Year: 1895

page_text: Date claimed for Patent under Sect. 103 of Act, 1
being date of first Foreign Application (in 5th Mar.. 1895
United States of America),
Date of Application (in United Kingdom), 4th Oct., 1895
Complete Specification Left, 4th Oct., 1895-Accepted, 16th Nov., 1895
United States of America),
Date of Application (in United Kingdom), 4th Oct., 1895
Complete Specification Left, 4th Oct., 1895-Accepted, 16th Nov., 1895
I, WILLIAM EDGAR GARD, Gentleman, of 206, Washington Avenue, in the City
of Brooklyn County of Kings and State of New York, United States of America,
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 relates to cranks, and particularly to cranks for bicycles or other
similar vehicles; and my invention consists in the novel construction of the crank,
in the novel means employed for holding the parts of the crank together, in the
novel means employed for permitting access to the crank-bearings, and in the
novel form, construction, and arrangement of the parts constituting my improved
crank.
The objects of my invention are, first, to provide a crank having as few parts as
possible, which shall be light and of simple construction, easily taken apart and
put together, and which shall not be liable to come apart unintentionally; second,
to provide a crank so constructed as to permit of easy access to the bearings and
to permit one crank-section to be removed without disturbing the other crank-
section; third, to provide simple means for interlocking the ends of the crank-
shaft sections and for fastening the two parts of the crank together, and to so
arrange the crank-bearings that pressure upon the crank-bearings, due to pressure
upon the pedals, may cause the sections of the crank-shaft to be pressed together,
thereby removing strain from the device which primarily holds the shaft-sections
together, reducing the danger of breakage of this device, and enabling the bicycle
to be used, even though this device, which primarily holds the shaft-sections
together, is broken, and fourth, to make the crank strong, durable, and as inexpensive
as possible.
These objects are attained in the crank herein described, and illustrated in the
drawings which accompany and form a part of this application, in which the same
reference numerals indicate the same or corresponding parts, and in which :-
Figure 1 is a longitudinal section of the crank-bearings and crank-bracket of a
bicycle, showing my improved bicycle-crank; Figure 2 is a similar view showing
modifications thereof and in particular a modified method of securing the crank-
bearing cones in place, and also means for stiffening the joint between the two
crank-sections, so as to resist tendency toward flexure at the joint;
Figure 3 is an end view of one of the sections of the crank-shaft shown in
Figure 2, showing particularly the slots in which the flat keys are placed; and
Figure 4 illustrates another method for stiffening the joint between the crank-
sections against flexure.

page_text: In the drawings, 1 is an ordinary bottom or crank-bracket formed upon the
lower portion of the frame of the bicycle, which receives the crank-shaft and crank-
bearings.
2 and 2 are the crank-arins, which are secured to or formed integrally with the
crank-shaft sections 3 and 31, which together form the crank-shaft. The ends of
these sections 3 and 31 are formed with projecting tongues or tenons 4 and 4',
separated by corresponding grooves or mortises, which are so formed that the
tongues of one section of the crank-shaft fit into the grooves of the other section,
the two sections of the crank-shaft being thereby interlocked, so that one must turn
with the other.
Various forms of corresponding and interlocking tongues and grooves may be
used, and I do not limit myself to any particular form; but if the ends of the
sections of the shaft be formed as shown in the drawings they may be made exactly
alike, and if in other respects the two parts of the crank are alike these parts may
be both made from one and the same pattern.
The two sections of the crank-shaft are held together and are prevented from
separating longitudinally by a screw or key 5, passing through the crank-shaft
from one side to the other, and accessible through an aperture 6 in the bracket 1,
through which a screw-driver may be inserted for turning the screw in and out.
This aperture may be provided with a suitable cover to prevent the entrance
of dust.
Directly upon the sections of the crank-shaft are placed cones
and 71 for the
ball bearings in which the crank-shaft runs, and into the ends of the bracket 1 are
screwed corresponding cones 8 and 8. Between the cones 7 and 8 and 7 and 8'
are placed the balls 9.
In the form of crank shown in Figure 1 shaft sections 3 and 31 are provided with
shoulders 10 and 10¹, slightly larger in diameter than the main portion of the shaft
and screw-threaded, and the cones 7 and 7' are arranged to screw upon these
shoulders 10 and 10' and against the ends of shoulders 11 and 11', which are
slightly larger in diameter than the shoulders 10 and 10¹, and which determine the
positions of these cones, therefore. If necessary lock-nuts may be used to prevent
the cones from moving backward; but in general this will be unnecessary, as the
direction of rotation of the crank is such as to tend to cause the cones to press
more and more tightly against the shoulders 11 and 11'.
In the form of crank shown in Figure 2 the cones 7 and 71 are shown as secured
in place by keys or by brazing. They may be secured to the shaft-sections in any
other suitable way, or may be formed integral with the shaft-sections.
Upon the crank-shaft section 3' is carried the sprocket wheel 13, which may he
secured in place in any ordinary and common manner, as by keys, set-screws, or by
shrinking it in place. In the construction shown in Figure 1 the sprocket wheel 13
rests upon the shoulder 11 and is put in place before the cones 8 and 7 are put on.
In the construction shown in Figure 2, since the cones 7 and 7' are fixed in place
permanently, it is impossible to pass the sprocket-wheel and cones 8 and 8¹ over
these cones 7 and 7' unless the sprocket-wheel and the cones 8 and 8¹ be made
excessively large, and I have made the crank-arms with a more gradual curve so
that the cones and the sprocket-wheel may be put in place by passing them over
the crank-arms.
It will be noted that the cones 7 and 8 and 71 and 8' are so placed with reference
to each other that the pressure of the bearing-surfaces tends to press the sections
of the crank together, and therefore takes from the screw 5 a large portion of the
strain that might otherwise come upon it should there be any tendency of the
crank-sections to separate longitudinally. The screw 5, therefore, may be made
much smaller than would otherwise be advisable. This arrangement of the cones
likewise has the additional advantage that if through any accident the screw 5
should break, the sections of the crankshaft will not come apart and the bicycle
may still be used, the only result, if any, being a slightly greater friction at the
crauk-bearings and a slightly greater danger of wear at these hearings.

