Improvements in Sprocket Chains.
Year: 1896

page_text: Date of Application, 29th Dec., 1896-Accepted, 20th Feb., 1897
Improvements in Sprocket Chains.
We, FREDERICK WILLIAM BARKER, of Dunellen, in the County of Middlesex,
State of New Jersey, U.S.A., Patent Agent, and VAN DYKE CRUSER Of
Brooklyn, in the County of Kings, State of New York, U.S.A. Gentleman, 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 relates to sprocket chains, such as are used for propelling bioyoles
and the like, and its main features may be summarized as follows:-
1. The introduction of an anti-friction substance into the centre blocks of a
aprocket chain, said anti-friction substance being disposed to receive the major
portion of impact from the sprocket teeth, and to present the largest bearing
surface to the pin or pivot.
2. The utilization of raw hide (compressed or non-compressed) as an anti-friction
substance combined with re-inforce portions of steel, to form the centre blocks of a
sprocket chain, the inherent oiliness of the raw hide serving all purposes of
lubrication; and its consistency avoiding the clicking wbich occurs with the impact
of metal sprocket teeth upon all metal centre blocks.
3. The employment and special construction of re-inforce side plates upon centre
blocks of raw hide or other suitable anti-friction substance, together with the
special construction of pins or rivets to prevent said parts from spreading apart,
affording an ample pivotal surface, and also providing against the binding of said
compound centre blocks against their pivotal surface.
In the drawings accompanying this specification:-
Figure 1 is a side elevation showing a portion of our improved chain.
Figure 2 is a plan view of Figure 1.
Figure 3 is a horizontal sectional view of a centre block, with portions of its
connecting side links, and with the uniting and pivotal pins, the latter not being in
section.
Figure 4 is a detail view of our preferred form of construction of pivotal
connecting pin or rivet.
Figure 5 is a longitudinal sectional modified view of a form of chain end uniting
pin, and
Figure 6 shows a chain end uniting rivet..
In said figures, A indicates the usual side links, arranged in pairs, and having
holes at both ends to receive the narrow ends a of pins B, the said ends being
riveted to said links. Cindicates our improved compound centre blocks, which
are pivotally mounted on pins B. These centre blocks are composed of the central
portion 6 having pivot holes at both ende, said portion b consisting of raw hide
(preferably compressed); and the re-inforce side plates c, having pivot holes c'.
In the construction of what is known as a quarter inch chain, viz.: one in which
the centre blocks are a quarter of an inch in thickness, we preferably employ a
central portion of raw hide approximating in thickness the one eighth of an inch,
and each of the side plates care approximately the one sixteenth of an inch in
thickness. This rule is however by no means arbitrary, and is merely intended here
as a guide. The functions of the two materials of which the centre block is
composed being entirely different, it is necessary to equalize their respective
qualities. Thus the raw hide, whilst capable of a oertain amount of strain, is
21

