Improvement in Chains for Chain-wheel Gear,
Year: 1899

page_text: Date of Application, 6th Dec., 1899-Accepted, 20th Jan., 1900
Improvement in Chains for Chain-wheel Gear,
I, CHARLES BROOKS HOLMES, Citizen of the United States of America, residing
at Minneapolis, in the State of Minnesota, United States of America, Lawyer,
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 fol-
lowing statement:-
My invention relates to sprocket chains, and has for its primary object the
production of an improved driving chain for bicycles.
To this end my invention consists of the novel devices and combinations of.
devices hereinafter described and defined in the claims.
The several points of my improvement will be hereinafter described. The
preferred form of my improved driving chain is illustrated in the accompanying
drawings, wherein like characters indicating like parts throughout the several
views:
Fig. 1 is a view principally in side elevation, but with some parts broken
away, illustrating my improved chain and shewing in diagram, a portion of the
co-operating sprocket wheel.
Fig. 2 is a plan view of the chain, with some parts broken away and some parts
shewn in section; and
Fig. 3 is a bottom plan of one of the solid blocks or sections of the chain.
The letter A indicates in diagram a portion of the sprocket wheel as shewn in
Fig. 1.
The block links of the chain are indicated by the numeral 1, and the
side links which connect the block links are indicated by the numeral 2. The
block links 1 are integrally formed, being preferably milled or otherwise cut
from solid steel blanks, and they are provided at their ends with laterally spaced
ears 3, between which seats 4 for the rollers (to be presently noted) are formed.
These seats 4 are approximately semi-cylindrical, and it is important to note
that the outer surface of the block projects at its ends, as shewn at Fig. 5, so as
to form guard sections that nearly or quite cover the rollers.
The links 2 are formed in longitudinal split sections, or, in other words, with
separable sides, and these sides are provided with inwardly projecting trunnions G
that are pressed together to form complete trunnions that space apart the said
side sections 2 of the links. The trunnions 6 are passed inward through the
co-operating ears 3 of the block links 1, approximately on the axis of the co-
operating seats 4. The anti-friction rollers, indicated at 7, are mounted on the
co-operating trunnions 6 and work closely within the corresponding seats 4, with
their outer and lower surfaces projecting very slightly beyond the embracing
ears 3. Rivets 8 are then passed through suitable perforations in the co-opera-
ting trunnions 6 and are riveted at their outer ends to secure the sections of
the chain together. Of course, bolts might be substituted for these rivets, but
the rivets are, for obvious reasons, preferred.

page_text: Now, it will be noted, by reference particularly to Fig. 2, that the outer sur-
faces of the blocks 1 have complete circular engagements with the sides of the
links 2 adjacent to their trunnions 6. This prevents side play in the chain.
When the rivets S are tightly riveted—and they should be so of course-the
cooperating trunnions are tightly drawn together in perfect alignment, and are
thus, in effect, rendered practically integral. The lateral spacing of the sections
of the links 2 is predetermined by the lengths of the trunnions, and, by specially
designed machinery, these trunnions may be very quickly and accurately formed.
Hence, just the exact desired fit between the block links and the side links may
be easily accomplished, and the chain when connected as above described will
have practically no side play or swing.
The guard flanges 5 of the block links 1 serve both as sand guards, to prevent
sand from falling onto the anti-friction rollers 7, and to rigidly tie together the
ears 3, thereby preventing spreading or bending of the same under side strains
on the chain. The parts of the block links being integrally formed, are much
stronger and more durable than if they were separately formed and afterwards
connected together.
It will of course be understood that my invention above described is capable
of modification as to its detail.
Having now particularly described and ascertained the nature of this invention
and in what manner the same is to be performed, I declare that what I claim
is:-
1. A chain for chain wheel gear consisting of the combination of block links
and side links, of which the latter have trunnions pivotally working in the former,
and carrying antifriction rollers seated within cavities in the block links, sub-
stantially as described.
2. In a chain for chain wheel gear such as it is referred to in the first claim,
constructing the side links of two separate sections from the inner faces of which
project half trunnions that are passed through the eyes of the block trunnion
and of the antifriction rollers so as to meet within the latter, the two sections
and their half trunnions being secured rigidly together by rivets or equivalent
devices passing through them.
3. In a chain for chain wheel gear, the combination with the sectional side
links 2, having the trunnions 6, of the block links 1 having the seats 4 and cars 3,
the anti-friction rollers 7 mounted on said trunnions 6 within said seats 4, and
means for securing the links together, substantially as described.
4. In a chain for chain wheel gear the combination with the sectional side
links 2 having trunnions 6, of the block links 1, having the integrally formed
cars 3 spaced to form the seats 4, rivets 8 passed through the co-operating trun-
nion 6 and rigidly securing the co-operating links together and in pivotal con-
nection with the block links, and anti-friction rollers 7, mounted on said trun-
nions 6 and working in the said seats 4, substantially as described.
5. In a chain for chain wheel gear the combination with the block links 1
having the ears 3, roller seats 4 and extended web portions 5 connecting said
ears and constituting roller shields, of the side links 2 pivotally connected
to the said ears 3, and the anti-friction rollers 7, mounted on the link joints,
working in the said seats 4 and shielded by said web portions 5, substantially
as described.