Improvements in Tandem Bicycles.
Year: 1893

page_text: Date of Application, 9th Aug., 1893
Complete Specification Left, 3rd May, 1894-Accepted, 16th June, 1894
PROVISIONAL SPECIFICATION.
Improvements in Tandem Bicycles.
I JOHN VERNON PUGH of Whitworth Works Rea Street South Birmingham
in the County of Warwick Mechanical Engineer do hereby declare the nature of
this invention to be as follows:-
My invention has reference to those bicycles commonly called tandem safety
bicycles and consists in constructing and arranging the parts of the said bicycles in
the manner hereinafter described whereby the distance between the first driving
chain wheel and the second driving chain wheel inay be adjusted so as to keep the
requisite tension on the front driving chain of the bicycle. The tension on the
rear driving chain is maintained in the ordinary way. My invention consists
further in arranging the fixed handle bar for the rear rider in the manner herein-
after described whereby a separate post for the rear handle bar is dispensed with.
I construct the front part of the framing of the bicycle in the ordinary way but
I connect the bearing bracket for the crank axle of the front driving chain wheel
to the framing of the bicycle carrying the rear or driving wheel of the bicycle by
means of two parallel rods situated in a plane parallel with the plane on which
the two wheels of the bicycle travel.
I make the bearing bracket of the rear driving chain wheel separate from the
frame of the bicycle and connect it to the said frame by means of a clip the upper
half of which is carried by the said bearing bracket and the lower half is secured
thereto by means of screws. The said clip takes onto and embraces the two
parallel rods connecting the bearing bracket of the front driving chain wheel to the
framing of the bicycle carrying the rear or driving wheel.
By unscrewing the screws of the clip the tension of the two parts on the parallel
rods may be relaxed and the said clip and bearing bracket carried by it may be
adjusted on the said parallel rod, and by driving home the screws of the clip the
movable bearing bracket may be refixed in its adjusted position.
I prefer that the two chain wheels on the rear crank axle shall consist of two
chain rings carried by arins made in one piece with the crank.
My invention consists further in providing the rear handle bar at its middle with
a clip for taking upon and permitting of the adjustment of the handle bar on the
seat pillar of the front saddle.
My improvements may be applied to tandem safety bicycles for more than two
riders by making the two parallel rods connecting the front or fixed bearing bracket
with the framing of the bicycle carrying the rear or driving wheel of a sufficient
length to receive two or more movable bearing brackets the rear handle bars for
the several riders being fixed to the seat posts immediately in front of the riders
respectively.
Dated the 9th day of August 1893.
W. T. WHITEMAN,
Agent for the Applicant.