page_text: To give rigidity to the joint between the shafts 3 and 3¹ and to enable it to
resist any possible tendency toward flexure at the joint it may be advisable to use
two or more screws 5, placed longitudinally a short distance from each other. The
same result may be accomplished in another way. (Shown in Figures 2 and 3.)
Each shaft-section is provided with a thin slit 15 running longitudinally and in
line with the center of the screw-hole through which the screw 5 passes. This
slit is slightly wider upon the side without the screw-hole than it is upon the side
within the screw-hole. A thin plate or key 16 is inserted in the slit in each shaft-
section, the width of this key being such that when driven to the bottom of the
slit it will come to or nearly to the edge of the screw-hole. This plate is of such
thickness as to make a drive fit with the lower or inner portion of the slot, which
is slightly narrower than the upper or outer portion, while it merely makes a close
fit with the corresponding slit in the other crank-shaft section, within which it
lies when the two shaft-sections are together. These two plates then constitute
a practically continuous key, which greatly stiffens the joint and prevents any
possible bending. The same result may also be accomplished in the manner
shown in Figure 4 by inclosing the sections of the crank-shaft in a closely fitting
sleeve 17 of considerable length. In this sleeve, opposite the ends of the screw 5,
are holes through which this screw may be removed; and to prevent the sleeve
from turning with respect to the crank-shaft, as well as to prevent the sleeve from
covering the ends of the screw 5 and so preventing access thereto the length of
the screw 5 should preferably be slightly greater than the diameter of the
crank-shaft.
In Figure 2 the ends of the crank-shaft sections are shown enlarged to strengthen
them at the joint.
In assembling the parts of the crank and crank-bearings above described, if the
construction be that of Figure 1, the sprocket-wheel 13 is slipped over the end of
the section 3', seated upon the shoulder 111, and is secured in place. The cone 8¹
is then put upon the section 3', which it fits loosely, and after it the cone 7',
which is screwed upon the shoulder 10' until it rests against the end of the
shoulder 11'. If the sprocket-wheel is too close to the cones 71 and 8¹ to perinit
the balls 9 to be put in place between these cones after the cone 7 is in place
they may be placed between the cones before the cone 71 is quite in place, and
the cone 7 may then be screwed down into place. The cones 7 and 8 are then
placed upon the section 3 in a similar manner, the balls 9 being placed between
them. The two sections of the crank-shaft are then placed within the bracket 1
and pressed together, the tongues of the one section fitting into the grooves of the
other. When they have thus engaged and have been pushed as near together as
is possible with the cones 8 and 8 unscrewed, these cones are screwed into the
ends of the bracket 1, thus forcing the two parts of the crank together. The
screw 5 is then inserted through the hole 6 in the bracket and into the screw-hole
in the crank-shaft and is screwed home, thus securing the parts together finally.
In assembling the sections of the crank, when constructed as shown in Figure 2,
the operation is in general the same, except that in this case, since the cones 7
and 7 are rigid upon the sections 3 and 31, the cones 8 and 81 and the sprocket-
wheel must be put in place by passing them over the ends of the crank-arms 2
and 2 before the crank-treadles are attached.
If the flat keys 16 are used to stiffen the joint between the crank-sections they
are driven each into the slot in its respective shaft end before the cones are put on
and thereafter stay in place. When the two ends of the crank-shafts are put
together, each key slips into the slot in the end of the other shaft-section. If the
sleeve 17 is used to stiffen the joint, it is put upon one shaft-section after the cones
are in place thereon, and is slipped into the crank-bracket with the shaft-section.
The end of the other shaft-section is then inserted into this sleeve and the parts
are attached as before, the screw 5 being passed through the holes in the side of
the sleeve and into the screw-hole in the crank shaft.
As shown in Figures 1 and 2, the lengths of the shaft-sections 3 and 3' are

