Improvements in Bottom Brackets for Tandem and other Safety Bicycles.
Year: 1895

page_text: Date of Application, 25th Feb., 1895
Complete Specification Left, 16th Oct., 1895-Accepted, 16th Nov., 1895
PROVISIONAL SPECIFICATION
Improvements in Bottom Brackets for Tandem and other Safety
Bicycles.
I, GEORGE LUCкMAN of 32 Newtown Row Birmingham, Cycle Manufacturer
do hereby declare the nature of this invention to be as follows :-
My invention consists of improvements in bottom-brackets for tandem and other
safety bicycles; by means of which the adjustment of the chain, of the bicycle is
greatly facilitated.
I accomplish this by making the bottom bracket in two distinct parts, instead
of one piece of metal as is usual. These parts I will call the "barrel" and
the "lugs."
The lugs" are made as usual from one casting or stamping of metal, to braze
to the tubes of the frame, but are distinct from the barrel.
The barrel is a casting or stamping of metal, bored to carry the chain wheel
spindle, and has a flat surface upon one side; and is constructed so as to slide
evenly over a similar face on the underside of the "lugs," in the direction of the
bottom tubes of the bicycle frame, and is kept in a direct line with the path of the
chain by means of two studs which protrude from the metal of the barrel, and are
made to fit the inside of the bottom tubes of the bicycle frame.
The adjustment of the loose barrel which carries the chain wheel and spindle, is
accomplished by an ordinary set screw and locknut, carried by a boss made solid
with the part of the bracket I have described as the " lugs," thus effecting the
adjustment of the chain of the bicycle. This improvement applies to ordinary
safety bicycles also.
Dated this 23rd day of February 1895.
Improvements in Bottom Brackets for Tandem and other Safety
Bicycles.
I, GEORGE LUCKMAN of 32 Newtown Row, Birmingham, Warwick, Cycle
Manufacturer 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 consists of improvements in bottom brackets of tandem safety
bicycles; by means of which the adjustment of the chain of the bicycle is.
facilitatied.
I accomplish this by making the bottom bracket in two distinct parts, which I
call the barrel and the lugs.
In my drawing B is the barrel, and the lugs which are cast or stamped in one
piece I will call L.
The barrel B is grooved out in the form of a dovetail, and a projecting slide
formed out of the metal of the lugs L, fits in the groove, so that the barrel moves

page_text: freely along it in the direction of the bottom tubes of the bicycle frame T. T; the
barrel being kept in a direct line with the path of the chain of the bicycle by two
studs S S, which protrude from the metal of the bracket, and are made to fit the
inside of the bottom tubes of the bicycle frame T. T.
The adjustment of the barrel, which is necessary to tighten or loosen the bicycle
chain, is accomplished by means of an ordinary screw A.
The socket of the lug casting, and the ends of the tubes T. T, are split, where
the studs of the barrel fit into them, and the pins G G, prevent the barrel moving,
when the bicycle chain is adjusted.
Having now particularly described and ascertained the nature of my said
invention, and the manner the same is to be performed, I declare that what I
claim is.
Improvements in bottom brackets of tandem bicycles in which the barrel is free
from the lugs, and the adjustment of the chain of the bicycle effected, in the
manner heretofore described.
GEORGE LUCKMAN.