page_text: Improvements in Tandem Bicycles.
1 JOHN VERNON PUGH of Whitworth Works Rea Street South, Birmingham
in the County of Warwick Mechanical Engineer do hereby declare the nature of
my 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 has reference to those bicycles commonly called tandem safety
bicycles and consists in constructing and arranging the parts of the said bicycles
in the manner hereinafter described whereby the distance between the first driving
chain wheel and the second driving chain wheel may be adjusted so as to keep the
requisite tension on the front driving chain of the bicycle. The tension on the rear
driving chain is maintained in the ordinary way. The fixed handle bar for the
rear rider may be arranged in the manner hereinafter described whereby a separate
post for the rear handle bar is dispensed with.
I construct the front part of the framing of the bicycle in the ordinary way but
I connect the bearing bracket for the crank axle of the front driving chain wheel
to the framing of the bicycle carrying the rear or driving wheel of the bicycle by
means of two parallel rods situated in a plane parallel with the plane on which the
two wheels of the bicycle travel.
I make the bearing bracket of the rear driving chain wheel separate from the
frame of the bicycle and connect it to the said frame by means of a clip the upper
half of which is carried by the said bearing bracket and the lower half is secured
thereto by means of screws. The said clip takes onto and embraces the two
parallel rods connecting the bearing bracket of the front driving chain wheel
to the framing of the bicycle carrying the rear or driving wheel.
By unscrewing the screws of the clip the tension of the two parts on the parallel
rods may be relaxed and the said clip and bearing bracket carried by it may be
adjusted on the said parallel rods and by driving home the screws of the clip the
movable bearing bracket may be refixed in its adjusted position.
I prefer that the two chain wheels on the rear crank axle shall consist of two
chain rings carried by arms made in one piece with the crank.
The rear handle bar is provided at its middle with a clip for taking upon and
permitting of the adjustment of the handle bar on the seat pillar of the front saddle.
My improvements may be applied to tandem safety bicycles for more than two
riders by making the two parallel rods connecting the front or fixed bearing
bracket with the framing of the bicycle carrying the rear or driving wheel of a
sufficient length to receive two or more movable bearing brackets the rear handle
bars for the several riders being fixed to the seat posts immediately in front of the
riders respectively.
Figure 1. of the accompanying drawings represents in side elevation a tandem
bicycle containing my improvements.
Figures 2. 3. and 4. represent respectively in side elevation; end elevation and
plan that part of the frame of the said taudem bicycle carrying the rear bottom or
bearing bracket for the crank axle of the rear rider;
Figure 5 represents the same view as Figure 2 with the crank and chain wheels
removed and
Figure 6. is a cross section on the line . z. Figure 4, drawn to a larger scale;
Figures 7. and 8. represent in side elevation and plan that part of the front seat
pillar carrying the handle for the rear rider.
The same letters of reference indicate the same parts in the several figures of
the drawings.
a. a. are the two parallel rods of the lower part of the framing of the bicycle
connecting that part of the said framing carrying the front bottom or bearing

page_text: bracket b. for the crank axle of the front driving chain wheel with the part of the
framing of the bicycle carrying the rear or driving wheel c.
The rear bottom or bearing bracket for the rear crank and rear driving chain
wheel axle is carried by the lower half d. of a clip, the upper half of the said clip
being composed of two separate plates d³, d³, bolted to the lower halfd. by the screw
bolts e. e. e, the parts of the said clip gripping the parallel rods a. a. of the frame
between them as best seen in Figures 3. and 6. The front driving-chain wheel f. (see.
Figure 1.) gears with the chain wheel g. on the axle of the rear driving chain
wheel h. the said rear driving chain wheel h. gearing directly with the chain wheel
on the rear or driving wheel c. of the bicycle as usual.
In order to ensure that the chain wheels g. h shall rotate together and to prevent
the possibility of either of the said wheels becoming loose with respect to the
other I construct them of two interchangeable chain rings secured to one set of
chain ring carrying arms as illustrated in Figure 2. the said chain ring carrying
arms being by preference in one piece with the crank arm.
When it is required through wear or from any other cause to re-adjust the
tension on the front driving chain of the bicycle it is only necessary to unscrew the
nuts e. e. e, and thereby relax the grip of the clip d. d', d², on the parallel rods a. a.
of the frame when the rear bottom or bearing bracket may be adjusted and fixed in
its adjusted position by sliding the said clip d. d', d, on the parallel rods a. a. and
screwing home the screw nuts e. e. e², of the clip.
The adjustment of the tension of the rear driving chain is effected in the
ordinary way.
The handle i. for the rear rider is fixed by means of the clip k on the front seat
pillar 1. as best seen in Figures 7. and 8. and an independent handle post for the rear
rider is thereby obviated the weight and cost of manufacture of the bicycle being
consequently reduced.
Having now particularly described and ascertained the nature of my invention
and in what manner the same is to be performed I declare that I claim as my
invention:
In tandem bicycles, connecting the bottom or bearing bracket, for the front.
crank and driving chain wheel axle, to that part of the framing of the bicycle
carrying the rear or driving wheel by means of two parallel reds and connecting the
bottom or bearing bracket, for the rear crank and driving chain wheel axle, to the
said rods by means of an adjustable clip for the purpose and substantially as.
hereinbefore described and illustrated in the accompanying drawings.
Dated the Second day of May 1894.
JOHN VERNON PUGH.