page_text: "
exactly the same, as the two parts of the crank are designed to be interchangeable,
and as the section 3 of the crank-shaft has no sprocket-wheel 13 upon it, it follows
that it is comparatively easy to gain access to the bearing on the side of the crank
by simply unscrewing the cone 8, but if, as is usually the case, the "tread of the
machine is made as narrow as possible, so that the crank-arm 2' and sprocket-
wheel 13 fit closely to the cone 8', there is not sufficient room to remove the cone 81
in order to obtain access to the bearing upon its side of the crank. Access to this
bearing may be gained by removing the screw 5 and then drawing out the section 31
of the crank-shaft, at the same time unscrewing the cone 81, and this may be done
without in the least disturbing the bearing upon the other side of the crank.
It will often happen that it is more important to have as great a distance as
practicable between the crank-bearings than it is to have the two parts of the
crank interchangeable. Where such is the case the length of the bracket 1 will
be such that the cone 8 is very close to the crank-arm 2; but in this case access to
the bearing may be obtained in the same manner as to the bearing upon the
sprocket side of the crank and without in the least disturbing the bearing on that
side and the sprocket-wheel.
My invention is not limited in its application to bicycles and similar vehicles, but
may be applied to other machinery driven by cranks. Neither is it limited to ball
bearings, but may be used with other types of bearings-as for instance, the ordinary
conical bearings.
Having thus completely described my invention, what I claim, and desire to
secure by Letters Patent is :
1. In a crank the combination, with two crank arms, and two crank shaft
sections, secured each to one of said crank arns, and having ends adapted to
interlock, of independent bearing cones mounted upon said crank shaft sections,
and facing toward the crank arms, and other bearing cones suitably supported and
adapted to engage with said shaft cones, and facing toward the center of the
crank-shaft, substantially as described.
2. In a crank, the combination, with two crank arms, and two crank shaft
sections, secured each to one of said crank arms, and having ends adapted to
interlock, of independent bearing cones mounted upon said crank shaft sections, and
facing toward the crank arms, other bearing cones, suitably supported and adapted
to engage with said shaft cones, and facing toward the center of the crank shaft,
and a key passing through the interlocking ends of said shaft sections and adapted
to hold the same together, substantially as described.
3. In a crank, the combination, with two crank arms, and two crank shaft
sections, secured each to one of said crank arms, and having mortised and tenoned
ends adapted to interlock, of independent hearing cones mounted upon said crank
shaft sections, and facing toward the crank arins, other bearing cones suitably
supported and adapted to engage with said shaft cones, and facing toward the
center of the crank shaft, and a screw passing through the interlocking ends of
said shaft sections and adapted to hold the same together, substantially as described.
4. In a crank, the combination, with two crank arms, and two crank shaft
sectious, secured each to one of said crank arms, and having ends adapted to
interlock, of independent bearing cones mounted upon said crauk shaft sections,
and facing toward the crank arms, other bearing cones suitably supported and
adapted to engage with said shaft cones, and facing toward the center of the crank
shaft, and means for stiffening the joint between said crank shaft sections at said
joint and preventing flexure thereat, substantially as described.
5. In a crank, the combination, with two crank arms, and two crank shaft
sections, secured each to one of said crank arms, having ends adapted to interlock,
and having in said ends longitudinal and registering slots adapted to receive keys,
of bearing cones mounted upon said crank shatt sections, other bearing cones
suitably supported and adapted to engage with said shaft cones, flat keys, lying
within the slots in the ends of said shaft sections, and arranged to stiffen the joint

page_text: between said shaft sections and prevent flexure thereat, and a key, passing througħi
the interlocking ends of said shaft sections and holding the same together,
substantially as described.
6. The herein described crank, consisting of two separable crank sections,
each consisting of a crank arm having secured rigidly thereto or formed
integrally therewith a section of the crank shaft, the ends of said crank-shaft
sections being adapted to interlock and being provided with an equal number of
corresponding and registering mortises and tenons, whereby both of said crank-
sections may be made alike, and means for holding said crank-sections together,
substantially as described.
8 4th day of October 1893,
ROBERT E. PHILLIPS, Assoc. M. Inst. C.E., M.I. Mech. E.,
Consulting Engineer and Patent Agent,
70, Chancery Lane, London, W.C., Associate Agent.