page_text: especially included to become the main pivotal hearing and to deaden the sound of
the impact of the sprocket teeth, and to minimize friction; whereas the re-inforce
side plates c are intended to receive the pulling strain upon the chain, and also to
protect the raw bide.
The pivot holes e in plates c are countersunk at the outer sides of said plates for
a purpose to be.described hereinafter.
We have found in the course of extensive experimenting that the result of the
sprocket teeth striking upon our aforesaid compound centre block is to cause the
central raw hide portion to expand laterally somewhat, thereby forcing the re-inforce
plates against the side links, in consequence of which the chain has become stiff
and unworkable.
We now avoid this difficulty in the following manner;
We employ pins as B, having the thick central portion d, and narrow ends a.
At the shoulder e 'we form an inclined depression or recess f, and, when the
compound centre blocks Care mounted upon portion d of the pins, the recessed
shoulder e fis turned over by means of a hollow punch or otherwise forming a burr
or collar g, which is adapted to fit pivotally within the countersunk portion of pivot
hole in plates c. In this manner the compound centre-blocks are: prevented
from binding against the side links, and at the same time their frictional bearing
is limited to the contact between collars g'and countersink holes c. The parts b
and c'may also be united by a pin h passed therethrough, and riveted at both its
ends at the outer side of plates c, and said rivet may be used alone or in addition
to the anti-spreading devices hérein referred to.
In Figure 5 will be seen a special form of connecting pin, used in place of a
rivet for joining the chain. Said tpin:fconsists of a hollow interiorly threaded
portion hand the solid threaded portion is said portions and i being adapted to
screw together, and to form the pivot for the centre block C. Each of said
portions and has a collar to fit pivotally within the countersunk hule e!, and
said portions are provided each with a screw end k to receive a nut.
As will be clearly seen the part between the shoulderst serves as the pivotal
surface for the centre block C; and the portions kl, between shoulders and
thread, which may have a squared or rounded surface, support the side links A.
Figure 6 shows a modified form of chain uniting pin; wherein indicates a
tubular piece having the shoulders n which are formed at each end after said
piece has been passed through the centre block C, the said shoulders being turned
down by a punch or otherwise to form a bearing in the holes,c of plates where
countersunk. m' indicates a bolt passed through said tubular piece l, and having a
screw head n'at one end and a thread with put o at its other end. The links: A are
mounted upon said bolt m' at the points between the screw head n and shoulder'm,
and between the 'nut o and shoulder m.
Whilst we have shown special means for uniting the component parts of our
improved centre block we do not wish to be limited thereby, but 'desire to cover
broadly the employment of raw hide or other suitable anti-friction, sound deadening,
and oleaginous substance astthe bearing portion of assprocket chain; and also such
means as will serve to prevent the lateral spreading of said component parts.
Although we believe that the form of compound centre block, comprising a
central portion of raw hide with flanking re-inforce metal plates; as herein shown
and described, is the best, we'do not wish it to be understood that our invention is
limitedito such special arrangement. In the course of our 'experiments we have
tried differéut arrangements such as the insertion of a central portion of metal
flanked by rawhide plates: the employment of alternate plates of metal raw hide
to form a laminated block the employment of a metal plate and a rawhide plate
of equal or different thicknesses placed side by side, in this instance adjacent-blocks
having the metal und rawhide parts on opposite sides, also numerous other methods,
all having more or less merit, aud in view of the numerous modifications to which
the construction of our raw hide chain is susceptible, we being the first to
produce a raw hide chain, we desire to cover the invention in its broadest sense.

page_text: Having now particularly described and ascertained the nature of our said inven--
tion, and in what manner the same is to be performed, we declare that what we-
claim is :-
1. A sprocket chain whose bearing portions consist in part of raw hide,.
substantially as set forth.
2. In a sprocket chain, the centre blocks thereof formed of a suitable anti--
friction substance, and having metallic re-inforce plates, substantially as set.
forth.
3. In a sprocket chain, in combination, pairs of side links arranged in parallel
lines, centre blocks arranged end to end in a single line between said side links,.
and forming spaces to receive sprocket teeth, said centre blocks consisting each of
a central portion of raw hide, having re-inforce metallic side plates, together with.
pins riveted to said side links and being passed through pivotal holes in the centre
blocks, the holes in the re-inforce plates being countersunk, and the pins having-
collars to pivotally fit therein, substantially as and for the purpose set forth.
4. In a sprocket chain including pairs of side links arranged end to end, and
centre blocks uniting adjacent pairs of side links, said centre blocks each consisting:
of a central portion of raw hide having re-inforce metallic side plates, and means.
preventing said centre blocks from spreading laterally by the impact of sprocket.
teeth, substantially as set forth.
5. Ina sprocket chain, a pair of side links, and a compound centre block between
said links, said centre block consisting of an inner portion of raw hide and side-
plates of metal, there being holes through said side links; raw hide, and side plates,
the boles in said side plates being countersunk, and a pin connecting said parts.
together through said holes, said pin having collars which fit pivotally-in the
countersunk holes in said side plates; and said pin being secured to said side linka,.
substantially as set forth.
6. A sprocket chain uniting pin, consisting of a bollow portion serving as a.
pivotal bearing for a centre block, an annular shoulder at both ends of said 'hollow
portion to locate the centre block, and bearings extending outwardly from said.
annular shoulders to support the usual side links, together with means for securing
said side links upon their bearings, substantially as set forth.
7. A sprocket chain uniting piu consisting of a hollow piece having an interior
screw thread, and a solid threaded portion, said portions arranged to screw together
to form a pivotal bearing, and a collar upon each of said portions, near their outer
ends, together with a screw thread upon each of said portions, to receive nuts,.
substantially as set forth.
8. The improvements in sprocket chains, substantially as and for the purposes.
hereinbefore described, set forth and illustrated'.
Dated this 29th day of December 1896..
F: W. BARKER,,
Applicants' Agent..