do not limit the application of my invention to cycles of any one form or pattern
but adapt the same with such modifications as may be necessary to such machines
of varying types, and to mechanically propelled carriages having frames similar to that
of a cycle and in which the power is transmitted by means of pitch chains and chain
hools

page_text: 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 cycles and other vehicles having chain driving gear, the arrangement of
the compression or stay tubes integral with the driving side of the frame in such a
manner as to permit of the chain passing through them substantially as and for the
purpose described.
2. The arrangement and combination of parts forming the improved gear case for
a cycle or other vehicle, substantially as described and as illustrated.
Dated this 9th day of December 1897.
MARKS & CLERK,
18, Southampton Buildings, London, W.C., and
13, Temple Street, Birmingham, Agents for the Applicant.